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 = scope_push(new_scope)
 122 #define POP_SCOPE() (assert(current_scope == new_scope), scope_pop(old_scope), environment_pop_to(top))
 123
 124 #define PUSH_EXTENSION() \
 125         (void)0; \
 126         bool const old_gcc_extension = in_gcc_extension; \
 127         while (next_if(T___extension__)) { \
 128                 in_gcc_extension = true; \
 129         } \
 130         do {} while (0)
 131 #define POP_EXTENSION() \
 132         ((void)(in_gcc_extension = old_gcc_extension))
 133
 134 /** special symbol used for anonymous entities. */
 135 static symbol_t *sym_anonymous = NULL;
 136
 137 /** The token anchor set */
 138 static unsigned short token_anchor_set[T_LAST_TOKEN];
 139
 140 /** The current source position. */
 141 #define HERE (&token.base.source_position)
 142
 143 /** true if we are in GCC mode. */
 144 #define GNU_MODE ((c_mode & _GNUC) || in_gcc_extension)
 145
 146 static statement_t *parse_compound_statement(bool inside_expression_statement);
 147 static statement_t *parse_statement(void);
 148
 149 static expression_t *parse_subexpression(precedence_t);
 150 static expression_t *parse_expression(void);
 151 static type_t       *parse_typename(void);
 152 static void          parse_externals(void);
 153 static void          parse_external(void);
 154
 155 static void parse_compound_type_entries(compound_t *compound_declaration);
 156
 157 static void check_call_argument(type_t          *expected_type,
 158                                                                 call_argument_t *argument, unsigned pos);
 159
 160 typedef enum declarator_flags_t {
 161         DECL_FLAGS_NONE             = 0,
 162         DECL_MAY_BE_ABSTRACT        = 1U << 0,
 163         DECL_CREATE_COMPOUND_MEMBER = 1U << 1,
 164         DECL_IS_PARAMETER           = 1U << 2
 165 } declarator_flags_t;
 166
 167 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
 168                                   declarator_flags_t flags);
 169
 170 static void semantic_comparison(binary_expression_t *expression);
 171
 172 #define STORAGE_CLASSES       \
 173         STORAGE_CLASSES_NO_EXTERN \
 174         case T_extern:
 175
 176 #define STORAGE_CLASSES_NO_EXTERN \
 177         case T_typedef:         \
 178         case T_static:          \
 179         case T_auto:            \
 180         case T_register:        \
 181         case T___thread:
 182
 183 #define TYPE_QUALIFIERS     \
 184         case T_const:           \
 185         case T_restrict:        \
 186         case T_volatile:        \
 187         case T_inline:          \
 188         case T__forceinline:    \
 189         case T___attribute__:
 190
 191 #define COMPLEX_SPECIFIERS  \
 192         case T__Complex:
 193 #define IMAGINARY_SPECIFIERS \
 194         case T__Imaginary:
 195
 196 #define TYPE_SPECIFIERS       \
 197         case T__Bool:             \
 198         case T___builtin_va_list: \
 199         case T___typeof__:        \
 200         case T__declspec:         \
 201         case T_bool:              \
 202         case T_char:              \
 203         case T_double:            \
 204         case T_enum:              \
 205         case T_float:             \
 206         case T_int:               \
 207         case T_long:              \
 208         case T_short:             \
 209         case T_signed:            \
 210         case T_struct:            \
 211         case T_union:             \
 212         case T_unsigned:          \
 213         case T_void:              \
 214         case T_wchar_t:           \
 215         case T__int8:             \
 216         case T__int16:            \
 217         case T__int32:            \
 218         case T__int64:            \
 219         case T__int128:           \
 220         COMPLEX_SPECIFIERS        \
 221         IMAGINARY_SPECIFIERS
 222
 223 #define DECLARATION_START   \
 224         STORAGE_CLASSES         \
 225         TYPE_QUALIFIERS         \
 226         TYPE_SPECIFIERS
 227
 228 #define DECLARATION_START_NO_EXTERN \
 229         STORAGE_CLASSES_NO_EXTERN       \
 230         TYPE_QUALIFIERS                 \
 231         TYPE_SPECIFIERS
 232
 233 #define EXPRESSION_START              \
 234         case '!':                         \
 235         case '&':                         \
 236         case '(':                         \
 237         case '*':                         \
 238         case '+':                         \
 239         case '-':                         \
 240         case '~':                         \
 241         case T_ANDAND:                    \
 242         case T_CHARACTER_CONSTANT:        \
 243         case T_FLOATINGPOINT:             \
 244         case T_FLOATINGPOINT_HEXADECIMAL: \
 245         case T_INTEGER:                   \
 246         case T_INTEGER_HEXADECIMAL:       \
 247         case T_INTEGER_OCTAL:             \
 248         case T_MINUSMINUS:                \
 249         case T_PLUSPLUS:                  \
 250         case T_STRING_LITERAL:            \
 251         case T_WIDE_CHARACTER_CONSTANT:   \
 252         case T_WIDE_STRING_LITERAL:       \
 253         case T___FUNCDNAME__:             \
 254         case T___FUNCSIG__:               \
 255         case T___FUNCTION__:              \
 256         case T___PRETTY_FUNCTION__:       \
 257         case T___alignof__:               \
 258         case T___builtin_classify_type:   \
 259         case T___builtin_constant_p:      \
 260         case T___builtin_isgreater:       \
 261         case T___builtin_isgreaterequal:  \
 262         case T___builtin_isless:          \
 263         case T___builtin_islessequal:     \
 264         case T___builtin_islessgreater:   \
 265         case T___builtin_isunordered:     \
 266         case T___builtin_offsetof:        \
 267         case T___builtin_va_arg:          \
 268         case T___builtin_va_copy:         \
 269         case T___builtin_va_start:        \
 270         case T___func__:                  \
 271         case T___noop:                    \
 272         case T__assume:                   \
 273         case T_delete:                    \
 274         case T_false:                     \
 275         case T_sizeof:                    \
 276         case T_throw:                     \
 277         case T_true:
 278
 279 /**
 280  * Returns the size of a statement node.
 281  *
 282  * @param kind  the statement kind
 283  */
 284 static size_t get_statement_struct_size(statement_kind_t kind)
 285 {
 286         static const size_t sizes[] = {
 287                 [STATEMENT_ERROR]       = sizeof(statement_base_t),
 288                 [STATEMENT_EMPTY]       = sizeof(statement_base_t),
 289                 [STATEMENT_COMPOUND]    = sizeof(compound_statement_t),
 290                 [STATEMENT_RETURN]      = sizeof(return_statement_t),
 291                 [STATEMENT_DECLARATION] = sizeof(declaration_statement_t),
 292                 [STATEMENT_IF]          = sizeof(if_statement_t),
 293                 [STATEMENT_SWITCH]      = sizeof(switch_statement_t),
 294                 [STATEMENT_EXPRESSION]  = sizeof(expression_statement_t),
 295                 [STATEMENT_CONTINUE]    = sizeof(statement_base_t),
 296                 [STATEMENT_BREAK]       = sizeof(statement_base_t),
 297                 [STATEMENT_GOTO]        = sizeof(goto_statement_t),
 298                 [STATEMENT_LABEL]       = sizeof(label_statement_t),
 299                 [STATEMENT_CASE_LABEL]  = sizeof(case_label_statement_t),
 300                 [STATEMENT_WHILE]       = sizeof(while_statement_t),
 301                 [STATEMENT_DO_WHILE]    = sizeof(do_while_statement_t),
 302                 [STATEMENT_FOR]         = sizeof(for_statement_t),
 303                 [STATEMENT_ASM]         = sizeof(asm_statement_t),
 304                 [STATEMENT_MS_TRY]      = sizeof(ms_try_statement_t),
 305                 [STATEMENT_LEAVE]       = sizeof(leave_statement_t)
 306         };
 307         assert((size_t)kind < lengthof(sizes));
 308         assert(sizes[kind] != 0);
 309         return sizes[kind];
 310 }
 311
 312 /**
 313  * Returns the size of an expression node.
 314  *
 315  * @param kind  the expression kind
 316  */
 317 static size_t get_expression_struct_size(expression_kind_t kind)
 318 {
 319         static const size_t sizes[] = {
 320                 [EXPR_ERROR]                      = sizeof(expression_base_t),
 321                 [EXPR_REFERENCE]                  = sizeof(reference_expression_t),
 322                 [EXPR_REFERENCE_ENUM_VALUE]       = sizeof(reference_expression_t),
 323                 [EXPR_LITERAL_BOOLEAN]            = sizeof(literal_expression_t),
 324                 [EXPR_LITERAL_INTEGER]            = sizeof(literal_expression_t),
 325                 [EXPR_LITERAL_INTEGER_OCTAL]      = sizeof(literal_expression_t),
 326                 [EXPR_LITERAL_INTEGER_HEXADECIMAL]= sizeof(literal_expression_t),
 327                 [EXPR_LITERAL_FLOATINGPOINT]      = sizeof(literal_expression_t),
 328                 [EXPR_LITERAL_FLOATINGPOINT_HEXADECIMAL] = sizeof(literal_expression_t),
 329                 [EXPR_LITERAL_CHARACTER]          = sizeof(literal_expression_t),
 330                 [EXPR_LITERAL_WIDE_CHARACTER]     = sizeof(literal_expression_t),
 331                 [EXPR_STRING_LITERAL]             = sizeof(string_literal_expression_t),
 332                 [EXPR_WIDE_STRING_LITERAL]        = sizeof(string_literal_expression_t),
 333                 [EXPR_COMPOUND_LITERAL]           = sizeof(compound_literal_expression_t),
 334                 [EXPR_CALL]                       = sizeof(call_expression_t),
 335                 [EXPR_UNARY_FIRST]                = sizeof(unary_expression_t),
 336                 [EXPR_BINARY_FIRST]               = sizeof(binary_expression_t),
 337                 [EXPR_CONDITIONAL]                = sizeof(conditional_expression_t),
 338                 [EXPR_SELECT]                     = sizeof(select_expression_t),
 339                 [EXPR_ARRAY_ACCESS]               = sizeof(array_access_expression_t),
 340                 [EXPR_SIZEOF]                     = sizeof(typeprop_expression_t),
 341                 [EXPR_ALIGNOF]                    = sizeof(typeprop_expression_t),
 342                 [EXPR_CLASSIFY_TYPE]              = sizeof(classify_type_expression_t),
 343                 [EXPR_FUNCNAME]                   = sizeof(funcname_expression_t),
 344                 [EXPR_BUILTIN_CONSTANT_P]         = sizeof(builtin_constant_expression_t),
 345                 [EXPR_BUILTIN_TYPES_COMPATIBLE_P] = sizeof(builtin_types_compatible_expression_t),
 346                 [EXPR_OFFSETOF]                   = sizeof(offsetof_expression_t),
 347                 [EXPR_VA_START]                   = sizeof(va_start_expression_t),
 348                 [EXPR_VA_ARG]                     = sizeof(va_arg_expression_t),
 349                 [EXPR_VA_COPY]                    = sizeof(va_copy_expression_t),
 350                 [EXPR_STATEMENT]                  = sizeof(statement_expression_t),
 351                 [EXPR_LABEL_ADDRESS]              = sizeof(label_address_expression_t),
 352         };
 353         if (kind >= EXPR_UNARY_FIRST && kind <= EXPR_UNARY_LAST) {
 354                 return sizes[EXPR_UNARY_FIRST];
 355         }
 356         if (kind >= EXPR_BINARY_FIRST && kind <= EXPR_BINARY_LAST) {
 357                 return sizes[EXPR_BINARY_FIRST];
 358         }
 359         assert((size_t)kind < lengthof(sizes));
 360         assert(sizes[kind] != 0);
 361         return sizes[kind];
 362 }
 363
 364 /**
 365  * Allocate a statement node of given kind and initialize all
 366  * fields with zero. Sets its source position to the position
 367  * of the current token.
 368  */
 369 static statement_t *allocate_statement_zero(statement_kind_t kind)
 370 {
 371         size_t       size = get_statement_struct_size(kind);
 372         statement_t *res  = allocate_ast_zero(size);
 373
 374         res->base.kind            = kind;
 375         res->base.parent          = current_parent;
 376         res->base.source_position = token.base.source_position;
 377         return res;
 378 }
 379
 380 /**
 381  * Allocate an expression node of given kind and initialize all
 382  * fields with zero.
 383  *
 384  * @param kind  the kind of the expression to allocate
 385  */
 386 static expression_t *allocate_expression_zero(expression_kind_t kind)
 387 {
 388         size_t        size = get_expression_struct_size(kind);
 389         expression_t *res  = allocate_ast_zero(size);
 390
 391         res->base.kind            = kind;
 392         res->base.type            = type_error_type;
 393         res->base.source_position = token.base.source_position;
 394         return res;
 395 }
 396
 397 /**
 398  * Creates a new invalid expression at the source position
 399  * of the current token.
 400  */
 401 static expression_t *create_error_expression(void)
 402 {
 403         expression_t *expression = allocate_expression_zero(EXPR_ERROR);
 404         expression->base.type = type_error_type;
 405         return expression;
 406 }
 407
 408 /**
 409  * Creates a new invalid statement.
 410  */
 411 static statement_t *create_error_statement(void)
 412 {
 413         return allocate_statement_zero(STATEMENT_ERROR);
 414 }
 415
 416 /**
 417  * Allocate a new empty statement.
 418  */
 419 static statement_t *create_empty_statement(void)
 420 {
 421         return allocate_statement_zero(STATEMENT_EMPTY);
 422 }
 423
 424 /**
 425  * Returns the size of an initializer node.
 426  *
 427  * @param kind  the initializer kind
 428  */
 429 static size_t get_initializer_size(initializer_kind_t kind)
 430 {
 431         static const size_t sizes[] = {
 432                 [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
 433                 [INITIALIZER_STRING]      = sizeof(initializer_string_t),
 434                 [INITIALIZER_WIDE_STRING] = sizeof(initializer_wide_string_t),
 435                 [INITIALIZER_LIST]        = sizeof(initializer_list_t),
 436                 [INITIALIZER_DESIGNATOR]  = sizeof(initializer_designator_t)
 437         };
 438         assert((size_t)kind < lengthof(sizes));
 439         assert(sizes[kind] != 0);
 440         return sizes[kind];
 441 }
 442
 443 /**
 444  * Allocate an initializer node of given kind and initialize all
 445  * fields with zero.
 446  */
 447 static initializer_t *allocate_initializer_zero(initializer_kind_t kind)
 448 {
 449         initializer_t *result = allocate_ast_zero(get_initializer_size(kind));
 450         result->kind          = kind;
 451
 452         return result;
 453 }
 454
 455 /**
 456  * Returns the index of the top element of the environment stack.
 457  */
 458 static size_t environment_top(void)
 459 {
 460         return ARR_LEN(environment_stack);
 461 }
 462
 463 /**
 464  * Returns the index of the top element of the global label stack.
 465  */
 466 static size_t label_top(void)
 467 {
 468         return ARR_LEN(label_stack);
 469 }
 470
 471 /**
 472  * Return the next token.
 473  */
 474 static inline void next_token(void)
 475 {
 476         token                              = lookahead_buffer[lookahead_bufpos];
 477         lookahead_buffer[lookahead_bufpos] = lexer_token;
 478         lexer_next_token();
 479
 480         lookahead_bufpos = (lookahead_bufpos + 1) % MAX_LOOKAHEAD;
 481
 482 #ifdef PRINT_TOKENS
 483         print_token(stderr, &token);
 484         fprintf(stderr, "\n");
 485 #endif
 486 }
 487
 488 static inline bool next_if(int const type)
 489 {
 490         if (token.kind == type) {
 491                 next_token();
 492                 return true;
 493         } else {
 494                 return false;
 495         }
 496 }
 497
 498 /**
 499  * Return the next token with a given lookahead.
 500  */
 501 static inline const token_t *look_ahead(size_t num)
 502 {
 503         assert(0 < num && num <= MAX_LOOKAHEAD);
 504         size_t pos = (lookahead_bufpos + num - 1) % MAX_LOOKAHEAD;
 505         return &lookahead_buffer[pos];
 506 }
 507
 508 /**
 509  * Adds a token type to the token type anchor set (a multi-set).
 510  */
 511 static void add_anchor_token(int token_kind)
 512 {
 513         assert(0 <= token_kind && token_kind < T_LAST_TOKEN);
 514         ++token_anchor_set[token_kind];
 515 }
 516
 517 /**
 518  * Set the number of tokens types of the given type
 519  * to zero and return the old count.
 520  */
 521 static int save_and_reset_anchor_state(int token_kind)
 522 {
 523         assert(0 <= token_kind && token_kind < T_LAST_TOKEN);
 524         int count = token_anchor_set[token_kind];
 525         token_anchor_set[token_kind] = 0;
 526         return count;
 527 }
 528
 529 /**
 530  * Restore the number of token types to the given count.
 531  */
 532 static void restore_anchor_state(int token_kind, int count)
 533 {
 534         assert(0 <= token_kind && token_kind < T_LAST_TOKEN);
 535         token_anchor_set[token_kind] = count;
 536 }
 537
 538 /**
 539  * Remove a token type from the token type anchor set (a multi-set).
 540  */
 541 static void rem_anchor_token(int token_kind)
 542 {
 543         assert(0 <= token_kind && token_kind < T_LAST_TOKEN);
 544         assert(token_anchor_set[token_kind] != 0);
 545         --token_anchor_set[token_kind];
 546 }
 547
 548 /**
 549  * Return true if the token type of the current token is
 550  * in the anchor set.
 551  */
 552 static bool at_anchor(void)
 553 {
 554         if (token.kind < 0)
 555                 return false;
 556         return token_anchor_set[token.kind];
 557 }
 558
 559 /**
 560  * Eat tokens until a matching token type is found.
 561  */
 562 static void eat_until_matching_token(int type)
 563 {
 564         int end_token;
 565         switch (type) {
 566                 case '(': end_token = ')';  break;
 567                 case '{': end_token = '}';  break;
 568                 case '[': end_token = ']';  break;
 569                 default:  end_token = type; break;
 570         }
 571
 572         unsigned parenthesis_count = 0;
 573         unsigned brace_count       = 0;
 574         unsigned bracket_count     = 0;
 575         while (token.kind        != end_token ||
 576                parenthesis_count != 0         ||
 577                brace_count       != 0         ||
 578                bracket_count     != 0) {
 579                 switch (token.kind) {
 580                 case T_EOF: return;
 581                 case '(': ++parenthesis_count; break;
 582                 case '{': ++brace_count;       break;
 583                 case '[': ++bracket_count;     break;
 584
 585                 case ')':
 586                         if (parenthesis_count > 0)
 587                                 --parenthesis_count;
 588                         goto check_stop;
 589
 590                 case '}':
 591                         if (brace_count > 0)
 592                                 --brace_count;
 593                         goto check_stop;
 594
 595                 case ']':
 596                         if (bracket_count > 0)
 597                                 --bracket_count;
 598 check_stop:
 599                         if (token.kind        == end_token &&
 600                             parenthesis_count == 0         &&
 601                             brace_count       == 0         &&
 602                             bracket_count     == 0)
 603                                 return;
 604                         break;
 605
 606                 default:
 607                         break;
 608                 }
 609                 next_token();
 610         }
 611 }
 612
 613 /**
 614  * Eat input tokens until an anchor is found.
 615  */
 616 static void eat_until_anchor(void)
 617 {
 618         while (token_anchor_set[token.kind] == 0) {
 619                 if (token.kind == '(' || token.kind == '{' || token.kind == '[')
 620                         eat_until_matching_token(token.kind);
 621                 next_token();
 622         }
 623 }
 624
 625 /**
 626  * Eat a whole block from input tokens.
 627  */
 628 static void eat_block(void)
 629 {
 630         eat_until_matching_token('{');
 631         next_if('}');
 632 }
 633
 634 #define eat(token_kind) (assert(token.kind == (token_kind)), next_token())
 635
 636 /**
 637  * Report a parse error because an expected token was not found.
 638  */
 639 static
 640 #if defined __GNUC__ && __GNUC__ >= 4
 641 __attribute__((sentinel))
 642 #endif
 643 void parse_error_expected(const char *message, ...)
 644 {
 645         if (message != NULL) {
 646                 errorf(HERE, "%s", message);
 647         }
 648         va_list ap;
 649         va_start(ap, message);
 650         errorf(HERE, "got %K, expected %#k", &token, &ap, ", ");
 651         va_end(ap);
 652 }
 653
 654 /**
 655  * Report an incompatible type.
 656  */
 657 static void type_error_incompatible(const char *msg,
 658                 const source_position_t *source_position, type_t *type1, type_t *type2)
 659 {
 660         errorf(source_position, "%s, incompatible types: '%T' - '%T'",
 661                msg, type1, type2);
 662 }
 663
 664 /**
 665  * Expect the current token is the expected token.
 666  * If not, generate an error, eat the current statement,
 667  * and goto the error_label label.
 668  */
 669 #define expect(expected, error_label)                     \
 670         do {                                                  \
 671                 if (UNLIKELY(token.kind != (expected))) {         \
 672                         parse_error_expected(NULL, (expected), NULL); \
 673                         add_anchor_token(expected);                   \
 674                         eat_until_anchor();                           \
 675                         rem_anchor_token(expected);                   \
 676                         if (token.kind != (expected))                 \
 677                           goto error_label;                           \
 678                 }                                                 \
 679                 next_token();                                     \
 680         } while (0)
 681
 682 /**
 683  * Push a given scope on the scope stack and make it the
 684  * current scope
 685  */
 686 static scope_t *scope_push(scope_t *new_scope)
 687 {
 688         if (current_scope != NULL) {
 689                 new_scope->depth = current_scope->depth + 1;
 690         }
 691
 692         scope_t *old_scope = current_scope;
 693         current_scope      = new_scope;
 694         return old_scope;
 695 }
 696
 697 /**
 698  * Pop the current scope from the scope stack.
 699  */
 700 static void scope_pop(scope_t *old_scope)
 701 {
 702         current_scope = old_scope;
 703 }
 704
 705 /**
 706  * Search an entity by its symbol in a given namespace.
 707  */
 708 static entity_t *get_entity(const symbol_t *const symbol,
 709                             namespace_tag_t namespc)
 710 {
 711         entity_t *entity = symbol->entity;
 712         for (; entity != NULL; entity = entity->base.symbol_next) {
 713                 if ((namespace_tag_t)entity->base.namespc == namespc)
 714                         return entity;
 715         }
 716
 717         return NULL;
 718 }
 719
 720 /* §6.2.3:1 24)  There is only one name space for tags even though three are
 721  * possible. */
 722 static entity_t *get_tag(symbol_t const *const symbol,
 723                          entity_kind_tag_t const kind)
 724 {
 725         entity_t *entity = get_entity(symbol, NAMESPACE_TAG);
 726         if (entity != NULL && (entity_kind_tag_t)entity->kind != kind) {
 727                 errorf(HERE,
 728                                 "'%Y' defined as wrong kind of tag (previous definition %P)",
 729                                 symbol, &entity->base.source_position);
 730                 entity = NULL;
 731         }
 732         return entity;
 733 }
 734
 735 /**
 736  * pushs an entity on the environment stack and links the corresponding symbol
 737  * it.
 738  */
 739 static void stack_push(stack_entry_t **stack_ptr, entity_t *entity)
 740 {
 741         symbol_t           *symbol  = entity->base.symbol;
 742         entity_namespace_t  namespc = entity->base.namespc;
 743         assert(namespc != 0);
 744
 745         /* replace/add entity into entity list of the symbol */
 746         entity_t **anchor;
 747         entity_t  *iter;
 748         for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 749                 iter = *anchor;
 750                 if (iter == NULL)
 751                         break;
 752
 753                 /* replace an entry? */
 754                 if (iter->base.namespc == namespc) {
 755                         entity->base.symbol_next = iter->base.symbol_next;
 756                         break;
 757                 }
 758         }
 759         *anchor = entity;
 760
 761         /* remember old declaration */
 762         stack_entry_t entry;
 763         entry.symbol     = symbol;
 764         entry.old_entity = iter;
 765         entry.namespc    = namespc;
 766         ARR_APP1(stack_entry_t, *stack_ptr, entry);
 767 }
 768
 769 /**
 770  * Push an entity on the environment stack.
 771  */
 772 static void environment_push(entity_t *entity)
 773 {
 774         assert(entity->base.source_position.input_name != NULL);
 775         assert(entity->base.parent_scope != NULL);
 776         stack_push(&environment_stack, entity);
 777 }
 778
 779 /**
 780  * Push a declaration on the global label stack.
 781  *
 782  * @param declaration  the declaration
 783  */
 784 static void label_push(entity_t *label)
 785 {
 786         /* we abuse the parameters scope as parent for the labels */
 787         label->base.parent_scope = &current_function->parameters;
 788         stack_push(&label_stack, label);
 789 }
 790
 791 /**
 792  * pops symbols from the environment stack until @p new_top is the top element
 793  */
 794 static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
 795 {
 796         stack_entry_t *stack = *stack_ptr;
 797         size_t         top   = ARR_LEN(stack);
 798         size_t         i;
 799
 800         assert(new_top <= top);
 801         if (new_top == top)
 802                 return;
 803
 804         for (i = top; i > new_top; --i) {
 805                 stack_entry_t *entry = &stack[i - 1];
 806
 807                 entity_t           *old_entity = entry->old_entity;
 808                 symbol_t           *symbol     = entry->symbol;
 809                 entity_namespace_t  namespc    = entry->namespc;
 810
 811                 /* replace with old_entity/remove */
 812                 entity_t **anchor;
 813                 entity_t  *iter;
 814                 for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 815                         iter = *anchor;
 816                         assert(iter != NULL);
 817                         /* replace an entry? */
 818                         if (iter->base.namespc == namespc)
 819                                 break;
 820                 }
 821
 822                 /* restore definition from outer scopes (if there was one) */
 823                 if (old_entity != NULL) {
 824                         old_entity->base.symbol_next = iter->base.symbol_next;
 825                         *anchor                      = old_entity;
 826                 } else {
 827                         /* remove entry from list */
 828                         *anchor = iter->base.symbol_next;
 829                 }
 830         }
 831
 832         ARR_SHRINKLEN(*stack_ptr, new_top);
 833 }
 834
 835 /**
 836  * Pop all entries from the environment stack until the new_top
 837  * is reached.
 838  *
 839  * @param new_top  the new stack top
 840  */
 841 static void environment_pop_to(size_t new_top)
 842 {
 843         stack_pop_to(&environment_stack, new_top);
 844 }
 845
 846 /**
 847  * Pop all entries from the global label stack until the new_top
 848  * is reached.
 849  *
 850  * @param new_top  the new stack top
 851  */
 852 static void label_pop_to(size_t new_top)
 853 {
 854         stack_pop_to(&label_stack, new_top);
 855 }
 856
 857 static atomic_type_kind_t get_akind(const type_t *type)
 858 {
 859         assert(type->kind == TYPE_ATOMIC || type->kind == TYPE_COMPLEX
 860                || type->kind == TYPE_IMAGINARY || type->kind == TYPE_ENUM);
 861         return type->atomic.akind;
 862 }
 863
 864 /**
 865  * §6.3.1.1:2  Do integer promotion for a given type.
 866  *
 867  * @param type  the type to promote
 868  * @return the promoted type
 869  */
 870 static type_t *promote_integer(type_t *type)
 871 {
 872         if (get_akind_rank(get_akind(type)) < get_akind_rank(ATOMIC_TYPE_INT))
 873                 type = type_int;
 874
 875         return type;
 876 }
 877
 878 /**
 879  * Check if a given expression represents a null pointer constant.
 880  *
 881  * @param expression  the expression to check
 882  */
 883 static bool is_null_pointer_constant(const expression_t *expression)
 884 {
 885         /* skip void* cast */
 886         if (expression->kind == EXPR_UNARY_CAST) {
 887                 type_t *const type = skip_typeref(expression->base.type);
 888                 if (types_compatible(type, type_void_ptr))
 889                         expression = expression->unary.value;
 890         }
 891
 892         type_t *const type = skip_typeref(expression->base.type);
 893         if (!is_type_integer(type))
 894                 return false;
 895         switch (is_constant_expression(expression)) {
 896                 case EXPR_CLASS_ERROR:    return true;
 897                 case EXPR_CLASS_CONSTANT: return !fold_constant_to_bool(expression);
 898                 default:                  return false;
 899         }
 900 }
 901
 902 /**
 903  * Create an implicit cast expression.
 904  *
 905  * @param expression  the expression to cast
 906  * @param dest_type   the destination type
 907  */
 908 static expression_t *create_implicit_cast(expression_t *expression,
 909                                           type_t *dest_type)
 910 {
 911         type_t *const source_type = expression->base.type;
 912
 913         if (source_type == dest_type)
 914                 return expression;
 915
 916         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
 917         cast->unary.value   = expression;
 918         cast->base.type     = dest_type;
 919         cast->base.implicit = true;
 920
 921         return cast;
 922 }
 923
 924 typedef enum assign_error_t {
 925         ASSIGN_SUCCESS,
 926         ASSIGN_ERROR_INCOMPATIBLE,
 927         ASSIGN_ERROR_POINTER_QUALIFIER_MISSING,
 928         ASSIGN_WARNING_POINTER_INCOMPATIBLE,
 929         ASSIGN_WARNING_POINTER_FROM_INT,
 930         ASSIGN_WARNING_INT_FROM_POINTER
 931 } assign_error_t;
 932
 933 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)
 934 {
 935         type_t *const orig_type_right = right->base.type;
 936         type_t *const type_left       = skip_typeref(orig_type_left);
 937         type_t *const type_right      = skip_typeref(orig_type_right);
 938
 939         switch (error) {
 940         case ASSIGN_SUCCESS:
 941                 return;
 942         case ASSIGN_ERROR_INCOMPATIBLE:
 943                 errorf(pos, "destination type '%T' in %s is incompatible with type '%T'", orig_type_left, context, orig_type_right);
 944                 return;
 945
 946         case ASSIGN_ERROR_POINTER_QUALIFIER_MISSING: {
 947                 type_t *points_to_left  = skip_typeref(type_left->pointer.points_to);
 948                 type_t *points_to_right = skip_typeref(type_right->pointer.points_to);
 949
 950                 /* the left type has all qualifiers from the right type */
 951                 unsigned missing_qualifiers = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 952                 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);
 953                 return;
 954         }
 955
 956         case ASSIGN_WARNING_POINTER_INCOMPATIBLE:
 957                 warningf(WARN_OTHER, pos, "destination type '%T' in %s is incompatible with '%E' of type '%T'", orig_type_left, context, right, orig_type_right);
 958                 return;
 959
 960         case ASSIGN_WARNING_POINTER_FROM_INT:
 961                 warningf(WARN_OTHER, pos, "%s makes pointer '%T' from integer '%T' without a cast", context, orig_type_left, orig_type_right);
 962                 return;
 963
 964         case ASSIGN_WARNING_INT_FROM_POINTER:
 965                 warningf(WARN_OTHER, pos, "%s makes integer '%T' from pointer '%T' without a cast", context, orig_type_left, orig_type_right);
 966                 return;
 967
 968         default:
 969                 panic("invalid error value");
 970         }
 971 }
 972
 973 /** Implements the rules from §6.5.16.1 */
 974 static assign_error_t semantic_assign(type_t *orig_type_left,
 975                                       const expression_t *const right)
 976 {
 977         type_t *const orig_type_right = right->base.type;
 978         type_t *const type_left       = skip_typeref(orig_type_left);
 979         type_t *const type_right      = skip_typeref(orig_type_right);
 980
 981         if (is_type_pointer(type_left)) {
 982                 if (is_null_pointer_constant(right)) {
 983                         return ASSIGN_SUCCESS;
 984                 } else if (is_type_pointer(type_right)) {
 985                         type_t *points_to_left
 986                                 = skip_typeref(type_left->pointer.points_to);
 987                         type_t *points_to_right
 988                                 = skip_typeref(type_right->pointer.points_to);
 989                         assign_error_t res = ASSIGN_SUCCESS;
 990
 991                         /* the left type has all qualifiers from the right type */
 992                         unsigned missing_qualifiers
 993                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 994                         if (missing_qualifiers != 0) {
 995                                 res = ASSIGN_ERROR_POINTER_QUALIFIER_MISSING;
 996                         }
 997
 998                         points_to_left  = get_unqualified_type(points_to_left);
 999                         points_to_right = get_unqualified_type(points_to_right);
1000
1001                         if (is_type_atomic(points_to_left, ATOMIC_TYPE_VOID))
1002                                 return res;
1003
1004                         if (is_type_atomic(points_to_right, ATOMIC_TYPE_VOID)) {
1005                                 /* ISO/IEC 14882:1998(E) §C.1.2:6 */
1006                                 return c_mode & _CXX ? ASSIGN_ERROR_INCOMPATIBLE : res;
1007                         }
1008
1009                         if (!types_compatible(points_to_left, points_to_right)) {
1010                                 return ASSIGN_WARNING_POINTER_INCOMPATIBLE;
1011                         }
1012
1013                         return res;
1014                 } else if (is_type_integer(type_right)) {
1015                         return ASSIGN_WARNING_POINTER_FROM_INT;
1016                 }
1017         } else if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
1018                         (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
1019                                 && is_type_pointer(type_right))) {
1020                 return ASSIGN_SUCCESS;
1021         } else if (is_type_compound(type_left) && is_type_compound(type_right)) {
1022                 type_t *const unqual_type_left  = get_unqualified_type(type_left);
1023                 type_t *const unqual_type_right = get_unqualified_type(type_right);
1024                 if (types_compatible(unqual_type_left, unqual_type_right)) {
1025                         return ASSIGN_SUCCESS;
1026                 }
1027         } else if (is_type_integer(type_left) && is_type_pointer(type_right)) {
1028                 return ASSIGN_WARNING_INT_FROM_POINTER;
1029         }
1030
1031         if (!is_type_valid(type_left) || !is_type_valid(type_right))
1032                 return ASSIGN_SUCCESS;
1033
1034         return ASSIGN_ERROR_INCOMPATIBLE;
1035 }
1036
1037 static expression_t *parse_constant_expression(void)
1038 {
1039         expression_t *result = parse_subexpression(PREC_CONDITIONAL);
1040
1041         if (is_constant_expression(result) == EXPR_CLASS_VARIABLE) {
1042                 errorf(&result->base.source_position,
1043                        "expression '%E' is not constant", result);
1044         }
1045
1046         return result;
1047 }
1048
1049 static expression_t *parse_assignment_expression(void)
1050 {
1051         return parse_subexpression(PREC_ASSIGNMENT);
1052 }
1053
1054 static void warn_string_concat(const source_position_t *pos)
1055 {
1056         warningf(WARN_TRADITIONAL, pos, "traditional C rejects string constant concatenation");
1057 }
1058
1059 static string_t parse_string_literals(void)
1060 {
1061         assert(token.kind == T_STRING_LITERAL);
1062         string_t result = token.string.string;
1063
1064         next_token();
1065
1066         while (token.kind == T_STRING_LITERAL) {
1067                 warn_string_concat(&token.base.source_position);
1068                 result = concat_strings(&result, &token.string.string);
1069                 next_token();
1070         }
1071
1072         return result;
1073 }
1074
1075 static attribute_t *allocate_attribute_zero(attribute_kind_t kind)
1076 {
1077         attribute_t *attribute = allocate_ast_zero(sizeof(*attribute));
1078         attribute->kind            = kind;
1079         attribute->source_position = *HERE;
1080         return attribute;
1081 }
1082
1083 /**
1084  * Parse (gcc) attribute argument. From gcc comments in gcc source:
1085  *
1086  *  attribute:
1087  *    __attribute__ ( ( attribute-list ) )
1088  *
1089  *  attribute-list:
1090  *    attrib
1091  *    attribute_list , attrib
1092  *
1093  *  attrib:
1094  *    empty
1095  *    any-word
1096  *    any-word ( identifier )
1097  *    any-word ( identifier , nonempty-expr-list )
1098  *    any-word ( expr-list )
1099  *
1100  *  where the "identifier" must not be declared as a type, and
1101  *  "any-word" may be any identifier (including one declared as a
1102  *  type), a reserved word storage class specifier, type specifier or
1103  *  type qualifier.  ??? This still leaves out most reserved keywords
1104  *  (following the old parser), shouldn't we include them, and why not
1105  *  allow identifiers declared as types to start the arguments?
1106  *
1107  *  Matze: this all looks confusing and little systematic, so we're even less
1108  *  strict and parse any list of things which are identifiers or
1109  *  (assignment-)expressions.
1110  */
1111 static attribute_argument_t *parse_attribute_arguments(void)
1112 {
1113         attribute_argument_t  *first  = NULL;
1114         attribute_argument_t **anchor = &first;
1115         if (token.kind != ')') do {
1116                 attribute_argument_t *argument = allocate_ast_zero(sizeof(*argument));
1117
1118                 /* is it an identifier */
1119                 if (token.kind == T_IDENTIFIER
1120                                 && (look_ahead(1)->kind == ',' || look_ahead(1)->kind == ')')) {
1121                         symbol_t *symbol   = token.identifier.symbol;
1122                         argument->kind     = ATTRIBUTE_ARGUMENT_SYMBOL;
1123                         argument->v.symbol = symbol;
1124                         next_token();
1125                 } else {
1126                         /* must be an expression */
1127                         expression_t *expression = parse_assignment_expression();
1128
1129                         argument->kind         = ATTRIBUTE_ARGUMENT_EXPRESSION;
1130                         argument->v.expression = expression;
1131                 }
1132
1133                 /* append argument */
1134                 *anchor = argument;
1135                 anchor  = &argument->next;
1136         } while (next_if(','));
1137         expect(')', end_error);
1138
1139         return first;
1140
1141 end_error:
1142         /* TODO... */
1143         return first;
1144 }
1145
1146 static attribute_t *parse_attribute_asm(void)
1147 {
1148         attribute_t *attribute = allocate_attribute_zero(ATTRIBUTE_GNU_ASM);
1149         eat(T_asm);
1150
1151         expect('(', end_error);
1152         attribute->a.arguments = parse_attribute_arguments();
1153         return attribute;
1154
1155 end_error:
1156         return NULL;
1157 }
1158
1159 static symbol_t *get_symbol_from_token(void)
1160 {
1161         switch(token.kind) {
1162         case T_IDENTIFIER:
1163                 return token.identifier.symbol;
1164         case T_auto:
1165         case T_char:
1166         case T_double:
1167         case T_enum:
1168         case T_extern:
1169         case T_float:
1170         case T_int:
1171         case T_long:
1172         case T_register:
1173         case T_short:
1174         case T_static:
1175         case T_struct:
1176         case T_union:
1177         case T_unsigned:
1178         case T_void:
1179         case T_bool:
1180         case T__Bool:
1181         case T_class:
1182         case T_explicit:
1183         case T_export:
1184         case T_wchar_t:
1185         case T_const:
1186         case T_signed:
1187         case T___real__:
1188         case T___imag__:
1189         case T_restrict:
1190         case T_volatile:
1191         case T_inline:
1192                 /* maybe we need more tokens ... add them on demand */
1193                 return get_token_kind_symbol(token.kind);
1194         default:
1195                 return NULL;
1196         }
1197 }
1198
1199 static attribute_t *parse_attribute_gnu_single(void)
1200 {
1201         /* parse "any-word" */
1202         symbol_t *symbol = get_symbol_from_token();
1203         if (symbol == NULL) {
1204                 parse_error_expected("while parsing attribute((", T_IDENTIFIER, NULL);
1205                 return NULL;
1206         }
1207
1208         attribute_kind_t  kind;
1209         char const *const name = symbol->string;
1210         for (kind = ATTRIBUTE_GNU_FIRST;; ++kind) {
1211                 if (kind > ATTRIBUTE_GNU_LAST) {
1212                         warningf(WARN_ATTRIBUTE, HERE, "unknown attribute '%s' ignored", name);
1213                         /* TODO: we should still save the attribute in the list... */
1214                         kind = ATTRIBUTE_UNKNOWN;
1215                         break;
1216                 }
1217
1218                 const char *attribute_name = get_attribute_name(kind);
1219                 if (attribute_name != NULL && streq_underscore(attribute_name, name))
1220                         break;
1221         }
1222
1223         attribute_t *attribute = allocate_attribute_zero(kind);
1224         next_token();
1225
1226         /* parse arguments */
1227         if (next_if('('))
1228                 attribute->a.arguments = parse_attribute_arguments();
1229
1230         return attribute;
1231 }
1232
1233 static attribute_t *parse_attribute_gnu(void)
1234 {
1235         attribute_t  *first  = NULL;
1236         attribute_t **anchor = &first;
1237
1238         eat(T___attribute__);
1239         expect('(', end_error);
1240         expect('(', end_error);
1241
1242         if (token.kind != ')') do {
1243                 attribute_t *attribute = parse_attribute_gnu_single();
1244                 if (attribute == NULL)
1245                         goto end_error;
1246
1247                 *anchor = attribute;
1248                 anchor  = &attribute->next;
1249         } while (next_if(','));
1250         expect(')', end_error);
1251         expect(')', end_error);
1252
1253 end_error:
1254         return first;
1255 }
1256
1257 /** Parse attributes. */
1258 static attribute_t *parse_attributes(attribute_t *first)
1259 {
1260         attribute_t **anchor = &first;
1261         for (;;) {
1262                 while (*anchor != NULL)
1263                         anchor = &(*anchor)->next;
1264
1265                 attribute_t *attribute;
1266                 switch (token.kind) {
1267                 case T___attribute__:
1268                         attribute = parse_attribute_gnu();
1269                         if (attribute == NULL)
1270                                 continue;
1271                         break;
1272
1273                 case T_asm:
1274                         attribute = parse_attribute_asm();
1275                         break;
1276
1277                 case T_cdecl:
1278                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_CDECL);
1279                         eat(T_cdecl);
1280                         break;
1281
1282                 case T__fastcall:
1283                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FASTCALL);
1284                         eat(T__fastcall);
1285                         break;
1286
1287                 case T__forceinline:
1288                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FORCEINLINE);
1289                         eat(T__forceinline);
1290                         break;
1291
1292                 case T__stdcall:
1293                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_STDCALL);
1294                         eat(T__stdcall);
1295                         break;
1296
1297                 case T___thiscall:
1298                         /* TODO record modifier */
1299                         warningf(WARN_OTHER, HERE, "Ignoring declaration modifier %K", &token);
1300                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_THISCALL);
1301                         eat(T___thiscall);
1302                         break;
1303
1304                 default:
1305                         return first;
1306                 }
1307
1308                 *anchor = attribute;
1309                 anchor  = &attribute->next;
1310         }
1311 }
1312
1313 static void mark_vars_read(expression_t *expr, entity_t *lhs_ent);
1314
1315 static entity_t *determine_lhs_ent(expression_t *const expr,
1316                                    entity_t *lhs_ent)
1317 {
1318         switch (expr->kind) {
1319                 case EXPR_REFERENCE: {
1320                         entity_t *const entity = expr->reference.entity;
1321                         /* we should only find variables as lvalues... */
1322                         if (entity->base.kind != ENTITY_VARIABLE
1323                                         && entity->base.kind != ENTITY_PARAMETER)
1324                                 return NULL;
1325
1326                         return entity;
1327                 }
1328
1329                 case EXPR_ARRAY_ACCESS: {
1330                         expression_t *const ref = expr->array_access.array_ref;
1331                         entity_t     *      ent = NULL;
1332                         if (is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1333                                 ent     = determine_lhs_ent(ref, lhs_ent);
1334                                 lhs_ent = ent;
1335                         } else {
1336                                 mark_vars_read(ref, lhs_ent);
1337                         }
1338                         mark_vars_read(expr->array_access.index, lhs_ent);
1339                         return ent;
1340                 }
1341
1342                 case EXPR_SELECT: {
1343                         mark_vars_read(expr->select.compound, lhs_ent);
1344                         if (is_type_compound(skip_typeref(expr->base.type)))
1345                                 return determine_lhs_ent(expr->select.compound, lhs_ent);
1346                         return NULL;
1347                 }
1348
1349                 case EXPR_UNARY_DEREFERENCE: {
1350                         expression_t *const val = expr->unary.value;
1351                         if (val->kind == EXPR_UNARY_TAKE_ADDRESS) {
1352                                 /* *&x is a NOP */
1353                                 return determine_lhs_ent(val->unary.value, lhs_ent);
1354                         } else {
1355                                 mark_vars_read(val, NULL);
1356                                 return NULL;
1357                         }
1358                 }
1359
1360                 default:
1361                         mark_vars_read(expr, NULL);
1362                         return NULL;
1363         }
1364 }
1365
1366 #define ENT_ANY ((entity_t*)-1)
1367
1368 /**
1369  * Mark declarations, which are read.  This is used to detect variables, which
1370  * are never read.
1371  * Example:
1372  * x = x + 1;
1373  *   x is not marked as "read", because it is only read to calculate its own new
1374  *   value.
1375  *
1376  * x += y; y += x;
1377  *   x and y are not detected as "not read", because multiple variables are
1378  *   involved.
