nsz Git - cparser/blob - parser.c

   1 /*
   2  * This file is part of cparser.
   3  * Copyright (C) 2007-2008 Matthias Braun <matze@braunis.de>
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; either version 2
   8  * of the License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  18  * 02111-1307, USA.
  19  */
  20 #include <config.h>
  21
  22 #include <assert.h>
  23 #include <stdarg.h>
  24 #include <stdbool.h>
  25
  26 #include "parser.h"
  27 #include "diagnostic.h"
  28 #include "format_check.h"
  29 #include "lexer.h"
  30 #include "symbol_t.h"
  31 #include "token_t.h"
  32 #include "types.h"
  33 #include "type_t.h"
  34 #include "type_hash.h"
  35 #include "ast_t.h"
  36 #include "entity_t.h"
  37 #include "lang_features.h"
  38 #include "walk_statements.h"
  39 #include "warning.h"
  40 #include "adt/bitfiddle.h"
  41 #include "adt/error.h"
  42 #include "adt/array.h"
  43
  44 //#define PRINT_TOKENS
  45 #define MAX_LOOKAHEAD 2
  46
  47 typedef struct {
  48         entity_t           *old_entity;
  49         symbol_t           *symbol;
  50         entity_namespace_t  namespc;
  51 } stack_entry_t;
  52
  53 typedef struct argument_list_t argument_list_t;
  54 struct argument_list_t {
  55         long              argument;
  56         argument_list_t  *next;
  57 };
  58
  59 typedef struct gnu_attribute_t gnu_attribute_t;
  60 struct gnu_attribute_t {
  61         gnu_attribute_kind_t kind;           /**< The kind of the GNU attribute. */
  62         gnu_attribute_t     *next;
  63         bool                 invalid;        /**< Set if this attribute had argument errors, */
  64         bool                 have_arguments; /**< True, if this attribute has arguments. */
  65         union {
  66                 size_t              value;
  67                 string_t            string;
  68                 atomic_type_kind_t  akind;
  69                 long                argument;  /**< Single argument. */
  70                 argument_list_t    *arguments; /**< List of argument expressions. */
  71         } u;
  72 };
  73
  74 typedef struct declaration_specifiers_t  declaration_specifiers_t;
  75 struct declaration_specifiers_t {
  76         source_position_t  source_position;
  77         storage_class_t    storage_class;
  78         unsigned char      alignment;         /**< Alignment, 0 if not set. */
  79         bool               is_inline : 1;
  80         bool               deprecated : 1;
  81         decl_modifiers_t   modifiers;         /**< declaration modifiers */
  82         gnu_attribute_t   *gnu_attributes;    /**< list of GNU attributes */
  83         const char        *deprecated_string; /**< can be set if declaration was marked deprecated. */
  84         symbol_t          *get_property_sym;  /**< the name of the get property if set. */
  85         symbol_t          *put_property_sym;  /**< the name of the put property if set. */
  86         type_t            *type;
  87         variable_t        *based_variable;    /**< Microsoft __based variable. */
  88 };
  89
  90 /**
  91  * An environment for parsing initializers (and compound literals).
  92  */
  93 typedef struct parse_initializer_env_t {
  94         type_t     *type;   /**< the type of the initializer. In case of an
  95                                  array type with unspecified size this gets
  96                                  adjusted to the actual size. */
  97         entity_t   *entity; /**< the variable that is initialized if any */
  98         bool        must_be_constant;
  99 } parse_initializer_env_t;
 100
 101 typedef entity_t* (*parsed_declaration_func) (entity_t *declaration, bool is_definition);
 102
 103 /** The current token. */
 104 static token_t              token;
 105 /** The lookahead ring-buffer. */
 106 static token_t              lookahead_buffer[MAX_LOOKAHEAD];
 107 /** Position of the next token in the lookahead buffer. */
 108 static int                  lookahead_bufpos;
 109 static stack_entry_t       *environment_stack = NULL;
 110 static stack_entry_t       *label_stack       = NULL;
 111 static scope_t             *file_scope        = NULL;
 112 static scope_t             *current_scope     = NULL;
 113 /** Point to the current function declaration if inside a function. */
 114 static function_t          *current_function  = NULL;
 115 static entity_t            *current_init_decl = NULL;
 116 static switch_statement_t  *current_switch    = NULL;
 117 static statement_t         *current_loop      = NULL;
 118 static statement_t         *current_parent    = NULL;
 119 static ms_try_statement_t  *current_try       = NULL;
 120 static linkage_kind_t       current_linkage   = LINKAGE_INVALID;
 121 static goto_statement_t    *goto_first        = NULL;
 122 static goto_statement_t   **goto_anchor       = NULL;
 123 static label_statement_t   *label_first       = NULL;
 124 static label_statement_t  **label_anchor      = NULL;
 125 /** current translation unit. */
 126 static translation_unit_t  *unit              = NULL;
 127 /** true if we are in a type property context (evaluation only for type. */
 128 static bool                 in_type_prop      = false;
 129 /** true in we are in a __extension__ context. */
 130 static bool                 in_gcc_extension  = false;
 131 static struct obstack       temp_obst;
 132
 133
 134 #define PUSH_PARENT(stmt)                          \
 135         statement_t *const prev_parent = current_parent; \
 136         ((void)(current_parent = (stmt)))
 137 #define POP_PARENT ((void)(current_parent = prev_parent))
 138
 139 /** special symbol used for anonymous entities. */
 140 static const symbol_t *sym_anonymous = NULL;
 141
 142 /* symbols for Microsoft extended-decl-modifier */
 143 static const symbol_t *sym_align      = NULL;
 144 static const symbol_t *sym_allocate   = NULL;
 145 static const symbol_t *sym_dllimport  = NULL;
 146 static const symbol_t *sym_dllexport  = NULL;
 147 static const symbol_t *sym_naked      = NULL;
 148 static const symbol_t *sym_noinline   = NULL;
 149 static const symbol_t *sym_noreturn   = NULL;
 150 static const symbol_t *sym_nothrow    = NULL;
 151 static const symbol_t *sym_novtable   = NULL;
 152 static const symbol_t *sym_property   = NULL;
 153 static const symbol_t *sym_get        = NULL;
 154 static const symbol_t *sym_put        = NULL;
 155 static const symbol_t *sym_selectany  = NULL;
 156 static const symbol_t *sym_thread     = NULL;
 157 static const symbol_t *sym_uuid       = NULL;
 158 static const symbol_t *sym_deprecated = NULL;
 159 static const symbol_t *sym_restrict   = NULL;
 160 static const symbol_t *sym_noalias    = NULL;
 161
 162 /** The token anchor set */
 163 static unsigned char token_anchor_set[T_LAST_TOKEN];
 164
 165 /** The current source position. */
 166 #define HERE (&token.source_position)
 167
 168 /** true if we are in GCC mode. */
 169 #define GNU_MODE ((c_mode & _GNUC) || in_gcc_extension)
 170
 171 static type_t *type_valist;
 172
 173 static statement_t *parse_compound_statement(bool inside_expression_statement);
 174 static statement_t *parse_statement(void);
 175
 176 static expression_t *parse_sub_expression(precedence_t);
 177 static expression_t *parse_expression(void);
 178 static type_t       *parse_typename(void);
 179 static void          parse_externals(void);
 180 static void          parse_external(void);
 181
 182 static void parse_compound_type_entries(compound_t *compound_declaration);
 183 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
 184                                   bool may_be_abstract,
 185                                   bool create_compound_member);
 186 static entity_t *record_entity(entity_t *entity, bool is_definition);
 187
 188 static void semantic_comparison(binary_expression_t *expression);
 189
 190 #define STORAGE_CLASSES     \
 191         case T_typedef:         \
 192         case T_extern:          \
 193         case T_static:          \
 194         case T_auto:            \
 195         case T_register:        \
 196         case T___thread:
 197
 198 #define STORAGE_CLASSES_NO_EXTERN \
 199         case T_typedef:         \
 200         case T_static:          \
 201         case T_auto:            \
 202         case T_register:        \
 203         case T___thread:
 204
 205 #define TYPE_QUALIFIERS     \
 206         case T_const:           \
 207         case T_restrict:        \
 208         case T_volatile:        \
 209         case T_inline:          \
 210         case T__forceinline:    \
 211         case T___attribute__:
 212
 213 #define COMPLEX_SPECIFIERS  \
 214         case T__Complex:
 215 #define IMAGINARY_SPECIFIERS \
 216         case T__Imaginary:
 217
 218 #define TYPE_SPECIFIERS       \
 219         case T__Bool:             \
 220         case T___builtin_va_list: \
 221         case T___typeof__:        \
 222         case T__declspec:         \
 223         case T_bool:              \
 224         case T_char:              \
 225         case T_double:            \
 226         case T_enum:              \
 227         case T_float:             \
 228         case T_int:               \
 229         case T_long:              \
 230         case T_short:             \
 231         case T_signed:            \
 232         case T_struct:            \
 233         case T_union:             \
 234         case T_unsigned:          \
 235         case T_void:              \
 236         COMPLEX_SPECIFIERS        \
 237         IMAGINARY_SPECIFIERS
 238
 239 #define DECLARATION_START   \
 240         STORAGE_CLASSES         \
 241         TYPE_QUALIFIERS         \
 242         TYPE_SPECIFIERS
 243
 244 #define DECLARATION_START_NO_EXTERN \
 245         STORAGE_CLASSES_NO_EXTERN       \
 246         TYPE_QUALIFIERS                 \
 247         TYPE_SPECIFIERS
 248
 249 #define TYPENAME_START      \
 250         TYPE_QUALIFIERS         \
 251         TYPE_SPECIFIERS
 252
 253 #define EXPRESSION_START           \
 254         case '!':                        \
 255         case '&':                        \
 256         case '(':                        \
 257         case '*':                        \
 258         case '+':                        \
 259         case '-':                        \
 260         case '~':                        \
 261         case T_ANDAND:                   \
 262         case T_CHARACTER_CONSTANT:       \
 263         case T_FLOATINGPOINT:            \
 264         case T_INTEGER:                  \
 265         case T_MINUSMINUS:               \
 266         case T_PLUSPLUS:                 \
 267         case T_STRING_LITERAL:           \
 268         case T_WIDE_CHARACTER_CONSTANT:  \
 269         case T_WIDE_STRING_LITERAL:      \
 270         case T___FUNCDNAME__:            \
 271         case T___FUNCSIG__:              \
 272         case T___FUNCTION__:             \
 273         case T___PRETTY_FUNCTION__:      \
 274         case T___alignof__:              \
 275         case T___builtin_alloca:         \
 276         case T___builtin_classify_type:  \
 277         case T___builtin_constant_p:     \
 278         case T___builtin_expect:         \
 279         case T___builtin_huge_val:       \
 280         case T___builtin_inf:            \
 281         case T___builtin_inff:           \
 282         case T___builtin_infl:           \
 283         case T___builtin_isgreater:      \
 284         case T___builtin_isgreaterequal: \
 285         case T___builtin_isless:         \
 286         case T___builtin_islessequal:    \
 287         case T___builtin_islessgreater:  \
 288         case T___builtin_isunordered:    \
 289         case T___builtin_nan:            \
 290         case T___builtin_nanf:           \
 291         case T___builtin_nanl:           \
 292         case T___builtin_offsetof:       \
 293         case T___builtin_prefetch:       \
 294         case T___builtin_va_arg:         \
 295         case T___builtin_va_end:         \
 296         case T___builtin_va_start:       \
 297         case T___func__:                 \
 298         case T___noop:                   \
 299         case T__assume:                  \
 300         case T_delete:                   \
 301         case T_false:                    \
 302         case T_sizeof:                   \
 303         case T_throw:                    \
 304         case T_true:
 305
 306 /**
 307  * Allocate an AST node with given size and
 308  * initialize all fields with zero.
 309  */
 310 static void *allocate_ast_zero(size_t size)
 311 {
 312         void *res = allocate_ast(size);
 313         memset(res, 0, size);
 314         return res;
 315 }
 316
 317 static size_t get_entity_struct_size(entity_kind_t kind)
 318 {
 319         static const size_t sizes[] = {
 320                 [ENTITY_VARIABLE]        = sizeof(variable_t),
 321                 [ENTITY_COMPOUND_MEMBER] = sizeof(variable_t),
 322                 [ENTITY_FUNCTION]        = sizeof(function_t),
 323                 [ENTITY_TYPEDEF]         = sizeof(typedef_t),
 324                 [ENTITY_STRUCT]          = sizeof(compound_t),
 325                 [ENTITY_UNION]           = sizeof(compound_t),
 326                 [ENTITY_ENUM]            = sizeof(enum_t),
 327                 [ENTITY_ENUM_VALUE]      = sizeof(enum_value_t),
 328                 [ENTITY_LABEL]           = sizeof(label_t),
 329                 [ENTITY_LOCAL_LABEL]     = sizeof(label_t),
 330                 [ENTITY_NAMESPACE]       = sizeof(namespace_t)
 331         };
 332         assert(kind < sizeof(sizes) / sizeof(sizes[0]));
 333         assert(sizes[kind] != 0);
 334         return sizes[kind];
 335 }
 336
 337 static entity_t *allocate_entity_zero(entity_kind_t kind)
 338 {
 339         size_t    size   = get_entity_struct_size(kind);
 340         entity_t *entity = allocate_ast_zero(size);
 341         entity->kind     = kind;
 342         return entity;
 343 }
 344
 345 /**
 346  * Returns the size of a statement node.
 347  *
 348  * @param kind  the statement kind
 349  */
 350 static size_t get_statement_struct_size(statement_kind_t kind)
 351 {
 352         static const size_t sizes[] = {
 353                 [STATEMENT_INVALID]     = sizeof(invalid_statement_t),
 354                 [STATEMENT_EMPTY]       = sizeof(empty_statement_t),
 355                 [STATEMENT_COMPOUND]    = sizeof(compound_statement_t),
 356                 [STATEMENT_RETURN]      = sizeof(return_statement_t),
 357                 [STATEMENT_DECLARATION] = sizeof(declaration_statement_t),
 358                 [STATEMENT_LOCAL_LABEL] = sizeof(local_label_statement_t),
 359                 [STATEMENT_IF]          = sizeof(if_statement_t),
 360                 [STATEMENT_SWITCH]      = sizeof(switch_statement_t),
 361                 [STATEMENT_EXPRESSION]  = sizeof(expression_statement_t),
 362                 [STATEMENT_CONTINUE]    = sizeof(statement_base_t),
 363                 [STATEMENT_BREAK]       = sizeof(statement_base_t),
 364                 [STATEMENT_GOTO]        = sizeof(goto_statement_t),
 365                 [STATEMENT_LABEL]       = sizeof(label_statement_t),
 366                 [STATEMENT_CASE_LABEL]  = sizeof(case_label_statement_t),
 367                 [STATEMENT_WHILE]       = sizeof(while_statement_t),
 368                 [STATEMENT_DO_WHILE]    = sizeof(do_while_statement_t),
 369                 [STATEMENT_FOR]         = sizeof(for_statement_t),
 370                 [STATEMENT_ASM]         = sizeof(asm_statement_t),
 371                 [STATEMENT_MS_TRY]      = sizeof(ms_try_statement_t),
 372                 [STATEMENT_LEAVE]       = sizeof(leave_statement_t)
 373         };
 374         assert(kind < sizeof(sizes) / sizeof(sizes[0]));
 375         assert(sizes[kind] != 0);
 376         return sizes[kind];
 377 }
 378
 379 /**
 380  * Returns the size of an expression node.
 381  *
 382  * @param kind  the expression kind
 383  */
 384 static size_t get_expression_struct_size(expression_kind_t kind)
 385 {
 386         static const size_t sizes[] = {
 387                 [EXPR_INVALID]                 = sizeof(expression_base_t),
 388                 [EXPR_REFERENCE]               = sizeof(reference_expression_t),
 389                 [EXPR_REFERENCE_ENUM_VALUE]    = sizeof(reference_expression_t),
 390                 [EXPR_CONST]                   = sizeof(const_expression_t),
 391                 [EXPR_CHARACTER_CONSTANT]      = sizeof(const_expression_t),
 392                 [EXPR_WIDE_CHARACTER_CONSTANT] = sizeof(const_expression_t),
 393                 [EXPR_STRING_LITERAL]          = sizeof(string_literal_expression_t),
 394                 [EXPR_WIDE_STRING_LITERAL]     = sizeof(wide_string_literal_expression_t),
 395                 [EXPR_COMPOUND_LITERAL]        = sizeof(compound_literal_expression_t),
 396                 [EXPR_CALL]                    = sizeof(call_expression_t),
 397                 [EXPR_UNARY_FIRST]             = sizeof(unary_expression_t),
 398                 [EXPR_BINARY_FIRST]            = sizeof(binary_expression_t),
 399                 [EXPR_CONDITIONAL]             = sizeof(conditional_expression_t),
 400                 [EXPR_SELECT]                  = sizeof(select_expression_t),
 401                 [EXPR_ARRAY_ACCESS]            = sizeof(array_access_expression_t),
 402                 [EXPR_SIZEOF]                  = sizeof(typeprop_expression_t),
 403                 [EXPR_ALIGNOF]                 = sizeof(typeprop_expression_t),
 404                 [EXPR_CLASSIFY_TYPE]           = sizeof(classify_type_expression_t),
 405                 [EXPR_FUNCNAME]                = sizeof(funcname_expression_t),
 406                 [EXPR_BUILTIN_SYMBOL]          = sizeof(builtin_symbol_expression_t),
 407                 [EXPR_BUILTIN_CONSTANT_P]      = sizeof(builtin_constant_expression_t),
 408                 [EXPR_BUILTIN_PREFETCH]        = sizeof(builtin_prefetch_expression_t),
 409                 [EXPR_OFFSETOF]                = sizeof(offsetof_expression_t),
 410                 [EXPR_VA_START]                = sizeof(va_start_expression_t),
 411                 [EXPR_VA_ARG]                  = sizeof(va_arg_expression_t),
 412                 [EXPR_STATEMENT]               = sizeof(statement_expression_t),
 413                 [EXPR_LABEL_ADDRESS]           = sizeof(label_address_expression_t),
 414         };
 415         if (kind >= EXPR_UNARY_FIRST && kind <= EXPR_UNARY_LAST) {
 416                 return sizes[EXPR_UNARY_FIRST];
 417         }
 418         if (kind >= EXPR_BINARY_FIRST && kind <= EXPR_BINARY_LAST) {
 419                 return sizes[EXPR_BINARY_FIRST];
 420         }
 421         assert(kind < sizeof(sizes) / sizeof(sizes[0]));
 422         assert(sizes[kind] != 0);
 423         return sizes[kind];
 424 }
 425
 426 /**
 427  * Allocate a statement node of given kind and initialize all
 428  * fields with zero.
 429  */
 430 static statement_t *allocate_statement_zero(statement_kind_t kind)
 431 {
 432         size_t       size = get_statement_struct_size(kind);
 433         statement_t *res  = allocate_ast_zero(size);
 434
 435         res->base.kind            = kind;
 436         res->base.parent          = current_parent;
 437         res->base.source_position = token.source_position;
 438         return res;
 439 }
 440
 441 /**
 442  * Allocate an expression node of given kind and initialize all
 443  * fields with zero.
 444  */
 445 static expression_t *allocate_expression_zero(expression_kind_t kind)
 446 {
 447         size_t        size = get_expression_struct_size(kind);
 448         expression_t *res  = allocate_ast_zero(size);
 449
 450         res->base.kind            = kind;
 451         res->base.type            = type_error_type;
 452         res->base.source_position = token.source_position;
 453         return res;
 454 }
 455
 456 /**
 457  * Creates a new invalid expression.
 458  */
 459 static expression_t *create_invalid_expression(void)
 460 {
 461         return allocate_expression_zero(EXPR_INVALID);
 462 }
 463
 464 /**
 465  * Creates a new invalid statement.
 466  */
 467 static statement_t *create_invalid_statement(void)
 468 {
 469         return allocate_statement_zero(STATEMENT_INVALID);
 470 }
 471
 472 /**
 473  * Allocate a new empty statement.
 474  */
 475 static statement_t *create_empty_statement(void)
 476 {
 477         return allocate_statement_zero(STATEMENT_EMPTY);
 478 }
 479
 480 /**
 481  * Returns the size of a type node.
 482  *
 483  * @param kind  the type kind
 484  */
 485 static size_t get_type_struct_size(type_kind_t kind)
 486 {
 487         static const size_t sizes[] = {
 488                 [TYPE_ATOMIC]          = sizeof(atomic_type_t),
 489                 [TYPE_COMPLEX]         = sizeof(complex_type_t),
 490                 [TYPE_IMAGINARY]       = sizeof(imaginary_type_t),
 491                 [TYPE_BITFIELD]        = sizeof(bitfield_type_t),
 492                 [TYPE_COMPOUND_STRUCT] = sizeof(compound_type_t),
 493                 [TYPE_COMPOUND_UNION]  = sizeof(compound_type_t),
 494                 [TYPE_ENUM]            = sizeof(enum_type_t),
 495                 [TYPE_FUNCTION]        = sizeof(function_type_t),
 496                 [TYPE_POINTER]         = sizeof(pointer_type_t),
 497                 [TYPE_ARRAY]           = sizeof(array_type_t),
 498                 [TYPE_BUILTIN]         = sizeof(builtin_type_t),
 499                 [TYPE_TYPEDEF]         = sizeof(typedef_type_t),
 500                 [TYPE_TYPEOF]          = sizeof(typeof_type_t),
 501         };
 502         assert(sizeof(sizes) / sizeof(sizes[0]) == (int) TYPE_TYPEOF + 1);
 503         assert(kind <= TYPE_TYPEOF);
 504         assert(sizes[kind] != 0);
 505         return sizes[kind];
 506 }
 507
 508 /**
 509  * Allocate a type node of given kind and initialize all
 510  * fields with zero.
 511  *
 512  * @param kind             type kind to allocate
 513  */
 514 static type_t *allocate_type_zero(type_kind_t kind)
 515 {
 516         size_t  size = get_type_struct_size(kind);
 517         type_t *res  = obstack_alloc(type_obst, size);
 518         memset(res, 0, size);
 519         res->base.kind = kind;
 520
 521         return res;
 522 }
 523
 524 /**
 525  * Returns the size of an initializer node.
 526  *
 527  * @param kind  the initializer kind
 528  */
 529 static size_t get_initializer_size(initializer_kind_t kind)
 530 {
 531         static const size_t sizes[] = {
 532                 [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
 533                 [INITIALIZER_STRING]      = sizeof(initializer_string_t),
 534                 [INITIALIZER_WIDE_STRING] = sizeof(initializer_wide_string_t),
 535                 [INITIALIZER_LIST]        = sizeof(initializer_list_t),
 536                 [INITIALIZER_DESIGNATOR]  = sizeof(initializer_designator_t)
 537         };
 538         assert(kind < sizeof(sizes) / sizeof(*sizes));
 539         assert(sizes[kind] != 0);
 540         return sizes[kind];
 541 }
 542
 543 /**
 544  * Allocate an initializer node of given kind and initialize all
 545  * fields with zero.
 546  */
 547 static initializer_t *allocate_initializer_zero(initializer_kind_t kind)
 548 {
 549         initializer_t *result = allocate_ast_zero(get_initializer_size(kind));
 550         result->kind          = kind;
 551
 552         return result;
 553 }
 554
 555 /**
 556  * Free a type from the type obstack.
 557  */
 558 static void free_type(void *type)
 559 {
 560         obstack_free(type_obst, type);
 561 }
 562
 563 /**
 564  * Returns the index of the top element of the environment stack.
 565  */
 566 static size_t environment_top(void)
 567 {
 568         return ARR_LEN(environment_stack);
 569 }
 570
 571 /**
 572  * Returns the index of the top element of the global label stack.
 573  */
 574 static size_t label_top(void)
 575 {
 576         return ARR_LEN(label_stack);
 577 }
 578
 579 /**
 580  * Return the next token.
 581  */
 582 static inline void next_token(void)
 583 {
 584         token                              = lookahead_buffer[lookahead_bufpos];
 585         lookahead_buffer[lookahead_bufpos] = lexer_token;
 586         lexer_next_token();
 587
 588         lookahead_bufpos = (lookahead_bufpos+1) % MAX_LOOKAHEAD;
 589
 590 #ifdef PRINT_TOKENS
 591         print_token(stderr, &token);
 592         fprintf(stderr, "\n");
 593 #endif
 594 }
 595
 596 /**
 597  * Return the next token with a given lookahead.
 598  */
 599 static inline const token_t *look_ahead(int num)
 600 {
 601         assert(num > 0 && num <= MAX_LOOKAHEAD);
 602         int pos = (lookahead_bufpos+num-1) % MAX_LOOKAHEAD;
 603         return &lookahead_buffer[pos];
 604 }
 605
 606 /**
 607  * Adds a token to the token anchor set (a multi-set).
 608  */
 609 static void add_anchor_token(int token_type)
 610 {
 611         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 612         ++token_anchor_set[token_type];
 613 }
 614
 615 static int save_and_reset_anchor_state(int token_type)
 616 {
 617         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 618         int count = token_anchor_set[token_type];
 619         token_anchor_set[token_type] = 0;
 620         return count;
 621 }
 622
 623 static void restore_anchor_state(int token_type, int count)
 624 {
 625         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 626         token_anchor_set[token_type] = count;
 627 }
 628
 629 /**
 630  * Remove a token from the token anchor set (a multi-set).
 631  */
 632 static void rem_anchor_token(int token_type)
 633 {
 634         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 635         assert(token_anchor_set[token_type] != 0);
 636         --token_anchor_set[token_type];
 637 }
 638
 639 static bool at_anchor(void)
 640 {
 641         if (token.type < 0)
 642                 return false;
 643         return token_anchor_set[token.type];
 644 }
 645
 646 /**
 647  * Eat tokens until a matching token is found.
 648  */
 649 static void eat_until_matching_token(int type)
 650 {
 651         int end_token;
 652         switch (type) {
 653                 case '(': end_token = ')';  break;
 654                 case '{': end_token = '}';  break;
 655                 case '[': end_token = ']';  break;
 656                 default:  end_token = type; break;
 657         }
 658
 659         unsigned parenthesis_count = 0;
 660         unsigned brace_count       = 0;
 661         unsigned bracket_count     = 0;
 662         while (token.type        != end_token ||
 663                parenthesis_count != 0         ||
 664                brace_count       != 0         ||
 665                bracket_count     != 0) {
 666                 switch (token.type) {
 667                 case T_EOF: return;
 668                 case '(': ++parenthesis_count; break;
 669                 case '{': ++brace_count;       break;
 670                 case '[': ++bracket_count;     break;
 671
 672                 case ')':
 673                         if (parenthesis_count > 0)
 674                                 --parenthesis_count;
 675                         goto check_stop;
 676
 677                 case '}':
 678                         if (brace_count > 0)
 679                                 --brace_count;
 680                         goto check_stop;
 681
 682                 case ']':
 683                         if (bracket_count > 0)
 684                                 --bracket_count;
 685 check_stop:
 686                         if (token.type        == end_token &&
 687                             parenthesis_count == 0         &&
 688                             brace_count       == 0         &&
 689                             bracket_count     == 0)
 690                                 return;
 691                         break;
 692
 693                 default:
 694                         break;
 695                 }
 696                 next_token();
 697         }
 698 }
 699
 700 /**
 701  * Eat input tokens until an anchor is found.
 702  */
 703 static void eat_until_anchor(void)
 704 {
 705         while (token_anchor_set[token.type] == 0) {
 706                 if (token.type == '(' || token.type == '{' || token.type == '[')
 707                         eat_until_matching_token(token.type);
 708                 next_token();
 709         }
 710 }
 711
 712 static void eat_block(void)
 713 {
 714         eat_until_matching_token('{');
 715         if (token.type == '}')
 716                 next_token();
 717 }
 718
 719 #define eat(token_type)  do { assert(token.type == (token_type)); next_token(); } while (0)
 720
 721 /**
 722  * Report a parse error because an expected token was not found.
 723  */
 724 static
 725 #if defined __GNUC__ && __GNUC__ >= 4
 726 __attribute__((sentinel))
 727 #endif
 728 void parse_error_expected(const char *message, ...)
 729 {
 730         if (message != NULL) {
 731                 errorf(HERE, "%s", message);
 732         }
 733         va_list ap;
 734         va_start(ap, message);
 735         errorf(HERE, "got %K, expected %#k", &token, &ap, ", ");
 736         va_end(ap);
 737 }
 738
 739 /**
 740  * Report a type error.
 741  */
 742 static void type_error(const char *msg, const source_position_t *source_position,
 743                        type_t *type)
 744 {
 745         errorf(source_position, "%s, but found type '%T'", msg, type);
 746 }
 747
 748 /**
 749  * Report an incompatible type.
 750  */
 751 static void type_error_incompatible(const char *msg,
 752                 const source_position_t *source_position, type_t *type1, type_t *type2)
 753 {
 754         errorf(source_position, "%s, incompatible types: '%T' - '%T'",
 755                msg, type1, type2);
 756 }
 757
 758 /**
 759  * Expect the the current token is the expected token.
 760  * If not, generate an error, eat the current statement,
 761  * and goto the end_error label.
 762  */
 763 #define expect(expected)                                  \
 764         do {                                                  \
 765                 if (UNLIKELY(token.type != (expected))) {         \
 766                         parse_error_expected(NULL, (expected), NULL); \
 767                         add_anchor_token(expected);                   \
 768                         eat_until_anchor();                           \
 769                         if (token.type == expected)                   \
 770                                 next_token();                             \
 771                         rem_anchor_token(expected);                   \
 772                         goto end_error;                               \
 773                 }                                                 \
 774                 next_token();                                     \
 775         } while (0)
 776
 777 static void scope_push(scope_t *new_scope)
 778 {
 779         if (current_scope != NULL) {
 780                 new_scope->depth = current_scope->depth + 1;
 781         }
 782         new_scope->parent = current_scope;
 783         current_scope     = new_scope;
 784 }
 785
 786 static void scope_pop(void)
 787 {
 788         current_scope = current_scope->parent;
 789 }
 790
 791 /**
 792  * Search an entity by its symbol in a given namespace.
 793  */
 794 static entity_t *get_entity(const symbol_t *const symbol,
 795                             namespace_tag_t namespc)
 796 {
 797         entity_t *entity = symbol->entity;
 798         for (; entity != NULL; entity = entity->base.symbol_next) {
 799                 if (entity->base.namespc == namespc)
 800                         return entity;
 801         }
 802
 803         return NULL;
 804 }
 805
 806 /**
 807  * pushs an entity on the environment stack and links the corresponding symbol
 808  * it.
 809  */
 810 static void stack_push(stack_entry_t **stack_ptr, entity_t *entity)
 811 {
 812         symbol_t           *symbol  = entity->base.symbol;
 813         entity_namespace_t  namespc = entity->base.namespc;
 814         assert(namespc != NAMESPACE_INVALID);
 815
 816         /* replace/add entity into entity list of the symbol */
 817         entity_t **anchor;
 818         entity_t  *iter;
 819         for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 820                 iter = *anchor;
 821                 if (iter == NULL)
 822                         break;
 823
 824                 /* replace an entry? */
 825                 if (iter->base.namespc == namespc) {
 826                         entity->base.symbol_next = iter->base.symbol_next;
 827                         break;
 828                 }
 829         }
 830         *anchor = entity;
 831
 832         /* remember old declaration */
 833         stack_entry_t entry;
 834         entry.symbol     = symbol;
 835         entry.old_entity = iter;
 836         entry.namespc    = namespc;
 837         ARR_APP1(stack_entry_t, *stack_ptr, entry);
 838 }
 839
 840 /**
 841  * Push an entity on the environment stack.
 842  */
 843 static void environment_push(entity_t *entity)
 844 {
 845         assert(entity->base.source_position.input_name != NULL);
 846         assert(entity->base.parent_scope != NULL);
 847         stack_push(&environment_stack, entity);
 848 }
 849
 850 /**
 851  * Push a declaration on the global label stack.
 852  *
 853  * @param declaration  the declaration
 854  */
 855 static void label_push(entity_t *label)
 856 {
 857         /* we abuse the parameters scope as parent for the labels */
 858         label->base.parent_scope = &current_function->parameters;
 859         stack_push(&label_stack, label);
 860 }
 861
 862 /**
 863  * pops symbols from the environment stack until @p new_top is the top element
 864  */
 865 static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
 866 {
 867         stack_entry_t *stack = *stack_ptr;
 868         size_t         top   = ARR_LEN(stack);
 869         size_t         i;
 870
 871         assert(new_top <= top);
 872         if (new_top == top)
 873                 return;
 874
 875         for (i = top; i > new_top; --i) {
 876                 stack_entry_t *entry = &stack[i - 1];
 877
 878                 entity_t           *old_entity = entry->old_entity;
 879                 symbol_t           *symbol     = entry->symbol;
 880                 entity_namespace_t  namespc    = entry->namespc;
 881
 882                 /* replace with old_entity/remove */
 883                 entity_t **anchor;
 884                 entity_t  *iter;
 885                 for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 886                         iter = *anchor;
 887                         assert(iter != NULL);
 888                         /* replace an entry? */
 889                         if (iter->base.namespc == namespc)
 890                                 break;
 891                 }
 892
 893                 /* restore definition from outer scopes (if there was one) */
 894                 if (old_entity != NULL) {
 895                         old_entity->base.symbol_next = iter->base.symbol_next;
 896                         *anchor                      = old_entity;
 897                 } else {
 898                         /* remove entry from list */
 899                         *anchor = iter->base.symbol_next;
 900                 }
 901         }
 902
 903         ARR_SHRINKLEN(*stack_ptr, (int) new_top);
 904 }
 905
 906 /**
 907  * Pop all entries from the environment stack until the new_top
 908  * is reached.
 909  *
 910  * @param new_top  the new stack top
 911  */
 912 static void environment_pop_to(size_t new_top)
 913 {
 914         stack_pop_to(&environment_stack, new_top);
 915 }
 916
 917 /**
 918  * Pop all entries from the global label stack until the new_top
 919  * is reached.
 920  *
 921  * @param new_top  the new stack top
 922  */
 923 static void label_pop_to(size_t new_top)
 924 {
 925         stack_pop_to(&label_stack, new_top);
 926 }
 927
 928 static int get_akind_rank(atomic_type_kind_t akind)
 929 {
 930         return (int) akind;
 931 }
 932
 933 static int get_rank(const type_t *type)
 934 {
 935         assert(!is_typeref(type));
 936         /* The C-standard allows promoting enums to int or unsigned int (see § 7.2.2
 937          * and esp. footnote 108). However we can't fold constants (yet), so we
 938          * can't decide whether unsigned int is possible, while int always works.
 939          * (unsigned int would be preferable when possible... for stuff like
 940          *  struct { enum { ... } bla : 4; } ) */
 941         if (type->kind == TYPE_ENUM)
 942                 return get_akind_rank(ATOMIC_TYPE_INT);
 943
 944         assert(type->kind == TYPE_ATOMIC);
 945         return get_akind_rank(type->atomic.akind);
 946 }
 947
 948 static type_t *promote_integer(type_t *type)
 949 {
 950         if (type->kind == TYPE_BITFIELD)
 951                 type = type->bitfield.base_type;
 952
 953         if (get_rank(type) < get_akind_rank(ATOMIC_TYPE_INT))
 954                 type = type_int;
 955
 956         return type;
 957 }
 958
 959 /**
 960  * Create a cast expression.
 961  *
 962  * @param expression  the expression to cast
 963  * @param dest_type   the destination type
 964  */
 965 static expression_t *create_cast_expression(expression_t *expression,
 966                                             type_t *dest_type)
 967 {
 968         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST_IMPLICIT);
 969
 970         cast->unary.value = expression;
 971         cast->base.type   = dest_type;
 972
 973         return cast;
 974 }
 975
 976 /**
 977  * Check if a given expression represents the 0 pointer constant.
 978  */
 979 static bool is_null_pointer_constant(const expression_t *expression)
 980 {
 981         /* skip void* cast */
 982         if (expression->kind == EXPR_UNARY_CAST
 983                         || expression->kind == EXPR_UNARY_CAST_IMPLICIT) {
 984                 expression = expression->unary.value;
 985         }
 986
 987         /* TODO: not correct yet, should be any constant integer expression
 988          * which evaluates to 0 */
 989         if (expression->kind != EXPR_CONST)
 990                 return false;
 991
 992         type_t *const type = skip_typeref(expression->base.type);
 993         if (!is_type_integer(type))
 994                 return false;
 995
 996         return expression->conste.v.int_value == 0;
 997 }
 998
 999 /**
1000  * Create an implicit cast expression.
1001  *
1002  * @param expression  the expression to cast
1003  * @param dest_type   the destination type
1004  */
1005 static expression_t *create_implicit_cast(expression_t *expression,
1006                                           type_t *dest_type)
1007 {
1008         type_t *const source_type = expression->base.type;
1009
1010         if (source_type == dest_type)
1011                 return expression;
1012
1013         return create_cast_expression(expression, dest_type);
1014 }
1015
1016 typedef enum assign_error_t {
1017         ASSIGN_SUCCESS,
1018         ASSIGN_ERROR_INCOMPATIBLE,
1019         ASSIGN_ERROR_POINTER_QUALIFIER_MISSING,
1020         ASSIGN_WARNING_POINTER_INCOMPATIBLE,
1021         ASSIGN_WARNING_POINTER_FROM_INT,
1022         ASSIGN_WARNING_INT_FROM_POINTER
1023 } assign_error_t;
1024
1025 static void report_assign_error(assign_error_t error, type_t *orig_type_left,
1026                                 const expression_t *const right,
1027                                 const char *context,
1028                                 const source_position_t *source_position)
1029 {
1030         type_t *const orig_type_right = right->base.type;
1031         type_t *const type_left       = skip_typeref(orig_type_left);
1032         type_t *const type_right      = skip_typeref(orig_type_right);
1033
1034         switch (error) {
1035         case ASSIGN_SUCCESS:
1036                 return;
1037         case ASSIGN_ERROR_INCOMPATIBLE:
1038                 errorf(source_position,
1039                        "destination type '%T' in %s is incompatible with type '%T'",
1040                        orig_type_left, context, orig_type_right);
1041                 return;
1042
1043         case ASSIGN_ERROR_POINTER_QUALIFIER_MISSING: {
1044                 if (warning.other) {
1045                         type_t *points_to_left  = skip_typeref(type_left->pointer.points_to);
1046                         type_t *points_to_right = skip_typeref(type_right->pointer.points_to);
1047
1048                         /* the left type has all qualifiers from the right type */
1049                         unsigned missing_qualifiers
1050                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
1051                         warningf(source_position,
1052                                         "destination type '%T' in %s from type '%T' lacks qualifiers '%Q' in pointer target type",
1053                                         orig_type_left, context, orig_type_right, missing_qualifiers);
1054                 }
1055                 return;
1056         }
1057
1058         case ASSIGN_WARNING_POINTER_INCOMPATIBLE:
1059                 if (warning.other) {
1060                         warningf(source_position,
1061                                         "destination type '%T' in %s is incompatible with '%E' of type '%T'",
1062                                         orig_type_left, context, right, orig_type_right);
1063                 }
1064                 return;
1065
1066         case ASSIGN_WARNING_POINTER_FROM_INT:
1067                 if (warning.other) {
1068                         warningf(source_position,
1069                                         "%s makes pointer '%T' from integer '%T' without a cast",
1070                                         context, orig_type_left, orig_type_right);
1071                 }
1072                 return;
1073
1074         case ASSIGN_WARNING_INT_FROM_POINTER:
1075                 if (warning.other) {
1076                         warningf(source_position,
1077                                         "%s makes integer '%T' from pointer '%T' without a cast",
1078                                         context, orig_type_left, orig_type_right);
1079                 }
1080                 return;
1081
1082         default:
1083                 panic("invalid error value");
1084         }
1085 }
1086
1087 /** Implements the rules from § 6.5.16.1 */
1088 static assign_error_t semantic_assign(type_t *orig_type_left,
1089                                       const expression_t *const right)
1090 {
1091         type_t *const orig_type_right = right->base.type;
1092         type_t *const type_left       = skip_typeref(orig_type_left);
1093         type_t *const type_right      = skip_typeref(orig_type_right);
1094
1095         if (is_type_pointer(type_left)) {
1096                 if (is_null_pointer_constant(right)) {
1097                         return ASSIGN_SUCCESS;
1098                 } else if (is_type_pointer(type_right)) {
1099                         type_t *points_to_left
1100                                 = skip_typeref(type_left->pointer.points_to);
1101                         type_t *points_to_right
1102                                 = skip_typeref(type_right->pointer.points_to);
1103                         assign_error_t res = ASSIGN_SUCCESS;
1104
1105                         /* the left type has all qualifiers from the right type */
1106                         unsigned missing_qualifiers
1107                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
1108                         if (missing_qualifiers != 0) {
1109                                 res = ASSIGN_ERROR_POINTER_QUALIFIER_MISSING;
1110                         }
1111
1112                         points_to_left  = get_unqualified_type(points_to_left);
1113                         points_to_right = get_unqualified_type(points_to_right);
1114
1115                         if (is_type_atomic(points_to_left, ATOMIC_TYPE_VOID))
1116                                 return res;
1117
1118                         if (is_type_atomic(points_to_right, ATOMIC_TYPE_VOID)) {
1119                                 /* ISO/IEC 14882:1998(E) §C.1.2:6 */
1120                                 return c_mode & _CXX ? ASSIGN_ERROR_INCOMPATIBLE : res;
1121                         }
1122
1123                         if (!types_compatible(points_to_left, points_to_right)) {
1124                                 return ASSIGN_WARNING_POINTER_INCOMPATIBLE;
1125                         }
1126
1127                         return res;
1128                 } else if (is_type_integer(type_right)) {
1129                         return ASSIGN_WARNING_POINTER_FROM_INT;
1130                 }
1131         } else if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
1132             (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
1133                 && is_type_pointer(type_right))) {
1134                 return ASSIGN_SUCCESS;
1135         } else if ((is_type_compound(type_left)  && is_type_compound(type_right))
1136                         || (is_type_builtin(type_left) && is_type_builtin(type_right))) {
1137                 type_t *const unqual_type_left  = get_unqualified_type(type_left);
1138                 type_t *const unqual_type_right = get_unqualified_type(type_right);
1139                 if (types_compatible(unqual_type_left, unqual_type_right)) {
1140                         return ASSIGN_SUCCESS;
1141                 }
1142         } else if (is_type_integer(type_left) && is_type_pointer(type_right)) {
1143                 return ASSIGN_WARNING_INT_FROM_POINTER;
1144         }
1145
1146         if (!is_type_valid(type_left) || !is_type_valid(type_right))
1147                 return ASSIGN_SUCCESS;
1148
1149         return ASSIGN_ERROR_INCOMPATIBLE;
1150 }
1151
1152 static expression_t *parse_constant_expression(void)
1153 {
1154         expression_t *result = parse_sub_expression(PREC_CONDITIONAL);
1155
1156         if (!is_constant_expression(result)) {
1157                 errorf(&result->base.source_position,
1158                        "expression '%E' is not constant\n", result);
1159         }
1160
1161         return result;
1162 }
1163
1164 static expression_t *parse_assignment_expression(void)
1165 {
1166         return parse_sub_expression(PREC_ASSIGNMENT);
1167 }
1168
1169 static string_t parse_string_literals(void)
1170 {
1171         assert(token.type == T_STRING_LITERAL);
1172         string_t result = token.v.string;
1173
1174         next_token();
1175
1176         while (token.type == T_STRING_LITERAL) {
1177                 result = concat_strings(&result, &token.v.string);
1178                 next_token();
1179         }
1180
1181         return result;
1182 }
1183
1184 static const char *const gnu_attribute_names[GNU_AK_LAST] = {
1185         [GNU_AK_CONST]                  = "const",
1186         [GNU_AK_VOLATILE]               = "volatile",
1187         [GNU_AK_CDECL]                  = "cdecl",
1188         [GNU_AK_STDCALL]                = "stdcall",
1189         [GNU_AK_FASTCALL]               = "fastcall",
1190         [GNU_AK_DEPRECATED]             = "deprecated",
1191         [GNU_AK_NOINLINE]               = "noinline",
1192         [GNU_AK_NORETURN]               = "noreturn",
1193         [GNU_AK_NAKED]                  = "naked",
1194         [GNU_AK_PURE]                   = "pure",
1195         [GNU_AK_ALWAYS_INLINE]          = "always_inline",
1196         [GNU_AK_MALLOC]                 = "malloc",
1197         [GNU_AK_WEAK]                   = "weak",
1198         [GNU_AK_CONSTRUCTOR]            = "constructor",
1199         [GNU_AK_DESTRUCTOR]             = "destructor",
1200         [GNU_AK_NOTHROW]                = "nothrow",
1201         [GNU_AK_TRANSPARENT_UNION]      = "transparent_union",
1202         [GNU_AK_COMMON]                 = "common",
1203         [GNU_AK_NOCOMMON]               = "nocommon",
1204         [GNU_AK_PACKED]                 = "packed",
1205         [GNU_AK_SHARED]                 = "shared",
1206         [GNU_AK_NOTSHARED]              = "notshared",
1207         [GNU_AK_USED]                   = "used",
1208         [GNU_AK_UNUSED]                 = "unused",
1209         [GNU_AK_NO_INSTRUMENT_FUNCTION] = "no_instrument_function",
1210         [GNU_AK_WARN_UNUSED_RESULT]     = "warn_unused_result",
1211         [GNU_AK_LONGCALL]               = "longcall",
1212         [GNU_AK_SHORTCALL]              = "shortcall",
1213         [GNU_AK_LONG_CALL]              = "long_call",
1214         [GNU_AK_SHORT_CALL]             = "short_call",
1215         [GNU_AK_FUNCTION_VECTOR]        = "function_vector",
1216         [GNU_AK_INTERRUPT]              = "interrupt",
1217         [GNU_AK_INTERRUPT_HANDLER]      = "interrupt_handler",
1218         [GNU_AK_NMI_HANDLER]            = "nmi_handler",
1219         [GNU_AK_NESTING]                = "nesting",
1220         [GNU_AK_NEAR]                   = "near",
1221         [GNU_AK_FAR]                    = "far",
1222         [GNU_AK_SIGNAL]                 = "signal",
1223         [GNU_AK_EIGTHBIT_DATA]          = "eightbit_data",
1224         [GNU_AK_TINY_DATA]              = "tiny_data",
1225         [GNU_AK_SAVEALL]                = "saveall",
1226         [GNU_AK_FLATTEN]                = "flatten",
1227         [GNU_AK_SSEREGPARM]             = "sseregparm",
1228         [GNU_AK_EXTERNALLY_VISIBLE]     = "externally_visible",
1229         [GNU_AK_RETURN_TWICE]           = "return_twice",
1230         [GNU_AK_MAY_ALIAS]              = "may_alias",
1231         [GNU_AK_MS_STRUCT]              = "ms_struct",
1232         [GNU_AK_GCC_STRUCT]             = "gcc_struct",
1233         [GNU_AK_DLLIMPORT]              = "dllimport",
1234         [GNU_AK_DLLEXPORT]              = "dllexport",
1235         [GNU_AK_ALIGNED]                = "aligned",
1236         [GNU_AK_ALIAS]                  = "alias",
1237         [GNU_AK_SECTION]                = "section",
1238         [GNU_AK_FORMAT]                 = "format",
1239         [GNU_AK_FORMAT_ARG]             = "format_arg",
1240         [GNU_AK_WEAKREF]                = "weakref",
1241         [GNU_AK_NONNULL]                = "nonnull",
1242         [GNU_AK_TLS_MODEL]              = "tls_model",
1243         [GNU_AK_VISIBILITY]             = "visibility",
1244         [GNU_AK_REGPARM]                = "regparm",
1245         [GNU_AK_MODE]                   = "mode",
1246         [GNU_AK_MODEL]                  = "model",
1247         [GNU_AK_TRAP_EXIT]              = "trap_exit",
1248         [GNU_AK_SP_SWITCH]              = "sp_switch",
1249         [GNU_AK_SENTINEL]               = "sentinel"
1250 };
1251
1252 /**
1253  * compare two string, ignoring double underscores on the second.
