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_COMPUTED_GOTO] = sizeof(computed_goto_statement_t),
 298                 [STATEMENT_GOTO]          = sizeof(goto_statement_t),
 299                 [STATEMENT_LABEL]         = sizeof(label_statement_t),
 300                 [STATEMENT_CASE_LABEL]    = sizeof(case_label_statement_t),
 301                 [STATEMENT_WHILE]         = sizeof(while_statement_t),
 302                 [STATEMENT_DO_WHILE]      = sizeof(do_while_statement_t),
 303                 [STATEMENT_FOR]           = sizeof(for_statement_t),
 304                 [STATEMENT_ASM]           = sizeof(asm_statement_t),
 305                 [STATEMENT_MS_TRY]        = sizeof(ms_try_statement_t),
 306                 [STATEMENT_LEAVE]         = sizeof(leave_statement_t)
 307         };
 308         assert((size_t)kind < lengthof(sizes));
 309         assert(sizes[kind] != 0);
 310         return sizes[kind];
 311 }
 312
 313 /**
 314  * Returns the size of an expression node.
 315  *
 316  * @param kind  the expression kind
 317  */
 318 static size_t get_expression_struct_size(expression_kind_t kind)
 319 {
 320         static const size_t sizes[] = {
 321                 [EXPR_ERROR]                      = sizeof(expression_base_t),
 322                 [EXPR_REFERENCE]                  = sizeof(reference_expression_t),
 323                 [EXPR_ENUM_CONSTANT]              = sizeof(reference_expression_t),
 324                 [EXPR_LITERAL_BOOLEAN]            = sizeof(literal_expression_t),
 325                 [EXPR_LITERAL_INTEGER]            = sizeof(literal_expression_t),
 326                 [EXPR_LITERAL_INTEGER_OCTAL]      = sizeof(literal_expression_t),
 327                 [EXPR_LITERAL_INTEGER_HEXADECIMAL]= sizeof(literal_expression_t),
 328                 [EXPR_LITERAL_FLOATINGPOINT]      = sizeof(literal_expression_t),
 329                 [EXPR_LITERAL_FLOATINGPOINT_HEXADECIMAL] = sizeof(literal_expression_t),
 330                 [EXPR_LITERAL_CHARACTER]          = sizeof(literal_expression_t),
 331                 [EXPR_LITERAL_WIDE_CHARACTER]     = sizeof(literal_expression_t),
 332                 [EXPR_STRING_LITERAL]             = sizeof(string_literal_expression_t),
 333                 [EXPR_WIDE_STRING_LITERAL]        = sizeof(string_literal_expression_t),
 334                 [EXPR_COMPOUND_LITERAL]           = sizeof(compound_literal_expression_t),
 335                 [EXPR_CALL]                       = sizeof(call_expression_t),
 336                 [EXPR_UNARY_FIRST]                = sizeof(unary_expression_t),
 337                 [EXPR_BINARY_FIRST]               = sizeof(binary_expression_t),
 338                 [EXPR_CONDITIONAL]                = sizeof(conditional_expression_t),
 339                 [EXPR_SELECT]                     = sizeof(select_expression_t),
 340                 [EXPR_ARRAY_ACCESS]               = sizeof(array_access_expression_t),
 341                 [EXPR_SIZEOF]                     = sizeof(typeprop_expression_t),
 342                 [EXPR_ALIGNOF]                    = sizeof(typeprop_expression_t),
 343                 [EXPR_CLASSIFY_TYPE]              = sizeof(classify_type_expression_t),
 344                 [EXPR_FUNCNAME]                   = sizeof(funcname_expression_t),
 345                 [EXPR_BUILTIN_CONSTANT_P]         = sizeof(builtin_constant_expression_t),
 346                 [EXPR_BUILTIN_TYPES_COMPATIBLE_P] = sizeof(builtin_types_compatible_expression_t),
 347                 [EXPR_OFFSETOF]                   = sizeof(offsetof_expression_t),
 348                 [EXPR_VA_START]                   = sizeof(va_start_expression_t),
 349                 [EXPR_VA_ARG]                     = sizeof(va_arg_expression_t),
 350                 [EXPR_VA_COPY]                    = sizeof(va_copy_expression_t),
 351                 [EXPR_STATEMENT]                  = sizeof(statement_expression_t),
 352                 [EXPR_LABEL_ADDRESS]              = sizeof(label_address_expression_t),
 353         };
 354         if (kind >= EXPR_UNARY_FIRST && kind <= EXPR_UNARY_LAST) {
 355                 return sizes[EXPR_UNARY_FIRST];
 356         }
 357         if (kind >= EXPR_BINARY_FIRST && kind <= EXPR_BINARY_LAST) {
 358                 return sizes[EXPR_BINARY_FIRST];
 359         }
 360         assert((size_t)kind < lengthof(sizes));
 361         assert(sizes[kind] != 0);
 362         return sizes[kind];
 363 }
 364
 365 /**
 366  * Allocate a statement node of given kind and initialize all
 367  * fields with zero. Sets its source position to the position
 368  * of the current token.
 369  */
 370 static statement_t *allocate_statement_zero(statement_kind_t kind)
 371 {
 372         size_t       size = get_statement_struct_size(kind);
 373         statement_t *res  = allocate_ast_zero(size);
 374
 375         res->base.kind            = kind;
 376         res->base.parent          = current_parent;
 377         res->base.source_position = token.base.source_position;
 378         return res;
 379 }
 380
 381 /**
 382  * Allocate an expression node of given kind and initialize all
 383  * fields with zero.
 384  *
 385  * @param kind  the kind of the expression to allocate
 386  */
 387 static expression_t *allocate_expression_zero(expression_kind_t kind)
 388 {
 389         size_t        size = get_expression_struct_size(kind);
 390         expression_t *res  = allocate_ast_zero(size);
 391
 392         res->base.kind            = kind;
 393         res->base.type            = type_error_type;
 394         res->base.source_position = token.base.source_position;
 395         return res;
 396 }
 397
 398 /**
 399  * Creates a new invalid expression at the source position
 400  * of the current token.
 401  */
 402 static expression_t *create_error_expression(void)
 403 {
 404         expression_t *expression = allocate_expression_zero(EXPR_ERROR);
 405         expression->base.type = type_error_type;
 406         return expression;
 407 }
 408
 409 /**
 410  * Creates a new invalid statement.
 411  */
 412 static statement_t *create_error_statement(void)
 413 {
 414         return allocate_statement_zero(STATEMENT_ERROR);
 415 }
 416
 417 /**
 418  * Allocate a new empty statement.
 419  */
 420 static statement_t *create_empty_statement(void)
 421 {
 422         return allocate_statement_zero(STATEMENT_EMPTY);
 423 }
 424
 425 /**
 426  * Returns the size of an initializer node.
 427  *
 428  * @param kind  the initializer kind
 429  */
 430 static size_t get_initializer_size(initializer_kind_t kind)
 431 {
 432         static const size_t sizes[] = {
 433                 [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
 434                 [INITIALIZER_STRING]      = sizeof(initializer_string_t),
 435                 [INITIALIZER_WIDE_STRING] = sizeof(initializer_wide_string_t),
 436                 [INITIALIZER_LIST]        = sizeof(initializer_list_t),
 437                 [INITIALIZER_DESIGNATOR]  = sizeof(initializer_designator_t)
 438         };
 439         assert((size_t)kind < lengthof(sizes));
 440         assert(sizes[kind] != 0);
 441         return sizes[kind];
 442 }
 443
 444 /**
 445  * Allocate an initializer node of given kind and initialize all
 446  * fields with zero.
 447  */
 448 static initializer_t *allocate_initializer_zero(initializer_kind_t kind)
 449 {
 450         initializer_t *result = allocate_ast_zero(get_initializer_size(kind));
 451         result->kind          = kind;
 452
 453         return result;
 454 }
 455
 456 /**
 457  * Returns the index of the top element of the environment stack.
 458  */
 459 static size_t environment_top(void)
 460 {
 461         return ARR_LEN(environment_stack);
 462 }
 463
 464 /**
 465  * Returns the index of the top element of the global label stack.
 466  */
 467 static size_t label_top(void)
 468 {
 469         return ARR_LEN(label_stack);
 470 }
 471
 472 /**
 473  * Return the next token.
 474  */
 475 static inline void next_token(void)
 476 {
 477         token                              = lookahead_buffer[lookahead_bufpos];
 478         lookahead_buffer[lookahead_bufpos] = lexer_token;
 479         lexer_next_token();
 480
 481         lookahead_bufpos = (lookahead_bufpos + 1) % MAX_LOOKAHEAD;
 482
 483 #ifdef PRINT_TOKENS
 484         print_token(stderr, &token);
 485         fprintf(stderr, "\n");
 486 #endif
 487 }
 488
 489 static inline bool next_if(int const type)
 490 {
 491         if (token.kind == type) {
 492                 next_token();
 493                 return true;
 494         } else {
 495                 return false;
 496         }
 497 }
 498
 499 /**
 500  * Return the next token with a given lookahead.
 501  */
 502 static inline const token_t *look_ahead(size_t num)
 503 {
 504         assert(0 < num && num <= MAX_LOOKAHEAD);
 505         size_t pos = (lookahead_bufpos + num - 1) % MAX_LOOKAHEAD;
 506         return &lookahead_buffer[pos];
 507 }
 508
 509 /**
 510  * Adds a token type to the token type anchor set (a multi-set).
 511  */
 512 static void add_anchor_token(int token_kind)
 513 {
 514         assert(0 <= token_kind && token_kind < T_LAST_TOKEN);
 515         ++token_anchor_set[token_kind];
 516 }
 517
 518 /**
 519  * Set the number of tokens types of the given type
 520  * to zero and return the old count.
 521  */
 522 static int save_and_reset_anchor_state(int token_kind)
 523 {
 524         assert(0 <= token_kind && token_kind < T_LAST_TOKEN);
 525         int count = token_anchor_set[token_kind];
 526         token_anchor_set[token_kind] = 0;
 527         return count;
 528 }
 529
 530 /**
 531  * Restore the number of token types to the given count.
 532  */
 533 static void restore_anchor_state(int token_kind, int count)
 534 {
 535         assert(0 <= token_kind && token_kind < T_LAST_TOKEN);
 536         token_anchor_set[token_kind] = count;
 537 }
 538
 539 /**
 540  * Remove a token type from the token type anchor set (a multi-set).
 541  */
 542 static void rem_anchor_token(int token_kind)
 543 {
 544         assert(0 <= token_kind && token_kind < T_LAST_TOKEN);
 545         assert(token_anchor_set[token_kind] != 0);
 546         --token_anchor_set[token_kind];
 547 }
 548
 549 /**
 550  * Eat tokens until a matching token type is found.
 551  */
 552 static void eat_until_matching_token(int type)
 553 {
 554         int end_token;
 555         switch (type) {
 556                 case '(': end_token = ')';  break;
 557                 case '{': end_token = '}';  break;
 558                 case '[': end_token = ']';  break;
 559                 default:  end_token = type; break;
 560         }
 561
 562         unsigned parenthesis_count = 0;
 563         unsigned brace_count       = 0;
 564         unsigned bracket_count     = 0;
 565         while (token.kind        != end_token ||
 566                parenthesis_count != 0         ||
 567                brace_count       != 0         ||
 568                bracket_count     != 0) {
 569                 switch (token.kind) {
 570                 case T_EOF: return;
 571                 case '(': ++parenthesis_count; break;
 572                 case '{': ++brace_count;       break;
 573                 case '[': ++bracket_count;     break;
 574
 575                 case ')':
 576                         if (parenthesis_count > 0)
 577                                 --parenthesis_count;
 578                         goto check_stop;
 579
 580                 case '}':
 581                         if (brace_count > 0)
 582                                 --brace_count;
 583                         goto check_stop;
 584
 585                 case ']':
 586                         if (bracket_count > 0)
 587                                 --bracket_count;
 588 check_stop:
 589                         if (token.kind        == end_token &&
 590                             parenthesis_count == 0         &&
 591                             brace_count       == 0         &&
 592                             bracket_count     == 0)
 593                                 return;
 594                         break;
 595
 596                 default:
 597                         break;
 598                 }
 599                 next_token();
 600         }
 601 }
 602
 603 /**
 604  * Eat input tokens until an anchor is found.
 605  */
 606 static void eat_until_anchor(void)
 607 {
 608         while (token_anchor_set[token.kind] == 0) {
 609                 if (token.kind == '(' || token.kind == '{' || token.kind == '[')
 610                         eat_until_matching_token(token.kind);
 611                 next_token();
 612         }
 613 }
 614
 615 /**
 616  * Eat a whole block from input tokens.
 617  */
 618 static void eat_block(void)
 619 {
 620         eat_until_matching_token('{');
 621         next_if('}');
 622 }
 623
 624 #define eat(token_kind) (assert(token.kind == (token_kind)), next_token())
 625
 626 /**
 627  * Report a parse error because an expected token was not found.
 628  */
 629 static
 630 #if defined __GNUC__ && __GNUC__ >= 4
 631 __attribute__((sentinel))
 632 #endif
 633 void parse_error_expected(const char *message, ...)
 634 {
 635         if (message != NULL) {
 636                 errorf(HERE, "%s", message);
 637         }
 638         va_list ap;
 639         va_start(ap, message);
 640         errorf(HERE, "got %K, expected %#k", &token, &ap, ", ");
 641         va_end(ap);
 642 }
 643
 644 /**
 645  * Report an incompatible type.
 646  */
 647 static void type_error_incompatible(const char *msg,
 648                 const source_position_t *source_position, type_t *type1, type_t *type2)
 649 {
 650         errorf(source_position, "%s, incompatible types: '%T' - '%T'",
 651                msg, type1, type2);
 652 }
 653
 654 /**
 655  * Expect the current token is the expected token.
 656  * If not, generate an error, eat the current statement,
 657  * and goto the error_label label.
 658  */
 659 #define expect(expected, error_label)                     \
 660         do {                                                  \
 661                 if (UNLIKELY(token.kind != (expected))) {         \
 662                         parse_error_expected(NULL, (expected), NULL); \
 663                         add_anchor_token(expected);                   \
 664                         eat_until_anchor();                           \
 665                         rem_anchor_token(expected);                   \
 666                         if (token.kind != (expected))                 \
 667                           goto error_label;                           \
 668                 }                                                 \
 669                 next_token();                                     \
 670         } while (0)
 671
 672 /**
 673  * Push a given scope on the scope stack and make it the
 674  * current scope
 675  */
 676 static scope_t *scope_push(scope_t *new_scope)
 677 {
 678         if (current_scope != NULL) {
 679                 new_scope->depth = current_scope->depth + 1;
 680         }
 681
 682         scope_t *old_scope = current_scope;
 683         current_scope      = new_scope;
 684         return old_scope;
 685 }
 686
 687 /**
 688  * Pop the current scope from the scope stack.
 689  */
 690 static void scope_pop(scope_t *old_scope)
 691 {
 692         current_scope = old_scope;
 693 }
 694
 695 /**
 696  * Search an entity by its symbol in a given namespace.
 697  */
 698 static entity_t *get_entity(const symbol_t *const symbol,
 699                             namespace_tag_t namespc)
 700 {
 701         entity_t *entity = symbol->entity;
 702         for (; entity != NULL; entity = entity->base.symbol_next) {
 703                 if ((namespace_tag_t)entity->base.namespc == namespc)
 704                         return entity;
 705         }
 706
 707         return NULL;
 708 }
 709
 710 /* §6.2.3:1 24)  There is only one name space for tags even though three are
 711  * possible. */
 712 static entity_t *get_tag(symbol_t const *const symbol,
 713                          entity_kind_tag_t const kind)
 714 {
 715         entity_t *entity = get_entity(symbol, NAMESPACE_TAG);
 716         if (entity != NULL && (entity_kind_tag_t)entity->kind != kind) {
 717                 errorf(HERE,
 718                                 "'%Y' defined as wrong kind of tag (previous definition %P)",
 719                                 symbol, &entity->base.source_position);
 720                 entity = NULL;
 721         }
 722         return entity;
 723 }
 724
 725 /**
 726  * pushs an entity on the environment stack and links the corresponding symbol
 727  * it.
 728  */
 729 static void stack_push(stack_entry_t **stack_ptr, entity_t *entity)
 730 {
 731         symbol_t           *symbol  = entity->base.symbol;
 732         entity_namespace_t  namespc = entity->base.namespc;
 733         assert(namespc != 0);
 734
 735         /* replace/add entity into entity list of the symbol */
 736         entity_t **anchor;
 737         entity_t  *iter;
 738         for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 739                 iter = *anchor;
 740                 if (iter == NULL)
 741                         break;
 742
 743                 /* replace an entry? */
 744                 if (iter->base.namespc == namespc) {
 745                         entity->base.symbol_next = iter->base.symbol_next;
 746                         break;
 747                 }
 748         }
 749         *anchor = entity;
 750
 751         /* remember old declaration */
 752         stack_entry_t entry;
 753         entry.symbol     = symbol;
 754         entry.old_entity = iter;
 755         entry.namespc    = namespc;
 756         ARR_APP1(stack_entry_t, *stack_ptr, entry);
 757 }
 758
 759 /**
 760  * Push an entity on the environment stack.
 761  */
 762 static void environment_push(entity_t *entity)
 763 {
 764         assert(entity->base.source_position.input_name != NULL);
 765         assert(entity->base.parent_scope != NULL);
 766         stack_push(&environment_stack, entity);
 767 }
 768
 769 /**
 770  * Push a declaration on the global label stack.
 771  *
 772  * @param declaration  the declaration
 773  */
 774 static void label_push(entity_t *label)
 775 {
 776         /* we abuse the parameters scope as parent for the labels */
 777         label->base.parent_scope = &current_function->parameters;
 778         stack_push(&label_stack, label);
 779 }
 780
 781 /**
 782  * pops symbols from the environment stack until @p new_top is the top element
 783  */
 784 static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
 785 {
 786         stack_entry_t *stack = *stack_ptr;
 787         size_t         top   = ARR_LEN(stack);
 788         size_t         i;
 789
 790         assert(new_top <= top);
 791         if (new_top == top)
 792                 return;
 793
 794         for (i = top; i > new_top; --i) {
 795                 stack_entry_t *entry = &stack[i - 1];
 796
 797                 entity_t           *old_entity = entry->old_entity;
 798                 symbol_t           *symbol     = entry->symbol;
 799                 entity_namespace_t  namespc    = entry->namespc;
 800
 801                 /* replace with old_entity/remove */
 802                 entity_t **anchor;
 803                 entity_t  *iter;
 804                 for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 805                         iter = *anchor;
 806                         assert(iter != NULL);
 807                         /* replace an entry? */
 808                         if (iter->base.namespc == namespc)
 809                                 break;
 810                 }
 811
 812                 /* restore definition from outer scopes (if there was one) */
 813                 if (old_entity != NULL) {
 814                         old_entity->base.symbol_next = iter->base.symbol_next;
 815                         *anchor                      = old_entity;
 816                 } else {
 817                         /* remove entry from list */
 818                         *anchor = iter->base.symbol_next;
 819                 }
 820         }
 821
 822         ARR_SHRINKLEN(*stack_ptr, new_top);
 823 }
 824
 825 /**
 826  * Pop all entries from the environment stack until the new_top
 827  * is reached.
 828  *
 829  * @param new_top  the new stack top
 830  */
 831 static void environment_pop_to(size_t new_top)
 832 {
 833         stack_pop_to(&environment_stack, new_top);
 834 }
 835
 836 /**
 837  * Pop all entries from the global label stack until the new_top
 838  * is reached.
 839  *
 840  * @param new_top  the new stack top
 841  */
 842 static void label_pop_to(size_t new_top)
 843 {
 844         stack_pop_to(&label_stack, new_top);
 845 }
 846
 847 static atomic_type_kind_t get_akind(const type_t *type)
 848 {
 849         assert(type->kind == TYPE_ATOMIC || type->kind == TYPE_COMPLEX
 850                || type->kind == TYPE_IMAGINARY || type->kind == TYPE_ENUM);
 851         return type->atomic.akind;
 852 }
 853
 854 /**
 855  * §6.3.1.1:2  Do integer promotion for a given type.
 856  *
 857  * @param type  the type to promote
 858  * @return the promoted type
 859  */
 860 static type_t *promote_integer(type_t *type)
 861 {
 862         if (get_akind_rank(get_akind(type)) < get_akind_rank(ATOMIC_TYPE_INT))
 863                 type = type_int;
 864
 865         return type;
 866 }
 867
 868 /**
 869  * Check if a given expression represents a null pointer constant.
 870  *
 871  * @param expression  the expression to check
 872  */
 873 static bool is_null_pointer_constant(const expression_t *expression)
 874 {
 875         /* skip void* cast */
 876         if (expression->kind == EXPR_UNARY_CAST) {
 877                 type_t *const type = skip_typeref(expression->base.type);
 878                 if (types_compatible(type, type_void_ptr))
 879                         expression = expression->unary.value;
 880         }
 881
 882         type_t *const type = skip_typeref(expression->base.type);
 883         if (!is_type_integer(type))
 884                 return false;
 885         switch (is_constant_expression(expression)) {
 886                 case EXPR_CLASS_ERROR:    return true;
 887                 case EXPR_CLASS_CONSTANT: return !fold_constant_to_bool(expression);
 888                 default:                  return false;
 889         }
 890 }
 891
 892 /**
 893  * Create an implicit cast expression.
 894  *
 895  * @param expression  the expression to cast
 896  * @param dest_type   the destination type
 897  */
 898 static expression_t *create_implicit_cast(expression_t *expression,
 899                                           type_t *dest_type)
 900 {
 901         type_t *const source_type = expression->base.type;
 902
 903         if (source_type == dest_type)
 904                 return expression;
 905
 906         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
 907         cast->unary.value   = expression;
 908         cast->base.type     = dest_type;
 909         cast->base.implicit = true;
 910
 911         return cast;
 912 }
 913
 914 typedef enum assign_error_t {
 915         ASSIGN_SUCCESS,
 916         ASSIGN_ERROR_INCOMPATIBLE,
 917         ASSIGN_ERROR_POINTER_QUALIFIER_MISSING,
 918         ASSIGN_WARNING_POINTER_INCOMPATIBLE,
 919         ASSIGN_WARNING_POINTER_FROM_INT,
 920         ASSIGN_WARNING_INT_FROM_POINTER
 921 } assign_error_t;
 922
 923 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)
 924 {
 925         type_t *const orig_type_right = right->base.type;
 926         type_t *const type_left       = skip_typeref(orig_type_left);
 927         type_t *const type_right      = skip_typeref(orig_type_right);
 928
 929         switch (error) {
 930         case ASSIGN_SUCCESS:
 931                 return;
 932         case ASSIGN_ERROR_INCOMPATIBLE:
 933                 errorf(pos, "destination type '%T' in %s is incompatible with type '%T'", orig_type_left, context, orig_type_right);
 934                 return;
 935
 936         case ASSIGN_ERROR_POINTER_QUALIFIER_MISSING: {
 937                 type_t *points_to_left  = skip_typeref(type_left->pointer.points_to);
 938                 type_t *points_to_right = skip_typeref(type_right->pointer.points_to);
 939
 940                 /* the left type has all qualifiers from the right type */
 941                 unsigned missing_qualifiers = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 942                 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);
 943                 return;
 944         }
 945
 946         case ASSIGN_WARNING_POINTER_INCOMPATIBLE:
 947                 warningf(WARN_OTHER, pos, "destination type '%T' in %s is incompatible with '%E' of type '%T'", orig_type_left, context, right, orig_type_right);
 948                 return;
 949
 950         case ASSIGN_WARNING_POINTER_FROM_INT:
 951                 warningf(WARN_OTHER, pos, "%s makes pointer '%T' from integer '%T' without a cast", context, orig_type_left, orig_type_right);
 952                 return;
 953
 954         case ASSIGN_WARNING_INT_FROM_POINTER:
 955                 warningf(WARN_OTHER, pos, "%s makes integer '%T' from pointer '%T' without a cast", context, orig_type_left, orig_type_right);
 956                 return;
 957
 958         default:
 959                 panic("invalid error value");
 960         }
 961 }
 962
 963 /** Implements the rules from §6.5.16.1 */
 964 static assign_error_t semantic_assign(type_t *orig_type_left,
 965                                       const expression_t *const right)
 966 {
 967         type_t *const orig_type_right = right->base.type;
 968         type_t *const type_left       = skip_typeref(orig_type_left);
 969         type_t *const type_right      = skip_typeref(orig_type_right);
 970
 971         if (is_type_pointer(type_left)) {
 972                 if (is_null_pointer_constant(right)) {
 973                         return ASSIGN_SUCCESS;
 974                 } else if (is_type_pointer(type_right)) {
 975                         type_t *points_to_left
 976                                 = skip_typeref(type_left->pointer.points_to);
 977                         type_t *points_to_right
 978                                 = skip_typeref(type_right->pointer.points_to);
 979                         assign_error_t res = ASSIGN_SUCCESS;
 980
 981                         /* the left type has all qualifiers from the right type */
 982                         unsigned missing_qualifiers
 983                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 984                         if (missing_qualifiers != 0) {
 985                                 res = ASSIGN_ERROR_POINTER_QUALIFIER_MISSING;
 986                         }
 987
 988                         points_to_left  = get_unqualified_type(points_to_left);
 989                         points_to_right = get_unqualified_type(points_to_right);
 990
 991                         if (is_type_void(points_to_left))
 992                                 return res;
 993
 994                         if (is_type_void(points_to_right)) {
 995                                 /* ISO/IEC 14882:1998(E) §C.1.2:6 */
 996                                 return c_mode & _CXX ? ASSIGN_ERROR_INCOMPATIBLE : res;
 997                         }
 998
 999                         if (!types_compatible(points_to_left, points_to_right)) {
1000                                 return ASSIGN_WARNING_POINTER_INCOMPATIBLE;
1001                         }
1002
1003                         return res;
1004                 } else if (is_type_integer(type_right)) {
1005                         return ASSIGN_WARNING_POINTER_FROM_INT;
1006                 }
1007         } else if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
1008                         (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
1009                                 && is_type_pointer(type_right))) {
1010                 return ASSIGN_SUCCESS;
1011         } else if (is_type_compound(type_left) && is_type_compound(type_right)) {
1012                 type_t *const unqual_type_left  = get_unqualified_type(type_left);
1013                 type_t *const unqual_type_right = get_unqualified_type(type_right);
1014                 if (types_compatible(unqual_type_left, unqual_type_right)) {
1015                         return ASSIGN_SUCCESS;
1016                 }
1017         } else if (is_type_integer(type_left) && is_type_pointer(type_right)) {
1018                 return ASSIGN_WARNING_INT_FROM_POINTER;
1019         }
1020
1021         if (!is_type_valid(type_left) || !is_type_valid(type_right))
1022                 return ASSIGN_SUCCESS;
1023
1024         return ASSIGN_ERROR_INCOMPATIBLE;
1025 }
1026
1027 static expression_t *parse_constant_expression(void)
1028 {
1029         expression_t *result = parse_subexpression(PREC_CONDITIONAL);
1030
1031         if (is_constant_expression(result) == EXPR_CLASS_VARIABLE) {
1032                 errorf(&result->base.source_position,
1033                        "expression '%E' is not constant", result);
1034         }
1035
1036         return result;
1037 }
1038
1039 static expression_t *parse_assignment_expression(void)
1040 {
1041         return parse_subexpression(PREC_ASSIGNMENT);
1042 }
1043
1044 static void warn_string_concat(const source_position_t *pos)
1045 {
1046         warningf(WARN_TRADITIONAL, pos, "traditional C rejects string constant concatenation");
1047 }
1048
1049 static string_t parse_string_literals(void)
1050 {
1051         assert(token.kind == T_STRING_LITERAL);
1052         string_t result = token.string.string;
1053
1054         next_token();
1055
1056         while (token.kind == T_STRING_LITERAL) {
1057                 warn_string_concat(&token.base.source_position);
1058                 result = concat_strings(&result, &token.string.string);
1059                 next_token();
1060         }
1061
1062         return result;
1063 }
1064
1065 static attribute_t *allocate_attribute_zero(attribute_kind_t kind)
1066 {
1067         attribute_t *attribute = allocate_ast_zero(sizeof(*attribute));
1068         attribute->kind            = kind;
1069         attribute->source_position = *HERE;
1070         return attribute;
1071 }
1072
1073 /**
1074  * Parse (gcc) attribute argument. From gcc comments in gcc source:
1075  *
1076  *  attribute:
1077  *    __attribute__ ( ( attribute-list ) )
1078  *
1079  *  attribute-list:
1080  *    attrib
1081  *    attribute_list , attrib
1082  *
1083  *  attrib:
1084  *    empty
1085  *    any-word
1086  *    any-word ( identifier )
1087  *    any-word ( identifier , nonempty-expr-list )
1088  *    any-word ( expr-list )
1089  *
1090  *  where the "identifier" must not be declared as a type, and
1091  *  "any-word" may be any identifier (including one declared as a
1092  *  type), a reserved word storage class specifier, type specifier or
1093  *  type qualifier.  ??? This still leaves out most reserved keywords
1094  *  (following the old parser), shouldn't we include them, and why not
1095  *  allow identifiers declared as types to start the arguments?
1096  *
1097  *  Matze: this all looks confusing and little systematic, so we're even less
1098  *  strict and parse any list of things which are identifiers or
1099  *  (assignment-)expressions.
1100  */
1101 static attribute_argument_t *parse_attribute_arguments(void)
1102 {
1103         attribute_argument_t  *first  = NULL;
1104         attribute_argument_t **anchor = &first;
1105         if (token.kind != ')') do {
1106                 attribute_argument_t *argument = allocate_ast_zero(sizeof(*argument));
1107
1108                 /* is it an identifier */
1109                 if (token.kind == T_IDENTIFIER
1110                                 && (look_ahead(1)->kind == ',' || look_ahead(1)->kind == ')')) {
1111                         symbol_t *symbol   = token.identifier.symbol;
1112                         argument->kind     = ATTRIBUTE_ARGUMENT_SYMBOL;
1113                         argument->v.symbol = symbol;
1114                         next_token();
1115                 } else {
1116                         /* must be an expression */
1117                         expression_t *expression = parse_assignment_expression();
1118
1119                         argument->kind         = ATTRIBUTE_ARGUMENT_EXPRESSION;
1120                         argument->v.expression = expression;
1121                 }
1122
1123                 /* append argument */
1124                 *anchor = argument;
1125                 anchor  = &argument->next;
1126         } while (next_if(','));
1127         expect(')', end_error);
1128 end_error:
1129         return first;
1130 }
1131
1132 static attribute_t *parse_attribute_asm(void)
1133 {
1134         attribute_t *attribute = allocate_attribute_zero(ATTRIBUTE_GNU_ASM);
1135         eat(T_asm);
1136
1137         expect('(', end_error);
1138         attribute->a.arguments = parse_attribute_arguments();
1139         return attribute;
1140
1141 end_error:
1142         return NULL;
1143 }
1144
1145 static symbol_t *get_symbol_from_token(void)
1146 {
1147         switch(token.kind) {
1148         case T_IDENTIFIER:
1149                 return token.identifier.symbol;
1150         case T_auto:
1151         case T_char:
1152         case T_double:
1153         case T_enum:
1154         case T_extern:
1155         case T_float:
1156         case T_int:
1157         case T_long:
1158         case T_register:
1159         case T_short:
1160         case T_static:
1161         case T_struct:
1162         case T_union:
1163         case T_unsigned:
1164         case T_void:
1165         case T_bool:
1166         case T__Bool:
1167         case T_class:
1168         case T_explicit:
1169         case T_export:
1170         case T_wchar_t:
1171         case T_const:
1172         case T_signed:
1173         case T___real__:
1174         case T___imag__:
1175         case T_restrict:
1176         case T_volatile:
1177         case T_inline:
1178                 /* maybe we need more tokens ... add them on demand */
1179                 return get_token_kind_symbol(token.kind);
1180         default:
1181                 return NULL;
1182         }
1183 }
1184
1185 static attribute_t *parse_attribute_gnu_single(void)
1186 {
1187         /* parse "any-word" */
1188         symbol_t *symbol = get_symbol_from_token();
1189         if (symbol == NULL) {
1190                 parse_error_expected("while parsing attribute((", T_IDENTIFIER, NULL);
1191                 return NULL;
1192         }
1193
1194         attribute_kind_t  kind;
1195         char const *const name = symbol->string;
1196         for (kind = ATTRIBUTE_GNU_FIRST;; ++kind) {
1197                 if (kind > ATTRIBUTE_GNU_LAST) {
1198                         warningf(WARN_ATTRIBUTE, HERE, "unknown attribute '%s' ignored", name);
1199                         /* TODO: we should still save the attribute in the list... */
1200                         kind = ATTRIBUTE_UNKNOWN;
1201                         break;
1202                 }
1203
1204                 const char *attribute_name = get_attribute_name(kind);
1205                 if (attribute_name != NULL && streq_underscore(attribute_name, name))
1206                         break;
1207         }
1208
1209         attribute_t *attribute = allocate_attribute_zero(kind);
1210         next_token();
1211
1212         /* parse arguments */
1213         if (next_if('('))
1214                 attribute->a.arguments = parse_attribute_arguments();
1215
1216         return attribute;
1217 }
1218
1219 static attribute_t *parse_attribute_gnu(void)
1220 {
1221         attribute_t  *first  = NULL;
1222         attribute_t **anchor = &first;
1223
1224         eat(T___attribute__);
1225         expect('(', end_error);
1226         expect('(', end_error);
1227
1228         if (token.kind != ')') do {
1229                 attribute_t *attribute = parse_attribute_gnu_single();
1230                 if (attribute == NULL)
1231                         goto end_error;
1232
1233                 *anchor = attribute;
1234                 anchor  = &attribute->next;
1235         } while (next_if(','));
1236         expect(')', end_error);
1237         expect(')', end_error);
1238
1239 end_error:
1240         return first;
1241 }
1242
1243 /** Parse attributes. */
1244 static attribute_t *parse_attributes(attribute_t *first)
1245 {
1246         attribute_t **anchor = &first;
1247         for (;;) {
1248                 while (*anchor != NULL)
1249                         anchor = &(*anchor)->next;
1250
1251                 attribute_t *attribute;
1252                 switch (token.kind) {
1253                 case T___attribute__:
1254                         attribute = parse_attribute_gnu();
1255                         if (attribute == NULL)
1256                                 continue;
1257                         break;
1258
1259                 case T_asm:
1260                         attribute = parse_attribute_asm();
1261                         break;
1262
1263                 case T_cdecl:
1264                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_CDECL);
1265                         eat(T_cdecl);
1266                         break;
1267
1268                 case T__fastcall:
1269                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FASTCALL);
1270                         eat(T__fastcall);
1271                         break;
1272
1273                 case T__forceinline:
1274                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FORCEINLINE);
1275                         eat(T__forceinline);
1276                         break;
1277
1278                 case T__stdcall:
1279                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_STDCALL);
1280                         eat(T__stdcall);
1281                         break;
1282
1283                 case T___thiscall:
1284                         /* TODO record modifier */
1285                         warningf(WARN_OTHER, HERE, "Ignoring declaration modifier %K", &token);
1286                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_THISCALL);
1287                         eat(T___thiscall);
1288                         break;
1289
1290                 default:
1291                         return first;
1292                 }
1293
1294                 *anchor = attribute;
1295                 anchor  = &attribute->next;
1296         }
1297 }
1298
1299 static void mark_vars_read(expression_t *expr, entity_t *lhs_ent);
1300
1301 static entity_t *determine_lhs_ent(expression_t *const expr,
1302                                    entity_t *lhs_ent)
1303 {
1304         switch (expr->kind) {
1305                 case EXPR_REFERENCE: {
1306                         entity_t *const entity = expr->reference.entity;
1307                         /* we should only find variables as lvalues... */
1308                         if (entity->base.kind != ENTITY_VARIABLE
1309                                         && entity->base.kind != ENTITY_PARAMETER)
1310                                 return NULL;
1311
1312                         return entity;
1313                 }
1314
1315                 case EXPR_ARRAY_ACCESS: {
1316                         expression_t *const ref = expr->array_access.array_ref;
1317                         entity_t     *      ent = NULL;
1318                         if (is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1319                                 ent     = determine_lhs_ent(ref, lhs_ent);
1320                                 lhs_ent = ent;
1321                         } else {
1322                                 mark_vars_read(ref, lhs_ent);
1323                         }
1324                         mark_vars_read(expr->array_access.index, lhs_ent);
1325                         return ent;
1326                 }
1327
1328                 case EXPR_SELECT: {
1329                         mark_vars_read(expr->select.compound, lhs_ent);
1330                         if (is_type_compound(skip_typeref(expr->base.type)))
1331                                 return determine_lhs_ent(expr->select.compound, lhs_ent);
1332                         return NULL;
1333                 }
1334
1335                 case EXPR_UNARY_DEREFERENCE: {
1336                         expression_t *const val = expr->unary.value;
1337                         if (val->kind == EXPR_UNARY_TAKE_ADDRESS) {
1338                                 /* *&x is a NOP */
1339                                 return determine_lhs_ent(val->unary.value, lhs_ent);
1340                         } else {
1341                                 mark_vars_read(val, NULL);
1342                                 return NULL;
1343                         }
1344                 }
1345
1346                 default:
1347                         mark_vars_read(expr, NULL);
1348                         return NULL;
1349         }
1350 }
1351
1352 #define ENT_ANY ((entity_t*)-1)
1353
1354 /**
1355  * Mark declarations, which are read.  This is used to detect variables, which
1356  * are never read.
1357  * Example:
1358  * x = x + 1;
1359  *   x is not marked as "read", because it is only read to calculate its own new
1360  *   value.
1361  *
1362  * x += y; y += x;
1363  *   x and y are not detected as "not read", because multiple variables are
1364  *   involved.
1365  */
1366 static void mark_vars_read(expression_t *const expr, entity_t *lhs_ent)
1367 {
1368         switch (expr->kind) {
1369                 case EXPR_REFERENCE: {
1370                         entity_t *const entity = expr->reference.entity;
1371                         if (entity->kind != ENTITY_VARIABLE
1372                                         && entity->kind != ENTITY_PARAMETER)
1373                                 return;
1374
1375                         if (lhs_ent != entity && lhs_ent != ENT_ANY) {
1376                                 if (entity->kind == ENTITY_VARIABLE) {
1377                                         entity->variable.read = true;
1378                                 } else {
1379                                         entity->parameter.read = true;
1380                                 }
1381                         }
1382                         return;
1383                 }
1384
1385                 case EXPR_CALL:
1386                         // TODO respect pure/const
1387                         mark_vars_read(expr->call.function, NULL);
1388                         for (call_argument_t *arg = expr->call.arguments; arg != NULL; arg = arg->next) {
1389                                 mark_vars_read(arg->expression, NULL);
1390                         }
1391                         return;
1392
1393                 case EXPR_CONDITIONAL:
1394                         // TODO lhs_decl should depend on whether true/false have an effect
1395                         mark_vars_read(expr->conditional.condition, NULL);
1396                         if (expr->conditional.true_expression != NULL)
1397                                 mark_vars_read(expr->conditional.true_expression, lhs_ent);
1398                         mark_vars_read(expr->conditional.false_expression, lhs_ent);
1399                         return;
1400
1401                 case EXPR_SELECT:
1402                         if (lhs_ent == ENT_ANY
1403                                         && !is_type_compound(skip_typeref(expr->base.type)))
1404                                 lhs_ent = NULL;
1405                         mark_vars_read(expr->select.compound, lhs_ent);
1406                         return;
1407
1408                 case EXPR_ARRAY_ACCESS: {
1409                         mark_vars_read(expr->array_access.index, lhs_ent);
1410                         expression_t *const ref = expr->array_access.array_ref;
1411                         if (!is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1412                                 if (lhs_ent == ENT_ANY)
1413                                         lhs_ent = NULL;
1414                         }
1415                         mark_vars_read(ref, lhs_ent);
1416                         return;
1417                 }
1418
1419                 case EXPR_VA_ARG:
1420                         mark_vars_read(expr->va_arge.ap, lhs_ent);
1421                         return;
1422
1423                 case EXPR_VA_COPY:
1424                         mark_vars_read(expr->va_copye.src, lhs_ent);
1425                         return;
1426
1427                 case EXPR_UNARY_CAST:
1428                         /* Special case: Use void cast to mark a variable as "read" */
1429                         if (is_type_void(skip_typeref(expr->base.type)))
1430                                 lhs_ent = NULL;
1431                         goto unary;
1432
1433
1434                 case EXPR_UNARY_THROW:
1435                         if (expr->unary.value == NULL)
1436                                 return;
1437                         /* FALLTHROUGH */
1438                 case EXPR_UNARY_DEREFERENCE:
1439                 case EXPR_UNARY_DELETE:
1440                 case EXPR_UNARY_DELETE_ARRAY:
1441                         if (lhs_ent == ENT_ANY)
1442                                 lhs_ent = NULL;
1443                         goto unary;
1444
1445                 case EXPR_UNARY_NEGATE:
1446                 case EXPR_UNARY_PLUS:
1447                 case EXPR_UNARY_BITWISE_NEGATE:
1448                 case EXPR_UNARY_NOT:
1449                 case EXPR_UNARY_TAKE_ADDRESS:
1450                 case EXPR_UNARY_POSTFIX_INCREMENT:
1451                 case EXPR_UNARY_POSTFIX_DECREMENT:
1452                 case EXPR_UNARY_PREFIX_INCREMENT:
1453                 case EXPR_UNARY_PREFIX_DECREMENT:
1454                 case EXPR_UNARY_ASSUME:
1455 unary:
1456                         mark_vars_read(expr->unary.value, lhs_ent);
1457                         return;
1458
1459                 case EXPR_BINARY_ADD:
1460                 case EXPR_BINARY_SUB:
1461                 case EXPR_BINARY_MUL:
1462                 case EXPR_BINARY_DIV:
1463                 case EXPR_BINARY_MOD:
1464                 case EXPR_BINARY_EQUAL:
1465                 case EXPR_BINARY_NOTEQUAL:
1466                 case EXPR_BINARY_LESS:
1467                 case EXPR_BINARY_LESSEQUAL:
1468                 case EXPR_BINARY_GREATER:
1469                 case EXPR_BINARY_GREATEREQUAL:
1470                 case EXPR_BINARY_BITWISE_AND:
1471                 case EXPR_BINARY_BITWISE_OR:
1472                 case EXPR_BINARY_BITWISE_XOR:
1473                 case EXPR_BINARY_LOGICAL_AND:
1474                 case EXPR_BINARY_LOGICAL_OR:
1475                 case EXPR_BINARY_SHIFTLEFT:
1476                 case EXPR_BINARY_SHIFTRIGHT:
1477                 case EXPR_BINARY_COMMA:
1478                 case EXPR_BINARY_ISGREATER:
1479                 case EXPR_BINARY_ISGREATEREQUAL:
1480                 case EXPR_BINARY_ISLESS:
1481                 case EXPR_BINARY_ISLESSEQUAL:
1482                 case EXPR_BINARY_ISLESSGREATER:
1483                 case EXPR_BINARY_ISUNORDERED:
1484                         mark_vars_read(expr->binary.left,  lhs_ent);
1485                         mark_vars_read(expr->binary.right, lhs_ent);
1486                         return;
1487
1488                 case EXPR_BINARY_ASSIGN:
1489                 case EXPR_BINARY_MUL_ASSIGN:
1490                 case EXPR_BINARY_DIV_ASSIGN:
1491                 case EXPR_BINARY_MOD_ASSIGN:
1492                 case EXPR_BINARY_ADD_ASSIGN:
1493                 case EXPR_BINARY_SUB_ASSIGN:
1494                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:
1495                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:
1496                 case EXPR_BINARY_BITWISE_AND_ASSIGN:
1497                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:
1498                 case EXPR_BINARY_BITWISE_OR_ASSIGN: {
1499                         if (lhs_ent == ENT_ANY)
1500                                 lhs_ent = NULL;
1501                         lhs_ent = determine_lhs_ent(expr->binary.left, lhs_ent);
1502                         mark_vars_read(expr->binary.right, lhs_ent);
1503                         return;
1504                 }
1505
1506                 case EXPR_VA_START:
1507                         determine_lhs_ent(expr->va_starte.ap, lhs_ent);
1508                         return;
1509
1510                 case EXPR_LITERAL_CASES:
1511                 case EXPR_ERROR:
1512                 case EXPR_STRING_LITERAL:
1513                 case EXPR_WIDE_STRING_LITERAL:
1514                 case EXPR_COMPOUND_LITERAL: // TODO init?
1515                 case EXPR_SIZEOF:
1516                 case EXPR_CLASSIFY_TYPE:
1517                 case EXPR_ALIGNOF:
1518                 case EXPR_FUNCNAME:
1519                 case EXPR_BUILTIN_CONSTANT_P:
1520                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
1521                 case EXPR_OFFSETOF:
1522                 case EXPR_STATEMENT: // TODO
1523                 case EXPR_LABEL_ADDRESS:
1524                 case EXPR_ENUM_CONSTANT:
1525                         return;
1526         }
1527
1528         panic("unhandled expression");
1529 }
1530
1531 static designator_t *parse_designation(void)
1532 {
1533         designator_t  *result = NULL;
1534         designator_t **anchor = &result;
1535
1536         for (;;) {
1537                 designator_t *designator;
1538                 switch (token.kind) {
1539                 case '[':
1540                         designator = allocate_ast_zero(sizeof(designator[0]));
1541                         designator->source_position = token.base.source_position;
1542                         next_token();
1543                         add_anchor_token(']');
1544                         designator->array_index = parse_constant_expression();
1545                         rem_anchor_token(']');
1546                         expect(']', end_error);
1547                         break;
1548                 case '.':
1549                         designator = allocate_ast_zero(sizeof(designator[0]));
1550                         designator->source_position = token.base.source_position;
1551                         next_token();
1552                         if (token.kind != T_IDENTIFIER) {
1553                                 parse_error_expected("while parsing designator",
1554                                                      T_IDENTIFIER, NULL);
1555                                 return NULL;
1556                         }
1557                         designator->symbol = token.identifier.symbol;
1558                         next_token();
1559                         break;
1560                 default:
1561                         expect('=', end_error);
1562                         return result;
1563                 }
1564
1565                 assert(designator != NULL);
1566                 *anchor = designator;
1567                 anchor  = &designator->next;
1568         }
1569 end_error:
1570         return NULL;
1571 }
1572
1573 static initializer_t *initializer_from_string(array_type_t *const type,
1574                                               const string_t *const string)
1575 {
1576         /* TODO: check len vs. size of array type */
1577         (void) type;
1578
1579         initializer_t *initializer = allocate_initializer_zero(INITIALIZER_STRING);
1580         initializer->string.string = *string;
1581
1582         return initializer;
1583 }
1584
1585 static initializer_t *initializer_from_wide_string(array_type_t *const type,
1586                                                    const string_t *const string)
1587 {
1588         /* TODO: check len vs. size of array type */
1589         (void) type;
1590
1591         initializer_t *const initializer =
1592                 allocate_initializer_zero(INITIALIZER_WIDE_STRING);
1593         initializer->wide_string.string = *string;
1594
1595         return initializer;
1596 }
1597
1598 /**
1599  * Build an initializer from a given expression.