1379  */
1380 static void mark_vars_read(expression_t *const expr, entity_t *lhs_ent)
1381 {
1382         switch (expr->kind) {
1383                 case EXPR_REFERENCE: {
1384                         entity_t *const entity = expr->reference.entity;
1385                         if (entity->kind != ENTITY_VARIABLE
1386                                         && entity->kind != ENTITY_PARAMETER)
1387                                 return;
1388
1389                         if (lhs_ent != entity && lhs_ent != ENT_ANY) {
1390                                 if (entity->kind == ENTITY_VARIABLE) {
1391                                         entity->variable.read = true;
1392                                 } else {
1393                                         entity->parameter.read = true;
1394                                 }
1395                         }
1396                         return;
1397                 }
1398
1399                 case EXPR_CALL:
1400                         // TODO respect pure/const
1401                         mark_vars_read(expr->call.function, NULL);
1402                         for (call_argument_t *arg = expr->call.arguments; arg != NULL; arg = arg->next) {
1403                                 mark_vars_read(arg->expression, NULL);
1404                         }
1405                         return;
1406
1407                 case EXPR_CONDITIONAL:
1408                         // TODO lhs_decl should depend on whether true/false have an effect
1409                         mark_vars_read(expr->conditional.condition, NULL);
1410                         if (expr->conditional.true_expression != NULL)
1411                                 mark_vars_read(expr->conditional.true_expression, lhs_ent);
1412                         mark_vars_read(expr->conditional.false_expression, lhs_ent);
1413                         return;
1414
1415                 case EXPR_SELECT:
1416                         if (lhs_ent == ENT_ANY
1417                                         && !is_type_compound(skip_typeref(expr->base.type)))
1418                                 lhs_ent = NULL;
1419                         mark_vars_read(expr->select.compound, lhs_ent);
1420                         return;
1421
1422                 case EXPR_ARRAY_ACCESS: {
1423                         mark_vars_read(expr->array_access.index, lhs_ent);
1424                         expression_t *const ref = expr->array_access.array_ref;
1425                         if (!is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1426                                 if (lhs_ent == ENT_ANY)
1427                                         lhs_ent = NULL;
1428                         }
1429                         mark_vars_read(ref, lhs_ent);
1430                         return;
1431                 }
1432
1433                 case EXPR_VA_ARG:
1434                         mark_vars_read(expr->va_arge.ap, lhs_ent);
1435                         return;
1436
1437                 case EXPR_VA_COPY:
1438                         mark_vars_read(expr->va_copye.src, lhs_ent);
1439                         return;
1440
1441                 case EXPR_UNARY_CAST:
1442                         /* Special case: Use void cast to mark a variable as "read" */
1443                         if (is_type_atomic(skip_typeref(expr->base.type), ATOMIC_TYPE_VOID))
1444                                 lhs_ent = NULL;
1445                         goto unary;
1446
1447
1448                 case EXPR_UNARY_THROW:
1449                         if (expr->unary.value == NULL)
1450                                 return;
1451                         /* FALLTHROUGH */
1452                 case EXPR_UNARY_DEREFERENCE:
1453                 case EXPR_UNARY_DELETE:
1454                 case EXPR_UNARY_DELETE_ARRAY:
1455                         if (lhs_ent == ENT_ANY)
1456                                 lhs_ent = NULL;
1457                         goto unary;
1458
1459                 case EXPR_UNARY_NEGATE:
1460                 case EXPR_UNARY_PLUS:
1461                 case EXPR_UNARY_BITWISE_NEGATE:
1462                 case EXPR_UNARY_NOT:
1463                 case EXPR_UNARY_TAKE_ADDRESS:
1464                 case EXPR_UNARY_POSTFIX_INCREMENT:
1465                 case EXPR_UNARY_POSTFIX_DECREMENT:
1466                 case EXPR_UNARY_PREFIX_INCREMENT:
1467                 case EXPR_UNARY_PREFIX_DECREMENT:
1468                 case EXPR_UNARY_ASSUME:
1469 unary:
1470                         mark_vars_read(expr->unary.value, lhs_ent);
1471                         return;
1472
1473                 case EXPR_BINARY_ADD:
1474                 case EXPR_BINARY_SUB:
1475                 case EXPR_BINARY_MUL:
1476                 case EXPR_BINARY_DIV:
1477                 case EXPR_BINARY_MOD:
1478                 case EXPR_BINARY_EQUAL:
1479                 case EXPR_BINARY_NOTEQUAL:
1480                 case EXPR_BINARY_LESS:
1481                 case EXPR_BINARY_LESSEQUAL:
1482                 case EXPR_BINARY_GREATER:
1483                 case EXPR_BINARY_GREATEREQUAL:
1484                 case EXPR_BINARY_BITWISE_AND:
1485                 case EXPR_BINARY_BITWISE_OR:
1486                 case EXPR_BINARY_BITWISE_XOR:
1487                 case EXPR_BINARY_LOGICAL_AND:
1488                 case EXPR_BINARY_LOGICAL_OR:
1489                 case EXPR_BINARY_SHIFTLEFT:
1490                 case EXPR_BINARY_SHIFTRIGHT:
1491                 case EXPR_BINARY_COMMA:
1492                 case EXPR_BINARY_ISGREATER:
1493                 case EXPR_BINARY_ISGREATEREQUAL:
1494                 case EXPR_BINARY_ISLESS:
1495                 case EXPR_BINARY_ISLESSEQUAL:
1496                 case EXPR_BINARY_ISLESSGREATER:
1497                 case EXPR_BINARY_ISUNORDERED:
1498                         mark_vars_read(expr->binary.left,  lhs_ent);
1499                         mark_vars_read(expr->binary.right, lhs_ent);
1500                         return;
1501
1502                 case EXPR_BINARY_ASSIGN:
1503                 case EXPR_BINARY_MUL_ASSIGN:
1504                 case EXPR_BINARY_DIV_ASSIGN:
1505                 case EXPR_BINARY_MOD_ASSIGN:
1506                 case EXPR_BINARY_ADD_ASSIGN:
1507                 case EXPR_BINARY_SUB_ASSIGN:
1508                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:
1509                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:
1510                 case EXPR_BINARY_BITWISE_AND_ASSIGN:
1511                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:
1512                 case EXPR_BINARY_BITWISE_OR_ASSIGN: {
1513                         if (lhs_ent == ENT_ANY)
1514                                 lhs_ent = NULL;
1515                         lhs_ent = determine_lhs_ent(expr->binary.left, lhs_ent);
1516                         mark_vars_read(expr->binary.right, lhs_ent);
1517                         return;
1518                 }
1519
1520                 case EXPR_VA_START:
1521                         determine_lhs_ent(expr->va_starte.ap, lhs_ent);
1522                         return;
1523
1524                 EXPR_LITERAL_CASES
1525                 case EXPR_ERROR:
1526                 case EXPR_STRING_LITERAL:
1527                 case EXPR_WIDE_STRING_LITERAL:
1528                 case EXPR_COMPOUND_LITERAL: // TODO init?
1529                 case EXPR_SIZEOF:
1530                 case EXPR_CLASSIFY_TYPE:
1531                 case EXPR_ALIGNOF:
1532                 case EXPR_FUNCNAME:
1533                 case EXPR_BUILTIN_CONSTANT_P:
1534                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
1535                 case EXPR_OFFSETOF:
1536                 case EXPR_STATEMENT: // TODO
1537                 case EXPR_LABEL_ADDRESS:
1538                 case EXPR_REFERENCE_ENUM_VALUE:
1539                         return;
1540         }
1541
1542         panic("unhandled expression");
1543 }
1544
1545 static designator_t *parse_designation(void)
1546 {
1547         designator_t  *result = NULL;
1548         designator_t **anchor = &result;
1549
1550         for (;;) {
1551                 designator_t *designator;
1552                 switch (token.kind) {
1553                 case '[':
1554                         designator = allocate_ast_zero(sizeof(designator[0]));
1555                         designator->source_position = token.base.source_position;
1556                         next_token();
1557                         add_anchor_token(']');
1558                         designator->array_index = parse_constant_expression();
1559                         rem_anchor_token(']');
1560                         expect(']', end_error);
1561                         break;
1562                 case '.':
1563                         designator = allocate_ast_zero(sizeof(designator[0]));
1564                         designator->source_position = token.base.source_position;
1565                         next_token();
1566                         if (token.kind != T_IDENTIFIER) {
1567                                 parse_error_expected("while parsing designator",
1568                                                      T_IDENTIFIER, NULL);
1569                                 return NULL;
1570                         }
1571                         designator->symbol = token.identifier.symbol;
1572                         next_token();
1573                         break;
1574                 default:
1575                         expect('=', end_error);
1576                         return result;
1577                 }
1578
1579                 assert(designator != NULL);
1580                 *anchor = designator;
1581                 anchor  = &designator->next;
1582         }
1583 end_error:
1584         return NULL;
1585 }
1586
1587 static initializer_t *initializer_from_string(array_type_t *const type,
1588                                               const string_t *const string)
1589 {
1590         /* TODO: check len vs. size of array type */
1591         (void) type;
1592
1593         initializer_t *initializer = allocate_initializer_zero(INITIALIZER_STRING);
1594         initializer->string.string = *string;
1595
1596         return initializer;
1597 }
1598
1599 static initializer_t *initializer_from_wide_string(array_type_t *const type,
1600                                                    const string_t *const string)
1601 {
1602         /* TODO: check len vs. size of array type */
1603         (void) type;
1604
1605         initializer_t *const initializer =
1606                 allocate_initializer_zero(INITIALIZER_WIDE_STRING);
1607         initializer->wide_string.string = *string;
1608
1609         return initializer;
1610 }
1611
1612 /**
1613  * Build an initializer from a given expression.
1614  */
1615 static initializer_t *initializer_from_expression(type_t *orig_type,
1616                                                   expression_t *expression)
1617 {
1618         /* TODO check that expression is a constant expression */
1619
1620         /* §6.7.8.14/15 char array may be initialized by string literals */
1621         type_t *type           = skip_typeref(orig_type);
1622         type_t *expr_type_orig = expression->base.type;
1623         type_t *expr_type      = skip_typeref(expr_type_orig);
1624
1625         if (is_type_array(type) && expr_type->kind == TYPE_POINTER) {
1626                 array_type_t *const array_type   = &type->array;
1627                 type_t       *const element_type = skip_typeref(array_type->element_type);
1628
1629                 if (element_type->kind == TYPE_ATOMIC) {
1630                         atomic_type_kind_t akind = element_type->atomic.akind;
1631                         switch (expression->kind) {
1632                         case EXPR_STRING_LITERAL:
1633                                 if (akind == ATOMIC_TYPE_CHAR
1634                                                 || akind == ATOMIC_TYPE_SCHAR
1635                                                 || akind == ATOMIC_TYPE_UCHAR) {
1636                                         return initializer_from_string(array_type,
1637                                                         &expression->string_literal.value);
1638                                 }
1639                                 break;
1640
1641                         case EXPR_WIDE_STRING_LITERAL: {
1642                                 type_t *bare_wchar_type = skip_typeref(type_wchar_t);
1643                                 if (get_unqualified_type(element_type) == bare_wchar_type) {
1644                                         return initializer_from_wide_string(array_type,
1645                                                         &expression->string_literal.value);
1646                                 }
1647                                 break;
1648                         }
1649
1650                         default:
1651                                 break;
1652                         }
1653                 }
1654         }
1655
1656         assign_error_t error = semantic_assign(type, expression);
1657         if (error == ASSIGN_ERROR_INCOMPATIBLE)
1658                 return NULL;
1659         report_assign_error(error, type, expression, "initializer",
1660                             &expression->base.source_position);
1661
1662         initializer_t *const result = allocate_initializer_zero(INITIALIZER_VALUE);
1663         result->value.value = create_implicit_cast(expression, type);
1664
1665         return result;
1666 }
1667
1668 /**
1669  * Parses an scalar initializer.
1670  *
1671  * §6.7.8.11; eat {} without warning
1672  */
1673 static initializer_t *parse_scalar_initializer(type_t *type,
1674                                                bool must_be_constant)
1675 {
1676         /* there might be extra {} hierarchies */
1677         int braces = 0;
1678         if (token.kind == '{') {
1679                 warningf(WARN_OTHER, HERE, "extra curly braces around scalar initializer");
1680                 do {
1681                         eat('{');
1682                         ++braces;
1683                 } while (token.kind == '{');
1684         }
1685
1686         expression_t *expression = parse_assignment_expression();
1687         mark_vars_read(expression, NULL);
1688         if (must_be_constant && !is_linker_constant(expression)) {
1689                 errorf(&expression->base.source_position,
1690                        "initialisation expression '%E' is not constant",
1691                        expression);
1692         }
1693
1694         initializer_t *initializer = initializer_from_expression(type, expression);
1695
1696         if (initializer == NULL) {
1697                 errorf(&expression->base.source_position,
1698                        "expression '%E' (type '%T') doesn't match expected type '%T'",
1699                        expression, expression->base.type, type);
1700                 /* TODO */
1701                 return NULL;
1702         }
1703
1704         bool additional_warning_displayed = false;
1705         while (braces > 0) {
1706                 next_if(',');
1707                 if (token.kind != '}') {
1708                         if (!additional_warning_displayed) {
1709                                 warningf(WARN_OTHER, HERE, "additional elements in scalar initializer");
1710                                 additional_warning_displayed = true;
1711                         }
1712                 }
1713                 eat_block();
1714                 braces--;
1715         }
1716
1717         return initializer;
1718 }
1719
1720 /**
1721  * An entry in the type path.
1722  */
1723 typedef struct type_path_entry_t type_path_entry_t;
1724 struct type_path_entry_t {
1725         type_t *type;       /**< the upper top type. restored to path->top_tye if this entry is popped. */
1726         union {
1727                 size_t         index;          /**< For array types: the current index. */
1728                 declaration_t *compound_entry; /**< For compound types: the current declaration. */
1729         } v;
1730 };
1731
1732 /**
1733  * A type path expression a position inside compound or array types.
1734  */
1735 typedef struct type_path_t type_path_t;
1736 struct type_path_t {
1737         type_path_entry_t *path;         /**< An flexible array containing the current path. */
1738         type_t            *top_type;     /**< type of the element the path points */
1739         size_t             max_index;    /**< largest index in outermost array */
1740 };
1741
1742 /**
1743  * Prints a type path for debugging.
1744  */
1745 static __attribute__((unused)) void debug_print_type_path(
1746                 const type_path_t *path)
1747 {
1748         size_t len = ARR_LEN(path->path);
1749
1750         for (size_t i = 0; i < len; ++i) {
1751                 const type_path_entry_t *entry = & path->path[i];
1752
1753                 type_t *type = skip_typeref(entry->type);
1754                 if (is_type_compound(type)) {
1755                         /* in gcc mode structs can have no members */
1756                         if (entry->v.compound_entry == NULL) {
1757                                 assert(i == len-1);
1758                                 continue;
1759                         }
1760                         fprintf(stderr, ".%s",
1761                                 entry->v.compound_entry->base.symbol->string);
1762                 } else if (is_type_array(type)) {
1763                         fprintf(stderr, "[%u]", (unsigned) entry->v.index);
1764                 } else {
1765                         fprintf(stderr, "-INVALID-");
1766                 }
1767         }
1768         if (path->top_type != NULL) {
1769                 fprintf(stderr, "  (");
1770                 print_type(path->top_type);
1771                 fprintf(stderr, ")");
1772         }
1773 }
1774
1775 /**
1776  * Return the top type path entry, ie. in a path
1777  * (type).a.b returns the b.
1778  */
1779 static type_path_entry_t *get_type_path_top(const type_path_t *path)
1780 {
1781         size_t len = ARR_LEN(path->path);
1782         assert(len > 0);
1783         return &path->path[len-1];
1784 }
1785
1786 /**
1787  * Enlarge the type path by an (empty) element.
1788  */
1789 static type_path_entry_t *append_to_type_path(type_path_t *path)
1790 {
1791         size_t len = ARR_LEN(path->path);
1792         ARR_RESIZE(type_path_entry_t, path->path, len+1);
1793
1794         type_path_entry_t *result = & path->path[len];
1795         memset(result, 0, sizeof(result[0]));
1796         return result;
1797 }
1798
1799 /**
1800  * Descending into a sub-type. Enter the scope of the current top_type.
1801  */
1802 static void descend_into_subtype(type_path_t *path)
1803 {
1804         type_t *orig_top_type = path->top_type;
1805         type_t *top_type      = skip_typeref(orig_top_type);
1806
1807         type_path_entry_t *top = append_to_type_path(path);
1808         top->type              = top_type;
1809
1810         if (is_type_compound(top_type)) {
1811                 compound_t *const compound = top_type->compound.compound;
1812                 entity_t   *const entry    = skip_unnamed_bitfields(compound->members.entities);
1813
1814                 if (entry != NULL) {
1815                         top->v.compound_entry = &entry->declaration;
1816                         path->top_type = entry->declaration.type;
1817                 } else {
1818                         path->top_type = NULL;
1819                 }
1820         } else if (is_type_array(top_type)) {
1821                 top->v.index   = 0;
1822                 path->top_type = top_type->array.element_type;
1823         } else {
1824                 assert(!is_type_valid(top_type));
1825         }
1826 }
1827
1828 /**
1829  * Pop an entry from the given type path, ie. returning from
1830  * (type).a.b to (type).a
1831  */
1832 static void ascend_from_subtype(type_path_t *path)
1833 {
1834         type_path_entry_t *top = get_type_path_top(path);
1835
1836         path->top_type = top->type;
1837
1838         size_t len = ARR_LEN(path->path);
1839         ARR_RESIZE(type_path_entry_t, path->path, len-1);
1840 }
1841
1842 /**
1843  * Pop entries from the given type path until the given
1844  * path level is reached.
1845  */
1846 static void ascend_to(type_path_t *path, size_t top_path_level)
1847 {
1848         size_t len = ARR_LEN(path->path);
1849
1850         while (len > top_path_level) {
1851                 ascend_from_subtype(path);
1852                 len = ARR_LEN(path->path);
1853         }
1854 }
1855
1856 static bool walk_designator(type_path_t *path, const designator_t *designator,
1857                             bool used_in_offsetof)
1858 {
1859         for (; designator != NULL; designator = designator->next) {
1860                 type_path_entry_t *top       = get_type_path_top(path);
1861                 type_t            *orig_type = top->type;
1862
1863                 type_t *type = skip_typeref(orig_type);
1864
1865                 if (designator->symbol != NULL) {
1866                         symbol_t *symbol = designator->symbol;
1867                         if (!is_type_compound(type)) {
1868                                 if (is_type_valid(type)) {
1869                                         errorf(&designator->source_position,
1870                                                "'.%Y' designator used for non-compound type '%T'",
1871                                                symbol, orig_type);
1872                                 }
1873
1874                                 top->type             = type_error_type;
1875                                 top->v.compound_entry = NULL;
1876                                 orig_type             = type_error_type;
1877                         } else {
1878                                 compound_t *compound = type->compound.compound;
1879                                 entity_t   *iter     = compound->members.entities;
1880                                 for (; iter != NULL; iter = iter->base.next) {
1881                                         if (iter->base.symbol == symbol) {
1882                                                 break;
1883                                         }
1884                                 }
1885                                 if (iter == NULL) {
1886                                         errorf(&designator->source_position,
1887                                                "'%T' has no member named '%Y'", orig_type, symbol);
1888                                         return false;
1889                                 }
1890                                 assert(iter->kind == ENTITY_COMPOUND_MEMBER);
1891                                 if (used_in_offsetof && iter->compound_member.bitfield) {
1892                                         errorf(&designator->source_position,
1893                                                    "offsetof designator '%Y' must not specify bitfield",
1894                                                    symbol);
1895                                         return false;
1896                                 }
1897
1898                                 top->type             = orig_type;
1899                                 top->v.compound_entry = &iter->declaration;
1900                                 orig_type             = iter->declaration.type;
1901                         }
1902                 } else {
1903                         expression_t *array_index = designator->array_index;
1904                         assert(designator->array_index != NULL);
1905
1906                         if (!is_type_array(type)) {
1907                                 if (is_type_valid(type)) {
1908                                         errorf(&designator->source_position,
1909                                                "[%E] designator used for non-array type '%T'",
1910                                                array_index, orig_type);
1911                                 }
1912                                 return false;
1913                         }
1914
1915                         long index = fold_constant_to_int(array_index);
1916                         if (!used_in_offsetof) {
1917                                 if (index < 0) {
1918                                         errorf(&designator->source_position,
1919                                                "array index [%E] must be positive", array_index);
1920                                 } else if (type->array.size_constant) {
1921                                         long array_size = type->array.size;
1922                                         if (index >= array_size) {
1923                                                 errorf(&designator->source_position,
1924                                                        "designator [%E] (%d) exceeds array size %d",
1925                                                        array_index, index, array_size);
1926                                         }
1927                                 }
1928                         }
1929
1930                         top->type    = orig_type;
1931                         top->v.index = (size_t) index;
1932                         orig_type    = type->array.element_type;
1933                 }
1934                 path->top_type = orig_type;
1935
1936                 if (designator->next != NULL) {
1937                         descend_into_subtype(path);
1938                 }
1939         }
1940         return true;
1941 }
1942
1943 static void advance_current_object(type_path_t *path, size_t top_path_level)
1944 {
1945         type_path_entry_t *top = get_type_path_top(path);
1946
1947         type_t *type = skip_typeref(top->type);
1948         if (is_type_union(type)) {
1949                 /* in unions only the first element is initialized */
1950                 top->v.compound_entry = NULL;
1951         } else if (is_type_struct(type)) {
1952                 declaration_t *entry = top->v.compound_entry;
1953
1954                 entity_t *const next_entity = skip_unnamed_bitfields(entry->base.next);
1955                 if (next_entity != NULL) {
1956                         assert(is_declaration(next_entity));
1957                         entry = &next_entity->declaration;
1958                 } else {
1959                         entry = NULL;
1960                 }
1961
1962                 top->v.compound_entry = entry;
1963                 if (entry != NULL) {
1964                         path->top_type = entry->type;
1965                         return;
1966                 }
1967         } else if (is_type_array(type)) {
1968                 assert(is_type_array(type));
1969
1970                 top->v.index++;
1971
1972                 if (!type->array.size_constant || top->v.index < type->array.size) {
1973                         return;
1974                 }
1975         } else {
1976                 assert(!is_type_valid(type));
1977                 return;
1978         }
1979
1980         /* we're past the last member of the current sub-aggregate, try if we
1981          * can ascend in the type hierarchy and continue with another subobject */
1982         size_t len = ARR_LEN(path->path);
1983
1984         if (len > top_path_level) {
1985                 ascend_from_subtype(path);
1986                 advance_current_object(path, top_path_level);
1987         } else {
1988                 path->top_type = NULL;
1989         }
1990 }
1991
1992 /**
1993  * skip any {...} blocks until a closing bracket is reached.
1994  */
1995 static void skip_initializers(void)
1996 {
1997         next_if('{');
1998
1999         while (token.kind != '}') {
2000                 if (token.kind == T_EOF)
2001                         return;
2002                 if (token.kind == '{') {
2003                         eat_block();
2004                         continue;
2005                 }
2006                 next_token();
2007         }
2008 }
2009
2010 static initializer_t *create_empty_initializer(void)
2011 {
2012         static initializer_t empty_initializer
2013                 = { .list = { { INITIALIZER_LIST }, 0 } };
2014         return &empty_initializer;
2015 }
2016
2017 /**
2018  * Parse a part of an initialiser for a struct or union,
2019  */
2020 static initializer_t *parse_sub_initializer(type_path_t *path,
2021                 type_t *outer_type, size_t top_path_level,
2022                 parse_initializer_env_t *env)
2023 {
2024         if (token.kind == '}') {
2025                 /* empty initializer */
2026                 return create_empty_initializer();
2027         }
2028
2029         type_t *orig_type = path->top_type;
2030         type_t *type      = NULL;
2031
2032         if (orig_type == NULL) {
2033                 /* We are initializing an empty compound. */
2034         } else {
2035                 type = skip_typeref(orig_type);
2036         }
2037
2038         initializer_t **initializers = NEW_ARR_F(initializer_t*, 0);
2039
2040         while (true) {
2041                 designator_t *designator = NULL;
2042                 if (token.kind == '.' || token.kind == '[') {
2043                         designator = parse_designation();
2044                         goto finish_designator;
2045                 } else if (token.kind == T_IDENTIFIER && look_ahead(1)->kind == ':') {
2046                         /* GNU-style designator ("identifier: value") */
2047                         designator = allocate_ast_zero(sizeof(designator[0]));
2048                         designator->source_position = token.base.source_position;
2049                         designator->symbol          = token.identifier.symbol;
2050                         eat(T_IDENTIFIER);
2051                         eat(':');
2052
2053 finish_designator:
2054                         /* reset path to toplevel, evaluate designator from there */
2055                         ascend_to(path, top_path_level);
2056                         if (!walk_designator(path, designator, false)) {
2057                                 /* can't continue after designation error */
2058                                 goto end_error;
2059                         }
2060
2061                         initializer_t *designator_initializer
2062                                 = allocate_initializer_zero(INITIALIZER_DESIGNATOR);
2063                         designator_initializer->designator.designator = designator;
2064                         ARR_APP1(initializer_t*, initializers, designator_initializer);
2065
2066                         orig_type = path->top_type;
2067                         type      = orig_type != NULL ? skip_typeref(orig_type) : NULL;
2068                 }
2069
2070                 initializer_t *sub;
2071
2072                 if (token.kind == '{') {
2073                         if (type != NULL && is_type_scalar(type)) {
2074                                 sub = parse_scalar_initializer(type, env->must_be_constant);
2075                         } else {
2076                                 if (type == NULL) {
2077                                         if (env->entity != NULL) {
2078                                                 errorf(HERE,
2079                                                      "extra brace group at end of initializer for '%Y'",
2080                                                      env->entity->base.symbol);
2081                                         } else {
2082                                                 errorf(HERE, "extra brace group at end of initializer");
2083                                         }
2084                                         eat('{');
2085                                 } else {
2086                                         eat('{');
2087                                         descend_into_subtype(path);
2088                                 }
2089
2090                                 add_anchor_token('}');
2091                                 sub = parse_sub_initializer(path, orig_type, top_path_level+1,
2092                                                             env);
2093                                 rem_anchor_token('}');
2094
2095                                 if (type != NULL) {
2096                                         ascend_from_subtype(path);
2097                                         expect('}', end_error);
2098                                 } else {
2099                                         expect('}', end_error);
2100                                         goto error_parse_next;
2101                                 }
2102                         }
2103                 } else {
2104                         /* must be an expression */
2105                         expression_t *expression = parse_assignment_expression();
2106                         mark_vars_read(expression, NULL);
2107
2108                         if (env->must_be_constant && !is_linker_constant(expression)) {
2109                                 errorf(&expression->base.source_position,
2110                                        "Initialisation expression '%E' is not constant",
2111                                        expression);
2112                         }
2113
2114                         if (type == NULL) {
2115                                 /* we are already outside, ... */
2116                                 if (outer_type == NULL)
2117                                         goto error_parse_next;
2118                                 type_t *const outer_type_skip = skip_typeref(outer_type);
2119                                 if (is_type_compound(outer_type_skip) &&
2120                                                 !outer_type_skip->compound.compound->complete) {
2121                                         goto error_parse_next;
2122                                 }
2123
2124                                 source_position_t const* const pos = &expression->base.source_position;
2125                                 if (env->entity != NULL) {
2126                                         warningf(WARN_OTHER, pos, "excess elements in initializer for '%Y'", env->entity->base.symbol);
2127                                 } else {
2128                                         warningf(WARN_OTHER, pos, "excess elements in initializer");
2129                                 }
2130                                 goto error_parse_next;
2131                         }
2132
2133                         /* handle { "string" } special case */
2134                         if ((expression->kind == EXPR_STRING_LITERAL
2135                                         || expression->kind == EXPR_WIDE_STRING_LITERAL)
2136                                         && outer_type != NULL) {
2137                                 sub = initializer_from_expression(outer_type, expression);
2138                                 if (sub != NULL) {
2139                                         next_if(',');
2140                                         if (token.kind != '}') {
2141                                                 warningf(WARN_OTHER, HERE, "excessive elements in initializer for type '%T'", orig_type);
2142                                         }
2143                                         /* TODO: eat , ... */
2144                                         return sub;
2145                                 }
2146                         }
2147
2148                         /* descend into subtypes until expression matches type */
2149                         while (true) {
2150                                 orig_type = path->top_type;
2151                                 type      = skip_typeref(orig_type);
2152
2153                                 sub = initializer_from_expression(orig_type, expression);
2154                                 if (sub != NULL) {
2155                                         break;
2156                                 }
2157                                 if (!is_type_valid(type)) {
2158                                         goto end_error;
2159                                 }
2160                                 if (is_type_scalar(type)) {
2161                                         errorf(&expression->base.source_position,
2162                                                         "expression '%E' doesn't match expected type '%T'",
2163                                                         expression, orig_type);
2164                                         goto end_error;
2165                                 }
2166
2167                                 descend_into_subtype(path);
2168                         }
2169                 }
2170
2171                 /* update largest index of top array */
2172                 const type_path_entry_t *first      = &path->path[0];
2173                 type_t                  *first_type = first->type;
2174                 first_type                          = skip_typeref(first_type);
2175                 if (is_type_array(first_type)) {
2176                         size_t index = first->v.index;
2177                         if (index > path->max_index)
2178                                 path->max_index = index;
2179                 }
2180
2181                 /* append to initializers list */
2182                 ARR_APP1(initializer_t*, initializers, sub);
2183
2184 error_parse_next:
2185                 if (token.kind == '}') {
2186                         break;
2187                 }
2188                 expect(',', end_error);
2189                 if (token.kind == '}') {
2190                         break;
2191                 }
2192
2193                 if (type != NULL) {
2194                         /* advance to the next declaration if we are not at the end */
2195                         advance_current_object(path, top_path_level);
2196                         orig_type = path->top_type;
2197                         if (orig_type != NULL)
2198                                 type = skip_typeref(orig_type);
2199                         else
2200                                 type = NULL;
2201                 }
2202         }
2203
2204         size_t len  = ARR_LEN(initializers);
2205         size_t size = sizeof(initializer_list_t) + len * sizeof(initializers[0]);
2206         initializer_t *result = allocate_ast_zero(size);
2207         result->kind          = INITIALIZER_LIST;
2208         result->list.len      = len;
2209         memcpy(&result->list.initializers, initializers,
2210                len * sizeof(initializers[0]));
2211
2212         DEL_ARR_F(initializers);
2213         ascend_to(path, top_path_level+1);
2214
2215         return result;
2216
2217 end_error:
2218         skip_initializers();
2219         DEL_ARR_F(initializers);
2220         ascend_to(path, top_path_level+1);
2221         return NULL;
2222 }
2223
2224 static expression_t *make_size_literal(size_t value)
2225 {
2226         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_INTEGER);
2227         literal->base.type    = type_size_t;
2228
2229         char buf[128];
2230         snprintf(buf, sizeof(buf), "%u", (unsigned) value);
2231         literal->literal.value = make_string(buf);
2232
2233         return literal;
2234 }
2235
2236 /**
2237  * Parses an initializer. Parsers either a compound literal
2238  * (env->declaration == NULL) or an initializer of a declaration.
2239  */
2240 static initializer_t *parse_initializer(parse_initializer_env_t *env)
2241 {
2242         type_t        *type      = skip_typeref(env->type);
2243         size_t         max_index = 0;
2244         initializer_t *result;
2245
2246         if (is_type_scalar(type)) {
2247                 result = parse_scalar_initializer(type, env->must_be_constant);
2248         } else if (token.kind == '{') {
2249                 eat('{');
2250
2251                 type_path_t path;
2252                 memset(&path, 0, sizeof(path));
2253                 path.top_type = env->type;
2254                 path.path     = NEW_ARR_F(type_path_entry_t, 0);
2255
2256                 descend_into_subtype(&path);
2257
2258                 add_anchor_token('}');
2259                 result = parse_sub_initializer(&path, env->type, 1, env);
2260                 rem_anchor_token('}');
2261
2262                 max_index = path.max_index;
2263                 DEL_ARR_F(path.path);
2264
2265                 expect('}', end_error);
2266 end_error:;
2267         } else {
2268                 /* parse_scalar_initializer() also works in this case: we simply
2269                  * have an expression without {} around it */
2270                 result = parse_scalar_initializer(type, env->must_be_constant);
2271         }
2272
2273         /* §6.7.8:22 array initializers for arrays with unknown size determine
2274          * the array type size */
2275         if (is_type_array(type) && type->array.size_expression == NULL
2276                         && result != NULL) {
2277                 size_t size;
2278                 switch (result->kind) {
2279                 case INITIALIZER_LIST:
2280                         assert(max_index != 0xdeadbeaf);
2281                         size = max_index + 1;
2282                         break;
2283
2284                 case INITIALIZER_STRING:
2285                         size = result->string.string.size;
2286                         break;
2287
2288                 case INITIALIZER_WIDE_STRING:
2289                         size = result->wide_string.string.size;
2290                         break;
2291
2292                 case INITIALIZER_DESIGNATOR:
2293                 case INITIALIZER_VALUE:
2294                         /* can happen for parse errors */
2295                         size = 0;
2296                         break;
2297
2298                 default:
2299                         internal_errorf(HERE, "invalid initializer type");
2300                 }
2301
2302                 type_t *new_type = duplicate_type(type);
2303
2304                 new_type->array.size_expression   = make_size_literal(size);
2305                 new_type->array.size_constant     = true;
2306                 new_type->array.has_implicit_size = true;
2307                 new_type->array.size              = size;
2308                 env->type = new_type;
2309         }
2310
2311         return result;
2312 }
2313
2314 static void append_entity(scope_t *scope, entity_t *entity)
2315 {
2316         if (scope->last_entity != NULL) {
2317                 scope->last_entity->base.next = entity;
2318         } else {
2319                 scope->entities = entity;
2320         }
2321         entity->base.parent_entity = current_entity;
2322         scope->last_entity         = entity;
2323 }
2324
2325
2326 static compound_t *parse_compound_type_specifier(bool is_struct)
2327 {
2328         source_position_t const pos = *HERE;
2329         eat(is_struct ? T_struct : T_union);
2330
2331         symbol_t    *symbol     = NULL;
2332         entity_t    *entity     = NULL;
2333         attribute_t *attributes = NULL;
2334
2335         if (token.kind == T___attribute__) {
2336                 attributes = parse_attributes(NULL);
2337         }
2338
2339         entity_kind_tag_t const kind = is_struct ? ENTITY_STRUCT : ENTITY_UNION;
2340         if (token.kind == T_IDENTIFIER) {
2341                 /* the compound has a name, check if we have seen it already */
2342                 symbol = token.identifier.symbol;
2343                 entity = get_tag(symbol, kind);
2344                 next_token();
2345
2346                 if (entity != NULL) {
2347                         if (entity->base.parent_scope != current_scope &&
2348                             (token.kind == '{' || token.kind == ';')) {
2349                                 /* we're in an inner scope and have a definition. Shadow
2350                                  * existing definition in outer scope */
2351                                 entity = NULL;
2352                         } else if (entity->compound.complete && token.kind == '{') {
2353                                 source_position_t const *const ppos = &entity->base.source_position;
2354                                 errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
2355                                 /* clear members in the hope to avoid further errors */
2356                                 entity->compound.members.entities = NULL;
2357                         }
2358                 }
2359         } else if (token.kind != '{') {
2360                 char const *const msg =
2361                         is_struct ? "while parsing struct type specifier" :
2362                                     "while parsing union type specifier";
2363                 parse_error_expected(msg, T_IDENTIFIER, '{', NULL);
2364
2365                 return NULL;
2366         }
2367
2368         if (entity == NULL) {
2369                 entity = allocate_entity_zero(kind, NAMESPACE_TAG, symbol);
2370                 entity->compound.alignment   = 1;
2371                 entity->base.source_position = pos;
2372                 entity->base.parent_scope    = current_scope;
2373                 if (symbol != NULL) {
2374                         environment_push(entity);
2375                 }
2376                 append_entity(current_scope, entity);
2377         }
2378
2379         if (token.kind == '{') {
2380                 parse_compound_type_entries(&entity->compound);
2381
2382                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2383                 if (symbol == NULL) {
2384                         assert(anonymous_entity == NULL);
2385                         anonymous_entity = entity;
2386                 }
2387         }
2388
2389         if (attributes != NULL) {
2390                 handle_entity_attributes(attributes, entity);
2391         }
2392
2393         return &entity->compound;
2394 }
2395
2396 static void parse_enum_entries(type_t *const enum_type)
2397 {
2398         eat('{');
2399
2400         if (token.kind == '}') {
2401                 errorf(HERE, "empty enum not allowed");
2402                 next_token();
2403                 return;
2404         }
2405
2406         add_anchor_token('}');
2407         do {
2408                 if (token.kind != T_IDENTIFIER) {
2409                         parse_error_expected("while parsing enum entry", T_IDENTIFIER, NULL);
2410                         eat_block();
2411                         rem_anchor_token('}');
2412                         return;
2413                 }
2414
2415                 symbol_t *symbol       = token.identifier.symbol;
2416                 entity_t *const entity
2417                         = allocate_entity_zero(ENTITY_ENUM_VALUE, NAMESPACE_NORMAL, symbol);
2418                 entity->enum_value.enum_type = enum_type;
2419                 entity->base.source_position = token.base.source_position;
2420                 next_token();
2421
2422                 if (next_if('=')) {
2423                         expression_t *value = parse_constant_expression();
2424
2425                         value = create_implicit_cast(value, enum_type);
2426                         entity->enum_value.value = value;
2427
2428                         /* TODO semantic */
2429                 }
2430
2431                 record_entity(entity, false);
2432         } while (next_if(',') && token.kind != '}');
2433         rem_anchor_token('}');
2434
2435         expect('}', end_error);
2436
2437 end_error:
2438         ;
2439 }
2440
2441 static type_t *parse_enum_specifier(void)
2442 {
2443         source_position_t const pos = *HERE;
2444         entity_t               *entity;
2445         symbol_t               *symbol;
2446
2447         eat(T_enum);
2448         switch (token.kind) {
2449                 case T_IDENTIFIER:
2450                         symbol = token.identifier.symbol;
2451                         entity = get_tag(symbol, ENTITY_ENUM);
2452                         next_token();
2453
2454                         if (entity != NULL) {
2455                                 if (entity->base.parent_scope != current_scope &&
2456                                                 (token.kind == '{' || token.kind == ';')) {
2457                                         /* we're in an inner scope and have a definition. Shadow
2458                                          * existing definition in outer scope */
2459                                         entity = NULL;
2460                                 } else if (entity->enume.complete && token.kind == '{') {
2461                                         source_position_t const *const ppos = &entity->base.source_position;
2462                                         errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
2463                                 }
2464                         }
2465                         break;
2466
2467                 case '{':
2468                         entity = NULL;
2469                         symbol = NULL;
2470                         break;
2471
2472                 default:
2473                         parse_error_expected("while parsing enum type specifier",
2474                                         T_IDENTIFIER, '{', NULL);
2475                         return NULL;
2476         }
2477
2478         if (entity == NULL) {
2479                 entity = allocate_entity_zero(ENTITY_ENUM, NAMESPACE_TAG, symbol);
2480                 entity->base.source_position = pos;
2481                 entity->base.parent_scope    = current_scope;
2482         }
2483
2484         type_t *const type     = allocate_type_zero(TYPE_ENUM);
2485         type->enumt.enume      = &entity->enume;
2486         type->enumt.base.akind = ATOMIC_TYPE_INT;
2487
2488         if (token.kind == '{') {
2489                 if (symbol != NULL) {
2490                         environment_push(entity);
2491                 }
2492                 append_entity(current_scope, entity);
2493                 entity->enume.complete = true;
2494
2495                 parse_enum_entries(type);
2496                 parse_attributes(NULL);
2497
2498                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2499                 if (symbol == NULL) {
2500                         assert(anonymous_entity == NULL);
2501                         anonymous_entity = entity;
2502                 }
2503         } else if (!entity->enume.complete && !(c_mode & _GNUC)) {
2504                 errorf(HERE, "'%T' used before definition (incomplete enums are a GNU extension)", type);
2505         }
2506
2507         return type;
2508 }
2509
2510 /**
2511  * if a symbol is a typedef to another type, return true
2512  */
2513 static bool is_typedef_symbol(symbol_t *symbol)
2514 {
2515         const entity_t *const entity = get_entity(symbol, NAMESPACE_NORMAL);
2516         return entity != NULL && entity->kind == ENTITY_TYPEDEF;
2517 }
2518
2519 static type_t *parse_typeof(void)
2520 {
2521         eat(T___typeof__);
2522
2523         type_t *type;
2524
2525         expect('(', end_error);
2526         add_anchor_token(')');
2527
2528         expression_t *expression  = NULL;
2529
2530         switch (token.kind) {
2531         case T_IDENTIFIER:
2532                 if (is_typedef_symbol(token.identifier.symbol)) {
2533         DECLARATION_START
2534                         type = parse_typename();
2535                 } else {
2536         default:
2537                         expression = parse_expression();
2538                         type       = revert_automatic_type_conversion(expression);
2539                 }
2540                 break;
2541         }
2542
2543         rem_anchor_token(')');
2544         expect(')', end_error);
2545
2546         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF);
2547         typeof_type->typeoft.expression  = expression;
2548         typeof_type->typeoft.typeof_type = type;
2549
2550         return typeof_type;
2551 end_error:
2552         return NULL;
2553 }
2554
2555 typedef enum specifiers_t {
2556         SPECIFIER_SIGNED    = 1 << 0,
2557         SPECIFIER_UNSIGNED  = 1 << 1,
2558         SPECIFIER_LONG      = 1 << 2,
2559         SPECIFIER_INT       = 1 << 3,
2560         SPECIFIER_DOUBLE    = 1 << 4,
2561         SPECIFIER_CHAR      = 1 << 5,
2562         SPECIFIER_WCHAR_T   = 1 << 6,
2563         SPECIFIER_SHORT     = 1 << 7,
2564         SPECIFIER_LONG_LONG = 1 << 8,
2565         SPECIFIER_FLOAT     = 1 << 9,
2566         SPECIFIER_BOOL      = 1 << 10,
2567         SPECIFIER_VOID      = 1 << 11,
2568         SPECIFIER_INT8      = 1 << 12,
2569         SPECIFIER_INT16     = 1 << 13,
2570         SPECIFIER_INT32     = 1 << 14,
2571         SPECIFIER_INT64     = 1 << 15,
2572         SPECIFIER_INT128    = 1 << 16,
2573         SPECIFIER_COMPLEX   = 1 << 17,
2574         SPECIFIER_IMAGINARY = 1 << 18,
2575 } specifiers_t;
2576
2577 static type_t *get_typedef_type(symbol_t *symbol)
2578 {
2579         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
2580         if (entity == NULL || entity->kind != ENTITY_TYPEDEF)
2581                 return NULL;
2582
2583         type_t *type            = allocate_type_zero(TYPE_TYPEDEF);
2584         type->typedeft.typedefe = &entity->typedefe;
2585
2586         return type;
2587 }
2588
2589 static attribute_t *parse_attribute_ms_property(attribute_t *attribute)
2590 {
2591         expect('(', end_error);
2592
2593         attribute_property_argument_t *property
2594                 = allocate_ast_zero(sizeof(*property));
2595
2596         do {
2597                 if (token.kind != T_IDENTIFIER) {
2598                         parse_error_expected("while parsing property declspec",
2599                                              T_IDENTIFIER, NULL);
2600                         goto end_error;
2601                 }
2602
2603                 symbol_t **prop;
2604                 symbol_t  *symbol = token.identifier.symbol;
2605                 if (streq(symbol->string, "put")) {
2606                         prop = &property->put_symbol;
2607                 } else if (streq(symbol->string, "get")) {
2608                         prop = &property->get_symbol;
2609                 } else {
2610                         errorf(HERE, "expected put or get in property declspec");
2611                         prop = NULL;
2612                 }
2613                 eat(T_IDENTIFIER);
2614                 expect('=', end_error);
2615                 if (token.kind != T_IDENTIFIER) {
2616                         parse_error_expected("while parsing property declspec",
2617                                              T_IDENTIFIER, NULL);
2618                         goto end_error;
2619                 }
2620                 if (prop != NULL)
2621                         *prop = token.identifier.symbol;
2622                 next_token();
2623         } while (next_if(','));
2624
2625         attribute->a.property = property;
2626
2627         expect(')', end_error);
2628
2629 end_error:
2630         return attribute;
2631 }
2632
2633 static attribute_t *parse_microsoft_extended_decl_modifier_single(void)
2634 {
2635         attribute_kind_t kind = ATTRIBUTE_UNKNOWN;
2636         if (next_if(T_restrict)) {
2637                 kind = ATTRIBUTE_MS_RESTRICT;
2638         } else if (token.kind == T_IDENTIFIER) {
2639                 const char *name = token.identifier.symbol->string;
2640                 for (attribute_kind_t k = ATTRIBUTE_MS_FIRST; k <= ATTRIBUTE_MS_LAST;
2641                      ++k) {
2642                         const char *attribute_name = get_attribute_name(k);
2643                         if (attribute_name != NULL && streq(attribute_name, name)) {
2644                                 kind = k;
2645                                 break;
2646                         }
2647                 }
2648
2649                 if (kind == ATTRIBUTE_UNKNOWN) {
2650                         warningf(WARN_ATTRIBUTE, HERE, "unknown __declspec '%s' ignored", name);
2651                 }
2652         } else {
2653                 parse_error_expected("while parsing __declspec", T_IDENTIFIER, NULL);
2654                 return NULL;
2655         }
2656
2657         attribute_t *attribute = allocate_attribute_zero(kind);
2658         eat(T_IDENTIFIER);
2659
2660         if (kind == ATTRIBUTE_MS_PROPERTY) {
2661                 return parse_attribute_ms_property(attribute);
2662         }
2663
2664         /* parse arguments */
2665         if (next_if('('))
2666                 attribute->a.arguments = parse_attribute_arguments();
2667
2668         return attribute;
2669 }
2670
2671 static attribute_t *parse_microsoft_extended_decl_modifier(attribute_t *first)
2672 {
2673         eat(T__declspec);
2674
2675         expect('(', end_error);
2676
2677         if (next_if(')'))
2678                 return NULL;
2679
2680         add_anchor_token(')');
2681
2682         attribute_t **anchor = &first;
2683         do {
2684                 while (*anchor != NULL)
2685                         anchor = &(*anchor)->next;
2686
2687                 attribute_t *attribute
2688                         = parse_microsoft_extended_decl_modifier_single();
2689                 if (attribute == NULL)
2690                         goto end_error;
2691
2692                 *anchor = attribute;
2693                 anchor  = &attribute->next;
2694         } while (next_if(','));
2695
2696         rem_anchor_token(')');
2697         expect(')', end_error);
2698         return first;
2699
2700 end_error:
2701         rem_anchor_token(')');
2702         return first;
2703 }
2704
2705 static entity_t *create_error_entity(symbol_t *symbol, entity_kind_tag_t kind)
2706 {
2707         entity_t *const entity = allocate_entity_zero(kind, NAMESPACE_NORMAL, symbol);
2708         entity->base.source_position = *HERE;
2709         if (is_declaration(entity)) {
2710                 entity->declaration.type     = type_error_type;
2711                 entity->declaration.implicit = true;
2712         } else if (kind == ENTITY_TYPEDEF) {
2713                 entity->typedefe.type    = type_error_type;
2714                 entity->typedefe.builtin = true;
2715         }
2716         if (kind != ENTITY_COMPOUND_MEMBER)
2717                 record_entity(entity, false);
2718         return entity;
2719 }
2720
2721 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
2722 {
2723         type_t            *type            = NULL;
2724         type_qualifiers_t  qualifiers      = TYPE_QUALIFIER_NONE;
2725         unsigned           type_specifiers = 0;
2726         bool               newtype         = false;
2727         bool               saw_error       = false;
2728
2729         memset(specifiers, 0, sizeof(*specifiers));
2730         specifiers->source_position = token.base.source_position;
2731
2732         while (true) {
2733                 specifiers->attributes = parse_attributes(specifiers->attributes);
2734
2735                 switch (token.kind) {
2736                 /* storage class */
2737 #define MATCH_STORAGE_CLASS(token, class)                                  \
2738                 case token:                                                        \
2739                         if (specifiers->storage_class != STORAGE_CLASS_NONE) {         \
2740                                 errorf(HERE, "multiple storage classes in declaration specifiers"); \
2741                         }                                                              \
2742                         specifiers->storage_class = class;                             \
2743                         if (specifiers->thread_local)                                  \
2744                                 goto check_thread_storage_class;                           \
2745                         next_token();                                                  \
2746                         break;
2747
2748                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
2749                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
2750                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
2751                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
2752                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
2753
2754                 case T__declspec:
2755                         specifiers->attributes
2756                                 = parse_microsoft_extended_decl_modifier(specifiers->attributes);
2757                         break;
2758
2759                 case T___thread:
2760                         if (specifiers->thread_local) {
