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               thread_local : 1;  /**< GCC __thread */
  81         bool               deprecated   : 1;
  82         decl_modifiers_t   modifiers;         /**< declaration modifiers */
  83         gnu_attribute_t   *gnu_attributes;    /**< list of GNU attributes */
  84         const char        *deprecated_string; /**< can be set if declaration was marked deprecated. */
  85         symbol_t          *get_property_sym;  /**< the name of the get property if set. */
  86         symbol_t          *put_property_sym;  /**< the name of the put property if set. */
  87         type_t            *type;
  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 /**
 102  * Capture a MS __base extension.
 103  */
 104 typedef struct based_spec_t {
 105         source_position_t  source_position;
 106         variable_t        *base_variable;
 107 } based_spec_t;
 108
 109 typedef entity_t* (*parsed_declaration_func) (entity_t *declaration, bool is_definition);
 110
 111 /** The current token. */
 112 static token_t              token;
 113 /** The lookahead ring-buffer. */
 114 static token_t              lookahead_buffer[MAX_LOOKAHEAD];
 115 /** Position of the next token in the lookahead buffer. */
 116 static int                  lookahead_bufpos;
 117 static stack_entry_t       *environment_stack = NULL;
 118 static stack_entry_t       *label_stack       = NULL;
 119 static scope_t             *file_scope        = NULL;
 120 static scope_t             *current_scope     = NULL;
 121 /** Point to the current function declaration if inside a function. */
 122 static function_t          *current_function  = NULL;
 123 static entity_t            *current_init_decl = NULL;
 124 static switch_statement_t  *current_switch    = NULL;
 125 static statement_t         *current_loop      = NULL;
 126 static statement_t         *current_parent    = NULL;
 127 static ms_try_statement_t  *current_try       = NULL;
 128 static linkage_kind_t       current_linkage   = LINKAGE_INVALID;
 129 static goto_statement_t    *goto_first        = NULL;
 130 static goto_statement_t   **goto_anchor       = NULL;
 131 static label_statement_t   *label_first       = NULL;
 132 static label_statement_t  **label_anchor      = NULL;
 133 /** current translation unit. */
 134 static translation_unit_t  *unit              = NULL;
 135 /** true if we are in a type property context (evaluation only for type. */
 136 static bool                 in_type_prop      = false;
 137 /** true in we are in a __extension__ context. */
 138 static bool                 in_gcc_extension  = false;
 139 static struct obstack       temp_obst;
 140 static entity_t            *anonymous_entity;
 141 static declaration_t      **incomplete_arrays;
 142
 143
 144 #define PUSH_PARENT(stmt)                          \
 145         statement_t *const prev_parent = current_parent; \
 146         ((void)(current_parent = (stmt)))
 147 #define POP_PARENT ((void)(current_parent = prev_parent))
 148
 149 /** special symbol used for anonymous entities. */
 150 static const symbol_t *sym_anonymous = NULL;
 151
 152 /* symbols for Microsoft extended-decl-modifier */
 153 static const symbol_t *sym_align         = NULL;
 154 static const symbol_t *sym_allocate      = NULL;
 155 static const symbol_t *sym_dllimport     = NULL;
 156 static const symbol_t *sym_dllexport     = NULL;
 157 static const symbol_t *sym_naked         = NULL;
 158 static const symbol_t *sym_noinline      = NULL;
 159 static const symbol_t *sym_returns_twice = NULL;
 160 static const symbol_t *sym_noreturn      = NULL;
 161 static const symbol_t *sym_nothrow       = NULL;
 162 static const symbol_t *sym_novtable      = NULL;
 163 static const symbol_t *sym_property      = NULL;
 164 static const symbol_t *sym_get           = NULL;
 165 static const symbol_t *sym_put           = NULL;
 166 static const symbol_t *sym_selectany     = NULL;
 167 static const symbol_t *sym_thread        = NULL;
 168 static const symbol_t *sym_uuid          = NULL;
 169 static const symbol_t *sym_deprecated    = NULL;
 170 static const symbol_t *sym_restrict      = NULL;
 171 static const symbol_t *sym_noalias       = NULL;
 172
 173 /** The token anchor set */
 174 static unsigned char token_anchor_set[T_LAST_TOKEN];
 175
 176 /** The current source position. */
 177 #define HERE (&token.source_position)
 178
 179 /** true if we are in GCC mode. */
 180 #define GNU_MODE ((c_mode & _GNUC) || in_gcc_extension)
 181
 182 static type_t *type_valist;
 183
 184 static statement_t *parse_compound_statement(bool inside_expression_statement);
 185 static statement_t *parse_statement(void);
 186
 187 static expression_t *parse_sub_expression(precedence_t);
 188 static expression_t *parse_expression(void);
 189 static type_t       *parse_typename(void);
 190 static void          parse_externals(void);
 191 static void          parse_external(void);
 192
 193 static void parse_compound_type_entries(compound_t *compound_declaration);
 194
 195 typedef enum declarator_flags_t {
 196         DECL_FLAGS_NONE             = 0,
 197         DECL_MAY_BE_ABSTRACT        = 1U << 0,
 198         DECL_CREATE_COMPOUND_MEMBER = 1U << 1,
 199         DECL_IS_PARAMETER           = 1U << 2
 200 } declarator_flags_t;
 201
 202 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
 203                                   declarator_flags_t flags);
 204
 205 static entity_t *record_entity(entity_t *entity, bool is_definition);
 206
 207 static void semantic_comparison(binary_expression_t *expression);
 208
 209 #define STORAGE_CLASSES       \
 210         STORAGE_CLASSES_NO_EXTERN \
 211         case T_extern:
 212
 213 #define STORAGE_CLASSES_NO_EXTERN \
 214         case T_typedef:         \
 215         case T_static:          \
 216         case T_auto:            \
 217         case T_register:        \
 218         case T___thread:
 219
 220 #define TYPE_QUALIFIERS     \
 221         case T_const:           \
 222         case T_restrict:        \
 223         case T_volatile:        \
 224         case T_inline:          \
 225         case T__forceinline:    \
 226         case T___attribute__:
 227
 228 #define COMPLEX_SPECIFIERS  \
 229         case T__Complex:
 230 #define IMAGINARY_SPECIFIERS \
 231         case T__Imaginary:
 232
 233 #define TYPE_SPECIFIERS       \
 234         case T__Bool:             \
 235         case T___builtin_va_list: \
 236         case T___typeof__:        \
 237         case T__declspec:         \
 238         case T_bool:              \
 239         case T_char:              \
 240         case T_double:            \
 241         case T_enum:              \
 242         case T_float:             \
 243         case T_int:               \
 244         case T_long:              \
 245         case T_short:             \
 246         case T_signed:            \
 247         case T_struct:            \
 248         case T_union:             \
 249         case T_unsigned:          \
 250         case T_void:              \
 251         case T_wchar_t:           \
 252         COMPLEX_SPECIFIERS        \
 253         IMAGINARY_SPECIFIERS
 254
 255 #define DECLARATION_START   \
 256         STORAGE_CLASSES         \
 257         TYPE_QUALIFIERS         \
 258         TYPE_SPECIFIERS
 259
 260 #define DECLARATION_START_NO_EXTERN \
 261         STORAGE_CLASSES_NO_EXTERN       \
 262         TYPE_QUALIFIERS                 \
 263         TYPE_SPECIFIERS
 264
 265 #define TYPENAME_START      \
 266         TYPE_QUALIFIERS         \
 267         TYPE_SPECIFIERS
 268
 269 #define EXPRESSION_START           \
 270         case '!':                        \
 271         case '&':                        \
 272         case '(':                        \
 273         case '*':                        \
 274         case '+':                        \
 275         case '-':                        \
 276         case '~':                        \
 277         case T_ANDAND:                   \
 278         case T_CHARACTER_CONSTANT:       \
 279         case T_FLOATINGPOINT:            \
 280         case T_INTEGER:                  \
 281         case T_MINUSMINUS:               \
 282         case T_PLUSPLUS:                 \
 283         case T_STRING_LITERAL:           \
 284         case T_WIDE_CHARACTER_CONSTANT:  \
 285         case T_WIDE_STRING_LITERAL:      \
 286         case T___FUNCDNAME__:            \
 287         case T___FUNCSIG__:              \
 288         case T___FUNCTION__:             \
 289         case T___PRETTY_FUNCTION__:      \
 290         case T___alignof__:              \
 291         case T___builtin_alloca:         \
 292         case T___builtin_classify_type:  \
 293         case T___builtin_constant_p:     \
 294         case T___builtin_expect:         \
 295         case T___builtin_huge_val:       \
 296         case T___builtin_inf:            \
 297         case T___builtin_inff:           \
 298         case T___builtin_infl:           \
 299         case T___builtin_isgreater:      \
 300         case T___builtin_isgreaterequal: \
 301         case T___builtin_isless:         \
 302         case T___builtin_islessequal:    \
 303         case T___builtin_islessgreater:  \
 304         case T___builtin_isunordered:    \
 305         case T___builtin_nan:            \
 306         case T___builtin_nanf:           \
 307         case T___builtin_nanl:           \
 308         case T___builtin_offsetof:       \
 309         case T___builtin_prefetch:       \
 310         case T___builtin_va_arg:         \
 311         case T___builtin_va_end:         \
 312         case T___builtin_va_start:       \
 313         case T___func__:                 \
 314         case T___noop:                   \
 315         case T__assume:                  \
 316         case T_delete:                   \
 317         case T_false:                    \
 318         case T_sizeof:                   \
 319         case T_throw:                    \
 320         case T_true:
 321
 322 /**
 323  * Allocate an AST node with given size and
 324  * initialize all fields with zero.
 325  */
 326 static void *allocate_ast_zero(size_t size)
 327 {
 328         void *res = allocate_ast(size);
 329         memset(res, 0, size);
 330         return res;
 331 }
 332
 333 /**
 334  * Returns the size of an entity node.
 335  *
 336  * @param kind  the entity kind
 337  */
 338 static size_t get_entity_struct_size(entity_kind_t kind)
 339 {
 340         static const size_t sizes[] = {
 341                 [ENTITY_VARIABLE]        = sizeof(variable_t),
 342                 [ENTITY_PARAMETER]       = sizeof(parameter_t),
 343                 [ENTITY_COMPOUND_MEMBER] = sizeof(compound_member_t),
 344                 [ENTITY_FUNCTION]        = sizeof(function_t),
 345                 [ENTITY_TYPEDEF]         = sizeof(typedef_t),
 346                 [ENTITY_STRUCT]          = sizeof(compound_t),
 347                 [ENTITY_UNION]           = sizeof(compound_t),
 348                 [ENTITY_ENUM]            = sizeof(enum_t),
 349                 [ENTITY_ENUM_VALUE]      = sizeof(enum_value_t),
 350                 [ENTITY_LABEL]           = sizeof(label_t),
 351                 [ENTITY_LOCAL_LABEL]     = sizeof(label_t),
 352                 [ENTITY_NAMESPACE]       = sizeof(namespace_t)
 353         };
 354         assert(kind < sizeof(sizes) / sizeof(sizes[0]));
 355         assert(sizes[kind] != 0);
 356         return sizes[kind];
 357 }
 358
 359 /**
 360  * Allocate an entity of given kind and initialize all
 361  * fields with zero.
 362  */
 363 static entity_t *allocate_entity_zero(entity_kind_t kind)
 364 {
 365         size_t    size   = get_entity_struct_size(kind);
 366         entity_t *entity = allocate_ast_zero(size);
 367         entity->kind     = kind;
 368         return entity;
 369 }
 370
 371 /**
 372  * Returns the size of a statement node.
 373  *
 374  * @param kind  the statement kind
 375  */
 376 static size_t get_statement_struct_size(statement_kind_t kind)
 377 {
 378         static const size_t sizes[] = {
 379                 [STATEMENT_INVALID]     = sizeof(invalid_statement_t),
 380                 [STATEMENT_EMPTY]       = sizeof(empty_statement_t),
 381                 [STATEMENT_COMPOUND]    = sizeof(compound_statement_t),
 382                 [STATEMENT_RETURN]      = sizeof(return_statement_t),
 383                 [STATEMENT_DECLARATION] = sizeof(declaration_statement_t),
 384                 [STATEMENT_LOCAL_LABEL] = sizeof(local_label_statement_t),
 385                 [STATEMENT_IF]          = sizeof(if_statement_t),
 386                 [STATEMENT_SWITCH]      = sizeof(switch_statement_t),
 387                 [STATEMENT_EXPRESSION]  = sizeof(expression_statement_t),
 388                 [STATEMENT_CONTINUE]    = sizeof(statement_base_t),
 389                 [STATEMENT_BREAK]       = sizeof(statement_base_t),
 390                 [STATEMENT_GOTO]        = sizeof(goto_statement_t),
 391                 [STATEMENT_LABEL]       = sizeof(label_statement_t),
 392                 [STATEMENT_CASE_LABEL]  = sizeof(case_label_statement_t),
 393                 [STATEMENT_WHILE]       = sizeof(while_statement_t),
 394                 [STATEMENT_DO_WHILE]    = sizeof(do_while_statement_t),
 395                 [STATEMENT_FOR]         = sizeof(for_statement_t),
 396                 [STATEMENT_ASM]         = sizeof(asm_statement_t),
 397                 [STATEMENT_MS_TRY]      = sizeof(ms_try_statement_t),
 398                 [STATEMENT_LEAVE]       = sizeof(leave_statement_t)
 399         };
 400         assert(kind < sizeof(sizes) / sizeof(sizes[0]));
 401         assert(sizes[kind] != 0);
 402         return sizes[kind];
 403 }
 404
 405 /**
 406  * Returns the size of an expression node.
 407  *
 408  * @param kind  the expression kind
 409  */
 410 static size_t get_expression_struct_size(expression_kind_t kind)
 411 {
 412         static const size_t sizes[] = {
 413                 [EXPR_INVALID]                 = sizeof(expression_base_t),
 414                 [EXPR_REFERENCE]               = sizeof(reference_expression_t),
 415                 [EXPR_REFERENCE_ENUM_VALUE]    = sizeof(reference_expression_t),
 416                 [EXPR_CONST]                   = sizeof(const_expression_t),
 417                 [EXPR_CHARACTER_CONSTANT]      = sizeof(const_expression_t),
 418                 [EXPR_WIDE_CHARACTER_CONSTANT] = sizeof(const_expression_t),
 419                 [EXPR_STRING_LITERAL]          = sizeof(string_literal_expression_t),
 420                 [EXPR_WIDE_STRING_LITERAL]     = sizeof(wide_string_literal_expression_t),
 421                 [EXPR_COMPOUND_LITERAL]        = sizeof(compound_literal_expression_t),
 422                 [EXPR_CALL]                    = sizeof(call_expression_t),
 423                 [EXPR_UNARY_FIRST]             = sizeof(unary_expression_t),
 424                 [EXPR_BINARY_FIRST]            = sizeof(binary_expression_t),
 425                 [EXPR_CONDITIONAL]             = sizeof(conditional_expression_t),
 426                 [EXPR_SELECT]                  = sizeof(select_expression_t),
 427                 [EXPR_ARRAY_ACCESS]            = sizeof(array_access_expression_t),
 428                 [EXPR_SIZEOF]                  = sizeof(typeprop_expression_t),
 429                 [EXPR_ALIGNOF]                 = sizeof(typeprop_expression_t),
 430                 [EXPR_CLASSIFY_TYPE]           = sizeof(classify_type_expression_t),
 431                 [EXPR_FUNCNAME]                = sizeof(funcname_expression_t),
 432                 [EXPR_BUILTIN_SYMBOL]          = sizeof(builtin_symbol_expression_t),
 433                 [EXPR_BUILTIN_CONSTANT_P]      = sizeof(builtin_constant_expression_t),
 434                 [EXPR_BUILTIN_PREFETCH]        = sizeof(builtin_prefetch_expression_t),
 435                 [EXPR_OFFSETOF]                = sizeof(offsetof_expression_t),
 436                 [EXPR_VA_START]                = sizeof(va_start_expression_t),
 437                 [EXPR_VA_ARG]                  = sizeof(va_arg_expression_t),
 438                 [EXPR_STATEMENT]               = sizeof(statement_expression_t),
 439                 [EXPR_LABEL_ADDRESS]           = sizeof(label_address_expression_t),
 440         };
 441         if (kind >= EXPR_UNARY_FIRST && kind <= EXPR_UNARY_LAST) {
 442                 return sizes[EXPR_UNARY_FIRST];
 443         }
 444         if (kind >= EXPR_BINARY_FIRST && kind <= EXPR_BINARY_LAST) {
 445                 return sizes[EXPR_BINARY_FIRST];
 446         }
 447         assert(kind < sizeof(sizes) / sizeof(sizes[0]));
 448         assert(sizes[kind] != 0);
 449         return sizes[kind];
 450 }
 451
 452 /**
 453  * Allocate a statement node of given kind and initialize all
 454  * fields with zero. Sets its source position to the position
 455  * of the current token.
 456  */
 457 static statement_t *allocate_statement_zero(statement_kind_t kind)
 458 {
 459         size_t       size = get_statement_struct_size(kind);
 460         statement_t *res  = allocate_ast_zero(size);
 461
 462         res->base.kind            = kind;
 463         res->base.parent          = current_parent;
 464         res->base.source_position = token.source_position;
 465         return res;
 466 }
 467
 468 /**
 469  * Allocate an expression node of given kind and initialize all
 470  * fields with zero.
 471  */
 472 static expression_t *allocate_expression_zero(expression_kind_t kind)
 473 {
 474         size_t        size = get_expression_struct_size(kind);
 475         expression_t *res  = allocate_ast_zero(size);
 476
 477         res->base.kind            = kind;
 478         res->base.type            = type_error_type;
 479         res->base.source_position = token.source_position;
 480         return res;
 481 }
 482
 483 /**
 484  * Creates a new invalid expression at the source position
 485  * of the current token.
 486  */
 487 static expression_t *create_invalid_expression(void)
 488 {
 489         return allocate_expression_zero(EXPR_INVALID);
 490 }
 491
 492 /**
 493  * Creates a new invalid statement.
 494  */
 495 static statement_t *create_invalid_statement(void)
 496 {
 497         return allocate_statement_zero(STATEMENT_INVALID);
 498 }
 499
 500 /**
 501  * Allocate a new empty statement.
 502  */
 503 static statement_t *create_empty_statement(void)
 504 {
 505         return allocate_statement_zero(STATEMENT_EMPTY);
 506 }
 507
 508 /**
 509  * Returns the size of a type node.
 510  *
 511  * @param kind  the type kind
 512  */
 513 static size_t get_type_struct_size(type_kind_t kind)
 514 {
 515         static const size_t sizes[] = {
 516                 [TYPE_ATOMIC]          = sizeof(atomic_type_t),
 517                 [TYPE_COMPLEX]         = sizeof(complex_type_t),
 518                 [TYPE_IMAGINARY]       = sizeof(imaginary_type_t),
 519                 [TYPE_BITFIELD]        = sizeof(bitfield_type_t),
 520                 [TYPE_COMPOUND_STRUCT] = sizeof(compound_type_t),
 521                 [TYPE_COMPOUND_UNION]  = sizeof(compound_type_t),
 522                 [TYPE_ENUM]            = sizeof(enum_type_t),
 523                 [TYPE_FUNCTION]        = sizeof(function_type_t),
 524                 [TYPE_POINTER]         = sizeof(pointer_type_t),
 525                 [TYPE_ARRAY]           = sizeof(array_type_t),
 526                 [TYPE_BUILTIN]         = sizeof(builtin_type_t),
 527                 [TYPE_TYPEDEF]         = sizeof(typedef_type_t),
 528                 [TYPE_TYPEOF]          = sizeof(typeof_type_t),
 529         };
 530         assert(sizeof(sizes) / sizeof(sizes[0]) == (int) TYPE_TYPEOF + 1);
 531         assert(kind <= TYPE_TYPEOF);
 532         assert(sizes[kind] != 0);
 533         return sizes[kind];
 534 }
 535
 536 /**
 537  * Allocate a type node of given kind and initialize all
 538  * fields with zero.
 539  *
 540  * @param kind             type kind to allocate
 541  */
 542 static type_t *allocate_type_zero(type_kind_t kind)
 543 {
 544         size_t  size = get_type_struct_size(kind);
 545         type_t *res  = obstack_alloc(type_obst, size);
 546         memset(res, 0, size);
 547         res->base.kind = kind;
 548
 549         return res;
 550 }
 551
 552 /**
 553  * Returns the size of an initializer node.
 554  *
 555  * @param kind  the initializer kind
 556  */
 557 static size_t get_initializer_size(initializer_kind_t kind)
 558 {
 559         static const size_t sizes[] = {
 560                 [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
 561                 [INITIALIZER_STRING]      = sizeof(initializer_string_t),
 562                 [INITIALIZER_WIDE_STRING] = sizeof(initializer_wide_string_t),
 563                 [INITIALIZER_LIST]        = sizeof(initializer_list_t),
 564                 [INITIALIZER_DESIGNATOR]  = sizeof(initializer_designator_t)
 565         };
 566         assert(kind < sizeof(sizes) / sizeof(*sizes));
 567         assert(sizes[kind] != 0);
 568         return sizes[kind];
 569 }
 570
 571 /**
 572  * Allocate an initializer node of given kind and initialize all
 573  * fields with zero.
 574  */
 575 static initializer_t *allocate_initializer_zero(initializer_kind_t kind)
 576 {
 577         initializer_t *result = allocate_ast_zero(get_initializer_size(kind));
 578         result->kind          = kind;
 579
 580         return result;
 581 }
 582
 583 /**
 584  * Free a type from the type obstack.
 585  */
 586 static void free_type(void *type)
 587 {
 588         obstack_free(type_obst, type);
 589 }
 590
 591 /**
 592  * Returns the index of the top element of the environment stack.
 593  */
 594 static size_t environment_top(void)
 595 {
 596         return ARR_LEN(environment_stack);
 597 }
 598
 599 /**
 600  * Returns the index of the top element of the global label stack.
 601  */
 602 static size_t label_top(void)
 603 {
 604         return ARR_LEN(label_stack);
 605 }
 606
 607 /**
 608  * Return the next token.
 609  */
 610 static inline void next_token(void)
 611 {
 612         token                              = lookahead_buffer[lookahead_bufpos];
 613         lookahead_buffer[lookahead_bufpos] = lexer_token;
 614         lexer_next_token();
 615
 616         lookahead_bufpos = (lookahead_bufpos+1) % MAX_LOOKAHEAD;
 617
 618 #ifdef PRINT_TOKENS
 619         print_token(stderr, &token);
 620         fprintf(stderr, "\n");
 621 #endif
 622 }
 623
 624 /**
 625  * Return the next token with a given lookahead.
 626  */
 627 static inline const token_t *look_ahead(int num)
 628 {
 629         assert(num > 0 && num <= MAX_LOOKAHEAD);
 630         int pos = (lookahead_bufpos+num-1) % MAX_LOOKAHEAD;
 631         return &lookahead_buffer[pos];
 632 }
 633
 634 /**
 635  * Adds a token type to the token type anchor set (a multi-set).
 636  */
 637 static void add_anchor_token(int token_type)
 638 {
 639         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 640         ++token_anchor_set[token_type];
 641 }
 642
 643 /**
 644  * Set the number of tokens types of the given type
 645  * to zero and return the old count.
 646  */
 647 static int save_and_reset_anchor_state(int token_type)
 648 {
 649         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 650         int count = token_anchor_set[token_type];
 651         token_anchor_set[token_type] = 0;
 652         return count;
 653 }
 654
 655 /**
 656  * Restore the number of token types to the given count.
 657  */
 658 static void restore_anchor_state(int token_type, int count)
 659 {
 660         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 661         token_anchor_set[token_type] = count;
 662 }
 663
 664 /**
 665  * Remove a token type from the token type anchor set (a multi-set).
 666  */
 667 static void rem_anchor_token(int token_type)
 668 {
 669         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 670         assert(token_anchor_set[token_type] != 0);
 671         --token_anchor_set[token_type];
 672 }
 673
 674 /**
 675  * Return true if the token type of the current token is
 676  * in the anchor set.
 677  */
 678 static bool at_anchor(void)
 679 {
 680         if (token.type < 0)
 681                 return false;
 682         return token_anchor_set[token.type];
 683 }
 684
 685 /**
 686  * Eat tokens until a matching token type is found.
 687  */
 688 static void eat_until_matching_token(int type)
 689 {
 690         int end_token;
 691         switch (type) {
 692                 case '(': end_token = ')';  break;
 693                 case '{': end_token = '}';  break;
 694                 case '[': end_token = ']';  break;
 695                 default:  end_token = type; break;
 696         }
 697
 698         unsigned parenthesis_count = 0;
 699         unsigned brace_count       = 0;
 700         unsigned bracket_count     = 0;
 701         while (token.type        != end_token ||
 702                parenthesis_count != 0         ||
 703                brace_count       != 0         ||
 704                bracket_count     != 0) {
 705                 switch (token.type) {
 706                 case T_EOF: return;
 707                 case '(': ++parenthesis_count; break;
 708                 case '{': ++brace_count;       break;
 709                 case '[': ++bracket_count;     break;
 710
 711                 case ')':
 712                         if (parenthesis_count > 0)
 713                                 --parenthesis_count;
 714                         goto check_stop;
 715
 716                 case '}':
 717                         if (brace_count > 0)
 718                                 --brace_count;
 719                         goto check_stop;
 720
 721                 case ']':
 722                         if (bracket_count > 0)
 723                                 --bracket_count;
 724 check_stop:
 725                         if (token.type        == end_token &&
 726                             parenthesis_count == 0         &&
 727                             brace_count       == 0         &&
 728                             bracket_count     == 0)
 729                                 return;
 730                         break;
 731
 732                 default:
 733                         break;
 734                 }
 735                 next_token();
 736         }
 737 }
 738
 739 /**
 740  * Eat input tokens until an anchor is found.
 741  */
 742 static void eat_until_anchor(void)
 743 {
 744         while (token_anchor_set[token.type] == 0) {
 745                 if (token.type == '(' || token.type == '{' || token.type == '[')
 746                         eat_until_matching_token(token.type);
 747                 next_token();
 748         }
 749 }
 750
 751 /**
 752  * Eat a whole block from input tokens.
 753  */
 754 static void eat_block(void)
 755 {
 756         eat_until_matching_token('{');
 757         if (token.type == '}')
 758                 next_token();
 759 }
 760
 761 #define eat(token_type)  do { assert(token.type == (token_type)); next_token(); } while (0)
 762
 763 /**
 764  * Report a parse error because an expected token was not found.
 765  */
 766 static
 767 #if defined __GNUC__ && __GNUC__ >= 4
 768 __attribute__((sentinel))
 769 #endif
 770 void parse_error_expected(const char *message, ...)
 771 {
 772         if (message != NULL) {
 773                 errorf(HERE, "%s", message);
 774         }
 775         va_list ap;
 776         va_start(ap, message);
 777         errorf(HERE, "got %K, expected %#k", &token, &ap, ", ");
 778         va_end(ap);
 779 }
 780
 781 /**
 782  * Report an incompatible type.
 783  */
 784 static void type_error_incompatible(const char *msg,
 785                 const source_position_t *source_position, type_t *type1, type_t *type2)
 786 {
 787         errorf(source_position, "%s, incompatible types: '%T' - '%T'",
 788                msg, type1, type2);
 789 }
 790
 791 /**
 792  * Expect the current token is the expected token.
 793  * If not, generate an error, eat the current statement,
 794  * and goto the end_error label.
 795  */
 796 #define expect(expected, error_label)                     \
 797         do {                                                  \
 798                 if (UNLIKELY(token.type != (expected))) {         \
 799                         parse_error_expected(NULL, (expected), NULL); \
 800                         add_anchor_token(expected);                   \
 801                         eat_until_anchor();                           \
 802                         if (token.type == expected)                   \
 803                                 next_token();                             \
 804                         rem_anchor_token(expected);                   \
 805                         goto error_label;                             \
 806                 }                                                 \
 807                 next_token();                                     \
 808         } while (0)
 809
 810 /**
 811  * Push a given scope on the scope stack and make it the
 812  * current scope
 813  */
 814 static scope_t *scope_push(scope_t *new_scope)
 815 {
 816         if (current_scope != NULL) {
 817                 new_scope->depth = current_scope->depth + 1;
 818         }
 819
 820         scope_t *old_scope = current_scope;
 821         current_scope      = new_scope;
 822         return old_scope;
 823 }
 824
 825 /**
 826  * Pop the current scope from the scope stack.
 827  */
 828 static void scope_pop(scope_t *old_scope)
 829 {
 830         current_scope = old_scope;
 831 }
 832
 833 /**
 834  * Search an entity by its symbol in a given namespace.
 835  */
 836 static entity_t *get_entity(const symbol_t *const symbol,
 837                             namespace_tag_t namespc)
 838 {
 839         entity_t *entity = symbol->entity;
 840         for (; entity != NULL; entity = entity->base.symbol_next) {
 841                 if (entity->base.namespc == namespc)
 842                         return entity;
 843         }
 844
 845         return NULL;
 846 }
 847
 848 /**
 849  * pushs an entity on the environment stack and links the corresponding symbol
 850  * it.
 851  */
 852 static void stack_push(stack_entry_t **stack_ptr, entity_t *entity)
 853 {
 854         symbol_t           *symbol  = entity->base.symbol;
 855         entity_namespace_t  namespc = entity->base.namespc;
 856         assert(namespc != NAMESPACE_INVALID);
 857
 858         /* replace/add entity into entity list of the symbol */
 859         entity_t **anchor;
 860         entity_t  *iter;
 861         for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 862                 iter = *anchor;
 863                 if (iter == NULL)
 864                         break;
 865
 866                 /* replace an entry? */
 867                 if (iter->base.namespc == namespc) {
 868                         entity->base.symbol_next = iter->base.symbol_next;
 869                         break;
 870                 }
 871         }
 872         *anchor = entity;
 873
 874         /* remember old declaration */
 875         stack_entry_t entry;
 876         entry.symbol     = symbol;
 877         entry.old_entity = iter;
 878         entry.namespc    = namespc;
 879         ARR_APP1(stack_entry_t, *stack_ptr, entry);
 880 }
 881
 882 /**
 883  * Push an entity on the environment stack.
 884  */
 885 static void environment_push(entity_t *entity)
 886 {
 887         assert(entity->base.source_position.input_name != NULL);
 888         assert(entity->base.parent_scope != NULL);
 889         stack_push(&environment_stack, entity);
 890 }
 891
 892 /**
 893  * Push a declaration on the global label stack.
 894  *
 895  * @param declaration  the declaration
 896  */
 897 static void label_push(entity_t *label)
 898 {
 899         /* we abuse the parameters scope as parent for the labels */
 900         label->base.parent_scope = &current_function->parameters;
 901         stack_push(&label_stack, label);
 902 }
 903
 904 /**
 905  * pops symbols from the environment stack until @p new_top is the top element
 906  */
 907 static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
 908 {
 909         stack_entry_t *stack = *stack_ptr;
 910         size_t         top   = ARR_LEN(stack);
 911         size_t         i;
 912
 913         assert(new_top <= top);
 914         if (new_top == top)
 915                 return;
 916
 917         for (i = top; i > new_top; --i) {
 918                 stack_entry_t *entry = &stack[i - 1];
 919
 920                 entity_t           *old_entity = entry->old_entity;
 921                 symbol_t           *symbol     = entry->symbol;
 922                 entity_namespace_t  namespc    = entry->namespc;
 923
 924                 /* replace with old_entity/remove */
 925                 entity_t **anchor;
 926                 entity_t  *iter;
 927                 for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 928                         iter = *anchor;
 929                         assert(iter != NULL);
 930                         /* replace an entry? */
 931                         if (iter->base.namespc == namespc)
 932                                 break;
 933                 }
 934
 935                 /* restore definition from outer scopes (if there was one) */
 936                 if (old_entity != NULL) {
 937                         old_entity->base.symbol_next = iter->base.symbol_next;
 938                         *anchor                      = old_entity;
 939                 } else {
 940                         /* remove entry from list */
 941                         *anchor = iter->base.symbol_next;
 942                 }
 943         }
 944
 945         ARR_SHRINKLEN(*stack_ptr, (int) new_top);
 946 }
 947
 948 /**
 949  * Pop all entries from the environment stack until the new_top
 950  * is reached.
 951  *
 952  * @param new_top  the new stack top
 953  */
 954 static void environment_pop_to(size_t new_top)
 955 {
 956         stack_pop_to(&environment_stack, new_top);
 957 }
 958
 959 /**
 960  * Pop all entries from the global label stack until the new_top
 961  * is reached.
 962  *
 963  * @param new_top  the new stack top
 964  */
 965 static void label_pop_to(size_t new_top)
 966 {
 967         stack_pop_to(&label_stack, new_top);
 968 }
 969
 970 static int get_akind_rank(atomic_type_kind_t akind)
 971 {
 972         return (int) akind;
 973 }
 974
 975 /**
 976  * Return the type rank for an atomic type.
 977  */
 978 static int get_rank(const type_t *type)
 979 {
 980         assert(!is_typeref(type));
 981         /* The C-standard allows promoting enums to int or unsigned int (see § 7.2.2
 982          * and esp. footnote 108). However we can't fold constants (yet), so we
 983          * can't decide whether unsigned int is possible, while int always works.
 984          * (unsigned int would be preferable when possible... for stuff like
 985          *  struct { enum { ... } bla : 4; } ) */
 986         if (type->kind == TYPE_ENUM)
 987                 return get_akind_rank(ATOMIC_TYPE_INT);
 988
 989         assert(type->kind == TYPE_ATOMIC);
 990         return get_akind_rank(type->atomic.akind);
 991 }
 992
 993 /**
 994  * Do integer promotion for a given type.
 995  *
 996  * @param type  the type to promote
 997  * @return the promoted type
 998  */
 999 static type_t *promote_integer(type_t *type)
1000 {
1001         if (type->kind == TYPE_BITFIELD)
1002                 type = type->bitfield.base_type;
1003
1004         if (get_rank(type) < get_akind_rank(ATOMIC_TYPE_INT))
1005                 type = type_int;
1006
1007         return type;
1008 }
1009
1010 /**
1011  * Create a cast expression.
1012  *
1013  * @param expression  the expression to cast
1014  * @param dest_type   the destination type
1015  */
1016 static expression_t *create_cast_expression(expression_t *expression,
1017                                             type_t *dest_type)
1018 {
1019         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST_IMPLICIT);
1020
1021         cast->unary.value = expression;
1022         cast->base.type   = dest_type;
1023
1024         return cast;
1025 }
1026
1027 /**
1028  * Check if a given expression represents a null pointer constant.
1029  *
1030  * @param expression  the expression to check
1031  */
1032 static bool is_null_pointer_constant(const expression_t *expression)
1033 {
1034         /* skip void* cast */
1035         if (expression->kind == EXPR_UNARY_CAST
1036                         || expression->kind == EXPR_UNARY_CAST_IMPLICIT) {
1037                 expression = expression->unary.value;
1038         }
1039
1040         /* TODO: not correct yet, should be any constant integer expression
1041          * which evaluates to 0 */
1042         if (expression->kind != EXPR_CONST)
1043                 return false;
1044
1045         type_t *const type = skip_typeref(expression->base.type);
1046         if (!is_type_integer(type))
1047                 return false;
1048
1049         return expression->conste.v.int_value == 0;
1050 }
1051
1052 /**
1053  * Create an implicit cast expression.