1600  */
1601 static initializer_t *initializer_from_expression(type_t *orig_type,
1602                                                   expression_t *expression)
1603 {
1604         /* TODO check that expression is a constant expression */
1605
1606         /* §6.7.8.14/15 char array may be initialized by string literals */
1607         type_t *type           = skip_typeref(orig_type);
1608         type_t *expr_type_orig = expression->base.type;
1609         type_t *expr_type      = skip_typeref(expr_type_orig);
1610
1611         if (is_type_array(type) && expr_type->kind == TYPE_POINTER) {
1612                 array_type_t *const array_type   = &type->array;
1613                 type_t       *const element_type = skip_typeref(array_type->element_type);
1614
1615                 if (element_type->kind == TYPE_ATOMIC) {
1616                         atomic_type_kind_t akind = element_type->atomic.akind;
1617                         switch (expression->kind) {
1618                         case EXPR_STRING_LITERAL:
1619                                 if (akind == ATOMIC_TYPE_CHAR
1620                                                 || akind == ATOMIC_TYPE_SCHAR
1621                                                 || akind == ATOMIC_TYPE_UCHAR) {
1622                                         return initializer_from_string(array_type,
1623                                                         &expression->string_literal.value);
1624                                 }
1625                                 break;
1626
1627                         case EXPR_WIDE_STRING_LITERAL: {
1628                                 type_t *bare_wchar_type = skip_typeref(type_wchar_t);
1629                                 if (get_unqualified_type(element_type) == bare_wchar_type) {
1630                                         return initializer_from_wide_string(array_type,
1631                                                         &expression->string_literal.value);
1632                                 }
1633                                 break;
1634                         }
1635
1636                         default:
1637                                 break;
1638                         }
1639                 }
1640         }
1641
1642         assign_error_t error = semantic_assign(type, expression);
1643         if (error == ASSIGN_ERROR_INCOMPATIBLE)
1644                 return NULL;
1645         report_assign_error(error, type, expression, "initializer",
1646                             &expression->base.source_position);
1647
1648         initializer_t *const result = allocate_initializer_zero(INITIALIZER_VALUE);
1649         result->value.value = create_implicit_cast(expression, type);
1650
1651         return result;
1652 }
1653
1654 /**
1655  * Parses an scalar initializer.
1656  *
1657  * §6.7.8.11; eat {} without warning
1658  */
1659 static initializer_t *parse_scalar_initializer(type_t *type,
1660                                                bool must_be_constant)
1661 {
1662         /* there might be extra {} hierarchies */
1663         int braces = 0;
1664         if (token.kind == '{') {
1665                 warningf(WARN_OTHER, HERE, "extra curly braces around scalar initializer");
1666                 do {
1667                         eat('{');
1668                         ++braces;
1669                 } while (token.kind == '{');
1670         }
1671
1672         expression_t *expression = parse_assignment_expression();
1673         mark_vars_read(expression, NULL);
1674         if (must_be_constant && !is_linker_constant(expression)) {
1675                 errorf(&expression->base.source_position,
1676                        "initialisation expression '%E' is not constant",
1677                        expression);
1678         }
1679
1680         initializer_t *initializer = initializer_from_expression(type, expression);
1681
1682         if (initializer == NULL) {
1683                 errorf(&expression->base.source_position,
1684                        "expression '%E' (type '%T') doesn't match expected type '%T'",
1685                        expression, expression->base.type, type);
1686                 /* TODO */
1687                 return NULL;
1688         }
1689
1690         bool additional_warning_displayed = false;
1691         while (braces > 0) {
1692                 next_if(',');
1693                 if (token.kind != '}') {
1694                         if (!additional_warning_displayed) {
1695                                 warningf(WARN_OTHER, HERE, "additional elements in scalar initializer");
1696                                 additional_warning_displayed = true;
1697                         }
1698                 }
1699                 eat_block();
1700                 braces--;
1701         }
1702
1703         return initializer;
1704 }
1705
1706 /**
1707  * An entry in the type path.
1708  */
1709 typedef struct type_path_entry_t type_path_entry_t;
1710 struct type_path_entry_t {
1711         type_t *type;       /**< the upper top type. restored to path->top_tye if this entry is popped. */
1712         union {
1713                 size_t         index;          /**< For array types: the current index. */
1714                 declaration_t *compound_entry; /**< For compound types: the current declaration. */
1715         } v;
1716 };
1717
1718 /**
1719  * A type path expression a position inside compound or array types.
1720  */
1721 typedef struct type_path_t type_path_t;
1722 struct type_path_t {
1723         type_path_entry_t *path;         /**< An flexible array containing the current path. */
1724         type_t            *top_type;     /**< type of the element the path points */
1725         size_t             max_index;    /**< largest index in outermost array */
1726 };
1727
1728 /**
1729  * Prints a type path for debugging.
1730  */
1731 static __attribute__((unused)) void debug_print_type_path(
1732                 const type_path_t *path)
1733 {
1734         size_t len = ARR_LEN(path->path);
1735
1736         for (size_t i = 0; i < len; ++i) {
1737                 const type_path_entry_t *entry = & path->path[i];
1738
1739                 type_t *type = skip_typeref(entry->type);
1740                 if (is_type_compound(type)) {
1741                         /* in gcc mode structs can have no members */
1742                         if (entry->v.compound_entry == NULL) {
1743                                 assert(i == len-1);
1744                                 continue;
1745                         }
1746                         fprintf(stderr, ".%s",
1747                                 entry->v.compound_entry->base.symbol->string);
1748                 } else if (is_type_array(type)) {
1749                         fprintf(stderr, "[%u]", (unsigned) entry->v.index);
1750                 } else {
1751                         fprintf(stderr, "-INVALID-");
1752                 }
1753         }
1754         if (path->top_type != NULL) {
1755                 fprintf(stderr, "  (");
1756                 print_type(path->top_type);
1757                 fprintf(stderr, ")");
1758         }
1759 }
1760
1761 /**
1762  * Return the top type path entry, ie. in a path
1763  * (type).a.b returns the b.
1764  */
1765 static type_path_entry_t *get_type_path_top(const type_path_t *path)
1766 {
1767         size_t len = ARR_LEN(path->path);
1768         assert(len > 0);
1769         return &path->path[len-1];
1770 }
1771
1772 /**
1773  * Enlarge the type path by an (empty) element.
1774  */
1775 static type_path_entry_t *append_to_type_path(type_path_t *path)
1776 {
1777         size_t len = ARR_LEN(path->path);
1778         ARR_RESIZE(type_path_entry_t, path->path, len+1);
1779
1780         type_path_entry_t *result = & path->path[len];
1781         memset(result, 0, sizeof(result[0]));
1782         return result;
1783 }
1784
1785 /**
1786  * Descending into a sub-type. Enter the scope of the current top_type.
1787  */
1788 static void descend_into_subtype(type_path_t *path)
1789 {
1790         type_t *orig_top_type = path->top_type;
1791         type_t *top_type      = skip_typeref(orig_top_type);
1792
1793         type_path_entry_t *top = append_to_type_path(path);
1794         top->type              = top_type;
1795
1796         if (is_type_compound(top_type)) {
1797                 compound_t *const compound = top_type->compound.compound;
1798                 entity_t   *const entry    = skip_unnamed_bitfields(compound->members.entities);
1799
1800                 if (entry != NULL) {
1801                         top->v.compound_entry = &entry->declaration;
1802                         path->top_type = entry->declaration.type;
1803                 } else {
1804                         path->top_type = NULL;
1805                 }
1806         } else if (is_type_array(top_type)) {
1807                 top->v.index   = 0;
1808                 path->top_type = top_type->array.element_type;
1809         } else {
1810                 assert(!is_type_valid(top_type));
1811         }
1812 }
1813
1814 /**
1815  * Pop an entry from the given type path, ie. returning from
1816  * (type).a.b to (type).a
1817  */
1818 static void ascend_from_subtype(type_path_t *path)
1819 {
1820         type_path_entry_t *top = get_type_path_top(path);
1821
1822         path->top_type = top->type;
1823
1824         size_t len = ARR_LEN(path->path);
1825         ARR_RESIZE(type_path_entry_t, path->path, len-1);
1826 }
1827
1828 /**
1829  * Pop entries from the given type path until the given
1830  * path level is reached.
1831  */
1832 static void ascend_to(type_path_t *path, size_t top_path_level)
1833 {
1834         size_t len = ARR_LEN(path->path);
1835
1836         while (len > top_path_level) {
1837                 ascend_from_subtype(path);
1838                 len = ARR_LEN(path->path);
1839         }
1840 }
1841
1842 static bool walk_designator(type_path_t *path, const designator_t *designator,
1843                             bool used_in_offsetof)
1844 {
1845         for (; designator != NULL; designator = designator->next) {
1846                 type_path_entry_t *top       = get_type_path_top(path);
1847                 type_t            *orig_type = top->type;
1848
1849                 type_t *type = skip_typeref(orig_type);
1850
1851                 if (designator->symbol != NULL) {
1852                         symbol_t *symbol = designator->symbol;
1853                         if (!is_type_compound(type)) {
1854                                 if (is_type_valid(type)) {
1855                                         errorf(&designator->source_position,
1856                                                "'.%Y' designator used for non-compound type '%T'",
1857                                                symbol, orig_type);
1858                                 }
1859
1860                                 top->type             = type_error_type;
1861                                 top->v.compound_entry = NULL;
1862                                 orig_type             = type_error_type;
1863                         } else {
1864                                 compound_t *compound = type->compound.compound;
1865                                 entity_t   *iter     = compound->members.entities;
1866                                 for (; iter != NULL; iter = iter->base.next) {
1867                                         if (iter->base.symbol == symbol) {
1868                                                 break;
1869                                         }
1870                                 }
1871                                 if (iter == NULL) {
1872                                         errorf(&designator->source_position,
1873                                                "'%T' has no member named '%Y'", orig_type, symbol);
1874                                         return false;
1875                                 }
1876                                 assert(iter->kind == ENTITY_COMPOUND_MEMBER);
1877                                 if (used_in_offsetof && iter->compound_member.bitfield) {
1878                                         errorf(&designator->source_position,
1879                                                    "offsetof designator '%Y' must not specify bitfield",
1880                                                    symbol);
1881                                         return false;
1882                                 }
1883
1884                                 top->type             = orig_type;
1885                                 top->v.compound_entry = &iter->declaration;
1886                                 orig_type             = iter->declaration.type;
1887                         }
1888                 } else {
1889                         expression_t *array_index = designator->array_index;
1890                         assert(designator->array_index != NULL);
1891
1892                         if (!is_type_array(type)) {
1893                                 if (is_type_valid(type)) {
1894                                         errorf(&designator->source_position,
1895                                                "[%E] designator used for non-array type '%T'",
1896                                                array_index, orig_type);
1897                                 }
1898                                 return false;
1899                         }
1900
1901                         long index = fold_constant_to_int(array_index);
1902                         if (!used_in_offsetof) {
1903                                 if (index < 0) {
1904                                         errorf(&designator->source_position,
1905                                                "array index [%E] must be positive", array_index);
1906                                 } else if (type->array.size_constant) {
1907                                         long array_size = type->array.size;
1908                                         if (index >= array_size) {
1909                                                 errorf(&designator->source_position,
1910                                                        "designator [%E] (%d) exceeds array size %d",
1911                                                        array_index, index, array_size);
1912                                         }
1913                                 }
1914                         }
1915
1916                         top->type    = orig_type;
1917                         top->v.index = (size_t) index;
1918                         orig_type    = type->array.element_type;
1919                 }
1920                 path->top_type = orig_type;
1921
1922                 if (designator->next != NULL) {
1923                         descend_into_subtype(path);
1924                 }
1925         }
1926         return true;
1927 }
1928
1929 static void advance_current_object(type_path_t *path, size_t top_path_level)
1930 {
1931         type_path_entry_t *top = get_type_path_top(path);
1932
1933         type_t *type = skip_typeref(top->type);
1934         if (is_type_union(type)) {
1935                 /* in unions only the first element is initialized */
1936                 top->v.compound_entry = NULL;
1937         } else if (is_type_struct(type)) {
1938                 declaration_t *entry = top->v.compound_entry;
1939
1940                 entity_t *const next_entity = skip_unnamed_bitfields(entry->base.next);
1941                 if (next_entity != NULL) {
1942                         assert(is_declaration(next_entity));
1943                         entry = &next_entity->declaration;
1944                 } else {
1945                         entry = NULL;
1946                 }
1947
1948                 top->v.compound_entry = entry;
1949                 if (entry != NULL) {
1950                         path->top_type = entry->type;
1951                         return;
1952                 }
1953         } else if (is_type_array(type)) {
1954                 assert(is_type_array(type));
1955
1956                 top->v.index++;
1957
1958                 if (!type->array.size_constant || top->v.index < type->array.size) {
1959                         return;
1960                 }
1961         } else {
1962                 assert(!is_type_valid(type));
1963                 return;
1964         }
1965
1966         /* we're past the last member of the current sub-aggregate, try if we
1967          * can ascend in the type hierarchy and continue with another subobject */
1968         size_t len = ARR_LEN(path->path);
1969
1970         if (len > top_path_level) {
1971                 ascend_from_subtype(path);
1972                 advance_current_object(path, top_path_level);
1973         } else {
1974                 path->top_type = NULL;
1975         }
1976 }
1977
1978 /**
1979  * skip any {...} blocks until a closing bracket is reached.
1980  */
1981 static void skip_initializers(void)
1982 {
1983         next_if('{');
1984
1985         while (token.kind != '}') {
1986                 if (token.kind == T_EOF)
1987                         return;
1988                 if (token.kind == '{') {
1989                         eat_block();
1990                         continue;
1991                 }
1992                 next_token();
1993         }
1994 }
1995
1996 static initializer_t *create_empty_initializer(void)
1997 {
1998         static initializer_t empty_initializer
1999                 = { .list = { { INITIALIZER_LIST }, 0 } };
2000         return &empty_initializer;
2001 }
2002
2003 /**
2004  * Parse a part of an initialiser for a struct or union,
2005  */
2006 static initializer_t *parse_sub_initializer(type_path_t *path,
2007                 type_t *outer_type, size_t top_path_level,
2008                 parse_initializer_env_t *env)
2009 {
2010         if (token.kind == '}') {
2011                 /* empty initializer */
2012                 return create_empty_initializer();
2013         }
2014
2015         type_t *orig_type = path->top_type;
2016         type_t *type      = NULL;
2017
2018         if (orig_type == NULL) {
2019                 /* We are initializing an empty compound. */
2020         } else {
2021                 type = skip_typeref(orig_type);
2022         }
2023
2024         initializer_t **initializers = NEW_ARR_F(initializer_t*, 0);
2025
2026         while (true) {
2027                 designator_t *designator = NULL;
2028                 if (token.kind == '.' || token.kind == '[') {
2029                         designator = parse_designation();
2030                         goto finish_designator;
2031                 } else if (token.kind == T_IDENTIFIER && look_ahead(1)->kind == ':') {
2032                         /* GNU-style designator ("identifier: value") */
2033                         designator = allocate_ast_zero(sizeof(designator[0]));
2034                         designator->source_position = token.base.source_position;
2035                         designator->symbol          = token.identifier.symbol;
2036                         eat(T_IDENTIFIER);
2037                         eat(':');
2038
2039 finish_designator:
2040                         /* reset path to toplevel, evaluate designator from there */
2041                         ascend_to(path, top_path_level);
2042                         if (!walk_designator(path, designator, false)) {
2043                                 /* can't continue after designation error */
2044                                 goto end_error;
2045                         }
2046
2047                         initializer_t *designator_initializer
2048                                 = allocate_initializer_zero(INITIALIZER_DESIGNATOR);
2049                         designator_initializer->designator.designator = designator;
2050                         ARR_APP1(initializer_t*, initializers, designator_initializer);
2051
2052                         orig_type = path->top_type;
2053                         type      = orig_type != NULL ? skip_typeref(orig_type) : NULL;
2054                 }
2055
2056                 initializer_t *sub;
2057
2058                 if (token.kind == '{') {
2059                         if (type != NULL && is_type_scalar(type)) {
2060                                 sub = parse_scalar_initializer(type, env->must_be_constant);
2061                         } else {
2062                                 if (type == NULL) {
2063                                         if (env->entity != NULL) {
2064                                                 errorf(HERE,
2065                                                      "extra brace group at end of initializer for '%Y'",
2066                                                      env->entity->base.symbol);
2067                                         } else {
2068                                                 errorf(HERE, "extra brace group at end of initializer");
2069                                         }
2070                                         eat('{');
2071                                 } else {
2072                                         eat('{');
2073                                         descend_into_subtype(path);
2074                                 }
2075
2076                                 add_anchor_token('}');
2077                                 sub = parse_sub_initializer(path, orig_type, top_path_level+1,
2078                                                             env);
2079                                 rem_anchor_token('}');
2080
2081                                 if (type != NULL) {
2082                                         ascend_from_subtype(path);
2083                                         expect('}', end_error);
2084                                 } else {
2085                                         expect('}', end_error);
2086                                         goto error_parse_next;
2087                                 }
2088                         }
2089                 } else {
2090                         /* must be an expression */
2091                         expression_t *expression = parse_assignment_expression();
2092                         mark_vars_read(expression, NULL);
2093
2094                         if (env->must_be_constant && !is_linker_constant(expression)) {
2095                                 errorf(&expression->base.source_position,
2096                                        "Initialisation expression '%E' is not constant",
2097                                        expression);
2098                         }
2099
2100                         if (type == NULL) {
2101                                 /* we are already outside, ... */
2102                                 if (outer_type == NULL)
2103                                         goto error_parse_next;
2104                                 type_t *const outer_type_skip = skip_typeref(outer_type);
2105                                 if (is_type_compound(outer_type_skip) &&
2106                                                 !outer_type_skip->compound.compound->complete) {
2107                                         goto error_parse_next;
2108                                 }
2109
2110                                 source_position_t const* const pos = &expression->base.source_position;
2111                                 if (env->entity != NULL) {
2112                                         warningf(WARN_OTHER, pos, "excess elements in initializer for '%Y'", env->entity->base.symbol);
2113                                 } else {
2114                                         warningf(WARN_OTHER, pos, "excess elements in initializer");
2115                                 }
2116                                 goto error_parse_next;
2117                         }
2118
2119                         /* handle { "string" } special case */
2120                         if ((expression->kind == EXPR_STRING_LITERAL
2121                                         || expression->kind == EXPR_WIDE_STRING_LITERAL)
2122                                         && outer_type != NULL) {
2123                                 sub = initializer_from_expression(outer_type, expression);
2124                                 if (sub != NULL) {
2125                                         next_if(',');
2126                                         if (token.kind != '}') {
2127                                                 warningf(WARN_OTHER, HERE, "excessive elements in initializer for type '%T'", orig_type);
2128                                         }
2129                                         /* TODO: eat , ... */
2130                                         return sub;
2131                                 }
2132                         }
2133
2134                         /* descend into subtypes until expression matches type */
2135                         while (true) {
2136                                 orig_type = path->top_type;
2137                                 type      = skip_typeref(orig_type);
2138
2139                                 sub = initializer_from_expression(orig_type, expression);
2140                                 if (sub != NULL) {
2141                                         break;
2142                                 }
2143                                 if (!is_type_valid(type)) {
2144                                         goto end_error;
2145                                 }
2146                                 if (is_type_scalar(type)) {
2147                                         errorf(&expression->base.source_position,
2148                                                         "expression '%E' doesn't match expected type '%T'",
2149                                                         expression, orig_type);
2150                                         goto end_error;
2151                                 }
2152
2153                                 descend_into_subtype(path);
2154                         }
2155                 }
2156
2157                 /* update largest index of top array */
2158                 const type_path_entry_t *first      = &path->path[0];
2159                 type_t                  *first_type = first->type;
2160                 first_type                          = skip_typeref(first_type);
2161                 if (is_type_array(first_type)) {
2162                         size_t index = first->v.index;
2163                         if (index > path->max_index)
2164                                 path->max_index = index;
2165                 }
2166
2167                 /* append to initializers list */
2168                 ARR_APP1(initializer_t*, initializers, sub);
2169
2170 error_parse_next:
2171                 if (token.kind == '}') {
2172                         break;
2173                 }
2174                 expect(',', end_error);
2175                 if (token.kind == '}') {
2176                         break;
2177                 }
2178
2179                 if (type != NULL) {
2180                         /* advance to the next declaration if we are not at the end */
2181                         advance_current_object(path, top_path_level);
2182                         orig_type = path->top_type;
2183                         if (orig_type != NULL)
2184                                 type = skip_typeref(orig_type);
2185                         else
2186                                 type = NULL;
2187                 }
2188         }
2189
2190         size_t len  = ARR_LEN(initializers);
2191         size_t size = sizeof(initializer_list_t) + len * sizeof(initializers[0]);
2192         initializer_t *result = allocate_ast_zero(size);
2193         result->kind          = INITIALIZER_LIST;
2194         result->list.len      = len;
2195         memcpy(&result->list.initializers, initializers,
2196                len * sizeof(initializers[0]));
2197
2198         DEL_ARR_F(initializers);
2199         ascend_to(path, top_path_level+1);
2200
2201         return result;
2202
2203 end_error:
2204         skip_initializers();
2205         DEL_ARR_F(initializers);
2206         ascend_to(path, top_path_level+1);
2207         return NULL;
2208 }
2209
2210 static expression_t *make_size_literal(size_t value)
2211 {
2212         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_INTEGER);
2213         literal->base.type    = type_size_t;
2214
2215         char buf[128];
2216         snprintf(buf, sizeof(buf), "%u", (unsigned) value);
2217         literal->literal.value = make_string(buf);
2218
2219         return literal;
2220 }
2221
2222 /**
2223  * Parses an initializer. Parsers either a compound literal
2224  * (env->declaration == NULL) or an initializer of a declaration.
2225  */
2226 static initializer_t *parse_initializer(parse_initializer_env_t *env)
2227 {
2228         type_t        *type      = skip_typeref(env->type);
2229         size_t         max_index = 0;
2230         initializer_t *result;
2231
2232         if (is_type_scalar(type)) {
2233                 result = parse_scalar_initializer(type, env->must_be_constant);
2234         } else if (token.kind == '{') {
2235                 eat('{');
2236
2237                 type_path_t path;
2238                 memset(&path, 0, sizeof(path));
2239                 path.top_type = env->type;
2240                 path.path     = NEW_ARR_F(type_path_entry_t, 0);
2241
2242                 descend_into_subtype(&path);
2243
2244                 add_anchor_token('}');
2245                 result = parse_sub_initializer(&path, env->type, 1, env);
2246                 rem_anchor_token('}');
2247
2248                 max_index = path.max_index;
2249                 DEL_ARR_F(path.path);
2250
2251                 expect('}', end_error);
2252 end_error:;
2253         } else {
2254                 /* parse_scalar_initializer() also works in this case: we simply
2255                  * have an expression without {} around it */
2256                 result = parse_scalar_initializer(type, env->must_be_constant);
2257         }
2258
2259         /* §6.7.8:22 array initializers for arrays with unknown size determine
2260          * the array type size */
2261         if (is_type_array(type) && type->array.size_expression == NULL
2262                         && result != NULL) {
2263                 size_t size;
2264                 switch (result->kind) {
2265                 case INITIALIZER_LIST:
2266                         assert(max_index != 0xdeadbeaf);
2267                         size = max_index + 1;
2268                         break;
2269
2270                 case INITIALIZER_STRING:
2271                         size = result->string.string.size;
2272                         break;
2273
2274                 case INITIALIZER_WIDE_STRING:
2275                         size = result->wide_string.string.size;
2276                         break;
2277
2278                 case INITIALIZER_DESIGNATOR:
2279                 case INITIALIZER_VALUE:
2280                         /* can happen for parse errors */
2281                         size = 0;
2282                         break;
2283
2284                 default:
2285                         internal_errorf(HERE, "invalid initializer type");
2286                 }
2287
2288                 type_t *new_type = duplicate_type(type);
2289
2290                 new_type->array.size_expression   = make_size_literal(size);
2291                 new_type->array.size_constant     = true;
2292                 new_type->array.has_implicit_size = true;
2293                 new_type->array.size              = size;
2294                 env->type = new_type;
2295         }
2296
2297         return result;
2298 }
2299
2300 static void append_entity(scope_t *scope, entity_t *entity)
2301 {
2302         if (scope->last_entity != NULL) {
2303                 scope->last_entity->base.next = entity;
2304         } else {
2305                 scope->entities = entity;
2306         }
2307         entity->base.parent_entity = current_entity;
2308         scope->last_entity         = entity;
2309 }
2310
2311
2312 static compound_t *parse_compound_type_specifier(bool is_struct)
2313 {
2314         source_position_t const pos = *HERE;
2315         eat(is_struct ? T_struct : T_union);
2316
2317         symbol_t    *symbol     = NULL;
2318         entity_t    *entity     = NULL;
2319         attribute_t *attributes = NULL;
2320
2321         if (token.kind == T___attribute__) {
2322                 attributes = parse_attributes(NULL);
2323         }
2324
2325         entity_kind_tag_t const kind = is_struct ? ENTITY_STRUCT : ENTITY_UNION;
2326         if (token.kind == T_IDENTIFIER) {
2327                 /* the compound has a name, check if we have seen it already */
2328                 symbol = token.identifier.symbol;
2329                 entity = get_tag(symbol, kind);
2330                 next_token();
2331
2332                 if (entity != NULL) {
2333                         if (entity->base.parent_scope != current_scope &&
2334                             (token.kind == '{' || token.kind == ';')) {
2335                                 /* we're in an inner scope and have a definition. Shadow
2336                                  * existing definition in outer scope */
2337                                 entity = NULL;
2338                         } else if (entity->compound.complete && token.kind == '{') {
2339                                 source_position_t const *const ppos = &entity->base.source_position;
2340                                 errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
2341                                 /* clear members in the hope to avoid further errors */
2342                                 entity->compound.members.entities = NULL;
2343                         }
2344                 }
2345         } else if (token.kind != '{') {
2346                 char const *const msg =
2347                         is_struct ? "while parsing struct type specifier" :
2348                                     "while parsing union type specifier";
2349                 parse_error_expected(msg, T_IDENTIFIER, '{', NULL);
2350
2351                 return NULL;
2352         }
2353
2354         if (entity == NULL) {
2355                 entity = allocate_entity_zero(kind, NAMESPACE_TAG, symbol);
2356                 entity->compound.alignment   = 1;
2357                 entity->base.source_position = pos;
2358                 entity->base.parent_scope    = current_scope;
2359                 if (symbol != NULL) {
2360                         environment_push(entity);
2361                 }
2362                 append_entity(current_scope, entity);
2363         }
2364
2365         if (token.kind == '{') {
2366                 parse_compound_type_entries(&entity->compound);
2367
2368                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2369                 if (symbol == NULL) {
2370                         assert(anonymous_entity == NULL);
2371                         anonymous_entity = entity;
2372                 }
2373         }
2374
2375         if (attributes != NULL) {
2376                 handle_entity_attributes(attributes, entity);
2377         }
2378
2379         return &entity->compound;
2380 }
2381
2382 static void parse_enum_entries(type_t *const enum_type)
2383 {
2384         eat('{');
2385
2386         if (token.kind == '}') {
2387                 errorf(HERE, "empty enum not allowed");
2388                 next_token();
2389                 return;
2390         }
2391
2392         add_anchor_token('}');
2393         do {
2394                 if (token.kind != T_IDENTIFIER) {
2395                         parse_error_expected("while parsing enum entry", T_IDENTIFIER, NULL);
2396                         eat_block();
2397                         rem_anchor_token('}');
2398                         return;
2399                 }
2400
2401                 symbol_t *symbol       = token.identifier.symbol;
2402                 entity_t *const entity
2403                         = allocate_entity_zero(ENTITY_ENUM_VALUE, NAMESPACE_NORMAL, symbol);
2404                 entity->enum_value.enum_type = enum_type;
2405                 entity->base.source_position = token.base.source_position;
2406                 next_token();
2407
2408                 if (next_if('=')) {
2409                         expression_t *value = parse_constant_expression();
2410
2411                         value = create_implicit_cast(value, enum_type);
2412                         entity->enum_value.value = value;
2413
2414                         /* TODO semantic */
2415                 }
2416
2417                 record_entity(entity, false);
2418         } while (next_if(',') && token.kind != '}');
2419         rem_anchor_token('}');
2420
2421         expect('}', end_error);
2422
2423 end_error:
2424         ;
2425 }
2426
2427 static type_t *parse_enum_specifier(void)
2428 {
2429         source_position_t const pos = *HERE;
2430         entity_t               *entity;
2431         symbol_t               *symbol;
2432
2433         eat(T_enum);
2434         switch (token.kind) {
2435                 case T_IDENTIFIER:
2436                         symbol = token.identifier.symbol;
2437                         entity = get_tag(symbol, ENTITY_ENUM);
2438                         next_token();
2439
2440                         if (entity != NULL) {
2441                                 if (entity->base.parent_scope != current_scope &&
2442                                                 (token.kind == '{' || token.kind == ';')) {
2443                                         /* we're in an inner scope and have a definition. Shadow
2444                                          * existing definition in outer scope */
2445                                         entity = NULL;
2446                                 } else if (entity->enume.complete && token.kind == '{') {
2447                                         source_position_t const *const ppos = &entity->base.source_position;
2448                                         errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
2449                                 }
2450                         }
2451                         break;
2452
2453                 case '{':
2454                         entity = NULL;
2455                         symbol = NULL;
2456                         break;
2457
2458                 default:
2459                         parse_error_expected("while parsing enum type specifier",
2460                                         T_IDENTIFIER, '{', NULL);
2461                         return NULL;
2462         }
2463
2464         if (entity == NULL) {
2465                 entity = allocate_entity_zero(ENTITY_ENUM, NAMESPACE_TAG, symbol);
2466                 entity->base.source_position = pos;
2467                 entity->base.parent_scope    = current_scope;
2468         }
2469
2470         type_t *const type     = allocate_type_zero(TYPE_ENUM);
2471         type->enumt.enume      = &entity->enume;
2472         type->enumt.base.akind = ATOMIC_TYPE_INT;
2473
2474         if (token.kind == '{') {
2475                 if (symbol != NULL) {
2476                         environment_push(entity);
2477                 }
2478                 append_entity(current_scope, entity);
2479                 entity->enume.complete = true;
2480
2481                 parse_enum_entries(type);
2482                 parse_attributes(NULL);
2483
2484                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2485                 if (symbol == NULL) {
2486                         assert(anonymous_entity == NULL);
2487                         anonymous_entity = entity;
2488                 }
2489         } else if (!entity->enume.complete && !(c_mode & _GNUC)) {
2490                 errorf(HERE, "'%T' used before definition (incomplete enums are a GNU extension)", type);
2491         }
2492
2493         return type;
2494 }
2495
2496 /**
2497  * if a symbol is a typedef to another type, return true
2498  */
2499 static bool is_typedef_symbol(symbol_t *symbol)
2500 {
2501         const entity_t *const entity = get_entity(symbol, NAMESPACE_NORMAL);
2502         return entity != NULL && entity->kind == ENTITY_TYPEDEF;
2503 }
2504
2505 static type_t *parse_typeof(void)
2506 {
2507         eat(T___typeof__);
2508
2509         type_t *type;
2510
2511         expect('(', end_error);
2512         add_anchor_token(')');
2513
2514         expression_t *expression  = NULL;
2515
2516         switch (token.kind) {
2517         case T_IDENTIFIER:
2518                 if (is_typedef_symbol(token.identifier.symbol)) {
2519         DECLARATION_START
2520                         type = parse_typename();
2521                 } else {
2522         default:
2523                         expression = parse_expression();
2524                         type       = revert_automatic_type_conversion(expression);
2525                 }
2526                 break;
2527         }
2528
2529         rem_anchor_token(')');
2530         expect(')', end_error);
2531
2532         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF);
2533         typeof_type->typeoft.expression  = expression;
2534         typeof_type->typeoft.typeof_type = type;
2535
2536         return typeof_type;
2537 end_error:
2538         return NULL;
2539 }
2540
2541 typedef enum specifiers_t {
2542         SPECIFIER_SIGNED    = 1 << 0,
2543         SPECIFIER_UNSIGNED  = 1 << 1,
2544         SPECIFIER_LONG      = 1 << 2,
2545         SPECIFIER_INT       = 1 << 3,
2546         SPECIFIER_DOUBLE    = 1 << 4,
2547         SPECIFIER_CHAR      = 1 << 5,
2548         SPECIFIER_WCHAR_T   = 1 << 6,
2549         SPECIFIER_SHORT     = 1 << 7,
2550         SPECIFIER_LONG_LONG = 1 << 8,
2551         SPECIFIER_FLOAT     = 1 << 9,
2552         SPECIFIER_BOOL      = 1 << 10,
2553         SPECIFIER_VOID      = 1 << 11,
2554         SPECIFIER_INT8      = 1 << 12,
2555         SPECIFIER_INT16     = 1 << 13,
2556         SPECIFIER_INT32     = 1 << 14,
2557         SPECIFIER_INT64     = 1 << 15,
2558         SPECIFIER_INT128    = 1 << 16,
2559         SPECIFIER_COMPLEX   = 1 << 17,
2560         SPECIFIER_IMAGINARY = 1 << 18,
2561 } specifiers_t;
2562
2563 static type_t *get_typedef_type(symbol_t *symbol)
2564 {
2565         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
2566         if (entity == NULL || entity->kind != ENTITY_TYPEDEF)
2567                 return NULL;
2568
2569         type_t *type            = allocate_type_zero(TYPE_TYPEDEF);
2570         type->typedeft.typedefe = &entity->typedefe;
2571
2572         return type;
2573 }
2574
2575 static attribute_t *parse_attribute_ms_property(attribute_t *attribute)
2576 {
2577         expect('(', end_error);
2578
2579         attribute_property_argument_t *property
2580                 = allocate_ast_zero(sizeof(*property));
2581
2582         do {
2583                 if (token.kind != T_IDENTIFIER) {
2584                         parse_error_expected("while parsing property declspec",
2585                                              T_IDENTIFIER, NULL);
2586                         goto end_error;
2587                 }
2588
2589                 symbol_t **prop;
2590                 symbol_t  *symbol = token.identifier.symbol;
2591                 if (streq(symbol->string, "put")) {
2592                         prop = &property->put_symbol;
2593                 } else if (streq(symbol->string, "get")) {
2594                         prop = &property->get_symbol;
2595                 } else {
2596                         errorf(HERE, "expected put or get in property declspec");
2597                         prop = NULL;
2598                 }
2599                 eat(T_IDENTIFIER);
2600                 expect('=', end_error);
2601                 if (token.kind != T_IDENTIFIER) {
2602                         parse_error_expected("while parsing property declspec",
2603                                              T_IDENTIFIER, NULL);
2604                         goto end_error;
2605                 }
2606                 if (prop != NULL)
2607                         *prop = token.identifier.symbol;
2608                 next_token();
2609         } while (next_if(','));
2610
2611         attribute->a.property = property;
2612
2613         expect(')', end_error);
2614
2615 end_error:
2616         return attribute;
2617 }
2618
2619 static attribute_t *parse_microsoft_extended_decl_modifier_single(void)
2620 {
2621         attribute_kind_t kind = ATTRIBUTE_UNKNOWN;
2622         if (next_if(T_restrict)) {
2623                 kind = ATTRIBUTE_MS_RESTRICT;
2624         } else if (token.kind == T_IDENTIFIER) {
2625                 const char *name = token.identifier.symbol->string;
2626                 for (attribute_kind_t k = ATTRIBUTE_MS_FIRST; k <= ATTRIBUTE_MS_LAST;
2627                      ++k) {
2628                         const char *attribute_name = get_attribute_name(k);
2629                         if (attribute_name != NULL && streq(attribute_name, name)) {
2630                                 kind = k;
2631                                 break;
2632                         }
2633                 }
2634
2635                 if (kind == ATTRIBUTE_UNKNOWN) {
2636                         warningf(WARN_ATTRIBUTE, HERE, "unknown __declspec '%s' ignored", name);
2637                 }
2638         } else {
2639                 parse_error_expected("while parsing __declspec", T_IDENTIFIER, NULL);
2640                 return NULL;
2641         }
2642
2643         attribute_t *attribute = allocate_attribute_zero(kind);
2644         eat(T_IDENTIFIER);
2645
2646         if (kind == ATTRIBUTE_MS_PROPERTY) {
2647                 return parse_attribute_ms_property(attribute);
2648         }
2649
2650         /* parse arguments */
2651         if (next_if('('))
2652                 attribute->a.arguments = parse_attribute_arguments();
2653
2654         return attribute;
2655 }
2656
2657 static attribute_t *parse_microsoft_extended_decl_modifier(attribute_t *first)
2658 {
2659         eat(T__declspec);
2660
2661         expect('(', end_error);
2662         if (token.kind != ')') {
2663                 add_anchor_token(')');
2664
2665                 attribute_t **anchor = &first;
2666                 do {
2667                         while (*anchor != NULL)
2668                                 anchor = &(*anchor)->next;
2669
2670                         attribute_t *attribute
2671                                 = parse_microsoft_extended_decl_modifier_single();
2672                         if (attribute == NULL)
2673                                 break;
2674
2675                         *anchor = attribute;
2676                         anchor  = &attribute->next;
2677                 } while (next_if(','));
2678
2679                 rem_anchor_token(')');
2680         }
2681         expect(')', end_error);
2682 end_error:
2683         return first;
2684 }
2685
2686 static entity_t *create_error_entity(symbol_t *symbol, entity_kind_tag_t kind)
2687 {
2688         entity_t *const entity = allocate_entity_zero(kind, NAMESPACE_NORMAL, symbol);
2689         entity->base.source_position = *HERE;
2690         if (is_declaration(entity)) {
2691                 entity->declaration.type     = type_error_type;
2692                 entity->declaration.implicit = true;
2693         } else if (kind == ENTITY_TYPEDEF) {
2694                 entity->typedefe.type    = type_error_type;
2695                 entity->typedefe.builtin = true;
2696         }
2697         if (kind != ENTITY_COMPOUND_MEMBER)
2698                 record_entity(entity, false);
2699         return entity;
2700 }
2701
2702 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
2703 {
2704         type_t            *type            = NULL;
2705         type_qualifiers_t  qualifiers      = TYPE_QUALIFIER_NONE;
2706         unsigned           type_specifiers = 0;
2707         bool               newtype         = false;
2708         bool               saw_error       = false;
2709
2710         memset(specifiers, 0, sizeof(*specifiers));
2711         specifiers->source_position = token.base.source_position;
2712
2713         while (true) {
2714                 specifiers->attributes = parse_attributes(specifiers->attributes);
2715
2716                 switch (token.kind) {
2717                 /* storage class */
2718 #define MATCH_STORAGE_CLASS(token, class)                                  \
2719                 case token:                                                        \
2720                         if (specifiers->storage_class != STORAGE_CLASS_NONE) {         \
2721                                 errorf(HERE, "multiple storage classes in declaration specifiers"); \
2722                         }                                                              \
2723                         specifiers->storage_class = class;                             \
2724                         if (specifiers->thread_local)                                  \
2725                                 goto check_thread_storage_class;                           \
2726                         next_token();                                                  \
2727                         break;
2728
2729                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
2730                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
2731                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
2732                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
2733                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
2734
2735                 case T__declspec:
2736                         specifiers->attributes
2737                                 = parse_microsoft_extended_decl_modifier(specifiers->attributes);
2738                         break;
2739
2740                 case T___thread:
2741                         if (specifiers->thread_local) {
2742                                 errorf(HERE, "duplicate '__thread'");
2743                         } else {
2744                                 specifiers->thread_local = true;
2745 check_thread_storage_class:
2746                                 switch (specifiers->storage_class) {
2747                                         case STORAGE_CLASS_EXTERN:
2748                                         case STORAGE_CLASS_NONE:
2749                                         case STORAGE_CLASS_STATIC:
2750                                                 break;
2751
2752                                                 char const* wrong;
2753                                         case STORAGE_CLASS_AUTO:     wrong = "auto";     goto wrong_thread_storage_class;
2754                                         case STORAGE_CLASS_REGISTER: wrong = "register"; goto wrong_thread_storage_class;
2755                                         case STORAGE_CLASS_TYPEDEF:  wrong = "typedef";  goto wrong_thread_storage_class;
2756 wrong_thread_storage_class:
2757                                                 errorf(HERE, "'__thread' used with '%s'", wrong);
2758                                                 break;
2759                                 }
2760                         }
2761                         next_token();
2762                         break;
2763
2764                 /* type qualifiers */
2765 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
2766                 case token:                                                     \
2767                         qualifiers |= qualifier;                                    \
2768                         next_token();                                               \
2769                         break
2770
2771                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
2772                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
2773                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
2774                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
2775                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
2776                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
2777                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
2778                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
2779
2780                 /* type specifiers */
2781 #define MATCH_SPECIFIER(token, specifier, name)                         \
2782                 case token:                                                     \
2783                         if (type_specifiers & specifier) {                           \
2784                                 errorf(HERE, "multiple " name " type specifiers given"); \
2785                         } else {                                                    \
2786                                 type_specifiers |= specifier;                           \
2787                         }                                                           \
2788                         next_token();                                               \
2789                         break
2790
2791                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool");
2792                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex");
2793                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary");
2794                 MATCH_SPECIFIER(T__int128,    SPECIFIER_INT128,    "_int128");
2795                 MATCH_SPECIFIER(T__int16,     SPECIFIER_INT16,     "_int16");
2796                 MATCH_SPECIFIER(T__int32,     SPECIFIER_INT32,     "_int32");
2797                 MATCH_SPECIFIER(T__int64,     SPECIFIER_INT64,     "_int64");
2798                 MATCH_SPECIFIER(T__int8,      SPECIFIER_INT8,      "_int8");
2799                 MATCH_SPECIFIER(T_bool,       SPECIFIER_BOOL,      "bool");
2800                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char");
2801                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double");
2802                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float");
2803                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int");
2804                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short");
2805                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed");
2806                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned");
2807                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void");
2808                 MATCH_SPECIFIER(T_wchar_t,    SPECIFIER_WCHAR_T,   "wchar_t");
2809
2810                 case T_inline:
2811                         next_token();
2812                         specifiers->is_inline = true;
2813                         break;
2814
2815 #if 0
2816                 case T__forceinline:
2817                         next_token();
2818                         specifiers->modifiers |= DM_FORCEINLINE;
2819                         break;
2820 #endif
2821
2822                 case T_long:
2823                         if (type_specifiers & SPECIFIER_LONG_LONG) {
2824                                 errorf(HERE, "too many long type specifiers given");
2825                         } else if (type_specifiers & SPECIFIER_LONG) {
2826                                 type_specifiers |= SPECIFIER_LONG_LONG;
2827                         } else {
2828                                 type_specifiers |= SPECIFIER_LONG;
2829                         }
2830                         next_token();
2831                         break;
2832
2833 #define CHECK_DOUBLE_TYPE() \
2834         (type != NULL ? errorf(HERE, "multiple types in declaration specifiers") : (void)0)