2761                                 errorf(HERE, "duplicate '__thread'");
2762                         } else {
2763                                 specifiers->thread_local = true;
2764 check_thread_storage_class:
2765                                 switch (specifiers->storage_class) {
2766                                         case STORAGE_CLASS_EXTERN:
2767                                         case STORAGE_CLASS_NONE:
2768                                         case STORAGE_CLASS_STATIC:
2769                                                 break;
2770
2771                                                 char const* wrong;
2772                                         case STORAGE_CLASS_AUTO:     wrong = "auto";     goto wrong_thread_storage_class;
2773                                         case STORAGE_CLASS_REGISTER: wrong = "register"; goto wrong_thread_storage_class;
2774                                         case STORAGE_CLASS_TYPEDEF:  wrong = "typedef";  goto wrong_thread_storage_class;
2775 wrong_thread_storage_class:
2776                                                 errorf(HERE, "'__thread' used with '%s'", wrong);
2777                                                 break;
2778                                 }
2779                         }
2780                         next_token();
2781                         break;
2782
2783                 /* type qualifiers */
2784 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
2785                 case token:                                                     \
2786                         qualifiers |= qualifier;                                    \
2787                         next_token();                                               \
2788                         break
2789
2790                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
2791                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
2792                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
2793                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
2794                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
2795                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
2796                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
2797                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
2798
2799                 /* type specifiers */
2800 #define MATCH_SPECIFIER(token, specifier, name)                         \
2801                 case token:                                                     \
2802                         if (type_specifiers & specifier) {                           \
2803                                 errorf(HERE, "multiple " name " type specifiers given"); \
2804                         } else {                                                    \
2805                                 type_specifiers |= specifier;                           \
2806                         }                                                           \
2807                         next_token();                                               \
2808                         break
2809
2810                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool");
2811                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex");
2812                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary");
2813                 MATCH_SPECIFIER(T__int128,    SPECIFIER_INT128,    "_int128");
2814                 MATCH_SPECIFIER(T__int16,     SPECIFIER_INT16,     "_int16");
2815                 MATCH_SPECIFIER(T__int32,     SPECIFIER_INT32,     "_int32");
2816                 MATCH_SPECIFIER(T__int64,     SPECIFIER_INT64,     "_int64");
2817                 MATCH_SPECIFIER(T__int8,      SPECIFIER_INT8,      "_int8");
2818                 MATCH_SPECIFIER(T_bool,       SPECIFIER_BOOL,      "bool");
2819                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char");
2820                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double");
2821                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float");
2822                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int");
2823                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short");
2824                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed");
2825                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned");
2826                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void");
2827                 MATCH_SPECIFIER(T_wchar_t,    SPECIFIER_WCHAR_T,   "wchar_t");
2828
2829                 case T_inline:
2830                         next_token();
2831                         specifiers->is_inline = true;
2832                         break;
2833
2834 #if 0
2835                 case T__forceinline:
2836                         next_token();
2837                         specifiers->modifiers |= DM_FORCEINLINE;
2838                         break;
2839 #endif
2840
2841                 case T_long:
2842                         if (type_specifiers & SPECIFIER_LONG_LONG) {
2843                                 errorf(HERE, "too many long type specifiers given");
2844                         } else if (type_specifiers & SPECIFIER_LONG) {
2845                                 type_specifiers |= SPECIFIER_LONG_LONG;
2846                         } else {
2847                                 type_specifiers |= SPECIFIER_LONG;
2848                         }
2849                         next_token();
2850                         break;
2851
2852 #define CHECK_DOUBLE_TYPE() \
2853         (type != NULL ? errorf(HERE, "multiple types in declaration specifiers") : (void)0)
2854
2855                 case T_struct:
2856                         CHECK_DOUBLE_TYPE();
2857                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
2858
2859                         type->compound.compound = parse_compound_type_specifier(true);
2860                         break;
2861                 case T_union:
2862                         CHECK_DOUBLE_TYPE();
2863                         type = allocate_type_zero(TYPE_COMPOUND_UNION);
2864                         type->compound.compound = parse_compound_type_specifier(false);
2865                         break;
2866                 case T_enum:
2867                         CHECK_DOUBLE_TYPE();
2868                         type = parse_enum_specifier();
2869                         break;
2870                 case T___typeof__:
2871                         CHECK_DOUBLE_TYPE();
2872                         type = parse_typeof();
2873                         break;
2874                 case T___builtin_va_list:
2875                         CHECK_DOUBLE_TYPE();
2876                         type = duplicate_type(type_valist);
2877                         next_token();
2878                         break;
2879
2880                 case T_IDENTIFIER: {
2881                         /* only parse identifier if we haven't found a type yet */
2882                         if (type != NULL || type_specifiers != 0) {
2883                                 /* Be somewhat resilient to typos like 'unsigned lng* f()' in a
2884                                  * declaration, so it doesn't generate errors about expecting '(' or
2885                                  * '{' later on. */
2886                                 switch (look_ahead(1)->kind) {
2887                                         STORAGE_CLASSES
2888                                         TYPE_SPECIFIERS
2889                                         case T_const:
2890                                         case T_restrict:
2891                                         case T_volatile:
2892                                         case T_inline:
2893                                         case T__forceinline: /* ^ DECLARATION_START except for __attribute__ */
2894                                         case T_IDENTIFIER:
2895                                         case '&':
2896                                         case '*':
2897                                                 errorf(HERE, "discarding stray %K in declaration specifier", &token);
2898                                                 next_token();
2899                                                 continue;
2900
2901                                         default:
2902                                                 goto finish_specifiers;
2903                                 }
2904                         }
2905
2906                         type_t *const typedef_type = get_typedef_type(token.identifier.symbol);
2907                         if (typedef_type == NULL) {
2908                                 /* Be somewhat resilient to typos like 'vodi f()' at the beginning of a
2909                                  * declaration, so it doesn't generate 'implicit int' followed by more
2910                                  * errors later on. */
2911                                 token_kind_t const la1_type = (token_kind_t)look_ahead(1)->kind;
2912                                 switch (la1_type) {
2913                                         DECLARATION_START
2914                                         case T_IDENTIFIER:
2915                                         case '&':
2916                                         case '*': {
2917                                                 errorf(HERE, "%K does not name a type", &token);
2918
2919                                                 symbol_t *symbol = token.identifier.symbol;
2920                                                 entity_t *entity
2921                                                         = create_error_entity(symbol, ENTITY_TYPEDEF);
2922
2923                                                 type = allocate_type_zero(TYPE_TYPEDEF);
2924                                                 type->typedeft.typedefe = &entity->typedefe;
2925
2926                                                 next_token();
2927                                                 saw_error = true;
2928                                                 continue;
2929                                         }
2930
2931                                         default:
2932                                                 goto finish_specifiers;
2933                                 }
2934                         }
2935
2936                         next_token();
2937                         type = typedef_type;
2938                         break;
2939                 }
2940
2941                 /* function specifier */
2942                 default:
2943                         goto finish_specifiers;
2944                 }
2945         }
2946
2947 finish_specifiers:
2948         specifiers->attributes = parse_attributes(specifiers->attributes);
2949
2950         if (type == NULL || (saw_error && type_specifiers != 0)) {
2951                 atomic_type_kind_t atomic_type;
2952
2953                 /* match valid basic types */
2954                 switch (type_specifiers) {
2955                 case SPECIFIER_VOID:
2956                         atomic_type = ATOMIC_TYPE_VOID;
2957                         break;
2958                 case SPECIFIER_WCHAR_T:
2959                         atomic_type = ATOMIC_TYPE_WCHAR_T;
2960                         break;
2961                 case SPECIFIER_CHAR:
2962                         atomic_type = ATOMIC_TYPE_CHAR;
2963                         break;
2964                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
2965                         atomic_type = ATOMIC_TYPE_SCHAR;
2966                         break;
2967                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
2968                         atomic_type = ATOMIC_TYPE_UCHAR;
2969                         break;
2970                 case SPECIFIER_SHORT:
2971                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
2972                 case SPECIFIER_SHORT | SPECIFIER_INT:
2973                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
2974                         atomic_type = ATOMIC_TYPE_SHORT;
2975                         break;
2976                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
2977                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
2978                         atomic_type = ATOMIC_TYPE_USHORT;
2979                         break;
2980                 case SPECIFIER_INT:
2981                 case SPECIFIER_SIGNED:
2982                 case SPECIFIER_SIGNED | SPECIFIER_INT:
2983                         atomic_type = ATOMIC_TYPE_INT;
2984                         break;
2985                 case SPECIFIER_UNSIGNED:
2986                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
2987                         atomic_type = ATOMIC_TYPE_UINT;
2988                         break;
2989                 case SPECIFIER_LONG:
2990                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
2991                 case SPECIFIER_LONG | SPECIFIER_INT:
2992                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
2993                         atomic_type = ATOMIC_TYPE_LONG;
2994                         break;
2995                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
2996                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
2997                         atomic_type = ATOMIC_TYPE_ULONG;
2998                         break;
2999
3000                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3001                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3002                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
3003                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3004                         | SPECIFIER_INT:
3005                         atomic_type = ATOMIC_TYPE_LONGLONG;
3006                         goto warn_about_long_long;
3007
3008                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3009                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3010                         | SPECIFIER_INT:
3011                         atomic_type = ATOMIC_TYPE_ULONGLONG;
3012 warn_about_long_long:
3013                         warningf(WARN_LONG_LONG, &specifiers->source_position, "ISO C90 does not support 'long long'");
3014                         break;
3015
3016                 case SPECIFIER_UNSIGNED | SPECIFIER_INT8:
3017                         atomic_type = unsigned_int8_type_kind;
3018                         break;
3019
3020                 case SPECIFIER_UNSIGNED | SPECIFIER_INT16:
3021                         atomic_type = unsigned_int16_type_kind;
3022                         break;
3023
3024                 case SPECIFIER_UNSIGNED | SPECIFIER_INT32:
3025                         atomic_type = unsigned_int32_type_kind;
3026                         break;
3027
3028                 case SPECIFIER_UNSIGNED | SPECIFIER_INT64:
3029                         atomic_type = unsigned_int64_type_kind;
3030                         break;
3031
3032                 case SPECIFIER_UNSIGNED | SPECIFIER_INT128:
3033                         atomic_type = unsigned_int128_type_kind;
3034                         break;
3035
3036                 case SPECIFIER_INT8:
3037                 case SPECIFIER_SIGNED | SPECIFIER_INT8:
3038                         atomic_type = int8_type_kind;
3039                         break;
3040
3041                 case SPECIFIER_INT16:
3042                 case SPECIFIER_SIGNED | SPECIFIER_INT16:
3043                         atomic_type = int16_type_kind;
3044                         break;
3045
3046                 case SPECIFIER_INT32:
3047                 case SPECIFIER_SIGNED | SPECIFIER_INT32:
3048                         atomic_type = int32_type_kind;
3049                         break;
3050
3051                 case SPECIFIER_INT64:
3052                 case SPECIFIER_SIGNED | SPECIFIER_INT64:
3053                         atomic_type = int64_type_kind;
3054                         break;
3055
3056                 case SPECIFIER_INT128:
3057                 case SPECIFIER_SIGNED | SPECIFIER_INT128:
3058                         atomic_type = int128_type_kind;
3059                         break;
3060
3061                 case SPECIFIER_FLOAT:
3062                         atomic_type = ATOMIC_TYPE_FLOAT;
3063                         break;
3064                 case SPECIFIER_DOUBLE:
3065                         atomic_type = ATOMIC_TYPE_DOUBLE;
3066                         break;
3067                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
3068                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
3069                         break;
3070                 case SPECIFIER_BOOL:
3071                         atomic_type = ATOMIC_TYPE_BOOL;
3072                         break;
3073                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
3074                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
3075                         atomic_type = ATOMIC_TYPE_FLOAT;
3076                         break;
3077                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3078                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3079                         atomic_type = ATOMIC_TYPE_DOUBLE;
3080                         break;
3081                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3082                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3083                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
3084                         break;
3085                 default: {
3086                         /* invalid specifier combination, give an error message */
3087                         source_position_t const* const pos = &specifiers->source_position;
3088                         if (type_specifiers == 0) {
3089                                 if (!saw_error) {
3090                                         /* ISO/IEC 14882:1998(E) §C.1.5:4 */
3091                                         if (!(c_mode & _CXX) && !strict_mode) {
3092                                                 warningf(WARN_IMPLICIT_INT, pos, "no type specifiers in declaration, using 'int'");
3093                                                 atomic_type = ATOMIC_TYPE_INT;
3094                                                 break;
3095                                         } else {
3096                                                 errorf(pos, "no type specifiers given in declaration");
3097                                         }
3098                                 }
3099                         } else if ((type_specifiers & SPECIFIER_SIGNED) &&
3100                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
3101                                 errorf(pos, "signed and unsigned specifiers given");
3102                         } else if (type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
3103                                 errorf(pos, "only integer types can be signed or unsigned");
3104                         } else {
3105                                 errorf(pos, "multiple datatypes in declaration");
3106                         }
3107                         goto end_error;
3108                 }
3109                 }
3110
3111                 if (type_specifiers & SPECIFIER_COMPLEX) {
3112                         type = allocate_type_zero(TYPE_COMPLEX);
3113                 } else if (type_specifiers & SPECIFIER_IMAGINARY) {
3114                         type = allocate_type_zero(TYPE_IMAGINARY);
3115                 } else {
3116                         type = allocate_type_zero(TYPE_ATOMIC);
3117                 }
3118                 type->atomic.akind = atomic_type;
3119                 newtype = true;
3120         } else if (type_specifiers != 0) {
3121                 errorf(&specifiers->source_position, "multiple datatypes in declaration");
3122         }
3123
3124         /* FIXME: check type qualifiers here */
3125         type->base.qualifiers = qualifiers;
3126
3127         if (newtype) {
3128                 type = identify_new_type(type);
3129         } else {
3130                 type = typehash_insert(type);
3131         }
3132
3133         if (specifiers->attributes != NULL)
3134                 type = handle_type_attributes(specifiers->attributes, type);
3135         specifiers->type = type;
3136         return;
3137
3138 end_error:
3139         specifiers->type = type_error_type;
3140 }
3141
3142 static type_qualifiers_t parse_type_qualifiers(void)
3143 {
3144         type_qualifiers_t qualifiers = TYPE_QUALIFIER_NONE;
3145
3146         while (true) {
3147                 switch (token.kind) {
3148                 /* type qualifiers */
3149                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3150                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3151                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3152                 /* microsoft extended type modifiers */
3153                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3154                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3155                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3156                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3157                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3158
3159                 default:
3160                         return qualifiers;
3161                 }
3162         }
3163 }
3164
3165 /**
3166  * Parses an K&R identifier list
3167  */
3168 static void parse_identifier_list(scope_t *scope)
3169 {
3170         assert(token.kind == T_IDENTIFIER);
3171         do {
3172                 entity_t *const entity = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, token.identifier.symbol);
3173                 entity->base.source_position = token.base.source_position;
3174                 /* a K&R parameter has no type, yet */
3175                 next_token();
3176
3177                 if (scope != NULL)
3178                         append_entity(scope, entity);
3179         } while (next_if(',') && token.kind == T_IDENTIFIER);
3180 }
3181
3182 static entity_t *parse_parameter(void)
3183 {
3184         declaration_specifiers_t specifiers;
3185         parse_declaration_specifiers(&specifiers);
3186
3187         entity_t *entity = parse_declarator(&specifiers,
3188                         DECL_MAY_BE_ABSTRACT | DECL_IS_PARAMETER);
3189         anonymous_entity = NULL;
3190         return entity;
3191 }
3192
3193 static void semantic_parameter_incomplete(const entity_t *entity)
3194 {
3195         assert(entity->kind == ENTITY_PARAMETER);
3196
3197         /* §6.7.5.3:4  After adjustment, the parameters in a parameter type
3198          *             list in a function declarator that is part of a
3199          *             definition of that function shall not have
3200          *             incomplete type. */
3201         type_t *type = skip_typeref(entity->declaration.type);
3202         if (is_type_incomplete(type)) {
3203                 errorf(&entity->base.source_position, "'%N' has incomplete type", entity);
3204         }
3205 }
3206
3207 static bool has_parameters(void)
3208 {
3209         /* func(void) is not a parameter */
3210         if (token.kind == T_IDENTIFIER) {
3211                 entity_t const *const entity
3212                         = get_entity(token.identifier.symbol, NAMESPACE_NORMAL);
3213                 if (entity == NULL)
3214                         return true;
3215                 if (entity->kind != ENTITY_TYPEDEF)
3216                         return true;
3217                 if (skip_typeref(entity->typedefe.type) != type_void)
3218                         return true;
3219         } else if (token.kind != T_void) {
3220                 return true;
3221         }
3222         if (look_ahead(1)->kind != ')')
3223                 return true;
3224         next_token();
3225         return false;
3226 }
3227
3228 /**
3229  * Parses function type parameters (and optionally creates variable_t entities
3230  * for them in a scope)
3231  */
3232 static void parse_parameters(function_type_t *type, scope_t *scope)
3233 {
3234         eat('(');
3235         add_anchor_token(')');
3236         int saved_comma_state = save_and_reset_anchor_state(',');
3237
3238         if (token.kind == T_IDENTIFIER
3239             && !is_typedef_symbol(token.identifier.symbol)) {
3240                 token_kind_t la1_type = (token_kind_t)look_ahead(1)->kind;
3241                 if (la1_type == ',' || la1_type == ')') {
3242                         type->kr_style_parameters = true;
3243                         parse_identifier_list(scope);
3244                         goto parameters_finished;
3245                 }
3246         }
3247
3248         if (token.kind == ')') {
3249                 /* ISO/IEC 14882:1998(E) §C.1.6:1 */
3250                 if (!(c_mode & _CXX))
3251                         type->unspecified_parameters = true;
3252         } else if (has_parameters()) {
3253                 function_parameter_t **anchor = &type->parameters;
3254                 do {
3255                         switch (token.kind) {
3256                         case T_DOTDOTDOT:
3257                                 next_token();
3258                                 type->variadic = true;
3259                                 goto parameters_finished;
3260
3261                         case T_IDENTIFIER:
3262                         DECLARATION_START
3263                         {
3264                                 entity_t *entity = parse_parameter();
3265                                 if (entity->kind == ENTITY_TYPEDEF) {
3266                                         errorf(&entity->base.source_position,
3267                                                         "typedef not allowed as function parameter");
3268                                         break;
3269                                 }
3270                                 assert(is_declaration(entity));
3271
3272                                 semantic_parameter_incomplete(entity);
3273
3274                                 function_parameter_t *const parameter =
3275                                         allocate_parameter(entity->declaration.type);
3276
3277                                 if (scope != NULL) {
3278                                         append_entity(scope, entity);
3279                                 }
3280
3281                                 *anchor = parameter;
3282                                 anchor  = &parameter->next;
3283                                 break;
3284                         }
3285
3286                         default:
3287                                 goto parameters_finished;
3288                         }
3289                 } while (next_if(','));
3290         }
3291
3292 parameters_finished:
3293         rem_anchor_token(')');
3294         expect(')', end_error);
3295
3296 end_error:
3297         restore_anchor_state(',', saved_comma_state);
3298 }
3299
3300 typedef enum construct_type_kind_t {
3301         CONSTRUCT_POINTER = 1,
3302         CONSTRUCT_REFERENCE,
3303         CONSTRUCT_FUNCTION,
3304         CONSTRUCT_ARRAY
3305 } construct_type_kind_t;
3306
3307 typedef union construct_type_t construct_type_t;
3308
3309 typedef struct construct_type_base_t {
3310         construct_type_kind_t  kind;
3311         source_position_t      pos;
3312         construct_type_t      *next;
3313 } construct_type_base_t;
3314
3315 typedef struct parsed_pointer_t {
3316         construct_type_base_t  base;
3317         type_qualifiers_t      type_qualifiers;
3318         variable_t            *base_variable;  /**< MS __based extension. */
3319 } parsed_pointer_t;
3320
3321 typedef struct parsed_reference_t {
3322         construct_type_base_t base;
3323 } parsed_reference_t;
3324
3325 typedef struct construct_function_type_t {
3326         construct_type_base_t  base;
3327         type_t                *function_type;
3328 } construct_function_type_t;
3329
3330 typedef struct parsed_array_t {
3331         construct_type_base_t  base;
3332         type_qualifiers_t      type_qualifiers;
3333         bool                   is_static;
3334         bool                   is_variable;
3335         expression_t          *size;
3336 } parsed_array_t;
3337
3338 union construct_type_t {
3339         construct_type_kind_t     kind;
3340         construct_type_base_t     base;
3341         parsed_pointer_t          pointer;
3342         parsed_reference_t        reference;
3343         construct_function_type_t function;
3344         parsed_array_t            array;
3345 };
3346
3347 static construct_type_t *allocate_declarator_zero(construct_type_kind_t const kind, size_t const size)
3348 {
3349         construct_type_t *const cons = obstack_alloc(&temp_obst, size);
3350         memset(cons, 0, size);
3351         cons->kind     = kind;
3352         cons->base.pos = *HERE;
3353         return cons;
3354 }
3355
3356 /* §6.7.5.1 */
3357 static construct_type_t *parse_pointer_declarator(void)
3358 {
3359         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_POINTER, sizeof(parsed_pointer_t));
3360         eat('*');
3361         cons->pointer.type_qualifiers = parse_type_qualifiers();
3362         //cons->pointer.base_variable   = base_variable;
3363
3364         return cons;
3365 }
3366
3367 /* ISO/IEC 14882:1998(E) §8.3.2 */
3368 static construct_type_t *parse_reference_declarator(void)
3369 {
3370         if (!(c_mode & _CXX))
3371                 errorf(HERE, "references are only available for C++");
3372
3373         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_REFERENCE, sizeof(parsed_reference_t));
3374         eat('&');
3375
3376         return cons;
3377 }
3378
3379 /* §6.7.5.2 */
3380 static construct_type_t *parse_array_declarator(void)
3381 {
3382         construct_type_t *const cons  = allocate_declarator_zero(CONSTRUCT_ARRAY, sizeof(parsed_array_t));
3383         parsed_array_t   *const array = &cons->array;
3384
3385         eat('[');
3386         add_anchor_token(']');
3387
3388         bool is_static = next_if(T_static);
3389
3390         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
3391
3392         if (!is_static)
3393                 is_static = next_if(T_static);
3394
3395         array->type_qualifiers = type_qualifiers;
3396         array->is_static       = is_static;
3397
3398         expression_t *size = NULL;
3399         if (token.kind == '*' && look_ahead(1)->kind == ']') {
3400                 array->is_variable = true;
3401                 next_token();
3402         } else if (token.kind != ']') {
3403                 size = parse_assignment_expression();
3404
3405                 /* §6.7.5.2:1  Array size must have integer type */
3406                 type_t *const orig_type = size->base.type;
3407                 type_t *const type      = skip_typeref(orig_type);
3408                 if (!is_type_integer(type) && is_type_valid(type)) {
3409                         errorf(&size->base.source_position,
3410                                "array size '%E' must have integer type but has type '%T'",
3411                                size, orig_type);
3412                 }
3413
3414                 array->size = size;
3415                 mark_vars_read(size, NULL);
3416         }
3417
3418         if (is_static && size == NULL)
3419                 errorf(&array->base.pos, "static array parameters require a size");
3420
3421         rem_anchor_token(']');
3422         expect(']', end_error);
3423
3424 end_error:
3425         return cons;
3426 }
3427
3428 /* §6.7.5.3 */
3429 static construct_type_t *parse_function_declarator(scope_t *scope)
3430 {
3431         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_FUNCTION, sizeof(construct_function_type_t));
3432
3433         type_t          *type  = allocate_type_zero(TYPE_FUNCTION);
3434         function_type_t *ftype = &type->function;
3435
3436         ftype->linkage            = current_linkage;
3437         ftype->calling_convention = CC_DEFAULT;
3438
3439         parse_parameters(ftype, scope);
3440
3441         cons->function.function_type = type;
3442
3443         return cons;
3444 }
3445
3446 typedef struct parse_declarator_env_t {
3447         bool               may_be_abstract : 1;
3448         bool               must_be_abstract : 1;
3449         decl_modifiers_t   modifiers;
3450         symbol_t          *symbol;
3451         source_position_t  source_position;
3452         scope_t            parameters;
3453         attribute_t       *attributes;
3454 } parse_declarator_env_t;
3455
3456 /* §6.7.5 */
3457 static construct_type_t *parse_inner_declarator(parse_declarator_env_t *env)
3458 {
3459         /* construct a single linked list of construct_type_t's which describe
3460          * how to construct the final declarator type */
3461         construct_type_t  *first      = NULL;
3462         construct_type_t **anchor     = &first;
3463
3464         env->attributes = parse_attributes(env->attributes);
3465
3466         for (;;) {
3467                 construct_type_t *type;
3468                 //variable_t       *based = NULL; /* MS __based extension */
3469                 switch (token.kind) {
3470                         case '&':
3471                                 type = parse_reference_declarator();
3472                                 break;
3473
3474                         case T__based: {
3475                                 panic("based not supported anymore");
3476                                 /* FALLTHROUGH */
3477                         }
3478
3479                         case '*':
3480                                 type = parse_pointer_declarator();
3481                                 break;
3482
3483                         default:
3484                                 goto ptr_operator_end;
3485                 }
3486
3487                 *anchor = type;
3488                 anchor  = &type->base.next;
3489
3490                 /* TODO: find out if this is correct */
3491                 env->attributes = parse_attributes(env->attributes);
3492         }
3493
3494 ptr_operator_end: ;
3495         construct_type_t *inner_types = NULL;
3496
3497         switch (token.kind) {
3498         case T_IDENTIFIER:
3499                 if (env->must_be_abstract) {
3500                         errorf(HERE, "no identifier expected in typename");
3501                 } else {
3502                         env->symbol          = token.identifier.symbol;
3503                         env->source_position = token.base.source_position;
3504                 }
3505                 next_token();
3506                 break;
3507
3508         case '(': {
3509                 /* Parenthesized declarator or function declarator? */
3510                 token_t const *const la1 = look_ahead(1);
3511                 switch (la1->kind) {
3512                         case T_IDENTIFIER:
3513                                 if (is_typedef_symbol(la1->identifier.symbol)) {
3514                         case ')':
3515                                         /* §6.7.6:2 footnote 126:  Empty parentheses in a type name are
3516                                          * interpreted as ``function with no parameter specification'', rather
3517                                          * than redundant parentheses around the omitted identifier. */
3518                         default:
3519                                         /* Function declarator. */
3520                                         if (!env->may_be_abstract) {
3521                                                 errorf(HERE, "function declarator must have a name");
3522                                         }
3523                                 } else {
3524                         case '&':
3525                         case '(':
3526                         case '*':
3527                         case '[':
3528                         case T___attribute__: /* FIXME __attribute__ might also introduce a parameter of a function declarator. */
3529                                         /* Paranthesized declarator. */
3530                                         next_token();
3531                                         add_anchor_token(')');
3532                                         inner_types = parse_inner_declarator(env);
3533                                         if (inner_types != NULL) {
3534                                                 /* All later declarators only modify the return type */
3535                                                 env->must_be_abstract = true;
3536                                         }
3537                                         rem_anchor_token(')');
3538                                         expect(')', end_error);
3539                                 }
3540                                 break;
3541                 }
3542                 break;
3543         }
3544
3545         default:
3546                 if (env->may_be_abstract)
3547                         break;
3548                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', NULL);
3549                 eat_until_anchor();
3550                 return NULL;
3551         }
3552
3553         construct_type_t **const p = anchor;
3554
3555         for (;;) {
3556                 construct_type_t *type;
3557                 switch (token.kind) {
3558                 case '(': {
3559                         scope_t *scope = NULL;
3560                         if (!env->must_be_abstract) {
3561                                 scope = &env->parameters;
3562                         }
3563
3564                         type = parse_function_declarator(scope);
3565                         break;
3566                 }
3567                 case '[':
3568                         type = parse_array_declarator();
3569                         break;
3570                 default:
3571                         goto declarator_finished;
3572                 }
3573
3574                 /* insert in the middle of the list (at p) */
3575                 type->base.next = *p;
3576                 *p              = type;
3577                 if (anchor == p)
3578                         anchor = &type->base.next;
3579         }
3580
3581 declarator_finished:
3582         /* append inner_types at the end of the list, we don't to set anchor anymore
3583          * as it's not needed anymore */
3584         *anchor = inner_types;
3585
3586         return first;
3587 end_error:
3588         return NULL;
3589 }
3590
3591 static type_t *construct_declarator_type(construct_type_t *construct_list,
3592                                          type_t *type)
3593 {
3594         construct_type_t *iter = construct_list;
3595         for (; iter != NULL; iter = iter->base.next) {
3596                 source_position_t const* const pos = &iter->base.pos;
3597                 switch (iter->kind) {
3598                 case CONSTRUCT_FUNCTION: {
3599                         construct_function_type_t *function      = &iter->function;
3600                         type_t                    *function_type = function->function_type;
3601
3602                         function_type->function.return_type = type;
3603
3604                         type_t *skipped_return_type = skip_typeref(type);
3605                         /* §6.7.5.3:1 */
3606                         if (is_type_function(skipped_return_type)) {
3607                                 errorf(pos, "function returning function is not allowed");
3608                         } else if (is_type_array(skipped_return_type)) {
3609                                 errorf(pos, "function returning array is not allowed");
3610                         } else {
3611                                 if (skipped_return_type->base.qualifiers != 0) {
3612                                         warningf(WARN_IGNORED_QUALIFIERS, pos, "type qualifiers in return type of function type are meaningless");
3613                                 }
3614                         }
3615
3616                         /* The function type was constructed earlier.  Freeing it here will
3617                          * destroy other types. */
3618                         type = typehash_insert(function_type);
3619                         continue;
3620                 }
3621
3622                 case CONSTRUCT_POINTER: {
3623                         if (is_type_reference(skip_typeref(type)))
3624                                 errorf(pos, "cannot declare a pointer to reference");
3625
3626                         parsed_pointer_t *pointer = &iter->pointer;
3627                         type = make_based_pointer_type(type, pointer->type_qualifiers, pointer->base_variable);
3628                         continue;
3629                 }
3630
3631                 case CONSTRUCT_REFERENCE:
3632                         if (is_type_reference(skip_typeref(type)))
3633                                 errorf(pos, "cannot declare a reference to reference");
3634
3635                         type = make_reference_type(type);
3636                         continue;
3637
3638                 case CONSTRUCT_ARRAY: {
3639                         if (is_type_reference(skip_typeref(type)))
3640                                 errorf(pos, "cannot declare an array of references");
3641
3642                         parsed_array_t *array      = &iter->array;
3643                         type_t         *array_type = allocate_type_zero(TYPE_ARRAY);
3644
3645                         expression_t *size_expression = array->size;
3646                         if (size_expression != NULL) {
3647                                 size_expression
3648                                         = create_implicit_cast(size_expression, type_size_t);
3649                         }
3650
3651                         array_type->base.qualifiers       = array->type_qualifiers;
3652                         array_type->array.element_type    = type;
3653                         array_type->array.is_static       = array->is_static;
3654                         array_type->array.is_variable     = array->is_variable;
3655                         array_type->array.size_expression = size_expression;
3656
3657                         if (size_expression != NULL) {
3658                                 switch (is_constant_expression(size_expression)) {
3659                                 case EXPR_CLASS_CONSTANT: {
3660                                         long const size = fold_constant_to_int(size_expression);
3661                                         array_type->array.size          = size;
3662                                         array_type->array.size_constant = true;
3663                                         /* §6.7.5.2:1  If the expression is a constant expression,
3664                                          * it shall have a value greater than zero. */
3665                                         if (size < 0) {
3666                                                 errorf(&size_expression->base.source_position,
3667                                                            "size of array must be greater than zero");
3668                                         } else if (size == 0 && !GNU_MODE) {
3669                                                 errorf(&size_expression->base.source_position,
3670                                                            "size of array must be greater than zero (zero length arrays are a GCC extension)");
3671                                         }
3672                                         break;
3673                                 }
3674
3675                                 case EXPR_CLASS_VARIABLE:
3676                                         array_type->array.is_vla = true;
3677                                         break;
3678
3679                                 case EXPR_CLASS_ERROR:
3680                                         break;
3681                                 }
3682                         }
3683
3684                         type_t *skipped_type = skip_typeref(type);
3685                         /* §6.7.5.2:1 */
3686                         if (is_type_incomplete(skipped_type)) {
3687                                 errorf(pos, "array of incomplete type '%T' is not allowed", type);
3688                         } else if (is_type_function(skipped_type)) {
3689                                 errorf(pos, "array of functions is not allowed");
3690                         }
3691                         type = identify_new_type(array_type);
3692                         continue;
3693                 }
3694                 }
3695                 internal_errorf(pos, "invalid type construction found");
3696         }
3697
3698         return type;
3699 }
3700
3701 static type_t *automatic_type_conversion(type_t *orig_type);
3702
3703 static type_t *semantic_parameter(const source_position_t *pos,
3704                                   type_t *type,
3705                                   const declaration_specifiers_t *specifiers,
3706                                   entity_t const *const param)
3707 {
3708         /* §6.7.5.3:7  A declaration of a parameter as ``array of type''
3709          *             shall be adjusted to ``qualified pointer to type'',
3710          *             [...]
3711          * §6.7.5.3:8  A declaration of a parameter as ``function returning
3712          *             type'' shall be adjusted to ``pointer to function
3713          *             returning type'', as in 6.3.2.1. */
3714         type = automatic_type_conversion(type);
3715
3716         if (specifiers->is_inline && is_type_valid(type)) {
3717                 errorf(pos, "'%N' declared 'inline'", param);
3718         }
3719
3720         /* §6.9.1:6  The declarations in the declaration list shall contain
3721          *           no storage-class specifier other than register and no
3722          *           initializations. */
3723         if (specifiers->thread_local || (
3724                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3725                         specifiers->storage_class != STORAGE_CLASS_REGISTER)
3726            ) {
3727                 errorf(pos, "invalid storage class for '%N'", param);
3728         }
3729
3730         /* delay test for incomplete type, because we might have (void)
3731          * which is legal but incomplete... */
3732
3733         return type;
3734 }
3735
3736 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
3737                                   declarator_flags_t flags)
3738 {
3739         parse_declarator_env_t env;
3740         memset(&env, 0, sizeof(env));
3741         env.may_be_abstract = (flags & DECL_MAY_BE_ABSTRACT) != 0;
3742
3743         construct_type_t *construct_type = parse_inner_declarator(&env);
3744         type_t           *orig_type      =
3745                 construct_declarator_type(construct_type, specifiers->type);
3746         type_t           *type           = skip_typeref(orig_type);
3747
3748         if (construct_type != NULL) {
3749                 obstack_free(&temp_obst, construct_type);
3750         }
3751
3752         attribute_t *attributes = parse_attributes(env.attributes);
3753         /* append (shared) specifier attribute behind attributes of this
3754          * declarator */
3755         attribute_t **anchor = &attributes;
3756         while (*anchor != NULL)
3757                 anchor = &(*anchor)->next;
3758         *anchor = specifiers->attributes;
3759
3760         entity_t *entity;
3761         if (specifiers->storage_class == STORAGE_CLASS_TYPEDEF) {
3762                 entity = allocate_entity_zero(ENTITY_TYPEDEF, NAMESPACE_NORMAL, env.symbol);
3763                 entity->base.source_position = env.source_position;
3764                 entity->typedefe.type        = orig_type;
3765
3766                 if (anonymous_entity != NULL) {
3767                         if (is_type_compound(type)) {
3768                                 assert(anonymous_entity->compound.alias == NULL);
3769                                 assert(anonymous_entity->kind == ENTITY_STRUCT ||
3770                                        anonymous_entity->kind == ENTITY_UNION);
3771                                 anonymous_entity->compound.alias = entity;
3772                                 anonymous_entity = NULL;
3773                         } else if (is_type_enum(type)) {
3774                                 assert(anonymous_entity->enume.alias == NULL);
3775                                 assert(anonymous_entity->kind == ENTITY_ENUM);
3776                                 anonymous_entity->enume.alias = entity;
3777                                 anonymous_entity = NULL;
3778                         }
3779                 }
3780         } else {
3781                 /* create a declaration type entity */
3782                 if (flags & DECL_CREATE_COMPOUND_MEMBER) {
3783                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER, NAMESPACE_NORMAL, env.symbol);
3784
3785                         if (env.symbol != NULL) {
3786                                 if (specifiers->is_inline && is_type_valid(type)) {
3787                                         errorf(&env.source_position,
3788                                                         "compound member '%Y' declared 'inline'", env.symbol);
3789                                 }
3790
3791                                 if (specifiers->thread_local ||
3792                                                 specifiers->storage_class != STORAGE_CLASS_NONE) {
3793                                         errorf(&env.source_position,
3794                                                         "compound member '%Y' must have no storage class",
3795                                                         env.symbol);
3796                                 }
3797                         }
3798                 } else if (flags & DECL_IS_PARAMETER) {
3799                         entity    = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, env.symbol);
3800                         orig_type = semantic_parameter(&env.source_position, orig_type, specifiers, entity);
3801                 } else if (is_type_function(type)) {
3802                         entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, env.symbol);
3803                         entity->function.is_inline      = specifiers->is_inline;
3804                         entity->function.elf_visibility = default_visibility;
3805                         entity->function.parameters     = env.parameters;
3806
3807                         if (env.symbol != NULL) {
3808                                 /* this needs fixes for C++ */
3809                                 bool in_function_scope = current_function != NULL;
3810
3811                                 if (specifiers->thread_local || (
3812                                                         specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3813                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3814                                                         (in_function_scope || specifiers->storage_class != STORAGE_CLASS_STATIC)
3815                                                 )) {
3816                                         errorf(&env.source_position, "invalid storage class for '%N'", entity);
3817                                 }
3818                         }
3819                 } else {
3820                         entity = allocate_entity_zero(ENTITY_VARIABLE, NAMESPACE_NORMAL, env.symbol);
3821                         entity->variable.elf_visibility = default_visibility;
3822                         entity->variable.thread_local   = specifiers->thread_local;
3823
3824                         if (env.symbol != NULL) {
3825                                 if (specifiers->is_inline && is_type_valid(type)) {
3826                                         errorf(&env.source_position, "'%N' declared 'inline'", entity);
3827                                 }
3828
3829                                 bool invalid_storage_class = false;
3830                                 if (current_scope == file_scope) {
3831                                         if (specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3832                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3833                                                         specifiers->storage_class != STORAGE_CLASS_STATIC) {
3834                                                 invalid_storage_class = true;
3835                                         }
3836                                 } else {
3837                                         if (specifiers->thread_local &&
3838                                                         specifiers->storage_class == STORAGE_CLASS_NONE) {
3839                                                 invalid_storage_class = true;
3840                                         }
3841                                 }
3842                                 if (invalid_storage_class) {
3843                                         errorf(&env.source_position, "invalid storage class for variable '%N'", entity);
3844                                 }
3845                         }
3846                 }
3847
3848                 entity->base.source_position   = env.symbol != NULL ? env.source_position : specifiers->source_position;
3849                 entity->declaration.type       = orig_type;
3850                 entity->declaration.alignment  = get_type_alignment(orig_type);
3851                 entity->declaration.modifiers  = env.modifiers;
3852                 entity->declaration.attributes = attributes;
3853
3854                 storage_class_t storage_class = specifiers->storage_class;
3855                 entity->declaration.declared_storage_class = storage_class;
3856
3857                 if (storage_class == STORAGE_CLASS_NONE && current_function != NULL)
3858                         storage_class = STORAGE_CLASS_AUTO;
3859                 entity->declaration.storage_class = storage_class;
3860         }
3861
3862         if (attributes != NULL) {
3863                 handle_entity_attributes(attributes, entity);
3864         }
3865
3866         if (entity->kind == ENTITY_FUNCTION && !freestanding) {
3867                 adapt_special_functions(&entity->function);
3868         }
3869
3870         return entity;
3871 }
3872
3873 static type_t *parse_abstract_declarator(type_t *base_type)
3874 {
3875         parse_declarator_env_t env;
3876         memset(&env, 0, sizeof(env));
3877         env.may_be_abstract = true;
3878         env.must_be_abstract = true;
3879
3880         construct_type_t *construct_type = parse_inner_declarator(&env);
3881
3882         type_t *result = construct_declarator_type(construct_type, base_type);
3883         if (construct_type != NULL) {
3884                 obstack_free(&temp_obst, construct_type);
3885         }
3886         result = handle_type_attributes(env.attributes, result);
3887
3888         return result;
3889 }
3890
3891 /**
3892  * Check if the declaration of main is suspicious.  main should be a
3893  * function with external linkage, returning int, taking either zero
3894  * arguments, two, or three arguments of appropriate types, ie.
3895  *
3896  * int main([ int argc, char **argv [, char **env ] ]).
3897  *
3898  * @param decl    the declaration to check
3899  * @param type    the function type of the declaration
3900  */
3901 static void check_main(const entity_t *entity)
3902 {
3903         const source_position_t *pos = &entity->base.source_position;
3904         if (entity->kind != ENTITY_FUNCTION) {
3905                 warningf(WARN_MAIN, pos, "'main' is not a function");
3906                 return;
3907         }
3908
3909         if (entity->declaration.storage_class == STORAGE_CLASS_STATIC) {
3910                 warningf(WARN_MAIN, pos, "'main' is normally a non-static function");
3911         }
3912
3913         type_t *type = skip_typeref(entity->declaration.type);
3914         assert(is_type_function(type));
3915
3916         function_type_t const *const func_type = &type->function;
3917         type_t                *const ret_type  = func_type->return_type;
3918         if (!types_compatible(skip_typeref(ret_type), type_int)) {
3919                 warningf(WARN_MAIN, pos, "return type of 'main' should be 'int', but is '%T'", ret_type);
3920         }
3921         const function_parameter_t *parm = func_type->parameters;
3922         if (parm != NULL) {
3923                 type_t *const first_type        = skip_typeref(parm->type);
3924                 type_t *const first_type_unqual = get_unqualified_type(first_type);
3925                 if (!types_compatible(first_type_unqual, type_int)) {
3926                         warningf(WARN_MAIN, pos, "first argument of 'main' should be 'int', but is '%T'", parm->type);
3927                 }
3928                 parm = parm->next;
3929                 if (parm != NULL) {
3930                         type_t *const second_type = skip_typeref(parm->type);
3931                         type_t *const second_type_unqual
3932                                 = get_unqualified_type(second_type);
3933                         if (!types_compatible(second_type_unqual, type_char_ptr_ptr)) {
3934                                 warningf(WARN_MAIN, pos, "second argument of 'main' should be 'char**', but is '%T'", parm->type);
3935                         }
3936                         parm = parm->next;
3937                         if (parm != NULL) {
3938                                 type_t *const third_type = skip_typeref(parm->type);
3939                                 type_t *const third_type_unqual
3940                                         = get_unqualified_type(third_type);
3941                                 if (!types_compatible(third_type_unqual, type_char_ptr_ptr)) {
3942                                         warningf(WARN_MAIN, pos, "third argument of 'main' should be 'char**', but is '%T'", parm->type);
3943                                 }
3944                                 parm = parm->next;
3945                                 if (parm != NULL)
3946                                         goto warn_arg_count;
3947                         }
3948                 } else {
3949 warn_arg_count:
3950                         warningf(WARN_MAIN, pos, "'main' takes only zero, two or three arguments");
3951                 }
3952         }
3953 }
3954
3955 /**
3956  * Check if a symbol is the equal to "main".
3957  */
3958 static bool is_sym_main(const symbol_t *const sym)
3959 {
3960         return streq(sym->string, "main");
3961 }
3962
3963 static void error_redefined_as_different_kind(const source_position_t *pos,
3964                 const entity_t *old, entity_kind_t new_kind)
3965 {
3966         char              const *const what = get_entity_kind_name(new_kind);
3967         source_position_t const *const ppos = &old->base.source_position;
3968         errorf(pos, "redeclaration of '%N' as %s (declared %P)", old, what, ppos);
3969 }
3970
3971 static bool is_entity_valid(entity_t *const ent)
3972 {
3973         if (is_declaration(ent)) {
3974                 return is_type_valid(skip_typeref(ent->declaration.type));
3975         } else if (ent->kind == ENTITY_TYPEDEF) {
3976                 return is_type_valid(skip_typeref(ent->typedefe.type));
3977         }
3978         return true;
3979 }
3980
3981 static bool contains_attribute(const attribute_t *list, const attribute_t *attr)
3982 {
3983         for (const attribute_t *tattr = list; tattr != NULL; tattr = tattr->next) {
3984                 if (attributes_equal(tattr, attr))
3985                         return true;
3986         }
3987         return false;
3988 }
3989
3990 /**
3991  * test wether new_list contains any attributes not included in old_list
3992  */
3993 static bool has_new_attributes(const attribute_t *old_list,
3994                                const attribute_t *new_list)
3995 {
3996         for (const attribute_t *attr = new_list; attr != NULL; attr = attr->next) {
3997                 if (!contains_attribute(old_list, attr))
3998                         return true;
3999         }
4000         return false;
4001 }
4002
4003 /**
4004  * Merge in attributes from an attribute list (probably from a previous
4005  * declaration with the same name). Warning: destroys the old structure
4006  * of the attribute list - don't reuse attributes after this call.