1054  *
1055  * @param expression  the expression to cast
1056  * @param dest_type   the destination type
1057  */
1058 static expression_t *create_implicit_cast(expression_t *expression,
1059                                           type_t *dest_type)
1060 {
1061         type_t *const source_type = expression->base.type;
1062
1063         if (source_type == dest_type)
1064                 return expression;
1065
1066         return create_cast_expression(expression, dest_type);
1067 }
1068
1069 typedef enum assign_error_t {
1070         ASSIGN_SUCCESS,
1071         ASSIGN_ERROR_INCOMPATIBLE,
1072         ASSIGN_ERROR_POINTER_QUALIFIER_MISSING,
1073         ASSIGN_WARNING_POINTER_INCOMPATIBLE,
1074         ASSIGN_WARNING_POINTER_FROM_INT,
1075         ASSIGN_WARNING_INT_FROM_POINTER
1076 } assign_error_t;
1077
1078 static void report_assign_error(assign_error_t error, type_t *orig_type_left,
1079                                 const expression_t *const right,
1080                                 const char *context,
1081                                 const source_position_t *source_position)
1082 {
1083         type_t *const orig_type_right = right->base.type;
1084         type_t *const type_left       = skip_typeref(orig_type_left);
1085         type_t *const type_right      = skip_typeref(orig_type_right);
1086
1087         switch (error) {
1088         case ASSIGN_SUCCESS:
1089                 return;
1090         case ASSIGN_ERROR_INCOMPATIBLE:
1091                 errorf(source_position,
1092                        "destination type '%T' in %s is incompatible with type '%T'",
1093                        orig_type_left, context, orig_type_right);
1094                 return;
1095
1096         case ASSIGN_ERROR_POINTER_QUALIFIER_MISSING: {
1097                 if (warning.other) {
1098                         type_t *points_to_left  = skip_typeref(type_left->pointer.points_to);
1099                         type_t *points_to_right = skip_typeref(type_right->pointer.points_to);
1100
1101                         /* the left type has all qualifiers from the right type */
1102                         unsigned missing_qualifiers
1103                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
1104                         warningf(source_position,
1105                                         "destination type '%T' in %s from type '%T' lacks qualifiers '%Q' in pointer target type",
1106                                         orig_type_left, context, orig_type_right, missing_qualifiers);
1107                 }
1108                 return;
1109         }
1110
1111         case ASSIGN_WARNING_POINTER_INCOMPATIBLE:
1112                 if (warning.other) {
1113                         warningf(source_position,
1114                                         "destination type '%T' in %s is incompatible with '%E' of type '%T'",
1115                                         orig_type_left, context, right, orig_type_right);
1116                 }
1117                 return;
1118
1119         case ASSIGN_WARNING_POINTER_FROM_INT:
1120                 if (warning.other) {
1121                         warningf(source_position,
1122                                         "%s makes pointer '%T' from integer '%T' without a cast",
1123                                         context, orig_type_left, orig_type_right);
1124                 }
1125                 return;
1126
1127         case ASSIGN_WARNING_INT_FROM_POINTER:
1128                 if (warning.other) {
1129                         warningf(source_position,
1130                                         "%s makes integer '%T' from pointer '%T' without a cast",
1131                                         context, orig_type_left, orig_type_right);
1132                 }
1133                 return;
1134
1135         default:
1136                 panic("invalid error value");
1137         }
1138 }
1139
1140 /** Implements the rules from § 6.5.16.1 */
1141 static assign_error_t semantic_assign(type_t *orig_type_left,
1142                                       const expression_t *const right)
1143 {
1144         type_t *const orig_type_right = right->base.type;
1145         type_t *const type_left       = skip_typeref(orig_type_left);
1146         type_t *const type_right      = skip_typeref(orig_type_right);
1147
1148         if (is_type_pointer(type_left)) {
1149                 if (is_null_pointer_constant(right)) {
1150                         return ASSIGN_SUCCESS;
1151                 } else if (is_type_pointer(type_right)) {
1152                         type_t *points_to_left
1153                                 = skip_typeref(type_left->pointer.points_to);
1154                         type_t *points_to_right
1155                                 = skip_typeref(type_right->pointer.points_to);
1156                         assign_error_t res = ASSIGN_SUCCESS;
1157
1158                         /* the left type has all qualifiers from the right type */
1159                         unsigned missing_qualifiers
1160                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
1161                         if (missing_qualifiers != 0) {
1162                                 res = ASSIGN_ERROR_POINTER_QUALIFIER_MISSING;
1163                         }
1164
1165                         points_to_left  = get_unqualified_type(points_to_left);
1166                         points_to_right = get_unqualified_type(points_to_right);
1167
1168                         if (is_type_atomic(points_to_left, ATOMIC_TYPE_VOID))
1169                                 return res;
1170
1171                         if (is_type_atomic(points_to_right, ATOMIC_TYPE_VOID)) {
1172                                 /* ISO/IEC 14882:1998(E) §C.1.2:6 */
1173                                 return c_mode & _CXX ? ASSIGN_ERROR_INCOMPATIBLE : res;
1174                         }
1175
1176                         if (!types_compatible(points_to_left, points_to_right)) {
1177                                 return ASSIGN_WARNING_POINTER_INCOMPATIBLE;
1178                         }
1179
1180                         return res;
1181                 } else if (is_type_integer(type_right)) {
1182                         return ASSIGN_WARNING_POINTER_FROM_INT;
1183                 }
1184         } else if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
1185             (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
1186                 && is_type_pointer(type_right))) {
1187                 return ASSIGN_SUCCESS;
1188         } else if ((is_type_compound(type_left)  && is_type_compound(type_right))
1189                         || (is_type_builtin(type_left) && is_type_builtin(type_right))) {
1190                 type_t *const unqual_type_left  = get_unqualified_type(type_left);
1191                 type_t *const unqual_type_right = get_unqualified_type(type_right);
1192                 if (types_compatible(unqual_type_left, unqual_type_right)) {
1193                         return ASSIGN_SUCCESS;
1194                 }
1195         } else if (is_type_integer(type_left) && is_type_pointer(type_right)) {
1196                 return ASSIGN_WARNING_INT_FROM_POINTER;
1197         }
1198
1199         if (!is_type_valid(type_left) || !is_type_valid(type_right))
1200                 return ASSIGN_SUCCESS;
1201
1202         return ASSIGN_ERROR_INCOMPATIBLE;
1203 }
1204
1205 static expression_t *parse_constant_expression(void)
1206 {
1207         expression_t *result = parse_sub_expression(PREC_CONDITIONAL);
1208
1209         if (!is_constant_expression(result)) {
1210                 errorf(&result->base.source_position,
1211                        "expression '%E' is not constant", result);
1212         }
1213
1214         return result;
1215 }
1216
1217 static expression_t *parse_assignment_expression(void)
1218 {
1219         return parse_sub_expression(PREC_ASSIGNMENT);
1220 }
1221
1222 static string_t parse_string_literals(void)
1223 {
1224         assert(token.type == T_STRING_LITERAL);
1225         string_t result = token.v.string;
1226
1227         next_token();
1228
1229         while (token.type == T_STRING_LITERAL) {
1230                 result = concat_strings(&result, &token.v.string);
1231                 next_token();
1232         }
1233
1234         return result;
1235 }
1236
1237 static const char *const gnu_attribute_names[GNU_AK_LAST] = {
1238         [GNU_AK_CONST]                  = "const",
1239         [GNU_AK_VOLATILE]               = "volatile",
1240         [GNU_AK_CDECL]                  = "cdecl",
1241         [GNU_AK_STDCALL]                = "stdcall",
1242         [GNU_AK_FASTCALL]               = "fastcall",
1243         [GNU_AK_DEPRECATED]             = "deprecated",
1244         [GNU_AK_NOINLINE]               = "noinline",
1245         [GNU_AK_RETURNS_TWICE]          = "returns_twice",
1246         [GNU_AK_NORETURN]               = "noreturn",
1247         [GNU_AK_NAKED]                  = "naked",
1248         [GNU_AK_PURE]                   = "pure",
1249         [GNU_AK_ALWAYS_INLINE]          = "always_inline",
1250         [GNU_AK_MALLOC]                 = "malloc",
1251         [GNU_AK_WEAK]                   = "weak",
1252         [GNU_AK_CONSTRUCTOR]            = "constructor",
1253         [GNU_AK_DESTRUCTOR]             = "destructor",
1254         [GNU_AK_NOTHROW]                = "nothrow",
1255         [GNU_AK_TRANSPARENT_UNION]      = "transparent_union",
1256         [GNU_AK_COMMON]                 = "common",
1257         [GNU_AK_NOCOMMON]               = "nocommon",
1258         [GNU_AK_PACKED]                 = "packed",
1259         [GNU_AK_SHARED]                 = "shared",
1260         [GNU_AK_NOTSHARED]              = "notshared",
1261         [GNU_AK_USED]                   = "used",
1262         [GNU_AK_UNUSED]                 = "unused",
1263         [GNU_AK_NO_INSTRUMENT_FUNCTION] = "no_instrument_function",
1264         [GNU_AK_WARN_UNUSED_RESULT]     = "warn_unused_result",
1265         [GNU_AK_LONGCALL]               = "longcall",
1266         [GNU_AK_SHORTCALL]              = "shortcall",
1267         [GNU_AK_LONG_CALL]              = "long_call",
1268         [GNU_AK_SHORT_CALL]             = "short_call",
1269         [GNU_AK_FUNCTION_VECTOR]        = "function_vector",
1270         [GNU_AK_INTERRUPT]              = "interrupt",
1271         [GNU_AK_INTERRUPT_HANDLER]      = "interrupt_handler",
1272         [GNU_AK_NMI_HANDLER]            = "nmi_handler",
1273         [GNU_AK_NESTING]                = "nesting",
1274         [GNU_AK_NEAR]                   = "near",
1275         [GNU_AK_FAR]                    = "far",
1276         [GNU_AK_SIGNAL]                 = "signal",
1277         [GNU_AK_EIGTHBIT_DATA]          = "eightbit_data",
1278         [GNU_AK_TINY_DATA]              = "tiny_data",
1279         [GNU_AK_SAVEALL]                = "saveall",
1280         [GNU_AK_FLATTEN]                = "flatten",
1281         [GNU_AK_SSEREGPARM]             = "sseregparm",
1282         [GNU_AK_EXTERNALLY_VISIBLE]     = "externally_visible",
1283         [GNU_AK_RETURN_TWICE]           = "return_twice",
1284         [GNU_AK_MAY_ALIAS]              = "may_alias",
1285         [GNU_AK_MS_STRUCT]              = "ms_struct",
1286         [GNU_AK_GCC_STRUCT]             = "gcc_struct",
1287         [GNU_AK_DLLIMPORT]              = "dllimport",
1288         [GNU_AK_DLLEXPORT]              = "dllexport",
1289         [GNU_AK_ALIGNED]                = "aligned",
1290         [GNU_AK_ALIAS]                  = "alias",
1291         [GNU_AK_SECTION]                = "section",
1292         [GNU_AK_FORMAT]                 = "format",
1293         [GNU_AK_FORMAT_ARG]             = "format_arg",
1294         [GNU_AK_WEAKREF]                = "weakref",
1295         [GNU_AK_NONNULL]                = "nonnull",
1296         [GNU_AK_TLS_MODEL]              = "tls_model",
1297         [GNU_AK_VISIBILITY]             = "visibility",
1298         [GNU_AK_REGPARM]                = "regparm",
1299         [GNU_AK_MODE]                   = "mode",
1300         [GNU_AK_MODEL]                  = "model",
1301         [GNU_AK_TRAP_EXIT]              = "trap_exit",
1302         [GNU_AK_SP_SWITCH]              = "sp_switch",
1303         [GNU_AK_SENTINEL]               = "sentinel"
1304 };
1305
1306 /**
1307  * compare two string, ignoring double underscores on the second.
1308  */
1309 static int strcmp_underscore(const char *s1, const char *s2)
1310 {
1311         if (s2[0] == '_' && s2[1] == '_') {
1312                 size_t len2 = strlen(s2);
1313                 size_t len1 = strlen(s1);
1314                 if (len1 == len2-4 && s2[len2-2] == '_' && s2[len2-1] == '_') {
1315                         return strncmp(s1, s2+2, len2-4);
1316                 }
1317         }
1318
1319         return strcmp(s1, s2);
1320 }
1321
1322 /**
1323  * Allocate a new gnu temporal attribute of given kind.
1324  */
1325 static gnu_attribute_t *allocate_gnu_attribute(gnu_attribute_kind_t kind)
1326 {
1327         gnu_attribute_t *attribute = obstack_alloc(&temp_obst, sizeof(*attribute));
1328         attribute->kind            = kind;
1329         attribute->next            = NULL;
1330         attribute->invalid         = false;
1331         attribute->have_arguments  = false;
1332
1333         return attribute;
1334 }
1335
1336 /**
1337  * Parse one constant expression argument of the given attribute.
1338  */
1339 static void parse_gnu_attribute_const_arg(gnu_attribute_t *attribute)
1340 {
1341         expression_t *expression;
1342         add_anchor_token(')');
1343         expression = parse_constant_expression();
1344         rem_anchor_token(')');
1345         expect(')', end_error);
1346         attribute->u.argument = fold_constant(expression);
1347         return;
1348 end_error:
1349         attribute->invalid = true;
1350 }
1351
1352 /**
1353  * Parse a list of constant expressions arguments of the given attribute.
1354  */
1355 static void parse_gnu_attribute_const_arg_list(gnu_attribute_t *attribute)
1356 {
1357         argument_list_t **list = &attribute->u.arguments;
1358         argument_list_t  *entry;
1359         expression_t     *expression;
1360         add_anchor_token(')');
1361         add_anchor_token(',');
1362         while (true) {
1363                 expression = parse_constant_expression();
1364                 entry = obstack_alloc(&temp_obst, sizeof(entry));
1365                 entry->argument = fold_constant(expression);
1366                 entry->next     = NULL;
1367                 *list = entry;
1368                 list = &entry->next;
1369                 if (token.type != ',')
1370                         break;
1371                 next_token();
1372         }
1373         rem_anchor_token(',');
1374         rem_anchor_token(')');
1375         expect(')', end_error);
1376         return;
1377 end_error:
1378         attribute->invalid = true;
1379 }
1380
1381 /**
1382  * Parse one string literal argument of the given attribute.
1383  */
1384 static void parse_gnu_attribute_string_arg(gnu_attribute_t *attribute,
1385                                            string_t *string)
1386 {
1387         add_anchor_token('(');
1388         if (token.type != T_STRING_LITERAL) {
1389                 parse_error_expected("while parsing attribute directive",
1390                                      T_STRING_LITERAL, NULL);
1391                 goto end_error;
1392         }
1393         *string = parse_string_literals();
1394         rem_anchor_token('(');
1395         expect(')', end_error);
1396         return;
1397 end_error:
1398         attribute->invalid = true;
1399 }
1400
1401 /**
1402  * Parse one tls model of the given attribute.
1403  */
1404 static void parse_gnu_attribute_tls_model_arg(gnu_attribute_t *attribute)
1405 {
1406         static const char *const tls_models[] = {
1407                 "global-dynamic",
1408                 "local-dynamic",
1409                 "initial-exec",
1410                 "local-exec"
1411         };
1412         string_t string = { NULL, 0 };
1413         parse_gnu_attribute_string_arg(attribute, &string);
1414         if (string.begin != NULL) {
1415                 for (size_t i = 0; i < 4; ++i) {
1416                         if (strcmp(tls_models[i], string.begin) == 0) {
1417                                 attribute->u.value = i;
1418                                 return;
1419                         }
1420                 }
1421                 errorf(HERE, "'%s' is an unrecognized tls model", string.begin);
1422         }
1423         attribute->invalid = true;
1424 }
1425
1426 /**
1427  * Parse one tls model of the given attribute.
1428  */
1429 static void parse_gnu_attribute_visibility_arg(gnu_attribute_t *attribute)
1430 {
1431         static const char *const visibilities[] = {
1432                 "default",
1433                 "protected",
1434                 "hidden",
1435                 "internal"
1436         };
1437         string_t string = { NULL, 0 };
1438         parse_gnu_attribute_string_arg(attribute, &string);
1439         if (string.begin != NULL) {
1440                 for (size_t i = 0; i < 4; ++i) {
1441                         if (strcmp(visibilities[i], string.begin) == 0) {
1442                                 attribute->u.value = i;
1443                                 return;
1444                         }
1445                 }
1446                 errorf(HERE, "'%s' is an unrecognized visibility", string.begin);
1447         }
1448         attribute->invalid = true;
1449 }
1450
1451 /**
1452  * Parse one (code) model of the given attribute.
1453  */
1454 static void parse_gnu_attribute_model_arg(gnu_attribute_t *attribute)
1455 {
1456         static const char *const visibilities[] = {
1457                 "small",
1458                 "medium",
1459                 "large"
1460         };
1461         string_t string = { NULL, 0 };
1462         parse_gnu_attribute_string_arg(attribute, &string);
1463         if (string.begin != NULL) {
1464                 for (int i = 0; i < 3; ++i) {
1465                         if (strcmp(visibilities[i], string.begin) == 0) {
1466                                 attribute->u.value = i;
1467                                 return;
1468                         }
1469                 }
1470                 errorf(HERE, "'%s' is an unrecognized model", string.begin);
1471         }
1472         attribute->invalid = true;
1473 }
1474
1475 /**
1476  * Parse one mode of the given attribute.
1477  */
1478 static void parse_gnu_attribute_mode_arg(gnu_attribute_t *attribute)
1479 {
1480         /* TODO: find out what is allowed here... */
1481
1482         /* at least: byte, word, pointer, list of machine modes
1483          * __XXX___ is interpreted as XXX */
1484         add_anchor_token(')');
1485
1486         if (token.type != T_IDENTIFIER) {
1487                 expect(T_IDENTIFIER, end_error);
1488         }
1489
1490         /* This isn't really correct, the backend should provide a list of machine
1491          * specific modes (according to gcc philosophy that is...) */
1492         const char *symbol_str = token.v.symbol->string;
1493         if (strcmp_underscore("QI",   symbol_str) == 0 ||
1494             strcmp_underscore("byte", symbol_str) == 0) {
1495                 attribute->u.akind = ATOMIC_TYPE_CHAR;
1496         } else if (strcmp_underscore("HI", symbol_str) == 0) {
1497                 attribute->u.akind = ATOMIC_TYPE_SHORT;
1498         } else if (strcmp_underscore("SI",      symbol_str) == 0
1499                 || strcmp_underscore("word",    symbol_str) == 0
1500                 || strcmp_underscore("pointer", symbol_str) == 0) {
1501                 attribute->u.akind = ATOMIC_TYPE_INT;
1502         } else if (strcmp_underscore("DI", symbol_str) == 0) {
1503                 attribute->u.akind = ATOMIC_TYPE_LONGLONG;
1504         } else {
1505                 if (warning.other)
1506                         warningf(HERE, "ignoring unknown mode '%s'", symbol_str);
1507                 attribute->invalid = true;
1508         }
1509         next_token();
1510
1511         rem_anchor_token(')');
1512         expect(')', end_error);
1513         return;
1514 end_error:
1515         attribute->invalid = true;
1516 }
1517
1518 /**
1519  * Parse one interrupt argument of the given attribute.
1520  */
1521 static void parse_gnu_attribute_interrupt_arg(gnu_attribute_t *attribute)
1522 {
1523         static const char *const interrupts[] = {
1524                 "IRQ",
1525                 "FIQ",
1526                 "SWI",
1527                 "ABORT",
1528                 "UNDEF"
1529         };
1530         string_t string = { NULL, 0 };
1531         parse_gnu_attribute_string_arg(attribute, &string);
1532         if (string.begin != NULL) {
1533                 for (size_t i = 0; i < 5; ++i) {
1534                         if (strcmp(interrupts[i], string.begin) == 0) {
1535                                 attribute->u.value = i;
1536                                 return;
1537                         }
1538                 }
1539                 errorf(HERE, "'%s' is not an interrupt", string.begin);
1540         }
1541         attribute->invalid = true;
1542 }
1543
1544 /**
1545  * Parse ( identifier, const expression, const expression )
1546  */
1547 static void parse_gnu_attribute_format_args(gnu_attribute_t *attribute)
1548 {
1549         static const char *const format_names[] = {
1550                 "printf",
1551                 "scanf",
1552                 "strftime",
1553                 "strfmon"
1554         };
1555         int i;
1556
1557         if (token.type != T_IDENTIFIER) {
1558                 parse_error_expected("while parsing format attribute directive", T_IDENTIFIER, NULL);
1559                 goto end_error;
1560         }
1561         const char *name = token.v.symbol->string;
1562         for (i = 0; i < 4; ++i) {
1563                 if (strcmp_underscore(format_names[i], name) == 0)
1564                         break;
1565         }
1566         if (i >= 4) {
1567                 if (warning.attribute)
1568                         warningf(HERE, "'%s' is an unrecognized format function type", name);
1569         }
1570         next_token();
1571
1572         expect(',', end_error);
1573         add_anchor_token(')');
1574         add_anchor_token(',');
1575         parse_constant_expression();
1576         rem_anchor_token(',');
1577         rem_anchor_token(')');
1578
1579         expect(',', end_error);
1580         add_anchor_token(')');
1581         parse_constant_expression();
1582         rem_anchor_token(')');
1583         expect(')', end_error);
1584         return;
1585 end_error:
1586         attribute->u.value = true;
1587 }
1588
1589 /**
1590  * Check that a given GNU attribute has no arguments.
1591  */
1592 static void check_no_argument(gnu_attribute_t *attribute, const char *name)
1593 {
1594         if (!attribute->have_arguments)
1595                 return;
1596
1597         /* should have no arguments */
1598         errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1599         eat_until_matching_token('(');
1600         /* we have already consumed '(', so we stop before ')', eat it */
1601         eat(')');
1602         attribute->invalid = true;
1603 }
1604
1605 /**
1606  * Parse one GNU attribute.
1607  *
1608  * Note that attribute names can be specified WITH or WITHOUT
1609  * double underscores, ie const or __const__.
1610  *
1611  * The following attributes are parsed without arguments
1612  *  const
1613  *  volatile
1614  *  cdecl
1615  *  stdcall
1616  *  fastcall
1617  *  deprecated
1618  *  noinline
1619  *  noreturn
1620  *  naked
1621  *  pure
1622  *  always_inline
1623  *  malloc
1624  *  weak
1625  *  constructor
1626  *  destructor
1627  *  nothrow
1628  *  transparent_union
1629  *  common
1630  *  nocommon
1631  *  packed
1632  *  shared
1633  *  notshared
1634  *  used
1635  *  unused
1636  *  no_instrument_function
1637  *  warn_unused_result
1638  *  longcall
1639  *  shortcall
1640  *  long_call
1641  *  short_call
1642  *  function_vector
1643  *  interrupt_handler
1644  *  nmi_handler
1645  *  nesting
1646  *  near
1647  *  far
1648  *  signal
1649  *  eightbit_data
1650  *  tiny_data
1651  *  saveall
1652  *  flatten
1653  *  sseregparm
1654  *  externally_visible
1655  *  return_twice
1656  *  may_alias
1657  *  ms_struct
1658  *  gcc_struct
1659  *  dllimport
1660  *  dllexport
1661  *
1662  * The following attributes are parsed with arguments
1663  *  aligned( const expression )
1664  *  alias( string literal )
1665  *  section( string literal )
1666  *  format( identifier, const expression, const expression )
1667  *  format_arg( const expression )
1668  *  tls_model( string literal )
1669  *  visibility( string literal )
1670  *  regparm( const expression )
1671  *  model( string leteral )
1672  *  trap_exit( const expression )
1673  *  sp_switch( string literal )
1674  *
1675  * The following attributes might have arguments
1676  *  weak_ref( string literal )
1677  *  non_null( const expression // ',' )
1678  *  interrupt( string literal )
1679  *  sentinel( constant expression )
1680  */
1681 static decl_modifiers_t parse_gnu_attribute(gnu_attribute_t **attributes)
1682 {
1683         gnu_attribute_t *head      = *attributes;
1684         gnu_attribute_t *last      = *attributes;
1685         decl_modifiers_t modifiers = 0;
1686         gnu_attribute_t *attribute;
1687
1688         eat(T___attribute__);
1689         expect('(', end_error);
1690         expect('(', end_error);
1691
1692         if (token.type != ')') {
1693                 /* find the end of the list */
1694                 if (last != NULL) {
1695                         while (last->next != NULL)
1696                                 last = last->next;
1697                 }
1698
1699                 /* non-empty attribute list */
1700                 while (true) {
1701                         const char *name;
1702                         if (token.type == T_const) {
1703                                 name = "const";
1704                         } else if (token.type == T_volatile) {
1705                                 name = "volatile";
1706                         } else if (token.type == T_cdecl) {
1707                                 /* __attribute__((cdecl)), WITH ms mode */
1708                                 name = "cdecl";
1709                         } else if (token.type == T_IDENTIFIER) {
1710                                 const symbol_t *sym = token.v.symbol;
1711                                 name = sym->string;
1712                         } else {
1713                                 parse_error_expected("while parsing GNU attribute", T_IDENTIFIER, NULL);
1714                                 break;
1715                         }
1716
1717                         next_token();
1718
1719                         int i;
1720                         for (i = 0; i < GNU_AK_LAST; ++i) {
1721                                 if (strcmp_underscore(gnu_attribute_names[i], name) == 0)
1722                                         break;
1723                         }
1724                         gnu_attribute_kind_t kind = (gnu_attribute_kind_t)i;
1725
1726                         attribute = NULL;
1727                         if (kind == GNU_AK_LAST) {
1728                                 if (warning.attribute)
1729                                         warningf(HERE, "'%s' attribute directive ignored", name);
1730
1731                                 /* skip possible arguments */
1732                                 if (token.type == '(') {
1733                                         eat_until_matching_token(')');
1734                                 }
1735                         } else {
1736                                 /* check for arguments */
1737                                 attribute = allocate_gnu_attribute(kind);
1738                                 if (token.type == '(') {
1739                                         next_token();
1740                                         if (token.type == ')') {
1741                                                 /* empty args are allowed */
1742                                                 next_token();
1743                                         } else
1744                                                 attribute->have_arguments = true;
1745                                 }
1746
1747                                 switch (kind) {
1748                                 case GNU_AK_VOLATILE:
1749                                 case GNU_AK_NAKED:
1750                                 case GNU_AK_MALLOC:
1751                                 case GNU_AK_WEAK:
1752                                 case GNU_AK_COMMON:
1753                                 case GNU_AK_NOCOMMON:
1754                                 case GNU_AK_SHARED:
1755                                 case GNU_AK_NOTSHARED:
1756                                 case GNU_AK_NO_INSTRUMENT_FUNCTION:
1757                                 case GNU_AK_WARN_UNUSED_RESULT:
1758                                 case GNU_AK_LONGCALL:
1759                                 case GNU_AK_SHORTCALL:
1760                                 case GNU_AK_LONG_CALL:
1761                                 case GNU_AK_SHORT_CALL:
1762                                 case GNU_AK_FUNCTION_VECTOR:
1763                                 case GNU_AK_INTERRUPT_HANDLER:
1764                                 case GNU_AK_NMI_HANDLER:
1765                                 case GNU_AK_NESTING:
1766                                 case GNU_AK_NEAR:
1767                                 case GNU_AK_FAR:
1768                                 case GNU_AK_SIGNAL:
1769                                 case GNU_AK_EIGTHBIT_DATA:
1770                                 case GNU_AK_TINY_DATA:
1771                                 case GNU_AK_SAVEALL:
1772                                 case GNU_AK_FLATTEN:
1773                                 case GNU_AK_SSEREGPARM:
1774                                 case GNU_AK_EXTERNALLY_VISIBLE:
1775                                 case GNU_AK_RETURN_TWICE:
1776                                 case GNU_AK_MAY_ALIAS:
1777                                 case GNU_AK_MS_STRUCT:
1778                                 case GNU_AK_GCC_STRUCT:
1779                                         goto no_arg;
1780
1781                                 case GNU_AK_CDECL:             modifiers |= DM_CDECL;             goto no_arg;
1782                                 case GNU_AK_FASTCALL:          modifiers |= DM_FASTCALL;          goto no_arg;
1783                                 case GNU_AK_STDCALL:           modifiers |= DM_STDCALL;           goto no_arg;
1784                                 case GNU_AK_UNUSED:            modifiers |= DM_UNUSED;            goto no_arg;
1785                                 case GNU_AK_USED:              modifiers |= DM_USED;              goto no_arg;
1786                                 case GNU_AK_PURE:              modifiers |= DM_PURE;              goto no_arg;
1787                                 case GNU_AK_CONST:             modifiers |= DM_CONST;             goto no_arg;
1788                                 case GNU_AK_ALWAYS_INLINE:     modifiers |= DM_FORCEINLINE;       goto no_arg;
1789                                 case GNU_AK_DLLIMPORT:         modifiers |= DM_DLLIMPORT;         goto no_arg;
1790                                 case GNU_AK_DLLEXPORT:         modifiers |= DM_DLLEXPORT;         goto no_arg;
1791                                 case GNU_AK_PACKED:            modifiers |= DM_PACKED;            goto no_arg;
1792                                 case GNU_AK_NOINLINE:          modifiers |= DM_NOINLINE;          goto no_arg;
1793                                 case GNU_AK_RETURNS_TWICE:     modifiers |= DM_RETURNS_TWICE;     goto no_arg;
1794                                 case GNU_AK_NORETURN:          modifiers |= DM_NORETURN;          goto no_arg;
1795                                 case GNU_AK_NOTHROW:           modifiers |= DM_NOTHROW;           goto no_arg;
1796                                 case GNU_AK_TRANSPARENT_UNION: modifiers |= DM_TRANSPARENT_UNION; goto no_arg;
1797                                 case GNU_AK_CONSTRUCTOR:       modifiers |= DM_CONSTRUCTOR;       goto no_arg;
1798                                 case GNU_AK_DESTRUCTOR:        modifiers |= DM_DESTRUCTOR;        goto no_arg;
1799                                 case GNU_AK_DEPRECATED:        modifiers |= DM_DEPRECATED;        goto no_arg;
1800
1801                                 case GNU_AK_ALIGNED:
1802                                         /* __align__ may be used without an argument */
1803                                         if (attribute->have_arguments) {
1804                                                 parse_gnu_attribute_const_arg(attribute);
1805                                         }
1806                                         break;
1807
1808                                 case GNU_AK_FORMAT_ARG:
1809                                 case GNU_AK_REGPARM:
1810                                 case GNU_AK_TRAP_EXIT:
1811                                         if (!attribute->have_arguments) {
1812                                                 /* should have arguments */
1813                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1814                                                 attribute->invalid = true;
1815                                         } else
1816                                                 parse_gnu_attribute_const_arg(attribute);
1817                                         break;
1818                                 case GNU_AK_ALIAS:
1819                                 case GNU_AK_SECTION:
1820                                 case GNU_AK_SP_SWITCH:
1821                                         if (!attribute->have_arguments) {
1822                                                 /* should have arguments */
1823                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1824                                                 attribute->invalid = true;
1825                                         } else
1826                                                 parse_gnu_attribute_string_arg(attribute, &attribute->u.string);
1827                                         break;
1828                                 case GNU_AK_FORMAT:
1829                                         if (!attribute->have_arguments) {
1830                                                 /* should have arguments */
1831                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1832                                                 attribute->invalid = true;
1833                                         } else
1834                                                 parse_gnu_attribute_format_args(attribute);
1835                                         break;
1836                                 case GNU_AK_WEAKREF:
1837                                         /* may have one string argument */
1838                                         if (attribute->have_arguments)
1839                                                 parse_gnu_attribute_string_arg(attribute, &attribute->u.string);
1840                                         break;
1841                                 case GNU_AK_NONNULL:
1842                                         if (attribute->have_arguments)
1843                                                 parse_gnu_attribute_const_arg_list(attribute);
1844                                         break;
1845                                 case GNU_AK_TLS_MODEL:
1846                                         if (!attribute->have_arguments) {
1847                                                 /* should have arguments */
1848                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1849                                         } else
1850                                                 parse_gnu_attribute_tls_model_arg(attribute);
1851                                         break;
1852                                 case GNU_AK_VISIBILITY:
1853                                         if (!attribute->have_arguments) {
1854                                                 /* should have arguments */
1855                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1856                                         } else
1857                                                 parse_gnu_attribute_visibility_arg(attribute);
1858                                         break;
1859                                 case GNU_AK_MODEL:
1860                                         if (!attribute->have_arguments) {
1861                                                 /* should have arguments */
1862                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1863                                         } else {
1864                                                 parse_gnu_attribute_model_arg(attribute);
1865                                         }
1866                                         break;
1867                                 case GNU_AK_MODE:
1868                                         if (!attribute->have_arguments) {
1869                                                 /* should have arguments */
1870                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1871                                         } else {
1872                                                 parse_gnu_attribute_mode_arg(attribute);
1873                                         }
1874                                         break;
1875                                 case GNU_AK_INTERRUPT:
1876                                         /* may have one string argument */
1877                                         if (attribute->have_arguments)
1878                                                 parse_gnu_attribute_interrupt_arg(attribute);
1879                                         break;
1880                                 case GNU_AK_SENTINEL:
1881                                         /* may have one string argument */
1882                                         if (attribute->have_arguments)
1883                                                 parse_gnu_attribute_const_arg(attribute);
1884                                         break;
1885                                 case GNU_AK_LAST:
1886                                         /* already handled */
1887                                         break;
1888
1889 no_arg:
1890                                         check_no_argument(attribute, name);
1891                                 }
1892                         }
1893                         if (attribute != NULL) {
1894                                 if (last != NULL) {
1895                                         last->next = attribute;
1896                                         last       = attribute;
1897                                 } else {
1898                                         head = last = attribute;
1899                                 }
1900                         }
1901
1902                         if (token.type != ',')
1903                                 break;
1904                         next_token();
1905                 }
1906         }
1907         expect(')', end_error);
1908         expect(')', end_error);
1909 end_error:
1910         *attributes = head;
1911
1912         return modifiers;
1913 }
1914
1915 /**
1916  * Parse GNU attributes.
1917  */
1918 static decl_modifiers_t parse_attributes(gnu_attribute_t **attributes)
1919 {
1920         decl_modifiers_t modifiers = 0;
1921
1922         while (true) {
1923                 switch (token.type) {
1924                 case T___attribute__:
1925                         modifiers |= parse_gnu_attribute(attributes);
1926                         continue;
1927
1928                 case T_asm:
1929                         next_token();
1930                         expect('(', end_error);
1931                         if (token.type != T_STRING_LITERAL) {
1932                                 parse_error_expected("while parsing assembler attribute",
1933                                                      T_STRING_LITERAL, NULL);
1934                                 eat_until_matching_token('(');
1935                                 break;
1936                         } else {
1937                                 parse_string_literals();
1938                         }
1939                         expect(')', end_error);
1940                         continue;
1941
1942                 case T_cdecl:     modifiers |= DM_CDECL;    break;
1943                 case T__fastcall: modifiers |= DM_FASTCALL; break;
1944                 case T__stdcall:  modifiers |= DM_STDCALL;  break;
1945
1946                 case T___thiscall:
1947                         /* TODO record modifier */
1948                         if (warning.other)
1949                                 warningf(HERE, "Ignoring declaration modifier %K", &token);
1950                         break;
1951
1952 end_error:
1953                 default: return modifiers;
1954                 }
1955
1956                 next_token();
1957         }
1958 }
1959
1960 static void mark_vars_read(expression_t *expr, entity_t *lhs_ent);
1961
1962 static entity_t *determine_lhs_ent(expression_t *const expr,
1963                                    entity_t *lhs_ent)
1964 {
1965         switch (expr->kind) {
1966                 case EXPR_REFERENCE: {
1967                         entity_t *const entity = expr->reference.entity;
1968                         /* we should only find variables as lvalues... */
1969                         if (entity->base.kind != ENTITY_VARIABLE
1970                                         && entity->base.kind != ENTITY_PARAMETER)
1971                                 return NULL;
1972
1973                         return entity;
1974                 }
1975
1976                 case EXPR_ARRAY_ACCESS: {
1977                         expression_t *const ref = expr->array_access.array_ref;
1978                         entity_t     *      ent = NULL;
1979                         if (is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1980                                 ent     = determine_lhs_ent(ref, lhs_ent);
1981                                 lhs_ent = ent;
1982                         } else {
1983                                 mark_vars_read(expr->select.compound, lhs_ent);
1984                         }
1985                         mark_vars_read(expr->array_access.index, lhs_ent);
1986                         return ent;
1987                 }
1988
1989                 case EXPR_SELECT: {
1990                         if (is_type_compound(skip_typeref(expr->base.type))) {
1991                                 return determine_lhs_ent(expr->select.compound, lhs_ent);
1992                         } else {
1993                                 mark_vars_read(expr->select.compound, lhs_ent);
1994                                 return NULL;
1995                         }
1996                 }
1997
1998                 case EXPR_UNARY_DEREFERENCE: {
1999                         expression_t *const val = expr->unary.value;
2000                         if (val->kind == EXPR_UNARY_TAKE_ADDRESS) {
2001                                 /* *&x is a NOP */
2002                                 return determine_lhs_ent(val->unary.value, lhs_ent);
2003                         } else {
2004                                 mark_vars_read(val, NULL);
2005                                 return NULL;
2006                         }
2007                 }
2008
2009                 default:
2010                         mark_vars_read(expr, NULL);
2011                         return NULL;
2012         }
2013 }
2014
2015 #define ENT_ANY ((entity_t*)-1)
2016
2017 /**
2018  * Mark declarations, which are read.  This is used to detect variables, which
2019  * are never read.
2020  * Example:
2021  * x = x + 1;
2022  *   x is not marked as "read", because it is only read to calculate its own new
2023  *   value.
2024  *
2025  * x += y; y += x;
2026  *   x and y are not detected as "not read", because multiple variables are
2027  *   involved.
2028  */
2029 static void mark_vars_read(expression_t *const expr, entity_t *lhs_ent)
2030 {
2031         switch (expr->kind) {
2032                 case EXPR_REFERENCE: {
2033                         entity_t *const entity = expr->reference.entity;
2034                         if (entity->kind != ENTITY_VARIABLE
2035                                         && entity->kind != ENTITY_PARAMETER)
2036                                 return;
2037
2038                         if (lhs_ent != entity && lhs_ent != ENT_ANY) {
2039                                 if (entity->kind == ENTITY_VARIABLE) {
2040                                         entity->variable.read = true;
2041                                 } else {
2042                                         entity->parameter.read = true;
2043                                 }
2044                         }
2045                         return;
2046                 }
2047
2048                 case EXPR_CALL:
2049                         // TODO respect pure/const
2050                         mark_vars_read(expr->call.function, NULL);
2051                         for (call_argument_t *arg = expr->call.arguments; arg != NULL; arg = arg->next) {
2052                                 mark_vars_read(arg->expression, NULL);
2053                         }
2054                         return;
2055
2056                 case EXPR_CONDITIONAL:
2057                         // TODO lhs_decl should depend on whether true/false have an effect
2058                         mark_vars_read(expr->conditional.condition, NULL);
2059                         if (expr->conditional.true_expression != NULL)
2060                                 mark_vars_read(expr->conditional.true_expression, lhs_ent);
2061                         mark_vars_read(expr->conditional.false_expression, lhs_ent);
2062                         return;
2063
2064                 case EXPR_SELECT:
2065                         if (lhs_ent == ENT_ANY
2066                                         && !is_type_compound(skip_typeref(expr->base.type)))
2067                                 lhs_ent = NULL;
2068                         mark_vars_read(expr->select.compound, lhs_ent);
2069                         return;
2070
2071                 case EXPR_ARRAY_ACCESS: {
2072                         expression_t *const ref = expr->array_access.array_ref;
2073                         mark_vars_read(ref, lhs_ent);
2074                         lhs_ent = determine_lhs_ent(ref, lhs_ent);
2075                         mark_vars_read(expr->array_access.index, lhs_ent);
2076                         return;
2077                 }
2078
2079                 case EXPR_VA_ARG:
2080                         mark_vars_read(expr->va_arge.ap, lhs_ent);
2081                         return;
2082
2083                 case EXPR_UNARY_CAST:
2084                         /* Special case: Use void cast to mark a variable as "read" */
2085                         if (is_type_atomic(skip_typeref(expr->base.type), ATOMIC_TYPE_VOID))
2086                                 lhs_ent = NULL;
2087                         goto unary;
2088
2089
2090                 case EXPR_UNARY_THROW:
2091                         if (expr->unary.value == NULL)
2092                                 return;
2093                         /* FALLTHROUGH */
2094                 case EXPR_UNARY_DEREFERENCE:
2095                 case EXPR_UNARY_DELETE:
2096                 case EXPR_UNARY_DELETE_ARRAY:
2097                         if (lhs_ent == ENT_ANY)
2098                                 lhs_ent = NULL;
2099                         goto unary;
2100
2101                 case EXPR_UNARY_NEGATE:
2102                 case EXPR_UNARY_PLUS:
2103                 case EXPR_UNARY_BITWISE_NEGATE:
2104                 case EXPR_UNARY_NOT:
2105                 case EXPR_UNARY_TAKE_ADDRESS:
2106                 case EXPR_UNARY_POSTFIX_INCREMENT:
2107                 case EXPR_UNARY_POSTFIX_DECREMENT:
2108                 case EXPR_UNARY_PREFIX_INCREMENT:
2109                 case EXPR_UNARY_PREFIX_DECREMENT:
2110                 case EXPR_UNARY_CAST_IMPLICIT:
2111                 case EXPR_UNARY_ASSUME:
2112 unary:
2113                         mark_vars_read(expr->unary.value, lhs_ent);
2114                         return;
2115
2116                 case EXPR_BINARY_ADD:
2117                 case EXPR_BINARY_SUB:
2118                 case EXPR_BINARY_MUL:
2119                 case EXPR_BINARY_DIV:
2120                 case EXPR_BINARY_MOD:
2121                 case EXPR_BINARY_EQUAL:
2122                 case EXPR_BINARY_NOTEQUAL:
2123                 case EXPR_BINARY_LESS:
2124                 case EXPR_BINARY_LESSEQUAL:
2125                 case EXPR_BINARY_GREATER:
2126                 case EXPR_BINARY_GREATEREQUAL:
2127                 case EXPR_BINARY_BITWISE_AND:
2128                 case EXPR_BINARY_BITWISE_OR:
2129                 case EXPR_BINARY_BITWISE_XOR:
2130                 case EXPR_BINARY_LOGICAL_AND:
2131                 case EXPR_BINARY_LOGICAL_OR:
2132                 case EXPR_BINARY_SHIFTLEFT:
2133                 case EXPR_BINARY_SHIFTRIGHT:
2134                 case EXPR_BINARY_COMMA:
2135                 case EXPR_BINARY_ISGREATER:
2136                 case EXPR_BINARY_ISGREATEREQUAL:
2137                 case EXPR_BINARY_ISLESS:
2138                 case EXPR_BINARY_ISLESSEQUAL:
2139                 case EXPR_BINARY_ISLESSGREATER:
2140                 case EXPR_BINARY_ISUNORDERED:
2141                         mark_vars_read(expr->binary.left,  lhs_ent);
2142                         mark_vars_read(expr->binary.right, lhs_ent);
2143                         return;
2144
2145                 case EXPR_BINARY_ASSIGN:
2146                 case EXPR_BINARY_MUL_ASSIGN:
2147                 case EXPR_BINARY_DIV_ASSIGN:
2148                 case EXPR_BINARY_MOD_ASSIGN:
2149                 case EXPR_BINARY_ADD_ASSIGN:
2150                 case EXPR_BINARY_SUB_ASSIGN:
2151                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:
2152                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:
2153                 case EXPR_BINARY_BITWISE_AND_ASSIGN:
2154                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:
2155                 case EXPR_BINARY_BITWISE_OR_ASSIGN: {
2156                         if (lhs_ent == ENT_ANY)
2157                                 lhs_ent = NULL;
2158                         lhs_ent = determine_lhs_ent(expr->binary.left, lhs_ent);
2159                         mark_vars_read(expr->binary.right, lhs_ent);
2160                         return;
2161                 }
2162
2163                 case EXPR_VA_START:
2164                         determine_lhs_ent(expr->va_starte.ap, lhs_ent);
2165                         return;
2166
2167                 case EXPR_UNKNOWN:
2168                 case EXPR_INVALID:
2169                 case EXPR_CONST:
2170                 case EXPR_CHARACTER_CONSTANT:
2171                 case EXPR_WIDE_CHARACTER_CONSTANT:
2172                 case EXPR_STRING_LITERAL:
2173                 case EXPR_WIDE_STRING_LITERAL:
2174                 case EXPR_COMPOUND_LITERAL: // TODO init?