2835
2836                 case T_struct:
2837                         CHECK_DOUBLE_TYPE();
2838                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
2839
2840                         type->compound.compound = parse_compound_type_specifier(true);
2841                         break;
2842                 case T_union:
2843                         CHECK_DOUBLE_TYPE();
2844                         type = allocate_type_zero(TYPE_COMPOUND_UNION);
2845                         type->compound.compound = parse_compound_type_specifier(false);
2846                         break;
2847                 case T_enum:
2848                         CHECK_DOUBLE_TYPE();
2849                         type = parse_enum_specifier();
2850                         break;
2851                 case T___typeof__:
2852                         CHECK_DOUBLE_TYPE();
2853                         type = parse_typeof();
2854                         break;
2855                 case T___builtin_va_list:
2856                         CHECK_DOUBLE_TYPE();
2857                         type = duplicate_type(type_valist);
2858                         next_token();
2859                         break;
2860
2861                 case T_IDENTIFIER: {
2862                         /* only parse identifier if we haven't found a type yet */
2863                         if (type != NULL || type_specifiers != 0) {
2864                                 /* Be somewhat resilient to typos like 'unsigned lng* f()' in a
2865                                  * declaration, so it doesn't generate errors about expecting '(' or
2866                                  * '{' later on. */
2867                                 switch (look_ahead(1)->kind) {
2868                                         STORAGE_CLASSES
2869                                         TYPE_SPECIFIERS
2870                                         case T_const:
2871                                         case T_restrict:
2872                                         case T_volatile:
2873                                         case T_inline:
2874                                         case T__forceinline: /* ^ DECLARATION_START except for __attribute__ */
2875                                         case T_IDENTIFIER:
2876                                         case '&':
2877                                         case '*':
2878                                                 errorf(HERE, "discarding stray %K in declaration specifier", &token);
2879                                                 next_token();
2880                                                 continue;
2881
2882                                         default:
2883                                                 goto finish_specifiers;
2884                                 }
2885                         }
2886
2887                         type_t *const typedef_type = get_typedef_type(token.identifier.symbol);
2888                         if (typedef_type == NULL) {
2889                                 /* Be somewhat resilient to typos like 'vodi f()' at the beginning of a
2890                                  * declaration, so it doesn't generate 'implicit int' followed by more
2891                                  * errors later on. */
2892                                 token_kind_t const la1_type = (token_kind_t)look_ahead(1)->kind;
2893                                 switch (la1_type) {
2894                                         DECLARATION_START
2895                                         case T_IDENTIFIER:
2896                                         case '&':
2897                                         case '*': {
2898                                                 errorf(HERE, "%K does not name a type", &token);
2899
2900                                                 symbol_t *symbol = token.identifier.symbol;
2901                                                 entity_t *entity
2902                                                         = create_error_entity(symbol, ENTITY_TYPEDEF);
2903
2904                                                 type = allocate_type_zero(TYPE_TYPEDEF);
2905                                                 type->typedeft.typedefe = &entity->typedefe;
2906
2907                                                 next_token();
2908                                                 saw_error = true;
2909                                                 continue;
2910                                         }
2911
2912                                         default:
2913                                                 goto finish_specifiers;
2914                                 }
2915                         }
2916
2917                         next_token();
2918                         type = typedef_type;
2919                         break;
2920                 }
2921
2922                 /* function specifier */
2923                 default:
2924                         goto finish_specifiers;
2925                 }
2926         }
2927
2928 finish_specifiers:
2929         specifiers->attributes = parse_attributes(specifiers->attributes);
2930
2931         if (type == NULL || (saw_error && type_specifiers != 0)) {
2932                 atomic_type_kind_t atomic_type;
2933
2934                 /* match valid basic types */
2935                 switch (type_specifiers) {
2936                 case SPECIFIER_VOID:
2937                         atomic_type = ATOMIC_TYPE_VOID;
2938                         break;
2939                 case SPECIFIER_WCHAR_T:
2940                         atomic_type = ATOMIC_TYPE_WCHAR_T;
2941                         break;
2942                 case SPECIFIER_CHAR:
2943                         atomic_type = ATOMIC_TYPE_CHAR;
2944                         break;
2945                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
2946                         atomic_type = ATOMIC_TYPE_SCHAR;
2947                         break;
2948                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
2949                         atomic_type = ATOMIC_TYPE_UCHAR;
2950                         break;
2951                 case SPECIFIER_SHORT:
2952                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
2953                 case SPECIFIER_SHORT | SPECIFIER_INT:
2954                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
2955                         atomic_type = ATOMIC_TYPE_SHORT;
2956                         break;
2957                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
2958                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
2959                         atomic_type = ATOMIC_TYPE_USHORT;
2960                         break;
2961                 case SPECIFIER_INT:
2962                 case SPECIFIER_SIGNED:
2963                 case SPECIFIER_SIGNED | SPECIFIER_INT:
2964                         atomic_type = ATOMIC_TYPE_INT;
2965                         break;
2966                 case SPECIFIER_UNSIGNED:
2967                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
2968                         atomic_type = ATOMIC_TYPE_UINT;
2969                         break;
2970                 case SPECIFIER_LONG:
2971                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
2972                 case SPECIFIER_LONG | SPECIFIER_INT:
2973                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
2974                         atomic_type = ATOMIC_TYPE_LONG;
2975                         break;
2976                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
2977                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
2978                         atomic_type = ATOMIC_TYPE_ULONG;
2979                         break;
2980
2981                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2982                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2983                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
2984                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
2985                         | SPECIFIER_INT:
2986                         atomic_type = ATOMIC_TYPE_LONGLONG;
2987                         goto warn_about_long_long;
2988
2989                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2990                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
2991                         | SPECIFIER_INT:
2992                         atomic_type = ATOMIC_TYPE_ULONGLONG;
2993 warn_about_long_long:
2994                         warningf(WARN_LONG_LONG, &specifiers->source_position, "ISO C90 does not support 'long long'");
2995                         break;
2996
2997                 case SPECIFIER_UNSIGNED | SPECIFIER_INT8:
2998                         atomic_type = unsigned_int8_type_kind;
2999                         break;
3000
3001                 case SPECIFIER_UNSIGNED | SPECIFIER_INT16:
3002                         atomic_type = unsigned_int16_type_kind;
3003                         break;
3004
3005                 case SPECIFIER_UNSIGNED | SPECIFIER_INT32:
3006                         atomic_type = unsigned_int32_type_kind;
3007                         break;
3008
3009                 case SPECIFIER_UNSIGNED | SPECIFIER_INT64:
3010                         atomic_type = unsigned_int64_type_kind;
3011                         break;
3012
3013                 case SPECIFIER_UNSIGNED | SPECIFIER_INT128:
3014                         atomic_type = unsigned_int128_type_kind;
3015                         break;
3016
3017                 case SPECIFIER_INT8:
3018                 case SPECIFIER_SIGNED | SPECIFIER_INT8:
3019                         atomic_type = int8_type_kind;
3020                         break;
3021
3022                 case SPECIFIER_INT16:
3023                 case SPECIFIER_SIGNED | SPECIFIER_INT16:
3024                         atomic_type = int16_type_kind;
3025                         break;
3026
3027                 case SPECIFIER_INT32:
3028                 case SPECIFIER_SIGNED | SPECIFIER_INT32:
3029                         atomic_type = int32_type_kind;
3030                         break;
3031
3032                 case SPECIFIER_INT64:
3033                 case SPECIFIER_SIGNED | SPECIFIER_INT64:
3034                         atomic_type = int64_type_kind;
3035                         break;
3036
3037                 case SPECIFIER_INT128:
3038                 case SPECIFIER_SIGNED | SPECIFIER_INT128:
3039                         atomic_type = int128_type_kind;
3040                         break;
3041
3042                 case SPECIFIER_FLOAT:
3043                         atomic_type = ATOMIC_TYPE_FLOAT;
3044                         break;
3045                 case SPECIFIER_DOUBLE:
3046                         atomic_type = ATOMIC_TYPE_DOUBLE;
3047                         break;
3048                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
3049                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
3050                         break;
3051                 case SPECIFIER_BOOL:
3052                         atomic_type = ATOMIC_TYPE_BOOL;
3053                         break;
3054                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
3055                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
3056                         atomic_type = ATOMIC_TYPE_FLOAT;
3057                         break;
3058                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3059                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3060                         atomic_type = ATOMIC_TYPE_DOUBLE;
3061                         break;
3062                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3063                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3064                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
3065                         break;
3066                 default: {
3067                         /* invalid specifier combination, give an error message */
3068                         source_position_t const* const pos = &specifiers->source_position;
3069                         if (type_specifiers == 0) {
3070                                 if (!saw_error) {
3071                                         /* ISO/IEC 14882:1998(E) §C.1.5:4 */
3072                                         if (!(c_mode & _CXX) && !strict_mode) {
3073                                                 warningf(WARN_IMPLICIT_INT, pos, "no type specifiers in declaration, using 'int'");
3074                                                 atomic_type = ATOMIC_TYPE_INT;
3075                                                 break;
3076                                         } else {
3077                                                 errorf(pos, "no type specifiers given in declaration");
3078                                         }
3079                                 }
3080                         } else if ((type_specifiers & SPECIFIER_SIGNED) &&
3081                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
3082                                 errorf(pos, "signed and unsigned specifiers given");
3083                         } else if (type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
3084                                 errorf(pos, "only integer types can be signed or unsigned");
3085                         } else {
3086                                 errorf(pos, "multiple datatypes in declaration");
3087                         }
3088                         goto end_error;
3089                 }
3090                 }
3091
3092                 if (type_specifiers & SPECIFIER_COMPLEX) {
3093                         type = allocate_type_zero(TYPE_COMPLEX);
3094                 } else if (type_specifiers & SPECIFIER_IMAGINARY) {
3095                         type = allocate_type_zero(TYPE_IMAGINARY);
3096                 } else {
3097                         type = allocate_type_zero(TYPE_ATOMIC);
3098                 }
3099                 type->atomic.akind = atomic_type;
3100                 newtype = true;
3101         } else if (type_specifiers != 0) {
3102                 errorf(&specifiers->source_position, "multiple datatypes in declaration");
3103         }
3104
3105         /* FIXME: check type qualifiers here */
3106         type->base.qualifiers = qualifiers;
3107
3108         if (newtype) {
3109                 type = identify_new_type(type);
3110         } else {
3111                 type = typehash_insert(type);
3112         }
3113
3114         if (specifiers->attributes != NULL)
3115                 type = handle_type_attributes(specifiers->attributes, type);
3116         specifiers->type = type;
3117         return;
3118
3119 end_error:
3120         specifiers->type = type_error_type;
3121 }
3122
3123 static type_qualifiers_t parse_type_qualifiers(void)
3124 {
3125         type_qualifiers_t qualifiers = TYPE_QUALIFIER_NONE;
3126
3127         while (true) {
3128                 switch (token.kind) {
3129                 /* type qualifiers */
3130                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3131                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3132                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3133                 /* microsoft extended type modifiers */
3134                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3135                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3136                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3137                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3138                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3139
3140                 default:
3141                         return qualifiers;
3142                 }
3143         }
3144 }
3145
3146 /**
3147  * Parses an K&R identifier list
3148  */
3149 static void parse_identifier_list(scope_t *scope)
3150 {
3151         assert(token.kind == T_IDENTIFIER);
3152         do {
3153                 entity_t *const entity = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, token.identifier.symbol);
3154                 entity->base.source_position = token.base.source_position;
3155                 /* a K&R parameter has no type, yet */
3156                 next_token();
3157
3158                 if (scope != NULL)
3159                         append_entity(scope, entity);
3160         } while (next_if(',') && token.kind == T_IDENTIFIER);
3161 }
3162
3163 static entity_t *parse_parameter(void)
3164 {
3165         declaration_specifiers_t specifiers;
3166         parse_declaration_specifiers(&specifiers);
3167
3168         entity_t *entity = parse_declarator(&specifiers,
3169                         DECL_MAY_BE_ABSTRACT | DECL_IS_PARAMETER);
3170         anonymous_entity = NULL;
3171         return entity;
3172 }
3173
3174 static void semantic_parameter_incomplete(const entity_t *entity)
3175 {
3176         assert(entity->kind == ENTITY_PARAMETER);
3177
3178         /* §6.7.5.3:4  After adjustment, the parameters in a parameter type
3179          *             list in a function declarator that is part of a
3180          *             definition of that function shall not have
3181          *             incomplete type. */
3182         type_t *type = skip_typeref(entity->declaration.type);
3183         if (is_type_incomplete(type)) {
3184                 errorf(&entity->base.source_position, "'%N' has incomplete type", entity);
3185         }
3186 }
3187
3188 static bool has_parameters(void)
3189 {
3190         /* func(void) is not a parameter */
3191         if (look_ahead(1)->kind != ')')
3192                 return true;
3193         if (token.kind == T_IDENTIFIER) {
3194                 entity_t const *const entity
3195                         = get_entity(token.identifier.symbol, NAMESPACE_NORMAL);
3196                 if (entity == NULL)
3197                         return true;
3198                 if (entity->kind != ENTITY_TYPEDEF)
3199                         return true;
3200                 type_t const *const type = skip_typeref(entity->typedefe.type);
3201                 if (!is_type_void(type))
3202                         return true;
3203                 if (c_mode & _CXX) {
3204                         /* ISO/IEC 14882:1998(E) §8.3.5:2  It must be literally (void).  A typedef
3205                          * is not allowed. */
3206                         errorf(HERE, "empty parameter list defined with a typedef of 'void' not allowed in C++");
3207                 } else if (type->base.qualifiers != TYPE_QUALIFIER_NONE) {
3208                         /* §6.7.5.3:10  Qualification is not allowed here. */
3209                         errorf(HERE, "'void' as parameter must not have type qualifiers");
3210                 }
3211         } else if (token.kind != T_void) {
3212                 return true;
3213         }
3214         next_token();
3215         return false;
3216 }
3217
3218 /**
3219  * Parses function type parameters (and optionally creates variable_t entities
3220  * for them in a scope)
3221  */
3222 static void parse_parameters(function_type_t *type, scope_t *scope)
3223 {
3224         eat('(');
3225         add_anchor_token(')');
3226         int saved_comma_state = save_and_reset_anchor_state(',');
3227
3228         if (token.kind == T_IDENTIFIER
3229             && !is_typedef_symbol(token.identifier.symbol)) {
3230                 token_kind_t la1_type = (token_kind_t)look_ahead(1)->kind;
3231                 if (la1_type == ',' || la1_type == ')') {
3232                         type->kr_style_parameters = true;
3233                         parse_identifier_list(scope);
3234                         goto parameters_finished;
3235                 }
3236         }
3237
3238         if (token.kind == ')') {
3239                 /* ISO/IEC 14882:1998(E) §C.1.6:1 */
3240                 if (!(c_mode & _CXX))
3241                         type->unspecified_parameters = true;
3242         } else if (has_parameters()) {
3243                 function_parameter_t **anchor = &type->parameters;
3244                 do {
3245                         switch (token.kind) {
3246                         case T_DOTDOTDOT:
3247                                 next_token();
3248                                 type->variadic = true;
3249                                 goto parameters_finished;
3250
3251                         case T_IDENTIFIER:
3252                         DECLARATION_START
3253                         {
3254                                 entity_t *entity = parse_parameter();
3255                                 if (entity->kind == ENTITY_TYPEDEF) {
3256                                         errorf(&entity->base.source_position,
3257                                                         "typedef not allowed as function parameter");
3258                                         break;
3259                                 }
3260                                 assert(is_declaration(entity));
3261
3262                                 semantic_parameter_incomplete(entity);
3263
3264                                 function_parameter_t *const parameter =
3265                                         allocate_parameter(entity->declaration.type);
3266
3267                                 if (scope != NULL) {
3268                                         append_entity(scope, entity);
3269                                 }
3270
3271                                 *anchor = parameter;
3272                                 anchor  = &parameter->next;
3273                                 break;
3274                         }
3275
3276                         default:
3277                                 goto parameters_finished;
3278                         }
3279                 } while (next_if(','));
3280         }
3281
3282 parameters_finished:
3283         rem_anchor_token(')');
3284         expect(')', end_error);
3285
3286 end_error:
3287         restore_anchor_state(',', saved_comma_state);
3288 }
3289
3290 typedef enum construct_type_kind_t {
3291         CONSTRUCT_POINTER = 1,
3292         CONSTRUCT_REFERENCE,
3293         CONSTRUCT_FUNCTION,
3294         CONSTRUCT_ARRAY
3295 } construct_type_kind_t;
3296
3297 typedef union construct_type_t construct_type_t;
3298
3299 typedef struct construct_type_base_t {
3300         construct_type_kind_t  kind;
3301         source_position_t      pos;
3302         construct_type_t      *next;
3303 } construct_type_base_t;
3304
3305 typedef struct parsed_pointer_t {
3306         construct_type_base_t  base;
3307         type_qualifiers_t      type_qualifiers;
3308         variable_t            *base_variable;  /**< MS __based extension. */
3309 } parsed_pointer_t;
3310
3311 typedef struct parsed_reference_t {
3312         construct_type_base_t base;
3313 } parsed_reference_t;
3314
3315 typedef struct construct_function_type_t {
3316         construct_type_base_t  base;
3317         type_t                *function_type;
3318 } construct_function_type_t;
3319
3320 typedef struct parsed_array_t {
3321         construct_type_base_t  base;
3322         type_qualifiers_t      type_qualifiers;
3323         bool                   is_static;
3324         bool                   is_variable;
3325         expression_t          *size;
3326 } parsed_array_t;
3327
3328 union construct_type_t {
3329         construct_type_kind_t     kind;
3330         construct_type_base_t     base;
3331         parsed_pointer_t          pointer;
3332         parsed_reference_t        reference;
3333         construct_function_type_t function;
3334         parsed_array_t            array;
3335 };
3336
3337 static construct_type_t *allocate_declarator_zero(construct_type_kind_t const kind, size_t const size)
3338 {
3339         construct_type_t *const cons = obstack_alloc(&temp_obst, size);
3340         memset(cons, 0, size);
3341         cons->kind     = kind;
3342         cons->base.pos = *HERE;
3343         return cons;
3344 }
3345
3346 /* §6.7.5.1 */
3347 static construct_type_t *parse_pointer_declarator(void)
3348 {
3349         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_POINTER, sizeof(parsed_pointer_t));
3350         eat('*');
3351         cons->pointer.type_qualifiers = parse_type_qualifiers();
3352         //cons->pointer.base_variable   = base_variable;
3353
3354         return cons;
3355 }
3356
3357 /* ISO/IEC 14882:1998(E) §8.3.2 */
3358 static construct_type_t *parse_reference_declarator(void)
3359 {
3360         if (!(c_mode & _CXX))
3361                 errorf(HERE, "references are only available for C++");
3362
3363         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_REFERENCE, sizeof(parsed_reference_t));
3364         eat('&');
3365
3366         return cons;
3367 }
3368
3369 /* §6.7.5.2 */
3370 static construct_type_t *parse_array_declarator(void)
3371 {
3372         construct_type_t *const cons  = allocate_declarator_zero(CONSTRUCT_ARRAY, sizeof(parsed_array_t));
3373         parsed_array_t   *const array = &cons->array;
3374
3375         eat('[');
3376         add_anchor_token(']');
3377
3378         bool is_static = next_if(T_static);
3379
3380         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
3381
3382         if (!is_static)
3383                 is_static = next_if(T_static);
3384
3385         array->type_qualifiers = type_qualifiers;
3386         array->is_static       = is_static;
3387
3388         expression_t *size = NULL;
3389         if (token.kind == '*' && look_ahead(1)->kind == ']') {
3390                 array->is_variable = true;
3391                 next_token();
3392         } else if (token.kind != ']') {
3393                 size = parse_assignment_expression();
3394
3395                 /* §6.7.5.2:1  Array size must have integer type */
3396                 type_t *const orig_type = size->base.type;
3397                 type_t *const type      = skip_typeref(orig_type);
3398                 if (!is_type_integer(type) && is_type_valid(type)) {
3399                         errorf(&size->base.source_position,
3400                                "array size '%E' must have integer type but has type '%T'",
3401                                size, orig_type);
3402                 }
3403
3404                 array->size = size;
3405                 mark_vars_read(size, NULL);
3406         }
3407
3408         if (is_static && size == NULL)
3409                 errorf(&array->base.pos, "static array parameters require a size");
3410
3411         rem_anchor_token(']');
3412         expect(']', end_error);
3413
3414 end_error:
3415         return cons;
3416 }
3417
3418 /* §6.7.5.3 */
3419 static construct_type_t *parse_function_declarator(scope_t *scope)
3420 {
3421         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_FUNCTION, sizeof(construct_function_type_t));
3422
3423         type_t          *type  = allocate_type_zero(TYPE_FUNCTION);
3424         function_type_t *ftype = &type->function;
3425
3426         ftype->linkage            = current_linkage;
3427         ftype->calling_convention = CC_DEFAULT;
3428
3429         parse_parameters(ftype, scope);
3430
3431         cons->function.function_type = type;
3432
3433         return cons;
3434 }
3435
3436 typedef struct parse_declarator_env_t {
3437         bool               may_be_abstract : 1;
3438         bool               must_be_abstract : 1;
3439         decl_modifiers_t   modifiers;
3440         symbol_t          *symbol;
3441         source_position_t  source_position;
3442         scope_t            parameters;
3443         attribute_t       *attributes;
3444 } parse_declarator_env_t;
3445
3446 /* §6.7.5 */
3447 static construct_type_t *parse_inner_declarator(parse_declarator_env_t *env)
3448 {
3449         /* construct a single linked list of construct_type_t's which describe
3450          * how to construct the final declarator type */
3451         construct_type_t  *first      = NULL;
3452         construct_type_t **anchor     = &first;
3453
3454         env->attributes = parse_attributes(env->attributes);
3455
3456         for (;;) {
3457                 construct_type_t *type;
3458                 //variable_t       *based = NULL; /* MS __based extension */
3459                 switch (token.kind) {
3460                         case '&':
3461                                 type = parse_reference_declarator();
3462                                 break;
3463
3464                         case T__based: {
3465                                 panic("based not supported anymore");
3466                                 /* FALLTHROUGH */
3467                         }
3468
3469                         case '*':
3470                                 type = parse_pointer_declarator();
3471                                 break;
3472
3473                         default:
3474                                 goto ptr_operator_end;
3475                 }
3476
3477                 *anchor = type;
3478                 anchor  = &type->base.next;
3479
3480                 /* TODO: find out if this is correct */
3481                 env->attributes = parse_attributes(env->attributes);
3482         }
3483
3484 ptr_operator_end: ;
3485         construct_type_t *inner_types = NULL;
3486
3487         switch (token.kind) {
3488         case T_IDENTIFIER:
3489                 if (env->must_be_abstract) {
3490                         errorf(HERE, "no identifier expected in typename");
3491                 } else {
3492                         env->symbol          = token.identifier.symbol;
3493                         env->source_position = token.base.source_position;
3494                 }
3495                 next_token();
3496                 break;
3497
3498         case '(': {
3499                 /* Parenthesized declarator or function declarator? */
3500                 token_t const *const la1 = look_ahead(1);
3501                 switch (la1->kind) {
3502                         case T_IDENTIFIER:
3503                                 if (is_typedef_symbol(la1->identifier.symbol)) {
3504                         case ')':
3505                                         /* §6.7.6:2 footnote 126:  Empty parentheses in a type name are
3506                                          * interpreted as ``function with no parameter specification'', rather
3507                                          * than redundant parentheses around the omitted identifier. */
3508                         default:
3509                                         /* Function declarator. */
3510                                         if (!env->may_be_abstract) {
3511                                                 errorf(HERE, "function declarator must have a name");
3512                                         }
3513                                 } else {
3514                         case '&':
3515                         case '(':
3516                         case '*':
3517                         case '[':
3518                         case T___attribute__: /* FIXME __attribute__ might also introduce a parameter of a function declarator. */
3519                                         /* Paranthesized declarator. */
3520                                         next_token();
3521                                         add_anchor_token(')');
3522                                         inner_types = parse_inner_declarator(env);
3523                                         if (inner_types != NULL) {
3524                                                 /* All later declarators only modify the return type */
3525                                                 env->must_be_abstract = true;
3526                                         }
3527                                         rem_anchor_token(')');
3528                                         expect(')', end_error);
3529                                 }
3530                                 break;
3531                 }
3532                 break;
3533         }
3534
3535         default:
3536                 if (env->may_be_abstract)
3537                         break;
3538                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', NULL);
3539                 eat_until_anchor();
3540                 return NULL;
3541         }
3542
3543         construct_type_t **const p = anchor;
3544
3545         for (;;) {
3546                 construct_type_t *type;
3547                 switch (token.kind) {
3548                 case '(': {
3549                         scope_t *scope = NULL;
3550                         if (!env->must_be_abstract) {
3551                                 scope = &env->parameters;
3552                         }
3553
3554                         type = parse_function_declarator(scope);
3555                         break;
3556                 }
3557                 case '[':
3558                         type = parse_array_declarator();
3559                         break;
3560                 default:
3561                         goto declarator_finished;
3562                 }
3563
3564                 /* insert in the middle of the list (at p) */
3565                 type->base.next = *p;
3566                 *p              = type;
3567                 if (anchor == p)
3568                         anchor = &type->base.next;
3569         }
3570
3571 declarator_finished:
3572         /* append inner_types at the end of the list, we don't to set anchor anymore
3573          * as it's not needed anymore */
3574         *anchor = inner_types;
3575
3576         return first;
3577 end_error:
3578         return NULL;
3579 }
3580
3581 static type_t *construct_declarator_type(construct_type_t *construct_list,
3582                                          type_t *type)
3583 {
3584         construct_type_t *iter = construct_list;
3585         for (; iter != NULL; iter = iter->base.next) {
3586                 source_position_t const* const pos = &iter->base.pos;
3587                 switch (iter->kind) {
3588                 case CONSTRUCT_FUNCTION: {
3589                         construct_function_type_t *function      = &iter->function;
3590                         type_t                    *function_type = function->function_type;
3591
3592                         function_type->function.return_type = type;
3593
3594                         type_t *skipped_return_type = skip_typeref(type);
3595                         /* §6.7.5.3:1 */
3596                         if (is_type_function(skipped_return_type)) {
3597                                 errorf(pos, "function returning function is not allowed");
3598                         } else if (is_type_array(skipped_return_type)) {
3599                                 errorf(pos, "function returning array is not allowed");
3600                         } else {
3601                                 if (skipped_return_type->base.qualifiers != 0) {
3602                                         warningf(WARN_IGNORED_QUALIFIERS, pos, "type qualifiers in return type of function type are meaningless");
3603                                 }
3604                         }
3605
3606                         /* The function type was constructed earlier.  Freeing it here will
3607                          * destroy other types. */
3608                         type = typehash_insert(function_type);
3609                         continue;
3610                 }
3611
3612                 case CONSTRUCT_POINTER: {
3613                         if (is_type_reference(skip_typeref(type)))
3614                                 errorf(pos, "cannot declare a pointer to reference");
3615
3616                         parsed_pointer_t *pointer = &iter->pointer;
3617                         type = make_based_pointer_type(type, pointer->type_qualifiers, pointer->base_variable);
3618                         continue;
3619                 }
3620
3621                 case CONSTRUCT_REFERENCE:
3622                         if (is_type_reference(skip_typeref(type)))
3623                                 errorf(pos, "cannot declare a reference to reference");
3624
3625                         type = make_reference_type(type);
3626                         continue;
3627
3628                 case CONSTRUCT_ARRAY: {
3629                         if (is_type_reference(skip_typeref(type)))
3630                                 errorf(pos, "cannot declare an array of references");
3631
3632                         parsed_array_t *array      = &iter->array;
3633                         type_t         *array_type = allocate_type_zero(TYPE_ARRAY);
3634
3635                         expression_t *size_expression = array->size;
3636                         if (size_expression != NULL) {
3637                                 size_expression
3638                                         = create_implicit_cast(size_expression, type_size_t);
3639                         }
3640
3641                         array_type->base.qualifiers       = array->type_qualifiers;
3642                         array_type->array.element_type    = type;
3643                         array_type->array.is_static       = array->is_static;
3644                         array_type->array.is_variable     = array->is_variable;
3645                         array_type->array.size_expression = size_expression;
3646
3647                         if (size_expression != NULL) {
3648                                 switch (is_constant_expression(size_expression)) {
3649                                 case EXPR_CLASS_CONSTANT: {
3650                                         long const size = fold_constant_to_int(size_expression);
3651                                         array_type->array.size          = size;
3652                                         array_type->array.size_constant = true;
3653                                         /* §6.7.5.2:1  If the expression is a constant expression,
3654                                          * it shall have a value greater than zero. */
3655                                         if (size < 0) {
3656                                                 errorf(&size_expression->base.source_position,
3657                                                            "size of array must be greater than zero");
3658                                         } else if (size == 0 && !GNU_MODE) {
3659                                                 errorf(&size_expression->base.source_position,
3660                                                            "size of array must be greater than zero (zero length arrays are a GCC extension)");
3661                                         }
3662                                         break;
3663                                 }
3664
3665                                 case EXPR_CLASS_VARIABLE:
3666                                         array_type->array.is_vla = true;
3667                                         break;
3668
3669                                 case EXPR_CLASS_ERROR:
3670                                         break;
3671                                 }
3672                         }
3673
3674                         type_t *skipped_type = skip_typeref(type);
3675                         /* §6.7.5.2:1 */
3676                         if (is_type_incomplete(skipped_type)) {
3677                                 errorf(pos, "array of incomplete type '%T' is not allowed", type);
3678                         } else if (is_type_function(skipped_type)) {
3679                                 errorf(pos, "array of functions is not allowed");
3680                         }
3681                         type = identify_new_type(array_type);
3682                         continue;
3683                 }
3684                 }
3685                 internal_errorf(pos, "invalid type construction found");
3686         }
3687
3688         return type;
3689 }
3690
3691 static type_t *automatic_type_conversion(type_t *orig_type);
3692
3693 static type_t *semantic_parameter(const source_position_t *pos,
3694                                   type_t *type,
3695                                   const declaration_specifiers_t *specifiers,
3696                                   entity_t const *const param)
3697 {
3698         /* §6.7.5.3:7  A declaration of a parameter as ``array of type''
3699          *             shall be adjusted to ``qualified pointer to type'',
3700          *             [...]
3701          * §6.7.5.3:8  A declaration of a parameter as ``function returning
3702          *             type'' shall be adjusted to ``pointer to function
3703          *             returning type'', as in 6.3.2.1. */
3704         type = automatic_type_conversion(type);
3705
3706         if (specifiers->is_inline && is_type_valid(type)) {
3707                 errorf(pos, "'%N' declared 'inline'", param);
3708         }
3709
3710         /* §6.9.1:6  The declarations in the declaration list shall contain
3711          *           no storage-class specifier other than register and no
3712          *           initializations. */
3713         if (specifiers->thread_local || (
3714                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3715                         specifiers->storage_class != STORAGE_CLASS_REGISTER)
3716            ) {
3717                 errorf(pos, "invalid storage class for '%N'", param);
3718         }
3719
3720         /* delay test for incomplete type, because we might have (void)
3721          * which is legal but incomplete... */
3722
3723         return type;
3724 }
3725
3726 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
3727                                   declarator_flags_t flags)
3728 {
3729         parse_declarator_env_t env;
3730         memset(&env, 0, sizeof(env));
3731         env.may_be_abstract = (flags & DECL_MAY_BE_ABSTRACT) != 0;
3732
3733         construct_type_t *construct_type = parse_inner_declarator(&env);
3734         type_t           *orig_type      =
3735                 construct_declarator_type(construct_type, specifiers->type);
3736         type_t           *type           = skip_typeref(orig_type);
3737
3738         if (construct_type != NULL) {
3739                 obstack_free(&temp_obst, construct_type);
3740         }
3741
3742         attribute_t *attributes = parse_attributes(env.attributes);
3743         /* append (shared) specifier attribute behind attributes of this
3744          * declarator */
3745         attribute_t **anchor = &attributes;
3746         while (*anchor != NULL)
3747                 anchor = &(*anchor)->next;
3748         *anchor = specifiers->attributes;
3749
3750         entity_t *entity;
3751         if (specifiers->storage_class == STORAGE_CLASS_TYPEDEF) {
3752                 entity = allocate_entity_zero(ENTITY_TYPEDEF, NAMESPACE_NORMAL, env.symbol);
3753                 entity->base.source_position = env.source_position;
3754                 entity->typedefe.type        = orig_type;
3755
3756                 if (anonymous_entity != NULL) {
3757                         if (is_type_compound(type)) {
3758                                 assert(anonymous_entity->compound.alias == NULL);
3759                                 assert(anonymous_entity->kind == ENTITY_STRUCT ||
3760                                        anonymous_entity->kind == ENTITY_UNION);
3761                                 anonymous_entity->compound.alias = entity;
3762                                 anonymous_entity = NULL;
3763                         } else if (is_type_enum(type)) {
3764                                 assert(anonymous_entity->enume.alias == NULL);
3765                                 assert(anonymous_entity->kind == ENTITY_ENUM);
3766                                 anonymous_entity->enume.alias = entity;
3767                                 anonymous_entity = NULL;
3768                         }
3769                 }
3770         } else {
3771                 /* create a declaration type entity */
3772                 if (flags & DECL_CREATE_COMPOUND_MEMBER) {
3773                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER, NAMESPACE_NORMAL, env.symbol);
3774
3775                         if (env.symbol != NULL) {
3776                                 if (specifiers->is_inline && is_type_valid(type)) {
3777                                         errorf(&env.source_position,
3778                                                         "compound member '%Y' declared 'inline'", env.symbol);
3779                                 }
3780
3781                                 if (specifiers->thread_local ||
3782                                                 specifiers->storage_class != STORAGE_CLASS_NONE) {
3783                                         errorf(&env.source_position,
3784                                                         "compound member '%Y' must have no storage class",
3785                                                         env.symbol);
3786                                 }
3787                         }
3788                 } else if (flags & DECL_IS_PARAMETER) {
3789                         entity    = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, env.symbol);
3790                         orig_type = semantic_parameter(&env.source_position, orig_type, specifiers, entity);
3791                 } else if (is_type_function(type)) {
3792                         entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, env.symbol);
3793                         entity->function.is_inline      = specifiers->is_inline;
3794                         entity->function.elf_visibility = default_visibility;
3795                         entity->function.parameters     = env.parameters;
3796
3797                         if (env.symbol != NULL) {
3798                                 /* this needs fixes for C++ */
3799                                 bool in_function_scope = current_function != NULL;
3800
3801                                 if (specifiers->thread_local || (
3802                                                         specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3803                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3804                                                         (in_function_scope || specifiers->storage_class != STORAGE_CLASS_STATIC)
3805                                                 )) {
3806                                         errorf(&env.source_position, "invalid storage class for '%N'", entity);
3807                                 }
3808                         }
3809                 } else {
3810                         entity = allocate_entity_zero(ENTITY_VARIABLE, NAMESPACE_NORMAL, env.symbol);
3811                         entity->variable.elf_visibility = default_visibility;
3812                         entity->variable.thread_local   = specifiers->thread_local;
3813
3814                         if (env.symbol != NULL) {
3815                                 if (specifiers->is_inline && is_type_valid(type)) {
3816                                         errorf(&env.source_position, "'%N' declared 'inline'", entity);
3817                                 }
3818
3819                                 bool invalid_storage_class = false;
3820                                 if (current_scope == file_scope) {
3821                                         if (specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3822                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3823                                                         specifiers->storage_class != STORAGE_CLASS_STATIC) {
3824                                                 invalid_storage_class = true;
3825                                         }
3826                                 } else {
3827                                         if (specifiers->thread_local &&
3828                                                         specifiers->storage_class == STORAGE_CLASS_NONE) {
3829                                                 invalid_storage_class = true;
3830                                         }
3831                                 }
3832                                 if (invalid_storage_class) {
3833                                         errorf(&env.source_position, "invalid storage class for variable '%N'", entity);
3834                                 }
3835                         }
3836                 }
3837
3838                 entity->base.source_position   = env.symbol != NULL ? env.source_position : specifiers->source_position;
3839                 entity->declaration.type       = orig_type;
3840                 entity->declaration.alignment  = get_type_alignment(orig_type);
3841                 entity->declaration.modifiers  = env.modifiers;
3842                 entity->declaration.attributes = attributes;
3843
3844                 storage_class_t storage_class = specifiers->storage_class;
3845                 entity->declaration.declared_storage_class = storage_class;
3846
3847                 if (storage_class == STORAGE_CLASS_NONE && current_function != NULL)
3848                         storage_class = STORAGE_CLASS_AUTO;
3849                 entity->declaration.storage_class = storage_class;
3850         }
3851
3852         if (attributes != NULL) {
3853                 handle_entity_attributes(attributes, entity);
3854         }
3855
3856         if (entity->kind == ENTITY_FUNCTION && !freestanding) {
3857                 adapt_special_functions(&entity->function);
3858         }
3859
3860         return entity;
3861 }
3862
3863 static type_t *parse_abstract_declarator(type_t *base_type)
3864 {
3865         parse_declarator_env_t env;
3866         memset(&env, 0, sizeof(env));
3867         env.may_be_abstract = true;
3868         env.must_be_abstract = true;
3869
3870         construct_type_t *construct_type = parse_inner_declarator(&env);
3871
3872         type_t *result = construct_declarator_type(construct_type, base_type);
3873         if (construct_type != NULL) {
3874                 obstack_free(&temp_obst, construct_type);
3875         }
3876         result = handle_type_attributes(env.attributes, result);
3877
3878         return result;
3879 }
3880
3881 /**
3882  * Check if the declaration of main is suspicious.  main should be a
3883  * function with external linkage, returning int, taking either zero
3884  * arguments, two, or three arguments of appropriate types, ie.
3885  *
3886  * int main([ int argc, char **argv [, char **env ] ]).
3887  *
3888  * @param decl    the declaration to check
3889  * @param type    the function type of the declaration
3890  */
3891 static void check_main(const entity_t *entity)
3892 {
3893         const source_position_t *pos = &entity->base.source_position;
3894         if (entity->kind != ENTITY_FUNCTION) {
3895                 warningf(WARN_MAIN, pos, "'main' is not a function");
3896                 return;
3897         }
3898
3899         if (entity->declaration.storage_class == STORAGE_CLASS_STATIC) {
3900                 warningf(WARN_MAIN, pos, "'main' is normally a non-static function");
3901         }
3902
3903         type_t *type = skip_typeref(entity->declaration.type);
3904         assert(is_type_function(type));
3905
3906         function_type_t const *const func_type = &type->function;
3907         type_t                *const ret_type  = func_type->return_type;
3908         if (!types_compatible(skip_typeref(ret_type), type_int)) {
3909                 warningf(WARN_MAIN, pos, "return type of 'main' should be 'int', but is '%T'", ret_type);
3910         }
3911         const function_parameter_t *parm = func_type->parameters;
3912         if (parm != NULL) {
3913                 type_t *const first_type        = skip_typeref(parm->type);
3914                 type_t *const first_type_unqual = get_unqualified_type(first_type);
3915                 if (!types_compatible(first_type_unqual, type_int)) {
3916                         warningf(WARN_MAIN, pos, "first argument of 'main' should be 'int', but is '%T'", parm->type);
3917                 }
3918                 parm = parm->next;
3919                 if (parm != NULL) {
3920                         type_t *const second_type = skip_typeref(parm->type);
3921                         type_t *const second_type_unqual
3922                                 = get_unqualified_type(second_type);
3923                         if (!types_compatible(second_type_unqual, type_char_ptr_ptr)) {
3924                                 warningf(WARN_MAIN, pos, "second argument of 'main' should be 'char**', but is '%T'", parm->type);
3925                         }
3926                         parm = parm->next;
3927                         if (parm != NULL) {
3928                                 type_t *const third_type = skip_typeref(parm->type);
3929                                 type_t *const third_type_unqual
3930                                         = get_unqualified_type(third_type);
3931                                 if (!types_compatible(third_type_unqual, type_char_ptr_ptr)) {
3932                                         warningf(WARN_MAIN, pos, "third argument of 'main' should be 'char**', but is '%T'", parm->type);
3933                                 }
3934                                 parm = parm->next;
3935                                 if (parm != NULL)
3936                                         goto warn_arg_count;
3937                         }
3938                 } else {
3939 warn_arg_count:
3940                         warningf(WARN_MAIN, pos, "'main' takes only zero, two or three arguments");
3941                 }
3942         }
3943 }
3944
3945 /**
3946  * Check if a symbol is the equal to "main".
3947  */
3948 static bool is_sym_main(const symbol_t *const sym)
3949 {
3950         return streq(sym->string, "main");
3951 }
3952
3953 static void error_redefined_as_different_kind(const source_position_t *pos,
3954                 const entity_t *old, entity_kind_t new_kind)
3955 {
3956         char              const *const what = get_entity_kind_name(new_kind);
3957         source_position_t const *const ppos = &old->base.source_position;
3958         errorf(pos, "redeclaration of '%N' as %s (declared %P)", old, what, ppos);
3959 }
3960
3961 static bool is_entity_valid(entity_t *const ent)
3962 {
3963         if (is_declaration(ent)) {
3964                 return is_type_valid(skip_typeref(ent->declaration.type));
3965         } else if (ent->kind == ENTITY_TYPEDEF) {
3966                 return is_type_valid(skip_typeref(ent->typedefe.type));
3967         }
3968         return true;
3969 }
3970
3971 static bool contains_attribute(const attribute_t *list, const attribute_t *attr)
3972 {
3973         for (const attribute_t *tattr = list; tattr != NULL; tattr = tattr->next) {
3974                 if (attributes_equal(tattr, attr))
3975                         return true;
3976         }
3977         return false;
3978 }
3979
3980 /**
3981  * test wether new_list contains any attributes not included in old_list
3982  */
3983 static bool has_new_attributes(const attribute_t *old_list,
3984                                const attribute_t *new_list)
3985 {
3986         for (const attribute_t *attr = new_list; attr != NULL; attr = attr->next) {
3987                 if (!contains_attribute(old_list, attr))
3988                         return true;
3989         }
3990         return false;
3991 }
3992
3993 /**
3994  * Merge in attributes from an attribute list (probably from a previous
3995  * declaration with the same name). Warning: destroys the old structure
3996  * of the attribute list - don't reuse attributes after this call.