1254  */
1255 static int strcmp_underscore(const char *s1, const char *s2)
1256 {
1257         if (s2[0] == '_' && s2[1] == '_') {
1258                 size_t len2 = strlen(s2);
1259                 size_t len1 = strlen(s1);
1260                 if (len1 == len2-4 && s2[len2-2] == '_' && s2[len2-1] == '_') {
1261                         return strncmp(s1, s2+2, len2-4);
1262                 }
1263         }
1264
1265         return strcmp(s1, s2);
1266 }
1267
1268 /**
1269  * Allocate a new gnu temporal attribute.
1270  */
1271 static gnu_attribute_t *allocate_gnu_attribute(gnu_attribute_kind_t kind)
1272 {
1273         gnu_attribute_t *attribute = obstack_alloc(&temp_obst, sizeof(*attribute));
1274         attribute->kind            = kind;
1275         attribute->next            = NULL;
1276         attribute->invalid         = false;
1277         attribute->have_arguments  = false;
1278
1279         return attribute;
1280 }
1281
1282 /**
1283  * parse one constant expression argument.
1284  */
1285 static void parse_gnu_attribute_const_arg(gnu_attribute_t *attribute)
1286 {
1287         expression_t *expression;
1288         add_anchor_token(')');
1289         expression = parse_constant_expression();
1290         rem_anchor_token(')');
1291         expect(')');
1292         attribute->u.argument = fold_constant(expression);
1293         return;
1294 end_error:
1295         attribute->invalid = true;
1296 }
1297
1298 /**
1299  * parse a list of constant expressions arguments.
1300  */
1301 static void parse_gnu_attribute_const_arg_list(gnu_attribute_t *attribute)
1302 {
1303         argument_list_t **list = &attribute->u.arguments;
1304         argument_list_t  *entry;
1305         expression_t     *expression;
1306         add_anchor_token(')');
1307         add_anchor_token(',');
1308         while (true) {
1309                 expression = parse_constant_expression();
1310                 entry = obstack_alloc(&temp_obst, sizeof(entry));
1311                 entry->argument = fold_constant(expression);
1312                 entry->next     = NULL;
1313                 *list = entry;
1314                 list = &entry->next;
1315                 if (token.type != ',')
1316                         break;
1317                 next_token();
1318         }
1319         rem_anchor_token(',');
1320         rem_anchor_token(')');
1321         expect(')');
1322         return;
1323 end_error:
1324         attribute->invalid = true;
1325 }
1326
1327 /**
1328  * parse one string literal argument.
1329  */
1330 static void parse_gnu_attribute_string_arg(gnu_attribute_t *attribute,
1331                                            string_t *string)
1332 {
1333         add_anchor_token('(');
1334         if (token.type != T_STRING_LITERAL) {
1335                 parse_error_expected("while parsing attribute directive",
1336                                      T_STRING_LITERAL, NULL);
1337                 goto end_error;
1338         }
1339         *string = parse_string_literals();
1340         rem_anchor_token('(');
1341         expect(')');
1342         return;
1343 end_error:
1344         attribute->invalid = true;
1345 }
1346
1347 /**
1348  * parse one tls model.
1349  */
1350 static void parse_gnu_attribute_tls_model_arg(gnu_attribute_t *attribute)
1351 {
1352         static const char *const tls_models[] = {
1353                 "global-dynamic",
1354                 "local-dynamic",
1355                 "initial-exec",
1356                 "local-exec"
1357         };
1358         string_t string = { NULL, 0 };
1359         parse_gnu_attribute_string_arg(attribute, &string);
1360         if (string.begin != NULL) {
1361                 for (size_t i = 0; i < 4; ++i) {
1362                         if (strcmp(tls_models[i], string.begin) == 0) {
1363                                 attribute->u.value = i;
1364                                 return;
1365                         }
1366                 }
1367                 errorf(HERE, "'%s' is an unrecognized tls model", string.begin);
1368         }
1369         attribute->invalid = true;
1370 }
1371
1372 /**
1373  * parse one tls model.
1374  */
1375 static void parse_gnu_attribute_visibility_arg(gnu_attribute_t *attribute)
1376 {
1377         static const char *const visibilities[] = {
1378                 "default",
1379                 "protected",
1380                 "hidden",
1381                 "internal"
1382         };
1383         string_t string = { NULL, 0 };
1384         parse_gnu_attribute_string_arg(attribute, &string);
1385         if (string.begin != NULL) {
1386                 for (size_t i = 0; i < 4; ++i) {
1387                         if (strcmp(visibilities[i], string.begin) == 0) {
1388                                 attribute->u.value = i;
1389                                 return;
1390                         }
1391                 }
1392                 errorf(HERE, "'%s' is an unrecognized visibility", string.begin);
1393         }
1394         attribute->invalid = true;
1395 }
1396
1397 /**
1398  * parse one (code) model.
1399  */
1400 static void parse_gnu_attribute_model_arg(gnu_attribute_t *attribute)
1401 {
1402         static const char *const visibilities[] = {
1403                 "small",
1404                 "medium",
1405                 "large"
1406         };
1407         string_t string = { NULL, 0 };
1408         parse_gnu_attribute_string_arg(attribute, &string);
1409         if (string.begin != NULL) {
1410                 for (int i = 0; i < 3; ++i) {
1411                         if (strcmp(visibilities[i], string.begin) == 0) {
1412                                 attribute->u.value = i;
1413                                 return;
1414                         }
1415                 }
1416                 errorf(HERE, "'%s' is an unrecognized model", string.begin);
1417         }
1418         attribute->invalid = true;
1419 }
1420
1421 static void parse_gnu_attribute_mode_arg(gnu_attribute_t *attribute)
1422 {
1423         /* TODO: find out what is allowed here... */
1424
1425         /* at least: byte, word, pointer, list of machine modes
1426          * __XXX___ is interpreted as XXX */
1427         add_anchor_token(')');
1428
1429         if (token.type != T_IDENTIFIER) {
1430                 expect(T_IDENTIFIER);
1431         }
1432
1433         /* This isn't really correct, the backend should provide a list of machine
1434          * specific modes (according to gcc philosophy that is...) */
1435         const char *symbol_str = token.v.symbol->string;
1436         if (strcmp_underscore("QI",   symbol_str) == 0 ||
1437             strcmp_underscore("byte", symbol_str) == 0) {
1438                 attribute->u.akind = ATOMIC_TYPE_CHAR;
1439         } else if (strcmp_underscore("HI", symbol_str) == 0) {
1440                 attribute->u.akind = ATOMIC_TYPE_SHORT;
1441         } else if (strcmp_underscore("SI",      symbol_str) == 0
1442                 || strcmp_underscore("word",    symbol_str) == 0
1443                 || strcmp_underscore("pointer", symbol_str) == 0) {
1444                 attribute->u.akind = ATOMIC_TYPE_INT;
1445         } else if (strcmp_underscore("DI", symbol_str) == 0) {
1446                 attribute->u.akind = ATOMIC_TYPE_LONGLONG;
1447         } else {
1448                 if (warning.other)
1449                         warningf(HERE, "ignoring unknown mode '%s'", symbol_str);
1450                 attribute->invalid = true;
1451         }
1452         next_token();
1453
1454         rem_anchor_token(')');
1455         expect(')');
1456         return;
1457 end_error:
1458         attribute->invalid = true;
1459 }
1460
1461 /**
1462  * parse one interrupt argument.
1463  */
1464 static void parse_gnu_attribute_interrupt_arg(gnu_attribute_t *attribute)
1465 {
1466         static const char *const interrupts[] = {
1467                 "IRQ",
1468                 "FIQ",
1469                 "SWI",
1470                 "ABORT",
1471                 "UNDEF"
1472         };
1473         string_t string = { NULL, 0 };
1474         parse_gnu_attribute_string_arg(attribute, &string);
1475         if (string.begin != NULL) {
1476                 for (size_t i = 0; i < 5; ++i) {
1477                         if (strcmp(interrupts[i], string.begin) == 0) {
1478                                 attribute->u.value = i;
1479                                 return;
1480                         }
1481                 }
1482                 errorf(HERE, "'%s' is not an interrupt", string.begin);
1483         }
1484         attribute->invalid = true;
1485 }
1486
1487 /**
1488  * parse ( identifier, const expression, const expression )
1489  */
1490 static void parse_gnu_attribute_format_args(gnu_attribute_t *attribute)
1491 {
1492         static const char *const format_names[] = {
1493                 "printf",
1494                 "scanf",
1495                 "strftime",
1496                 "strfmon"
1497         };
1498         int i;
1499
1500         if (token.type != T_IDENTIFIER) {
1501                 parse_error_expected("while parsing format attribute directive", T_IDENTIFIER, NULL);
1502                 goto end_error;
1503         }
1504         const char *name = token.v.symbol->string;
1505         for (i = 0; i < 4; ++i) {
1506                 if (strcmp_underscore(format_names[i], name) == 0)
1507                         break;
1508         }
1509         if (i >= 4) {
1510                 if (warning.attribute)
1511                         warningf(HERE, "'%s' is an unrecognized format function type", name);
1512         }
1513         next_token();
1514
1515         expect(',');
1516         add_anchor_token(')');
1517         add_anchor_token(',');
1518         parse_constant_expression();
1519         rem_anchor_token(',');
1520         rem_anchor_token(')');
1521
1522         expect(',');
1523         add_anchor_token(')');
1524         parse_constant_expression();
1525         rem_anchor_token(')');
1526         expect(')');
1527         return;
1528 end_error:
1529         attribute->u.value = true;
1530 }
1531
1532 static void check_no_argument(gnu_attribute_t *attribute, const char *name)
1533 {
1534         if (!attribute->have_arguments)
1535                 return;
1536
1537         /* should have no arguments */
1538         errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1539         eat_until_matching_token('(');
1540         /* we have already consumed '(', so we stop before ')', eat it */
1541         eat(')');
1542         attribute->invalid = true;
1543 }
1544
1545 /**
1546  * Parse one GNU attribute.
1547  *
1548  * Note that attribute names can be specified WITH or WITHOUT
1549  * double underscores, ie const or __const__.
1550  *
1551  * The following attributes are parsed without arguments
1552  *  const
1553  *  volatile
1554  *  cdecl
1555  *  stdcall
1556  *  fastcall
1557  *  deprecated
1558  *  noinline
1559  *  noreturn
1560  *  naked
1561  *  pure
1562  *  always_inline
1563  *  malloc
1564  *  weak
1565  *  constructor
1566  *  destructor
1567  *  nothrow
1568  *  transparent_union
1569  *  common
1570  *  nocommon
1571  *  packed
1572  *  shared
1573  *  notshared
1574  *  used
1575  *  unused
1576  *  no_instrument_function
1577  *  warn_unused_result
1578  *  longcall
1579  *  shortcall
1580  *  long_call
1581  *  short_call
1582  *  function_vector
1583  *  interrupt_handler
1584  *  nmi_handler
1585  *  nesting
1586  *  near
1587  *  far
1588  *  signal
1589  *  eightbit_data
1590  *  tiny_data
1591  *  saveall
1592  *  flatten
1593  *  sseregparm
1594  *  externally_visible
1595  *  return_twice
1596  *  may_alias
1597  *  ms_struct
1598  *  gcc_struct
1599  *  dllimport
1600  *  dllexport
1601  *
1602  * The following attributes are parsed with arguments
1603  *  aligned( const expression )
1604  *  alias( string literal )
1605  *  section( string literal )
1606  *  format( identifier, const expression, const expression )
1607  *  format_arg( const expression )
1608  *  tls_model( string literal )
1609  *  visibility( string literal )
1610  *  regparm( const expression )
1611  *  model( string leteral )
1612  *  trap_exit( const expression )
1613  *  sp_switch( string literal )
1614  *
1615  * The following attributes might have arguments
1616  *  weak_ref( string literal )
1617  *  non_null( const expression // ',' )
1618  *  interrupt( string literal )
1619  *  sentinel( constant expression )
1620  */
1621 static decl_modifiers_t parse_gnu_attribute(gnu_attribute_t **attributes)
1622 {
1623         gnu_attribute_t *head      = *attributes;
1624         gnu_attribute_t *last      = *attributes;
1625         decl_modifiers_t modifiers = 0;
1626         gnu_attribute_t *attribute;
1627
1628         eat(T___attribute__);
1629         expect('(');
1630         expect('(');
1631
1632         if (token.type != ')') {
1633                 /* find the end of the list */
1634                 if (last != NULL) {
1635                         while (last->next != NULL)
1636                                 last = last->next;
1637                 }
1638
1639                 /* non-empty attribute list */
1640                 while (true) {
1641                         const char *name;
1642                         if (token.type == T_const) {
1643                                 name = "const";
1644                         } else if (token.type == T_volatile) {
1645                                 name = "volatile";
1646                         } else if (token.type == T_cdecl) {
1647                                 /* __attribute__((cdecl)), WITH ms mode */
1648                                 name = "cdecl";
1649                         } else if (token.type == T_IDENTIFIER) {
1650                                 const symbol_t *sym = token.v.symbol;
1651                                 name = sym->string;
1652                         } else {
1653                                 parse_error_expected("while parsing GNU attribute", T_IDENTIFIER, NULL);
1654                                 break;
1655                         }
1656
1657                         next_token();
1658
1659                         int i;
1660                         for (i = 0; i < GNU_AK_LAST; ++i) {
1661                                 if (strcmp_underscore(gnu_attribute_names[i], name) == 0)
1662                                         break;
1663                         }
1664                         gnu_attribute_kind_t kind = (gnu_attribute_kind_t)i;
1665
1666                         attribute = NULL;
1667                         if (kind == GNU_AK_LAST) {
1668                                 if (warning.attribute)
1669                                         warningf(HERE, "'%s' attribute directive ignored", name);
1670
1671                                 /* skip possible arguments */
1672                                 if (token.type == '(') {
1673                                         eat_until_matching_token(')');
1674                                 }
1675                         } else {
1676                                 /* check for arguments */
1677                                 attribute = allocate_gnu_attribute(kind);
1678                                 if (token.type == '(') {
1679                                         next_token();
1680                                         if (token.type == ')') {
1681                                                 /* empty args are allowed */
1682                                                 next_token();
1683                                         } else
1684                                                 attribute->have_arguments = true;
1685                                 }
1686
1687                                 switch (kind) {
1688                                 case GNU_AK_VOLATILE:
1689                                 case GNU_AK_NAKED:
1690                                 case GNU_AK_MALLOC:
1691                                 case GNU_AK_WEAK:
1692                                 case GNU_AK_COMMON:
1693                                 case GNU_AK_NOCOMMON:
1694                                 case GNU_AK_SHARED:
1695                                 case GNU_AK_NOTSHARED:
1696                                 case GNU_AK_NO_INSTRUMENT_FUNCTION:
1697                                 case GNU_AK_WARN_UNUSED_RESULT:
1698                                 case GNU_AK_LONGCALL:
1699                                 case GNU_AK_SHORTCALL:
1700                                 case GNU_AK_LONG_CALL:
1701                                 case GNU_AK_SHORT_CALL:
1702                                 case GNU_AK_FUNCTION_VECTOR:
1703                                 case GNU_AK_INTERRUPT_HANDLER:
1704                                 case GNU_AK_NMI_HANDLER:
1705                                 case GNU_AK_NESTING:
1706                                 case GNU_AK_NEAR:
1707                                 case GNU_AK_FAR:
1708                                 case GNU_AK_SIGNAL:
1709                                 case GNU_AK_EIGTHBIT_DATA:
1710                                 case GNU_AK_TINY_DATA:
1711                                 case GNU_AK_SAVEALL:
1712                                 case GNU_AK_FLATTEN:
1713                                 case GNU_AK_SSEREGPARM:
1714                                 case GNU_AK_EXTERNALLY_VISIBLE:
1715                                 case GNU_AK_RETURN_TWICE:
1716                                 case GNU_AK_MAY_ALIAS:
1717                                 case GNU_AK_MS_STRUCT:
1718                                 case GNU_AK_GCC_STRUCT:
1719                                         goto no_arg;
1720
1721                                 case GNU_AK_CDECL:             modifiers |= DM_CDECL;             goto no_arg;
1722                                 case GNU_AK_FASTCALL:          modifiers |= DM_FASTCALL;          goto no_arg;
1723                                 case GNU_AK_STDCALL:           modifiers |= DM_STDCALL;           goto no_arg;
1724                                 case GNU_AK_UNUSED:            modifiers |= DM_UNUSED;            goto no_arg;
1725                                 case GNU_AK_USED:              modifiers |= DM_USED;              goto no_arg;
1726                                 case GNU_AK_PURE:              modifiers |= DM_PURE;              goto no_arg;
1727                                 case GNU_AK_CONST:             modifiers |= DM_CONST;             goto no_arg;
1728                                 case GNU_AK_ALWAYS_INLINE:     modifiers |= DM_FORCEINLINE;       goto no_arg;
1729                                 case GNU_AK_DLLIMPORT:         modifiers |= DM_DLLIMPORT;         goto no_arg;
1730                                 case GNU_AK_DLLEXPORT:         modifiers |= DM_DLLEXPORT;         goto no_arg;
1731                                 case GNU_AK_PACKED:            modifiers |= DM_PACKED;            goto no_arg;
1732                                 case GNU_AK_NOINLINE:          modifiers |= DM_NOINLINE;          goto no_arg;
1733                                 case GNU_AK_NORETURN:          modifiers |= DM_NORETURN;          goto no_arg;
1734                                 case GNU_AK_NOTHROW:           modifiers |= DM_NOTHROW;           goto no_arg;
1735                                 case GNU_AK_TRANSPARENT_UNION: modifiers |= DM_TRANSPARENT_UNION; goto no_arg;
1736                                 case GNU_AK_CONSTRUCTOR:       modifiers |= DM_CONSTRUCTOR;       goto no_arg;
1737                                 case GNU_AK_DESTRUCTOR:        modifiers |= DM_DESTRUCTOR;        goto no_arg;
1738                                 case GNU_AK_DEPRECATED:        modifiers |= DM_DEPRECATED;        goto no_arg;
1739
1740                                 case GNU_AK_ALIGNED:
1741                                         /* __align__ may be used without an argument */
1742                                         if (attribute->have_arguments) {
1743                                                 parse_gnu_attribute_const_arg(attribute);
1744                                         }
1745                                         break;
1746
1747                                 case GNU_AK_FORMAT_ARG:
1748                                 case GNU_AK_REGPARM:
1749                                 case GNU_AK_TRAP_EXIT:
1750                                         if (!attribute->have_arguments) {
1751                                                 /* should have arguments */
1752                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1753                                                 attribute->invalid = true;
1754                                         } else
1755                                                 parse_gnu_attribute_const_arg(attribute);
1756                                         break;
1757                                 case GNU_AK_ALIAS:
1758                                 case GNU_AK_SECTION:
1759                                 case GNU_AK_SP_SWITCH:
1760                                         if (!attribute->have_arguments) {
1761                                                 /* should have arguments */
1762                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1763                                                 attribute->invalid = true;
1764                                         } else
1765                                                 parse_gnu_attribute_string_arg(attribute, &attribute->u.string);
1766                                         break;
1767                                 case GNU_AK_FORMAT:
1768                                         if (!attribute->have_arguments) {
1769                                                 /* should have arguments */
1770                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1771                                                 attribute->invalid = true;
1772                                         } else
1773                                                 parse_gnu_attribute_format_args(attribute);
1774                                         break;
1775                                 case GNU_AK_WEAKREF:
1776                                         /* may have one string argument */
1777                                         if (attribute->have_arguments)
1778                                                 parse_gnu_attribute_string_arg(attribute, &attribute->u.string);
1779                                         break;
1780                                 case GNU_AK_NONNULL:
1781                                         if (attribute->have_arguments)
1782                                                 parse_gnu_attribute_const_arg_list(attribute);
1783                                         break;
1784                                 case GNU_AK_TLS_MODEL:
1785                                         if (!attribute->have_arguments) {
1786                                                 /* should have arguments */
1787                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1788                                         } else
1789                                                 parse_gnu_attribute_tls_model_arg(attribute);
1790                                         break;
1791                                 case GNU_AK_VISIBILITY:
1792                                         if (!attribute->have_arguments) {
1793                                                 /* should have arguments */
1794                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1795                                         } else
1796                                                 parse_gnu_attribute_visibility_arg(attribute);
1797                                         break;
1798                                 case GNU_AK_MODEL:
1799                                         if (!attribute->have_arguments) {
1800                                                 /* should have arguments */
1801                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1802                                         } else {
1803                                                 parse_gnu_attribute_model_arg(attribute);
1804                                         }
1805                                         break;
1806                                 case GNU_AK_MODE:
1807                                         if (!attribute->have_arguments) {
1808                                                 /* should have arguments */
1809                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1810                                         } else {
1811                                                 parse_gnu_attribute_mode_arg(attribute);
1812                                         }
1813                                         break;
1814                                 case GNU_AK_INTERRUPT:
1815                                         /* may have one string argument */
1816                                         if (attribute->have_arguments)
1817                                                 parse_gnu_attribute_interrupt_arg(attribute);
1818                                         break;
1819                                 case GNU_AK_SENTINEL:
1820                                         /* may have one string argument */
1821                                         if (attribute->have_arguments)
1822                                                 parse_gnu_attribute_const_arg(attribute);
1823                                         break;
1824                                 case GNU_AK_LAST:
1825                                         /* already handled */
1826                                         break;
1827
1828 no_arg:
1829                                         check_no_argument(attribute, name);
1830                                 }
1831                         }
1832                         if (attribute != NULL) {
1833                                 if (last != NULL) {
1834                                         last->next = attribute;
1835                                         last       = attribute;
1836                                 } else {
1837                                         head = last = attribute;
1838                                 }
1839                         }
1840
1841                         if (token.type != ',')
1842                                 break;
1843                         next_token();
1844                 }
1845         }
1846         expect(')');
1847         expect(')');
1848 end_error:
1849         *attributes = head;
1850
1851         return modifiers;
1852 }
1853
1854 /**
1855  * Parse GNU attributes.
1856  */
1857 static decl_modifiers_t parse_attributes(gnu_attribute_t **attributes)
1858 {
1859         decl_modifiers_t modifiers = 0;
1860
1861         while (true) {
1862                 switch (token.type) {
1863                 case T___attribute__:
1864                         modifiers |= parse_gnu_attribute(attributes);
1865                         continue;
1866
1867                 case T_asm:
1868                         next_token();
1869                         expect('(');
1870                         if (token.type != T_STRING_LITERAL) {
1871                                 parse_error_expected("while parsing assembler attribute",
1872                                                      T_STRING_LITERAL, NULL);
1873                                 eat_until_matching_token('(');
1874                                 break;
1875                         } else {
1876                                 parse_string_literals();
1877                         }
1878                         expect(')');
1879                         continue;
1880
1881                 case T_cdecl:     modifiers |= DM_CDECL;    break;
1882                 case T__fastcall: modifiers |= DM_FASTCALL; break;
1883                 case T__stdcall:  modifiers |= DM_STDCALL;  break;
1884
1885                 case T___thiscall:
1886                         /* TODO record modifier */
1887                         if (warning.other)
1888                                 warningf(HERE, "Ignoring declaration modifier %K", &token);
1889                         break;
1890
1891 end_error:
1892                 default: return modifiers;
1893                 }
1894
1895                 next_token();
1896         }
1897 }
1898
1899 static void mark_vars_read(expression_t *expr, variable_t *lhs_var);
1900
1901 static variable_t *determine_lhs_var(expression_t *const expr,
1902                                      variable_t *lhs_var)
1903 {
1904         switch (expr->kind) {
1905                 case EXPR_REFERENCE: {
1906                         entity_t *const entity = expr->reference.entity;
1907                         /* we should only find variables as lavlues... */
1908                         if (entity->base.kind != ENTITY_VARIABLE)
1909                                 return NULL;
1910
1911                         return &entity->variable;
1912                 }
1913
1914                 case EXPR_ARRAY_ACCESS: {
1915                         expression_t  *const ref = expr->array_access.array_ref;
1916                         variable_t    *      var = NULL;
1917                         if (is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1918                                 var     = determine_lhs_var(ref, lhs_var);
1919                                 lhs_var = var;
1920                         } else {
1921                                 mark_vars_read(expr->select.compound, lhs_var);
1922                         }
1923                         mark_vars_read(expr->array_access.index, lhs_var);
1924                         return var;
1925                 }
1926
1927                 case EXPR_SELECT: {
1928                         if (is_type_compound(skip_typeref(expr->base.type))) {
1929                                 return determine_lhs_var(expr->select.compound, lhs_var);
1930                         } else {
1931                                 mark_vars_read(expr->select.compound, lhs_var);
1932                                 return NULL;
1933                         }
1934                 }
1935
1936                 case EXPR_UNARY_DEREFERENCE: {
1937                         expression_t *const val = expr->unary.value;
1938                         if (val->kind == EXPR_UNARY_TAKE_ADDRESS) {
1939                                 /* *&x is a NOP */
1940                                 return determine_lhs_var(val->unary.value, lhs_var);
1941                         } else {
1942                                 mark_vars_read(val, NULL);
1943                                 return NULL;
1944                         }
1945                 }
1946
1947                 default:
1948                         mark_vars_read(expr, NULL);
1949                         return NULL;
1950         }
1951 }
1952
1953 #define VAR_ANY ((variable_t*)-1)
1954
1955 /**
1956  * Mark declarations, which are read.  This is used to deted variables, which
1957  * are never read.
1958  * Example:
1959  * x = x + 1;
1960  *   x is not marked as "read", because it is only read to calculate its own new
1961  *   value.
1962  *
1963  * x += y; y += x;
1964  *   x and y are not detected as "not read", because multiple variables are
1965  *   involved.
1966  */
1967 static void mark_vars_read(expression_t *const expr, variable_t *lhs_var)
1968 {
1969         switch (expr->kind) {
1970                 case EXPR_REFERENCE: {
1971                         entity_t *const entity = expr->reference.entity;
1972                         if (entity->kind != ENTITY_VARIABLE)
1973                                 return;
1974
1975                         variable_t *variable = &entity->variable;
1976                         if (lhs_var != variable && lhs_var != VAR_ANY) {
1977                                 variable->read = true;
1978                         }
1979                         return;
1980                 }
1981
1982                 case EXPR_CALL:
1983                         // TODO respect pure/const
1984                         mark_vars_read(expr->call.function, NULL);
1985                         for (call_argument_t *arg = expr->call.arguments; arg != NULL; arg = arg->next) {
1986                                 mark_vars_read(arg->expression, NULL);
1987                         }
1988                         return;
1989
1990                 case EXPR_CONDITIONAL:
1991                         // TODO lhs_decl should depend on whether true/false have an effect
1992                         mark_vars_read(expr->conditional.condition, NULL);
1993                         if (expr->conditional.true_expression != NULL)
1994                                 mark_vars_read(expr->conditional.true_expression, lhs_var);
1995                         mark_vars_read(expr->conditional.false_expression, lhs_var);
1996                         return;
1997
1998                 case EXPR_SELECT:
1999                         if (lhs_var == VAR_ANY && !is_type_compound(skip_typeref(expr->base.type)))
2000                                 lhs_var = NULL;
2001                         mark_vars_read(expr->select.compound, lhs_var);
2002                         return;
2003
2004                 case EXPR_ARRAY_ACCESS: {
2005                         expression_t *const ref = expr->array_access.array_ref;
2006                         mark_vars_read(ref, lhs_var);
2007                         lhs_var = determine_lhs_var(ref, lhs_var);
2008                         mark_vars_read(expr->array_access.index, lhs_var);
2009                         return;
2010                 }
2011
2012                 case EXPR_VA_ARG:
2013                         mark_vars_read(expr->va_arge.ap, lhs_var);
2014                         return;
2015
2016                 case EXPR_UNARY_CAST:
2017                         /* Special case: Use void cast to mark a variable as "read" */
2018                         if (is_type_atomic(skip_typeref(expr->base.type), ATOMIC_TYPE_VOID))
2019                                 lhs_var = NULL;
2020                         goto unary;
2021
2022
2023                 case EXPR_UNARY_THROW:
2024                         if (expr->unary.value == NULL)
2025                                 return;
2026                         /* FALLTHROUGH */
2027                 case EXPR_UNARY_DEREFERENCE:
2028                 case EXPR_UNARY_DELETE:
2029                 case EXPR_UNARY_DELETE_ARRAY:
2030                         if (lhs_var == VAR_ANY)
2031                                 lhs_var = NULL;
2032                         goto unary;
2033
2034                 case EXPR_UNARY_NEGATE:
2035                 case EXPR_UNARY_PLUS:
2036                 case EXPR_UNARY_BITWISE_NEGATE:
2037                 case EXPR_UNARY_NOT:
2038                 case EXPR_UNARY_TAKE_ADDRESS:
2039                 case EXPR_UNARY_POSTFIX_INCREMENT:
2040                 case EXPR_UNARY_POSTFIX_DECREMENT:
2041                 case EXPR_UNARY_PREFIX_INCREMENT:
2042                 case EXPR_UNARY_PREFIX_DECREMENT:
2043                 case EXPR_UNARY_CAST_IMPLICIT:
2044                 case EXPR_UNARY_ASSUME:
2045 unary:
2046                         mark_vars_read(expr->unary.value, lhs_var);
2047                         return;
2048
2049                 case EXPR_BINARY_ADD:
2050                 case EXPR_BINARY_SUB:
2051                 case EXPR_BINARY_MUL:
2052                 case EXPR_BINARY_DIV:
2053                 case EXPR_BINARY_MOD:
2054                 case EXPR_BINARY_EQUAL:
2055                 case EXPR_BINARY_NOTEQUAL:
2056                 case EXPR_BINARY_LESS:
2057                 case EXPR_BINARY_LESSEQUAL:
2058                 case EXPR_BINARY_GREATER:
2059                 case EXPR_BINARY_GREATEREQUAL:
2060                 case EXPR_BINARY_BITWISE_AND:
2061                 case EXPR_BINARY_BITWISE_OR:
2062                 case EXPR_BINARY_BITWISE_XOR:
2063                 case EXPR_BINARY_LOGICAL_AND:
2064                 case EXPR_BINARY_LOGICAL_OR:
2065                 case EXPR_BINARY_SHIFTLEFT:
2066                 case EXPR_BINARY_SHIFTRIGHT:
2067                 case EXPR_BINARY_COMMA:
2068                 case EXPR_BINARY_ISGREATER:
2069                 case EXPR_BINARY_ISGREATEREQUAL:
2070                 case EXPR_BINARY_ISLESS:
2071                 case EXPR_BINARY_ISLESSEQUAL:
2072                 case EXPR_BINARY_ISLESSGREATER:
2073                 case EXPR_BINARY_ISUNORDERED:
2074                         mark_vars_read(expr->binary.left,  lhs_var);
2075                         mark_vars_read(expr->binary.right, lhs_var);
2076                         return;
2077
2078                 case EXPR_BINARY_ASSIGN:
2079                 case EXPR_BINARY_MUL_ASSIGN:
2080                 case EXPR_BINARY_DIV_ASSIGN:
2081                 case EXPR_BINARY_MOD_ASSIGN:
2082                 case EXPR_BINARY_ADD_ASSIGN:
2083                 case EXPR_BINARY_SUB_ASSIGN:
2084                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:
2085                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:
2086                 case EXPR_BINARY_BITWISE_AND_ASSIGN:
2087                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:
2088                 case EXPR_BINARY_BITWISE_OR_ASSIGN: {
2089                         if (lhs_var == VAR_ANY)
2090                                 lhs_var = NULL;
2091                         lhs_var = determine_lhs_var(expr->binary.left, lhs_var);
2092                         mark_vars_read(expr->binary.right, lhs_var);
2093                         return;
2094                 }
2095
2096                 case EXPR_VA_START:
2097                         determine_lhs_var(expr->va_starte.ap, lhs_var);
2098                         return;
2099
2100                 case EXPR_UNKNOWN:
2101                 case EXPR_INVALID:
2102                 case EXPR_CONST:
2103                 case EXPR_CHARACTER_CONSTANT:
2104                 case EXPR_WIDE_CHARACTER_CONSTANT:
2105                 case EXPR_STRING_LITERAL:
2106                 case EXPR_WIDE_STRING_LITERAL:
2107                 case EXPR_COMPOUND_LITERAL: // TODO init?
2108                 case EXPR_SIZEOF:
2109                 case EXPR_CLASSIFY_TYPE:
2110                 case EXPR_ALIGNOF:
2111                 case EXPR_FUNCNAME:
2112                 case EXPR_BUILTIN_SYMBOL:
2113                 case EXPR_BUILTIN_CONSTANT_P:
2114                 case EXPR_BUILTIN_PREFETCH:
2115                 case EXPR_OFFSETOF:
2116                 case EXPR_STATEMENT: // TODO
2117                 case EXPR_LABEL_ADDRESS:
2118                 case EXPR_BINARY_BUILTIN_EXPECT:
2119                 case EXPR_REFERENCE_ENUM_VALUE:
2120                         return;
2121         }
2122
2123         panic("unhandled expression");
2124 }
2125
2126 static designator_t *parse_designation(void)
2127 {
2128         designator_t *result = NULL;
2129         designator_t *last   = NULL;
2130
2131         while (true) {
2132                 designator_t *designator;
2133                 switch (token.type) {
2134                 case '[':
2135                         designator = allocate_ast_zero(sizeof(designator[0]));
2136                         designator->source_position = token.source_position;
2137                         next_token();
2138                         add_anchor_token(']');
2139                         designator->array_index = parse_constant_expression();
2140                         rem_anchor_token(']');
2141                         expect(']');
2142                         break;
2143                 case '.':
2144                         designator = allocate_ast_zero(sizeof(designator[0]));
2145                         designator->source_position = token.source_position;
2146                         next_token();
2147                         if (token.type != T_IDENTIFIER) {
2148                                 parse_error_expected("while parsing designator",
2149                                                      T_IDENTIFIER, NULL);
2150                                 return NULL;
2151                         }
2152                         designator->symbol = token.v.symbol;
2153                         next_token();
2154                         break;
2155                 default:
2156                         expect('=');
2157                         return result;
2158                 }
2159
2160                 assert(designator != NULL);
2161                 if (last != NULL) {
2162                         last->next = designator;
2163                 } else {
2164                         result = designator;
2165                 }
2166                 last = designator;
2167         }
2168 end_error:
2169         return NULL;
2170 }
2171
2172 static initializer_t *initializer_from_string(array_type_t *type,
2173                                               const string_t *const string)
2174 {
2175         /* TODO: check len vs. size of array type */
2176         (void) type;
2177
2178         initializer_t *initializer = allocate_initializer_zero(INITIALIZER_STRING);
2179         initializer->string.string = *string;
2180
2181         return initializer;
2182 }
2183
2184 static initializer_t *initializer_from_wide_string(array_type_t *const type,
2185                                                    wide_string_t *const string)
2186 {
2187         /* TODO: check len vs. size of array type */
2188         (void) type;
2189
2190         initializer_t *const initializer =
2191                 allocate_initializer_zero(INITIALIZER_WIDE_STRING);
2192         initializer->wide_string.string = *string;
2193
2194         return initializer;
2195 }
2196
2197 /**
2198  * Build an initializer from a given expression.
2199  */
2200 static initializer_t *initializer_from_expression(type_t *orig_type,
2201                                                   expression_t *expression)
2202 {
2203         /* TODO check that expression is a constant expression */
2204
2205         /* § 6.7.8.14/15 char array may be initialized by string literals */
2206         type_t *type           = skip_typeref(orig_type);
2207         type_t *expr_type_orig = expression->base.type;
2208         type_t *expr_type      = skip_typeref(expr_type_orig);
2209         if (is_type_array(type) && expr_type->kind == TYPE_POINTER) {
2210                 array_type_t *const array_type   = &type->array;
2211                 type_t       *const element_type = skip_typeref(array_type->element_type);
2212
2213                 if (element_type->kind == TYPE_ATOMIC) {
2214                         atomic_type_kind_t akind = element_type->atomic.akind;
2215                         switch (expression->kind) {
2216                                 case EXPR_STRING_LITERAL:
2217                                         if (akind == ATOMIC_TYPE_CHAR
2218                                                         || akind == ATOMIC_TYPE_SCHAR
2219                                                         || akind == ATOMIC_TYPE_UCHAR) {
2220                                                 return initializer_from_string(array_type,
2221                                                         &expression->string.value);
2222                                         }
2223
2224                                 case EXPR_WIDE_STRING_LITERAL: {
2225                                         type_t *bare_wchar_type = skip_typeref(type_wchar_t);
2226                                         if (get_unqualified_type(element_type) == bare_wchar_type) {
2227                                                 return initializer_from_wide_string(array_type,
2228                                                         &expression->wide_string.value);
2229                                         }
2230                                 }
2231
2232                                 default:
2233                                         break;
2234                         }
2235                 }
2236         }
2237
2238         assign_error_t error = semantic_assign(type, expression);
2239         if (error == ASSIGN_ERROR_INCOMPATIBLE)
2240                 return NULL;
2241         report_assign_error(error, type, expression, "initializer",
2242                             &expression->base.source_position);
2243
2244         initializer_t *const result = allocate_initializer_zero(INITIALIZER_VALUE);
2245 #if 0
2246         if (type->kind == TYPE_BITFIELD) {
2247                 type = type->bitfield.base_type;
2248         }
2249 #endif
2250         result->value.value = create_implicit_cast(expression, type);
2251
2252         return result;
2253 }
2254
2255 /**
2256  * Checks if a given expression can be used as an constant initializer.
2257  */
2258 static bool is_initializer_constant(const expression_t *expression)
2259 {
2260         return is_constant_expression(expression)
2261                 || is_address_constant(expression);
2262 }
2263
2264 /**
2265  * Parses an scalar initializer.
2266  *
2267  * § 6.7.8.11; eat {} without warning
2268  */
2269 static initializer_t *parse_scalar_initializer(type_t *type,
2270                                                bool must_be_constant)
2271 {
2272         /* there might be extra {} hierarchies */
2273         int braces = 0;
2274         if (token.type == '{') {
2275                 if (warning.other)
2276                         warningf(HERE, "extra curly braces around scalar initializer");
2277                 do {
2278                         ++braces;
2279                         next_token();
2280                 } while (token.type == '{');
2281         }
2282
2283         expression_t *expression = parse_assignment_expression();
2284         mark_vars_read(expression, NULL);
2285         if (must_be_constant && !is_initializer_constant(expression)) {
2286                 errorf(&expression->base.source_position,
2287                        "Initialisation expression '%E' is not constant\n",
2288                        expression);
2289         }
2290
2291         initializer_t *initializer = initializer_from_expression(type, expression);
2292
2293         if (initializer == NULL) {
2294                 errorf(&expression->base.source_position,
2295                        "expression '%E' (type '%T') doesn't match expected type '%T'",
2296                        expression, expression->base.type, type);
2297                 /* TODO */
2298                 return NULL;
2299         }
2300
2301         bool additional_warning_displayed = false;
2302         while (braces > 0) {
2303                 if (token.type == ',') {
2304                         next_token();
2305                 }
2306                 if (token.type != '}') {
2307                         if (!additional_warning_displayed && warning.other) {
2308                                 warningf(HERE, "additional elements in scalar initializer");
2309                                 additional_warning_displayed = true;
2310                         }
2311                 }
2312                 eat_block();
2313                 braces--;
2314         }
2315
2316         return initializer;
2317 }
2318
2319 /**
2320  * An entry in the type path.
2321  */
2322 typedef struct type_path_entry_t type_path_entry_t;
2323 struct type_path_entry_t {
2324         type_t *type;       /**< the upper top type. restored to path->top_tye if this entry is popped. */
2325         union {
2326                 size_t         index;          /**< For array types: the current index. */
2327                 declaration_t *compound_entry; /**< For compound types: the current declaration. */
2328         } v;
2329 };
2330
2331 /**
2332  * A type path expression a position inside compound or array types.
2333  */
2334 typedef struct type_path_t type_path_t;
2335 struct type_path_t {
2336         type_path_entry_t *path;         /**< An flexible array containing the current path. */
2337         type_t            *top_type;     /**< type of the element the path points */
2338         size_t             max_index;    /**< largest index in outermost array */
2339 };
2340
2341 /**
2342  * Prints a type path for debugging.
2343  */
2344 static __attribute__((unused)) void debug_print_type_path(
2345                 const type_path_t *path)
2346 {
2347         size_t len = ARR_LEN(path->path);
2348
2349         for (size_t i = 0; i < len; ++i) {
2350                 const type_path_entry_t *entry = & path->path[i];
2351
2352                 type_t *type = skip_typeref(entry->type);
2353                 if (is_type_compound(type)) {
2354                         /* in gcc mode structs can have no members */
2355                         if (entry->v.compound_entry == NULL) {
2356                                 assert(i == len-1);
2357                                 continue;
2358                         }
2359                         fprintf(stderr, ".%s",
2360                                 entry->v.compound_entry->base.symbol->string);
2361                 } else if (is_type_array(type)) {
2362                         fprintf(stderr, "[%u]", (unsigned) entry->v.index);
2363                 } else {
2364                         fprintf(stderr, "-INVALID-");
2365                 }
2366         }
2367         if (path->top_type != NULL) {
2368                 fprintf(stderr, "  (");
2369                 print_type(path->top_type);
2370                 fprintf(stderr, ")");
2371         }
2372 }
2373
2374 /**
2375  * Return the top type path entry, ie. in a path
2376  * (type).a.b returns the b.
2377  */
2378 static type_path_entry_t *get_type_path_top(const type_path_t *path)
2379 {
2380         size_t len = ARR_LEN(path->path);
2381         assert(len > 0);
2382         return &path->path[len-1];
2383 }
2384
2385 /**
2386  * Enlarge the type path by an (empty) element.
2387  */
2388 static type_path_entry_t *append_to_type_path(type_path_t *path)
2389 {
2390         size_t len = ARR_LEN(path->path);
2391         ARR_RESIZE(type_path_entry_t, path->path, len+1);
2392
2393         type_path_entry_t *result = & path->path[len];
2394         memset(result, 0, sizeof(result[0]));
2395         return result;
2396 }
2397
2398 /**
2399  * Descending into a sub-type. Enter the scope of the current top_type.
2400  */
2401 static void descend_into_subtype(type_path_t *path)
2402 {
2403         type_t *orig_top_type = path->top_type;
2404         type_t *top_type      = skip_typeref(orig_top_type);
2405
2406         type_path_entry_t *top = append_to_type_path(path);
2407         top->type              = top_type;
2408
2409         if (is_type_compound(top_type)) {
2410                 compound_t *compound  = top_type->compound.compound;
2411                 entity_t   *entry     = compound->members.entities;
2412
2413                 if (entry != NULL) {
2414                         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
2415                         top->v.compound_entry = &entry->declaration;
2416                         path->top_type = entry->declaration.type;
2417                 } else {
2418                         path->top_type = NULL;
2419                 }
2420         } else if (is_type_array(top_type)) {
2421                 top->v.index   = 0;
2422                 path->top_type = top_type->array.element_type;
2423         } else {
2424                 assert(!is_type_valid(top_type));
2425         }
2426 }
2427
2428 /**
2429  * Pop an entry from the given type path, ie. returning from
2430  * (type).a.b to (type).a
2431  */
2432 static void ascend_from_subtype(type_path_t *path)
2433 {
2434         type_path_entry_t *top = get_type_path_top(path);
2435
2436         path->top_type = top->type;
2437
2438         size_t len = ARR_LEN(path->path);
2439         ARR_RESIZE(type_path_entry_t, path->path, len-1);
2440 }
2441
2442 /**
2443  * Pop entries from the given type path until the given
2444  * path level is reached.
2445  */
2446 static void ascend_to(type_path_t *path, size_t top_path_level)
2447 {
2448         size_t len = ARR_LEN(path->path);
2449
2450         while (len > top_path_level) {
2451                 ascend_from_subtype(path);
2452                 len = ARR_LEN(path->path);
2453         }
2454 }
2455
2456 static bool walk_designator(type_path_t *path, const designator_t *designator,
2457                             bool used_in_offsetof)
2458 {
2459         for (; designator != NULL; designator = designator->next) {
2460                 type_path_entry_t *top       = get_type_path_top(path);
2461                 type_t            *orig_type = top->type;
2462
2463                 type_t *type = skip_typeref(orig_type);
2464
2465                 if (designator->symbol != NULL) {
2466                         symbol_t *symbol = designator->symbol;
2467                         if (!is_type_compound(type)) {
2468                                 if (is_type_valid(type)) {
2469                                         errorf(&designator->source_position,
2470                                                "'.%Y' designator used for non-compound type '%T'",
2471                                                symbol, orig_type);
2472                                 }
2473
2474                                 top->type             = type_error_type;
2475                                 top->v.compound_entry = NULL;
2476                                 orig_type             = type_error_type;
2477                         } else {
2478                                 compound_t *compound = type->compound.compound;
2479                                 entity_t   *iter     = compound->members.entities;
2480                                 for (; iter != NULL; iter = iter->base.next) {
2481                                         if (iter->base.symbol == symbol) {
2482                                                 break;
2483                                         }
2484                                 }
2485                                 if (iter == NULL) {
2486                                         errorf(&designator->source_position,
2487                                                "'%T' has no member named '%Y'", orig_type, symbol);
2488                                         goto failed;
2489                                 }
2490                                 assert(iter->kind == ENTITY_COMPOUND_MEMBER);
2491                                 if (used_in_offsetof) {
2492                                         type_t *real_type = skip_typeref(iter->declaration.type);
2493                                         if (real_type->kind == TYPE_BITFIELD) {
2494                                                 errorf(&designator->source_position,
2495                                                        "offsetof designator '%Y' may not specify bitfield",
2496                                                        symbol);
2497                                                 goto failed;
2498                                         }
2499                                 }
2500
2501                                 top->type             = orig_type;
2502                                 top->v.compound_entry = &iter->declaration;
2503                                 orig_type             = iter->declaration.type;
2504                         }
2505                 } else {
2506                         expression_t *array_index = designator->array_index;
2507                         assert(designator->array_index != NULL);
2508
2509                         if (!is_type_array(type)) {
2510                                 if (is_type_valid(type)) {
2511                                         errorf(&designator->source_position,
2512                                                "[%E] designator used for non-array type '%T'",
2513                                                array_index, orig_type);
2514                                 }
2515                                 goto failed;
2516                         }
2517
2518                         long index = fold_constant(array_index);
2519                         if (!used_in_offsetof) {
2520                                 if (index < 0) {
2521                                         errorf(&designator->source_position,
2522                                                "array index [%E] must be positive", array_index);
2523                                 } else if (type->array.size_constant) {
2524                                         long array_size = type->array.size;
2525                                         if (index >= array_size) {
2526                                                 errorf(&designator->source_position,
2527                                                        "designator [%E] (%d) exceeds array size %d",
2528                                                        array_index, index, array_size);
2529                                         }
2530                                 }
2531                         }
2532
2533                         top->type    = orig_type;
2534                         top->v.index = (size_t) index;
2535                         orig_type    = type->array.element_type;
2536                 }
2537                 path->top_type = orig_type;
2538
2539                 if (designator->next != NULL) {
2540                         descend_into_subtype(path);
2541                 }
2542         }
2543         return true;
2544
2545 failed:
2546         return false;
2547 }
2548
2549 static void advance_current_object(type_path_t *path, size_t top_path_level)
2550 {
2551         type_path_entry_t *top = get_type_path_top(path);
2552
2553         type_t *type = skip_typeref(top->type);
2554         if (is_type_union(type)) {
2555                 /* in unions only the first element is initialized */
2556                 top->v.compound_entry = NULL;
2557         } else if (is_type_struct(type)) {
2558                 declaration_t *entry = top->v.compound_entry;
2559
2560                 entity_t *next_entity = entry->base.next;
2561                 if (next_entity != NULL) {
2562                         assert(is_declaration(next_entity));
2563                         entry = &next_entity->declaration;
2564                 } else {
2565                         entry = NULL;
2566                 }
2567
2568                 top->v.compound_entry = entry;
2569                 if (entry != NULL) {
2570                         path->top_type = entry->type;
2571                         return;
2572                 }
2573         } else if (is_type_array(type)) {
2574                 assert(is_type_array(type));
2575
2576                 top->v.index++;
2577
2578                 if (!type->array.size_constant || top->v.index < type->array.size) {
2579                         return;
2580                 }
2581         } else {
2582                 assert(!is_type_valid(type));
2583                 return;
2584         }
2585
2586         /* we're past the last member of the current sub-aggregate, try if we
2587          * can ascend in the type hierarchy and continue with another subobject */
2588         size_t len = ARR_LEN(path->path);
2589
2590         if (len > top_path_level) {
2591                 ascend_from_subtype(path);
2592                 advance_current_object(path, top_path_level);
2593         } else {
2594                 path->top_type = NULL;
2595         }
2596 }
2597
2598 /**
2599  * skip until token is found.