2175                 case EXPR_SIZEOF:
2176                 case EXPR_CLASSIFY_TYPE:
2177                 case EXPR_ALIGNOF:
2178                 case EXPR_FUNCNAME:
2179                 case EXPR_BUILTIN_SYMBOL:
2180                 case EXPR_BUILTIN_CONSTANT_P:
2181                 case EXPR_BUILTIN_PREFETCH:
2182                 case EXPR_OFFSETOF:
2183                 case EXPR_STATEMENT: // TODO
2184                 case EXPR_LABEL_ADDRESS:
2185                 case EXPR_REFERENCE_ENUM_VALUE:
2186                         return;
2187         }
2188
2189         panic("unhandled expression");
2190 }
2191
2192 static designator_t *parse_designation(void)
2193 {
2194         designator_t *result = NULL;
2195         designator_t *last   = NULL;
2196
2197         while (true) {
2198                 designator_t *designator;
2199                 switch (token.type) {
2200                 case '[':
2201                         designator = allocate_ast_zero(sizeof(designator[0]));
2202                         designator->source_position = token.source_position;
2203                         next_token();
2204                         add_anchor_token(']');
2205                         designator->array_index = parse_constant_expression();
2206                         rem_anchor_token(']');
2207                         expect(']', end_error);
2208                         break;
2209                 case '.':
2210                         designator = allocate_ast_zero(sizeof(designator[0]));
2211                         designator->source_position = token.source_position;
2212                         next_token();
2213                         if (token.type != T_IDENTIFIER) {
2214                                 parse_error_expected("while parsing designator",
2215                                                      T_IDENTIFIER, NULL);
2216                                 return NULL;
2217                         }
2218                         designator->symbol = token.v.symbol;
2219                         next_token();
2220                         break;
2221                 default:
2222                         expect('=', end_error);
2223                         return result;
2224                 }
2225
2226                 assert(designator != NULL);
2227                 if (last != NULL) {
2228                         last->next = designator;
2229                 } else {
2230                         result = designator;
2231                 }
2232                 last = designator;
2233         }
2234 end_error:
2235         return NULL;
2236 }
2237
2238 static initializer_t *initializer_from_string(array_type_t *type,
2239                                               const string_t *const string)
2240 {
2241         /* TODO: check len vs. size of array type */
2242         (void) type;
2243
2244         initializer_t *initializer = allocate_initializer_zero(INITIALIZER_STRING);
2245         initializer->string.string = *string;
2246
2247         return initializer;
2248 }
2249
2250 static initializer_t *initializer_from_wide_string(array_type_t *const type,
2251                                                    wide_string_t *const string)
2252 {
2253         /* TODO: check len vs. size of array type */
2254         (void) type;
2255
2256         initializer_t *const initializer =
2257                 allocate_initializer_zero(INITIALIZER_WIDE_STRING);
2258         initializer->wide_string.string = *string;
2259
2260         return initializer;
2261 }
2262
2263 /**
2264  * Build an initializer from a given expression.
2265  */
2266 static initializer_t *initializer_from_expression(type_t *orig_type,
2267                                                   expression_t *expression)
2268 {
2269         /* TODO check that expression is a constant expression */
2270
2271         /* § 6.7.8.14/15 char array may be initialized by string literals */
2272         type_t *type           = skip_typeref(orig_type);
2273         type_t *expr_type_orig = expression->base.type;
2274         type_t *expr_type      = skip_typeref(expr_type_orig);
2275         if (is_type_array(type) && expr_type->kind == TYPE_POINTER) {
2276                 array_type_t *const array_type   = &type->array;
2277                 type_t       *const element_type = skip_typeref(array_type->element_type);
2278
2279                 if (element_type->kind == TYPE_ATOMIC) {
2280                         atomic_type_kind_t akind = element_type->atomic.akind;
2281                         switch (expression->kind) {
2282                                 case EXPR_STRING_LITERAL:
2283                                         if (akind == ATOMIC_TYPE_CHAR
2284                                                         || akind == ATOMIC_TYPE_SCHAR
2285                                                         || akind == ATOMIC_TYPE_UCHAR) {
2286                                                 return initializer_from_string(array_type,
2287                                                         &expression->string.value);
2288                                         }
2289
2290                                 case EXPR_WIDE_STRING_LITERAL: {
2291                                         type_t *bare_wchar_type = skip_typeref(type_wchar_t);
2292                                         if (get_unqualified_type(element_type) == bare_wchar_type) {
2293                                                 return initializer_from_wide_string(array_type,
2294                                                         &expression->wide_string.value);
2295                                         }
2296                                 }
2297
2298                                 default:
2299                                         break;
2300                         }
2301                 }
2302         }
2303
2304         assign_error_t error = semantic_assign(type, expression);
2305         if (error == ASSIGN_ERROR_INCOMPATIBLE)
2306                 return NULL;
2307         report_assign_error(error, type, expression, "initializer",
2308                             &expression->base.source_position);
2309
2310         initializer_t *const result = allocate_initializer_zero(INITIALIZER_VALUE);
2311 #if 0
2312         if (type->kind == TYPE_BITFIELD) {
2313                 type = type->bitfield.base_type;
2314         }
2315 #endif
2316         result->value.value = create_implicit_cast(expression, type);
2317
2318         return result;
2319 }
2320
2321 /**
2322  * Checks if a given expression can be used as an constant initializer.
2323  */
2324 static bool is_initializer_constant(const expression_t *expression)
2325 {
2326         return is_constant_expression(expression)
2327                 || is_address_constant(expression);
2328 }
2329
2330 /**
2331  * Parses an scalar initializer.
2332  *
2333  * § 6.7.8.11; eat {} without warning
2334  */
2335 static initializer_t *parse_scalar_initializer(type_t *type,
2336                                                bool must_be_constant)
2337 {
2338         /* there might be extra {} hierarchies */
2339         int braces = 0;
2340         if (token.type == '{') {
2341                 if (warning.other)
2342                         warningf(HERE, "extra curly braces around scalar initializer");
2343                 do {
2344                         ++braces;
2345                         next_token();
2346                 } while (token.type == '{');
2347         }
2348
2349         expression_t *expression = parse_assignment_expression();
2350         mark_vars_read(expression, NULL);
2351         if (must_be_constant && !is_initializer_constant(expression)) {
2352                 errorf(&expression->base.source_position,
2353                        "Initialisation expression '%E' is not constant",
2354                        expression);
2355         }
2356
2357         initializer_t *initializer = initializer_from_expression(type, expression);
2358
2359         if (initializer == NULL) {
2360                 errorf(&expression->base.source_position,
2361                        "expression '%E' (type '%T') doesn't match expected type '%T'",
2362                        expression, expression->base.type, type);
2363                 /* TODO */
2364                 return NULL;
2365         }
2366
2367         bool additional_warning_displayed = false;
2368         while (braces > 0) {
2369                 if (token.type == ',') {
2370                         next_token();
2371                 }
2372                 if (token.type != '}') {
2373                         if (!additional_warning_displayed && warning.other) {
2374                                 warningf(HERE, "additional elements in scalar initializer");
2375                                 additional_warning_displayed = true;
2376                         }
2377                 }
2378                 eat_block();
2379                 braces--;
2380         }
2381
2382         return initializer;
2383 }
2384
2385 /**
2386  * An entry in the type path.
2387  */
2388 typedef struct type_path_entry_t type_path_entry_t;
2389 struct type_path_entry_t {
2390         type_t *type;       /**< the upper top type. restored to path->top_tye if this entry is popped. */
2391         union {
2392                 size_t         index;          /**< For array types: the current index. */
2393                 declaration_t *compound_entry; /**< For compound types: the current declaration. */
2394         } v;
2395 };
2396
2397 /**
2398  * A type path expression a position inside compound or array types.
2399  */
2400 typedef struct type_path_t type_path_t;
2401 struct type_path_t {
2402         type_path_entry_t *path;         /**< An flexible array containing the current path. */
2403         type_t            *top_type;     /**< type of the element the path points */
2404         size_t             max_index;    /**< largest index in outermost array */
2405 };
2406
2407 /**
2408  * Prints a type path for debugging.
2409  */
2410 static __attribute__((unused)) void debug_print_type_path(
2411                 const type_path_t *path)
2412 {
2413         size_t len = ARR_LEN(path->path);
2414
2415         for (size_t i = 0; i < len; ++i) {
2416                 const type_path_entry_t *entry = & path->path[i];
2417
2418                 type_t *type = skip_typeref(entry->type);
2419                 if (is_type_compound(type)) {
2420                         /* in gcc mode structs can have no members */
2421                         if (entry->v.compound_entry == NULL) {
2422                                 assert(i == len-1);
2423                                 continue;
2424                         }
2425                         fprintf(stderr, ".%s",
2426                                 entry->v.compound_entry->base.symbol->string);
2427                 } else if (is_type_array(type)) {
2428                         fprintf(stderr, "[%u]", (unsigned) entry->v.index);
2429                 } else {
2430                         fprintf(stderr, "-INVALID-");
2431                 }
2432         }
2433         if (path->top_type != NULL) {
2434                 fprintf(stderr, "  (");
2435                 print_type(path->top_type);
2436                 fprintf(stderr, ")");
2437         }
2438 }
2439
2440 /**
2441  * Return the top type path entry, ie. in a path
2442  * (type).a.b returns the b.
2443  */
2444 static type_path_entry_t *get_type_path_top(const type_path_t *path)
2445 {
2446         size_t len = ARR_LEN(path->path);
2447         assert(len > 0);
2448         return &path->path[len-1];
2449 }
2450
2451 /**
2452  * Enlarge the type path by an (empty) element.
2453  */
2454 static type_path_entry_t *append_to_type_path(type_path_t *path)
2455 {
2456         size_t len = ARR_LEN(path->path);
2457         ARR_RESIZE(type_path_entry_t, path->path, len+1);
2458
2459         type_path_entry_t *result = & path->path[len];
2460         memset(result, 0, sizeof(result[0]));
2461         return result;
2462 }
2463
2464 /**
2465  * Descending into a sub-type. Enter the scope of the current top_type.
2466  */
2467 static void descend_into_subtype(type_path_t *path)
2468 {
2469         type_t *orig_top_type = path->top_type;
2470         type_t *top_type      = skip_typeref(orig_top_type);
2471
2472         type_path_entry_t *top = append_to_type_path(path);
2473         top->type              = top_type;
2474
2475         if (is_type_compound(top_type)) {
2476                 compound_t *compound  = top_type->compound.compound;
2477                 entity_t   *entry     = compound->members.entities;
2478
2479                 if (entry != NULL) {
2480                         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
2481                         top->v.compound_entry = &entry->declaration;
2482                         path->top_type = entry->declaration.type;
2483                 } else {
2484                         path->top_type = NULL;
2485                 }
2486         } else if (is_type_array(top_type)) {
2487                 top->v.index   = 0;
2488                 path->top_type = top_type->array.element_type;
2489         } else {
2490                 assert(!is_type_valid(top_type));
2491         }
2492 }
2493
2494 /**
2495  * Pop an entry from the given type path, ie. returning from
2496  * (type).a.b to (type).a
2497  */
2498 static void ascend_from_subtype(type_path_t *path)
2499 {
2500         type_path_entry_t *top = get_type_path_top(path);
2501
2502         path->top_type = top->type;
2503
2504         size_t len = ARR_LEN(path->path);
2505         ARR_RESIZE(type_path_entry_t, path->path, len-1);
2506 }
2507
2508 /**
2509  * Pop entries from the given type path until the given
2510  * path level is reached.
2511  */
2512 static void ascend_to(type_path_t *path, size_t top_path_level)
2513 {
2514         size_t len = ARR_LEN(path->path);
2515
2516         while (len > top_path_level) {
2517                 ascend_from_subtype(path);
2518                 len = ARR_LEN(path->path);
2519         }
2520 }
2521
2522 static bool walk_designator(type_path_t *path, const designator_t *designator,
2523                             bool used_in_offsetof)
2524 {
2525         for (; designator != NULL; designator = designator->next) {
2526                 type_path_entry_t *top       = get_type_path_top(path);
2527                 type_t            *orig_type = top->type;
2528
2529                 type_t *type = skip_typeref(orig_type);
2530
2531                 if (designator->symbol != NULL) {
2532                         symbol_t *symbol = designator->symbol;
2533                         if (!is_type_compound(type)) {
2534                                 if (is_type_valid(type)) {
2535                                         errorf(&designator->source_position,
2536                                                "'.%Y' designator used for non-compound type '%T'",
2537                                                symbol, orig_type);
2538                                 }
2539
2540                                 top->type             = type_error_type;
2541                                 top->v.compound_entry = NULL;
2542                                 orig_type             = type_error_type;
2543                         } else {
2544                                 compound_t *compound = type->compound.compound;
2545                                 entity_t   *iter     = compound->members.entities;
2546                                 for (; iter != NULL; iter = iter->base.next) {
2547                                         if (iter->base.symbol == symbol) {
2548                                                 break;
2549                                         }
2550                                 }
2551                                 if (iter == NULL) {
2552                                         errorf(&designator->source_position,
2553                                                "'%T' has no member named '%Y'", orig_type, symbol);
2554                                         goto failed;
2555                                 }
2556                                 assert(iter->kind == ENTITY_COMPOUND_MEMBER);
2557                                 if (used_in_offsetof) {
2558                                         type_t *real_type = skip_typeref(iter->declaration.type);
2559                                         if (real_type->kind == TYPE_BITFIELD) {
2560                                                 errorf(&designator->source_position,
2561                                                        "offsetof designator '%Y' may not specify bitfield",
2562                                                        symbol);
2563                                                 goto failed;
2564                                         }
2565                                 }
2566
2567                                 top->type             = orig_type;
2568                                 top->v.compound_entry = &iter->declaration;
2569                                 orig_type             = iter->declaration.type;
2570                         }
2571                 } else {
2572                         expression_t *array_index = designator->array_index;
2573                         assert(designator->array_index != NULL);
2574
2575                         if (!is_type_array(type)) {
2576                                 if (is_type_valid(type)) {
2577                                         errorf(&designator->source_position,
2578                                                "[%E] designator used for non-array type '%T'",
2579                                                array_index, orig_type);
2580                                 }
2581                                 goto failed;
2582                         }
2583
2584                         long index = fold_constant(array_index);
2585                         if (!used_in_offsetof) {
2586                                 if (index < 0) {
2587                                         errorf(&designator->source_position,
2588                                                "array index [%E] must be positive", array_index);
2589                                 } else if (type->array.size_constant) {
2590                                         long array_size = type->array.size;
2591                                         if (index >= array_size) {
2592                                                 errorf(&designator->source_position,
2593                                                        "designator [%E] (%d) exceeds array size %d",
2594                                                        array_index, index, array_size);
2595                                         }
2596                                 }
2597                         }
2598
2599                         top->type    = orig_type;
2600                         top->v.index = (size_t) index;
2601                         orig_type    = type->array.element_type;
2602                 }
2603                 path->top_type = orig_type;
2604
2605                 if (designator->next != NULL) {
2606                         descend_into_subtype(path);
2607                 }
2608         }
2609         return true;
2610
2611 failed:
2612         return false;
2613 }
2614
2615 static void advance_current_object(type_path_t *path, size_t top_path_level)
2616 {
2617         type_path_entry_t *top = get_type_path_top(path);
2618
2619         type_t *type = skip_typeref(top->type);
2620         if (is_type_union(type)) {
2621                 /* in unions only the first element is initialized */
2622                 top->v.compound_entry = NULL;
2623         } else if (is_type_struct(type)) {
2624                 declaration_t *entry = top->v.compound_entry;
2625
2626                 entity_t *next_entity = entry->base.next;
2627                 if (next_entity != NULL) {
2628                         assert(is_declaration(next_entity));
2629                         entry = &next_entity->declaration;
2630                 } else {
2631                         entry = NULL;
2632                 }
2633
2634                 top->v.compound_entry = entry;
2635                 if (entry != NULL) {
2636                         path->top_type = entry->type;
2637                         return;
2638                 }
2639         } else if (is_type_array(type)) {
2640                 assert(is_type_array(type));
2641
2642                 top->v.index++;
2643
2644                 if (!type->array.size_constant || top->v.index < type->array.size) {
2645                         return;
2646                 }
2647         } else {
2648                 assert(!is_type_valid(type));
2649                 return;
2650         }
2651
2652         /* we're past the last member of the current sub-aggregate, try if we
2653          * can ascend in the type hierarchy and continue with another subobject */
2654         size_t len = ARR_LEN(path->path);
2655
2656         if (len > top_path_level) {
2657                 ascend_from_subtype(path);
2658                 advance_current_object(path, top_path_level);
2659         } else {
2660                 path->top_type = NULL;
2661         }
2662 }
2663
2664 /**
2665  * skip until token is found.
2666  */
2667 static void skip_until(int type)
2668 {
2669         while (token.type != type) {
2670                 if (token.type == T_EOF)
2671                         return;
2672                 next_token();
2673         }
2674 }
2675
2676 /**
2677  * skip any {...} blocks until a closing bracket is reached.
2678  */
2679 static void skip_initializers(void)
2680 {
2681         if (token.type == '{')
2682                 next_token();
2683
2684         while (token.type != '}') {
2685                 if (token.type == T_EOF)
2686                         return;
2687                 if (token.type == '{') {
2688                         eat_block();
2689                         continue;
2690                 }
2691                 next_token();
2692         }
2693 }
2694
2695 static initializer_t *create_empty_initializer(void)
2696 {
2697         static initializer_t empty_initializer
2698                 = { .list = { { INITIALIZER_LIST }, 0 } };
2699         return &empty_initializer;
2700 }
2701
2702 /**
2703  * Parse a part of an initialiser for a struct or union,
2704  */
2705 static initializer_t *parse_sub_initializer(type_path_t *path,
2706                 type_t *outer_type, size_t top_path_level,
2707                 parse_initializer_env_t *env)
2708 {
2709         if (token.type == '}') {
2710                 /* empty initializer */
2711                 return create_empty_initializer();
2712         }
2713
2714         type_t *orig_type = path->top_type;
2715         type_t *type      = NULL;
2716
2717         if (orig_type == NULL) {
2718                 /* We are initializing an empty compound. */
2719         } else {
2720                 type = skip_typeref(orig_type);
2721         }
2722
2723         initializer_t **initializers = NEW_ARR_F(initializer_t*, 0);
2724
2725         while (true) {
2726                 designator_t *designator = NULL;
2727                 if (token.type == '.' || token.type == '[') {
2728                         designator = parse_designation();
2729                         goto finish_designator;
2730                 } else if (token.type == T_IDENTIFIER && look_ahead(1)->type == ':') {
2731                         /* GNU-style designator ("identifier: value") */
2732                         designator = allocate_ast_zero(sizeof(designator[0]));
2733                         designator->source_position = token.source_position;
2734                         designator->symbol          = token.v.symbol;
2735                         eat(T_IDENTIFIER);
2736                         eat(':');
2737
2738 finish_designator:
2739                         /* reset path to toplevel, evaluate designator from there */
2740                         ascend_to(path, top_path_level);
2741                         if (!walk_designator(path, designator, false)) {
2742                                 /* can't continue after designation error */
2743                                 goto end_error;
2744                         }
2745
2746                         initializer_t *designator_initializer
2747                                 = allocate_initializer_zero(INITIALIZER_DESIGNATOR);
2748                         designator_initializer->designator.designator = designator;
2749                         ARR_APP1(initializer_t*, initializers, designator_initializer);
2750
2751                         orig_type = path->top_type;
2752                         type      = orig_type != NULL ? skip_typeref(orig_type) : NULL;
2753                 }
2754
2755                 initializer_t *sub;
2756
2757                 if (token.type == '{') {
2758                         if (type != NULL && is_type_scalar(type)) {
2759                                 sub = parse_scalar_initializer(type, env->must_be_constant);
2760                         } else {
2761                                 eat('{');
2762                                 if (type == NULL) {
2763                                         if (env->entity != NULL) {
2764                                                 errorf(HERE,
2765                                                      "extra brace group at end of initializer for '%Y'",
2766                                                      env->entity->base.symbol);
2767                                         } else {
2768                                                 errorf(HERE, "extra brace group at end of initializer");
2769                                         }
2770                                 } else
2771                                         descend_into_subtype(path);
2772
2773                                 add_anchor_token('}');
2774                                 sub = parse_sub_initializer(path, orig_type, top_path_level+1,
2775                                                             env);
2776                                 rem_anchor_token('}');
2777
2778                                 if (type != NULL) {
2779                                         ascend_from_subtype(path);
2780                                         expect('}', end_error);
2781                                 } else {
2782                                         expect('}', end_error);
2783                                         goto error_parse_next;
2784                                 }
2785                         }
2786                 } else {
2787                         /* must be an expression */
2788                         expression_t *expression = parse_assignment_expression();
2789                         mark_vars_read(expression, NULL);
2790
2791                         if (env->must_be_constant && !is_initializer_constant(expression)) {
2792                                 errorf(&expression->base.source_position,
2793                                        "Initialisation expression '%E' is not constant",
2794                                        expression);
2795                         }
2796
2797                         if (type == NULL) {
2798                                 /* we are already outside, ... */
2799                                 type_t *const outer_type_skip = skip_typeref(outer_type);
2800                                 if (is_type_compound(outer_type_skip) &&
2801                                     !outer_type_skip->compound.compound->complete) {
2802                                         goto error_parse_next;
2803                                 }
2804                                 goto error_excess;
2805                         }
2806
2807                         /* handle { "string" } special case */
2808                         if ((expression->kind == EXPR_STRING_LITERAL
2809                                         || expression->kind == EXPR_WIDE_STRING_LITERAL)
2810                                         && outer_type != NULL) {
2811                                 sub = initializer_from_expression(outer_type, expression);
2812                                 if (sub != NULL) {
2813                                         if (token.type == ',') {
2814                                                 next_token();
2815                                         }
2816                                         if (token.type != '}' && warning.other) {
2817                                                 warningf(HERE, "excessive elements in initializer for type '%T'",
2818                                                                  orig_type);
2819                                         }
2820                                         /* TODO: eat , ... */
2821                                         return sub;
2822                                 }
2823                         }
2824
2825                         /* descend into subtypes until expression matches type */
2826                         while (true) {
2827                                 orig_type = path->top_type;
2828                                 type      = skip_typeref(orig_type);
2829
2830                                 sub = initializer_from_expression(orig_type, expression);
2831                                 if (sub != NULL) {
2832                                         break;
2833                                 }
2834                                 if (!is_type_valid(type)) {
2835                                         goto end_error;
2836                                 }
2837                                 if (is_type_scalar(type)) {
2838                                         errorf(&expression->base.source_position,
2839                                                         "expression '%E' doesn't match expected type '%T'",
2840                                                         expression, orig_type);
2841                                         goto end_error;
2842                                 }
2843
2844                                 descend_into_subtype(path);
2845                         }
2846                 }
2847
2848                 /* update largest index of top array */
2849                 const type_path_entry_t *first      = &path->path[0];
2850                 type_t                  *first_type = first->type;
2851                 first_type                          = skip_typeref(first_type);
2852                 if (is_type_array(first_type)) {
2853                         size_t index = first->v.index;
2854                         if (index > path->max_index)
2855                                 path->max_index = index;
2856                 }
2857
2858                 if (type != NULL) {
2859                         /* append to initializers list */
2860                         ARR_APP1(initializer_t*, initializers, sub);
2861                 } else {
2862 error_excess:
2863                         if (warning.other) {
2864                                 if (env->entity != NULL) {
2865                                         warningf(HERE, "excess elements in struct initializer for '%Y'",
2866                                            env->entity->base.symbol);
2867                                 } else {
2868                                         warningf(HERE, "excess elements in struct initializer");
2869                                 }
2870                         }
2871                 }
2872
2873 error_parse_next:
2874                 if (token.type == '}') {
2875                         break;
2876                 }
2877                 expect(',', end_error);
2878                 if (token.type == '}') {
2879                         break;
2880                 }
2881
2882                 if (type != NULL) {
2883                         /* advance to the next declaration if we are not at the end */
2884                         advance_current_object(path, top_path_level);
2885                         orig_type = path->top_type;
2886                         if (orig_type != NULL)
2887                                 type = skip_typeref(orig_type);
2888                         else
2889                                 type = NULL;
2890                 }
2891         }
2892
2893         size_t len  = ARR_LEN(initializers);
2894         size_t size = sizeof(initializer_list_t) + len * sizeof(initializers[0]);
2895         initializer_t *result = allocate_ast_zero(size);
2896         result->kind          = INITIALIZER_LIST;
2897         result->list.len      = len;
2898         memcpy(&result->list.initializers, initializers,
2899                len * sizeof(initializers[0]));
2900
2901         DEL_ARR_F(initializers);
2902         ascend_to(path, top_path_level+1);
2903
2904         return result;
2905
2906 end_error:
2907         skip_initializers();
2908         DEL_ARR_F(initializers);
2909         ascend_to(path, top_path_level+1);
2910         return NULL;
2911 }
2912
2913 /**
2914  * Parses an initializer. Parsers either a compound literal
2915  * (env->declaration == NULL) or an initializer of a declaration.
2916  */
2917 static initializer_t *parse_initializer(parse_initializer_env_t *env)
2918 {
2919         type_t        *type      = skip_typeref(env->type);
2920         size_t         max_index = 0xdeadbeaf;   // TODO: Resolve this uninitialized variable problem
2921         initializer_t *result;
2922
2923         if (is_type_scalar(type)) {
2924                 result = parse_scalar_initializer(type, env->must_be_constant);
2925         } else if (token.type == '{') {
2926                 eat('{');
2927
2928                 type_path_t path;
2929                 memset(&path, 0, sizeof(path));
2930                 path.top_type = env->type;
2931                 path.path     = NEW_ARR_F(type_path_entry_t, 0);
2932
2933                 descend_into_subtype(&path);
2934
2935                 add_anchor_token('}');
2936                 result = parse_sub_initializer(&path, env->type, 1, env);
2937                 rem_anchor_token('}');
2938
2939                 max_index = path.max_index;
2940                 DEL_ARR_F(path.path);
2941
2942                 expect('}', end_error);
2943         } else {
2944                 /* parse_scalar_initializer() also works in this case: we simply
2945                  * have an expression without {} around it */
2946                 result = parse_scalar_initializer(type, env->must_be_constant);
2947         }
2948
2949         /* § 6.7.8 (22) array initializers for arrays with unknown size determine
2950          * the array type size */
2951         if (is_type_array(type) && type->array.size_expression == NULL
2952                         && result != NULL) {
2953                 size_t size;
2954                 switch (result->kind) {
2955                 case INITIALIZER_LIST:
2956                         assert(max_index != 0xdeadbeaf);
2957                         size = max_index + 1;
2958                         break;
2959
2960                 case INITIALIZER_STRING:
2961                         size = result->string.string.size;
2962                         break;
2963
2964                 case INITIALIZER_WIDE_STRING:
2965                         size = result->wide_string.string.size;
2966                         break;
2967
2968                 case INITIALIZER_DESIGNATOR:
2969                 case INITIALIZER_VALUE:
2970                         /* can happen for parse errors */
2971                         size = 0;
2972                         break;
2973
2974                 default:
2975                         internal_errorf(HERE, "invalid initializer type");
2976                 }
2977
2978                 expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
2979                 cnst->base.type          = type_size_t;
2980                 cnst->conste.v.int_value = size;
2981
2982                 type_t *new_type = duplicate_type(type);
2983
2984                 new_type->array.size_expression   = cnst;
2985                 new_type->array.size_constant     = true;
2986                 new_type->array.has_implicit_size = true;
2987                 new_type->array.size              = size;
2988                 env->type = new_type;
2989         }
2990
2991         return result;
2992 end_error:
2993         return NULL;
2994 }
2995
2996 static void append_entity(scope_t *scope, entity_t *entity)
2997 {
2998         if (scope->last_entity != NULL) {
2999                 scope->last_entity->base.next = entity;
3000         } else {
3001                 scope->entities = entity;
3002         }
3003         scope->last_entity = entity;
3004 }
3005
3006
3007 static compound_t *parse_compound_type_specifier(bool is_struct)
3008 {
3009         gnu_attribute_t  *attributes = NULL;
3010         decl_modifiers_t  modifiers  = 0;
3011         if (is_struct) {
3012                 eat(T_struct);
3013         } else {
3014                 eat(T_union);
3015         }
3016
3017         symbol_t   *symbol   = NULL;
3018         compound_t *compound = NULL;
3019
3020         if (token.type == T___attribute__) {
3021                 modifiers |= parse_attributes(&attributes);
3022         }
3023
3024         if (token.type == T_IDENTIFIER) {
3025                 symbol = token.v.symbol;
3026                 next_token();
3027
3028                 namespace_tag_t const namespc =
3029                         is_struct ? NAMESPACE_STRUCT : NAMESPACE_UNION;
3030                 entity_t *entity = get_entity(symbol, namespc);
3031                 if (entity != NULL) {
3032                         assert(entity->kind == (is_struct ? ENTITY_STRUCT : ENTITY_UNION));
3033                         compound = &entity->compound;
3034                         if (compound->base.parent_scope != current_scope &&
3035                             (token.type == '{' || token.type == ';')) {
3036                                 /* we're in an inner scope and have a definition. Override
3037                                    existing definition in outer scope */
3038                                 compound = NULL;
3039                         } else if (compound->complete && token.type == '{') {
3040                                 assert(symbol != NULL);
3041                                 errorf(HERE, "multiple definitions of '%s %Y' (previous definition %P)",
3042                                        is_struct ? "struct" : "union", symbol,
3043                                        &compound->base.source_position);
3044                                 /* clear members in the hope to avoid further errors */
3045                                 compound->members.entities = NULL;
3046                         }
3047                 }
3048         } else if (token.type != '{') {
3049                 if (is_struct) {
3050                         parse_error_expected("while parsing struct type specifier",
3051                                              T_IDENTIFIER, '{', NULL);
3052                 } else {
3053                         parse_error_expected("while parsing union type specifier",
3054                                              T_IDENTIFIER, '{', NULL);
3055                 }
3056
3057                 return NULL;
3058         }
3059
3060         if (compound == NULL) {
3061                 entity_kind_t  kind   = is_struct ? ENTITY_STRUCT : ENTITY_UNION;
3062                 entity_t      *entity = allocate_entity_zero(kind);
3063                 compound              = &entity->compound;
3064
3065                 compound->base.namespc =
3066                         (is_struct ? NAMESPACE_STRUCT : NAMESPACE_UNION);
3067                 compound->base.source_position = token.source_position;
3068                 compound->base.symbol          = symbol;
3069                 compound->base.parent_scope    = current_scope;
3070                 if (symbol != NULL) {
3071                         environment_push(entity);
3072                 }
3073                 append_entity(current_scope, entity);
3074         }
3075
3076         if (token.type == '{') {
3077                 parse_compound_type_entries(compound);
3078                 modifiers |= parse_attributes(&attributes);
3079
3080                 if (symbol == NULL) {
3081                         assert(anonymous_entity == NULL);
3082                         anonymous_entity = (entity_t*)compound;
3083                 }
3084         }
3085
3086         compound->modifiers |= modifiers;
3087         return compound;
3088 }
3089
3090 static void parse_enum_entries(type_t *const enum_type)
3091 {
3092         eat('{');
3093
3094         if (token.type == '}') {
3095                 errorf(HERE, "empty enum not allowed");
3096                 next_token();
3097                 return;
3098         }
3099
3100         add_anchor_token('}');
3101         do {
3102                 if (token.type != T_IDENTIFIER) {
3103                         parse_error_expected("while parsing enum entry", T_IDENTIFIER, NULL);
3104                         eat_block();
3105                         rem_anchor_token('}');
3106                         return;
3107                 }
3108
3109                 entity_t *entity             = allocate_entity_zero(ENTITY_ENUM_VALUE);
3110                 entity->enum_value.enum_type = enum_type;
3111                 entity->base.symbol          = token.v.symbol;
3112                 entity->base.source_position = token.source_position;
3113                 next_token();
3114
3115                 if (token.type == '=') {
3116                         next_token();
3117                         expression_t *value = parse_constant_expression();
3118
3119                         value = create_implicit_cast(value, enum_type);
3120                         entity->enum_value.value = value;
3121
3122                         /* TODO semantic */
3123                 }
3124
3125                 record_entity(entity, false);
3126
3127                 if (token.type != ',')
3128                         break;
3129                 next_token();
3130         } while (token.type != '}');
3131         rem_anchor_token('}');
3132
3133         expect('}', end_error);
3134
3135 end_error:
3136         ;
3137 }
3138
3139 static type_t *parse_enum_specifier(void)
3140 {
3141         gnu_attribute_t *attributes = NULL;
3142         entity_t        *entity;
3143         symbol_t        *symbol;
3144
3145         eat(T_enum);
3146         if (token.type == T_IDENTIFIER) {
3147                 symbol = token.v.symbol;
3148                 next_token();
3149
3150                 entity = get_entity(symbol, NAMESPACE_ENUM);
3151                 assert(entity == NULL || entity->kind == ENTITY_ENUM);
3152         } else if (token.type != '{') {
3153                 parse_error_expected("while parsing enum type specifier",
3154                                      T_IDENTIFIER, '{', NULL);
3155                 return NULL;
3156         } else {
3157                 entity  = NULL;
3158                 symbol  = NULL;
3159         }
3160
3161         if (entity == NULL) {
3162                 entity                       = allocate_entity_zero(ENTITY_ENUM);
3163                 entity->base.namespc         = NAMESPACE_ENUM;
3164                 entity->base.source_position = token.source_position;
3165                 entity->base.symbol          = symbol;
3166                 entity->base.parent_scope    = current_scope;
3167         }
3168
3169         type_t *const type = allocate_type_zero(TYPE_ENUM);
3170         type->enumt.enume  = &entity->enume;
3171
3172         if (token.type == '{') {
3173                 if (entity->enume.complete) {
3174                         errorf(HERE, "multiple definitions of 'enum %Y' (previous definition %P)",
3175                                symbol, &entity->base.source_position);
3176                 }
3177                 if (symbol != NULL) {
3178                         environment_push(entity);
3179                 }
3180                 append_entity(current_scope, entity);
3181                 entity->enume.complete = true;
3182
3183                 parse_enum_entries(type);
3184                 parse_attributes(&attributes);
3185
3186                 if (symbol == NULL) {
3187                         assert(anonymous_entity == NULL);
3188                         anonymous_entity = entity;
3189                 }
3190         } else if (!entity->enume.complete && !(c_mode & _GNUC)) {
3191                 errorf(HERE, "'enum %Y' used before definition (incomplete enums are a GNU extension)",
3192                        symbol);
3193         }
3194
3195         return type;
3196 }
3197
3198 /**
3199  * if a symbol is a typedef to another type, return true
3200  */
3201 static bool is_typedef_symbol(symbol_t *symbol)
3202 {
3203         const entity_t *const entity = get_entity(symbol, NAMESPACE_NORMAL);
3204         return entity != NULL && entity->kind == ENTITY_TYPEDEF;
3205 }
3206
3207 static type_t *parse_typeof(void)
3208 {
3209         eat(T___typeof__);
3210
3211         type_t *type;
3212
3213         expect('(', end_error);
3214         add_anchor_token(')');
3215
3216         expression_t *expression  = NULL;
3217
3218         bool old_type_prop     = in_type_prop;
3219         bool old_gcc_extension = in_gcc_extension;
3220         in_type_prop           = true;
3221
3222         while (token.type == T___extension__) {
3223                 /* This can be a prefix to a typename or an expression. */
3224                 next_token();
3225                 in_gcc_extension = true;
3226         }
3227         switch (token.type) {
3228         case T_IDENTIFIER:
3229                 if (is_typedef_symbol(token.v.symbol)) {
3230                         type = parse_typename();
3231                 } else {
3232                         expression = parse_expression();
3233                         type       = expression->base.type;
3234                 }
3235                 break;
3236
3237         TYPENAME_START
3238                 type = parse_typename();
3239                 break;
3240
3241         default:
3242                 expression = parse_expression();
3243                 type       = expression->base.type;
3244                 break;
3245         }
3246         in_type_prop     = old_type_prop;
3247         in_gcc_extension = old_gcc_extension;
3248
3249         rem_anchor_token(')');
3250         expect(')', end_error);
3251
3252         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF);
3253         typeof_type->typeoft.expression  = expression;
3254         typeof_type->typeoft.typeof_type = type;
3255
3256         return typeof_type;
3257 end_error:
3258         return NULL;
3259 }
3260
3261 typedef enum specifiers_t {
3262         SPECIFIER_SIGNED    = 1 << 0,
3263         SPECIFIER_UNSIGNED  = 1 << 1,
3264         SPECIFIER_LONG      = 1 << 2,
3265         SPECIFIER_INT       = 1 << 3,
3266         SPECIFIER_DOUBLE    = 1 << 4,
3267         SPECIFIER_CHAR      = 1 << 5,
3268         SPECIFIER_WCHAR_T   = 1 << 6,
3269         SPECIFIER_SHORT     = 1 << 7,
3270         SPECIFIER_LONG_LONG = 1 << 8,
3271         SPECIFIER_FLOAT     = 1 << 9,
3272         SPECIFIER_BOOL      = 1 << 10,
3273         SPECIFIER_VOID      = 1 << 11,
3274         SPECIFIER_INT8      = 1 << 12,
3275         SPECIFIER_INT16     = 1 << 13,
3276         SPECIFIER_INT32     = 1 << 14,
3277         SPECIFIER_INT64     = 1 << 15,
3278         SPECIFIER_INT128    = 1 << 16,
3279         SPECIFIER_COMPLEX   = 1 << 17,
3280         SPECIFIER_IMAGINARY = 1 << 18,
3281 } specifiers_t;
3282
3283 static type_t *create_builtin_type(symbol_t *const symbol,
3284                                    type_t *const real_type)
3285 {
3286         type_t *type            = allocate_type_zero(TYPE_BUILTIN);
3287         type->builtin.symbol    = symbol;
3288         type->builtin.real_type = real_type;
3289
3290         type_t *result = typehash_insert(type);
3291         if (type != result) {
3292                 free_type(type);
3293         }
3294
3295         return result;
3296 }
3297
3298 static type_t *get_typedef_type(symbol_t *symbol)
3299 {
3300         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
3301         if (entity == NULL || entity->kind != ENTITY_TYPEDEF)
3302                 return NULL;
3303
3304         type_t *type            = allocate_type_zero(TYPE_TYPEDEF);
3305         type->typedeft.typedefe = &entity->typedefe;
3306
3307         return type;
3308 }
3309
3310 /**
3311  * check for the allowed MS alignment values.