4007  */
4008 static void merge_in_attributes(declaration_t *decl, attribute_t *attributes)
4009 {
4010         attribute_t *next;
4011         for (attribute_t *attr = attributes; attr != NULL; attr = next) {
4012                 next = attr->next;
4013                 if (contains_attribute(decl->attributes, attr))
4014                         continue;
4015
4016                 /* move attribute to new declarations attributes list */
4017                 attr->next       = decl->attributes;
4018                 decl->attributes = attr;
4019         }
4020 }
4021
4022 /**
4023  * record entities for the NAMESPACE_NORMAL, and produce error messages/warnings
4024  * for various problems that occur for multiple definitions
4025  */
4026 entity_t *record_entity(entity_t *entity, const bool is_definition)
4027 {
4028         const symbol_t *const    symbol  = entity->base.symbol;
4029         const namespace_tag_t    namespc = (namespace_tag_t)entity->base.namespc;
4030         const source_position_t *pos     = &entity->base.source_position;
4031
4032         /* can happen in error cases */
4033         if (symbol == NULL)
4034                 return entity;
4035
4036         entity_t *const previous_entity = get_entity(symbol, namespc);
4037         /* pushing the same entity twice will break the stack structure */
4038         assert(previous_entity != entity);
4039
4040         if (entity->kind == ENTITY_FUNCTION) {
4041                 type_t *const orig_type = entity->declaration.type;
4042                 type_t *const type      = skip_typeref(orig_type);
4043
4044                 assert(is_type_function(type));
4045                 if (type->function.unspecified_parameters &&
4046                     previous_entity == NULL               &&
4047                     !entity->declaration.implicit) {
4048                         warningf(WARN_STRICT_PROTOTYPES, pos, "function declaration '%#N' is not a prototype", entity);
4049                 }
4050
4051                 if (current_scope == file_scope && is_sym_main(symbol)) {
4052                         check_main(entity);
4053                 }
4054         }
4055
4056         if (is_declaration(entity)                                    &&
4057             entity->declaration.storage_class == STORAGE_CLASS_EXTERN &&
4058             current_scope != file_scope                               &&
4059             !entity->declaration.implicit) {
4060                 warningf(WARN_NESTED_EXTERNS, pos, "nested extern declaration of '%#N'", entity);
4061         }
4062
4063         if (previous_entity != NULL) {
4064                 source_position_t const *const ppos = &previous_entity->base.source_position;
4065
4066                 if (previous_entity->base.parent_scope == &current_function->parameters &&
4067                                 previous_entity->base.parent_scope->depth + 1 == current_scope->depth) {
4068                         assert(previous_entity->kind == ENTITY_PARAMETER);
4069                         errorf(pos, "declaration of '%N' redeclares the '%N' (declared %P)", entity, previous_entity, ppos);
4070                         goto finish;
4071                 }
4072
4073                 if (previous_entity->base.parent_scope == current_scope) {
4074                         if (previous_entity->kind != entity->kind) {
4075                                 if (is_entity_valid(previous_entity) && is_entity_valid(entity)) {
4076                                         error_redefined_as_different_kind(pos, previous_entity,
4077                                                         entity->kind);
4078                                 }
4079                                 goto finish;
4080                         }
4081                         if (previous_entity->kind == ENTITY_ENUM_VALUE) {
4082                                 errorf(pos, "redeclaration of '%N' (declared %P)", entity, ppos);
4083                                 goto finish;
4084                         }
4085                         if (previous_entity->kind == ENTITY_TYPEDEF) {
4086                                 type_t *const type      = skip_typeref(entity->typedefe.type);
4087                                 type_t *const prev_type
4088                                         = skip_typeref(previous_entity->typedefe.type);
4089                                 if (c_mode & _CXX) {
4090                                         /* C++ allows double typedef if they are identical
4091                                          * (after skipping typedefs) */
4092                                         if (type == prev_type)
4093                                                 goto finish;
4094                                 } else {
4095                                         /* GCC extension: redef in system headers is allowed */
4096                                         if ((pos->is_system_header || ppos->is_system_header) &&
4097                                             types_compatible(type, prev_type))
4098                                                 goto finish;
4099                                 }
4100                                 errorf(pos, "redefinition of '%N' (declared %P)",
4101                                        entity, ppos);
4102                                 goto finish;
4103                         }
4104
4105                         /* at this point we should have only VARIABLES or FUNCTIONS */
4106                         assert(is_declaration(previous_entity) && is_declaration(entity));
4107
4108                         declaration_t *const prev_decl = &previous_entity->declaration;
4109                         declaration_t *const decl      = &entity->declaration;
4110
4111                         /* can happen for K&R style declarations */
4112                         if (prev_decl->type       == NULL             &&
4113                                         previous_entity->kind == ENTITY_PARAMETER &&
4114                                         entity->kind          == ENTITY_PARAMETER) {
4115                                 prev_decl->type                   = decl->type;
4116                                 prev_decl->storage_class          = decl->storage_class;
4117                                 prev_decl->declared_storage_class = decl->declared_storage_class;
4118                                 prev_decl->modifiers              = decl->modifiers;
4119                                 return previous_entity;
4120                         }
4121
4122                         type_t *const type      = skip_typeref(decl->type);
4123                         type_t *const prev_type = skip_typeref(prev_decl->type);
4124
4125                         if (!types_compatible(type, prev_type)) {
4126                                 errorf(pos, "declaration '%#N' is incompatible with '%#N' (declared %P)", entity, previous_entity, ppos);
4127                         } else {
4128                                 unsigned old_storage_class = prev_decl->storage_class;
4129
4130                                 if (is_definition                     &&
4131                                                 !prev_decl->used                  &&
4132                                                 !(prev_decl->modifiers & DM_USED) &&
4133                                                 prev_decl->storage_class == STORAGE_CLASS_STATIC) {
4134                                         warningf(WARN_REDUNDANT_DECLS, ppos, "unnecessary static forward declaration for '%#N'", previous_entity);
4135                                 }
4136
4137                                 storage_class_t new_storage_class = decl->storage_class;
4138
4139                                 /* pretend no storage class means extern for function
4140                                  * declarations (except if the previous declaration is neither
4141                                  * none nor extern) */
4142                                 if (entity->kind == ENTITY_FUNCTION) {
4143                                         /* the previous declaration could have unspecified parameters or
4144                                          * be a typedef, so use the new type */
4145                                         if (prev_type->function.unspecified_parameters || is_definition)
4146                                                 prev_decl->type = type;
4147
4148                                         switch (old_storage_class) {
4149                                                 case STORAGE_CLASS_NONE:
4150                                                         old_storage_class = STORAGE_CLASS_EXTERN;
4151                                                         /* FALLTHROUGH */
4152
4153                                                 case STORAGE_CLASS_EXTERN:
4154                                                         if (is_definition) {
4155                                                                 if (prev_type->function.unspecified_parameters && !is_sym_main(symbol)) {
4156                                                                         warningf(WARN_MISSING_PROTOTYPES, pos, "no previous prototype for '%#N'", entity);
4157                                                                 }
4158                                                         } else if (new_storage_class == STORAGE_CLASS_NONE) {
4159                                                                 new_storage_class = STORAGE_CLASS_EXTERN;
4160                                                         }
4161                                                         break;
4162
4163                                                 default:
4164                                                         break;
4165                                         }
4166                                 } else if (is_type_incomplete(prev_type)) {
4167                                         prev_decl->type = type;
4168                                 }
4169
4170                                 if (old_storage_class == STORAGE_CLASS_EXTERN &&
4171                                                 new_storage_class == STORAGE_CLASS_EXTERN) {
4172
4173 warn_redundant_declaration: ;
4174                                         bool has_new_attrs
4175                                                 = has_new_attributes(prev_decl->attributes,
4176                                                                      decl->attributes);
4177                                         if (has_new_attrs) {
4178                                                 merge_in_attributes(decl, prev_decl->attributes);
4179                                         } else if (!is_definition        &&
4180                                                         is_type_valid(prev_type) &&
4181                                                         !pos->is_system_header) {
4182                                                 warningf(WARN_REDUNDANT_DECLS, pos, "redundant declaration for '%Y' (declared %P)", symbol, ppos);
4183                                         }
4184                                 } else if (current_function == NULL) {
4185                                         if (old_storage_class != STORAGE_CLASS_STATIC &&
4186                                                         new_storage_class == STORAGE_CLASS_STATIC) {
4187                                                 errorf(pos, "static declaration of '%Y' follows non-static declaration (declared %P)", symbol, ppos);
4188                                         } else if (old_storage_class == STORAGE_CLASS_EXTERN) {
4189                                                 prev_decl->storage_class          = STORAGE_CLASS_NONE;
4190                                                 prev_decl->declared_storage_class = STORAGE_CLASS_NONE;
4191                                         } else {
4192                                                 /* ISO/IEC 14882:1998(E) §C.1.2:1 */
4193                                                 if (c_mode & _CXX)
4194                                                         goto error_redeclaration;
4195                                                 goto warn_redundant_declaration;
4196                                         }
4197                                 } else if (is_type_valid(prev_type)) {
4198                                         if (old_storage_class == new_storage_class) {
4199 error_redeclaration:
4200                                                 errorf(pos, "redeclaration of '%Y' (declared %P)", symbol, ppos);
4201                                         } else {
4202                                                 errorf(pos, "redeclaration of '%Y' with different linkage (declared %P)", symbol, ppos);
4203                                         }
4204                                 }
4205                         }
4206
4207                         prev_decl->modifiers |= decl->modifiers;
4208                         if (entity->kind == ENTITY_FUNCTION) {
4209                                 previous_entity->function.is_inline |= entity->function.is_inline;
4210                         }
4211                         return previous_entity;
4212                 }
4213
4214                 warning_t why;
4215                 if (is_warn_on(why = WARN_SHADOW) ||
4216                     (is_warn_on(why = WARN_SHADOW_LOCAL) && previous_entity->base.parent_scope != file_scope)) {
4217                         char const *const what = get_entity_kind_name(previous_entity->kind);
4218                         warningf(why, pos, "'%N' shadows %s (declared %P)", entity, what, ppos);
4219                 }
4220         }
4221
4222         if (entity->kind == ENTITY_FUNCTION) {
4223                 if (is_definition &&
4224                                 entity->declaration.storage_class != STORAGE_CLASS_STATIC &&
4225                                 !is_sym_main(symbol)) {
4226                         if (is_warn_on(WARN_MISSING_PROTOTYPES)) {
4227                                 warningf(WARN_MISSING_PROTOTYPES, pos, "no previous prototype for '%#N'", entity);
4228                         } else {
4229                                 goto warn_missing_declaration;
4230                         }
4231                 }
4232         } else if (entity->kind == ENTITY_VARIABLE) {
4233                 if (current_scope                     == file_scope &&
4234                                 entity->declaration.storage_class == STORAGE_CLASS_NONE &&
4235                                 !entity->declaration.implicit) {
4236 warn_missing_declaration:
4237                         warningf(WARN_MISSING_DECLARATIONS, pos, "no previous declaration for '%#N'", entity);
4238                 }
4239         }
4240
4241 finish:
4242         assert(entity->base.parent_scope == NULL);
4243         assert(current_scope != NULL);
4244
4245         entity->base.parent_scope = current_scope;
4246         environment_push(entity);
4247         append_entity(current_scope, entity);
4248
4249         return entity;
4250 }
4251
4252 static void parser_error_multiple_definition(entity_t *entity,
4253                 const source_position_t *source_position)
4254 {
4255         errorf(source_position, "multiple definition of '%Y' (declared %P)",
4256                entity->base.symbol, &entity->base.source_position);
4257 }
4258
4259 static bool is_declaration_specifier(const token_t *token)
4260 {
4261         switch (token->kind) {
4262                 DECLARATION_START
4263                         return true;
4264                 case T_IDENTIFIER:
4265                         return is_typedef_symbol(token->identifier.symbol);
4266
4267                 default:
4268                         return false;
4269         }
4270 }
4271
4272 static void parse_init_declarator_rest(entity_t *entity)
4273 {
4274         type_t *orig_type = type_error_type;
4275
4276         if (entity->base.kind == ENTITY_TYPEDEF) {
4277                 source_position_t const *const pos = &entity->base.source_position;
4278                 errorf(pos, "'%N' is initialized (use __typeof__ instead)", entity);
4279         } else {
4280                 assert(is_declaration(entity));
4281                 orig_type = entity->declaration.type;
4282         }
4283
4284         type_t *type = skip_typeref(orig_type);
4285
4286         if (entity->kind == ENTITY_VARIABLE
4287                         && entity->variable.initializer != NULL) {
4288                 parser_error_multiple_definition(entity, HERE);
4289         }
4290         eat('=');
4291
4292         declaration_t *const declaration = &entity->declaration;
4293         bool must_be_constant = false;
4294         if (declaration->storage_class == STORAGE_CLASS_STATIC ||
4295             entity->base.parent_scope  == file_scope) {
4296                 must_be_constant = true;
4297         }
4298
4299         if (is_type_function(type)) {
4300                 source_position_t const *const pos = &entity->base.source_position;
4301                 errorf(pos, "'%N' is initialized like a variable", entity);
4302                 orig_type = type_error_type;
4303         }
4304
4305         parse_initializer_env_t env;
4306         env.type             = orig_type;
4307         env.must_be_constant = must_be_constant;
4308         env.entity           = entity;
4309
4310         initializer_t *initializer = parse_initializer(&env);
4311
4312         if (entity->kind == ENTITY_VARIABLE) {
4313                 /* §6.7.5:22  array initializers for arrays with unknown size
4314                  * determine the array type size */
4315                 declaration->type            = env.type;
4316                 entity->variable.initializer = initializer;
4317         }
4318 }
4319
4320 /* parse rest of a declaration without any declarator */
4321 static void parse_anonymous_declaration_rest(
4322                 const declaration_specifiers_t *specifiers)
4323 {
4324         eat(';');
4325         anonymous_entity = NULL;
4326
4327         source_position_t const *const pos = &specifiers->source_position;
4328         if (specifiers->storage_class != STORAGE_CLASS_NONE ||
4329                         specifiers->thread_local) {
4330                 warningf(WARN_OTHER, pos, "useless storage class in empty declaration");
4331         }
4332
4333         type_t *type = specifiers->type;
4334         switch (type->kind) {
4335                 case TYPE_COMPOUND_STRUCT:
4336                 case TYPE_COMPOUND_UNION: {
4337                         if (type->compound.compound->base.symbol == NULL) {
4338                                 warningf(WARN_OTHER, pos, "unnamed struct/union that defines no instances");
4339                         }
4340                         break;
4341                 }
4342
4343                 case TYPE_ENUM:
4344                         break;
4345
4346                 default:
4347                         warningf(WARN_OTHER, pos, "empty declaration");
4348                         break;
4349         }
4350 }
4351
4352 static void check_variable_type_complete(entity_t *ent)
4353 {
4354         if (ent->kind != ENTITY_VARIABLE)
4355                 return;
4356
4357         /* §6.7:7  If an identifier for an object is declared with no linkage, the
4358          *         type for the object shall be complete [...] */
4359         declaration_t *decl = &ent->declaration;
4360         if (decl->storage_class == STORAGE_CLASS_EXTERN ||
4361                         decl->storage_class == STORAGE_CLASS_STATIC)
4362                 return;
4363
4364         type_t *const type = skip_typeref(decl->type);
4365         if (!is_type_incomplete(type))
4366                 return;
4367
4368         /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
4369          * are given length one. */
4370         if (is_type_array(type) && ent->base.parent_scope == file_scope) {
4371                 ARR_APP1(declaration_t*, incomplete_arrays, decl);
4372                 return;
4373         }
4374
4375         errorf(&ent->base.source_position, "variable '%#N' has incomplete type", ent);
4376 }
4377
4378
4379 static void parse_declaration_rest(entity_t *ndeclaration,
4380                 const declaration_specifiers_t *specifiers,
4381                 parsed_declaration_func         finished_declaration,
4382                 declarator_flags_t              flags)
4383 {
4384         add_anchor_token(';');
4385         add_anchor_token(',');
4386         while (true) {
4387                 entity_t *entity = finished_declaration(ndeclaration, token.kind == '=');
4388
4389                 if (token.kind == '=') {
4390                         parse_init_declarator_rest(entity);
4391                 } else if (entity->kind == ENTITY_VARIABLE) {
4392                         /* ISO/IEC 14882:1998(E) §8.5.3:3  The initializer can be omitted
4393                          * [...] where the extern specifier is explicitly used. */
4394                         declaration_t *decl = &entity->declaration;
4395                         if (decl->storage_class != STORAGE_CLASS_EXTERN) {
4396                                 type_t *type = decl->type;
4397                                 if (is_type_reference(skip_typeref(type))) {
4398                                         source_position_t const *const pos = &entity->base.source_position;
4399                                         errorf(pos, "reference '%#N' must be initialized", entity);
4400                                 }
4401                         }
4402                 }
4403
4404                 check_variable_type_complete(entity);
4405
4406                 if (!next_if(','))
4407                         break;
4408
4409                 add_anchor_token('=');
4410                 ndeclaration = parse_declarator(specifiers, flags);
4411                 rem_anchor_token('=');
4412         }
4413         expect(';', end_error);
4414
4415 end_error:
4416         anonymous_entity = NULL;
4417         rem_anchor_token(';');
4418         rem_anchor_token(',');
4419 }
4420
4421 static entity_t *finished_kr_declaration(entity_t *entity, bool is_definition)
4422 {
4423         symbol_t *symbol = entity->base.symbol;
4424         if (symbol == NULL)
4425                 return entity;
4426
4427         assert(entity->base.namespc == NAMESPACE_NORMAL);
4428         entity_t *previous_entity = get_entity(symbol, NAMESPACE_NORMAL);
4429         if (previous_entity == NULL
4430                         || previous_entity->base.parent_scope != current_scope) {
4431                 errorf(&entity->base.source_position, "expected declaration of a function parameter, found '%Y'",
4432                        symbol);
4433                 return entity;
4434         }
4435
4436         if (is_definition) {
4437                 errorf(HERE, "'%N' is initialised", entity);
4438         }
4439
4440         return record_entity(entity, false);
4441 }
4442
4443 static void parse_declaration(parsed_declaration_func finished_declaration,
4444                               declarator_flags_t      flags)
4445 {
4446         add_anchor_token(';');
4447         declaration_specifiers_t specifiers;
4448         parse_declaration_specifiers(&specifiers);
4449         rem_anchor_token(';');
4450
4451         if (token.kind == ';') {
4452                 parse_anonymous_declaration_rest(&specifiers);
4453         } else {
4454                 entity_t *entity = parse_declarator(&specifiers, flags);
4455                 parse_declaration_rest(entity, &specifiers, finished_declaration, flags);
4456         }
4457 }
4458
4459 /* §6.5.2.2:6 */
4460 static type_t *get_default_promoted_type(type_t *orig_type)
4461 {
4462         type_t *result = orig_type;
4463
4464         type_t *type = skip_typeref(orig_type);
4465         if (is_type_integer(type)) {
4466                 result = promote_integer(type);
4467         } else if (is_type_atomic(type, ATOMIC_TYPE_FLOAT)) {
4468                 result = type_double;
4469         }
4470
4471         return result;
4472 }
4473
4474 static void parse_kr_declaration_list(entity_t *entity)
4475 {
4476         if (entity->kind != ENTITY_FUNCTION)
4477                 return;
4478
4479         type_t *type = skip_typeref(entity->declaration.type);
4480         assert(is_type_function(type));
4481         if (!type->function.kr_style_parameters)
4482                 return;
4483
4484         add_anchor_token('{');
4485
4486         PUSH_SCOPE(&entity->function.parameters);
4487
4488         entity_t *parameter = entity->function.parameters.entities;
4489         for ( ; parameter != NULL; parameter = parameter->base.next) {
4490                 assert(parameter->base.parent_scope == NULL);
4491                 parameter->base.parent_scope = current_scope;
4492                 environment_push(parameter);
4493         }
4494
4495         /* parse declaration list */
4496         for (;;) {
4497                 switch (token.kind) {
4498                         DECLARATION_START
4499                         /* This covers symbols, which are no type, too, and results in
4500                          * better error messages.  The typical cases are misspelled type
4501                          * names and missing includes. */
4502                         case T_IDENTIFIER:
4503                                 parse_declaration(finished_kr_declaration, DECL_IS_PARAMETER);
4504                                 break;
4505                         default:
4506                                 goto decl_list_end;
4507                 }
4508         }
4509 decl_list_end:
4510
4511         POP_SCOPE();
4512
4513         /* update function type */
4514         type_t *new_type = duplicate_type(type);
4515
4516         function_parameter_t  *parameters = NULL;
4517         function_parameter_t **anchor     = &parameters;
4518
4519         /* did we have an earlier prototype? */
4520         entity_t *proto_type = get_entity(entity->base.symbol, NAMESPACE_NORMAL);
4521         if (proto_type != NULL && proto_type->kind != ENTITY_FUNCTION)
4522                 proto_type = NULL;
4523
4524         function_parameter_t *proto_parameter = NULL;
4525         if (proto_type != NULL) {
4526                 type_t *proto_type_type = proto_type->declaration.type;
4527                 proto_parameter         = proto_type_type->function.parameters;
4528                 /* If a K&R function definition has a variadic prototype earlier, then
4529                  * make the function definition variadic, too. This should conform to
4530                  * §6.7.5.3:15 and §6.9.1:8. */
4531                 new_type->function.variadic = proto_type_type->function.variadic;
4532         } else {
4533                 /* §6.9.1.7: A K&R style parameter list does NOT act as a function
4534                  * prototype */
4535                 new_type->function.unspecified_parameters = true;
4536         }
4537
4538         bool need_incompatible_warning = false;
4539         parameter = entity->function.parameters.entities;
4540         for (; parameter != NULL; parameter = parameter->base.next,
4541                         proto_parameter =
4542                                 proto_parameter == NULL ? NULL : proto_parameter->next) {
4543                 if (parameter->kind != ENTITY_PARAMETER)
4544                         continue;
4545
4546                 type_t *parameter_type = parameter->declaration.type;
4547                 if (parameter_type == NULL) {
4548                         source_position_t const* const pos = &parameter->base.source_position;
4549                         if (strict_mode) {
4550                                 errorf(pos, "no type specified for function '%N'", parameter);
4551                                 parameter_type = type_error_type;
4552                         } else {
4553                                 warningf(WARN_IMPLICIT_INT, pos, "no type specified for function parameter '%N', using 'int'", parameter);
4554                                 parameter_type = type_int;
4555                         }
4556                         parameter->declaration.type = parameter_type;
4557                 }
4558
4559                 semantic_parameter_incomplete(parameter);
4560
4561                 /* we need the default promoted types for the function type */
4562                 type_t *not_promoted = parameter_type;
4563                 parameter_type       = get_default_promoted_type(parameter_type);
4564
4565                 /* gcc special: if the type of the prototype matches the unpromoted
4566                  * type don't promote */
4567                 if (!strict_mode && proto_parameter != NULL) {
4568                         type_t *proto_p_type = skip_typeref(proto_parameter->type);
4569                         type_t *promo_skip   = skip_typeref(parameter_type);
4570                         type_t *param_skip   = skip_typeref(not_promoted);
4571                         if (!types_compatible(proto_p_type, promo_skip)
4572                                 && types_compatible(proto_p_type, param_skip)) {
4573                                 /* don't promote */
4574                                 need_incompatible_warning = true;
4575                                 parameter_type = not_promoted;
4576                         }
4577                 }
4578                 function_parameter_t *const function_parameter
4579                         = allocate_parameter(parameter_type);
4580
4581                 *anchor = function_parameter;
4582                 anchor  = &function_parameter->next;
4583         }
4584
4585         new_type->function.parameters = parameters;
4586         new_type = identify_new_type(new_type);
4587
4588         if (need_incompatible_warning) {
4589                 symbol_t          const *const sym  = entity->base.symbol;
4590                 source_position_t const *const pos  = &entity->base.source_position;
4591                 source_position_t const *const ppos = &proto_type->base.source_position;
4592                 warningf(WARN_OTHER, pos, "declaration '%#N' is incompatible with '%#T' (declared %P)", proto_type, new_type, sym, ppos);
4593         }
4594         entity->declaration.type = new_type;
4595
4596         rem_anchor_token('{');
4597 }
4598
4599 static bool first_err = true;
4600
4601 /**
4602  * When called with first_err set, prints the name of the current function,
4603  * else does noting.
4604  */
4605 static void print_in_function(void)
4606 {
4607         if (first_err) {
4608                 first_err = false;
4609                 char const *const file = current_function->base.base.source_position.input_name;
4610                 diagnosticf("%s: In '%N':\n", file, (entity_t const*)current_function);
4611         }
4612 }
4613
4614 /**
4615  * Check if all labels are defined in the current function.
4616  * Check if all labels are used in the current function.
4617  */
4618 static void check_labels(void)
4619 {
4620         for (const goto_statement_t *goto_statement = goto_first;
4621             goto_statement != NULL;
4622             goto_statement = goto_statement->next) {
4623                 /* skip computed gotos */
4624                 if (goto_statement->expression != NULL)
4625                         continue;
4626
4627                 label_t *label = goto_statement->label;
4628                 if (label->base.source_position.input_name == NULL) {
4629                         print_in_function();
4630                         source_position_t const *const pos = &goto_statement->base.source_position;
4631                         errorf(pos, "'%N' used but not defined", (entity_t const*)label);
4632                  }
4633         }
4634
4635         if (is_warn_on(WARN_UNUSED_LABEL)) {
4636                 for (const label_statement_t *label_statement = label_first;
4637                          label_statement != NULL;
4638                          label_statement = label_statement->next) {
4639                         label_t *label = label_statement->label;
4640
4641                         if (! label->used) {
4642                                 print_in_function();
4643                                 source_position_t const *const pos = &label_statement->base.source_position;
4644                                 warningf(WARN_UNUSED_LABEL, pos, "'%N' defined but not used", (entity_t const*)label);
4645                         }
4646                 }
4647         }
4648 }
4649
4650 static void warn_unused_entity(warning_t const why, entity_t *entity, entity_t *const last)
4651 {
4652         entity_t const *const end = last != NULL ? last->base.next : NULL;
4653         for (; entity != end; entity = entity->base.next) {
4654                 if (!is_declaration(entity))
4655                         continue;
4656
4657                 declaration_t *declaration = &entity->declaration;
4658                 if (declaration->implicit)
4659                         continue;
4660
4661                 if (!declaration->used) {
4662                         print_in_function();
4663                         warningf(why, &entity->base.source_position, "'%N' is unused", entity);
4664                 } else if (entity->kind == ENTITY_VARIABLE && !entity->variable.read) {
4665                         print_in_function();
4666                         warningf(why, &entity->base.source_position, "'%N' is never read", entity);
4667                 }
4668         }
4669 }
4670
4671 static void check_unused_variables(statement_t *const stmt, void *const env)
4672 {
4673         (void)env;
4674
4675         switch (stmt->kind) {
4676                 case STATEMENT_DECLARATION: {
4677                         declaration_statement_t const *const decls = &stmt->declaration;
4678                         warn_unused_entity(WARN_UNUSED_VARIABLE, decls->declarations_begin, decls->declarations_end);
4679                         return;
4680                 }
4681
4682                 case STATEMENT_FOR:
4683                         warn_unused_entity(WARN_UNUSED_VARIABLE, stmt->fors.scope.entities, NULL);
4684                         return;
4685
4686                 default:
4687                         return;
4688         }
4689 }
4690
4691 /**
4692  * Check declarations of current_function for unused entities.
4693  */
4694 static void check_declarations(void)
4695 {
4696         if (is_warn_on(WARN_UNUSED_PARAMETER)) {
4697                 const scope_t *scope = &current_function->parameters;
4698
4699                 /* do not issue unused warnings for main */
4700                 if (!is_sym_main(current_function->base.base.symbol)) {
4701                         warn_unused_entity(WARN_UNUSED_PARAMETER, scope->entities, NULL);
4702                 }
4703         }
4704         if (is_warn_on(WARN_UNUSED_VARIABLE)) {
4705                 walk_statements(current_function->statement, check_unused_variables,
4706                                 NULL);
4707         }
4708 }
4709
4710 static int determine_truth(expression_t const* const cond)
4711 {
4712         return
4713                 is_constant_expression(cond) != EXPR_CLASS_CONSTANT ? 0 :
4714                 fold_constant_to_bool(cond)                         ? 1 :
4715                 -1;
4716 }
4717
4718 static void check_reachable(statement_t *);
4719 static bool reaches_end;
4720
4721 static bool expression_returns(expression_t const *const expr)
4722 {
4723         switch (expr->kind) {
4724                 case EXPR_CALL: {
4725                         expression_t const *const func = expr->call.function;
4726                         type_t       const *const type = skip_typeref(func->base.type);
4727                         if (type->kind == TYPE_POINTER) {
4728                                 type_t const *const points_to
4729                                         = skip_typeref(type->pointer.points_to);
4730                                 if (points_to->kind == TYPE_FUNCTION
4731                                     && points_to->function.modifiers & DM_NORETURN)
4732                                         return false;
4733                         }
4734
4735                         if (!expression_returns(func))
4736                                 return false;
4737
4738                         for (call_argument_t const* arg = expr->call.arguments; arg != NULL; arg = arg->next) {
4739                                 if (!expression_returns(arg->expression))
4740                                         return false;
4741                         }
4742
4743                         return true;
4744                 }
4745
4746                 case EXPR_REFERENCE:
4747                 case EXPR_REFERENCE_ENUM_VALUE:
4748                 EXPR_LITERAL_CASES
4749                 case EXPR_STRING_LITERAL:
4750                 case EXPR_WIDE_STRING_LITERAL:
4751                 case EXPR_COMPOUND_LITERAL: // TODO descend into initialisers
4752                 case EXPR_LABEL_ADDRESS:
4753                 case EXPR_CLASSIFY_TYPE:
4754                 case EXPR_SIZEOF: // TODO handle obscure VLA case
4755                 case EXPR_ALIGNOF:
4756                 case EXPR_FUNCNAME:
4757                 case EXPR_BUILTIN_CONSTANT_P:
4758                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
4759                 case EXPR_OFFSETOF:
4760                 case EXPR_ERROR:
4761                         return true;
4762
4763                 case EXPR_STATEMENT: {
4764                         bool old_reaches_end = reaches_end;
4765                         reaches_end = false;
4766                         check_reachable(expr->statement.statement);
4767                         bool returns = reaches_end;
4768                         reaches_end = old_reaches_end;
4769                         return returns;
4770                 }
4771
4772                 case EXPR_CONDITIONAL:
4773                         // TODO handle constant expression
4774
4775                         if (!expression_returns(expr->conditional.condition))
4776                                 return false;
4777
4778                         if (expr->conditional.true_expression != NULL
4779                                         && expression_returns(expr->conditional.true_expression))
4780                                 return true;
4781
4782                         return expression_returns(expr->conditional.false_expression);
4783
4784                 case EXPR_SELECT:
4785                         return expression_returns(expr->select.compound);
4786
4787                 case EXPR_ARRAY_ACCESS:
4788                         return
4789                                 expression_returns(expr->array_access.array_ref) &&
4790                                 expression_returns(expr->array_access.index);
4791
4792                 case EXPR_VA_START:
4793                         return expression_returns(expr->va_starte.ap);
4794
4795                 case EXPR_VA_ARG:
4796                         return expression_returns(expr->va_arge.ap);
4797
4798                 case EXPR_VA_COPY:
4799                         return expression_returns(expr->va_copye.src);
4800
4801                 EXPR_UNARY_CASES_MANDATORY
4802                         return expression_returns(expr->unary.value);
4803
4804                 case EXPR_UNARY_THROW:
4805                         return false;
4806
4807                 EXPR_BINARY_CASES
4808                         // TODO handle constant lhs of && and ||
4809                         return
4810                                 expression_returns(expr->binary.left) &&
4811                                 expression_returns(expr->binary.right);
4812         }
4813
4814         panic("unhandled expression");
4815 }
4816
4817 static bool initializer_returns(initializer_t const *const init)
4818 {
4819         switch (init->kind) {
4820                 case INITIALIZER_VALUE:
4821                         return expression_returns(init->value.value);
4822
4823                 case INITIALIZER_LIST: {
4824                         initializer_t * const*       i       = init->list.initializers;
4825                         initializer_t * const* const end     = i + init->list.len;
4826                         bool                         returns = true;
4827                         for (; i != end; ++i) {
4828                                 if (!initializer_returns(*i))
4829                                         returns = false;
4830                         }
4831                         return returns;
4832                 }
4833
4834                 case INITIALIZER_STRING:
4835                 case INITIALIZER_WIDE_STRING:
4836                 case INITIALIZER_DESIGNATOR: // designators have no payload
4837                         return true;
4838         }
4839         panic("unhandled initializer");
4840 }
4841
4842 static bool noreturn_candidate;
4843
4844 static void check_reachable(statement_t *const stmt)
4845 {
4846         if (stmt->base.reachable)
4847                 return;
4848         if (stmt->kind != STATEMENT_DO_WHILE)
4849                 stmt->base.reachable = true;
4850
4851         statement_t *last = stmt;
4852         statement_t *next;
4853         switch (stmt->kind) {
4854                 case STATEMENT_ERROR:
4855                 case STATEMENT_EMPTY:
4856                 case STATEMENT_ASM:
4857                         next = stmt->base.next;
4858                         break;
4859
4860                 case STATEMENT_DECLARATION: {
4861                         declaration_statement_t const *const decl = &stmt->declaration;
4862                         entity_t                const *      ent  = decl->declarations_begin;
4863                         entity_t                const *const last_decl = decl->declarations_end;
4864                         if (ent != NULL) {
4865                                 for (;; ent = ent->base.next) {
4866                                         if (ent->kind                 == ENTITY_VARIABLE &&
4867                                             ent->variable.initializer != NULL            &&
4868                                             !initializer_returns(ent->variable.initializer)) {
4869                                                 return;
4870                                         }
4871                                         if (ent == last_decl)
4872                                                 break;
4873                                 }
4874                         }
4875                         next = stmt->base.next;
4876                         break;
4877                 }
4878
4879                 case STATEMENT_COMPOUND:
4880                         next = stmt->compound.statements;
4881                         if (next == NULL)
4882                                 next = stmt->base.next;
4883                         break;
4884
4885                 case STATEMENT_RETURN: {
4886                         expression_t const *const val = stmt->returns.value;
4887                         if (val == NULL || expression_returns(val))
4888                                 noreturn_candidate = false;
4889                         return;
4890                 }
4891
4892                 case STATEMENT_IF: {
4893                         if_statement_t const *const ifs  = &stmt->ifs;
4894                         expression_t   const *const cond = ifs->condition;
4895
4896                         if (!expression_returns(cond))
4897                                 return;
4898
4899                         int const val = determine_truth(cond);
4900
4901                         if (val >= 0)
4902                                 check_reachable(ifs->true_statement);
4903
4904                         if (val > 0)
4905                                 return;
4906
4907                         if (ifs->false_statement != NULL) {
4908                                 check_reachable(ifs->false_statement);
4909                                 return;
4910                         }
4911
4912                         next = stmt->base.next;
4913                         break;
4914                 }
4915
4916                 case STATEMENT_SWITCH: {
4917                         switch_statement_t const *const switchs = &stmt->switchs;
4918                         expression_t       const *const expr    = switchs->expression;
4919
4920                         if (!expression_returns(expr))
4921                                 return;
4922
4923                         if (is_constant_expression(expr) == EXPR_CLASS_CONSTANT) {
4924                                 long                    const val      = fold_constant_to_int(expr);
4925                                 case_label_statement_t *      defaults = NULL;
4926                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
4927                                         if (i->expression == NULL) {
4928                                                 defaults = i;
4929                                                 continue;
4930                                         }
4931
4932                                         if (i->first_case <= val && val <= i->last_case) {
4933                                                 check_reachable((statement_t*)i);
4934                                                 return;
4935                                         }
4936                                 }
4937
4938                                 if (defaults != NULL) {
4939                                         check_reachable((statement_t*)defaults);
4940                                         return;
4941                                 }
4942                         } else {
4943                                 bool has_default = false;
4944                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
4945                                         if (i->expression == NULL)
4946                                                 has_default = true;
4947
4948                                         check_reachable((statement_t*)i);
4949                                 }
4950
4951                                 if (has_default)
4952                                         return;
4953                         }
4954
4955                         next = stmt->base.next;
4956                         break;
4957                 }
4958
4959                 case STATEMENT_EXPRESSION: {
4960                         /* Check for noreturn function call */
4961                         expression_t const *const expr = stmt->expression.expression;
4962                         if (!expression_returns(expr))
4963                                 return;
4964
4965                         next = stmt->base.next;
4966                         break;
4967                 }
4968
4969                 case STATEMENT_CONTINUE:
4970                         for (statement_t *parent = stmt;;) {
4971                                 parent = parent->base.parent;
4972                                 if (parent == NULL) /* continue not within loop */
4973                                         return;
4974
4975                                 next = parent;
4976                                 switch (parent->kind) {
4977                                         case STATEMENT_WHILE:    goto continue_while;
4978                                         case STATEMENT_DO_WHILE: goto continue_do_while;
4979                                         case STATEMENT_FOR:      goto continue_for;
4980
4981                                         default: break;
4982                                 }
4983                         }
4984
4985                 case STATEMENT_BREAK:
4986                         for (statement_t *parent = stmt;;) {
4987                                 parent = parent->base.parent;
4988                                 if (parent == NULL) /* break not within loop/switch */
4989                                         return;
4990
4991                                 switch (parent->kind) {
4992                                         case STATEMENT_SWITCH:
4993                                         case STATEMENT_WHILE:
4994                                         case STATEMENT_DO_WHILE:
4995                                         case STATEMENT_FOR:
4996                                                 last = parent;
4997                                                 next = parent->base.next;
4998                                                 goto found_break_parent;
4999
5000                                         default: break;
5001                                 }
5002                         }
5003 found_break_parent:
5004                         break;
5005
5006                 case STATEMENT_GOTO:
5007                         if (stmt->gotos.expression) {
5008                                 if (!expression_returns(stmt->gotos.expression))
5009                                         return;
5010
5011                                 statement_t *parent = stmt->base.parent;
5012                                 if (parent == NULL) /* top level goto */
5013                                         return;
5014                                 next = parent;
5015                         } else {
5016                                 next = stmt->gotos.label->statement;
5017                                 if (next == NULL) /* missing label */
5018                                         return;
5019                         }
5020                         break;
5021
5022                 case STATEMENT_LABEL:
5023                         next = stmt->label.statement;
5024                         break;
5025
5026                 case STATEMENT_CASE_LABEL:
5027                         next = stmt->case_label.statement;
5028                         break;
5029
5030                 case STATEMENT_WHILE: {
5031                         while_statement_t const *const whiles = &stmt->whiles;
5032                         expression_t      const *const cond   = whiles->condition;
5033
5034                         if (!expression_returns(cond))
5035                                 return;
5036
5037                         int const val = determine_truth(cond);
5038
5039                         if (val >= 0)
5040                                 check_reachable(whiles->body);
5041
5042                         if (val > 0)
5043                                 return;
5044
5045                         next = stmt->base.next;
5046                         break;
5047                 }
5048
5049                 case STATEMENT_DO_WHILE:
5050                         next = stmt->do_while.body;
5051                         break;
5052
5053                 case STATEMENT_FOR: {
5054                         for_statement_t *const fors = &stmt->fors;
5055
5056                         if (fors->condition_reachable)
5057                                 return;
5058                         fors->condition_reachable = true;
5059
5060                         expression_t const *const cond = fors->condition;
5061
5062                         int val;
5063                         if (cond == NULL) {
5064                                 val = 1;
5065                         } else if (expression_returns(cond)) {
5066                                 val = determine_truth(cond);
5067                         } else {
5068                                 return;
5069                         }
5070
5071                         if (val >= 0)
5072                                 check_reachable(fors->body);
5073
5074                         if (val > 0)
5075                                 return;
5076
5077                         next = stmt->base.next;
5078                         break;
5079                 }
5080
5081                 case STATEMENT_MS_TRY: {
5082                         ms_try_statement_t const *const ms_try = &stmt->ms_try;
5083                         check_reachable(ms_try->try_statement);
5084                         next = ms_try->final_statement;
5085                         break;
5086                 }
5087
5088                 case STATEMENT_LEAVE: {
5089                         statement_t *parent = stmt;
5090                         for (;;) {
5091                                 parent = parent->base.parent;
5092                                 if (parent == NULL) /* __leave not within __try */
5093                                         return;
5094
5095                                 if (parent->kind == STATEMENT_MS_TRY) {
5096                                         last = parent;
5097                                         next = parent->ms_try.final_statement;
5098                                         break;
5099                                 }
5100                         }
5101                         break;
5102                 }
5103
5104                 default:
5105                         panic("invalid statement kind");
5106         }
5107
5108         while (next == NULL) {
5109                 next = last->base.parent;
5110                 if (next == NULL) {
5111                         noreturn_candidate = false;
5112
5113                         type_t *const type = skip_typeref(current_function->base.type);
5114                         assert(is_type_function(type));
5115                         type_t *const ret  = skip_typeref(type->function.return_type);
5116                         if (!is_type_atomic(ret, ATOMIC_TYPE_VOID) &&
5117                             is_type_valid(ret)                     &&
5118                             !is_sym_main(current_function->base.base.symbol)) {
5119                                 source_position_t const *const pos = &stmt->base.source_position;
5120                                 warningf(WARN_RETURN_TYPE, pos, "control reaches end of non-void function");
5121                         }
5122                         return;
5123                 }
5124
5125                 switch (next->kind) {
5126                         case STATEMENT_ERROR:
5127                         case STATEMENT_EMPTY:
5128                         case STATEMENT_DECLARATION:
5129                         case STATEMENT_EXPRESSION:
5130                         case STATEMENT_ASM:
5131                         case STATEMENT_RETURN:
5132                         case STATEMENT_CONTINUE:
5133                         case STATEMENT_BREAK:
5134                         case STATEMENT_GOTO:
5135                         case STATEMENT_LEAVE:
5136                                 panic("invalid control flow in function");
5137
5138                         case STATEMENT_COMPOUND:
5139                                 if (next->compound.stmt_expr) {
5140                                         reaches_end = true;
5141                                         return;
5142                                 }
5143                                 /* FALLTHROUGH */
5144                         case STATEMENT_IF:
5145                         case STATEMENT_SWITCH:
5146                         case STATEMENT_LABEL:
5147                         case STATEMENT_CASE_LABEL:
5148                                 last = next;
5149                                 next = next->base.next;
5150                                 break;
5151
5152                         case STATEMENT_WHILE: {
5153 continue_while:
5154                                 if (next->base.reachable)
5155                                         return;
5156                                 next->base.reachable = true;
5157
5158                                 while_statement_t const *const whiles = &next->whiles;
5159                                 expression_t      const *const cond   = whiles->condition;
5160
5161                                 if (!expression_returns(cond))
5162                                         return;
5163
5164                                 int const val = determine_truth(cond);
5165
5166                                 if (val >= 0)
5167                                         check_reachable(whiles->body);
5168
5169                                 if (val > 0)
5170                                         return;
5171
5172                                 last = next;
5173                                 next = next->base.next;
5174                                 break;
5175                         }
5176
5177                         case STATEMENT_DO_WHILE: {
5178 continue_do_while:
5179                                 if (next->base.reachable)
5180                                         return;
5181                                 next->base.reachable = true;
5182
5183                                 do_while_statement_t const *const dw   = &next->do_while;
5184                                 expression_t         const *const cond = dw->condition;
5185
5186                                 if (!expression_returns(cond))
5187                                         return;
5188
5189                                 int const val = determine_truth(cond);
5190
5191                                 if (val >= 0)
5192                                         check_reachable(dw->body);
5193
5194                                 if (val > 0)
5195                                         return;
5196
5197                                 last = next;
5198                                 next = next->base.next;
5199                                 break;
5200                         }
5201
5202                         case STATEMENT_FOR: {
5203 continue_for:;
5204                                 for_statement_t *const fors = &next->fors;
5205
5206                                 fors->step_reachable = true;
5207
5208                                 if (fors->condition_reachable)
5209                                         return;
5210                                 fors->condition_reachable = true;
5211
5212                                 expression_t const *const cond = fors->condition;
5213
5214                                 int val;
5215                                 if (cond == NULL) {
5216                                         val = 1;
5217                                 } else if (expression_returns(cond)) {
5218                                         val = determine_truth(cond);
5219                                 } else {
5220                                         return;
5221                                 }
5222
5223                                 if (val >= 0)
5224                                         check_reachable(fors->body);
5225
5226                                 if (val > 0)
5227                                         return;
5228
5229                                 last = next;
5230                                 next = next->base.next;
5231                                 break;
5232                         }
5233
5234                         case STATEMENT_MS_TRY:
5235                                 last = next;
5236                                 next = next->ms_try.final_statement;
5237                                 break;
5238                 }
5239         }
5240
5241         check_reachable(next);
5242 }
5243
5244 static void check_unreachable(statement_t* const stmt, void *const env)
5245 {
5246         (void)env;
5247
5248         switch (stmt->kind) {
5249                 case STATEMENT_DO_WHILE:
5250                         if (!stmt->base.reachable) {
5251                                 expression_t const *const cond = stmt->do_while.condition;
5252                                 if (determine_truth(cond) >= 0) {
5253                                         source_position_t const *const pos = &cond->base.source_position;
5254                                         warningf(WARN_UNREACHABLE_CODE, pos, "condition of do-while-loop is unreachable");
5255                                 }
5256                         }
5257                         return;
5258
5259                 case STATEMENT_FOR: {
5260                         for_statement_t const* const fors = &stmt->fors;
5261
5262                         // if init and step are unreachable, cond is unreachable, too
5263                         if (!stmt->base.reachable && !fors->step_reachable) {
5264                                 goto warn_unreachable;
5265                         } else {
5266                                 if (!stmt->base.reachable && fors->initialisation != NULL) {
5267                                         source_position_t const *const pos = &fors->initialisation->base.source_position;
5268                                         warningf(WARN_UNREACHABLE_CODE, pos, "initialisation of for-statement is unreachable");
5269                                 }
5270
5271                                 if (!fors->condition_reachable && fors->condition != NULL) {
5272                                         source_position_t const *const pos = &fors->condition->base.source_position;
5273                                         warningf(WARN_UNREACHABLE_CODE, pos, "condition of for-statement is unreachable");
5274                                 }
5275
5276                                 if (!fors->step_reachable && fors->step != NULL) {
5277                                         source_position_t const *const pos = &fors->step->base.source_position;
5278                                         warningf(WARN_UNREACHABLE_CODE, pos, "step of for-statement is unreachable");
5279                                 }
5280                         }
5281                         return;
5282                 }
5283
5284                 case STATEMENT_COMPOUND:
5285                         if (stmt->compound.statements != NULL)
5286                                 return;
5287                         goto warn_unreachable;
5288
5289                 case STATEMENT_DECLARATION: {
5290                         /* Only warn if there is at least one declarator with an initializer.
5291                          * This typically occurs in switch statements. */
5292                         declaration_statement_t const *const decl = &stmt->declaration;
5293                         entity_t                const *      ent  = decl->declarations_begin;
5294                         entity_t                const *const last = decl->declarations_end;
5295                         if (ent != NULL) {
5296                                 for (;; ent = ent->base.next) {
5297                                         if (ent->kind                 == ENTITY_VARIABLE &&
5298                                                         ent->variable.initializer != NULL) {
5299                                                 goto warn_unreachable;
5300                                         }
5301                                         if (ent == last)
5302                                                 return;
5303                                 }
5304                         }
5305                 }
5306
5307                 default:
5308 warn_unreachable:
5309                         if (!stmt->base.reachable) {
5310                                 source_position_t const *const pos = &stmt->base.source_position;
5311                                 warningf(WARN_UNREACHABLE_CODE, pos, "statement is unreachable");
5312                         }
5313                         return;
5314         }
5315 }
5316
5317 static bool is_main(entity_t *entity)
5318 {
5319         static symbol_t *sym_main = NULL;
5320         if (sym_main == NULL) {
5321                 sym_main = symbol_table_insert("main");
5322         }
5323
5324         if (entity->base.symbol != sym_main)
5325                 return false;
5326         /* must be in outermost scope */
5327         if (entity->base.parent_scope != file_scope)
5328                 return false;
5329
5330         return true;
5331 }
5332
5333 static void parse_external_declaration(void)
5334 {
5335         /* function-definitions and declarations both start with declaration
5336          * specifiers */
5337         add_anchor_token(';');
5338         declaration_specifiers_t specifiers;
5339         parse_declaration_specifiers(&specifiers);
5340         rem_anchor_token(';');
5341
5342         /* must be a declaration */
5343         if (token.kind == ';') {
5344                 parse_anonymous_declaration_rest(&specifiers);
5345                 return;
5346         }
5347
5348         add_anchor_token(',');
5349         add_anchor_token('=');
5350         add_anchor_token(';');
5351         add_anchor_token('{');
5352
5353         /* declarator is common to both function-definitions and declarations */
5354         entity_t *ndeclaration = parse_declarator(&specifiers, DECL_FLAGS_NONE);
5355
5356         rem_anchor_token('{');
5357         rem_anchor_token(';');
5358         rem_anchor_token('=');
5359         rem_anchor_token(',');
5360
5361         /* must be a declaration */
5362         switch (token.kind) {
5363                 case ',':
5364                 case ';':
5365                 case '=':
5366                         parse_declaration_rest(ndeclaration, &specifiers, record_entity,
5367                                         DECL_FLAGS_NONE);
5368                         return;
5369         }
5370
5371         /* must be a function definition */
5372         parse_kr_declaration_list(ndeclaration);
5373
5374         if (token.kind != '{') {
5375                 parse_error_expected("while parsing function definition", '{', NULL);
5376                 eat_until_matching_token(';');
5377                 return;
5378         }
5379
5380         assert(is_declaration(ndeclaration));
5381         type_t *const orig_type = ndeclaration->declaration.type;
5382         type_t *      type      = skip_typeref(orig_type);
5383
5384         if (!is_type_function(type)) {
5385                 if (is_type_valid(type)) {
5386                         errorf(HERE, "declarator '%#N' has a body but is not a function type", ndeclaration);
5387                 }
5388                 eat_block();
5389                 return;
5390         }
5391
5392         source_position_t const *const pos = &ndeclaration->base.source_position;
5393         if (is_typeref(orig_type)) {
5394                 /* §6.9.1:2 */
5395                 errorf(pos, "type of function definition '%#N' is a typedef", ndeclaration);
5396         }
5397
5398         if (is_type_compound(skip_typeref(type->function.return_type))) {
5399                 warningf(WARN_AGGREGATE_RETURN, pos, "'%N' returns an aggregate", ndeclaration);
5400         }
5401         if (type->function.unspecified_parameters) {
5402                 warningf(WARN_OLD_STYLE_DEFINITION, pos, "old-style definition of '%N'", ndeclaration);
5403         } else {
5404                 warningf(WARN_TRADITIONAL, pos, "traditional C rejects ISO C style definition of '%N'", ndeclaration);
5405         }
5406
5407         /* §6.7.5.3:14 a function definition with () means no
5408          * parameters (and not unspecified parameters) */
5409         if (type->function.unspecified_parameters &&
5410                         type->function.parameters == NULL) {
5411                 type_t *copy                          = duplicate_type(type);
5412                 copy->function.unspecified_parameters = false;
5413                 type                                  = identify_new_type(copy);
5414
5415                 ndeclaration->declaration.type = type;
5416         }
5417
5418         entity_t *const entity = record_entity(ndeclaration, true);
5419         assert(entity->kind == ENTITY_FUNCTION);
5420         assert(ndeclaration->kind == ENTITY_FUNCTION);
5421
5422         function_t *const function = &entity->function;
5423         if (ndeclaration != entity) {
5424                 function->parameters = ndeclaration->function.parameters;
5425         }
5426         assert(is_declaration(entity));
5427         type = skip_typeref(entity->declaration.type);
5428
5429         PUSH_SCOPE(&function->parameters);
5430
5431         entity_t *parameter = function->parameters.entities;
5432         for (; parameter != NULL; parameter = parameter->base.next) {
5433                 if (parameter->base.parent_scope == &ndeclaration->function.parameters) {
5434                         parameter->base.parent_scope = current_scope;
5435                 }
5436                 assert(parameter->base.parent_scope == NULL
5437                                 || parameter->base.parent_scope == current_scope);
5438                 parameter->base.parent_scope = current_scope;
5439                 if (parameter->base.symbol == NULL) {
5440                         errorf(&parameter->base.source_position, "parameter name omitted");
5441                         continue;
5442                 }
5443                 environment_push(parameter);
5444         }
5445
5446         if (function->statement != NULL) {
5447                 parser_error_multiple_definition(entity, HERE);
5448                 eat_block();
5449         } else {
5450                 /* parse function body */
5451                 int         label_stack_top      = label_top();
5452                 function_t *old_current_function = current_function;
5453                 entity_t   *old_current_entity   = current_entity;
5454                 current_function                 = function;
5455                 current_entity                   = entity;
5456                 PUSH_PARENT(NULL);
5457
5458                 goto_first   = NULL;
5459                 goto_anchor  = &goto_first;
5460                 label_first  = NULL;
5461                 label_anchor = &label_first;
5462
5463                 statement_t *const body = parse_compound_statement(false);
5464                 function->statement = body;
5465                 first_err = true;
5466                 check_labels();
5467                 check_declarations();
5468                 if (is_warn_on(WARN_RETURN_TYPE)      ||
5469                     is_warn_on(WARN_UNREACHABLE_CODE) ||
5470                     (is_warn_on(WARN_MISSING_NORETURN) && !(function->base.modifiers & DM_NORETURN))) {
5471                         noreturn_candidate = true;
5472                         check_reachable(body);
5473                         if (is_warn_on(WARN_UNREACHABLE_CODE))
5474                                 walk_statements(body, check_unreachable, NULL);
5475                         if (noreturn_candidate &&
5476                             !(function->base.modifiers & DM_NORETURN)) {
5477                                 source_position_t const *const pos = &body->base.source_position;
5478                                 warningf(WARN_MISSING_NORETURN, pos, "function '%#N' is candidate for attribute 'noreturn'", entity);
5479                         }
5480                 }
5481
5482                 if (is_main(entity) && enable_main_collect2_hack)
5483                         prepare_main_collect2(entity);
5484
5485                 POP_PARENT();
5486                 assert(current_function == function);
5487                 assert(current_entity   == entity);
5488                 current_entity   = old_current_entity;
5489                 current_function = old_current_function;
5490                 label_pop_to(label_stack_top);
5491         }
5492
5493         POP_SCOPE();
5494 }
5495
5496 static entity_t *find_compound_entry(compound_t *compound, symbol_t *symbol)
5497 {
5498         entity_t *iter = compound->members.entities;
5499         for (; iter != NULL; iter = iter->base.next) {
5500                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5501                         continue;
5502
5503                 if (iter->base.symbol == symbol) {
5504                         return iter;
5505                 } else if (iter->base.symbol == NULL) {
5506                         /* search in anonymous structs and unions */
5507                         type_t *type = skip_typeref(iter->declaration.type);
5508                         if (is_type_compound(type)) {
5509                                 if (find_compound_entry(type->compound.compound, symbol)
5510                                                 != NULL)
5511                                         return iter;
5512                         }
5513                         continue;
5514                 }
5515         }
5516
5517         return NULL;
5518 }
5519
5520 static void check_deprecated(const source_position_t *source_position,
5521                              const entity_t *entity)
5522 {
5523         if (!is_declaration(entity))
5524                 return;
5525         if ((entity->declaration.modifiers & DM_DEPRECATED) == 0)
5526                 return;
5527
5528         source_position_t const *const epos = &entity->base.source_position;
5529         char              const *const msg  = get_deprecated_string(entity->declaration.attributes);
5530         if (msg != NULL) {
5531                 warningf(WARN_DEPRECATED_DECLARATIONS, source_position, "'%N' is deprecated (declared %P): \"%s\"", entity, epos, msg);
5532         } else {
5533                 warningf(WARN_DEPRECATED_DECLARATIONS, source_position, "'%N' is deprecated (declared %P)", entity, epos);
5534         }
5535 }
5536
5537
5538 static expression_t *create_select(const source_position_t *pos,
5539                                    expression_t *addr,
5540                                    type_qualifiers_t qualifiers,
5541                                                                    entity_t *entry)
5542 {
5543         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
5544
5545         check_deprecated(pos, entry);
5546
5547         expression_t *select          = allocate_expression_zero(EXPR_SELECT);
5548         select->select.compound       = addr;
5549         select->select.compound_entry = entry;
5550
5551         type_t *entry_type = entry->declaration.type;
5552         type_t *res_type   = get_qualified_type(entry_type, qualifiers);
5553
5554         /* bitfields need special treatment */
5555         if (entry->compound_member.bitfield) {
5556                 unsigned bit_size = entry->compound_member.bit_size;
5557                 /* if fewer bits than an int, convert to int (see §6.3.1.1) */
5558                 if (bit_size < get_atomic_type_size(ATOMIC_TYPE_INT) * BITS_PER_BYTE) {
5559                         res_type = type_int;
5560                 }
5561         }
5562
5563         /* we always do the auto-type conversions; the & and sizeof parser contains
5564          * code to revert this! */
5565         select->base.type = automatic_type_conversion(res_type);
5566
5567
5568         return select;
5569 }
5570
5571 /**
5572  * Find entry with symbol in compound. Search anonymous structs and unions and
5573  * creates implicit select expressions for them.