3997  */
3998 static void merge_in_attributes(declaration_t *decl, attribute_t *attributes)
3999 {
4000         attribute_t *next;
4001         for (attribute_t *attr = attributes; attr != NULL; attr = next) {
4002                 next = attr->next;
4003                 if (contains_attribute(decl->attributes, attr))
4004                         continue;
4005
4006                 /* move attribute to new declarations attributes list */
4007                 attr->next       = decl->attributes;
4008                 decl->attributes = attr;
4009         }
4010 }
4011
4012 /**
4013  * record entities for the NAMESPACE_NORMAL, and produce error messages/warnings
4014  * for various problems that occur for multiple definitions
4015  */
4016 entity_t *record_entity(entity_t *entity, const bool is_definition)
4017 {
4018         const symbol_t *const    symbol  = entity->base.symbol;
4019         const namespace_tag_t    namespc = (namespace_tag_t)entity->base.namespc;
4020         const source_position_t *pos     = &entity->base.source_position;
4021
4022         /* can happen in error cases */
4023         if (symbol == NULL)
4024                 return entity;
4025
4026         entity_t *const previous_entity = get_entity(symbol, namespc);
4027         /* pushing the same entity twice will break the stack structure */
4028         assert(previous_entity != entity);
4029
4030         if (entity->kind == ENTITY_FUNCTION) {
4031                 type_t *const orig_type = entity->declaration.type;
4032                 type_t *const type      = skip_typeref(orig_type);
4033
4034                 assert(is_type_function(type));
4035                 if (type->function.unspecified_parameters &&
4036                     previous_entity == NULL               &&
4037                     !entity->declaration.implicit) {
4038                         warningf(WARN_STRICT_PROTOTYPES, pos, "function declaration '%#N' is not a prototype", entity);
4039                 }
4040
4041                 if (current_scope == file_scope && is_sym_main(symbol)) {
4042                         check_main(entity);
4043                 }
4044         }
4045
4046         if (is_declaration(entity)                                    &&
4047             entity->declaration.storage_class == STORAGE_CLASS_EXTERN &&
4048             current_scope != file_scope                               &&
4049             !entity->declaration.implicit) {
4050                 warningf(WARN_NESTED_EXTERNS, pos, "nested extern declaration of '%#N'", entity);
4051         }
4052
4053         if (previous_entity != NULL) {
4054                 source_position_t const *const ppos = &previous_entity->base.source_position;
4055
4056                 if (previous_entity->base.parent_scope == &current_function->parameters &&
4057                                 previous_entity->base.parent_scope->depth + 1 == current_scope->depth) {
4058                         assert(previous_entity->kind == ENTITY_PARAMETER);
4059                         errorf(pos, "declaration of '%N' redeclares the '%N' (declared %P)", entity, previous_entity, ppos);
4060                         goto finish;
4061                 }
4062
4063                 if (previous_entity->base.parent_scope == current_scope) {
4064                         if (previous_entity->kind != entity->kind) {
4065                                 if (is_entity_valid(previous_entity) && is_entity_valid(entity)) {
4066                                         error_redefined_as_different_kind(pos, previous_entity,
4067                                                         entity->kind);
4068                                 }
4069                                 goto finish;
4070                         }
4071                         if (previous_entity->kind == ENTITY_ENUM_VALUE) {
4072                                 errorf(pos, "redeclaration of '%N' (declared %P)", entity, ppos);
4073                                 goto finish;
4074                         }
4075                         if (previous_entity->kind == ENTITY_TYPEDEF) {
4076                                 type_t *const type      = skip_typeref(entity->typedefe.type);
4077                                 type_t *const prev_type
4078                                         = skip_typeref(previous_entity->typedefe.type);
4079                                 if (c_mode & _CXX) {
4080                                         /* C++ allows double typedef if they are identical
4081                                          * (after skipping typedefs) */
4082                                         if (type == prev_type)
4083                                                 goto finish;
4084                                 } else {
4085                                         /* GCC extension: redef in system headers is allowed */
4086                                         if ((pos->is_system_header || ppos->is_system_header) &&
4087                                             types_compatible(type, prev_type))
4088                                                 goto finish;
4089                                 }
4090                                 errorf(pos, "redefinition of '%N' (declared %P)",
4091                                        entity, ppos);
4092                                 goto finish;
4093                         }
4094
4095                         /* at this point we should have only VARIABLES or FUNCTIONS */
4096                         assert(is_declaration(previous_entity) && is_declaration(entity));
4097
4098                         declaration_t *const prev_decl = &previous_entity->declaration;
4099                         declaration_t *const decl      = &entity->declaration;
4100
4101                         /* can happen for K&R style declarations */
4102                         if (prev_decl->type       == NULL             &&
4103                                         previous_entity->kind == ENTITY_PARAMETER &&
4104                                         entity->kind          == ENTITY_PARAMETER) {
4105                                 prev_decl->type                   = decl->type;
4106                                 prev_decl->storage_class          = decl->storage_class;
4107                                 prev_decl->declared_storage_class = decl->declared_storage_class;
4108                                 prev_decl->modifiers              = decl->modifiers;
4109                                 return previous_entity;
4110                         }
4111
4112                         type_t *const type      = skip_typeref(decl->type);
4113                         type_t *const prev_type = skip_typeref(prev_decl->type);
4114
4115                         if (!types_compatible(type, prev_type)) {
4116                                 errorf(pos, "declaration '%#N' is incompatible with '%#N' (declared %P)", entity, previous_entity, ppos);
4117                         } else {
4118                                 unsigned old_storage_class = prev_decl->storage_class;
4119
4120                                 if (is_definition                     &&
4121                                                 !prev_decl->used                  &&
4122                                                 !(prev_decl->modifiers & DM_USED) &&
4123                                                 prev_decl->storage_class == STORAGE_CLASS_STATIC) {
4124                                         warningf(WARN_REDUNDANT_DECLS, ppos, "unnecessary static forward declaration for '%#N'", previous_entity);
4125                                 }
4126
4127                                 storage_class_t new_storage_class = decl->storage_class;
4128
4129                                 /* pretend no storage class means extern for function
4130                                  * declarations (except if the previous declaration is neither
4131                                  * none nor extern) */
4132                                 if (entity->kind == ENTITY_FUNCTION) {
4133                                         /* the previous declaration could have unspecified parameters or
4134                                          * be a typedef, so use the new type */
4135                                         if (prev_type->function.unspecified_parameters || is_definition)
4136                                                 prev_decl->type = type;
4137
4138                                         switch (old_storage_class) {
4139                                                 case STORAGE_CLASS_NONE:
4140                                                         old_storage_class = STORAGE_CLASS_EXTERN;
4141                                                         /* FALLTHROUGH */
4142
4143                                                 case STORAGE_CLASS_EXTERN:
4144                                                         if (is_definition) {
4145                                                                 if (prev_type->function.unspecified_parameters && !is_sym_main(symbol)) {
4146                                                                         warningf(WARN_MISSING_PROTOTYPES, pos, "no previous prototype for '%#N'", entity);
4147                                                                 }
4148                                                         } else if (new_storage_class == STORAGE_CLASS_NONE) {
4149                                                                 new_storage_class = STORAGE_CLASS_EXTERN;
4150                                                         }
4151                                                         break;
4152
4153                                                 default:
4154                                                         break;
4155                                         }
4156                                 } else if (is_type_incomplete(prev_type)) {
4157                                         prev_decl->type = type;
4158                                 }
4159
4160                                 if (old_storage_class == STORAGE_CLASS_EXTERN &&
4161                                                 new_storage_class == STORAGE_CLASS_EXTERN) {
4162
4163 warn_redundant_declaration: ;
4164                                         bool has_new_attrs
4165                                                 = has_new_attributes(prev_decl->attributes,
4166                                                                      decl->attributes);
4167                                         if (has_new_attrs) {
4168                                                 merge_in_attributes(decl, prev_decl->attributes);
4169                                         } else if (!is_definition        &&
4170                                                         is_type_valid(prev_type) &&
4171                                                         !pos->is_system_header) {
4172                                                 warningf(WARN_REDUNDANT_DECLS, pos, "redundant declaration for '%Y' (declared %P)", symbol, ppos);
4173                                         }
4174                                 } else if (current_function == NULL) {
4175                                         if (old_storage_class != STORAGE_CLASS_STATIC &&
4176                                                         new_storage_class == STORAGE_CLASS_STATIC) {
4177                                                 errorf(pos, "static declaration of '%Y' follows non-static declaration (declared %P)", symbol, ppos);
4178                                         } else if (old_storage_class == STORAGE_CLASS_EXTERN) {
4179                                                 prev_decl->storage_class          = STORAGE_CLASS_NONE;
4180                                                 prev_decl->declared_storage_class = STORAGE_CLASS_NONE;
4181                                         } else {
4182                                                 /* ISO/IEC 14882:1998(E) §C.1.2:1 */
4183                                                 if (c_mode & _CXX)
4184                                                         goto error_redeclaration;
4185                                                 goto warn_redundant_declaration;
4186                                         }
4187                                 } else if (is_type_valid(prev_type)) {
4188                                         if (old_storage_class == new_storage_class) {
4189 error_redeclaration:
4190                                                 errorf(pos, "redeclaration of '%Y' (declared %P)", symbol, ppos);
4191                                         } else {
4192                                                 errorf(pos, "redeclaration of '%Y' with different linkage (declared %P)", symbol, ppos);
4193                                         }
4194                                 }
4195                         }
4196
4197                         prev_decl->modifiers |= decl->modifiers;
4198                         if (entity->kind == ENTITY_FUNCTION) {
4199                                 previous_entity->function.is_inline |= entity->function.is_inline;
4200                         }
4201                         return previous_entity;
4202                 }
4203
4204                 warning_t why;
4205                 if (is_warn_on(why = WARN_SHADOW) ||
4206                     (is_warn_on(why = WARN_SHADOW_LOCAL) && previous_entity->base.parent_scope != file_scope)) {
4207                         char const *const what = get_entity_kind_name(previous_entity->kind);
4208                         warningf(why, pos, "'%N' shadows %s (declared %P)", entity, what, ppos);
4209                 }
4210         }
4211
4212         if (entity->kind == ENTITY_FUNCTION) {
4213                 if (is_definition &&
4214                                 entity->declaration.storage_class != STORAGE_CLASS_STATIC &&
4215                                 !is_sym_main(symbol)) {
4216                         if (is_warn_on(WARN_MISSING_PROTOTYPES)) {
4217                                 warningf(WARN_MISSING_PROTOTYPES, pos, "no previous prototype for '%#N'", entity);
4218                         } else {
4219                                 goto warn_missing_declaration;
4220                         }
4221                 }
4222         } else if (entity->kind == ENTITY_VARIABLE) {
4223                 if (current_scope                     == file_scope &&
4224                                 entity->declaration.storage_class == STORAGE_CLASS_NONE &&
4225                                 !entity->declaration.implicit) {
4226 warn_missing_declaration:
4227                         warningf(WARN_MISSING_DECLARATIONS, pos, "no previous declaration for '%#N'", entity);
4228                 }
4229         }
4230
4231 finish:
4232         assert(entity->base.parent_scope == NULL);
4233         assert(current_scope != NULL);
4234
4235         entity->base.parent_scope = current_scope;
4236         environment_push(entity);
4237         append_entity(current_scope, entity);
4238
4239         return entity;
4240 }
4241
4242 static void parser_error_multiple_definition(entity_t *entity,
4243                 const source_position_t *source_position)
4244 {
4245         errorf(source_position, "multiple definition of '%Y' (declared %P)",
4246                entity->base.symbol, &entity->base.source_position);
4247 }
4248
4249 static bool is_declaration_specifier(const token_t *token)
4250 {
4251         switch (token->kind) {
4252                 DECLARATION_START
4253                         return true;
4254                 case T_IDENTIFIER:
4255                         return is_typedef_symbol(token->identifier.symbol);
4256
4257                 default:
4258                         return false;
4259         }
4260 }
4261
4262 static void parse_init_declarator_rest(entity_t *entity)
4263 {
4264         type_t *orig_type = type_error_type;
4265
4266         if (entity->base.kind == ENTITY_TYPEDEF) {
4267                 source_position_t const *const pos = &entity->base.source_position;
4268                 errorf(pos, "'%N' is initialized (use __typeof__ instead)", entity);
4269         } else {
4270                 assert(is_declaration(entity));
4271                 orig_type = entity->declaration.type;
4272         }
4273
4274         type_t *type = skip_typeref(orig_type);
4275
4276         if (entity->kind == ENTITY_VARIABLE
4277                         && entity->variable.initializer != NULL) {
4278                 parser_error_multiple_definition(entity, HERE);
4279         }
4280         eat('=');
4281
4282         declaration_t *const declaration = &entity->declaration;
4283         bool must_be_constant = false;
4284         if (declaration->storage_class == STORAGE_CLASS_STATIC ||
4285             entity->base.parent_scope  == file_scope) {
4286                 must_be_constant = true;
4287         }
4288
4289         if (is_type_function(type)) {
4290                 source_position_t const *const pos = &entity->base.source_position;
4291                 errorf(pos, "'%N' is initialized like a variable", entity);
4292                 orig_type = type_error_type;
4293         }
4294
4295         parse_initializer_env_t env;
4296         env.type             = orig_type;
4297         env.must_be_constant = must_be_constant;
4298         env.entity           = entity;
4299
4300         initializer_t *initializer = parse_initializer(&env);
4301
4302         if (entity->kind == ENTITY_VARIABLE) {
4303                 /* §6.7.5:22  array initializers for arrays with unknown size
4304                  * determine the array type size */
4305                 declaration->type            = env.type;
4306                 entity->variable.initializer = initializer;
4307         }
4308 }
4309
4310 /* parse rest of a declaration without any declarator */
4311 static void parse_anonymous_declaration_rest(
4312                 const declaration_specifiers_t *specifiers)
4313 {
4314         eat(';');
4315         anonymous_entity = NULL;
4316
4317         source_position_t const *const pos = &specifiers->source_position;
4318         if (specifiers->storage_class != STORAGE_CLASS_NONE ||
4319                         specifiers->thread_local) {
4320                 warningf(WARN_OTHER, pos, "useless storage class in empty declaration");
4321         }
4322
4323         type_t *type = specifiers->type;
4324         switch (type->kind) {
4325                 case TYPE_COMPOUND_STRUCT:
4326                 case TYPE_COMPOUND_UNION: {
4327                         if (type->compound.compound->base.symbol == NULL) {
4328                                 warningf(WARN_OTHER, pos, "unnamed struct/union that defines no instances");
4329                         }
4330                         break;
4331                 }
4332
4333                 case TYPE_ENUM:
4334                         break;
4335
4336                 default:
4337                         warningf(WARN_OTHER, pos, "empty declaration");
4338                         break;
4339         }
4340 }
4341
4342 static void check_variable_type_complete(entity_t *ent)
4343 {
4344         if (ent->kind != ENTITY_VARIABLE)
4345                 return;
4346
4347         /* §6.7:7  If an identifier for an object is declared with no linkage, the
4348          *         type for the object shall be complete [...] */
4349         declaration_t *decl = &ent->declaration;
4350         if (decl->storage_class == STORAGE_CLASS_EXTERN ||
4351                         decl->storage_class == STORAGE_CLASS_STATIC)
4352                 return;
4353
4354         type_t *const type = skip_typeref(decl->type);
4355         if (!is_type_incomplete(type))
4356                 return;
4357
4358         /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
4359          * are given length one. */
4360         if (is_type_array(type) && ent->base.parent_scope == file_scope) {
4361                 ARR_APP1(declaration_t*, incomplete_arrays, decl);
4362                 return;
4363         }
4364
4365         errorf(&ent->base.source_position, "variable '%#N' has incomplete type", ent);
4366 }
4367
4368
4369 static void parse_declaration_rest(entity_t *ndeclaration,
4370                 const declaration_specifiers_t *specifiers,
4371                 parsed_declaration_func         finished_declaration,
4372                 declarator_flags_t              flags)
4373 {
4374         add_anchor_token(';');
4375         add_anchor_token(',');
4376         while (true) {
4377                 entity_t *entity = finished_declaration(ndeclaration, token.kind == '=');
4378
4379                 if (token.kind == '=') {
4380                         parse_init_declarator_rest(entity);
4381                 } else if (entity->kind == ENTITY_VARIABLE) {
4382                         /* ISO/IEC 14882:1998(E) §8.5.3:3  The initializer can be omitted
4383                          * [...] where the extern specifier is explicitly used. */
4384                         declaration_t *decl = &entity->declaration;
4385                         if (decl->storage_class != STORAGE_CLASS_EXTERN &&
4386                             is_type_reference(skip_typeref(decl->type))) {
4387                                 source_position_t const *const pos = &entity->base.source_position;
4388                                 errorf(pos, "reference '%#N' must be initialized", entity);
4389                         }
4390                 }
4391
4392                 check_variable_type_complete(entity);
4393
4394                 if (!next_if(','))
4395                         break;
4396
4397                 add_anchor_token('=');
4398                 ndeclaration = parse_declarator(specifiers, flags);
4399                 rem_anchor_token('=');
4400         }
4401         rem_anchor_token(',');
4402         rem_anchor_token(';');
4403         expect(';', end_error);
4404
4405 end_error:
4406         anonymous_entity = NULL;
4407 }
4408
4409 static entity_t *finished_kr_declaration(entity_t *entity, bool is_definition)
4410 {
4411         symbol_t *symbol = entity->base.symbol;
4412         if (symbol == NULL)
4413                 return entity;
4414
4415         assert(entity->base.namespc == NAMESPACE_NORMAL);
4416         entity_t *previous_entity = get_entity(symbol, NAMESPACE_NORMAL);
4417         if (previous_entity == NULL
4418                         || previous_entity->base.parent_scope != current_scope) {
4419                 errorf(&entity->base.source_position, "expected declaration of a function parameter, found '%Y'",
4420                        symbol);
4421                 return entity;
4422         }
4423
4424         if (is_definition) {
4425                 errorf(HERE, "'%N' is initialised", entity);
4426         }
4427
4428         return record_entity(entity, false);
4429 }
4430
4431 static void parse_declaration(parsed_declaration_func finished_declaration,
4432                               declarator_flags_t      flags)
4433 {
4434         add_anchor_token(';');
4435         declaration_specifiers_t specifiers;
4436         parse_declaration_specifiers(&specifiers);
4437         rem_anchor_token(';');
4438
4439         if (token.kind == ';') {
4440                 parse_anonymous_declaration_rest(&specifiers);
4441         } else {
4442                 entity_t *entity = parse_declarator(&specifiers, flags);
4443                 parse_declaration_rest(entity, &specifiers, finished_declaration, flags);
4444         }
4445 }
4446
4447 /* §6.5.2.2:6 */
4448 static type_t *get_default_promoted_type(type_t *orig_type)
4449 {
4450         type_t *result = orig_type;
4451
4452         type_t *type = skip_typeref(orig_type);
4453         if (is_type_integer(type)) {
4454                 result = promote_integer(type);
4455         } else if (is_type_atomic(type, ATOMIC_TYPE_FLOAT)) {
4456                 result = type_double;
4457         }
4458
4459         return result;
4460 }
4461
4462 static void parse_kr_declaration_list(entity_t *entity)
4463 {
4464         if (entity->kind != ENTITY_FUNCTION)
4465                 return;
4466
4467         type_t *type = skip_typeref(entity->declaration.type);
4468         assert(is_type_function(type));
4469         if (!type->function.kr_style_parameters)
4470                 return;
4471
4472         add_anchor_token('{');
4473
4474         PUSH_SCOPE(&entity->function.parameters);
4475
4476         entity_t *parameter = entity->function.parameters.entities;
4477         for ( ; parameter != NULL; parameter = parameter->base.next) {
4478                 assert(parameter->base.parent_scope == NULL);
4479                 parameter->base.parent_scope = current_scope;
4480                 environment_push(parameter);
4481         }
4482
4483         /* parse declaration list */
4484         for (;;) {
4485                 switch (token.kind) {
4486                         DECLARATION_START
4487                         /* This covers symbols, which are no type, too, and results in
4488                          * better error messages.  The typical cases are misspelled type
4489                          * names and missing includes. */
4490                         case T_IDENTIFIER:
4491                                 parse_declaration(finished_kr_declaration, DECL_IS_PARAMETER);
4492                                 break;
4493                         default:
4494                                 goto decl_list_end;
4495                 }
4496         }
4497 decl_list_end:
4498
4499         POP_SCOPE();
4500
4501         /* update function type */
4502         type_t *new_type = duplicate_type(type);
4503
4504         function_parameter_t  *parameters = NULL;
4505         function_parameter_t **anchor     = &parameters;
4506
4507         /* did we have an earlier prototype? */
4508         entity_t *proto_type = get_entity(entity->base.symbol, NAMESPACE_NORMAL);
4509         if (proto_type != NULL && proto_type->kind != ENTITY_FUNCTION)
4510                 proto_type = NULL;
4511
4512         function_parameter_t *proto_parameter = NULL;
4513         if (proto_type != NULL) {
4514                 type_t *proto_type_type = proto_type->declaration.type;
4515                 proto_parameter         = proto_type_type->function.parameters;
4516                 /* If a K&R function definition has a variadic prototype earlier, then
4517                  * make the function definition variadic, too. This should conform to
4518                  * §6.7.5.3:15 and §6.9.1:8. */
4519                 new_type->function.variadic = proto_type_type->function.variadic;
4520         } else {
4521                 /* §6.9.1.7: A K&R style parameter list does NOT act as a function
4522                  * prototype */
4523                 new_type->function.unspecified_parameters = true;
4524         }
4525
4526         bool need_incompatible_warning = false;
4527         parameter = entity->function.parameters.entities;
4528         for (; parameter != NULL; parameter = parameter->base.next,
4529                         proto_parameter =
4530                                 proto_parameter == NULL ? NULL : proto_parameter->next) {
4531                 if (parameter->kind != ENTITY_PARAMETER)
4532                         continue;
4533
4534                 type_t *parameter_type = parameter->declaration.type;
4535                 if (parameter_type == NULL) {
4536                         source_position_t const* const pos = &parameter->base.source_position;
4537                         if (strict_mode) {
4538                                 errorf(pos, "no type specified for function '%N'", parameter);
4539                                 parameter_type = type_error_type;
4540                         } else {
4541                                 warningf(WARN_IMPLICIT_INT, pos, "no type specified for function parameter '%N', using 'int'", parameter);
4542                                 parameter_type = type_int;
4543                         }
4544                         parameter->declaration.type = parameter_type;
4545                 }
4546
4547                 semantic_parameter_incomplete(parameter);
4548
4549                 /* we need the default promoted types for the function type */
4550                 type_t *not_promoted = parameter_type;
4551                 parameter_type       = get_default_promoted_type(parameter_type);
4552
4553                 /* gcc special: if the type of the prototype matches the unpromoted
4554                  * type don't promote */
4555                 if (!strict_mode && proto_parameter != NULL) {
4556                         type_t *proto_p_type = skip_typeref(proto_parameter->type);
4557                         type_t *promo_skip   = skip_typeref(parameter_type);
4558                         type_t *param_skip   = skip_typeref(not_promoted);
4559                         if (!types_compatible(proto_p_type, promo_skip)
4560                                 && types_compatible(proto_p_type, param_skip)) {
4561                                 /* don't promote */
4562                                 need_incompatible_warning = true;
4563                                 parameter_type = not_promoted;
4564                         }
4565                 }
4566                 function_parameter_t *const function_parameter
4567                         = allocate_parameter(parameter_type);
4568
4569                 *anchor = function_parameter;
4570                 anchor  = &function_parameter->next;
4571         }
4572
4573         new_type->function.parameters = parameters;
4574         new_type = identify_new_type(new_type);
4575
4576         if (need_incompatible_warning) {
4577                 symbol_t          const *const sym  = entity->base.symbol;
4578                 source_position_t const *const pos  = &entity->base.source_position;
4579                 source_position_t const *const ppos = &proto_type->base.source_position;
4580                 warningf(WARN_OTHER, pos, "declaration '%#N' is incompatible with '%#T' (declared %P)", proto_type, new_type, sym, ppos);
4581         }
4582         entity->declaration.type = new_type;
4583
4584         rem_anchor_token('{');
4585 }
4586
4587 static bool first_err = true;
4588
4589 /**
4590  * When called with first_err set, prints the name of the current function,
4591  * else does noting.
4592  */
4593 static void print_in_function(void)
4594 {
4595         if (first_err) {
4596                 first_err = false;
4597                 char const *const file = current_function->base.base.source_position.input_name;
4598                 diagnosticf("%s: In '%N':\n", file, (entity_t const*)current_function);
4599         }
4600 }
4601
4602 /**
4603  * Check if all labels are defined in the current function.
4604  * Check if all labels are used in the current function.
4605  */
4606 static void check_labels(void)
4607 {
4608         for (const goto_statement_t *goto_statement = goto_first;
4609             goto_statement != NULL;
4610             goto_statement = goto_statement->next) {
4611                 label_t *label = goto_statement->label;
4612                 if (label->base.source_position.input_name == NULL) {
4613                         print_in_function();
4614                         source_position_t const *const pos = &goto_statement->base.source_position;
4615                         errorf(pos, "'%N' used but not defined", (entity_t const*)label);
4616                  }
4617         }
4618
4619         if (is_warn_on(WARN_UNUSED_LABEL)) {
4620                 for (const label_statement_t *label_statement = label_first;
4621                          label_statement != NULL;
4622                          label_statement = label_statement->next) {
4623                         label_t *label = label_statement->label;
4624
4625                         if (! label->used) {
4626                                 print_in_function();
4627                                 source_position_t const *const pos = &label_statement->base.source_position;
4628                                 warningf(WARN_UNUSED_LABEL, pos, "'%N' defined but not used", (entity_t const*)label);
4629                         }
4630                 }
4631         }
4632 }
4633
4634 static void warn_unused_entity(warning_t const why, entity_t *entity, entity_t *const last)
4635 {
4636         entity_t const *const end = last != NULL ? last->base.next : NULL;
4637         for (; entity != end; entity = entity->base.next) {
4638                 if (!is_declaration(entity))
4639                         continue;
4640
4641                 declaration_t *declaration = &entity->declaration;
4642                 if (declaration->implicit)
4643                         continue;
4644
4645                 if (!declaration->used) {
4646                         print_in_function();
4647                         warningf(why, &entity->base.source_position, "'%N' is unused", entity);
4648                 } else if (entity->kind == ENTITY_VARIABLE && !entity->variable.read) {
4649                         print_in_function();
4650                         warningf(why, &entity->base.source_position, "'%N' is never read", entity);
4651                 }
4652         }
4653 }
4654
4655 static void check_unused_variables(statement_t *const stmt, void *const env)
4656 {
4657         (void)env;
4658
4659         switch (stmt->kind) {
4660                 case STATEMENT_DECLARATION: {
4661                         declaration_statement_t const *const decls = &stmt->declaration;
4662                         warn_unused_entity(WARN_UNUSED_VARIABLE, decls->declarations_begin, decls->declarations_end);
4663                         return;
4664                 }
4665
4666                 case STATEMENT_FOR:
4667                         warn_unused_entity(WARN_UNUSED_VARIABLE, stmt->fors.scope.entities, NULL);
4668                         return;
4669
4670                 default:
4671                         return;
4672         }
4673 }
4674
4675 /**
4676  * Check declarations of current_function for unused entities.
4677  */
4678 static void check_declarations(void)
4679 {
4680         if (is_warn_on(WARN_UNUSED_PARAMETER)) {
4681                 const scope_t *scope = &current_function->parameters;
4682
4683                 /* do not issue unused warnings for main */
4684                 if (!is_sym_main(current_function->base.base.symbol)) {
4685                         warn_unused_entity(WARN_UNUSED_PARAMETER, scope->entities, NULL);
4686                 }
4687         }
4688         if (is_warn_on(WARN_UNUSED_VARIABLE)) {
4689                 walk_statements(current_function->statement, check_unused_variables,
4690                                 NULL);
4691         }
4692 }
4693
4694 static int determine_truth(expression_t const* const cond)
4695 {
4696         return
4697                 is_constant_expression(cond) != EXPR_CLASS_CONSTANT ? 0 :
4698                 fold_constant_to_bool(cond)                         ? 1 :
4699                 -1;
4700 }
4701
4702 static void check_reachable(statement_t *);
4703 static bool reaches_end;
4704
4705 static bool expression_returns(expression_t const *const expr)
4706 {
4707         switch (expr->kind) {
4708                 case EXPR_CALL: {
4709                         expression_t const *const func = expr->call.function;
4710                         type_t       const *const type = skip_typeref(func->base.type);
4711                         if (type->kind == TYPE_POINTER) {
4712                                 type_t const *const points_to
4713                                         = skip_typeref(type->pointer.points_to);
4714                                 if (points_to->kind == TYPE_FUNCTION
4715                                     && points_to->function.modifiers & DM_NORETURN)
4716                                         return false;
4717                         }
4718
4719                         if (!expression_returns(func))
4720                                 return false;
4721
4722                         for (call_argument_t const* arg = expr->call.arguments; arg != NULL; arg = arg->next) {
4723                                 if (!expression_returns(arg->expression))
4724                                         return false;
4725                         }
4726
4727                         return true;
4728                 }
4729
4730                 case EXPR_REFERENCE:
4731                 case EXPR_ENUM_CONSTANT:
4732                 case EXPR_LITERAL_CASES:
4733                 case EXPR_STRING_LITERAL:
4734                 case EXPR_WIDE_STRING_LITERAL:
4735                 case EXPR_COMPOUND_LITERAL: // TODO descend into initialisers
4736                 case EXPR_LABEL_ADDRESS:
4737                 case EXPR_CLASSIFY_TYPE:
4738                 case EXPR_SIZEOF: // TODO handle obscure VLA case
4739                 case EXPR_ALIGNOF:
4740                 case EXPR_FUNCNAME:
4741                 case EXPR_BUILTIN_CONSTANT_P:
4742                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
4743                 case EXPR_OFFSETOF:
4744                 case EXPR_ERROR:
4745                         return true;
4746
4747                 case EXPR_STATEMENT: {
4748                         bool old_reaches_end = reaches_end;
4749                         reaches_end = false;
4750                         check_reachable(expr->statement.statement);
4751                         bool returns = reaches_end;
4752                         reaches_end = old_reaches_end;
4753                         return returns;
4754                 }
4755
4756                 case EXPR_CONDITIONAL:
4757                         // TODO handle constant expression
4758
4759                         if (!expression_returns(expr->conditional.condition))
4760                                 return false;
4761
4762                         if (expr->conditional.true_expression != NULL
4763                                         && expression_returns(expr->conditional.true_expression))
4764                                 return true;
4765
4766                         return expression_returns(expr->conditional.false_expression);
4767
4768                 case EXPR_SELECT:
4769                         return expression_returns(expr->select.compound);
4770
4771                 case EXPR_ARRAY_ACCESS:
4772                         return
4773                                 expression_returns(expr->array_access.array_ref) &&
4774                                 expression_returns(expr->array_access.index);
4775
4776                 case EXPR_VA_START:
4777                         return expression_returns(expr->va_starte.ap);
4778
4779                 case EXPR_VA_ARG:
4780                         return expression_returns(expr->va_arge.ap);
4781
4782                 case EXPR_VA_COPY:
4783                         return expression_returns(expr->va_copye.src);
4784
4785                 case EXPR_UNARY_CASES_MANDATORY:
4786                         return expression_returns(expr->unary.value);
4787
4788                 case EXPR_UNARY_THROW:
4789                         return false;
4790
4791                 case EXPR_BINARY_CASES:
4792                         // TODO handle constant lhs of && and ||
4793                         return
4794                                 expression_returns(expr->binary.left) &&
4795                                 expression_returns(expr->binary.right);
4796         }
4797
4798         panic("unhandled expression");
4799 }
4800
4801 static bool initializer_returns(initializer_t const *const init)
4802 {
4803         switch (init->kind) {
4804                 case INITIALIZER_VALUE:
4805                         return expression_returns(init->value.value);
4806
4807                 case INITIALIZER_LIST: {
4808                         initializer_t * const*       i       = init->list.initializers;
4809                         initializer_t * const* const end     = i + init->list.len;
4810                         bool                         returns = true;
4811                         for (; i != end; ++i) {
4812                                 if (!initializer_returns(*i))
4813                                         returns = false;
4814                         }
4815                         return returns;
4816                 }
4817
4818                 case INITIALIZER_STRING:
4819                 case INITIALIZER_WIDE_STRING:
4820                 case INITIALIZER_DESIGNATOR: // designators have no payload
4821                         return true;
4822         }
4823         panic("unhandled initializer");
4824 }
4825
4826 static bool noreturn_candidate;
4827
4828 static void check_reachable(statement_t *const stmt)
4829 {
4830         if (stmt->base.reachable)
4831                 return;
4832         if (stmt->kind != STATEMENT_DO_WHILE)
4833                 stmt->base.reachable = true;
4834
4835         statement_t *last = stmt;
4836         statement_t *next;
4837         switch (stmt->kind) {
4838                 case STATEMENT_ERROR:
4839                 case STATEMENT_EMPTY:
4840                 case STATEMENT_ASM:
4841                         next = stmt->base.next;
4842                         break;
4843
4844                 case STATEMENT_DECLARATION: {
4845                         declaration_statement_t const *const decl = &stmt->declaration;
4846                         entity_t                const *      ent  = decl->declarations_begin;
4847                         entity_t                const *const last_decl = decl->declarations_end;
4848                         if (ent != NULL) {
4849                                 for (;; ent = ent->base.next) {
4850                                         if (ent->kind                 == ENTITY_VARIABLE &&
4851                                             ent->variable.initializer != NULL            &&
4852                                             !initializer_returns(ent->variable.initializer)) {
4853                                                 return;
4854                                         }
4855                                         if (ent == last_decl)
4856                                                 break;
4857                                 }
4858                         }
4859                         next = stmt->base.next;
4860                         break;
4861                 }
4862
4863                 case STATEMENT_COMPOUND:
4864                         next = stmt->compound.statements;
4865                         if (next == NULL)
4866                                 next = stmt->base.next;
4867                         break;
4868
4869                 case STATEMENT_RETURN: {
4870                         expression_t const *const val = stmt->returns.value;
4871                         if (val == NULL || expression_returns(val))
4872                                 noreturn_candidate = false;
4873                         return;
4874                 }
4875
4876                 case STATEMENT_IF: {
4877                         if_statement_t const *const ifs  = &stmt->ifs;
4878                         expression_t   const *const cond = ifs->condition;
4879
4880                         if (!expression_returns(cond))
4881                                 return;
4882
4883                         int const val = determine_truth(cond);
4884
4885                         if (val >= 0)
4886                                 check_reachable(ifs->true_statement);
4887
4888                         if (val > 0)
4889                                 return;
4890
4891                         if (ifs->false_statement != NULL) {
4892                                 check_reachable(ifs->false_statement);
4893                                 return;
4894                         }
4895
4896                         next = stmt->base.next;
4897                         break;
4898                 }
4899
4900                 case STATEMENT_SWITCH: {
4901                         switch_statement_t const *const switchs = &stmt->switchs;
4902                         expression_t       const *const expr    = switchs->expression;
4903
4904                         if (!expression_returns(expr))
4905                                 return;
4906
4907                         if (is_constant_expression(expr) == EXPR_CLASS_CONSTANT) {
4908                                 long                    const val      = fold_constant_to_int(expr);
4909                                 case_label_statement_t *      defaults = NULL;
4910                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
4911                                         if (i->expression == NULL) {
4912                                                 defaults = i;
4913                                                 continue;
4914                                         }
4915
4916                                         if (i->first_case <= val && val <= i->last_case) {
4917                                                 check_reachable((statement_t*)i);
4918                                                 return;
4919                                         }
4920                                 }
4921
4922                                 if (defaults != NULL) {
4923                                         check_reachable((statement_t*)defaults);
4924                                         return;
4925                                 }
4926                         } else {
4927                                 bool has_default = false;
4928                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
4929                                         if (i->expression == NULL)
4930                                                 has_default = true;
4931
4932                                         check_reachable((statement_t*)i);
4933                                 }
4934
4935                                 if (has_default)
4936                                         return;
4937                         }
4938
4939                         next = stmt->base.next;
4940                         break;
4941                 }
4942
4943                 case STATEMENT_EXPRESSION: {
4944                         /* Check for noreturn function call */
4945                         expression_t const *const expr = stmt->expression.expression;
4946                         if (!expression_returns(expr))
4947                                 return;
4948
4949                         next = stmt->base.next;
4950                         break;
4951                 }
4952
4953                 case STATEMENT_CONTINUE:
4954                         for (statement_t *parent = stmt;;) {
4955                                 parent = parent->base.parent;
4956                                 if (parent == NULL) /* continue not within loop */
4957                                         return;
4958
4959                                 next = parent;
4960                                 switch (parent->kind) {
4961                                         case STATEMENT_WHILE:    goto continue_while;
4962                                         case STATEMENT_DO_WHILE: goto continue_do_while;
4963                                         case STATEMENT_FOR:      goto continue_for;
4964
4965                                         default: break;
4966                                 }
4967                         }
4968
4969                 case STATEMENT_BREAK:
4970                         for (statement_t *parent = stmt;;) {
4971                                 parent = parent->base.parent;
4972                                 if (parent == NULL) /* break not within loop/switch */
4973                                         return;
4974
4975                                 switch (parent->kind) {
4976                                         case STATEMENT_SWITCH:
4977                                         case STATEMENT_WHILE:
4978                                         case STATEMENT_DO_WHILE:
4979                                         case STATEMENT_FOR:
4980                                                 last = parent;
4981                                                 next = parent->base.next;
4982                                                 goto found_break_parent;
4983
4984                                         default: break;
4985                                 }
4986                         }
4987 found_break_parent:
4988                         break;
4989
4990                 case STATEMENT_COMPUTED_GOTO: {
4991                         if (!expression_returns(stmt->computed_goto.expression))
4992                                 return;
4993
4994                         statement_t *parent = stmt->base.parent;
4995                         if (parent == NULL) /* top level goto */
4996                                 return;
4997                         next = parent;
4998                         break;
4999                 }
5000
5001                 case STATEMENT_GOTO:
5002                         next = stmt->gotos.label->statement;
5003                         if (next == NULL) /* missing label */
5004                                 return;
5005                         break;
5006
5007                 case STATEMENT_LABEL:
5008                         next = stmt->label.statement;
5009                         break;
5010
5011                 case STATEMENT_CASE_LABEL:
5012                         next = stmt->case_label.statement;
5013                         break;
5014
5015                 case STATEMENT_WHILE: {
5016                         while_statement_t const *const whiles = &stmt->whiles;
5017                         expression_t      const *const cond   = whiles->condition;
5018
5019                         if (!expression_returns(cond))
5020                                 return;
5021
5022                         int const val = determine_truth(cond);
5023
5024                         if (val >= 0)
5025                                 check_reachable(whiles->body);
5026
5027                         if (val > 0)
5028                                 return;
5029
5030                         next = stmt->base.next;
5031                         break;
5032                 }
5033
5034                 case STATEMENT_DO_WHILE:
5035                         next = stmt->do_while.body;
5036                         break;
5037
5038                 case STATEMENT_FOR: {
5039                         for_statement_t *const fors = &stmt->fors;
5040
5041                         if (fors->condition_reachable)
5042                                 return;
5043                         fors->condition_reachable = true;
5044
5045                         expression_t const *const cond = fors->condition;
5046
5047                         int val;
5048                         if (cond == NULL) {
5049                                 val = 1;
5050                         } else if (expression_returns(cond)) {
5051                                 val = determine_truth(cond);
5052                         } else {
5053                                 return;
5054                         }
5055
5056                         if (val >= 0)
5057                                 check_reachable(fors->body);
5058
5059                         if (val > 0)
5060                                 return;
5061
5062                         next = stmt->base.next;
5063                         break;
5064                 }
5065
5066                 case STATEMENT_MS_TRY: {
5067                         ms_try_statement_t const *const ms_try = &stmt->ms_try;
5068                         check_reachable(ms_try->try_statement);
5069                         next = ms_try->final_statement;
5070                         break;
5071                 }
5072
5073                 case STATEMENT_LEAVE: {
5074                         statement_t *parent = stmt;
5075                         for (;;) {
5076                                 parent = parent->base.parent;
5077                                 if (parent == NULL) /* __leave not within __try */
5078                                         return;
5079
5080                                 if (parent->kind == STATEMENT_MS_TRY) {
5081                                         last = parent;
5082                                         next = parent->ms_try.final_statement;
5083                                         break;
5084                                 }
5085                         }
5086                         break;
5087                 }
5088
5089                 default:
5090                         panic("invalid statement kind");
5091         }
5092
5093         while (next == NULL) {
5094                 next = last->base.parent;
5095                 if (next == NULL) {
5096                         noreturn_candidate = false;
5097
5098                         type_t *const type = skip_typeref(current_function->base.type);
5099                         assert(is_type_function(type));
5100                         type_t *const ret  = skip_typeref(type->function.return_type);
5101                         if (!is_type_void(ret) &&
5102                             is_type_valid(ret) &&
5103                             !is_sym_main(current_function->base.base.symbol)) {
5104                                 source_position_t const *const pos = &stmt->base.source_position;
5105                                 warningf(WARN_RETURN_TYPE, pos, "control reaches end of non-void function");
5106                         }
5107                         return;
5108                 }
5109
5110                 switch (next->kind) {
5111                         case STATEMENT_ERROR:
5112                         case STATEMENT_EMPTY:
5113                         case STATEMENT_DECLARATION:
5114                         case STATEMENT_EXPRESSION:
5115                         case STATEMENT_ASM:
5116                         case STATEMENT_RETURN:
5117                         case STATEMENT_CONTINUE:
5118                         case STATEMENT_BREAK:
5119                         case STATEMENT_COMPUTED_GOTO:
5120                         case STATEMENT_GOTO:
5121                         case STATEMENT_LEAVE:
5122                                 panic("invalid control flow in function");
5123
5124                         case STATEMENT_COMPOUND:
5125                                 if (next->compound.stmt_expr) {
5126                                         reaches_end = true;
5127                                         return;
5128                                 }
5129                                 /* FALLTHROUGH */
5130                         case STATEMENT_IF:
5131                         case STATEMENT_SWITCH:
5132                         case STATEMENT_LABEL:
5133                         case STATEMENT_CASE_LABEL:
5134                                 last = next;
5135                                 next = next->base.next;
5136                                 break;
5137
5138                         case STATEMENT_WHILE: {
5139 continue_while:
5140                                 if (next->base.reachable)
5141                                         return;
5142                                 next->base.reachable = true;
5143
5144                                 while_statement_t const *const whiles = &next->whiles;
5145                                 expression_t      const *const cond   = whiles->condition;
5146
5147                                 if (!expression_returns(cond))
5148                                         return;
5149
5150                                 int const val = determine_truth(cond);
5151
5152                                 if (val >= 0)
5153                                         check_reachable(whiles->body);
5154
5155                                 if (val > 0)
5156                                         return;
5157
5158                                 last = next;
5159                                 next = next->base.next;
5160                                 break;
5161                         }
5162
5163                         case STATEMENT_DO_WHILE: {
5164 continue_do_while:
5165                                 if (next->base.reachable)
5166                                         return;
5167                                 next->base.reachable = true;
5168
5169                                 do_while_statement_t const *const dw   = &next->do_while;
5170                                 expression_t         const *const cond = dw->condition;
5171
5172                                 if (!expression_returns(cond))
5173                                         return;
5174
5175                                 int const val = determine_truth(cond);
5176
5177                                 if (val >= 0)
5178                                         check_reachable(dw->body);
5179
5180                                 if (val > 0)
5181                                         return;
5182
5183                                 last = next;
5184                                 next = next->base.next;
5185                                 break;
5186                         }
5187
5188                         case STATEMENT_FOR: {
5189 continue_for:;
5190                                 for_statement_t *const fors = &next->fors;
5191
5192                                 fors->step_reachable = true;
5193
5194                                 if (fors->condition_reachable)
5195                                         return;
5196                                 fors->condition_reachable = true;
5197
5198                                 expression_t const *const cond = fors->condition;
5199
5200                                 int val;
5201                                 if (cond == NULL) {
5202                                         val = 1;
5203                                 } else if (expression_returns(cond)) {
5204                                         val = determine_truth(cond);
5205                                 } else {
5206                                         return;
5207                                 }
5208
5209                                 if (val >= 0)
5210                                         check_reachable(fors->body);
5211
5212                                 if (val > 0)
5213                                         return;
5214
5215                                 last = next;
5216                                 next = next->base.next;
5217                                 break;
5218                         }
5219
5220                         case STATEMENT_MS_TRY:
5221                                 last = next;
5222                                 next = next->ms_try.final_statement;
5223                                 break;
5224                 }
5225         }
5226
5227         check_reachable(next);
5228 }
5229
5230 static void check_unreachable(statement_t* const stmt, void *const env)
5231 {
5232         (void)env;
5233
5234         switch (stmt->kind) {
5235                 case STATEMENT_DO_WHILE:
5236                         if (!stmt->base.reachable) {
5237                                 expression_t const *const cond = stmt->do_while.condition;
5238                                 if (determine_truth(cond) >= 0) {
5239                                         source_position_t const *const pos = &cond->base.source_position;
5240                                         warningf(WARN_UNREACHABLE_CODE, pos, "condition of do-while-loop is unreachable");
5241                                 }
5242                         }
5243                         return;
5244
5245                 case STATEMENT_FOR: {
5246                         for_statement_t const* const fors = &stmt->fors;
5247
5248                         // if init and step are unreachable, cond is unreachable, too
5249                         if (!stmt->base.reachable && !fors->step_reachable) {
5250                                 goto warn_unreachable;
5251                         } else {
5252                                 if (!stmt->base.reachable && fors->initialisation != NULL) {
5253                                         source_position_t const *const pos = &fors->initialisation->base.source_position;
5254                                         warningf(WARN_UNREACHABLE_CODE, pos, "initialisation of for-statement is unreachable");
5255                                 }
5256
5257                                 if (!fors->condition_reachable && fors->condition != NULL) {
5258                                         source_position_t const *const pos = &fors->condition->base.source_position;
5259                                         warningf(WARN_UNREACHABLE_CODE, pos, "condition of for-statement is unreachable");
5260                                 }
5261
5262                                 if (!fors->step_reachable && fors->step != NULL) {
5263                                         source_position_t const *const pos = &fors->step->base.source_position;
5264                                         warningf(WARN_UNREACHABLE_CODE, pos, "step of for-statement is unreachable");
5265                                 }
5266                         }
5267                         return;
5268                 }
5269
5270                 case STATEMENT_COMPOUND:
5271                         if (stmt->compound.statements != NULL)
5272                                 return;
5273                         goto warn_unreachable;
5274
5275                 case STATEMENT_DECLARATION: {
5276                         /* Only warn if there is at least one declarator with an initializer.
5277                          * This typically occurs in switch statements. */
5278                         declaration_statement_t const *const decl = &stmt->declaration;
5279                         entity_t                const *      ent  = decl->declarations_begin;
5280                         entity_t                const *const last = decl->declarations_end;
5281                         if (ent != NULL) {
5282                                 for (;; ent = ent->base.next) {
5283                                         if (ent->kind                 == ENTITY_VARIABLE &&
5284                                                         ent->variable.initializer != NULL) {
5285                                                 goto warn_unreachable;
5286                                         }
5287                                         if (ent == last)
5288                                                 return;
5289                                 }
5290                         }
5291                 }
5292
5293                 default:
5294 warn_unreachable:
5295                         if (!stmt->base.reachable) {
5296                                 source_position_t const *const pos = &stmt->base.source_position;
5297                                 warningf(WARN_UNREACHABLE_CODE, pos, "statement is unreachable");
5298                         }
5299                         return;
5300         }
5301 }
5302
5303 static bool is_main(entity_t *entity)
5304 {
5305         static symbol_t *sym_main = NULL;
5306         if (sym_main == NULL) {
5307                 sym_main = symbol_table_insert("main");
5308         }
5309
5310         if (entity->base.symbol != sym_main)
5311                 return false;
5312         /* must be in outermost scope */
5313         if (entity->base.parent_scope != file_scope)
5314                 return false;
5315
5316         return true;
5317 }
5318
5319 static void parse_external_declaration(void)
5320 {
5321         /* function-definitions and declarations both start with declaration
5322          * specifiers */
5323         add_anchor_token(';');
5324         declaration_specifiers_t specifiers;
5325         parse_declaration_specifiers(&specifiers);
5326         rem_anchor_token(';');
5327
5328         /* must be a declaration */
5329         if (token.kind == ';') {
5330                 parse_anonymous_declaration_rest(&specifiers);
5331                 return;
5332         }
5333
5334         add_anchor_token(',');
5335         add_anchor_token('=');
5336         add_anchor_token(';');
5337         add_anchor_token('{');
5338
5339         /* declarator is common to both function-definitions and declarations */
5340         entity_t *ndeclaration = parse_declarator(&specifiers, DECL_FLAGS_NONE);
5341
5342         rem_anchor_token('{');
5343         rem_anchor_token(';');
5344         rem_anchor_token('=');
5345         rem_anchor_token(',');
5346
5347         /* must be a declaration */
5348         switch (token.kind) {
5349                 case ',':
5350                 case ';':
5351                 case '=':
5352                         parse_declaration_rest(ndeclaration, &specifiers, record_entity,
5353                                         DECL_FLAGS_NONE);
5354                         return;
5355         }
5356
5357         /* must be a function definition */
5358         parse_kr_declaration_list(ndeclaration);
5359
5360         if (token.kind != '{') {
5361                 parse_error_expected("while parsing function definition", '{', NULL);
5362                 eat_until_matching_token(';');
5363                 return;
5364         }
5365
5366         assert(is_declaration(ndeclaration));
5367         type_t *const orig_type = ndeclaration->declaration.type;
5368         type_t *      type      = skip_typeref(orig_type);
5369
5370         if (!is_type_function(type)) {
5371                 if (is_type_valid(type)) {
5372                         errorf(HERE, "declarator '%#N' has a body but is not a function type", ndeclaration);
5373                 }
5374                 eat_block();
5375                 return;
5376         }
5377
5378         source_position_t const *const pos = &ndeclaration->base.source_position;
5379         if (is_typeref(orig_type)) {
5380                 /* §6.9.1:2 */
5381                 errorf(pos, "type of function definition '%#N' is a typedef", ndeclaration);
5382         }
5383
5384         if (is_type_compound(skip_typeref(type->function.return_type))) {
5385                 warningf(WARN_AGGREGATE_RETURN, pos, "'%N' returns an aggregate", ndeclaration);
5386         }
5387         if (type->function.unspecified_parameters) {
5388                 warningf(WARN_OLD_STYLE_DEFINITION, pos, "old-style definition of '%N'", ndeclaration);
5389         } else {
5390                 warningf(WARN_TRADITIONAL, pos, "traditional C rejects ISO C style definition of '%N'", ndeclaration);
5391         }
5392
5393         /* §6.7.5.3:14 a function definition with () means no
5394          * parameters (and not unspecified parameters) */
5395         if (type->function.unspecified_parameters &&
5396                         type->function.parameters == NULL) {
5397                 type_t *copy                          = duplicate_type(type);
5398                 copy->function.unspecified_parameters = false;
5399                 type                                  = identify_new_type(copy);
5400
5401                 ndeclaration->declaration.type = type;
5402         }
5403
5404         entity_t *const entity = record_entity(ndeclaration, true);
5405         assert(entity->kind == ENTITY_FUNCTION);
5406         assert(ndeclaration->kind == ENTITY_FUNCTION);
5407
5408         function_t *const function = &entity->function;
5409         if (ndeclaration != entity) {
5410                 function->parameters = ndeclaration->function.parameters;
5411         }
5412         assert(is_declaration(entity));
5413         type = skip_typeref(entity->declaration.type);
5414
5415         PUSH_SCOPE(&function->parameters);
5416
5417         entity_t *parameter = function->parameters.entities;
5418         for (; parameter != NULL; parameter = parameter->base.next) {
5419                 if (parameter->base.parent_scope == &ndeclaration->function.parameters) {
5420                         parameter->base.parent_scope = current_scope;
5421                 }
5422                 assert(parameter->base.parent_scope == NULL
5423                                 || parameter->base.parent_scope == current_scope);
5424                 parameter->base.parent_scope = current_scope;
5425                 if (parameter->base.symbol == NULL) {
5426                         errorf(&parameter->base.source_position, "parameter name omitted");
5427                         continue;
5428                 }
5429                 environment_push(parameter);
5430         }
5431
5432         if (function->statement != NULL) {
5433                 parser_error_multiple_definition(entity, HERE);
5434                 eat_block();
5435         } else {
5436                 /* parse function body */
5437                 int         label_stack_top      = label_top();
5438                 function_t *old_current_function = current_function;
5439                 entity_t   *old_current_entity   = current_entity;
5440                 current_function                 = function;
5441                 current_entity                   = entity;
5442                 PUSH_PARENT(NULL);
5443
5444                 goto_first   = NULL;
5445                 goto_anchor  = &goto_first;
5446                 label_first  = NULL;
5447                 label_anchor = &label_first;
5448
5449                 statement_t *const body = parse_compound_statement(false);
5450                 function->statement = body;
5451                 first_err = true;
5452                 check_labels();
5453                 check_declarations();
5454                 if (is_warn_on(WARN_RETURN_TYPE)      ||
5455                     is_warn_on(WARN_UNREACHABLE_CODE) ||
5456                     (is_warn_on(WARN_MISSING_NORETURN) && !(function->base.modifiers & DM_NORETURN))) {
5457                         noreturn_candidate = true;
5458                         check_reachable(body);
5459                         if (is_warn_on(WARN_UNREACHABLE_CODE))
5460                                 walk_statements(body, check_unreachable, NULL);
5461                         if (noreturn_candidate &&
5462                             !(function->base.modifiers & DM_NORETURN)) {
5463                                 source_position_t const *const pos = &body->base.source_position;
5464                                 warningf(WARN_MISSING_NORETURN, pos, "function '%#N' is candidate for attribute 'noreturn'", entity);
5465                         }
5466                 }
5467
5468                 if (is_main(entity) && enable_main_collect2_hack)
5469                         prepare_main_collect2(entity);
5470
5471                 POP_PARENT();
5472                 assert(current_function == function);
5473                 assert(current_entity   == entity);
5474                 current_entity   = old_current_entity;
5475                 current_function = old_current_function;
5476                 label_pop_to(label_stack_top);
5477         }
5478
5479         POP_SCOPE();
5480 }
5481
5482 static entity_t *find_compound_entry(compound_t *compound, symbol_t *symbol)
5483 {
5484         entity_t *iter = compound->members.entities;
5485         for (; iter != NULL; iter = iter->base.next) {
5486                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5487                         continue;
5488
5489                 if (iter->base.symbol == symbol) {
5490                         return iter;
5491                 } else if (iter->base.symbol == NULL) {
5492                         /* search in anonymous structs and unions */
5493                         type_t *type = skip_typeref(iter->declaration.type);
5494                         if (is_type_compound(type)) {
5495                                 if (find_compound_entry(type->compound.compound, symbol)
5496                                                 != NULL)
5497                                         return iter;
5498                         }
5499                         continue;
5500                 }
5501         }
5502
5503         return NULL;
5504 }
5505
5506 static void check_deprecated(const source_position_t *source_position,
5507                              const entity_t *entity)
5508 {
5509         if (!is_declaration(entity))
5510                 return;
5511         if ((entity->declaration.modifiers & DM_DEPRECATED) == 0)
5512                 return;
5513
5514         source_position_t const *const epos = &entity->base.source_position;
5515         char              const *const msg  = get_deprecated_string(entity->declaration.attributes);
5516         if (msg != NULL) {
5517                 warningf(WARN_DEPRECATED_DECLARATIONS, source_position, "'%N' is deprecated (declared %P): \"%s\"", entity, epos, msg);
5518         } else {
5519                 warningf(WARN_DEPRECATED_DECLARATIONS, source_position, "'%N' is deprecated (declared %P)", entity, epos);
5520         }
5521 }
5522
5523
5524 static expression_t *create_select(const source_position_t *pos,
5525                                    expression_t *addr,
5526                                    type_qualifiers_t qualifiers,
5527                                                                    entity_t *entry)
5528 {
5529         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
5530
5531         check_deprecated(pos, entry);
5532
5533         expression_t *select          = allocate_expression_zero(EXPR_SELECT);
5534         select->select.compound       = addr;
5535         select->select.compound_entry = entry;
5536
5537         type_t *entry_type = entry->declaration.type;
5538         type_t *res_type   = get_qualified_type(entry_type, qualifiers);
5539
5540         /* bitfields need special treatment */
5541         if (entry->compound_member.bitfield) {
5542                 unsigned bit_size = entry->compound_member.bit_size;
5543                 /* if fewer bits than an int, convert to int (see §6.3.1.1) */
5544                 if (bit_size < get_atomic_type_size(ATOMIC_TYPE_INT) * BITS_PER_BYTE) {
5545                         res_type = type_int;
5546                 }
5547         }
5548
5549         /* we always do the auto-type conversions; the & and sizeof parser contains
5550          * code to revert this! */
5551         select->base.type = automatic_type_conversion(res_type);
5552
5553
5554         return select;
5555 }
5556
5557 /**
5558  * Find entry with symbol in compound. Search anonymous structs and unions and
5559  * creates implicit select expressions for them.