2600  */
2601 static void skip_until(int type)
2602 {
2603         while (token.type != type) {
2604                 if (token.type == T_EOF)
2605                         return;
2606                 next_token();
2607         }
2608 }
2609
2610 /**
2611  * skip any {...} blocks until a closing bracket is reached.
2612  */
2613 static void skip_initializers(void)
2614 {
2615         if (token.type == '{')
2616                 next_token();
2617
2618         while (token.type != '}') {
2619                 if (token.type == T_EOF)
2620                         return;
2621                 if (token.type == '{') {
2622                         eat_block();
2623                         continue;
2624                 }
2625                 next_token();
2626         }
2627 }
2628
2629 static initializer_t *create_empty_initializer(void)
2630 {
2631         static initializer_t empty_initializer
2632                 = { .list = { { INITIALIZER_LIST }, 0 } };
2633         return &empty_initializer;
2634 }
2635
2636 /**
2637  * Parse a part of an initialiser for a struct or union,
2638  */
2639 static initializer_t *parse_sub_initializer(type_path_t *path,
2640                 type_t *outer_type, size_t top_path_level,
2641                 parse_initializer_env_t *env)
2642 {
2643         if (token.type == '}') {
2644                 /* empty initializer */
2645                 return create_empty_initializer();
2646         }
2647
2648         type_t *orig_type = path->top_type;
2649         type_t *type      = NULL;
2650
2651         if (orig_type == NULL) {
2652                 /* We are initializing an empty compound. */
2653         } else {
2654                 type = skip_typeref(orig_type);
2655         }
2656
2657         initializer_t **initializers = NEW_ARR_F(initializer_t*, 0);
2658
2659         while (true) {
2660                 designator_t *designator = NULL;
2661                 if (token.type == '.' || token.type == '[') {
2662                         designator = parse_designation();
2663                         goto finish_designator;
2664                 } else if (token.type == T_IDENTIFIER && look_ahead(1)->type == ':') {
2665                         /* GNU-style designator ("identifier: value") */
2666                         designator = allocate_ast_zero(sizeof(designator[0]));
2667                         designator->source_position = token.source_position;
2668                         designator->symbol          = token.v.symbol;
2669                         eat(T_IDENTIFIER);
2670                         eat(':');
2671
2672 finish_designator:
2673                         /* reset path to toplevel, evaluate designator from there */
2674                         ascend_to(path, top_path_level);
2675                         if (!walk_designator(path, designator, false)) {
2676                                 /* can't continue after designation error */
2677                                 goto end_error;
2678                         }
2679
2680                         initializer_t *designator_initializer
2681                                 = allocate_initializer_zero(INITIALIZER_DESIGNATOR);
2682                         designator_initializer->designator.designator = designator;
2683                         ARR_APP1(initializer_t*, initializers, designator_initializer);
2684
2685                         orig_type = path->top_type;
2686                         type      = orig_type != NULL ? skip_typeref(orig_type) : NULL;
2687                 }
2688
2689                 initializer_t *sub;
2690
2691                 if (token.type == '{') {
2692                         if (type != NULL && is_type_scalar(type)) {
2693                                 sub = parse_scalar_initializer(type, env->must_be_constant);
2694                         } else {
2695                                 eat('{');
2696                                 if (type == NULL) {
2697                                         if (env->entity != NULL) {
2698                                                 errorf(HERE,
2699                                                      "extra brace group at end of initializer for '%Y'",
2700                                                      env->entity->base.symbol);
2701                                         } else {
2702                                                 errorf(HERE, "extra brace group at end of initializer");
2703                                         }
2704                                 } else
2705                                         descend_into_subtype(path);
2706
2707                                 add_anchor_token('}');
2708                                 sub = parse_sub_initializer(path, orig_type, top_path_level+1,
2709                                                             env);
2710                                 rem_anchor_token('}');
2711
2712                                 if (type != NULL) {
2713                                         ascend_from_subtype(path);
2714                                         expect('}');
2715                                 } else {
2716                                         expect('}');
2717                                         goto error_parse_next;
2718                                 }
2719                         }
2720                 } else {
2721                         /* must be an expression */
2722                         expression_t *expression = parse_assignment_expression();
2723
2724                         if (env->must_be_constant && !is_initializer_constant(expression)) {
2725                                 errorf(&expression->base.source_position,
2726                                        "Initialisation expression '%E' is not constant\n",
2727                                        expression);
2728                         }
2729
2730                         if (type == NULL) {
2731                                 /* we are already outside, ... */
2732                                 type_t *const outer_type_skip = skip_typeref(outer_type);
2733                                 if (is_type_compound(outer_type_skip) &&
2734                                     !outer_type_skip->compound.compound->complete) {
2735                                         goto error_parse_next;
2736                                 }
2737                                 goto error_excess;
2738                         }
2739
2740                         /* handle { "string" } special case */
2741                         if ((expression->kind == EXPR_STRING_LITERAL
2742                                         || expression->kind == EXPR_WIDE_STRING_LITERAL)
2743                                         && outer_type != NULL) {
2744                                 sub = initializer_from_expression(outer_type, expression);
2745                                 if (sub != NULL) {
2746                                         if (token.type == ',') {
2747                                                 next_token();
2748                                         }
2749                                         if (token.type != '}' && warning.other) {
2750                                                 warningf(HERE, "excessive elements in initializer for type '%T'",
2751                                                                  orig_type);
2752                                         }
2753                                         /* TODO: eat , ... */
2754                                         return sub;
2755                                 }
2756                         }
2757
2758                         /* descend into subtypes until expression matches type */
2759                         while (true) {
2760                                 orig_type = path->top_type;
2761                                 type      = skip_typeref(orig_type);
2762
2763                                 sub = initializer_from_expression(orig_type, expression);
2764                                 if (sub != NULL) {
2765                                         break;
2766                                 }
2767                                 if (!is_type_valid(type)) {
2768                                         goto end_error;
2769                                 }
2770                                 if (is_type_scalar(type)) {
2771                                         errorf(&expression->base.source_position,
2772                                                         "expression '%E' doesn't match expected type '%T'",
2773                                                         expression, orig_type);
2774                                         goto end_error;
2775                                 }
2776
2777                                 descend_into_subtype(path);
2778                         }
2779                 }
2780
2781                 /* update largest index of top array */
2782                 const type_path_entry_t *first      = &path->path[0];
2783                 type_t                  *first_type = first->type;
2784                 first_type                          = skip_typeref(first_type);
2785                 if (is_type_array(first_type)) {
2786                         size_t index = first->v.index;
2787                         if (index > path->max_index)
2788                                 path->max_index = index;
2789                 }
2790
2791                 if (type != NULL) {
2792                         /* append to initializers list */
2793                         ARR_APP1(initializer_t*, initializers, sub);
2794                 } else {
2795 error_excess:
2796                         if (warning.other) {
2797                                 if (env->entity != NULL) {
2798                                         warningf(HERE, "excess elements in struct initializer for '%Y'",
2799                                            env->entity->base.symbol);
2800                                 } else {
2801                                         warningf(HERE, "excess elements in struct initializer");
2802                                 }
2803                         }
2804                 }
2805
2806 error_parse_next:
2807                 if (token.type == '}') {
2808                         break;
2809                 }
2810                 expect(',');
2811                 if (token.type == '}') {
2812                         break;
2813                 }
2814
2815                 if (type != NULL) {
2816                         /* advance to the next declaration if we are not at the end */
2817                         advance_current_object(path, top_path_level);
2818                         orig_type = path->top_type;
2819                         if (orig_type != NULL)
2820                                 type = skip_typeref(orig_type);
2821                         else
2822                                 type = NULL;
2823                 }
2824         }
2825
2826         size_t len  = ARR_LEN(initializers);
2827         size_t size = sizeof(initializer_list_t) + len * sizeof(initializers[0]);
2828         initializer_t *result = allocate_ast_zero(size);
2829         result->kind          = INITIALIZER_LIST;
2830         result->list.len      = len;
2831         memcpy(&result->list.initializers, initializers,
2832                len * sizeof(initializers[0]));
2833
2834         DEL_ARR_F(initializers);
2835         ascend_to(path, top_path_level+1);
2836
2837         return result;
2838
2839 end_error:
2840         skip_initializers();
2841         DEL_ARR_F(initializers);
2842         ascend_to(path, top_path_level+1);
2843         return NULL;
2844 }
2845
2846 /**
2847  * Parses an initializer. Parsers either a compound literal
2848  * (env->declaration == NULL) or an initializer of a declaration.
2849  */
2850 static initializer_t *parse_initializer(parse_initializer_env_t *env)
2851 {
2852         type_t        *type   = skip_typeref(env->type);
2853         initializer_t *result = NULL;
2854         size_t         max_index;
2855
2856         if (is_type_scalar(type)) {
2857                 result = parse_scalar_initializer(type, env->must_be_constant);
2858         } else if (token.type == '{') {
2859                 eat('{');
2860
2861                 type_path_t path;
2862                 memset(&path, 0, sizeof(path));
2863                 path.top_type = env->type;
2864                 path.path     = NEW_ARR_F(type_path_entry_t, 0);
2865
2866                 descend_into_subtype(&path);
2867
2868                 add_anchor_token('}');
2869                 result = parse_sub_initializer(&path, env->type, 1, env);
2870                 rem_anchor_token('}');
2871
2872                 max_index = path.max_index;
2873                 DEL_ARR_F(path.path);
2874
2875                 expect('}');
2876         } else {
2877                 /* parse_scalar_initializer() also works in this case: we simply
2878                  * have an expression without {} around it */
2879                 result = parse_scalar_initializer(type, env->must_be_constant);
2880         }
2881
2882         /* § 6.7.8 (22) array initializers for arrays with unknown size determine
2883          * the array type size */
2884         if (is_type_array(type) && type->array.size_expression == NULL
2885                         && result != NULL) {
2886                 size_t size;
2887                 switch (result->kind) {
2888                 case INITIALIZER_LIST:
2889                         size = max_index + 1;
2890                         break;
2891
2892                 case INITIALIZER_STRING:
2893                         size = result->string.string.size;
2894                         break;
2895
2896                 case INITIALIZER_WIDE_STRING:
2897                         size = result->wide_string.string.size;
2898                         break;
2899
2900                 case INITIALIZER_DESIGNATOR:
2901                 case INITIALIZER_VALUE:
2902                         /* can happen for parse errors */
2903                         size = 0;
2904                         break;
2905
2906                 default:
2907                         internal_errorf(HERE, "invalid initializer type");
2908                 }
2909
2910                 expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
2911                 cnst->base.type          = type_size_t;
2912                 cnst->conste.v.int_value = size;
2913
2914                 type_t *new_type = duplicate_type(type);
2915
2916                 new_type->array.size_expression   = cnst;
2917                 new_type->array.size_constant     = true;
2918                 new_type->array.has_implicit_size = true;
2919                 new_type->array.size              = size;
2920                 env->type = new_type;
2921         }
2922
2923         return result;
2924 end_error:
2925         return NULL;
2926 }
2927
2928 static void append_entity(scope_t *scope, entity_t *entity)
2929 {
2930         if (scope->last_entity != NULL) {
2931                 scope->last_entity->base.next = entity;
2932         } else {
2933                 scope->entities = entity;
2934         }
2935         scope->last_entity = entity;
2936 }
2937
2938
2939 static compound_t *parse_compound_type_specifier(bool is_struct)
2940 {
2941         gnu_attribute_t  *attributes = NULL;
2942         decl_modifiers_t  modifiers  = 0;
2943         if (is_struct) {
2944                 eat(T_struct);
2945         } else {
2946                 eat(T_union);
2947         }
2948
2949         symbol_t   *symbol      = NULL;
2950         compound_t *compound = NULL;
2951
2952         if (token.type == T___attribute__) {
2953                 modifiers |= parse_attributes(&attributes);
2954         }
2955
2956         if (token.type == T_IDENTIFIER) {
2957                 symbol = token.v.symbol;
2958                 next_token();
2959
2960                 namespace_tag_t const namespc =
2961                         is_struct ? NAMESPACE_STRUCT : NAMESPACE_UNION;
2962                 entity_t *entity = get_entity(symbol, namespc);
2963                 if (entity != NULL) {
2964                         assert(entity->kind == (is_struct ? ENTITY_STRUCT : ENTITY_UNION));
2965                         compound = &entity->compound;
2966                         if (compound->base.parent_scope != current_scope &&
2967                             (token.type == '{' || token.type == ';')) {
2968                                 /* we're in an inner scope and have a definition. Override
2969                                    existing definition in outer scope */
2970                                 compound = NULL;
2971                         } else if (compound->complete && token.type == '{') {
2972                                 assert(symbol != NULL);
2973                                 errorf(HERE, "multiple definitions of '%s %Y' (previous definition %P)",
2974                                        is_struct ? "struct" : "union", symbol,
2975                                        &compound->base.source_position);
2976                                 /* clear members in the hope to avoid further errors */
2977                                 compound->members.entities = NULL;
2978                         }
2979                 }
2980         } else if (token.type != '{') {
2981                 if (is_struct) {
2982                         parse_error_expected("while parsing struct type specifier",
2983                                              T_IDENTIFIER, '{', NULL);
2984                 } else {
2985                         parse_error_expected("while parsing union type specifier",
2986                                              T_IDENTIFIER, '{', NULL);
2987                 }
2988
2989                 return NULL;
2990         }
2991
2992         if (compound == NULL) {
2993                 entity_kind_t  kind   = is_struct ? ENTITY_STRUCT : ENTITY_UNION;
2994                 entity_t      *entity = allocate_entity_zero(kind);
2995                 compound              = &entity->compound;
2996
2997                 compound->base.namespc =
2998                         (is_struct ? NAMESPACE_STRUCT : NAMESPACE_UNION);
2999                 compound->base.source_position = token.source_position;
3000                 compound->base.symbol          = symbol;
3001                 compound->base.parent_scope    = current_scope;
3002                 if (symbol != NULL) {
3003                         environment_push(entity);
3004                 }
3005                 append_entity(current_scope, entity);
3006         }
3007
3008         if (token.type == '{') {
3009                 parse_compound_type_entries(compound);
3010                 modifiers |= parse_attributes(&attributes);
3011         }
3012
3013         compound->modifiers |= modifiers;
3014         return compound;
3015 }
3016
3017 static void parse_enum_entries(type_t *const enum_type)
3018 {
3019         eat('{');
3020
3021         if (token.type == '}') {
3022                 next_token();
3023                 errorf(HERE, "empty enum not allowed");
3024                 return;
3025         }
3026
3027         add_anchor_token('}');
3028         do {
3029                 if (token.type != T_IDENTIFIER) {
3030                         parse_error_expected("while parsing enum entry", T_IDENTIFIER, NULL);
3031                         eat_block();
3032                         rem_anchor_token('}');
3033                         return;
3034                 }
3035
3036                 entity_t *entity             = allocate_entity_zero(ENTITY_ENUM_VALUE);
3037                 entity->enum_value.enum_type = enum_type;
3038                 entity->base.symbol          = token.v.symbol;
3039                 entity->base.source_position = token.source_position;
3040                 next_token();
3041
3042                 if (token.type == '=') {
3043                         next_token();
3044                         expression_t *value = parse_constant_expression();
3045
3046                         value = create_implicit_cast(value, enum_type);
3047                         entity->enum_value.value = value;
3048
3049                         /* TODO semantic */
3050                 }
3051
3052                 record_entity(entity, false);
3053
3054                 if (token.type != ',')
3055                         break;
3056                 next_token();
3057         } while (token.type != '}');
3058         rem_anchor_token('}');
3059
3060         expect('}');
3061
3062 end_error:
3063         ;
3064 }
3065
3066 static type_t *parse_enum_specifier(void)
3067 {
3068         gnu_attribute_t *attributes = NULL;
3069         entity_t        *entity;
3070         symbol_t        *symbol;
3071
3072         eat(T_enum);
3073         if (token.type == T_IDENTIFIER) {
3074                 symbol = token.v.symbol;
3075                 next_token();
3076
3077                 entity = get_entity(symbol, NAMESPACE_ENUM);
3078                 assert(entity == NULL || entity->kind == ENTITY_ENUM);
3079         } else if (token.type != '{') {
3080                 parse_error_expected("while parsing enum type specifier",
3081                                      T_IDENTIFIER, '{', NULL);
3082                 return NULL;
3083         } else {
3084                 entity  = NULL;
3085                 symbol  = NULL;
3086         }
3087
3088         if (entity == NULL) {
3089                 entity                       = allocate_entity_zero(ENTITY_ENUM);
3090                 entity->base.namespc         = NAMESPACE_ENUM;
3091                 entity->base.source_position = token.source_position;
3092                 entity->base.symbol          = symbol;
3093                 entity->base.parent_scope    = current_scope;
3094         }
3095
3096         type_t *const type = allocate_type_zero(TYPE_ENUM);
3097         type->enumt.enume  = &entity->enume;
3098
3099         if (token.type == '{') {
3100                 if (entity->enume.complete) {
3101                         errorf(HERE, "multiple definitions of enum %Y (previous definition %P)",
3102                                symbol, &entity->base.source_position);
3103                 }
3104                 if (symbol != NULL) {
3105                         environment_push(entity);
3106                 }
3107                 append_entity(current_scope, entity);
3108                 entity->enume.complete = true;
3109
3110                 parse_enum_entries(type);
3111                 parse_attributes(&attributes);
3112         } else if (!entity->enume.complete && !(c_mode & _GNUC)) {
3113                 errorf(HERE, "enum %Y used before definition (incomplete enumes are a GNU extension)",
3114                        symbol);
3115         }
3116
3117         return type;
3118 }
3119
3120 /**
3121  * if a symbol is a typedef to another type, return true
3122  */
3123 static bool is_typedef_symbol(symbol_t *symbol)
3124 {
3125         const entity_t *const entity = get_entity(symbol, NAMESPACE_NORMAL);
3126         return entity != NULL && entity->kind == ENTITY_TYPEDEF;
3127 }
3128
3129 static type_t *parse_typeof(void)
3130 {
3131         eat(T___typeof__);
3132
3133         type_t *type;
3134
3135         expect('(');
3136         add_anchor_token(')');
3137
3138         expression_t *expression  = NULL;
3139
3140         bool old_type_prop     = in_type_prop;
3141         bool old_gcc_extension = in_gcc_extension;
3142         in_type_prop           = true;
3143
3144         while (token.type == T___extension__) {
3145                 /* This can be a prefix to a typename or an expression. */
3146                 next_token();
3147                 in_gcc_extension = true;
3148         }
3149         switch (token.type) {
3150         case T_IDENTIFIER:
3151                 if (is_typedef_symbol(token.v.symbol)) {
3152                         type = parse_typename();
3153                 } else {
3154                         expression = parse_expression();
3155                         type       = expression->base.type;
3156                 }
3157                 break;
3158
3159         TYPENAME_START
3160                 type = parse_typename();
3161                 break;
3162
3163         default:
3164                 expression = parse_expression();
3165                 type       = expression->base.type;
3166                 break;
3167         }
3168         in_type_prop     = old_type_prop;
3169         in_gcc_extension = old_gcc_extension;
3170
3171         rem_anchor_token(')');
3172         expect(')');
3173
3174         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF);
3175         typeof_type->typeoft.expression  = expression;
3176         typeof_type->typeoft.typeof_type = type;
3177
3178         return typeof_type;
3179 end_error:
3180         return NULL;
3181 }
3182
3183 typedef enum specifiers_t {
3184         SPECIFIER_SIGNED    = 1 << 0,
3185         SPECIFIER_UNSIGNED  = 1 << 1,
3186         SPECIFIER_LONG      = 1 << 2,
3187         SPECIFIER_INT       = 1 << 3,
3188         SPECIFIER_DOUBLE    = 1 << 4,
3189         SPECIFIER_CHAR      = 1 << 5,
3190         SPECIFIER_SHORT     = 1 << 6,
3191         SPECIFIER_LONG_LONG = 1 << 7,
3192         SPECIFIER_FLOAT     = 1 << 8,
3193         SPECIFIER_BOOL      = 1 << 9,
3194         SPECIFIER_VOID      = 1 << 10,
3195         SPECIFIER_INT8      = 1 << 11,
3196         SPECIFIER_INT16     = 1 << 12,
3197         SPECIFIER_INT32     = 1 << 13,
3198         SPECIFIER_INT64     = 1 << 14,
3199         SPECIFIER_INT128    = 1 << 15,
3200         SPECIFIER_COMPLEX   = 1 << 16,
3201         SPECIFIER_IMAGINARY = 1 << 17,
3202 } specifiers_t;
3203
3204 static type_t *create_builtin_type(symbol_t *const symbol,
3205                                    type_t *const real_type)
3206 {
3207         type_t *type            = allocate_type_zero(TYPE_BUILTIN);
3208         type->builtin.symbol    = symbol;
3209         type->builtin.real_type = real_type;
3210
3211         type_t *result = typehash_insert(type);
3212         if (type != result) {
3213                 free_type(type);
3214         }
3215
3216         return result;
3217 }
3218
3219 static type_t *get_typedef_type(symbol_t *symbol)
3220 {
3221         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
3222         if (entity == NULL || entity->kind != ENTITY_TYPEDEF)
3223                 return NULL;
3224
3225         type_t *type            = allocate_type_zero(TYPE_TYPEDEF);
3226         type->typedeft.typedefe = &entity->typedefe;
3227
3228         return type;
3229 }
3230
3231 /**
3232  * check for the allowed MS alignment values.
3233  */
3234 static bool check_alignment_value(long long intvalue)
3235 {
3236         if (intvalue < 1 || intvalue > 8192) {
3237                 errorf(HERE, "illegal alignment value");
3238                 return false;
3239         }
3240         unsigned v = (unsigned)intvalue;
3241         for (unsigned i = 1; i <= 8192; i += i) {
3242                 if (i == v)
3243                         return true;
3244         }
3245         errorf(HERE, "alignment must be power of two");
3246         return false;
3247 }
3248
3249 #define DET_MOD(name, tag) do { \
3250         if (*modifiers & tag && warning.other) warningf(HERE, #name " used more than once"); \
3251         *modifiers |= tag; \
3252 } while (0)
3253
3254 static void parse_microsoft_extended_decl_modifier(declaration_specifiers_t *specifiers)
3255 {
3256         decl_modifiers_t *modifiers = &specifiers->modifiers;
3257
3258         while (true) {
3259                 if (token.type == T_restrict) {
3260                         next_token();
3261                         DET_MOD(restrict, DM_RESTRICT);
3262                         goto end_loop;
3263                 } else if (token.type != T_IDENTIFIER)
3264                         break;
3265                 symbol_t *symbol = token.v.symbol;
3266                 if (symbol == sym_align) {
3267                         next_token();
3268                         expect('(');
3269                         if (token.type != T_INTEGER)
3270                                 goto end_error;
3271                         if (check_alignment_value(token.v.intvalue)) {
3272                                 if (specifiers->alignment != 0 && warning.other)
3273                                         warningf(HERE, "align used more than once");
3274                                 specifiers->alignment = (unsigned char)token.v.intvalue;
3275                         }
3276                         next_token();
3277                         expect(')');
3278                 } else if (symbol == sym_allocate) {
3279                         next_token();
3280                         expect('(');
3281                         if (token.type != T_IDENTIFIER)
3282                                 goto end_error;
3283                         (void)token.v.symbol;
3284                         expect(')');
3285                 } else if (symbol == sym_dllimport) {
3286                         next_token();
3287                         DET_MOD(dllimport, DM_DLLIMPORT);
3288                 } else if (symbol == sym_dllexport) {
3289                         next_token();
3290                         DET_MOD(dllexport, DM_DLLEXPORT);
3291                 } else if (symbol == sym_thread) {
3292                         next_token();
3293                         DET_MOD(thread, DM_THREAD);
3294                 } else if (symbol == sym_naked) {
3295                         next_token();
3296                         DET_MOD(naked, DM_NAKED);
3297                 } else if (symbol == sym_noinline) {
3298                         next_token();
3299                         DET_MOD(noinline, DM_NOINLINE);
3300                 } else if (symbol == sym_noreturn) {
3301                         next_token();
3302                         DET_MOD(noreturn, DM_NORETURN);
3303                 } else if (symbol == sym_nothrow) {
3304                         next_token();
3305                         DET_MOD(nothrow, DM_NOTHROW);
3306                 } else if (symbol == sym_novtable) {
3307                         next_token();
3308                         DET_MOD(novtable, DM_NOVTABLE);
3309                 } else if (symbol == sym_property) {
3310                         next_token();
3311                         expect('(');
3312                         for (;;) {
3313                                 bool is_get = false;
3314                                 if (token.type != T_IDENTIFIER)
3315                                         goto end_error;
3316                                 if (token.v.symbol == sym_get) {
3317                                         is_get = true;
3318                                 } else if (token.v.symbol == sym_put) {
3319                                 } else {
3320                                         errorf(HERE, "Bad property name '%Y'", token.v.symbol);
3321                                         goto end_error;
3322                                 }
3323                                 next_token();
3324                                 expect('=');
3325                                 if (token.type != T_IDENTIFIER)
3326                                         goto end_error;
3327                                 if (is_get) {
3328                                         if (specifiers->get_property_sym != NULL) {
3329                                                 errorf(HERE, "get property name already specified");
3330                                         } else {
3331                                                 specifiers->get_property_sym = token.v.symbol;
3332                                         }
3333                                 } else {
3334                                         if (specifiers->put_property_sym != NULL) {
3335                                                 errorf(HERE, "put property name already specified");
3336                                         } else {
3337                                                 specifiers->put_property_sym = token.v.symbol;
3338                                         }
3339                                 }
3340                                 next_token();
3341                                 if (token.type == ',') {
3342                                         next_token();
3343                                         continue;
3344                                 }
3345                                 break;
3346                         }
3347                         expect(')');
3348                 } else if (symbol == sym_selectany) {
3349                         next_token();
3350                         DET_MOD(selectany, DM_SELECTANY);
3351                 } else if (symbol == sym_uuid) {
3352                         next_token();
3353                         expect('(');
3354                         if (token.type != T_STRING_LITERAL)
3355                                 goto end_error;
3356                         next_token();
3357                         expect(')');
3358                 } else if (symbol == sym_deprecated) {
3359                         next_token();
3360                         if (specifiers->deprecated != 0 && warning.other)
3361                                 warningf(HERE, "deprecated used more than once");
3362                         specifiers->deprecated = true;
3363                         if (token.type == '(') {
3364                                 next_token();
3365                                 if (token.type == T_STRING_LITERAL) {
3366                                         specifiers->deprecated_string = token.v.string.begin;
3367                                         next_token();
3368                                 } else {
3369                                         errorf(HERE, "string literal expected");
3370                                 }
3371                                 expect(')');
3372                         }
3373                 } else if (symbol == sym_noalias) {
3374                         next_token();
3375                         DET_MOD(noalias, DM_NOALIAS);
3376                 } else {
3377                         if (warning.other)
3378                                 warningf(HERE, "Unknown modifier %Y ignored", token.v.symbol);
3379                         next_token();
3380                         if (token.type == '(')
3381                                 skip_until(')');
3382                 }
3383 end_loop:
3384                 if (token.type == ',')
3385                         next_token();
3386         }
3387 end_error:
3388         return;
3389 }
3390
3391 static entity_t *create_error_entity(symbol_t *symbol, entity_kind_tag_t kind)
3392 {
3393         entity_t *entity             = allocate_entity_zero(kind);
3394         entity->base.source_position = *HERE;
3395         entity->base.symbol          = symbol;
3396         if (is_declaration(entity)) {
3397                 entity->declaration.type     = type_error_type;
3398                 entity->declaration.implicit = true;
3399         } else if (kind == ENTITY_TYPEDEF) {
3400                 entity->typedefe.type = type_error_type;
3401         }
3402         record_entity(entity, false);
3403         return entity;
3404 }
3405
3406 static void parse_microsoft_based(declaration_specifiers_t *specifiers)
3407 {
3408         if (token.type != T_IDENTIFIER) {
3409                 parse_error_expected("while parsing __based", T_IDENTIFIER, NULL);
3410                 return;
3411         }
3412         symbol_t *symbol = token.v.symbol;
3413         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
3414
3415         if (entity == NULL || entity->base.kind != ENTITY_VARIABLE) {
3416                 errorf(HERE, "'%Y' is not a variable name.", symbol);
3417                 entity = create_error_entity(symbol, ENTITY_VARIABLE);
3418         } else {
3419                 variable_t *variable = &entity->variable;
3420
3421                 if (specifiers->based_variable != NULL) {
3422                         errorf(HERE, "__based type qualifier specified more than once");
3423                 }
3424                 specifiers->based_variable = variable;
3425
3426                 type_t *const type = variable->base.type;
3427
3428                 if (is_type_valid(type)) {
3429                         if (! is_type_pointer(skip_typeref(type))) {
3430                                 errorf(HERE, "variable in __based modifier must have pointer type instead of %T", type);
3431                         }
3432                         if (variable->base.base.parent_scope != file_scope) {
3433                                 errorf(HERE, "a nonstatic local variable may not be used in a __based specification");
3434                         }
3435                 }
3436         }
3437         next_token();
3438 }
3439
3440 /**
3441  * Finish the construction of a struct type by calculating
3442  * its size, offsets, alignment.
3443  */
3444 static void finish_struct_type(compound_type_t *type)
3445 {
3446         assert(type->compound != NULL);
3447
3448         compound_t *compound = type->compound;
3449         if (!compound->complete)
3450                 return;
3451
3452         il_size_t      size           = 0;
3453         il_size_t      offset;
3454         il_alignment_t alignment      = 1;
3455         bool           need_pad       = false;
3456
3457         entity_t *entry = compound->members.entities;
3458         for (; entry != NULL; entry = entry->base.next) {
3459                 if (entry->kind != ENTITY_COMPOUND_MEMBER)
3460                         continue;
3461
3462                 type_t *m_type = skip_typeref(entry->declaration.type);
3463                 if (! is_type_valid(m_type)) {
3464                         /* simply ignore errors here */
3465                         continue;
3466                 }
3467                 il_alignment_t m_alignment = m_type->base.alignment;
3468                 if (m_alignment > alignment)
3469                         alignment = m_alignment;
3470
3471                 offset = (size + m_alignment - 1) & -m_alignment;
3472
3473                 if (offset > size)
3474                         need_pad = true;
3475                 entry->compound_member.offset = offset;
3476                 size = offset + m_type->base.size;
3477         }
3478         if (type->base.alignment != 0) {
3479                 alignment = type->base.alignment;
3480         }
3481
3482         offset = (size + alignment - 1) & -alignment;
3483         if (offset > size)
3484                 need_pad = true;
3485
3486         if (warning.padded && need_pad) {
3487                 warningf(&compound->base.source_position,
3488                         "'%#T' needs padding", type, compound->base.symbol);
3489         }
3490         if (warning.packed && !need_pad) {
3491                 warningf(&compound->base.source_position,
3492                         "superfluous packed attribute on '%#T'",
3493                         type, compound->base.symbol);
3494         }
3495
3496         type->base.size      = offset;
3497         type->base.alignment = alignment;
3498 }
3499
3500 /**
3501  * Finish the construction of an union type by calculating
3502  * its size and alignment.
3503  */
3504 static void finish_union_type(compound_type_t *type)
3505 {
3506         assert(type->compound != NULL);
3507
3508         compound_t *compound = type->compound;
3509         if (! compound->complete)
3510                 return;
3511
3512         il_size_t      size      = 0;
3513         il_alignment_t alignment = 1;
3514
3515         entity_t *entry = compound->members.entities;
3516         for (; entry != NULL; entry = entry->base.next) {
3517                 if (entry->kind != ENTITY_COMPOUND_MEMBER)
3518                         continue;
3519
3520                 type_t *m_type = skip_typeref(entry->declaration.type);
3521                 if (! is_type_valid(m_type))
3522                         continue;
3523
3524                 entry->compound_member.offset = 0;
3525                 if (m_type->base.size > size)
3526                         size = m_type->base.size;
3527                 if (m_type->base.alignment > alignment)
3528                         alignment = m_type->base.alignment;
3529         }
3530         if (type->base.alignment != 0) {
3531                 alignment = type->base.alignment;
3532         }
3533         size = (size + alignment - 1) & -alignment;
3534         type->base.size      = size;
3535         type->base.alignment = alignment;
3536 }
3537
3538 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
3539 {
3540         type_t            *type              = NULL;
3541         type_qualifiers_t  qualifiers        = TYPE_QUALIFIER_NONE;
3542         type_modifiers_t   modifiers         = TYPE_MODIFIER_NONE;
3543         unsigned           type_specifiers   = 0;
3544         bool               newtype           = false;
3545         bool               saw_error         = false;
3546         bool               old_gcc_extension = in_gcc_extension;
3547
3548         specifiers->source_position = token.source_position;
3549
3550         while (true) {
3551                 specifiers->modifiers
3552                         |= parse_attributes(&specifiers->gnu_attributes);
3553                 if (specifiers->modifiers & DM_TRANSPARENT_UNION)
3554                         modifiers |= TYPE_MODIFIER_TRANSPARENT_UNION;
3555
3556                 switch (token.type) {
3557
3558                 /* storage class */
3559 #define MATCH_STORAGE_CLASS(token, class)                                  \
3560                 case token:                                                        \
3561                         if (specifiers->storage_class != STORAGE_CLASS_NONE) {         \
3562                                 errorf(HERE, "multiple storage classes in declaration specifiers"); \
3563                         }                                                              \
3564                         specifiers->storage_class = class;                             \
3565                         next_token();                                                  \
3566                         break;
3567
3568                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
3569                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
3570                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
3571                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
3572                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
3573
3574                 case T__declspec:
3575                         next_token();
3576                         expect('(');
3577                         add_anchor_token(')');
3578                         parse_microsoft_extended_decl_modifier(specifiers);
3579                         rem_anchor_token(')');
3580                         expect(')');
3581                         break;
3582
3583                 case T__based:
3584                         next_token();
3585                         expect('(');
3586                         add_anchor_token(')');
3587                         parse_microsoft_based(specifiers);
3588                         rem_anchor_token(')');
3589                         expect(')');
3590                         break;
3591
3592                 case T___thread:
3593                         switch (specifiers->storage_class) {
3594                         case STORAGE_CLASS_NONE:
3595                                 specifiers->storage_class = STORAGE_CLASS_THREAD;
3596                                 break;
3597
3598                         case STORAGE_CLASS_EXTERN:
3599                                 specifiers->storage_class = STORAGE_CLASS_THREAD_EXTERN;
3600                                 break;
3601
3602                         case STORAGE_CLASS_STATIC:
3603                                 specifiers->storage_class = STORAGE_CLASS_THREAD_STATIC;
3604                                 break;
3605
3606                         default:
3607                                 errorf(HERE, "multiple storage classes in declaration specifiers");
3608                                 break;
3609                         }
3610                         next_token();
3611                         break;
3612
3613                 /* type qualifiers */
3614 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
3615                 case token:                                                     \
3616                         qualifiers |= qualifier;                                    \
3617                         next_token();                                               \
3618                         break
3619
3620                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3621                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3622                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3623                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3624                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3625                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3626                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3627                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3628
3629                 case T___extension__:
3630                         next_token();
3631                         in_gcc_extension = true;
3632                         break;
3633
3634                 /* type specifiers */
3635 #define MATCH_SPECIFIER(token, specifier, name)                         \
3636                 case token:                                                     \
3637                         if (type_specifiers & specifier) {                           \
3638                                 errorf(HERE, "multiple " name " type specifiers given"); \
3639                         } else {                                                    \
3640                                 type_specifiers |= specifier;                           \
3641                         }                                                           \
3642                         next_token();                                               \
3643                         break
3644
3645                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool");
3646                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex");
3647                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary");
3648                 MATCH_SPECIFIER(T__int128,    SPECIFIER_INT128,    "_int128");
3649                 MATCH_SPECIFIER(T__int16,     SPECIFIER_INT16,     "_int16");
3650                 MATCH_SPECIFIER(T__int32,     SPECIFIER_INT32,     "_int32");
3651                 MATCH_SPECIFIER(T__int64,     SPECIFIER_INT64,     "_int64");
3652                 MATCH_SPECIFIER(T__int8,      SPECIFIER_INT8,      "_int8");
3653                 MATCH_SPECIFIER(T_bool,       SPECIFIER_BOOL,      "bool");
3654                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char");
3655                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double");
3656                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float");
3657                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int");
3658                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short");
3659                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed");
3660                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned");
3661                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void");
3662
3663                 case T__forceinline:
3664                         /* only in microsoft mode */
3665                         specifiers->modifiers |= DM_FORCEINLINE;
3666                         /* FALLTHROUGH */
3667
3668                 case T_inline:
3669                         next_token();
3670                         specifiers->is_inline = true;
3671                         break;
3672
3673                 case T_long:
3674                         if (type_specifiers & SPECIFIER_LONG_LONG) {
3675                                 errorf(HERE, "multiple type specifiers given");
3676                         } else if (type_specifiers & SPECIFIER_LONG) {
3677                                 type_specifiers |= SPECIFIER_LONG_LONG;
3678                         } else {
3679                                 type_specifiers |= SPECIFIER_LONG;
3680                         }
3681                         next_token();
3682                         break;
3683
3684                 case T_struct: {
3685                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
3686
3687                         type->compound.compound = parse_compound_type_specifier(true);
3688                         finish_struct_type(&type->compound);
3689                         break;
3690                 }
3691                 case T_union: {
3692                         type = allocate_type_zero(TYPE_COMPOUND_UNION);
3693                         type->compound.compound = parse_compound_type_specifier(false);
3694                         if (type->compound.compound->modifiers & DM_TRANSPARENT_UNION)
3695                                 modifiers |= TYPE_MODIFIER_TRANSPARENT_UNION;
3696                         finish_union_type(&type->compound);
3697                         break;
3698                 }
3699                 case T_enum:
3700                         type = parse_enum_specifier();
3701                         break;
3702                 case T___typeof__:
3703                         type = parse_typeof();
3704                         break;
3705                 case T___builtin_va_list:
3706                         type = duplicate_type(type_valist);
3707                         next_token();
3708                         break;
3709
3710                 case T_IDENTIFIER: {
3711                         /* only parse identifier if we haven't found a type yet */
3712                         if (type != NULL || type_specifiers != 0) {
3713                                 /* Be somewhat resilient to typos like 'unsigned lng* f()' in a
3714                                  * declaration, so it doesn't generate errors about expecting '(' or
3715                                  * '{' later on. */
3716                                 switch (look_ahead(1)->type) {
3717                                         STORAGE_CLASSES
3718                                         TYPE_SPECIFIERS
3719                                         case T_const:
3720                                         case T_restrict:
3721                                         case T_volatile:
3722                                         case T_inline:
3723                                         case T__forceinline: /* ^ DECLARATION_START except for __attribute__ */
3724                                         case T_IDENTIFIER:
3725                                         case '*':
3726                                                 errorf(HERE, "discarding stray %K in declaration specifier", &token);
3727                                                 next_token();
3728                                                 continue;
3729
3730                                         default:
3731                                                 goto finish_specifiers;
3732                                 }
3733                         }
3734
3735                         type_t *const typedef_type = get_typedef_type(token.v.symbol);
3736                         if (typedef_type == NULL) {
3737                                 /* Be somewhat resilient to typos like 'vodi f()' at the beginning of a
3738                                  * declaration, so it doesn't generate 'implicit int' followed by more
3739                                  * errors later on. */
3740                                 token_type_t const la1_type = (token_type_t)look_ahead(1)->type;
3741                                 switch (la1_type) {
3742                                         DECLARATION_START
3743                                         case T_IDENTIFIER:
3744                                         case '*': {
3745                                                 errorf(HERE, "%K does not name a type", &token);
3746
3747                                                 entity_t *entity =
3748                                                         create_error_entity(token.v.symbol, ENTITY_TYPEDEF);
3749
3750                                                 type = allocate_type_zero(TYPE_TYPEDEF);
3751                                                 type->typedeft.typedefe = &entity->typedefe;
3752
3753                                                 next_token();
3754                                                 saw_error = true;
3755                                                 if (la1_type == '*')
3756                                                         goto finish_specifiers;
3757                                                 continue;
3758                                         }
3759
3760                                         default:
3761                                                 goto finish_specifiers;
3762                                 }
3763                         }
3764
3765                         next_token();
3766                         type = typedef_type;
3767                         break;
3768                 }
3769
3770                 /* function specifier */
3771                 default:
3772                         goto finish_specifiers;
3773                 }
3774         }
3775
3776 finish_specifiers:
3777         in_gcc_extension = old_gcc_extension;
3778
3779         if (type == NULL || (saw_error && type_specifiers != 0)) {
3780                 atomic_type_kind_t atomic_type;
3781
3782                 /* match valid basic types */
3783                 switch (type_specifiers) {
3784                 case SPECIFIER_VOID:
3785                         atomic_type = ATOMIC_TYPE_VOID;
3786                         break;
3787                 case SPECIFIER_CHAR:
3788                         atomic_type = ATOMIC_TYPE_CHAR;
3789                         break;
3790                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
3791                         atomic_type = ATOMIC_TYPE_SCHAR;
3792                         break;
3793                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
3794                         atomic_type = ATOMIC_TYPE_UCHAR;
3795                         break;
3796                 case SPECIFIER_SHORT:
3797                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
3798                 case SPECIFIER_SHORT | SPECIFIER_INT:
3799                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
3800                         atomic_type = ATOMIC_TYPE_SHORT;
3801                         break;
3802                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
3803                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
3804                         atomic_type = ATOMIC_TYPE_USHORT;
3805                         break;
3806                 case SPECIFIER_INT:
3807                 case SPECIFIER_SIGNED:
3808                 case SPECIFIER_SIGNED | SPECIFIER_INT:
3809                         atomic_type = ATOMIC_TYPE_INT;
3810                         break;
3811                 case SPECIFIER_UNSIGNED:
3812                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
3813                         atomic_type = ATOMIC_TYPE_UINT;
3814                         break;
3815                 case SPECIFIER_LONG:
3816                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
3817                 case SPECIFIER_LONG | SPECIFIER_INT:
3818                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
3819                         atomic_type = ATOMIC_TYPE_LONG;
3820                         break;
3821                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
3822                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
3823                         atomic_type = ATOMIC_TYPE_ULONG;
3824                         break;
3825
3826                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3827                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3828                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
3829                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3830                         | SPECIFIER_INT:
3831                         atomic_type = ATOMIC_TYPE_LONGLONG;
3832                         goto warn_about_long_long;
3833
3834                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3835                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3836                         | SPECIFIER_INT:
3837                         atomic_type = ATOMIC_TYPE_ULONGLONG;
3838 warn_about_long_long:
3839                         if (warning.long_long) {
3840                                 warningf(&specifiers->source_position,
3841                                          "ISO C90 does not support 'long long'");
3842                         }
3843                         break;
3844
3845                 case SPECIFIER_UNSIGNED | SPECIFIER_INT8:
3846                         atomic_type = unsigned_int8_type_kind;
3847                         break;
3848
3849                 case SPECIFIER_UNSIGNED | SPECIFIER_INT16:
3850                         atomic_type = unsigned_int16_type_kind;
3851                         break;
3852
3853                 case SPECIFIER_UNSIGNED | SPECIFIER_INT32:
3854                         atomic_type = unsigned_int32_type_kind;
3855                         break;
3856
3857                 case SPECIFIER_UNSIGNED | SPECIFIER_INT64:
3858                         atomic_type = unsigned_int64_type_kind;
3859                         break;
3860
3861                 case SPECIFIER_UNSIGNED | SPECIFIER_INT128:
3862                         atomic_type = unsigned_int128_type_kind;
3863                         break;
3864
3865                 case SPECIFIER_INT8:
3866                 case SPECIFIER_SIGNED | SPECIFIER_INT8:
3867                         atomic_type = int8_type_kind;
3868                         break;
3869
3870                 case SPECIFIER_INT16:
3871                 case SPECIFIER_SIGNED | SPECIFIER_INT16:
3872                         atomic_type = int16_type_kind;
3873                         break;
3874
3875                 case SPECIFIER_INT32:
3876                 case SPECIFIER_SIGNED | SPECIFIER_INT32:
3877                         atomic_type = int32_type_kind;
3878                         break;
3879
3880                 case SPECIFIER_INT64:
3881                 case SPECIFIER_SIGNED | SPECIFIER_INT64:
3882                         atomic_type = int64_type_kind;
3883                         break;
3884
3885                 case SPECIFIER_INT128:
3886                 case SPECIFIER_SIGNED | SPECIFIER_INT128:
3887                         atomic_type = int128_type_kind;
3888                         break;
3889
3890                 case SPECIFIER_FLOAT:
3891                         atomic_type = ATOMIC_TYPE_FLOAT;
3892                         break;
3893                 case SPECIFIER_DOUBLE:
3894                         atomic_type = ATOMIC_TYPE_DOUBLE;
3895                         break;
3896                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
3897                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
3898                         break;
3899                 case SPECIFIER_BOOL:
3900                         atomic_type = ATOMIC_TYPE_BOOL;
3901                         break;
3902                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
3903                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
3904                         atomic_type = ATOMIC_TYPE_FLOAT;
3905                         break;
3906                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3907                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3908                         atomic_type = ATOMIC_TYPE_DOUBLE;
3909                         break;
3910                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3911                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3912                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
3913                         break;
3914                 default:
3915                         /* invalid specifier combination, give an error message */
3916                         if (type_specifiers == 0) {
3917                                 if (saw_error)
3918                                         goto end_error;
3919
3920                                 /* ISO/IEC 14882:1998(E) §C.1.5:4 */
3921                                 if (!(c_mode & _CXX) && !strict_mode) {
3922                                         if (warning.implicit_int) {
3923                                                 warningf(HERE, "no type specifiers in declaration, using 'int'");
3924                                         }
3925                                         atomic_type = ATOMIC_TYPE_INT;
3926                                         break;
3927                                 } else {
3928                                         errorf(HERE, "no type specifiers given in declaration");
3929                                 }
3930                         } else if ((type_specifiers & SPECIFIER_SIGNED) &&
3931                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
3932                                 errorf(HERE, "signed and unsigned specifiers given");
3933                         } else if (type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
3934                                 errorf(HERE, "only integer types can be signed or unsigned");
3935                         } else {
3936                                 errorf(HERE, "multiple datatypes in declaration");
3937                         }
3938                         goto end_error;
3939                 }
3940
3941                 if (type_specifiers & SPECIFIER_COMPLEX) {
3942                         type                = allocate_type_zero(TYPE_COMPLEX);
3943                         type->complex.akind = atomic_type;
3944                 } else if (type_specifiers & SPECIFIER_IMAGINARY) {
3945                         type                  = allocate_type_zero(TYPE_IMAGINARY);
3946                         type->imaginary.akind = atomic_type;
3947                 } else {
3948                         type               = allocate_type_zero(TYPE_ATOMIC);
3949                         type->atomic.akind = atomic_type;
3950                 }
3951                 newtype = true;
3952         } else if (type_specifiers != 0) {
3953                 errorf(HERE, "multiple datatypes in declaration");
3954         }
3955
3956         /* FIXME: check type qualifiers here */
3957
3958         type->base.qualifiers = qualifiers;
3959         type->base.modifiers  = modifiers;
3960
3961         type_t *result = typehash_insert(type);
3962         if (newtype && result != type) {
3963                 free_type(type);
3964         }
3965
3966         specifiers->type = result;
3967         return;
3968
3969 end_error:
3970         specifiers->type = type_error_type;
3971         return;
3972 }
3973
3974 static type_qualifiers_t parse_type_qualifiers(void)
3975 {
3976         type_qualifiers_t qualifiers = TYPE_QUALIFIER_NONE;
3977
3978         while (true) {
3979                 switch (token.type) {
3980                 /* type qualifiers */
3981                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3982                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3983                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3984                 /* microsoft extended type modifiers */
3985                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3986                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3987                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3988                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3989                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3990
3991                 default:
3992                         return qualifiers;
3993                 }
3994         }
3995 }
3996
3997 /**
3998  * Parses an K&R identifier list
3999  */
4000 static void parse_identifier_list(scope_t *scope)
4001 {
4002         do {
4003                 entity_t *entity = allocate_entity_zero(ENTITY_VARIABLE);
4004                 entity->base.source_position = token.source_position;
4005                 entity->base.namespc         = NAMESPACE_NORMAL;
4006                 entity->base.symbol          = token.v.symbol;
4007                 /* a K&R parameter has no type, yet */
4008                 next_token();
4009
4010                 append_entity(scope, entity);
4011
4012                 if (token.type != ',') {
4013                         break;
4014                 }
4015                 next_token();
4016         } while (token.type == T_IDENTIFIER);
4017 }
4018
4019 static type_t *automatic_type_conversion(type_t *orig_type);
4020
4021 static void semantic_parameter(declaration_t *declaration)
4022 {
4023         /* TODO: improve error messages */
4024         source_position_t const* const pos = &declaration->base.source_position;
4025
4026         /* §6.9.1:6 */
4027         switch (declaration->declared_storage_class) {
4028                 /* Allowed storage classes */
4029                 case STORAGE_CLASS_NONE:
4030                 case STORAGE_CLASS_REGISTER:
4031                         break;
4032
4033                 default:
4034                         errorf(pos, "parameter may only have none or register storage class");
4035                         break;
4036         }
4037
4038         type_t *const orig_type = declaration->type;
4039         /* §6.7.5.3(7): Array as last part of a parameter type is just syntactic
4040          * sugar.  Turn it into a pointer.