5574  * Returns the adress for the innermost compound.
5575  */
5576 static expression_t *find_create_select(const source_position_t *pos,
5577                                         expression_t *addr,
5578                                         type_qualifiers_t qualifiers,
5579                                         compound_t *compound, symbol_t *symbol)
5580 {
5581         entity_t *iter = compound->members.entities;
5582         for (; iter != NULL; iter = iter->base.next) {
5583                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5584                         continue;
5585
5586                 symbol_t *iter_symbol = iter->base.symbol;
5587                 if (iter_symbol == NULL) {
5588                         type_t *type = iter->declaration.type;
5589                         if (type->kind != TYPE_COMPOUND_STRUCT
5590                                         && type->kind != TYPE_COMPOUND_UNION)
5591                                 continue;
5592
5593                         compound_t *sub_compound = type->compound.compound;
5594
5595                         if (find_compound_entry(sub_compound, symbol) == NULL)
5596                                 continue;
5597
5598                         expression_t *sub_addr = create_select(pos, addr, qualifiers, iter);
5599                         sub_addr->base.source_position = *pos;
5600                         sub_addr->base.implicit        = true;
5601                         return find_create_select(pos, sub_addr, qualifiers, sub_compound,
5602                                                   symbol);
5603                 }
5604
5605                 if (iter_symbol == symbol) {
5606                         return create_select(pos, addr, qualifiers, iter);
5607                 }
5608         }
5609
5610         return NULL;
5611 }
5612
5613 static void parse_bitfield_member(entity_t *entity)
5614 {
5615         eat(':');
5616
5617         expression_t *size = parse_constant_expression();
5618         long          size_long;
5619
5620         assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5621         type_t *type = entity->declaration.type;
5622         if (!is_type_integer(skip_typeref(type))) {
5623                 errorf(HERE, "bitfield base type '%T' is not an integer type",
5624                            type);
5625         }
5626
5627         if (is_constant_expression(size) != EXPR_CLASS_CONSTANT) {
5628                 /* error already reported by parse_constant_expression */
5629                 size_long = get_type_size(type) * 8;
5630         } else {
5631                 size_long = fold_constant_to_int(size);
5632
5633                 const symbol_t *symbol = entity->base.symbol;
5634                 const symbol_t *user_symbol
5635                         = symbol == NULL ? sym_anonymous : symbol;
5636                 unsigned bit_size = get_type_size(type) * 8;
5637                 if (size_long < 0) {
5638                         errorf(HERE, "negative width in bit-field '%Y'", user_symbol);
5639                 } else if (size_long == 0 && symbol != NULL) {
5640                         errorf(HERE, "zero width for bit-field '%Y'", user_symbol);
5641                 } else if (bit_size > 0 && (unsigned)size_long > bit_size) {
5642                         errorf(HERE, "width of bitfield '%Y' exceeds its type",
5643                                    user_symbol);
5644                 } else {
5645                         /* hope that people don't invent crazy types with more bits
5646                          * than our struct can hold */
5647                         assert(size_long <
5648                                    (1 << sizeof(entity->compound_member.bit_size)*8));
5649                 }
5650         }
5651
5652         entity->compound_member.bitfield = true;
5653         entity->compound_member.bit_size = (unsigned char)size_long;
5654 }
5655
5656 static void parse_compound_declarators(compound_t *compound,
5657                 const declaration_specifiers_t *specifiers)
5658 {
5659         do {
5660                 entity_t *entity;
5661
5662                 if (token.kind == ':') {
5663                         /* anonymous bitfield */
5664                         type_t *type = specifiers->type;
5665                         entity_t *entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER,
5666                                                                 NAMESPACE_NORMAL, NULL);
5667                         entity->base.source_position               = *HERE;
5668                         entity->declaration.declared_storage_class = STORAGE_CLASS_NONE;
5669                         entity->declaration.storage_class          = STORAGE_CLASS_NONE;
5670                         entity->declaration.type                   = type;
5671
5672                         parse_bitfield_member(entity);
5673
5674                         attribute_t  *attributes = parse_attributes(NULL);
5675                         attribute_t **anchor     = &attributes;
5676                         while (*anchor != NULL)
5677                                 anchor = &(*anchor)->next;
5678                         *anchor = specifiers->attributes;
5679                         if (attributes != NULL) {
5680                                 handle_entity_attributes(attributes, entity);
5681                         }
5682                         entity->declaration.attributes = attributes;
5683
5684                         append_entity(&compound->members, entity);
5685                 } else {
5686                         entity = parse_declarator(specifiers,
5687                                         DECL_MAY_BE_ABSTRACT | DECL_CREATE_COMPOUND_MEMBER);
5688                         source_position_t const *const pos = &entity->base.source_position;
5689                         if (entity->kind == ENTITY_TYPEDEF) {
5690                                 errorf(pos, "typedef not allowed as compound member");
5691                         } else {
5692                                 assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5693
5694                                 /* make sure we don't define a symbol multiple times */
5695                                 symbol_t *symbol = entity->base.symbol;
5696                                 if (symbol != NULL) {
5697                                         entity_t *prev = find_compound_entry(compound, symbol);
5698                                         if (prev != NULL) {
5699                                                 source_position_t const *const ppos = &prev->base.source_position;
5700                                                 errorf(pos, "multiple declarations of symbol '%Y' (declared %P)", symbol, ppos);
5701                                         }
5702                                 }
5703
5704                                 if (token.kind == ':') {
5705                                         parse_bitfield_member(entity);
5706
5707                                         attribute_t *attributes = parse_attributes(NULL);
5708                                         handle_entity_attributes(attributes, entity);
5709                                 } else {
5710                                         type_t *orig_type = entity->declaration.type;
5711                                         type_t *type      = skip_typeref(orig_type);
5712                                         if (is_type_function(type)) {
5713                                                 errorf(pos, "'%N' must not have function type '%T'", entity, orig_type);
5714                                         } else if (is_type_incomplete(type)) {
5715                                                 /* §6.7.2.1:16 flexible array member */
5716                                                 if (!is_type_array(type)       ||
5717                                                                 token.kind          != ';' ||
5718                                                                 look_ahead(1)->kind != '}') {
5719                                                         errorf(pos, "'%N' has incomplete type '%T'", entity, orig_type);
5720                                                 } else if (compound->members.entities == NULL) {
5721                                                         errorf(pos, "flexible array member in otherwise empty struct");
5722                                                 }
5723                                         }
5724                                 }
5725
5726                                 append_entity(&compound->members, entity);
5727                         }
5728                 }
5729         } while (next_if(','));
5730         expect(';', end_error);
5731
5732 end_error:
5733         anonymous_entity = NULL;
5734 }
5735
5736 static void parse_compound_type_entries(compound_t *compound)
5737 {
5738         eat('{');
5739         add_anchor_token('}');
5740
5741         for (;;) {
5742                 switch (token.kind) {
5743                         DECLARATION_START
5744                         case T___extension__:
5745                         case T_IDENTIFIER: {
5746                                 PUSH_EXTENSION();
5747                                 declaration_specifiers_t specifiers;
5748                                 parse_declaration_specifiers(&specifiers);
5749                                 parse_compound_declarators(compound, &specifiers);
5750                                 POP_EXTENSION();
5751                                 break;
5752                         }
5753
5754                         default:
5755                                 rem_anchor_token('}');
5756                                 expect('}', end_error);
5757 end_error:
5758                                 /* §6.7.2.1:7 */
5759                                 compound->complete = true;
5760                                 return;
5761                 }
5762         }
5763 }
5764
5765 static type_t *parse_typename(void)
5766 {
5767         declaration_specifiers_t specifiers;
5768         parse_declaration_specifiers(&specifiers);
5769         if (specifiers.storage_class != STORAGE_CLASS_NONE
5770                         || specifiers.thread_local) {
5771                 /* TODO: improve error message, user does probably not know what a
5772                  * storage class is...
5773                  */
5774                 errorf(&specifiers.source_position, "typename must not have a storage class");
5775         }
5776
5777         type_t *result = parse_abstract_declarator(specifiers.type);
5778
5779         return result;
5780 }
5781
5782
5783
5784
5785 typedef expression_t* (*parse_expression_function)(void);
5786 typedef expression_t* (*parse_expression_infix_function)(expression_t *left);
5787
5788 typedef struct expression_parser_function_t expression_parser_function_t;
5789 struct expression_parser_function_t {
5790         parse_expression_function        parser;
5791         precedence_t                     infix_precedence;
5792         parse_expression_infix_function  infix_parser;
5793 };
5794
5795 static expression_parser_function_t expression_parsers[T_LAST_TOKEN];
5796
5797 /**
5798  * Prints an error message if an expression was expected but not read
5799  */
5800 static expression_t *expected_expression_error(void)
5801 {
5802         /* skip the error message if the error token was read */
5803         if (token.kind != T_ERROR) {
5804                 errorf(HERE, "expected expression, got token %K", &token);
5805         }
5806         next_token();
5807
5808         return create_error_expression();
5809 }
5810
5811 static type_t *get_string_type(void)
5812 {
5813         return is_warn_on(WARN_WRITE_STRINGS) ? type_const_char_ptr : type_char_ptr;
5814 }
5815
5816 static type_t *get_wide_string_type(void)
5817 {
5818         return is_warn_on(WARN_WRITE_STRINGS) ? type_const_wchar_t_ptr : type_wchar_t_ptr;
5819 }
5820
5821 /**
5822  * Parse a string constant.
5823  */
5824 static expression_t *parse_string_literal(void)
5825 {
5826         source_position_t begin   = token.base.source_position;
5827         string_t          res     = token.string.string;
5828         bool              is_wide = (token.kind == T_WIDE_STRING_LITERAL);
5829
5830         next_token();
5831         while (token.kind == T_STRING_LITERAL
5832                         || token.kind == T_WIDE_STRING_LITERAL) {
5833                 warn_string_concat(&token.base.source_position);
5834                 res = concat_strings(&res, &token.string.string);
5835                 next_token();
5836                 is_wide |= token.kind == T_WIDE_STRING_LITERAL;
5837         }
5838
5839         expression_t *literal;
5840         if (is_wide) {
5841                 literal = allocate_expression_zero(EXPR_WIDE_STRING_LITERAL);
5842                 literal->base.type = get_wide_string_type();
5843         } else {
5844                 literal = allocate_expression_zero(EXPR_STRING_LITERAL);
5845                 literal->base.type = get_string_type();
5846         }
5847         literal->base.source_position = begin;
5848         literal->literal.value        = res;
5849
5850         return literal;
5851 }
5852
5853 /**
5854  * Parse a boolean constant.
5855  */
5856 static expression_t *parse_boolean_literal(bool value)
5857 {
5858         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_BOOLEAN);
5859         literal->base.type           = type_bool;
5860         literal->literal.value.begin = value ? "true" : "false";
5861         literal->literal.value.size  = value ? 4 : 5;
5862
5863         next_token();
5864         return literal;
5865 }
5866
5867 static void warn_traditional_suffix(void)
5868 {
5869         warningf(WARN_TRADITIONAL, HERE, "traditional C rejects the '%S' suffix",
5870                  &token.number.suffix);
5871 }
5872
5873 static void check_integer_suffix(void)
5874 {
5875         const string_t *suffix = &token.number.suffix;
5876         if (suffix->size == 0)
5877                 return;
5878
5879         bool not_traditional = false;
5880         const char *c = suffix->begin;
5881         if (*c == 'l' || *c == 'L') {
5882                 ++c;
5883                 if (*c == *(c-1)) {
5884                         not_traditional = true;
5885                         ++c;
5886                         if (*c == 'u' || *c == 'U') {
5887                                 ++c;
5888                         }
5889                 } else if (*c == 'u' || *c == 'U') {
5890                         not_traditional = true;
5891                         ++c;
5892                 }
5893         } else if (*c == 'u' || *c == 'U') {
5894                 not_traditional = true;
5895                 ++c;
5896                 if (*c == 'l' || *c == 'L') {
5897                         ++c;
5898                         if (*c == *(c-1)) {
5899                                 ++c;
5900                         }
5901                 }
5902         }
5903         if (*c != '\0') {
5904                 errorf(&token.base.source_position,
5905                        "invalid suffix '%S' on integer constant", suffix);
5906         } else if (not_traditional) {
5907                 warn_traditional_suffix();
5908         }
5909 }
5910
5911 static type_t *check_floatingpoint_suffix(void)
5912 {
5913         const string_t *suffix = &token.number.suffix;
5914         type_t         *type   = type_double;
5915         if (suffix->size == 0)
5916                 return type;
5917
5918         bool not_traditional = false;
5919         const char *c = suffix->begin;
5920         if (*c == 'f' || *c == 'F') {
5921                 ++c;
5922                 type = type_float;
5923         } else if (*c == 'l' || *c == 'L') {
5924                 ++c;
5925                 type = type_long_double;
5926         }
5927         if (*c != '\0') {
5928                 errorf(&token.base.source_position,
5929                        "invalid suffix '%S' on floatingpoint constant", suffix);
5930         } else if (not_traditional) {
5931                 warn_traditional_suffix();
5932         }
5933
5934         return type;
5935 }
5936
5937 /**
5938  * Parse an integer constant.
5939  */
5940 static expression_t *parse_number_literal(void)
5941 {
5942         expression_kind_t  kind;
5943         type_t            *type;
5944
5945         switch (token.kind) {
5946         case T_INTEGER:
5947                 kind = EXPR_LITERAL_INTEGER;
5948                 check_integer_suffix();
5949                 type = type_int;
5950                 break;
5951         case T_INTEGER_OCTAL:
5952                 kind = EXPR_LITERAL_INTEGER_OCTAL;
5953                 check_integer_suffix();
5954                 type = type_int;
5955                 break;
5956         case T_INTEGER_HEXADECIMAL:
5957                 kind = EXPR_LITERAL_INTEGER_HEXADECIMAL;
5958                 check_integer_suffix();
5959                 type = type_int;
5960                 break;
5961         case T_FLOATINGPOINT:
5962                 kind = EXPR_LITERAL_FLOATINGPOINT;
5963                 type = check_floatingpoint_suffix();
5964                 break;
5965         case T_FLOATINGPOINT_HEXADECIMAL:
5966                 kind = EXPR_LITERAL_FLOATINGPOINT_HEXADECIMAL;
5967                 type = check_floatingpoint_suffix();
5968                 break;
5969         default:
5970                 panic("unexpected token type in parse_number_literal");
5971         }
5972
5973         expression_t *literal = allocate_expression_zero(kind);
5974         literal->base.type      = type;
5975         literal->literal.value  = token.number.number;
5976         literal->literal.suffix = token.number.suffix;
5977         next_token();
5978
5979         /* integer type depends on the size of the number and the size
5980          * representable by the types. The backend/codegeneration has to determine
5981          * that
5982          */
5983         determine_literal_type(&literal->literal);
5984         return literal;
5985 }
5986
5987 /**
5988  * Parse a character constant.
5989  */
5990 static expression_t *parse_character_constant(void)
5991 {
5992         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_CHARACTER);
5993         literal->base.type     = c_mode & _CXX ? type_char : type_int;
5994         literal->literal.value = token.string.string;
5995
5996         size_t len = literal->literal.value.size;
5997         if (len > 1) {
5998                 if (!GNU_MODE && !(c_mode & _C99)) {
5999                         errorf(HERE, "more than 1 character in character constant");
6000                 } else {
6001                         literal->base.type = type_int;
6002                         warningf(WARN_MULTICHAR, HERE, "multi-character character constant");
6003                 }
6004         }
6005
6006         next_token();
6007         return literal;
6008 }
6009
6010 /**
6011  * Parse a wide character constant.
6012  */
6013 static expression_t *parse_wide_character_constant(void)
6014 {
6015         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_WIDE_CHARACTER);
6016         literal->base.type     = type_int;
6017         literal->literal.value = token.string.string;
6018
6019         size_t len = wstrlen(&literal->literal.value);
6020         if (len > 1) {
6021                 warningf(WARN_MULTICHAR, HERE, "multi-character character constant");
6022         }
6023
6024         next_token();
6025         return literal;
6026 }
6027
6028 static entity_t *create_implicit_function(symbol_t *symbol,
6029                 const source_position_t *source_position)
6030 {
6031         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
6032         ntype->function.return_type            = type_int;
6033         ntype->function.unspecified_parameters = true;
6034         ntype->function.linkage                = LINKAGE_C;
6035         type_t *type                           = identify_new_type(ntype);
6036
6037         entity_t *const entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, symbol);
6038         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
6039         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
6040         entity->declaration.type                   = type;
6041         entity->declaration.implicit               = true;
6042         entity->base.source_position               = *source_position;
6043
6044         if (current_scope != NULL)
6045                 record_entity(entity, false);
6046
6047         return entity;
6048 }
6049
6050 /**
6051  * Performs automatic type cast as described in §6.3.2.1.
6052  *
6053  * @param orig_type  the original type
6054  */
6055 static type_t *automatic_type_conversion(type_t *orig_type)
6056 {
6057         type_t *type = skip_typeref(orig_type);
6058         if (is_type_array(type)) {
6059                 array_type_t *array_type   = &type->array;
6060                 type_t       *element_type = array_type->element_type;
6061                 unsigned      qualifiers   = array_type->base.qualifiers;
6062
6063                 return make_pointer_type(element_type, qualifiers);
6064         }
6065
6066         if (is_type_function(type)) {
6067                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
6068         }
6069
6070         return orig_type;
6071 }
6072
6073 /**
6074  * reverts the automatic casts of array to pointer types and function
6075  * to function-pointer types as defined §6.3.2.1
6076  */
6077 type_t *revert_automatic_type_conversion(const expression_t *expression)
6078 {
6079         switch (expression->kind) {
6080         case EXPR_REFERENCE: {
6081                 entity_t *entity = expression->reference.entity;
6082                 if (is_declaration(entity)) {
6083                         return entity->declaration.type;
6084                 } else if (entity->kind == ENTITY_ENUM_VALUE) {
6085                         return entity->enum_value.enum_type;
6086                 } else {
6087                         panic("no declaration or enum in reference");
6088                 }
6089         }
6090
6091         case EXPR_SELECT: {
6092                 entity_t *entity = expression->select.compound_entry;
6093                 assert(is_declaration(entity));
6094                 type_t   *type   = entity->declaration.type;
6095                 return get_qualified_type(type, expression->base.type->base.qualifiers);
6096         }
6097
6098         case EXPR_UNARY_DEREFERENCE: {
6099                 const expression_t *const value = expression->unary.value;
6100                 type_t             *const type  = skip_typeref(value->base.type);
6101                 if (!is_type_pointer(type))
6102                         return type_error_type;
6103                 return type->pointer.points_to;
6104         }
6105
6106         case EXPR_ARRAY_ACCESS: {
6107                 const expression_t *array_ref = expression->array_access.array_ref;
6108                 type_t             *type_left = skip_typeref(array_ref->base.type);
6109                 if (!is_type_pointer(type_left))
6110                         return type_error_type;
6111                 return type_left->pointer.points_to;
6112         }
6113
6114         case EXPR_STRING_LITERAL: {
6115                 size_t size = expression->string_literal.value.size;
6116                 return make_array_type(type_char, size, TYPE_QUALIFIER_NONE);
6117         }
6118
6119         case EXPR_WIDE_STRING_LITERAL: {
6120                 size_t size = wstrlen(&expression->string_literal.value);
6121                 return make_array_type(type_wchar_t, size, TYPE_QUALIFIER_NONE);
6122         }
6123
6124         case EXPR_COMPOUND_LITERAL:
6125                 return expression->compound_literal.type;
6126
6127         default:
6128                 break;
6129         }
6130         return expression->base.type;
6131 }
6132
6133 /**
6134  * Find an entity matching a symbol in a scope.
6135  * Uses current scope if scope is NULL
6136  */
6137 static entity_t *lookup_entity(const scope_t *scope, symbol_t *symbol,
6138                                namespace_tag_t namespc)
6139 {
6140         if (scope == NULL) {
6141                 return get_entity(symbol, namespc);
6142         }
6143
6144         /* we should optimize here, if scope grows above a certain size we should
6145            construct a hashmap here... */
6146         entity_t *entity = scope->entities;
6147         for ( ; entity != NULL; entity = entity->base.next) {
6148                 if (entity->base.symbol == symbol
6149                     && (namespace_tag_t)entity->base.namespc == namespc)
6150                         break;
6151         }
6152
6153         return entity;
6154 }
6155
6156 static entity_t *parse_qualified_identifier(void)
6157 {
6158         /* namespace containing the symbol */
6159         symbol_t          *symbol;
6160         source_position_t  pos;
6161         const scope_t     *lookup_scope = NULL;
6162
6163         if (next_if(T_COLONCOLON))
6164                 lookup_scope = &unit->scope;
6165
6166         entity_t *entity;
6167         while (true) {
6168                 if (token.kind != T_IDENTIFIER) {
6169                         parse_error_expected("while parsing identifier", T_IDENTIFIER, NULL);
6170                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6171                 }
6172                 symbol = token.identifier.symbol;
6173                 pos    = *HERE;
6174                 next_token();
6175
6176                 /* lookup entity */
6177                 entity = lookup_entity(lookup_scope, symbol, NAMESPACE_NORMAL);
6178
6179                 if (!next_if(T_COLONCOLON))
6180                         break;
6181
6182                 switch (entity->kind) {
6183                 case ENTITY_NAMESPACE:
6184                         lookup_scope = &entity->namespacee.members;
6185                         break;
6186                 case ENTITY_STRUCT:
6187                 case ENTITY_UNION:
6188                 case ENTITY_CLASS:
6189                         lookup_scope = &entity->compound.members;
6190                         break;
6191                 default:
6192                         errorf(&pos, "'%Y' must be a namespace, class, struct or union (but is a %s)",
6193                                symbol, get_entity_kind_name(entity->kind));
6194
6195                         /* skip further qualifications */
6196                         while (next_if(T_IDENTIFIER) && next_if(T_COLONCOLON)) {}
6197
6198                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6199                 }
6200         }
6201
6202         if (entity == NULL) {
6203                 if (!strict_mode && token.kind == '(') {
6204                         /* an implicitly declared function */
6205                         warningf(WARN_IMPLICIT_FUNCTION_DECLARATION, &pos,
6206                                  "implicit declaration of function '%Y'", symbol);
6207                         entity = create_implicit_function(symbol, &pos);
6208                 } else {
6209                         errorf(&pos, "unknown identifier '%Y' found.", symbol);
6210                         entity = create_error_entity(symbol, ENTITY_VARIABLE);
6211                 }
6212         }
6213
6214         return entity;
6215 }
6216
6217 static expression_t *parse_reference(void)
6218 {
6219         source_position_t const pos    = token.base.source_position;
6220         entity_t         *const entity = parse_qualified_identifier();
6221
6222         type_t *orig_type;
6223         if (is_declaration(entity)) {
6224                 orig_type = entity->declaration.type;
6225         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6226                 orig_type = entity->enum_value.enum_type;
6227         } else {
6228                 panic("expected declaration or enum value in reference");
6229         }
6230
6231         /* we always do the auto-type conversions; the & and sizeof parser contains
6232          * code to revert this! */
6233         type_t *type = automatic_type_conversion(orig_type);
6234
6235         expression_kind_t kind = EXPR_REFERENCE;
6236         if (entity->kind == ENTITY_ENUM_VALUE)
6237                 kind = EXPR_REFERENCE_ENUM_VALUE;
6238
6239         expression_t *expression         = allocate_expression_zero(kind);
6240         expression->base.source_position = pos;
6241         expression->base.type            = type;
6242         expression->reference.entity     = entity;
6243
6244         /* this declaration is used */
6245         if (is_declaration(entity)) {
6246                 entity->declaration.used = true;
6247         }
6248
6249         if (entity->base.parent_scope != file_scope
6250                 && (current_function != NULL
6251                         && entity->base.parent_scope->depth < current_function->parameters.depth)
6252                 && (entity->kind == ENTITY_VARIABLE || entity->kind == ENTITY_PARAMETER)) {
6253                 if (entity->kind == ENTITY_VARIABLE) {
6254                         /* access of a variable from an outer function */
6255                         entity->variable.address_taken = true;
6256                 } else if (entity->kind == ENTITY_PARAMETER) {
6257                         entity->parameter.address_taken = true;
6258                 }
6259                 current_function->need_closure = true;
6260         }
6261
6262         check_deprecated(&pos, entity);
6263
6264         return expression;
6265 }
6266
6267 static bool semantic_cast(expression_t *cast)
6268 {
6269         expression_t            *expression      = cast->unary.value;
6270         type_t                  *orig_dest_type  = cast->base.type;
6271         type_t                  *orig_type_right = expression->base.type;
6272         type_t            const *dst_type        = skip_typeref(orig_dest_type);
6273         type_t            const *src_type        = skip_typeref(orig_type_right);
6274         source_position_t const *pos             = &cast->base.source_position;
6275
6276         /* §6.5.4 A (void) cast is explicitly permitted, more for documentation than for utility. */
6277         if (dst_type == type_void)
6278                 return true;
6279
6280         /* only integer and pointer can be casted to pointer */
6281         if (is_type_pointer(dst_type)  &&
6282             !is_type_pointer(src_type) &&
6283             !is_type_integer(src_type) &&
6284             is_type_valid(src_type)) {
6285                 errorf(pos, "cannot convert type '%T' to a pointer type", orig_type_right);
6286                 return false;
6287         }
6288
6289         if (!is_type_scalar(dst_type) && is_type_valid(dst_type)) {
6290                 errorf(pos, "conversion to non-scalar type '%T' requested", orig_dest_type);
6291                 return false;
6292         }
6293
6294         if (!is_type_scalar(src_type) && is_type_valid(src_type)) {
6295                 errorf(pos, "conversion from non-scalar type '%T' requested", orig_type_right);
6296                 return false;
6297         }
6298
6299         if (is_type_pointer(src_type) && is_type_pointer(dst_type)) {
6300                 type_t *src = skip_typeref(src_type->pointer.points_to);
6301                 type_t *dst = skip_typeref(dst_type->pointer.points_to);
6302                 unsigned missing_qualifiers =
6303                         src->base.qualifiers & ~dst->base.qualifiers;
6304                 if (missing_qualifiers != 0) {
6305                         warningf(WARN_CAST_QUAL, pos, "cast discards qualifiers '%Q' in pointer target type of '%T'", missing_qualifiers, orig_type_right);
6306                 }
6307         }
6308         return true;
6309 }
6310
6311 static expression_t *parse_compound_literal(source_position_t const *const pos, type_t *type)
6312 {
6313         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
6314         expression->base.source_position = *pos;
6315
6316         parse_initializer_env_t env;
6317         env.type             = type;
6318         env.entity           = NULL;
6319         env.must_be_constant = false;
6320         initializer_t *initializer = parse_initializer(&env);
6321         type = env.type;
6322
6323         expression->compound_literal.initializer = initializer;
6324         expression->compound_literal.type        = type;
6325         expression->base.type                    = automatic_type_conversion(type);
6326
6327         return expression;
6328 }
6329
6330 /**
6331  * Parse a cast expression.
6332  */
6333 static expression_t *parse_cast(void)
6334 {
6335         source_position_t const pos = *HERE;
6336
6337         eat('(');
6338         add_anchor_token(')');
6339
6340         type_t *type = parse_typename();
6341
6342         rem_anchor_token(')');
6343         expect(')', end_error);
6344
6345         if (token.kind == '{') {
6346                 return parse_compound_literal(&pos, type);
6347         }
6348
6349         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
6350         cast->base.source_position = pos;
6351
6352         expression_t *value = parse_subexpression(PREC_CAST);
6353         cast->base.type   = type;
6354         cast->unary.value = value;
6355
6356         if (! semantic_cast(cast)) {
6357                 /* TODO: record the error in the AST. else it is impossible to detect it */
6358         }
6359
6360         return cast;
6361 end_error:
6362         return create_error_expression();
6363 }
6364
6365 /**
6366  * Parse a statement expression.
6367  */
6368 static expression_t *parse_statement_expression(void)
6369 {
6370         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
6371
6372         eat('(');
6373         add_anchor_token(')');
6374
6375         statement_t *statement          = parse_compound_statement(true);
6376         statement->compound.stmt_expr   = true;
6377         expression->statement.statement = statement;
6378
6379         /* find last statement and use its type */
6380         type_t *type = type_void;
6381         const statement_t *stmt = statement->compound.statements;
6382         if (stmt != NULL) {
6383                 while (stmt->base.next != NULL)
6384                         stmt = stmt->base.next;
6385
6386                 if (stmt->kind == STATEMENT_EXPRESSION) {
6387                         type = stmt->expression.expression->base.type;
6388                 }
6389         } else {
6390                 source_position_t const *const pos = &expression->base.source_position;
6391                 warningf(WARN_OTHER, pos, "empty statement expression ({})");
6392         }
6393         expression->base.type = type;
6394
6395         rem_anchor_token(')');
6396         expect(')', end_error);
6397
6398 end_error:
6399         return expression;
6400 }
6401
6402 /**
6403  * Parse a parenthesized expression.
6404  */
6405 static expression_t *parse_parenthesized_expression(void)
6406 {
6407         token_t const* const la1 = look_ahead(1);
6408         switch (la1->kind) {
6409         case '{':
6410                 /* gcc extension: a statement expression */
6411                 return parse_statement_expression();
6412
6413         case T_IDENTIFIER:
6414                 if (is_typedef_symbol(la1->identifier.symbol)) {
6415         DECLARATION_START
6416                         return parse_cast();
6417                 }
6418         }
6419
6420         eat('(');
6421         add_anchor_token(')');
6422         expression_t *result = parse_expression();
6423         result->base.parenthesized = true;
6424         rem_anchor_token(')');
6425         expect(')', end_error);
6426
6427 end_error:
6428         return result;
6429 }
6430
6431 static expression_t *parse_function_keyword(void)
6432 {
6433         /* TODO */
6434
6435         if (current_function == NULL) {
6436                 errorf(HERE, "'__func__' used outside of a function");
6437         }
6438
6439         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6440         expression->base.type     = type_char_ptr;
6441         expression->funcname.kind = FUNCNAME_FUNCTION;
6442
6443         next_token();
6444
6445         return expression;
6446 }
6447
6448 static expression_t *parse_pretty_function_keyword(void)
6449 {
6450         if (current_function == NULL) {
6451                 errorf(HERE, "'__PRETTY_FUNCTION__' used outside of a function");
6452         }
6453
6454         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6455         expression->base.type     = type_char_ptr;
6456         expression->funcname.kind = FUNCNAME_PRETTY_FUNCTION;
6457
6458         eat(T___PRETTY_FUNCTION__);
6459
6460         return expression;
6461 }
6462
6463 static expression_t *parse_funcsig_keyword(void)
6464 {
6465         if (current_function == NULL) {
6466                 errorf(HERE, "'__FUNCSIG__' used outside of a function");
6467         }
6468
6469         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6470         expression->base.type     = type_char_ptr;
6471         expression->funcname.kind = FUNCNAME_FUNCSIG;
6472
6473         eat(T___FUNCSIG__);
6474
6475         return expression;
6476 }
6477
6478 static expression_t *parse_funcdname_keyword(void)
6479 {
6480         if (current_function == NULL) {
6481                 errorf(HERE, "'__FUNCDNAME__' used outside of a function");
6482         }
6483
6484         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6485         expression->base.type     = type_char_ptr;
6486         expression->funcname.kind = FUNCNAME_FUNCDNAME;
6487
6488         eat(T___FUNCDNAME__);
6489
6490         return expression;
6491 }
6492
6493 static designator_t *parse_designator(void)
6494 {
6495         designator_t *result    = allocate_ast_zero(sizeof(result[0]));
6496         result->source_position = *HERE;
6497
6498         if (token.kind != T_IDENTIFIER) {
6499                 parse_error_expected("while parsing member designator",
6500                                      T_IDENTIFIER, NULL);
6501                 return NULL;
6502         }
6503         result->symbol = token.identifier.symbol;
6504         next_token();
6505
6506         designator_t *last_designator = result;
6507         while (true) {
6508                 if (next_if('.')) {
6509                         if (token.kind != T_IDENTIFIER) {
6510                                 parse_error_expected("while parsing member designator",
6511                                                      T_IDENTIFIER, NULL);
6512                                 return NULL;
6513                         }
6514                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
6515                         designator->source_position = *HERE;
6516                         designator->symbol          = token.identifier.symbol;
6517                         next_token();
6518
6519                         last_designator->next = designator;
6520                         last_designator       = designator;
6521                         continue;
6522                 }
6523                 if (next_if('[')) {
6524                         add_anchor_token(']');
6525                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
6526                         designator->source_position = *HERE;
6527                         designator->array_index     = parse_expression();
6528                         rem_anchor_token(']');
6529                         expect(']', end_error);
6530                         if (designator->array_index == NULL) {
6531                                 return NULL;
6532                         }
6533
6534                         last_designator->next = designator;
6535                         last_designator       = designator;
6536                         continue;
6537                 }
6538                 break;
6539         }
6540
6541         return result;
6542 end_error:
6543         return NULL;
6544 }
6545
6546 /**
6547  * Parse the __builtin_offsetof() expression.
6548  */
6549 static expression_t *parse_offsetof(void)
6550 {
6551         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
6552         expression->base.type    = type_size_t;
6553
6554         eat(T___builtin_offsetof);
6555
6556         expect('(', end_error);
6557         add_anchor_token(',');
6558         type_t *type = parse_typename();
6559         rem_anchor_token(',');
6560         expect(',', end_error);
6561         add_anchor_token(')');
6562         designator_t *designator = parse_designator();
6563         rem_anchor_token(')');
6564         expect(')', end_error);
6565
6566         expression->offsetofe.type       = type;
6567         expression->offsetofe.designator = designator;
6568
6569         type_path_t path;
6570         memset(&path, 0, sizeof(path));
6571         path.top_type = type;
6572         path.path     = NEW_ARR_F(type_path_entry_t, 0);
6573
6574         descend_into_subtype(&path);
6575
6576         if (!walk_designator(&path, designator, true)) {
6577                 return create_error_expression();
6578         }
6579
6580         DEL_ARR_F(path.path);
6581
6582         return expression;
6583 end_error:
6584         return create_error_expression();
6585 }
6586
6587 /**
6588  * Parses a _builtin_va_start() expression.
6589  */
6590 static expression_t *parse_va_start(void)
6591 {
6592         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
6593
6594         eat(T___builtin_va_start);
6595
6596         expect('(', end_error);
6597         add_anchor_token(',');
6598         expression->va_starte.ap = parse_assignment_expression();
6599         rem_anchor_token(',');
6600         expect(',', end_error);
6601         expression_t *const expr = parse_assignment_expression();
6602         if (expr->kind == EXPR_REFERENCE) {
6603                 entity_t *const entity = expr->reference.entity;
6604                 if (!current_function->base.type->function.variadic) {
6605                         errorf(&expr->base.source_position,
6606                                         "'va_start' used in non-variadic function");
6607                 } else if (entity->base.parent_scope != &current_function->parameters ||
6608                                 entity->base.next != NULL ||
6609                                 entity->kind != ENTITY_PARAMETER) {
6610                         errorf(&expr->base.source_position,
6611                                "second argument of 'va_start' must be last parameter of the current function");
6612                 } else {
6613                         expression->va_starte.parameter = &entity->variable;
6614                 }
6615                 expect(')', end_error);
6616                 return expression;
6617         }
6618         expect(')', end_error);
6619 end_error:
6620         return create_error_expression();
6621 }
6622
6623 /**
6624  * Parses a __builtin_va_arg() expression.
6625  */
6626 static expression_t *parse_va_arg(void)
6627 {
6628         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
6629
6630         eat(T___builtin_va_arg);
6631
6632         expect('(', end_error);
6633         call_argument_t ap;
6634         ap.expression = parse_assignment_expression();
6635         expression->va_arge.ap = ap.expression;
6636         check_call_argument(type_valist, &ap, 1);
6637
6638         expect(',', end_error);
6639         expression->base.type = parse_typename();
6640         expect(')', end_error);
6641
6642         return expression;
6643 end_error:
6644         return create_error_expression();
6645 }
6646
6647 /**
6648  * Parses a __builtin_va_copy() expression.
6649  */
6650 static expression_t *parse_va_copy(void)
6651 {
6652         expression_t *expression = allocate_expression_zero(EXPR_VA_COPY);
6653
6654         eat(T___builtin_va_copy);
6655
6656         expect('(', end_error);
6657         expression_t *dst = parse_assignment_expression();
6658         assign_error_t error = semantic_assign(type_valist, dst);
6659         report_assign_error(error, type_valist, dst, "call argument 1",
6660                             &dst->base.source_position);
6661         expression->va_copye.dst = dst;
6662
6663         expect(',', end_error);
6664
6665         call_argument_t src;
6666         src.expression = parse_assignment_expression();
6667         check_call_argument(type_valist, &src, 2);
6668         expression->va_copye.src = src.expression;
6669         expect(')', end_error);
6670
6671         return expression;
6672 end_error:
6673         return create_error_expression();
6674 }
6675
6676 /**
6677  * Parses a __builtin_constant_p() expression.
6678  */
6679 static expression_t *parse_builtin_constant(void)
6680 {
6681         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
6682
6683         eat(T___builtin_constant_p);
6684
6685         expect('(', end_error);
6686         add_anchor_token(')');
6687         expression->builtin_constant.value = parse_assignment_expression();
6688         rem_anchor_token(')');
6689         expect(')', end_error);
6690         expression->base.type = type_int;
6691
6692         return expression;
6693 end_error:
6694         return create_error_expression();
6695 }
6696
6697 /**
6698  * Parses a __builtin_types_compatible_p() expression.
6699  */
6700 static expression_t *parse_builtin_types_compatible(void)
6701 {
6702         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_TYPES_COMPATIBLE_P);
6703
6704         eat(T___builtin_types_compatible_p);
6705
6706         expect('(', end_error);
6707         add_anchor_token(')');
6708         add_anchor_token(',');
6709         expression->builtin_types_compatible.left = parse_typename();
6710         rem_anchor_token(',');
6711         expect(',', end_error);
6712         expression->builtin_types_compatible.right = parse_typename();
6713         rem_anchor_token(')');
6714         expect(')', end_error);
6715         expression->base.type = type_int;
6716
6717         return expression;
6718 end_error:
6719         return create_error_expression();
6720 }
6721
6722 /**
6723  * Parses a __builtin_is_*() compare expression.
6724  */
6725 static expression_t *parse_compare_builtin(void)
6726 {
6727         expression_t *expression;
6728
6729         switch (token.kind) {
6730         case T___builtin_isgreater:
6731                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATER);
6732                 break;
6733         case T___builtin_isgreaterequal:
6734                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATEREQUAL);
6735                 break;
6736         case T___builtin_isless:
6737                 expression = allocate_expression_zero(EXPR_BINARY_ISLESS);
6738                 break;
6739         case T___builtin_islessequal:
6740                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSEQUAL);
6741                 break;
6742         case T___builtin_islessgreater:
6743                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSGREATER);
6744                 break;
6745         case T___builtin_isunordered:
6746                 expression = allocate_expression_zero(EXPR_BINARY_ISUNORDERED);
6747                 break;
6748         default:
6749                 internal_errorf(HERE, "invalid compare builtin found");
6750         }
6751         expression->base.source_position = *HERE;
6752         next_token();
6753
6754         expect('(', end_error);
6755         expression->binary.left = parse_assignment_expression();
6756         expect(',', end_error);
6757         expression->binary.right = parse_assignment_expression();
6758         expect(')', end_error);
6759
6760         type_t *const orig_type_left  = expression->binary.left->base.type;
6761         type_t *const orig_type_right = expression->binary.right->base.type;
6762
6763         type_t *const type_left  = skip_typeref(orig_type_left);
6764         type_t *const type_right = skip_typeref(orig_type_right);
6765         if (!is_type_float(type_left) && !is_type_float(type_right)) {
6766                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
6767                         type_error_incompatible("invalid operands in comparison",
6768                                 &expression->base.source_position, orig_type_left, orig_type_right);
6769                 }
6770         } else {
6771                 semantic_comparison(&expression->binary);
6772         }
6773
6774         return expression;
6775 end_error:
6776         return create_error_expression();
6777 }
6778
6779 /**
6780  * Parses a MS assume() expression.
6781  */
6782 static expression_t *parse_assume(void)
6783 {
6784         expression_t *expression = allocate_expression_zero(EXPR_UNARY_ASSUME);
6785
6786         eat(T__assume);
6787
6788         expect('(', end_error);
6789         add_anchor_token(')');
6790         expression->unary.value = parse_assignment_expression();
6791         rem_anchor_token(')');
6792         expect(')', end_error);
6793
6794         expression->base.type = type_void;
6795         return expression;
6796 end_error:
6797         return create_error_expression();
6798 }
6799
6800 /**
6801  * Return the label for the current symbol or create a new one.
6802  */
6803 static label_t *get_label(void)
6804 {
6805         assert(token.kind == T_IDENTIFIER);
6806         assert(current_function != NULL);
6807
6808         entity_t *label = get_entity(token.identifier.symbol, NAMESPACE_LABEL);
6809         /* If we find a local label, we already created the declaration. */
6810         if (label != NULL && label->kind == ENTITY_LOCAL_LABEL) {
6811                 if (label->base.parent_scope != current_scope) {
6812                         assert(label->base.parent_scope->depth < current_scope->depth);
6813                         current_function->goto_to_outer = true;
6814                 }
6815         } else if (label == NULL || label->base.parent_scope != &current_function->parameters) {
6816                 /* There is no matching label in the same function, so create a new one. */
6817                 label = allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, token.identifier.symbol);
6818                 label_push(label);
6819         }
6820
6821         eat(T_IDENTIFIER);
6822         return &label->label;
6823 }
6824
6825 /**
6826  * Parses a GNU && label address expression.
6827  */
6828 static expression_t *parse_label_address(void)
6829 {
6830         source_position_t source_position = token.base.source_position;
6831         eat(T_ANDAND);
6832         if (token.kind != T_IDENTIFIER) {
6833                 parse_error_expected("while parsing label address", T_IDENTIFIER, NULL);
6834                 return create_error_expression();
6835         }
6836
6837         label_t *const label = get_label();
6838         label->used          = true;
6839         label->address_taken = true;
6840
6841         expression_t *expression = allocate_expression_zero(EXPR_LABEL_ADDRESS);
6842         expression->base.source_position = source_position;
6843
6844         /* label address is treated as a void pointer */
6845         expression->base.type           = type_void_ptr;
6846         expression->label_address.label = label;
6847         return expression;
6848 }
6849
6850 /**
6851  * Parse a microsoft __noop expression.