3312  */
3313 static bool check_alignment_value(long long intvalue)
3314 {
3315         if (intvalue < 1 || intvalue > 8192) {
3316                 errorf(HERE, "illegal alignment value");
3317                 return false;
3318         }
3319         unsigned v = (unsigned)intvalue;
3320         for (unsigned i = 1; i <= 8192; i += i) {
3321                 if (i == v)
3322                         return true;
3323         }
3324         errorf(HERE, "alignment must be power of two");
3325         return false;
3326 }
3327
3328 #define DET_MOD(name, tag) do { \
3329         if (*modifiers & tag && warning.other) warningf(HERE, #name " used more than once"); \
3330         *modifiers |= tag; \
3331 } while (0)
3332
3333 static void parse_microsoft_extended_decl_modifier(declaration_specifiers_t *specifiers)
3334 {
3335         decl_modifiers_t *modifiers = &specifiers->modifiers;
3336
3337         while (true) {
3338                 if (token.type == T_restrict) {
3339                         next_token();
3340                         DET_MOD(restrict, DM_RESTRICT);
3341                         goto end_loop;
3342                 } else if (token.type != T_IDENTIFIER)
3343                         break;
3344                 symbol_t *symbol = token.v.symbol;
3345                 if (symbol == sym_align) {
3346                         next_token();
3347                         expect('(', end_error);
3348                         if (token.type != T_INTEGER)
3349                                 goto end_error;
3350                         if (check_alignment_value(token.v.intvalue)) {
3351                                 if (specifiers->alignment != 0 && warning.other)
3352                                         warningf(HERE, "align used more than once");
3353                                 specifiers->alignment = (unsigned char)token.v.intvalue;
3354                         }
3355                         next_token();
3356                         expect(')', end_error);
3357                 } else if (symbol == sym_allocate) {
3358                         next_token();
3359                         expect('(', end_error);
3360                         if (token.type != T_IDENTIFIER)
3361                                 goto end_error;
3362                         (void)token.v.symbol;
3363                         expect(')', end_error);
3364                 } else if (symbol == sym_dllimport) {
3365                         next_token();
3366                         DET_MOD(dllimport, DM_DLLIMPORT);
3367                 } else if (symbol == sym_dllexport) {
3368                         next_token();
3369                         DET_MOD(dllexport, DM_DLLEXPORT);
3370                 } else if (symbol == sym_thread) {
3371                         next_token();
3372                         DET_MOD(thread, DM_THREAD);
3373                 } else if (symbol == sym_naked) {
3374                         next_token();
3375                         DET_MOD(naked, DM_NAKED);
3376                 } else if (symbol == sym_noinline) {
3377                         next_token();
3378                         DET_MOD(noinline, DM_NOINLINE);
3379                 } else if (symbol == sym_returns_twice) {
3380                         next_token();
3381                         DET_MOD(returns_twice, DM_RETURNS_TWICE);
3382                 } else if (symbol == sym_noreturn) {
3383                         next_token();
3384                         DET_MOD(noreturn, DM_NORETURN);
3385                 } else if (symbol == sym_nothrow) {
3386                         next_token();
3387                         DET_MOD(nothrow, DM_NOTHROW);
3388                 } else if (symbol == sym_novtable) {
3389                         next_token();
3390                         DET_MOD(novtable, DM_NOVTABLE);
3391                 } else if (symbol == sym_property) {
3392                         next_token();
3393                         expect('(', end_error);
3394                         for (;;) {
3395                                 bool is_get = false;
3396                                 if (token.type != T_IDENTIFIER)
3397                                         goto end_error;
3398                                 if (token.v.symbol == sym_get) {
3399                                         is_get = true;
3400                                 } else if (token.v.symbol == sym_put) {
3401                                 } else {
3402                                         errorf(HERE, "Bad property name '%Y'", token.v.symbol);
3403                                         goto end_error;
3404                                 }
3405                                 next_token();
3406                                 expect('=', end_error);
3407                                 if (token.type != T_IDENTIFIER)
3408                                         goto end_error;
3409                                 if (is_get) {
3410                                         if (specifiers->get_property_sym != NULL) {
3411                                                 errorf(HERE, "get property name already specified");
3412                                         } else {
3413                                                 specifiers->get_property_sym = token.v.symbol;
3414                                         }
3415                                 } else {
3416                                         if (specifiers->put_property_sym != NULL) {
3417                                                 errorf(HERE, "put property name already specified");
3418                                         } else {
3419                                                 specifiers->put_property_sym = token.v.symbol;
3420                                         }
3421                                 }
3422                                 next_token();
3423                                 if (token.type == ',') {
3424                                         next_token();
3425                                         continue;
3426                                 }
3427                                 break;
3428                         }
3429                         expect(')', end_error);
3430                 } else if (symbol == sym_selectany) {
3431                         next_token();
3432                         DET_MOD(selectany, DM_SELECTANY);
3433                 } else if (symbol == sym_uuid) {
3434                         next_token();
3435                         expect('(', end_error);
3436                         if (token.type != T_STRING_LITERAL)
3437                                 goto end_error;
3438                         next_token();
3439                         expect(')', end_error);
3440                 } else if (symbol == sym_deprecated) {
3441                         next_token();
3442                         if (specifiers->deprecated != 0 && warning.other)
3443                                 warningf(HERE, "deprecated used more than once");
3444                         specifiers->deprecated = true;
3445                         if (token.type == '(') {
3446                                 next_token();
3447                                 if (token.type == T_STRING_LITERAL) {
3448                                         specifiers->deprecated_string = token.v.string.begin;
3449                                         next_token();
3450                                 } else {
3451                                         errorf(HERE, "string literal expected");
3452                                 }
3453                                 expect(')', end_error);
3454                         }
3455                 } else if (symbol == sym_noalias) {
3456                         next_token();
3457                         DET_MOD(noalias, DM_NOALIAS);
3458                 } else {
3459                         if (warning.other)
3460                                 warningf(HERE, "Unknown modifier '%Y' ignored", token.v.symbol);
3461                         next_token();
3462                         if (token.type == '(')
3463                                 skip_until(')');
3464                 }
3465 end_loop:
3466                 if (token.type == ',')
3467                         next_token();
3468         }
3469 end_error:
3470         return;
3471 }
3472
3473 static entity_t *create_error_entity(symbol_t *symbol, entity_kind_tag_t kind)
3474 {
3475         entity_t *entity             = allocate_entity_zero(kind);
3476         entity->base.source_position = *HERE;
3477         entity->base.symbol          = symbol;
3478         if (is_declaration(entity)) {
3479                 entity->declaration.type     = type_error_type;
3480                 entity->declaration.implicit = true;
3481         } else if (kind == ENTITY_TYPEDEF) {
3482                 entity->typedefe.type    = type_error_type;
3483                 entity->typedefe.builtin = true;
3484         }
3485         if (kind != ENTITY_COMPOUND_MEMBER)
3486                 record_entity(entity, false);
3487         return entity;
3488 }
3489
3490 static void parse_microsoft_based(based_spec_t *based_spec)
3491 {
3492         if (token.type != T_IDENTIFIER) {
3493                 parse_error_expected("while parsing __based", T_IDENTIFIER, NULL);
3494                 return;
3495         }
3496         symbol_t *symbol = token.v.symbol;
3497         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
3498
3499         if (entity == NULL || entity->base.kind != ENTITY_VARIABLE) {
3500                 errorf(HERE, "'%Y' is not a variable name.", symbol);
3501                 entity = create_error_entity(symbol, ENTITY_VARIABLE);
3502         } else {
3503                 variable_t *variable = &entity->variable;
3504
3505                 if (based_spec->base_variable != NULL) {
3506                         errorf(HERE, "__based type qualifier specified more than once");
3507                 }
3508                 based_spec->source_position = token.source_position;
3509                 based_spec->base_variable   = variable;
3510
3511                 type_t *const type = variable->base.type;
3512
3513                 if (is_type_valid(type)) {
3514                         if (! is_type_pointer(skip_typeref(type))) {
3515                                 errorf(HERE, "variable in __based modifier must have pointer type instead of '%T'", type);
3516                         }
3517                         if (variable->base.base.parent_scope != file_scope) {
3518                                 errorf(HERE, "a nonstatic local variable may not be used in a __based specification");
3519                         }
3520                 }
3521         }
3522         next_token();
3523 }
3524
3525 /**
3526  * Finish the construction of a struct type by calculating
3527  * its size, offsets, alignment.
3528  */
3529 static void finish_struct_type(compound_type_t *type)
3530 {
3531         assert(type->compound != NULL);
3532
3533         compound_t *compound = type->compound;
3534         if (!compound->complete)
3535                 return;
3536
3537         il_size_t      size           = 0;
3538         il_size_t      offset;
3539         il_alignment_t alignment      = 1;
3540         bool           need_pad       = false;
3541
3542         entity_t *entry = compound->members.entities;
3543         for (; entry != NULL; entry = entry->base.next) {
3544                 if (entry->kind != ENTITY_COMPOUND_MEMBER)
3545                         continue;
3546
3547                 type_t *m_type = skip_typeref(entry->declaration.type);
3548                 if (! is_type_valid(m_type)) {
3549                         /* simply ignore errors here */
3550                         continue;
3551                 }
3552                 il_alignment_t m_alignment = m_type->base.alignment;
3553                 if (m_alignment > alignment)
3554                         alignment = m_alignment;
3555
3556                 offset = (size + m_alignment - 1) & -m_alignment;
3557
3558                 if (offset > size)
3559                         need_pad = true;
3560                 entry->compound_member.offset = offset;
3561                 size = offset + m_type->base.size;
3562         }
3563         if (type->base.alignment != 0) {
3564                 alignment = type->base.alignment;
3565         }
3566
3567         offset = (size + alignment - 1) & -alignment;
3568         if (offset > size)
3569                 need_pad = true;
3570
3571         if (need_pad) {
3572                 if (warning.padded) {
3573                         warningf(&compound->base.source_position, "'%T' needs padding", type);
3574                 }
3575         } else {
3576                 if (compound->modifiers & DM_PACKED && warning.packed) {
3577                         warningf(&compound->base.source_position,
3578                                         "superfluous packed attribute on '%T'", type);
3579                 }
3580         }
3581
3582         type->base.size      = offset;
3583         type->base.alignment = alignment;
3584 }
3585
3586 /**
3587  * Finish the construction of an union type by calculating
3588  * its size and alignment.
3589  */
3590 static void finish_union_type(compound_type_t *type)
3591 {
3592         assert(type->compound != NULL);
3593
3594         compound_t *compound = type->compound;
3595         if (! compound->complete)
3596                 return;
3597
3598         il_size_t      size      = 0;
3599         il_alignment_t alignment = 1;
3600
3601         entity_t *entry = compound->members.entities;
3602         for (; entry != NULL; entry = entry->base.next) {
3603                 if (entry->kind != ENTITY_COMPOUND_MEMBER)
3604                         continue;
3605
3606                 type_t *m_type = skip_typeref(entry->declaration.type);
3607                 if (! is_type_valid(m_type))
3608                         continue;
3609
3610                 entry->compound_member.offset = 0;
3611                 if (m_type->base.size > size)
3612                         size = m_type->base.size;
3613                 if (m_type->base.alignment > alignment)
3614                         alignment = m_type->base.alignment;
3615         }
3616         if (type->base.alignment != 0) {
3617                 alignment = type->base.alignment;
3618         }
3619         size = (size + alignment - 1) & -alignment;
3620         type->base.size      = size;
3621         type->base.alignment = alignment;
3622 }
3623
3624 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
3625 {
3626         type_t            *type              = NULL;
3627         type_qualifiers_t  qualifiers        = TYPE_QUALIFIER_NONE;
3628         type_modifiers_t   modifiers         = TYPE_MODIFIER_NONE;
3629         unsigned           type_specifiers   = 0;
3630         bool               newtype           = false;
3631         bool               saw_error         = false;
3632         bool               old_gcc_extension = in_gcc_extension;
3633
3634         specifiers->source_position = token.source_position;
3635
3636         while (true) {
3637                 specifiers->modifiers
3638                         |= parse_attributes(&specifiers->gnu_attributes);
3639                 if (specifiers->modifiers & DM_TRANSPARENT_UNION)
3640                         modifiers |= TYPE_MODIFIER_TRANSPARENT_UNION;
3641
3642                 switch (token.type) {
3643                 /* storage class */
3644 #define MATCH_STORAGE_CLASS(token, class)                                  \
3645                 case token:                                                        \
3646                         if (specifiers->storage_class != STORAGE_CLASS_NONE) {         \
3647                                 errorf(HERE, "multiple storage classes in declaration specifiers"); \
3648                         }                                                              \
3649                         specifiers->storage_class = class;                             \
3650                         if (specifiers->thread_local)                                  \
3651                                 goto check_thread_storage_class;                           \
3652                         next_token();                                                  \
3653                         break;
3654
3655                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
3656                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
3657                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
3658                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
3659                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
3660
3661                 case T__declspec:
3662                         next_token();
3663                         expect('(', end_error);
3664                         add_anchor_token(')');
3665                         parse_microsoft_extended_decl_modifier(specifiers);
3666                         rem_anchor_token(')');
3667                         expect(')', end_error);
3668                         break;
3669
3670                 case T___thread:
3671                         if (specifiers->thread_local) {
3672                                 errorf(HERE, "duplicate '__thread'");
3673                         } else {
3674                                 specifiers->thread_local = true;
3675 check_thread_storage_class:
3676                                 switch (specifiers->storage_class) {
3677                                         case STORAGE_CLASS_EXTERN:
3678                                         case STORAGE_CLASS_NONE:
3679                                         case STORAGE_CLASS_STATIC:
3680                                                 break;
3681
3682                                                 char const* wrong;
3683                                         case STORAGE_CLASS_AUTO:     wrong = "auto";     goto wrong_thread_stoarge_class;
3684                                         case STORAGE_CLASS_REGISTER: wrong = "register"; goto wrong_thread_stoarge_class;
3685                                         case STORAGE_CLASS_TYPEDEF:  wrong = "typedef";  goto wrong_thread_stoarge_class;
3686 wrong_thread_stoarge_class:
3687                                                 errorf(HERE, "'__thread' used with '%s'", wrong);
3688                                                 break;
3689                                 }
3690                         }
3691                         next_token();
3692                         break;
3693
3694                 /* type qualifiers */
3695 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
3696                 case token:                                                     \
3697                         qualifiers |= qualifier;                                    \
3698                         next_token();                                               \
3699                         break
3700
3701                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3702                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3703                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3704                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3705                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3706                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3707                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3708                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3709
3710                 case T___extension__:
3711                         next_token();
3712                         in_gcc_extension = true;
3713                         break;
3714
3715                 /* type specifiers */
3716 #define MATCH_SPECIFIER(token, specifier, name)                         \
3717                 case token:                                                     \
3718                         if (type_specifiers & specifier) {                           \
3719                                 errorf(HERE, "multiple " name " type specifiers given"); \
3720                         } else {                                                    \
3721                                 type_specifiers |= specifier;                           \
3722                         }                                                           \
3723                         next_token();                                               \
3724                         break
3725
3726                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool");
3727                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex");
3728                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary");
3729                 MATCH_SPECIFIER(T__int128,    SPECIFIER_INT128,    "_int128");
3730                 MATCH_SPECIFIER(T__int16,     SPECIFIER_INT16,     "_int16");
3731                 MATCH_SPECIFIER(T__int32,     SPECIFIER_INT32,     "_int32");
3732                 MATCH_SPECIFIER(T__int64,     SPECIFIER_INT64,     "_int64");
3733                 MATCH_SPECIFIER(T__int8,      SPECIFIER_INT8,      "_int8");
3734                 MATCH_SPECIFIER(T_bool,       SPECIFIER_BOOL,      "bool");
3735                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char");
3736                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double");
3737                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float");
3738                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int");
3739                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short");
3740                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed");
3741                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned");
3742                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void");
3743                 MATCH_SPECIFIER(T_wchar_t,    SPECIFIER_WCHAR_T,   "wchar_t");
3744
3745                 case T__forceinline:
3746                         /* only in microsoft mode */
3747                         specifiers->modifiers |= DM_FORCEINLINE;
3748                         /* FALLTHROUGH */
3749
3750                 case T_inline:
3751                         next_token();
3752                         specifiers->is_inline = true;
3753                         break;
3754
3755                 case T_long:
3756                         if (type_specifiers & SPECIFIER_LONG_LONG) {
3757                                 errorf(HERE, "multiple type specifiers given");
3758                         } else if (type_specifiers & SPECIFIER_LONG) {
3759                                 type_specifiers |= SPECIFIER_LONG_LONG;
3760                         } else {
3761                                 type_specifiers |= SPECIFIER_LONG;
3762                         }
3763                         next_token();
3764                         break;
3765
3766                 case T_struct: {
3767                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
3768
3769                         type->compound.compound = parse_compound_type_specifier(true);
3770                         finish_struct_type(&type->compound);
3771                         break;
3772                 }
3773                 case T_union: {
3774                         type = allocate_type_zero(TYPE_COMPOUND_UNION);
3775                         type->compound.compound = parse_compound_type_specifier(false);
3776                         if (type->compound.compound->modifiers & DM_TRANSPARENT_UNION)
3777                                 modifiers |= TYPE_MODIFIER_TRANSPARENT_UNION;
3778                         finish_union_type(&type->compound);
3779                         break;
3780                 }
3781                 case T_enum:
3782                         type = parse_enum_specifier();
3783                         break;
3784                 case T___typeof__:
3785                         type = parse_typeof();
3786                         break;
3787                 case T___builtin_va_list:
3788                         type = duplicate_type(type_valist);
3789                         next_token();
3790                         break;
3791
3792                 case T_IDENTIFIER: {
3793                         /* only parse identifier if we haven't found a type yet */
3794                         if (type != NULL || type_specifiers != 0) {
3795                                 /* Be somewhat resilient to typos like 'unsigned lng* f()' in a
3796                                  * declaration, so it doesn't generate errors about expecting '(' or
3797                                  * '{' later on. */
3798                                 switch (look_ahead(1)->type) {
3799                                         STORAGE_CLASSES
3800                                         TYPE_SPECIFIERS
3801                                         case T_const:
3802                                         case T_restrict:
3803                                         case T_volatile:
3804                                         case T_inline:
3805                                         case T__forceinline: /* ^ DECLARATION_START except for __attribute__ */
3806                                         case T_IDENTIFIER:
3807                                         case '&':
3808                                         case '*':
3809                                                 errorf(HERE, "discarding stray %K in declaration specifier", &token);
3810                                                 next_token();
3811                                                 continue;
3812
3813                                         default:
3814                                                 goto finish_specifiers;
3815                                 }
3816                         }
3817
3818                         type_t *const typedef_type = get_typedef_type(token.v.symbol);
3819                         if (typedef_type == NULL) {
3820                                 /* Be somewhat resilient to typos like 'vodi f()' at the beginning of a
3821                                  * declaration, so it doesn't generate 'implicit int' followed by more
3822                                  * errors later on. */
3823                                 token_type_t const la1_type = (token_type_t)look_ahead(1)->type;
3824                                 switch (la1_type) {
3825                                         DECLARATION_START
3826                                         case T_IDENTIFIER:
3827                                         case '&':
3828                                         case '*': {
3829                                                 errorf(HERE, "%K does not name a type", &token);
3830
3831                                                 entity_t *entity =
3832                                                         create_error_entity(token.v.symbol, ENTITY_TYPEDEF);
3833
3834                                                 type = allocate_type_zero(TYPE_TYPEDEF);
3835                                                 type->typedeft.typedefe = &entity->typedefe;
3836
3837                                                 next_token();
3838                                                 saw_error = true;
3839                                                 if (la1_type == '&' || la1_type == '*')
3840                                                         goto finish_specifiers;
3841                                                 continue;
3842                                         }
3843
3844                                         default:
3845                                                 goto finish_specifiers;
3846                                 }
3847                         }
3848
3849                         next_token();
3850                         type = typedef_type;
3851                         break;
3852                 }
3853
3854                 /* function specifier */
3855                 default:
3856                         goto finish_specifiers;
3857                 }
3858         }
3859
3860 finish_specifiers:
3861         in_gcc_extension = old_gcc_extension;
3862
3863         if (type == NULL || (saw_error && type_specifiers != 0)) {
3864                 atomic_type_kind_t atomic_type;
3865
3866                 /* match valid basic types */
3867                 switch (type_specifiers) {
3868                 case SPECIFIER_VOID:
3869                         atomic_type = ATOMIC_TYPE_VOID;
3870                         break;
3871                 case SPECIFIER_WCHAR_T:
3872                         atomic_type = ATOMIC_TYPE_WCHAR_T;
3873                         break;
3874                 case SPECIFIER_CHAR:
3875                         atomic_type = ATOMIC_TYPE_CHAR;
3876                         break;
3877                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
3878                         atomic_type = ATOMIC_TYPE_SCHAR;
3879                         break;
3880                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
3881                         atomic_type = ATOMIC_TYPE_UCHAR;
3882                         break;
3883                 case SPECIFIER_SHORT:
3884                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
3885                 case SPECIFIER_SHORT | SPECIFIER_INT:
3886                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
3887                         atomic_type = ATOMIC_TYPE_SHORT;
3888                         break;
3889                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
3890                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
3891                         atomic_type = ATOMIC_TYPE_USHORT;
3892                         break;
3893                 case SPECIFIER_INT:
3894                 case SPECIFIER_SIGNED:
3895                 case SPECIFIER_SIGNED | SPECIFIER_INT:
3896                         atomic_type = ATOMIC_TYPE_INT;
3897                         break;
3898                 case SPECIFIER_UNSIGNED:
3899                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
3900                         atomic_type = ATOMIC_TYPE_UINT;
3901                         break;
3902                 case SPECIFIER_LONG:
3903                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
3904                 case SPECIFIER_LONG | SPECIFIER_INT:
3905                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
3906                         atomic_type = ATOMIC_TYPE_LONG;
3907                         break;
3908                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
3909                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
3910                         atomic_type = ATOMIC_TYPE_ULONG;
3911                         break;
3912
3913                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3914                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3915                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
3916                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3917                         | SPECIFIER_INT:
3918                         atomic_type = ATOMIC_TYPE_LONGLONG;
3919                         goto warn_about_long_long;
3920
3921                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3922                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3923                         | SPECIFIER_INT:
3924                         atomic_type = ATOMIC_TYPE_ULONGLONG;
3925 warn_about_long_long:
3926                         if (warning.long_long) {
3927                                 warningf(&specifiers->source_position,
3928                                          "ISO C90 does not support 'long long'");
3929                         }
3930                         break;
3931
3932                 case SPECIFIER_UNSIGNED | SPECIFIER_INT8:
3933                         atomic_type = unsigned_int8_type_kind;
3934                         break;
3935
3936                 case SPECIFIER_UNSIGNED | SPECIFIER_INT16:
3937                         atomic_type = unsigned_int16_type_kind;
3938                         break;
3939
3940                 case SPECIFIER_UNSIGNED | SPECIFIER_INT32:
3941                         atomic_type = unsigned_int32_type_kind;
3942                         break;
3943
3944                 case SPECIFIER_UNSIGNED | SPECIFIER_INT64:
3945                         atomic_type = unsigned_int64_type_kind;
3946                         break;
3947
3948                 case SPECIFIER_UNSIGNED | SPECIFIER_INT128:
3949                         atomic_type = unsigned_int128_type_kind;
3950                         break;
3951
3952                 case SPECIFIER_INT8:
3953                 case SPECIFIER_SIGNED | SPECIFIER_INT8:
3954                         atomic_type = int8_type_kind;
3955                         break;
3956
3957                 case SPECIFIER_INT16:
3958                 case SPECIFIER_SIGNED | SPECIFIER_INT16:
3959                         atomic_type = int16_type_kind;
3960                         break;
3961
3962                 case SPECIFIER_INT32:
3963                 case SPECIFIER_SIGNED | SPECIFIER_INT32:
3964                         atomic_type = int32_type_kind;
3965                         break;
3966
3967                 case SPECIFIER_INT64:
3968                 case SPECIFIER_SIGNED | SPECIFIER_INT64:
3969                         atomic_type = int64_type_kind;
3970                         break;
3971
3972                 case SPECIFIER_INT128:
3973                 case SPECIFIER_SIGNED | SPECIFIER_INT128:
3974                         atomic_type = int128_type_kind;
3975                         break;
3976
3977                 case SPECIFIER_FLOAT:
3978                         atomic_type = ATOMIC_TYPE_FLOAT;
3979                         break;
3980                 case SPECIFIER_DOUBLE:
3981                         atomic_type = ATOMIC_TYPE_DOUBLE;
3982                         break;
3983                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
3984                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
3985                         break;
3986                 case SPECIFIER_BOOL:
3987                         atomic_type = ATOMIC_TYPE_BOOL;
3988                         break;
3989                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
3990                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
3991                         atomic_type = ATOMIC_TYPE_FLOAT;
3992                         break;
3993                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3994                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3995                         atomic_type = ATOMIC_TYPE_DOUBLE;
3996                         break;
3997                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3998                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3999                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
4000                         break;
4001                 default:
4002                         /* invalid specifier combination, give an error message */
4003                         if (type_specifiers == 0) {
4004                                 if (saw_error)
4005                                         goto end_error;
4006
4007                                 /* ISO/IEC 14882:1998(E) §C.1.5:4 */
4008                                 if (!(c_mode & _CXX) && !strict_mode) {
4009                                         if (warning.implicit_int) {
4010                                                 warningf(HERE, "no type specifiers in declaration, using 'int'");
4011                                         }
4012                                         atomic_type = ATOMIC_TYPE_INT;
4013                                         break;
4014                                 } else {
4015                                         errorf(HERE, "no type specifiers given in declaration");
4016                                 }
4017                         } else if ((type_specifiers & SPECIFIER_SIGNED) &&
4018                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
4019                                 errorf(HERE, "signed and unsigned specifiers given");
4020                         } else if (type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
4021                                 errorf(HERE, "only integer types can be signed or unsigned");
4022                         } else {
4023                                 errorf(HERE, "multiple datatypes in declaration");
4024                         }
4025                         goto end_error;
4026                 }
4027
4028                 if (type_specifiers & SPECIFIER_COMPLEX) {
4029                         type                = allocate_type_zero(TYPE_COMPLEX);
4030                         type->complex.akind = atomic_type;
4031                 } else if (type_specifiers & SPECIFIER_IMAGINARY) {
4032                         type                  = allocate_type_zero(TYPE_IMAGINARY);
4033                         type->imaginary.akind = atomic_type;
4034                 } else {
4035                         type               = allocate_type_zero(TYPE_ATOMIC);
4036                         type->atomic.akind = atomic_type;
4037                 }
4038                 newtype = true;
4039         } else if (type_specifiers != 0) {
4040                 errorf(HERE, "multiple datatypes in declaration");
4041         }
4042
4043         /* FIXME: check type qualifiers here */
4044
4045         type->base.qualifiers = qualifiers;
4046         type->base.modifiers  = modifiers;
4047
4048         type_t *result = typehash_insert(type);
4049         if (newtype && result != type) {
4050                 free_type(type);
4051         }
4052
4053         specifiers->type = result;
4054         return;
4055
4056 end_error:
4057         specifiers->type = type_error_type;
4058         return;
4059 }
4060
4061 static type_qualifiers_t parse_type_qualifiers(void)
4062 {
4063         type_qualifiers_t qualifiers = TYPE_QUALIFIER_NONE;
4064
4065         while (true) {
4066                 switch (token.type) {
4067                 /* type qualifiers */
4068                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
4069                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
4070                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
4071                 /* microsoft extended type modifiers */
4072                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
4073                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
4074                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
4075                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
4076                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
4077
4078                 default:
4079                         return qualifiers;
4080                 }
4081         }
4082 }
4083
4084 /**
4085  * Parses an K&R identifier list
4086  */
4087 static void parse_identifier_list(scope_t *scope)
4088 {
4089         do {
4090                 entity_t *entity = allocate_entity_zero(ENTITY_PARAMETER);
4091                 entity->base.source_position = token.source_position;
4092                 entity->base.namespc         = NAMESPACE_NORMAL;
4093                 entity->base.symbol          = token.v.symbol;
4094                 /* a K&R parameter has no type, yet */
4095                 next_token();
4096
4097                 if (scope != NULL)
4098                         append_entity(scope, entity);
4099
4100                 if (token.type != ',') {
4101                         break;
4102                 }
4103                 next_token();
4104         } while (token.type == T_IDENTIFIER);
4105 }
4106
4107 static entity_t *parse_parameter(void)
4108 {
4109         declaration_specifiers_t specifiers;
4110         memset(&specifiers, 0, sizeof(specifiers));
4111
4112         parse_declaration_specifiers(&specifiers);
4113
4114         entity_t *entity = parse_declarator(&specifiers,
4115                         DECL_MAY_BE_ABSTRACT | DECL_IS_PARAMETER);
4116         anonymous_entity = NULL;
4117         return entity;
4118 }
4119
4120 static void semantic_parameter_incomplete(const entity_t *entity)
4121 {
4122         assert(entity->kind == ENTITY_PARAMETER);
4123
4124         /* §6.7.5.3:4  After adjustment, the parameters in a parameter type
4125          *             list in a function declarator that is part of a
4126          *             definition of that function shall not have
4127          *             incomplete type. */
4128         type_t *type = skip_typeref(entity->declaration.type);
4129         if (is_type_incomplete(type)) {
4130                 errorf(&entity->base.source_position,
4131                        "parameter '%Y' has incomplete type '%T'", entity->base.symbol,
4132                        entity->declaration.type);
4133         }
4134 }
4135
4136 /**
4137  * Parses function type parameters (and optionally creates variable_t entities
4138  * for them in a scope)
4139  */
4140 static void parse_parameters(function_type_t *type, scope_t *scope)
4141 {
4142         eat('(');
4143         add_anchor_token(')');
4144         int saved_comma_state = save_and_reset_anchor_state(',');
4145
4146         if (token.type == T_IDENTIFIER &&
4147             !is_typedef_symbol(token.v.symbol)) {
4148                 token_type_t la1_type = (token_type_t)look_ahead(1)->type;
4149                 if (la1_type == ',' || la1_type == ')') {
4150                         type->kr_style_parameters    = true;
4151                         type->unspecified_parameters = true;
4152                         parse_identifier_list(scope);
4153                         goto parameters_finished;
4154                 }
4155         }
4156
4157         if (token.type == ')') {
4158                 /* ISO/IEC 14882:1998(E) §C.1.6:1 */
4159                 if (!(c_mode & _CXX))
4160                         type->unspecified_parameters = true;
4161                 goto parameters_finished;
4162         }
4163
4164         function_parameter_t *parameter;
4165         function_parameter_t *last_parameter = NULL;
4166
4167         while (true) {
4168                 switch (token.type) {
4169                 case T_DOTDOTDOT:
4170                         next_token();
4171                         type->variadic = true;
4172                         goto parameters_finished;
4173
4174                 case T_IDENTIFIER:
4175                 case T___extension__:
4176                 DECLARATION_START
4177                 {
4178                         entity_t *entity = parse_parameter();
4179                         if (entity->kind == ENTITY_TYPEDEF) {
4180                                 errorf(&entity->base.source_position,
4181                                        "typedef not allowed as function parameter");
4182                                 break;
4183                         }
4184                         assert(is_declaration(entity));
4185
4186                         /* func(void) is not a parameter */
4187                         if (last_parameter == NULL
4188                                         && token.type == ')'
4189                                         && entity->base.symbol == NULL
4190                                         && skip_typeref(entity->declaration.type) == type_void) {
4191                                 goto parameters_finished;
4192                         }
4193                         semantic_parameter_incomplete(entity);
4194
4195                         parameter = obstack_alloc(type_obst, sizeof(parameter[0]));
4196                         memset(parameter, 0, sizeof(parameter[0]));
4197                         parameter->type = entity->declaration.type;
4198
4199                         if (scope != NULL) {
4200                                 append_entity(scope, entity);
4201                         }
4202
4203                         if (last_parameter != NULL) {
4204                                 last_parameter->next = parameter;
4205                         } else {
4206                                 type->parameters = parameter;
4207                         }
4208                         last_parameter   = parameter;
4209                         break;
4210                 }
4211
4212                 default:
4213                         goto parameters_finished;
4214                 }
4215                 if (token.type != ',') {
4216                         goto parameters_finished;
4217                 }
4218                 next_token();
4219         }
4220
4221
4222 parameters_finished:
4223         rem_anchor_token(')');
4224         expect(')', end_error);
4225
4226 end_error:
4227         restore_anchor_state(',', saved_comma_state);
4228 }
4229
4230 typedef enum construct_type_kind_t {
4231         CONSTRUCT_INVALID,
4232         CONSTRUCT_POINTER,
4233         CONSTRUCT_REFERENCE,
4234         CONSTRUCT_FUNCTION,
4235         CONSTRUCT_ARRAY
4236 } construct_type_kind_t;
4237
4238 typedef struct construct_type_t construct_type_t;
4239 struct construct_type_t {
4240         construct_type_kind_t  kind;
4241         construct_type_t      *next;
4242 };
4243
4244 typedef struct parsed_pointer_t parsed_pointer_t;
4245 struct parsed_pointer_t {
4246         construct_type_t  construct_type;
4247         type_qualifiers_t type_qualifiers;
4248         variable_t        *base_variable;  /**< MS __based extension. */
4249 };
4250
4251 typedef struct parsed_reference_t parsed_reference_t;
4252 struct parsed_reference_t {
4253         construct_type_t construct_type;
4254 };
4255
4256 typedef struct construct_function_type_t construct_function_type_t;
4257 struct construct_function_type_t {
4258         construct_type_t  construct_type;
4259         type_t           *function_type;
4260 };
4261
4262 typedef struct parsed_array_t parsed_array_t;
4263 struct parsed_array_t {
4264         construct_type_t  construct_type;
4265         type_qualifiers_t type_qualifiers;
4266         bool              is_static;
4267         bool              is_variable;
4268         expression_t     *size;
4269 };
4270
4271 typedef struct construct_base_type_t construct_base_type_t;
4272 struct construct_base_type_t {
4273         construct_type_t  construct_type;
4274         type_t           *type;
4275 };
4276
4277 static construct_type_t *parse_pointer_declarator(variable_t *base_variable)
4278 {
4279         eat('*');
4280
4281         parsed_pointer_t *pointer = obstack_alloc(&temp_obst, sizeof(pointer[0]));
4282         memset(pointer, 0, sizeof(pointer[0]));
4283         pointer->construct_type.kind = CONSTRUCT_POINTER;
4284         pointer->type_qualifiers     = parse_type_qualifiers();
4285         pointer->base_variable       = base_variable;
4286
4287         return &pointer->construct_type;
4288 }
4289
4290 static construct_type_t *parse_reference_declarator(void)
4291 {
4292         eat('&');
4293
4294         parsed_reference_t *reference = obstack_alloc(&temp_obst, sizeof(reference[0]));
4295         memset(reference, 0, sizeof(reference[0]));
4296         reference->construct_type.kind = CONSTRUCT_REFERENCE;
4297
4298         return (construct_type_t*)reference;
4299 }
4300
4301 static construct_type_t *parse_array_declarator(void)
4302 {
4303         eat('[');
4304         add_anchor_token(']');
4305
4306         parsed_array_t *array = obstack_alloc(&temp_obst, sizeof(array[0]));
4307         memset(array, 0, sizeof(array[0]));
4308         array->construct_type.kind = CONSTRUCT_ARRAY;
4309
4310         if (token.type == T_static) {
4311                 array->is_static = true;
4312                 next_token();
4313         }
4314
4315         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
4316         if (type_qualifiers != 0) {
4317                 if (token.type == T_static) {
4318                         array->is_static = true;
4319                         next_token();
4320                 }
4321         }
4322         array->type_qualifiers = type_qualifiers;
4323
4324         if (token.type == '*' && look_ahead(1)->type == ']') {
4325                 array->is_variable = true;
4326                 next_token();
4327         } else if (token.type != ']') {
4328                 expression_t *const size = parse_assignment_expression();
4329                 array->size = size;
4330                 mark_vars_read(size, NULL);
4331         }
4332
4333         rem_anchor_token(']');
4334         expect(']', end_error);
4335
4336 end_error:
4337         return &array->construct_type;
4338 }
4339
4340 static construct_type_t *parse_function_declarator(scope_t *scope,
4341                                                    decl_modifiers_t modifiers)
4342 {
4343         type_t          *type  = allocate_type_zero(TYPE_FUNCTION);
4344         function_type_t *ftype = &type->function;
4345
4346         ftype->linkage = current_linkage;
4347
4348         switch (modifiers & (DM_CDECL | DM_STDCALL | DM_FASTCALL | DM_THISCALL)) {
4349                 case DM_NONE:     break;
4350                 case DM_CDECL:    ftype->calling_convention = CC_CDECL;    break;
4351                 case DM_STDCALL:  ftype->calling_convention = CC_STDCALL;  break;
4352                 case DM_FASTCALL: ftype->calling_convention = CC_FASTCALL; break;
4353                 case DM_THISCALL: ftype->calling_convention = CC_THISCALL; break;
4354
4355                 default:
4356                         errorf(HERE, "multiple calling conventions in declaration");
4357                         break;
4358         }
4359
4360         parse_parameters(ftype, scope);
4361
4362         construct_function_type_t *construct_function_type =
4363                 obstack_alloc(&temp_obst, sizeof(construct_function_type[0]));
4364         memset(construct_function_type, 0, sizeof(construct_function_type[0]));
4365         construct_function_type->construct_type.kind = CONSTRUCT_FUNCTION;
4366         construct_function_type->function_type       = type;
4367
4368         return &construct_function_type->construct_type;
4369 }
4370
4371 typedef struct parse_declarator_env_t {
4372         decl_modifiers_t   modifiers;
4373         symbol_t          *symbol;
4374         source_position_t  source_position;
4375         scope_t            parameters;
4376 } parse_declarator_env_t;
4377
4378 static construct_type_t *parse_inner_declarator(parse_declarator_env_t *env,
4379                 bool may_be_abstract)
4380 {
4381         /* construct a single linked list of construct_type_t's which describe
4382          * how to construct the final declarator type */
4383         construct_type_t *first      = NULL;
4384         construct_type_t *last       = NULL;
4385         gnu_attribute_t  *attributes = NULL;
4386
4387         decl_modifiers_t modifiers = parse_attributes(&attributes);
4388
4389         /* MS __based extension */
4390         based_spec_t base_spec;
4391         base_spec.base_variable = NULL;
4392
4393         for (;;) {
4394                 construct_type_t *type;
4395                 switch (token.type) {
4396                         case '&':
4397                                 if (!(c_mode & _CXX))
4398                                         errorf(HERE, "references are only available for C++");
4399                                 if (base_spec.base_variable != NULL && warning.other) {
4400                                         warningf(&base_spec.source_position,
4401                                                  "__based does not precede a pointer operator, ignored");
4402                                 }
4403                                 type = parse_reference_declarator();
4404                                 /* consumed */
4405                                 base_spec.base_variable = NULL;
4406                                 break;
4407
4408                         case '*':
4409                                 type = parse_pointer_declarator(base_spec.base_variable);
4410                                 /* consumed */
4411                                 base_spec.base_variable = NULL;
4412                                 break;
4413
4414                         case T__based:
4415                                 next_token();
4416                                 expect('(', end_error);
4417                                 add_anchor_token(')');
4418                                 parse_microsoft_based(&base_spec);
4419                                 rem_anchor_token(')');
4420                                 expect(')', end_error);
4421                                 continue;
4422
4423                         default:
4424                                 goto ptr_operator_end;
4425                 }
4426
4427                 if (last == NULL) {
4428                         first = type;
4429                         last  = type;
4430                 } else {
4431                         last->next = type;
4432                         last       = type;
4433                 }
4434
4435                 /* TODO: find out if this is correct */
4436                 modifiers |= parse_attributes(&attributes);
4437         }
4438 ptr_operator_end:
4439         if (base_spec.base_variable != NULL && warning.other) {
4440                 warningf(&base_spec.source_position,
4441                          "__based does not precede a pointer operator, ignored");
4442         }
4443
4444         if (env != NULL) {
4445                 modifiers      |= env->modifiers;
4446                 env->modifiers  = modifiers;
4447         }
4448
4449         construct_type_t *inner_types = NULL;
4450
4451         switch (token.type) {
4452         case T_IDENTIFIER:
4453                 if (env == NULL) {
4454                         errorf(HERE, "no identifier expected in typename");
4455                 } else {
4456                         env->symbol          = token.v.symbol;
4457                         env->source_position = token.source_position;
4458                 }
4459                 next_token();
4460                 break;
4461         case '(':
4462                 /* §6.7.6:2 footnote 126:  Empty parentheses in a type name are
4463                  * interpreted as ``function with no parameter specification'', rather
4464                  * than redundant parentheses around the omitted identifier. */
4465                 if (look_ahead(1)->type != ')') {
4466                         next_token();
4467                         add_anchor_token(')');
4468                         inner_types = parse_inner_declarator(env, may_be_abstract);
4469                         if (inner_types != NULL) {
4470                                 /* All later declarators only modify the return type */
4471                                 env = NULL;
4472                         }
4473                         rem_anchor_token(')');
4474                         expect(')', end_error);
4475                 }
4476                 break;
4477         default:
4478                 if (may_be_abstract)
4479                         break;
4480                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', NULL);
4481                 eat_until_anchor();
4482                 return NULL;
4483         }
4484
4485         construct_type_t *p = last;
4486
4487         while (true) {
4488                 construct_type_t *type;
4489                 switch (token.type) {
4490                 case '(': {
4491                         scope_t *scope = NULL;
4492                         if (env != NULL)
4493                                 scope = &env->parameters;
4494
4495                         type = parse_function_declarator(scope, modifiers);
4496                         break;
4497                 }
4498                 case '[':
4499                         type = parse_array_declarator();
4500                         break;
4501                 default:
4502                         goto declarator_finished;
4503                 }
4504
4505                 /* insert in the middle of the list (behind p) */
4506                 if (p != NULL) {
4507                         type->next = p->next;
4508                         p->next    = type;
4509                 } else {
4510                         type->next = first;
4511                         first      = type;
4512                 }
4513                 if (last == p) {
4514                         last = type;
4515                 }
4516         }
4517
4518 declarator_finished:
4519         /* append inner_types at the end of the list, we don't to set last anymore
4520          * as it's not needed anymore */
4521         if (last == NULL) {
4522                 assert(first == NULL);
4523                 first = inner_types;
4524         } else {
4525                 last->next = inner_types;
4526         }
4527
4528         return first;
4529 end_error:
4530         return NULL;
4531 }
4532
4533 static void parse_declaration_attributes(entity_t *entity)
4534 {
4535         gnu_attribute_t  *attributes = NULL;
4536         decl_modifiers_t  modifiers  = parse_attributes(&attributes);
4537
4538         if (entity == NULL)
4539                 return;
4540
4541         type_t *type;
4542         if (entity->kind == ENTITY_TYPEDEF) {
4543                 modifiers |= entity->typedefe.modifiers;
4544                 type       = entity->typedefe.type;
4545         } else {
4546                 assert(is_declaration(entity));
4547                 modifiers |= entity->declaration.modifiers;
4548                 type       = entity->declaration.type;
4549         }
4550         if (type == NULL)
4551                 return;
4552
4553         /* handle these strange/stupid mode attributes */
4554         gnu_attribute_t *attribute = attributes;
4555         for ( ; attribute != NULL; attribute = attribute->next) {
4556                 if (attribute->kind != GNU_AK_MODE || attribute->invalid)
4557                         continue;
4558
4559                 atomic_type_kind_t  akind = attribute->u.akind;
4560                 if (!is_type_signed(type)) {
4561                         switch (akind) {
4562                         case ATOMIC_TYPE_CHAR: akind = ATOMIC_TYPE_UCHAR; break;
4563                         case ATOMIC_TYPE_SHORT: akind = ATOMIC_TYPE_USHORT; break;
4564                         case ATOMIC_TYPE_INT: akind = ATOMIC_TYPE_UINT; break;
4565                         case ATOMIC_TYPE_LONGLONG: akind = ATOMIC_TYPE_ULONGLONG; break;
4566                         default:
4567                                 panic("invalid akind in mode attribute");
4568                         }
4569                 } else {
4570                         switch (akind) {
4571                         case ATOMIC_TYPE_CHAR: akind = ATOMIC_TYPE_SCHAR; break;
4572                         case ATOMIC_TYPE_SHORT: akind = ATOMIC_TYPE_SHORT; break;
4573                         case ATOMIC_TYPE_INT: akind = ATOMIC_TYPE_INT; break;
4574                         case ATOMIC_TYPE_LONGLONG: akind = ATOMIC_TYPE_LONGLONG; break;
4575                         default:
4576                                 panic("invalid akind in mode attribute");
4577                         }
4578                 }
4579
4580                 type = make_atomic_type(akind, type->base.qualifiers);
4581         }
4582
4583         type_modifiers_t type_modifiers = type->base.modifiers;
4584         if (modifiers & DM_TRANSPARENT_UNION)
4585                 type_modifiers |= TYPE_MODIFIER_TRANSPARENT_UNION;
4586
4587         if (type->base.modifiers != type_modifiers) {
4588                 type_t *copy = duplicate_type(type);
4589                 copy->base.modifiers = type_modifiers;
4590
4591                 type = typehash_insert(copy);
4592                 if (type != copy) {
4593                         obstack_free(type_obst, copy);
4594                 }
4595         }
4596
4597         if (entity->kind == ENTITY_TYPEDEF) {
4598                 entity->typedefe.type      = type;
4599                 entity->typedefe.modifiers = modifiers;
4600         } else {
4601                 entity->declaration.type      = type;
4602                 entity->declaration.modifiers = modifiers;
4603         }
4604 }
4605
4606 static type_t *construct_declarator_type(construct_type_t *construct_list, type_t *type)
4607 {
4608         construct_type_t *iter = construct_list;
4609         for (; iter != NULL; iter = iter->next) {
4610                 switch (iter->kind) {
4611                 case CONSTRUCT_INVALID:
4612                         internal_errorf(HERE, "invalid type construction found");
4613                 case CONSTRUCT_FUNCTION: {
4614                         construct_function_type_t *construct_function_type
4615                                 = (construct_function_type_t*) iter;
4616
4617                         type_t *function_type = construct_function_type->function_type;
4618
4619                         function_type->function.return_type = type;
4620
4621                         type_t *skipped_return_type = skip_typeref(type);
4622                         /* §6.7.5.3(1) */
4623                         if (is_type_function(skipped_return_type)) {
4624                                 errorf(HERE, "function returning function is not allowed");
4625                         } else if (is_type_array(skipped_return_type)) {
4626                                 errorf(HERE, "function returning array is not allowed");
4627                         } else {
4628                                 if (skipped_return_type->base.qualifiers != 0 && warning.other) {
4629                                         warningf(HERE,
4630                                                 "type qualifiers in return type of function type are meaningless");
4631                                 }
4632                         }
4633
4634                         type = function_type;
4635                         break;
4636                 }
4637
4638                 case CONSTRUCT_POINTER: {
4639                         if (is_type_reference(skip_typeref(type)))
4640                                 errorf(HERE, "cannot declare a pointer to reference");
4641
4642                         parsed_pointer_t *parsed_pointer = (parsed_pointer_t*) iter;
4643                         type = make_based_pointer_type(type, parsed_pointer->type_qualifiers, parsed_pointer->base_variable);
4644                         continue;
4645                 }
4646
4647                 case CONSTRUCT_REFERENCE:
4648                         if (is_type_reference(skip_typeref(type)))
4649                                 errorf(HERE, "cannot declare a reference to reference");
4650
4651                         type = make_reference_type(type);
4652                         continue;
4653
4654                 case CONSTRUCT_ARRAY: {
4655                         if (is_type_reference(skip_typeref(type)))
4656                                 errorf(HERE, "cannot declare an array of references");
4657
4658                         parsed_array_t *parsed_array  = (parsed_array_t*) iter;
4659                         type_t         *array_type    = allocate_type_zero(TYPE_ARRAY);
4660
4661                         expression_t *size_expression = parsed_array->size;
4662                         if (size_expression != NULL) {
4663                                 size_expression
4664                                         = create_implicit_cast(size_expression, type_size_t);
4665                         }
4666
4667                         array_type->base.qualifiers       = parsed_array->type_qualifiers;
4668                         array_type->array.element_type    = type;
4669                         array_type->array.is_static       = parsed_array->is_static;
4670                         array_type->array.is_variable     = parsed_array->is_variable;
4671                         array_type->array.size_expression = size_expression;
4672
4673                         if (size_expression != NULL) {
4674                                 if (is_constant_expression(size_expression)) {
4675                                         array_type->array.size_constant = true;
4676                                         array_type->array.size
4677                                                 = fold_constant(size_expression);
4678                                 } else {
4679                                         array_type->array.is_vla = true;
4680                                 }
4681                         }
4682
4683                         type_t *skipped_type = skip_typeref(type);
4684                         /* §6.7.5.2(1) */
4685                         if (is_type_incomplete(skipped_type)) {
4686                                 errorf(HERE, "array of incomplete type '%T' is not allowed", type);
4687                         } else if (is_type_function(skipped_type)) {
4688                                 errorf(HERE, "array of functions is not allowed");
4689                         }
4690                         type = array_type;
4691                         break;
4692                 }
4693                 }
4694
4695                 type_t *hashed_type = typehash_insert(type);
4696                 if (hashed_type != type) {
4697                         /* the function type was constructed earlier freeing it here will
4698                          * destroy other types... */
4699                         if (iter->kind != CONSTRUCT_FUNCTION) {
4700                                 free_type(type);
4701                         }
4702                         type = hashed_type;
4703                 }
4704         }
4705
4706         return type;
4707 }
4708
4709 static type_t *automatic_type_conversion(type_t *orig_type);
4710
4711 static type_t *semantic_parameter(const source_position_t *pos,
4712                                   type_t *type,
4713                                   const declaration_specifiers_t *specifiers,
4714                                   symbol_t *symbol)
4715 {
4716         /* §6.7.5.3:7  A declaration of a parameter as ``array of type''
4717          *             shall be adjusted to ``qualified pointer to type'',
4718          *             [...]
4719          * §6.7.5.3:8  A declaration of a parameter as ``function returning
4720          *             type'' shall be adjusted to ``pointer to function
4721          *             returning type'', as in 6.3.2.1. */
4722         type = automatic_type_conversion(type);
4723
4724         if (specifiers->is_inline && is_type_valid(type)) {
4725                 errorf(pos, "parameter '%Y' declared 'inline'", symbol);
4726         }
4727
4728         /* §6.9.1:6  The declarations in the declaration list shall contain
4729          *           no storage-class specifier other than register and no
4730          *           initializations. */
4731         if (specifiers->thread_local || (
4732                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
4733                         specifiers->storage_class != STORAGE_CLASS_REGISTER)
4734            ) {
4735                 errorf(pos, "invalid storage class for parameter '%Y'", symbol);
4736         }
4737
4738         /* delay test for incomplete type, because we might have (void)
4739          * which is legal but incomplete... */
4740
4741         return type;
4742 }
4743
4744 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
4745                                   declarator_flags_t flags)
4746 {
4747         parse_declarator_env_t env;
4748         memset(&env, 0, sizeof(env));
4749         env.modifiers = specifiers->modifiers;
4750
4751         construct_type_t *construct_type =
4752                 parse_inner_declarator(&env, (flags & DECL_MAY_BE_ABSTRACT) != 0);
4753         type_t           *orig_type      =
4754                 construct_declarator_type(construct_type, specifiers->type);
4755         type_t           *type           = skip_typeref(orig_type);
4756
4757         if (construct_type != NULL) {
4758                 obstack_free(&temp_obst, construct_type);
4759         }
4760
4761         entity_t *entity;
4762         if (specifiers->storage_class == STORAGE_CLASS_TYPEDEF) {
4763                 entity                       = allocate_entity_zero(ENTITY_TYPEDEF);
4764                 entity->base.symbol          = env.symbol;
4765                 entity->base.source_position = env.source_position;
4766                 entity->typedefe.type        = orig_type;
4767
4768                 if (anonymous_entity != NULL) {
4769                         if (is_type_compound(type)) {
4770                                 assert(anonymous_entity->compound.alias == NULL);
4771                                 assert(anonymous_entity->kind == ENTITY_STRUCT ||
4772                                        anonymous_entity->kind == ENTITY_UNION);
4773                                 anonymous_entity->compound.alias = entity;
4774                                 anonymous_entity = NULL;
4775                         } else if (is_type_enum(type)) {
4776                                 assert(anonymous_entity->enume.alias == NULL);
4777                                 assert(anonymous_entity->kind == ENTITY_ENUM);
4778                                 anonymous_entity->enume.alias = entity;
4779                                 anonymous_entity = NULL;
4780                         }
4781                 }
4782         } else {
4783                 /* create a declaration type entity */
4784                 if (flags & DECL_CREATE_COMPOUND_MEMBER) {
4785                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER);
4786
4787                         if (specifiers->is_inline && is_type_valid(type)) {
4788                                 errorf(&env.source_position,
4789                                                 "compound member '%Y' declared 'inline'", env.symbol);
4790                         }
4791
4792                         if (specifiers->thread_local ||
4793                                 specifiers->storage_class != STORAGE_CLASS_NONE) {
4794                                 errorf(&env.source_position,
4795                                            "compound member '%Y' must have no storage class",
4796                                            env.symbol);
4797                         }
4798                 } else if (flags & DECL_IS_PARAMETER) {
4799                         orig_type = semantic_parameter(&env.source_position, orig_type,
4800                                                        specifiers, env.symbol);
4801
4802                         entity = allocate_entity_zero(ENTITY_PARAMETER);
4803                 } else if (is_type_function(type)) {
4804                         entity = allocate_entity_zero(ENTITY_FUNCTION);
4805
4806                         entity->function.is_inline  = specifiers->is_inline;
4807                         entity->function.parameters = env.parameters;
4808
4809                         if (specifiers->thread_local || (
4810                                         specifiers->storage_class != STORAGE_CLASS_EXTERN &&
4811                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
4812                                         specifiers->storage_class != STORAGE_CLASS_STATIC)
4813                            ) {
4814                                 errorf(&env.source_position,
4815                                            "invalid storage class for function '%Y'", env.symbol);
4816                         }
4817                 } else {
4818                         entity = allocate_entity_zero(ENTITY_VARIABLE);
4819
4820                         entity->variable.get_property_sym = specifiers->get_property_sym;
4821                         entity->variable.put_property_sym = specifiers->put_property_sym;
4822                         if (specifiers->alignment != 0) {
4823                                 /* TODO: add checks here */
4824                                 entity->variable.alignment = specifiers->alignment;
4825                         }
4826
4827                         if (specifiers->is_inline && is_type_valid(type)) {
4828                                 errorf(&env.source_position,
4829                                            "variable '%Y' declared 'inline'", env.symbol);
4830                         }
4831
4832                         entity->variable.thread_local = specifiers->thread_local;
4833
4834                         bool invalid_storage_class = false;
4835                         if (current_scope == file_scope) {
4836                                 if (specifiers->storage_class != STORAGE_CLASS_EXTERN &&
4837                                                 specifiers->storage_class != STORAGE_CLASS_NONE   &&
4838                                                 specifiers->storage_class != STORAGE_CLASS_STATIC) {
4839                                         invalid_storage_class = true;
4840                                 }
4841                         } else {
4842                                 if (specifiers->thread_local &&
4843                                                 specifiers->storage_class == STORAGE_CLASS_NONE) {
4844                                         invalid_storage_class = true;
4845                                 }
4846                         }
4847                         if (invalid_storage_class) {
4848                                 errorf(&env.source_position,
4849                                                 "invalid storage class for variable '%Y'", env.symbol);
4850                         }
4851                 }
4852
4853                 entity->base.source_position          = env.source_position;
4854                 entity->base.symbol                   = env.symbol;
4855                 entity->base.namespc                  = NAMESPACE_NORMAL;
4856                 entity->declaration.type              = orig_type;
4857                 entity->declaration.modifiers         = env.modifiers;
4858                 entity->declaration.deprecated_string = specifiers->deprecated_string;
4859
4860                 storage_class_t storage_class = specifiers->storage_class;
4861                 entity->declaration.declared_storage_class = storage_class;
4862
4863                 if (storage_class == STORAGE_CLASS_NONE && current_scope != file_scope)
4864                         storage_class = STORAGE_CLASS_AUTO;
4865                 entity->declaration.storage_class = storage_class;
4866         }
4867
4868         parse_declaration_attributes(entity);
4869
4870         return entity;
4871 }
4872
4873 static type_t *parse_abstract_declarator(type_t *base_type)
4874 {
4875         construct_type_t *construct_type = parse_inner_declarator(NULL, 1);
4876
4877         type_t *result = construct_declarator_type(construct_type, base_type);
4878         if (construct_type != NULL) {
4879                 obstack_free(&temp_obst, construct_type);
4880         }
4881
4882         return result;
4883 }
4884
4885 /**
4886  * Check if the declaration of main is suspicious.  main should be a
4887  * function with external linkage, returning int, taking either zero
4888  * arguments, two, or three arguments of appropriate types, ie.
4889  *
4890  * int main([ int argc, char **argv [, char **env ] ]).
4891  *
4892  * @param decl    the declaration to check
4893  * @param type    the function type of the declaration
4894  */
4895 static void check_type_of_main(const entity_t *entity)
4896 {
4897         const source_position_t *pos = &entity->base.source_position;
4898         if (entity->kind != ENTITY_FUNCTION) {
4899                 warningf(pos, "'main' is not a function");
4900                 return;
4901         }
4902
4903         if (entity->declaration.storage_class == STORAGE_CLASS_STATIC) {
4904                 warningf(pos, "'main' is normally a non-static function");
4905         }
4906
4907         type_t *type = skip_typeref(entity->declaration.type);
4908         assert(is_type_function(type));
4909
4910         function_type_t *func_type = &type->function;
4911         if (!types_compatible(skip_typeref(func_type->return_type), type_int)) {
4912                 warningf(pos, "return type of 'main' should be 'int', but is '%T'",
4913                          func_type->return_type);
4914         }
4915         const function_parameter_t *parm = func_type->parameters;
4916         if (parm != NULL) {
4917                 type_t *const first_type = parm->type;
4918                 if (!types_compatible(skip_typeref(first_type), type_int)) {
4919                         warningf(pos,
4920                                  "first argument of 'main' should be 'int', but is '%T'",
4921                                  first_type);
4922                 }
4923                 parm = parm->next;
4924                 if (parm != NULL) {
4925                         type_t *const second_type = parm->type;
4926                         if (!types_compatible(skip_typeref(second_type), type_char_ptr_ptr)) {
4927                                 warningf(pos, "second argument of 'main' should be 'char**', but is '%T'", second_type);
4928                         }
4929                         parm = parm->next;
4930                         if (parm != NULL) {
4931                                 type_t *const third_type = parm->type;
4932                                 if (!types_compatible(skip_typeref(third_type), type_char_ptr_ptr)) {
4933                                         warningf(pos, "third argument of 'main' should be 'char**', but is '%T'", third_type);
4934                                 }
4935                                 parm = parm->next;
4936                                 if (parm != NULL)
4937                                         goto warn_arg_count;
4938                         }
4939                 } else {
4940 warn_arg_count:
4941                         warningf(pos, "'main' takes only zero, two or three arguments");
4942                 }
4943         }
4944 }
4945
4946 /**
4947  * Check if a symbol is the equal to "main".
4948  */
4949 static bool is_sym_main(const symbol_t *const sym)
4950 {
4951         return strcmp(sym->string, "main") == 0;
4952 }
4953
4954 static void error_redefined_as_different_kind(const source_position_t *pos,
4955                 const entity_t *old, entity_kind_t new_kind)
4956 {
4957         errorf(pos, "redeclaration of %s '%Y' as %s (declared %P)",
4958                get_entity_kind_name(old->kind), old->base.symbol,
4959                get_entity_kind_name(new_kind), &old->base.source_position);
4960 }
4961
4962 /**
4963  * record entities for the NAMESPACE_NORMAL, and produce error messages/warnings
4964  * for various problems that occur for multiple definitions
4965  */
4966 static entity_t *record_entity(entity_t *entity, const bool is_definition)
4967 {
4968         const symbol_t *const    symbol  = entity->base.symbol;
4969         const namespace_tag_t    namespc = (namespace_tag_t)entity->base.namespc;
4970         const source_position_t *pos     = &entity->base.source_position;
4971
4972         /* can happen in error cases */
4973         if (symbol == NULL)
4974                 return entity;
4975
4976         entity_t *previous_entity = get_entity(symbol, namespc);
4977         /* pushing the same entity twice will break the stack structure */
4978         assert(previous_entity != entity);
4979
4980         if (entity->kind == ENTITY_FUNCTION) {
4981                 type_t *const orig_type = entity->declaration.type;
4982                 type_t *const type      = skip_typeref(orig_type);
4983
4984                 assert(is_type_function(type));
4985                 if (type->function.unspecified_parameters &&
4986                                 warning.strict_prototypes &&
4987                                 previous_entity == NULL) {
4988                         warningf(pos, "function declaration '%#T' is not a prototype",
4989                                          orig_type, symbol);
4990                 }
4991
4992                 if (warning.main && current_scope == file_scope
4993                                 && is_sym_main(symbol)) {
4994                         check_type_of_main(entity);
4995                 }
4996         }
4997
4998         if (is_declaration(entity) &&
4999                         warning.nested_externs &&
5000                         entity->declaration.storage_class == STORAGE_CLASS_EXTERN &&
5001                         current_scope != file_scope) {
5002                 warningf(pos, "nested extern declaration of '%#T'",
5003                          entity->declaration.type, symbol);
5004         }
5005
5006         if (previous_entity != NULL &&
5007                         previous_entity->base.parent_scope == &current_function->parameters &&
5008                         previous_entity->base.parent_scope->depth + 1 == current_scope->depth) {
5009                 assert(previous_entity->kind == ENTITY_PARAMETER);
5010                 errorf(pos,
5011                        "declaration '%#T' redeclares the parameter '%#T' (declared %P)",
5012                                          entity->declaration.type, symbol,
5013                                          previous_entity->declaration.type, symbol,
5014                                          &previous_entity->base.source_position);
5015                 goto finish;
5016         }
5017
5018         if (previous_entity != NULL &&
5019                         previous_entity->base.parent_scope == current_scope) {
5020                 if (previous_entity->kind != entity->kind) {
5021                         error_redefined_as_different_kind(pos, previous_entity,
5022                                                           entity->kind);
5023                         goto finish;
5024                 }
5025                 if (previous_entity->kind == ENTITY_ENUM_VALUE) {
5026                         errorf(pos, "redeclaration of enum entry '%Y' (declared %P)",
5027                                    symbol, &previous_entity->base.source_position);
5028                         goto finish;
5029                 }
5030                 if (previous_entity->kind == ENTITY_TYPEDEF) {
5031                         /* TODO: C++ allows this for exactly the same type */
5032                         errorf(pos, "redefinition of typedef '%Y' (declared %P)",
5033                                symbol, &previous_entity->base.source_position);
5034                         goto finish;
5035                 }
5036
5037                 /* at this point we should have only VARIABLES or FUNCTIONS */
5038                 assert(is_declaration(previous_entity) && is_declaration(entity));
5039
5040                 declaration_t *const prev_decl = &previous_entity->declaration;
5041                 declaration_t *const decl      = &entity->declaration;
5042
5043                 /* can happen for K&R style declarations */
5044                 if (prev_decl->type       == NULL             &&
5045                                 previous_entity->kind == ENTITY_PARAMETER &&
5046                                 entity->kind          == ENTITY_PARAMETER) {
5047                         prev_decl->type                   = decl->type;
5048                         prev_decl->storage_class          = decl->storage_class;
5049                         prev_decl->declared_storage_class = decl->declared_storage_class;
5050                         prev_decl->modifiers              = decl->modifiers;
5051                         prev_decl->deprecated_string      = decl->deprecated_string;
5052                         return previous_entity;
5053                 }
5054
5055                 type_t *const orig_type = decl->type;
5056                 assert(orig_type != NULL);
5057                 type_t *const type      = skip_typeref(orig_type);
5058                 type_t *      prev_type = skip_typeref(prev_decl->type);
5059
5060                 if (!types_compatible(type, prev_type)) {
5061                         errorf(pos,
5062                                    "declaration '%#T' is incompatible with '%#T' (declared %P)",
5063                                    orig_type, symbol, prev_decl->type, symbol,
5064                                    &previous_entity->base.source_position);
5065                 } else {
5066                         unsigned old_storage_class = prev_decl->storage_class;
5067                         if (warning.redundant_decls               &&
5068                                         is_definition                     &&
5069                                         !prev_decl->used                  &&
5070                                         !(prev_decl->modifiers & DM_USED) &&
5071                                         prev_decl->storage_class == STORAGE_CLASS_STATIC) {
5072                                 warningf(&previous_entity->base.source_position,
5073                                          "unnecessary static forward declaration for '%#T'",
5074                                          prev_decl->type, symbol);
5075                         }
5076
5077                         unsigned new_storage_class = decl->storage_class;
5078                         if (is_type_incomplete(prev_type)) {
5079                                 prev_decl->type = type;
5080                                 prev_type       = type;
5081                         }
5082
5083                         /* pretend no storage class means extern for function
5084                          * declarations (except if the previous declaration is neither
5085                          * none nor extern) */
5086                         if (entity->kind == ENTITY_FUNCTION) {
5087                                 if (prev_type->function.unspecified_parameters) {
5088                                         prev_decl->type = type;
5089                                         prev_type       = type;
5090                                 }
5091
5092                                 switch (old_storage_class) {
5093                                 case STORAGE_CLASS_NONE:
5094                                         old_storage_class = STORAGE_CLASS_EXTERN;
5095                                         /* FALLTHROUGH */
5096
5097                                 case STORAGE_CLASS_EXTERN:
5098                                         if (is_definition) {
5099                                                 if (warning.missing_prototypes &&
5100                                                     prev_type->function.unspecified_parameters &&
5101                                                     !is_sym_main(symbol)) {
5102                                                         warningf(pos, "no previous prototype for '%#T'",
5103                                                                          orig_type, symbol);
5104                                                 }
5105                                         } else if (new_storage_class == STORAGE_CLASS_NONE) {
5106                                                 new_storage_class = STORAGE_CLASS_EXTERN;
5107                                         }
5108                                         break;
5109
5110                                 default:
5111                                         break;
5112                                 }
5113                         }
5114
5115                         if (old_storage_class == STORAGE_CLASS_EXTERN &&
5116                                         new_storage_class == STORAGE_CLASS_EXTERN) {
5117 warn_redundant_declaration:
5118                                 if (!is_definition           &&
5119                                     warning.redundant_decls  &&
5120                                     is_type_valid(prev_type) &&
5121                                     strcmp(previous_entity->base.source_position.input_name,
5122                                            "<builtin>") != 0) {
5123                                         warningf(pos,
5124                                                  "redundant declaration for '%Y' (declared %P)",
5125                                                  symbol, &previous_entity->base.source_position);
5126                                 }
5127                         } else if (current_function == NULL) {
5128                                 if (old_storage_class != STORAGE_CLASS_STATIC &&
5129                                     new_storage_class == STORAGE_CLASS_STATIC) {
5130                                         errorf(pos,
5131                                                "static declaration of '%Y' follows non-static declaration (declared %P)",
5132                                                symbol, &previous_entity->base.source_position);
5133                                 } else if (old_storage_class == STORAGE_CLASS_EXTERN) {
5134                                         prev_decl->storage_class          = STORAGE_CLASS_NONE;
5135                                         prev_decl->declared_storage_class = STORAGE_CLASS_NONE;
5136                                 } else {
5137                                         /* ISO/IEC 14882:1998(E) §C.1.2:1 */
5138                                         if (c_mode & _CXX)
5139                                                 goto error_redeclaration;
5140                                         goto warn_redundant_declaration;
5141                                 }
5142                         } else if (is_type_valid(prev_type)) {
5143                                 if (old_storage_class == new_storage_class) {
5144 error_redeclaration:
5145                                         errorf(pos, "redeclaration of '%Y' (declared %P)",
5146                                                symbol, &previous_entity->base.source_position);
5147                                 } else {
5148                                         errorf(pos,
5149                                                "redeclaration of '%Y' with different linkage (declared %P)",
5150                                                symbol, &previous_entity->base.source_position);
5151                                 }
5152                         }
5153                 }
5154
5155                 prev_decl->modifiers |= decl->modifiers;
5156                 if (entity->kind == ENTITY_FUNCTION) {
5157                         previous_entity->function.is_inline |= entity->function.is_inline;
5158                 }
5159                 return previous_entity;
5160         }
5161
5162         if (entity->kind == ENTITY_FUNCTION) {
5163                 if (is_definition &&
5164                                 entity->declaration.storage_class != STORAGE_CLASS_STATIC) {
5165                         if (warning.missing_prototypes && !is_sym_main(symbol)) {
5166                                 warningf(pos, "no previous prototype for '%#T'",
5167                                          entity->declaration.type, symbol);
5168                         } else if (warning.missing_declarations && !is_sym_main(symbol)) {
5169                                 warningf(pos, "no previous declaration for '%#T'",
5170                                          entity->declaration.type, symbol);
5171                         }
5172                 }
5173         } else if (warning.missing_declarations &&
5174                         entity->kind == ENTITY_VARIABLE &&
5175                         current_scope == file_scope) {
5176                 declaration_t *declaration = &entity->declaration;
5177                 if (declaration->storage_class == STORAGE_CLASS_NONE) {
5178                         warningf(pos, "no previous declaration for '%#T'",
5179                                  declaration->type, symbol);
5180                 }
5181         }
5182
5183 finish:
5184         assert(entity->base.parent_scope == NULL);
5185         assert(current_scope != NULL);
5186
5187         entity->base.parent_scope = current_scope;
5188         entity->base.namespc      = NAMESPACE_NORMAL;
5189         environment_push(entity);
5190         append_entity(current_scope, entity);
5191
5192         return entity;
5193 }
5194
5195 static void parser_error_multiple_definition(entity_t *entity,
5196                 const source_position_t *source_position)
5197 {
5198         errorf(source_position, "multiple definition of '%Y' (declared %P)",
5199                entity->base.symbol, &entity->base.source_position);
5200 }
5201
5202 static bool is_declaration_specifier(const token_t *token,
5203                                      bool only_specifiers_qualifiers)
5204 {
5205         switch (token->type) {
5206                 TYPE_SPECIFIERS
5207                 TYPE_QUALIFIERS
5208                         return true;
5209                 case T_IDENTIFIER:
5210                         return is_typedef_symbol(token->v.symbol);
5211
5212                 case T___extension__:
5213                 STORAGE_CLASSES
5214                         return !only_specifiers_qualifiers;
5215
5216                 default:
5217                         return false;
5218         }
5219 }
5220
5221 static void parse_init_declarator_rest(entity_t *entity)
5222 {
5223         assert(is_declaration(entity));
5224         declaration_t *const declaration = &entity->declaration;
5225
5226         eat('=');
5227
5228         type_t *orig_type = declaration->type;
5229         type_t *type      = skip_typeref(orig_type);
5230
5231         if (entity->kind == ENTITY_VARIABLE
5232                         && entity->variable.initializer != NULL) {
5233                 parser_error_multiple_definition(entity, HERE);
5234         }
5235
5236         bool must_be_constant = false;
5237         if (declaration->storage_class == STORAGE_CLASS_STATIC ||
5238             entity->base.parent_scope  == file_scope) {
5239                 must_be_constant = true;
5240         }
5241
5242         if (is_type_function(type)) {
5243                 errorf(&entity->base.source_position,
5244                        "function '%#T' is initialized like a variable",
5245                        orig_type, entity->base.symbol);
5246                 orig_type = type_error_type;
5247         }
5248
5249         parse_initializer_env_t env;
5250         env.type             = orig_type;
5251         env.must_be_constant = must_be_constant;
5252         env.entity           = entity;
5253         current_init_decl    = entity;
5254
5255         initializer_t *initializer = parse_initializer(&env);
5256         current_init_decl = NULL;
5257
5258         if (entity->kind == ENTITY_VARIABLE) {
5259                 /* § 6.7.5 (22)  array initializers for arrays with unknown size
5260                  * determine the array type size */
5261                 declaration->type            = env.type;
5262                 entity->variable.initializer = initializer;
5263         }
5264 }
5265
5266 /* parse rest of a declaration without any declarator */
5267 static void parse_anonymous_declaration_rest(
5268                 const declaration_specifiers_t *specifiers)
5269 {
5270         eat(';');
5271         anonymous_entity = NULL;
5272
5273         if (warning.other) {
5274                 if (specifiers->storage_class != STORAGE_CLASS_NONE ||
5275                                 specifiers->thread_local) {
5276                         warningf(&specifiers->source_position,
5277                                  "useless storage class in empty declaration");
5278                 }
5279
5280                 type_t *type = specifiers->type;
5281                 switch (type->kind) {
5282                         case TYPE_COMPOUND_STRUCT:
5283                         case TYPE_COMPOUND_UNION: {
5284                                 if (type->compound.compound->base.symbol == NULL) {
5285                                         warningf(&specifiers->source_position,
5286                                                  "unnamed struct/union that defines no instances");
5287                                 }
5288                                 break;
5289                         }
5290
5291                         case TYPE_ENUM:
5292                                 break;
5293
5294                         default:
5295                                 warningf(&specifiers->source_position, "empty declaration");
5296                                 break;
5297                 }
5298         }
5299 }
5300
5301 static void check_variable_type_complete(entity_t *ent)
5302 {
5303         if (ent->kind != ENTITY_VARIABLE)
5304                 return;
5305
5306         /* §6.7:7  If an identifier for an object is declared with no linkage, the
5307          *         type for the object shall be complete [...] */
5308         declaration_t *decl = &ent->declaration;
5309         if (decl->storage_class != STORAGE_CLASS_NONE)
5310                 return;
5311
5312         type_t *const orig_type = decl->type;
5313         type_t *const type      = skip_typeref(orig_type);
5314         if (!is_type_incomplete(type))
5315                 return;
5316
5317         /* GCC allows global arrays without size and assigns them a length of one,
5318          * if no different declaration follows */
5319         if (is_type_array(type) &&
5320                         c_mode & _GNUC      &&
5321                         ent->base.parent_scope == file_scope) {
5322                 ARR_APP1(declaration_t*, incomplete_arrays, decl);
5323                 return;
5324         }
5325
5326         errorf(&ent->base.source_position, "variable '%#T' has incomplete type",
5327                         orig_type, ent->base.symbol);
5328 }
5329
5330
5331 static void parse_declaration_rest(entity_t *ndeclaration,
5332                 const declaration_specifiers_t *specifiers,
5333                 parsed_declaration_func         finished_declaration,
5334                 declarator_flags_t              flags)
5335 {
5336         add_anchor_token(';');
5337         add_anchor_token(',');
5338         while (true) {
5339                 entity_t *entity = finished_declaration(ndeclaration, token.type == '=');
5340
5341                 if (token.type == '=') {
5342                         parse_init_declarator_rest(entity);
5343                 } else if (entity->kind == ENTITY_VARIABLE) {
5344                         /* ISO/IEC 14882:1998(E) §8.5.3:3  The initializer can be omitted
5345                          * [...] where the extern specifier is explicitly used. */
5346                         declaration_t *decl = &entity->declaration;
5347                         if (decl->storage_class != STORAGE_CLASS_EXTERN) {
5348                                 type_t *type = decl->type;
5349                                 if (is_type_reference(skip_typeref(type))) {
5350                                         errorf(&entity->base.source_position,
5351                                                         "reference '%#T' must be initialized",
5352                                                         type, entity->base.symbol);
5353                                 }
5354                         }
5355                 }
5356
5357                 check_variable_type_complete(entity);
5358
5359                 if (token.type != ',')
5360                         break;
5361                 eat(',');
5362
5363                 add_anchor_token('=');
5364                 ndeclaration = parse_declarator(specifiers, flags);
5365                 rem_anchor_token('=');
5366         }
5367         expect(';', end_error);
5368
5369 end_error:
5370         anonymous_entity = NULL;
5371         rem_anchor_token(';');
5372         rem_anchor_token(',');
5373 }
5374
5375 static entity_t *finished_kr_declaration(entity_t *entity, bool is_definition)
5376 {
5377         symbol_t *symbol = entity->base.symbol;
5378         if (symbol == NULL) {
5379                 errorf(HERE, "anonymous declaration not valid as function parameter");
5380                 return entity;
5381         }
5382
5383         assert(entity->base.namespc == NAMESPACE_NORMAL);
5384         entity_t *previous_entity = get_entity(symbol, NAMESPACE_NORMAL);
5385         if (previous_entity == NULL
5386                         || previous_entity->base.parent_scope != current_scope) {
5387                 errorf(HERE, "expected declaration of a function parameter, found '%Y'",
5388                        symbol);
5389                 return entity;
5390         }
5391
5392         if (is_definition) {
5393                 errorf(HERE, "parameter '%Y' is initialised", entity->base.symbol);
5394         }
5395
5396         return record_entity(entity, false);
5397 }
5398
5399 static void parse_declaration(parsed_declaration_func finished_declaration,
5400                               declarator_flags_t      flags)
5401 {
5402         declaration_specifiers_t specifiers;
5403         memset(&specifiers, 0, sizeof(specifiers));
5404
5405         add_anchor_token(';');
5406         parse_declaration_specifiers(&specifiers);
5407         rem_anchor_token(';');
5408
5409         if (token.type == ';') {
5410                 parse_anonymous_declaration_rest(&specifiers);
5411         } else {
5412                 entity_t *entity = parse_declarator(&specifiers, flags);
5413                 parse_declaration_rest(entity, &specifiers, finished_declaration, flags);
5414         }
5415 }
5416
5417 static type_t *get_default_promoted_type(type_t *orig_type)
5418 {
5419         type_t *result = orig_type;
5420
5421         type_t *type = skip_typeref(orig_type);
5422         if (is_type_integer(type)) {
5423                 result = promote_integer(type);
5424         } else if (type == type_float) {
5425                 result = type_double;
5426         }
5427
5428         return result;
5429 }
5430
5431 static void parse_kr_declaration_list(entity_t *entity)
5432 {
5433         if (entity->kind != ENTITY_FUNCTION)
5434                 return;
5435
5436         type_t *type = skip_typeref(entity->declaration.type);
5437         assert(is_type_function(type));
5438         if (!type->function.kr_style_parameters)
5439                 return;
5440
5441
5442         add_anchor_token('{');
5443
5444         /* push function parameters */
5445         size_t const  top       = environment_top();
5446         scope_t      *old_scope = scope_push(&entity->function.parameters);
5447
5448         entity_t *parameter = entity->function.parameters.entities;
5449         for ( ; parameter != NULL; parameter = parameter->base.next) {
5450                 assert(parameter->base.parent_scope == NULL);
5451                 parameter->base.parent_scope = current_scope;
5452                 environment_push(parameter);
5453         }
5454
5455         /* parse declaration list */
5456         for (;;) {
5457                 switch (token.type) {
5458                         DECLARATION_START
5459                         case T___extension__:
5460                         /* This covers symbols, which are no type, too, and results in
5461                          * better error messages.  The typical cases are misspelled type
5462                          * names and missing includes. */
5463                         case T_IDENTIFIER:
5464                                 parse_declaration(finished_kr_declaration, DECL_IS_PARAMETER);
5465                                 break;
5466                         default:
5467                                 goto decl_list_end;
5468                 }
5469         }
5470 decl_list_end:
5471
5472         /* pop function parameters */
5473         assert(current_scope == &entity->function.parameters);
5474         scope_pop(old_scope);
5475         environment_pop_to(top);
5476
5477         /* update function type */
5478         type_t *new_type = duplicate_type(type);
5479
5480         function_parameter_t *parameters     = NULL;
5481         function_parameter_t *last_parameter = NULL;
5482
5483         parameter = entity->function.parameters.entities;
5484         for (; parameter != NULL; parameter = parameter->base.next) {
5485                 type_t *parameter_type = parameter->declaration.type;
5486                 if (parameter_type == NULL) {
5487                         if (strict_mode) {
5488                                 errorf(HERE, "no type specified for function parameter '%Y'",
5489                                        parameter->base.symbol);
5490                         } else {
5491                                 if (warning.implicit_int) {
5492                                         warningf(HERE, "no type specified for function parameter '%Y', using 'int'",
5493                                                  parameter->base.symbol);
5494                                 }
5495                                 parameter_type              = type_int;
5496                                 parameter->declaration.type = parameter_type;
5497                         }
5498                 }
5499
5500                 semantic_parameter_incomplete(parameter);
5501                 parameter_type = parameter->declaration.type;
5502
5503                 /*
5504                  * we need the default promoted types for the function type
5505                  */
5506                 parameter_type = get_default_promoted_type(parameter_type);
5507
5508                 function_parameter_t *function_parameter
5509                         = obstack_alloc(type_obst, sizeof(function_parameter[0]));
5510                 memset(function_parameter, 0, sizeof(function_parameter[0]));
5511
5512                 function_parameter->type = parameter_type;
5513                 if (last_parameter != NULL) {
5514                         last_parameter->next = function_parameter;
5515                 } else {
5516                         parameters = function_parameter;
5517                 }
5518                 last_parameter = function_parameter;
5519         }
5520
5521         /* § 6.9.1.7: A K&R style parameter list does NOT act as a function
5522          * prototype */
5523         new_type->function.parameters             = parameters;
5524         new_type->function.unspecified_parameters = true;
5525
5526         type = typehash_insert(new_type);
5527         if (type != new_type) {
5528                 obstack_free(type_obst, new_type);
5529         }
5530
5531         entity->declaration.type = type;
5532
5533         rem_anchor_token('{');
5534 }
5535
5536 static bool first_err = true;
5537
5538 /**
5539  * When called with first_err set, prints the name of the current function,
5540  * else does noting.