4041          * §6.7.5.3(8): A declaration of a parameter as ``function returning type''
4042          * shall be adjusted to ``pointer to function returning type'', as in 6.3.2.1.
4043          */
4044         type_t *const type = automatic_type_conversion(orig_type);
4045         declaration->type = type;
4046
4047         if (is_type_incomplete(skip_typeref(type))) {
4048                 errorf(pos, "parameter '%#T' is of incomplete type",
4049                        orig_type, declaration->base.symbol);
4050         }
4051 }
4052
4053 static entity_t *parse_parameter(void)
4054 {
4055         declaration_specifiers_t specifiers;
4056         memset(&specifiers, 0, sizeof(specifiers));
4057
4058         parse_declaration_specifiers(&specifiers);
4059
4060         entity_t *entity = parse_declarator(&specifiers, true, false);
4061         return entity;
4062 }
4063
4064 /**
4065  * Parses function type parameters (and optionally creates variable_t entities
4066  * for them in a scope)
4067  */
4068 static void parse_parameters(function_type_t *type, scope_t *scope)
4069 {
4070         eat('(');
4071         add_anchor_token(')');
4072         int saved_comma_state = save_and_reset_anchor_state(',');
4073
4074         if (token.type == T_IDENTIFIER &&
4075             !is_typedef_symbol(token.v.symbol)) {
4076                 token_type_t la1_type = (token_type_t)look_ahead(1)->type;
4077                 if (la1_type == ',' || la1_type == ')') {
4078                         type->kr_style_parameters = true;
4079                         parse_identifier_list(scope);
4080                         goto parameters_finished;
4081                 }
4082         }
4083
4084         if (token.type == ')') {
4085                 /* ISO/IEC 14882:1998(E) §C.1.6:1 */
4086                 if (!(c_mode & _CXX))
4087                         type->unspecified_parameters = true;
4088                 goto parameters_finished;
4089         }
4090
4091         function_parameter_t *parameter;
4092         function_parameter_t *last_parameter = NULL;
4093
4094         while (true) {
4095                 switch (token.type) {
4096                 case T_DOTDOTDOT:
4097                         next_token();
4098                         type->variadic = true;
4099                         goto parameters_finished;
4100
4101                 case T_IDENTIFIER:
4102                 case T___extension__:
4103                 DECLARATION_START
4104                 {
4105                         entity_t *entity = parse_parameter();
4106                         if (entity->kind == ENTITY_TYPEDEF) {
4107                                 errorf(&entity->base.source_position,
4108                                        "typedef not allowed as function parameter");
4109                                 break;
4110                         }
4111                         assert(is_declaration(entity));
4112
4113                         /* func(void) is not a parameter */
4114                         if (last_parameter == NULL
4115                                         && token.type == ')'
4116                                         && entity->base.symbol == NULL
4117                                         && skip_typeref(entity->declaration.type) == type_void) {
4118                                 goto parameters_finished;
4119                         }
4120                         semantic_parameter(&entity->declaration);
4121
4122                         parameter = obstack_alloc(type_obst, sizeof(parameter[0]));
4123                         memset(parameter, 0, sizeof(parameter[0]));
4124                         parameter->type = entity->declaration.type;
4125
4126                         if (scope != NULL) {
4127                                 append_entity(scope, entity);
4128                         }
4129
4130                         if (last_parameter != NULL) {
4131                                 last_parameter->next = parameter;
4132                         } else {
4133                                 type->parameters = parameter;
4134                         }
4135                         last_parameter   = parameter;
4136                         break;
4137                 }
4138
4139                 default:
4140                         goto parameters_finished;
4141                 }
4142                 if (token.type != ',') {
4143                         goto parameters_finished;
4144                 }
4145                 next_token();
4146         }
4147
4148
4149 parameters_finished:
4150         rem_anchor_token(')');
4151         expect(')');
4152
4153 end_error:
4154         restore_anchor_state(',', saved_comma_state);
4155 }
4156
4157 typedef enum construct_type_kind_t {
4158         CONSTRUCT_INVALID,
4159         CONSTRUCT_POINTER,
4160         CONSTRUCT_FUNCTION,
4161         CONSTRUCT_ARRAY
4162 } construct_type_kind_t;
4163
4164 typedef struct construct_type_t construct_type_t;
4165 struct construct_type_t {
4166         construct_type_kind_t  kind;
4167         construct_type_t      *next;
4168 };
4169
4170 typedef struct parsed_pointer_t parsed_pointer_t;
4171 struct parsed_pointer_t {
4172         construct_type_t  construct_type;
4173         type_qualifiers_t type_qualifiers;
4174 };
4175
4176 typedef struct construct_function_type_t construct_function_type_t;
4177 struct construct_function_type_t {
4178         construct_type_t  construct_type;
4179         type_t           *function_type;
4180 };
4181
4182 typedef struct parsed_array_t parsed_array_t;
4183 struct parsed_array_t {
4184         construct_type_t  construct_type;
4185         type_qualifiers_t type_qualifiers;
4186         bool              is_static;
4187         bool              is_variable;
4188         expression_t     *size;
4189 };
4190
4191 typedef struct construct_base_type_t construct_base_type_t;
4192 struct construct_base_type_t {
4193         construct_type_t  construct_type;
4194         type_t           *type;
4195 };
4196
4197 static construct_type_t *parse_pointer_declarator(void)
4198 {
4199         eat('*');
4200
4201         parsed_pointer_t *pointer = obstack_alloc(&temp_obst, sizeof(pointer[0]));
4202         memset(pointer, 0, sizeof(pointer[0]));
4203         pointer->construct_type.kind = CONSTRUCT_POINTER;
4204         pointer->type_qualifiers     = parse_type_qualifiers();
4205
4206         return (construct_type_t*) pointer;
4207 }
4208
4209 static construct_type_t *parse_array_declarator(void)
4210 {
4211         eat('[');
4212         add_anchor_token(']');
4213
4214         parsed_array_t *array = obstack_alloc(&temp_obst, sizeof(array[0]));
4215         memset(array, 0, sizeof(array[0]));
4216         array->construct_type.kind = CONSTRUCT_ARRAY;
4217
4218         if (token.type == T_static) {
4219                 array->is_static = true;
4220                 next_token();
4221         }
4222
4223         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
4224         if (type_qualifiers != 0) {
4225                 if (token.type == T_static) {
4226                         array->is_static = true;
4227                         next_token();
4228                 }
4229         }
4230         array->type_qualifiers = type_qualifiers;
4231
4232         if (token.type == '*' && look_ahead(1)->type == ']') {
4233                 array->is_variable = true;
4234                 next_token();
4235         } else if (token.type != ']') {
4236                 array->size = parse_assignment_expression();
4237         }
4238
4239         rem_anchor_token(']');
4240         expect(']');
4241
4242 end_error:
4243         return (construct_type_t*) array;
4244 }
4245
4246 static construct_type_t *parse_function_declarator(scope_t *scope,
4247                                                    decl_modifiers_t modifiers)
4248 {
4249         type_t          *type  = allocate_type_zero(TYPE_FUNCTION);
4250         function_type_t *ftype = &type->function;
4251
4252         ftype->linkage = current_linkage;
4253
4254         switch (modifiers & (DM_CDECL | DM_STDCALL | DM_FASTCALL | DM_THISCALL)) {
4255                 case DM_NONE:     break;
4256                 case DM_CDECL:    ftype->calling_convention = CC_CDECL;    break;
4257                 case DM_STDCALL:  ftype->calling_convention = CC_STDCALL;  break;
4258                 case DM_FASTCALL: ftype->calling_convention = CC_FASTCALL; break;
4259                 case DM_THISCALL: ftype->calling_convention = CC_THISCALL; break;
4260
4261                 default:
4262                         errorf(HERE, "multiple calling conventions in declaration");
4263                         break;
4264         }
4265
4266         parse_parameters(ftype, scope);
4267
4268         construct_function_type_t *construct_function_type =
4269                 obstack_alloc(&temp_obst, sizeof(construct_function_type[0]));
4270         memset(construct_function_type, 0, sizeof(construct_function_type[0]));
4271         construct_function_type->construct_type.kind = CONSTRUCT_FUNCTION;
4272         construct_function_type->function_type       = type;
4273
4274         return &construct_function_type->construct_type;
4275 }
4276
4277 typedef struct parse_declarator_env_t {
4278         decl_modifiers_t   modifiers;
4279         symbol_t          *symbol;
4280         source_position_t  source_position;
4281         scope_t            parameters;
4282 } parse_declarator_env_t;
4283
4284 static construct_type_t *parse_inner_declarator(parse_declarator_env_t *env,
4285                 bool may_be_abstract)
4286 {
4287         /* construct a single linked list of construct_type_t's which describe
4288          * how to construct the final declarator type */
4289         construct_type_t *first      = NULL;
4290         construct_type_t *last       = NULL;
4291         gnu_attribute_t  *attributes = NULL;
4292
4293         decl_modifiers_t modifiers = parse_attributes(&attributes);
4294
4295         /* pointers */
4296         while (token.type == '*') {
4297                 construct_type_t *type = parse_pointer_declarator();
4298
4299                 if (last == NULL) {
4300                         first = type;
4301                         last  = type;
4302                 } else {
4303                         last->next = type;
4304                         last       = type;
4305                 }
4306
4307                 /* TODO: find out if this is correct */
4308                 modifiers |= parse_attributes(&attributes);
4309         }
4310
4311         if (env != NULL) {
4312                 modifiers      |= env->modifiers;
4313                 env->modifiers  = modifiers;
4314         }
4315
4316         construct_type_t *inner_types = NULL;
4317
4318         switch (token.type) {
4319         case T_IDENTIFIER:
4320                 if (env == NULL) {
4321                         errorf(HERE, "no identifier expected in typename");
4322                 } else {
4323                         env->symbol          = token.v.symbol;
4324                         env->source_position = token.source_position;
4325                 }
4326                 next_token();
4327                 break;
4328         case '(':
4329                 next_token();
4330                 add_anchor_token(')');
4331                 inner_types = parse_inner_declarator(env, may_be_abstract);
4332                 if (inner_types != NULL) {
4333                         /* All later declarators only modify the return type */
4334                         env = NULL;
4335                 }
4336                 rem_anchor_token(')');
4337                 expect(')');
4338                 break;
4339         default:
4340                 if (may_be_abstract)
4341                         break;
4342                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', NULL);
4343                 eat_until_anchor();
4344                 return NULL;
4345         }
4346
4347         construct_type_t *p = last;
4348
4349         while (true) {
4350                 construct_type_t *type;
4351                 switch (token.type) {
4352                 case '(': {
4353                         scope_t *scope = NULL;
4354                         if (env != NULL)
4355                                 scope = &env->parameters;
4356
4357                         type = parse_function_declarator(scope, modifiers);
4358                         break;
4359                 }
4360                 case '[':
4361                         type = parse_array_declarator();
4362                         break;
4363                 default:
4364                         goto declarator_finished;
4365                 }
4366
4367                 /* insert in the middle of the list (behind p) */
4368                 if (p != NULL) {
4369                         type->next = p->next;
4370                         p->next    = type;
4371                 } else {
4372                         type->next = first;
4373                         first      = type;
4374                 }
4375                 if (last == p) {
4376                         last = type;
4377                 }
4378         }
4379
4380 declarator_finished:
4381         /* append inner_types at the end of the list, we don't to set last anymore
4382          * as it's not needed anymore */
4383         if (last == NULL) {
4384                 assert(first == NULL);
4385                 first = inner_types;
4386         } else {
4387                 last->next = inner_types;
4388         }
4389
4390         return first;
4391 end_error:
4392         return NULL;
4393 }
4394
4395 static void parse_declaration_attributes(entity_t *entity)
4396 {
4397         gnu_attribute_t  *attributes = NULL;
4398         decl_modifiers_t  modifiers  = parse_attributes(&attributes);
4399
4400         if (entity == NULL)
4401                 return;
4402
4403         type_t *type;
4404         if (entity->kind == ENTITY_TYPEDEF) {
4405                 modifiers |= entity->typedefe.modifiers;
4406                 type       = entity->typedefe.type;
4407         } else {
4408                 assert(is_declaration(entity));
4409                 modifiers |= entity->declaration.modifiers;
4410                 type       = entity->declaration.type;
4411         }
4412         if (type == NULL)
4413                 return;
4414
4415         /* handle these strange/stupid mode attributes */
4416         gnu_attribute_t *attribute = attributes;
4417         for ( ; attribute != NULL; attribute = attribute->next) {
4418                 if (attribute->kind != GNU_AK_MODE || attribute->invalid)
4419                         continue;
4420
4421                 atomic_type_kind_t  akind = attribute->u.akind;
4422                 if (!is_type_signed(type)) {
4423                         switch (akind) {
4424                         case ATOMIC_TYPE_CHAR: akind = ATOMIC_TYPE_UCHAR; break;
4425                         case ATOMIC_TYPE_SHORT: akind = ATOMIC_TYPE_USHORT; break;
4426                         case ATOMIC_TYPE_INT: akind = ATOMIC_TYPE_UINT; break;
4427                         case ATOMIC_TYPE_LONGLONG: akind = ATOMIC_TYPE_ULONGLONG; break;
4428                         default:
4429                                 panic("invalid akind in mode attribute");
4430                         }
4431                 } else {
4432                         switch (akind) {
4433                         case ATOMIC_TYPE_CHAR: akind = ATOMIC_TYPE_SCHAR; break;
4434                         case ATOMIC_TYPE_SHORT: akind = ATOMIC_TYPE_SHORT; break;
4435                         case ATOMIC_TYPE_INT: akind = ATOMIC_TYPE_INT; break;
4436                         case ATOMIC_TYPE_LONGLONG: akind = ATOMIC_TYPE_LONGLONG; break;
4437                         default:
4438                                 panic("invalid akind in mode attribute");
4439                         }
4440                 }
4441
4442                 type = make_atomic_type(akind, type->base.qualifiers);
4443         }
4444
4445         type_modifiers_t type_modifiers = type->base.modifiers;
4446         if (modifiers & DM_TRANSPARENT_UNION)
4447                 modifiers |= TYPE_MODIFIER_TRANSPARENT_UNION;
4448
4449         if (type->base.modifiers != type_modifiers) {
4450                 type_t *copy = duplicate_type(type);
4451                 copy->base.modifiers = type_modifiers;
4452
4453                 type = typehash_insert(copy);
4454                 if (type != copy) {
4455                         obstack_free(type_obst, copy);
4456                 }
4457         }
4458
4459         if (entity->kind == ENTITY_TYPEDEF) {
4460                 entity->typedefe.type      = type;
4461                 entity->typedefe.modifiers = modifiers;
4462         } else {
4463                 entity->declaration.type      = type;
4464                 entity->declaration.modifiers = modifiers;
4465         }
4466 }
4467
4468 static type_t *construct_declarator_type(construct_type_t *construct_list,
4469                                          type_t *type, variable_t *variable)
4470 {
4471         construct_type_t *iter = construct_list;
4472         for (; iter != NULL; iter = iter->next) {
4473                 switch (iter->kind) {
4474                 case CONSTRUCT_INVALID:
4475                         internal_errorf(HERE, "invalid type construction found");
4476                 case CONSTRUCT_FUNCTION: {
4477                         construct_function_type_t *construct_function_type
4478                                 = (construct_function_type_t*) iter;
4479
4480                         type_t *function_type = construct_function_type->function_type;
4481
4482                         function_type->function.return_type = type;
4483
4484                         type_t *skipped_return_type = skip_typeref(type);
4485                         /* §6.7.5.3(1) */
4486                         if (is_type_function(skipped_return_type)) {
4487                                 errorf(HERE, "function returning function is not allowed");
4488                         } else if (is_type_array(skipped_return_type)) {
4489                                 errorf(HERE, "function returning array is not allowed");
4490                         } else {
4491                                 if (skipped_return_type->base.qualifiers != 0 && warning.other) {
4492                                         warningf(HERE,
4493                                                 "type qualifiers in return type of function type are meaningless");
4494                                 }
4495                         }
4496
4497                         type = function_type;
4498                         break;
4499                 }
4500
4501                 case CONSTRUCT_POINTER: {
4502                         parsed_pointer_t *parsed_pointer = (parsed_pointer_t*) iter;
4503                         type = make_based_pointer_type(type, parsed_pointer->type_qualifiers, variable);
4504                         continue;
4505                 }
4506
4507                 case CONSTRUCT_ARRAY: {
4508                         parsed_array_t *parsed_array  = (parsed_array_t*) iter;
4509                         type_t         *array_type    = allocate_type_zero(TYPE_ARRAY);
4510
4511                         expression_t *size_expression = parsed_array->size;
4512                         if (size_expression != NULL) {
4513                                 size_expression
4514                                         = create_implicit_cast(size_expression, type_size_t);
4515                         }
4516
4517                         array_type->base.qualifiers       = parsed_array->type_qualifiers;
4518                         array_type->array.element_type    = type;
4519                         array_type->array.is_static       = parsed_array->is_static;
4520                         array_type->array.is_variable     = parsed_array->is_variable;
4521                         array_type->array.size_expression = size_expression;
4522
4523                         if (size_expression != NULL) {
4524                                 if (is_constant_expression(size_expression)) {
4525                                         array_type->array.size_constant = true;
4526                                         array_type->array.size
4527                                                 = fold_constant(size_expression);
4528                                 } else {
4529                                         array_type->array.is_vla = true;
4530                                 }
4531                         }
4532
4533                         type_t *skipped_type = skip_typeref(type);
4534                         /* §6.7.5.2(1) */
4535                         if (is_type_incomplete(skipped_type)) {
4536                                 errorf(HERE, "array of incomplete type '%T' is not allowed", type);
4537                         } else if (is_type_function(skipped_type)) {
4538                                 errorf(HERE, "array of functions is not allowed");
4539                         }
4540                         type = array_type;
4541                         break;
4542                 }
4543                 }
4544
4545                 type_t *hashed_type = typehash_insert(type);
4546                 if (hashed_type != type) {
4547                         /* the function type was constructed earlier freeing it here will
4548                          * destroy other types... */
4549                         if (iter->kind != CONSTRUCT_FUNCTION) {
4550                                 free_type(type);
4551                         }
4552                         type = hashed_type;
4553                 }
4554         }
4555
4556         return type;
4557 }
4558
4559 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
4560                                   bool may_be_abstract,
4561                                   bool create_compound_member)
4562 {
4563         parse_declarator_env_t env;
4564         memset(&env, 0, sizeof(env));
4565         env.modifiers = specifiers->modifiers;
4566
4567         construct_type_t *construct_type
4568                 = parse_inner_declarator(&env, may_be_abstract);
4569         type_t *type = construct_declarator_type(construct_type, specifiers->type, specifiers->based_variable);
4570
4571         if (construct_type != NULL) {
4572                 obstack_free(&temp_obst, construct_type);
4573         }
4574
4575         entity_t *entity;
4576         if (specifiers->storage_class == STORAGE_CLASS_TYPEDEF) {
4577                 entity                       = allocate_entity_zero(ENTITY_TYPEDEF);
4578                 entity->base.symbol          = env.symbol;
4579                 entity->base.source_position = env.source_position;
4580                 entity->typedefe.type        = type;
4581         } else {
4582                 if (create_compound_member) {
4583                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER);
4584                 } else if (is_type_function(skip_typeref(type))) {
4585                         entity = allocate_entity_zero(ENTITY_FUNCTION);
4586
4587                         entity->function.is_inline  = specifiers->is_inline;
4588                         entity->function.parameters = env.parameters;
4589                 } else {
4590                         entity = allocate_entity_zero(ENTITY_VARIABLE);
4591
4592                         entity->variable.get_property_sym = specifiers->get_property_sym;
4593                         entity->variable.put_property_sym = specifiers->put_property_sym;
4594                         if (specifiers->alignment != 0) {
4595                                 /* TODO: add checks here */
4596                                 entity->variable.alignment = specifiers->alignment;
4597                         }
4598
4599                         if (warning.other && specifiers->is_inline && is_type_valid(type)) {
4600                                 warningf(&env.source_position,
4601                                                  "variable '%Y' declared 'inline'\n", env.symbol);
4602                         }
4603                 }
4604
4605                 entity->base.source_position          = env.source_position;
4606                 entity->base.symbol                   = env.symbol;
4607                 entity->base.namespc                  = NAMESPACE_NORMAL;
4608                 entity->declaration.type              = type;
4609                 entity->declaration.modifiers         = env.modifiers;
4610                 entity->declaration.deprecated_string = specifiers->deprecated_string;
4611
4612                 storage_class_t storage_class = specifiers->storage_class;
4613                 entity->declaration.declared_storage_class = storage_class;
4614
4615                 if (storage_class == STORAGE_CLASS_NONE
4616                                 && current_scope != file_scope) {
4617                         storage_class = STORAGE_CLASS_AUTO;
4618                 }
4619                 entity->declaration.storage_class = storage_class;
4620         }
4621
4622         parse_declaration_attributes(entity);
4623
4624         return entity;
4625 }
4626
4627 static type_t *parse_abstract_declarator(type_t *base_type)
4628 {
4629         construct_type_t *construct_type = parse_inner_declarator(NULL, 1);
4630
4631         type_t *result = construct_declarator_type(construct_type, base_type, NULL);
4632         if (construct_type != NULL) {
4633                 obstack_free(&temp_obst, construct_type);
4634         }
4635
4636         return result;
4637 }
4638
4639 /**
4640  * Check if the declaration of main is suspicious.  main should be a
4641  * function with external linkage, returning int, taking either zero
4642  * arguments, two, or three arguments of appropriate types, ie.
4643  *
4644  * int main([ int argc, char **argv [, char **env ] ]).
4645  *
4646  * @param decl    the declaration to check
4647  * @param type    the function type of the declaration
4648  */
4649 static void check_type_of_main(const entity_t *entity)
4650 {
4651         const source_position_t *pos = &entity->base.source_position;
4652         if (entity->kind != ENTITY_FUNCTION) {
4653                 warningf(pos, "'main' is not a function");
4654                 return;
4655         }
4656
4657         if (entity->declaration.storage_class == STORAGE_CLASS_STATIC) {
4658                 warningf(pos, "'main' is normally a non-static function");
4659         }
4660
4661         type_t *type = skip_typeref(entity->declaration.type);
4662         assert(is_type_function(type));
4663
4664         function_type_t *func_type = &type->function;
4665         if (!types_compatible(skip_typeref(func_type->return_type), type_int)) {
4666                 warningf(pos, "return type of 'main' should be 'int', but is '%T'",
4667                          func_type->return_type);
4668         }
4669         const function_parameter_t *parm = func_type->parameters;
4670         if (parm != NULL) {
4671                 type_t *const first_type = parm->type;
4672                 if (!types_compatible(skip_typeref(first_type), type_int)) {
4673                         warningf(pos,
4674                                  "first argument of 'main' should be 'int', but is '%T'",
4675                                  first_type);
4676                 }
4677                 parm = parm->next;
4678                 if (parm != NULL) {
4679                         type_t *const second_type = parm->type;
4680                         if (!types_compatible(skip_typeref(second_type), type_char_ptr_ptr)) {
4681                                 warningf(pos, "second argument of 'main' should be 'char**', but is '%T'", second_type);
4682                         }
4683                         parm = parm->next;
4684                         if (parm != NULL) {
4685                                 type_t *const third_type = parm->type;
4686                                 if (!types_compatible(skip_typeref(third_type), type_char_ptr_ptr)) {
4687                                         warningf(pos, "third argument of 'main' should be 'char**', but is '%T'", third_type);
4688                                 }
4689                                 parm = parm->next;
4690                                 if (parm != NULL)
4691                                         goto warn_arg_count;
4692                         }
4693                 } else {
4694 warn_arg_count:
4695                         warningf(pos, "'main' takes only zero, two or three arguments");
4696                 }
4697         }
4698 }
4699
4700 /**
4701  * Check if a symbol is the equal to "main".
4702  */
4703 static bool is_sym_main(const symbol_t *const sym)
4704 {
4705         return strcmp(sym->string, "main") == 0;
4706 }
4707
4708 static const char *get_entity_kind_name(entity_kind_t kind)
4709 {
4710         switch ((entity_kind_tag_t) kind) {
4711         case ENTITY_FUNCTION:        return "function";
4712         case ENTITY_VARIABLE:        return "variable";
4713         case ENTITY_COMPOUND_MEMBER: return "compound type member";
4714         case ENTITY_STRUCT:          return "struct";
4715         case ENTITY_UNION:           return "union";
4716         case ENTITY_ENUM:            return "enum";
4717         case ENTITY_ENUM_VALUE:      return "enum value";
4718         case ENTITY_LABEL:           return "label";
4719         case ENTITY_LOCAL_LABEL:     return "local label";
4720         case ENTITY_TYPEDEF:         return "typedef";
4721         case ENTITY_NAMESPACE:       return "namespace";
4722         case ENTITY_INVALID:         break;
4723         }
4724
4725         panic("Invalid entity kind encountered in get_entity_kind_name");
4726 }
4727
4728 static void error_redefined_as_different_kind(const source_position_t *pos,
4729                 const entity_t *old, entity_kind_t new_kind)
4730 {
4731         errorf(pos, "redeclaration of %s '%Y' as %s (declared %P)",
4732                get_entity_kind_name(old->kind), old->base.symbol,
4733                get_entity_kind_name(new_kind), &old->base.source_position);
4734 }
4735
4736 /**
4737  * record entities for the NAMESPACE_NORMAL, and produce error messages/warnings
4738  * for various problems that occur for multiple definitions
4739  */
4740 static entity_t *record_entity(entity_t *entity, const bool is_definition)
4741 {
4742         const symbol_t *const    symbol  = entity->base.symbol;
4743         const namespace_tag_t    namespc = (namespace_tag_t)entity->base.namespc;
4744         const source_position_t *pos     = &entity->base.source_position;
4745
4746         assert(symbol != NULL);
4747         entity_t *previous_entity = get_entity(symbol, namespc);
4748         /* pushing the same entity twice will break the stack structure */
4749         assert(previous_entity != entity);
4750
4751         if (entity->kind == ENTITY_FUNCTION) {
4752                 type_t *const orig_type = entity->declaration.type;
4753                 type_t *const type      = skip_typeref(orig_type);
4754
4755                 assert(is_type_function(type));
4756                 if (type->function.unspecified_parameters &&
4757                                 warning.strict_prototypes &&
4758                                 previous_entity == NULL) {
4759                         warningf(pos, "function declaration '%#T' is not a prototype",
4760                                          orig_type, symbol);
4761                 }
4762
4763                 if (warning.main && current_scope == file_scope
4764                                 && is_sym_main(symbol)) {
4765                         check_type_of_main(entity);
4766                 }
4767         }
4768
4769         if (is_declaration(entity)) {
4770                 if (warning.nested_externs
4771                                 && entity->declaration.storage_class == STORAGE_CLASS_EXTERN
4772                                 && current_scope != file_scope) {
4773                         warningf(pos, "nested extern declaration of '%#T'",
4774                                  entity->declaration.type, symbol);
4775                 }
4776         }
4777
4778         if (previous_entity != NULL
4779             && previous_entity->base.parent_scope == &current_function->parameters
4780                 && current_scope->depth == previous_entity->base.parent_scope->depth+1){
4781
4782                 assert(previous_entity->kind == ENTITY_VARIABLE);
4783                 errorf(pos,
4784                        "declaration '%#T' redeclares the parameter '%#T' (declared %P)",
4785                        entity->declaration.type, symbol,
4786                            previous_entity->declaration.type, symbol,
4787                            &previous_entity->base.source_position);
4788                 goto finish;
4789         }
4790
4791         if (previous_entity != NULL
4792                         && previous_entity->base.parent_scope == current_scope) {
4793
4794                 if (previous_entity->kind != entity->kind) {
4795                         error_redefined_as_different_kind(pos, previous_entity,
4796                                                           entity->kind);
4797                         goto finish;
4798                 }
4799                 if (previous_entity->kind == ENTITY_ENUM_VALUE) {
4800                         errorf(pos,
4801                                    "redeclaration of enum entry '%Y' (declared %P)",
4802                                    symbol, &previous_entity->base.source_position);
4803                         goto finish;
4804                 }
4805                 if (previous_entity->kind == ENTITY_TYPEDEF) {
4806                         /* TODO: C++ allows this for exactly the same type */
4807                         errorf(pos,
4808                                "redefinition of typedef '%Y' (declared %P)",
4809                                symbol, &previous_entity->base.source_position);
4810                         goto finish;
4811                 }
4812
4813                 /* at this point we should have only VARIABLES or FUNCTIONS */
4814                 assert(is_declaration(previous_entity) && is_declaration(entity));
4815
4816                 /* can happen for K&R style declarations */
4817                 if (previous_entity->kind == ENTITY_VARIABLE
4818                                 && previous_entity->declaration.type == NULL
4819                                 && entity->kind == ENTITY_VARIABLE) {
4820                         previous_entity->declaration.type = entity->declaration.type;
4821                         previous_entity->declaration.storage_class
4822                                 = entity->declaration.storage_class;
4823                         previous_entity->declaration.declared_storage_class
4824                                 = entity->declaration.declared_storage_class;
4825                         previous_entity->declaration.modifiers
4826                                 = entity->declaration.modifiers;
4827                         previous_entity->declaration.deprecated_string
4828                                 = entity->declaration.deprecated_string;
4829                 }
4830                 assert(entity->declaration.type != NULL);
4831
4832                 declaration_t *const previous_declaration
4833                         = &previous_entity->declaration;
4834                 declaration_t *const declaration = &entity->declaration;
4835                 type_t *const orig_type = entity->declaration.type;
4836                 type_t *const type      = skip_typeref(orig_type);
4837
4838                 type_t *prev_type       = skip_typeref(previous_declaration->type);
4839
4840                 if (!types_compatible(type, prev_type)) {
4841                         errorf(pos,
4842                                    "declaration '%#T' is incompatible with '%#T' (declared %P)",
4843                                    orig_type, symbol, previous_declaration->type, symbol,
4844                                    &previous_entity->base.source_position);
4845                 } else {
4846                         unsigned old_storage_class = previous_declaration->storage_class;
4847                         if (warning.redundant_decls     && is_definition
4848                                 && previous_declaration->storage_class == STORAGE_CLASS_STATIC
4849                                 && !(previous_declaration->modifiers & DM_USED)
4850                                 && !previous_declaration->used) {
4851                                 warningf(&previous_entity->base.source_position,
4852                                          "unnecessary static forward declaration for '%#T'",
4853                                          previous_declaration->type, symbol);
4854                         }
4855
4856                         unsigned new_storage_class = declaration->storage_class;
4857                         if (is_type_incomplete(prev_type)) {
4858                                 previous_declaration->type = type;
4859                                 prev_type                  = type;
4860                         }
4861
4862                         /* pretend no storage class means extern for function
4863                          * declarations (except if the previous declaration is neither
4864                          * none nor extern) */
4865                         if (entity->kind == ENTITY_FUNCTION) {
4866                                 if (prev_type->function.unspecified_parameters) {
4867                                         previous_declaration->type = type;
4868                                         prev_type                  = type;
4869                                 }
4870
4871                                 switch (old_storage_class) {
4872                                 case STORAGE_CLASS_NONE:
4873                                         old_storage_class = STORAGE_CLASS_EXTERN;
4874                                         /* FALLTHROUGH */
4875
4876                                 case STORAGE_CLASS_EXTERN:
4877                                         if (is_definition) {
4878                                                 if (warning.missing_prototypes &&
4879                                                     prev_type->function.unspecified_parameters &&
4880                                                     !is_sym_main(symbol)) {
4881                                                         warningf(pos, "no previous prototype for '%#T'",
4882                                                                          orig_type, symbol);
4883                                                 }
4884                                         } else if (new_storage_class == STORAGE_CLASS_NONE) {
4885                                                 new_storage_class = STORAGE_CLASS_EXTERN;
4886                                         }
4887                                         break;
4888
4889                                 default:
4890                                         break;
4891                                 }
4892                         }
4893
4894                         if (old_storage_class == STORAGE_CLASS_EXTERN &&
4895                                         new_storage_class == STORAGE_CLASS_EXTERN) {
4896 warn_redundant_declaration:
4897                                 if (!is_definition           &&
4898                                     warning.redundant_decls  &&
4899                                     is_type_valid(prev_type) &&
4900                                     strcmp(previous_entity->base.source_position.input_name, "<builtin>") != 0) {
4901                                         warningf(pos,
4902                                                  "redundant declaration for '%Y' (declared %P)",
4903                                                  symbol, &previous_entity->base.source_position);
4904                                 }
4905                         } else if (current_function == NULL) {
4906                                 if (old_storage_class != STORAGE_CLASS_STATIC &&
4907                                     new_storage_class == STORAGE_CLASS_STATIC) {
4908                                         errorf(pos,
4909                                                "static declaration of '%Y' follows non-static declaration (declared %P)",
4910                                                symbol, &previous_entity->base.source_position);
4911                                 } else if (old_storage_class == STORAGE_CLASS_EXTERN) {
4912                                         previous_declaration->storage_class          = STORAGE_CLASS_NONE;
4913                                         previous_declaration->declared_storage_class = STORAGE_CLASS_NONE;
4914                                 } else {
4915                                         /* ISO/IEC 14882:1998(E) §C.1.2:1 */
4916                                         if (c_mode & _CXX)
4917                                                 goto error_redeclaration;
4918                                         goto warn_redundant_declaration;
4919                                 }
4920                         } else if (is_type_valid(prev_type)) {
4921                                 if (old_storage_class == new_storage_class) {
4922 error_redeclaration:
4923                                         errorf(pos, "redeclaration of '%Y' (declared %P)",
4924                                                symbol, &previous_entity->base.source_position);
4925                                 } else {
4926                                         errorf(pos,
4927                                                "redeclaration of '%Y' with different linkage (declared %P)",
4928                                                symbol, &previous_entity->base.source_position);
4929                                 }
4930                         }
4931                 }
4932
4933                 previous_declaration->modifiers |= declaration->modifiers;
4934                 if (entity->kind == ENTITY_FUNCTION) {
4935                         previous_entity->function.is_inline |= entity->function.is_inline;
4936                 }
4937                 return previous_entity;
4938         }
4939
4940         if (entity->kind == ENTITY_FUNCTION) {
4941                 if (is_definition &&
4942                                 entity->declaration.storage_class != STORAGE_CLASS_STATIC) {
4943                         if (warning.missing_prototypes && !is_sym_main(symbol)) {
4944                                 warningf(pos, "no previous prototype for '%#T'",
4945                                          entity->declaration.type, symbol);
4946                         } else if (warning.missing_declarations && !is_sym_main(symbol)) {
4947                                 warningf(pos, "no previous declaration for '%#T'",
4948                                          entity->declaration.type, symbol);
4949                         }
4950                 }
4951         } else if (warning.missing_declarations
4952                         && entity->kind == ENTITY_VARIABLE
4953                         && current_scope == file_scope) {
4954                 declaration_t *declaration = &entity->declaration;
4955                 if (declaration->storage_class == STORAGE_CLASS_NONE ||
4956                                 declaration->storage_class == STORAGE_CLASS_THREAD) {
4957                         warningf(pos, "no previous declaration for '%#T'",
4958                                  declaration->type, symbol);
4959                 }
4960         }
4961
4962 finish:
4963         assert(entity->base.parent_scope == NULL);
4964         assert(current_scope != NULL);
4965
4966         entity->base.parent_scope = current_scope;
4967         entity->base.namespc      = NAMESPACE_NORMAL;
4968         environment_push(entity);
4969         append_entity(current_scope, entity);
4970
4971         return entity;
4972 }
4973
4974 static void parser_error_multiple_definition(entity_t *entity,
4975                 const source_position_t *source_position)
4976 {
4977         errorf(source_position, "multiple definition of symbol '%Y' (declared %P)",
4978                entity->base.symbol, &entity->base.source_position);
4979 }
4980
4981 static bool is_declaration_specifier(const token_t *token,
4982                                      bool only_specifiers_qualifiers)
4983 {
4984         switch (token->type) {
4985                 TYPE_SPECIFIERS
4986                 TYPE_QUALIFIERS
4987                         return true;
4988                 case T_IDENTIFIER:
4989                         return is_typedef_symbol(token->v.symbol);
4990
4991                 case T___extension__:
4992                 STORAGE_CLASSES
4993                         return !only_specifiers_qualifiers;
4994
4995                 default:
4996                         return false;
4997         }
4998 }
4999
5000 static void parse_init_declarator_rest(entity_t *entity)
5001 {
5002         assert(is_declaration(entity));
5003         declaration_t *const declaration = &entity->declaration;
5004
5005         eat('=');
5006
5007         type_t *orig_type = declaration->type;
5008         type_t *type      = skip_typeref(orig_type);
5009
5010         if (entity->kind == ENTITY_VARIABLE
5011                         && entity->variable.initializer != NULL) {
5012                 parser_error_multiple_definition(entity, HERE);
5013         }
5014
5015         bool must_be_constant = false;
5016         if (declaration->storage_class == STORAGE_CLASS_STATIC        ||
5017             declaration->storage_class == STORAGE_CLASS_THREAD_STATIC ||
5018             entity->base.parent_scope  == file_scope) {
5019                 must_be_constant = true;
5020         }
5021
5022         if (is_type_function(type)) {
5023                 errorf(&entity->base.source_position,
5024                        "function '%#T' is initialized like a variable",
5025                        orig_type, entity->base.symbol);
5026                 orig_type = type_error_type;
5027         }
5028
5029         parse_initializer_env_t env;
5030         env.type             = orig_type;
5031         env.must_be_constant = must_be_constant;
5032         env.entity           = entity;
5033         current_init_decl    = entity;
5034
5035         initializer_t *initializer = parse_initializer(&env);
5036         current_init_decl = NULL;
5037
5038         if (entity->kind == ENTITY_VARIABLE) {
5039                 /* § 6.7.5 (22)  array initializers for arrays with unknown size
5040                  * determine the array type size */
5041                 declaration->type            = env.type;
5042                 entity->variable.initializer = initializer;
5043         }
5044 }
5045
5046 /* parse rest of a declaration without any declarator */
5047 static void parse_anonymous_declaration_rest(
5048                 const declaration_specifiers_t *specifiers)
5049 {
5050         eat(';');
5051
5052         if (warning.other) {
5053                 if (specifiers->storage_class != STORAGE_CLASS_NONE) {
5054                         warningf(&specifiers->source_position,
5055                                  "useless storage class in empty declaration");
5056                 }
5057
5058                 type_t *type = specifiers->type;
5059                 switch (type->kind) {
5060                         case TYPE_COMPOUND_STRUCT:
5061                         case TYPE_COMPOUND_UNION: {
5062                                 if (type->compound.compound->base.symbol == NULL) {
5063                                         warningf(&specifiers->source_position,
5064                                                  "unnamed struct/union that defines no instances");
5065                                 }
5066                                 break;
5067                         }
5068
5069                         case TYPE_ENUM:
5070                                 break;
5071
5072                         default:
5073                                 warningf(&specifiers->source_position, "empty declaration");
5074                                 break;
5075                 }
5076         }
5077 }
5078
5079 static void parse_declaration_rest(entity_t *ndeclaration,
5080                 const declaration_specifiers_t *specifiers,
5081                 parsed_declaration_func finished_declaration)
5082 {
5083         add_anchor_token(';');
5084         add_anchor_token(',');
5085         while (true) {
5086                 entity_t *entity = finished_declaration(ndeclaration, token.type == '=');
5087
5088                 if (token.type == '=') {
5089                         parse_init_declarator_rest(entity);
5090                 }
5091
5092                 if (token.type != ',')
5093                         break;
5094                 eat(',');
5095
5096                 add_anchor_token('=');
5097                 ndeclaration = parse_declarator(specifiers, /*may_be_abstract=*/false, false);
5098                 rem_anchor_token('=');
5099         }
5100         expect(';');
5101
5102 end_error:
5103         rem_anchor_token(';');
5104         rem_anchor_token(',');
5105 }
5106
5107 static entity_t *finished_kr_declaration(entity_t *entity, bool is_definition)
5108 {
5109         symbol_t *symbol = entity->base.symbol;
5110         if (symbol == NULL) {
5111                 errorf(HERE, "anonymous declaration not valid as function parameter");
5112                 return entity;
5113         }
5114
5115         assert(entity->base.namespc == NAMESPACE_NORMAL);
5116         entity_t *previous_entity = get_entity(symbol, NAMESPACE_NORMAL);
5117         if (previous_entity == NULL
5118                         || previous_entity->base.parent_scope != current_scope) {
5119                 errorf(HERE, "expected declaration of a function parameter, found '%Y'",
5120                        symbol);
5121                 return entity;
5122         }
5123
5124         if (is_definition) {
5125                 errorf(HERE, "parameter %Y is initialised", entity->base.symbol);
5126         }
5127
5128         return record_entity(entity, false);
5129 }
5130
5131 static void parse_declaration(parsed_declaration_func finished_declaration)
5132 {
5133         declaration_specifiers_t specifiers;
5134         memset(&specifiers, 0, sizeof(specifiers));
5135
5136         add_anchor_token(';');
5137         parse_declaration_specifiers(&specifiers);
5138         rem_anchor_token(';');
5139
5140         if (token.type == ';') {
5141                 parse_anonymous_declaration_rest(&specifiers);
5142         } else {
5143                 entity_t *entity = parse_declarator(&specifiers, /*may_be_abstract=*/false, false);
5144                 parse_declaration_rest(entity, &specifiers, finished_declaration);
5145         }
5146 }
5147
5148 static type_t *get_default_promoted_type(type_t *orig_type)
5149 {
5150         type_t *result = orig_type;
5151
5152         type_t *type = skip_typeref(orig_type);
5153         if (is_type_integer(type)) {
5154                 result = promote_integer(type);
5155         } else if (type == type_float) {
5156                 result = type_double;
5157         }
5158
5159         return result;
5160 }
5161
5162 static void parse_kr_declaration_list(entity_t *entity)
5163 {
5164         if (entity->kind != ENTITY_FUNCTION)
5165                 return;
5166
5167         type_t *type = skip_typeref(entity->declaration.type);
5168         assert(is_type_function(type));
5169         if (!type->function.kr_style_parameters)
5170                 return;
5171
5172
5173         add_anchor_token('{');
5174
5175         /* push function parameters */
5176         size_t const top = environment_top();
5177         scope_push(&entity->function.parameters);
5178
5179         entity_t *parameter = entity->function.parameters.entities;
5180         for ( ; parameter != NULL; parameter = parameter->base.next) {
5181                 assert(parameter->base.parent_scope == NULL);
5182                 parameter->base.parent_scope = current_scope;
5183                 environment_push(parameter);
5184         }
5185
5186         /* parse declaration list */
5187         while (is_declaration_specifier(&token, false)) {
5188                 parse_declaration(finished_kr_declaration);
5189         }
5190
5191         /* pop function parameters */
5192         assert(current_scope == &entity->function.parameters);
5193         scope_pop();
5194         environment_pop_to(top);
5195
5196         /* update function type */
5197         type_t *new_type = duplicate_type(type);
5198
5199         function_parameter_t *parameters     = NULL;
5200         function_parameter_t *last_parameter = NULL;
5201
5202         entity_t *parameter_declaration = entity->function.parameters.entities;
5203         for (; parameter_declaration != NULL;
5204                         parameter_declaration = parameter_declaration->base.next) {
5205                 type_t *parameter_type = parameter_declaration->declaration.type;
5206                 if (parameter_type == NULL) {
5207                         if (strict_mode) {
5208                                 errorf(HERE, "no type specified for function parameter '%Y'",
5209                                        parameter_declaration->base.symbol);
5210                         } else {
5211                                 if (warning.implicit_int) {
5212                                         warningf(HERE, "no type specified for function parameter '%Y', using 'int'",
5213                                                  parameter_declaration->base.symbol);
5214                                 }
5215                                 parameter_type                          = type_int;
5216                                 parameter_declaration->declaration.type = parameter_type;
5217                         }
5218                 }
5219
5220                 semantic_parameter(&parameter_declaration->declaration);
5221                 parameter_type = parameter_declaration->declaration.type;
5222
5223                 /*
5224                  * we need the default promoted types for the function type
5225                  */
5226                 parameter_type = get_default_promoted_type(parameter_type);
5227
5228                 function_parameter_t *function_parameter
5229                         = obstack_alloc(type_obst, sizeof(function_parameter[0]));
5230                 memset(function_parameter, 0, sizeof(function_parameter[0]));
5231
5232                 function_parameter->type = parameter_type;
5233                 if (last_parameter != NULL) {
5234                         last_parameter->next = function_parameter;
5235                 } else {
5236                         parameters = function_parameter;
5237                 }
5238                 last_parameter = function_parameter;
5239         }
5240
5241         /* § 6.9.1.7: A K&R style parameter list does NOT act as a function
5242          * prototype */
5243         new_type->function.parameters             = parameters;
5244         new_type->function.unspecified_parameters = true;
5245
5246         type = typehash_insert(new_type);
5247         if (type != new_type) {
5248                 obstack_free(type_obst, new_type);
5249         }
5250
5251         entity->declaration.type = type;
5252
5253         rem_anchor_token('{');
5254 }
5255
5256 static bool first_err = true;
5257
5258 /**
5259  * When called with first_err set, prints the name of the current function,
5260  * else does noting.