6852  */
6853 static expression_t *parse_noop_expression(void)
6854 {
6855         /* the result is a (int)0 */
6856         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_MS_NOOP);
6857         literal->base.type           = type_int;
6858         literal->literal.value.begin = "__noop";
6859         literal->literal.value.size  = 6;
6860
6861         eat(T___noop);
6862
6863         if (token.kind == '(') {
6864                 /* parse arguments */
6865                 eat('(');
6866                 add_anchor_token(')');
6867                 add_anchor_token(',');
6868
6869                 if (token.kind != ')') do {
6870                         (void)parse_assignment_expression();
6871                 } while (next_if(','));
6872         }
6873         rem_anchor_token(',');
6874         rem_anchor_token(')');
6875         expect(')', end_error);
6876
6877 end_error:
6878         return literal;
6879 }
6880
6881 /**
6882  * Parses a primary expression.
6883  */
6884 static expression_t *parse_primary_expression(void)
6885 {
6886         switch (token.kind) {
6887         case T_false:                        return parse_boolean_literal(false);
6888         case T_true:                         return parse_boolean_literal(true);
6889         case T_INTEGER:
6890         case T_INTEGER_OCTAL:
6891         case T_INTEGER_HEXADECIMAL:
6892         case T_FLOATINGPOINT:
6893         case T_FLOATINGPOINT_HEXADECIMAL:    return parse_number_literal();
6894         case T_CHARACTER_CONSTANT:           return parse_character_constant();
6895         case T_WIDE_CHARACTER_CONSTANT:      return parse_wide_character_constant();
6896         case T_STRING_LITERAL:
6897         case T_WIDE_STRING_LITERAL:          return parse_string_literal();
6898         case T___FUNCTION__:
6899         case T___func__:                     return parse_function_keyword();
6900         case T___PRETTY_FUNCTION__:          return parse_pretty_function_keyword();
6901         case T___FUNCSIG__:                  return parse_funcsig_keyword();
6902         case T___FUNCDNAME__:                return parse_funcdname_keyword();
6903         case T___builtin_offsetof:           return parse_offsetof();
6904         case T___builtin_va_start:           return parse_va_start();
6905         case T___builtin_va_arg:             return parse_va_arg();
6906         case T___builtin_va_copy:            return parse_va_copy();
6907         case T___builtin_isgreater:
6908         case T___builtin_isgreaterequal:
6909         case T___builtin_isless:
6910         case T___builtin_islessequal:
6911         case T___builtin_islessgreater:
6912         case T___builtin_isunordered:        return parse_compare_builtin();
6913         case T___builtin_constant_p:         return parse_builtin_constant();
6914         case T___builtin_types_compatible_p: return parse_builtin_types_compatible();
6915         case T__assume:                      return parse_assume();
6916         case T_ANDAND:
6917                 if (GNU_MODE)
6918                         return parse_label_address();
6919                 break;
6920
6921         case '(':                            return parse_parenthesized_expression();
6922         case T___noop:                       return parse_noop_expression();
6923
6924         /* Gracefully handle type names while parsing expressions. */
6925         case T_COLONCOLON:
6926                 return parse_reference();
6927         case T_IDENTIFIER:
6928                 if (!is_typedef_symbol(token.identifier.symbol)) {
6929                         return parse_reference();
6930                 }
6931                 /* FALLTHROUGH */
6932         DECLARATION_START {
6933                 source_position_t const  pos = *HERE;
6934                 declaration_specifiers_t specifiers;
6935                 parse_declaration_specifiers(&specifiers);
6936                 type_t const *const type = parse_abstract_declarator(specifiers.type);
6937                 errorf(&pos, "encountered type '%T' while parsing expression", type);
6938                 return create_error_expression();
6939         }
6940         }
6941
6942         errorf(HERE, "unexpected token %K, expected an expression", &token);
6943         eat_until_anchor();
6944         return create_error_expression();
6945 }
6946
6947 static expression_t *parse_array_expression(expression_t *left)
6948 {
6949         expression_t              *const expr = allocate_expression_zero(EXPR_ARRAY_ACCESS);
6950         array_access_expression_t *const arr  = &expr->array_access;
6951
6952         eat('[');
6953         add_anchor_token(']');
6954
6955         expression_t *const inside = parse_expression();
6956
6957         type_t *const orig_type_left   = left->base.type;
6958         type_t *const orig_type_inside = inside->base.type;
6959
6960         type_t *const type_left   = skip_typeref(orig_type_left);
6961         type_t *const type_inside = skip_typeref(orig_type_inside);
6962
6963         expression_t *ref;
6964         expression_t *idx;
6965         type_t       *idx_type;
6966         type_t       *res_type;
6967         if (is_type_pointer(type_left)) {
6968                 ref      = left;
6969                 idx      = inside;
6970                 idx_type = type_inside;
6971                 res_type = type_left->pointer.points_to;
6972                 goto check_idx;
6973         } else if (is_type_pointer(type_inside)) {
6974                 arr->flipped = true;
6975                 ref      = inside;
6976                 idx      = left;
6977                 idx_type = type_left;
6978                 res_type = type_inside->pointer.points_to;
6979 check_idx:
6980                 res_type = automatic_type_conversion(res_type);
6981                 if (!is_type_integer(idx_type)) {
6982                         errorf(&idx->base.source_position, "array subscript must have integer type");
6983                 } else if (is_type_atomic(idx_type, ATOMIC_TYPE_CHAR)) {
6984                         source_position_t const *const pos = &idx->base.source_position;
6985                         warningf(WARN_CHAR_SUBSCRIPTS, pos, "array subscript has char type");
6986                 }
6987         } else {
6988                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
6989                         errorf(&expr->base.source_position, "invalid types '%T[%T]' for array access", orig_type_left, orig_type_inside);
6990                 }
6991                 res_type = type_error_type;
6992                 ref      = left;
6993                 idx      = inside;
6994         }
6995
6996         arr->array_ref = ref;
6997         arr->index     = idx;
6998         arr->base.type = res_type;
6999
7000         rem_anchor_token(']');
7001         expect(']', end_error);
7002 end_error:
7003         return expr;
7004 }
7005
7006 static bool is_bitfield(const expression_t *expression)
7007 {
7008         return expression->kind == EXPR_SELECT
7009                 && expression->select.compound_entry->compound_member.bitfield;
7010 }
7011
7012 static expression_t *parse_typeprop(expression_kind_t const kind)
7013 {
7014         expression_t  *tp_expression = allocate_expression_zero(kind);
7015         tp_expression->base.type     = type_size_t;
7016
7017         eat(kind == EXPR_SIZEOF ? T_sizeof : T___alignof__);
7018
7019         type_t       *orig_type;
7020         expression_t *expression;
7021         if (token.kind == '(' && is_declaration_specifier(look_ahead(1))) {
7022                 source_position_t const pos = *HERE;
7023                 next_token();
7024                 add_anchor_token(')');
7025                 orig_type = parse_typename();
7026                 rem_anchor_token(')');
7027                 expect(')', end_error);
7028
7029                 if (token.kind == '{') {
7030                         /* It was not sizeof(type) after all.  It is sizeof of an expression
7031                          * starting with a compound literal */
7032                         expression = parse_compound_literal(&pos, orig_type);
7033                         goto typeprop_expression;
7034                 }
7035         } else {
7036                 expression = parse_subexpression(PREC_UNARY);
7037
7038 typeprop_expression:
7039                 if (is_bitfield(expression)) {
7040                         char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
7041                         errorf(&tp_expression->base.source_position,
7042                                    "operand of %s expression must not be a bitfield", what);
7043                 }
7044
7045                 tp_expression->typeprop.tp_expression = expression;
7046
7047                 orig_type = revert_automatic_type_conversion(expression);
7048                 expression->base.type = orig_type;
7049         }
7050
7051         tp_expression->typeprop.type   = orig_type;
7052         type_t const* const type       = skip_typeref(orig_type);
7053         char   const*       wrong_type = NULL;
7054         if (is_type_incomplete(type)) {
7055                 if (!is_type_atomic(type, ATOMIC_TYPE_VOID) || !GNU_MODE)
7056                         wrong_type = "incomplete";
7057         } else if (type->kind == TYPE_FUNCTION) {
7058                 if (GNU_MODE) {
7059                         /* function types are allowed (and return 1) */
7060                         source_position_t const *const pos  = &tp_expression->base.source_position;
7061                         char              const *const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
7062                         warningf(WARN_OTHER, pos, "%s expression with function argument returns invalid result", what);
7063                 } else {
7064                         wrong_type = "function";
7065                 }
7066         }
7067
7068         if (wrong_type != NULL) {
7069                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
7070                 errorf(&tp_expression->base.source_position,
7071                                 "operand of %s expression must not be of %s type '%T'",
7072                                 what, wrong_type, orig_type);
7073         }
7074
7075 end_error:
7076         return tp_expression;
7077 }
7078
7079 static expression_t *parse_sizeof(void)
7080 {
7081         return parse_typeprop(EXPR_SIZEOF);
7082 }
7083
7084 static expression_t *parse_alignof(void)
7085 {
7086         return parse_typeprop(EXPR_ALIGNOF);
7087 }
7088
7089 static expression_t *parse_select_expression(expression_t *addr)
7090 {
7091         assert(token.kind == '.' || token.kind == T_MINUSGREATER);
7092         bool select_left_arrow = (token.kind == T_MINUSGREATER);
7093         source_position_t const pos = *HERE;
7094         next_token();
7095
7096         if (token.kind != T_IDENTIFIER) {
7097                 parse_error_expected("while parsing select", T_IDENTIFIER, NULL);
7098                 return create_error_expression();
7099         }
7100         symbol_t *symbol = token.identifier.symbol;
7101         next_token();
7102
7103         type_t *const orig_type = addr->base.type;
7104         type_t *const type      = skip_typeref(orig_type);
7105
7106         type_t *type_left;
7107         bool    saw_error = false;
7108         if (is_type_pointer(type)) {
7109                 if (!select_left_arrow) {
7110                         errorf(&pos,
7111                                "request for member '%Y' in something not a struct or union, but '%T'",
7112                                symbol, orig_type);
7113                         saw_error = true;
7114                 }
7115                 type_left = skip_typeref(type->pointer.points_to);
7116         } else {
7117                 if (select_left_arrow && is_type_valid(type)) {
7118                         errorf(&pos, "left hand side of '->' is not a pointer, but '%T'", orig_type);
7119                         saw_error = true;
7120                 }
7121                 type_left = type;
7122         }
7123
7124         if (type_left->kind != TYPE_COMPOUND_STRUCT &&
7125             type_left->kind != TYPE_COMPOUND_UNION) {
7126
7127                 if (is_type_valid(type_left) && !saw_error) {
7128                         errorf(&pos,
7129                                "request for member '%Y' in something not a struct or union, but '%T'",
7130                                symbol, type_left);
7131                 }
7132                 return create_error_expression();
7133         }
7134
7135         compound_t *compound = type_left->compound.compound;
7136         if (!compound->complete) {
7137                 errorf(&pos, "request for member '%Y' in incomplete type '%T'",
7138                        symbol, type_left);
7139                 return create_error_expression();
7140         }
7141
7142         type_qualifiers_t  qualifiers = type_left->base.qualifiers;
7143         expression_t      *result     =
7144                 find_create_select(&pos, addr, qualifiers, compound, symbol);
7145
7146         if (result == NULL) {
7147                 errorf(&pos, "'%T' has no member named '%Y'", orig_type, symbol);
7148                 return create_error_expression();
7149         }
7150
7151         return result;
7152 }
7153
7154 static void check_call_argument(type_t          *expected_type,
7155                                 call_argument_t *argument, unsigned pos)
7156 {
7157         type_t         *expected_type_skip = skip_typeref(expected_type);
7158         assign_error_t  error              = ASSIGN_ERROR_INCOMPATIBLE;
7159         expression_t   *arg_expr           = argument->expression;
7160         type_t         *arg_type           = skip_typeref(arg_expr->base.type);
7161
7162         /* handle transparent union gnu extension */
7163         if (is_type_union(expected_type_skip)
7164                         && (get_type_modifiers(expected_type) & DM_TRANSPARENT_UNION)) {
7165                 compound_t *union_decl  = expected_type_skip->compound.compound;
7166                 type_t     *best_type   = NULL;
7167                 entity_t   *entry       = union_decl->members.entities;
7168                 for ( ; entry != NULL; entry = entry->base.next) {
7169                         assert(is_declaration(entry));
7170                         type_t *decl_type = entry->declaration.type;
7171                         error = semantic_assign(decl_type, arg_expr);
7172                         if (error == ASSIGN_ERROR_INCOMPATIBLE
7173                                 || error == ASSIGN_ERROR_POINTER_QUALIFIER_MISSING)
7174                                 continue;
7175
7176                         if (error == ASSIGN_SUCCESS) {
7177                                 best_type = decl_type;
7178                         } else if (best_type == NULL) {
7179                                 best_type = decl_type;
7180                         }
7181                 }
7182
7183                 if (best_type != NULL) {
7184                         expected_type = best_type;
7185                 }
7186         }
7187
7188         error                = semantic_assign(expected_type, arg_expr);
7189         argument->expression = create_implicit_cast(arg_expr, expected_type);
7190
7191         if (error != ASSIGN_SUCCESS) {
7192                 /* report exact scope in error messages (like "in argument 3") */
7193                 char buf[64];
7194                 snprintf(buf, sizeof(buf), "call argument %u", pos);
7195                 report_assign_error(error, expected_type, arg_expr, buf,
7196                                     &arg_expr->base.source_position);
7197         } else {
7198                 type_t *const promoted_type = get_default_promoted_type(arg_type);
7199                 if (!types_compatible(expected_type_skip, promoted_type) &&
7200                     !types_compatible(expected_type_skip, type_void_ptr) &&
7201                     !types_compatible(type_void_ptr,      promoted_type)) {
7202                         /* Deliberately show the skipped types in this warning */
7203                         source_position_t const *const apos = &arg_expr->base.source_position;
7204                         warningf(WARN_TRADITIONAL, apos, "passing call argument %u as '%T' rather than '%T' due to prototype", pos, expected_type_skip, promoted_type);
7205                 }
7206         }
7207 }
7208
7209 /**
7210  * Handle the semantic restrictions of builtin calls
7211  */
7212 static void handle_builtin_argument_restrictions(call_expression_t *call)
7213 {
7214         entity_t *entity = call->function->reference.entity;
7215         switch (entity->function.btk) {
7216         case BUILTIN_FIRM:
7217                 switch (entity->function.b.firm_builtin_kind) {
7218                 case ir_bk_return_address:
7219                 case ir_bk_frame_address: {
7220                         /* argument must be constant */
7221                         call_argument_t *argument = call->arguments;
7222
7223                         if (is_constant_expression(argument->expression) == EXPR_CLASS_VARIABLE) {
7224                                 errorf(&call->base.source_position,
7225                                            "argument of '%Y' must be a constant expression",
7226                                            call->function->reference.entity->base.symbol);
7227                         }
7228                         break;
7229                 }
7230                 case ir_bk_prefetch:
7231                         /* second and third argument must be constant if existent */
7232                         if (call->arguments == NULL)
7233                                 break;
7234                         call_argument_t *rw = call->arguments->next;
7235                         call_argument_t *locality = NULL;
7236
7237                         if (rw != NULL) {
7238                                 if (is_constant_expression(rw->expression) == EXPR_CLASS_VARIABLE) {
7239                                         errorf(&call->base.source_position,
7240                                                    "second argument of '%Y' must be a constant expression",
7241                                                    call->function->reference.entity->base.symbol);
7242                                 }
7243                                 locality = rw->next;
7244                         }
7245                         if (locality != NULL) {
7246                                 if (is_constant_expression(locality->expression) == EXPR_CLASS_VARIABLE) {
7247                                         errorf(&call->base.source_position,
7248                                                    "third argument of '%Y' must be a constant expression",
7249                                                    call->function->reference.entity->base.symbol);
7250                                 }
7251                                 locality = rw->next;
7252                         }
7253                         break;
7254                 default:
7255                         break;
7256                 }
7257
7258         case BUILTIN_OBJECT_SIZE:
7259                 if (call->arguments == NULL)
7260                         break;
7261
7262                 call_argument_t *arg = call->arguments->next;
7263                 if (arg != NULL && is_constant_expression(arg->expression) == EXPR_CLASS_VARIABLE) {
7264                         errorf(&call->base.source_position,
7265                                    "second argument of '%Y' must be a constant expression",
7266                                    call->function->reference.entity->base.symbol);
7267                 }
7268                 break;
7269         default:
7270                 break;
7271         }
7272 }
7273
7274 /**
7275  * Parse a call expression, ie. expression '( ... )'.
7276  *
7277  * @param expression  the function address
7278  */
7279 static expression_t *parse_call_expression(expression_t *expression)
7280 {
7281         expression_t      *result = allocate_expression_zero(EXPR_CALL);
7282         call_expression_t *call   = &result->call;
7283         call->function            = expression;
7284
7285         type_t *const orig_type = expression->base.type;
7286         type_t *const type      = skip_typeref(orig_type);
7287
7288         function_type_t *function_type = NULL;
7289         if (is_type_pointer(type)) {
7290                 type_t *const to_type = skip_typeref(type->pointer.points_to);
7291
7292                 if (is_type_function(to_type)) {
7293                         function_type   = &to_type->function;
7294                         call->base.type = function_type->return_type;
7295                 }
7296         }
7297
7298         if (function_type == NULL && is_type_valid(type)) {
7299                 errorf(HERE,
7300                        "called object '%E' (type '%T') is not a pointer to a function",
7301                        expression, orig_type);
7302         }
7303
7304         /* parse arguments */
7305         eat('(');
7306         add_anchor_token(')');
7307         add_anchor_token(',');
7308
7309         if (token.kind != ')') {
7310                 call_argument_t **anchor = &call->arguments;
7311                 do {
7312                         call_argument_t *argument = allocate_ast_zero(sizeof(*argument));
7313                         argument->expression = parse_assignment_expression();
7314
7315                         *anchor = argument;
7316                         anchor  = &argument->next;
7317                 } while (next_if(','));
7318         }
7319         rem_anchor_token(',');
7320         rem_anchor_token(')');
7321         expect(')', end_error);
7322
7323         if (function_type == NULL)
7324                 return result;
7325
7326         /* check type and count of call arguments */
7327         function_parameter_t *parameter = function_type->parameters;
7328         call_argument_t      *argument  = call->arguments;
7329         if (!function_type->unspecified_parameters) {
7330                 for (unsigned pos = 0; parameter != NULL && argument != NULL;
7331                                 parameter = parameter->next, argument = argument->next) {
7332                         check_call_argument(parameter->type, argument, ++pos);
7333                 }
7334
7335                 if (parameter != NULL) {
7336                         errorf(&expression->base.source_position, "too few arguments to function '%E'", expression);
7337                 } else if (argument != NULL && !function_type->variadic) {
7338                         errorf(&argument->expression->base.source_position, "too many arguments to function '%E'", expression);
7339                 }
7340         }
7341
7342         /* do default promotion for other arguments */
7343         for (; argument != NULL; argument = argument->next) {
7344                 type_t *argument_type = argument->expression->base.type;
7345                 if (!is_type_object(skip_typeref(argument_type))) {
7346                         errorf(&argument->expression->base.source_position,
7347                                "call argument '%E' must not be void", argument->expression);
7348                 }
7349
7350                 argument_type = get_default_promoted_type(argument_type);
7351
7352                 argument->expression
7353                         = create_implicit_cast(argument->expression, argument_type);
7354         }
7355
7356         check_format(call);
7357
7358         if (is_type_compound(skip_typeref(function_type->return_type))) {
7359                 source_position_t const *const pos = &expression->base.source_position;
7360                 warningf(WARN_AGGREGATE_RETURN, pos, "function call has aggregate value");
7361         }
7362
7363         if (expression->kind == EXPR_REFERENCE) {
7364                 reference_expression_t *reference = &expression->reference;
7365                 if (reference->entity->kind == ENTITY_FUNCTION &&
7366                     reference->entity->function.btk != BUILTIN_NONE)
7367                         handle_builtin_argument_restrictions(call);
7368         }
7369
7370 end_error:
7371         return result;
7372 }
7373
7374 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
7375
7376 static bool same_compound_type(const type_t *type1, const type_t *type2)
7377 {
7378         return
7379                 is_type_compound(type1) &&
7380                 type1->kind == type2->kind &&
7381                 type1->compound.compound == type2->compound.compound;
7382 }
7383
7384 static expression_t const *get_reference_address(expression_t const *expr)
7385 {
7386         bool regular_take_address = true;
7387         for (;;) {
7388                 if (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
7389                         expr = expr->unary.value;
7390                 } else {
7391                         regular_take_address = false;
7392                 }
7393
7394                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
7395                         break;
7396
7397                 expr = expr->unary.value;
7398         }
7399
7400         if (expr->kind != EXPR_REFERENCE)
7401                 return NULL;
7402
7403         /* special case for functions which are automatically converted to a
7404          * pointer to function without an extra TAKE_ADDRESS operation */
7405         if (!regular_take_address &&
7406                         expr->reference.entity->kind != ENTITY_FUNCTION) {
7407                 return NULL;
7408         }
7409
7410         return expr;
7411 }
7412
7413 static void warn_reference_address_as_bool(expression_t const* expr)
7414 {
7415         expr = get_reference_address(expr);
7416         if (expr != NULL) {
7417                 source_position_t const *const pos = &expr->base.source_position;
7418                 entity_t          const *const ent = expr->reference.entity;
7419                 warningf(WARN_ADDRESS, pos, "the address of '%N' will always evaluate as 'true'", ent);
7420         }
7421 }
7422
7423 static void warn_assignment_in_condition(const expression_t *const expr)
7424 {
7425         if (expr->base.kind != EXPR_BINARY_ASSIGN)
7426                 return;
7427         if (expr->base.parenthesized)
7428                 return;
7429         source_position_t const *const pos = &expr->base.source_position;
7430         warningf(WARN_PARENTHESES, pos, "suggest parentheses around assignment used as truth value");
7431 }
7432
7433 static void semantic_condition(expression_t const *const expr,
7434                                char const *const context)
7435 {
7436         type_t *const type = skip_typeref(expr->base.type);
7437         if (is_type_scalar(type)) {
7438                 warn_reference_address_as_bool(expr);
7439                 warn_assignment_in_condition(expr);
7440         } else if (is_type_valid(type)) {
7441                 errorf(&expr->base.source_position,
7442                                 "%s must have scalar type", context);
7443         }
7444 }
7445
7446 /**
7447  * Parse a conditional expression, ie. 'expression ? ... : ...'.
7448  *
7449  * @param expression  the conditional expression
7450  */
7451 static expression_t *parse_conditional_expression(expression_t *expression)
7452 {
7453         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
7454
7455         conditional_expression_t *conditional = &result->conditional;
7456         conditional->condition                = expression;
7457
7458         eat('?');
7459         add_anchor_token(':');
7460
7461         /* §6.5.15:2  The first operand shall have scalar type. */
7462         semantic_condition(expression, "condition of conditional operator");
7463
7464         expression_t *true_expression = expression;
7465         bool          gnu_cond = false;
7466         if (GNU_MODE && token.kind == ':') {
7467                 gnu_cond = true;
7468         } else {
7469                 true_expression = parse_expression();
7470         }
7471         rem_anchor_token(':');
7472         expect(':', end_error);
7473 end_error:;
7474         expression_t *false_expression =
7475                 parse_subexpression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
7476
7477         type_t *const orig_true_type  = true_expression->base.type;
7478         type_t *const orig_false_type = false_expression->base.type;
7479         type_t *const true_type       = skip_typeref(orig_true_type);
7480         type_t *const false_type      = skip_typeref(orig_false_type);
7481
7482         /* 6.5.15.3 */
7483         source_position_t const *const pos = &conditional->base.source_position;
7484         type_t                        *result_type;
7485         if (is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
7486                         is_type_atomic(false_type, ATOMIC_TYPE_VOID)) {
7487                 /* ISO/IEC 14882:1998(E) §5.16:2 */
7488                 if (true_expression->kind == EXPR_UNARY_THROW) {
7489                         result_type = false_type;
7490                 } else if (false_expression->kind == EXPR_UNARY_THROW) {
7491                         result_type = true_type;
7492                 } else {
7493                         if (!is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
7494                             !is_type_atomic(false_type, ATOMIC_TYPE_VOID)) {
7495                                 warningf(WARN_OTHER, pos, "ISO C forbids conditional expression with only one void side");
7496                         }
7497                         result_type = type_void;
7498                 }
7499         } else if (is_type_arithmetic(true_type)
7500                    && is_type_arithmetic(false_type)) {
7501                 result_type = semantic_arithmetic(true_type, false_type);
7502         } else if (same_compound_type(true_type, false_type)) {
7503                 /* just take 1 of the 2 types */
7504                 result_type = true_type;
7505         } else if (is_type_pointer(true_type) || is_type_pointer(false_type)) {
7506                 type_t *pointer_type;
7507                 type_t *other_type;
7508                 expression_t *other_expression;
7509                 if (is_type_pointer(true_type) &&
7510                                 (!is_type_pointer(false_type) || is_null_pointer_constant(false_expression))) {
7511                         pointer_type     = true_type;
7512                         other_type       = false_type;
7513                         other_expression = false_expression;
7514                 } else {
7515                         pointer_type     = false_type;
7516                         other_type       = true_type;
7517                         other_expression = true_expression;
7518                 }
7519
7520                 if (is_null_pointer_constant(other_expression)) {
7521                         result_type = pointer_type;
7522                 } else if (is_type_pointer(other_type)) {
7523                         type_t *to1 = skip_typeref(pointer_type->pointer.points_to);
7524                         type_t *to2 = skip_typeref(other_type->pointer.points_to);
7525
7526                         type_t *to;
7527                         if (is_type_atomic(to1, ATOMIC_TYPE_VOID) ||
7528                             is_type_atomic(to2, ATOMIC_TYPE_VOID)) {
7529                                 to = type_void;
7530                         } else if (types_compatible(get_unqualified_type(to1),
7531                                                     get_unqualified_type(to2))) {
7532                                 to = to1;
7533                         } else {
7534                                 warningf(WARN_OTHER, pos, "pointer types '%T' and '%T' in conditional expression are incompatible", true_type, false_type);
7535                                 to = type_void;
7536                         }
7537
7538                         type_t *const type =
7539                                 get_qualified_type(to, to1->base.qualifiers | to2->base.qualifiers);
7540                         result_type = make_pointer_type(type, TYPE_QUALIFIER_NONE);
7541                 } else if (is_type_integer(other_type)) {
7542                         warningf(WARN_OTHER, pos, "pointer/integer type mismatch in conditional expression ('%T' and '%T')", true_type, false_type);
7543                         result_type = pointer_type;
7544                 } else {
7545                         goto types_incompatible;
7546                 }
7547         } else {
7548 types_incompatible:
7549                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
7550                         type_error_incompatible("while parsing conditional", pos, true_type, false_type);
7551                 }
7552                 result_type = type_error_type;
7553         }
7554
7555         conditional->true_expression
7556                 = gnu_cond ? NULL : create_implicit_cast(true_expression, result_type);
7557         conditional->false_expression
7558                 = create_implicit_cast(false_expression, result_type);
7559         conditional->base.type = result_type;
7560         return result;
7561 }
7562
7563 /**
7564  * Parse an extension expression.
7565  */
7566 static expression_t *parse_extension(void)
7567 {
7568         PUSH_EXTENSION();
7569         expression_t *expression = parse_subexpression(PREC_UNARY);
7570         POP_EXTENSION();
7571         return expression;
7572 }
7573
7574 /**
7575  * Parse a __builtin_classify_type() expression.
7576  */
7577 static expression_t *parse_builtin_classify_type(void)
7578 {
7579         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
7580         result->base.type    = type_int;
7581
7582         eat(T___builtin_classify_type);
7583
7584         expect('(', end_error);
7585         add_anchor_token(')');
7586         expression_t *expression = parse_expression();
7587         rem_anchor_token(')');
7588         expect(')', end_error);
7589         result->classify_type.type_expression = expression;
7590
7591         return result;
7592 end_error:
7593         return create_error_expression();
7594 }
7595
7596 /**
7597  * Parse a delete expression
7598  * ISO/IEC 14882:1998(E) §5.3.5
7599  */
7600 static expression_t *parse_delete(void)
7601 {
7602         expression_t *const result = allocate_expression_zero(EXPR_UNARY_DELETE);
7603         result->base.type          = type_void;
7604
7605         eat(T_delete);
7606
7607         if (next_if('[')) {
7608                 result->kind = EXPR_UNARY_DELETE_ARRAY;
7609                 expect(']', end_error);
7610 end_error:;
7611         }
7612
7613         expression_t *const value = parse_subexpression(PREC_CAST);
7614         result->unary.value = value;
7615
7616         type_t *const type = skip_typeref(value->base.type);
7617         if (!is_type_pointer(type)) {
7618                 if (is_type_valid(type)) {
7619                         errorf(&value->base.source_position,
7620                                         "operand of delete must have pointer type");
7621                 }
7622         } else if (is_type_atomic(skip_typeref(type->pointer.points_to), ATOMIC_TYPE_VOID)) {
7623                 source_position_t const *const pos = &value->base.source_position;
7624                 warningf(WARN_OTHER, pos, "deleting 'void*' is undefined");
7625         }
7626
7627         return result;
7628 }
7629
7630 /**
7631  * Parse a throw expression
7632  * ISO/IEC 14882:1998(E) §15:1
7633  */
7634 static expression_t *parse_throw(void)
7635 {
7636         expression_t *const result = allocate_expression_zero(EXPR_UNARY_THROW);
7637         result->base.type          = type_void;
7638
7639         eat(T_throw);
7640
7641         expression_t *value = NULL;
7642         switch (token.kind) {
7643                 EXPRESSION_START {
7644                         value = parse_assignment_expression();
7645                         /* ISO/IEC 14882:1998(E) §15.1:3 */
7646                         type_t *const orig_type = value->base.type;
7647                         type_t *const type      = skip_typeref(orig_type);
7648                         if (is_type_incomplete(type)) {
7649                                 errorf(&value->base.source_position,
7650                                                 "cannot throw object of incomplete type '%T'", orig_type);
7651                         } else if (is_type_pointer(type)) {
7652                                 type_t *const points_to = skip_typeref(type->pointer.points_to);
7653                                 if (is_type_incomplete(points_to) &&
7654                                                 !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
7655                                         errorf(&value->base.source_position,
7656                                                         "cannot throw pointer to incomplete type '%T'", orig_type);
7657                                 }
7658                         }
7659                 }
7660
7661                 default:
7662                         break;
7663         }
7664         result->unary.value = value;
7665
7666         return result;
7667 }
7668
7669 static bool check_pointer_arithmetic(const source_position_t *source_position,
7670                                      type_t *pointer_type,
7671                                      type_t *orig_pointer_type)
7672 {
7673         type_t *points_to = pointer_type->pointer.points_to;
7674         points_to = skip_typeref(points_to);
7675
7676         if (is_type_incomplete(points_to)) {
7677                 if (!GNU_MODE || !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
7678                         errorf(source_position,
7679                                "arithmetic with pointer to incomplete type '%T' not allowed",
7680                                orig_pointer_type);
7681                         return false;
7682                 } else {
7683                         warningf(WARN_POINTER_ARITH, source_position, "pointer of type '%T' used in arithmetic", orig_pointer_type);
7684                 }
7685         } else if (is_type_function(points_to)) {
7686                 if (!GNU_MODE) {
7687                         errorf(source_position,
7688                                "arithmetic with pointer to function type '%T' not allowed",
7689                                orig_pointer_type);
7690                         return false;
7691                 } else {
7692                         warningf(WARN_POINTER_ARITH, source_position, "pointer to a function '%T' used in arithmetic", orig_pointer_type);
7693                 }
7694         }
7695         return true;
7696 }
7697
7698 static bool is_lvalue(const expression_t *expression)
7699 {
7700         /* TODO: doesn't seem to be consistent with §6.3.2.1:1 */
7701         switch (expression->kind) {
7702         case EXPR_ARRAY_ACCESS:
7703         case EXPR_COMPOUND_LITERAL:
7704         case EXPR_REFERENCE:
7705         case EXPR_SELECT:
7706         case EXPR_UNARY_DEREFERENCE:
7707                 return true;
7708
7709         default: {
7710                 type_t *type = skip_typeref(expression->base.type);
7711                 return
7712                         /* ISO/IEC 14882:1998(E) §3.10:3 */
7713                         is_type_reference(type) ||
7714                         /* Claim it is an lvalue, if the type is invalid.  There was a parse
7715                          * error before, which maybe prevented properly recognizing it as
7716                          * lvalue. */
7717                         !is_type_valid(type);
7718         }
7719         }
7720 }
7721
7722 static void semantic_incdec(unary_expression_t *expression)
7723 {
7724         type_t *const orig_type = expression->value->base.type;
7725         type_t *const type      = skip_typeref(orig_type);
7726         if (is_type_pointer(type)) {
7727                 if (!check_pointer_arithmetic(&expression->base.source_position,
7728                                               type, orig_type)) {
7729                         return;
7730                 }
7731         } else if (!is_type_real(type) && is_type_valid(type)) {
7732                 /* TODO: improve error message */
7733                 errorf(&expression->base.source_position,
7734                        "operation needs an arithmetic or pointer type");
7735                 return;
7736         }
7737         if (!is_lvalue(expression->value)) {
7738                 /* TODO: improve error message */
7739                 errorf(&expression->base.source_position, "lvalue required as operand");
7740         }
7741         expression->base.type = orig_type;
7742 }
7743
7744 static void promote_unary_int_expr(unary_expression_t *const expr, type_t *const type)
7745 {
7746         type_t *const res_type = promote_integer(type);
7747         expr->base.type = res_type;
7748         expr->value     = create_implicit_cast(expr->value, res_type);
7749 }
7750
7751 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
7752 {
7753         type_t *const orig_type = expression->value->base.type;
7754         type_t *const type      = skip_typeref(orig_type);
7755         if (!is_type_arithmetic(type)) {
7756                 if (is_type_valid(type)) {
7757                         /* TODO: improve error message */
7758                         errorf(&expression->base.source_position,
7759                                 "operation needs an arithmetic type");
7760                 }
7761                 return;
7762         } else if (is_type_integer(type)) {
7763                 promote_unary_int_expr(expression, type);
7764         } else {
7765                 expression->base.type = orig_type;
7766         }
7767 }
7768
7769 static void semantic_unexpr_plus(unary_expression_t *expression)
7770 {
7771         semantic_unexpr_arithmetic(expression);
7772         source_position_t const *const pos = &expression->base.source_position;
7773         warningf(WARN_TRADITIONAL, pos, "traditional C rejects the unary plus operator");
7774 }
7775
7776 static void semantic_not(unary_expression_t *expression)
7777 {
7778         /* §6.5.3.3:1  The operand [...] of the ! operator, scalar type. */
7779         semantic_condition(expression->value, "operand of !");
7780         expression->base.type = c_mode & _CXX ? type_bool : type_int;
7781 }
7782
7783 static void semantic_unexpr_integer(unary_expression_t *expression)
7784 {
7785         type_t *const orig_type = expression->value->base.type;
7786         type_t *const type      = skip_typeref(orig_type);
7787         if (!is_type_integer(type)) {
7788                 if (is_type_valid(type)) {
7789                         errorf(&expression->base.source_position,
7790                                "operand of ~ must be of integer type");
7791                 }
7792                 return;
7793         }
7794
7795         promote_unary_int_expr(expression, type);
7796 }
7797
7798 static void semantic_dereference(unary_expression_t *expression)
7799 {
7800         type_t *const orig_type = expression->value->base.type;
7801         type_t *const type      = skip_typeref(orig_type);
7802         if (!is_type_pointer(type)) {
7803                 if (is_type_valid(type)) {
7804                         errorf(&expression->base.source_position,
7805                                "Unary '*' needs pointer or array type, but type '%T' given", orig_type);
7806                 }
7807                 return;
7808         }
7809
7810         type_t *result_type   = type->pointer.points_to;
7811         result_type           = automatic_type_conversion(result_type);
7812         expression->base.type = result_type;
7813 }
7814
7815 /**
7816  * Record that an address is taken (expression represents an lvalue).
7817  *
7818  * @param expression       the expression
7819  * @param may_be_register  if true, the expression might be an register
7820  */
7821 static void set_address_taken(expression_t *expression, bool may_be_register)
7822 {
7823         if (expression->kind != EXPR_REFERENCE)
7824                 return;
7825
7826         entity_t *const entity = expression->reference.entity;
7827
7828         if (entity->kind != ENTITY_VARIABLE && entity->kind != ENTITY_PARAMETER)
7829                 return;
7830
7831         if (entity->declaration.storage_class == STORAGE_CLASS_REGISTER
7832                         && !may_be_register) {
7833                 source_position_t const *const pos = &expression->base.source_position;
7834                 errorf(pos, "address of register '%N' requested", entity);
7835         }
7836
7837         if (entity->kind == ENTITY_VARIABLE) {
7838                 entity->variable.address_taken = true;
7839         } else {
7840                 assert(entity->kind == ENTITY_PARAMETER);
7841                 entity->parameter.address_taken = true;
7842         }
7843 }
7844
7845 /**
7846  * Check the semantic of the address taken expression.
7847  */
7848 static void semantic_take_addr(unary_expression_t *expression)
7849 {
7850         expression_t *value = expression->value;
7851         value->base.type    = revert_automatic_type_conversion(value);
7852
7853         type_t *orig_type = value->base.type;
7854         type_t *type      = skip_typeref(orig_type);
7855         if (!is_type_valid(type))
7856                 return;
7857
7858         /* §6.5.3.2 */
7859         if (!is_lvalue(value)) {
7860                 errorf(&expression->base.source_position, "'&' requires an lvalue");
7861         }
7862         if (is_bitfield(value)) {
7863                 errorf(&expression->base.source_position,
7864                        "'&' not allowed on bitfield");
7865         }
7866
7867         set_address_taken(value, false);
7868
7869         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
7870 }
7871
7872 #define CREATE_UNARY_EXPRESSION_PARSER(token_kind, unexpression_type, sfunc) \
7873 static expression_t *parse_##unexpression_type(void)                         \
7874 {                                                                            \
7875         expression_t *unary_expression                                           \
7876                 = allocate_expression_zero(unexpression_type);                       \
7877         eat(token_kind);                                                         \
7878         unary_expression->unary.value = parse_subexpression(PREC_UNARY);         \
7879                                                                                  \
7880         sfunc(&unary_expression->unary);                                         \
7881                                                                                  \
7882         return unary_expression;                                                 \
7883 }
7884
7885 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
7886                                semantic_unexpr_arithmetic)
7887 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
7888                                semantic_unexpr_plus)
7889 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
7890                                semantic_not)
7891 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
7892                                semantic_dereference)
7893 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
7894                                semantic_take_addr)
7895 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
7896                                semantic_unexpr_integer)
7897 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
7898                                semantic_incdec)
7899 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
7900                                semantic_incdec)
7901
7902 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_kind, unexpression_type, \
7903                                                sfunc)                         \
7904 static expression_t *parse_##unexpression_type(expression_t *left)            \
7905 {                                                                             \
7906         expression_t *unary_expression                                            \
7907                 = allocate_expression_zero(unexpression_type);                        \
7908         eat(token_kind);                                                          \
7909         unary_expression->unary.value = left;                                     \
7910                                                                                   \
7911         sfunc(&unary_expression->unary);                                          \
7912                                                                               \
7913         return unary_expression;                                                  \
7914 }
7915
7916 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
7917                                        EXPR_UNARY_POSTFIX_INCREMENT,
7918                                        semantic_incdec)
7919 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
7920                                        EXPR_UNARY_POSTFIX_DECREMENT,
7921                                        semantic_incdec)
7922
7923 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
7924 {
7925         /* TODO: handle complex + imaginary types */
7926
7927         type_left  = get_unqualified_type(type_left);
7928         type_right = get_unqualified_type(type_right);
7929
7930         /* §6.3.1.8 Usual arithmetic conversions */
7931         if (type_left == type_long_double || type_right == type_long_double) {
7932                 return type_long_double;
7933         } else if (type_left == type_double || type_right == type_double) {
7934                 return type_double;
7935         } else if (type_left == type_float || type_right == type_float) {
7936                 return type_float;
7937         }
7938
7939         type_left  = promote_integer(type_left);
7940         type_right = promote_integer(type_right);
7941
7942         if (type_left == type_right)
7943                 return type_left;
7944
7945         bool     const signed_left  = is_type_signed(type_left);
7946         bool     const signed_right = is_type_signed(type_right);
7947         unsigned const rank_left    = get_akind_rank(get_akind(type_left));
7948         unsigned const rank_right   = get_akind_rank(get_akind(type_right));
7949
7950         if (signed_left == signed_right)
7951                 return rank_left >= rank_right ? type_left : type_right;
7952
7953         unsigned           s_rank;
7954         unsigned           u_rank;
7955         atomic_type_kind_t s_akind;
7956         atomic_type_kind_t u_akind;
7957         type_t *s_type;
7958         type_t *u_type;
7959         if (signed_left) {
7960                 s_type = type_left;
7961                 u_type = type_right;
7962         } else {
7963                 s_type = type_right;
7964                 u_type = type_left;
7965         }
7966         s_akind = get_akind(s_type);
7967         u_akind = get_akind(u_type);
7968         s_rank  = get_akind_rank(s_akind);
7969         u_rank  = get_akind_rank(u_akind);
7970
7971         if (u_rank >= s_rank)
7972                 return u_type;
7973
7974         if (get_atomic_type_size(s_akind) > get_atomic_type_size(u_akind))
7975                 return s_type;
7976
7977         switch (s_akind) {
7978         case ATOMIC_TYPE_INT:      return type_unsigned_int;
7979         case ATOMIC_TYPE_LONG:     return type_unsigned_long;
7980         case ATOMIC_TYPE_LONGLONG: return type_unsigned_long_long;
7981
7982         default: panic("invalid atomic type");
7983         }
7984 }
7985
7986 /**
7987  * Check the semantic restrictions for a binary expression.
7988  */
7989 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
7990 {
7991         expression_t *const left            = expression->left;
7992         expression_t *const right           = expression->right;
7993         type_t       *const orig_type_left  = left->base.type;
7994         type_t       *const orig_type_right = right->base.type;
7995         type_t       *const type_left       = skip_typeref(orig_type_left);
7996         type_t       *const type_right      = skip_typeref(orig_type_right);
7997
7998         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
7999                 /* TODO: improve error message */
8000                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8001                         errorf(&expression->base.source_position,
8002                                "operation needs arithmetic types");
8003                 }
8004                 return;
8005         }
8006
8007         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8008         expression->left      = create_implicit_cast(left, arithmetic_type);
8009         expression->right     = create_implicit_cast(right, arithmetic_type);
8010         expression->base.type = arithmetic_type;
8011 }
8012
8013 static void semantic_binexpr_integer(binary_expression_t *const expression)
8014 {
8015         expression_t *const left            = expression->left;
8016         expression_t *const right           = expression->right;
8017         type_t       *const orig_type_left  = left->base.type;
8018         type_t       *const orig_type_right = right->base.type;
8019         type_t       *const type_left       = skip_typeref(orig_type_left);
8020         type_t       *const type_right      = skip_typeref(orig_type_right);
8021
8022         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8023                 /* TODO: improve error message */
8024                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8025                         errorf(&expression->base.source_position,
8026                                "operation needs integer types");
8027                 }
8028                 return;
8029         }
8030
8031         type_t *const result_type = semantic_arithmetic(type_left, type_right);
8032         expression->left      = create_implicit_cast(left, result_type);
8033         expression->right     = create_implicit_cast(right, result_type);
8034         expression->base.type = result_type;
8035 }
8036
8037 static void warn_div_by_zero(binary_expression_t const *const expression)
8038 {
8039         if (!is_type_integer(expression->base.type))
8040                 return;
8041
8042         expression_t const *const right = expression->right;
8043         /* The type of the right operand can be different for /= */
8044         if (is_type_integer(right->base.type)                    &&
8045             is_constant_expression(right) == EXPR_CLASS_CONSTANT &&
8046             !fold_constant_to_bool(right)) {
8047                 source_position_t const *const pos = &expression->base.source_position;
8048                 warningf(WARN_DIV_BY_ZERO, pos, "division by zero");
8049         }
8050 }
8051
8052 /**
8053  * Check the semantic restrictions for a div/mod expression.