5560  * Returns the adress for the innermost compound.
5561  */
5562 static expression_t *find_create_select(const source_position_t *pos,
5563                                         expression_t *addr,
5564                                         type_qualifiers_t qualifiers,
5565                                         compound_t *compound, symbol_t *symbol)
5566 {
5567         entity_t *iter = compound->members.entities;
5568         for (; iter != NULL; iter = iter->base.next) {
5569                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5570                         continue;
5571
5572                 symbol_t *iter_symbol = iter->base.symbol;
5573                 if (iter_symbol == NULL) {
5574                         type_t *type = iter->declaration.type;
5575                         if (type->kind != TYPE_COMPOUND_STRUCT
5576                                         && type->kind != TYPE_COMPOUND_UNION)
5577                                 continue;
5578
5579                         compound_t *sub_compound = type->compound.compound;
5580
5581                         if (find_compound_entry(sub_compound, symbol) == NULL)
5582                                 continue;
5583
5584                         expression_t *sub_addr = create_select(pos, addr, qualifiers, iter);
5585                         sub_addr->base.source_position = *pos;
5586                         sub_addr->base.implicit        = true;
5587                         return find_create_select(pos, sub_addr, qualifiers, sub_compound,
5588                                                   symbol);
5589                 }
5590
5591                 if (iter_symbol == symbol) {
5592                         return create_select(pos, addr, qualifiers, iter);
5593                 }
5594         }
5595
5596         return NULL;
5597 }
5598
5599 static void parse_bitfield_member(entity_t *entity)
5600 {
5601         eat(':');
5602
5603         expression_t *size = parse_constant_expression();
5604         long          size_long;
5605
5606         assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5607         type_t *type = entity->declaration.type;
5608         if (!is_type_integer(skip_typeref(type))) {
5609                 errorf(HERE, "bitfield base type '%T' is not an integer type",
5610                            type);
5611         }
5612
5613         if (is_constant_expression(size) != EXPR_CLASS_CONSTANT) {
5614                 /* error already reported by parse_constant_expression */
5615                 size_long = get_type_size(type) * 8;
5616         } else {
5617                 size_long = fold_constant_to_int(size);
5618
5619                 const symbol_t *symbol = entity->base.symbol;
5620                 const symbol_t *user_symbol
5621                         = symbol == NULL ? sym_anonymous : symbol;
5622                 unsigned bit_size = get_type_size(type) * 8;
5623                 if (size_long < 0) {
5624                         errorf(HERE, "negative width in bit-field '%Y'", user_symbol);
5625                 } else if (size_long == 0 && symbol != NULL) {
5626                         errorf(HERE, "zero width for bit-field '%Y'", user_symbol);
5627                 } else if (bit_size > 0 && (unsigned)size_long > bit_size) {
5628                         errorf(HERE, "width of bitfield '%Y' exceeds its type",
5629                                    user_symbol);
5630                 } else {
5631                         /* hope that people don't invent crazy types with more bits
5632                          * than our struct can hold */
5633                         assert(size_long <
5634                                    (1 << sizeof(entity->compound_member.bit_size)*8));
5635                 }
5636         }
5637
5638         entity->compound_member.bitfield = true;
5639         entity->compound_member.bit_size = (unsigned char)size_long;
5640 }
5641
5642 static void parse_compound_declarators(compound_t *compound,
5643                 const declaration_specifiers_t *specifiers)
5644 {
5645         do {
5646                 entity_t *entity;
5647
5648                 if (token.kind == ':') {
5649                         /* anonymous bitfield */
5650                         type_t *type = specifiers->type;
5651                         entity_t *entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER,
5652                                                                 NAMESPACE_NORMAL, NULL);
5653                         entity->base.source_position               = *HERE;
5654                         entity->declaration.declared_storage_class = STORAGE_CLASS_NONE;
5655                         entity->declaration.storage_class          = STORAGE_CLASS_NONE;
5656                         entity->declaration.type                   = type;
5657
5658                         parse_bitfield_member(entity);
5659
5660                         attribute_t  *attributes = parse_attributes(NULL);
5661                         attribute_t **anchor     = &attributes;
5662                         while (*anchor != NULL)
5663                                 anchor = &(*anchor)->next;
5664                         *anchor = specifiers->attributes;
5665                         if (attributes != NULL) {
5666                                 handle_entity_attributes(attributes, entity);
5667                         }
5668                         entity->declaration.attributes = attributes;
5669
5670                         append_entity(&compound->members, entity);
5671                 } else {
5672                         entity = parse_declarator(specifiers,
5673                                         DECL_MAY_BE_ABSTRACT | DECL_CREATE_COMPOUND_MEMBER);
5674                         source_position_t const *const pos = &entity->base.source_position;
5675                         if (entity->kind == ENTITY_TYPEDEF) {
5676                                 errorf(pos, "typedef not allowed as compound member");
5677                         } else {
5678                                 assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5679
5680                                 /* make sure we don't define a symbol multiple times */
5681                                 symbol_t *symbol = entity->base.symbol;
5682                                 if (symbol != NULL) {
5683                                         entity_t *prev = find_compound_entry(compound, symbol);
5684                                         if (prev != NULL) {
5685                                                 source_position_t const *const ppos = &prev->base.source_position;
5686                                                 errorf(pos, "multiple declarations of symbol '%Y' (declared %P)", symbol, ppos);
5687                                         }
5688                                 }
5689
5690                                 if (token.kind == ':') {
5691                                         parse_bitfield_member(entity);
5692
5693                                         attribute_t *attributes = parse_attributes(NULL);
5694                                         handle_entity_attributes(attributes, entity);
5695                                 } else {
5696                                         type_t *orig_type = entity->declaration.type;
5697                                         type_t *type      = skip_typeref(orig_type);
5698                                         if (is_type_function(type)) {
5699                                                 errorf(pos, "'%N' must not have function type '%T'", entity, orig_type);
5700                                         } else if (is_type_incomplete(type)) {
5701                                                 /* §6.7.2.1:16 flexible array member */
5702                                                 if (!is_type_array(type)       ||
5703                                                                 token.kind          != ';' ||
5704                                                                 look_ahead(1)->kind != '}') {
5705                                                         errorf(pos, "'%N' has incomplete type '%T'", entity, orig_type);
5706                                                 } else if (compound->members.entities == NULL) {
5707                                                         errorf(pos, "flexible array member in otherwise empty struct");
5708                                                 }
5709                                         }
5710                                 }
5711
5712                                 append_entity(&compound->members, entity);
5713                         }
5714                 }
5715         } while (next_if(','));
5716         expect(';', end_error);
5717
5718 end_error:
5719         anonymous_entity = NULL;
5720 }
5721
5722 static void parse_compound_type_entries(compound_t *compound)
5723 {
5724         eat('{');
5725         add_anchor_token('}');
5726
5727         for (;;) {
5728                 switch (token.kind) {
5729                         DECLARATION_START
5730                         case T___extension__:
5731                         case T_IDENTIFIER: {
5732                                 PUSH_EXTENSION();
5733                                 declaration_specifiers_t specifiers;
5734                                 parse_declaration_specifiers(&specifiers);
5735                                 parse_compound_declarators(compound, &specifiers);
5736                                 POP_EXTENSION();
5737                                 break;
5738                         }
5739
5740                         default:
5741                                 rem_anchor_token('}');
5742                                 expect('}', end_error);
5743 end_error:
5744                                 /* §6.7.2.1:7 */
5745                                 compound->complete = true;
5746                                 return;
5747                 }
5748         }
5749 }
5750
5751 static type_t *parse_typename(void)
5752 {
5753         declaration_specifiers_t specifiers;
5754         parse_declaration_specifiers(&specifiers);
5755         if (specifiers.storage_class != STORAGE_CLASS_NONE
5756                         || specifiers.thread_local) {
5757                 /* TODO: improve error message, user does probably not know what a
5758                  * storage class is...
5759                  */
5760                 errorf(&specifiers.source_position, "typename must not have a storage class");
5761         }
5762
5763         type_t *result = parse_abstract_declarator(specifiers.type);
5764
5765         return result;
5766 }
5767
5768
5769
5770
5771 typedef expression_t* (*parse_expression_function)(void);
5772 typedef expression_t* (*parse_expression_infix_function)(expression_t *left);
5773
5774 typedef struct expression_parser_function_t expression_parser_function_t;
5775 struct expression_parser_function_t {
5776         parse_expression_function        parser;
5777         precedence_t                     infix_precedence;
5778         parse_expression_infix_function  infix_parser;
5779 };
5780
5781 static expression_parser_function_t expression_parsers[T_LAST_TOKEN];
5782
5783 /**
5784  * Prints an error message if an expression was expected but not read
5785  */
5786 static expression_t *expected_expression_error(void)
5787 {
5788         /* skip the error message if the error token was read */
5789         if (token.kind != T_ERROR) {
5790                 errorf(HERE, "expected expression, got token %K", &token);
5791         }
5792         next_token();
5793
5794         return create_error_expression();
5795 }
5796
5797 static type_t *get_string_type(void)
5798 {
5799         return is_warn_on(WARN_WRITE_STRINGS) ? type_const_char_ptr : type_char_ptr;
5800 }
5801
5802 static type_t *get_wide_string_type(void)
5803 {
5804         return is_warn_on(WARN_WRITE_STRINGS) ? type_const_wchar_t_ptr : type_wchar_t_ptr;
5805 }
5806
5807 /**
5808  * Parse a string constant.
5809  */
5810 static expression_t *parse_string_literal(void)
5811 {
5812         source_position_t begin   = token.base.source_position;
5813         string_t          res     = token.string.string;
5814         bool              is_wide = (token.kind == T_WIDE_STRING_LITERAL);
5815
5816         next_token();
5817         while (token.kind == T_STRING_LITERAL
5818                         || token.kind == T_WIDE_STRING_LITERAL) {
5819                 warn_string_concat(&token.base.source_position);
5820                 res = concat_strings(&res, &token.string.string);
5821                 next_token();
5822                 is_wide |= token.kind == T_WIDE_STRING_LITERAL;
5823         }
5824
5825         expression_t *literal;
5826         if (is_wide) {
5827                 literal = allocate_expression_zero(EXPR_WIDE_STRING_LITERAL);
5828                 literal->base.type = get_wide_string_type();
5829         } else {
5830                 literal = allocate_expression_zero(EXPR_STRING_LITERAL);
5831                 literal->base.type = get_string_type();
5832         }
5833         literal->base.source_position = begin;
5834         literal->literal.value        = res;
5835
5836         return literal;
5837 }
5838
5839 /**
5840  * Parse a boolean constant.
5841  */
5842 static expression_t *parse_boolean_literal(bool value)
5843 {
5844         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_BOOLEAN);
5845         literal->base.type           = type_bool;
5846         literal->literal.value.begin = value ? "true" : "false";
5847         literal->literal.value.size  = value ? 4 : 5;
5848
5849         next_token();
5850         return literal;
5851 }
5852
5853 static void warn_traditional_suffix(void)
5854 {
5855         warningf(WARN_TRADITIONAL, HERE, "traditional C rejects the '%S' suffix",
5856                  &token.number.suffix);
5857 }
5858
5859 static void check_integer_suffix(void)
5860 {
5861         const string_t *suffix = &token.number.suffix;
5862         if (suffix->size == 0)
5863                 return;
5864
5865         bool not_traditional = false;
5866         const char *c = suffix->begin;
5867         if (*c == 'l' || *c == 'L') {
5868                 ++c;
5869                 if (*c == *(c-1)) {
5870                         not_traditional = true;
5871                         ++c;
5872                         if (*c == 'u' || *c == 'U') {
5873                                 ++c;
5874                         }
5875                 } else if (*c == 'u' || *c == 'U') {
5876                         not_traditional = true;
5877                         ++c;
5878                 }
5879         } else if (*c == 'u' || *c == 'U') {
5880                 not_traditional = true;
5881                 ++c;
5882                 if (*c == 'l' || *c == 'L') {
5883                         ++c;
5884                         if (*c == *(c-1)) {
5885                                 ++c;
5886                         }
5887                 }
5888         }
5889         if (*c != '\0') {
5890                 errorf(&token.base.source_position,
5891                        "invalid suffix '%S' on integer constant", suffix);
5892         } else if (not_traditional) {
5893                 warn_traditional_suffix();
5894         }
5895 }
5896
5897 static type_t *check_floatingpoint_suffix(void)
5898 {
5899         const string_t *suffix = &token.number.suffix;
5900         type_t         *type   = type_double;
5901         if (suffix->size == 0)
5902                 return type;
5903
5904         bool not_traditional = false;
5905         const char *c = suffix->begin;
5906         if (*c == 'f' || *c == 'F') {
5907                 ++c;
5908                 type = type_float;
5909         } else if (*c == 'l' || *c == 'L') {
5910                 ++c;
5911                 type = type_long_double;
5912         }
5913         if (*c != '\0') {
5914                 errorf(&token.base.source_position,
5915                        "invalid suffix '%S' on floatingpoint constant", suffix);
5916         } else if (not_traditional) {
5917                 warn_traditional_suffix();
5918         }
5919
5920         return type;
5921 }
5922
5923 /**
5924  * Parse an integer constant.
5925  */
5926 static expression_t *parse_number_literal(void)
5927 {
5928         expression_kind_t  kind;
5929         type_t            *type;
5930
5931         switch (token.kind) {
5932         case T_INTEGER:
5933                 kind = EXPR_LITERAL_INTEGER;
5934                 check_integer_suffix();
5935                 type = type_int;
5936                 break;
5937         case T_INTEGER_OCTAL:
5938                 kind = EXPR_LITERAL_INTEGER_OCTAL;
5939                 check_integer_suffix();
5940                 type = type_int;
5941                 break;
5942         case T_INTEGER_HEXADECIMAL:
5943                 kind = EXPR_LITERAL_INTEGER_HEXADECIMAL;
5944                 check_integer_suffix();
5945                 type = type_int;
5946                 break;
5947         case T_FLOATINGPOINT:
5948                 kind = EXPR_LITERAL_FLOATINGPOINT;
5949                 type = check_floatingpoint_suffix();
5950                 break;
5951         case T_FLOATINGPOINT_HEXADECIMAL:
5952                 kind = EXPR_LITERAL_FLOATINGPOINT_HEXADECIMAL;
5953                 type = check_floatingpoint_suffix();
5954                 break;
5955         default:
5956                 panic("unexpected token type in parse_number_literal");
5957         }
5958
5959         expression_t *literal = allocate_expression_zero(kind);
5960         literal->base.type      = type;
5961         literal->literal.value  = token.number.number;
5962         literal->literal.suffix = token.number.suffix;
5963         next_token();
5964
5965         /* integer type depends on the size of the number and the size
5966          * representable by the types. The backend/codegeneration has to determine
5967          * that
5968          */
5969         determine_literal_type(&literal->literal);
5970         return literal;
5971 }
5972
5973 /**
5974  * Parse a character constant.
5975  */
5976 static expression_t *parse_character_constant(void)
5977 {
5978         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_CHARACTER);
5979         literal->base.type     = c_mode & _CXX ? type_char : type_int;
5980         literal->literal.value = token.string.string;
5981
5982         size_t len = literal->literal.value.size;
5983         if (len > 1) {
5984                 if (!GNU_MODE && !(c_mode & _C99)) {
5985                         errorf(HERE, "more than 1 character in character constant");
5986                 } else {
5987                         literal->base.type = type_int;
5988                         warningf(WARN_MULTICHAR, HERE, "multi-character character constant");
5989                 }
5990         }
5991
5992         next_token();
5993         return literal;
5994 }
5995
5996 /**
5997  * Parse a wide character constant.
5998  */
5999 static expression_t *parse_wide_character_constant(void)
6000 {
6001         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_WIDE_CHARACTER);
6002         literal->base.type     = type_int;
6003         literal->literal.value = token.string.string;
6004
6005         size_t len = wstrlen(&literal->literal.value);
6006         if (len > 1) {
6007                 warningf(WARN_MULTICHAR, HERE, "multi-character character constant");
6008         }
6009
6010         next_token();
6011         return literal;
6012 }
6013
6014 static entity_t *create_implicit_function(symbol_t *symbol,
6015                 const source_position_t *source_position)
6016 {
6017         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
6018         ntype->function.return_type            = type_int;
6019         ntype->function.unspecified_parameters = true;
6020         ntype->function.linkage                = LINKAGE_C;
6021         type_t *type                           = identify_new_type(ntype);
6022
6023         entity_t *const entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, symbol);
6024         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
6025         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
6026         entity->declaration.type                   = type;
6027         entity->declaration.implicit               = true;
6028         entity->base.source_position               = *source_position;
6029
6030         if (current_scope != NULL)
6031                 record_entity(entity, false);
6032
6033         return entity;
6034 }
6035
6036 /**
6037  * Performs automatic type cast as described in §6.3.2.1.
6038  *
6039  * @param orig_type  the original type
6040  */
6041 static type_t *automatic_type_conversion(type_t *orig_type)
6042 {
6043         type_t *type = skip_typeref(orig_type);
6044         if (is_type_array(type)) {
6045                 array_type_t *array_type   = &type->array;
6046                 type_t       *element_type = array_type->element_type;
6047                 unsigned      qualifiers   = array_type->base.qualifiers;
6048
6049                 return make_pointer_type(element_type, qualifiers);
6050         }
6051
6052         if (is_type_function(type)) {
6053                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
6054         }
6055
6056         return orig_type;
6057 }
6058
6059 /**
6060  * reverts the automatic casts of array to pointer types and function
6061  * to function-pointer types as defined §6.3.2.1
6062  */
6063 type_t *revert_automatic_type_conversion(const expression_t *expression)
6064 {
6065         switch (expression->kind) {
6066         case EXPR_REFERENCE: {
6067                 entity_t *entity = expression->reference.entity;
6068                 if (is_declaration(entity)) {
6069                         return entity->declaration.type;
6070                 } else if (entity->kind == ENTITY_ENUM_VALUE) {
6071                         return entity->enum_value.enum_type;
6072                 } else {
6073                         panic("no declaration or enum in reference");
6074                 }
6075         }
6076
6077         case EXPR_SELECT: {
6078                 entity_t *entity = expression->select.compound_entry;
6079                 assert(is_declaration(entity));
6080                 type_t   *type   = entity->declaration.type;
6081                 return get_qualified_type(type, expression->base.type->base.qualifiers);
6082         }
6083
6084         case EXPR_UNARY_DEREFERENCE: {
6085                 const expression_t *const value = expression->unary.value;
6086                 type_t             *const type  = skip_typeref(value->base.type);
6087                 if (!is_type_pointer(type))
6088                         return type_error_type;
6089                 return type->pointer.points_to;
6090         }
6091
6092         case EXPR_ARRAY_ACCESS: {
6093                 const expression_t *array_ref = expression->array_access.array_ref;
6094                 type_t             *type_left = skip_typeref(array_ref->base.type);
6095                 if (!is_type_pointer(type_left))
6096                         return type_error_type;
6097                 return type_left->pointer.points_to;
6098         }
6099
6100         case EXPR_STRING_LITERAL: {
6101                 size_t size = expression->string_literal.value.size;
6102                 return make_array_type(type_char, size, TYPE_QUALIFIER_NONE);
6103         }
6104
6105         case EXPR_WIDE_STRING_LITERAL: {
6106                 size_t size = wstrlen(&expression->string_literal.value);
6107                 return make_array_type(type_wchar_t, size, TYPE_QUALIFIER_NONE);
6108         }
6109
6110         case EXPR_COMPOUND_LITERAL:
6111                 return expression->compound_literal.type;
6112
6113         default:
6114                 break;
6115         }
6116         return expression->base.type;
6117 }
6118
6119 /**
6120  * Find an entity matching a symbol in a scope.
6121  * Uses current scope if scope is NULL
6122  */
6123 static entity_t *lookup_entity(const scope_t *scope, symbol_t *symbol,
6124                                namespace_tag_t namespc)
6125 {
6126         if (scope == NULL) {
6127                 return get_entity(symbol, namespc);
6128         }
6129
6130         /* we should optimize here, if scope grows above a certain size we should
6131            construct a hashmap here... */
6132         entity_t *entity = scope->entities;
6133         for ( ; entity != NULL; entity = entity->base.next) {
6134                 if (entity->base.symbol == symbol
6135                     && (namespace_tag_t)entity->base.namespc == namespc)
6136                         break;
6137         }
6138
6139         return entity;
6140 }
6141
6142 static entity_t *parse_qualified_identifier(void)
6143 {
6144         /* namespace containing the symbol */
6145         symbol_t          *symbol;
6146         source_position_t  pos;
6147         const scope_t     *lookup_scope = NULL;
6148
6149         if (next_if(T_COLONCOLON))
6150                 lookup_scope = &unit->scope;
6151
6152         entity_t *entity;
6153         while (true) {
6154                 if (token.kind != T_IDENTIFIER) {
6155                         parse_error_expected("while parsing identifier", T_IDENTIFIER, NULL);
6156                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6157                 }
6158                 symbol = token.identifier.symbol;
6159                 pos    = *HERE;
6160                 next_token();
6161
6162                 /* lookup entity */
6163                 entity = lookup_entity(lookup_scope, symbol, NAMESPACE_NORMAL);
6164
6165                 if (!next_if(T_COLONCOLON))
6166                         break;
6167
6168                 switch (entity->kind) {
6169                 case ENTITY_NAMESPACE:
6170                         lookup_scope = &entity->namespacee.members;
6171                         break;
6172                 case ENTITY_STRUCT:
6173                 case ENTITY_UNION:
6174                 case ENTITY_CLASS:
6175                         lookup_scope = &entity->compound.members;
6176                         break;
6177                 default:
6178                         errorf(&pos, "'%Y' must be a namespace, class, struct or union (but is a %s)",
6179                                symbol, get_entity_kind_name(entity->kind));
6180
6181                         /* skip further qualifications */
6182                         while (next_if(T_IDENTIFIER) && next_if(T_COLONCOLON)) {}
6183
6184                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6185                 }
6186         }
6187
6188         if (entity == NULL) {
6189                 if (!strict_mode && token.kind == '(') {
6190                         /* an implicitly declared function */
6191                         warningf(WARN_IMPLICIT_FUNCTION_DECLARATION, &pos,
6192                                  "implicit declaration of function '%Y'", symbol);
6193                         entity = create_implicit_function(symbol, &pos);
6194                 } else {
6195                         errorf(&pos, "unknown identifier '%Y' found.", symbol);
6196                         entity = create_error_entity(symbol, ENTITY_VARIABLE);
6197                 }
6198         }
6199
6200         return entity;
6201 }
6202
6203 static expression_t *parse_reference(void)
6204 {
6205         source_position_t const pos    = token.base.source_position;
6206         entity_t         *const entity = parse_qualified_identifier();
6207
6208         type_t *orig_type;
6209         if (is_declaration(entity)) {
6210                 orig_type = entity->declaration.type;
6211         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6212                 orig_type = entity->enum_value.enum_type;
6213         } else {
6214                 panic("expected declaration or enum value in reference");
6215         }
6216
6217         /* we always do the auto-type conversions; the & and sizeof parser contains
6218          * code to revert this! */
6219         type_t *type = automatic_type_conversion(orig_type);
6220
6221         expression_kind_t kind = EXPR_REFERENCE;
6222         if (entity->kind == ENTITY_ENUM_VALUE)
6223                 kind = EXPR_ENUM_CONSTANT;
6224
6225         expression_t *expression         = allocate_expression_zero(kind);
6226         expression->base.source_position = pos;
6227         expression->base.type            = type;
6228         expression->reference.entity     = entity;
6229
6230         /* this declaration is used */
6231         if (is_declaration(entity)) {
6232                 entity->declaration.used = true;
6233         }
6234
6235         if (entity->base.parent_scope != file_scope
6236                 && (current_function != NULL
6237                         && entity->base.parent_scope->depth < current_function->parameters.depth)
6238                 && (entity->kind == ENTITY_VARIABLE || entity->kind == ENTITY_PARAMETER)) {
6239                 if (entity->kind == ENTITY_VARIABLE) {
6240                         /* access of a variable from an outer function */
6241                         entity->variable.address_taken = true;
6242                 } else if (entity->kind == ENTITY_PARAMETER) {
6243                         entity->parameter.address_taken = true;
6244                 }
6245                 current_function->need_closure = true;
6246         }
6247
6248         check_deprecated(&pos, entity);
6249
6250         return expression;
6251 }
6252
6253 static bool semantic_cast(expression_t *cast)
6254 {
6255         expression_t            *expression      = cast->unary.value;
6256         type_t                  *orig_dest_type  = cast->base.type;
6257         type_t                  *orig_type_right = expression->base.type;
6258         type_t            const *dst_type        = skip_typeref(orig_dest_type);
6259         type_t            const *src_type        = skip_typeref(orig_type_right);
6260         source_position_t const *pos             = &cast->base.source_position;
6261
6262         /* §6.5.4 A (void) cast is explicitly permitted, more for documentation than for utility. */
6263         if (is_type_void(dst_type))
6264                 return true;
6265
6266         /* only integer and pointer can be casted to pointer */
6267         if (is_type_pointer(dst_type)  &&
6268             !is_type_pointer(src_type) &&
6269             !is_type_integer(src_type) &&
6270             is_type_valid(src_type)) {
6271                 errorf(pos, "cannot convert type '%T' to a pointer type", orig_type_right);
6272                 return false;
6273         }
6274
6275         if (!is_type_scalar(dst_type) && is_type_valid(dst_type)) {
6276                 errorf(pos, "conversion to non-scalar type '%T' requested", orig_dest_type);
6277                 return false;
6278         }
6279
6280         if (!is_type_scalar(src_type) && is_type_valid(src_type)) {
6281                 errorf(pos, "conversion from non-scalar type '%T' requested", orig_type_right);
6282                 return false;
6283         }
6284
6285         if (is_type_pointer(src_type) && is_type_pointer(dst_type)) {
6286                 type_t *src = skip_typeref(src_type->pointer.points_to);
6287                 type_t *dst = skip_typeref(dst_type->pointer.points_to);
6288                 unsigned missing_qualifiers =
6289                         src->base.qualifiers & ~dst->base.qualifiers;
6290                 if (missing_qualifiers != 0) {
6291                         warningf(WARN_CAST_QUAL, pos, "cast discards qualifiers '%Q' in pointer target type of '%T'", missing_qualifiers, orig_type_right);
6292                 }
6293         }
6294         return true;
6295 }
6296
6297 static expression_t *parse_compound_literal(source_position_t const *const pos, type_t *type)
6298 {
6299         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
6300         expression->base.source_position = *pos;
6301
6302         parse_initializer_env_t env;
6303         env.type             = type;
6304         env.entity           = NULL;
6305         env.must_be_constant = false;
6306         initializer_t *initializer = parse_initializer(&env);
6307         type = env.type;
6308
6309         expression->compound_literal.initializer = initializer;
6310         expression->compound_literal.type        = type;
6311         expression->base.type                    = automatic_type_conversion(type);
6312
6313         return expression;
6314 }
6315
6316 /**
6317  * Parse a cast expression.
6318  */
6319 static expression_t *parse_cast(void)
6320 {
6321         source_position_t const pos = *HERE;
6322
6323         eat('(');
6324         add_anchor_token(')');
6325
6326         type_t *type = parse_typename();
6327
6328         rem_anchor_token(')');
6329         expect(')', end_error);
6330
6331         if (token.kind == '{') {
6332                 return parse_compound_literal(&pos, type);
6333         }
6334
6335         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
6336         cast->base.source_position = pos;
6337
6338         expression_t *value = parse_subexpression(PREC_CAST);
6339         cast->base.type   = type;
6340         cast->unary.value = value;
6341
6342         if (! semantic_cast(cast)) {
6343                 /* TODO: record the error in the AST. else it is impossible to detect it */
6344         }
6345
6346         return cast;
6347 end_error:
6348         return create_error_expression();
6349 }
6350
6351 /**
6352  * Parse a statement expression.
6353  */
6354 static expression_t *parse_statement_expression(void)
6355 {
6356         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
6357
6358         eat('(');
6359         add_anchor_token(')');
6360
6361         statement_t *statement          = parse_compound_statement(true);
6362         statement->compound.stmt_expr   = true;
6363         expression->statement.statement = statement;
6364
6365         /* find last statement and use its type */
6366         type_t *type = type_void;
6367         const statement_t *stmt = statement->compound.statements;
6368         if (stmt != NULL) {
6369                 while (stmt->base.next != NULL)
6370                         stmt = stmt->base.next;
6371
6372                 if (stmt->kind == STATEMENT_EXPRESSION) {
6373                         type = stmt->expression.expression->base.type;
6374                 }
6375         } else {
6376                 source_position_t const *const pos = &expression->base.source_position;
6377                 warningf(WARN_OTHER, pos, "empty statement expression ({})");
6378         }
6379         expression->base.type = type;
6380
6381         rem_anchor_token(')');
6382         expect(')', end_error);
6383
6384 end_error:
6385         return expression;
6386 }
6387
6388 /**
6389  * Parse a parenthesized expression.
6390  */
6391 static expression_t *parse_parenthesized_expression(void)
6392 {
6393         token_t const* const la1 = look_ahead(1);
6394         switch (la1->kind) {
6395         case '{':
6396                 /* gcc extension: a statement expression */
6397                 return parse_statement_expression();
6398
6399         case T_IDENTIFIER:
6400                 if (is_typedef_symbol(la1->identifier.symbol)) {
6401         DECLARATION_START
6402                         return parse_cast();
6403                 }
6404         }
6405
6406         eat('(');
6407         add_anchor_token(')');
6408         expression_t *result = parse_expression();
6409         result->base.parenthesized = true;
6410         rem_anchor_token(')');
6411         expect(')', end_error);
6412
6413 end_error:
6414         return result;
6415 }
6416
6417 static expression_t *parse_function_keyword(void)
6418 {
6419         /* TODO */
6420
6421         if (current_function == NULL) {
6422                 errorf(HERE, "'__func__' used outside of a function");
6423         }
6424
6425         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6426         expression->base.type     = type_char_ptr;
6427         expression->funcname.kind = FUNCNAME_FUNCTION;
6428
6429         next_token();
6430
6431         return expression;
6432 }
6433
6434 static expression_t *parse_pretty_function_keyword(void)
6435 {
6436         if (current_function == NULL) {
6437                 errorf(HERE, "'__PRETTY_FUNCTION__' used outside of a function");
6438         }
6439
6440         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6441         expression->base.type     = type_char_ptr;
6442         expression->funcname.kind = FUNCNAME_PRETTY_FUNCTION;
6443
6444         eat(T___PRETTY_FUNCTION__);
6445
6446         return expression;
6447 }
6448
6449 static expression_t *parse_funcsig_keyword(void)
6450 {
6451         if (current_function == NULL) {
6452                 errorf(HERE, "'__FUNCSIG__' used outside of a function");
6453         }
6454
6455         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6456         expression->base.type     = type_char_ptr;
6457         expression->funcname.kind = FUNCNAME_FUNCSIG;
6458
6459         eat(T___FUNCSIG__);
6460
6461         return expression;
6462 }
6463
6464 static expression_t *parse_funcdname_keyword(void)
6465 {
6466         if (current_function == NULL) {
6467                 errorf(HERE, "'__FUNCDNAME__' used outside of a function");
6468         }
6469
6470         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6471         expression->base.type     = type_char_ptr;
6472         expression->funcname.kind = FUNCNAME_FUNCDNAME;
6473
6474         eat(T___FUNCDNAME__);
6475
6476         return expression;
6477 }
6478
6479 static designator_t *parse_designator(void)
6480 {
6481         designator_t *result    = allocate_ast_zero(sizeof(result[0]));
6482         result->source_position = *HERE;
6483
6484         if (token.kind != T_IDENTIFIER) {
6485                 parse_error_expected("while parsing member designator",
6486                                      T_IDENTIFIER, NULL);
6487                 return NULL;
6488         }
6489         result->symbol = token.identifier.symbol;
6490         next_token();
6491
6492         designator_t *last_designator = result;
6493         while (true) {
6494                 if (next_if('.')) {
6495                         if (token.kind != T_IDENTIFIER) {
6496                                 parse_error_expected("while parsing member designator",
6497                                                      T_IDENTIFIER, NULL);
6498                                 return NULL;
6499                         }
6500                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
6501                         designator->source_position = *HERE;
6502                         designator->symbol          = token.identifier.symbol;
6503                         next_token();
6504
6505                         last_designator->next = designator;
6506                         last_designator       = designator;
6507                         continue;
6508                 }
6509                 if (next_if('[')) {
6510                         add_anchor_token(']');
6511                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
6512                         designator->source_position = *HERE;
6513                         designator->array_index     = parse_expression();
6514                         rem_anchor_token(']');
6515                         expect(']', end_error);
6516                         if (designator->array_index == NULL) {
6517                                 return NULL;
6518                         }
6519
6520                         last_designator->next = designator;
6521                         last_designator       = designator;
6522                         continue;
6523                 }
6524                 break;
6525         }
6526
6527         return result;
6528 end_error:
6529         return NULL;
6530 }
6531
6532 /**
6533  * Parse the __builtin_offsetof() expression.
6534  */
6535 static expression_t *parse_offsetof(void)
6536 {
6537         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
6538         expression->base.type    = type_size_t;
6539
6540         eat(T___builtin_offsetof);
6541
6542         expect('(', end_error);
6543         add_anchor_token(',');
6544         type_t *type = parse_typename();
6545         rem_anchor_token(',');
6546         expect(',', end_error);
6547         add_anchor_token(')');
6548         designator_t *designator = parse_designator();
6549         rem_anchor_token(')');
6550         expect(')', end_error);
6551
6552         expression->offsetofe.type       = type;
6553         expression->offsetofe.designator = designator;
6554
6555         type_path_t path;
6556         memset(&path, 0, sizeof(path));
6557         path.top_type = type;
6558         path.path     = NEW_ARR_F(type_path_entry_t, 0);
6559
6560         descend_into_subtype(&path);
6561
6562         if (!walk_designator(&path, designator, true)) {
6563                 return create_error_expression();
6564         }
6565
6566         DEL_ARR_F(path.path);
6567
6568         return expression;
6569 end_error:
6570         return create_error_expression();
6571 }
6572
6573 /**
6574  * Parses a _builtin_va_start() expression.
6575  */
6576 static expression_t *parse_va_start(void)
6577 {
6578         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
6579
6580         eat(T___builtin_va_start);
6581
6582         expect('(', end_error);
6583         add_anchor_token(',');
6584         expression->va_starte.ap = parse_assignment_expression();
6585         rem_anchor_token(',');
6586         expect(',', end_error);
6587         expression_t *const expr = parse_assignment_expression();
6588         if (expr->kind == EXPR_REFERENCE) {
6589                 entity_t *const entity = expr->reference.entity;
6590                 if (!current_function->base.type->function.variadic) {
6591                         errorf(&expr->base.source_position,
6592                                         "'va_start' used in non-variadic function");
6593                 } else if (entity->base.parent_scope != &current_function->parameters ||
6594                                 entity->base.next != NULL ||
6595                                 entity->kind != ENTITY_PARAMETER) {
6596                         errorf(&expr->base.source_position,
6597                                "second argument of 'va_start' must be last parameter of the current function");
6598                 } else {
6599                         expression->va_starte.parameter = &entity->variable;
6600                 }
6601                 expect(')', end_error);
6602                 return expression;
6603         }
6604         expect(')', end_error);
6605 end_error:
6606         return create_error_expression();
6607 }
6608
6609 /**
6610  * Parses a __builtin_va_arg() expression.
6611  */
6612 static expression_t *parse_va_arg(void)
6613 {
6614         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
6615
6616         eat(T___builtin_va_arg);
6617
6618         expect('(', end_error);
6619         call_argument_t ap;
6620         ap.expression = parse_assignment_expression();
6621         expression->va_arge.ap = ap.expression;
6622         check_call_argument(type_valist, &ap, 1);
6623
6624         expect(',', end_error);
6625         expression->base.type = parse_typename();
6626         expect(')', end_error);
6627
6628         return expression;
6629 end_error:
6630         return create_error_expression();
6631 }
6632
6633 /**
6634  * Parses a __builtin_va_copy() expression.
6635  */
6636 static expression_t *parse_va_copy(void)
6637 {
6638         expression_t *expression = allocate_expression_zero(EXPR_VA_COPY);
6639
6640         eat(T___builtin_va_copy);
6641
6642         expect('(', end_error);
6643         expression_t *dst = parse_assignment_expression();
6644         assign_error_t error = semantic_assign(type_valist, dst);
6645         report_assign_error(error, type_valist, dst, "call argument 1",
6646                             &dst->base.source_position);
6647         expression->va_copye.dst = dst;
6648
6649         expect(',', end_error);
6650
6651         call_argument_t src;
6652         src.expression = parse_assignment_expression();
6653         check_call_argument(type_valist, &src, 2);
6654         expression->va_copye.src = src.expression;
6655         expect(')', end_error);
6656
6657         return expression;
6658 end_error:
6659         return create_error_expression();
6660 }
6661
6662 /**
6663  * Parses a __builtin_constant_p() expression.
6664  */
6665 static expression_t *parse_builtin_constant(void)
6666 {
6667         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
6668
6669         eat(T___builtin_constant_p);
6670
6671         expect('(', end_error);
6672         add_anchor_token(')');
6673         expression->builtin_constant.value = parse_assignment_expression();
6674         rem_anchor_token(')');
6675         expect(')', end_error);
6676         expression->base.type = type_int;
6677
6678         return expression;
6679 end_error:
6680         return create_error_expression();
6681 }
6682
6683 /**
6684  * Parses a __builtin_types_compatible_p() expression.
6685  */
6686 static expression_t *parse_builtin_types_compatible(void)
6687 {
6688         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_TYPES_COMPATIBLE_P);
6689
6690         eat(T___builtin_types_compatible_p);
6691
6692         expect('(', end_error);
6693         add_anchor_token(')');
6694         add_anchor_token(',');
6695         expression->builtin_types_compatible.left = parse_typename();
6696         rem_anchor_token(',');
6697         expect(',', end_error);
6698         expression->builtin_types_compatible.right = parse_typename();
6699         rem_anchor_token(')');
6700         expect(')', end_error);
6701         expression->base.type = type_int;
6702
6703         return expression;
6704 end_error:
6705         return create_error_expression();
6706 }
6707
6708 /**
6709  * Parses a __builtin_is_*() compare expression.
6710  */
6711 static expression_t *parse_compare_builtin(void)
6712 {
6713         expression_t *expression;
6714
6715         switch (token.kind) {
6716         case T___builtin_isgreater:
6717                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATER);
6718                 break;
6719         case T___builtin_isgreaterequal:
6720                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATEREQUAL);
6721                 break;
6722         case T___builtin_isless:
6723                 expression = allocate_expression_zero(EXPR_BINARY_ISLESS);
6724                 break;
6725         case T___builtin_islessequal:
6726                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSEQUAL);
6727                 break;
6728         case T___builtin_islessgreater:
6729                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSGREATER);
6730                 break;
6731         case T___builtin_isunordered:
6732                 expression = allocate_expression_zero(EXPR_BINARY_ISUNORDERED);
6733                 break;
6734         default:
6735                 internal_errorf(HERE, "invalid compare builtin found");
6736         }
6737         expression->base.source_position = *HERE;
6738         next_token();
6739
6740         expect('(', end_error);
6741         expression->binary.left = parse_assignment_expression();
6742         expect(',', end_error);
6743         expression->binary.right = parse_assignment_expression();
6744         expect(')', end_error);
6745
6746         type_t *const orig_type_left  = expression->binary.left->base.type;
6747         type_t *const orig_type_right = expression->binary.right->base.type;
6748
6749         type_t *const type_left  = skip_typeref(orig_type_left);
6750         type_t *const type_right = skip_typeref(orig_type_right);
6751         if (!is_type_float(type_left) && !is_type_float(type_right)) {
6752                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
6753                         type_error_incompatible("invalid operands in comparison",
6754                                 &expression->base.source_position, orig_type_left, orig_type_right);
6755                 }
6756         } else {
6757                 semantic_comparison(&expression->binary);
6758         }
6759
6760         return expression;
6761 end_error:
6762         return create_error_expression();
6763 }
6764
6765 /**
6766  * Parses a MS assume() expression.
6767  */
6768 static expression_t *parse_assume(void)
6769 {
6770         expression_t *expression = allocate_expression_zero(EXPR_UNARY_ASSUME);
6771
6772         eat(T__assume);
6773
6774         expect('(', end_error);
6775         add_anchor_token(')');
6776         expression->unary.value = parse_assignment_expression();
6777         rem_anchor_token(')');
6778         expect(')', end_error);
6779
6780         expression->base.type = type_void;
6781         return expression;
6782 end_error:
6783         return create_error_expression();
6784 }
6785
6786 /**
6787  * Return the label for the current symbol or create a new one.
6788  */
6789 static label_t *get_label(void)
6790 {
6791         assert(token.kind == T_IDENTIFIER);
6792         assert(current_function != NULL);
6793
6794         entity_t *label = get_entity(token.identifier.symbol, NAMESPACE_LABEL);
6795         /* If we find a local label, we already created the declaration. */
6796         if (label != NULL && label->kind == ENTITY_LOCAL_LABEL) {
6797                 if (label->base.parent_scope != current_scope) {
6798                         assert(label->base.parent_scope->depth < current_scope->depth);
6799                         current_function->goto_to_outer = true;
6800                 }
6801         } else if (label == NULL || label->base.parent_scope != &current_function->parameters) {
6802                 /* There is no matching label in the same function, so create a new one. */
6803                 label = allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, token.identifier.symbol);
6804                 label_push(label);
6805         }
6806
6807         eat(T_IDENTIFIER);
6808         return &label->label;
6809 }
6810
6811 /**
6812  * Parses a GNU && label address expression.
6813  */
6814 static expression_t *parse_label_address(void)
6815 {
6816         source_position_t source_position = token.base.source_position;
6817         eat(T_ANDAND);
6818         if (token.kind != T_IDENTIFIER) {
6819                 parse_error_expected("while parsing label address", T_IDENTIFIER, NULL);
6820                 return create_error_expression();
6821         }
6822
6823         label_t *const label = get_label();
6824         label->used          = true;
6825         label->address_taken = true;
6826
6827         expression_t *expression = allocate_expression_zero(EXPR_LABEL_ADDRESS);
6828         expression->base.source_position = source_position;
6829
6830         /* label address is treated as a void pointer */
6831         expression->base.type           = type_void_ptr;
6832         expression->label_address.label = label;
6833         return expression;
6834 }
6835
6836 /**
6837  * Parse a microsoft __noop expression.
6838  */
6839 static expression_t *parse_noop_expression(void)
6840 {
6841         /* the result is a (int)0 */
6842         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_MS_NOOP);
6843         literal->base.type           = type_int;
6844         literal->literal.value.begin = "__noop";
6845         literal->literal.value.size  = 6;
6846
6847         eat(T___noop);
6848
6849         if (token.kind == '(') {
6850                 /* parse arguments */
6851                 eat('(');
6852                 add_anchor_token(')');
6853                 add_anchor_token(',');
6854
6855                 if (token.kind != ')') do {
6856                         (void)parse_assignment_expression();
6857                 } while (next_if(','));
6858
6859                 rem_anchor_token(',');
6860                 rem_anchor_token(')');
6861         }
6862         expect(')', end_error);
6863
6864 end_error:
6865         return literal;
6866 }
6867
6868 /**
6869  * Parses a primary expression.