5541  */
5542 static void print_in_function(void)
5543 {
5544         if (first_err) {
5545                 first_err = false;
5546                 diagnosticf("%s: In function '%Y':\n",
5547                             current_function->base.base.source_position.input_name,
5548                             current_function->base.base.symbol);
5549         }
5550 }
5551
5552 /**
5553  * Check if all labels are defined in the current function.
5554  * Check if all labels are used in the current function.
5555  */
5556 static void check_labels(void)
5557 {
5558         for (const goto_statement_t *goto_statement = goto_first;
5559             goto_statement != NULL;
5560             goto_statement = goto_statement->next) {
5561                 /* skip computed gotos */
5562                 if (goto_statement->expression != NULL)
5563                         continue;
5564
5565                 label_t *label = goto_statement->label;
5566
5567                 label->used = true;
5568                 if (label->base.source_position.input_name == NULL) {
5569                         print_in_function();
5570                         errorf(&goto_statement->base.source_position,
5571                                "label '%Y' used but not defined", label->base.symbol);
5572                  }
5573         }
5574
5575         if (warning.unused_label) {
5576                 for (const label_statement_t *label_statement = label_first;
5577                          label_statement != NULL;
5578                          label_statement = label_statement->next) {
5579                         label_t *label = label_statement->label;
5580
5581                         if (! label->used) {
5582                                 print_in_function();
5583                                 warningf(&label_statement->base.source_position,
5584                                          "label '%Y' defined but not used", label->base.symbol);
5585                         }
5586                 }
5587         }
5588 }
5589
5590 static void warn_unused_entity(entity_t *entity, entity_t *last)
5591 {
5592         entity_t const *const end = last != NULL ? last->base.next : NULL;
5593         for (; entity != end; entity = entity->base.next) {
5594                 if (!is_declaration(entity))
5595                         continue;
5596
5597                 declaration_t *declaration = &entity->declaration;
5598                 if (declaration->implicit)
5599                         continue;
5600
5601                 if (!declaration->used) {
5602                         print_in_function();
5603                         const char *what = get_entity_kind_name(entity->kind);
5604                         warningf(&entity->base.source_position, "%s '%Y' is unused",
5605                                  what, entity->base.symbol);
5606                 } else if (entity->kind == ENTITY_VARIABLE && !entity->variable.read) {
5607                         print_in_function();
5608                         const char *what = get_entity_kind_name(entity->kind);
5609                         warningf(&entity->base.source_position, "%s '%Y' is never read",
5610                                  what, entity->base.symbol);
5611                 }
5612         }
5613 }
5614
5615 static void check_unused_variables(statement_t *const stmt, void *const env)
5616 {
5617         (void)env;
5618
5619         switch (stmt->kind) {
5620                 case STATEMENT_DECLARATION: {
5621                         declaration_statement_t const *const decls = &stmt->declaration;
5622                         warn_unused_entity(decls->declarations_begin,
5623                                            decls->declarations_end);
5624                         return;
5625                 }
5626
5627                 case STATEMENT_FOR:
5628                         warn_unused_entity(stmt->fors.scope.entities, NULL);
5629                         return;
5630
5631                 default:
5632                         return;
5633         }
5634 }
5635
5636 /**
5637  * Check declarations of current_function for unused entities.
5638  */
5639 static void check_declarations(void)
5640 {
5641         if (warning.unused_parameter) {
5642                 const scope_t *scope = &current_function->parameters;
5643
5644                 /* do not issue unused warnings for main */
5645                 if (!is_sym_main(current_function->base.base.symbol)) {
5646                         warn_unused_entity(scope->entities, NULL);
5647                 }
5648         }
5649         if (warning.unused_variable) {
5650                 walk_statements(current_function->statement, check_unused_variables,
5651                                 NULL);
5652         }
5653 }
5654
5655 static int determine_truth(expression_t const* const cond)
5656 {
5657         return
5658                 !is_constant_expression(cond) ? 0 :
5659                 fold_constant(cond) != 0      ? 1 :
5660                 -1;
5661 }
5662
5663 static void check_reachable(statement_t *);
5664 static bool reaches_end;
5665
5666 static bool expression_returns(expression_t const *const expr)
5667 {
5668         switch (expr->kind) {
5669                 case EXPR_CALL: {
5670                         expression_t const *const func = expr->call.function;
5671                         if (func->kind == EXPR_REFERENCE) {
5672                                 entity_t *entity = func->reference.entity;
5673                                 if (entity->kind == ENTITY_FUNCTION
5674                                                 && entity->declaration.modifiers & DM_NORETURN)
5675                                         return false;
5676                         }
5677
5678                         if (!expression_returns(func))
5679                                 return false;
5680
5681                         for (call_argument_t const* arg = expr->call.arguments; arg != NULL; arg = arg->next) {
5682                                 if (!expression_returns(arg->expression))
5683                                         return false;
5684                         }
5685
5686                         return true;
5687                 }
5688
5689                 case EXPR_REFERENCE:
5690                 case EXPR_REFERENCE_ENUM_VALUE:
5691                 case EXPR_CONST:
5692                 case EXPR_CHARACTER_CONSTANT:
5693                 case EXPR_WIDE_CHARACTER_CONSTANT:
5694                 case EXPR_STRING_LITERAL:
5695                 case EXPR_WIDE_STRING_LITERAL:
5696                 case EXPR_COMPOUND_LITERAL: // TODO descend into initialisers
5697                 case EXPR_LABEL_ADDRESS:
5698                 case EXPR_CLASSIFY_TYPE:
5699                 case EXPR_SIZEOF: // TODO handle obscure VLA case
5700                 case EXPR_ALIGNOF:
5701                 case EXPR_FUNCNAME:
5702                 case EXPR_BUILTIN_SYMBOL:
5703                 case EXPR_BUILTIN_CONSTANT_P:
5704                 case EXPR_BUILTIN_PREFETCH:
5705                 case EXPR_OFFSETOF:
5706                 case EXPR_INVALID:
5707                         return true;
5708
5709                 case EXPR_STATEMENT: {
5710                         bool old_reaches_end = reaches_end;
5711                         reaches_end = false;
5712                         check_reachable(expr->statement.statement);
5713                         bool returns = reaches_end;
5714                         reaches_end = old_reaches_end;
5715                         return returns;
5716                 }
5717
5718                 case EXPR_CONDITIONAL:
5719                         // TODO handle constant expression
5720
5721                         if (!expression_returns(expr->conditional.condition))
5722                                 return false;
5723
5724                         if (expr->conditional.true_expression != NULL
5725                                         && expression_returns(expr->conditional.true_expression))
5726                                 return true;
5727
5728                         return expression_returns(expr->conditional.false_expression);
5729
5730                 case EXPR_SELECT:
5731                         return expression_returns(expr->select.compound);
5732
5733                 case EXPR_ARRAY_ACCESS:
5734                         return
5735                                 expression_returns(expr->array_access.array_ref) &&
5736                                 expression_returns(expr->array_access.index);
5737
5738                 case EXPR_VA_START:
5739                         return expression_returns(expr->va_starte.ap);
5740
5741                 case EXPR_VA_ARG:
5742                         return expression_returns(expr->va_arge.ap);
5743
5744                 EXPR_UNARY_CASES_MANDATORY
5745                         return expression_returns(expr->unary.value);
5746
5747                 case EXPR_UNARY_THROW:
5748                         return false;
5749
5750                 EXPR_BINARY_CASES
5751                         // TODO handle constant lhs of && and ||
5752                         return
5753                                 expression_returns(expr->binary.left) &&
5754                                 expression_returns(expr->binary.right);
5755
5756                 case EXPR_UNKNOWN:
5757                         break;
5758         }
5759
5760         panic("unhandled expression");
5761 }
5762
5763 static bool initializer_returns(initializer_t const *const init)
5764 {
5765         switch (init->kind) {
5766                 case INITIALIZER_VALUE:
5767                         return expression_returns(init->value.value);
5768
5769                 case INITIALIZER_LIST: {
5770                         initializer_t * const*       i       = init->list.initializers;
5771                         initializer_t * const* const end     = i + init->list.len;
5772                         bool                         returns = true;
5773                         for (; i != end; ++i) {
5774                                 if (!initializer_returns(*i))
5775                                         returns = false;
5776                         }
5777                         return returns;
5778                 }
5779
5780                 case INITIALIZER_STRING:
5781                 case INITIALIZER_WIDE_STRING:
5782                 case INITIALIZER_DESIGNATOR: // designators have no payload
5783                         return true;
5784         }
5785         panic("unhandled initializer");
5786 }
5787
5788 static bool noreturn_candidate;
5789
5790 static void check_reachable(statement_t *const stmt)
5791 {
5792         if (stmt->base.reachable)
5793                 return;
5794         if (stmt->kind != STATEMENT_DO_WHILE)
5795                 stmt->base.reachable = true;
5796
5797         statement_t *last = stmt;
5798         statement_t *next;
5799         switch (stmt->kind) {
5800                 case STATEMENT_INVALID:
5801                 case STATEMENT_EMPTY:
5802                 case STATEMENT_LOCAL_LABEL:
5803                 case STATEMENT_ASM:
5804                         next = stmt->base.next;
5805                         break;
5806
5807                 case STATEMENT_DECLARATION: {
5808                         declaration_statement_t const *const decl = &stmt->declaration;
5809                         entity_t                const *      ent  = decl->declarations_begin;
5810                         entity_t                const *const last = decl->declarations_end;
5811                         if (ent != NULL) {
5812                                 for (;; ent = ent->base.next) {
5813                                         if (ent->kind                 == ENTITY_VARIABLE &&
5814                                                         ent->variable.initializer != NULL            &&
5815                                                         !initializer_returns(ent->variable.initializer)) {
5816                                                 return;
5817                                         }
5818                                         if (ent == last)
5819                                                 break;
5820                                 }
5821                         }
5822                         next = stmt->base.next;
5823                         break;
5824                 }
5825
5826                 case STATEMENT_COMPOUND:
5827                         next = stmt->compound.statements;
5828                         if (next == NULL)
5829                                 next = stmt->base.next;
5830                         break;
5831
5832                 case STATEMENT_RETURN: {
5833                         expression_t const *const val = stmt->returns.value;
5834                         if (val == NULL || expression_returns(val))
5835                                 noreturn_candidate = false;
5836                         return;
5837                 }
5838
5839                 case STATEMENT_IF: {
5840                         if_statement_t const *const ifs  = &stmt->ifs;
5841                         expression_t   const *const cond = ifs->condition;
5842
5843                         if (!expression_returns(cond))
5844                                 return;
5845
5846                         int const val = determine_truth(cond);
5847
5848                         if (val >= 0)
5849                                 check_reachable(ifs->true_statement);
5850
5851                         if (val > 0)
5852                                 return;
5853
5854                         if (ifs->false_statement != NULL) {
5855                                 check_reachable(ifs->false_statement);
5856                                 return;
5857                         }
5858
5859                         next = stmt->base.next;
5860                         break;
5861                 }
5862
5863                 case STATEMENT_SWITCH: {
5864                         switch_statement_t const *const switchs = &stmt->switchs;
5865                         expression_t       const *const expr    = switchs->expression;
5866
5867                         if (!expression_returns(expr))
5868                                 return;
5869
5870                         if (is_constant_expression(expr)) {
5871                                 long                    const val      = fold_constant(expr);
5872                                 case_label_statement_t *      defaults = NULL;
5873                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
5874                                         if (i->expression == NULL) {
5875                                                 defaults = i;
5876                                                 continue;
5877                                         }
5878
5879                                         if (i->first_case <= val && val <= i->last_case) {
5880                                                 check_reachable((statement_t*)i);
5881                                                 return;
5882                                         }
5883                                 }
5884
5885                                 if (defaults != NULL) {
5886                                         check_reachable((statement_t*)defaults);
5887                                         return;
5888                                 }
5889                         } else {
5890                                 bool has_default = false;
5891                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
5892                                         if (i->expression == NULL)
5893                                                 has_default = true;
5894
5895                                         check_reachable((statement_t*)i);
5896                                 }
5897
5898                                 if (has_default)
5899                                         return;
5900                         }
5901
5902                         next = stmt->base.next;
5903                         break;
5904                 }
5905
5906                 case STATEMENT_EXPRESSION: {
5907                         /* Check for noreturn function call */
5908                         expression_t const *const expr = stmt->expression.expression;
5909                         if (!expression_returns(expr))
5910                                 return;
5911
5912                         next = stmt->base.next;
5913                         break;
5914                 }
5915
5916                 case STATEMENT_CONTINUE: {
5917                         statement_t *parent = stmt;
5918                         for (;;) {
5919                                 parent = parent->base.parent;
5920                                 if (parent == NULL) /* continue not within loop */
5921                                         return;
5922
5923                                 next = parent;
5924                                 switch (parent->kind) {
5925                                         case STATEMENT_WHILE:    goto continue_while;
5926                                         case STATEMENT_DO_WHILE: goto continue_do_while;
5927                                         case STATEMENT_FOR:      goto continue_for;
5928
5929                                         default: break;
5930                                 }
5931                         }
5932                 }
5933
5934                 case STATEMENT_BREAK: {
5935                         statement_t *parent = stmt;
5936                         for (;;) {
5937                                 parent = parent->base.parent;
5938                                 if (parent == NULL) /* break not within loop/switch */
5939                                         return;
5940
5941                                 switch (parent->kind) {
5942                                         case STATEMENT_SWITCH:
5943                                         case STATEMENT_WHILE:
5944                                         case STATEMENT_DO_WHILE:
5945                                         case STATEMENT_FOR:
5946                                                 last = parent;
5947                                                 next = parent->base.next;
5948                                                 goto found_break_parent;
5949
5950                                         default: break;
5951                                 }
5952                         }
5953 found_break_parent:
5954                         break;
5955                 }
5956
5957                 case STATEMENT_GOTO:
5958                         if (stmt->gotos.expression) {
5959                                 if (!expression_returns(stmt->gotos.expression))
5960                                         return;
5961
5962                                 statement_t *parent = stmt->base.parent;
5963                                 if (parent == NULL) /* top level goto */
5964                                         return;
5965                                 next = parent;
5966                         } else {
5967                                 next = stmt->gotos.label->statement;
5968                                 if (next == NULL) /* missing label */
5969                                         return;
5970                         }
5971                         break;
5972
5973                 case STATEMENT_LABEL:
5974                         next = stmt->label.statement;
5975                         break;
5976
5977                 case STATEMENT_CASE_LABEL:
5978                         next = stmt->case_label.statement;
5979                         break;
5980
5981                 case STATEMENT_WHILE: {
5982                         while_statement_t const *const whiles = &stmt->whiles;
5983                         expression_t      const *const cond   = whiles->condition;
5984
5985                         if (!expression_returns(cond))
5986                                 return;
5987
5988                         int const val = determine_truth(cond);
5989
5990                         if (val >= 0)
5991                                 check_reachable(whiles->body);
5992
5993                         if (val > 0)
5994                                 return;
5995
5996                         next = stmt->base.next;
5997                         break;
5998                 }
5999
6000                 case STATEMENT_DO_WHILE:
6001                         next = stmt->do_while.body;
6002                         break;
6003
6004                 case STATEMENT_FOR: {
6005                         for_statement_t *const fors = &stmt->fors;
6006
6007                         if (fors->condition_reachable)
6008                                 return;
6009                         fors->condition_reachable = true;
6010
6011                         expression_t const *const cond = fors->condition;
6012
6013                         int val;
6014                         if (cond == NULL) {
6015                                 val = 1;
6016                         } else if (expression_returns(cond)) {
6017                                 val = determine_truth(cond);
6018                         } else {
6019                                 return;
6020                         }
6021
6022                         if (val >= 0)
6023                                 check_reachable(fors->body);
6024
6025                         if (val > 0)
6026                                 return;
6027
6028                         next = stmt->base.next;
6029                         break;
6030                 }
6031
6032                 case STATEMENT_MS_TRY: {
6033                         ms_try_statement_t const *const ms_try = &stmt->ms_try;
6034                         check_reachable(ms_try->try_statement);
6035                         next = ms_try->final_statement;
6036                         break;
6037                 }
6038
6039                 case STATEMENT_LEAVE: {
6040                         statement_t *parent = stmt;
6041                         for (;;) {
6042                                 parent = parent->base.parent;
6043                                 if (parent == NULL) /* __leave not within __try */
6044                                         return;
6045
6046                                 if (parent->kind == STATEMENT_MS_TRY) {
6047                                         last = parent;
6048                                         next = parent->ms_try.final_statement;
6049                                         break;
6050                                 }
6051                         }
6052                         break;
6053                 }
6054
6055                 default:
6056                         panic("invalid statement kind");
6057         }
6058
6059         while (next == NULL) {
6060                 next = last->base.parent;
6061                 if (next == NULL) {
6062                         noreturn_candidate = false;
6063
6064                         type_t *const type = current_function->base.type;
6065                         assert(is_type_function(type));
6066                         type_t *const ret  = skip_typeref(type->function.return_type);
6067                         if (warning.return_type                    &&
6068                             !is_type_atomic(ret, ATOMIC_TYPE_VOID) &&
6069                             is_type_valid(ret)                     &&
6070                             !is_sym_main(current_function->base.base.symbol)) {
6071                                 warningf(&stmt->base.source_position,
6072                                          "control reaches end of non-void function");
6073                         }
6074                         return;
6075                 }
6076
6077                 switch (next->kind) {
6078                         case STATEMENT_INVALID:
6079                         case STATEMENT_EMPTY:
6080                         case STATEMENT_DECLARATION:
6081                         case STATEMENT_LOCAL_LABEL:
6082                         case STATEMENT_EXPRESSION:
6083                         case STATEMENT_ASM:
6084                         case STATEMENT_RETURN:
6085                         case STATEMENT_CONTINUE:
6086                         case STATEMENT_BREAK:
6087                         case STATEMENT_GOTO:
6088                         case STATEMENT_LEAVE:
6089                                 panic("invalid control flow in function");
6090
6091                         case STATEMENT_COMPOUND:
6092                                 if (next->compound.stmt_expr) {
6093                                         reaches_end = true;
6094                                         return;
6095                                 }
6096                                 /* FALLTHROUGH */
6097                         case STATEMENT_IF:
6098                         case STATEMENT_SWITCH:
6099                         case STATEMENT_LABEL:
6100                         case STATEMENT_CASE_LABEL:
6101                                 last = next;
6102                                 next = next->base.next;
6103                                 break;
6104
6105                         case STATEMENT_WHILE: {
6106 continue_while:
6107                                 if (next->base.reachable)
6108                                         return;
6109                                 next->base.reachable = true;
6110
6111                                 while_statement_t const *const whiles = &next->whiles;
6112                                 expression_t      const *const cond   = whiles->condition;
6113
6114                                 if (!expression_returns(cond))
6115                                         return;
6116
6117                                 int const val = determine_truth(cond);
6118
6119                                 if (val >= 0)
6120                                         check_reachable(whiles->body);
6121
6122                                 if (val > 0)
6123                                         return;
6124
6125                                 last = next;
6126                                 next = next->base.next;
6127                                 break;
6128                         }
6129
6130                         case STATEMENT_DO_WHILE: {
6131 continue_do_while:
6132                                 if (next->base.reachable)
6133                                         return;
6134                                 next->base.reachable = true;
6135
6136                                 do_while_statement_t const *const dw   = &next->do_while;
6137                                 expression_t         const *const cond = dw->condition;
6138
6139                                 if (!expression_returns(cond))
6140                                         return;
6141
6142                                 int const val = determine_truth(cond);
6143
6144                                 if (val >= 0)
6145                                         check_reachable(dw->body);
6146
6147                                 if (val > 0)
6148                                         return;
6149
6150                                 last = next;
6151                                 next = next->base.next;
6152                                 break;
6153                         }
6154
6155                         case STATEMENT_FOR: {
6156 continue_for:;
6157                                 for_statement_t *const fors = &next->fors;
6158
6159                                 fors->step_reachable = true;
6160
6161                                 if (fors->condition_reachable)
6162                                         return;
6163                                 fors->condition_reachable = true;
6164
6165                                 expression_t const *const cond = fors->condition;
6166
6167                                 int val;
6168                                 if (cond == NULL) {
6169                                         val = 1;
6170                                 } else if (expression_returns(cond)) {
6171                                         val = determine_truth(cond);
6172                                 } else {
6173                                         return;
6174                                 }
6175
6176                                 if (val >= 0)
6177                                         check_reachable(fors->body);
6178
6179                                 if (val > 0)
6180                                         return;
6181
6182                                 last = next;
6183                                 next = next->base.next;
6184                                 break;
6185                         }
6186
6187                         case STATEMENT_MS_TRY:
6188                                 last = next;
6189                                 next = next->ms_try.final_statement;
6190                                 break;
6191                 }
6192         }
6193
6194         check_reachable(next);
6195 }
6196
6197 static void check_unreachable(statement_t* const stmt, void *const env)
6198 {
6199         (void)env;
6200
6201         switch (stmt->kind) {
6202                 case STATEMENT_DO_WHILE:
6203                         if (!stmt->base.reachable) {
6204                                 expression_t const *const cond = stmt->do_while.condition;
6205                                 if (determine_truth(cond) >= 0) {
6206                                         warningf(&cond->base.source_position,
6207                                                  "condition of do-while-loop is unreachable");
6208                                 }
6209                         }
6210                         return;
6211
6212                 case STATEMENT_FOR: {
6213                         for_statement_t const* const fors = &stmt->fors;
6214
6215                         // if init and step are unreachable, cond is unreachable, too
6216                         if (!stmt->base.reachable && !fors->step_reachable) {
6217                                 warningf(&stmt->base.source_position, "statement is unreachable");
6218                         } else {
6219                                 if (!stmt->base.reachable && fors->initialisation != NULL) {
6220                                         warningf(&fors->initialisation->base.source_position,
6221                                                  "initialisation of for-statement is unreachable");
6222                                 }
6223
6224                                 if (!fors->condition_reachable && fors->condition != NULL) {
6225                                         warningf(&fors->condition->base.source_position,
6226                                                  "condition of for-statement is unreachable");
6227                                 }
6228
6229                                 if (!fors->step_reachable && fors->step != NULL) {
6230                                         warningf(&fors->step->base.source_position,
6231                                                  "step of for-statement is unreachable");
6232                                 }
6233                         }
6234                         return;
6235                 }
6236
6237                 case STATEMENT_COMPOUND:
6238                         if (stmt->compound.statements != NULL)
6239                                 return;
6240                         goto warn_unreachable;
6241
6242                 case STATEMENT_DECLARATION: {
6243                         /* Only warn if there is at least one declarator with an initializer.
6244                          * This typically occurs in switch statements. */
6245                         declaration_statement_t const *const decl = &stmt->declaration;
6246                         entity_t                const *      ent  = decl->declarations_begin;
6247                         entity_t                const *const last = decl->declarations_end;
6248                         if (ent != NULL) {
6249                                 for (;; ent = ent->base.next) {
6250                                         if (ent->kind                 == ENTITY_VARIABLE &&
6251                                                         ent->variable.initializer != NULL) {
6252                                                 goto warn_unreachable;
6253                                         }
6254                                         if (ent == last)
6255                                                 return;
6256                                 }
6257                         }
6258                 }
6259
6260                 default:
6261 warn_unreachable:
6262                         if (!stmt->base.reachable)
6263                                 warningf(&stmt->base.source_position, "statement is unreachable");
6264                         return;
6265         }
6266 }
6267
6268 static void parse_external_declaration(void)
6269 {
6270         /* function-definitions and declarations both start with declaration
6271          * specifiers */
6272         declaration_specifiers_t specifiers;
6273         memset(&specifiers, 0, sizeof(specifiers));
6274
6275         add_anchor_token(';');
6276         parse_declaration_specifiers(&specifiers);
6277         rem_anchor_token(';');
6278
6279         /* must be a declaration */
6280         if (token.type == ';') {
6281                 parse_anonymous_declaration_rest(&specifiers);
6282                 return;
6283         }
6284
6285         add_anchor_token(',');
6286         add_anchor_token('=');
6287         add_anchor_token(';');
6288         add_anchor_token('{');
6289
6290         /* declarator is common to both function-definitions and declarations */
6291         entity_t *ndeclaration = parse_declarator(&specifiers, DECL_FLAGS_NONE);
6292
6293         rem_anchor_token('{');
6294         rem_anchor_token(';');
6295         rem_anchor_token('=');
6296         rem_anchor_token(',');
6297
6298         /* must be a declaration */
6299         switch (token.type) {
6300                 case ',':
6301                 case ';':
6302                 case '=':
6303                         parse_declaration_rest(ndeclaration, &specifiers, record_entity,
6304                                         DECL_FLAGS_NONE);
6305                         return;
6306         }
6307
6308         /* must be a function definition */
6309         parse_kr_declaration_list(ndeclaration);
6310
6311         if (token.type != '{') {
6312                 parse_error_expected("while parsing function definition", '{', NULL);
6313                 eat_until_matching_token(';');
6314                 return;
6315         }
6316
6317         assert(is_declaration(ndeclaration));
6318         type_t *type = skip_typeref(ndeclaration->declaration.type);
6319
6320         if (!is_type_function(type)) {
6321                 if (is_type_valid(type)) {
6322                         errorf(HERE, "declarator '%#T' has a body but is not a function type",
6323                                type, ndeclaration->base.symbol);
6324                 }
6325                 eat_block();
6326                 return;
6327         }
6328
6329         if (warning.aggregate_return &&
6330             is_type_compound(skip_typeref(type->function.return_type))) {
6331                 warningf(HERE, "function '%Y' returns an aggregate",
6332                          ndeclaration->base.symbol);
6333         }
6334         if (warning.traditional && !type->function.unspecified_parameters) {
6335                 warningf(HERE, "traditional C rejects ISO C style function definition of function '%Y'",
6336                         ndeclaration->base.symbol);
6337         }
6338         if (warning.old_style_definition && type->function.unspecified_parameters) {
6339                 warningf(HERE, "old-style function definition '%Y'",
6340                         ndeclaration->base.symbol);
6341         }
6342
6343         /* § 6.7.5.3 (14) a function definition with () means no
6344          * parameters (and not unspecified parameters) */
6345         if (type->function.unspecified_parameters
6346                         && type->function.parameters == NULL
6347                         && !type->function.kr_style_parameters) {
6348                 type_t *duplicate = duplicate_type(type);
6349                 duplicate->function.unspecified_parameters = false;
6350
6351                 type = typehash_insert(duplicate);
6352                 if (type != duplicate) {
6353                         obstack_free(type_obst, duplicate);
6354                 }
6355                 ndeclaration->declaration.type = type;
6356         }
6357
6358         entity_t *const entity = record_entity(ndeclaration, true);
6359         assert(entity->kind == ENTITY_FUNCTION);
6360         assert(ndeclaration->kind == ENTITY_FUNCTION);
6361
6362         function_t *function = &entity->function;
6363         if (ndeclaration != entity) {
6364                 function->parameters = ndeclaration->function.parameters;
6365         }
6366         assert(is_declaration(entity));
6367         type = skip_typeref(entity->declaration.type);
6368
6369         /* push function parameters and switch scope */
6370         size_t const  top       = environment_top();
6371         scope_t      *old_scope = scope_push(&function->parameters);
6372
6373         entity_t *parameter = function->parameters.entities;
6374         for (; parameter != NULL; parameter = parameter->base.next) {
6375                 if (parameter->base.parent_scope == &ndeclaration->function.parameters) {
6376                         parameter->base.parent_scope = current_scope;
6377                 }
6378                 assert(parameter->base.parent_scope == NULL
6379                                 || parameter->base.parent_scope == current_scope);
6380                 parameter->base.parent_scope = current_scope;
6381                 if (parameter->base.symbol == NULL) {
6382                         errorf(&parameter->base.source_position, "parameter name omitted");
6383                         continue;
6384                 }
6385                 environment_push(parameter);
6386         }
6387
6388         if (function->statement != NULL) {
6389                 parser_error_multiple_definition(entity, HERE);
6390                 eat_block();
6391         } else {
6392                 /* parse function body */
6393                 int         label_stack_top      = label_top();
6394                 function_t *old_current_function = current_function;
6395                 current_function                 = function;
6396                 current_parent                   = NULL;
6397
6398                 goto_first   = NULL;
6399                 goto_anchor  = &goto_first;
6400                 label_first  = NULL;
6401                 label_anchor = &label_first;
6402
6403                 statement_t *const body = parse_compound_statement(false);
6404                 function->statement = body;
6405                 first_err = true;
6406                 check_labels();
6407                 check_declarations();
6408                 if (warning.return_type      ||
6409                     warning.unreachable_code ||
6410                     (warning.missing_noreturn
6411                      && !(function->base.modifiers & DM_NORETURN))) {
6412                         noreturn_candidate = true;
6413                         check_reachable(body);
6414                         if (warning.unreachable_code)
6415                                 walk_statements(body, check_unreachable, NULL);
6416                         if (warning.missing_noreturn &&
6417                             noreturn_candidate       &&
6418                             !(function->base.modifiers & DM_NORETURN)) {
6419                                 warningf(&body->base.source_position,
6420                                          "function '%#T' is candidate for attribute 'noreturn'",
6421                                          type, entity->base.symbol);
6422                         }
6423                 }
6424
6425                 assert(current_parent   == NULL);
6426                 assert(current_function == function);
6427                 current_function = old_current_function;
6428                 label_pop_to(label_stack_top);
6429         }
6430
6431         assert(current_scope == &function->parameters);
6432         scope_pop(old_scope);
6433         environment_pop_to(top);
6434 }
6435
6436 static type_t *make_bitfield_type(type_t *base_type, expression_t *size,
6437                                   source_position_t *source_position,
6438                                   const symbol_t *symbol)
6439 {
6440         type_t *type = allocate_type_zero(TYPE_BITFIELD);
6441
6442         type->bitfield.base_type       = base_type;
6443         type->bitfield.size_expression = size;
6444
6445         il_size_t bit_size;
6446         type_t *skipped_type = skip_typeref(base_type);
6447         if (!is_type_integer(skipped_type)) {
6448                 errorf(HERE, "bitfield base type '%T' is not an integer type",
6449                         base_type);
6450                 bit_size = 0;
6451         } else {
6452                 bit_size = skipped_type->base.size * 8;
6453         }
6454
6455         if (is_constant_expression(size)) {
6456                 long v = fold_constant(size);
6457
6458                 if (v < 0) {
6459                         errorf(source_position, "negative width in bit-field '%Y'", symbol);
6460                 } else if (v == 0) {
6461                         errorf(source_position, "zero width for bit-field '%Y'", symbol);
6462                 } else if (bit_size > 0 && (il_size_t)v > bit_size) {
6463                         errorf(source_position, "width of '%Y' exceeds its type", symbol);
6464                 } else {
6465                         type->bitfield.bit_size = v;
6466                 }
6467         }
6468
6469         return type;
6470 }
6471
6472 static entity_t *find_compound_entry(compound_t *compound, symbol_t *symbol)
6473 {
6474         entity_t *iter = compound->members.entities;
6475         for (; iter != NULL; iter = iter->base.next) {
6476                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
6477                         continue;
6478
6479                 if (iter->base.symbol == symbol) {
6480                         return iter;
6481                 } else if (iter->base.symbol == NULL) {
6482                         type_t *type = skip_typeref(iter->declaration.type);
6483                         if (is_type_compound(type)) {
6484                                 entity_t *result
6485                                         = find_compound_entry(type->compound.compound, symbol);
6486                                 if (result != NULL)
6487                                         return result;
6488                         }
6489                         continue;
6490                 }
6491         }
6492
6493         return NULL;
6494 }
6495
6496 static void parse_compound_declarators(compound_t *compound,
6497                 const declaration_specifiers_t *specifiers)
6498 {
6499         while (true) {
6500                 entity_t *entity;
6501
6502                 if (token.type == ':') {
6503                         source_position_t source_position = *HERE;
6504                         next_token();
6505
6506                         type_t *base_type = specifiers->type;
6507                         expression_t *size = parse_constant_expression();
6508
6509                         type_t *type = make_bitfield_type(base_type, size,
6510                                         &source_position, sym_anonymous);
6511
6512                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER);
6513                         entity->base.namespc                       = NAMESPACE_NORMAL;
6514                         entity->base.source_position               = source_position;
6515                         entity->declaration.declared_storage_class = STORAGE_CLASS_NONE;
6516                         entity->declaration.storage_class          = STORAGE_CLASS_NONE;
6517                         entity->declaration.modifiers              = specifiers->modifiers;
6518                         entity->declaration.type                   = type;
6519                         append_entity(&compound->members, entity);
6520                 } else {
6521                         entity = parse_declarator(specifiers,
6522                                         DECL_MAY_BE_ABSTRACT | DECL_CREATE_COMPOUND_MEMBER);
6523                         if (entity->kind == ENTITY_TYPEDEF) {
6524                                 errorf(&entity->base.source_position,
6525                                                 "typedef not allowed as compound member");
6526                         } else {
6527                                 assert(entity->kind == ENTITY_COMPOUND_MEMBER);
6528
6529                                 /* make sure we don't define a symbol multiple times */
6530                                 symbol_t *symbol = entity->base.symbol;
6531                                 if (symbol != NULL) {
6532                                         entity_t *prev = find_compound_entry(compound, symbol);
6533                                         if (prev != NULL) {
6534                                                 errorf(&entity->base.source_position,
6535                                                                 "multiple declarations of symbol '%Y' (declared %P)",
6536                                                                 symbol, &prev->base.source_position);
6537                                         }
6538                                 }
6539
6540                                 if (token.type == ':') {
6541                                         source_position_t source_position = *HERE;
6542                                         next_token();
6543                                         expression_t *size = parse_constant_expression();
6544
6545                                         type_t *type          = entity->declaration.type;
6546                                         type_t *bitfield_type = make_bitfield_type(type, size,
6547                                                         &source_position, entity->base.symbol);
6548                                         entity->declaration.type = bitfield_type;
6549                                 } else {
6550                                         type_t *orig_type = entity->declaration.type;
6551                                         type_t *type      = skip_typeref(orig_type);
6552                                         if (is_type_function(type)) {
6553                                                 errorf(&entity->base.source_position,
6554                                                                 "compound member '%Y' must not have function type '%T'",
6555                                                                 entity->base.symbol, orig_type);
6556                                         } else if (is_type_incomplete(type)) {
6557                                                 /* §6.7.2.1:16 flexible array member */
6558                                                 if (is_type_array(type) &&
6559                                                                 token.type == ';'   &&
6560                                                                 look_ahead(1)->type == '}') {
6561                                                         compound->has_flexible_member = true;
6562                                                 } else {
6563                                                         errorf(&entity->base.source_position,
6564                                                                         "compound member '%Y' has incomplete type '%T'",
6565                                                                         entity->base.symbol, orig_type);
6566                                                 }
6567                                         }
6568                                 }
6569
6570                                 append_entity(&compound->members, entity);
6571                         }
6572                 }
6573
6574                 if (token.type != ',')
6575                         break;
6576                 next_token();
6577         }
6578         expect(';', end_error);
6579
6580 end_error:
6581         anonymous_entity = NULL;
6582 }
6583
6584 static void parse_compound_type_entries(compound_t *compound)
6585 {
6586         eat('{');
6587         add_anchor_token('}');
6588
6589         while (token.type != '}') {
6590                 if (token.type == T_EOF) {
6591                         errorf(HERE, "EOF while parsing struct");
6592                         break;
6593                 }
6594                 declaration_specifiers_t specifiers;
6595                 memset(&specifiers, 0, sizeof(specifiers));
6596                 parse_declaration_specifiers(&specifiers);
6597
6598                 parse_compound_declarators(compound, &specifiers);
6599         }
6600         rem_anchor_token('}');
6601         next_token();
6602
6603         /* §6.7.2.1:7 */
6604         compound->complete = true;
6605 }
6606
6607 static type_t *parse_typename(void)
6608 {
6609         declaration_specifiers_t specifiers;
6610         memset(&specifiers, 0, sizeof(specifiers));
6611         parse_declaration_specifiers(&specifiers);
6612         if (specifiers.storage_class != STORAGE_CLASS_NONE ||
6613                         specifiers.thread_local) {
6614                 /* TODO: improve error message, user does probably not know what a
6615                  * storage class is...