8054  */
8055 static void semantic_divmod_arithmetic(binary_expression_t *expression)
8056 {
8057         semantic_binexpr_arithmetic(expression);
8058         warn_div_by_zero(expression);
8059 }
8060
8061 static void warn_addsub_in_shift(const expression_t *const expr)
8062 {
8063         if (expr->base.parenthesized)
8064                 return;
8065
8066         char op;
8067         switch (expr->kind) {
8068                 case EXPR_BINARY_ADD: op = '+'; break;
8069                 case EXPR_BINARY_SUB: op = '-'; break;
8070                 default:              return;
8071         }
8072
8073         source_position_t const *const pos = &expr->base.source_position;
8074         warningf(WARN_PARENTHESES, pos, "suggest parentheses around '%c' inside shift", op);
8075 }
8076
8077 static bool semantic_shift(binary_expression_t *expression)
8078 {
8079         expression_t *const left            = expression->left;
8080         expression_t *const right           = expression->right;
8081         type_t       *const orig_type_left  = left->base.type;
8082         type_t       *const orig_type_right = right->base.type;
8083         type_t       *      type_left       = skip_typeref(orig_type_left);
8084         type_t       *      type_right      = skip_typeref(orig_type_right);
8085
8086         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8087                 /* TODO: improve error message */
8088                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8089                         errorf(&expression->base.source_position,
8090                                "operands of shift operation must have integer types");
8091                 }
8092                 return false;
8093         }
8094
8095         type_left = promote_integer(type_left);
8096
8097         if (is_constant_expression(right) == EXPR_CLASS_CONSTANT) {
8098                 source_position_t const *const pos   = &right->base.source_position;
8099                 long                     const count = fold_constant_to_int(right);
8100                 if (count < 0) {
8101                         warningf(WARN_OTHER, pos, "shift count must be non-negative");
8102                 } else if ((unsigned long)count >=
8103                                 get_atomic_type_size(type_left->atomic.akind) * 8) {
8104                         warningf(WARN_OTHER, pos, "shift count must be less than type width");
8105                 }
8106         }
8107
8108         type_right        = promote_integer(type_right);
8109         expression->right = create_implicit_cast(right, type_right);
8110
8111         return true;
8112 }
8113
8114 static void semantic_shift_op(binary_expression_t *expression)
8115 {
8116         expression_t *const left  = expression->left;
8117         expression_t *const right = expression->right;
8118
8119         if (!semantic_shift(expression))
8120                 return;
8121
8122         warn_addsub_in_shift(left);
8123         warn_addsub_in_shift(right);
8124
8125         type_t *const orig_type_left = left->base.type;
8126         type_t *      type_left      = skip_typeref(orig_type_left);
8127
8128         type_left             = promote_integer(type_left);
8129         expression->left      = create_implicit_cast(left, type_left);
8130         expression->base.type = type_left;
8131 }
8132
8133 static void semantic_add(binary_expression_t *expression)
8134 {
8135         expression_t *const left            = expression->left;
8136         expression_t *const right           = expression->right;
8137         type_t       *const orig_type_left  = left->base.type;
8138         type_t       *const orig_type_right = right->base.type;
8139         type_t       *const type_left       = skip_typeref(orig_type_left);
8140         type_t       *const type_right      = skip_typeref(orig_type_right);
8141
8142         /* §6.5.6 */
8143         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8144                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8145                 expression->left  = create_implicit_cast(left, arithmetic_type);
8146                 expression->right = create_implicit_cast(right, arithmetic_type);
8147                 expression->base.type = arithmetic_type;
8148         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8149                 check_pointer_arithmetic(&expression->base.source_position,
8150                                          type_left, orig_type_left);
8151                 expression->base.type = type_left;
8152         } else if (is_type_pointer(type_right) && is_type_integer(type_left)) {
8153                 check_pointer_arithmetic(&expression->base.source_position,
8154                                          type_right, orig_type_right);
8155                 expression->base.type = type_right;
8156         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8157                 errorf(&expression->base.source_position,
8158                        "invalid operands to binary + ('%T', '%T')",
8159                        orig_type_left, orig_type_right);
8160         }
8161 }
8162
8163 static void semantic_sub(binary_expression_t *expression)
8164 {
8165         expression_t            *const left            = expression->left;
8166         expression_t            *const right           = expression->right;
8167         type_t                  *const orig_type_left  = left->base.type;
8168         type_t                  *const orig_type_right = right->base.type;
8169         type_t                  *const type_left       = skip_typeref(orig_type_left);
8170         type_t                  *const type_right      = skip_typeref(orig_type_right);
8171         source_position_t const *const pos             = &expression->base.source_position;
8172
8173         /* §5.6.5 */
8174         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8175                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8176                 expression->left        = create_implicit_cast(left, arithmetic_type);
8177                 expression->right       = create_implicit_cast(right, arithmetic_type);
8178                 expression->base.type =  arithmetic_type;
8179         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8180                 check_pointer_arithmetic(&expression->base.source_position,
8181                                          type_left, orig_type_left);
8182                 expression->base.type = type_left;
8183         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8184                 type_t *const unqual_left  = get_unqualified_type(skip_typeref(type_left->pointer.points_to));
8185                 type_t *const unqual_right = get_unqualified_type(skip_typeref(type_right->pointer.points_to));
8186                 if (!types_compatible(unqual_left, unqual_right)) {
8187                         errorf(pos,
8188                                "subtracting pointers to incompatible types '%T' and '%T'",
8189                                orig_type_left, orig_type_right);
8190                 } else if (!is_type_object(unqual_left)) {
8191                         if (!is_type_atomic(unqual_left, ATOMIC_TYPE_VOID)) {
8192                                 errorf(pos, "subtracting pointers to non-object types '%T'",
8193                                        orig_type_left);
8194                         } else {
8195                                 warningf(WARN_OTHER, pos, "subtracting pointers to void");
8196                         }
8197                 }
8198                 expression->base.type = type_ptrdiff_t;
8199         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8200                 errorf(pos, "invalid operands of types '%T' and '%T' to binary '-'",
8201                        orig_type_left, orig_type_right);
8202         }
8203 }
8204
8205 static void warn_string_literal_address(expression_t const* expr)
8206 {
8207         while (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
8208                 expr = expr->unary.value;
8209                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
8210                         return;
8211                 expr = expr->unary.value;
8212         }
8213
8214         if (expr->kind == EXPR_STRING_LITERAL
8215                         || expr->kind == EXPR_WIDE_STRING_LITERAL) {
8216                 source_position_t const *const pos = &expr->base.source_position;
8217                 warningf(WARN_ADDRESS, pos, "comparison with string literal results in unspecified behaviour");
8218         }
8219 }
8220
8221 static bool maybe_negative(expression_t const *const expr)
8222 {
8223         switch (is_constant_expression(expr)) {
8224                 case EXPR_CLASS_ERROR:    return false;
8225                 case EXPR_CLASS_CONSTANT: return constant_is_negative(expr);
8226                 default:                  return true;
8227         }
8228 }
8229
8230 static void warn_comparison(source_position_t const *const pos, expression_t const *const expr, expression_t const *const other)
8231 {
8232         warn_string_literal_address(expr);
8233
8234         expression_t const* const ref = get_reference_address(expr);
8235         if (ref != NULL && is_null_pointer_constant(other)) {
8236                 entity_t const *const ent = ref->reference.entity;
8237                 warningf(WARN_ADDRESS, pos, "the address of '%N' will never be NULL", ent);
8238         }
8239
8240         if (!expr->base.parenthesized) {
8241                 switch (expr->base.kind) {
8242                         case EXPR_BINARY_LESS:
8243                         case EXPR_BINARY_GREATER:
8244                         case EXPR_BINARY_LESSEQUAL:
8245                         case EXPR_BINARY_GREATEREQUAL:
8246                         case EXPR_BINARY_NOTEQUAL:
8247                         case EXPR_BINARY_EQUAL:
8248                                 warningf(WARN_PARENTHESES, pos, "comparisons like 'x <= y < z' do not have their mathematical meaning");
8249                                 break;
8250                         default:
8251                                 break;
8252                 }
8253         }
8254 }
8255
8256 /**
8257  * Check the semantics of comparison expressions.
8258  *
8259  * @param expression   The expression to check.
8260  */
8261 static void semantic_comparison(binary_expression_t *expression)
8262 {
8263         source_position_t const *const pos   = &expression->base.source_position;
8264         expression_t            *const left  = expression->left;
8265         expression_t            *const right = expression->right;
8266
8267         warn_comparison(pos, left, right);
8268         warn_comparison(pos, right, left);
8269
8270         type_t *orig_type_left  = left->base.type;
8271         type_t *orig_type_right = right->base.type;
8272         type_t *type_left       = skip_typeref(orig_type_left);
8273         type_t *type_right      = skip_typeref(orig_type_right);
8274
8275         /* TODO non-arithmetic types */
8276         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8277                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8278
8279                 /* test for signed vs unsigned compares */
8280                 if (is_type_integer(arithmetic_type)) {
8281                         bool const signed_left  = is_type_signed(type_left);
8282                         bool const signed_right = is_type_signed(type_right);
8283                         if (signed_left != signed_right) {
8284                                 /* FIXME long long needs better const folding magic */
8285                                 /* TODO check whether constant value can be represented by other type */
8286                                 if ((signed_left  && maybe_negative(left)) ||
8287                                                 (signed_right && maybe_negative(right))) {
8288                                         warningf(WARN_SIGN_COMPARE, pos, "comparison between signed and unsigned");
8289                                 }
8290                         }
8291                 }
8292
8293                 expression->left        = create_implicit_cast(left, arithmetic_type);
8294                 expression->right       = create_implicit_cast(right, arithmetic_type);
8295                 expression->base.type   = arithmetic_type;
8296                 if ((expression->base.kind == EXPR_BINARY_EQUAL ||
8297                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
8298                     is_type_float(arithmetic_type)) {
8299                         warningf(WARN_FLOAT_EQUAL, pos, "comparing floating point with == or != is unsafe");
8300                 }
8301         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8302                 /* TODO check compatibility */
8303         } else if (is_type_pointer(type_left)) {
8304                 expression->right = create_implicit_cast(right, type_left);
8305         } else if (is_type_pointer(type_right)) {
8306                 expression->left = create_implicit_cast(left, type_right);
8307         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8308                 type_error_incompatible("invalid operands in comparison", pos, type_left, type_right);
8309         }
8310         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8311 }
8312
8313 /**
8314  * Checks if a compound type has constant fields.
8315  */
8316 static bool has_const_fields(const compound_type_t *type)
8317 {
8318         compound_t *compound = type->compound;
8319         entity_t   *entry    = compound->members.entities;
8320
8321         for (; entry != NULL; entry = entry->base.next) {
8322                 if (!is_declaration(entry))
8323                         continue;
8324
8325                 const type_t *decl_type = skip_typeref(entry->declaration.type);
8326                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
8327                         return true;
8328         }
8329
8330         return false;
8331 }
8332
8333 static bool is_valid_assignment_lhs(expression_t const* const left)
8334 {
8335         type_t *const orig_type_left = revert_automatic_type_conversion(left);
8336         type_t *const type_left      = skip_typeref(orig_type_left);
8337
8338         if (!is_lvalue(left)) {
8339                 errorf(&left->base.source_position, "left hand side '%E' of assignment is not an lvalue",
8340                        left);
8341                 return false;
8342         }
8343
8344         if (left->kind == EXPR_REFERENCE
8345                         && left->reference.entity->kind == ENTITY_FUNCTION) {
8346                 errorf(&left->base.source_position, "cannot assign to function '%E'", left);
8347                 return false;
8348         }
8349
8350         if (is_type_array(type_left)) {
8351                 errorf(&left->base.source_position, "cannot assign to array '%E'", left);
8352                 return false;
8353         }
8354         if (type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
8355                 errorf(&left->base.source_position, "assignment to read-only location '%E' (type '%T')", left,
8356                        orig_type_left);
8357                 return false;
8358         }
8359         if (is_type_incomplete(type_left)) {
8360                 errorf(&left->base.source_position, "left-hand side '%E' of assignment has incomplete type '%T'",
8361                        left, orig_type_left);
8362                 return false;
8363         }
8364         if (is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
8365                 errorf(&left->base.source_position, "cannot assign to '%E' because compound type '%T' has read-only fields",
8366                        left, orig_type_left);
8367                 return false;
8368         }
8369
8370         return true;
8371 }
8372
8373 static void semantic_arithmetic_assign(binary_expression_t *expression)
8374 {
8375         expression_t *left            = expression->left;
8376         expression_t *right           = expression->right;
8377         type_t       *orig_type_left  = left->base.type;
8378         type_t       *orig_type_right = right->base.type;
8379
8380         if (!is_valid_assignment_lhs(left))
8381                 return;
8382
8383         type_t *type_left  = skip_typeref(orig_type_left);
8384         type_t *type_right = skip_typeref(orig_type_right);
8385
8386         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8387                 /* TODO: improve error message */
8388                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8389                         errorf(&expression->base.source_position,
8390                                "operation needs arithmetic types");
8391                 }
8392                 return;
8393         }
8394
8395         /* combined instructions are tricky. We can't create an implicit cast on
8396          * the left side, because we need the uncasted form for the store.
8397          * The ast2firm pass has to know that left_type must be right_type
8398          * for the arithmetic operation and create a cast by itself */
8399         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8400         expression->right       = create_implicit_cast(right, arithmetic_type);
8401         expression->base.type   = type_left;
8402 }
8403
8404 static void semantic_divmod_assign(binary_expression_t *expression)
8405 {
8406         semantic_arithmetic_assign(expression);
8407         warn_div_by_zero(expression);
8408 }
8409
8410 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
8411 {
8412         expression_t *const left            = expression->left;
8413         expression_t *const right           = expression->right;
8414         type_t       *const orig_type_left  = left->base.type;
8415         type_t       *const orig_type_right = right->base.type;
8416         type_t       *const type_left       = skip_typeref(orig_type_left);
8417         type_t       *const type_right      = skip_typeref(orig_type_right);
8418
8419         if (!is_valid_assignment_lhs(left))
8420                 return;
8421
8422         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8423                 /* combined instructions are tricky. We can't create an implicit cast on
8424                  * the left side, because we need the uncasted form for the store.
8425                  * The ast2firm pass has to know that left_type must be right_type
8426                  * for the arithmetic operation and create a cast by itself */
8427                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
8428                 expression->right     = create_implicit_cast(right, arithmetic_type);
8429                 expression->base.type = type_left;
8430         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8431                 check_pointer_arithmetic(&expression->base.source_position,
8432                                          type_left, orig_type_left);
8433                 expression->base.type = type_left;
8434         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8435                 errorf(&expression->base.source_position,
8436                        "incompatible types '%T' and '%T' in assignment",
8437                        orig_type_left, orig_type_right);
8438         }
8439 }
8440
8441 static void semantic_integer_assign(binary_expression_t *expression)
8442 {
8443         expression_t *left            = expression->left;
8444         expression_t *right           = expression->right;
8445         type_t       *orig_type_left  = left->base.type;
8446         type_t       *orig_type_right = right->base.type;
8447
8448         if (!is_valid_assignment_lhs(left))
8449                 return;
8450
8451         type_t *type_left  = skip_typeref(orig_type_left);
8452         type_t *type_right = skip_typeref(orig_type_right);
8453
8454         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8455                 /* TODO: improve error message */
8456                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8457                         errorf(&expression->base.source_position,
8458                                "operation needs integer types");
8459                 }
8460                 return;
8461         }
8462
8463         /* combined instructions are tricky. We can't create an implicit cast on
8464          * the left side, because we need the uncasted form for the store.
8465          * The ast2firm pass has to know that left_type must be right_type
8466          * for the arithmetic operation and create a cast by itself */
8467         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8468         expression->right       = create_implicit_cast(right, arithmetic_type);
8469         expression->base.type   = type_left;
8470 }
8471
8472 static void semantic_shift_assign(binary_expression_t *expression)
8473 {
8474         expression_t *left           = expression->left;
8475
8476         if (!is_valid_assignment_lhs(left))
8477                 return;
8478
8479         if (!semantic_shift(expression))
8480                 return;
8481
8482         expression->base.type = skip_typeref(left->base.type);
8483 }
8484
8485 static void warn_logical_and_within_or(const expression_t *const expr)
8486 {
8487         if (expr->base.kind != EXPR_BINARY_LOGICAL_AND)
8488                 return;
8489         if (expr->base.parenthesized)
8490                 return;
8491         source_position_t const *const pos = &expr->base.source_position;
8492         warningf(WARN_PARENTHESES, pos, "suggest parentheses around && within ||");
8493 }
8494
8495 /**
8496  * Check the semantic restrictions of a logical expression.
8497  */
8498 static void semantic_logical_op(binary_expression_t *expression)
8499 {
8500         /* §6.5.13:2  Each of the operands shall have scalar type.
8501          * §6.5.14:2  Each of the operands shall have scalar type. */
8502         semantic_condition(expression->left,   "left operand of logical operator");
8503         semantic_condition(expression->right, "right operand of logical operator");
8504         if (expression->base.kind == EXPR_BINARY_LOGICAL_OR) {
8505                 warn_logical_and_within_or(expression->left);
8506                 warn_logical_and_within_or(expression->right);
8507         }
8508         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8509 }
8510
8511 /**
8512  * Check the semantic restrictions of a binary assign expression.
8513  */
8514 static void semantic_binexpr_assign(binary_expression_t *expression)
8515 {
8516         expression_t *left           = expression->left;
8517         type_t       *orig_type_left = left->base.type;
8518
8519         if (!is_valid_assignment_lhs(left))
8520                 return;
8521
8522         assign_error_t error = semantic_assign(orig_type_left, expression->right);
8523         report_assign_error(error, orig_type_left, expression->right,
8524                         "assignment", &left->base.source_position);
8525         expression->right = create_implicit_cast(expression->right, orig_type_left);
8526         expression->base.type = orig_type_left;
8527 }
8528
8529 /**
8530  * Determine if the outermost operation (or parts thereof) of the given
8531  * expression has no effect in order to generate a warning about this fact.
8532  * Therefore in some cases this only examines some of the operands of the
8533  * expression (see comments in the function and examples below).
8534  * Examples:
8535  *   f() + 23;    // warning, because + has no effect
8536  *   x || f();    // no warning, because x controls execution of f()
8537  *   x ? y : f(); // warning, because y has no effect
8538  *   (void)x;     // no warning to be able to suppress the warning
8539  * This function can NOT be used for an "expression has definitely no effect"-
8540  * analysis. */
8541 static bool expression_has_effect(const expression_t *const expr)
8542 {
8543         switch (expr->kind) {
8544                 case EXPR_ERROR:                      return true; /* do NOT warn */
8545                 case EXPR_REFERENCE:                  return false;
8546                 case EXPR_REFERENCE_ENUM_VALUE:       return false;
8547                 case EXPR_LABEL_ADDRESS:              return false;
8548
8549                 /* suppress the warning for microsoft __noop operations */
8550                 case EXPR_LITERAL_MS_NOOP:            return true;
8551                 case EXPR_LITERAL_BOOLEAN:
8552                 case EXPR_LITERAL_CHARACTER:
8553                 case EXPR_LITERAL_WIDE_CHARACTER:
8554                 case EXPR_LITERAL_INTEGER:
8555                 case EXPR_LITERAL_INTEGER_OCTAL:
8556                 case EXPR_LITERAL_INTEGER_HEXADECIMAL:
8557                 case EXPR_LITERAL_FLOATINGPOINT:
8558                 case EXPR_LITERAL_FLOATINGPOINT_HEXADECIMAL: return false;
8559                 case EXPR_STRING_LITERAL:             return false;
8560                 case EXPR_WIDE_STRING_LITERAL:        return false;
8561
8562                 case EXPR_CALL: {
8563                         const call_expression_t *const call = &expr->call;
8564                         if (call->function->kind != EXPR_REFERENCE)
8565                                 return true;
8566
8567                         switch (call->function->reference.entity->function.btk) {
8568                                 /* FIXME: which builtins have no effect? */
8569                                 default:                      return true;
8570                         }
8571                 }
8572
8573                 /* Generate the warning if either the left or right hand side of a
8574                  * conditional expression has no effect */
8575                 case EXPR_CONDITIONAL: {
8576                         conditional_expression_t const *const cond = &expr->conditional;
8577                         expression_t             const *const t    = cond->true_expression;
8578                         return
8579                                 (t == NULL || expression_has_effect(t)) &&
8580                                 expression_has_effect(cond->false_expression);
8581                 }
8582
8583                 case EXPR_SELECT:                     return false;
8584                 case EXPR_ARRAY_ACCESS:               return false;
8585                 case EXPR_SIZEOF:                     return false;
8586                 case EXPR_CLASSIFY_TYPE:              return false;
8587                 case EXPR_ALIGNOF:                    return false;
8588
8589                 case EXPR_FUNCNAME:                   return false;
8590                 case EXPR_BUILTIN_CONSTANT_P:         return false;
8591                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P: return false;
8592                 case EXPR_OFFSETOF:                   return false;
8593                 case EXPR_VA_START:                   return true;
8594                 case EXPR_VA_ARG:                     return true;
8595                 case EXPR_VA_COPY:                    return true;
8596                 case EXPR_STATEMENT:                  return true; // TODO
8597                 case EXPR_COMPOUND_LITERAL:           return false;
8598
8599                 case EXPR_UNARY_NEGATE:               return false;
8600                 case EXPR_UNARY_PLUS:                 return false;
8601                 case EXPR_UNARY_BITWISE_NEGATE:       return false;
8602                 case EXPR_UNARY_NOT:                  return false;
8603                 case EXPR_UNARY_DEREFERENCE:          return false;
8604                 case EXPR_UNARY_TAKE_ADDRESS:         return false;
8605                 case EXPR_UNARY_POSTFIX_INCREMENT:    return true;
8606                 case EXPR_UNARY_POSTFIX_DECREMENT:    return true;
8607                 case EXPR_UNARY_PREFIX_INCREMENT:     return true;
8608                 case EXPR_UNARY_PREFIX_DECREMENT:     return true;
8609
8610                 /* Treat void casts as if they have an effect in order to being able to
8611                  * suppress the warning */
8612                 case EXPR_UNARY_CAST: {
8613                         type_t *const type = skip_typeref(expr->base.type);
8614                         return is_type_atomic(type, ATOMIC_TYPE_VOID);
8615                 }
8616
8617                 case EXPR_UNARY_ASSUME:               return true;
8618                 case EXPR_UNARY_DELETE:               return true;
8619                 case EXPR_UNARY_DELETE_ARRAY:         return true;
8620                 case EXPR_UNARY_THROW:                return true;
8621
8622                 case EXPR_BINARY_ADD:                 return false;
8623                 case EXPR_BINARY_SUB:                 return false;
8624                 case EXPR_BINARY_MUL:                 return false;
8625                 case EXPR_BINARY_DIV:                 return false;
8626                 case EXPR_BINARY_MOD:                 return false;
8627                 case EXPR_BINARY_EQUAL:               return false;
8628                 case EXPR_BINARY_NOTEQUAL:            return false;
8629                 case EXPR_BINARY_LESS:                return false;
8630                 case EXPR_BINARY_LESSEQUAL:           return false;
8631                 case EXPR_BINARY_GREATER:             return false;
8632                 case EXPR_BINARY_GREATEREQUAL:        return false;
8633                 case EXPR_BINARY_BITWISE_AND:         return false;
8634                 case EXPR_BINARY_BITWISE_OR:          return false;
8635                 case EXPR_BINARY_BITWISE_XOR:         return false;
8636                 case EXPR_BINARY_SHIFTLEFT:           return false;
8637                 case EXPR_BINARY_SHIFTRIGHT:          return false;
8638                 case EXPR_BINARY_ASSIGN:              return true;
8639                 case EXPR_BINARY_MUL_ASSIGN:          return true;
8640                 case EXPR_BINARY_DIV_ASSIGN:          return true;
8641                 case EXPR_BINARY_MOD_ASSIGN:          return true;
8642                 case EXPR_BINARY_ADD_ASSIGN:          return true;
8643                 case EXPR_BINARY_SUB_ASSIGN:          return true;
8644                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:    return true;
8645                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:   return true;
8646                 case EXPR_BINARY_BITWISE_AND_ASSIGN:  return true;
8647                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:  return true;
8648                 case EXPR_BINARY_BITWISE_OR_ASSIGN:   return true;
8649
8650                 /* Only examine the right hand side of && and ||, because the left hand
8651                  * side already has the effect of controlling the execution of the right
8652                  * hand side */
8653                 case EXPR_BINARY_LOGICAL_AND:
8654                 case EXPR_BINARY_LOGICAL_OR:
8655                 /* Only examine the right hand side of a comma expression, because the left
8656                  * hand side has a separate warning */
8657                 case EXPR_BINARY_COMMA:
8658                         return expression_has_effect(expr->binary.right);
8659
8660                 case EXPR_BINARY_ISGREATER:           return false;
8661                 case EXPR_BINARY_ISGREATEREQUAL:      return false;
8662                 case EXPR_BINARY_ISLESS:              return false;
8663                 case EXPR_BINARY_ISLESSEQUAL:         return false;
8664                 case EXPR_BINARY_ISLESSGREATER:       return false;
8665                 case EXPR_BINARY_ISUNORDERED:         return false;
8666         }
8667
8668         internal_errorf(HERE, "unexpected expression");
8669 }
8670
8671 static void semantic_comma(binary_expression_t *expression)
8672 {
8673         const expression_t *const left = expression->left;
8674         if (!expression_has_effect(left)) {
8675                 source_position_t const *const pos = &left->base.source_position;
8676                 warningf(WARN_UNUSED_VALUE, pos, "left-hand operand of comma expression has no effect");
8677         }
8678         expression->base.type = expression->right->base.type;
8679 }
8680
8681 /**
8682  * @param prec_r precedence of the right operand
8683  */
8684 #define CREATE_BINEXPR_PARSER(token_kind, binexpression_type, prec_r, sfunc) \
8685 static expression_t *parse_##binexpression_type(expression_t *left)          \
8686 {                                                                            \
8687         expression_t *binexpr = allocate_expression_zero(binexpression_type);    \
8688         binexpr->binary.left  = left;                                            \
8689         eat(token_kind);                                                         \
8690                                                                              \
8691         expression_t *right = parse_subexpression(prec_r);                       \
8692                                                                              \
8693         binexpr->binary.right = right;                                           \
8694         sfunc(&binexpr->binary);                                                 \
8695                                                                              \
8696         return binexpr;                                                          \
8697 }
8698
8699 CREATE_BINEXPR_PARSER('*',                    EXPR_BINARY_MUL,                PREC_CAST,           semantic_binexpr_arithmetic)
8700 CREATE_BINEXPR_PARSER('/',                    EXPR_BINARY_DIV,                PREC_CAST,           semantic_divmod_arithmetic)
8701 CREATE_BINEXPR_PARSER('%',                    EXPR_BINARY_MOD,                PREC_CAST,           semantic_divmod_arithmetic)
8702 CREATE_BINEXPR_PARSER('+',                    EXPR_BINARY_ADD,                PREC_MULTIPLICATIVE, semantic_add)
8703 CREATE_BINEXPR_PARSER('-',                    EXPR_BINARY_SUB,                PREC_MULTIPLICATIVE, semantic_sub)
8704 CREATE_BINEXPR_PARSER(T_LESSLESS,             EXPR_BINARY_SHIFTLEFT,          PREC_ADDITIVE,       semantic_shift_op)
8705 CREATE_BINEXPR_PARSER(T_GREATERGREATER,       EXPR_BINARY_SHIFTRIGHT,         PREC_ADDITIVE,       semantic_shift_op)
8706 CREATE_BINEXPR_PARSER('<',                    EXPR_BINARY_LESS,               PREC_SHIFT,          semantic_comparison)
8707 CREATE_BINEXPR_PARSER('>',                    EXPR_BINARY_GREATER,            PREC_SHIFT,          semantic_comparison)
8708 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,          PREC_SHIFT,          semantic_comparison)
8709 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,       PREC_SHIFT,          semantic_comparison)
8710 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,           PREC_RELATIONAL,     semantic_comparison)
8711 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,              PREC_RELATIONAL,     semantic_comparison)
8712 CREATE_BINEXPR_PARSER('&',                    EXPR_BINARY_BITWISE_AND,        PREC_EQUALITY,       semantic_binexpr_integer)
8713 CREATE_BINEXPR_PARSER('^',                    EXPR_BINARY_BITWISE_XOR,        PREC_AND,            semantic_binexpr_integer)
8714 CREATE_BINEXPR_PARSER('|',                    EXPR_BINARY_BITWISE_OR,         PREC_XOR,            semantic_binexpr_integer)
8715 CREATE_BINEXPR_PARSER(T_ANDAND,               EXPR_BINARY_LOGICAL_AND,        PREC_OR,             semantic_logical_op)
8716 CREATE_BINEXPR_PARSER(T_PIPEPIPE,             EXPR_BINARY_LOGICAL_OR,         PREC_LOGICAL_AND,    semantic_logical_op)
8717 CREATE_BINEXPR_PARSER('=',                    EXPR_BINARY_ASSIGN,             PREC_ASSIGNMENT,     semantic_binexpr_assign)
8718 CREATE_BINEXPR_PARSER(T_PLUSEQUAL,            EXPR_BINARY_ADD_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8719 CREATE_BINEXPR_PARSER(T_MINUSEQUAL,           EXPR_BINARY_SUB_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8720 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL,        EXPR_BINARY_MUL_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_assign)
8721 CREATE_BINEXPR_PARSER(T_SLASHEQUAL,           EXPR_BINARY_DIV_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8722 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL,         EXPR_BINARY_MOD_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8723 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL,        EXPR_BINARY_SHIFTLEFT_ASSIGN,   PREC_ASSIGNMENT,     semantic_shift_assign)
8724 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL,  EXPR_BINARY_SHIFTRIGHT_ASSIGN,  PREC_ASSIGNMENT,     semantic_shift_assign)
8725 CREATE_BINEXPR_PARSER(T_ANDEQUAL,             EXPR_BINARY_BITWISE_AND_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8726 CREATE_BINEXPR_PARSER(T_PIPEEQUAL,            EXPR_BINARY_BITWISE_OR_ASSIGN,  PREC_ASSIGNMENT,     semantic_integer_assign)
8727 CREATE_BINEXPR_PARSER(T_CARETEQUAL,           EXPR_BINARY_BITWISE_XOR_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8728 CREATE_BINEXPR_PARSER(',',                    EXPR_BINARY_COMMA,              PREC_ASSIGNMENT,     semantic_comma)
8729
8730
8731 static expression_t *parse_subexpression(precedence_t precedence)
8732 {
8733         if (token.kind < 0) {
8734                 return expected_expression_error();
8735         }
8736
8737         expression_parser_function_t *parser
8738                 = &expression_parsers[token.kind];
8739         expression_t                 *left;
8740
8741         if (parser->parser != NULL) {
8742                 left = parser->parser();
8743         } else {
8744                 left = parse_primary_expression();
8745         }
8746         assert(left != NULL);
8747
8748         while (true) {
8749                 if (token.kind < 0) {
8750                         return expected_expression_error();
8751                 }
8752
8753                 parser = &expression_parsers[token.kind];
8754                 if (parser->infix_parser == NULL)
8755                         break;
8756                 if (parser->infix_precedence < precedence)
8757                         break;
8758
8759                 left = parser->infix_parser(left);
8760
8761                 assert(left != NULL);
8762         }
8763
8764         return left;
8765 }
8766
8767 /**
8768  * Parse an expression.
8769  */
8770 static expression_t *parse_expression(void)
8771 {
8772         return parse_subexpression(PREC_EXPRESSION);
8773 }
8774
8775 /**
8776  * Register a parser for a prefix-like operator.
8777  *
8778  * @param parser      the parser function
8779  * @param token_kind  the token type of the prefix token
8780  */
8781 static void register_expression_parser(parse_expression_function parser,
8782                                        int token_kind)
8783 {
8784         expression_parser_function_t *entry = &expression_parsers[token_kind];
8785
8786         if (entry->parser != NULL) {
8787                 diagnosticf("for token '%k'\n", (token_kind_t)token_kind);
8788                 panic("trying to register multiple expression parsers for a token");
8789         }
8790         entry->parser = parser;
8791 }
8792
8793 /**
8794  * Register a parser for an infix operator with given precedence.
8795  *
8796  * @param parser      the parser function
8797  * @param token_kind  the token type of the infix operator
8798  * @param precedence  the precedence of the operator
8799  */
8800 static void register_infix_parser(parse_expression_infix_function parser,
8801                                   int token_kind, precedence_t precedence)
8802 {
8803         expression_parser_function_t *entry = &expression_parsers[token_kind];
8804
8805         if (entry->infix_parser != NULL) {
8806                 diagnosticf("for token '%k'\n", (token_kind_t)token_kind);
8807                 panic("trying to register multiple infix expression parsers for a "
8808                       "token");
8809         }
8810         entry->infix_parser     = parser;
8811         entry->infix_precedence = precedence;
8812 }
8813
8814 /**
8815  * Initialize the expression parsers.
8816  */
8817 static void init_expression_parsers(void)
8818 {
8819         memset(&expression_parsers, 0, sizeof(expression_parsers));
8820
8821         register_infix_parser(parse_array_expression,               '[',                    PREC_POSTFIX);
8822         register_infix_parser(parse_call_expression,                '(',                    PREC_POSTFIX);
8823         register_infix_parser(parse_select_expression,              '.',                    PREC_POSTFIX);
8824         register_infix_parser(parse_select_expression,              T_MINUSGREATER,         PREC_POSTFIX);
8825         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,   T_PLUSPLUS,             PREC_POSTFIX);
8826         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,   T_MINUSMINUS,           PREC_POSTFIX);
8827         register_infix_parser(parse_EXPR_BINARY_MUL,                '*',                    PREC_MULTIPLICATIVE);
8828         register_infix_parser(parse_EXPR_BINARY_DIV,                '/',                    PREC_MULTIPLICATIVE);
8829         register_infix_parser(parse_EXPR_BINARY_MOD,                '%',                    PREC_MULTIPLICATIVE);
8830         register_infix_parser(parse_EXPR_BINARY_ADD,                '+',                    PREC_ADDITIVE);
8831         register_infix_parser(parse_EXPR_BINARY_SUB,                '-',                    PREC_ADDITIVE);
8832         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,          T_LESSLESS,             PREC_SHIFT);
8833         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,         T_GREATERGREATER,       PREC_SHIFT);
8834         register_infix_parser(parse_EXPR_BINARY_LESS,               '<',                    PREC_RELATIONAL);
8835         register_infix_parser(parse_EXPR_BINARY_GREATER,            '>',                    PREC_RELATIONAL);
8836         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,          T_LESSEQUAL,            PREC_RELATIONAL);
8837         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL,       T_GREATEREQUAL,         PREC_RELATIONAL);
8838         register_infix_parser(parse_EXPR_BINARY_EQUAL,              T_EQUALEQUAL,           PREC_EQUALITY);
8839         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,           T_EXCLAMATIONMARKEQUAL, PREC_EQUALITY);
8840         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,        '&',                    PREC_AND);
8841         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,        '^',                    PREC_XOR);
8842         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,         '|',                    PREC_OR);
8843         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,        T_ANDAND,               PREC_LOGICAL_AND);
8844         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,         T_PIPEPIPE,             PREC_LOGICAL_OR);
8845         register_infix_parser(parse_conditional_expression,         '?',                    PREC_CONDITIONAL);
8846         register_infix_parser(parse_EXPR_BINARY_ASSIGN,             '=',                    PREC_ASSIGNMENT);
8847         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,         T_PLUSEQUAL,            PREC_ASSIGNMENT);
8848         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,         T_MINUSEQUAL,           PREC_ASSIGNMENT);
8849         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,         T_ASTERISKEQUAL,        PREC_ASSIGNMENT);
8850         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,         T_SLASHEQUAL,           PREC_ASSIGNMENT);
8851         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,         T_PERCENTEQUAL,         PREC_ASSIGNMENT);
8852         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,   T_LESSLESSEQUAL,        PREC_ASSIGNMENT);
8853         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,  T_GREATERGREATEREQUAL,  PREC_ASSIGNMENT);
8854         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN, T_ANDEQUAL,             PREC_ASSIGNMENT);
8855         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,  T_PIPEEQUAL,            PREC_ASSIGNMENT);
8856         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN, T_CARETEQUAL,           PREC_ASSIGNMENT);
8857         register_infix_parser(parse_EXPR_BINARY_COMMA,              ',',                    PREC_EXPRESSION);
8858
8859         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-');
8860         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+');
8861         register_expression_parser(parse_EXPR_UNARY_NOT,              '!');
8862         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~');
8863         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*');
8864         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&');
8865         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT, T_PLUSPLUS);
8866         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT, T_MINUSMINUS);
8867         register_expression_parser(parse_sizeof,                      T_sizeof);
8868         register_expression_parser(parse_alignof,                     T___alignof__);
8869         register_expression_parser(parse_extension,                   T___extension__);
8870         register_expression_parser(parse_builtin_classify_type,       T___builtin_classify_type);
8871         register_expression_parser(parse_delete,                      T_delete);
8872         register_expression_parser(parse_throw,                       T_throw);
8873 }
8874
8875 /**
8876  * Parse a asm statement arguments specification.
8877  */
8878 static asm_argument_t *parse_asm_arguments(bool is_out)
8879 {
8880         asm_argument_t  *result = NULL;
8881         asm_argument_t **anchor = &result;
8882
8883         while (token.kind == T_STRING_LITERAL || token.kind == '[') {
8884                 asm_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
8885                 memset(argument, 0, sizeof(argument[0]));
8886
8887                 if (next_if('[')) {
8888                         if (token.kind != T_IDENTIFIER) {
8889                                 parse_error_expected("while parsing asm argument",
8890                                                      T_IDENTIFIER, NULL);
8891                                 return NULL;
8892                         }
8893                         argument->symbol = token.identifier.symbol;
8894
8895                         expect(']', end_error);
8896                 }
8897
8898                 argument->constraints = parse_string_literals();
8899                 expect('(', end_error);
8900                 add_anchor_token(')');
8901                 expression_t *expression = parse_expression();
8902                 rem_anchor_token(')');
8903                 if (is_out) {
8904                         /* Ugly GCC stuff: Allow lvalue casts.  Skip casts, when they do not
8905                          * change size or type representation (e.g. int -> long is ok, but
8906                          * int -> float is not) */
8907                         if (expression->kind == EXPR_UNARY_CAST) {
8908                                 type_t      *const type = expression->base.type;
8909                                 type_kind_t  const kind = type->kind;
8910                                 if (kind == TYPE_ATOMIC || kind == TYPE_POINTER) {
8911                                         unsigned flags;
8912                                         unsigned size;
8913                                         if (kind == TYPE_ATOMIC) {
8914                                                 atomic_type_kind_t const akind = type->atomic.akind;
8915                                                 flags = get_atomic_type_flags(akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
8916                                                 size  = get_atomic_type_size(akind);
8917                                         } else {
8918                                                 flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
8919                                                 size  = get_type_size(type_void_ptr);
8920                                         }
8921
8922                                         do {
8923                                                 expression_t *const value      = expression->unary.value;
8924                                                 type_t       *const value_type = value->base.type;
8925                                                 type_kind_t   const value_kind = value_type->kind;
8926
8927                                                 unsigned value_flags;
8928                                                 unsigned value_size;
8929                                                 if (value_kind == TYPE_ATOMIC) {
8930                                                         atomic_type_kind_t const value_akind = value_type->atomic.akind;
8931                                                         value_flags = get_atomic_type_flags(value_akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
8932                                                         value_size  = get_atomic_type_size(value_akind);
8933                                                 } else if (value_kind == TYPE_POINTER) {
8934                                                         value_flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
8935                                                         value_size  = get_type_size(type_void_ptr);
8936                                                 } else {
8937                                                         break;
8938                                                 }
8939
8940                                                 if (value_flags != flags || value_size != size)
8941                                                         break;
8942
8943                                                 expression = value;
8944                                         } while (expression->kind == EXPR_UNARY_CAST);
8945                                 }
8946                         }
8947
8948                         if (!is_lvalue(expression)) {
8949                                 errorf(&expression->base.source_position,
8950                                        "asm output argument is not an lvalue");
8951                         }
8952
8953                         if (argument->constraints.begin[0] == '=')
8954                                 determine_lhs_ent(expression, NULL);
8955                         else
8956                                 mark_vars_read(expression, NULL);
8957                 } else {
8958                         mark_vars_read(expression, NULL);
8959                 }
8960                 argument->expression = expression;
8961                 expect(')', end_error);
8962
8963                 set_address_taken(expression, true);
8964
8965                 *anchor = argument;
8966                 anchor  = &argument->next;
8967
8968                 if (!next_if(','))
8969                         break;
8970         }
8971
8972         return result;
8973 end_error:
8974         return NULL;
8975 }
8976
8977 /**
8978  * Parse a asm statement clobber specification.
8979  */
8980 static asm_clobber_t *parse_asm_clobbers(void)
8981 {
8982         asm_clobber_t *result  = NULL;
8983         asm_clobber_t **anchor = &result;
8984
8985         while (token.kind == T_STRING_LITERAL) {
8986                 asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
8987                 clobber->clobber       = parse_string_literals();
8988
8989                 *anchor = clobber;
8990                 anchor  = &clobber->next;
8991
8992                 if (!next_if(','))
8993                         break;
8994         }
8995
8996         return result;
8997 }
8998
8999 /**
9000  * Parse an asm statement.
9001  */
9002 static statement_t *parse_asm_statement(void)
9003 {
9004         statement_t     *statement     = allocate_statement_zero(STATEMENT_ASM);
9005         asm_statement_t *asm_statement = &statement->asms;
9006
9007         eat(T_asm);
9008
9009         if (next_if(T_volatile))
9010                 asm_statement->is_volatile = true;
9011
9012         expect('(', end_error);
9013         add_anchor_token(')');
9014         if (token.kind != T_STRING_LITERAL) {
9015                 parse_error_expected("after asm(", T_STRING_LITERAL, NULL);
9016                 goto end_of_asm;
9017         }
9018         asm_statement->asm_text = parse_string_literals();
9019
9020         add_anchor_token(':');
9021         if (!next_if(':')) {
9022                 rem_anchor_token(':');
9023                 goto end_of_asm;
9024         }
9025
9026         asm_statement->outputs = parse_asm_arguments(true);
9027         if (!next_if(':')) {
9028                 rem_anchor_token(':');
9029                 goto end_of_asm;
9030         }
9031
9032         asm_statement->inputs = parse_asm_arguments(false);
9033         if (!next_if(':')) {
9034                 rem_anchor_token(':');
9035                 goto end_of_asm;
9036         }
9037         rem_anchor_token(':');
9038
9039         asm_statement->clobbers = parse_asm_clobbers();
9040
9041 end_of_asm:
9042         rem_anchor_token(')');
9043         expect(')', end_error);
9044         expect(';', end_error);
9045
9046         if (asm_statement->outputs == NULL) {
9047                 /* GCC: An 'asm' instruction without any output operands will be treated
9048                  * identically to a volatile 'asm' instruction. */
9049                 asm_statement->is_volatile = true;
9050         }
9051
9052         return statement;
9053 end_error:
9054         return create_error_statement();
9055 }
9056
9057 static statement_t *parse_label_inner_statement(statement_t const *const label, char const *const label_kind)
9058 {
9059         statement_t *inner_stmt;
9060         switch (token.kind) {
9061                 case '}':
9062                         errorf(&label->base.source_position, "%s at end of compound statement", label_kind);
9063                         inner_stmt = create_error_statement();
9064                         break;
9065
9066                 case ';':
9067                         if (label->kind == STATEMENT_LABEL) {
9068                                 /* Eat an empty statement here, to avoid the warning about an empty
9069                                  * statement after a label.  label:; is commonly used to have a label
9070                                  * before a closing brace. */
9071                                 inner_stmt = create_empty_statement();
9072                                 next_token();
9073                                 break;
9074                         }
9075                         /* FALLTHROUGH */
9076
9077                 default:
9078                         inner_stmt = parse_statement();
9079                         /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
9080                         /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
9081                         if (inner_stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
9082                                 errorf(&inner_stmt->base.source_position, "declaration after %s", label_kind);
9083                         }
9084                         break;
9085         }
9086         return inner_stmt;
9087 }
9088
9089 /**
9090  * Parse a case statement.
9091  */
9092 static statement_t *parse_case_statement(void)
9093 {
9094         statement_t       *const statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9095         source_position_t *const pos       = &statement->base.source_position;
9096
9097         eat(T_case);
9098
9099         expression_t *expression = parse_expression();
9100         type_t *expression_type = expression->base.type;
9101         type_t *skipped         = skip_typeref(expression_type);
9102         if (!is_type_integer(skipped) && is_type_valid(skipped)) {
9103                 errorf(pos, "case expression '%E' must have integer type but has type '%T'",
9104                        expression, expression_type);
9105         }
9106
9107         type_t *type = expression_type;
9108         if (current_switch != NULL) {
9109                 type_t *switch_type = current_switch->expression->base.type;
9110                 if (is_type_valid(switch_type)) {
9111                         expression = create_implicit_cast(expression, switch_type);
9112                 }
9113         }
9114
9115         statement->case_label.expression = expression;
9116         expression_classification_t const expr_class = is_constant_expression(expression);
9117         if (expr_class != EXPR_CLASS_CONSTANT) {
9118                 if (expr_class != EXPR_CLASS_ERROR) {
9119                         errorf(pos, "case label does not reduce to an integer constant");
9120                 }
9121                 statement->case_label.is_bad = true;
9122         } else {
9123                 long const val = fold_constant_to_int(expression);
9124                 statement->case_label.first_case = val;
9125                 statement->case_label.last_case  = val;
9126         }
9127
9128         if (GNU_MODE) {
9129                 if (next_if(T_DOTDOTDOT)) {
9130                         expression_t *end_range = parse_expression();
9131                         expression_type = expression->base.type;
9132                         skipped         = skip_typeref(expression_type);
9133                         if (!is_type_integer(skipped) && is_type_valid(skipped)) {
9134                                 errorf(pos, "case expression '%E' must have integer type but has type '%T'",
9135                                            expression, expression_type);
9136                         }
9137
9138                         end_range = create_implicit_cast(end_range, type);
9139                         statement->case_label.end_range = end_range;
9140                         expression_classification_t const end_class = is_constant_expression(end_range);
9141                         if (end_class != EXPR_CLASS_CONSTANT) {
9142                                 if (end_class != EXPR_CLASS_ERROR) {
9143                                         errorf(pos, "case range does not reduce to an integer constant");
9144                                 }
9145                                 statement->case_label.is_bad = true;
9146                         } else {
9147                                 long const val = fold_constant_to_int(end_range);
9148                                 statement->case_label.last_case = val;
9149
9150                                 if (val < statement->case_label.first_case) {
9151                                         statement->case_label.is_empty_range = true;
9152                                         warningf(WARN_OTHER, pos, "empty range specified");
9153                                 }
9154                         }
9155                 }
9156         }
9157
9158         PUSH_PARENT(statement);
9159
9160         expect(':', end_error);
9161 end_error:
9162
9163         if (current_switch != NULL) {
9164                 if (! statement->case_label.is_bad) {
9165                         /* Check for duplicate case values */
9166                         case_label_statement_t *c = &statement->case_label;
9167                         for (case_label_statement_t *l = current_switch->first_case; l != NULL; l = l->next) {
9168                                 if (l->is_bad || l->is_empty_range || l->expression == NULL)
9169                                         continue;
9170
9171                                 if (c->last_case < l->first_case || c->first_case > l->last_case)
9172                                         continue;
9173
9174                                 errorf(pos, "duplicate case value (previously used %P)",
9175                                        &l->base.source_position);
9176                                 break;
9177                         }
9178                 }
9179                 /* link all cases into the switch statement */
9180                 if (current_switch->last_case == NULL) {
9181                         current_switch->first_case      = &statement->case_label;
9182                 } else {
9183                         current_switch->last_case->next = &statement->case_label;
9184                 }
9185                 current_switch->last_case = &statement->case_label;
9186         } else {
9187                 errorf(pos, "case label not within a switch statement");
9188         }
9189
9190         statement->case_label.statement = parse_label_inner_statement(statement, "case label");
9191
9192         POP_PARENT();
9193         return statement;
9194 }
9195
9196 /**
9197  * Parse a default statement.
9198  */
9199 static statement_t *parse_default_statement(void)
9200 {
9201         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9202
9203         eat(T_default);
9204
9205         PUSH_PARENT(statement);
9206
9207         expect(':', end_error);
9208 end_error:
9209
9210         if (current_switch != NULL) {
9211                 const case_label_statement_t *def_label = current_switch->default_label;
9212                 if (def_label != NULL) {
9213                         errorf(&statement->base.source_position, "multiple default labels in one switch (previous declared %P)", &def_label->base.source_position);
9214                 } else {
9215                         current_switch->default_label = &statement->case_label;
9216
9217                         /* link all cases into the switch statement */
9218                         if (current_switch->last_case == NULL) {
9219                                 current_switch->first_case      = &statement->case_label;
9220                         } else {
9221                                 current_switch->last_case->next = &statement->case_label;
9222                         }
9223                         current_switch->last_case = &statement->case_label;
9224                 }
9225         } else {
9226                 errorf(&statement->base.source_position,
9227                         "'default' label not within a switch statement");
9228         }
9229
9230         statement->case_label.statement = parse_label_inner_statement(statement, "default label");
9231
9232         POP_PARENT();
9233         return statement;
9234 }
9235
9236 /**
9237  * Parse a label statement.
9238  */
9239 static statement_t *parse_label_statement(void)
9240 {
9241         statement_t *const statement = allocate_statement_zero(STATEMENT_LABEL);
9242         label_t     *const label     = get_label();
9243         statement->label.label = label;
9244
9245         PUSH_PARENT(statement);
9246
9247         /* if statement is already set then the label is defined twice,
9248          * otherwise it was just mentioned in a goto/local label declaration so far
9249          */
9250         source_position_t const* const pos = &statement->base.source_position;
9251         if (label->statement != NULL) {
9252                 errorf(pos, "duplicate '%N' (declared %P)", (entity_t const*)label, &label->base.source_position);
9253         } else {
9254                 label->base.source_position = *pos;
9255                 label->statement            = statement;
9256         }
9257
9258         eat(':');
9259
9260         if (token.kind == T___attribute__ && !(c_mode & _CXX)) {
9261                 parse_attributes(NULL); // TODO process attributes
9262         }
9263
9264         statement->label.statement = parse_label_inner_statement(statement, "label");
9265
9266         /* remember the labels in a list for later checking */
9267         *label_anchor = &statement->label;
9268         label_anchor  = &statement->label.next;
9269
9270         POP_PARENT();
9271         return statement;
9272 }
9273
9274 static statement_t *parse_inner_statement(void)
9275 {
9276         statement_t *const stmt = parse_statement();
9277         /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
9278         /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
9279         if (stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
9280                 errorf(&stmt->base.source_position, "declaration as inner statement, use {}");
9281         }
9282         return stmt;
9283 }
9284
9285 /**
9286  * Parse an if statement.