5261  */
5262 static void print_in_function(void)
5263 {
5264         if (first_err) {
5265                 first_err = false;
5266                 diagnosticf("%s: In function '%Y':\n",
5267                             current_function->base.base.source_position.input_name,
5268                             current_function->base.base.symbol);
5269         }
5270 }
5271
5272 /**
5273  * Check if all labels are defined in the current function.
5274  * Check if all labels are used in the current function.
5275  */
5276 static void check_labels(void)
5277 {
5278         for (const goto_statement_t *goto_statement = goto_first;
5279             goto_statement != NULL;
5280             goto_statement = goto_statement->next) {
5281                 /* skip computed gotos */
5282                 if (goto_statement->expression != NULL)
5283                         continue;
5284
5285                 label_t *label = goto_statement->label;
5286
5287                 label->used = true;
5288                 if (label->base.source_position.input_name == NULL) {
5289                         print_in_function();
5290                         errorf(&goto_statement->base.source_position,
5291                                "label '%Y' used but not defined", label->base.symbol);
5292                  }
5293         }
5294
5295         if (warning.unused_label) {
5296                 for (const label_statement_t *label_statement = label_first;
5297                          label_statement != NULL;
5298                          label_statement = label_statement->next) {
5299                         label_t *label = label_statement->label;
5300
5301                         if (! label->used) {
5302                                 print_in_function();
5303                                 warningf(&label_statement->base.source_position,
5304                                          "label '%Y' defined but not used", label->base.symbol);
5305                         }
5306                 }
5307         }
5308 }
5309
5310 static void warn_unused_decl(entity_t *entity, entity_t *end,
5311                              char const *const what)
5312 {
5313         for (; entity != NULL; entity = entity->base.next) {
5314                 if (!is_declaration(entity))
5315                         continue;
5316
5317                 declaration_t *declaration = &entity->declaration;
5318                 if (declaration->implicit)
5319                         continue;
5320
5321                 if (!declaration->used) {
5322                         print_in_function();
5323                         warningf(&entity->base.source_position, "%s '%Y' is unused",
5324                                  what, entity->base.symbol);
5325                 } else if (entity->kind == ENTITY_VARIABLE && !entity->variable.read) {
5326                         print_in_function();
5327                         warningf(&entity->base.source_position, "%s '%Y' is never read",
5328                                  what, entity->base.symbol);
5329                 }
5330
5331                 if (entity == end)
5332                         break;
5333         }
5334 }
5335
5336 static void check_unused_variables(statement_t *const stmt, void *const env)
5337 {
5338         (void)env;
5339
5340         switch (stmt->kind) {
5341                 case STATEMENT_DECLARATION: {
5342                         declaration_statement_t const *const decls = &stmt->declaration;
5343                         warn_unused_decl(decls->declarations_begin, decls->declarations_end,
5344                                          "variable");
5345                         return;
5346                 }
5347
5348                 case STATEMENT_FOR:
5349                         warn_unused_decl(stmt->fors.scope.entities, NULL, "variable");
5350                         return;
5351
5352                 default:
5353                         return;
5354         }
5355 }
5356
5357 /**
5358  * Check declarations of current_function for unused entities.
5359  */
5360 static void check_declarations(void)
5361 {
5362         if (warning.unused_parameter) {
5363                 const scope_t *scope = &current_function->parameters;
5364
5365                 /* do not issue unused warnings for main */
5366                 if (!is_sym_main(current_function->base.base.symbol)) {
5367                         warn_unused_decl(scope->entities, NULL, "parameter");
5368                 }
5369         }
5370         if (warning.unused_variable) {
5371                 walk_statements(current_function->statement, check_unused_variables,
5372                                 NULL);
5373         }
5374 }
5375
5376 static int determine_truth(expression_t const* const cond)
5377 {
5378         return
5379                 !is_constant_expression(cond) ? 0 :
5380                 fold_constant(cond) != 0      ? 1 :
5381                 -1;
5382 }
5383
5384 static bool expression_returns(expression_t const *const expr)
5385 {
5386         switch (expr->kind) {
5387                 case EXPR_CALL: {
5388                         expression_t const *const func = expr->call.function;
5389                         if (func->kind == EXPR_REFERENCE) {
5390                                 entity_t *entity = func->reference.entity;
5391                                 if (entity->kind == ENTITY_FUNCTION
5392                                                 && entity->declaration.modifiers & DM_NORETURN)
5393                                         return false;
5394                         }
5395
5396                         if (!expression_returns(func))
5397                                 return false;
5398
5399                         for (call_argument_t const* arg = expr->call.arguments; arg != NULL; arg = arg->next) {
5400                                 if (!expression_returns(arg->expression))
5401                                         return false;
5402                         }
5403
5404                         return true;
5405                 }
5406
5407                 case EXPR_REFERENCE:
5408                 case EXPR_REFERENCE_ENUM_VALUE:
5409                 case EXPR_CONST:
5410                 case EXPR_CHARACTER_CONSTANT:
5411                 case EXPR_WIDE_CHARACTER_CONSTANT:
5412                 case EXPR_STRING_LITERAL:
5413                 case EXPR_WIDE_STRING_LITERAL:
5414                 case EXPR_COMPOUND_LITERAL: // TODO descend into initialisers
5415                 case EXPR_LABEL_ADDRESS:
5416                 case EXPR_CLASSIFY_TYPE:
5417                 case EXPR_SIZEOF: // TODO handle obscure VLA case
5418                 case EXPR_ALIGNOF:
5419                 case EXPR_FUNCNAME:
5420                 case EXPR_BUILTIN_SYMBOL:
5421                 case EXPR_BUILTIN_CONSTANT_P:
5422                 case EXPR_BUILTIN_PREFETCH:
5423                 case EXPR_OFFSETOF:
5424                 case EXPR_INVALID:
5425                 case EXPR_STATEMENT: // TODO implement
5426                         return true;
5427
5428                 case EXPR_CONDITIONAL:
5429                         // TODO handle constant expression
5430                         return
5431                                 expression_returns(expr->conditional.condition) && (
5432                                         expression_returns(expr->conditional.true_expression) ||
5433                                         expression_returns(expr->conditional.false_expression)
5434                                 );
5435
5436                 case EXPR_SELECT:
5437                         return expression_returns(expr->select.compound);
5438
5439                 case EXPR_ARRAY_ACCESS:
5440                         return
5441                                 expression_returns(expr->array_access.array_ref) &&
5442                                 expression_returns(expr->array_access.index);
5443
5444                 case EXPR_VA_START:
5445                         return expression_returns(expr->va_starte.ap);
5446
5447                 case EXPR_VA_ARG:
5448                         return expression_returns(expr->va_arge.ap);
5449
5450                 EXPR_UNARY_CASES_MANDATORY
5451                         return expression_returns(expr->unary.value);
5452
5453                 case EXPR_UNARY_THROW:
5454                         return false;
5455
5456                 EXPR_BINARY_CASES
5457                         // TODO handle constant lhs of && and ||
5458                         return
5459                                 expression_returns(expr->binary.left) &&
5460                                 expression_returns(expr->binary.right);
5461
5462                 case EXPR_UNKNOWN:
5463                         break;
5464         }
5465
5466         panic("unhandled expression");
5467 }
5468
5469 static bool noreturn_candidate;
5470
5471 static void check_reachable(statement_t *const stmt)
5472 {
5473         if (stmt->base.reachable)
5474                 return;
5475         if (stmt->kind != STATEMENT_DO_WHILE)
5476                 stmt->base.reachable = true;
5477
5478         statement_t *last = stmt;
5479         statement_t *next;
5480         switch (stmt->kind) {
5481                 case STATEMENT_INVALID:
5482                 case STATEMENT_EMPTY:
5483                 case STATEMENT_DECLARATION:
5484                 case STATEMENT_LOCAL_LABEL:
5485                 case STATEMENT_ASM:
5486                         next = stmt->base.next;
5487                         break;
5488
5489                 case STATEMENT_COMPOUND:
5490                         next = stmt->compound.statements;
5491                         break;
5492
5493                 case STATEMENT_RETURN:
5494                         noreturn_candidate = false;
5495                         return;
5496
5497                 case STATEMENT_IF: {
5498                         if_statement_t const* const ifs = &stmt->ifs;
5499                         int            const        val = determine_truth(ifs->condition);
5500
5501                         if (val >= 0)
5502                                 check_reachable(ifs->true_statement);
5503
5504                         if (val > 0)
5505                                 return;
5506
5507                         if (ifs->false_statement != NULL) {
5508                                 check_reachable(ifs->false_statement);
5509                                 return;
5510                         }
5511
5512                         next = stmt->base.next;
5513                         break;
5514                 }
5515
5516                 case STATEMENT_SWITCH: {
5517                         switch_statement_t const *const switchs = &stmt->switchs;
5518                         expression_t       const *const expr    = switchs->expression;
5519
5520                         if (is_constant_expression(expr)) {
5521                                 long                    const val      = fold_constant(expr);
5522                                 case_label_statement_t *      defaults = NULL;
5523                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
5524                                         if (i->expression == NULL) {
5525                                                 defaults = i;
5526                                                 continue;
5527                                         }
5528
5529                                         if (i->first_case <= val && val <= i->last_case) {
5530                                                 check_reachable((statement_t*)i);
5531                                                 return;
5532                                         }
5533                                 }
5534
5535                                 if (defaults != NULL) {
5536                                         check_reachable((statement_t*)defaults);
5537                                         return;
5538                                 }
5539                         } else {
5540                                 bool has_default = false;
5541                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
5542                                         if (i->expression == NULL)
5543                                                 has_default = true;
5544
5545                                         check_reachable((statement_t*)i);
5546                                 }
5547
5548                                 if (has_default)
5549                                         return;
5550                         }
5551
5552                         next = stmt->base.next;
5553                         break;
5554                 }
5555
5556                 case STATEMENT_EXPRESSION: {
5557                         /* Check for noreturn function call */
5558                         expression_t const *const expr = stmt->expression.expression;
5559                         if (!expression_returns(expr))
5560                                 return;
5561
5562                         next = stmt->base.next;
5563                         break;
5564                 }
5565
5566                 case STATEMENT_CONTINUE: {
5567                         statement_t *parent = stmt;
5568                         for (;;) {
5569                                 parent = parent->base.parent;
5570                                 if (parent == NULL) /* continue not within loop */
5571                                         return;
5572
5573                                 next = parent;
5574                                 switch (parent->kind) {
5575                                         case STATEMENT_WHILE:    goto continue_while;
5576                                         case STATEMENT_DO_WHILE: goto continue_do_while;
5577                                         case STATEMENT_FOR:      goto continue_for;
5578
5579                                         default: break;
5580                                 }
5581                         }
5582                 }
5583
5584                 case STATEMENT_BREAK: {
5585                         statement_t *parent = stmt;
5586                         for (;;) {
5587                                 parent = parent->base.parent;
5588                                 if (parent == NULL) /* break not within loop/switch */
5589                                         return;
5590
5591                                 switch (parent->kind) {
5592                                         case STATEMENT_SWITCH:
5593                                         case STATEMENT_WHILE:
5594                                         case STATEMENT_DO_WHILE:
5595                                         case STATEMENT_FOR:
5596                                                 last = parent;
5597                                                 next = parent->base.next;
5598                                                 goto found_break_parent;
5599
5600                                         default: break;
5601                                 }
5602                         }
5603 found_break_parent:
5604                         break;
5605                 }
5606
5607                 case STATEMENT_GOTO:
5608                         if (stmt->gotos.expression) {
5609                                 statement_t *parent = stmt->base.parent;
5610                                 if (parent == NULL) /* top level goto */
5611                                         return;
5612                                 next = parent;
5613                         } else {
5614                                 next = stmt->gotos.label->statement;
5615                                 if (next == NULL) /* missing label */
5616                                         return;
5617                         }
5618                         break;
5619
5620                 case STATEMENT_LABEL:
5621                         next = stmt->label.statement;
5622                         break;
5623
5624                 case STATEMENT_CASE_LABEL:
5625                         next = stmt->case_label.statement;
5626                         break;
5627
5628                 case STATEMENT_WHILE: {
5629                         while_statement_t const *const whiles = &stmt->whiles;
5630                         int                      const val    = determine_truth(whiles->condition);
5631
5632                         if (val >= 0)
5633                                 check_reachable(whiles->body);
5634
5635                         if (val > 0)
5636                                 return;
5637
5638                         next = stmt->base.next;
5639                         break;
5640                 }
5641
5642                 case STATEMENT_DO_WHILE:
5643                         next = stmt->do_while.body;
5644                         break;
5645
5646                 case STATEMENT_FOR: {
5647                         for_statement_t *const fors = &stmt->fors;
5648
5649                         if (fors->condition_reachable)
5650                                 return;
5651                         fors->condition_reachable = true;
5652
5653                         expression_t const *const cond = fors->condition;
5654                         int          const        val  =
5655                                 cond == NULL ? 1 : determine_truth(cond);
5656
5657                         if (val >= 0)
5658                                 check_reachable(fors->body);
5659
5660                         if (val > 0)
5661                                 return;
5662
5663                         next = stmt->base.next;
5664                         break;
5665                 }
5666
5667                 case STATEMENT_MS_TRY: {
5668                         ms_try_statement_t const *const ms_try = &stmt->ms_try;
5669                         check_reachable(ms_try->try_statement);
5670                         next = ms_try->final_statement;
5671                         break;
5672                 }
5673
5674                 case STATEMENT_LEAVE: {
5675                         statement_t *parent = stmt;
5676                         for (;;) {
5677                                 parent = parent->base.parent;
5678                                 if (parent == NULL) /* __leave not within __try */
5679                                         return;
5680
5681                                 if (parent->kind == STATEMENT_MS_TRY) {
5682                                         last = parent;
5683                                         next = parent->ms_try.final_statement;
5684                                         break;
5685                                 }
5686                         }
5687                         break;
5688                 }
5689         }
5690
5691         while (next == NULL) {
5692                 next = last->base.parent;
5693                 if (next == NULL) {
5694                         noreturn_candidate = false;
5695
5696                         type_t *const type = current_function->base.type;
5697                         assert(is_type_function(type));
5698                         type_t *const ret  = skip_typeref(type->function.return_type);
5699                         if (warning.return_type                    &&
5700                             !is_type_atomic(ret, ATOMIC_TYPE_VOID) &&
5701                             is_type_valid(ret)                     &&
5702                             !is_sym_main(current_function->base.base.symbol)) {
5703                                 warningf(&stmt->base.source_position,
5704                                          "control reaches end of non-void function");
5705                         }
5706                         return;
5707                 }
5708
5709                 switch (next->kind) {
5710                         case STATEMENT_INVALID:
5711                         case STATEMENT_EMPTY:
5712                         case STATEMENT_DECLARATION:
5713                         case STATEMENT_LOCAL_LABEL:
5714                         case STATEMENT_EXPRESSION:
5715                         case STATEMENT_ASM:
5716                         case STATEMENT_RETURN:
5717                         case STATEMENT_CONTINUE:
5718                         case STATEMENT_BREAK:
5719                         case STATEMENT_GOTO:
5720                         case STATEMENT_LEAVE:
5721                                 panic("invalid control flow in function");
5722
5723                         case STATEMENT_COMPOUND:
5724                         case STATEMENT_IF:
5725                         case STATEMENT_SWITCH:
5726                         case STATEMENT_LABEL:
5727                         case STATEMENT_CASE_LABEL:
5728                                 last = next;
5729                                 next = next->base.next;
5730                                 break;
5731
5732                         case STATEMENT_WHILE: {
5733 continue_while:
5734                                 if (next->base.reachable)
5735                                         return;
5736                                 next->base.reachable = true;
5737
5738                                 while_statement_t const *const whiles = &next->whiles;
5739                                 int                      const val    = determine_truth(whiles->condition);
5740
5741                                 if (val >= 0)
5742                                         check_reachable(whiles->body);
5743
5744                                 if (val > 0)
5745                                         return;
5746
5747                                 last = next;
5748                                 next = next->base.next;
5749                                 break;
5750                         }
5751
5752                         case STATEMENT_DO_WHILE: {
5753 continue_do_while:
5754                                 if (next->base.reachable)
5755                                         return;
5756                                 next->base.reachable = true;
5757
5758                                 do_while_statement_t const *const dw  = &next->do_while;
5759                                 int                  const        val = determine_truth(dw->condition);
5760
5761                                 if (val >= 0)
5762                                         check_reachable(dw->body);
5763
5764                                 if (val > 0)
5765                                         return;
5766
5767                                 last = next;
5768                                 next = next->base.next;
5769                                 break;
5770                         }
5771
5772                         case STATEMENT_FOR: {
5773 continue_for:;
5774                                 for_statement_t *const fors = &next->fors;
5775
5776                                 fors->step_reachable = true;
5777
5778                                 if (fors->condition_reachable)
5779                                         return;
5780                                 fors->condition_reachable = true;
5781
5782                                 expression_t const *const cond = fors->condition;
5783                                 int          const        val  =
5784                                         cond == NULL ? 1 : determine_truth(cond);
5785
5786                                 if (val >= 0)
5787                                         check_reachable(fors->body);
5788
5789                                 if (val > 0)
5790                                         return;
5791
5792                                 last = next;
5793                                 next = next->base.next;
5794                                 break;
5795                         }
5796
5797                         case STATEMENT_MS_TRY:
5798                                 last = next;
5799                                 next = next->ms_try.final_statement;
5800                                 break;
5801                 }
5802         }
5803
5804         check_reachable(next);
5805 }
5806
5807 static void check_unreachable(statement_t* const stmt, void *const env)
5808 {
5809         (void)env;
5810
5811         switch (stmt->kind) {
5812                 case STATEMENT_DO_WHILE:
5813                         if (!stmt->base.reachable) {
5814                                 expression_t const *const cond = stmt->do_while.condition;
5815                                 if (determine_truth(cond) >= 0) {
5816                                         warningf(&cond->base.source_position,
5817                                                  "condition of do-while-loop is unreachable");
5818                                 }
5819                         }
5820                         return;
5821
5822                 case STATEMENT_FOR: {
5823                         for_statement_t const* const fors = &stmt->fors;
5824
5825                         // if init and step are unreachable, cond is unreachable, too
5826                         if (!stmt->base.reachable && !fors->step_reachable) {
5827                                 warningf(&stmt->base.source_position, "statement is unreachable");
5828                         } else {
5829                                 if (!stmt->base.reachable && fors->initialisation != NULL) {
5830                                         warningf(&fors->initialisation->base.source_position,
5831                                                  "initialisation of for-statement is unreachable");
5832                                 }
5833
5834                                 if (!fors->condition_reachable && fors->condition != NULL) {
5835                                         warningf(&fors->condition->base.source_position,
5836                                                  "condition of for-statement is unreachable");
5837                                 }
5838
5839                                 if (!fors->step_reachable && fors->step != NULL) {
5840                                         warningf(&fors->step->base.source_position,
5841                                                  "step of for-statement is unreachable");
5842                                 }
5843                         }
5844                         return;
5845                 }
5846
5847                 case STATEMENT_COMPOUND:
5848                         if (stmt->compound.statements != NULL)
5849                                 return;
5850                         /* FALLTHROUGH*/
5851
5852                 default:
5853                         if (!stmt->base.reachable)
5854                                 warningf(&stmt->base.source_position, "statement is unreachable");
5855                         return;
5856         }
5857 }
5858
5859 static void parse_external_declaration(void)
5860 {
5861         /* function-definitions and declarations both start with declaration
5862          * specifiers */
5863         declaration_specifiers_t specifiers;
5864         memset(&specifiers, 0, sizeof(specifiers));
5865
5866         add_anchor_token(';');
5867         parse_declaration_specifiers(&specifiers);
5868         rem_anchor_token(';');
5869
5870         /* must be a declaration */
5871         if (token.type == ';') {
5872                 parse_anonymous_declaration_rest(&specifiers);
5873                 return;
5874         }
5875
5876         add_anchor_token(',');
5877         add_anchor_token('=');
5878         add_anchor_token(';');
5879         add_anchor_token('{');
5880
5881         /* declarator is common to both function-definitions and declarations */
5882         entity_t *ndeclaration = parse_declarator(&specifiers, /*may_be_abstract=*/false, false);
5883
5884         rem_anchor_token('{');
5885         rem_anchor_token(';');
5886         rem_anchor_token('=');
5887         rem_anchor_token(',');
5888
5889         /* must be a declaration */
5890         switch (token.type) {
5891                 case ',':
5892                 case ';':
5893                 case '=':
5894                         parse_declaration_rest(ndeclaration, &specifiers, record_entity);
5895                         return;
5896         }
5897
5898         /* must be a function definition */
5899         parse_kr_declaration_list(ndeclaration);
5900
5901         if (token.type != '{') {
5902                 parse_error_expected("while parsing function definition", '{', NULL);
5903                 eat_until_matching_token(';');
5904                 return;
5905         }
5906
5907         assert(is_declaration(ndeclaration));
5908         type_t *type = skip_typeref(ndeclaration->declaration.type);
5909
5910         if (!is_type_function(type)) {
5911                 if (is_type_valid(type)) {
5912                         errorf(HERE, "declarator '%#T' has a body but is not a function type",
5913                                type, ndeclaration->base.symbol);
5914                 }
5915                 eat_block();
5916                 return;
5917         }
5918
5919         if (warning.aggregate_return &&
5920             is_type_compound(skip_typeref(type->function.return_type))) {
5921                 warningf(HERE, "function '%Y' returns an aggregate",
5922                          ndeclaration->base.symbol);
5923         }
5924         if (warning.traditional && !type->function.unspecified_parameters) {
5925                 warningf(HERE, "traditional C rejects ISO C style function definition of function '%Y'",
5926                         ndeclaration->base.symbol);
5927         }
5928         if (warning.old_style_definition && type->function.unspecified_parameters) {
5929                 warningf(HERE, "old-style function definition '%Y'",
5930                         ndeclaration->base.symbol);
5931         }
5932
5933         /* § 6.7.5.3 (14) a function definition with () means no
5934          * parameters (and not unspecified parameters) */
5935         if (type->function.unspecified_parameters
5936                         && type->function.parameters == NULL
5937                         && !type->function.kr_style_parameters) {
5938                 type_t *duplicate = duplicate_type(type);
5939                 duplicate->function.unspecified_parameters = false;
5940
5941                 type = typehash_insert(duplicate);
5942                 if (type != duplicate) {
5943                         obstack_free(type_obst, duplicate);
5944                 }
5945                 ndeclaration->declaration.type = type;
5946         }
5947
5948         entity_t *const entity = record_entity(ndeclaration, true);
5949         assert(entity->kind == ENTITY_FUNCTION);
5950         assert(ndeclaration->kind == ENTITY_FUNCTION);
5951
5952         function_t *function = &entity->function;
5953         if (ndeclaration != entity) {
5954                 function->parameters = ndeclaration->function.parameters;
5955         }
5956         assert(is_declaration(entity));
5957         type = skip_typeref(entity->declaration.type);
5958
5959         /* push function parameters and switch scope */
5960         size_t const top = environment_top();
5961         scope_push(&function->parameters);
5962
5963         entity_t *parameter = function->parameters.entities;
5964         for (; parameter != NULL; parameter = parameter->base.next) {
5965                 if (parameter->base.parent_scope == &ndeclaration->function.parameters) {
5966                         parameter->base.parent_scope = current_scope;
5967                 }
5968                 assert(parameter->base.parent_scope == NULL
5969                                 || parameter->base.parent_scope == current_scope);
5970                 parameter->base.parent_scope = current_scope;
5971                 if (parameter->base.symbol == NULL) {
5972                         errorf(&parameter->base.source_position, "parameter name omitted");
5973                         continue;
5974                 }
5975                 environment_push(parameter);
5976         }
5977
5978         if (function->statement != NULL) {
5979                 parser_error_multiple_definition(entity, HERE);
5980                 eat_block();
5981         } else {
5982                 /* parse function body */
5983                 int         label_stack_top      = label_top();
5984                 function_t *old_current_function = current_function;
5985                 current_function                 = function;
5986                 current_parent                   = NULL;
5987
5988                 goto_first   = NULL;
5989                 goto_anchor  = &goto_first;
5990                 label_first  = NULL;
5991                 label_anchor = &label_first;
5992
5993                 statement_t *const body = parse_compound_statement(false);
5994                 function->statement = body;
5995                 first_err = true;
5996                 check_labels();
5997                 check_declarations();
5998                 if (warning.return_type      ||
5999                     warning.unreachable_code ||
6000                     (warning.missing_noreturn
6001                      && !(function->base.modifiers & DM_NORETURN))) {
6002                         noreturn_candidate = true;
6003                         check_reachable(body);
6004                         if (warning.unreachable_code)
6005                                 walk_statements(body, check_unreachable, NULL);
6006                         if (warning.missing_noreturn &&
6007                             noreturn_candidate       &&
6008                             !(function->base.modifiers & DM_NORETURN)) {
6009                                 warningf(&body->base.source_position,
6010                                          "function '%#T' is candidate for attribute 'noreturn'",
6011                                          type, entity->base.symbol);
6012                         }
6013                 }
6014
6015                 assert(current_parent   == NULL);
6016                 assert(current_function == function);
6017                 current_function = old_current_function;
6018                 label_pop_to(label_stack_top);
6019         }
6020
6021         assert(current_scope == &function->parameters);
6022         scope_pop();
6023         environment_pop_to(top);
6024 }
6025
6026 static type_t *make_bitfield_type(type_t *base_type, expression_t *size,
6027                                   source_position_t *source_position,
6028                                   const symbol_t *symbol)
6029 {
6030         type_t *type = allocate_type_zero(TYPE_BITFIELD);
6031
6032         type->bitfield.base_type       = base_type;
6033         type->bitfield.size_expression = size;
6034
6035         il_size_t bit_size;
6036         type_t *skipped_type = skip_typeref(base_type);
6037         if (!is_type_integer(skipped_type)) {
6038                 errorf(HERE, "bitfield base type '%T' is not an integer type",
6039                         base_type);
6040                 bit_size = 0;
6041         } else {
6042                 bit_size = skipped_type->base.size * 8;
6043         }
6044
6045         if (is_constant_expression(size)) {
6046                 long v = fold_constant(size);
6047
6048                 if (v < 0) {
6049                         errorf(source_position, "negative width in bit-field '%Y'", symbol);
6050                 } else if (v == 0) {
6051                         errorf(source_position, "zero width for bit-field '%Y'", symbol);
6052                 } else if (bit_size > 0 && (il_size_t)v > bit_size) {
6053                         errorf(source_position, "width of '%Y' exceeds its type", symbol);
6054                 } else {
6055                         type->bitfield.bit_size = v;
6056                 }
6057         }
6058
6059         return type;
6060 }
6061
6062 static entity_t *find_compound_entry(compound_t *compound, symbol_t *symbol)
6063 {
6064         entity_t *iter = compound->members.entities;
6065         for (; iter != NULL; iter = iter->base.next) {
6066                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
6067                         continue;
6068
6069                 if (iter->base.symbol == symbol) {
6070                         return iter;
6071                 } else if (iter->base.symbol == NULL) {
6072                         type_t *type = skip_typeref(iter->declaration.type);
6073                         if (is_type_compound(type)) {
6074                                 entity_t *result
6075                                         = find_compound_entry(type->compound.compound, symbol);
6076                                 if (result != NULL)
6077                                         return result;
6078                         }
6079                         continue;
6080                 }
6081         }
6082
6083         return NULL;
6084 }
6085
6086 static void parse_compound_declarators(compound_t *compound,
6087                 const declaration_specifiers_t *specifiers)
6088 {
6089         while (true) {
6090                 entity_t *entity;
6091
6092                 if (token.type == ':') {
6093                         source_position_t source_position = *HERE;
6094                         next_token();
6095
6096                         type_t *base_type = specifiers->type;
6097                         expression_t *size = parse_constant_expression();
6098
6099                         type_t *type = make_bitfield_type(base_type, size,
6100                                         &source_position, sym_anonymous);
6101
6102                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER);
6103                         entity->base.namespc                       = NAMESPACE_NORMAL;
6104                         entity->base.source_position               = source_position;
6105                         entity->declaration.declared_storage_class = STORAGE_CLASS_NONE;
6106                         entity->declaration.storage_class          = STORAGE_CLASS_NONE;
6107                         entity->declaration.modifiers              = specifiers->modifiers;
6108                         entity->declaration.type                   = type;
6109                 } else {
6110                         entity = parse_declarator(specifiers,/*may_be_abstract=*/true, true);
6111                         assert(entity->kind == ENTITY_COMPOUND_MEMBER);
6112
6113                         if (token.type == ':') {
6114                                 source_position_t source_position = *HERE;
6115                                 next_token();
6116                                 expression_t *size = parse_constant_expression();
6117
6118                                 type_t *type = entity->declaration.type;
6119                                 type_t *bitfield_type = make_bitfield_type(type, size,
6120                                                 &source_position, entity->base.symbol);
6121                                 entity->declaration.type = bitfield_type;
6122                         }
6123                 }
6124
6125                 /* make sure we don't define a symbol multiple times */
6126                 symbol_t *symbol = entity->base.symbol;
6127                 if (symbol != NULL) {
6128                         entity_t *prev = find_compound_entry(compound, symbol);
6129
6130                         if (prev != NULL) {
6131                                 assert(prev->base.symbol == symbol);
6132                                 errorf(&entity->base.source_position,
6133                                        "multiple declarations of symbol '%Y' (declared %P)",
6134                                        symbol, &prev->base.source_position);
6135                         }
6136                 }
6137
6138                 append_entity(&compound->members, entity);
6139
6140                 type_t *orig_type = entity->declaration.type;
6141                 type_t *type      = skip_typeref(orig_type);
6142                 if (is_type_function(type)) {
6143                         errorf(&entity->base.source_position,
6144                                         "compound member '%Y' must not have function type '%T'",
6145                                         entity->base.symbol, orig_type);
6146                 } else if (is_type_incomplete(type)) {
6147                         /* §6.7.2.1:16 flexible array member */
6148                         if (is_type_array(type) &&
6149                                         token.type == ';'   &&
6150                                         look_ahead(1)->type == '}') {
6151                                 compound->has_flexible_member = true;
6152                         } else {
6153                                 errorf(&entity->base.source_position,
6154                                                 "compound member '%Y' has incomplete type '%T'",
6155                                                 entity->base.symbol, orig_type);
6156                         }
6157                 }
6158
6159                 if (token.type != ',')
6160                         break;
6161                 next_token();
6162         }
6163         expect(';');
6164
6165 end_error:
6166         ;
6167 }
6168
6169 static void parse_compound_type_entries(compound_t *compound)
6170 {
6171         eat('{');
6172         add_anchor_token('}');
6173
6174         while (token.type != '}') {
6175                 if (token.type == T_EOF) {
6176                         errorf(HERE, "EOF while parsing struct");
6177                         break;
6178                 }
6179                 declaration_specifiers_t specifiers;
6180                 memset(&specifiers, 0, sizeof(specifiers));
6181                 parse_declaration_specifiers(&specifiers);
6182
6183                 parse_compound_declarators(compound, &specifiers);
6184         }
6185         rem_anchor_token('}');
6186         next_token();
6187
6188         /* §6.7.2.1:7 */
6189         compound->complete = true;
6190 }
6191
6192 static type_t *parse_typename(void)
6193 {
6194         declaration_specifiers_t specifiers;
6195         memset(&specifiers, 0, sizeof(specifiers));
6196         parse_declaration_specifiers(&specifiers);
6197         if (specifiers.storage_class != STORAGE_CLASS_NONE) {
6198                 /* TODO: improve error message, user does probably not know what a
6199                  * storage class is...
6200                  */
6201                 errorf(HERE, "typename may not have a storage class");
6202         }
6203
6204         type_t *result = parse_abstract_declarator(specifiers.type);
6205
6206         return result;
6207 }
6208
6209
6210
6211
6212 typedef expression_t* (*parse_expression_function)(void);
6213 typedef expression_t* (*parse_expression_infix_function)(expression_t *left);
6214
6215 typedef struct expression_parser_function_t expression_parser_function_t;
6216 struct expression_parser_function_t {
6217         parse_expression_function        parser;
6218         unsigned                         infix_precedence;
6219         parse_expression_infix_function  infix_parser;
6220 };
6221
6222 expression_parser_function_t expression_parsers[T_LAST_TOKEN];
6223
6224 /**
6225  * Prints an error message if an expression was expected but not read
6226  */
6227 static expression_t *expected_expression_error(void)
6228 {
6229         /* skip the error message if the error token was read */
6230         if (token.type != T_ERROR) {
6231                 errorf(HERE, "expected expression, got token '%K'", &token);
6232         }
6233         next_token();
6234
6235         return create_invalid_expression();
6236 }
6237
6238 /**
6239  * Parse a string constant.
6240  */
6241 static expression_t *parse_string_const(void)
6242 {
6243         wide_string_t wres;
6244         if (token.type == T_STRING_LITERAL) {
6245                 string_t res = token.v.string;
6246                 next_token();
6247                 while (token.type == T_STRING_LITERAL) {
6248                         res = concat_strings(&res, &token.v.string);
6249                         next_token();
6250                 }
6251                 if (token.type != T_WIDE_STRING_LITERAL) {
6252                         expression_t *const cnst = allocate_expression_zero(EXPR_STRING_LITERAL);
6253                         /* note: that we use type_char_ptr here, which is already the
6254                          * automatic converted type. revert_automatic_type_conversion
6255                          * will construct the array type */
6256                         cnst->base.type    = warning.write_strings ? type_const_char_ptr : type_char_ptr;
6257                         cnst->string.value = res;
6258                         return cnst;
6259                 }
6260
6261                 wres = concat_string_wide_string(&res, &token.v.wide_string);
6262         } else {
6263                 wres = token.v.wide_string;
6264         }
6265         next_token();
6266
6267         for (;;) {
6268                 switch (token.type) {
6269                         case T_WIDE_STRING_LITERAL:
6270                                 wres = concat_wide_strings(&wres, &token.v.wide_string);
6271                                 break;
6272
6273                         case T_STRING_LITERAL:
6274                                 wres = concat_wide_string_string(&wres, &token.v.string);
6275                                 break;
6276
6277                         default: {
6278                                 expression_t *const cnst = allocate_expression_zero(EXPR_WIDE_STRING_LITERAL);
6279                                 cnst->base.type         = warning.write_strings ? type_const_wchar_t_ptr : type_wchar_t_ptr;
6280                                 cnst->wide_string.value = wres;
6281                                 return cnst;
6282                         }
6283                 }
6284                 next_token();
6285         }
6286 }
6287
6288 /**
6289  * Parse a boolean constant.
6290  */
6291 static expression_t *parse_bool_const(bool value)
6292 {
6293         expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
6294         cnst->base.type          = type_bool;
6295         cnst->conste.v.int_value = value;
6296
6297         next_token();
6298
6299         return cnst;
6300 }
6301
6302 /**
6303  * Parse an integer constant.
6304  */
6305 static expression_t *parse_int_const(void)
6306 {
6307         expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
6308         cnst->base.type          = token.datatype;
6309         cnst->conste.v.int_value = token.v.intvalue;
6310
6311         next_token();
6312
6313         return cnst;
6314 }
6315
6316 /**
6317  * Parse a character constant.
6318  */
6319 static expression_t *parse_character_constant(void)
6320 {
6321         expression_t *cnst = allocate_expression_zero(EXPR_CHARACTER_CONSTANT);
6322         cnst->base.type          = token.datatype;
6323         cnst->conste.v.character = token.v.string;
6324
6325         if (cnst->conste.v.character.size != 1) {
6326                 if (!GNU_MODE) {
6327                         errorf(HERE, "more than 1 character in character constant");
6328                 } else if (warning.multichar) {
6329                         warningf(HERE, "multi-character character constant");
6330                 }
6331         }
6332         next_token();
6333
6334         return cnst;
6335 }
6336
6337 /**
6338  * Parse a wide character constant.
6339  */
6340 static expression_t *parse_wide_character_constant(void)
6341 {
6342         expression_t *cnst = allocate_expression_zero(EXPR_WIDE_CHARACTER_CONSTANT);
6343         cnst->base.type               = token.datatype;
6344         cnst->conste.v.wide_character = token.v.wide_string;
6345
6346         if (cnst->conste.v.wide_character.size != 1) {
6347                 if (!GNU_MODE) {
6348                         errorf(HERE, "more than 1 character in character constant");
6349                 } else if (warning.multichar) {
6350                         warningf(HERE, "multi-character character constant");
6351                 }
6352         }
6353         next_token();
6354
6355         return cnst;
6356 }
6357
6358 /**
6359  * Parse a float constant.
6360  */
6361 static expression_t *parse_float_const(void)
6362 {
6363         expression_t *cnst         = allocate_expression_zero(EXPR_CONST);
6364         cnst->base.type            = token.datatype;
6365         cnst->conste.v.float_value = token.v.floatvalue;
6366
6367         next_token();
6368
6369         return cnst;
6370 }
6371
6372 static entity_t *create_implicit_function(symbol_t *symbol,
6373                 const source_position_t *source_position)
6374 {
6375         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
6376         ntype->function.return_type            = type_int;
6377         ntype->function.unspecified_parameters = true;
6378
6379         type_t *type = typehash_insert(ntype);
6380         if (type != ntype) {
6381                 free_type(ntype);
6382         }
6383
6384         entity_t *entity = allocate_entity_zero(ENTITY_FUNCTION);
6385         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
6386         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
6387         entity->declaration.type                   = type;
6388         entity->declaration.implicit               = true;
6389         entity->base.symbol                        = symbol;
6390         entity->base.source_position               = *source_position;
6391
6392         bool strict_prototypes_old = warning.strict_prototypes;
6393         warning.strict_prototypes  = false;
6394         record_entity(entity, false);
6395         warning.strict_prototypes = strict_prototypes_old;
6396
6397         return entity;
6398 }
6399
6400 /**
6401  * Creates a return_type (func)(argument_type) function type if not
6402  * already exists.
6403  */
6404 static type_t *make_function_2_type(type_t *return_type, type_t *argument_type1,
6405                                     type_t *argument_type2)
6406 {
6407         function_parameter_t *parameter2
6408                 = obstack_alloc(type_obst, sizeof(parameter2[0]));
6409         memset(parameter2, 0, sizeof(parameter2[0]));
6410         parameter2->type = argument_type2;
6411
6412         function_parameter_t *parameter1
6413                 = obstack_alloc(type_obst, sizeof(parameter1[0]));
6414         memset(parameter1, 0, sizeof(parameter1[0]));
6415         parameter1->type = argument_type1;
6416         parameter1->next = parameter2;
6417
6418         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6419         type->function.return_type = return_type;
6420         type->function.parameters  = parameter1;
6421
6422         type_t *result = typehash_insert(type);
6423         if (result != type) {
6424                 free_type(type);
6425         }
6426
6427         return result;
6428 }
6429
6430 /**
6431  * Creates a return_type (func)(argument_type) function type if not
6432  * already exists.
6433  *
6434  * @param return_type    the return type
6435  * @param argument_type  the argument type
6436  */
6437 static type_t *make_function_1_type(type_t *return_type, type_t *argument_type)
6438 {
6439         function_parameter_t *parameter
6440                 = obstack_alloc(type_obst, sizeof(parameter[0]));
6441         memset(parameter, 0, sizeof(parameter[0]));
6442         parameter->type = argument_type;
6443
6444         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6445         type->function.return_type = return_type;
6446         type->function.parameters  = parameter;
6447
6448         type_t *result = typehash_insert(type);
6449         if (result != type) {
6450                 free_type(type);
6451         }
6452
6453         return result;
6454 }
6455
6456 static type_t *make_function_0_type(type_t *return_type)
6457 {
6458         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6459         type->function.return_type = return_type;
6460         type->function.parameters  = NULL;
6461
6462         type_t *result = typehash_insert(type);
6463         if (result != type) {
6464                 free_type(type);
6465         }
6466
6467         return result;
6468 }
6469
6470 /**
6471  * Creates a function type for some function like builtins.
6472  *
6473  * @param symbol   the symbol describing the builtin
6474  */
6475 static type_t *get_builtin_symbol_type(symbol_t *symbol)
6476 {
6477         switch (symbol->ID) {
6478         case T___builtin_alloca:
6479                 return make_function_1_type(type_void_ptr, type_size_t);
6480         case T___builtin_huge_val:
6481                 return make_function_0_type(type_double);
6482         case T___builtin_inf:
6483                 return make_function_0_type(type_double);
6484         case T___builtin_inff:
6485                 return make_function_0_type(type_float);
6486         case T___builtin_infl:
6487                 return make_function_0_type(type_long_double);
6488         case T___builtin_nan:
6489                 return make_function_1_type(type_double, type_char_ptr);
6490         case T___builtin_nanf:
6491                 return make_function_1_type(type_float, type_char_ptr);
6492         case T___builtin_nanl:
6493                 return make_function_1_type(type_long_double, type_char_ptr);
6494         case T___builtin_va_end:
6495                 return make_function_1_type(type_void, type_valist);
6496         case T___builtin_expect:
6497                 return make_function_2_type(type_long, type_long, type_long);
6498         default:
6499                 internal_errorf(HERE, "not implemented builtin symbol found");
6500         }
6501 }
6502
6503 /**
6504  * Performs automatic type cast as described in § 6.3.2.1.
6505  *
6506  * @param orig_type  the original type
6507  */
6508 static type_t *automatic_type_conversion(type_t *orig_type)
6509 {
6510         type_t *type = skip_typeref(orig_type);
6511         if (is_type_array(type)) {
6512                 array_type_t *array_type   = &type->array;
6513                 type_t       *element_type = array_type->element_type;
6514                 unsigned      qualifiers   = array_type->base.qualifiers;
6515
6516                 return make_pointer_type(element_type, qualifiers);
6517         }
6518
6519         if (is_type_function(type)) {
6520                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
6521         }
6522
6523         return orig_type;
6524 }
6525
6526 /**
6527  * reverts the automatic casts of array to pointer types and function
6528  * to function-pointer types as defined § 6.3.2.1
6529  */
6530 type_t *revert_automatic_type_conversion(const expression_t *expression)
6531 {
6532         switch (expression->kind) {
6533                 case EXPR_REFERENCE: {
6534                         entity_t *entity = expression->reference.entity;
6535                         if (is_declaration(entity)) {
6536                                 return entity->declaration.type;
6537                         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6538                                 return entity->enum_value.enum_type;
6539                         } else {
6540                                 panic("no declaration or enum in reference");
6541                         }
6542                 }
6543
6544                 case EXPR_SELECT: {
6545                         entity_t *entity = expression->select.compound_entry;
6546                         assert(is_declaration(entity));
6547                         type_t   *type   = entity->declaration.type;
6548                         return get_qualified_type(type,
6549                                                   expression->base.type->base.qualifiers);
6550                 }
6551
6552                 case EXPR_UNARY_DEREFERENCE: {
6553                         const expression_t *const value = expression->unary.value;
6554                         type_t             *const type  = skip_typeref(value->base.type);
6555                         assert(is_type_pointer(type));
6556                         return type->pointer.points_to;
6557                 }
6558
6559                 case EXPR_BUILTIN_SYMBOL:
6560                         return get_builtin_symbol_type(expression->builtin_symbol.symbol);
6561
6562                 case EXPR_ARRAY_ACCESS: {
6563                         const expression_t *array_ref = expression->array_access.array_ref;
6564                         type_t             *type_left = skip_typeref(array_ref->base.type);
6565                         if (!is_type_valid(type_left))
6566                                 return type_left;
6567                         assert(is_type_pointer(type_left));
6568                         return type_left->pointer.points_to;
6569                 }
6570
6571                 case EXPR_STRING_LITERAL: {
6572                         size_t size = expression->string.value.size;
6573                         return make_array_type(type_char, size, TYPE_QUALIFIER_NONE);
6574                 }
6575
6576                 case EXPR_WIDE_STRING_LITERAL: {
6577                         size_t size = expression->wide_string.value.size;
6578                         return make_array_type(type_wchar_t, size, TYPE_QUALIFIER_NONE);
6579                 }
6580
6581                 case EXPR_COMPOUND_LITERAL:
6582                         return expression->compound_literal.type;
6583
6584                 default: break;
6585         }
6586
6587         return expression->base.type;
6588 }
6589
6590 static expression_t *parse_reference(void)
6591 {
6592         symbol_t *const symbol = token.v.symbol;
6593
6594         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
6595
6596         if (entity == NULL) {
6597                 if (!strict_mode && look_ahead(1)->type == '(') {
6598                         /* an implicitly declared function */
6599                         if (warning.implicit_function_declaration) {
6600                                 warningf(HERE, "implicit declaration of function '%Y'",
6601                                         symbol);
6602                         }
6603
6604                         entity = create_implicit_function(symbol, HERE);
6605                 } else {
6606                         errorf(HERE, "unknown symbol '%Y' found.", symbol);
6607                         entity = create_error_entity(symbol, ENTITY_VARIABLE);
6608                 }
6609         }
6610
6611         type_t *orig_type;
6612
6613         if (is_declaration(entity)) {
6614                 orig_type = entity->declaration.type;
6615         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6616                 orig_type = entity->enum_value.enum_type;
6617         } else if (entity->kind == ENTITY_TYPEDEF) {
6618                 errorf(HERE, "encountered typedef name '%Y' while parsing expression",
6619                         symbol);
6620                 next_token();
6621                 return create_invalid_expression();
6622         } else {
6623                 panic("expected declaration or enum value in reference");
6624         }
6625
6626         /* we always do the auto-type conversions; the & and sizeof parser contains
6627          * code to revert this! */
6628         type_t *type = automatic_type_conversion(orig_type);
6629
6630         expression_kind_t kind = EXPR_REFERENCE;
6631         if (entity->kind == ENTITY_ENUM_VALUE)
6632                 kind = EXPR_REFERENCE_ENUM_VALUE;
6633
6634         expression_t *expression     = allocate_expression_zero(kind);
6635         expression->reference.entity = entity;
6636         expression->base.type        = type;
6637
6638         /* this declaration is used */
6639         if (is_declaration(entity)) {
6640                 entity->declaration.used = true;
6641         }
6642
6643         if (entity->base.parent_scope != file_scope
6644                 && entity->base.parent_scope->depth < current_function->parameters.depth
6645                 && is_type_valid(orig_type) && !is_type_function(orig_type)) {
6646                 if (entity->kind == ENTITY_VARIABLE) {
6647                         /* access of a variable from an outer function */
6648                         entity->variable.address_taken = true;
6649                 }
6650                 current_function->need_closure = true;
6651         }
6652
6653         /* check for deprecated functions */
6654         if (warning.deprecated_declarations
6655                 && is_declaration(entity)
6656                 && entity->declaration.modifiers & DM_DEPRECATED) {
6657                 declaration_t *declaration = &entity->declaration;
6658
6659                 char const *const prefix = entity->kind == ENTITY_FUNCTION ?