6870  */
6871 static expression_t *parse_primary_expression(void)
6872 {
6873         switch (token.kind) {
6874         case T_false:                        return parse_boolean_literal(false);
6875         case T_true:                         return parse_boolean_literal(true);
6876         case T_INTEGER:
6877         case T_INTEGER_OCTAL:
6878         case T_INTEGER_HEXADECIMAL:
6879         case T_FLOATINGPOINT:
6880         case T_FLOATINGPOINT_HEXADECIMAL:    return parse_number_literal();
6881         case T_CHARACTER_CONSTANT:           return parse_character_constant();
6882         case T_WIDE_CHARACTER_CONSTANT:      return parse_wide_character_constant();
6883         case T_STRING_LITERAL:
6884         case T_WIDE_STRING_LITERAL:          return parse_string_literal();
6885         case T___FUNCTION__:
6886         case T___func__:                     return parse_function_keyword();
6887         case T___PRETTY_FUNCTION__:          return parse_pretty_function_keyword();
6888         case T___FUNCSIG__:                  return parse_funcsig_keyword();
6889         case T___FUNCDNAME__:                return parse_funcdname_keyword();
6890         case T___builtin_offsetof:           return parse_offsetof();
6891         case T___builtin_va_start:           return parse_va_start();
6892         case T___builtin_va_arg:             return parse_va_arg();
6893         case T___builtin_va_copy:            return parse_va_copy();
6894         case T___builtin_isgreater:
6895         case T___builtin_isgreaterequal:
6896         case T___builtin_isless:
6897         case T___builtin_islessequal:
6898         case T___builtin_islessgreater:
6899         case T___builtin_isunordered:        return parse_compare_builtin();
6900         case T___builtin_constant_p:         return parse_builtin_constant();
6901         case T___builtin_types_compatible_p: return parse_builtin_types_compatible();
6902         case T__assume:                      return parse_assume();
6903         case T_ANDAND:
6904                 if (GNU_MODE)
6905                         return parse_label_address();
6906                 break;
6907
6908         case '(':                            return parse_parenthesized_expression();
6909         case T___noop:                       return parse_noop_expression();
6910
6911         /* Gracefully handle type names while parsing expressions. */
6912         case T_COLONCOLON:
6913                 return parse_reference();
6914         case T_IDENTIFIER:
6915                 if (!is_typedef_symbol(token.identifier.symbol)) {
6916                         return parse_reference();
6917                 }
6918                 /* FALLTHROUGH */
6919         DECLARATION_START {
6920                 source_position_t const  pos = *HERE;
6921                 declaration_specifiers_t specifiers;
6922                 parse_declaration_specifiers(&specifiers);
6923                 type_t const *const type = parse_abstract_declarator(specifiers.type);
6924                 errorf(&pos, "encountered type '%T' while parsing expression", type);
6925                 return create_error_expression();
6926         }
6927         }
6928
6929         errorf(HERE, "unexpected token %K, expected an expression", &token);
6930         eat_until_anchor();
6931         return create_error_expression();
6932 }
6933
6934 static expression_t *parse_array_expression(expression_t *left)
6935 {
6936         expression_t              *const expr = allocate_expression_zero(EXPR_ARRAY_ACCESS);
6937         array_access_expression_t *const arr  = &expr->array_access;
6938
6939         eat('[');
6940         add_anchor_token(']');
6941
6942         expression_t *const inside = parse_expression();
6943
6944         type_t *const orig_type_left   = left->base.type;
6945         type_t *const orig_type_inside = inside->base.type;
6946
6947         type_t *const type_left   = skip_typeref(orig_type_left);
6948         type_t *const type_inside = skip_typeref(orig_type_inside);
6949
6950         expression_t *ref;
6951         expression_t *idx;
6952         type_t       *idx_type;
6953         type_t       *res_type;
6954         if (is_type_pointer(type_left)) {
6955                 ref      = left;
6956                 idx      = inside;
6957                 idx_type = type_inside;
6958                 res_type = type_left->pointer.points_to;
6959                 goto check_idx;
6960         } else if (is_type_pointer(type_inside)) {
6961                 arr->flipped = true;
6962                 ref      = inside;
6963                 idx      = left;
6964                 idx_type = type_left;
6965                 res_type = type_inside->pointer.points_to;
6966 check_idx:
6967                 res_type = automatic_type_conversion(res_type);
6968                 if (!is_type_integer(idx_type)) {
6969                         errorf(&idx->base.source_position, "array subscript must have integer type");
6970                 } else if (is_type_atomic(idx_type, ATOMIC_TYPE_CHAR)) {
6971                         source_position_t const *const pos = &idx->base.source_position;
6972                         warningf(WARN_CHAR_SUBSCRIPTS, pos, "array subscript has char type");
6973                 }
6974         } else {
6975                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
6976                         errorf(&expr->base.source_position, "invalid types '%T[%T]' for array access", orig_type_left, orig_type_inside);
6977                 }
6978                 res_type = type_error_type;
6979                 ref      = left;
6980                 idx      = inside;
6981         }
6982
6983         arr->array_ref = ref;
6984         arr->index     = idx;
6985         arr->base.type = res_type;
6986
6987         rem_anchor_token(']');
6988         expect(']', end_error);
6989 end_error:
6990         return expr;
6991 }
6992
6993 static bool is_bitfield(const expression_t *expression)
6994 {
6995         return expression->kind == EXPR_SELECT
6996                 && expression->select.compound_entry->compound_member.bitfield;
6997 }
6998
6999 static expression_t *parse_typeprop(expression_kind_t const kind)
7000 {
7001         expression_t  *tp_expression = allocate_expression_zero(kind);
7002         tp_expression->base.type     = type_size_t;
7003
7004         eat(kind == EXPR_SIZEOF ? T_sizeof : T___alignof__);
7005
7006         type_t       *orig_type;
7007         expression_t *expression;
7008         if (token.kind == '(' && is_declaration_specifier(look_ahead(1))) {
7009                 source_position_t const pos = *HERE;
7010                 next_token();
7011                 add_anchor_token(')');
7012                 orig_type = parse_typename();
7013                 rem_anchor_token(')');
7014                 expect(')', end_error);
7015
7016                 if (token.kind == '{') {
7017                         /* It was not sizeof(type) after all.  It is sizeof of an expression
7018                          * starting with a compound literal */
7019                         expression = parse_compound_literal(&pos, orig_type);
7020                         goto typeprop_expression;
7021                 }
7022         } else {
7023                 expression = parse_subexpression(PREC_UNARY);
7024
7025 typeprop_expression:
7026                 if (is_bitfield(expression)) {
7027                         char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
7028                         errorf(&tp_expression->base.source_position,
7029                                    "operand of %s expression must not be a bitfield", what);
7030                 }
7031
7032                 tp_expression->typeprop.tp_expression = expression;
7033
7034                 orig_type = revert_automatic_type_conversion(expression);
7035                 expression->base.type = orig_type;
7036         }
7037
7038         tp_expression->typeprop.type   = orig_type;
7039         type_t const* const type       = skip_typeref(orig_type);
7040         char   const*       wrong_type = NULL;
7041         if (is_type_incomplete(type)) {
7042                 if (!is_type_void(type) || !GNU_MODE)
7043                         wrong_type = "incomplete";
7044         } else if (type->kind == TYPE_FUNCTION) {
7045                 if (GNU_MODE) {
7046                         /* function types are allowed (and return 1) */
7047                         source_position_t const *const pos  = &tp_expression->base.source_position;
7048                         char              const *const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
7049                         warningf(WARN_OTHER, pos, "%s expression with function argument returns invalid result", what);
7050                 } else {
7051                         wrong_type = "function";
7052                 }
7053         }
7054
7055         if (wrong_type != NULL) {
7056                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
7057                 errorf(&tp_expression->base.source_position,
7058                                 "operand of %s expression must not be of %s type '%T'",
7059                                 what, wrong_type, orig_type);
7060         }
7061
7062 end_error:
7063         return tp_expression;
7064 }
7065
7066 static expression_t *parse_sizeof(void)
7067 {
7068         return parse_typeprop(EXPR_SIZEOF);
7069 }
7070
7071 static expression_t *parse_alignof(void)
7072 {
7073         return parse_typeprop(EXPR_ALIGNOF);
7074 }
7075
7076 static expression_t *parse_select_expression(expression_t *addr)
7077 {
7078         assert(token.kind == '.' || token.kind == T_MINUSGREATER);
7079         bool select_left_arrow = (token.kind == T_MINUSGREATER);
7080         source_position_t const pos = *HERE;
7081         next_token();
7082
7083         if (token.kind != T_IDENTIFIER) {
7084                 parse_error_expected("while parsing select", T_IDENTIFIER, NULL);
7085                 return create_error_expression();
7086         }
7087         symbol_t *symbol = token.identifier.symbol;
7088         next_token();
7089
7090         type_t *const orig_type = addr->base.type;
7091         type_t *const type      = skip_typeref(orig_type);
7092
7093         type_t *type_left;
7094         bool    saw_error = false;
7095         if (is_type_pointer(type)) {
7096                 if (!select_left_arrow) {
7097                         errorf(&pos,
7098                                "request for member '%Y' in something not a struct or union, but '%T'",
7099                                symbol, orig_type);
7100                         saw_error = true;
7101                 }
7102                 type_left = skip_typeref(type->pointer.points_to);
7103         } else {
7104                 if (select_left_arrow && is_type_valid(type)) {
7105                         errorf(&pos, "left hand side of '->' is not a pointer, but '%T'", orig_type);
7106                         saw_error = true;
7107                 }
7108                 type_left = type;
7109         }
7110
7111         if (type_left->kind != TYPE_COMPOUND_STRUCT &&
7112             type_left->kind != TYPE_COMPOUND_UNION) {
7113
7114                 if (is_type_valid(type_left) && !saw_error) {
7115                         errorf(&pos,
7116                                "request for member '%Y' in something not a struct or union, but '%T'",
7117                                symbol, type_left);
7118                 }
7119                 return create_error_expression();
7120         }
7121
7122         compound_t *compound = type_left->compound.compound;
7123         if (!compound->complete) {
7124                 errorf(&pos, "request for member '%Y' in incomplete type '%T'",
7125                        symbol, type_left);
7126                 return create_error_expression();
7127         }
7128
7129         type_qualifiers_t  qualifiers = type_left->base.qualifiers;
7130         expression_t      *result     =
7131                 find_create_select(&pos, addr, qualifiers, compound, symbol);
7132
7133         if (result == NULL) {
7134                 errorf(&pos, "'%T' has no member named '%Y'", orig_type, symbol);
7135                 return create_error_expression();
7136         }
7137
7138         return result;
7139 }
7140
7141 static void check_call_argument(type_t          *expected_type,
7142                                 call_argument_t *argument, unsigned pos)
7143 {
7144         type_t         *expected_type_skip = skip_typeref(expected_type);
7145         assign_error_t  error              = ASSIGN_ERROR_INCOMPATIBLE;
7146         expression_t   *arg_expr           = argument->expression;
7147         type_t         *arg_type           = skip_typeref(arg_expr->base.type);
7148
7149         /* handle transparent union gnu extension */
7150         if (is_type_union(expected_type_skip)
7151                         && (get_type_modifiers(expected_type) & DM_TRANSPARENT_UNION)) {
7152                 compound_t *union_decl  = expected_type_skip->compound.compound;
7153                 type_t     *best_type   = NULL;
7154                 entity_t   *entry       = union_decl->members.entities;
7155                 for ( ; entry != NULL; entry = entry->base.next) {
7156                         assert(is_declaration(entry));
7157                         type_t *decl_type = entry->declaration.type;
7158                         error = semantic_assign(decl_type, arg_expr);
7159                         if (error == ASSIGN_ERROR_INCOMPATIBLE
7160                                 || error == ASSIGN_ERROR_POINTER_QUALIFIER_MISSING)
7161                                 continue;
7162
7163                         if (error == ASSIGN_SUCCESS) {
7164                                 best_type = decl_type;
7165                         } else if (best_type == NULL) {
7166                                 best_type = decl_type;
7167                         }
7168                 }
7169
7170                 if (best_type != NULL) {
7171                         expected_type = best_type;
7172                 }
7173         }
7174
7175         error                = semantic_assign(expected_type, arg_expr);
7176         argument->expression = create_implicit_cast(arg_expr, expected_type);
7177
7178         if (error != ASSIGN_SUCCESS) {
7179                 /* report exact scope in error messages (like "in argument 3") */
7180                 char buf[64];
7181                 snprintf(buf, sizeof(buf), "call argument %u", pos);
7182                 report_assign_error(error, expected_type, arg_expr, buf,
7183                                     &arg_expr->base.source_position);
7184         } else {
7185                 type_t *const promoted_type = get_default_promoted_type(arg_type);
7186                 if (!types_compatible(expected_type_skip, promoted_type) &&
7187                     !types_compatible(expected_type_skip, type_void_ptr) &&
7188                     !types_compatible(type_void_ptr,      promoted_type)) {
7189                         /* Deliberately show the skipped types in this warning */
7190                         source_position_t const *const apos = &arg_expr->base.source_position;
7191                         warningf(WARN_TRADITIONAL, apos, "passing call argument %u as '%T' rather than '%T' due to prototype", pos, expected_type_skip, promoted_type);
7192                 }
7193         }
7194 }
7195
7196 /**
7197  * Handle the semantic restrictions of builtin calls
7198  */
7199 static void handle_builtin_argument_restrictions(call_expression_t *call)
7200 {
7201         entity_t *entity = call->function->reference.entity;
7202         switch (entity->function.btk) {
7203         case BUILTIN_FIRM:
7204                 switch (entity->function.b.firm_builtin_kind) {
7205                 case ir_bk_return_address:
7206                 case ir_bk_frame_address: {
7207                         /* argument must be constant */
7208                         call_argument_t *argument = call->arguments;
7209
7210                         if (is_constant_expression(argument->expression) == EXPR_CLASS_VARIABLE) {
7211                                 errorf(&call->base.source_position,
7212                                            "argument of '%Y' must be a constant expression",
7213                                            call->function->reference.entity->base.symbol);
7214                         }
7215                         break;
7216                 }
7217                 case ir_bk_prefetch:
7218                         /* second and third argument must be constant if existent */
7219                         if (call->arguments == NULL)
7220                                 break;
7221                         call_argument_t *rw = call->arguments->next;
7222                         call_argument_t *locality = NULL;
7223
7224                         if (rw != NULL) {
7225                                 if (is_constant_expression(rw->expression) == EXPR_CLASS_VARIABLE) {
7226                                         errorf(&call->base.source_position,
7227                                                    "second argument of '%Y' must be a constant expression",
7228                                                    call->function->reference.entity->base.symbol);
7229                                 }
7230                                 locality = rw->next;
7231                         }
7232                         if (locality != NULL) {
7233                                 if (is_constant_expression(locality->expression) == EXPR_CLASS_VARIABLE) {
7234                                         errorf(&call->base.source_position,
7235                                                    "third argument of '%Y' must be a constant expression",
7236                                                    call->function->reference.entity->base.symbol);
7237                                 }
7238                                 locality = rw->next;
7239                         }
7240                         break;
7241                 default:
7242                         break;
7243                 }
7244
7245         case BUILTIN_OBJECT_SIZE:
7246                 if (call->arguments == NULL)
7247                         break;
7248
7249                 call_argument_t *arg = call->arguments->next;
7250                 if (arg != NULL && is_constant_expression(arg->expression) == EXPR_CLASS_VARIABLE) {
7251                         errorf(&call->base.source_position,
7252                                    "second argument of '%Y' must be a constant expression",
7253                                    call->function->reference.entity->base.symbol);
7254                 }
7255                 break;
7256         default:
7257                 break;
7258         }
7259 }
7260
7261 /**
7262  * Parse a call expression, ie. expression '( ... )'.
7263  *
7264  * @param expression  the function address
7265  */
7266 static expression_t *parse_call_expression(expression_t *expression)
7267 {
7268         expression_t      *result = allocate_expression_zero(EXPR_CALL);
7269         call_expression_t *call   = &result->call;
7270         call->function            = expression;
7271
7272         type_t *const orig_type = expression->base.type;
7273         type_t *const type      = skip_typeref(orig_type);
7274
7275         function_type_t *function_type = NULL;
7276         if (is_type_pointer(type)) {
7277                 type_t *const to_type = skip_typeref(type->pointer.points_to);
7278
7279                 if (is_type_function(to_type)) {
7280                         function_type   = &to_type->function;
7281                         call->base.type = function_type->return_type;
7282                 }
7283         }
7284
7285         if (function_type == NULL && is_type_valid(type)) {
7286                 errorf(HERE,
7287                        "called object '%E' (type '%T') is not a pointer to a function",
7288                        expression, orig_type);
7289         }
7290
7291         /* parse arguments */
7292         eat('(');
7293         add_anchor_token(')');
7294         add_anchor_token(',');
7295
7296         if (token.kind != ')') {
7297                 call_argument_t **anchor = &call->arguments;
7298                 do {
7299                         call_argument_t *argument = allocate_ast_zero(sizeof(*argument));
7300                         argument->expression = parse_assignment_expression();
7301
7302                         *anchor = argument;
7303                         anchor  = &argument->next;
7304                 } while (next_if(','));
7305         }
7306         rem_anchor_token(',');
7307         rem_anchor_token(')');
7308         expect(')', end_error);
7309
7310         if (function_type == NULL)
7311                 return result;
7312
7313         /* check type and count of call arguments */
7314         function_parameter_t *parameter = function_type->parameters;
7315         call_argument_t      *argument  = call->arguments;
7316         if (!function_type->unspecified_parameters) {
7317                 for (unsigned pos = 0; parameter != NULL && argument != NULL;
7318                                 parameter = parameter->next, argument = argument->next) {
7319                         check_call_argument(parameter->type, argument, ++pos);
7320                 }
7321
7322                 if (parameter != NULL) {
7323                         errorf(&expression->base.source_position, "too few arguments to function '%E'", expression);
7324                 } else if (argument != NULL && !function_type->variadic) {
7325                         errorf(&argument->expression->base.source_position, "too many arguments to function '%E'", expression);
7326                 }
7327         }
7328
7329         /* do default promotion for other arguments */
7330         for (; argument != NULL; argument = argument->next) {
7331                 type_t *argument_type = argument->expression->base.type;
7332                 if (!is_type_object(skip_typeref(argument_type))) {
7333                         errorf(&argument->expression->base.source_position,
7334                                "call argument '%E' must not be void", argument->expression);
7335                 }
7336
7337                 argument_type = get_default_promoted_type(argument_type);
7338
7339                 argument->expression
7340                         = create_implicit_cast(argument->expression, argument_type);
7341         }
7342
7343         check_format(call);
7344
7345         if (is_type_compound(skip_typeref(function_type->return_type))) {
7346                 source_position_t const *const pos = &expression->base.source_position;
7347                 warningf(WARN_AGGREGATE_RETURN, pos, "function call has aggregate value");
7348         }
7349
7350         if (expression->kind == EXPR_REFERENCE) {
7351                 reference_expression_t *reference = &expression->reference;
7352                 if (reference->entity->kind == ENTITY_FUNCTION &&
7353                     reference->entity->function.btk != BUILTIN_NONE)
7354                         handle_builtin_argument_restrictions(call);
7355         }
7356
7357 end_error:
7358         return result;
7359 }
7360
7361 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
7362
7363 static bool same_compound_type(const type_t *type1, const type_t *type2)
7364 {
7365         return
7366                 is_type_compound(type1) &&
7367                 type1->kind == type2->kind &&
7368                 type1->compound.compound == type2->compound.compound;
7369 }
7370
7371 static expression_t const *get_reference_address(expression_t const *expr)
7372 {
7373         bool regular_take_address = true;
7374         for (;;) {
7375                 if (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
7376                         expr = expr->unary.value;
7377                 } else {
7378                         regular_take_address = false;
7379                 }
7380
7381                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
7382                         break;
7383
7384                 expr = expr->unary.value;
7385         }
7386
7387         if (expr->kind != EXPR_REFERENCE)
7388                 return NULL;
7389
7390         /* special case for functions which are automatically converted to a
7391          * pointer to function without an extra TAKE_ADDRESS operation */
7392         if (!regular_take_address &&
7393                         expr->reference.entity->kind != ENTITY_FUNCTION) {
7394                 return NULL;
7395         }
7396
7397         return expr;
7398 }
7399
7400 static void warn_reference_address_as_bool(expression_t const* expr)
7401 {
7402         expr = get_reference_address(expr);
7403         if (expr != NULL) {
7404                 source_position_t const *const pos = &expr->base.source_position;
7405                 entity_t          const *const ent = expr->reference.entity;
7406                 warningf(WARN_ADDRESS, pos, "the address of '%N' will always evaluate as 'true'", ent);
7407         }
7408 }
7409
7410 static void warn_assignment_in_condition(const expression_t *const expr)
7411 {
7412         if (expr->base.kind != EXPR_BINARY_ASSIGN)
7413                 return;
7414         if (expr->base.parenthesized)
7415                 return;
7416         source_position_t const *const pos = &expr->base.source_position;
7417         warningf(WARN_PARENTHESES, pos, "suggest parentheses around assignment used as truth value");
7418 }
7419
7420 static void semantic_condition(expression_t const *const expr,
7421                                char const *const context)
7422 {
7423         type_t *const type = skip_typeref(expr->base.type);
7424         if (is_type_scalar(type)) {
7425                 warn_reference_address_as_bool(expr);
7426                 warn_assignment_in_condition(expr);
7427         } else if (is_type_valid(type)) {
7428                 errorf(&expr->base.source_position,
7429                                 "%s must have scalar type", context);
7430         }
7431 }
7432
7433 /**
7434  * Parse a conditional expression, ie. 'expression ? ... : ...'.
7435  *
7436  * @param expression  the conditional expression
7437  */
7438 static expression_t *parse_conditional_expression(expression_t *expression)
7439 {
7440         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
7441
7442         conditional_expression_t *conditional = &result->conditional;
7443         conditional->condition                = expression;
7444
7445         eat('?');
7446         add_anchor_token(':');
7447
7448         /* §6.5.15:2  The first operand shall have scalar type. */
7449         semantic_condition(expression, "condition of conditional operator");
7450
7451         expression_t *true_expression = expression;
7452         bool          gnu_cond = false;
7453         if (GNU_MODE && token.kind == ':') {
7454                 gnu_cond = true;
7455         } else {
7456                 true_expression = parse_expression();
7457         }
7458         rem_anchor_token(':');
7459         expect(':', end_error);
7460 end_error:;
7461         expression_t *false_expression =
7462                 parse_subexpression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
7463
7464         type_t *const orig_true_type  = true_expression->base.type;
7465         type_t *const orig_false_type = false_expression->base.type;
7466         type_t *const true_type       = skip_typeref(orig_true_type);
7467         type_t *const false_type      = skip_typeref(orig_false_type);
7468
7469         /* 6.5.15.3 */
7470         source_position_t const *const pos = &conditional->base.source_position;
7471         type_t                        *result_type;
7472         if (is_type_void(true_type) || is_type_void(false_type)) {
7473                 /* ISO/IEC 14882:1998(E) §5.16:2 */
7474                 if (true_expression->kind == EXPR_UNARY_THROW) {
7475                         result_type = false_type;
7476                 } else if (false_expression->kind == EXPR_UNARY_THROW) {
7477                         result_type = true_type;
7478                 } else {
7479                         if (!is_type_void(true_type) || !is_type_void(false_type)) {
7480                                 warningf(WARN_OTHER, pos, "ISO C forbids conditional expression with only one void side");
7481                         }
7482                         result_type = type_void;
7483                 }
7484         } else if (is_type_arithmetic(true_type)
7485                    && is_type_arithmetic(false_type)) {
7486                 result_type = semantic_arithmetic(true_type, false_type);
7487         } else if (same_compound_type(true_type, false_type)) {
7488                 /* just take 1 of the 2 types */
7489                 result_type = true_type;
7490         } else if (is_type_pointer(true_type) || is_type_pointer(false_type)) {
7491                 type_t *pointer_type;
7492                 type_t *other_type;
7493                 expression_t *other_expression;
7494                 if (is_type_pointer(true_type) &&
7495                                 (!is_type_pointer(false_type) || is_null_pointer_constant(false_expression))) {
7496                         pointer_type     = true_type;
7497                         other_type       = false_type;
7498                         other_expression = false_expression;
7499                 } else {
7500                         pointer_type     = false_type;
7501                         other_type       = true_type;
7502                         other_expression = true_expression;
7503                 }
7504
7505                 if (is_null_pointer_constant(other_expression)) {
7506                         result_type = pointer_type;
7507                 } else if (is_type_pointer(other_type)) {
7508                         type_t *to1 = skip_typeref(pointer_type->pointer.points_to);
7509                         type_t *to2 = skip_typeref(other_type->pointer.points_to);
7510
7511                         type_t *to;
7512                         if (is_type_void(to1) || is_type_void(to2)) {
7513                                 to = type_void;
7514                         } else if (types_compatible(get_unqualified_type(to1),
7515                                                     get_unqualified_type(to2))) {
7516                                 to = to1;
7517                         } else {
7518                                 warningf(WARN_OTHER, pos, "pointer types '%T' and '%T' in conditional expression are incompatible", true_type, false_type);
7519                                 to = type_void;
7520                         }
7521
7522                         type_t *const type =
7523                                 get_qualified_type(to, to1->base.qualifiers | to2->base.qualifiers);
7524                         result_type = make_pointer_type(type, TYPE_QUALIFIER_NONE);
7525                 } else if (is_type_integer(other_type)) {
7526                         warningf(WARN_OTHER, pos, "pointer/integer type mismatch in conditional expression ('%T' and '%T')", true_type, false_type);
7527                         result_type = pointer_type;
7528                 } else {
7529                         goto types_incompatible;
7530                 }
7531         } else {
7532 types_incompatible:
7533                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
7534                         type_error_incompatible("while parsing conditional", pos, true_type, false_type);
7535                 }
7536                 result_type = type_error_type;
7537         }
7538
7539         conditional->true_expression
7540                 = gnu_cond ? NULL : create_implicit_cast(true_expression, result_type);
7541         conditional->false_expression
7542                 = create_implicit_cast(false_expression, result_type);
7543         conditional->base.type = result_type;
7544         return result;
7545 }
7546
7547 /**
7548  * Parse an extension expression.
7549  */
7550 static expression_t *parse_extension(void)
7551 {
7552         PUSH_EXTENSION();
7553         expression_t *expression = parse_subexpression(PREC_UNARY);
7554         POP_EXTENSION();
7555         return expression;
7556 }
7557
7558 /**
7559  * Parse a __builtin_classify_type() expression.
7560  */
7561 static expression_t *parse_builtin_classify_type(void)
7562 {
7563         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
7564         result->base.type    = type_int;
7565
7566         eat(T___builtin_classify_type);
7567
7568         expect('(', end_error);
7569         add_anchor_token(')');
7570         expression_t *expression = parse_expression();
7571         rem_anchor_token(')');
7572         expect(')', end_error);
7573         result->classify_type.type_expression = expression;
7574
7575         return result;
7576 end_error:
7577         return create_error_expression();
7578 }
7579
7580 /**
7581  * Parse a delete expression
7582  * ISO/IEC 14882:1998(E) §5.3.5
7583  */
7584 static expression_t *parse_delete(void)
7585 {
7586         expression_t *const result = allocate_expression_zero(EXPR_UNARY_DELETE);
7587         result->base.type          = type_void;
7588
7589         eat(T_delete);
7590
7591         if (next_if('[')) {
7592                 result->kind = EXPR_UNARY_DELETE_ARRAY;
7593                 expect(']', end_error);
7594 end_error:;
7595         }
7596
7597         expression_t *const value = parse_subexpression(PREC_CAST);
7598         result->unary.value = value;
7599
7600         type_t *const type = skip_typeref(value->base.type);
7601         if (!is_type_pointer(type)) {
7602                 if (is_type_valid(type)) {
7603                         errorf(&value->base.source_position,
7604                                         "operand of delete must have pointer type");
7605                 }
7606         } else if (is_type_void(skip_typeref(type->pointer.points_to))) {
7607                 source_position_t const *const pos = &value->base.source_position;
7608                 warningf(WARN_OTHER, pos, "deleting 'void*' is undefined");
7609         }
7610
7611         return result;
7612 }
7613
7614 /**
7615  * Parse a throw expression
7616  * ISO/IEC 14882:1998(E) §15:1
7617  */
7618 static expression_t *parse_throw(void)
7619 {
7620         expression_t *const result = allocate_expression_zero(EXPR_UNARY_THROW);
7621         result->base.type          = type_void;
7622
7623         eat(T_throw);
7624
7625         expression_t *value = NULL;
7626         switch (token.kind) {
7627                 EXPRESSION_START {
7628                         value = parse_assignment_expression();
7629                         /* ISO/IEC 14882:1998(E) §15.1:3 */
7630                         type_t *const orig_type = value->base.type;
7631                         type_t *const type      = skip_typeref(orig_type);
7632                         if (is_type_incomplete(type)) {
7633                                 errorf(&value->base.source_position,
7634                                                 "cannot throw object of incomplete type '%T'", orig_type);
7635                         } else if (is_type_pointer(type)) {
7636                                 type_t *const points_to = skip_typeref(type->pointer.points_to);
7637                                 if (is_type_incomplete(points_to) && !is_type_void(points_to)) {
7638                                         errorf(&value->base.source_position,
7639                                                         "cannot throw pointer to incomplete type '%T'", orig_type);
7640                                 }
7641                         }
7642                 }
7643
7644                 default:
7645                         break;
7646         }
7647         result->unary.value = value;
7648
7649         return result;
7650 }
7651
7652 static bool check_pointer_arithmetic(const source_position_t *source_position,
7653                                      type_t *pointer_type,
7654                                      type_t *orig_pointer_type)
7655 {
7656         type_t *points_to = pointer_type->pointer.points_to;
7657         points_to = skip_typeref(points_to);
7658
7659         if (is_type_incomplete(points_to)) {
7660                 if (!GNU_MODE || !is_type_void(points_to)) {
7661                         errorf(source_position,
7662                                "arithmetic with pointer to incomplete type '%T' not allowed",
7663                                orig_pointer_type);
7664                         return false;
7665                 } else {
7666                         warningf(WARN_POINTER_ARITH, source_position, "pointer of type '%T' used in arithmetic", orig_pointer_type);
7667                 }
7668         } else if (is_type_function(points_to)) {
7669                 if (!GNU_MODE) {
7670                         errorf(source_position,
7671                                "arithmetic with pointer to function type '%T' not allowed",
7672                                orig_pointer_type);
7673                         return false;
7674                 } else {
7675                         warningf(WARN_POINTER_ARITH, source_position, "pointer to a function '%T' used in arithmetic", orig_pointer_type);
7676                 }
7677         }
7678         return true;
7679 }
7680
7681 static bool is_lvalue(const expression_t *expression)
7682 {
7683         /* TODO: doesn't seem to be consistent with §6.3.2.1:1 */
7684         switch (expression->kind) {
7685         case EXPR_ARRAY_ACCESS:
7686         case EXPR_COMPOUND_LITERAL:
7687         case EXPR_REFERENCE:
7688         case EXPR_SELECT:
7689         case EXPR_UNARY_DEREFERENCE:
7690                 return true;
7691
7692         default: {
7693                 type_t *type = skip_typeref(expression->base.type);
7694                 return
7695                         /* ISO/IEC 14882:1998(E) §3.10:3 */
7696                         is_type_reference(type) ||
7697                         /* Claim it is an lvalue, if the type is invalid.  There was a parse
7698                          * error before, which maybe prevented properly recognizing it as
7699                          * lvalue. */
7700                         !is_type_valid(type);
7701         }
7702         }
7703 }
7704
7705 static void semantic_incdec(unary_expression_t *expression)
7706 {
7707         type_t *const orig_type = expression->value->base.type;
7708         type_t *const type      = skip_typeref(orig_type);
7709         if (is_type_pointer(type)) {
7710                 if (!check_pointer_arithmetic(&expression->base.source_position,
7711                                               type, orig_type)) {
7712                         return;
7713                 }
7714         } else if (!is_type_real(type) && is_type_valid(type)) {
7715                 /* TODO: improve error message */
7716                 errorf(&expression->base.source_position,
7717                        "operation needs an arithmetic or pointer type");
7718                 return;
7719         }
7720         if (!is_lvalue(expression->value)) {
7721                 /* TODO: improve error message */
7722                 errorf(&expression->base.source_position, "lvalue required as operand");
7723         }
7724         expression->base.type = orig_type;
7725 }
7726
7727 static void promote_unary_int_expr(unary_expression_t *const expr, type_t *const type)
7728 {
7729         type_t *const res_type = promote_integer(type);
7730         expr->base.type = res_type;
7731         expr->value     = create_implicit_cast(expr->value, res_type);
7732 }
7733
7734 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
7735 {
7736         type_t *const orig_type = expression->value->base.type;
7737         type_t *const type      = skip_typeref(orig_type);
7738         if (!is_type_arithmetic(type)) {
7739                 if (is_type_valid(type)) {
7740                         /* TODO: improve error message */
7741                         errorf(&expression->base.source_position,
7742                                 "operation needs an arithmetic type");
7743                 }
7744                 return;
7745         } else if (is_type_integer(type)) {
7746                 promote_unary_int_expr(expression, type);
7747         } else {
7748                 expression->base.type = orig_type;
7749         }
7750 }
7751
7752 static void semantic_unexpr_plus(unary_expression_t *expression)
7753 {
7754         semantic_unexpr_arithmetic(expression);
7755         source_position_t const *const pos = &expression->base.source_position;
7756         warningf(WARN_TRADITIONAL, pos, "traditional C rejects the unary plus operator");
7757 }
7758
7759 static void semantic_not(unary_expression_t *expression)
7760 {
7761         /* §6.5.3.3:1  The operand [...] of the ! operator, scalar type. */
7762         semantic_condition(expression->value, "operand of !");
7763         expression->base.type = c_mode & _CXX ? type_bool : type_int;
7764 }
7765
7766 static void semantic_unexpr_integer(unary_expression_t *expression)
7767 {
7768         type_t *const orig_type = expression->value->base.type;
7769         type_t *const type      = skip_typeref(orig_type);
7770         if (!is_type_integer(type)) {
7771                 if (is_type_valid(type)) {
7772                         errorf(&expression->base.source_position,
7773                                "operand of ~ must be of integer type");
7774                 }
7775                 return;
7776         }
7777
7778         promote_unary_int_expr(expression, type);
7779 }
7780
7781 static void semantic_dereference(unary_expression_t *expression)
7782 {
7783         type_t *const orig_type = expression->value->base.type;
7784         type_t *const type      = skip_typeref(orig_type);
7785         if (!is_type_pointer(type)) {
7786                 if (is_type_valid(type)) {
7787                         errorf(&expression->base.source_position,
7788                                "Unary '*' needs pointer or array type, but type '%T' given", orig_type);
7789                 }
7790                 return;
7791         }
7792
7793         type_t *result_type   = type->pointer.points_to;
7794         result_type           = automatic_type_conversion(result_type);
7795         expression->base.type = result_type;
7796 }
7797
7798 /**
7799  * Record that an address is taken (expression represents an lvalue).
7800  *
7801  * @param expression       the expression
7802  * @param may_be_register  if true, the expression might be an register
7803  */
7804 static void set_address_taken(expression_t *expression, bool may_be_register)
7805 {
7806         if (expression->kind != EXPR_REFERENCE)
7807                 return;
7808
7809         entity_t *const entity = expression->reference.entity;
7810
7811         if (entity->kind != ENTITY_VARIABLE && entity->kind != ENTITY_PARAMETER)
7812                 return;
7813
7814         if (entity->declaration.storage_class == STORAGE_CLASS_REGISTER
7815                         && !may_be_register) {
7816                 source_position_t const *const pos = &expression->base.source_position;
7817                 errorf(pos, "address of register '%N' requested", entity);
7818         }
7819
7820         if (entity->kind == ENTITY_VARIABLE) {
7821                 entity->variable.address_taken = true;
7822         } else {
7823                 assert(entity->kind == ENTITY_PARAMETER);
7824                 entity->parameter.address_taken = true;
7825         }
7826 }
7827
7828 /**
7829  * Check the semantic of the address taken expression.
7830  */
7831 static void semantic_take_addr(unary_expression_t *expression)
7832 {
7833         expression_t *value = expression->value;
7834         value->base.type    = revert_automatic_type_conversion(value);
7835
7836         type_t *orig_type = value->base.type;
7837         type_t *type      = skip_typeref(orig_type);
7838         if (!is_type_valid(type))
7839                 return;
7840
7841         /* §6.5.3.2 */
7842         if (!is_lvalue(value)) {
7843                 errorf(&expression->base.source_position, "'&' requires an lvalue");
7844         }
7845         if (is_bitfield(value)) {
7846                 errorf(&expression->base.source_position,
7847                        "'&' not allowed on bitfield");
7848         }
7849
7850         set_address_taken(value, false);
7851
7852         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
7853 }
7854
7855 #define CREATE_UNARY_EXPRESSION_PARSER(token_kind, unexpression_type, sfunc) \
7856 static expression_t *parse_##unexpression_type(void)                         \
7857 {                                                                            \
7858         expression_t *unary_expression                                           \
7859                 = allocate_expression_zero(unexpression_type);                       \
7860         eat(token_kind);                                                         \
7861         unary_expression->unary.value = parse_subexpression(PREC_UNARY);         \
7862                                                                                  \
7863         sfunc(&unary_expression->unary);                                         \
7864                                                                                  \
7865         return unary_expression;                                                 \
7866 }
7867
7868 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
7869                                semantic_unexpr_arithmetic)
7870 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
7871                                semantic_unexpr_plus)
7872 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
7873                                semantic_not)
7874 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
7875                                semantic_dereference)
7876 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
7877                                semantic_take_addr)
7878 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
7879                                semantic_unexpr_integer)
7880 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
7881                                semantic_incdec)
7882 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
7883                                semantic_incdec)
7884
7885 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_kind, unexpression_type, \
7886                                                sfunc)                         \
7887 static expression_t *parse_##unexpression_type(expression_t *left)            \
7888 {                                                                             \
7889         expression_t *unary_expression                                            \
7890                 = allocate_expression_zero(unexpression_type);                        \
7891         eat(token_kind);                                                          \
7892         unary_expression->unary.value = left;                                     \
7893                                                                                   \
7894         sfunc(&unary_expression->unary);                                          \
7895                                                                               \
7896         return unary_expression;                                                  \
7897 }
7898
7899 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
7900                                        EXPR_UNARY_POSTFIX_INCREMENT,
7901                                        semantic_incdec)
7902 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
7903                                        EXPR_UNARY_POSTFIX_DECREMENT,
7904                                        semantic_incdec)
7905
7906 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
7907 {
7908         /* TODO: handle complex + imaginary types */
7909
7910         type_left  = get_unqualified_type(type_left);
7911         type_right = get_unqualified_type(type_right);
7912
7913         /* §6.3.1.8 Usual arithmetic conversions */
7914         if (type_left == type_long_double || type_right == type_long_double) {
7915                 return type_long_double;
7916         } else if (type_left == type_double || type_right == type_double) {
7917                 return type_double;
7918         } else if (type_left == type_float || type_right == type_float) {
7919                 return type_float;
7920         }
7921
7922         type_left  = promote_integer(type_left);
7923         type_right = promote_integer(type_right);
7924
7925         if (type_left == type_right)
7926                 return type_left;
7927
7928         bool     const signed_left  = is_type_signed(type_left);
7929         bool     const signed_right = is_type_signed(type_right);
7930         unsigned const rank_left    = get_akind_rank(get_akind(type_left));
7931         unsigned const rank_right   = get_akind_rank(get_akind(type_right));
7932
7933         if (signed_left == signed_right)
7934                 return rank_left >= rank_right ? type_left : type_right;
7935
7936         unsigned           s_rank;
7937         unsigned           u_rank;
7938         atomic_type_kind_t s_akind;
7939         atomic_type_kind_t u_akind;
7940         type_t *s_type;
7941         type_t *u_type;
7942         if (signed_left) {
7943                 s_type = type_left;
7944                 u_type = type_right;
7945         } else {
7946                 s_type = type_right;
7947                 u_type = type_left;
7948         }
7949         s_akind = get_akind(s_type);
7950         u_akind = get_akind(u_type);
7951         s_rank  = get_akind_rank(s_akind);
7952         u_rank  = get_akind_rank(u_akind);
7953
7954         if (u_rank >= s_rank)
7955                 return u_type;
7956
7957         if (get_atomic_type_size(s_akind) > get_atomic_type_size(u_akind))
7958                 return s_type;
7959
7960         switch (s_akind) {
7961         case ATOMIC_TYPE_INT:      return type_unsigned_int;
7962         case ATOMIC_TYPE_LONG:     return type_unsigned_long;
7963         case ATOMIC_TYPE_LONGLONG: return type_unsigned_long_long;
7964
7965         default: panic("invalid atomic type");
7966         }
7967 }
7968
7969 /**
7970  * Check the semantic restrictions for a binary expression.
7971  */
7972 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
7973 {
7974         expression_t *const left            = expression->left;
7975         expression_t *const right           = expression->right;
7976         type_t       *const orig_type_left  = left->base.type;
7977         type_t       *const orig_type_right = right->base.type;
7978         type_t       *const type_left       = skip_typeref(orig_type_left);
7979         type_t       *const type_right      = skip_typeref(orig_type_right);
7980
7981         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
7982                 /* TODO: improve error message */
7983                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7984                         errorf(&expression->base.source_position,
7985                                "operation needs arithmetic types");
7986                 }
7987                 return;
7988         }
7989
7990         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7991         expression->left      = create_implicit_cast(left, arithmetic_type);
7992         expression->right     = create_implicit_cast(right, arithmetic_type);
7993         expression->base.type = arithmetic_type;
7994 }
7995
7996 static void semantic_binexpr_integer(binary_expression_t *const expression)
7997 {
7998         expression_t *const left            = expression->left;
7999         expression_t *const right           = expression->right;
8000         type_t       *const orig_type_left  = left->base.type;
8001         type_t       *const orig_type_right = right->base.type;
8002         type_t       *const type_left       = skip_typeref(orig_type_left);
8003         type_t       *const type_right      = skip_typeref(orig_type_right);
8004
8005         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8006                 /* TODO: improve error message */
8007                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8008                         errorf(&expression->base.source_position,
8009                                "operation needs integer types");
8010                 }
8011                 return;
8012         }
8013
8014         type_t *const result_type = semantic_arithmetic(type_left, type_right);
8015         expression->left      = create_implicit_cast(left, result_type);
8016         expression->right     = create_implicit_cast(right, result_type);
8017         expression->base.type = result_type;
8018 }
8019
8020 static void warn_div_by_zero(binary_expression_t const *const expression)
8021 {
8022         if (!is_type_integer(expression->base.type))
8023                 return;
8024
8025         expression_t const *const right = expression->right;
8026         /* The type of the right operand can be different for /= */
8027         if (is_type_integer(right->base.type)                    &&
8028             is_constant_expression(right) == EXPR_CLASS_CONSTANT &&
8029             !fold_constant_to_bool(right)) {
8030                 source_position_t const *const pos = &expression->base.source_position;
8031                 warningf(WARN_DIV_BY_ZERO, pos, "division by zero");
8032         }
8033 }
8034
8035 /**
8036  * Check the semantic restrictions for a div/mod expression.
8037  */
8038 static void semantic_divmod_arithmetic(binary_expression_t *expression)
8039 {
8040         semantic_binexpr_arithmetic(expression);
8041         warn_div_by_zero(expression);
8042 }
8043
8044 static void warn_addsub_in_shift(const expression_t *const expr)
8045 {
8046         if (expr->base.parenthesized)
8047                 return;
8048
8049         char op;
8050         switch (expr->kind) {
8051                 case EXPR_BINARY_ADD: op = '+'; break;
8052                 case EXPR_BINARY_SUB: op = '-'; break;
8053                 default:              return;
8054         }
8055
8056         source_position_t const *const pos = &expr->base.source_position;
8057         warningf(WARN_PARENTHESES, pos, "suggest parentheses around '%c' inside shift", op);
8058 }
8059
8060 static bool semantic_shift(binary_expression_t *expression)
8061 {
8062         expression_t *const left            = expression->left;
8063         expression_t *const right           = expression->right;
8064         type_t       *const orig_type_left  = left->base.type;
8065         type_t       *const orig_type_right = right->base.type;
8066         type_t       *      type_left       = skip_typeref(orig_type_left);
8067         type_t       *      type_right      = skip_typeref(orig_type_right);
8068
8069         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8070                 /* TODO: improve error message */
8071                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8072                         errorf(&expression->base.source_position,
8073                                "operands of shift operation must have integer types");
8074                 }
8075                 return false;
8076         }
8077
8078         type_left = promote_integer(type_left);
8079
8080         if (is_constant_expression(right) == EXPR_CLASS_CONSTANT) {
8081                 source_position_t const *const pos   = &right->base.source_position;
8082                 long                     const count = fold_constant_to_int(right);
8083                 if (count < 0) {
8084                         warningf(WARN_OTHER, pos, "shift count must be non-negative");
8085                 } else if ((unsigned long)count >=
8086                                 get_atomic_type_size(type_left->atomic.akind) * 8) {
8087                         warningf(WARN_OTHER, pos, "shift count must be less than type width");
8088                 }
8089         }
8090
8091         type_right        = promote_integer(type_right);
8092         expression->right = create_implicit_cast(right, type_right);
8093
8094         return true;
8095 }
8096
8097 static void semantic_shift_op(binary_expression_t *expression)
8098 {
8099         expression_t *const left  = expression->left;
8100         expression_t *const right = expression->right;
8101
8102         if (!semantic_shift(expression))
8103                 return;
8104
8105         warn_addsub_in_shift(left);
8106         warn_addsub_in_shift(right);
8107
8108         type_t *const orig_type_left = left->base.type;
8109         type_t *      type_left      = skip_typeref(orig_type_left);
8110
8111         type_left             = promote_integer(type_left);
8112         expression->left      = create_implicit_cast(left, type_left);
8113         expression->base.type = type_left;
8114 }
8115
8116 static void semantic_add(binary_expression_t *expression)
8117 {
8118         expression_t *const left            = expression->left;
8119         expression_t *const right           = expression->right;
8120         type_t       *const orig_type_left  = left->base.type;
8121         type_t       *const orig_type_right = right->base.type;
8122         type_t       *const type_left       = skip_typeref(orig_type_left);
8123         type_t       *const type_right      = skip_typeref(orig_type_right);
8124
8125         /* §6.5.6 */
8126         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8127                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8128                 expression->left  = create_implicit_cast(left, arithmetic_type);
8129                 expression->right = create_implicit_cast(right, arithmetic_type);
8130                 expression->base.type = arithmetic_type;
8131         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8132                 check_pointer_arithmetic(&expression->base.source_position,
8133                                          type_left, orig_type_left);
8134                 expression->base.type = type_left;
8135         } else if (is_type_pointer(type_right) && is_type_integer(type_left)) {
8136                 check_pointer_arithmetic(&expression->base.source_position,
8137                                          type_right, orig_type_right);
8138                 expression->base.type = type_right;
8139         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8140                 errorf(&expression->base.source_position,
8141                        "invalid operands to binary + ('%T', '%T')",
8142                        orig_type_left, orig_type_right);
8143         }
8144 }
8145
8146 static void semantic_sub(binary_expression_t *expression)
8147 {
8148         expression_t            *const left            = expression->left;
8149         expression_t            *const right           = expression->right;
8150         type_t                  *const orig_type_left  = left->base.type;
8151         type_t                  *const orig_type_right = right->base.type;
8152         type_t                  *const type_left       = skip_typeref(orig_type_left);
8153         type_t                  *const type_right      = skip_typeref(orig_type_right);
8154         source_position_t const *const pos             = &expression->base.source_position;
8155
8156         /* §5.6.5 */
8157         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8158                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8159                 expression->left        = create_implicit_cast(left, arithmetic_type);
8160                 expression->right       = create_implicit_cast(right, arithmetic_type);
8161                 expression->base.type =  arithmetic_type;
8162         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8163                 check_pointer_arithmetic(&expression->base.source_position,
8164                                          type_left, orig_type_left);
8165                 expression->base.type = type_left;
8166         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8167                 type_t *const unqual_left  = get_unqualified_type(skip_typeref(type_left->pointer.points_to));
8168                 type_t *const unqual_right = get_unqualified_type(skip_typeref(type_right->pointer.points_to));
8169                 if (!types_compatible(unqual_left, unqual_right)) {
8170                         errorf(pos,
8171                                "subtracting pointers to incompatible types '%T' and '%T'",
8172                                orig_type_left, orig_type_right);
8173                 } else if (!is_type_object(unqual_left)) {
8174                         if (!is_type_void(unqual_left)) {
8175                                 errorf(pos, "subtracting pointers to non-object types '%T'",
8176                                        orig_type_left);
8177                         } else {
8178                                 warningf(WARN_OTHER, pos, "subtracting pointers to void");
8179                         }
8180                 }
8181                 expression->base.type = type_ptrdiff_t;
8182         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8183                 errorf(pos, "invalid operands of types '%T' and '%T' to binary '-'",
8184                        orig_type_left, orig_type_right);
8185         }
8186 }
8187
8188 static void warn_string_literal_address(expression_t const* expr)
8189 {
8190         while (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
8191                 expr = expr->unary.value;
8192                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
8193                         return;
8194                 expr = expr->unary.value;
8195         }
8196
8197         if (expr->kind == EXPR_STRING_LITERAL
8198                         || expr->kind == EXPR_WIDE_STRING_LITERAL) {
8199                 source_position_t const *const pos = &expr->base.source_position;
8200                 warningf(WARN_ADDRESS, pos, "comparison with string literal results in unspecified behaviour");
8201         }
8202 }
8203
8204 static bool maybe_negative(expression_t const *const expr)
8205 {
8206         switch (is_constant_expression(expr)) {
8207                 case EXPR_CLASS_ERROR:    return false;
8208                 case EXPR_CLASS_CONSTANT: return constant_is_negative(expr);
8209                 default:                  return true;
8210         }
8211 }
8212
8213 static void warn_comparison(source_position_t const *const pos, expression_t const *const expr, expression_t const *const other)
8214 {
8215         warn_string_literal_address(expr);
8216
8217         expression_t const* const ref = get_reference_address(expr);
8218         if (ref != NULL && is_null_pointer_constant(other)) {
8219                 entity_t const *const ent = ref->reference.entity;
8220                 warningf(WARN_ADDRESS, pos, "the address of '%N' will never be NULL", ent);
8221         }
8222
8223         if (!expr->base.parenthesized) {
8224                 switch (expr->base.kind) {
8225                         case EXPR_BINARY_LESS:
8226                         case EXPR_BINARY_GREATER:
8227                         case EXPR_BINARY_LESSEQUAL:
8228                         case EXPR_BINARY_GREATEREQUAL:
8229                         case EXPR_BINARY_NOTEQUAL:
8230                         case EXPR_BINARY_EQUAL:
8231                                 warningf(WARN_PARENTHESES, pos, "comparisons like 'x <= y < z' do not have their mathematical meaning");
8232                                 break;
8233                         default:
8234                                 break;
8235                 }
8236         }
8237 }
8238
8239 /**
8240  * Check the semantics of comparison expressions.
8241  *
8242  * @param expression   The expression to check.
8243  */
8244 static void semantic_comparison(binary_expression_t *expression)
8245 {
8246         source_position_t const *const pos   = &expression->base.source_position;
8247         expression_t            *const left  = expression->left;
8248         expression_t            *const right = expression->right;
8249
8250         warn_comparison(pos, left, right);
8251         warn_comparison(pos, right, left);
8252
8253         type_t *orig_type_left  = left->base.type;
8254         type_t *orig_type_right = right->base.type;
8255         type_t *type_left       = skip_typeref(orig_type_left);
8256         type_t *type_right      = skip_typeref(orig_type_right);
8257
8258         /* TODO non-arithmetic types */
8259         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8260                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8261
8262                 /* test for signed vs unsigned compares */
8263                 if (is_type_integer(arithmetic_type)) {
8264                         bool const signed_left  = is_type_signed(type_left);
8265                         bool const signed_right = is_type_signed(type_right);
8266                         if (signed_left != signed_right) {
8267                                 /* FIXME long long needs better const folding magic */
8268                                 /* TODO check whether constant value can be represented by other type */
8269                                 if ((signed_left  && maybe_negative(left)) ||
8270                                                 (signed_right && maybe_negative(right))) {
8271                                         warningf(WARN_SIGN_COMPARE, pos, "comparison between signed and unsigned");
8272                                 }
8273                         }
8274                 }
8275
8276                 expression->left        = create_implicit_cast(left, arithmetic_type);
8277                 expression->right       = create_implicit_cast(right, arithmetic_type);
8278                 expression->base.type   = arithmetic_type;
8279                 if ((expression->base.kind == EXPR_BINARY_EQUAL ||
8280                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
8281                     is_type_float(arithmetic_type)) {
8282                         warningf(WARN_FLOAT_EQUAL, pos, "comparing floating point with == or != is unsafe");
8283                 }
8284         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8285                 /* TODO check compatibility */
8286         } else if (is_type_pointer(type_left)) {
8287                 expression->right = create_implicit_cast(right, type_left);
8288         } else if (is_type_pointer(type_right)) {
8289                 expression->left = create_implicit_cast(left, type_right);
8290         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8291                 type_error_incompatible("invalid operands in comparison", pos, type_left, type_right);
8292         }
8293         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8294 }
8295
8296 /**
8297  * Checks if a compound type has constant fields.
8298  */
8299 static bool has_const_fields(const compound_type_t *type)
8300 {
8301         compound_t *compound = type->compound;
8302         entity_t   *entry    = compound->members.entities;
8303
8304         for (; entry != NULL; entry = entry->base.next) {
8305                 if (!is_declaration(entry))
8306                         continue;
8307
8308                 const type_t *decl_type = skip_typeref(entry->declaration.type);
8309                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
8310                         return true;
8311         }
8312
8313         return false;
8314 }
8315
8316 static bool is_valid_assignment_lhs(expression_t const* const left)
8317 {
8318         type_t *const orig_type_left = revert_automatic_type_conversion(left);
8319         type_t *const type_left      = skip_typeref(orig_type_left);
8320
8321         if (!is_lvalue(left)) {
8322                 errorf(&left->base.source_position, "left hand side '%E' of assignment is not an lvalue",
8323                        left);
8324                 return false;
8325         }
8326
8327         if (left->kind == EXPR_REFERENCE
8328                         && left->reference.entity->kind == ENTITY_FUNCTION) {
8329                 errorf(&left->base.source_position, "cannot assign to function '%E'", left);
8330                 return false;
8331         }
8332
8333         if (is_type_array(type_left)) {
8334                 errorf(&left->base.source_position, "cannot assign to array '%E'", left);
8335                 return false;
8336         }
8337         if (type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
8338                 errorf(&left->base.source_position, "assignment to read-only location '%E' (type '%T')", left,
8339                        orig_type_left);
8340                 return false;
8341         }
8342         if (is_type_incomplete(type_left)) {
8343                 errorf(&left->base.source_position, "left-hand side '%E' of assignment has incomplete type '%T'",
8344                        left, orig_type_left);
8345                 return false;
8346         }
8347         if (is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
8348                 errorf(&left->base.source_position, "cannot assign to '%E' because compound type '%T' has read-only fields",
8349                        left, orig_type_left);
8350                 return false;
8351         }
8352
8353         return true;
8354 }
8355
8356 static void semantic_arithmetic_assign(binary_expression_t *expression)
8357 {
8358         expression_t *left            = expression->left;
8359         expression_t *right           = expression->right;
8360         type_t       *orig_type_left  = left->base.type;
8361         type_t       *orig_type_right = right->base.type;
8362
8363         if (!is_valid_assignment_lhs(left))
8364                 return;
8365
8366         type_t *type_left  = skip_typeref(orig_type_left);
8367         type_t *type_right = skip_typeref(orig_type_right);
8368
8369         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8370                 /* TODO: improve error message */
8371                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8372                         errorf(&expression->base.source_position,
8373                                "operation needs arithmetic types");
8374                 }
8375                 return;
8376         }
8377
8378         /* combined instructions are tricky. We can't create an implicit cast on
8379          * the left side, because we need the uncasted form for the store.
8380          * The ast2firm pass has to know that left_type must be right_type
8381          * for the arithmetic operation and create a cast by itself */
8382         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8383         expression->right       = create_implicit_cast(right, arithmetic_type);
8384         expression->base.type   = type_left;
8385 }
8386
8387 static void semantic_divmod_assign(binary_expression_t *expression)
8388 {
8389         semantic_arithmetic_assign(expression);
8390         warn_div_by_zero(expression);
8391 }
8392
8393 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
8394 {
8395         expression_t *const left            = expression->left;
8396         expression_t *const right           = expression->right;
8397         type_t       *const orig_type_left  = left->base.type;
8398         type_t       *const orig_type_right = right->base.type;
8399         type_t       *const type_left       = skip_typeref(orig_type_left);
8400         type_t       *const type_right      = skip_typeref(orig_type_right);
8401
8402         if (!is_valid_assignment_lhs(left))
8403                 return;
8404
8405         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8406                 /* combined instructions are tricky. We can't create an implicit cast on
8407                  * the left side, because we need the uncasted form for the store.
8408                  * The ast2firm pass has to know that left_type must be right_type
8409                  * for the arithmetic operation and create a cast by itself */
8410                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
8411                 expression->right     = create_implicit_cast(right, arithmetic_type);
8412                 expression->base.type = type_left;
8413         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8414                 check_pointer_arithmetic(&expression->base.source_position,
8415                                          type_left, orig_type_left);
8416                 expression->base.type = type_left;
8417         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8418                 errorf(&expression->base.source_position,
8419                        "incompatible types '%T' and '%T' in assignment",
8420                        orig_type_left, orig_type_right);
8421         }
8422 }
8423
8424 static void semantic_integer_assign(binary_expression_t *expression)
8425 {
8426         expression_t *left            = expression->left;
8427         expression_t *right           = expression->right;
8428         type_t       *orig_type_left  = left->base.type;
8429         type_t       *orig_type_right = right->base.type;
8430
8431         if (!is_valid_assignment_lhs(left))
8432                 return;
8433
8434         type_t *type_left  = skip_typeref(orig_type_left);
8435         type_t *type_right = skip_typeref(orig_type_right);
8436
8437         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8438                 /* TODO: improve error message */
8439                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8440                         errorf(&expression->base.source_position,
8441                                "operation needs integer types");
8442                 }
8443                 return;
8444         }
8445
8446         /* combined instructions are tricky. We can't create an implicit cast on
8447          * the left side, because we need the uncasted form for the store.
8448          * The ast2firm pass has to know that left_type must be right_type
8449          * for the arithmetic operation and create a cast by itself */
8450         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8451         expression->right       = create_implicit_cast(right, arithmetic_type);
8452         expression->base.type   = type_left;
8453 }
8454
8455 static void semantic_shift_assign(binary_expression_t *expression)
8456 {
8457         expression_t *left           = expression->left;
8458
8459         if (!is_valid_assignment_lhs(left))
8460                 return;
8461
8462         if (!semantic_shift(expression))
8463                 return;
8464
8465         expression->base.type = skip_typeref(left->base.type);
8466 }
8467
8468 static void warn_logical_and_within_or(const expression_t *const expr)
8469 {
8470         if (expr->base.kind != EXPR_BINARY_LOGICAL_AND)
8471                 return;
8472         if (expr->base.parenthesized)
8473                 return;
8474         source_position_t const *const pos = &expr->base.source_position;
8475         warningf(WARN_PARENTHESES, pos, "suggest parentheses around && within ||");
8476 }
8477
8478 /**
8479  * Check the semantic restrictions of a logical expression.
8480  */
8481 static void semantic_logical_op(binary_expression_t *expression)
8482 {
8483         /* §6.5.13:2  Each of the operands shall have scalar type.
8484          * §6.5.14:2  Each of the operands shall have scalar type. */
8485         semantic_condition(expression->left,   "left operand of logical operator");
8486         semantic_condition(expression->right, "right operand of logical operator");
8487         if (expression->base.kind == EXPR_BINARY_LOGICAL_OR) {
8488                 warn_logical_and_within_or(expression->left);
8489                 warn_logical_and_within_or(expression->right);
8490         }
8491         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8492 }
8493
8494 /**
8495  * Check the semantic restrictions of a binary assign expression.
8496  */
8497 static void semantic_binexpr_assign(binary_expression_t *expression)
8498 {
8499         expression_t *left           = expression->left;
8500         type_t       *orig_type_left = left->base.type;
8501
8502         if (!is_valid_assignment_lhs(left))
8503                 return;
8504
8505         assign_error_t error = semantic_assign(orig_type_left, expression->right);
8506         report_assign_error(error, orig_type_left, expression->right,
8507                         "assignment", &left->base.source_position);
8508         expression->right = create_implicit_cast(expression->right, orig_type_left);
8509         expression->base.type = orig_type_left;
8510 }
8511
8512 /**
8513  * Determine if the outermost operation (or parts thereof) of the given
8514  * expression has no effect in order to generate a warning about this fact.
8515  * Therefore in some cases this only examines some of the operands of the
8516  * expression (see comments in the function and examples below).
8517  * Examples:
8518  *   f() + 23;    // warning, because + has no effect
8519  *   x || f();    // no warning, because x controls execution of f()
8520  *   x ? y : f(); // warning, because y has no effect
8521  *   (void)x;     // no warning to be able to suppress the warning
8522  * This function can NOT be used for an "expression has definitely no effect"-
8523  * analysis. */
8524 static bool expression_has_effect(const expression_t *const expr)
8525 {
8526         switch (expr->kind) {
8527                 case EXPR_ERROR:                      return true; /* do NOT warn */
8528                 case EXPR_REFERENCE:                  return false;
8529                 case EXPR_ENUM_CONSTANT:              return false;
8530                 case EXPR_LABEL_ADDRESS:              return false;
8531
8532                 /* suppress the warning for microsoft __noop operations */
8533                 case EXPR_LITERAL_MS_NOOP:            return true;
8534                 case EXPR_LITERAL_BOOLEAN:
8535                 case EXPR_LITERAL_CHARACTER:
8536                 case EXPR_LITERAL_WIDE_CHARACTER:
8537                 case EXPR_LITERAL_INTEGER:
8538                 case EXPR_LITERAL_INTEGER_OCTAL:
8539                 case EXPR_LITERAL_INTEGER_HEXADECIMAL:
8540                 case EXPR_LITERAL_FLOATINGPOINT:
8541                 case EXPR_LITERAL_FLOATINGPOINT_HEXADECIMAL: return false;
8542                 case EXPR_STRING_LITERAL:             return false;
8543                 case EXPR_WIDE_STRING_LITERAL:        return false;
8544
8545                 case EXPR_CALL: {
8546                         const call_expression_t *const call = &expr->call;
8547                         if (call->function->kind != EXPR_REFERENCE)
8548                                 return true;
8549
8550                         switch (call->function->reference.entity->function.btk) {
8551                                 /* FIXME: which builtins have no effect? */
8552                                 default:                      return true;
8553                         }
8554                 }
8555
8556                 /* Generate the warning if either the left or right hand side of a
8557                  * conditional expression has no effect */
8558                 case EXPR_CONDITIONAL: {
8559                         conditional_expression_t const *const cond = &expr->conditional;
8560                         expression_t             const *const t    = cond->true_expression;
8561                         return
8562                                 (t == NULL || expression_has_effect(t)) &&
8563                                 expression_has_effect(cond->false_expression);
8564                 }
8565
8566                 case EXPR_SELECT:                     return false;
8567                 case EXPR_ARRAY_ACCESS:               return false;
8568                 case EXPR_SIZEOF:                     return false;
8569                 case EXPR_CLASSIFY_TYPE:              return false;
8570                 case EXPR_ALIGNOF:                    return false;
8571
8572                 case EXPR_FUNCNAME:                   return false;
8573                 case EXPR_BUILTIN_CONSTANT_P:         return false;
8574                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P: return false;
8575                 case EXPR_OFFSETOF:                   return false;
8576                 case EXPR_VA_START:                   return true;
8577                 case EXPR_VA_ARG:                     return true;
8578                 case EXPR_VA_COPY:                    return true;
8579                 case EXPR_STATEMENT:                  return true; // TODO
8580                 case EXPR_COMPOUND_LITERAL:           return false;
8581
8582                 case EXPR_UNARY_NEGATE:               return false;
8583                 case EXPR_UNARY_PLUS:                 return false;
8584                 case EXPR_UNARY_BITWISE_NEGATE:       return false;
8585                 case EXPR_UNARY_NOT:                  return false;
8586                 case EXPR_UNARY_DEREFERENCE:          return false;
8587                 case EXPR_UNARY_TAKE_ADDRESS:         return false;
8588                 case EXPR_UNARY_POSTFIX_INCREMENT:    return true;
8589                 case EXPR_UNARY_POSTFIX_DECREMENT:    return true;
8590                 case EXPR_UNARY_PREFIX_INCREMENT:     return true;
8591                 case EXPR_UNARY_PREFIX_DECREMENT:     return true;
8592
8593                 /* Treat void casts as if they have an effect in order to being able to
8594                  * suppress the warning */
8595                 case EXPR_UNARY_CAST: {
8596                         type_t *const type = skip_typeref(expr->base.type);
8597                         return is_type_void(type);
8598                 }
8599
8600                 case EXPR_UNARY_ASSUME:               return true;
8601                 case EXPR_UNARY_DELETE:               return true;
8602                 case EXPR_UNARY_DELETE_ARRAY:         return true;
8603                 case EXPR_UNARY_THROW:                return true;
8604
8605                 case EXPR_BINARY_ADD:                 return false;
8606                 case EXPR_BINARY_SUB:                 return false;
8607                 case EXPR_BINARY_MUL:                 return false;
8608                 case EXPR_BINARY_DIV:                 return false;
8609                 case EXPR_BINARY_MOD:                 return false;
8610                 case EXPR_BINARY_EQUAL:               return false;
8611                 case EXPR_BINARY_NOTEQUAL:            return false;
8612                 case EXPR_BINARY_LESS:                return false;
8613                 case EXPR_BINARY_LESSEQUAL:           return false;
8614                 case EXPR_BINARY_GREATER:             return false;
8615                 case EXPR_BINARY_GREATEREQUAL:        return false;
8616                 case EXPR_BINARY_BITWISE_AND:         return false;
8617                 case EXPR_BINARY_BITWISE_OR:          return false;
8618                 case EXPR_BINARY_BITWISE_XOR:         return false;
8619                 case EXPR_BINARY_SHIFTLEFT:           return false;
8620                 case EXPR_BINARY_SHIFTRIGHT:          return false;
8621                 case EXPR_BINARY_ASSIGN:              return true;
8622                 case EXPR_BINARY_MUL_ASSIGN:          return true;
8623                 case EXPR_BINARY_DIV_ASSIGN:          return true;
8624                 case EXPR_BINARY_MOD_ASSIGN:          return true;
8625                 case EXPR_BINARY_ADD_ASSIGN:          return true;
8626                 case EXPR_BINARY_SUB_ASSIGN:          return true;
8627                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:    return true;
8628                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:   return true;
8629                 case EXPR_BINARY_BITWISE_AND_ASSIGN:  return true;
8630                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:  return true;
8631                 case EXPR_BINARY_BITWISE_OR_ASSIGN:   return true;
8632
8633                 /* Only examine the right hand side of && and ||, because the left hand
8634                  * side already has the effect of controlling the execution of the right
8635                  * hand side */
8636                 case EXPR_BINARY_LOGICAL_AND:
8637                 case EXPR_BINARY_LOGICAL_OR:
8638                 /* Only examine the right hand side of a comma expression, because the left
8639                  * hand side has a separate warning */
8640                 case EXPR_BINARY_COMMA:
8641                         return expression_has_effect(expr->binary.right);
8642
8643                 case EXPR_BINARY_ISGREATER:           return false;
8644                 case EXPR_BINARY_ISGREATEREQUAL:      return false;
8645                 case EXPR_BINARY_ISLESS:              return false;
8646                 case EXPR_BINARY_ISLESSEQUAL:         return false;
8647                 case EXPR_BINARY_ISLESSGREATER:       return false;
8648                 case EXPR_BINARY_ISUNORDERED:         return false;
8649         }
8650
8651         internal_errorf(HERE, "unexpected expression");
8652 }
8653
8654 static void semantic_comma(binary_expression_t *expression)
8655 {
8656         const expression_t *const left = expression->left;
8657         if (!expression_has_effect(left)) {
8658                 source_position_t const *const pos = &left->base.source_position;
8659                 warningf(WARN_UNUSED_VALUE, pos, "left-hand operand of comma expression has no effect");
8660         }
8661         expression->base.type = expression->right->base.type;
8662 }
8663
8664 /**
8665  * @param prec_r precedence of the right operand
8666  */
8667 #define CREATE_BINEXPR_PARSER(token_kind, binexpression_type, prec_r, sfunc) \
8668 static expression_t *parse_##binexpression_type(expression_t *left)          \
8669 {                                                                            \
8670         expression_t *binexpr = allocate_expression_zero(binexpression_type);    \
8671         binexpr->binary.left  = left;                                            \
8672         eat(token_kind);                                                         \
8673                                                                              \
8674         expression_t *right = parse_subexpression(prec_r);                       \
8675                                                                              \
8676         binexpr->binary.right = right;                                           \
8677         sfunc(&binexpr->binary);                                                 \
8678                                                                              \
8679         return binexpr;                                                          \
8680 }
8681
8682 CREATE_BINEXPR_PARSER('*',                    EXPR_BINARY_MUL,                PREC_CAST,           semantic_binexpr_arithmetic)
8683 CREATE_BINEXPR_PARSER('/',                    EXPR_BINARY_DIV,                PREC_CAST,           semantic_divmod_arithmetic)
8684 CREATE_BINEXPR_PARSER('%',                    EXPR_BINARY_MOD,                PREC_CAST,           semantic_divmod_arithmetic)
8685 CREATE_BINEXPR_PARSER('+',                    EXPR_BINARY_ADD,                PREC_MULTIPLICATIVE, semantic_add)
8686 CREATE_BINEXPR_PARSER('-',                    EXPR_BINARY_SUB,                PREC_MULTIPLICATIVE, semantic_sub)
8687 CREATE_BINEXPR_PARSER(T_LESSLESS,             EXPR_BINARY_SHIFTLEFT,          PREC_ADDITIVE,       semantic_shift_op)
8688 CREATE_BINEXPR_PARSER(T_GREATERGREATER,       EXPR_BINARY_SHIFTRIGHT,         PREC_ADDITIVE,       semantic_shift_op)
8689 CREATE_BINEXPR_PARSER('<',                    EXPR_BINARY_LESS,               PREC_SHIFT,          semantic_comparison)
8690 CREATE_BINEXPR_PARSER('>',                    EXPR_BINARY_GREATER,            PREC_SHIFT,          semantic_comparison)
8691 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,          PREC_SHIFT,          semantic_comparison)
8692 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,       PREC_SHIFT,          semantic_comparison)
8693 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,           PREC_RELATIONAL,     semantic_comparison)
8694 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,              PREC_RELATIONAL,     semantic_comparison)
8695 CREATE_BINEXPR_PARSER('&',                    EXPR_BINARY_BITWISE_AND,        PREC_EQUALITY,       semantic_binexpr_integer)
8696 CREATE_BINEXPR_PARSER('^',                    EXPR_BINARY_BITWISE_XOR,        PREC_AND,            semantic_binexpr_integer)
8697 CREATE_BINEXPR_PARSER('|',                    EXPR_BINARY_BITWISE_OR,         PREC_XOR,            semantic_binexpr_integer)
8698 CREATE_BINEXPR_PARSER(T_ANDAND,               EXPR_BINARY_LOGICAL_AND,        PREC_OR,             semantic_logical_op)
8699 CREATE_BINEXPR_PARSER(T_PIPEPIPE,             EXPR_BINARY_LOGICAL_OR,         PREC_LOGICAL_AND,    semantic_logical_op)
8700 CREATE_BINEXPR_PARSER('=',                    EXPR_BINARY_ASSIGN,             PREC_ASSIGNMENT,     semantic_binexpr_assign)
8701 CREATE_BINEXPR_PARSER(T_PLUSEQUAL,            EXPR_BINARY_ADD_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8702 CREATE_BINEXPR_PARSER(T_MINUSEQUAL,           EXPR_BINARY_SUB_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8703 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL,        EXPR_BINARY_MUL_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_assign)
8704 CREATE_BINEXPR_PARSER(T_SLASHEQUAL,           EXPR_BINARY_DIV_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8705 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL,         EXPR_BINARY_MOD_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8706 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL,        EXPR_BINARY_SHIFTLEFT_ASSIGN,   PREC_ASSIGNMENT,     semantic_shift_assign)
8707 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL,  EXPR_BINARY_SHIFTRIGHT_ASSIGN,  PREC_ASSIGNMENT,     semantic_shift_assign)
8708 CREATE_BINEXPR_PARSER(T_ANDEQUAL,             EXPR_BINARY_BITWISE_AND_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8709 CREATE_BINEXPR_PARSER(T_PIPEEQUAL,            EXPR_BINARY_BITWISE_OR_ASSIGN,  PREC_ASSIGNMENT,     semantic_integer_assign)
8710 CREATE_BINEXPR_PARSER(T_CARETEQUAL,           EXPR_BINARY_BITWISE_XOR_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8711 CREATE_BINEXPR_PARSER(',',                    EXPR_BINARY_COMMA,              PREC_ASSIGNMENT,     semantic_comma)
8712
8713
8714 static expression_t *parse_subexpression(precedence_t precedence)
8715 {
8716         if (token.kind < 0) {
8717                 return expected_expression_error();
8718         }
8719
8720         expression_parser_function_t *parser
8721                 = &expression_parsers[token.kind];
8722         expression_t                 *left;
8723
8724         if (parser->parser != NULL) {
8725                 left = parser->parser();
8726         } else {
8727                 left = parse_primary_expression();
8728         }
8729         assert(left != NULL);
8730
8731         while (true) {
8732                 if (token.kind < 0) {
8733                         return expected_expression_error();
8734                 }
8735
8736                 parser = &expression_parsers[token.kind];
8737                 if (parser->infix_parser == NULL)
8738                         break;
8739                 if (parser->infix_precedence < precedence)
8740                         break;
8741
8742                 left = parser->infix_parser(left);
8743
8744                 assert(left != NULL);
8745         }
8746
8747         return left;
8748 }
8749
8750 /**
8751  * Parse an expression.
8752  */
8753 static expression_t *parse_expression(void)
8754 {
8755         return parse_subexpression(PREC_EXPRESSION);
8756 }
8757
8758 /**
8759  * Register a parser for a prefix-like operator.
8760  *
8761  * @param parser      the parser function
8762  * @param token_kind  the token type of the prefix token
8763  */
8764 static void register_expression_parser(parse_expression_function parser,
8765                                        int token_kind)
8766 {
8767         expression_parser_function_t *entry = &expression_parsers[token_kind];
8768
8769         if (entry->parser != NULL) {
8770                 diagnosticf("for token '%k'\n", (token_kind_t)token_kind);
8771                 panic("trying to register multiple expression parsers for a token");
8772         }
8773         entry->parser = parser;
8774 }
8775
8776 /**
8777  * Register a parser for an infix operator with given precedence.
8778  *
8779  * @param parser      the parser function
8780  * @param token_kind  the token type of the infix operator
8781  * @param precedence  the precedence of the operator
8782  */
8783 static void register_infix_parser(parse_expression_infix_function parser,
8784                                   int token_kind, precedence_t precedence)
8785 {
8786         expression_parser_function_t *entry = &expression_parsers[token_kind];
8787
8788         if (entry->infix_parser != NULL) {
8789                 diagnosticf("for token '%k'\n", (token_kind_t)token_kind);
8790                 panic("trying to register multiple infix expression parsers for a "
8791                       "token");
8792         }
8793         entry->infix_parser     = parser;
8794         entry->infix_precedence = precedence;
8795 }
8796
8797 /**
8798  * Initialize the expression parsers.
8799  */
8800 static void init_expression_parsers(void)
8801 {
8802         memset(&expression_parsers, 0, sizeof(expression_parsers));
8803
8804         register_infix_parser(parse_array_expression,               '[',                    PREC_POSTFIX);
8805         register_infix_parser(parse_call_expression,                '(',                    PREC_POSTFIX);
8806         register_infix_parser(parse_select_expression,              '.',                    PREC_POSTFIX);
8807         register_infix_parser(parse_select_expression,              T_MINUSGREATER,         PREC_POSTFIX);
8808         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,   T_PLUSPLUS,             PREC_POSTFIX);
8809         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,   T_MINUSMINUS,           PREC_POSTFIX);
8810         register_infix_parser(parse_EXPR_BINARY_MUL,                '*',                    PREC_MULTIPLICATIVE);
8811         register_infix_parser(parse_EXPR_BINARY_DIV,                '/',                    PREC_MULTIPLICATIVE);
8812         register_infix_parser(parse_EXPR_BINARY_MOD,                '%',                    PREC_MULTIPLICATIVE);
8813         register_infix_parser(parse_EXPR_BINARY_ADD,                '+',                    PREC_ADDITIVE);
8814         register_infix_parser(parse_EXPR_BINARY_SUB,                '-',                    PREC_ADDITIVE);
8815         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,          T_LESSLESS,             PREC_SHIFT);
8816         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,         T_GREATERGREATER,       PREC_SHIFT);
8817         register_infix_parser(parse_EXPR_BINARY_LESS,               '<',                    PREC_RELATIONAL);
8818         register_infix_parser(parse_EXPR_BINARY_GREATER,            '>',                    PREC_RELATIONAL);
8819         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,          T_LESSEQUAL,            PREC_RELATIONAL);
8820         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL,       T_GREATEREQUAL,         PREC_RELATIONAL);
8821         register_infix_parser(parse_EXPR_BINARY_EQUAL,              T_EQUALEQUAL,           PREC_EQUALITY);
8822         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,           T_EXCLAMATIONMARKEQUAL, PREC_EQUALITY);
8823         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,        '&',                    PREC_AND);
8824         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,        '^',                    PREC_XOR);
8825         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,         '|',                    PREC_OR);
8826         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,        T_ANDAND,               PREC_LOGICAL_AND);
8827         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,         T_PIPEPIPE,             PREC_LOGICAL_OR);
8828         register_infix_parser(parse_conditional_expression,         '?',                    PREC_CONDITIONAL);
8829         register_infix_parser(parse_EXPR_BINARY_ASSIGN,             '=',                    PREC_ASSIGNMENT);
8830         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,         T_PLUSEQUAL,            PREC_ASSIGNMENT);
8831         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,         T_MINUSEQUAL,           PREC_ASSIGNMENT);
8832         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,         T_ASTERISKEQUAL,        PREC_ASSIGNMENT);
8833         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,         T_SLASHEQUAL,           PREC_ASSIGNMENT);
8834         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,         T_PERCENTEQUAL,         PREC_ASSIGNMENT);
8835         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,   T_LESSLESSEQUAL,        PREC_ASSIGNMENT);
8836         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,  T_GREATERGREATEREQUAL,  PREC_ASSIGNMENT);
8837         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN, T_ANDEQUAL,             PREC_ASSIGNMENT);
8838         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,  T_PIPEEQUAL,            PREC_ASSIGNMENT);
8839         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN, T_CARETEQUAL,           PREC_ASSIGNMENT);
8840         register_infix_parser(parse_EXPR_BINARY_COMMA,              ',',                    PREC_EXPRESSION);
8841
8842         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-');
8843         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+');
8844         register_expression_parser(parse_EXPR_UNARY_NOT,              '!');
8845         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~');
8846         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*');
8847         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&');
8848         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT, T_PLUSPLUS);
8849         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT, T_MINUSMINUS);
8850         register_expression_parser(parse_sizeof,                      T_sizeof);
8851         register_expression_parser(parse_alignof,                     T___alignof__);
8852         register_expression_parser(parse_extension,                   T___extension__);
8853         register_expression_parser(parse_builtin_classify_type,       T___builtin_classify_type);
8854         register_expression_parser(parse_delete,                      T_delete);
8855         register_expression_parser(parse_throw,                       T_throw);
8856 }
8857
8858 /**
8859  * Parse a asm statement arguments specification.
8860  */
8861 static asm_argument_t *parse_asm_arguments(bool is_out)
8862 {
8863         asm_argument_t  *result = NULL;
8864         asm_argument_t **anchor = &result;
8865
8866         while (token.kind == T_STRING_LITERAL || token.kind == '[') {
8867                 asm_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
8868
8869                 if (next_if('[')) {
8870                         if (token.kind != T_IDENTIFIER) {
8871                                 parse_error_expected("while parsing asm argument",
8872                                                      T_IDENTIFIER, NULL);
8873                                 return NULL;
8874                         }
8875                         argument->symbol = token.identifier.symbol;
8876
8877                         expect(']', end_error);
8878                 }
8879
8880                 argument->constraints = parse_string_literals();
8881                 expect('(', end_error);
8882                 add_anchor_token(')');
8883                 expression_t *expression = parse_expression();
8884                 rem_anchor_token(')');
8885                 if (is_out) {
8886                         /* Ugly GCC stuff: Allow lvalue casts.  Skip casts, when they do not
8887                          * change size or type representation (e.g. int -> long is ok, but
8888                          * int -> float is not) */
8889                         if (expression->kind == EXPR_UNARY_CAST) {
8890                                 type_t      *const type = expression->base.type;
8891                                 type_kind_t  const kind = type->kind;
8892                                 if (kind == TYPE_ATOMIC || kind == TYPE_POINTER) {
8893                                         unsigned flags;
8894                                         unsigned size;
8895                                         if (kind == TYPE_ATOMIC) {
8896                                                 atomic_type_kind_t const akind = type->atomic.akind;
8897                                                 flags = get_atomic_type_flags(akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
8898                                                 size  = get_atomic_type_size(akind);
8899                                         } else {
8900                                                 flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
8901                                                 size  = get_type_size(type_void_ptr);
8902                                         }
8903
8904                                         do {
8905                                                 expression_t *const value      = expression->unary.value;
8906                                                 type_t       *const value_type = value->base.type;
8907                                                 type_kind_t   const value_kind = value_type->kind;
8908
8909                                                 unsigned value_flags;
8910                                                 unsigned value_size;
8911                                                 if (value_kind == TYPE_ATOMIC) {
8912                                                         atomic_type_kind_t const value_akind = value_type->atomic.akind;
8913                                                         value_flags = get_atomic_type_flags(value_akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
8914                                                         value_size  = get_atomic_type_size(value_akind);
8915                                                 } else if (value_kind == TYPE_POINTER) {
8916                                                         value_flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
8917                                                         value_size  = get_type_size(type_void_ptr);
8918                                                 } else {
8919                                                         break;
8920                                                 }
8921
8922                                                 if (value_flags != flags || value_size != size)
8923                                                         break;
8924
8925                                                 expression = value;
8926                                         } while (expression->kind == EXPR_UNARY_CAST);
8927                                 }
8928                         }
8929
8930                         if (!is_lvalue(expression)) {
8931                                 errorf(&expression->base.source_position,
8932                                        "asm output argument is not an lvalue");
8933                         }
8934
8935                         if (argument->constraints.begin[0] == '=')
8936                                 determine_lhs_ent(expression, NULL);
8937                         else
8938                                 mark_vars_read(expression, NULL);
8939                 } else {
8940                         mark_vars_read(expression, NULL);
8941                 }
8942                 argument->expression = expression;
8943                 expect(')', end_error);
8944
8945                 set_address_taken(expression, true);
8946
8947                 *anchor = argument;
8948                 anchor  = &argument->next;
8949
8950                 if (!next_if(','))
8951                         break;
8952         }
8953
8954         return result;
8955 end_error:
8956         return NULL;
8957 }
8958
8959 /**
8960  * Parse a asm statement clobber specification.
8961  */
8962 static asm_clobber_t *parse_asm_clobbers(void)
8963 {
8964         asm_clobber_t *result  = NULL;
8965         asm_clobber_t **anchor = &result;
8966
8967         while (token.kind == T_STRING_LITERAL) {
8968                 asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
8969                 clobber->clobber       = parse_string_literals();
8970
8971                 *anchor = clobber;
8972                 anchor  = &clobber->next;
8973
8974                 if (!next_if(','))
8975                         break;
8976         }
8977
8978         return result;
8979 }
8980
8981 /**
8982  * Parse an asm statement.
8983  */
8984 static statement_t *parse_asm_statement(void)
8985 {
8986         statement_t     *statement     = allocate_statement_zero(STATEMENT_ASM);
8987         asm_statement_t *asm_statement = &statement->asms;
8988
8989         eat(T_asm);
8990
8991         if (next_if(T_volatile))
8992                 asm_statement->is_volatile = true;
8993
8994         expect('(', end_error);
8995         add_anchor_token(')');
8996         if (token.kind != T_STRING_LITERAL) {
8997                 parse_error_expected("after asm(", T_STRING_LITERAL, NULL);
8998                 goto end_of_asm;
8999         }
9000         asm_statement->asm_text = parse_string_literals();
9001
9002         add_anchor_token(':');
9003         if (!next_if(':')) {
9004                 rem_anchor_token(':');
9005                 goto end_of_asm;
9006         }
9007
9008         asm_statement->outputs = parse_asm_arguments(true);
9009         if (!next_if(':')) {
9010                 rem_anchor_token(':');
9011                 goto end_of_asm;
9012         }
9013
9014         asm_statement->inputs = parse_asm_arguments(false);
9015         if (!next_if(':')) {
9016                 rem_anchor_token(':');
9017                 goto end_of_asm;
9018         }
9019         rem_anchor_token(':');
9020
9021         asm_statement->clobbers = parse_asm_clobbers();
9022
9023 end_of_asm:
9024         rem_anchor_token(')');
9025         expect(')', end_error);
9026         expect(';', end_error);
9027
9028 end_error:
9029         if (asm_statement->outputs == NULL) {
9030                 /* GCC: An 'asm' instruction without any output operands will be treated
9031                  * identically to a volatile 'asm' instruction. */
9032                 asm_statement->is_volatile = true;
9033         }
9034
9035         return statement;
9036 }
9037
9038 static statement_t *parse_label_inner_statement(statement_t const *const label, char const *const label_kind)
9039 {
9040         statement_t *inner_stmt;
9041         switch (token.kind) {
9042                 case '}':
9043                         errorf(&label->base.source_position, "%s at end of compound statement", label_kind);
9044                         inner_stmt = create_error_statement();
9045                         break;
9046
9047                 case ';':
9048                         if (label->kind == STATEMENT_LABEL) {
9049                                 /* Eat an empty statement here, to avoid the warning about an empty
9050                                  * statement after a label.  label:; is commonly used to have a label
9051                                  * before a closing brace. */
9052                                 inner_stmt = create_empty_statement();
9053                                 next_token();
9054                                 break;
9055                         }
9056                         /* FALLTHROUGH */
9057
9058                 default:
9059                         inner_stmt = parse_statement();
9060                         /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
9061                         /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
9062                         if (inner_stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
9063                                 errorf(&inner_stmt->base.source_position, "declaration after %s", label_kind);
9064                         }
9065                         break;
9066         }
9067         return inner_stmt;
9068 }
9069
9070 /**
9071  * Parse a case statement.
9072  */
9073 static statement_t *parse_case_statement(void)
9074 {
9075         statement_t       *const statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9076         source_position_t *const pos       = &statement->base.source_position;
9077
9078         eat(T_case);
9079
9080         expression_t *expression = parse_expression();
9081         type_t *expression_type = expression->base.type;
9082         type_t *skipped         = skip_typeref(expression_type);
9083         if (!is_type_integer(skipped) && is_type_valid(skipped)) {
9084                 errorf(pos, "case expression '%E' must have integer type but has type '%T'",
9085                        expression, expression_type);
9086         }
9087
9088         type_t *type = expression_type;
9089         if (current_switch != NULL) {
9090                 type_t *switch_type = current_switch->expression->base.type;
9091                 if (is_type_valid(switch_type)) {
9092                         expression = create_implicit_cast(expression, switch_type);
9093                 }
9094         }
9095
9096         statement->case_label.expression = expression;
9097         expression_classification_t const expr_class = is_constant_expression(expression);
9098         if (expr_class != EXPR_CLASS_CONSTANT) {
9099                 if (expr_class != EXPR_CLASS_ERROR) {
9100                         errorf(pos, "case label does not reduce to an integer constant");
9101                 }
9102                 statement->case_label.is_bad = true;
9103         } else {
9104                 long const val = fold_constant_to_int(expression);
9105                 statement->case_label.first_case = val;
9106                 statement->case_label.last_case  = val;
9107         }
9108
9109         if (GNU_MODE) {
9110                 if (next_if(T_DOTDOTDOT)) {
9111                         expression_t *end_range = parse_expression();
9112                         expression_type = expression->base.type;
9113                         skipped         = skip_typeref(expression_type);
9114                         if (!is_type_integer(skipped) && is_type_valid(skipped)) {
9115                                 errorf(pos, "case expression '%E' must have integer type but has type '%T'",
9116                                            expression, expression_type);
9117                         }
9118
9119                         end_range = create_implicit_cast(end_range, type);
9120                         statement->case_label.end_range = end_range;
9121                         expression_classification_t const end_class = is_constant_expression(end_range);
9122                         if (end_class != EXPR_CLASS_CONSTANT) {
9123                                 if (end_class != EXPR_CLASS_ERROR) {
9124                                         errorf(pos, "case range does not reduce to an integer constant");
9125                                 }
9126                                 statement->case_label.is_bad = true;
9127                         } else {
9128                                 long const val = fold_constant_to_int(end_range);
9129                                 statement->case_label.last_case = val;
9130
9131                                 if (val < statement->case_label.first_case) {
9132                                         statement->case_label.is_empty_range = true;
9133                                         warningf(WARN_OTHER, pos, "empty range specified");
9134                                 }
9135                         }
9136                 }
9137         }
9138
9139         PUSH_PARENT(statement);
9140
9141         expect(':', end_error);
9142 end_error:
9143
9144         if (current_switch != NULL) {
9145                 if (! statement->case_label.is_bad) {
9146                         /* Check for duplicate case values */
9147                         case_label_statement_t *c = &statement->case_label;
9148                         for (case_label_statement_t *l = current_switch->first_case; l != NULL; l = l->next) {
9149                                 if (l->is_bad || l->is_empty_range || l->expression == NULL)
9150                                         continue;
9151
9152                                 if (c->last_case < l->first_case || c->first_case > l->last_case)
9153                                         continue;
9154
9155                                 errorf(pos, "duplicate case value (previously used %P)",
9156                                        &l->base.source_position);
9157                                 break;
9158                         }
9159                 }
9160                 /* link all cases into the switch statement */
9161                 if (current_switch->last_case == NULL) {
9162                         current_switch->first_case      = &statement->case_label;
9163                 } else {
9164                         current_switch->last_case->next = &statement->case_label;
9165                 }
9166                 current_switch->last_case = &statement->case_label;
9167         } else {
9168                 errorf(pos, "case label not within a switch statement");
9169         }
9170
9171         statement->case_label.statement = parse_label_inner_statement(statement, "case label");
9172
9173         POP_PARENT();
9174         return statement;
9175 }
9176
9177 /**
9178  * Parse a default statement.
9179  */
9180 static statement_t *parse_default_statement(void)
9181 {
9182         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9183
9184         eat(T_default);
9185
9186         PUSH_PARENT(statement);
9187
9188         expect(':', end_error);
9189 end_error:
9190
9191         if (current_switch != NULL) {
9192                 const case_label_statement_t *def_label = current_switch->default_label;
9193                 if (def_label != NULL) {
9194                         errorf(&statement->base.source_position, "multiple default labels in one switch (previous declared %P)", &def_label->base.source_position);
9195                 } else {
9196                         current_switch->default_label = &statement->case_label;
9197
9198                         /* link all cases into the switch statement */
9199                         if (current_switch->last_case == NULL) {
9200                                 current_switch->first_case      = &statement->case_label;
9201                         } else {
9202                                 current_switch->last_case->next = &statement->case_label;
9203                         }
9204                         current_switch->last_case = &statement->case_label;
9205                 }
9206         } else {
9207                 errorf(&statement->base.source_position,
9208                         "'default' label not within a switch statement");
9209         }
9210
9211         statement->case_label.statement = parse_label_inner_statement(statement, "default label");
9212
9213         POP_PARENT();
9214         return statement;
9215 }
9216
9217 /**
9218  * Parse a label statement.
9219  */
9220 static statement_t *parse_label_statement(void)
9221 {
9222         statement_t *const statement = allocate_statement_zero(STATEMENT_LABEL);
9223         label_t     *const label     = get_label();
9224         statement->label.label = label;
9225
9226         PUSH_PARENT(statement);
9227
9228         /* if statement is already set then the label is defined twice,
9229          * otherwise it was just mentioned in a goto/local label declaration so far
9230          */
9231         source_position_t const* const pos = &statement->base.source_position;
9232         if (label->statement != NULL) {
9233                 errorf(pos, "duplicate '%N' (declared %P)", (entity_t const*)label, &label->base.source_position);
9234         } else {
9235                 label->base.source_position = *pos;
9236                 label->statement            = statement;
9237         }
9238
9239         eat(':');
9240
9241         if (token.kind == T___attribute__ && !(c_mode & _CXX)) {
9242                 parse_attributes(NULL); // TODO process attributes
9243         }
9244
9245         statement->label.statement = parse_label_inner_statement(statement, "label");
9246
9247         /* remember the labels in a list for later checking */
9248         *label_anchor = &statement->label;
9249         label_anchor  = &statement->label.next;
9250
9251         POP_PARENT();
9252         return statement;
9253 }
9254
9255 static statement_t *parse_inner_statement(void)
9256 {
9257         statement_t *const stmt = parse_statement();
9258         /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
9259         /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
9260         if (stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
9261                 errorf(&stmt->base.source_position, "declaration as inner statement, use {}");
9262         }
9263         return stmt;
9264 }
9265
9266 /**
9267  * Parse an expression in parentheses and mark its variables as read.
9268  */
9269 static expression_t *parse_condition(void)
9270 {
9271         expect('(', end_error0);
9272         add_anchor_token(')');
9273         expression_t *const expr = parse_expression();
9274         mark_vars_read(expr, NULL);
9275         rem_anchor_token(')');
9276         expect(')', end_error1);
9277 end_error1:
9278         return expr;
9279 end_error0:
9280         return create_error_expression();
9281 }
9282
9283 /**
9284  * Parse an if statement.