6616                  */
6617                 errorf(HERE, "typename may not have a storage class");
6618         }
6619
6620         type_t *result = parse_abstract_declarator(specifiers.type);
6621
6622         return result;
6623 }
6624
6625
6626
6627
6628 typedef expression_t* (*parse_expression_function)(void);
6629 typedef expression_t* (*parse_expression_infix_function)(expression_t *left);
6630
6631 typedef struct expression_parser_function_t expression_parser_function_t;
6632 struct expression_parser_function_t {
6633         parse_expression_function        parser;
6634         precedence_t                     infix_precedence;
6635         parse_expression_infix_function  infix_parser;
6636 };
6637
6638 expression_parser_function_t expression_parsers[T_LAST_TOKEN];
6639
6640 /**
6641  * Prints an error message if an expression was expected but not read
6642  */
6643 static expression_t *expected_expression_error(void)
6644 {
6645         /* skip the error message if the error token was read */
6646         if (token.type != T_ERROR) {
6647                 errorf(HERE, "expected expression, got token %K", &token);
6648         }
6649         next_token();
6650
6651         return create_invalid_expression();
6652 }
6653
6654 /**
6655  * Parse a string constant.
6656  */
6657 static expression_t *parse_string_const(void)
6658 {
6659         wide_string_t wres;
6660         if (token.type == T_STRING_LITERAL) {
6661                 string_t res = token.v.string;
6662                 next_token();
6663                 while (token.type == T_STRING_LITERAL) {
6664                         res = concat_strings(&res, &token.v.string);
6665                         next_token();
6666                 }
6667                 if (token.type != T_WIDE_STRING_LITERAL) {
6668                         expression_t *const cnst = allocate_expression_zero(EXPR_STRING_LITERAL);
6669                         /* note: that we use type_char_ptr here, which is already the
6670                          * automatic converted type. revert_automatic_type_conversion
6671                          * will construct the array type */
6672                         cnst->base.type    = warning.write_strings ? type_const_char_ptr : type_char_ptr;
6673                         cnst->string.value = res;
6674                         return cnst;
6675                 }
6676
6677                 wres = concat_string_wide_string(&res, &token.v.wide_string);
6678         } else {
6679                 wres = token.v.wide_string;
6680         }
6681         next_token();
6682
6683         for (;;) {
6684                 switch (token.type) {
6685                         case T_WIDE_STRING_LITERAL:
6686                                 wres = concat_wide_strings(&wres, &token.v.wide_string);
6687                                 break;
6688
6689                         case T_STRING_LITERAL:
6690                                 wres = concat_wide_string_string(&wres, &token.v.string);
6691                                 break;
6692
6693                         default: {
6694                                 expression_t *const cnst = allocate_expression_zero(EXPR_WIDE_STRING_LITERAL);
6695                                 cnst->base.type         = warning.write_strings ? type_const_wchar_t_ptr : type_wchar_t_ptr;
6696                                 cnst->wide_string.value = wres;
6697                                 return cnst;
6698                         }
6699                 }
6700                 next_token();
6701         }
6702 }
6703
6704 /**
6705  * Parse a boolean constant.
6706  */
6707 static expression_t *parse_bool_const(bool value)
6708 {
6709         expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
6710         cnst->base.type          = type_bool;
6711         cnst->conste.v.int_value = value;
6712
6713         next_token();
6714
6715         return cnst;
6716 }
6717
6718 /**
6719  * Parse an integer constant.
6720  */
6721 static expression_t *parse_int_const(void)
6722 {
6723         expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
6724         cnst->base.type          = token.datatype;
6725         cnst->conste.v.int_value = token.v.intvalue;
6726
6727         next_token();
6728
6729         return cnst;
6730 }
6731
6732 /**
6733  * Parse a character constant.
6734  */
6735 static expression_t *parse_character_constant(void)
6736 {
6737         expression_t *cnst = allocate_expression_zero(EXPR_CHARACTER_CONSTANT);
6738         cnst->base.type          = token.datatype;
6739         cnst->conste.v.character = token.v.string;
6740
6741         if (cnst->conste.v.character.size != 1) {
6742                 if (!GNU_MODE) {
6743                         errorf(HERE, "more than 1 character in character constant");
6744                 } else if (warning.multichar) {
6745                         warningf(HERE, "multi-character character constant");
6746                 }
6747         }
6748         next_token();
6749
6750         return cnst;
6751 }
6752
6753 /**
6754  * Parse a wide character constant.
6755  */
6756 static expression_t *parse_wide_character_constant(void)
6757 {
6758         expression_t *cnst = allocate_expression_zero(EXPR_WIDE_CHARACTER_CONSTANT);
6759         cnst->base.type               = token.datatype;
6760         cnst->conste.v.wide_character = token.v.wide_string;
6761
6762         if (cnst->conste.v.wide_character.size != 1) {
6763                 if (!GNU_MODE) {
6764                         errorf(HERE, "more than 1 character in character constant");
6765                 } else if (warning.multichar) {
6766                         warningf(HERE, "multi-character character constant");
6767                 }
6768         }
6769         next_token();
6770
6771         return cnst;
6772 }
6773
6774 /**
6775  * Parse a float constant.
6776  */
6777 static expression_t *parse_float_const(void)
6778 {
6779         expression_t *cnst         = allocate_expression_zero(EXPR_CONST);
6780         cnst->base.type            = token.datatype;
6781         cnst->conste.v.float_value = token.v.floatvalue;
6782
6783         next_token();
6784
6785         return cnst;
6786 }
6787
6788 static entity_t *create_implicit_function(symbol_t *symbol,
6789                 const source_position_t *source_position)
6790 {
6791         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
6792         ntype->function.return_type            = type_int;
6793         ntype->function.unspecified_parameters = true;
6794         ntype->function.linkage                = LINKAGE_C;
6795
6796         type_t *type = typehash_insert(ntype);
6797         if (type != ntype) {
6798                 free_type(ntype);
6799         }
6800
6801         entity_t *entity = allocate_entity_zero(ENTITY_FUNCTION);
6802         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
6803         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
6804         entity->declaration.type                   = type;
6805         entity->declaration.implicit               = true;
6806         entity->base.symbol                        = symbol;
6807         entity->base.source_position               = *source_position;
6808
6809         bool strict_prototypes_old = warning.strict_prototypes;
6810         warning.strict_prototypes  = false;
6811         record_entity(entity, false);
6812         warning.strict_prototypes = strict_prototypes_old;
6813
6814         return entity;
6815 }
6816
6817 /**
6818  * Creates a return_type (func)(argument_type) function type if not
6819  * already exists.
6820  */
6821 static type_t *make_function_2_type(type_t *return_type, type_t *argument_type1,
6822                                     type_t *argument_type2)
6823 {
6824         function_parameter_t *parameter2
6825                 = obstack_alloc(type_obst, sizeof(parameter2[0]));
6826         memset(parameter2, 0, sizeof(parameter2[0]));
6827         parameter2->type = argument_type2;
6828
6829         function_parameter_t *parameter1
6830                 = obstack_alloc(type_obst, sizeof(parameter1[0]));
6831         memset(parameter1, 0, sizeof(parameter1[0]));
6832         parameter1->type = argument_type1;
6833         parameter1->next = parameter2;
6834
6835         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6836         type->function.return_type = return_type;
6837         type->function.parameters  = parameter1;
6838
6839         type_t *result = typehash_insert(type);
6840         if (result != type) {
6841                 free_type(type);
6842         }
6843
6844         return result;
6845 }
6846
6847 /**
6848  * Creates a return_type (func)(argument_type) function type if not
6849  * already exists.
6850  *
6851  * @param return_type    the return type
6852  * @param argument_type  the argument type
6853  */
6854 static type_t *make_function_1_type(type_t *return_type, type_t *argument_type)
6855 {
6856         function_parameter_t *parameter
6857                 = obstack_alloc(type_obst, sizeof(parameter[0]));
6858         memset(parameter, 0, sizeof(parameter[0]));
6859         parameter->type = argument_type;
6860
6861         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6862         type->function.return_type = return_type;
6863         type->function.parameters  = parameter;
6864
6865         type_t *result = typehash_insert(type);
6866         if (result != type) {
6867                 free_type(type);
6868         }
6869
6870         return result;
6871 }
6872
6873 static type_t *make_function_0_type(type_t *return_type)
6874 {
6875         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6876         type->function.return_type = return_type;
6877         type->function.parameters  = NULL;
6878
6879         type_t *result = typehash_insert(type);
6880         if (result != type) {
6881                 free_type(type);
6882         }
6883
6884         return result;
6885 }
6886
6887 /**
6888  * Creates a function type for some function like builtins.
6889  *
6890  * @param symbol   the symbol describing the builtin
6891  */
6892 static type_t *get_builtin_symbol_type(symbol_t *symbol)
6893 {
6894         switch (symbol->ID) {
6895         case T___builtin_alloca:
6896                 return make_function_1_type(type_void_ptr, type_size_t);
6897         case T___builtin_huge_val:
6898                 return make_function_0_type(type_double);
6899         case T___builtin_inf:
6900                 return make_function_0_type(type_double);
6901         case T___builtin_inff:
6902                 return make_function_0_type(type_float);
6903         case T___builtin_infl:
6904                 return make_function_0_type(type_long_double);
6905         case T___builtin_nan:
6906                 return make_function_1_type(type_double, type_char_ptr);
6907         case T___builtin_nanf:
6908                 return make_function_1_type(type_float, type_char_ptr);
6909         case T___builtin_nanl:
6910                 return make_function_1_type(type_long_double, type_char_ptr);
6911         case T___builtin_va_end:
6912                 return make_function_1_type(type_void, type_valist);
6913         case T___builtin_expect:
6914                 return make_function_2_type(type_long, type_long, type_long);
6915         default:
6916                 internal_errorf(HERE, "not implemented builtin identifier found");
6917         }
6918 }
6919
6920 /**
6921  * Performs automatic type cast as described in § 6.3.2.1.
6922  *
6923  * @param orig_type  the original type
6924  */
6925 static type_t *automatic_type_conversion(type_t *orig_type)
6926 {
6927         type_t *type = skip_typeref(orig_type);
6928         if (is_type_array(type)) {
6929                 array_type_t *array_type   = &type->array;
6930                 type_t       *element_type = array_type->element_type;
6931                 unsigned      qualifiers   = array_type->base.qualifiers;
6932
6933                 return make_pointer_type(element_type, qualifiers);
6934         }
6935
6936         if (is_type_function(type)) {
6937                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
6938         }
6939
6940         return orig_type;
6941 }
6942
6943 /**
6944  * reverts the automatic casts of array to pointer types and function
6945  * to function-pointer types as defined § 6.3.2.1
6946  */
6947 type_t *revert_automatic_type_conversion(const expression_t *expression)
6948 {
6949         switch (expression->kind) {
6950                 case EXPR_REFERENCE: {
6951                         entity_t *entity = expression->reference.entity;
6952                         if (is_declaration(entity)) {
6953                                 return entity->declaration.type;
6954                         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6955                                 return entity->enum_value.enum_type;
6956                         } else {
6957                                 panic("no declaration or enum in reference");
6958                         }
6959                 }
6960
6961                 case EXPR_SELECT: {
6962                         entity_t *entity = expression->select.compound_entry;
6963                         assert(is_declaration(entity));
6964                         type_t   *type   = entity->declaration.type;
6965                         return get_qualified_type(type,
6966                                         expression->base.type->base.qualifiers);
6967                 }
6968
6969                 case EXPR_UNARY_DEREFERENCE: {
6970                         const expression_t *const value = expression->unary.value;
6971                         type_t             *const type  = skip_typeref(value->base.type);
6972                         if (!is_type_pointer(type))
6973                                 return type_error_type;
6974                         return type->pointer.points_to;
6975                 }
6976
6977                 case EXPR_BUILTIN_SYMBOL:
6978                         return get_builtin_symbol_type(expression->builtin_symbol.symbol);
6979
6980                 case EXPR_ARRAY_ACCESS: {
6981                         const expression_t *array_ref = expression->array_access.array_ref;
6982                         type_t             *type_left = skip_typeref(array_ref->base.type);
6983                         if (!is_type_pointer(type_left))
6984                                 return type_error_type;
6985                         return type_left->pointer.points_to;
6986                 }
6987
6988                 case EXPR_STRING_LITERAL: {
6989                         size_t size = expression->string.value.size;
6990                         return make_array_type(type_char, size, TYPE_QUALIFIER_NONE);
6991                 }
6992
6993                 case EXPR_WIDE_STRING_LITERAL: {
6994                         size_t size = expression->wide_string.value.size;
6995                         return make_array_type(type_wchar_t, size, TYPE_QUALIFIER_NONE);
6996                 }
6997
6998                 case EXPR_COMPOUND_LITERAL:
6999                         return expression->compound_literal.type;
7000
7001                 default:
7002                         return expression->base.type;
7003         }
7004 }
7005
7006 static expression_t *parse_reference(void)
7007 {
7008         symbol_t *const symbol = token.v.symbol;
7009
7010         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
7011
7012         if (entity == NULL) {
7013                 if (!strict_mode && look_ahead(1)->type == '(') {
7014                         /* an implicitly declared function */
7015                         if (warning.error_implicit_function_declaration) {
7016                                 errorf(HERE, "implicit declaration of function '%Y'", symbol);
7017                         } else if (warning.implicit_function_declaration) {
7018                                 warningf(HERE, "implicit declaration of function '%Y'", symbol);
7019                         }
7020
7021                         entity = create_implicit_function(symbol, HERE);
7022                 } else {
7023                         errorf(HERE, "unknown identifier '%Y' found.", symbol);
7024                         entity = create_error_entity(symbol, ENTITY_VARIABLE);
7025                 }
7026         }
7027
7028         type_t *orig_type;
7029
7030         if (is_declaration(entity)) {
7031                 orig_type = entity->declaration.type;
7032         } else if (entity->kind == ENTITY_ENUM_VALUE) {
7033                 orig_type = entity->enum_value.enum_type;
7034         } else if (entity->kind == ENTITY_TYPEDEF) {
7035                 errorf(HERE, "encountered typedef name '%Y' while parsing expression",
7036                         symbol);
7037                 next_token();
7038                 return create_invalid_expression();
7039         } else {
7040                 panic("expected declaration or enum value in reference");
7041         }
7042
7043         /* we always do the auto-type conversions; the & and sizeof parser contains
7044          * code to revert this! */
7045         type_t *type = automatic_type_conversion(orig_type);
7046
7047         expression_kind_t kind = EXPR_REFERENCE;
7048         if (entity->kind == ENTITY_ENUM_VALUE)
7049                 kind = EXPR_REFERENCE_ENUM_VALUE;
7050
7051         expression_t *expression     = allocate_expression_zero(kind);
7052         expression->reference.entity = entity;
7053         expression->base.type        = type;
7054
7055         /* this declaration is used */
7056         if (is_declaration(entity)) {
7057                 entity->declaration.used = true;
7058         }
7059
7060         if (entity->base.parent_scope != file_scope
7061                 && entity->base.parent_scope->depth < current_function->parameters.depth
7062                 && is_type_valid(orig_type) && !is_type_function(orig_type)) {
7063                 if (entity->kind == ENTITY_VARIABLE) {
7064                         /* access of a variable from an outer function */
7065                         entity->variable.address_taken = true;
7066                 } else if (entity->kind == ENTITY_PARAMETER) {
7067                         entity->parameter.address_taken = true;
7068                 }
7069                 current_function->need_closure = true;
7070         }
7071
7072         /* check for deprecated functions */
7073         if (warning.deprecated_declarations
7074                 && is_declaration(entity)
7075                 && entity->declaration.modifiers & DM_DEPRECATED) {
7076                 declaration_t *declaration = &entity->declaration;
7077
7078                 char const *const prefix = entity->kind == ENTITY_FUNCTION ?
7079                         "function" : "variable";
7080
7081                 if (declaration->deprecated_string != NULL) {
7082                         warningf(HERE, "%s '%Y' is deprecated (declared %P): \"%s\"",
7083                                  prefix, entity->base.symbol, &entity->base.source_position,
7084                                  declaration->deprecated_string);
7085                 } else {
7086                         warningf(HERE, "%s '%Y' is deprecated (declared %P)", prefix,
7087                                  entity->base.symbol, &entity->base.source_position);
7088                 }
7089         }
7090
7091         if (warning.init_self && entity == current_init_decl && !in_type_prop
7092             && entity->kind == ENTITY_VARIABLE) {
7093                 current_init_decl = NULL;
7094                 warningf(HERE, "variable '%#T' is initialized by itself",
7095                          entity->declaration.type, entity->base.symbol);
7096         }
7097
7098         next_token();
7099         return expression;
7100 }
7101
7102 static bool semantic_cast(expression_t *cast)
7103 {
7104         expression_t            *expression      = cast->unary.value;
7105         type_t                  *orig_dest_type  = cast->base.type;
7106         type_t                  *orig_type_right = expression->base.type;
7107         type_t            const *dst_type        = skip_typeref(orig_dest_type);
7108         type_t            const *src_type        = skip_typeref(orig_type_right);
7109         source_position_t const *pos             = &cast->base.source_position;
7110
7111         /* §6.5.4 A (void) cast is explicitly permitted, more for documentation than for utility. */
7112         if (dst_type == type_void)
7113                 return true;
7114
7115         /* only integer and pointer can be casted to pointer */
7116         if (is_type_pointer(dst_type)  &&
7117             !is_type_pointer(src_type) &&
7118             !is_type_integer(src_type) &&
7119             is_type_valid(src_type)) {
7120                 errorf(pos, "cannot convert type '%T' to a pointer type", orig_type_right);
7121                 return false;
7122         }
7123
7124         if (!is_type_scalar(dst_type) && is_type_valid(dst_type)) {
7125                 errorf(pos, "conversion to non-scalar type '%T' requested", orig_dest_type);
7126                 return false;
7127         }
7128
7129         if (!is_type_scalar(src_type) && is_type_valid(src_type)) {
7130                 errorf(pos, "conversion from non-scalar type '%T' requested", orig_type_right);
7131                 return false;
7132         }
7133
7134         if (warning.cast_qual &&
7135             is_type_pointer(src_type) &&
7136             is_type_pointer(dst_type)) {
7137                 type_t *src = skip_typeref(src_type->pointer.points_to);
7138                 type_t *dst = skip_typeref(dst_type->pointer.points_to);
7139                 unsigned missing_qualifiers =
7140                         src->base.qualifiers & ~dst->base.qualifiers;
7141                 if (missing_qualifiers != 0) {
7142                         warningf(pos,
7143                                  "cast discards qualifiers '%Q' in pointer target type of '%T'",
7144                                  missing_qualifiers, orig_type_right);
7145                 }
7146         }
7147         return true;
7148 }
7149
7150 static expression_t *parse_compound_literal(type_t *type)
7151 {
7152         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
7153
7154         parse_initializer_env_t env;
7155         env.type             = type;
7156         env.entity           = NULL;
7157         env.must_be_constant = false;
7158         initializer_t *initializer = parse_initializer(&env);
7159         type = env.type;
7160
7161         expression->compound_literal.initializer = initializer;
7162         expression->compound_literal.type        = type;
7163         expression->base.type                    = automatic_type_conversion(type);
7164
7165         return expression;
7166 }
7167
7168 /**
7169  * Parse a cast expression.
7170  */
7171 static expression_t *parse_cast(void)
7172 {
7173         add_anchor_token(')');
7174
7175         source_position_t source_position = token.source_position;
7176
7177         type_t *type = parse_typename();
7178
7179         rem_anchor_token(')');
7180         expect(')', end_error);
7181
7182         if (token.type == '{') {
7183                 return parse_compound_literal(type);
7184         }
7185
7186         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
7187         cast->base.source_position = source_position;
7188
7189         expression_t *value = parse_sub_expression(PREC_CAST);
7190         cast->base.type   = type;
7191         cast->unary.value = value;
7192
7193         if (! semantic_cast(cast)) {
7194                 /* TODO: record the error in the AST. else it is impossible to detect it */
7195         }
7196
7197         return cast;
7198 end_error:
7199         return create_invalid_expression();
7200 }
7201
7202 /**
7203  * Parse a statement expression.
7204  */
7205 static expression_t *parse_statement_expression(void)
7206 {
7207         add_anchor_token(')');
7208
7209         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
7210
7211         statement_t *statement          = parse_compound_statement(true);
7212         statement->compound.stmt_expr   = true;
7213         expression->statement.statement = statement;
7214
7215         /* find last statement and use its type */
7216         type_t *type = type_void;
7217         const statement_t *stmt = statement->compound.statements;
7218         if (stmt != NULL) {
7219                 while (stmt->base.next != NULL)
7220                         stmt = stmt->base.next;
7221
7222                 if (stmt->kind == STATEMENT_EXPRESSION) {
7223                         type = stmt->expression.expression->base.type;
7224                 }
7225         } else if (warning.other) {
7226                 warningf(&expression->base.source_position, "empty statement expression ({})");
7227         }
7228         expression->base.type = type;
7229
7230         rem_anchor_token(')');
7231         expect(')', end_error);
7232
7233 end_error:
7234         return expression;
7235 }
7236
7237 /**
7238  * Parse a parenthesized expression.
7239  */
7240 static expression_t *parse_parenthesized_expression(void)
7241 {
7242         eat('(');
7243
7244         switch (token.type) {
7245         case '{':
7246                 /* gcc extension: a statement expression */
7247                 return parse_statement_expression();
7248
7249         TYPE_QUALIFIERS
7250         TYPE_SPECIFIERS
7251                 return parse_cast();
7252         case T_IDENTIFIER:
7253                 if (is_typedef_symbol(token.v.symbol)) {
7254                         return parse_cast();
7255                 }
7256         }
7257
7258         add_anchor_token(')');
7259         expression_t *result = parse_expression();
7260         result->base.parenthesized = true;
7261         rem_anchor_token(')');
7262         expect(')', end_error);
7263
7264 end_error:
7265         return result;
7266 }
7267
7268 static expression_t *parse_function_keyword(void)
7269 {
7270         /* TODO */
7271
7272         if (current_function == NULL) {
7273                 errorf(HERE, "'__func__' used outside of a function");
7274         }
7275
7276         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
7277         expression->base.type     = type_char_ptr;
7278         expression->funcname.kind = FUNCNAME_FUNCTION;
7279
7280         next_token();
7281
7282         return expression;
7283 }
7284
7285 static expression_t *parse_pretty_function_keyword(void)
7286 {
7287         if (current_function == NULL) {
7288                 errorf(HERE, "'__PRETTY_FUNCTION__' used outside of a function");
7289         }
7290
7291         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
7292         expression->base.type     = type_char_ptr;
7293         expression->funcname.kind = FUNCNAME_PRETTY_FUNCTION;
7294
7295         eat(T___PRETTY_FUNCTION__);
7296
7297         return expression;
7298 }
7299
7300 static expression_t *parse_funcsig_keyword(void)
7301 {
7302         if (current_function == NULL) {
7303                 errorf(HERE, "'__FUNCSIG__' used outside of a function");
7304         }
7305
7306         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
7307         expression->base.type     = type_char_ptr;
7308         expression->funcname.kind = FUNCNAME_FUNCSIG;
7309
7310         eat(T___FUNCSIG__);
7311
7312         return expression;
7313 }
7314
7315 static expression_t *parse_funcdname_keyword(void)
7316 {
7317         if (current_function == NULL) {
7318                 errorf(HERE, "'__FUNCDNAME__' used outside of a function");
7319         }
7320
7321         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
7322         expression->base.type     = type_char_ptr;
7323         expression->funcname.kind = FUNCNAME_FUNCDNAME;
7324
7325         eat(T___FUNCDNAME__);
7326
7327         return expression;
7328 }
7329
7330 static designator_t *parse_designator(void)
7331 {
7332         designator_t *result    = allocate_ast_zero(sizeof(result[0]));
7333         result->source_position = *HERE;
7334
7335         if (token.type != T_IDENTIFIER) {
7336                 parse_error_expected("while parsing member designator",
7337                                      T_IDENTIFIER, NULL);
7338                 return NULL;
7339         }
7340         result->symbol = token.v.symbol;
7341         next_token();
7342
7343         designator_t *last_designator = result;
7344         while (true) {
7345                 if (token.type == '.') {
7346                         next_token();
7347                         if (token.type != T_IDENTIFIER) {
7348                                 parse_error_expected("while parsing member designator",
7349                                                      T_IDENTIFIER, NULL);
7350                                 return NULL;
7351                         }
7352                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
7353                         designator->source_position = *HERE;
7354                         designator->symbol          = token.v.symbol;
7355                         next_token();
7356
7357                         last_designator->next = designator;
7358                         last_designator       = designator;
7359                         continue;
7360                 }
7361                 if (token.type == '[') {
7362                         next_token();
7363                         add_anchor_token(']');
7364                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
7365                         designator->source_position = *HERE;
7366                         designator->array_index     = parse_expression();
7367                         rem_anchor_token(']');
7368                         expect(']', end_error);
7369                         if (designator->array_index == NULL) {
7370                                 return NULL;
7371                         }
7372
7373                         last_designator->next = designator;
7374                         last_designator       = designator;
7375                         continue;
7376                 }
7377                 break;
7378         }
7379
7380         return result;
7381 end_error:
7382         return NULL;
7383 }
7384
7385 /**
7386  * Parse the __builtin_offsetof() expression.
7387  */
7388 static expression_t *parse_offsetof(void)
7389 {
7390         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
7391         expression->base.type    = type_size_t;
7392
7393         eat(T___builtin_offsetof);
7394
7395         expect('(', end_error);
7396         add_anchor_token(',');
7397         type_t *type = parse_typename();
7398         rem_anchor_token(',');
7399         expect(',', end_error);
7400         add_anchor_token(')');
7401         designator_t *designator = parse_designator();
7402         rem_anchor_token(')');
7403         expect(')', end_error);
7404
7405         expression->offsetofe.type       = type;
7406         expression->offsetofe.designator = designator;
7407
7408         type_path_t path;
7409         memset(&path, 0, sizeof(path));
7410         path.top_type = type;
7411         path.path     = NEW_ARR_F(type_path_entry_t, 0);
7412
7413         descend_into_subtype(&path);
7414
7415         if (!walk_designator(&path, designator, true)) {
7416                 return create_invalid_expression();
7417         }
7418
7419         DEL_ARR_F(path.path);
7420
7421         return expression;
7422 end_error:
7423         return create_invalid_expression();
7424 }
7425
7426 /**
7427  * Parses a _builtin_va_start() expression.
7428  */
7429 static expression_t *parse_va_start(void)
7430 {
7431         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
7432
7433         eat(T___builtin_va_start);
7434
7435         expect('(', end_error);
7436         add_anchor_token(',');
7437         expression->va_starte.ap = parse_assignment_expression();
7438         rem_anchor_token(',');
7439         expect(',', end_error);
7440         expression_t *const expr = parse_assignment_expression();
7441         if (expr->kind == EXPR_REFERENCE) {
7442                 entity_t *const entity = expr->reference.entity;
7443                 if (entity->base.parent_scope != &current_function->parameters
7444                                 || entity->base.next != NULL
7445                                 || entity->kind != ENTITY_PARAMETER) {
7446                         errorf(&expr->base.source_position,
7447                                "second argument of 'va_start' must be last parameter of the current function");
7448                 } else {
7449                         expression->va_starte.parameter = &entity->variable;
7450                 }
7451                 expect(')', end_error);
7452                 return expression;
7453         }
7454         expect(')', end_error);
7455 end_error:
7456         return create_invalid_expression();
7457 }
7458
7459 /**
7460  * Parses a _builtin_va_arg() expression.
7461  */
7462 static expression_t *parse_va_arg(void)
7463 {
7464         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
7465
7466         eat(T___builtin_va_arg);
7467
7468         expect('(', end_error);
7469         expression->va_arge.ap = parse_assignment_expression();
7470         expect(',', end_error);
7471         expression->base.type = parse_typename();
7472         expect(')', end_error);
7473
7474         return expression;
7475 end_error:
7476         return create_invalid_expression();
7477 }
7478
7479 static expression_t *parse_builtin_symbol(void)
7480 {
7481         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_SYMBOL);
7482
7483         symbol_t *symbol = token.v.symbol;
7484
7485         expression->builtin_symbol.symbol = symbol;
7486         next_token();
7487
7488         type_t *type = get_builtin_symbol_type(symbol);
7489         type = automatic_type_conversion(type);
7490
7491         expression->base.type = type;
7492         return expression;
7493 }
7494
7495 /**
7496  * Parses a __builtin_constant() expression.
7497  */
7498 static expression_t *parse_builtin_constant(void)
7499 {
7500         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
7501
7502         eat(T___builtin_constant_p);
7503
7504         expect('(', end_error);
7505         add_anchor_token(')');
7506         expression->builtin_constant.value = parse_assignment_expression();
7507         rem_anchor_token(')');
7508         expect(')', end_error);
7509         expression->base.type = type_int;
7510
7511         return expression;
7512 end_error:
7513         return create_invalid_expression();
7514 }
7515
7516 /**
7517  * Parses a __builtin_prefetch() expression.
7518  */
7519 static expression_t *parse_builtin_prefetch(void)
7520 {
7521         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_PREFETCH);
7522
7523         eat(T___builtin_prefetch);
7524
7525         expect('(', end_error);
7526         add_anchor_token(')');
7527         expression->builtin_prefetch.adr = parse_assignment_expression();
7528         if (token.type == ',') {
7529                 next_token();
7530                 expression->builtin_prefetch.rw = parse_assignment_expression();
7531         }
7532         if (token.type == ',') {
7533                 next_token();
7534                 expression->builtin_prefetch.locality = parse_assignment_expression();
7535         }
7536         rem_anchor_token(')');
7537         expect(')', end_error);
7538         expression->base.type = type_void;
7539
7540         return expression;
7541 end_error:
7542         return create_invalid_expression();
7543 }
7544
7545 /**
7546  * Parses a __builtin_is_*() compare expression.
7547  */
7548 static expression_t *parse_compare_builtin(void)
7549 {
7550         expression_t *expression;
7551
7552         switch (token.type) {
7553         case T___builtin_isgreater:
7554                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATER);
7555                 break;
7556         case T___builtin_isgreaterequal:
7557                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATEREQUAL);
7558                 break;
7559         case T___builtin_isless:
7560                 expression = allocate_expression_zero(EXPR_BINARY_ISLESS);
7561                 break;
7562         case T___builtin_islessequal:
7563                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSEQUAL);
7564                 break;
7565         case T___builtin_islessgreater:
7566                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSGREATER);
7567                 break;
7568         case T___builtin_isunordered:
7569                 expression = allocate_expression_zero(EXPR_BINARY_ISUNORDERED);
7570                 break;
7571         default:
7572                 internal_errorf(HERE, "invalid compare builtin found");
7573         }
7574         expression->base.source_position = *HERE;
7575         next_token();
7576
7577         expect('(', end_error);
7578         expression->binary.left = parse_assignment_expression();
7579         expect(',', end_error);
7580         expression->binary.right = parse_assignment_expression();
7581         expect(')', end_error);
7582
7583         type_t *const orig_type_left  = expression->binary.left->base.type;
7584         type_t *const orig_type_right = expression->binary.right->base.type;
7585
7586         type_t *const type_left  = skip_typeref(orig_type_left);
7587         type_t *const type_right = skip_typeref(orig_type_right);
7588         if (!is_type_float(type_left) && !is_type_float(type_right)) {
7589                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7590                         type_error_incompatible("invalid operands in comparison",
7591                                 &expression->base.source_position, orig_type_left, orig_type_right);
7592                 }
7593         } else {
7594                 semantic_comparison(&expression->binary);
7595         }
7596
7597         return expression;
7598 end_error:
7599         return create_invalid_expression();
7600 }
7601
7602 #if 0
7603 /**
7604  * Parses a __builtin_expect(, end_error) expression.
7605  */
7606 static expression_t *parse_builtin_expect(void, end_error)
7607 {
7608         expression_t *expression
7609                 = allocate_expression_zero(EXPR_BINARY_BUILTIN_EXPECT);
7610
7611         eat(T___builtin_expect);
7612
7613         expect('(', end_error);
7614         expression->binary.left = parse_assignment_expression();
7615         expect(',', end_error);
7616         expression->binary.right = parse_constant_expression();
7617         expect(')', end_error);
7618
7619         expression->base.type = expression->binary.left->base.type;
7620
7621         return expression;
7622 end_error:
7623         return create_invalid_expression();
7624 }
7625 #endif
7626
7627 /**
7628  * Parses a MS assume() expression.
7629  */
7630 static expression_t *parse_assume(void)
7631 {
7632         expression_t *expression = allocate_expression_zero(EXPR_UNARY_ASSUME);
7633
7634         eat(T__assume);
7635
7636         expect('(', end_error);
7637         add_anchor_token(')');
7638         expression->unary.value = parse_assignment_expression();
7639         rem_anchor_token(')');
7640         expect(')', end_error);
7641
7642         expression->base.type = type_void;
7643         return expression;
7644 end_error:
7645         return create_invalid_expression();
7646 }
7647
7648 /**
7649  * Return the declaration for a given label symbol or create a new one.
7650  *
7651  * @param symbol  the symbol of the label
7652  */
7653 static label_t *get_label(symbol_t *symbol)
7654 {
7655         entity_t *label;
7656         assert(current_function != NULL);
7657
7658         label = get_entity(symbol, NAMESPACE_LABEL);
7659         /* if we found a local label, we already created the declaration */
7660         if (label != NULL && label->kind == ENTITY_LOCAL_LABEL) {
7661                 if (label->base.parent_scope != current_scope) {
7662                         assert(label->base.parent_scope->depth < current_scope->depth);
7663                         current_function->goto_to_outer = true;
7664                 }
7665                 return &label->label;
7666         }
7667
7668         label = get_entity(symbol, NAMESPACE_LABEL);
7669         /* if we found a label in the same function, then we already created the
7670          * declaration */
7671         if (label != NULL
7672                         && label->base.parent_scope == &current_function->parameters) {
7673                 return &label->label;
7674         }
7675
7676         /* otherwise we need to create a new one */
7677         label               = allocate_entity_zero(ENTITY_LABEL);
7678         label->base.namespc = NAMESPACE_LABEL;
7679         label->base.symbol  = symbol;
7680
7681         label_push(label);
7682
7683         return &label->label;
7684 }
7685
7686 /**
7687  * Parses a GNU && label address expression.
7688  */
7689 static expression_t *parse_label_address(void)
7690 {
7691         source_position_t source_position = token.source_position;
7692         eat(T_ANDAND);
7693         if (token.type != T_IDENTIFIER) {
7694                 parse_error_expected("while parsing label address", T_IDENTIFIER, NULL);
7695                 goto end_error;
7696         }
7697         symbol_t *symbol = token.v.symbol;
7698         next_token();
7699
7700         label_t *label       = get_label(symbol);
7701         label->used          = true;
7702         label->address_taken = true;
7703
7704         expression_t *expression = allocate_expression_zero(EXPR_LABEL_ADDRESS);
7705         expression->base.source_position = source_position;
7706
7707         /* label address is threaten as a void pointer */
7708         expression->base.type           = type_void_ptr;
7709         expression->label_address.label = label;
7710         return expression;
7711 end_error:
7712         return create_invalid_expression();
7713 }
7714
7715 /**
7716  * Parse a microsoft __noop expression.
7717  */
7718 static expression_t *parse_noop_expression(void)
7719 {
7720         /* the result is a (int)0 */
7721         expression_t *cnst         = allocate_expression_zero(EXPR_CONST);
7722         cnst->base.type            = type_int;
7723         cnst->conste.v.int_value   = 0;
7724         cnst->conste.is_ms_noop    = true;
7725
7726         eat(T___noop);
7727
7728         if (token.type == '(') {
7729                 /* parse arguments */
7730                 eat('(');
7731                 add_anchor_token(')');
7732                 add_anchor_token(',');
7733
7734                 if (token.type != ')') {
7735                         while (true) {
7736                                 (void)parse_assignment_expression();
7737                                 if (token.type != ',')
7738                                         break;
7739                                 next_token();
7740                         }
7741                 }
7742         }
7743         rem_anchor_token(',');
7744         rem_anchor_token(')');
7745         expect(')', end_error);
7746
7747 end_error:
7748         return cnst;
7749 }
7750
7751 /**
7752  * Parses a primary expression.