6660                         "function" : "variable";
6661
6662                 if (declaration->deprecated_string != NULL) {
6663                         warningf(HERE, "%s '%Y' is deprecated (declared %P): \"%s\"",
6664                                  prefix, entity->base.symbol, &entity->base.source_position,
6665                                  declaration->deprecated_string);
6666                 } else {
6667                         warningf(HERE, "%s '%Y' is deprecated (declared %P)", prefix,
6668                                  entity->base.symbol, &entity->base.source_position);
6669                 }
6670         }
6671
6672         if (warning.init_self && entity == current_init_decl && !in_type_prop
6673             && entity->kind == ENTITY_VARIABLE) {
6674                 current_init_decl = NULL;
6675                 warningf(HERE, "variable '%#T' is initialized by itself",
6676                          entity->declaration.type, entity->base.symbol);
6677         }
6678
6679         next_token();
6680         return expression;
6681 }
6682
6683 static bool semantic_cast(expression_t *cast)
6684 {
6685         expression_t            *expression      = cast->unary.value;
6686         type_t                  *orig_dest_type  = cast->base.type;
6687         type_t                  *orig_type_right = expression->base.type;
6688         type_t            const *dst_type        = skip_typeref(orig_dest_type);
6689         type_t            const *src_type        = skip_typeref(orig_type_right);
6690         source_position_t const *pos             = &cast->base.source_position;
6691
6692         /* §6.5.4 A (void) cast is explicitly permitted, more for documentation than for utility. */
6693         if (dst_type == type_void)
6694                 return true;
6695
6696         /* only integer and pointer can be casted to pointer */
6697         if (is_type_pointer(dst_type)  &&
6698             !is_type_pointer(src_type) &&
6699             !is_type_integer(src_type) &&
6700             is_type_valid(src_type)) {
6701                 errorf(pos, "cannot convert type '%T' to a pointer type", orig_type_right);
6702                 return false;
6703         }
6704
6705         if (!is_type_scalar(dst_type) && is_type_valid(dst_type)) {
6706                 errorf(pos, "conversion to non-scalar type '%T' requested", orig_dest_type);
6707                 return false;
6708         }
6709
6710         if (!is_type_scalar(src_type) && is_type_valid(src_type)) {
6711                 errorf(pos, "conversion from non-scalar type '%T' requested", orig_type_right);
6712                 return false;
6713         }
6714
6715         if (warning.cast_qual &&
6716             is_type_pointer(src_type) &&
6717             is_type_pointer(dst_type)) {
6718                 type_t *src = skip_typeref(src_type->pointer.points_to);
6719                 type_t *dst = skip_typeref(dst_type->pointer.points_to);
6720                 unsigned missing_qualifiers =
6721                         src->base.qualifiers & ~dst->base.qualifiers;
6722                 if (missing_qualifiers != 0) {
6723                         warningf(pos,
6724                                  "cast discards qualifiers '%Q' in pointer target type of '%T'",
6725                                  missing_qualifiers, orig_type_right);
6726                 }
6727         }
6728         return true;
6729 }
6730
6731 static expression_t *parse_compound_literal(type_t *type)
6732 {
6733         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
6734
6735         parse_initializer_env_t env;
6736         env.type             = type;
6737         env.entity           = NULL;
6738         env.must_be_constant = false;
6739         initializer_t *initializer = parse_initializer(&env);
6740         type = env.type;
6741
6742         expression->compound_literal.initializer = initializer;
6743         expression->compound_literal.type        = type;
6744         expression->base.type                    = automatic_type_conversion(type);
6745
6746         return expression;
6747 }
6748
6749 /**
6750  * Parse a cast expression.
6751  */
6752 static expression_t *parse_cast(void)
6753 {
6754         add_anchor_token(')');
6755
6756         source_position_t source_position = token.source_position;
6757
6758         type_t *type = parse_typename();
6759
6760         rem_anchor_token(')');
6761         expect(')');
6762
6763         if (token.type == '{') {
6764                 return parse_compound_literal(type);
6765         }
6766
6767         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
6768         cast->base.source_position = source_position;
6769
6770         expression_t *value = parse_sub_expression(PREC_CAST);
6771         cast->base.type   = type;
6772         cast->unary.value = value;
6773
6774         if (! semantic_cast(cast)) {
6775                 /* TODO: record the error in the AST. else it is impossible to detect it */
6776         }
6777
6778         return cast;
6779 end_error:
6780         return create_invalid_expression();
6781 }
6782
6783 /**
6784  * Parse a statement expression.
6785  */
6786 static expression_t *parse_statement_expression(void)
6787 {
6788         add_anchor_token(')');
6789
6790         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
6791
6792         statement_t *statement          = parse_compound_statement(true);
6793         expression->statement.statement = statement;
6794
6795         /* find last statement and use its type */
6796         type_t *type = type_void;
6797         const statement_t *stmt = statement->compound.statements;
6798         if (stmt != NULL) {
6799                 while (stmt->base.next != NULL)
6800                         stmt = stmt->base.next;
6801
6802                 if (stmt->kind == STATEMENT_EXPRESSION) {
6803                         type = stmt->expression.expression->base.type;
6804                 }
6805         } else if (warning.other) {
6806                 warningf(&expression->base.source_position, "empty statement expression ({})");
6807         }
6808         expression->base.type = type;
6809
6810         rem_anchor_token(')');
6811         expect(')');
6812
6813 end_error:
6814         return expression;
6815 }
6816
6817 /**
6818  * Parse a parenthesized expression.
6819  */
6820 static expression_t *parse_parenthesized_expression(void)
6821 {
6822         eat('(');
6823
6824         switch (token.type) {
6825         case '{':
6826                 /* gcc extension: a statement expression */
6827                 return parse_statement_expression();
6828
6829         TYPE_QUALIFIERS
6830         TYPE_SPECIFIERS
6831                 return parse_cast();
6832         case T_IDENTIFIER:
6833                 if (is_typedef_symbol(token.v.symbol)) {
6834                         return parse_cast();
6835                 }
6836         }
6837
6838         add_anchor_token(')');
6839         expression_t *result = parse_expression();
6840         rem_anchor_token(')');
6841         expect(')');
6842
6843 end_error:
6844         return result;
6845 }
6846
6847 static expression_t *parse_function_keyword(void)
6848 {
6849         /* TODO */
6850
6851         if (current_function == NULL) {
6852                 errorf(HERE, "'__func__' used outside of a function");
6853         }
6854
6855         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6856         expression->base.type     = type_char_ptr;
6857         expression->funcname.kind = FUNCNAME_FUNCTION;
6858
6859         next_token();
6860
6861         return expression;
6862 }
6863
6864 static expression_t *parse_pretty_function_keyword(void)
6865 {
6866         if (current_function == NULL) {
6867                 errorf(HERE, "'__PRETTY_FUNCTION__' used outside of a function");
6868         }
6869
6870         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6871         expression->base.type     = type_char_ptr;
6872         expression->funcname.kind = FUNCNAME_PRETTY_FUNCTION;
6873
6874         eat(T___PRETTY_FUNCTION__);
6875
6876         return expression;
6877 }
6878
6879 static expression_t *parse_funcsig_keyword(void)
6880 {
6881         if (current_function == NULL) {
6882                 errorf(HERE, "'__FUNCSIG__' used outside of a function");
6883         }
6884
6885         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6886         expression->base.type     = type_char_ptr;
6887         expression->funcname.kind = FUNCNAME_FUNCSIG;
6888
6889         eat(T___FUNCSIG__);
6890
6891         return expression;
6892 }
6893
6894 static expression_t *parse_funcdname_keyword(void)
6895 {
6896         if (current_function == NULL) {
6897                 errorf(HERE, "'__FUNCDNAME__' used outside of a function");
6898         }
6899
6900         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6901         expression->base.type     = type_char_ptr;
6902         expression->funcname.kind = FUNCNAME_FUNCDNAME;
6903
6904         eat(T___FUNCDNAME__);
6905
6906         return expression;
6907 }
6908
6909 static designator_t *parse_designator(void)
6910 {
6911         designator_t *result    = allocate_ast_zero(sizeof(result[0]));
6912         result->source_position = *HERE;
6913
6914         if (token.type != T_IDENTIFIER) {
6915                 parse_error_expected("while parsing member designator",
6916                                      T_IDENTIFIER, NULL);
6917                 return NULL;
6918         }
6919         result->symbol = token.v.symbol;
6920         next_token();
6921
6922         designator_t *last_designator = result;
6923         while (true) {
6924                 if (token.type == '.') {
6925                         next_token();
6926                         if (token.type != T_IDENTIFIER) {
6927                                 parse_error_expected("while parsing member designator",
6928                                                      T_IDENTIFIER, NULL);
6929                                 return NULL;
6930                         }
6931                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
6932                         designator->source_position = *HERE;
6933                         designator->symbol          = token.v.symbol;
6934                         next_token();
6935
6936                         last_designator->next = designator;
6937                         last_designator       = designator;
6938                         continue;
6939                 }
6940                 if (token.type == '[') {
6941                         next_token();
6942                         add_anchor_token(']');
6943                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
6944                         designator->source_position = *HERE;
6945                         designator->array_index     = parse_expression();
6946                         rem_anchor_token(']');
6947                         expect(']');
6948                         if (designator->array_index == NULL) {
6949                                 return NULL;
6950                         }
6951
6952                         last_designator->next = designator;
6953                         last_designator       = designator;
6954                         continue;
6955                 }
6956                 break;
6957         }
6958
6959         return result;
6960 end_error:
6961         return NULL;
6962 }
6963
6964 /**
6965  * Parse the __builtin_offsetof() expression.
6966  */
6967 static expression_t *parse_offsetof(void)
6968 {
6969         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
6970         expression->base.type    = type_size_t;
6971
6972         eat(T___builtin_offsetof);
6973
6974         expect('(');
6975         add_anchor_token(',');
6976         type_t *type = parse_typename();
6977         rem_anchor_token(',');
6978         expect(',');
6979         add_anchor_token(')');
6980         designator_t *designator = parse_designator();
6981         rem_anchor_token(')');
6982         expect(')');
6983
6984         expression->offsetofe.type       = type;
6985         expression->offsetofe.designator = designator;
6986
6987         type_path_t path;
6988         memset(&path, 0, sizeof(path));
6989         path.top_type = type;
6990         path.path     = NEW_ARR_F(type_path_entry_t, 0);
6991
6992         descend_into_subtype(&path);
6993
6994         if (!walk_designator(&path, designator, true)) {
6995                 return create_invalid_expression();
6996         }
6997
6998         DEL_ARR_F(path.path);
6999
7000         return expression;
7001 end_error:
7002         return create_invalid_expression();
7003 }
7004
7005 /**
7006  * Parses a _builtin_va_start() expression.
7007  */
7008 static expression_t *parse_va_start(void)
7009 {
7010         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
7011
7012         eat(T___builtin_va_start);
7013
7014         expect('(');
7015         add_anchor_token(',');
7016         expression->va_starte.ap = parse_assignment_expression();
7017         rem_anchor_token(',');
7018         expect(',');
7019         expression_t *const expr = parse_assignment_expression();
7020         if (expr->kind == EXPR_REFERENCE) {
7021                 entity_t *const entity = expr->reference.entity;
7022                 if (entity->base.parent_scope != &current_function->parameters
7023                                 || entity->base.next != NULL
7024                                 || entity->kind != ENTITY_VARIABLE) {
7025                         errorf(&expr->base.source_position,
7026                                "second argument of 'va_start' must be last parameter of the current function");
7027                 } else {
7028                         expression->va_starte.parameter = &entity->variable;
7029                 }
7030                 expect(')');
7031                 return expression;
7032         }
7033         expect(')');
7034 end_error:
7035         return create_invalid_expression();
7036 }
7037
7038 /**
7039  * Parses a _builtin_va_arg() expression.
7040  */
7041 static expression_t *parse_va_arg(void)
7042 {
7043         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
7044
7045         eat(T___builtin_va_arg);
7046
7047         expect('(');
7048         expression->va_arge.ap = parse_assignment_expression();
7049         expect(',');
7050         expression->base.type = parse_typename();
7051         expect(')');
7052
7053         return expression;
7054 end_error:
7055         return create_invalid_expression();
7056 }
7057
7058 static expression_t *parse_builtin_symbol(void)
7059 {
7060         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_SYMBOL);
7061
7062         symbol_t *symbol = token.v.symbol;
7063
7064         expression->builtin_symbol.symbol = symbol;
7065         next_token();
7066
7067         type_t *type = get_builtin_symbol_type(symbol);
7068         type = automatic_type_conversion(type);
7069
7070         expression->base.type = type;
7071         return expression;
7072 }
7073
7074 /**
7075  * Parses a __builtin_constant() expression.
7076  */
7077 static expression_t *parse_builtin_constant(void)
7078 {
7079         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
7080
7081         eat(T___builtin_constant_p);
7082
7083         expect('(');
7084         add_anchor_token(')');
7085         expression->builtin_constant.value = parse_assignment_expression();
7086         rem_anchor_token(')');
7087         expect(')');
7088         expression->base.type = type_int;
7089
7090         return expression;
7091 end_error:
7092         return create_invalid_expression();
7093 }
7094
7095 /**
7096  * Parses a __builtin_prefetch() expression.
7097  */
7098 static expression_t *parse_builtin_prefetch(void)
7099 {
7100         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_PREFETCH);
7101
7102         eat(T___builtin_prefetch);
7103
7104         expect('(');
7105         add_anchor_token(')');
7106         expression->builtin_prefetch.adr = parse_assignment_expression();
7107         if (token.type == ',') {
7108                 next_token();
7109                 expression->builtin_prefetch.rw = parse_assignment_expression();
7110         }
7111         if (token.type == ',') {
7112                 next_token();
7113                 expression->builtin_prefetch.locality = parse_assignment_expression();
7114         }
7115         rem_anchor_token(')');
7116         expect(')');
7117         expression->base.type = type_void;
7118
7119         return expression;
7120 end_error:
7121         return create_invalid_expression();
7122 }
7123
7124 /**
7125  * Parses a __builtin_is_*() compare expression.
7126  */
7127 static expression_t *parse_compare_builtin(void)
7128 {
7129         expression_t *expression;
7130
7131         switch (token.type) {
7132         case T___builtin_isgreater:
7133                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATER);
7134                 break;
7135         case T___builtin_isgreaterequal:
7136                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATEREQUAL);
7137                 break;
7138         case T___builtin_isless:
7139                 expression = allocate_expression_zero(EXPR_BINARY_ISLESS);
7140                 break;
7141         case T___builtin_islessequal:
7142                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSEQUAL);
7143                 break;
7144         case T___builtin_islessgreater:
7145                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSGREATER);
7146                 break;
7147         case T___builtin_isunordered:
7148                 expression = allocate_expression_zero(EXPR_BINARY_ISUNORDERED);
7149                 break;
7150         default:
7151                 internal_errorf(HERE, "invalid compare builtin found");
7152         }
7153         expression->base.source_position = *HERE;
7154         next_token();
7155
7156         expect('(');
7157         expression->binary.left = parse_assignment_expression();
7158         expect(',');
7159         expression->binary.right = parse_assignment_expression();
7160         expect(')');
7161
7162         type_t *const orig_type_left  = expression->binary.left->base.type;
7163         type_t *const orig_type_right = expression->binary.right->base.type;
7164
7165         type_t *const type_left  = skip_typeref(orig_type_left);
7166         type_t *const type_right = skip_typeref(orig_type_right);
7167         if (!is_type_float(type_left) && !is_type_float(type_right)) {
7168                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7169                         type_error_incompatible("invalid operands in comparison",
7170                                 &expression->base.source_position, orig_type_left, orig_type_right);
7171                 }
7172         } else {
7173                 semantic_comparison(&expression->binary);
7174         }
7175
7176         return expression;
7177 end_error:
7178         return create_invalid_expression();
7179 }
7180
7181 #if 0
7182 /**
7183  * Parses a __builtin_expect() expression.
7184  */
7185 static expression_t *parse_builtin_expect(void)
7186 {
7187         expression_t *expression
7188                 = allocate_expression_zero(EXPR_BINARY_BUILTIN_EXPECT);
7189
7190         eat(T___builtin_expect);
7191
7192         expect('(');
7193         expression->binary.left = parse_assignment_expression();
7194         expect(',');
7195         expression->binary.right = parse_constant_expression();
7196         expect(')');
7197
7198         expression->base.type = expression->binary.left->base.type;
7199
7200         return expression;
7201 end_error:
7202         return create_invalid_expression();
7203 }
7204 #endif
7205
7206 /**
7207  * Parses a MS assume() expression.
7208  */
7209 static expression_t *parse_assume(void)
7210 {
7211         expression_t *expression = allocate_expression_zero(EXPR_UNARY_ASSUME);
7212
7213         eat(T__assume);
7214
7215         expect('(');
7216         add_anchor_token(')');
7217         expression->unary.value = parse_assignment_expression();
7218         rem_anchor_token(')');
7219         expect(')');
7220
7221         expression->base.type = type_void;
7222         return expression;
7223 end_error:
7224         return create_invalid_expression();
7225 }
7226
7227 /**
7228  * Return the declaration for a given label symbol or create a new one.
7229  *
7230  * @param symbol  the symbol of the label
7231  */
7232 static label_t *get_label(symbol_t *symbol)
7233 {
7234         entity_t *label;
7235         assert(current_function != NULL);
7236
7237         label = get_entity(symbol, NAMESPACE_LABEL);
7238         /* if we found a local label, we already created the declaration */
7239         if (label != NULL && label->kind == ENTITY_LOCAL_LABEL) {
7240                 if (label->base.parent_scope != current_scope) {
7241                         assert(label->base.parent_scope->depth < current_scope->depth);
7242                         current_function->goto_to_outer = true;
7243                 }
7244                 return &label->label;
7245         }
7246
7247         label = get_entity(symbol, NAMESPACE_LABEL);
7248         /* if we found a label in the same function, then we already created the
7249          * declaration */
7250         if (label != NULL
7251                         && label->base.parent_scope == &current_function->parameters) {
7252                 return &label->label;
7253         }
7254
7255         /* otherwise we need to create a new one */
7256         label               = allocate_entity_zero(ENTITY_LABEL);
7257         label->base.namespc = NAMESPACE_LABEL;
7258         label->base.symbol  = symbol;
7259
7260         label_push(label);
7261
7262         return &label->label;
7263 }
7264
7265 /**
7266  * Parses a GNU && label address expression.
7267  */
7268 static expression_t *parse_label_address(void)
7269 {
7270         source_position_t source_position = token.source_position;
7271         eat(T_ANDAND);
7272         if (token.type != T_IDENTIFIER) {
7273                 parse_error_expected("while parsing label address", T_IDENTIFIER, NULL);
7274                 goto end_error;
7275         }
7276         symbol_t *symbol = token.v.symbol;
7277         next_token();
7278
7279         label_t *label       = get_label(symbol);
7280         label->used          = true;
7281         label->address_taken = true;
7282
7283         expression_t *expression = allocate_expression_zero(EXPR_LABEL_ADDRESS);
7284         expression->base.source_position = source_position;
7285
7286         /* label address is threaten as a void pointer */
7287         expression->base.type           = type_void_ptr;
7288         expression->label_address.label = label;
7289         return expression;
7290 end_error:
7291         return create_invalid_expression();
7292 }
7293
7294 /**
7295  * Parse a microsoft __noop expression.
7296  */
7297 static expression_t *parse_noop_expression(void)
7298 {
7299         /* the result is a (int)0 */
7300         expression_t *cnst         = allocate_expression_zero(EXPR_CONST);
7301         cnst->base.type            = type_int;
7302         cnst->conste.v.int_value   = 0;
7303         cnst->conste.is_ms_noop    = true;
7304
7305         eat(T___noop);
7306
7307         if (token.type == '(') {
7308                 /* parse arguments */
7309                 eat('(');
7310                 add_anchor_token(')');
7311                 add_anchor_token(',');
7312
7313                 if (token.type != ')') {
7314                         while (true) {
7315                                 (void)parse_assignment_expression();
7316                                 if (token.type != ',')
7317                                         break;
7318                                 next_token();
7319                         }
7320                 }
7321         }
7322         rem_anchor_token(',');
7323         rem_anchor_token(')');
7324         expect(')');
7325
7326 end_error:
7327         return cnst;
7328 }
7329
7330 /**
7331  * Parses a primary expression.
7332  */
7333 static expression_t *parse_primary_expression(void)
7334 {
7335         switch (token.type) {
7336                 case T_false:                    return parse_bool_const(false);
7337                 case T_true:                     return parse_bool_const(true);
7338                 case T_INTEGER:                  return parse_int_const();
7339                 case T_CHARACTER_CONSTANT:       return parse_character_constant();
7340                 case T_WIDE_CHARACTER_CONSTANT:  return parse_wide_character_constant();
7341                 case T_FLOATINGPOINT:            return parse_float_const();
7342                 case T_STRING_LITERAL:
7343                 case T_WIDE_STRING_LITERAL:      return parse_string_const();
7344                 case T_IDENTIFIER:               return parse_reference();
7345                 case T___FUNCTION__:
7346                 case T___func__:                 return parse_function_keyword();
7347                 case T___PRETTY_FUNCTION__:      return parse_pretty_function_keyword();
7348                 case T___FUNCSIG__:              return parse_funcsig_keyword();
7349                 case T___FUNCDNAME__:            return parse_funcdname_keyword();
7350                 case T___builtin_offsetof:       return parse_offsetof();
7351                 case T___builtin_va_start:       return parse_va_start();
7352                 case T___builtin_va_arg:         return parse_va_arg();
7353                 case T___builtin_expect:
7354                 case T___builtin_alloca:
7355                 case T___builtin_inf:
7356                 case T___builtin_inff:
7357                 case T___builtin_infl:
7358                 case T___builtin_nan:
7359                 case T___builtin_nanf:
7360                 case T___builtin_nanl:
7361                 case T___builtin_huge_val:
7362                 case T___builtin_va_end:         return parse_builtin_symbol();
7363                 case T___builtin_isgreater:
7364                 case T___builtin_isgreaterequal:
7365                 case T___builtin_isless:
7366                 case T___builtin_islessequal:
7367                 case T___builtin_islessgreater:
7368                 case T___builtin_isunordered:    return parse_compare_builtin();
7369                 case T___builtin_constant_p:     return parse_builtin_constant();
7370                 case T___builtin_prefetch:       return parse_builtin_prefetch();
7371                 case T__assume:                  return parse_assume();
7372                 case T_ANDAND:
7373                         if (GNU_MODE)
7374                                 return parse_label_address();
7375                         break;
7376
7377                 case '(':                        return parse_parenthesized_expression();
7378                 case T___noop:                   return parse_noop_expression();
7379         }
7380
7381         errorf(HERE, "unexpected token %K, expected an expression", &token);
7382         return create_invalid_expression();
7383 }
7384
7385 /**
7386  * Check if the expression has the character type and issue a warning then.
7387  */
7388 static void check_for_char_index_type(const expression_t *expression)
7389 {
7390         type_t       *const type      = expression->base.type;
7391         const type_t *const base_type = skip_typeref(type);
7392
7393         if (is_type_atomic(base_type, ATOMIC_TYPE_CHAR) &&
7394                         warning.char_subscripts) {
7395                 warningf(&expression->base.source_position,
7396                          "array subscript has type '%T'", type);
7397         }
7398 }
7399
7400 static expression_t *parse_array_expression(expression_t *left)
7401 {
7402         expression_t *expression = allocate_expression_zero(EXPR_ARRAY_ACCESS);
7403
7404         eat('[');
7405         add_anchor_token(']');
7406
7407         expression_t *inside = parse_expression();
7408
7409         type_t *const orig_type_left   = left->base.type;
7410         type_t *const orig_type_inside = inside->base.type;
7411
7412         type_t *const type_left   = skip_typeref(orig_type_left);
7413         type_t *const type_inside = skip_typeref(orig_type_inside);
7414
7415         type_t                    *return_type;
7416         array_access_expression_t *array_access = &expression->array_access;
7417         if (is_type_pointer(type_left)) {
7418                 return_type             = type_left->pointer.points_to;
7419                 array_access->array_ref = left;
7420                 array_access->index     = inside;
7421                 check_for_char_index_type(inside);
7422         } else if (is_type_pointer(type_inside)) {
7423                 return_type             = type_inside->pointer.points_to;
7424                 array_access->array_ref = inside;
7425                 array_access->index     = left;
7426                 array_access->flipped   = true;
7427                 check_for_char_index_type(left);
7428         } else {
7429                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
7430                         errorf(HERE,
7431                                 "array access on object with non-pointer types '%T', '%T'",
7432                                 orig_type_left, orig_type_inside);
7433                 }
7434                 return_type             = type_error_type;
7435                 array_access->array_ref = left;
7436                 array_access->index     = inside;
7437         }
7438
7439         expression->base.type = automatic_type_conversion(return_type);
7440
7441         rem_anchor_token(']');
7442         expect(']');
7443 end_error:
7444         return expression;
7445 }
7446
7447 static expression_t *parse_typeprop(expression_kind_t const kind)
7448 {
7449         expression_t  *tp_expression = allocate_expression_zero(kind);
7450         tp_expression->base.type     = type_size_t;
7451
7452         eat(kind == EXPR_SIZEOF ? T_sizeof : T___alignof__);
7453
7454         /* we only refer to a type property, mark this case */
7455         bool old     = in_type_prop;
7456         in_type_prop = true;
7457
7458         type_t       *orig_type;
7459         expression_t *expression;
7460         if (token.type == '(' && is_declaration_specifier(look_ahead(1), true)) {
7461                 next_token();
7462                 add_anchor_token(')');
7463                 orig_type = parse_typename();
7464                 rem_anchor_token(')');
7465                 expect(')');
7466
7467                 if (token.type == '{') {
7468                         /* It was not sizeof(type) after all.  It is sizeof of an expression
7469                          * starting with a compound literal */
7470                         expression = parse_compound_literal(orig_type);
7471                         goto typeprop_expression;
7472                 }
7473         } else {
7474                 expression = parse_sub_expression(PREC_UNARY);
7475
7476 typeprop_expression:
7477                 tp_expression->typeprop.tp_expression = expression;
7478
7479                 orig_type = revert_automatic_type_conversion(expression);
7480                 expression->base.type = orig_type;
7481         }
7482
7483         tp_expression->typeprop.type   = orig_type;
7484         type_t const* const type       = skip_typeref(orig_type);
7485         char   const* const wrong_type =
7486                 is_type_incomplete(type)    ? "incomplete"          :
7487                 type->kind == TYPE_FUNCTION ? "function designator" :
7488                 type->kind == TYPE_BITFIELD ? "bitfield"            :
7489                 NULL;
7490         if (wrong_type != NULL) {
7491                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
7492                 errorf(&tp_expression->base.source_position,
7493                                 "operand of %s expression must not be of %s type '%T'",
7494                                 what, wrong_type, orig_type);
7495         }
7496
7497 end_error:
7498         in_type_prop = old;
7499         return tp_expression;
7500 }
7501
7502 static expression_t *parse_sizeof(void)
7503 {
7504         return parse_typeprop(EXPR_SIZEOF);
7505 }
7506
7507 static expression_t *parse_alignof(void)
7508 {
7509         return parse_typeprop(EXPR_ALIGNOF);
7510 }
7511
7512 static expression_t *parse_select_expression(expression_t *compound)
7513 {
7514         expression_t *select    = allocate_expression_zero(EXPR_SELECT);
7515         select->select.compound = compound;
7516
7517         assert(token.type == '.' || token.type == T_MINUSGREATER);
7518         bool is_pointer = (token.type == T_MINUSGREATER);
7519         next_token();
7520
7521         if (token.type != T_IDENTIFIER) {
7522                 parse_error_expected("while parsing select", T_IDENTIFIER, NULL);
7523                 return select;
7524         }
7525         symbol_t *symbol = token.v.symbol;
7526         next_token();
7527
7528         type_t *const orig_type = compound->base.type;
7529         type_t *const type      = skip_typeref(orig_type);
7530
7531         type_t *type_left;
7532         bool    saw_error = false;
7533         if (is_type_pointer(type)) {
7534                 if (!is_pointer) {
7535                         errorf(HERE,
7536                                "request for member '%Y' in something not a struct or union, but '%T'",
7537                                symbol, orig_type);
7538                         saw_error = true;
7539                 }
7540                 type_left = skip_typeref(type->pointer.points_to);
7541         } else {
7542                 if (is_pointer && is_type_valid(type)) {
7543                         errorf(HERE, "left hand side of '->' is not a pointer, but '%T'", orig_type);
7544                         saw_error = true;
7545                 }
7546                 type_left = type;
7547         }
7548
7549         entity_t *entry;
7550         if (type_left->kind == TYPE_COMPOUND_STRUCT ||
7551             type_left->kind == TYPE_COMPOUND_UNION) {
7552                 compound_t *compound = type_left->compound.compound;
7553
7554                 if (!compound->complete) {
7555                         errorf(HERE, "request for member '%Y' of incomplete type '%T'",
7556                                symbol, type_left);
7557                         goto create_error_entry;
7558                 }
7559
7560                 entry = find_compound_entry(compound, symbol);
7561                 if (entry == NULL) {
7562                         errorf(HERE, "'%T' has no member named '%Y'", orig_type, symbol);
7563                         goto create_error_entry;
7564                 }
7565         } else {
7566                 if (is_type_valid(type_left) && !saw_error) {
7567                         errorf(HERE,
7568                                "request for member '%Y' in something not a struct or union, but '%T'",
7569                                symbol, type_left);
7570                 }
7571 create_error_entry:
7572                 return create_invalid_expression();
7573         }
7574
7575         assert(is_declaration(entry));
7576         select->select.compound_entry = entry;
7577
7578         type_t *entry_type = entry->declaration.type;
7579         type_t *res_type
7580                 = get_qualified_type(entry_type, type_left->base.qualifiers);
7581
7582         /* we always do the auto-type conversions; the & and sizeof parser contains
7583          * code to revert this! */
7584         select->base.type = automatic_type_conversion(res_type);
7585
7586         type_t *skipped = skip_typeref(res_type);
7587         if (skipped->kind == TYPE_BITFIELD) {
7588                 select->base.type = skipped->bitfield.base_type;
7589         }
7590
7591         return select;
7592 }
7593
7594 static void check_call_argument(const function_parameter_t *parameter,
7595                                 call_argument_t *argument, unsigned pos)
7596 {
7597         type_t         *expected_type      = parameter->type;
7598         type_t         *expected_type_skip = skip_typeref(expected_type);
7599         assign_error_t  error              = ASSIGN_ERROR_INCOMPATIBLE;
7600         expression_t   *arg_expr           = argument->expression;
7601         type_t         *arg_type           = skip_typeref(arg_expr->base.type);
7602
7603         /* handle transparent union gnu extension */
7604         if (is_type_union(expected_type_skip)
7605                         && (expected_type_skip->base.modifiers
7606                                 & TYPE_MODIFIER_TRANSPARENT_UNION)) {
7607                 compound_t *union_decl  = expected_type_skip->compound.compound;
7608                 type_t     *best_type   = NULL;
7609                 entity_t   *entry       = union_decl->members.entities;
7610                 for ( ; entry != NULL; entry = entry->base.next) {
7611                         assert(is_declaration(entry));
7612                         type_t *decl_type = entry->declaration.type;
7613                         error = semantic_assign(decl_type, arg_expr);
7614                         if (error == ASSIGN_ERROR_INCOMPATIBLE
7615                                 || error == ASSIGN_ERROR_POINTER_QUALIFIER_MISSING)
7616                                 continue;
7617
7618                         if (error == ASSIGN_SUCCESS) {
7619                                 best_type = decl_type;
7620                         } else if (best_type == NULL) {
7621                                 best_type = decl_type;
7622                         }
7623                 }
7624
7625                 if (best_type != NULL) {
7626                         expected_type = best_type;
7627                 }
7628         }
7629
7630         error                = semantic_assign(expected_type, arg_expr);
7631         argument->expression = create_implicit_cast(argument->expression,
7632                                                     expected_type);
7633
7634         if (error != ASSIGN_SUCCESS) {
7635                 /* report exact scope in error messages (like "in argument 3") */
7636                 char buf[64];
7637                 snprintf(buf, sizeof(buf), "call argument %u", pos);
7638                 report_assign_error(error, expected_type, arg_expr,     buf,
7639                                                         &arg_expr->base.source_position);
7640         } else if (warning.traditional || warning.conversion) {
7641                 type_t *const promoted_type = get_default_promoted_type(arg_type);
7642                 if (!types_compatible(expected_type_skip, promoted_type) &&
7643                     !types_compatible(expected_type_skip, type_void_ptr) &&
7644                     !types_compatible(type_void_ptr,      promoted_type)) {
7645                         /* Deliberately show the skipped types in this warning */
7646                         warningf(&arg_expr->base.source_position,
7647                                 "passing call argument %u as '%T' rather than '%T' due to prototype",
7648                                 pos, expected_type_skip, promoted_type);
7649                 }
7650         }
7651 }
7652
7653 /**
7654  * Parse a call expression, ie. expression '( ... )'.
7655  *
7656  * @param expression  the function address
7657  */
7658 static expression_t *parse_call_expression(expression_t *expression)
7659 {
7660         expression_t      *result = allocate_expression_zero(EXPR_CALL);
7661         call_expression_t *call   = &result->call;
7662         call->function            = expression;
7663
7664         type_t *const orig_type = expression->base.type;
7665         type_t *const type      = skip_typeref(orig_type);
7666
7667         function_type_t *function_type = NULL;
7668         if (is_type_pointer(type)) {
7669                 type_t *const to_type = skip_typeref(type->pointer.points_to);
7670
7671                 if (is_type_function(to_type)) {
7672                         function_type   = &to_type->function;
7673                         call->base.type = function_type->return_type;
7674                 }
7675         }
7676
7677         if (function_type == NULL && is_type_valid(type)) {
7678                 errorf(HERE, "called object '%E' (type '%T') is not a pointer to a function", expression, orig_type);
7679         }
7680
7681         /* parse arguments */
7682         eat('(');
7683         add_anchor_token(')');
7684         add_anchor_token(',');
7685
7686         if (token.type != ')') {
7687                 call_argument_t *last_argument = NULL;
7688
7689                 while (true) {
7690                         call_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
7691
7692                         argument->expression = parse_assignment_expression();
7693                         if (last_argument == NULL) {
7694                                 call->arguments = argument;
7695                         } else {
7696                                 last_argument->next = argument;
7697                         }
7698                         last_argument = argument;
7699
7700                         if (token.type != ',')
7701                                 break;
7702                         next_token();
7703                 }
7704         }
7705         rem_anchor_token(',');
7706         rem_anchor_token(')');
7707         expect(')');
7708
7709         if (function_type == NULL)
7710                 return result;
7711
7712         function_parameter_t *parameter = function_type->parameters;
7713         call_argument_t      *argument  = call->arguments;
7714         if (!function_type->unspecified_parameters) {
7715                 for (unsigned pos = 0; parameter != NULL && argument != NULL;
7716                                 parameter = parameter->next, argument = argument->next) {
7717                         check_call_argument(parameter, argument, ++pos);
7718                 }
7719
7720                 if (parameter != NULL) {
7721                         errorf(HERE, "too few arguments to function '%E'", expression);
7722                 } else if (argument != NULL && !function_type->variadic) {
7723                         errorf(HERE, "too many arguments to function '%E'", expression);
7724                 }
7725         }
7726
7727         /* do default promotion */
7728         for (; argument != NULL; argument = argument->next) {
7729                 type_t *type = argument->expression->base.type;
7730
7731                 type = get_default_promoted_type(type);
7732
7733                 argument->expression
7734                         = create_implicit_cast(argument->expression, type);
7735         }
7736
7737         check_format(&result->call);
7738
7739         if (warning.aggregate_return &&
7740             is_type_compound(skip_typeref(function_type->return_type))) {
7741                 warningf(&result->base.source_position,
7742                          "function call has aggregate value");
7743         }
7744
7745 end_error:
7746         return result;
7747 }
7748
7749 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
7750
7751 static bool same_compound_type(const type_t *type1, const type_t *type2)
7752 {
7753         return
7754                 is_type_compound(type1) &&
7755                 type1->kind == type2->kind &&
7756                 type1->compound.compound == type2->compound.compound;
7757 }
7758
7759 static expression_t const *get_reference_address(expression_t const *expr)
7760 {
7761         bool regular_take_address = true;
7762         for (;;) {
7763                 if (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
7764                         expr = expr->unary.value;
7765                 } else {
7766                         regular_take_address = false;
7767                 }
7768
7769                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
7770                         break;
7771
7772                 expr = expr->unary.value;
7773         }
7774
7775         if (expr->kind != EXPR_REFERENCE)
7776                 return NULL;
7777
7778         /* special case for functions which are automatically converted to a
7779          * pointer to function without an extra TAKE_ADDRESS operation */
7780         if (!regular_take_address &&
7781                         expr->reference.entity->kind != ENTITY_FUNCTION) {
7782                 return NULL;
7783         }
7784
7785         return expr;
7786 }
7787
7788 static void warn_reference_address_as_bool(expression_t const* expr)
7789 {
7790         if (!warning.address)
7791                 return;
7792
7793         expr = get_reference_address(expr);
7794         if (expr != NULL) {
7795                 warningf(&expr->base.source_position,
7796                          "the address of '%Y' will always evaluate as 'true'",
7797                          expr->reference.entity->base.symbol);
7798         }
7799 }
7800
7801 /**
7802  * Parse a conditional expression, ie. 'expression ? ... : ...'.
7803  *
7804  * @param expression  the conditional expression
7805  */
7806 static expression_t *parse_conditional_expression(expression_t *expression)
7807 {
7808         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
7809
7810         conditional_expression_t *conditional = &result->conditional;
7811         conditional->condition                = expression;
7812
7813         warn_reference_address_as_bool(expression);
7814
7815         eat('?');
7816         add_anchor_token(':');
7817
7818         /* 6.5.15.2 */
7819         type_t *const condition_type_orig = expression->base.type;
7820         type_t *const condition_type      = skip_typeref(condition_type_orig);
7821         if (!is_type_scalar(condition_type) && is_type_valid(condition_type)) {
7822                 type_error("expected a scalar type in conditional condition",
7823                            &expression->base.source_position, condition_type_orig);
7824         }
7825
7826         expression_t *true_expression = expression;
7827         bool          gnu_cond = false;
7828         if (GNU_MODE && token.type == ':') {
7829                 gnu_cond = true;
7830         } else {
7831                 true_expression = parse_expression();
7832         }
7833         rem_anchor_token(':');
7834         expect(':');
7835         expression_t *false_expression =
7836                 parse_sub_expression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
7837
7838         type_t *const orig_true_type  = true_expression->base.type;
7839         type_t *const orig_false_type = false_expression->base.type;
7840         type_t *const true_type       = skip_typeref(orig_true_type);
7841         type_t *const false_type      = skip_typeref(orig_false_type);
7842
7843         /* 6.5.15.3 */
7844         type_t *result_type;
7845         if (is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
7846                         is_type_atomic(false_type, ATOMIC_TYPE_VOID)) {
7847                 /* ISO/IEC 14882:1998(E) §5.16:2 */
7848                 if (true_expression->kind == EXPR_UNARY_THROW) {
7849                         result_type = false_type;
7850                 } else if (false_expression->kind == EXPR_UNARY_THROW) {
7851                         result_type = true_type;
7852                 } else {
7853                         if (warning.other && (
7854                                                 !is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
7855                                                 !is_type_atomic(false_type, ATOMIC_TYPE_VOID)
7856                                         )) {
7857                                 warningf(&conditional->base.source_position,
7858                                                 "ISO C forbids conditional expression with only one void side");
7859                         }
7860                         result_type = type_void;
7861                 }
7862         } else if (is_type_arithmetic(true_type)
7863                    && is_type_arithmetic(false_type)) {
7864                 result_type = semantic_arithmetic(true_type, false_type);
7865
7866                 true_expression  = create_implicit_cast(true_expression, result_type);
7867                 false_expression = create_implicit_cast(false_expression, result_type);
7868
7869                 conditional->true_expression  = true_expression;
7870                 conditional->false_expression = false_expression;
7871                 conditional->base.type        = result_type;
7872         } else if (same_compound_type(true_type, false_type)) {
7873                 /* just take 1 of the 2 types */
7874                 result_type = true_type;
7875         } else if (is_type_pointer(true_type) || is_type_pointer(false_type)) {
7876                 type_t *pointer_type;
7877                 type_t *other_type;
7878                 expression_t *other_expression;
7879                 if (is_type_pointer(true_type) &&
7880                                 (!is_type_pointer(false_type) || is_null_pointer_constant(false_expression))) {
7881                         pointer_type     = true_type;
7882                         other_type       = false_type;
7883                         other_expression = false_expression;
7884                 } else {
7885                         pointer_type     = false_type;
7886                         other_type       = true_type;
7887                         other_expression = true_expression;
7888                 }
7889
7890                 if (is_null_pointer_constant(other_expression)) {
7891                         result_type = pointer_type;
7892                 } else if (is_type_pointer(other_type)) {
7893                         type_t *to1 = skip_typeref(pointer_type->pointer.points_to);
7894                         type_t *to2 = skip_typeref(other_type->pointer.points_to);
7895
7896                         type_t *to;
7897                         if (is_type_atomic(to1, ATOMIC_TYPE_VOID) ||
7898                             is_type_atomic(to2, ATOMIC_TYPE_VOID)) {
7899                                 to = type_void;
7900                         } else if (types_compatible(get_unqualified_type(to1),
7901                                                     get_unqualified_type(to2))) {
7902                                 to = to1;
7903                         } else {
7904                                 if (warning.other) {
7905                                         warningf(&conditional->base.source_position,
7906                                                         "pointer types '%T' and '%T' in conditional expression are incompatible",
7907                                                         true_type, false_type);
7908                                 }
7909                                 to = type_void;
7910                         }
7911
7912                         type_t *const type =
7913                                 get_qualified_type(to, to1->base.qualifiers | to2->base.qualifiers);
7914                         result_type = make_pointer_type(type, TYPE_QUALIFIER_NONE);
7915                 } else if (is_type_integer(other_type)) {
7916                         if (warning.other) {
7917                                 warningf(&conditional->base.source_position,
7918                                                 "pointer/integer type mismatch in conditional expression ('%T' and '%T')", true_type, false_type);
7919                         }
7920                         result_type = pointer_type;
7921                 } else {
7922                         if (is_type_valid(other_type)) {
7923                                 type_error_incompatible("while parsing conditional",
7924                                                 &expression->base.source_position, true_type, false_type);
7925                         }
7926                         result_type = type_error_type;
7927                 }
7928         } else {
7929                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
7930                         type_error_incompatible("while parsing conditional",
7931                                                 &conditional->base.source_position, true_type,
7932                                                 false_type);
7933                 }
7934                 result_type = type_error_type;
7935         }
7936
7937         conditional->true_expression
7938                 = gnu_cond ? NULL : create_implicit_cast(true_expression, result_type);
7939         conditional->false_expression
7940                 = create_implicit_cast(false_expression, result_type);
7941         conditional->base.type = result_type;
7942         return result;
7943 end_error:
7944         return create_invalid_expression();
7945 }
7946
7947 /**
7948  * Parse an extension expression.
7949  */
7950 static expression_t *parse_extension(void)
7951 {
7952         eat(T___extension__);
7953
7954         bool old_gcc_extension   = in_gcc_extension;
7955         in_gcc_extension         = true;
7956         expression_t *expression = parse_sub_expression(PREC_UNARY);
7957         in_gcc_extension         = old_gcc_extension;
7958         return expression;
7959 }
7960
7961 /**
7962  * Parse a __builtin_classify_type() expression.