9285  */
9286 static statement_t *parse_if(void)
9287 {
9288         statement_t *statement = allocate_statement_zero(STATEMENT_IF);
9289
9290         eat(T_if);
9291
9292         PUSH_PARENT(statement);
9293
9294         add_anchor_token('{');
9295
9296         expression_t *const expr = parse_condition();
9297         statement->ifs.condition = expr;
9298         /* §6.8.4.1:1  The controlling expression of an if statement shall have
9299          *             scalar type. */
9300         semantic_condition(expr, "condition of 'if'-statment");
9301
9302         rem_anchor_token('{');
9303
9304         add_anchor_token(T_else);
9305         statement_t *const true_stmt = parse_inner_statement();
9306         statement->ifs.true_statement = true_stmt;
9307         rem_anchor_token(T_else);
9308
9309         if (true_stmt->kind == STATEMENT_EMPTY) {
9310                 warningf(WARN_EMPTY_BODY, HERE,
9311                         "suggest braces around empty body in an ‘if’ statement");
9312         }
9313
9314         if (next_if(T_else)) {
9315                 statement->ifs.false_statement = parse_inner_statement();
9316
9317                 if (statement->ifs.false_statement->kind == STATEMENT_EMPTY) {
9318                         warningf(WARN_EMPTY_BODY, HERE,
9319                                         "suggest braces around empty body in an ‘if’ statement");
9320                 }
9321         } else if (true_stmt->kind == STATEMENT_IF &&
9322                         true_stmt->ifs.false_statement != NULL) {
9323                 source_position_t const *const pos = &true_stmt->base.source_position;
9324                 warningf(WARN_PARENTHESES, pos, "suggest explicit braces to avoid ambiguous 'else'");
9325         }
9326
9327         POP_PARENT();
9328         return statement;
9329 }
9330
9331 /**
9332  * Check that all enums are handled in a switch.
9333  *
9334  * @param statement  the switch statement to check
9335  */
9336 static void check_enum_cases(const switch_statement_t *statement)
9337 {
9338         if (!is_warn_on(WARN_SWITCH_ENUM))
9339                 return;
9340         const type_t *type = skip_typeref(statement->expression->base.type);
9341         if (! is_type_enum(type))
9342                 return;
9343         const enum_type_t *enumt = &type->enumt;
9344
9345         /* if we have a default, no warnings */
9346         if (statement->default_label != NULL)
9347                 return;
9348
9349         /* FIXME: calculation of value should be done while parsing */
9350         /* TODO: quadratic algorithm here. Change to an n log n one */
9351         long            last_value = -1;
9352         const entity_t *entry      = enumt->enume->base.next;
9353         for (; entry != NULL && entry->kind == ENTITY_ENUM_VALUE;
9354              entry = entry->base.next) {
9355                 const expression_t *expression = entry->enum_value.value;
9356                 long                value      = expression != NULL ? fold_constant_to_int(expression) : last_value + 1;
9357                 bool                found      = false;
9358                 for (const case_label_statement_t *l = statement->first_case; l != NULL; l = l->next) {
9359                         if (l->expression == NULL)
9360                                 continue;
9361                         if (l->first_case <= value && value <= l->last_case) {
9362                                 found = true;
9363                                 break;
9364                         }
9365                 }
9366                 if (!found) {
9367                         source_position_t const *const pos = &statement->base.source_position;
9368                         warningf(WARN_SWITCH_ENUM, pos, "'%N' not handled in switch", entry);
9369                 }
9370                 last_value = value;
9371         }
9372 }
9373
9374 /**
9375  * Parse a switch statement.
9376  */
9377 static statement_t *parse_switch(void)
9378 {
9379         statement_t *statement = allocate_statement_zero(STATEMENT_SWITCH);
9380
9381         eat(T_switch);
9382
9383         PUSH_PARENT(statement);
9384
9385         expression_t *const expr = parse_condition();
9386         type_t       *      type = skip_typeref(expr->base.type);
9387         if (is_type_integer(type)) {
9388                 type = promote_integer(type);
9389                 if (get_akind_rank(get_akind(type)) >= get_akind_rank(ATOMIC_TYPE_LONG)) {
9390                         warningf(WARN_TRADITIONAL, &expr->base.source_position, "'%T' switch expression not converted to '%T' in ISO C", type, type_int);
9391                 }
9392         } else if (is_type_valid(type)) {
9393                 errorf(&expr->base.source_position,
9394                        "switch quantity is not an integer, but '%T'", type);
9395                 type = type_error_type;
9396         }
9397         statement->switchs.expression = create_implicit_cast(expr, type);
9398
9399         switch_statement_t *rem = current_switch;
9400         current_switch          = &statement->switchs;
9401         statement->switchs.body = parse_inner_statement();
9402         current_switch          = rem;
9403
9404         if (statement->switchs.default_label == NULL) {
9405                 warningf(WARN_SWITCH_DEFAULT, &statement->base.source_position, "switch has no default case");
9406         }
9407         check_enum_cases(&statement->switchs);
9408
9409         POP_PARENT();
9410         return statement;
9411 }
9412
9413 static statement_t *parse_loop_body(statement_t *const loop)
9414 {
9415         statement_t *const rem = current_loop;
9416         current_loop = loop;
9417
9418         statement_t *const body = parse_inner_statement();
9419
9420         current_loop = rem;
9421         return body;
9422 }
9423
9424 /**
9425  * Parse a while statement.
9426  */
9427 static statement_t *parse_while(void)
9428 {
9429         statement_t *statement = allocate_statement_zero(STATEMENT_WHILE);
9430
9431         eat(T_while);
9432
9433         PUSH_PARENT(statement);
9434
9435         expression_t *const cond = parse_condition();
9436         statement->whiles.condition = cond;
9437         /* §6.8.5:2    The controlling expression of an iteration statement shall
9438          *             have scalar type. */
9439         semantic_condition(cond, "condition of 'while'-statement");
9440
9441         statement->whiles.body = parse_loop_body(statement);
9442
9443         POP_PARENT();
9444         return statement;
9445 }
9446
9447 /**
9448  * Parse a do statement.
9449  */
9450 static statement_t *parse_do(void)
9451 {
9452         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
9453
9454         eat(T_do);
9455
9456         PUSH_PARENT(statement);
9457
9458         add_anchor_token(T_while);
9459         statement->do_while.body = parse_loop_body(statement);
9460         rem_anchor_token(T_while);
9461
9462         expect(T_while, end_error0);
9463 end_error0:;
9464         expression_t *const cond = parse_condition();
9465         statement->do_while.condition = cond;
9466         /* §6.8.5:2    The controlling expression of an iteration statement shall
9467          *             have scalar type. */
9468         semantic_condition(cond, "condition of 'do-while'-statement");
9469         expect(';', end_error1);
9470 end_error1:
9471
9472         POP_PARENT();
9473         return statement;
9474 }
9475
9476 /**
9477  * Parse a for statement.
9478  */
9479 static statement_t *parse_for(void)
9480 {
9481         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
9482
9483         eat(T_for);
9484
9485         PUSH_PARENT(statement);
9486         PUSH_SCOPE(&statement->fors.scope);
9487
9488         expect('(', end_error1);
9489         add_anchor_token(')');
9490
9491         PUSH_EXTENSION();
9492
9493         if (next_if(';')) {
9494         } else if (is_declaration_specifier(&token)) {
9495                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9496         } else {
9497                 add_anchor_token(';');
9498                 expression_t *const init = parse_expression();
9499                 statement->fors.initialisation = init;
9500                 mark_vars_read(init, ENT_ANY);
9501                 if (!expression_has_effect(init)) {
9502                         warningf(WARN_UNUSED_VALUE, &init->base.source_position, "initialisation of 'for'-statement has no effect");
9503                 }
9504                 rem_anchor_token(';');
9505                 expect(';', end_error3);
9506 end_error3:;
9507         }
9508
9509         POP_EXTENSION();
9510
9511         if (token.kind != ';') {
9512                 add_anchor_token(';');
9513                 expression_t *const cond = parse_expression();
9514                 statement->fors.condition = cond;
9515                 /* §6.8.5:2    The controlling expression of an iteration statement
9516                  *             shall have scalar type. */
9517                 semantic_condition(cond, "condition of 'for'-statement");
9518                 mark_vars_read(cond, NULL);
9519                 rem_anchor_token(';');
9520         }
9521         expect(';', end_error2);
9522 end_error2:
9523         if (token.kind != ')') {
9524                 expression_t *const step = parse_expression();
9525                 statement->fors.step = step;
9526                 mark_vars_read(step, ENT_ANY);
9527                 if (!expression_has_effect(step)) {
9528                         warningf(WARN_UNUSED_VALUE, &step->base.source_position, "step of 'for'-statement has no effect");
9529                 }
9530         }
9531         rem_anchor_token(')');
9532         expect(')', end_error1);
9533 end_error1:
9534         statement->fors.body = parse_loop_body(statement);
9535
9536         POP_SCOPE();
9537         POP_PARENT();
9538         return statement;
9539 }
9540
9541 /**
9542  * Parse a goto statement.
9543  */
9544 static statement_t *parse_goto(void)
9545 {
9546         statement_t *statement;
9547         if (GNU_MODE && look_ahead(1)->kind == '*') {
9548                 statement = allocate_statement_zero(STATEMENT_COMPUTED_GOTO);
9549                 eat(T_goto);
9550                 eat('*');
9551
9552                 expression_t *expression = parse_expression();
9553                 mark_vars_read(expression, NULL);
9554
9555                 /* Argh: although documentation says the expression must be of type void*,
9556                  * gcc accepts anything that can be casted into void* without error */
9557                 type_t *type = expression->base.type;
9558
9559                 if (type != type_error_type) {
9560                         if (!is_type_pointer(type) && !is_type_integer(type)) {
9561                                 errorf(&expression->base.source_position,
9562                                         "cannot convert to a pointer type");
9563                         } else if (type != type_void_ptr) {
9564                                 warningf(WARN_OTHER, &expression->base.source_position, "type of computed goto expression should be 'void*' not '%T'", type);
9565                         }
9566                         expression = create_implicit_cast(expression, type_void_ptr);
9567                 }
9568
9569                 statement->computed_goto.expression = expression;
9570         } else {
9571                 statement = allocate_statement_zero(STATEMENT_GOTO);
9572                 eat(T_goto);
9573                 if (token.kind == T_IDENTIFIER) {
9574                         label_t *const label = get_label();
9575                         label->used            = true;
9576                         statement->gotos.label = label;
9577
9578                         /* remember the goto's in a list for later checking */
9579                         *goto_anchor = &statement->gotos;
9580                         goto_anchor  = &statement->gotos.next;
9581                 } else {
9582                         if (GNU_MODE)
9583                                 parse_error_expected("while parsing goto", T_IDENTIFIER, '*', NULL);
9584                         else
9585                                 parse_error_expected("while parsing goto", T_IDENTIFIER, NULL);
9586                         eat_until_anchor();
9587                         statement->gotos.label = &allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, sym_anonymous)->label;
9588                 }
9589         }
9590
9591         expect(';', end_error);
9592
9593 end_error:
9594         return statement;
9595 }
9596
9597 /**
9598  * Parse a continue statement.
9599  */
9600 static statement_t *parse_continue(void)
9601 {
9602         if (current_loop == NULL) {
9603                 errorf(HERE, "continue statement not within loop");
9604         }
9605
9606         statement_t *statement = allocate_statement_zero(STATEMENT_CONTINUE);
9607
9608         eat(T_continue);
9609         expect(';', end_error);
9610
9611 end_error:
9612         return statement;
9613 }
9614
9615 /**
9616  * Parse a break statement.
9617  */
9618 static statement_t *parse_break(void)
9619 {
9620         if (current_switch == NULL && current_loop == NULL) {
9621                 errorf(HERE, "break statement not within loop or switch");
9622         }
9623
9624         statement_t *statement = allocate_statement_zero(STATEMENT_BREAK);
9625
9626         eat(T_break);
9627         expect(';', end_error);
9628
9629 end_error:
9630         return statement;
9631 }
9632
9633 /**
9634  * Parse a __leave statement.
9635  */
9636 static statement_t *parse_leave_statement(void)
9637 {
9638         if (current_try == NULL) {
9639                 errorf(HERE, "__leave statement not within __try");
9640         }
9641
9642         statement_t *statement = allocate_statement_zero(STATEMENT_LEAVE);
9643
9644         eat(T___leave);
9645         expect(';', end_error);
9646
9647 end_error:
9648         return statement;
9649 }
9650
9651 /**
9652  * Check if a given entity represents a local variable.
9653  */
9654 static bool is_local_variable(const entity_t *entity)
9655 {
9656         if (entity->kind != ENTITY_VARIABLE)
9657                 return false;
9658
9659         switch ((storage_class_tag_t) entity->declaration.storage_class) {
9660         case STORAGE_CLASS_AUTO:
9661         case STORAGE_CLASS_REGISTER: {
9662                 const type_t *type = skip_typeref(entity->declaration.type);
9663                 if (is_type_function(type)) {
9664                         return false;
9665                 } else {
9666                         return true;
9667                 }
9668         }
9669         default:
9670                 return false;
9671         }
9672 }
9673
9674 /**
9675  * Check if a given expression represents a local variable.
9676  */
9677 static bool expression_is_local_variable(const expression_t *expression)
9678 {
9679         if (expression->base.kind != EXPR_REFERENCE) {
9680                 return false;
9681         }
9682         const entity_t *entity = expression->reference.entity;
9683         return is_local_variable(entity);
9684 }
9685
9686 /**
9687  * Check if a given expression represents a local variable and
9688  * return its declaration then, else return NULL.
9689  */
9690 entity_t *expression_is_variable(const expression_t *expression)
9691 {
9692         if (expression->base.kind != EXPR_REFERENCE) {
9693                 return NULL;
9694         }
9695         entity_t *entity = expression->reference.entity;
9696         if (entity->kind != ENTITY_VARIABLE)
9697                 return NULL;
9698
9699         return entity;
9700 }
9701
9702 static void err_or_warn(source_position_t const *const pos, char const *const msg)
9703 {
9704         if (c_mode & _CXX || strict_mode) {
9705                 errorf(pos, msg);
9706         } else {
9707                 warningf(WARN_OTHER, pos, msg);
9708         }
9709 }
9710
9711 /**
9712  * Parse a return statement.
9713  */
9714 static statement_t *parse_return(void)
9715 {
9716         statement_t *statement = allocate_statement_zero(STATEMENT_RETURN);
9717         eat(T_return);
9718
9719         expression_t *return_value = NULL;
9720         if (token.kind != ';') {
9721                 return_value = parse_expression();
9722                 mark_vars_read(return_value, NULL);
9723         }
9724
9725         const type_t *const func_type = skip_typeref(current_function->base.type);
9726         assert(is_type_function(func_type));
9727         type_t *const return_type = skip_typeref(func_type->function.return_type);
9728
9729         source_position_t const *const pos = &statement->base.source_position;
9730         if (return_value != NULL) {
9731                 type_t *return_value_type = skip_typeref(return_value->base.type);
9732
9733                 if (is_type_void(return_type)) {
9734                         if (!is_type_void(return_value_type)) {
9735                                 /* ISO/IEC 14882:1998(E) §6.6.3:2 */
9736                                 /* Only warn in C mode, because GCC does the same */
9737                                 err_or_warn(pos, "'return' with a value, in function returning 'void'");
9738                         } else if (!(c_mode & _CXX)) { /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9739                                 /* Only warn in C mode, because GCC does the same */
9740                                 err_or_warn(pos, "'return' with expression in function returning 'void'");
9741                         }
9742                 } else {
9743                         assign_error_t error = semantic_assign(return_type, return_value);
9744                         report_assign_error(error, return_type, return_value, "'return'",
9745                                             pos);
9746                 }
9747                 return_value = create_implicit_cast(return_value, return_type);
9748                 /* check for returning address of a local var */
9749                 if (return_value != NULL && return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
9750                         const expression_t *expression = return_value->unary.value;
9751                         if (expression_is_local_variable(expression)) {
9752                                 warningf(WARN_OTHER, pos, "function returns address of local variable");
9753                         }
9754                 }
9755         } else if (!is_type_void(return_type)) {
9756                 /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9757                 err_or_warn(pos, "'return' without value, in function returning non-void");
9758         }
9759         statement->returns.value = return_value;
9760
9761         expect(';', end_error);
9762
9763 end_error:
9764         return statement;
9765 }
9766
9767 /**
9768  * Parse a declaration statement.
9769  */
9770 static statement_t *parse_declaration_statement(void)
9771 {
9772         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9773
9774         entity_t *before = current_scope->last_entity;
9775         if (GNU_MODE) {
9776                 parse_external_declaration();
9777         } else {
9778                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9779         }
9780
9781         declaration_statement_t *const decl  = &statement->declaration;
9782         entity_t                *const begin =
9783                 before != NULL ? before->base.next : current_scope->entities;
9784         decl->declarations_begin = begin;
9785         decl->declarations_end   = begin != NULL ? current_scope->last_entity : NULL;
9786
9787         return statement;
9788 }
9789
9790 /**
9791  * Parse an expression statement, ie. expr ';'.
9792  */
9793 static statement_t *parse_expression_statement(void)
9794 {
9795         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
9796
9797         expression_t *const expr         = parse_expression();
9798         statement->expression.expression = expr;
9799         mark_vars_read(expr, ENT_ANY);
9800
9801         expect(';', end_error);
9802
9803 end_error:
9804         return statement;
9805 }
9806
9807 /**
9808  * Parse a microsoft __try { } __finally { } or
9809  * __try{ } __except() { }
9810  */
9811 static statement_t *parse_ms_try_statment(void)
9812 {
9813         statement_t *statement = allocate_statement_zero(STATEMENT_MS_TRY);
9814         eat(T___try);
9815
9816         PUSH_PARENT(statement);
9817
9818         ms_try_statement_t *rem = current_try;
9819         current_try = &statement->ms_try;
9820         statement->ms_try.try_statement = parse_compound_statement(false);
9821         current_try = rem;
9822
9823         POP_PARENT();
9824
9825         if (next_if(T___except)) {
9826                 expression_t *const expr = parse_condition();
9827                 type_t       *      type = skip_typeref(expr->base.type);
9828                 if (is_type_integer(type)) {
9829                         type = promote_integer(type);
9830                 } else if (is_type_valid(type)) {
9831                         errorf(&expr->base.source_position,
9832                                "__expect expression is not an integer, but '%T'", type);
9833                         type = type_error_type;
9834                 }
9835                 statement->ms_try.except_expression = create_implicit_cast(expr, type);
9836         } else if (!next_if(T__finally)) {
9837                 parse_error_expected("while parsing __try statement", T___except, T___finally, NULL);
9838         }
9839         statement->ms_try.final_statement = parse_compound_statement(false);
9840         return statement;
9841 }
9842
9843 static statement_t *parse_empty_statement(void)
9844 {
9845         warningf(WARN_EMPTY_STATEMENT, HERE, "statement is empty");
9846         statement_t *const statement = create_empty_statement();
9847         eat(';');
9848         return statement;
9849 }
9850
9851 static statement_t *parse_local_label_declaration(void)
9852 {
9853         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9854
9855         eat(T___label__);
9856
9857         entity_t *begin   = NULL;
9858         entity_t *end     = NULL;
9859         entity_t **anchor = &begin;
9860         do {
9861                 if (token.kind != T_IDENTIFIER) {
9862                         parse_error_expected("while parsing local label declaration",
9863                                 T_IDENTIFIER, NULL);
9864                         goto end_error;
9865                 }
9866                 symbol_t *symbol = token.identifier.symbol;
9867                 entity_t *entity = get_entity(symbol, NAMESPACE_LABEL);
9868                 if (entity != NULL && entity->base.parent_scope == current_scope) {
9869                         source_position_t const *const ppos = &entity->base.source_position;
9870                         errorf(HERE, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
9871                 } else {
9872                         entity = allocate_entity_zero(ENTITY_LOCAL_LABEL, NAMESPACE_LABEL, symbol);
9873                         entity->base.parent_scope    = current_scope;
9874                         entity->base.source_position = token.base.source_position;
9875
9876                         *anchor = entity;
9877                         anchor  = &entity->base.next;
9878                         end     = entity;
9879
9880                         environment_push(entity);
9881                 }
9882                 next_token();
9883         } while (next_if(','));
9884         expect(';', end_error);
9885 end_error:
9886         statement->declaration.declarations_begin = begin;
9887         statement->declaration.declarations_end   = end;
9888         return statement;
9889 }
9890
9891 static void parse_namespace_definition(void)
9892 {
9893         eat(T_namespace);
9894
9895         entity_t *entity = NULL;
9896         symbol_t *symbol = NULL;
9897
9898         if (token.kind == T_IDENTIFIER) {
9899                 symbol = token.identifier.symbol;
9900                 next_token();
9901
9902                 entity = get_entity(symbol, NAMESPACE_NORMAL);
9903                 if (entity != NULL
9904                                 && entity->kind != ENTITY_NAMESPACE
9905                                 && entity->base.parent_scope == current_scope) {
9906                         if (is_entity_valid(entity)) {
9907                                 error_redefined_as_different_kind(&token.base.source_position,
9908                                                 entity, ENTITY_NAMESPACE);
9909                         }
9910                         entity = NULL;
9911                 }
9912         }
9913
9914         if (entity == NULL) {
9915                 entity = allocate_entity_zero(ENTITY_NAMESPACE, NAMESPACE_NORMAL, symbol);
9916                 entity->base.source_position = token.base.source_position;
9917                 entity->base.parent_scope    = current_scope;
9918         }
9919
9920         if (token.kind == '=') {
9921                 /* TODO: parse namespace alias */
9922                 panic("namespace alias definition not supported yet");
9923         }
9924
9925         environment_push(entity);
9926         append_entity(current_scope, entity);
9927
9928         PUSH_SCOPE(&entity->namespacee.members);
9929
9930         entity_t     *old_current_entity = current_entity;
9931         current_entity = entity;
9932
9933         expect('{', end_error);
9934         parse_externals();
9935         expect('}', end_error);
9936
9937 end_error:
9938         assert(current_entity == entity);
9939         current_entity = old_current_entity;
9940         POP_SCOPE();
9941 }
9942
9943 /**
9944  * Parse a statement.
9945  * There's also parse_statement() which additionally checks for
9946  * "statement has no effect" warnings
9947  */
9948 static statement_t *intern_parse_statement(void)
9949 {
9950         /* declaration or statement */
9951         statement_t *statement;
9952         switch (token.kind) {
9953         case T_IDENTIFIER: {
9954                 token_kind_t la1_type = (token_kind_t)look_ahead(1)->kind;
9955                 if (la1_type == ':') {
9956                         statement = parse_label_statement();
9957                 } else if (is_typedef_symbol(token.identifier.symbol)) {
9958                         statement = parse_declaration_statement();
9959                 } else {
9960                         /* it's an identifier, the grammar says this must be an
9961                          * expression statement. However it is common that users mistype
9962                          * declaration types, so we guess a bit here to improve robustness
9963                          * for incorrect programs */
9964                         switch (la1_type) {
9965                         case '&':
9966                         case '*':
9967                                 if (get_entity(token.identifier.symbol, NAMESPACE_NORMAL) != NULL) {
9968                         default:
9969                                         statement = parse_expression_statement();
9970                                 } else {
9971                         DECLARATION_START
9972                         case T_IDENTIFIER:
9973                                         statement = parse_declaration_statement();
9974                                 }
9975                                 break;
9976                         }
9977                 }
9978                 break;
9979         }
9980
9981         case T___extension__: {
9982                 /* This can be a prefix to a declaration or an expression statement.
9983                  * We simply eat it now and parse the rest with tail recursion. */
9984                 PUSH_EXTENSION();
9985                 statement = intern_parse_statement();
9986                 POP_EXTENSION();
9987                 break;
9988         }
9989
9990         DECLARATION_START
9991                 statement = parse_declaration_statement();
9992                 break;
9993
9994         case T___label__:
9995                 statement = parse_local_label_declaration();
9996                 break;
9997
9998         case ';':         statement = parse_empty_statement();         break;
9999         case '{':         statement = parse_compound_statement(false); break;
10000         case T___leave:   statement = parse_leave_statement();         break;
10001         case T___try:     statement = parse_ms_try_statment();         break;
10002         case T_asm:       statement = parse_asm_statement();           break;
10003         case T_break:     statement = parse_break();                   break;
10004         case T_case:      statement = parse_case_statement();          break;
10005         case T_continue:  statement = parse_continue();                break;
10006         case T_default:   statement = parse_default_statement();       break;
10007         case T_do:        statement = parse_do();                      break;
10008         case T_for:       statement = parse_for();                     break;
10009         case T_goto:      statement = parse_goto();                    break;
10010         case T_if:        statement = parse_if();                      break;
10011         case T_return:    statement = parse_return();                  break;
10012         case T_switch:    statement = parse_switch();                  break;
10013         case T_while:     statement = parse_while();                   break;
10014
10015         EXPRESSION_START
10016                 statement = parse_expression_statement();
10017                 break;
10018
10019         default:
10020                 errorf(HERE, "unexpected token %K while parsing statement", &token);
10021                 statement = create_error_statement();
10022                 eat_until_anchor();
10023                 break;
10024         }
10025
10026         return statement;
10027 }
10028
10029 /**
10030  * parse a statement and emits "statement has no effect" warning if needed
10031  * (This is really a wrapper around intern_parse_statement with check for 1
10032  *  single warning. It is needed, because for statement expressions we have
10033  *  to avoid the warning on the last statement)
10034  */
10035 static statement_t *parse_statement(void)
10036 {
10037         statement_t *statement = intern_parse_statement();
10038
10039         if (statement->kind == STATEMENT_EXPRESSION) {
10040                 expression_t *expression = statement->expression.expression;
10041                 if (!expression_has_effect(expression)) {
10042                         warningf(WARN_UNUSED_VALUE, &expression->base.source_position, "statement has no effect");
10043                 }
10044         }
10045
10046         return statement;
10047 }
10048
10049 /**
10050  * Parse a compound statement.
10051  */
10052 static statement_t *parse_compound_statement(bool inside_expression_statement)
10053 {
10054         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
10055
10056         PUSH_PARENT(statement);
10057         PUSH_SCOPE(&statement->compound.scope);
10058
10059         eat('{');
10060         add_anchor_token('}');
10061         /* tokens, which can start a statement */
10062         /* TODO MS, __builtin_FOO */
10063         add_anchor_token('!');
10064         add_anchor_token('&');
10065         add_anchor_token('(');
10066         add_anchor_token('*');
10067         add_anchor_token('+');
10068         add_anchor_token('-');
10069         add_anchor_token(';');
10070         add_anchor_token('{');
10071         add_anchor_token('~');
10072         add_anchor_token(T_CHARACTER_CONSTANT);
10073         add_anchor_token(T_COLONCOLON);
10074         add_anchor_token(T_FLOATINGPOINT);
10075         add_anchor_token(T_IDENTIFIER);
10076         add_anchor_token(T_INTEGER);
10077         add_anchor_token(T_MINUSMINUS);
10078         add_anchor_token(T_PLUSPLUS);
10079         add_anchor_token(T_STRING_LITERAL);
10080         add_anchor_token(T_WIDE_CHARACTER_CONSTANT);
10081         add_anchor_token(T_WIDE_STRING_LITERAL);
10082         add_anchor_token(T__Bool);
10083         add_anchor_token(T__Complex);
10084         add_anchor_token(T__Imaginary);
10085         add_anchor_token(T___FUNCTION__);
10086         add_anchor_token(T___PRETTY_FUNCTION__);
10087         add_anchor_token(T___alignof__);
10088         add_anchor_token(T___attribute__);
10089         add_anchor_token(T___builtin_va_start);
10090         add_anchor_token(T___extension__);
10091         add_anchor_token(T___func__);
10092         add_anchor_token(T___imag__);
10093         add_anchor_token(T___label__);
10094         add_anchor_token(T___real__);
10095         add_anchor_token(T___thread);
10096         add_anchor_token(T_asm);
10097         add_anchor_token(T_auto);
10098         add_anchor_token(T_bool);
10099         add_anchor_token(T_break);
10100         add_anchor_token(T_case);
10101         add_anchor_token(T_char);
10102         add_anchor_token(T_class);
10103         add_anchor_token(T_const);
10104         add_anchor_token(T_const_cast);
10105         add_anchor_token(T_continue);
10106         add_anchor_token(T_default);
10107         add_anchor_token(T_delete);
10108         add_anchor_token(T_double);
10109         add_anchor_token(T_do);
10110         add_anchor_token(T_dynamic_cast);
10111         add_anchor_token(T_enum);
10112         add_anchor_token(T_extern);
10113         add_anchor_token(T_false);
10114         add_anchor_token(T_float);
10115         add_anchor_token(T_for);
10116         add_anchor_token(T_goto);
10117         add_anchor_token(T_if);
10118         add_anchor_token(T_inline);
10119         add_anchor_token(T_int);
10120         add_anchor_token(T_long);
10121         add_anchor_token(T_new);
10122         add_anchor_token(T_operator);
10123         add_anchor_token(T_register);
10124         add_anchor_token(T_reinterpret_cast);
10125         add_anchor_token(T_restrict);
10126         add_anchor_token(T_return);
10127         add_anchor_token(T_short);
10128         add_anchor_token(T_signed);
10129         add_anchor_token(T_sizeof);
10130         add_anchor_token(T_static);
10131         add_anchor_token(T_static_cast);
10132         add_anchor_token(T_struct);
10133         add_anchor_token(T_switch);
10134         add_anchor_token(T_template);
10135         add_anchor_token(T_this);
10136         add_anchor_token(T_throw);
10137         add_anchor_token(T_true);
10138         add_anchor_token(T_try);
10139         add_anchor_token(T_typedef);
10140         add_anchor_token(T_typeid);
10141         add_anchor_token(T_typename);
10142         add_anchor_token(T_typeof);
10143         add_anchor_token(T_union);
10144         add_anchor_token(T_unsigned);
10145         add_anchor_token(T_using);
10146         add_anchor_token(T_void);
10147         add_anchor_token(T_volatile);
10148         add_anchor_token(T_wchar_t);
10149         add_anchor_token(T_while);
10150
10151         statement_t **anchor            = &statement->compound.statements;
10152         bool          only_decls_so_far = true;
10153         while (token.kind != '}' && token.kind != T_EOF) {
10154                 statement_t *sub_statement = intern_parse_statement();
10155                 if (sub_statement->kind == STATEMENT_ERROR) {
10156                         break;
10157                 }
10158
10159                 if (sub_statement->kind != STATEMENT_DECLARATION) {
10160                         only_decls_so_far = false;
10161                 } else if (!only_decls_so_far) {
10162                         source_position_t const *const pos = &sub_statement->base.source_position;
10163                         warningf(WARN_DECLARATION_AFTER_STATEMENT, pos, "ISO C90 forbids mixed declarations and code");
10164                 }
10165
10166                 *anchor = sub_statement;
10167                 anchor  = &sub_statement->base.next;
10168         }
10169         expect('}', end_error);
10170 end_error:
10171
10172         /* look over all statements again to produce no effect warnings */
10173         if (is_warn_on(WARN_UNUSED_VALUE)) {
10174                 statement_t *sub_statement = statement->compound.statements;
10175                 for (; sub_statement != NULL; sub_statement = sub_statement->base.next) {
10176                         if (sub_statement->kind != STATEMENT_EXPRESSION)
10177                                 continue;
10178                         /* don't emit a warning for the last expression in an expression
10179                          * statement as it has always an effect */
10180                         if (inside_expression_statement && sub_statement->base.next == NULL)
10181                                 continue;
10182
10183                         expression_t *expression = sub_statement->expression.expression;
10184                         if (!expression_has_effect(expression)) {
10185                                 warningf(WARN_UNUSED_VALUE, &expression->base.source_position, "statement has no effect");
10186                         }
10187                 }
10188         }
10189
10190         rem_anchor_token(T_while);
10191         rem_anchor_token(T_wchar_t);
10192         rem_anchor_token(T_volatile);
10193         rem_anchor_token(T_void);
10194         rem_anchor_token(T_using);
10195         rem_anchor_token(T_unsigned);
10196         rem_anchor_token(T_union);
10197         rem_anchor_token(T_typeof);
10198         rem_anchor_token(T_typename);
10199         rem_anchor_token(T_typeid);
10200         rem_anchor_token(T_typedef);
10201         rem_anchor_token(T_try);
10202         rem_anchor_token(T_true);
10203         rem_anchor_token(T_throw);
10204         rem_anchor_token(T_this);
10205         rem_anchor_token(T_template);
10206         rem_anchor_token(T_switch);
10207         rem_anchor_token(T_struct);
10208         rem_anchor_token(T_static_cast);
10209         rem_anchor_token(T_static);
10210         rem_anchor_token(T_sizeof);
10211         rem_anchor_token(T_signed);
10212         rem_anchor_token(T_short);
10213         rem_anchor_token(T_return);
10214         rem_anchor_token(T_restrict);
10215         rem_anchor_token(T_reinterpret_cast);
10216         rem_anchor_token(T_register);
10217         rem_anchor_token(T_operator);
10218         rem_anchor_token(T_new);
10219         rem_anchor_token(T_long);
10220         rem_anchor_token(T_int);
10221         rem_anchor_token(T_inline);
10222         rem_anchor_token(T_if);
10223         rem_anchor_token(T_goto);
10224         rem_anchor_token(T_for);
10225         rem_anchor_token(T_float);
10226         rem_anchor_token(T_false);
10227         rem_anchor_token(T_extern);
10228         rem_anchor_token(T_enum);
10229         rem_anchor_token(T_dynamic_cast);
10230         rem_anchor_token(T_do);
10231         rem_anchor_token(T_double);
10232         rem_anchor_token(T_delete);
10233         rem_anchor_token(T_default);
10234         rem_anchor_token(T_continue);
10235         rem_anchor_token(T_const_cast);
10236         rem_anchor_token(T_const);
10237         rem_anchor_token(T_class);
10238         rem_anchor_token(T_char);
10239         rem_anchor_token(T_case);
10240         rem_anchor_token(T_break);
10241         rem_anchor_token(T_bool);
10242         rem_anchor_token(T_auto);
10243         rem_anchor_token(T_asm);
10244         rem_anchor_token(T___thread);
10245         rem_anchor_token(T___real__);
10246         rem_anchor_token(T___label__);
10247         rem_anchor_token(T___imag__);
10248         rem_anchor_token(T___func__);
10249         rem_anchor_token(T___extension__);
10250         rem_anchor_token(T___builtin_va_start);
10251         rem_anchor_token(T___attribute__);
10252         rem_anchor_token(T___alignof__);
10253         rem_anchor_token(T___PRETTY_FUNCTION__);
10254         rem_anchor_token(T___FUNCTION__);
10255         rem_anchor_token(T__Imaginary);
10256         rem_anchor_token(T__Complex);
10257         rem_anchor_token(T__Bool);
10258         rem_anchor_token(T_WIDE_STRING_LITERAL);
10259         rem_anchor_token(T_WIDE_CHARACTER_CONSTANT);
10260         rem_anchor_token(T_STRING_LITERAL);
10261         rem_anchor_token(T_PLUSPLUS);
10262         rem_anchor_token(T_MINUSMINUS);
10263         rem_anchor_token(T_INTEGER);
10264         rem_anchor_token(T_IDENTIFIER);
10265         rem_anchor_token(T_FLOATINGPOINT);
10266         rem_anchor_token(T_COLONCOLON);
10267         rem_anchor_token(T_CHARACTER_CONSTANT);
10268         rem_anchor_token('~');
10269         rem_anchor_token('{');
10270         rem_anchor_token(';');
10271         rem_anchor_token('-');
10272         rem_anchor_token('+');
10273         rem_anchor_token('*');
10274         rem_anchor_token('(');
10275         rem_anchor_token('&');
10276         rem_anchor_token('!');
10277         rem_anchor_token('}');
10278
10279         POP_SCOPE();
10280         POP_PARENT();
10281         return statement;
10282 }
10283
10284 /**
10285  * Check for unused global static functions and variables
10286  */
10287 static void check_unused_globals(void)
10288 {
10289         if (!is_warn_on(WARN_UNUSED_FUNCTION) && !is_warn_on(WARN_UNUSED_VARIABLE))
10290                 return;
10291
10292         for (const entity_t *entity = file_scope->entities; entity != NULL;
10293              entity = entity->base.next) {
10294                 if (!is_declaration(entity))
10295                         continue;
10296
10297                 const declaration_t *declaration = &entity->declaration;
10298                 if (declaration->used                  ||
10299                     declaration->modifiers & DM_UNUSED ||
10300                     declaration->modifiers & DM_USED   ||
10301                     declaration->storage_class != STORAGE_CLASS_STATIC)
10302                         continue;
10303
10304                 warning_t   why;
10305                 char const *s;
10306                 if (entity->kind == ENTITY_FUNCTION) {
10307                         /* inhibit warning for static inline functions */
10308                         if (entity->function.is_inline)
10309                                 continue;
10310
10311                         why = WARN_UNUSED_FUNCTION;
10312                         s   = entity->function.statement != NULL ? "defined" : "declared";
10313                 } else {
10314                         why = WARN_UNUSED_VARIABLE;
10315                         s   = "defined";
10316                 }
10317
10318                 warningf(why, &declaration->base.source_position, "'%#N' %s but not used", entity, s);
10319         }
10320 }
10321
10322 static void parse_global_asm(void)
10323 {
10324         statement_t *statement = allocate_statement_zero(STATEMENT_ASM);
10325
10326         eat(T_asm);
10327         expect('(', end_error);
10328
10329         statement->asms.asm_text = parse_string_literals();
10330         statement->base.next     = unit->global_asm;
10331         unit->global_asm         = statement;
10332
10333         expect(')', end_error);
10334         expect(';', end_error);
10335
10336 end_error:;
10337 }
10338
10339 static void parse_linkage_specification(void)
10340 {
10341         eat(T_extern);
10342
10343         source_position_t const pos     = *HERE;
10344         char const       *const linkage = parse_string_literals().begin;
10345
10346         linkage_kind_t old_linkage = current_linkage;
10347         linkage_kind_t new_linkage;
10348         if (streq(linkage, "C")) {
10349                 new_linkage = LINKAGE_C;
10350         } else if (streq(linkage, "C++")) {
10351                 new_linkage = LINKAGE_CXX;
10352         } else {
10353                 errorf(&pos, "linkage string \"%s\" not recognized", linkage);
10354                 new_linkage = LINKAGE_C;
10355         }
10356         current_linkage = new_linkage;
10357
10358         if (next_if('{')) {
10359                 parse_externals();
10360                 expect('}', end_error);
10361         } else {
10362                 parse_external();
10363         }
10364
10365 end_error:
10366         assert(current_linkage == new_linkage);
10367         current_linkage = old_linkage;
10368 }
10369
10370 static void parse_external(void)
10371 {
10372         switch (token.kind) {
10373                 case T_extern:
10374                         if (look_ahead(1)->kind == T_STRING_LITERAL) {
10375                                 parse_linkage_specification();
10376                         } else {
10377                 DECLARATION_START_NO_EXTERN
10378                 case T_IDENTIFIER:
10379                 case T___extension__:
10380                 /* tokens below are for implicit int */
10381                 case '&':  /* & x; -> int& x; (and error later, because C++ has no
10382                               implicit int) */
10383                 case '*':  /* * x; -> int* x; */
10384                 case '(':  /* (x); -> int (x); */
10385                                 PUSH_EXTENSION();
10386                                 parse_external_declaration();
10387                                 POP_EXTENSION();
10388                         }
10389                         return;
10390
10391                 case T_asm:
10392                         parse_global_asm();
10393                         return;
10394
10395                 case T_namespace:
10396                         parse_namespace_definition();
10397                         return;
10398
10399                 case ';':
10400                         if (!strict_mode) {
10401                                 warningf(WARN_STRAY_SEMICOLON, HERE, "stray ';' outside of function");
10402                                 next_token();
10403                                 return;
10404                         }
10405                         /* FALLTHROUGH */
10406
10407                 default:
10408                         errorf(HERE, "stray %K outside of function", &token);
10409                         if (token.kind == '(' || token.kind == '{' || token.kind == '[')
10410                                 eat_until_matching_token(token.kind);
10411                         next_token();
10412                         return;
10413         }
10414 }
10415
10416 static void parse_externals(void)
10417 {
10418         add_anchor_token('}');
10419         add_anchor_token(T_EOF);
10420
10421 #ifndef NDEBUG
10422         /* make a copy of the anchor set, so we can check if it is restored after parsing */
10423         unsigned short token_anchor_copy[T_LAST_TOKEN];
10424         memcpy(token_anchor_copy, token_anchor_set, sizeof(token_anchor_copy));
10425 #endif
10426
10427         while (token.kind != T_EOF && token.kind != '}') {
10428 #ifndef NDEBUG
10429                 for (int i = 0; i < T_LAST_TOKEN; ++i) {
10430                         unsigned short count = token_anchor_set[i] - token_anchor_copy[i];
10431                         if (count != 0) {
10432                                 /* the anchor set and its copy differs */
10433                                 internal_errorf(HERE, "Leaked anchor token %k %d times", i, count);
10434                         }
10435                 }
10436                 if (in_gcc_extension) {
10437                         /* an gcc extension scope was not closed */
10438                         internal_errorf(HERE, "Leaked __extension__");
10439                 }
10440 #endif
10441
10442                 parse_external();
10443         }
10444
10445         rem_anchor_token(T_EOF);
10446         rem_anchor_token('}');
10447 }
10448
10449 /**
10450  * Parse a translation unit.
10451  */
10452 static void parse_translation_unit(void)
10453 {
10454         add_anchor_token(T_EOF);
10455
10456         while (true) {
10457                 parse_externals();
10458
10459                 if (token.kind == T_EOF)
10460                         break;
10461
10462                 errorf(HERE, "stray %K outside of function", &token);
10463                 if (token.kind == '(' || token.kind == '{' || token.kind == '[')
10464                         eat_until_matching_token(token.kind);
10465                 next_token();
10466         }
10467 }
10468
10469 void set_default_visibility(elf_visibility_tag_t visibility)
10470 {
10471         default_visibility = visibility;
10472 }
10473
10474 /**
10475  * Parse the input.
10476  *
10477  * @return  the translation unit or NULL if errors occurred.
10478  */
10479 void start_parsing(void)
10480 {
10481         environment_stack = NEW_ARR_F(stack_entry_t, 0);
10482         label_stack       = NEW_ARR_F(stack_entry_t, 0);
10483         diagnostic_count  = 0;
10484         error_count       = 0;
10485         warning_count     = 0;
10486
10487         print_to_file(stderr);
10488
10489         assert(unit == NULL);
10490         unit = allocate_ast_zero(sizeof(unit[0]));
10491
10492         assert(file_scope == NULL);
10493         file_scope = &unit->scope;
10494
10495         assert(current_scope == NULL);
10496         scope_push(&unit->scope);
10497
10498         create_gnu_builtins();
10499         if (c_mode & _MS)
10500                 create_microsoft_intrinsics();
10501 }
10502
10503 translation_unit_t *finish_parsing(void)
10504 {
10505         assert(current_scope == &unit->scope);
10506         scope_pop(NULL);
10507
10508         assert(file_scope == &unit->scope);
10509         check_unused_globals();
10510         file_scope = NULL;
10511
10512         DEL_ARR_F(environment_stack);
10513         DEL_ARR_F(label_stack);
10514
10515         translation_unit_t *result = unit;
10516         unit = NULL;
10517         return result;
10518 }
10519
10520 /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
10521  * are given length one. */
10522 static void complete_incomplete_arrays(void)
10523 {
10524         size_t n = ARR_LEN(incomplete_arrays);
10525         for (size_t i = 0; i != n; ++i) {
10526                 declaration_t *const decl = incomplete_arrays[i];
10527                 type_t        *const type = skip_typeref(decl->type);
10528
10529                 if (!is_type_incomplete(type))
10530                         continue;
10531
10532                 source_position_t const *const pos = &decl->base.source_position;
10533                 warningf(WARN_OTHER, pos, "array '%#N' assumed to have one element", (entity_t const*)decl);
10534
10535                 type_t *const new_type = duplicate_type(type);
10536                 new_type->array.size_constant     = true;
10537                 new_type->array.has_implicit_size = true;
10538                 new_type->array.size              = 1;
10539
10540                 type_t *const result = identify_new_type(new_type);
10541
10542                 decl->type = result;
10543         }
10544 }
10545
10546 void prepare_main_collect2(entity_t *entity)
10547 {
10548         PUSH_SCOPE(&entity->function.statement->compound.scope);
10549
10550         // create call to __main
10551         symbol_t *symbol         = symbol_table_insert("__main");
10552         entity_t *subsubmain_ent
10553                 = create_implicit_function(symbol, &builtin_source_position);
10554
10555         expression_t *ref         = allocate_expression_zero(EXPR_REFERENCE);
10556         type_t       *ftype       = subsubmain_ent->declaration.type;
10557         ref->base.source_position = builtin_source_position;
10558         ref->base.type            = make_pointer_type(ftype, TYPE_QUALIFIER_NONE);
10559         ref->reference.entity     = subsubmain_ent;
10560
10561         expression_t *call = allocate_expression_zero(EXPR_CALL);
10562         call->base.source_position = builtin_source_position;
10563         call->base.type            = type_void;
10564         call->call.function        = ref;
10565
10566         statement_t *expr_statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10567         expr_statement->base.source_position  = builtin_source_position;
10568         expr_statement->expression.expression = call;
10569
10570         statement_t *statement = entity->function.statement;
10571         assert(statement->kind == STATEMENT_COMPOUND);
10572         compound_statement_t *compounds = &statement->compound;
10573
10574         expr_statement->base.next = compounds->statements;
10575         compounds->statements     = expr_statement;
10576
10577         POP_SCOPE();
10578 }
10579
10580 void parse(void)
10581 {
10582         lookahead_bufpos = 0;
10583         for (int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
10584                 next_token();
10585         }
10586         current_linkage   = c_mode & _CXX ? LINKAGE_CXX : LINKAGE_C;
10587         incomplete_arrays = NEW_ARR_F(declaration_t*, 0);
10588         parse_translation_unit();
10589         complete_incomplete_arrays();
10590         DEL_ARR_F(incomplete_arrays);
10591         incomplete_arrays = NULL;
10592 }
10593
10594 /**
10595  * Initialize the parser.
10596  */
10597 void init_parser(void)
10598 {
10599         sym_anonymous = symbol_table_insert("<anonymous>");
10600
10601         memset(token_anchor_set, 0, sizeof(token_anchor_set));
10602
10603         init_expression_parsers();
10604         obstack_init(&temp_obst);
10605 }
10606
10607 /**
10608  * Terminate the parser.
10609  */
10610 void exit_parser(void)
10611 {
10612         obstack_free(&temp_obst, NULL);
10613 }