7753  */
7754 static expression_t *parse_primary_expression(void)
7755 {
7756         switch (token.type) {
7757                 case T_false:                    return parse_bool_const(false);
7758                 case T_true:                     return parse_bool_const(true);
7759                 case T_INTEGER:                  return parse_int_const();
7760                 case T_CHARACTER_CONSTANT:       return parse_character_constant();
7761                 case T_WIDE_CHARACTER_CONSTANT:  return parse_wide_character_constant();
7762                 case T_FLOATINGPOINT:            return parse_float_const();
7763                 case T_STRING_LITERAL:
7764                 case T_WIDE_STRING_LITERAL:      return parse_string_const();
7765                 case T_IDENTIFIER:               return parse_reference();
7766                 case T___FUNCTION__:
7767                 case T___func__:                 return parse_function_keyword();
7768                 case T___PRETTY_FUNCTION__:      return parse_pretty_function_keyword();
7769                 case T___FUNCSIG__:              return parse_funcsig_keyword();
7770                 case T___FUNCDNAME__:            return parse_funcdname_keyword();
7771                 case T___builtin_offsetof:       return parse_offsetof();
7772                 case T___builtin_va_start:       return parse_va_start();
7773                 case T___builtin_va_arg:         return parse_va_arg();
7774                 case T___builtin_expect:
7775                 case T___builtin_alloca:
7776                 case T___builtin_inf:
7777                 case T___builtin_inff:
7778                 case T___builtin_infl:
7779                 case T___builtin_nan:
7780                 case T___builtin_nanf:
7781                 case T___builtin_nanl:
7782                 case T___builtin_huge_val:
7783                 case T___builtin_va_end:         return parse_builtin_symbol();
7784                 case T___builtin_isgreater:
7785                 case T___builtin_isgreaterequal:
7786                 case T___builtin_isless:
7787                 case T___builtin_islessequal:
7788                 case T___builtin_islessgreater:
7789                 case T___builtin_isunordered:    return parse_compare_builtin();
7790                 case T___builtin_constant_p:     return parse_builtin_constant();
7791                 case T___builtin_prefetch:       return parse_builtin_prefetch();
7792                 case T__assume:                  return parse_assume();
7793                 case T_ANDAND:
7794                         if (GNU_MODE)
7795                                 return parse_label_address();
7796                         break;
7797
7798                 case '(':                        return parse_parenthesized_expression();
7799                 case T___noop:                   return parse_noop_expression();
7800         }
7801
7802         errorf(HERE, "unexpected token %K, expected an expression", &token);
7803         return create_invalid_expression();
7804 }
7805
7806 /**
7807  * Check if the expression has the character type and issue a warning then.
7808  */
7809 static void check_for_char_index_type(const expression_t *expression)
7810 {
7811         type_t       *const type      = expression->base.type;
7812         const type_t *const base_type = skip_typeref(type);
7813
7814         if (is_type_atomic(base_type, ATOMIC_TYPE_CHAR) &&
7815                         warning.char_subscripts) {
7816                 warningf(&expression->base.source_position,
7817                          "array subscript has type '%T'", type);
7818         }
7819 }
7820
7821 static expression_t *parse_array_expression(expression_t *left)
7822 {
7823         expression_t *expression = allocate_expression_zero(EXPR_ARRAY_ACCESS);
7824
7825         eat('[');
7826         add_anchor_token(']');
7827
7828         expression_t *inside = parse_expression();
7829
7830         type_t *const orig_type_left   = left->base.type;
7831         type_t *const orig_type_inside = inside->base.type;
7832
7833         type_t *const type_left   = skip_typeref(orig_type_left);
7834         type_t *const type_inside = skip_typeref(orig_type_inside);
7835
7836         type_t                    *return_type;
7837         array_access_expression_t *array_access = &expression->array_access;
7838         if (is_type_pointer(type_left)) {
7839                 return_type             = type_left->pointer.points_to;
7840                 array_access->array_ref = left;
7841                 array_access->index     = inside;
7842                 check_for_char_index_type(inside);
7843         } else if (is_type_pointer(type_inside)) {
7844                 return_type             = type_inside->pointer.points_to;
7845                 array_access->array_ref = inside;
7846                 array_access->index     = left;
7847                 array_access->flipped   = true;
7848                 check_for_char_index_type(left);
7849         } else {
7850                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
7851                         errorf(HERE,
7852                                 "array access on object with non-pointer types '%T', '%T'",
7853                                 orig_type_left, orig_type_inside);
7854                 }
7855                 return_type             = type_error_type;
7856                 array_access->array_ref = left;
7857                 array_access->index     = inside;
7858         }
7859
7860         expression->base.type = automatic_type_conversion(return_type);
7861
7862         rem_anchor_token(']');
7863         expect(']', end_error);
7864 end_error:
7865         return expression;
7866 }
7867
7868 static expression_t *parse_typeprop(expression_kind_t const kind)
7869 {
7870         expression_t  *tp_expression = allocate_expression_zero(kind);
7871         tp_expression->base.type     = type_size_t;
7872
7873         eat(kind == EXPR_SIZEOF ? T_sizeof : T___alignof__);
7874
7875         /* we only refer to a type property, mark this case */
7876         bool old     = in_type_prop;
7877         in_type_prop = true;
7878
7879         type_t       *orig_type;
7880         expression_t *expression;
7881         if (token.type == '(' && is_declaration_specifier(look_ahead(1), true)) {
7882                 next_token();
7883                 add_anchor_token(')');
7884                 orig_type = parse_typename();
7885                 rem_anchor_token(')');
7886                 expect(')', end_error);
7887
7888                 if (token.type == '{') {
7889                         /* It was not sizeof(type) after all.  It is sizeof of an expression
7890                          * starting with a compound literal */
7891                         expression = parse_compound_literal(orig_type);
7892                         goto typeprop_expression;
7893                 }
7894         } else {
7895                 expression = parse_sub_expression(PREC_UNARY);
7896
7897 typeprop_expression:
7898                 tp_expression->typeprop.tp_expression = expression;
7899
7900                 orig_type = revert_automatic_type_conversion(expression);
7901                 expression->base.type = orig_type;
7902         }
7903
7904         tp_expression->typeprop.type   = orig_type;
7905         type_t const* const type       = skip_typeref(orig_type);
7906         char   const* const wrong_type =
7907                 GNU_MODE && is_type_atomic(type, ATOMIC_TYPE_VOID) ? NULL                  :
7908                 is_type_incomplete(type)                           ? "incomplete"          :
7909                 type->kind == TYPE_FUNCTION                        ? "function designator" :
7910                 type->kind == TYPE_BITFIELD                        ? "bitfield"            :
7911                 NULL;
7912         if (wrong_type != NULL) {
7913                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
7914                 errorf(&tp_expression->base.source_position,
7915                                 "operand of %s expression must not be of %s type '%T'",
7916                                 what, wrong_type, orig_type);
7917         }
7918
7919 end_error:
7920         in_type_prop = old;
7921         return tp_expression;
7922 }
7923
7924 static expression_t *parse_sizeof(void)
7925 {
7926         return parse_typeprop(EXPR_SIZEOF);
7927 }
7928
7929 static expression_t *parse_alignof(void)
7930 {
7931         return parse_typeprop(EXPR_ALIGNOF);
7932 }
7933
7934 static expression_t *parse_select_expression(expression_t *compound)
7935 {
7936         expression_t *select    = allocate_expression_zero(EXPR_SELECT);
7937         select->select.compound = compound;
7938
7939         assert(token.type == '.' || token.type == T_MINUSGREATER);
7940         bool is_pointer = (token.type == T_MINUSGREATER);
7941         next_token();
7942
7943         if (token.type != T_IDENTIFIER) {
7944                 parse_error_expected("while parsing select", T_IDENTIFIER, NULL);
7945                 return select;
7946         }
7947         symbol_t *symbol = token.v.symbol;
7948         next_token();
7949
7950         type_t *const orig_type = compound->base.type;
7951         type_t *const type      = skip_typeref(orig_type);
7952
7953         type_t *type_left;
7954         bool    saw_error = false;
7955         if (is_type_pointer(type)) {
7956                 if (!is_pointer) {
7957                         errorf(HERE,
7958                                "request for member '%Y' in something not a struct or union, but '%T'",
7959                                symbol, orig_type);
7960                         saw_error = true;
7961                 }
7962                 type_left = skip_typeref(type->pointer.points_to);
7963         } else {
7964                 if (is_pointer && is_type_valid(type)) {
7965                         errorf(HERE, "left hand side of '->' is not a pointer, but '%T'", orig_type);
7966                         saw_error = true;
7967                 }
7968                 type_left = type;
7969         }
7970
7971         entity_t *entry;
7972         if (type_left->kind == TYPE_COMPOUND_STRUCT ||
7973             type_left->kind == TYPE_COMPOUND_UNION) {
7974                 compound_t *compound = type_left->compound.compound;
7975
7976                 if (!compound->complete) {
7977                         errorf(HERE, "request for member '%Y' of incomplete type '%T'",
7978                                symbol, type_left);
7979                         goto create_error_entry;
7980                 }
7981
7982                 entry = find_compound_entry(compound, symbol);
7983                 if (entry == NULL) {
7984                         errorf(HERE, "'%T' has no member named '%Y'", orig_type, symbol);
7985                         goto create_error_entry;
7986                 }
7987         } else {
7988                 if (is_type_valid(type_left) && !saw_error) {
7989                         errorf(HERE,
7990                                "request for member '%Y' in something not a struct or union, but '%T'",
7991                                symbol, type_left);
7992                 }
7993 create_error_entry:
7994                 entry = create_error_entity(symbol, ENTITY_COMPOUND_MEMBER);
7995         }
7996
7997         assert(is_declaration(entry));
7998         select->select.compound_entry = entry;
7999
8000         type_t *entry_type = entry->declaration.type;
8001         type_t *res_type
8002                 = get_qualified_type(entry_type, type_left->base.qualifiers);
8003
8004         /* we always do the auto-type conversions; the & and sizeof parser contains
8005          * code to revert this! */
8006         select->base.type = automatic_type_conversion(res_type);
8007
8008         type_t *skipped = skip_typeref(res_type);
8009         if (skipped->kind == TYPE_BITFIELD) {
8010                 select->base.type = skipped->bitfield.base_type;
8011         }
8012
8013         return select;
8014 }
8015
8016 static void check_call_argument(const function_parameter_t *parameter,
8017                                 call_argument_t *argument, unsigned pos)
8018 {
8019         type_t         *expected_type      = parameter->type;
8020         type_t         *expected_type_skip = skip_typeref(expected_type);
8021         assign_error_t  error              = ASSIGN_ERROR_INCOMPATIBLE;
8022         expression_t   *arg_expr           = argument->expression;
8023         type_t         *arg_type           = skip_typeref(arg_expr->base.type);
8024
8025         /* handle transparent union gnu extension */
8026         if (is_type_union(expected_type_skip)
8027                         && (expected_type_skip->base.modifiers
8028                                 & TYPE_MODIFIER_TRANSPARENT_UNION)) {
8029                 compound_t *union_decl  = expected_type_skip->compound.compound;
8030                 type_t     *best_type   = NULL;
8031                 entity_t   *entry       = union_decl->members.entities;
8032                 for ( ; entry != NULL; entry = entry->base.next) {
8033                         assert(is_declaration(entry));
8034                         type_t *decl_type = entry->declaration.type;
8035                         error = semantic_assign(decl_type, arg_expr);
8036                         if (error == ASSIGN_ERROR_INCOMPATIBLE
8037                                 || error == ASSIGN_ERROR_POINTER_QUALIFIER_MISSING)
8038                                 continue;
8039
8040                         if (error == ASSIGN_SUCCESS) {
8041                                 best_type = decl_type;
8042                         } else if (best_type == NULL) {
8043                                 best_type = decl_type;
8044                         }
8045                 }
8046
8047                 if (best_type != NULL) {
8048                         expected_type = best_type;
8049                 }
8050         }
8051
8052         error                = semantic_assign(expected_type, arg_expr);
8053         argument->expression = create_implicit_cast(argument->expression,
8054                                                     expected_type);
8055
8056         if (error != ASSIGN_SUCCESS) {
8057                 /* report exact scope in error messages (like "in argument 3") */
8058                 char buf[64];
8059                 snprintf(buf, sizeof(buf), "call argument %u", pos);
8060                 report_assign_error(error, expected_type, arg_expr,     buf,
8061                                                         &arg_expr->base.source_position);
8062         } else if (warning.traditional || warning.conversion) {
8063                 type_t *const promoted_type = get_default_promoted_type(arg_type);
8064                 if (!types_compatible(expected_type_skip, promoted_type) &&
8065                     !types_compatible(expected_type_skip, type_void_ptr) &&
8066                     !types_compatible(type_void_ptr,      promoted_type)) {
8067                         /* Deliberately show the skipped types in this warning */
8068                         warningf(&arg_expr->base.source_position,
8069                                 "passing call argument %u as '%T' rather than '%T' due to prototype",
8070                                 pos, expected_type_skip, promoted_type);
8071                 }
8072         }
8073 }
8074
8075 /**
8076  * Parse a call expression, ie. expression '( ... )'.
8077  *
8078  * @param expression  the function address
8079  */
8080 static expression_t *parse_call_expression(expression_t *expression)
8081 {
8082         expression_t      *result = allocate_expression_zero(EXPR_CALL);
8083         call_expression_t *call   = &result->call;
8084         call->function            = expression;
8085
8086         type_t *const orig_type = expression->base.type;
8087         type_t *const type      = skip_typeref(orig_type);
8088
8089         function_type_t *function_type = NULL;
8090         if (is_type_pointer(type)) {
8091                 type_t *const to_type = skip_typeref(type->pointer.points_to);
8092
8093                 if (is_type_function(to_type)) {
8094                         function_type   = &to_type->function;
8095                         call->base.type = function_type->return_type;
8096                 }
8097         }
8098
8099         if (function_type == NULL && is_type_valid(type)) {
8100                 errorf(HERE, "called object '%E' (type '%T') is not a pointer to a function", expression, orig_type);
8101         }
8102
8103         /* parse arguments */
8104         eat('(');
8105         add_anchor_token(')');
8106         add_anchor_token(',');
8107
8108         if (token.type != ')') {
8109                 call_argument_t *last_argument = NULL;
8110
8111                 while (true) {
8112                         call_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
8113
8114                         argument->expression = parse_assignment_expression();
8115                         if (last_argument == NULL) {
8116                                 call->arguments = argument;
8117                         } else {
8118                                 last_argument->next = argument;
8119                         }
8120                         last_argument = argument;
8121
8122                         if (token.type != ',')
8123                                 break;
8124                         next_token();
8125                 }
8126         }
8127         rem_anchor_token(',');
8128         rem_anchor_token(')');
8129         expect(')', end_error);
8130
8131         if (function_type == NULL)
8132                 return result;
8133
8134         function_parameter_t *parameter = function_type->parameters;
8135         call_argument_t      *argument  = call->arguments;
8136         if (!function_type->unspecified_parameters) {
8137                 for (unsigned pos = 0; parameter != NULL && argument != NULL;
8138                                 parameter = parameter->next, argument = argument->next) {
8139                         check_call_argument(parameter, argument, ++pos);
8140                 }
8141
8142                 if (parameter != NULL) {
8143                         errorf(HERE, "too few arguments to function '%E'", expression);
8144                 } else if (argument != NULL && !function_type->variadic) {
8145                         errorf(HERE, "too many arguments to function '%E'", expression);
8146                 }
8147         }
8148
8149         /* do default promotion */
8150         for (; argument != NULL; argument = argument->next) {
8151                 type_t *type = argument->expression->base.type;
8152
8153                 type = get_default_promoted_type(type);
8154
8155                 argument->expression
8156                         = create_implicit_cast(argument->expression, type);
8157         }
8158
8159         check_format(&result->call);
8160
8161         if (warning.aggregate_return &&
8162             is_type_compound(skip_typeref(function_type->return_type))) {
8163                 warningf(&result->base.source_position,
8164                          "function call has aggregate value");
8165         }
8166
8167 end_error:
8168         return result;
8169 }
8170
8171 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
8172
8173 static bool same_compound_type(const type_t *type1, const type_t *type2)
8174 {
8175         return
8176                 is_type_compound(type1) &&
8177                 type1->kind == type2->kind &&
8178                 type1->compound.compound == type2->compound.compound;
8179 }
8180
8181 static expression_t const *get_reference_address(expression_t const *expr)
8182 {
8183         bool regular_take_address = true;
8184         for (;;) {
8185                 if (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
8186                         expr = expr->unary.value;
8187                 } else {
8188                         regular_take_address = false;
8189                 }
8190
8191                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
8192                         break;
8193
8194                 expr = expr->unary.value;
8195         }
8196
8197         if (expr->kind != EXPR_REFERENCE)
8198                 return NULL;
8199
8200         /* special case for functions which are automatically converted to a
8201          * pointer to function without an extra TAKE_ADDRESS operation */
8202         if (!regular_take_address &&
8203                         expr->reference.entity->kind != ENTITY_FUNCTION) {
8204                 return NULL;
8205         }
8206
8207         return expr;
8208 }
8209
8210 static void warn_reference_address_as_bool(expression_t const* expr)
8211 {
8212         if (!warning.address)
8213                 return;
8214
8215         expr = get_reference_address(expr);
8216         if (expr != NULL) {
8217                 warningf(&expr->base.source_position,
8218                          "the address of '%Y' will always evaluate as 'true'",
8219                          expr->reference.entity->base.symbol);
8220         }
8221 }
8222
8223 static void warn_assignment_in_condition(const expression_t *const expr)
8224 {
8225         if (!warning.parentheses)
8226                 return;
8227         if (expr->base.kind != EXPR_BINARY_ASSIGN)
8228                 return;
8229         if (expr->base.parenthesized)
8230                 return;
8231         warningf(&expr->base.source_position,
8232                         "suggest parentheses around assignment used as truth value");
8233 }
8234
8235 static void semantic_condition(expression_t const *const expr,
8236                                char const *const context)
8237 {
8238         type_t *const type = skip_typeref(expr->base.type);
8239         if (is_type_scalar(type)) {
8240                 warn_reference_address_as_bool(expr);
8241                 warn_assignment_in_condition(expr);
8242         } else if (is_type_valid(type)) {
8243                 errorf(&expr->base.source_position,
8244                                 "%s must have scalar type", context);
8245         }
8246 }
8247
8248 /**
8249  * Parse a conditional expression, ie. 'expression ? ... : ...'.
8250  *
8251  * @param expression  the conditional expression
8252  */
8253 static expression_t *parse_conditional_expression(expression_t *expression)
8254 {
8255         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
8256
8257         conditional_expression_t *conditional = &result->conditional;
8258         conditional->condition                = expression;
8259
8260         eat('?');
8261         add_anchor_token(':');
8262
8263         /* §6.5.15:2  The first operand shall have scalar type. */
8264         semantic_condition(expression, "condition of conditional operator");
8265
8266         expression_t *true_expression = expression;
8267         bool          gnu_cond = false;
8268         if (GNU_MODE && token.type == ':') {
8269                 gnu_cond = true;
8270         } else {
8271                 true_expression = parse_expression();
8272         }
8273         rem_anchor_token(':');
8274         expect(':', end_error);
8275 end_error:;
8276         expression_t *false_expression =
8277                 parse_sub_expression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
8278
8279         type_t *const orig_true_type  = true_expression->base.type;
8280         type_t *const orig_false_type = false_expression->base.type;
8281         type_t *const true_type       = skip_typeref(orig_true_type);
8282         type_t *const false_type      = skip_typeref(orig_false_type);
8283
8284         /* 6.5.15.3 */
8285         type_t *result_type;
8286         if (is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
8287                         is_type_atomic(false_type, ATOMIC_TYPE_VOID)) {
8288                 /* ISO/IEC 14882:1998(E) §5.16:2 */
8289                 if (true_expression->kind == EXPR_UNARY_THROW) {
8290                         result_type = false_type;
8291                 } else if (false_expression->kind == EXPR_UNARY_THROW) {
8292                         result_type = true_type;
8293                 } else {
8294                         if (warning.other && (
8295                                                 !is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
8296                                                 !is_type_atomic(false_type, ATOMIC_TYPE_VOID)
8297                                         )) {
8298                                 warningf(&conditional->base.source_position,
8299                                                 "ISO C forbids conditional expression with only one void side");
8300                         }
8301                         result_type = type_void;
8302                 }
8303         } else if (is_type_arithmetic(true_type)
8304                    && is_type_arithmetic(false_type)) {
8305                 result_type = semantic_arithmetic(true_type, false_type);
8306
8307                 true_expression  = create_implicit_cast(true_expression, result_type);
8308                 false_expression = create_implicit_cast(false_expression, result_type);
8309
8310                 conditional->true_expression  = true_expression;
8311                 conditional->false_expression = false_expression;
8312                 conditional->base.type        = result_type;
8313         } else if (same_compound_type(true_type, false_type)) {
8314                 /* just take 1 of the 2 types */
8315                 result_type = true_type;
8316         } else if (is_type_pointer(true_type) || is_type_pointer(false_type)) {
8317                 type_t *pointer_type;
8318                 type_t *other_type;
8319                 expression_t *other_expression;
8320                 if (is_type_pointer(true_type) &&
8321                                 (!is_type_pointer(false_type) || is_null_pointer_constant(false_expression))) {
8322                         pointer_type     = true_type;
8323                         other_type       = false_type;
8324                         other_expression = false_expression;
8325                 } else {
8326                         pointer_type     = false_type;
8327                         other_type       = true_type;
8328                         other_expression = true_expression;
8329                 }
8330
8331                 if (is_null_pointer_constant(other_expression)) {
8332                         result_type = pointer_type;
8333                 } else if (is_type_pointer(other_type)) {
8334                         type_t *to1 = skip_typeref(pointer_type->pointer.points_to);
8335                         type_t *to2 = skip_typeref(other_type->pointer.points_to);
8336
8337                         type_t *to;
8338                         if (is_type_atomic(to1, ATOMIC_TYPE_VOID) ||
8339                             is_type_atomic(to2, ATOMIC_TYPE_VOID)) {
8340                                 to = type_void;
8341                         } else if (types_compatible(get_unqualified_type(to1),
8342                                                     get_unqualified_type(to2))) {
8343                                 to = to1;
8344                         } else {
8345                                 if (warning.other) {
8346                                         warningf(&conditional->base.source_position,
8347                                                         "pointer types '%T' and '%T' in conditional expression are incompatible",
8348                                                         true_type, false_type);
8349                                 }
8350                                 to = type_void;
8351                         }
8352
8353                         type_t *const type =
8354                                 get_qualified_type(to, to1->base.qualifiers | to2->base.qualifiers);
8355                         result_type = make_pointer_type(type, TYPE_QUALIFIER_NONE);
8356                 } else if (is_type_integer(other_type)) {
8357                         if (warning.other) {
8358                                 warningf(&conditional->base.source_position,
8359                                                 "pointer/integer type mismatch in conditional expression ('%T' and '%T')", true_type, false_type);
8360                         }
8361                         result_type = pointer_type;
8362                 } else {
8363                         if (is_type_valid(other_type)) {
8364                                 type_error_incompatible("while parsing conditional",
8365                                                 &expression->base.source_position, true_type, false_type);
8366                         }
8367                         result_type = type_error_type;
8368                 }
8369         } else {
8370                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
8371                         type_error_incompatible("while parsing conditional",
8372                                                 &conditional->base.source_position, true_type,
8373                                                 false_type);
8374                 }
8375                 result_type = type_error_type;
8376         }
8377
8378         conditional->true_expression
8379                 = gnu_cond ? NULL : create_implicit_cast(true_expression, result_type);
8380         conditional->false_expression
8381                 = create_implicit_cast(false_expression, result_type);
8382         conditional->base.type = result_type;
8383         return result;
8384 }
8385
8386 /**
8387  * Parse an extension expression.
8388  */
8389 static expression_t *parse_extension(void)
8390 {
8391         eat(T___extension__);
8392
8393         bool old_gcc_extension   = in_gcc_extension;
8394         in_gcc_extension         = true;
8395         expression_t *expression = parse_sub_expression(PREC_UNARY);
8396         in_gcc_extension         = old_gcc_extension;
8397         return expression;
8398 }
8399
8400 /**
8401  * Parse a __builtin_classify_type() expression.
8402  */
8403 static expression_t *parse_builtin_classify_type(void)
8404 {
8405         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
8406         result->base.type    = type_int;
8407
8408         eat(T___builtin_classify_type);
8409
8410         expect('(', end_error);
8411         add_anchor_token(')');
8412         expression_t *expression = parse_expression();
8413         rem_anchor_token(')');
8414         expect(')', end_error);
8415         result->classify_type.type_expression = expression;
8416
8417         return result;
8418 end_error:
8419         return create_invalid_expression();
8420 }
8421
8422 /**
8423  * Parse a delete expression
8424  * ISO/IEC 14882:1998(E) §5.3.5
8425  */
8426 static expression_t *parse_delete(void)
8427 {
8428         expression_t *const result = allocate_expression_zero(EXPR_UNARY_DELETE);
8429         result->base.type          = type_void;
8430
8431         eat(T_delete);
8432
8433         if (token.type == '[') {
8434                 next_token();
8435                 result->kind = EXPR_UNARY_DELETE_ARRAY;
8436                 expect(']', end_error);
8437 end_error:;
8438         }
8439
8440         expression_t *const value = parse_sub_expression(PREC_CAST);
8441         result->unary.value = value;
8442
8443         type_t *const type = skip_typeref(value->base.type);
8444         if (!is_type_pointer(type)) {
8445                 if (is_type_valid(type)) {
8446                         errorf(&value->base.source_position,
8447                                         "operand of delete must have pointer type");
8448                 }
8449         } else if (warning.other &&
8450                         is_type_atomic(skip_typeref(type->pointer.points_to), ATOMIC_TYPE_VOID)) {
8451                 warningf(&value->base.source_position,
8452                                 "deleting 'void*' is undefined");
8453         }
8454
8455         return result;
8456 }
8457
8458 /**
8459  * Parse a throw expression
8460  * ISO/IEC 14882:1998(E) §15:1
8461  */
8462 static expression_t *parse_throw(void)
8463 {
8464         expression_t *const result = allocate_expression_zero(EXPR_UNARY_THROW);
8465         result->base.type          = type_void;
8466
8467         eat(T_throw);
8468
8469         expression_t *value = NULL;
8470         switch (token.type) {
8471                 EXPRESSION_START {
8472                         value = parse_assignment_expression();
8473                         /* ISO/IEC 14882:1998(E) §15.1:3 */
8474                         type_t *const orig_type = value->base.type;
8475                         type_t *const type      = skip_typeref(orig_type);
8476                         if (is_type_incomplete(type)) {
8477                                 errorf(&value->base.source_position,
8478                                                 "cannot throw object of incomplete type '%T'", orig_type);
8479                         } else if (is_type_pointer(type)) {
8480                                 type_t *const points_to = skip_typeref(type->pointer.points_to);
8481                                 if (is_type_incomplete(points_to) &&
8482                                                 !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
8483                                         errorf(&value->base.source_position,
8484                                                         "cannot throw pointer to incomplete type '%T'", orig_type);
8485                                 }
8486                         }
8487                 }
8488
8489                 default:
8490                         break;
8491         }
8492         result->unary.value = value;
8493
8494         return result;
8495 }
8496
8497 static bool check_pointer_arithmetic(const source_position_t *source_position,
8498                                      type_t *pointer_type,
8499                                      type_t *orig_pointer_type)
8500 {
8501         type_t *points_to = pointer_type->pointer.points_to;
8502         points_to = skip_typeref(points_to);
8503
8504         if (is_type_incomplete(points_to)) {
8505                 if (!GNU_MODE || !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
8506                         errorf(source_position,
8507                                "arithmetic with pointer to incomplete type '%T' not allowed",
8508                                orig_pointer_type);
8509                         return false;
8510                 } else if (warning.pointer_arith) {
8511                         warningf(source_position,
8512                                  "pointer of type '%T' used in arithmetic",
8513                                  orig_pointer_type);
8514                 }
8515         } else if (is_type_function(points_to)) {
8516                 if (!GNU_MODE) {
8517                         errorf(source_position,
8518                                "arithmetic with pointer to function type '%T' not allowed",
8519                                orig_pointer_type);
8520                         return false;
8521                 } else if (warning.pointer_arith) {
8522                         warningf(source_position,
8523                                  "pointer to a function '%T' used in arithmetic",
8524                                  orig_pointer_type);
8525                 }
8526         }
8527         return true;
8528 }
8529
8530 static bool is_lvalue(const expression_t *expression)
8531 {
8532         /* TODO: doesn't seem to be consistent with §6.3.2.1 (1) */
8533         switch (expression->kind) {
8534         case EXPR_ARRAY_ACCESS:
8535         case EXPR_COMPOUND_LITERAL:
8536         case EXPR_REFERENCE:
8537         case EXPR_SELECT:
8538         case EXPR_UNARY_DEREFERENCE:
8539                 return true;
8540
8541         default: {
8542           type_t *type = skip_typeref(expression->base.type);
8543           return
8544                 /* ISO/IEC 14882:1998(E) §3.10:3 */
8545                 is_type_reference(type) ||
8546                 /* Claim it is an lvalue, if the type is invalid.  There was a parse
8547                  * error before, which maybe prevented properly recognizing it as
8548                  * lvalue. */
8549                 !is_type_valid(type);
8550         }
8551         }
8552 }
8553
8554 static void semantic_incdec(unary_expression_t *expression)
8555 {
8556         type_t *const orig_type = expression->value->base.type;
8557         type_t *const type      = skip_typeref(orig_type);
8558         if (is_type_pointer(type)) {
8559                 if (!check_pointer_arithmetic(&expression->base.source_position,
8560                                               type, orig_type)) {
8561                         return;
8562                 }
8563         } else if (!is_type_real(type) && is_type_valid(type)) {
8564                 /* TODO: improve error message */
8565                 errorf(&expression->base.source_position,
8566                        "operation needs an arithmetic or pointer type");
8567                 return;
8568         }
8569         if (!is_lvalue(expression->value)) {
8570                 /* TODO: improve error message */
8571                 errorf(&expression->base.source_position, "lvalue required as operand");
8572         }
8573         expression->base.type = orig_type;
8574 }
8575
8576 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
8577 {
8578         type_t *const orig_type = expression->value->base.type;
8579         type_t *const type      = skip_typeref(orig_type);
8580         if (!is_type_arithmetic(type)) {
8581                 if (is_type_valid(type)) {
8582                         /* TODO: improve error message */
8583                         errorf(&expression->base.source_position,
8584                                 "operation needs an arithmetic type");
8585                 }
8586                 return;
8587         }
8588
8589         expression->base.type = orig_type;
8590 }
8591
8592 static void semantic_unexpr_plus(unary_expression_t *expression)
8593 {
8594         semantic_unexpr_arithmetic(expression);
8595         if (warning.traditional)
8596                 warningf(&expression->base.source_position,
8597                         "traditional C rejects the unary plus operator");
8598 }
8599
8600 static void semantic_not(unary_expression_t *expression)
8601 {
8602         /* §6.5.3.3:1  The operand [...] of the ! operator, scalar type. */
8603         semantic_condition(expression->value, "operand of !");
8604         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8605 }
8606
8607 static void semantic_unexpr_integer(unary_expression_t *expression)
8608 {
8609         type_t *const orig_type = expression->value->base.type;
8610         type_t *const type      = skip_typeref(orig_type);
8611         if (!is_type_integer(type)) {
8612                 if (is_type_valid(type)) {
8613                         errorf(&expression->base.source_position,
8614                                "operand of ~ must be of integer type");
8615                 }
8616                 return;
8617         }
8618
8619         expression->base.type = orig_type;
8620 }
8621
8622 static void semantic_dereference(unary_expression_t *expression)
8623 {
8624         type_t *const orig_type = expression->value->base.type;
8625         type_t *const type      = skip_typeref(orig_type);
8626         if (!is_type_pointer(type)) {
8627                 if (is_type_valid(type)) {
8628                         errorf(&expression->base.source_position,
8629                                "Unary '*' needs pointer or array type, but type '%T' given", orig_type);
8630                 }
8631                 return;
8632         }
8633
8634         type_t *result_type   = type->pointer.points_to;
8635         result_type           = automatic_type_conversion(result_type);
8636         expression->base.type = result_type;
8637 }
8638
8639 /**
8640  * Record that an address is taken (expression represents an lvalue).
8641  *
8642  * @param expression       the expression
8643  * @param may_be_register  if true, the expression might be an register
8644  */
8645 static void set_address_taken(expression_t *expression, bool may_be_register)
8646 {
8647         if (expression->kind != EXPR_REFERENCE)
8648                 return;
8649
8650         entity_t *const entity = expression->reference.entity;
8651
8652         if (entity->kind != ENTITY_VARIABLE && entity->kind != ENTITY_PARAMETER)
8653                 return;
8654
8655         if (entity->declaration.storage_class == STORAGE_CLASS_REGISTER
8656                         && !may_be_register) {
8657                 errorf(&expression->base.source_position,
8658                                 "address of register %s '%Y' requested",
8659                                 get_entity_kind_name(entity->kind),     entity->base.symbol);
8660         }
8661
8662         if (entity->kind == ENTITY_VARIABLE) {
8663                 entity->variable.address_taken = true;
8664         } else {
8665                 assert(entity->kind == ENTITY_PARAMETER);
8666                 entity->parameter.address_taken = true;
8667         }
8668 }
8669
8670 /**
8671  * Check the semantic of the address taken expression.
8672  */
8673 static void semantic_take_addr(unary_expression_t *expression)
8674 {
8675         expression_t *value = expression->value;
8676         value->base.type    = revert_automatic_type_conversion(value);
8677
8678         type_t *orig_type = value->base.type;
8679         type_t *type      = skip_typeref(orig_type);
8680         if (!is_type_valid(type))
8681                 return;
8682
8683         /* §6.5.3.2 */
8684         if (!is_lvalue(value)) {
8685                 errorf(&expression->base.source_position, "'&' requires an lvalue");
8686         }
8687         if (type->kind == TYPE_BITFIELD) {
8688                 errorf(&expression->base.source_position,
8689                        "'&' not allowed on object with bitfield type '%T'",
8690                        type);
8691         }
8692
8693         set_address_taken(value, false);
8694
8695         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
8696 }
8697
8698 #define CREATE_UNARY_EXPRESSION_PARSER(token_type, unexpression_type, sfunc) \
8699 static expression_t *parse_##unexpression_type(void)                         \
8700 {                                                                            \
8701         expression_t *unary_expression                                           \
8702                 = allocate_expression_zero(unexpression_type);                       \
8703         eat(token_type);                                                         \
8704         unary_expression->unary.value = parse_sub_expression(PREC_UNARY);        \
8705                                                                                  \
8706         sfunc(&unary_expression->unary);                                         \
8707                                                                                  \
8708         return unary_expression;                                                 \
8709 }
8710
8711 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
8712                                semantic_unexpr_arithmetic)
8713 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
8714                                semantic_unexpr_plus)
8715 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
8716                                semantic_not)
8717 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
8718                                semantic_dereference)
8719 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
8720                                semantic_take_addr)
8721 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
8722                                semantic_unexpr_integer)
8723 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
8724                                semantic_incdec)
8725 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
8726                                semantic_incdec)
8727
8728 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_type, unexpression_type, \
8729                                                sfunc)                         \
8730 static expression_t *parse_##unexpression_type(expression_t *left)            \
8731 {                                                                             \
8732         expression_t *unary_expression                                            \
8733                 = allocate_expression_zero(unexpression_type);                        \
8734         eat(token_type);                                                          \
8735         unary_expression->unary.value = left;                                     \
8736                                                                                   \
8737         sfunc(&unary_expression->unary);                                          \
8738                                                                               \
8739         return unary_expression;                                                  \
8740 }
8741
8742 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
8743                                        EXPR_UNARY_POSTFIX_INCREMENT,
8744                                        semantic_incdec)
8745 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
8746                                        EXPR_UNARY_POSTFIX_DECREMENT,
8747                                        semantic_incdec)
8748
8749 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
8750 {
8751         /* TODO: handle complex + imaginary types */
8752
8753         type_left  = get_unqualified_type(type_left);
8754         type_right = get_unqualified_type(type_right);
8755
8756         /* § 6.3.1.8 Usual arithmetic conversions */
8757         if (type_left == type_long_double || type_right == type_long_double) {
8758                 return type_long_double;
8759         } else if (type_left == type_double || type_right == type_double) {
8760                 return type_double;
8761         } else if (type_left == type_float || type_right == type_float) {
8762                 return type_float;
8763         }
8764
8765         type_left  = promote_integer(type_left);
8766         type_right = promote_integer(type_right);
8767
8768         if (type_left == type_right)
8769                 return type_left;
8770
8771         bool const signed_left  = is_type_signed(type_left);
8772         bool const signed_right = is_type_signed(type_right);
8773         int const  rank_left    = get_rank(type_left);
8774         int const  rank_right   = get_rank(type_right);
8775
8776         if (signed_left == signed_right)
8777                 return rank_left >= rank_right ? type_left : type_right;
8778
8779         int     s_rank;
8780         int     u_rank;
8781         type_t *s_type;
8782         type_t *u_type;
8783         if (signed_left) {
8784                 s_rank = rank_left;
8785                 s_type = type_left;
8786                 u_rank = rank_right;
8787                 u_type = type_right;
8788         } else {
8789                 s_rank = rank_right;
8790                 s_type = type_right;
8791                 u_rank = rank_left;
8792                 u_type = type_left;
8793         }
8794
8795         if (u_rank >= s_rank)
8796                 return u_type;
8797
8798         /* casting rank to atomic_type_kind is a bit hacky, but makes things
8799          * easier here... */
8800         if (get_atomic_type_size((atomic_type_kind_t) s_rank)
8801                         > get_atomic_type_size((atomic_type_kind_t) u_rank))
8802                 return s_type;
8803
8804         switch (s_rank) {
8805                 case ATOMIC_TYPE_INT:      return type_unsigned_int;
8806                 case ATOMIC_TYPE_LONG:     return type_unsigned_long;
8807                 case ATOMIC_TYPE_LONGLONG: return type_unsigned_long_long;
8808
8809                 default: panic("invalid atomic type");
8810         }
8811 }
8812
8813 /**
8814  * Check the semantic restrictions for a binary expression.
8815  */
8816 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
8817 {
8818         expression_t *const left            = expression->left;
8819         expression_t *const right           = expression->right;
8820         type_t       *const orig_type_left  = left->base.type;
8821         type_t       *const orig_type_right = right->base.type;
8822         type_t       *const type_left       = skip_typeref(orig_type_left);
8823         type_t       *const type_right      = skip_typeref(orig_type_right);
8824
8825         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8826                 /* TODO: improve error message */
8827                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8828                         errorf(&expression->base.source_position,
8829                                "operation needs arithmetic types");
8830                 }
8831                 return;
8832         }
8833
8834         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8835         expression->left      = create_implicit_cast(left, arithmetic_type);
8836         expression->right     = create_implicit_cast(right, arithmetic_type);
8837         expression->base.type = arithmetic_type;
8838 }
8839
8840 static void warn_div_by_zero(binary_expression_t const *const expression)
8841 {
8842         if (!warning.div_by_zero ||
8843             !is_type_integer(expression->base.type))
8844                 return;
8845
8846         expression_t const *const right = expression->right;
8847         /* The type of the right operand can be different for /= */
8848         if (is_type_integer(right->base.type) &&
8849             is_constant_expression(right)     &&
8850             fold_constant(right) == 0) {
8851                 warningf(&expression->base.source_position, "division by zero");
8852         }
8853 }
8854
8855 /**
8856  * