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