9287  */
9288 static statement_t *parse_if(void)
9289 {
9290         statement_t *statement = allocate_statement_zero(STATEMENT_IF);
9291
9292         eat(T_if);
9293
9294         PUSH_PARENT(statement);
9295
9296         add_anchor_token('{');
9297
9298         expect('(', end_error);
9299         add_anchor_token(')');
9300         expression_t *const expr = parse_expression();
9301         statement->ifs.condition = expr;
9302         /* §6.8.4.1:1  The controlling expression of an if statement shall have
9303          *             scalar type. */
9304         semantic_condition(expr, "condition of 'if'-statment");
9305         mark_vars_read(expr, NULL);
9306         rem_anchor_token(')');
9307         expect(')', end_error);
9308
9309 end_error:
9310         rem_anchor_token('{');
9311
9312         add_anchor_token(T_else);
9313         statement_t *const true_stmt = parse_inner_statement();
9314         statement->ifs.true_statement = true_stmt;
9315         rem_anchor_token(T_else);
9316
9317         if (true_stmt->kind == STATEMENT_EMPTY) {
9318                 warningf(WARN_EMPTY_BODY, HERE,
9319                         "suggest braces around empty body in an ‘if’ statement");
9320         }
9321
9322         if (next_if(T_else)) {
9323                 statement->ifs.false_statement = parse_inner_statement();
9324
9325                 if (statement->ifs.false_statement->kind == STATEMENT_EMPTY) {
9326                         warningf(WARN_EMPTY_BODY, HERE,
9327                                         "suggest braces around empty body in an ‘if’ statement");
9328                 }
9329         } else if (true_stmt->kind == STATEMENT_IF &&
9330                         true_stmt->ifs.false_statement != NULL) {
9331                 source_position_t const *const pos = &true_stmt->base.source_position;
9332                 warningf(WARN_PARENTHESES, pos, "suggest explicit braces to avoid ambiguous 'else'");
9333         }
9334
9335         POP_PARENT();
9336         return statement;
9337 }
9338
9339 /**
9340  * Check that all enums are handled in a switch.
9341  *
9342  * @param statement  the switch statement to check
9343  */
9344 static void check_enum_cases(const switch_statement_t *statement)
9345 {
9346         if (!is_warn_on(WARN_SWITCH_ENUM))
9347                 return;
9348         const type_t *type = skip_typeref(statement->expression->base.type);
9349         if (! is_type_enum(type))
9350                 return;
9351         const enum_type_t *enumt = &type->enumt;
9352
9353         /* if we have a default, no warnings */
9354         if (statement->default_label != NULL)
9355                 return;
9356
9357         /* FIXME: calculation of value should be done while parsing */
9358         /* TODO: quadratic algorithm here. Change to an n log n one */
9359         long            last_value = -1;
9360         const entity_t *entry      = enumt->enume->base.next;
9361         for (; entry != NULL && entry->kind == ENTITY_ENUM_VALUE;
9362              entry = entry->base.next) {
9363                 const expression_t *expression = entry->enum_value.value;
9364                 long                value      = expression != NULL ? fold_constant_to_int(expression) : last_value + 1;
9365                 bool                found      = false;
9366                 for (const case_label_statement_t *l = statement->first_case; l != NULL; l = l->next) {
9367                         if (l->expression == NULL)
9368                                 continue;
9369                         if (l->first_case <= value && value <= l->last_case) {
9370                                 found = true;
9371                                 break;
9372                         }
9373                 }
9374                 if (!found) {
9375                         source_position_t const *const pos = &statement->base.source_position;
9376                         warningf(WARN_SWITCH_ENUM, pos, "'%N' not handled in switch", entry);
9377                 }
9378                 last_value = value;
9379         }
9380 }
9381
9382 /**
9383  * Parse a switch statement.
9384  */
9385 static statement_t *parse_switch(void)
9386 {
9387         statement_t *statement = allocate_statement_zero(STATEMENT_SWITCH);
9388
9389         eat(T_switch);
9390
9391         PUSH_PARENT(statement);
9392
9393         expect('(', end_error);
9394         add_anchor_token(')');
9395         expression_t *const expr = parse_expression();
9396         mark_vars_read(expr, NULL);
9397         type_t       *      type = skip_typeref(expr->base.type);
9398         if (is_type_integer(type)) {
9399                 type = promote_integer(type);
9400                 if (get_akind_rank(get_akind(type)) >= get_akind_rank(ATOMIC_TYPE_LONG)) {
9401                         warningf(WARN_TRADITIONAL, &expr->base.source_position, "'%T' switch expression not converted to '%T' in ISO C", type, type_int);
9402                 }
9403         } else if (is_type_valid(type)) {
9404                 errorf(&expr->base.source_position,
9405                        "switch quantity is not an integer, but '%T'", type);
9406                 type = type_error_type;
9407         }
9408         statement->switchs.expression = create_implicit_cast(expr, type);
9409         expect(')', end_error);
9410         rem_anchor_token(')');
9411
9412         switch_statement_t *rem = current_switch;
9413         current_switch          = &statement->switchs;
9414         statement->switchs.body = parse_inner_statement();
9415         current_switch          = rem;
9416
9417         if (statement->switchs.default_label == NULL) {
9418                 warningf(WARN_SWITCH_DEFAULT, &statement->base.source_position, "switch has no default case");
9419         }
9420         check_enum_cases(&statement->switchs);
9421
9422         POP_PARENT();
9423         return statement;
9424 end_error:
9425         POP_PARENT();
9426         return create_error_statement();
9427 }
9428
9429 static statement_t *parse_loop_body(statement_t *const loop)
9430 {
9431         statement_t *const rem = current_loop;
9432         current_loop = loop;
9433
9434         statement_t *const body = parse_inner_statement();
9435
9436         current_loop = rem;
9437         return body;
9438 }
9439
9440 /**
9441  * Parse a while statement.
9442  */
9443 static statement_t *parse_while(void)
9444 {
9445         statement_t *statement = allocate_statement_zero(STATEMENT_WHILE);
9446
9447         eat(T_while);
9448
9449         PUSH_PARENT(statement);
9450
9451         expect('(', end_error);
9452         add_anchor_token(')');
9453         expression_t *const cond = parse_expression();
9454         statement->whiles.condition = cond;
9455         /* §6.8.5:2    The controlling expression of an iteration statement shall
9456          *             have scalar type. */
9457         semantic_condition(cond, "condition of 'while'-statement");
9458         mark_vars_read(cond, NULL);
9459         rem_anchor_token(')');
9460         expect(')', end_error);
9461
9462         statement->whiles.body = parse_loop_body(statement);
9463
9464         POP_PARENT();
9465         return statement;
9466 end_error:
9467         POP_PARENT();
9468         return create_error_statement();
9469 }
9470
9471 /**
9472  * Parse a do statement.
9473  */
9474 static statement_t *parse_do(void)
9475 {
9476         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
9477
9478         eat(T_do);
9479
9480         PUSH_PARENT(statement);
9481
9482         add_anchor_token(T_while);
9483         statement->do_while.body = parse_loop_body(statement);
9484         rem_anchor_token(T_while);
9485
9486         expect(T_while, end_error);
9487         expect('(', end_error);
9488         add_anchor_token(')');
9489         expression_t *const cond = parse_expression();
9490         statement->do_while.condition = cond;
9491         /* §6.8.5:2    The controlling expression of an iteration statement shall
9492          *             have scalar type. */
9493         semantic_condition(cond, "condition of 'do-while'-statement");
9494         mark_vars_read(cond, NULL);
9495         rem_anchor_token(')');
9496         expect(')', end_error);
9497         expect(';', end_error);
9498
9499         POP_PARENT();
9500         return statement;
9501 end_error:
9502         POP_PARENT();
9503         return create_error_statement();
9504 }
9505
9506 /**
9507  * Parse a for statement.
9508  */
9509 static statement_t *parse_for(void)
9510 {
9511         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
9512
9513         eat(T_for);
9514
9515         expect('(', end_error1);
9516         add_anchor_token(')');
9517
9518         PUSH_PARENT(statement);
9519         PUSH_SCOPE(&statement->fors.scope);
9520
9521         PUSH_EXTENSION();
9522
9523         if (next_if(';')) {
9524         } else if (is_declaration_specifier(&token)) {
9525                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9526         } else {
9527                 add_anchor_token(';');
9528                 expression_t *const init = parse_expression();
9529                 statement->fors.initialisation = init;
9530                 mark_vars_read(init, ENT_ANY);
9531                 if (!expression_has_effect(init)) {
9532                         warningf(WARN_UNUSED_VALUE, &init->base.source_position, "initialisation of 'for'-statement has no effect");
9533                 }
9534                 rem_anchor_token(';');
9535                 expect(';', end_error2);
9536         }
9537
9538         POP_EXTENSION();
9539
9540         if (token.kind != ';') {
9541                 add_anchor_token(';');
9542                 expression_t *const cond = parse_expression();
9543                 statement->fors.condition = cond;
9544                 /* §6.8.5:2    The controlling expression of an iteration statement
9545                  *             shall have scalar type. */
9546                 semantic_condition(cond, "condition of 'for'-statement");
9547                 mark_vars_read(cond, NULL);
9548                 rem_anchor_token(';');
9549         }
9550         expect(';', end_error2);
9551         if (token.kind != ')') {
9552                 expression_t *const step = parse_expression();
9553                 statement->fors.step = step;
9554                 mark_vars_read(step, ENT_ANY);
9555                 if (!expression_has_effect(step)) {
9556                         warningf(WARN_UNUSED_VALUE, &step->base.source_position, "step of 'for'-statement has no effect");
9557                 }
9558         }
9559         expect(')', end_error2);
9560         rem_anchor_token(')');
9561         statement->fors.body = parse_loop_body(statement);
9562
9563         POP_SCOPE();
9564         POP_PARENT();
9565         return statement;
9566
9567 end_error2:
9568         POP_PARENT();
9569         rem_anchor_token(')');
9570         POP_SCOPE();
9571         /* fallthrough */
9572
9573 end_error1:
9574         return create_error_statement();
9575 }
9576
9577 /**
9578  * Parse a goto statement.
9579  */
9580 static statement_t *parse_goto(void)
9581 {
9582         statement_t *statement = allocate_statement_zero(STATEMENT_GOTO);
9583         eat(T_goto);
9584
9585         if (GNU_MODE && next_if('*')) {
9586                 expression_t *expression = parse_expression();
9587                 mark_vars_read(expression, NULL);
9588
9589                 /* Argh: although documentation says the expression must be of type void*,
9590                  * gcc accepts anything that can be casted into void* without error */
9591                 type_t *type = expression->base.type;
9592
9593                 if (type != type_error_type) {
9594                         if (!is_type_pointer(type) && !is_type_integer(type)) {
9595                                 errorf(&expression->base.source_position,
9596                                         "cannot convert to a pointer type");
9597                         } else if (type != type_void_ptr) {
9598                                 warningf(WARN_OTHER, &expression->base.source_position, "type of computed goto expression should be 'void*' not '%T'", type);
9599                         }
9600                         expression = create_implicit_cast(expression, type_void_ptr);
9601                 }
9602
9603                 statement->gotos.expression = expression;
9604         } else if (token.kind == T_IDENTIFIER) {
9605                 label_t *const label = get_label();
9606                 label->used            = true;
9607                 statement->gotos.label = label;
9608         } else {
9609                 if (GNU_MODE)
9610                         parse_error_expected("while parsing goto", T_IDENTIFIER, '*', NULL);
9611                 else
9612                         parse_error_expected("while parsing goto", T_IDENTIFIER, NULL);
9613                 eat_until_anchor();
9614                 return create_error_statement();
9615         }
9616
9617         /* remember the goto's in a list for later checking */
9618         *goto_anchor = &statement->gotos;
9619         goto_anchor  = &statement->gotos.next;
9620
9621         expect(';', end_error);
9622
9623 end_error:
9624         return statement;
9625 }
9626
9627 /**
9628  * Parse a continue statement.
9629  */
9630 static statement_t *parse_continue(void)
9631 {
9632         if (current_loop == NULL) {
9633                 errorf(HERE, "continue statement not within loop");
9634         }
9635
9636         statement_t *statement = allocate_statement_zero(STATEMENT_CONTINUE);
9637
9638         eat(T_continue);
9639         expect(';', end_error);
9640
9641 end_error:
9642         return statement;
9643 }
9644
9645 /**
9646  * Parse a break statement.
9647  */
9648 static statement_t *parse_break(void)
9649 {
9650         if (current_switch == NULL && current_loop == NULL) {
9651                 errorf(HERE, "break statement not within loop or switch");
9652         }
9653
9654         statement_t *statement = allocate_statement_zero(STATEMENT_BREAK);
9655
9656         eat(T_break);
9657         expect(';', end_error);
9658
9659 end_error:
9660         return statement;
9661 }
9662
9663 /**
9664  * Parse a __leave statement.
9665  */
9666 static statement_t *parse_leave_statement(void)
9667 {
9668         if (current_try == NULL) {
9669                 errorf(HERE, "__leave statement not within __try");
9670         }
9671
9672         statement_t *statement = allocate_statement_zero(STATEMENT_LEAVE);
9673
9674         eat(T___leave);
9675         expect(';', end_error);
9676
9677 end_error:
9678         return statement;
9679 }
9680
9681 /**
9682  * Check if a given entity represents a local variable.
9683  */
9684 static bool is_local_variable(const entity_t *entity)
9685 {
9686         if (entity->kind != ENTITY_VARIABLE)
9687                 return false;
9688
9689         switch ((storage_class_tag_t) entity->declaration.storage_class) {
9690         case STORAGE_CLASS_AUTO:
9691         case STORAGE_CLASS_REGISTER: {
9692                 const type_t *type = skip_typeref(entity->declaration.type);
9693                 if (is_type_function(type)) {
9694                         return false;
9695                 } else {
9696                         return true;
9697                 }
9698         }
9699         default:
9700                 return false;
9701         }
9702 }
9703
9704 /**
9705  * Check if a given expression represents a local variable.
9706  */
9707 static bool expression_is_local_variable(const expression_t *expression)
9708 {
9709         if (expression->base.kind != EXPR_REFERENCE) {
9710                 return false;
9711         }
9712         const entity_t *entity = expression->reference.entity;
9713         return is_local_variable(entity);
9714 }
9715
9716 /**
9717  * Check if a given expression represents a local variable and
9718  * return its declaration then, else return NULL.
9719  */
9720 entity_t *expression_is_variable(const expression_t *expression)
9721 {
9722         if (expression->base.kind != EXPR_REFERENCE) {
9723                 return NULL;
9724         }
9725         entity_t *entity = expression->reference.entity;
9726         if (entity->kind != ENTITY_VARIABLE)
9727                 return NULL;
9728
9729         return entity;
9730 }
9731
9732 /**
9733  * Parse a return statement.
9734  */
9735 static statement_t *parse_return(void)
9736 {
9737         statement_t *statement = allocate_statement_zero(STATEMENT_RETURN);
9738         eat(T_return);
9739
9740         expression_t *return_value = NULL;
9741         if (token.kind != ';') {
9742                 return_value = parse_expression();
9743                 mark_vars_read(return_value, NULL);
9744         }
9745
9746         const type_t *const func_type = skip_typeref(current_function->base.type);
9747         assert(is_type_function(func_type));
9748         type_t *const return_type = skip_typeref(func_type->function.return_type);
9749
9750         source_position_t const *const pos = &statement->base.source_position;
9751         if (return_value != NULL) {
9752                 type_t *return_value_type = skip_typeref(return_value->base.type);
9753
9754                 if (is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
9755                         if (is_type_atomic(return_value_type, ATOMIC_TYPE_VOID)) {
9756                                 /* ISO/IEC 14882:1998(E) §6.6.3:2 */
9757                                 /* Only warn in C mode, because GCC does the same */
9758                                 if (c_mode & _CXX || strict_mode) {
9759                                         errorf(pos,
9760                                                         "'return' with a value, in function returning 'void'");
9761                                 } else {
9762                                         warningf(WARN_OTHER, pos, "'return' with a value, in function returning 'void'");
9763                                 }
9764                         } else if (!(c_mode & _CXX)) { /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9765                                 /* Only warn in C mode, because GCC does the same */
9766                                 if (strict_mode) {
9767                                         errorf(pos,
9768                                                         "'return' with expression in function returning 'void'");
9769                                 } else {
9770                                         warningf(WARN_OTHER, pos, "'return' with expression in function returning 'void'");
9771                                 }
9772                         }
9773                 } else {
9774                         assign_error_t error = semantic_assign(return_type, return_value);
9775                         report_assign_error(error, return_type, return_value, "'return'",
9776                                             pos);
9777                 }
9778                 return_value = create_implicit_cast(return_value, return_type);
9779                 /* check for returning address of a local var */
9780                 if (return_value != NULL && return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
9781                         const expression_t *expression = return_value->unary.value;
9782                         if (expression_is_local_variable(expression)) {
9783                                 warningf(WARN_OTHER, pos, "function returns address of local variable");
9784                         }
9785                 }
9786         } else if (!is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
9787                 /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9788                 if (c_mode & _CXX || strict_mode) {
9789                         errorf(pos,
9790                                "'return' without value, in function returning non-void");
9791                 } else {
9792                         warningf(WARN_OTHER, pos, "'return' without value, in function returning non-void");
9793                 }
9794         }
9795         statement->returns.value = return_value;
9796
9797         expect(';', end_error);
9798
9799 end_error:
9800         return statement;
9801 }
9802
9803 /**
9804  * Parse a declaration statement.
9805  */
9806 static statement_t *parse_declaration_statement(void)
9807 {
9808         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9809
9810         entity_t *before = current_scope->last_entity;
9811         if (GNU_MODE) {
9812                 parse_external_declaration();
9813         } else {
9814                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9815         }
9816
9817         declaration_statement_t *const decl  = &statement->declaration;
9818         entity_t                *const begin =
9819                 before != NULL ? before->base.next : current_scope->entities;
9820         decl->declarations_begin = begin;
9821         decl->declarations_end   = begin != NULL ? current_scope->last_entity : NULL;
9822
9823         return statement;
9824 }
9825
9826 /**
9827  * Parse an expression statement, ie. expr ';'.
9828  */
9829 static statement_t *parse_expression_statement(void)
9830 {
9831         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
9832
9833         expression_t *const expr         = parse_expression();
9834         statement->expression.expression = expr;
9835         mark_vars_read(expr, ENT_ANY);
9836
9837         expect(';', end_error);
9838
9839 end_error:
9840         return statement;
9841 }
9842
9843 /**
9844  * Parse a microsoft __try { } __finally { } or
9845  * __try{ } __except() { }
9846  */
9847 static statement_t *parse_ms_try_statment(void)
9848 {
9849         statement_t *statement = allocate_statement_zero(STATEMENT_MS_TRY);
9850         eat(T___try);
9851
9852         PUSH_PARENT(statement);
9853
9854         ms_try_statement_t *rem = current_try;
9855         current_try = &statement->ms_try;
9856         statement->ms_try.try_statement = parse_compound_statement(false);
9857         current_try = rem;
9858
9859         POP_PARENT();
9860
9861         if (next_if(T___except)) {
9862                 expect('(', end_error);
9863                 add_anchor_token(')');
9864                 expression_t *const expr = parse_expression();
9865                 mark_vars_read(expr, NULL);
9866                 type_t       *      type = skip_typeref(expr->base.type);
9867                 if (is_type_integer(type)) {
9868                         type = promote_integer(type);
9869                 } else if (is_type_valid(type)) {
9870                         errorf(&expr->base.source_position,
9871                                "__expect expression is not an integer, but '%T'", type);
9872                         type = type_error_type;
9873                 }
9874                 statement->ms_try.except_expression = create_implicit_cast(expr, type);
9875                 rem_anchor_token(')');
9876                 expect(')', end_error);
9877                 statement->ms_try.final_statement = parse_compound_statement(false);
9878         } else if (next_if(T__finally)) {
9879                 statement->ms_try.final_statement = parse_compound_statement(false);
9880         } else {
9881                 parse_error_expected("while parsing __try statement", T___except, T___finally, NULL);
9882                 return create_error_statement();
9883         }
9884         return statement;
9885 end_error:
9886         return create_error_statement();
9887 }
9888
9889 static statement_t *parse_empty_statement(void)
9890 {
9891         warningf(WARN_EMPTY_STATEMENT, HERE, "statement is empty");
9892         statement_t *const statement = create_empty_statement();
9893         eat(';');
9894         return statement;
9895 }
9896
9897 static statement_t *parse_local_label_declaration(void)
9898 {
9899         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9900
9901         eat(T___label__);
9902
9903         entity_t *begin   = NULL;
9904         entity_t *end     = NULL;
9905         entity_t **anchor = &begin;
9906         do {
9907                 if (token.kind != T_IDENTIFIER) {
9908                         parse_error_expected("while parsing local label declaration",
9909                                 T_IDENTIFIER, NULL);
9910                         goto end_error;
9911                 }
9912                 symbol_t *symbol = token.identifier.symbol;
9913                 entity_t *entity = get_entity(symbol, NAMESPACE_LABEL);
9914                 if (entity != NULL && entity->base.parent_scope == current_scope) {
9915                         source_position_t const *const ppos = &entity->base.source_position;
9916                         errorf(HERE, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
9917                 } else {
9918                         entity = allocate_entity_zero(ENTITY_LOCAL_LABEL, NAMESPACE_LABEL, symbol);
9919                         entity->base.parent_scope    = current_scope;
9920                         entity->base.source_position = token.base.source_position;
9921
9922                         *anchor = entity;
9923                         anchor  = &entity->base.next;
9924                         end     = entity;
9925
9926                         environment_push(entity);
9927                 }
9928                 next_token();
9929         } while (next_if(','));
9930         expect(';', end_error);
9931 end_error:
9932         statement->declaration.declarations_begin = begin;
9933         statement->declaration.declarations_end   = end;
9934         return statement;
9935 }
9936
9937 static void parse_namespace_definition(void)
9938 {
9939         eat(T_namespace);
9940
9941         entity_t *entity = NULL;
9942         symbol_t *symbol = NULL;
9943
9944         if (token.kind == T_IDENTIFIER) {
9945                 symbol = token.identifier.symbol;
9946                 next_token();
9947
9948                 entity = get_entity(symbol, NAMESPACE_NORMAL);
9949                 if (entity != NULL
9950                                 && entity->kind != ENTITY_NAMESPACE
9951                                 && entity->base.parent_scope == current_scope) {
9952                         if (is_entity_valid(entity)) {
9953                                 error_redefined_as_different_kind(&token.base.source_position,
9954                                                 entity, ENTITY_NAMESPACE);
9955                         }
9956                         entity = NULL;
9957                 }
9958         }
9959
9960         if (entity == NULL) {
9961                 entity = allocate_entity_zero(ENTITY_NAMESPACE, NAMESPACE_NORMAL, symbol);
9962                 entity->base.source_position = token.base.source_position;
9963                 entity->base.parent_scope    = current_scope;
9964         }
9965
9966         if (token.kind == '=') {
9967                 /* TODO: parse namespace alias */
9968                 panic("namespace alias definition not supported yet");
9969         }
9970
9971         environment_push(entity);
9972         append_entity(current_scope, entity);
9973
9974         PUSH_SCOPE(&entity->namespacee.members);
9975
9976         entity_t     *old_current_entity = current_entity;
9977         current_entity = entity;
9978
9979         expect('{', end_error);
9980         parse_externals();
9981         expect('}', end_error);
9982
9983 end_error:
9984         assert(current_entity == entity);
9985         current_entity = old_current_entity;
9986         POP_SCOPE();
9987 }
9988
9989 /**
9990  * Parse a statement.
9991  * There's also parse_statement() which additionally checks for
9992  * "statement has no effect" warnings
9993  */
9994 static statement_t *intern_parse_statement(void)
9995 {
9996         statement_t *statement = NULL;
9997
9998         /* declaration or statement */
9999         add_anchor_token(';');
10000         switch (token.kind) {
10001         case T_IDENTIFIER: {
10002                 token_kind_t la1_type = (token_kind_t)look_ahead(1)->kind;
10003                 if (la1_type == ':') {
10004                         statement = parse_label_statement();
10005                 } else if (is_typedef_symbol(token.identifier.symbol)) {
10006                         statement = parse_declaration_statement();
10007                 } else {
10008                         /* it's an identifier, the grammar says this must be an
10009                          * expression statement. However it is common that users mistype
10010                          * declaration types, so we guess a bit here to improve robustness
10011                          * for incorrect programs */
10012                         switch (la1_type) {
10013                         case '&':
10014                         case '*':
10015                                 if (get_entity(token.identifier.symbol, NAMESPACE_NORMAL) != NULL) {
10016                         default:
10017                                         statement = parse_expression_statement();
10018                                 } else {
10019                         DECLARATION_START
10020                         case T_IDENTIFIER:
10021                                         statement = parse_declaration_statement();
10022                                 }
10023                                 break;
10024                         }
10025                 }
10026                 break;
10027         }
10028
10029         case T___extension__: {
10030                 /* This can be a prefix to a declaration or an expression statement.
10031                  * We simply eat it now and parse the rest with tail recursion. */
10032                 PUSH_EXTENSION();
10033                 statement = intern_parse_statement();
10034                 POP_EXTENSION();
10035                 break;
10036         }
10037
10038         DECLARATION_START
10039                 statement = parse_declaration_statement();
10040                 break;
10041
10042         case T___label__:
10043                 statement = parse_local_label_declaration();
10044                 break;
10045
10046         case ';':         statement = parse_empty_statement();         break;
10047         case '{':         statement = parse_compound_statement(false); break;
10048         case T___leave:   statement = parse_leave_statement();         break;
10049         case T___try:     statement = parse_ms_try_statment();         break;
10050         case T_asm:       statement = parse_asm_statement();           break;
10051         case T_break:     statement = parse_break();                   break;
10052         case T_case:      statement = parse_case_statement();          break;
10053         case T_continue:  statement = parse_continue();                break;
10054         case T_default:   statement = parse_default_statement();       break;
10055         case T_do:        statement = parse_do();                      break;
10056         case T_for:       statement = parse_for();                     break;
10057         case T_goto:      statement = parse_goto();                    break;
10058         case T_if:        statement = parse_if();                      break;
10059         case T_return:    statement = parse_return();                  break;
10060         case T_switch:    statement = parse_switch();                  break;
10061         case T_while:     statement = parse_while();                   break;
10062
10063         EXPRESSION_START
10064                 statement = parse_expression_statement();
10065                 break;
10066
10067         default:
10068                 errorf(HERE, "unexpected token %K while parsing statement", &token);
10069                 statement = create_error_statement();
10070                 if (!at_anchor())
10071                         next_token();
10072                 break;
10073         }
10074         rem_anchor_token(';');
10075
10076         assert(statement != NULL
10077                         && statement->base.source_position.input_name != NULL);
10078
10079         return statement;
10080 }
10081
10082 /**
10083  * parse a statement and emits "statement has no effect" warning if needed
10084  * (This is really a wrapper around intern_parse_statement with check for 1
10085  *  single warning. It is needed, because for statement expressions we have
10086  *  to avoid the warning on the last statement)
10087  */
10088 static statement_t *parse_statement(void)
10089 {
10090         statement_t *statement = intern_parse_statement();
10091
10092         if (statement->kind == STATEMENT_EXPRESSION) {
10093                 expression_t *expression = statement->expression.expression;
10094                 if (!expression_has_effect(expression)) {
10095                         warningf(WARN_UNUSED_VALUE, &expression->base.source_position, "statement has no effect");
10096                 }
10097         }
10098
10099         return statement;
10100 }
10101
10102 /**
10103  * Parse a compound statement.
10104  */
10105 static statement_t *parse_compound_statement(bool inside_expression_statement)
10106 {
10107         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
10108
10109         PUSH_PARENT(statement);
10110         PUSH_SCOPE(&statement->compound.scope);
10111
10112         eat('{');
10113         add_anchor_token('}');
10114         /* tokens, which can start a statement */
10115         /* TODO MS, __builtin_FOO */
10116         add_anchor_token('!');
10117         add_anchor_token('&');
10118         add_anchor_token('(');
10119         add_anchor_token('*');
10120         add_anchor_token('+');
10121         add_anchor_token('-');
10122         add_anchor_token('{');
10123         add_anchor_token('~');
10124         add_anchor_token(T_CHARACTER_CONSTANT);
10125         add_anchor_token(T_COLONCOLON);
10126         add_anchor_token(T_FLOATINGPOINT);
10127         add_anchor_token(T_IDENTIFIER);
10128         add_anchor_token(T_INTEGER);
10129         add_anchor_token(T_MINUSMINUS);
10130         add_anchor_token(T_PLUSPLUS);
10131         add_anchor_token(T_STRING_LITERAL);
10132         add_anchor_token(T_WIDE_CHARACTER_CONSTANT);
10133         add_anchor_token(T_WIDE_STRING_LITERAL);
10134         add_anchor_token(T__Bool);
10135         add_anchor_token(T__Complex);
10136         add_anchor_token(T__Imaginary);
10137         add_anchor_token(T___FUNCTION__);
10138         add_anchor_token(T___PRETTY_FUNCTION__);
10139         add_anchor_token(T___alignof__);
10140         add_anchor_token(T___attribute__);
10141         add_anchor_token(T___builtin_va_start);
10142         add_anchor_token(T___extension__);
10143         add_anchor_token(T___func__);
10144         add_anchor_token(T___imag__);
10145         add_anchor_token(T___label__);
10146         add_anchor_token(T___real__);
10147         add_anchor_token(T___thread);
10148         add_anchor_token(T_asm);
10149         add_anchor_token(T_auto);
10150         add_anchor_token(T_bool);
10151         add_anchor_token(T_break);
10152         add_anchor_token(T_case);
10153         add_anchor_token(T_char);
10154         add_anchor_token(T_class);
10155         add_anchor_token(T_const);
10156         add_anchor_token(T_const_cast);
10157         add_anchor_token(T_continue);
10158         add_anchor_token(T_default);
10159         add_anchor_token(T_delete);
10160         add_anchor_token(T_double);
10161         add_anchor_token(T_do);
10162         add_anchor_token(T_dynamic_cast);
10163         add_anchor_token(T_enum);
10164         add_anchor_token(T_extern);
10165         add_anchor_token(T_false);
10166         add_anchor_token(T_float);
10167         add_anchor_token(T_for);
10168         add_anchor_token(T_goto);
10169         add_anchor_token(T_if);
10170         add_anchor_token(T_inline);
10171         add_anchor_token(T_int);
10172         add_anchor_token(T_long);
10173         add_anchor_token(T_new);
10174         add_anchor_token(T_operator);
10175         add_anchor_token(T_register);
10176         add_anchor_token(T_reinterpret_cast);
10177         add_anchor_token(T_restrict);
10178         add_anchor_token(T_return);
10179         add_anchor_token(T_short);
10180         add_anchor_token(T_signed);
10181         add_anchor_token(T_sizeof);
10182         add_anchor_token(T_static);
10183         add_anchor_token(T_static_cast);
10184         add_anchor_token(T_struct);
10185         add_anchor_token(T_switch);
10186         add_anchor_token(T_template);
10187         add_anchor_token(T_this);
10188         add_anchor_token(T_throw);
10189         add_anchor_token(T_true);
10190         add_anchor_token(T_try);
10191         add_anchor_token(T_typedef);
10192         add_anchor_token(T_typeid);
10193         add_anchor_token(T_typename);
10194         add_anchor_token(T_typeof);
10195         add_anchor_token(T_union);
10196         add_anchor_token(T_unsigned);
10197         add_anchor_token(T_using);
10198         add_anchor_token(T_void);
10199         add_anchor_token(T_volatile);
10200         add_anchor_token(T_wchar_t);
10201         add_anchor_token(T_while);
10202
10203         statement_t **anchor            = &statement->compound.statements;
10204         bool          only_decls_so_far = true;
10205         while (token.kind != '}') {
10206                 if (token.kind == T_EOF) {
10207                         errorf(&statement->base.source_position,
10208                                "EOF while parsing compound statement");
10209                         break;
10210                 }
10211                 statement_t *sub_statement = intern_parse_statement();
10212                 if (sub_statement->kind == STATEMENT_ERROR) {
10213                         /* an error occurred. if we are at an anchor, return */
10214                         if (at_anchor())
10215                                 goto end_error;
10216                         continue;
10217                 }
10218
10219                 if (sub_statement->kind != STATEMENT_DECLARATION) {
10220                         only_decls_so_far = false;
10221                 } else if (!only_decls_so_far) {
10222                         source_position_t const *const pos = &sub_statement->base.source_position;
10223                         warningf(WARN_DECLARATION_AFTER_STATEMENT, pos, "ISO C90 forbids mixed declarations and code");
10224                 }
10225
10226                 *anchor = sub_statement;
10227
10228                 while (sub_statement->base.next != NULL)
10229                         sub_statement = sub_statement->base.next;
10230
10231                 anchor = &sub_statement->base.next;
10232         }
10233         next_token();
10234
10235         /* look over all statements again to produce no effect warnings */
10236         if (is_warn_on(WARN_UNUSED_VALUE)) {
10237                 statement_t *sub_statement = statement->compound.statements;
10238                 for (; sub_statement != NULL; sub_statement = sub_statement->base.next) {
10239                         if (sub_statement->kind != STATEMENT_EXPRESSION)
10240                                 continue;
10241                         /* don't emit a warning for the last expression in an expression
10242                          * statement as it has always an effect */
10243                         if (inside_expression_statement && sub_statement->base.next == NULL)
10244                                 continue;
10245
10246                         expression_t *expression = sub_statement->expression.expression;
10247                         if (!expression_has_effect(expression)) {
10248                                 warningf(WARN_UNUSED_VALUE, &expression->base.source_position, "statement has no effect");
10249                         }
10250                 }
10251         }
10252
10253 end_error:
10254         rem_anchor_token(T_while);
10255         rem_anchor_token(T_wchar_t);
10256         rem_anchor_token(T_volatile);
10257         rem_anchor_token(T_void);
10258         rem_anchor_token(T_using);
10259         rem_anchor_token(T_unsigned);
10260         rem_anchor_token(T_union);
10261         rem_anchor_token(T_typeof);
10262         rem_anchor_token(T_typename);
10263         rem_anchor_token(T_typeid);
10264         rem_anchor_token(T_typedef);
10265         rem_anchor_token(T_try);
10266         rem_anchor_token(T_true);
10267         rem_anchor_token(T_throw);
10268         rem_anchor_token(T_this);
10269         rem_anchor_token(T_template);
10270         rem_anchor_token(T_switch);
10271         rem_anchor_token(T_struct);
10272         rem_anchor_token(T_static_cast);
10273         rem_anchor_token(T_static);
10274         rem_anchor_token(T_sizeof);
10275         rem_anchor_token(T_signed);
10276         rem_anchor_token(T_short);
10277         rem_anchor_token(T_return);
10278         rem_anchor_token(T_restrict);
10279         rem_anchor_token(T_reinterpret_cast);
10280         rem_anchor_token(T_register);
10281         rem_anchor_token(T_operator);
10282         rem_anchor_token(T_new);
10283         rem_anchor_token(T_long);
10284         rem_anchor_token(T_int);
10285         rem_anchor_token(T_inline);
10286         rem_anchor_token(T_if);
10287         rem_anchor_token(T_goto);
10288         rem_anchor_token(T_for);
10289         rem_anchor_token(T_float);
10290         rem_anchor_token(T_false);
10291         rem_anchor_token(T_extern);
10292         rem_anchor_token(T_enum);
10293         rem_anchor_token(T_dynamic_cast);
10294         rem_anchor_token(T_do);
10295         rem_anchor_token(T_double);
10296         rem_anchor_token(T_delete);
10297         rem_anchor_token(T_default);
10298         rem_anchor_token(T_continue);
10299         rem_anchor_token(T_const_cast);
10300         rem_anchor_token(T_const);
10301         rem_anchor_token(T_class);
10302         rem_anchor_token(T_char);
10303         rem_anchor_token(T_case);
10304         rem_anchor_token(T_break);
10305         rem_anchor_token(T_bool);
10306         rem_anchor_token(T_auto);
10307         rem_anchor_token(T_asm);
10308         rem_anchor_token(T___thread);
10309         rem_anchor_token(T___real__);
10310         rem_anchor_token(T___label__);
10311         rem_anchor_token(T___imag__);
10312         rem_anchor_token(T___func__);
10313         rem_anchor_token(T___extension__);
10314         rem_anchor_token(T___builtin_va_start);
10315         rem_anchor_token(T___attribute__);
10316         rem_anchor_token(T___alignof__);
10317         rem_anchor_token(T___PRETTY_FUNCTION__);
10318         rem_anchor_token(T___FUNCTION__);
10319         rem_anchor_token(T__Imaginary);
10320         rem_anchor_token(T__Complex);
10321         rem_anchor_token(T__Bool);
10322         rem_anchor_token(T_WIDE_STRING_LITERAL);
10323         rem_anchor_token(T_WIDE_CHARACTER_CONSTANT);
10324         rem_anchor_token(T_STRING_LITERAL);
10325         rem_anchor_token(T_PLUSPLUS);
10326         rem_anchor_token(T_MINUSMINUS);
10327         rem_anchor_token(T_INTEGER);
10328         rem_anchor_token(T_IDENTIFIER);
10329         rem_anchor_token(T_FLOATINGPOINT);
10330         rem_anchor_token(T_COLONCOLON);
10331         rem_anchor_token(T_CHARACTER_CONSTANT);
10332         rem_anchor_token('~');
10333         rem_anchor_token('{');
10334         rem_anchor_token('-');
10335         rem_anchor_token('+');
10336         rem_anchor_token('*');
10337         rem_anchor_token('(');
10338         rem_anchor_token('&');
10339         rem_anchor_token('!');
10340         rem_anchor_token('}');
10341
10342         POP_SCOPE();
10343         POP_PARENT();
10344         return statement;
10345 }
10346
10347 /**
10348  * Check for unused global static functions and variables
10349  */
10350 static void check_unused_globals(void)
10351 {
10352         if (!is_warn_on(WARN_UNUSED_FUNCTION) && !is_warn_on(WARN_UNUSED_VARIABLE))
10353                 return;
10354
10355         for (const entity_t *entity = file_scope->entities; entity != NULL;
10356              entity = entity->base.next) {
10357                 if (!is_declaration(entity))
10358                         continue;
10359
10360                 const declaration_t *declaration = &entity->declaration;
10361                 if (declaration->used                  ||
10362                     declaration->modifiers & DM_UNUSED ||
10363                     declaration->modifiers & DM_USED   ||
10364                     declaration->storage_class != STORAGE_CLASS_STATIC)
10365                         continue;
10366
10367                 warning_t   why;
10368                 char const *s;
10369                 if (entity->kind == ENTITY_FUNCTION) {
10370                         /* inhibit warning for static inline functions */
10371                         if (entity->function.is_inline)
10372                                 continue;
10373
10374                         why = WARN_UNUSED_FUNCTION;
10375                         s   = entity->function.statement != NULL ? "defined" : "declared";
10376                 } else {
10377                         why = WARN_UNUSED_VARIABLE;
10378                         s   = "defined";
10379                 }
10380
10381                 warningf(why, &declaration->base.source_position, "'%#N' %s but not used", entity, s);
10382         }
10383 }
10384
10385 static void parse_global_asm(void)
10386 {
10387         statement_t *statement = allocate_statement_zero(STATEMENT_ASM);
10388
10389         eat(T_asm);
10390         expect('(', end_error);
10391
10392         statement->asms.asm_text = parse_string_literals();
10393         statement->base.next     = unit->global_asm;
10394         unit->global_asm         = statement;
10395
10396         expect(')', end_error);
10397         expect(';', end_error);
10398
10399 end_error:;
10400 }
10401
10402 static void parse_linkage_specification(void)
10403 {
10404         eat(T_extern);
10405
10406         source_position_t const pos     = *HERE;
10407         char const       *const linkage = parse_string_literals().begin;
10408
10409         linkage_kind_t old_linkage = current_linkage;
10410         linkage_kind_t new_linkage;
10411         if (streq(linkage, "C")) {
10412                 new_linkage = LINKAGE_C;
10413         } else if (streq(linkage, "C++")) {
10414                 new_linkage = LINKAGE_CXX;
10415         } else {
10416                 errorf(&pos, "linkage string \"%s\" not recognized", linkage);
10417                 new_linkage = LINKAGE_C;
10418         }
10419         current_linkage = new_linkage;
10420
10421         if (next_if('{')) {
10422                 parse_externals();
10423                 expect('}', end_error);
10424         } else {
10425                 parse_external();
10426         }
10427
10428 end_error:
10429         assert(current_linkage == new_linkage);
10430         current_linkage = old_linkage;
10431 }
10432
10433 static void parse_external(void)
10434 {
10435         switch (token.kind) {
10436                 case T_extern:
10437                         if (look_ahead(1)->kind == T_STRING_LITERAL) {
10438                                 parse_linkage_specification();
10439                         } else {
10440                 DECLARATION_START_NO_EXTERN
10441                 case T_IDENTIFIER:
10442                 case T___extension__:
10443                 /* tokens below are for implicit int */
10444                 case '&':  /* & x; -> int& x; (and error later, because C++ has no
10445                               implicit int) */
10446                 case '*':  /* * x; -> int* x; */
10447                 case '(':  /* (x); -> int (x); */
10448                                 PUSH_EXTENSION();
10449                                 parse_external_declaration();
10450                                 POP_EXTENSION();
10451                         }
10452                         return;
10453
10454                 case T_asm:
10455                         parse_global_asm();
10456                         return;
10457
10458                 case T_namespace:
10459                         parse_namespace_definition();
10460                         return;
10461
10462                 case ';':
10463                         if (!strict_mode) {
10464                                 warningf(WARN_STRAY_SEMICOLON, HERE, "stray ';' outside of function");
10465                                 next_token();
10466                                 return;
10467                         }
10468                         /* FALLTHROUGH */
10469
10470                 default:
10471                         errorf(HERE, "stray %K outside of function", &token);
10472                         if (token.kind == '(' || token.kind == '{' || token.kind == '[')
10473                                 eat_until_matching_token(token.kind);
10474                         next_token();
10475                         return;
10476         }
10477 }
10478
10479 static void parse_externals(void)
10480 {
10481         add_anchor_token('}');
10482         add_anchor_token(T_EOF);
10483
10484 #ifndef NDEBUG
10485         /* make a copy of the anchor set, so we can check if it is restored after parsing */
10486         unsigned short token_anchor_copy[T_LAST_TOKEN];
10487         memcpy(token_anchor_copy, token_anchor_set, sizeof(token_anchor_copy));
10488 #endif
10489
10490         while (token.kind != T_EOF && token.kind != '}') {
10491 #ifndef NDEBUG
10492                 for (int i = 0; i < T_LAST_TOKEN; ++i) {
10493                         unsigned short count = token_anchor_set[i] - token_anchor_copy[i];
10494                         if (count != 0) {
10495                                 /* the anchor set and its copy differs */
10496                                 internal_errorf(HERE, "Leaked anchor token %k %d times", i, count);
10497                         }
10498                 }
10499                 if (in_gcc_extension) {
10500                         /* an gcc extension scope was not closed */
10501                         internal_errorf(HERE, "Leaked __extension__");
10502                 }
10503 #endif
10504
10505                 parse_external();
10506         }
10507
10508         rem_anchor_token(T_EOF);
10509         rem_anchor_token('}');
10510 }
10511
10512 /**
10513  * Parse a translation unit.
10514  */
10515 static void parse_translation_unit(void)
10516 {
10517         add_anchor_token(T_EOF);
10518
10519         while (true) {
10520                 parse_externals();
10521
10522                 if (token.kind == T_EOF)
10523                         break;
10524
10525                 errorf(HERE, "stray %K outside of function", &token);
10526                 if (token.kind == '(' || token.kind == '{' || token.kind == '[')
10527                         eat_until_matching_token(token.kind);
10528                 next_token();
10529         }
10530 }
10531
10532 void set_default_visibility(elf_visibility_tag_t visibility)
10533 {
10534         default_visibility = visibility;
10535 }
10536
10537 /**
10538  * Parse the input.
10539  *
10540  * @return  the translation unit or NULL if errors occurred.
10541  */
10542 void start_parsing(void)
10543 {
10544         environment_stack = NEW_ARR_F(stack_entry_t, 0);
10545         label_stack       = NEW_ARR_F(stack_entry_t, 0);
10546         diagnostic_count  = 0;
10547         error_count       = 0;
10548         warning_count     = 0;
10549
10550         print_to_file(stderr);
10551
10552         assert(unit == NULL);
10553         unit = allocate_ast_zero(sizeof(unit[0]));
10554
10555         assert(file_scope == NULL);
10556         file_scope = &unit->scope;
10557
10558         assert(current_scope == NULL);
10559         scope_push(&unit->scope);
10560
10561         create_gnu_builtins();
10562         if (c_mode & _MS)
10563                 create_microsoft_intrinsics();
10564 }
10565
10566 translation_unit_t *finish_parsing(void)
10567 {
10568         assert(current_scope == &unit->scope);
10569         scope_pop(NULL);
10570
10571         assert(file_scope == &unit->scope);
10572         check_unused_globals();
10573         file_scope = NULL;
10574
10575         DEL_ARR_F(environment_stack);
10576         DEL_ARR_F(label_stack);
10577
10578         translation_unit_t *result = unit;
10579         unit = NULL;
10580         return result;
10581 }
10582
10583 /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
10584  * are given length one. */
10585 static void complete_incomplete_arrays(void)
10586 {
10587         size_t n = ARR_LEN(incomplete_arrays);
10588         for (size_t i = 0; i != n; ++i) {
10589                 declaration_t *const decl = incomplete_arrays[i];
10590                 type_t        *const type = skip_typeref(decl->type);
10591
10592                 if (!is_type_incomplete(type))
10593                         continue;
10594
10595                 source_position_t const *const pos = &decl->base.source_position;
10596                 warningf(WARN_OTHER, pos, "array '%#N' assumed to have one element", (entity_t const*)decl);
10597
10598                 type_t *const new_type = duplicate_type(type);
10599                 new_type->array.size_constant     = true;
10600                 new_type->array.has_implicit_size = true;
10601                 new_type->array.size              = 1;
10602
10603                 type_t *const result = identify_new_type(new_type);
10604
10605                 decl->type = result;
10606         }
10607 }
10608
10609 void prepare_main_collect2(entity_t *entity)
10610 {
10611         PUSH_SCOPE(&entity->function.statement->compound.scope);
10612
10613         // create call to __main
10614         symbol_t *symbol         = symbol_table_insert("__main");
10615         entity_t *subsubmain_ent
10616                 = create_implicit_function(symbol, &builtin_source_position);
10617
10618         expression_t *ref         = allocate_expression_zero(EXPR_REFERENCE);
10619         type_t       *ftype       = subsubmain_ent->declaration.type;
10620         ref->base.source_position = builtin_source_position;
10621         ref->base.type            = make_pointer_type(ftype, TYPE_QUALIFIER_NONE);
10622         ref->reference.entity     = subsubmain_ent;
10623
10624         expression_t *call = allocate_expression_zero(EXPR_CALL);
10625         call->base.source_position = builtin_source_position;
10626         call->base.type            = type_void;
10627         call->call.function        = ref;
10628
10629         statement_t *expr_statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10630         expr_statement->base.source_position  = builtin_source_position;
10631         expr_statement->expression.expression = call;
10632
10633         statement_t *statement = entity->function.statement;
10634         assert(statement->kind == STATEMENT_COMPOUND);
10635         compound_statement_t *compounds = &statement->compound;
10636
10637         expr_statement->base.next = compounds->statements;
10638         compounds->statements     = expr_statement;
10639
10640         POP_SCOPE();
10641 }
10642
10643 void parse(void)
10644 {
10645         lookahead_bufpos = 0;
10646         for (int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
10647                 next_token();
10648         }
10649         current_linkage   = c_mode & _CXX ? LINKAGE_CXX : LINKAGE_C;
10650         incomplete_arrays = NEW_ARR_F(declaration_t*, 0);
10651         parse_translation_unit();
10652         complete_incomplete_arrays();
10653         DEL_ARR_F(incomplete_arrays);
10654         incomplete_arrays = NULL;
10655 }
10656
10657 /**
10658  * Initialize the parser.
10659  */
10660 void init_parser(void)
10661 {
10662         sym_anonymous = symbol_table_insert("<anonymous>");
10663
10664         memset(token_anchor_set, 0, sizeof(token_anchor_set));
10665
10666         init_expression_parsers();
10667         obstack_init(&temp_obst);
10668 }
10669
10670 /**
10671  * Terminate the parser.
10672  */
10673 void exit_parser(void)
10674 {
10675         obstack_free(&temp_obst, NULL);
10676 }