7963  */
7964 static expression_t *parse_builtin_classify_type(void)
7965 {
7966         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
7967         result->base.type    = type_int;
7968
7969         eat(T___builtin_classify_type);
7970
7971         expect('(');
7972         add_anchor_token(')');
7973         expression_t *expression = parse_expression();
7974         rem_anchor_token(')');
7975         expect(')');
7976         result->classify_type.type_expression = expression;
7977
7978         return result;
7979 end_error:
7980         return create_invalid_expression();
7981 }
7982
7983 /**
7984  * Parse a delete expression
7985  * ISO/IEC 14882:1998(E) §5.3.5
7986  */
7987 static expression_t *parse_delete(void)
7988 {
7989         expression_t *const result = allocate_expression_zero(EXPR_UNARY_DELETE);
7990         result->base.type          = type_void;
7991
7992         eat(T_delete);
7993
7994         if (token.type == '[') {
7995                 next_token();
7996                 result->kind = EXPR_UNARY_DELETE_ARRAY;
7997                 expect(']');
7998 end_error:;
7999         }
8000
8001         expression_t *const value = parse_sub_expression(PREC_CAST);
8002         result->unary.value = value;
8003
8004         type_t *const type = skip_typeref(value->base.type);
8005         if (!is_type_pointer(type)) {
8006                 errorf(&value->base.source_position,
8007                                 "operand of delete must have pointer type");
8008         } else if (warning.other &&
8009                         is_type_atomic(skip_typeref(type->pointer.points_to), ATOMIC_TYPE_VOID)) {
8010                 warningf(&value->base.source_position,
8011                                 "deleting 'void*' is undefined");
8012         }
8013
8014         return result;
8015 }
8016
8017 /**
8018  * Parse a throw expression
8019  * ISO/IEC 14882:1998(E) §15:1
8020  */
8021 static expression_t *parse_throw(void)
8022 {
8023         expression_t *const result = allocate_expression_zero(EXPR_UNARY_THROW);
8024         result->base.type          = type_void;
8025
8026         eat(T_throw);
8027
8028         expression_t *value = NULL;
8029         switch (token.type) {
8030                 EXPRESSION_START {
8031                         value = parse_assignment_expression();
8032                         /* ISO/IEC 14882:1998(E) §15.1:3 */
8033                         type_t *const orig_type = value->base.type;
8034                         type_t *const type      = skip_typeref(orig_type);
8035                         if (is_type_incomplete(type)) {
8036                                 errorf(&value->base.source_position,
8037                                                 "cannot throw object of incomplete type '%T'", orig_type);
8038                         } else if (is_type_pointer(type)) {
8039                                 type_t *const points_to = skip_typeref(type->pointer.points_to);
8040                                 if (is_type_incomplete(points_to) &&
8041                                                 !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
8042                                         errorf(&value->base.source_position,
8043                                                         "cannot throw pointer to incomplete type '%T'", orig_type);
8044                                 }
8045                         }
8046                 }
8047
8048                 default:
8049                         break;
8050         }
8051         result->unary.value = value;
8052
8053         return result;
8054 }
8055
8056 static bool check_pointer_arithmetic(const source_position_t *source_position,
8057                                      type_t *pointer_type,
8058                                      type_t *orig_pointer_type)
8059 {
8060         type_t *points_to = pointer_type->pointer.points_to;
8061         points_to = skip_typeref(points_to);
8062
8063         if (is_type_incomplete(points_to)) {
8064                 if (!GNU_MODE || !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
8065                         errorf(source_position,
8066                                "arithmetic with pointer to incomplete type '%T' not allowed",
8067                                orig_pointer_type);
8068                         return false;
8069                 } else if (warning.pointer_arith) {
8070                         warningf(source_position,
8071                                  "pointer of type '%T' used in arithmetic",
8072                                  orig_pointer_type);
8073                 }
8074         } else if (is_type_function(points_to)) {
8075                 if (!GNU_MODE) {
8076                         errorf(source_position,
8077                                "arithmetic with pointer to function type '%T' not allowed",
8078                                orig_pointer_type);
8079                         return false;
8080                 } else if (warning.pointer_arith) {
8081                         warningf(source_position,
8082                                  "pointer to a function '%T' used in arithmetic",
8083                                  orig_pointer_type);
8084                 }
8085         }
8086         return true;
8087 }
8088
8089 static bool is_lvalue(const expression_t *expression)
8090 {
8091         /* TODO: doesn't seem to be consistent with §6.3.2.1 (1) */
8092         switch (expression->kind) {
8093         case EXPR_REFERENCE:
8094         case EXPR_ARRAY_ACCESS:
8095         case EXPR_SELECT:
8096         case EXPR_UNARY_DEREFERENCE:
8097                 return true;
8098
8099         default:
8100                 /* Claim it is an lvalue, if the type is invalid.  There was a parse
8101                  * error before, which maybe prevented properly recognizing it as
8102                  * lvalue. */
8103                 return !is_type_valid(skip_typeref(expression->base.type));
8104         }
8105 }
8106
8107 static void semantic_incdec(unary_expression_t *expression)
8108 {
8109         type_t *const orig_type = expression->value->base.type;
8110         type_t *const type      = skip_typeref(orig_type);
8111         if (is_type_pointer(type)) {
8112                 if (!check_pointer_arithmetic(&expression->base.source_position,
8113                                               type, orig_type)) {
8114                         return;
8115                 }
8116         } else if (!is_type_real(type) && is_type_valid(type)) {
8117                 /* TODO: improve error message */
8118                 errorf(&expression->base.source_position,
8119                        "operation needs an arithmetic or pointer type");
8120                 return;
8121         }
8122         if (!is_lvalue(expression->value)) {
8123                 /* TODO: improve error message */
8124                 errorf(&expression->base.source_position, "lvalue required as operand");
8125         }
8126         expression->base.type = orig_type;
8127 }
8128
8129 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
8130 {
8131         type_t *const orig_type = expression->value->base.type;
8132         type_t *const type      = skip_typeref(orig_type);
8133         if (!is_type_arithmetic(type)) {
8134                 if (is_type_valid(type)) {
8135                         /* TODO: improve error message */
8136                         errorf(&expression->base.source_position,
8137                                 "operation needs an arithmetic type");
8138                 }
8139                 return;
8140         }
8141
8142         expression->base.type = orig_type;
8143 }
8144
8145 static void semantic_unexpr_plus(unary_expression_t *expression)
8146 {
8147         semantic_unexpr_arithmetic(expression);
8148         if (warning.traditional)
8149                 warningf(&expression->base.source_position,
8150                         "traditional C rejects the unary plus operator");
8151 }
8152
8153 static void semantic_not(unary_expression_t *expression)
8154 {
8155         type_t *const orig_type = expression->value->base.type;
8156         type_t *const type      = skip_typeref(orig_type);
8157         if (!is_type_scalar(type) && is_type_valid(type)) {
8158                 errorf(&expression->base.source_position,
8159                        "operand of ! must be of scalar type");
8160         }
8161
8162         warn_reference_address_as_bool(expression->value);
8163
8164         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8165 }
8166
8167 static void semantic_unexpr_integer(unary_expression_t *expression)
8168 {
8169         type_t *const orig_type = expression->value->base.type;
8170         type_t *const type      = skip_typeref(orig_type);
8171         if (!is_type_integer(type)) {
8172                 if (is_type_valid(type)) {
8173                         errorf(&expression->base.source_position,
8174                                "operand of ~ must be of integer type");
8175                 }
8176                 return;
8177         }
8178
8179         expression->base.type = orig_type;
8180 }
8181
8182 static void semantic_dereference(unary_expression_t *expression)
8183 {
8184         type_t *const orig_type = expression->value->base.type;
8185         type_t *const type      = skip_typeref(orig_type);
8186         if (!is_type_pointer(type)) {
8187                 if (is_type_valid(type)) {
8188                         errorf(&expression->base.source_position,
8189                                "Unary '*' needs pointer or array type, but type '%T' given", orig_type);
8190                 }
8191                 return;
8192         }
8193
8194         type_t *result_type   = type->pointer.points_to;
8195         result_type           = automatic_type_conversion(result_type);
8196         expression->base.type = result_type;
8197 }
8198
8199 /**
8200  * Record that an address is taken (expression represents an lvalue).
8201  *
8202  * @param expression       the expression
8203  * @param may_be_register  if true, the expression might be an register
8204  */
8205 static void set_address_taken(expression_t *expression, bool may_be_register)
8206 {
8207         if (expression->kind != EXPR_REFERENCE)
8208                 return;
8209
8210         entity_t *const entity = expression->reference.entity;
8211
8212         if (entity->kind != ENTITY_VARIABLE)
8213                 return;
8214
8215         if (entity->declaration.storage_class == STORAGE_CLASS_REGISTER
8216                         && !may_be_register) {
8217                 errorf(&expression->base.source_position,
8218                                 "address of register variable '%Y' requested",
8219                                 entity->base.symbol);
8220         }
8221
8222         entity->variable.address_taken = true;
8223 }
8224
8225 /**
8226  * Check the semantic of the address taken expression.
8227  */
8228 static void semantic_take_addr(unary_expression_t *expression)
8229 {
8230         expression_t *value = expression->value;
8231         value->base.type    = revert_automatic_type_conversion(value);
8232
8233         type_t *orig_type = value->base.type;
8234         type_t *type      = skip_typeref(orig_type);
8235         if (!is_type_valid(type))
8236                 return;
8237
8238         /* §6.5.3.2 */
8239         if (!is_lvalue(value)) {
8240                 errorf(&expression->base.source_position, "'&' requires an lvalue");
8241         }
8242         if (type->kind == TYPE_BITFIELD) {
8243                 errorf(&expression->base.source_position,
8244                        "'&' not allowed on object with bitfield type '%T'",
8245                        type);
8246         }
8247
8248         set_address_taken(value, false);
8249
8250         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
8251 }
8252
8253 #define CREATE_UNARY_EXPRESSION_PARSER(token_type, unexpression_type, sfunc) \
8254 static expression_t *parse_##unexpression_type(void)                         \
8255 {                                                                            \
8256         expression_t *unary_expression                                           \
8257                 = allocate_expression_zero(unexpression_type);                       \
8258         eat(token_type);                                                         \
8259         unary_expression->unary.value = parse_sub_expression(PREC_UNARY);        \
8260                                                                                  \
8261         sfunc(&unary_expression->unary);                                         \
8262                                                                                  \
8263         return unary_expression;                                                 \
8264 }
8265
8266 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
8267                                semantic_unexpr_arithmetic)
8268 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
8269                                semantic_unexpr_plus)
8270 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
8271                                semantic_not)
8272 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
8273                                semantic_dereference)
8274 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
8275                                semantic_take_addr)
8276 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
8277                                semantic_unexpr_integer)
8278 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
8279                                semantic_incdec)
8280 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
8281                                semantic_incdec)
8282
8283 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_type, unexpression_type, \
8284                                                sfunc)                         \
8285 static expression_t *parse_##unexpression_type(expression_t *left)            \
8286 {                                                                             \
8287         expression_t *unary_expression                                            \
8288                 = allocate_expression_zero(unexpression_type);                        \
8289         eat(token_type);                                                          \
8290         unary_expression->unary.value = left;                                     \
8291                                                                                   \
8292         sfunc(&unary_expression->unary);                                          \
8293                                                                               \
8294         return unary_expression;                                                  \
8295 }
8296
8297 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
8298                                        EXPR_UNARY_POSTFIX_INCREMENT,
8299                                        semantic_incdec)
8300 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
8301                                        EXPR_UNARY_POSTFIX_DECREMENT,
8302                                        semantic_incdec)
8303
8304 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
8305 {
8306         /* TODO: handle complex + imaginary types */
8307
8308         type_left  = get_unqualified_type(type_left);
8309         type_right = get_unqualified_type(type_right);
8310
8311         /* § 6.3.1.8 Usual arithmetic conversions */
8312         if (type_left == type_long_double || type_right == type_long_double) {
8313                 return type_long_double;
8314         } else if (type_left == type_double || type_right == type_double) {
8315                 return type_double;
8316         } else if (type_left == type_float || type_right == type_float) {
8317                 return type_float;
8318         }
8319
8320         type_left  = promote_integer(type_left);
8321         type_right = promote_integer(type_right);
8322
8323         if (type_left == type_right)
8324                 return type_left;
8325
8326         bool const signed_left  = is_type_signed(type_left);
8327         bool const signed_right = is_type_signed(type_right);
8328         int const  rank_left    = get_rank(type_left);
8329         int const  rank_right   = get_rank(type_right);
8330
8331         if (signed_left == signed_right)
8332                 return rank_left >= rank_right ? type_left : type_right;
8333
8334         int     s_rank;
8335         int     u_rank;
8336         type_t *s_type;
8337         type_t *u_type;
8338         if (signed_left) {
8339                 s_rank = rank_left;
8340                 s_type = type_left;
8341                 u_rank = rank_right;
8342                 u_type = type_right;
8343         } else {
8344                 s_rank = rank_right;
8345                 s_type = type_right;
8346                 u_rank = rank_left;
8347                 u_type = type_left;
8348         }
8349
8350         if (u_rank >= s_rank)
8351                 return u_type;
8352
8353         /* casting rank to atomic_type_kind is a bit hacky, but makes things
8354          * easier here... */
8355         if (get_atomic_type_size((atomic_type_kind_t) s_rank)
8356                         > get_atomic_type_size((atomic_type_kind_t) u_rank))
8357                 return s_type;
8358
8359         switch (s_rank) {
8360                 case ATOMIC_TYPE_INT:      return type_unsigned_int;
8361                 case ATOMIC_TYPE_LONG:     return type_unsigned_long;
8362                 case ATOMIC_TYPE_LONGLONG: return type_unsigned_long_long;
8363
8364                 default: panic("invalid atomic type");
8365         }
8366 }
8367
8368 /**
8369  * Check the semantic restrictions for a binary expression.
8370  */
8371 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
8372 {
8373         expression_t *const left            = expression->left;
8374         expression_t *const right           = expression->right;
8375         type_t       *const orig_type_left  = left->base.type;
8376         type_t       *const orig_type_right = right->base.type;
8377         type_t       *const type_left       = skip_typeref(orig_type_left);
8378         type_t       *const type_right      = skip_typeref(orig_type_right);
8379
8380         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8381                 /* TODO: improve error message */
8382                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8383                         errorf(&expression->base.source_position,
8384                                "operation needs arithmetic types");
8385                 }
8386                 return;
8387         }
8388
8389         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8390         expression->left      = create_implicit_cast(left, arithmetic_type);
8391         expression->right     = create_implicit_cast(right, arithmetic_type);
8392         expression->base.type = arithmetic_type;
8393 }
8394
8395 static void warn_div_by_zero(binary_expression_t const *const expression)
8396 {
8397         if (!warning.div_by_zero ||
8398             !is_type_integer(expression->base.type))
8399                 return;
8400
8401         expression_t const *const right = expression->right;
8402         /* The type of the right operand can be different for /= */
8403         if (is_type_integer(right->base.type) &&
8404             is_constant_expression(right)     &&
8405             fold_constant(right) == 0) {
8406                 warningf(&expression->base.source_position, "division by zero");
8407         }
8408 }
8409
8410 /**
8411  * Check the semantic restrictions for a div/mod expression.
8412  */
8413 static void semantic_divmod_arithmetic(binary_expression_t *expression) {
8414         semantic_binexpr_arithmetic(expression);
8415         warn_div_by_zero(expression);
8416 }
8417
8418 static void semantic_shift_op(binary_expression_t *expression)
8419 {
8420         expression_t *const left            = expression->left;
8421         expression_t *const right           = expression->right;
8422         type_t       *const orig_type_left  = left->base.type;
8423         type_t       *const orig_type_right = right->base.type;
8424         type_t       *      type_left       = skip_typeref(orig_type_left);
8425         type_t       *      type_right      = skip_typeref(orig_type_right);
8426
8427         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8428                 /* TODO: improve error message */
8429                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8430                         errorf(&expression->base.source_position,
8431                                "operands of shift operation must have integer types");
8432                 }
8433                 return;
8434         }
8435
8436         type_left  = promote_integer(type_left);
8437         type_right = promote_integer(type_right);
8438
8439         expression->left      = create_implicit_cast(left, type_left);
8440         expression->right     = create_implicit_cast(right, type_right);
8441         expression->base.type = type_left;
8442 }
8443
8444 static void semantic_add(binary_expression_t *expression)
8445 {
8446         expression_t *const left            = expression->left;
8447         expression_t *const right           = expression->right;
8448         type_t       *const orig_type_left  = left->base.type;
8449         type_t       *const orig_type_right = right->base.type;
8450         type_t       *const type_left       = skip_typeref(orig_type_left);
8451         type_t       *const type_right      = skip_typeref(orig_type_right);
8452
8453         /* § 6.5.6 */
8454         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8455                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8456                 expression->left  = create_implicit_cast(left, arithmetic_type);
8457                 expression->right = create_implicit_cast(right, arithmetic_type);
8458                 expression->base.type = arithmetic_type;
8459                 return;
8460         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8461                 check_pointer_arithmetic(&expression->base.source_position,
8462                                          type_left, orig_type_left);
8463                 expression->base.type = type_left;
8464         } else if (is_type_pointer(type_right) && is_type_integer(type_left)) {
8465                 check_pointer_arithmetic(&expression->base.source_position,
8466                                          type_right, orig_type_right);
8467                 expression->base.type = type_right;
8468         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8469                 errorf(&expression->base.source_position,
8470                        "invalid operands to binary + ('%T', '%T')",
8471                        orig_type_left, orig_type_right);
8472         }
8473 }
8474
8475 static void semantic_sub(binary_expression_t *expression)
8476 {
8477         expression_t            *const left            = expression->left;
8478         expression_t            *const right           = expression->right;
8479         type_t                  *const orig_type_left  = left->base.type;
8480         type_t                  *const orig_type_right = right->base.type;
8481         type_t                  *const type_left       = skip_typeref(orig_type_left);
8482         type_t                  *const type_right      = skip_typeref(orig_type_right);
8483         source_position_t const *const pos             = &expression->base.source_position;
8484
8485         /* § 5.6.5 */
8486         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8487                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8488                 expression->left        = create_implicit_cast(left, arithmetic_type);
8489                 expression->right       = create_implicit_cast(right, arithmetic_type);
8490                 expression->base.type =  arithmetic_type;
8491                 return;
8492         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8493                 check_pointer_arithmetic(&expression->base.source_position,
8494                                          type_left, orig_type_left);
8495                 expression->base.type = type_left;
8496         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8497                 type_t *const unqual_left  = get_unqualified_type(skip_typeref(type_left->pointer.points_to));
8498                 type_t *const unqual_right = get_unqualified_type(skip_typeref(type_right->pointer.points_to));
8499                 if (!types_compatible(unqual_left, unqual_right)) {
8500                         errorf(pos,
8501                                "subtracting pointers to incompatible types '%T' and '%T'",
8502                                orig_type_left, orig_type_right);
8503                 } else if (!is_type_object(unqual_left)) {
8504                         if (!is_type_atomic(unqual_left, ATOMIC_TYPE_VOID)) {
8505                                 errorf(pos, "subtracting pointers to non-object types '%T'",
8506                                        orig_type_left);
8507                         } else if (warning.other) {
8508                                 warningf(pos, "subtracting pointers to void");
8509                         }
8510                 }
8511                 expression->base.type = type_ptrdiff_t;
8512         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8513                 errorf(pos, "invalid operands of types '%T' and '%T' to binary '-'",
8514                        orig_type_left, orig_type_right);
8515         }
8516 }
8517
8518 static void warn_string_literal_address(expression_t const* expr)
8519 {
8520         while (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
8521                 expr = expr->unary.value;
8522                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
8523                         return;
8524                 expr = expr->unary.value;
8525         }
8526
8527         if (expr->kind == EXPR_STRING_LITERAL ||
8528             expr->kind == EXPR_WIDE_STRING_LITERAL) {
8529                 warningf(&expr->base.source_position,
8530                         "comparison with string literal results in unspecified behaviour");
8531         }
8532 }
8533
8534 /**
8535  * Check the semantics of comparison expressions.
8536  *
8537  * @param expression   The expression to check.
8538  */
8539 static void semantic_comparison(binary_expression_t *expression)
8540 {
8541         expression_t *left  = expression->left;
8542         expression_t *right = expression->right;
8543
8544         if (warning.address) {
8545                 warn_string_literal_address(left);
8546                 warn_string_literal_address(right);
8547
8548                 expression_t const* const func_left = get_reference_address(left);
8549                 if (func_left != NULL && is_null_pointer_constant(right)) {
8550                         warningf(&expression->base.source_position,
8551                                  "the address of '%Y' will never be NULL",
8552                                  func_left->reference.entity->base.symbol);
8553                 }
8554
8555                 expression_t const* const func_right = get_reference_address(right);
8556                 if (func_right != NULL && is_null_pointer_constant(right)) {
8557                         warningf(&expression->base.source_position,
8558                                  "the address of '%Y' will never be NULL",
8559                                  func_right->reference.entity->base.symbol);
8560                 }
8561         }
8562
8563         type_t *orig_type_left  = left->base.type;
8564         type_t *orig_type_right = right->base.type;
8565         type_t *type_left       = skip_typeref(orig_type_left);
8566         type_t *type_right      = skip_typeref(orig_type_right);
8567
8568         /* TODO non-arithmetic types */
8569         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8570                 /* test for signed vs unsigned compares */
8571                 if (warning.sign_compare &&
8572                     (expression->base.kind != EXPR_BINARY_EQUAL &&
8573                      expression->base.kind != EXPR_BINARY_NOTEQUAL) &&
8574                     (is_type_signed(type_left) != is_type_signed(type_right))) {
8575
8576                         /* check if 1 of the operands is a constant, in this case we just
8577                          * check wether we can safely represent the resulting constant in
8578                          * the type of the other operand. */
8579                         expression_t *const_expr = NULL;
8580                         expression_t *other_expr = NULL;
8581
8582                         if (is_constant_expression(left)) {
8583                                 const_expr = left;
8584                                 other_expr = right;
8585                         } else if (is_constant_expression(right)) {
8586                                 const_expr = right;
8587                                 other_expr = left;
8588                         }
8589
8590                         if (const_expr != NULL) {
8591                                 type_t *other_type = skip_typeref(other_expr->base.type);
8592                                 long    val        = fold_constant(const_expr);
8593                                 /* TODO: check if val can be represented by other_type */
8594                                 (void) other_type;
8595                                 (void) val;
8596                         }
8597                         warningf(&expression->base.source_position,
8598                                  "comparison between signed and unsigned");
8599                 }
8600                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8601                 expression->left        = create_implicit_cast(left, arithmetic_type);
8602                 expression->right       = create_implicit_cast(right, arithmetic_type);
8603                 expression->base.type   = arithmetic_type;
8604                 if (warning.float_equal &&
8605                     (expression->base.kind == EXPR_BINARY_EQUAL ||
8606                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
8607                     is_type_float(arithmetic_type)) {
8608                         warningf(&expression->base.source_position,
8609                                  "comparing floating point with == or != is unsafe");
8610                 }
8611         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8612                 /* TODO check compatibility */
8613         } else if (is_type_pointer(type_left)) {
8614                 expression->right = create_implicit_cast(right, type_left);
8615         } else if (is_type_pointer(type_right)) {
8616                 expression->left = create_implicit_cast(left, type_right);
8617         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8618                 type_error_incompatible("invalid operands in comparison",
8619                                         &expression->base.source_position,
8620                                         type_left, type_right);
8621         }
8622         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8623 }
8624
8625 /**
8626  * Checks if a compound type has constant fields.
8627  */
8628 static bool has_const_fields(const compound_type_t *type)
8629 {
8630         compound_t *compound = type->compound;
8631         entity_t   *entry    = compound->members.entities;
8632
8633         for (; entry != NULL; entry = entry->base.next) {
8634                 if (!is_declaration(entry))
8635                         continue;
8636
8637                 const type_t *decl_type = skip_typeref(entry->declaration.type);
8638                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
8639                         return true;
8640         }
8641
8642         return false;
8643 }
8644
8645 static bool is_valid_assignment_lhs(expression_t const* const left)
8646 {
8647         type_t *const orig_type_left = revert_automatic_type_conversion(left);
8648         type_t *const type_left      = skip_typeref(orig_type_left);
8649
8650         if (!is_lvalue(left)) {
8651                 errorf(HERE, "left hand side '%E' of assignment is not an lvalue",
8652                        left);
8653                 return false;
8654         }
8655
8656         if (is_type_array(type_left)) {
8657                 errorf(HERE, "cannot assign to arrays ('%E')", left);
8658                 return false;
8659         }
8660         if (type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
8661                 errorf(HERE, "assignment to readonly location '%E' (type '%T')", left,
8662                        orig_type_left);
8663                 return false;
8664         }
8665         if (is_type_incomplete(type_left)) {
8666                 errorf(HERE, "left-hand side '%E' of assignment has incomplete type '%T'",
8667                        left, orig_type_left);
8668                 return false;
8669         }
8670         if (is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
8671                 errorf(HERE, "cannot assign to '%E' because compound type '%T' has readonly fields",
8672                        left, orig_type_left);
8673                 return false;
8674         }
8675
8676         return true;
8677 }
8678
8679 static void semantic_arithmetic_assign(binary_expression_t *expression)
8680 {
8681         expression_t *left            = expression->left;
8682         expression_t *right           = expression->right;
8683         type_t       *orig_type_left  = left->base.type;
8684         type_t       *orig_type_right = right->base.type;
8685
8686         if (!is_valid_assignment_lhs(left))
8687                 return;
8688
8689         type_t *type_left  = skip_typeref(orig_type_left);
8690         type_t *type_right = skip_typeref(orig_type_right);
8691
8692         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8693                 /* TODO: improve error message */
8694                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8695                         errorf(&expression->base.source_position,
8696                                "operation needs arithmetic types");
8697                 }
8698                 return;
8699         }
8700
8701         /* combined instructions are tricky. We can't create an implicit cast on
8702          * the left side, because we need the uncasted form for the store.
8703          * The ast2firm pass has to know that left_type must be right_type
8704          * for the arithmetic operation and create a cast by itself */
8705         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8706         expression->right       = create_implicit_cast(right, arithmetic_type);
8707         expression->base.type   = type_left;
8708 }
8709
8710 static void semantic_divmod_assign(binary_expression_t *expression)
8711 {
8712         semantic_arithmetic_assign(expression);
8713         warn_div_by_zero(expression);
8714 }
8715
8716 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
8717 {
8718         expression_t *const left            = expression->left;
8719         expression_t *const right           = expression->right;
8720         type_t       *const orig_type_left  = left->base.type;
8721         type_t       *const orig_type_right = right->base.type;
8722         type_t       *const type_left       = skip_typeref(orig_type_left);
8723         type_t       *const type_right      = skip_typeref(orig_type_right);
8724
8725         if (!is_valid_assignment_lhs(left))
8726                 return;
8727
8728         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8729                 /* combined instructions are tricky. We can't create an implicit cast on
8730                  * the left side, because we need the uncasted form for the store.
8731                  * The ast2firm pass has to know that left_type must be right_type
8732                  * for the arithmetic operation and create a cast by itself */
8733                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
8734                 expression->right     = create_implicit_cast(right, arithmetic_type);
8735                 expression->base.type = type_left;
8736         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8737                 check_pointer_arithmetic(&expression->base.source_position,
8738                                          type_left, orig_type_left);
8739                 expression->base.type = type_left;
8740         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8741                 errorf(&expression->base.source_position,
8742                        "incompatible types '%T' and '%T' in assignment",
8743                        orig_type_left, orig_type_right);
8744         }
8745 }
8746
8747 /**
8748  * Check the semantic restrictions of a logical expression.
8749  */
8750 static void semantic_logical_op(binary_expression_t *expression)
8751 {
8752         expression_t *const left            = expression->left;
8753         expression_t *const right           = expression->right;
8754         type_t       *const orig_type_left  = left->base.type;
8755         type_t       *const orig_type_right = right->base.type;
8756         type_t       *const type_left       = skip_typeref(orig_type_left);
8757         type_t       *const type_right      = skip_typeref(orig_type_right);
8758
8759         warn_reference_address_as_bool(left);
8760         warn_reference_address_as_bool(right);
8761
8762         if (!is_type_scalar(type_left) || !is_type_scalar(type_right)) {
8763                 /* TODO: improve error message */
8764                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8765                         errorf(&expression->base.source_position,
8766                                "operation needs scalar types");
8767                 }
8768                 return;
8769         }
8770
8771         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8772 }
8773
8774 /**
8775  * Check the semantic restrictions of a binary assign expression.
8776  */
8777 static void semantic_binexpr_assign(binary_expression_t *expression)
8778 {
8779         expression_t *left           = expression->left;
8780         type_t       *orig_type_left = left->base.type;
8781
8782         if (!is_valid_assignment_lhs(left))
8783                 return;
8784
8785         assign_error_t error = semantic_assign(orig_type_left, expression->right);
8786         report_assign_error(error, orig_type_left, expression->right,
8787                         "assignment", &left->base.source_position);
8788         expression->right = create_implicit_cast(expression->right, orig_type_left);
8789         expression->base.type = orig_type_left;
8790 }
8791
8792 /**
8793  * Determine if the outermost operation (or parts thereof) of the given
8794  * expression has no effect in order to generate a warning about this fact.
8795  * Therefore in some cases this only examines some of the operands of the
8796  * expression (see comments in the function and examples below).
8797  * Examples:
8798  *   f() + 23;    // warning, because + has no effect
8799  *   x || f();    // no warning, because x controls execution of f()
8800  *   x ? y : f(); // warning, because y has no effect
8801  *   (void)x;     // no warning to be able to suppress the warning
8802  * This function can NOT be used for an "expression has definitely no effect"-
8803  * analysis. */
8804 static bool expression_has_effect(const expression_t *const expr)
8805 {
8806         switch (expr->kind) {
8807                 case EXPR_UNKNOWN:                   break;
8808                 case EXPR_INVALID:                   return true; /* do NOT warn */
8809                 case EXPR_REFERENCE:                 return false;
8810                 case EXPR_REFERENCE_ENUM_VALUE:      return false;
8811                 /* suppress the warning for microsoft __noop operations */
8812                 case EXPR_CONST:                     return expr->conste.is_ms_noop;
8813                 case EXPR_CHARACTER_CONSTANT:        return false;
8814                 case EXPR_WIDE_CHARACTER_CONSTANT:   return false;
8815                 case EXPR_STRING_LITERAL:            return false;
8816                 case EXPR_WIDE_STRING_LITERAL:       return false;
8817                 case EXPR_LABEL_ADDRESS:             return false;
8818
8819                 case EXPR_CALL: {
8820                         const call_expression_t *const call = &expr->call;
8821                         if (call->function->kind != EXPR_BUILTIN_SYMBOL)
8822                                 return true;
8823
8824                         switch (call->function->builtin_symbol.symbol->ID) {
8825                                 case T___builtin_va_end: return true;
8826                                 default:                 return false;
8827                         }
8828                 }
8829
8830                 /* Generate the warning if either the left or right hand side of a
8831                  * conditional expression has no effect */
8832                 case EXPR_CONDITIONAL: {
8833                         const conditional_expression_t *const cond = &expr->conditional;
8834                         return
8835                                 expression_has_effect(cond->true_expression) &&
8836                                 expression_has_effect(cond->false_expression);
8837                 }
8838
8839                 case EXPR_SELECT:                    return false;
8840                 case EXPR_ARRAY_ACCESS:              return false;
8841                 case EXPR_SIZEOF:                    return false;
8842                 case EXPR_CLASSIFY_TYPE:             return false;
8843                 case EXPR_ALIGNOF:                   return false;
8844
8845                 case EXPR_FUNCNAME:                  return false;
8846                 case EXPR_BUILTIN_SYMBOL:            break; /* handled in EXPR_CALL */
8847                 case EXPR_BUILTIN_CONSTANT_P:        return false;
8848                 case EXPR_BUILTIN_PREFETCH:          return true;
8849                 case EXPR_OFFSETOF:                  return false;
8850                 case EXPR_VA_START:                  return true;
8851                 case EXPR_VA_ARG:                    return true;
8852                 case EXPR_STATEMENT:                 return true; // TODO
8853                 case EXPR_COMPOUND_LITERAL:          return false;
8854
8855                 case EXPR_UNARY_NEGATE:              return false;
8856                 case EXPR_UNARY_PLUS:                return false;
8857                 case EXPR_UNARY_BITWISE_NEGATE:      return false;
8858                 case EXPR_UNARY_NOT:                 return false;
8859                 case EXPR_UNARY_DEREFERENCE:         return false;
8860                 case EXPR_UNARY_TAKE_ADDRESS:        return false;
8861                 case EXPR_UNARY_POSTFIX_INCREMENT:   return true;
8862                 case EXPR_UNARY_POSTFIX_DECREMENT:   return true;
8863                 case EXPR_UNARY_PREFIX_INCREMENT:    return true;
8864                 case EXPR_UNARY_PREFIX_DECREMENT:    return true;
8865
8866                 /* Treat void casts as if they have an effect in order to being able to
8867                  * suppress the warning */
8868                 case EXPR_UNARY_CAST: {
8869                         type_t *const type = skip_typeref(expr->base.type);
8870                         return is_type_atomic(type, ATOMIC_TYPE_VOID);
8871                 }
8872
8873                 case EXPR_UNARY_CAST_IMPLICIT:       return true;
8874                 case EXPR_UNARY_ASSUME:              return true;
8875                 case EXPR_UNARY_DELETE:              return true;
8876                 case EXPR_UNARY_DELETE_ARRAY:        return true;
8877                 case EXPR_UNARY_THROW:               return true;
8878
8879                 case EXPR_BINARY_ADD:                return false;
8880                 case EXPR_BINARY_SUB:                return false;
8881                 case EXPR_BINARY_MUL:                return false;
8882                 case EXPR_BINARY_DIV:                return false;
8883                 case EXPR_BINARY_MOD:                return false;
8884                 case EXPR_BINARY_EQUAL:              return false;
8885                 case EXPR_BINARY_NOTEQUAL:           return false;
8886                 case EXPR_BINARY_LESS:               return false;
8887                 case EXPR_BINARY_LESSEQUAL:          return false;
8888                 case EXPR_BINARY_GREATER:            return false;
8889                 case EXPR_BINARY_GREATEREQUAL:       return false;
8890                 case EXPR_BINARY_BITWISE_AND:        return false;
8891                 case EXPR_BINARY_BITWISE_OR:         return false;
8892                 case EXPR_BINARY_BITWISE_XOR:        return false;
8893                 case EXPR_BINARY_SHIFTLEFT:          return false;
8894                 case EXPR_BINARY_SHIFTRIGHT:         return false;
8895                 case EXPR_BINARY_ASSIGN:             return true;
8896                 case EXPR_BINARY_MUL_ASSIGN:         return true;
8897                 case EXPR_BINARY_DIV_ASSIGN:         return true;
8898                 case EXPR_BINARY_MOD_ASSIGN:         return true;
8899                 case EXPR_BINARY_ADD_ASSIGN:         return true;
8900                 case EXPR_BINARY_SUB_ASSIGN:         return true;
8901                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:   return true;
8902                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:  return true;
8903                 case EXPR_BINARY_BITWISE_AND_ASSIGN: return true;
8904                 case EXPR_BINARY_BITWISE_XOR_ASSIGN: return true;
8905                 case EXPR_BINARY_BITWISE_OR_ASSIGN:  return true;
8906
8907                 /* Only examine the right hand side of && and ||, because the left hand
8908                  * side already has the effect of controlling the execution of the right
8909                  * hand side */
8910                 case EXPR_BINARY_LOGICAL_AND:
8911                 case EXPR_BINARY_LOGICAL_OR:
8912                 /* Only examine the right hand side of a comma expression, because the left
8913                  * hand side has a separate warning */
8914                 case EXPR_BINARY_COMMA:
8915                         return expression_has_effect(expr->binary.right);
8916
8917                 case EXPR_BINARY_BUILTIN_EXPECT:     return true;
8918                 case EXPR_BINARY_ISGREATER:          return false;
8919                 case EXPR_BINARY_ISGREATEREQUAL:     return false;
8920                 case EXPR_BINARY_ISLESS:             return false;
8921                 case EXPR_BINARY_ISLESSEQUAL:        return false;
8922                 case EXPR_BINARY_ISLESSGREATER:      return false;
8923                 case EXPR_BINARY_ISUNORDERED:        return false;
8924         }
8925
8926         internal_errorf(HERE, "unexpected expression");
8927 }
8928
8929 static void semantic_comma(binary_expression_t *expression)
8930 {
8931         if (warning.unused_value) {
8932                 const expression_t *const left = expression->left;
8933                 if (!expression_has_effect(left)) {
8934                         warningf(&left->base.source_position,
8935                                  "left-hand operand of comma expression has no effect");
8936                 }
8937         }
8938         expression->base.type = expression->right->base.type;
8939 }
8940
8941 /**
8942  * @param prec_r precedence of the right operand
8943  */
8944 #define CREATE_BINEXPR_PARSER(token_type, binexpression_type, prec_r, sfunc) \
8945 static expression_t *parse_##binexpression_type(expression_t *left)          \
8946 {                                                                            \
8947         expression_t *binexpr = allocate_expression_zero(binexpression_type);    \
8948         binexpr->binary.left  = left;                                            \
8949         eat(token_type);                                                         \
8950                                                                              \
8951         expression_t *right = parse_sub_expression(prec_r);                      \
8952                                                                              \
8953         binexpr->binary.right = right;                                           \
8954         sfunc(&binexpr->binary);                                                 \
8955                                                                              \
8956         return binexpr;                                                          \
8957 }
8958
8959 CREATE_BINEXPR_PARSER('*',                    EXPR_BINARY_MUL,                PREC_CAST,           semantic_binexpr_arithmetic)
8960 CREATE_BINEXPR_PARSER('/',                    EXPR_BINARY_DIV,                PREC_CAST,           semantic_divmod_arithmetic)
8961 CREATE_BINEXPR_PARSER('%',                    EXPR_BINARY_MOD,                PREC_CAST,           semantic_divmod_arithmetic)
8962 CREATE_BINEXPR_PARSER('+',                    EXPR_BINARY_ADD,                PREC_MULTIPLICATIVE, semantic_add)
8963 CREATE_BINEXPR_PARSER('-',                    EXPR_BINARY_SUB,                PREC_MULTIPLICATIVE, semantic_sub)
8964 CREATE_BINEXPR_PARSER(T_LESSLESS,             EXPR_BINARY_SHIFTLEFT,          PREC_ADDITIVE,       semantic_shift_op)
8965 CREATE_BINEXPR_PARSER(T_GREATERGREATER,       EXPR_BINARY_SHIFTRIGHT,         PREC_ADDITIVE,       semantic_shift_op)
8966 CREATE_BINEXPR_PARSER('<',                    EXPR_BINARY_LESS,               PREC_SHIFT,          semantic_comparison)
8967 CREATE_BINEXPR_PARSER('>',                    EXPR_BINARY_GREATER,            PREC_SHIFT,          semantic_comparison)
8968 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,          PREC_SHIFT,          semantic_comparison)
8969 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,       PREC_SHIFT,          semantic_comparison)
8970 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,           PREC_RELATIONAL,     semantic_comparison)
8971 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,              PREC_RELATIONAL,     semantic_comparison)
8972 CREATE_BINEXPR_PARSER('&',                    EXPR_BINARY_BITWISE_AND,        PREC_EQUALITY,       semantic_binexpr_arithmetic)
8973 CREATE_BINEXPR_PARSER('^',                    EXPR_BINARY_BITWISE_XOR,        PREC_AND,            semantic_binexpr_arithmetic)
8974 CREATE_BINEXPR_PARSER('|',                    EXPR_BINARY_BITWISE_OR,         PREC_XOR,            semantic_binexpr_arithmetic)
8975 CREATE_BINEXPR_PARSER(T_ANDAND,               EXPR_BINARY_LOGICAL_AND,        PREC_OR,             semantic_logical_op)
8976 CREATE_BINEXPR_PARSER(T_PIPEPIPE,             EXPR_BINARY_LOGICAL_OR,         PREC_LOGICAL_AND,    semantic_logical_op)
8977 CREATE_BINEXPR_PARSER('=',                    EXPR_BINARY_ASSIGN,             PREC_ASSIGNMENT,     semantic_binexpr_assign)
8978 CREATE_BINEXPR_PARSER(T_PLUSEQUAL,            EXPR_BINARY_ADD_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8979 CREATE_BINEXPR_PARSER(T_MINUSEQUAL,           EXPR_BINARY_SUB_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8980 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL,        EXPR_BINARY_MUL_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_assign)
8981 CREATE_BINEXPR_PARSER(T_SLASHEQUAL,           EXPR_BINARY_DIV_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8982 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL,         EXPR_BINARY_MOD_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8983 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL,        EXPR_BINARY_SHIFTLEFT_ASSIGN,   PREC_ASSIGNMENT,     semantic_arithmetic_assign)
8984 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL,  EXPR_BINARY_SHIFTRIGHT_ASSIGN,  PREC_ASSIGNMENT,     semantic_arithmetic_assign)
8985 CREATE_BINEXPR_PARSER(T_ANDEQUAL,             EXPR_BINARY_BITWISE_AND_ASSIGN, PREC_ASSIGNMENT,     semantic_arithmetic_assign)
8986 CREATE_BINEXPR_PARSER(T_PIPEEQUAL,            EXPR_BINARY_BITWISE_OR_ASSIGN,  PREC_ASSIGNMENT,     semantic_arithmetic_assign)
8987 CREATE_BINEXPR_PARSER(T_CARETEQUAL,           EXPR_BINARY_BITWISE_XOR_ASSIGN, PREC_ASSIGNMENT,     semantic_arithmetic_assign)
8988 CREATE_BINEXPR_PARSER(',',                    EXPR_BINARY_COMMA,              PREC_ASSIGNMENT,     semantic_comma)
8989
8990
8991 static expression_t *parse_sub_expression(precedence_t precedence)
8992 {
8993         if (token.type < 0) {
8994                 return expected_expression_error();
8995         }
8996
8997         expression_parser_function_t *parser
8998                 = &expression_parsers[token.type];
8999         source_position_t             source_position = token.source_position;
9000         expression_t                 *left;
9001
9002         if (parser->parser != NULL) {
9003                 left = parser->parser();
9004         } else {
9005                 left = parse_primary_expression();
9006         }
9007         assert(left != NULL);
9008         left->base.source_position = source_position;
9009
9010         while (true) {
9011                 if (token.type < 0) {
9012                         return expected_expression_error();
9013                 }
9014
9015                 parser = &expression_parsers[token.type];
9016                 if (parser->infix_parser == NULL)
9017                         break;
9018                 if (parser->infix_precedence < precedence)
9019                         break;
9020
9021                 left = parser->infix_parser(left);
9022
9023                 assert(left != NULL);
9024                 assert(left->kind != EXPR_UNKNOWN);
9025                 left->base.source_position = source_position;
9026         }
9027
9028         return left;
9029 }
9030
9031 /**
9032  * Parse an expression.
9033  */
9034 static expression_t *parse_expression(void)
9035 {
9036         return parse_sub_expression(PREC_EXPRESSION);
9037 }
9038
9039 /**
9040  * Register a parser for a prefix-like operator.
9041  *
9042  * @param parser      the parser function
9043  * @param token_type  the token type of the prefix token
9044  */
9045 static void register_expression_parser(parse_expression_function parser,
9046                                        int token_type)
9047 {
9048         expression_parser_function_t *entry = &expression_parsers[token_type];
9049
9050         if (entry->parser != NULL) {
9051                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
9052                 panic("trying to register multiple expression parsers for a token");
9053         }
9054         entry->parser = parser;
9055 }
9056
9057 /**
9058  * Register a parser for an infix operator with given precedence.
9059  *
9060  * @param parser      the parser function
9061  * @param token_type  the token type of the infix operator
9062  * @param precedence  the precedence of the operator
9063  */
9064 static void register_infix_parser(parse_expression_infix_function parser,
9065                 int token_type, unsigned precedence)
9066 {
9067         expression_parser_function_t *entry = &expression_parsers[token_type];
9068
9069         if (entry->infix_parser != NULL) {
9070                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
9071                 panic("trying to register multiple infix expression parsers for a "
9072                       "token");
9073         }
9074         entry->infix_parser     = parser;
9075         entry->infix_precedence = precedence;
9076 }
9077
9078 /**
9079  * Initialize the expression parsers.
9080  */
9081 static void init_expression_parsers(void)
9082 {
9083         memset(&expression_parsers, 0, sizeof(expression_parsers));
9084
9085         register_infix_parser(parse_array_expression,               '[',                    PREC_POSTFIX);
9086         register_infix_parser(parse_call_expression,                '(',                    PREC_POSTFIX);
9087         register_infix_parser(parse_select_expression,              '.',                    PREC_POSTFIX);
9088         register_infix_parser(parse_select_expression,              T_MINUSGREATER,         PREC_POSTFIX);
9089         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,   T_PLUSPLUS,             PREC_POSTFIX);
9090         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,   T_MINUSMINUS,           PREC_POSTFIX);
9091         register_infix_parser(parse_EXPR_BINARY_MUL,                '*',                    PREC_MULTIPLICATIVE);
9092         register_infix_parser(parse_EXPR_BINARY_DIV,                '/',                    PREC_MULTIPLICATIVE);
9093         register_infix_parser(parse_EXPR_BINARY_MOD,                '%',                    PREC_MULTIPLICATIVE);
9094         register_infix_parser(parse_EXPR_BINARY_ADD,                '+',                    PREC_ADDITIVE);
9095         register_infix_parser(parse_EXPR_BINARY_SUB,                '-',                    PREC_ADDITIVE);
9096         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,          T_LESSLESS,             PREC_SHIFT);
9097         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,         T_GREATERGREATER,       PREC_SHIFT);
9098         register_infix_parser(parse_EXPR_BINARY_LESS,               '<',                    PREC_RELATIONAL);
9099         register_infix_parser(parse_EXPR_BINARY_GREATER,            '>',                    PREC_RELATIONAL);
9100         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,          T_LESSEQUAL,            PREC_RELATIONAL);
9101         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL,       T_GREATEREQUAL,         PREC_RELATIONAL);
9102         register_infix_parser(parse_EXPR_BINARY_EQUAL,              T_EQUALEQUAL,           PREC_EQUALITY);
9103         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,           T_EXCLAMATIONMARKEQUAL, PREC_EQUALITY);
9104         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,        '&',                    PREC_AND);
9105         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,        '^',                    PREC_XOR);
9106         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,         '|',                    PREC_OR);
9107         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,        T_ANDAND,               PREC_LOGICAL_AND);
9108         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,         T_PIPEPIPE,             PREC_LOGICAL_OR);
9109         register_infix_parser(parse_conditional_expression,         '?',                    PREC_CONDITIONAL);
9110         register_infix_parser(parse_EXPR_BINARY_ASSIGN,             '=',                    PREC_ASSIGNMENT);
9111         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,         T_PLUSEQUAL,            PREC_ASSIGNMENT);
9112         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,         T_MINUSEQUAL,           PREC_ASSIGNMENT);
9113         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,         T_ASTERISKEQUAL,        PREC_ASSIGNMENT);
9114         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,         T_SLASHEQUAL,           PREC_ASSIGNMENT);
9115         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,         T_PERCENTEQUAL,         PREC_ASSIGNMENT);
9116         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,   T_LESSLESSEQUAL,        PREC_ASSIGNMENT);
9117         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,  T_GREATERGREATEREQUAL,  PREC_ASSIGNMENT);
9118         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN, T_ANDEQUAL,             PREC_ASSIGNMENT);
9119         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,  T_PIPEEQUAL,            PREC_ASSIGNMENT);
9120         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN, T_CARETEQUAL,           PREC_ASSIGNMENT);
9121         register_infix_parser(parse_EXPR_BINARY_COMMA,              ',',                    PREC_EXPRESSION);
9122
9123         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-');
9124         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+');
9125         register_expression_parser(parse_EXPR_UNARY_NOT,              '!');
9126         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~');
9127         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*');
9128         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&');
9129         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT, T_PLUSPLUS);
9130         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT, T_MINUSMINUS);
9131         register_expression_parser(parse_sizeof,                      T_sizeof);
9132         register_expression_parser(parse_alignof,                     T___alignof__);
9133         register_expression_parser(parse_extension,                   T___extension__);
9134         register_expression_parser(parse_builtin_classify_type,       T___builtin_classify_type);
9135         register_expression_parser(parse_delete,                      T_delete);
9136         register_expression_parser(parse_throw,                       T_throw);
9137 }
9138
9139 /**
9140  * Parse a asm statement arguments specification.
9141  */
9142 static asm_argument_t *parse_asm_arguments(bool is_out)
9143 {
9144         asm_argument_t  *result = NULL;
9145         asm_argument_t **anchor = &result;
9146
9147         while (token.type == T_STRING_LITERAL || token.type == '[') {
9148                 asm_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
9149                 memset(argument, 0, sizeof(argument[0]));
9150
9151                 if (token.type == '[') {
9152                         eat('[');
9153                         if (token.type != T_IDENTIFIER) {
9154                                 parse_error_expected("while parsing asm argument",
9155                                                      T_IDENTIFIER, NULL);
9156                                 return NULL;
9157                         }
9158                         argument->symbol = token.v.symbol;
9159
9160                         expect(']');
9161                 }
9162
9163                 argument->constraints = parse_string_literals();
9164                 expect('(');
9165                 add_anchor_token(')');
9166                 expression_t *expression = parse_expression();
9167                 rem_anchor_token(')');
9168                 if (is_out) {
9169                         /* Ugly GCC stuff: Allow lvalue casts.  Skip casts, when they do not
9170                          * change size or type representation (e.g. int -> long is ok, but
9171                          * int -> float is not) */
9172                         if (expression->kind == EXPR_UNARY_CAST) {
9173                                 type_t      *const type = expression->base.type;
9174                                 type_kind_t  const kind = type->kind;
9175                                 if (kind == TYPE_ATOMIC || kind == TYPE_POINTER) {
9176                                         unsigned flags;
9177                                         unsigned size;
9178                                         if (kind == TYPE_ATOMIC) {
9179                                                 atomic_type_kind_t const akind = type->atomic.akind;
9180                                                 flags = get_atomic_type_flags(akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
9181                                                 size  = get_atomic_type_size(akind);
9182                                         } else {
9183                                                 flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
9184                                                 size  = get_atomic_type_size(get_intptr_kind());
9185                                         }
9186
9187                                         do {
9188                                                 expression_t *const value      = expression->unary.value;
9189                                                 type_t       *const value_type = value->base.type;
9190                                                 type_kind_t   const value_kind = value_type->kind;
9191
9192                                                 unsigned value_flags;
9193                                                 unsigned value_size;
9194                                                 if (value_kind == TYPE_ATOMIC) {
9195                                                         atomic_type_kind_t const value_akind = value_type->atomic.akind;
9196                                                         value_flags = get_atomic_type_flags(value_akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
9197                                                         value_size  = get_atomic_type_size(value_akind);
9198                                                 } else if (value_kind == TYPE_POINTER) {
9199                                                         value_flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
9200                                                         value_size  = get_atomic_type_size(get_intptr_kind());
9201                                                 } else {
9202                                                         break;
9203                                                 }
9204
9205                                                 if (value_flags != flags || value_size != size)
9206                                                         break;
9207
9208                                                 expression = value;
9209                                         } while (expression->kind == EXPR_UNARY_CAST);
9210                                 }
9211                         }
9212
9213                         if (!is_lvalue(expression)) {
9214                                 errorf(&expression->base.source_position,
9215                                        "asm output argument is not an lvalue");
9216                         }
9217
9218                         if (argument->constraints.begin[0] == '+')
9219                                 mark_vars_read(expression, NULL);
9220                 } else {
9221                         mark_vars_read(expression, NULL);
9222                 }
9223                 argument->expression = expression;
9224                 expect(')');
9225
9226                 set_address_taken(expression, true);
9227
9228                 *anchor = argument;
9229                 anchor  = &argument->next;
9230
9231                 if (token.type != ',')
9232                         break;
9233                 eat(',');
9234         }
9235
9236         return result;
9237 end_error:
9238         return NULL;
9239 }
9240
9241 /**
9242  * Parse a asm statement clobber specification.
9243  */
9244 static asm_clobber_t *parse_asm_clobbers(void)
9245 {
9246         asm_clobber_t *result = NULL;
9247         asm_clobber_t *last   = NULL;
9248
9249         while (token.type == T_STRING_LITERAL) {
9250                 asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
9251                 clobber->clobber       = parse_string_literals();
9252
9253                 if (last != NULL) {
9254                         last->next = clobber;
9255                 } else {
9256                         result = clobber;
9257                 }
9258                 last = clobber;
9259
9260                 if (token.type != ',')
9261                         break;
9262                 eat(',');
9263         }
9264
9265         return result;
9266 }
9267
9268 /**
9269  * Parse an asm statement.
9270  */
9271 static statement_t *parse_asm_statement(void)
9272 {
9273         statement_t     *statement     = allocate_statement_zero(STATEMENT_ASM);
9274         asm_statement_t *asm_statement = &statement->asms;
9275
9276         eat(T_asm);
9277
9278         if (token.type == T_volatile) {
9279                 next_token();
9280                 asm_statement->is_volatile = true;
9281         }
9282
9283         expect('(');
9284         add_anchor_token(')');
9285         add_anchor_token(':');
9286         asm_statement->asm_text = parse_string_literals();
9287
9288         if (token.type != ':') {
9289                 rem_anchor_token(':');
9290                 goto end_of_asm;
9291         }
9292         eat(':');
9293
9294         asm_statement->outputs = parse_asm_arguments(true);
9295         if (token.type != ':') {
9296                 rem_anchor_token(':');
9297                 goto end_of_asm;
9298         }
9299         eat(':');
9300
9301         asm_statement->inputs = parse_asm_arguments(false);
9302         if (token.type != ':') {
9303                 rem_anchor_token(':');
9304                 goto end_of_asm;
9305         }
9306         rem_anchor_token(':');
9307         eat(':');
9308
9309         asm_statement->clobbers = parse_asm_clobbers();
9310
9311 end_of_asm:
9312         rem_anchor_token(')');
9313         expect(')');
9314         expect(';');
9315
9316         if (asm_statement->outputs == NULL) {
9317                 /* GCC: An 'asm' instruction without any output operands will be treated
9318                  * identically to a volatile 'asm' instruction. */
9319                 asm_statement->is_volatile = true;
9320         }
9321
9322         return statement;
9323 end_error:
9324         return create_invalid_statement();
9325 }
9326
9327 /**
9328  * Parse a case statement.
9329  */
9330 static statement_t *parse_case_statement(void)
9331 {
9332         statement_t       *const statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9333         source_position_t *const pos       = &statement->base.source_position;
9334
9335         eat(T_case);
9336
9337         expression_t *const expression   = parse_expression();
9338         statement->case_label.expression = expression;
9339         if (!is_constant_expression(expression)) {
9340                 /* This check does not prevent the error message in all cases of an
9341                  * prior error while parsing the expression.  At least it catches the
9342                  * common case of a mistyped enum entry. */
9343                 if (is_type_valid(skip_typeref(expression->base.type))) {
9344                         errorf(pos, "case label does not reduce to an integer constant");
9345                 }
9346                 statement->case_label.is_bad = true;
9347         } else {
9348                 long const val = fold_constant(expression);
9349                 statement->case_label.first_case = val;
9350                 statement->case_label.last_case  = val;
9351         }
9352
9353         if (GNU_MODE) {
9354                 if (token.type == T_DOTDOTDOT) {
9355                         next_token();
9356                         expression_t *const end_range   = parse_expression();
9357                         statement->case_label.end_range = end_range;
9358                         if (!is_constant_expression(end_range)) {
9359                                 /* This check does not prevent the error message in all cases of an
9360                                  * prior error while parsing the expression.  At least it catches the
9361                                  * common case of a mistyped enum entry. */
9362                                 if (is_type_valid(skip_typeref(end_range->base.type))) {
9363                                         errorf(pos, "case range does not reduce to an integer constant");
9364                                 }
9365                                 statement->case_label.is_bad = true;
9366                         } else {
9367                                 long const val = fold_constant(end_range);
9368                                 statement->case_label.last_case = val;
9369
9370                                 if (warning.other && val < statement->case_label.first_case) {
9371                                         statement->case_label.is_empty_range = true;
9372                                         warningf(pos, "empty range specified");
9373                                 }
9374                         }
9375                 }
9376         }
9377
9378         PUSH_PARENT(statement);
9379
9380         expect(':');
9381
9382         if (current_switch != NULL) {
9383                 if (! statement->case_label.is_bad) {
9384                         /* Check for duplicate case values */
9385                         case_label_statement_t *c = &statement->case_label;
9386                         for (case_label_statement_t *l = current_switch->first_case; l != NULL; l = l->next) {
9387                                 if (l->is_bad || l->is_empty_range || l->expression == NULL)
9388                                         continue;
9389
9390                                 if (c->last_case < l->first_case || c->first_case > l->last_case)
9391                                         continue;
9392
9393                                 errorf(pos, "duplicate case value (previously used %P)",
9394                                        &l->base.source_position);
9395                                 break;
9396                         }
9397                 }
9398                 /* link all cases into the switch statement */
9399                 if (current_switch->last_case == NULL) {
9400                         current_switch->first_case      = &statement->case_label;
9401                 } else {
9402                         current_switch->last_case->next = &statement->case_label;
9403                 }
9404                 current_switch->last_case = &statement->case_label;
9405         } else {
9406                 errorf(pos, "case label not within a switch statement");
9407         }
9408
9409         statement_t *const inner_stmt = parse_statement();
9410         statement->case_label.statement = inner_stmt;
9411         if (inner_stmt->kind == STATEMENT_DECLARATION) {
9412                 errorf(&inner_stmt->base.source_position, "declaration after case label");
9413         }
9414
9415         POP_PARENT;
9416         return statement;
9417 end_error:
9418         POP_PARENT;
9419         return create_invalid_statement();
9420 }
9421
9422 /**
9423  * Parse a default statement.
9424  */
9425 static statement_t *parse_default_statement(void)
9426 {
9427         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9428
9429         eat(T_default);
9430
9431         PUSH_PARENT(statement);
9432
9433         expect(':');
9434         if (current_switch != NULL) {
9435                 const case_label_statement_t *def_label = current_switch->default_label;
9436                 if (def_label != NULL) {
9437                         errorf(HERE, "multiple default labels in one switch (previous declared %P)",
9438                                &def_label->base.source_position);
9439                 } else {
9440                         current_switch->default_label = &statement->case_label;
9441
9442                         /* link all cases into the switch statement */
9443                         if (current_switch->last_case == NULL) {
9444                                 current_switch->first_case      = &statement->case_label;
9445                         } else {
9446                                 current_switch->last_case->next = &statement->case_label;
9447                         }
9448                         current_switch->last_case = &statement->case_label;
9449                 }
9450         } else {
9451                 errorf(&statement->base.source_position,
9452                         "'default' label not within a switch statement");
9453         }
9454
9455         statement_t *const inner_stmt = parse_statement();
9456         statement->case_label.statement = inner_stmt;
9457         if (inner_stmt->kind == STATEMENT_DECLARATION) {
9458                 errorf(&inner_stmt->base.source_position, "declaration after default label");
9459         }
9460
9461         POP_PARENT;
9462         return statement;
9463 end_error:
9464         POP_PARENT;
9465         return create_invalid_statement();
9466 }
9467
9468 /**
9469  * Parse a label statement.
9470  */
9471 static statement_t *parse_label_statement(void)
9472 {
9473         assert(token.type == T_IDENTIFIER);
9474         symbol_t *symbol = token.v.symbol;
9475         label_t  *label  = get_label(symbol);
9476
9477         statement_t *const statement = allocate_statement_zero(STATEMENT_LABEL);
9478         statement->label.label       = label;
9479
9480         next_token();
9481
9482         PUSH_PARENT(statement);
9483
9484         /* if statement is already set then the label is defined twice,
9485          * otherwise it was just mentioned in a goto/local label declaration so far
9486          */
9487         if (label->statement != NULL) {
9488                 errorf(HERE, "duplicate label '%Y' (declared %P)",
9489                        symbol, &label->base.source_position);
9490         } else {
9491                 label->base.source_position = token.source_position;
9492                 label->statement            = statement;
9493         }
9494
9495         eat(':');
9496
9497         if (token.type == '}') {
9498                 /* TODO only warn? */
9499                 if (warning.other && false) {
9500                         warningf(HERE, "label at end of compound statement");
9501                         statement->label.statement = create_empty_statement();
9502                 } else {
9503                         errorf(HERE, "label at end of compound statement");
9504                         statement->label.statement = create_invalid_statement();
9505                 }
9506         } else if (token.type == ';') {
9507                 /* Eat an empty statement here, to avoid the warning about an empty
9508                  * statement after a label.  label:; is commonly used to have a label
9509                  * before a closing brace. */
9510                 statement->label.statement = create_empty_statement();
9511                 next_token();
9512         } else {
9513                 statement_t *const inner_stmt = parse_statement();
9514                 statement->label.statement = inner_stmt;
9515                 if (inner_stmt->kind == STATEMENT_DECLARATION) {
9516                         errorf(&inner_stmt->base.source_position, "declaration after label");
9517                 }
9518         }
9519
9520         /* remember the labels in a list for later checking */
9521         *label_anchor = &statement->label;
9522         label_anchor  = &statement->label.next;
9523
9524         POP_PARENT;
9525         return statement;
9526 }
9527
9528 /**
9529  * Parse an if statement.
9530  */
9531 static statement_t *parse_if(void)
9532 {
9533         statement_t *statement = allocate_statement_zero(STATEMENT_IF);
9534
9535         eat(T_if);
9536
9537         PUSH_PARENT(statement);
9538
9539         add_anchor_token('{');
9540
9541         expect('(');
9542         add_anchor_token(')');
9543         expression_t *const expr = parse_expression();
9544         statement->ifs.condition = expr;
9545         warn_reference_address_as_bool(expr);
9546         mark_vars_read(expr, NULL);
9547         rem_anchor_token(')');
9548         expect(')');
9549
9550 end_error:
9551         rem_anchor_token('{');
9552
9553         add_anchor_token(T_else);
9554         statement->ifs.true_statement = parse_statement();
9555         rem_anchor_token(T_else);
9556
9557         if (token.type == T_else) {
9558                 next_token();
9559                 statement->ifs.false_statement = parse_statement();
9560         }
9561
9562         POP_PARENT;
9563         return statement;
9564 }
9565
9566 /**
9567  * Check that all enums are handled in a switch.
9568  *
9569  * @param statement  the switch statement to check
9570  */
9571 static void check_enum_cases(const switch_statement_t *statement) {
9572         const type_t *type = skip_typeref(statement->expression->base.type);
9573         if (! is_type_enum(type))
9574                 return;
9575         const enum_type_t *enumt = &type->enumt;
9576
9577         /* if we have a default, no warnings */
9578         if (statement->default_label != NULL)
9579                 return;
9580
9581         /* FIXME: calculation of value should be done while parsing */
9582         /* TODO: quadratic algorithm here. Change to an n log n one */
9583         long            last_value = -1;
9584         const entity_t *entry      = enumt->enume->base.next;
9585         for (; entry != NULL && entry->kind == ENTITY_ENUM_VALUE;
9586              entry = entry->base.next) {
9587                 const expression_t *expression = entry->enum_value.value;
9588                 long                value      = expression != NULL ? fold_constant(expression) : last_value + 1;
9589                 bool                found      = false;
9590                 for (const case_label_statement_t *l = statement->first_case; l != NULL; l = l->next) {
9591                         if (l->expression == NULL)
9592                                 continue;
9593                         if (l->first_case <= value && value <= l->last_case) {
9594                                 found = true;
9595                                 break;
9596                         }
9597                 }
9598                 if (! found) {
9599                         warningf(&statement->base.source_position,
9600                                  "enumeration value '%Y' not handled in switch",
9601                                  entry->base.symbol);
9602                 }
9603                 last_value = value;
9604         }
9605 }
9606
9607 /**
9608  * Parse a switch statement.
9609  */
9610 static statement_t *parse_switch(void)
9611 {
9612         statement_t *statement = allocate_statement_zero(STATEMENT_SWITCH);
9613
9614         eat(T_switch);
9615
9616         PUSH_PARENT(statement);
9617
9618         expect('(');
9619         add_anchor_token(')');
9620         expression_t *const expr = parse_expression();
9621         mark_vars_read(expr, NULL);
9622         type_t       *      type = skip_typeref(expr->base.type);
9623         if (is_type_integer(type)) {
9624                 type = promote_integer(type);
9625                 if (warning.traditional) {
9626                         if (get_rank(type) >= get_akind_rank(ATOMIC_TYPE_LONG)) {
9627                                 warningf(&expr->base.source_position,
9628                                         "'%T' switch expression not converted to '%T' in ISO C",
9629                                         type, type_int);
9630                         }
9631                 }
9632         } else if (is_type_valid(type)) {
9633                 errorf(&expr->base.source_position,
9634                        "switch quantity is not an integer, but '%T'", type);
9635                 type = type_error_type;
9636         }
9637         statement->switchs.expression = create_implicit_cast(expr, type);
9638         expect(')');
9639         rem_anchor_token(')');
9640
9641         switch_statement_t *rem = current_switch;
9642         current_switch          = &statement->switchs;
9643         statement->switchs.body = parse_statement();
9644         current_switch          = rem;
9645
9646         if (warning.switch_default &&
9647             statement->switchs.default_label == NULL) {
9648                 warningf(&statement->base.source_position, "switch has no default case");
9649         }
9650         if (warning.switch_enum)
9651                 check_enum_cases(&statement->switchs);
9652
9653         POP_PARENT;
9654         return statement;
9655 end_error:
9656         POP_PARENT;
9657         return create_invalid_statement();
9658 }
9659
9660 static statement_t *parse_loop_body(statement_t *const loop)
9661 {
9662         statement_t *const rem = current_loop;
9663         current_loop = loop;
9664
9665         statement_t *const body = parse_statement();
9666
9667         current_loop = rem;
9668         return body;
9669 }
9670
9671 /**
9672  * Parse a while statement.
9673  */
9674 static statement_t *parse_while(void)
9675 {
9676         statement_t *statement = allocate_statement_zero(STATEMENT_WHILE);
9677
9678         eat(T_while);
9679
9680         PUSH_PARENT(statement);
9681
9682         expect('(');
9683         add_anchor_token(')');
9684         expression_t *const cond = parse_expression();
9685         statement->whiles.condition = cond;
9686         warn_reference_address_as_bool(cond);
9687         mark_vars_read(cond, NULL);
9688         rem_anchor_token(')');
9689         expect(')');
9690
9691         statement->whiles.body = parse_loop_body(statement);
9692
9693         POP_PARENT;
9694         return statement;
9695 end_error:
9696         POP_PARENT;
9697         return create_invalid_statement();
9698 }
9699
9700 /**
9701  * Parse a do statement.
9702  */
9703 static statement_t *parse_do(void)
9704 {
9705         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
9706
9707         eat(T_do);
9708
9709         PUSH_PARENT(statement);
9710
9711         add_anchor_token(T_while);
9712         statement->do_while.body = parse_loop_body(statement);
9713         rem_anchor_token(T_while);
9714
9715         expect(T_while);
9716         expect('(');
9717         add_anchor_token(')');
9718         expression_t *const cond = parse_expression();
9719         statement->do_while.condition = cond;
9720         warn_reference_address_as_bool(cond);
9721         mark_vars_read(cond, NULL);
9722         rem_anchor_token(')');
9723         expect(')');
9724         expect(';');
9725
9726         POP_PARENT;
9727         return statement;
9728 end_error:
9729         POP_PARENT;
9730         return create_invalid_statement();
9731 }
9732
9733 /**
9734  * Parse a for statement.
9735  */
9736 static statement_t *parse_for(void)
9737 {
9738         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
9739
9740         eat(T_for);
9741
9742         PUSH_PARENT(statement);
9743
9744         size_t const top = environment_top();
9745         scope_push(&statement->fors.scope);
9746
9747         expect('(');
9748         add_anchor_token(')');
9749
9750         if (token.type != ';') {
9751                 if (is_declaration_specifier(&token, false)) {
9752                         parse_declaration(record_entity);
9753                 } else {
9754                         add_anchor_token(';');
9755                         expression_t *const init = parse_expression();
9756                         statement->fors.initialisation = init;
9757                         mark_vars_read(init, VAR_ANY);
9758                         if (warning.unused_value && !expression_has_effect(init)) {
9759                                 warningf(&init->base.source_position,
9760                                          "initialisation of 'for'-statement has no effect");
9761                         }
9762                         rem_anchor_token(';');
9763                         expect(';');
9764                 }
9765         } else {
9766                 expect(';');
9767         }
9768
9769         if (token.type != ';') {
9770                 add_anchor_token(';');
9771                 expression_t *const cond = parse_expression();
9772                 statement->fors.condition = cond;
9773                 warn_reference_address_as_bool(cond);
9774                 mark_vars_read(cond, NULL);
9775                 rem_anchor_token(';');
9776         }
9777         expect(';');
9778         if (token.type != ')') {
9779                 expression_t *const step = parse_expression();
9780                 statement->fors.step = step;
9781                 mark_vars_read(step, VAR_ANY);
9782                 if (warning.unused_value && !expression_has_effect(step)) {
9783                         warningf(&step->base.source_position,
9784                                  "step of 'for'-statement has no effect");
9785                 }
9786         }
9787         expect(')');
9788         rem_anchor_token(')');
9789         statement->fors.body = parse_loop_body(statement);
9790
9791         assert(current_scope == &statement->fors.scope);
9792         scope_pop();
9793         environment_pop_to(top);
9794
9795         POP_PARENT;
9796         return statement;
9797
9798 end_error:
9799         POP_PARENT;
9800         rem_anchor_token(')');
9801         assert(current_scope == &statement->fors.scope);
9802         scope_pop();
9803         environment_pop_to(top);
9804
9805         return create_invalid_statement();
9806 }
9807
9808 /**
9809  * Parse a goto statement.
9810  */
9811 static statement_t *parse_goto(void)
9812 {
9813         statement_t *statement = allocate_statement_zero(STATEMENT_GOTO);
9814         eat(T_goto);
9815
9816         if (GNU_MODE && token.type == '*') {
9817                 next_token();
9818                 expression_t *expression = parse_expression();
9819                 mark_vars_read(expression, NULL);
9820
9821                 /* Argh: although documentation says the expression must be of type void*,
9822                  * gcc accepts anything that can be casted into void* without error */
9823                 type_t *type = expression->base.type;
9824
9825                 if (type != type_error_type) {
9826                         if (!is_type_pointer(type) && !is_type_integer(type)) {
9827                                 errorf(&expression->base.source_position,
9828                                         "cannot convert to a pointer type");
9829                         } else if (warning.other && type != type_void_ptr) {
9830                                 warningf(&expression->base.source_position,
9831                                         "type of computed goto expression should be 'void*' not '%T'", type);
9832                         }
9833                         expression = create_implicit_cast(expression, type_void_ptr);
9834                 }
9835
9836                 statement->gotos.expression = expression;
9837         } else {
9838                 if (token.type != T_IDENTIFIER) {
9839                         if (GNU_MODE)
9840                                 parse_error_expected("while parsing goto", T_IDENTIFIER, '*', NULL);
9841                         else
9842                                 parse_error_expected("while parsing goto", T_IDENTIFIER, NULL);
9843                         eat_until_anchor();
9844                         goto end_error;
9845                 }
9846                 symbol_t *symbol = token.v.symbol;
9847                 next_token();
9848
9849                 statement->gotos.label = get_label(symbol);
9850         }
9851
9852         /* remember the goto's in a list for later checking */
9853         *goto_anchor = &statement->gotos;
9854         goto_anchor  = &statement->gotos.next;
9855
9856         expect(';');
9857
9858         return statement;
9859 end_error:
9860         return create_invalid_statement();
9861 }
9862
9863 /**
9864  * Parse a continue statement.
9865  */
9866 static statement_t *parse_continue(void)
9867 {
9868         if (current_loop == NULL) {
9869                 errorf(HERE, "continue statement not within loop");
9870         }
9871
9872         statement_t *statement = allocate_statement_zero(STATEMENT_CONTINUE);
9873
9874         eat(T_continue);
9875         expect(';');
9876
9877 end_error:
9878         return statement;
9879 }
9880
9881 /**
9882  * Parse a break statement.
9883  */
9884 static statement_t *parse_break(void)
9885 {
9886         if (current_switch == NULL && current_loop == NULL) {
9887                 errorf(HERE, "break statement not within loop or switch");
9888         }
9889
9890         statement_t *statement = allocate_statement_zero(STATEMENT_BREAK);
9891
9892         eat(T_break);
9893         expect(';');
9894
9895 end_error:
9896         return statement;
9897 }
9898
9899 /**
9900  * Parse a __leave statement.
9901  */
9902 static statement_t *parse_leave_statement(void)
9903 {
9904         if (current_try == NULL) {
9905                 errorf(HERE, "__leave statement not within __try");
9906         }
9907
9908         statement_t *statement = allocate_statement_zero(STATEMENT_LEAVE);
9909
9910         eat(T___leave);
9911         expect(';');
9912
9913 end_error:
9914         return statement;
9915 }
9916
9917 /**
9918  * Check if a given entity represents a local variable.
9919  */
9920 static bool is_local_variable(const entity_t *entity)
9921 {
9922         if (entity->kind != ENTITY_VARIABLE)
9923                 return false;
9924
9925         switch ((storage_class_tag_t) entity->declaration.storage_class) {
9926         case STORAGE_CLASS_AUTO:
9927         case STORAGE_CLASS_REGISTER: {
9928                 const type_t *type = skip_typeref(entity->declaration.type);
9929                 if (is_type_function(type)) {
9930                         return false;
9931                 } else {
9932                         return true;
9933                 }
9934         }
9935         default:
9936                 return false;
9937         }
9938 }
9939
9940 /**
9941  * Check if a given expression represents a local variable.
9942  */
9943 static bool expression_is_local_variable(const expression_t *expression)
9944 {
9945         if (expression->base.kind != EXPR_REFERENCE) {
9946                 return false;
9947         }
9948         const entity_t *entity = expression->reference.entity;
9949         return is_local_variable(entity);
9950 }
9951
9952 /**
9953  * Check if a given expression represents a local variable and
9954  * return its declaration then, else return NULL.
9955  */
9956 entity_t *expression_is_variable(const expression_t *expression)
9957 {
9958         if (expression->base.kind != EXPR_REFERENCE) {
9959                 return NULL;
9960         }
9961         entity_t *entity = expression->reference.entity;
9962         if (entity->kind != ENTITY_VARIABLE)
9963                 return NULL;
9964
9965         return entity;
9966 }
9967
9968 /**
9969  * Parse a return statement.
9970  */
9971 static statement_t *parse_return(void)
9972 {
9973         eat(T_return);
9974
9975         statement_t *statement = allocate_statement_zero(STATEMENT_RETURN);
9976
9977         expression_t *return_value = NULL;
9978         if (token.type != ';') {
9979                 return_value = parse_expression();
9980                 mark_vars_read(return_value, NULL);
9981         }
9982
9983         const type_t *const func_type = skip_typeref(current_function->base.type);
9984         assert(is_type_function(func_type));
9985         type_t *const return_type = skip_typeref(func_type->function.return_type);
9986
9987         if (return_value != NULL) {
9988                 type_t *return_value_type = skip_typeref(return_value->base.type);
9989
9990                 if (is_type_atomic(return_type,        ATOMIC_TYPE_VOID) &&
9991                                 !is_type_atomic(return_value_type, ATOMIC_TYPE_VOID)) {
9992                         if (warning.other) {
9993                                 warningf(&statement->base.source_position,
9994                                                 "'return' with a value, in function returning void");
9995                         }
9996                         return_value = NULL;
9997                 } else {
9998                         assign_error_t error = semantic_assign(return_type, return_value);
9999                         report_assign_error(error, return_type, return_value, "'return'",
10000                                             &statement->base.source_position);
10001                         return_value = create_implicit_cast(return_value, return_type);
10002                 }
10003                 /* check for returning address of a local var */
10004                 if (warning.other && return_value != NULL
10005                                 && return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
10006                         const expression_t *expression = return_value->unary.value;
10007                         if (expression_is_local_variable(expression)) {
10008                                 warningf(&statement->base.source_position,
10009                                          "function returns address of local variable");
10010                         }
10011                 }
10012         } else if (warning.other && !is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
10013                 warningf(&statement->base.source_position,
10014                                 "'return' without value, in function returning non-void");
10015         }
10016         statement->returns.value = return_value;
10017
10018         expect(';');
10019
10020 end_error:
10021         return statement;
10022 }
10023
10024 /**
10025  * Parse a declaration statement.
10026  */
10027 static statement_t *parse_declaration_statement(void)
10028 {
10029         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
10030
10031         entity_t *before = current_scope->last_entity;
10032         if (GNU_MODE)
10033                 parse_external_declaration();
10034         else
10035                 parse_declaration(record_entity);
10036
10037         if (before == NULL) {
10038                 statement->declaration.declarations_begin = current_scope->entities;
10039         } else {
10040                 statement->declaration.declarations_begin = before->base.next;
10041         }
10042         statement->declaration.declarations_end = current_scope->last_entity;
10043
10044         return statement;
10045 }
10046
10047 /**
10048  * Parse an expression statement, ie. expr ';'.
10049  */
10050 static statement_t *parse_expression_statement(void)
10051 {
10052         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10053
10054         expression_t *const expr         = parse_expression();
10055         statement->expression.expression = expr;
10056         mark_vars_read(expr, VAR_ANY);
10057
10058         expect(';');
10059
10060 end_error:
10061         return statement;
10062 }
10063
10064 /**
10065  * Parse a microsoft __try { } __finally { } or
10066  * __try{ } __except() { }
10067  */
10068 static statement_t *parse_ms_try_statment(void)
10069 {
10070         statement_t *statement = allocate_statement_zero(STATEMENT_MS_TRY);
10071         eat(T___try);
10072
10073         PUSH_PARENT(statement);
10074
10075         ms_try_statement_t *rem = current_try;
10076         current_try = &statement->ms_try;
10077         statement->ms_try.try_statement = parse_compound_statement(false);
10078         current_try = rem;
10079
10080         POP_PARENT;
10081
10082         if (token.type == T___except) {
10083                 eat(T___except);
10084                 expect('(');
10085                 add_anchor_token(')');
10086                 expression_t *const expr = parse_expression();
10087                 mark_vars_read(expr, NULL);
10088                 type_t       *      type = skip_typeref(expr->base.type);
10089                 if (is_type_integer(type)) {
10090                         type = promote_integer(type);
10091                 } else if (is_type_valid(type)) {
10092                         errorf(&expr->base.source_position,
10093                                "__expect expression is not an integer, but '%T'", type);
10094                         type = type_error_type;
10095                 }
10096                 statement->ms_try.except_expression = create_implicit_cast(expr, type);
10097                 rem_anchor_token(')');
10098                 expect(')');
10099                 statement->ms_try.final_statement = parse_compound_statement(false);
10100         } else if (token.type == T__finally) {
10101                 eat(T___finally);
10102                 statement->ms_try.final_statement = parse_compound_statement(false);
10103         } else {
10104                 parse_error_expected("while parsing __try statement", T___except, T___finally, NULL);
10105                 return create_invalid_statement();
10106         }
10107         return statement;
10108 end_error:
10109         return create_invalid_statement();
10110 }
10111
10112 static statement_t *parse_empty_statement(void)
10113 {
10114         if (warning.empty_statement) {
10115                 warningf(HERE, "statement is empty");
10116         }
10117         statement_t *const statement = create_empty_statement();
10118         eat(';');
10119         return statement;
10120 }
10121
10122 static statement_t *parse_local_label_declaration(void)
10123 {
10124         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
10125
10126         eat(T___label__);
10127
10128         entity_t *begin = NULL, *end = NULL;
10129
10130         while (true) {
10131                 if (token.type != T_IDENTIFIER) {
10132                         parse_error_expected("while parsing local label declaration",
10133                                 T_IDENTIFIER, NULL);
10134                         goto end_error;
10135                 }
10136                 symbol_t *symbol = token.v.symbol;
10137                 entity_t *entity = get_entity(symbol, NAMESPACE_LABEL);
10138                 if (entity != NULL && entity->base.parent_scope == current_scope) {
10139                         errorf(HERE, "multiple definitions of '__label__ %Y' (previous definition %P)",
10140                                symbol, &entity->base.source_position);
10141                 } else {
10142                         entity = allocate_entity_zero(ENTITY_LOCAL_LABEL);
10143
10144                         entity->base.parent_scope    = current_scope;
10145                         entity->base.namespc         = NAMESPACE_LABEL;
10146                         entity->base.source_position = token.source_position;
10147                         entity->base.symbol          = symbol;
10148
10149                         if (end != NULL)
10150                                 end->base.next = entity;
10151                         end = entity;
10152                         if (begin == NULL)
10153                                 begin = entity;
10154
10155                         environment_push(entity);
10156                 }
10157                 next_token();
10158
10159                 if (token.type != ',')
10160                         break;
10161                 next_token();
10162         }
10163         eat(';');
10164 end_error:
10165         statement->declaration.declarations_begin = begin;
10166         statement->declaration.declarations_end   = end;
10167         return statement;
10168 }
10169
10170 static void parse_namespace_definition(void)
10171 {
10172         eat(T_namespace);
10173
10174         entity_t *entity = NULL;
10175         symbol_t *symbol = NULL;
10176
10177         if (token.type == T_IDENTIFIER) {
10178                 symbol = token.v.symbol;
10179                 next_token();
10180
10181                 entity = get_entity(symbol, NAMESPACE_NORMAL);
10182                 if (entity != NULL && entity->kind != ENTITY_NAMESPACE
10183                                 && entity->base.parent_scope == current_scope) {
10184                         error_redefined_as_different_kind(&token.source_position,
10185                                                           entity, ENTITY_NAMESPACE);
10186                         entity = NULL;
10187                 }
10188         }
10189
10190         if (entity == NULL) {
10191                 entity                       = allocate_entity_zero(ENTITY_NAMESPACE);
10192                 entity->base.symbol          = symbol;
10193                 entity->base.source_position = token.source_position;
10194                 entity->base.namespc         = NAMESPACE_NORMAL;
10195                 entity->base.parent_scope    = current_scope;
10196         }
10197
10198         if (token.type == '=') {
10199                 /* TODO: parse namespace alias */
10200                 panic("namespace alias definition not supported yet");
10201         }
10202
10203         environment_push(entity);
10204         append_entity(current_scope, entity);
10205
10206         size_t const top = environment_top();
10207         scope_push(&entity->namespacee.members);
10208
10209         expect('{');
10210         parse_externals();
10211         expect('}');
10212
10213 end_error:
10214         assert(current_scope == &entity->namespacee.members);
10215         scope_pop();
10216         environment_pop_to(top);
10217 }
10218
10219 /**
10220  * Parse a statement.
10221  * There's also parse_statement() which additionally checks for
10222  * "statement has no effect" warnings
10223  */
10224 static statement_t *intern_parse_statement(void)
10225 {
10226         statement_t *statement = NULL;
10227
10228         /* declaration or statement */
10229         add_anchor_token(';');
10230         switch (token.type) {
10231         case T_IDENTIFIER: {
10232                 token_type_t la1_type = (token_type_t)look_ahead(1)->type;
10233                 if (la1_type == ':') {
10234                         statement = parse_label_statement();
10235                 } else if (is_typedef_symbol(token.v.symbol)) {
10236                         statement = parse_declaration_statement();
10237                 } else {
10238                         /* it's an identifier, the grammar says this must be an
10239                          * expression statement. However it is common that users mistype
10240                          * declaration types, so we guess a bit here to improve robustness
10241                          * for incorrect programs */
10242                         switch (la1_type) {
10243                         case '*':
10244                                 if (get_entity(token.v.symbol, NAMESPACE_NORMAL) != NULL)
10245                                         goto expression_statment;
10246                                 /* FALLTHROUGH */
10247
10248                         DECLARATION_START
10249                         case T_IDENTIFIER:
10250                                 statement = parse_declaration_statement();
10251                                 break;
10252
10253                         default:
10254 expression_statment:
10255                                 statement = parse_expression_statement();
10256                                 break;
10257                         }
10258                 }
10259                 break;
10260         }
10261
10262         case T___extension__:
10263                 /* This can be a prefix to a declaration or an expression statement.
10264                  * We simply eat it now and parse the rest with tail recursion. */
10265                 do {
10266                         next_token();
10267                 } while (token.type == T___extension__);
10268                 bool old_gcc_extension = in_gcc_extension;
10269                 in_gcc_extension       = true;
10270                 statement = parse_statement();
10271                 in_gcc_extension = old_gcc_extension;
10272                 break;
10273
10274         DECLARATION_START
10275                 statement = parse_declaration_statement();
10276                 break;
10277
10278         case T___label__:
10279                 statement = parse_local_label_declaration();
10280                 break;
10281
10282         case ';':         statement = parse_empty_statement();         break;
10283         case '{':         statement = parse_compound_statement(false); break;
10284         case T___leave:   statement = parse_leave_statement();         break;
10285         case T___try:     statement = parse_ms_try_statment();         break;
10286         case T_asm:       statement = parse_asm_statement();           break;
10287         case T_break:     statement = parse_break();                   break;
10288         case T_case:      statement = parse_case_statement();          break;
10289         case T_continue:  statement = parse_continue();                break;
10290         case T_default:   statement = parse_default_statement();       break;
10291         case T_do:        statement = parse_do();                      break;
10292         case T_for:       statement = parse_for();                     break;
10293         case T_goto:      statement = parse_goto();                    break;
10294         case T_if:        statement = parse_if();                      break;
10295         case T_return:    statement = parse_return();                  break;
10296         case T_switch:    statement = parse_switch();                  break;
10297         case T_while:     statement = parse_while();                   break;
10298
10299         EXPRESSION_START
10300                 statement = parse_expression_statement();
10301                 break;
10302
10303         default:
10304                 errorf(HERE, "unexpected token %K while parsing statement", &token);
10305                 statement = create_invalid_statement();
10306                 if (!at_anchor())
10307                         next_token();
10308                 break;
10309         }
10310         rem_anchor_token(';');
10311
10312         assert(statement != NULL
10313                         && statement->base.source_position.input_name != NULL);
10314
10315         return statement;
10316 }
10317
10318 /**
10319  * parse a statement and emits "statement has no effect" warning if needed
10320  * (This is really a wrapper around intern_parse_statement with check for 1
10321  *  single warning. It is needed, because for statement expressions we have
10322  *  to avoid the warning on the last statement)
10323  */
10324 static statement_t *parse_statement(void)
10325 {
10326         statement_t *statement = intern_parse_statement();
10327
10328         if (statement->kind == STATEMENT_EXPRESSION && warning.unused_value) {
10329                 expression_t *expression = statement->expression.expression;
10330                 if (!expression_has_effect(expression)) {
10331                         warningf(&expression->base.source_position,
10332                                         "statement has no effect");
10333                 }
10334         }
10335
10336         return statement;
10337 }
10338
10339 /**
10340  * Parse a compound statement.
10341  */
10342 static statement_t *parse_compound_statement(bool inside_expression_statement)
10343 {
10344         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
10345
10346         PUSH_PARENT(statement);
10347
10348         eat('{');
10349         add_anchor_token('}');
10350
10351         size_t const top = environment_top();
10352         scope_push(&statement->compound.scope);
10353
10354         statement_t **anchor            = &statement->compound.statements;
10355         bool          only_decls_so_far = true;
10356         while (token.type != '}') {
10357                 if (token.type == T_EOF) {
10358                         errorf(&statement->base.source_position,
10359                                "EOF while parsing compound statement");
10360                         break;
10361                 }
10362                 statement_t *sub_statement = intern_parse_statement();
10363                 if (is_invalid_statement(sub_statement)) {
10364                         /* an error occurred. if we are at an anchor, return */
10365                         if (at_anchor())
10366                                 goto end_error;
10367                         continue;
10368                 }
10369
10370                 if (warning.declaration_after_statement) {
10371                         if (sub_statement->kind != STATEMENT_DECLARATION) {
10372                                 only_decls_so_far = false;
10373                         } else if (!only_decls_so_far) {
10374                                 warningf(&sub_statement->base.source_position,
10375                                          "ISO C90 forbids mixed declarations and code");
10376                         }
10377                 }
10378
10379                 *anchor = sub_statement;
10380
10381                 while (sub_statement->base.next != NULL)
10382                         sub_statement = sub_statement->base.next;
10383
10384                 anchor = &sub_statement->base.next;
10385         }
10386         next_token();
10387
10388         /* look over all statements again to produce no effect warnings */
10389         if (warning.unused_value) {
10390                 statement_t *sub_statement = statement->compound.statements;
10391                 for (; sub_statement != NULL; sub_statement = sub_statement->base.next) {
10392                         if (sub_statement->kind != STATEMENT_EXPRESSION)
10393                                 continue;
10394                         /* don't emit a warning for the last expression in an expression
10395                          * statement as it has always an effect */
10396                         if (inside_expression_statement && sub_statement->base.next == NULL)
10397                                 continue;
10398
10399                         expression_t *expression = sub_statement->expression.expression;
10400                         if (!expression_has_effect(expression)) {
10401                                 warningf(&expression->base.source_position,
10402                                          "statement has no effect");
10403                         }
10404                 }
10405         }
10406
10407 end_error:
10408         rem_anchor_token('}');
10409         assert(current_scope == &statement->compound.scope);
10410         scope_pop();
10411         environment_pop_to(top);
10412
10413         POP_PARENT;
10414         return statement;
10415 }
10416
10417 /**
10418  * Check for unused global static functions and variables
10419  */
10420 static void check_unused_globals(void)
10421 {
10422         if (!warning.unused_function && !warning.unused_variable)
10423                 return;
10424
10425         for (const entity_t *entity = file_scope->entities; entity != NULL;
10426              entity = entity->base.next) {
10427                 if (!is_declaration(entity))
10428                         continue;
10429
10430                 const declaration_t *declaration = &entity->declaration;
10431                 if (declaration->used                  ||
10432                     declaration->modifiers & DM_UNUSED ||
10433                     declaration->modifiers & DM_USED   ||
10434                     declaration->storage_class != STORAGE_CLASS_STATIC)
10435                         continue;
10436
10437                 type_t *const type = declaration->type;
10438                 const char *s;
10439                 if (entity->kind == ENTITY_FUNCTION) {
10440                         /* inhibit warning for static inline functions */
10441                         if (entity->function.is_inline)
10442                                 continue;
10443
10444                         s = entity->function.statement != NULL ? "defined" : "declared";
10445                 } else {
10446                         s = "defined";
10447                 }
10448
10449                 warningf(&declaration->base.source_position, "'%#T' %s but not used",
10450                         type, declaration->base.symbol, s);
10451         }
10452 }
10453
10454 static void parse_global_asm(void)
10455 {
10456         statement_t *statement = allocate_statement_zero(STATEMENT_ASM);
10457
10458         eat(T_asm);
10459         expect('(');
10460
10461         statement->asms.asm_text = parse_string_literals();
10462         statement->base.next     = unit->global_asm;
10463         unit->global_asm         = statement;
10464
10465         expect(')');
10466         expect(';');
10467
10468 end_error:;
10469 }
10470
10471 static void parse_linkage_specification(void)
10472 {
10473         eat(T_extern);
10474         assert(token.type == T_STRING_LITERAL);
10475
10476         const char *linkage = parse_string_literals().begin;
10477
10478         linkage_kind_t old_linkage = current_linkage;
10479         linkage_kind_t new_linkage;
10480         if (strcmp(linkage, "C") == 0) {
10481                 new_linkage = LINKAGE_C;
10482         } else if (strcmp(linkage, "C++") == 0) {
10483                 new_linkage = LINKAGE_CXX;
10484         } else {
10485                 errorf(HERE, "linkage string \"%s\" not recognized", linkage);
10486                 new_linkage = LINKAGE_INVALID;
10487         }
10488         current_linkage = new_linkage;
10489
10490         if (token.type == '{') {
10491                 next_token();
10492                 parse_externals();
10493                 expect('}');
10494         } else {
10495                 parse_external();
10496         }
10497
10498 end_error:
10499         assert(current_linkage == new_linkage);
10500         current_linkage = old_linkage;
10501 }
10502
10503 static void parse_external(void)
10504 {
10505         switch (token.type) {
10506                 DECLARATION_START_NO_EXTERN
10507                 case T_IDENTIFIER:
10508                 case T___extension__:
10509                 case '(': /* for function declarations with implicit return type and
10510                                    * parenthesized declarator, i.e. (f)(void); */
10511                         parse_external_declaration();
10512                         return;
10513
10514                 case T_extern:
10515                         if (look_ahead(1)->type == T_STRING_LITERAL) {
10516                                 parse_linkage_specification();
10517                         } else {
10518                                 parse_external_declaration();
10519                         }
10520                         return;
10521
10522                 case T_asm:
10523                         parse_global_asm();
10524                         return;
10525
10526                 case T_namespace:
10527                         parse_namespace_definition();
10528                         return;
10529
10530                 case ';':
10531                         if (!strict_mode) {
10532                                 if (warning.other)
10533                                         warningf(HERE, "stray ';' outside of function");
10534                                 next_token();
10535                                 return;
10536                         }
10537                         /* FALLTHROUGH */
10538
10539                 default:
10540                         errorf(HERE, "stray %K outside of function", &token);
10541                         if (token.type == '(' || token.type == '{' || token.type == '[')
10542                                 eat_until_matching_token(token.type);
10543                         next_token();
10544                         return;
10545         }
10546 }
10547
10548 static void parse_externals(void)
10549 {
10550         add_anchor_token('}');
10551         add_anchor_token(T_EOF);
10552
10553 #ifndef NDEBUG
10554         unsigned char token_anchor_copy[T_LAST_TOKEN];
10555         memcpy(token_anchor_copy, token_anchor_set, sizeof(token_anchor_copy));
10556 #endif
10557
10558         while (token.type != T_EOF && token.type != '}') {
10559 #ifndef NDEBUG
10560                 bool anchor_leak = false;
10561                 for (int i = 0; i != T_LAST_TOKEN; ++i) {
10562                         unsigned char count = token_anchor_set[i] - token_anchor_copy[i];
10563                         if (count != 0) {
10564                                 errorf(HERE, "Leaked anchor token %k %d times", i, count);
10565                                 anchor_leak = true;
10566                         }
10567                 }
10568                 if (in_gcc_extension) {
10569                         errorf(HERE, "Leaked __extension__");
10570                         anchor_leak = true;
10571                 }
10572
10573                 if (anchor_leak)
10574                         abort();
10575 #endif
10576
10577                 parse_external();
10578         }
10579
10580         rem_anchor_token(T_EOF);
10581         rem_anchor_token('}');
10582 }
10583
10584 /**
10585  * Parse a translation unit.
10586  */
10587 static void parse_translation_unit(void)
10588 {
10589         add_anchor_token(T_EOF);
10590
10591         while (true) {
10592                 parse_externals();
10593
10594                 if (token.type == T_EOF)
10595                         break;
10596
10597                 errorf(HERE, "stray %K outside of function", &token);
10598                 if (token.type == '(' || token.type == '{' || token.type == '[')
10599                         eat_until_matching_token(token.type);
10600                 next_token();
10601         }
10602 }
10603
10604 /**
10605  * Parse the input.
10606  *
10607  * @return  the translation unit or NULL if errors occurred.
10608  */
10609 void start_parsing(void)
10610 {
10611         environment_stack = NEW_ARR_F(stack_entry_t, 0);
10612         label_stack       = NEW_ARR_F(stack_entry_t, 0);
10613         diagnostic_count  = 0;
10614         error_count       = 0;
10615         warning_count     = 0;
10616
10617         type_set_output(stderr);
10618         ast_set_output(stderr);
10619
10620         assert(unit == NULL);
10621         unit = allocate_ast_zero(sizeof(unit[0]));
10622
10623         assert(file_scope == NULL);
10624         file_scope = &unit->scope;
10625
10626         assert(current_scope == NULL);
10627         scope_push(&unit->scope);
10628 }
10629
10630 translation_unit_t *finish_parsing(void)
10631 {
10632         /* do NOT use scope_pop() here, this will crash, will it by hand */
10633         assert(current_scope == &unit->scope);
10634         current_scope = NULL;
10635
10636         assert(file_scope == &unit->scope);
10637         check_unused_globals();
10638         file_scope = NULL;
10639
10640         DEL_ARR_F(environment_stack);
10641         DEL_ARR_F(label_stack);
10642
10643         translation_unit_t *result = unit;
10644         unit = NULL;
10645         return result;
10646 }
10647
10648 void parse(void)
10649 {
10650         lookahead_bufpos = 0;
10651         for (int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
10652                 next_token();
10653         }
10654         current_linkage = c_mode & _CXX ? LINKAGE_CXX : LINKAGE_C;
10655         parse_translation_unit();
10656 }
10657
10658 /**
10659  * Initialize the parser.
10660  */
10661 void init_parser(void)
10662 {
10663         sym_anonymous = symbol_table_insert("<anonymous>");
10664
10665         if (c_mode & _MS) {
10666                 /* add predefined symbols for extended-decl-modifier */
10667                 sym_align      = symbol_table_insert("align");
10668                 sym_allocate   = symbol_table_insert("allocate");
10669                 sym_dllimport  = symbol_table_insert("dllimport");
10670                 sym_dllexport  = symbol_table_insert("dllexport");
10671                 sym_naked      = symbol_table_insert("naked");
10672                 sym_noinline   = symbol_table_insert("noinline");
10673                 sym_noreturn   = symbol_table_insert("noreturn");
10674                 sym_nothrow    = symbol_table_insert("nothrow");
10675                 sym_novtable   = symbol_table_insert("novtable");
10676                 sym_property   = symbol_table_insert("property");
10677                 sym_get        = symbol_table_insert("get");
10678                 sym_put        = symbol_table_insert("put");
10679                 sym_selectany  = symbol_table_insert("selectany");
10680                 sym_thread     = symbol_table_insert("thread");
10681                 sym_uuid       = symbol_table_insert("uuid");
10682                 sym_deprecated = symbol_table_insert("deprecated");
10683                 sym_restrict   = symbol_table_insert("restrict");
10684                 sym_noalias    = symbol_table_insert("noalias");
10685         }
10686         memset(token_anchor_set, 0, sizeof(token_anchor_set));
10687
10688         init_expression_parsers();
10689         obstack_init(&temp_obst);
10690
10691         symbol_t *const va_list_sym = symbol_table_insert("__builtin_va_list");
10692         type_valist = create_builtin_type(va_list_sym, type_void_ptr);
10693 }
10694
10695 /**
10696  * Terminate the parser.
10697  */
10698 void exit_parser(void)
10699 {
10700         obstack_free(&temp_obst, NULL);
10701 }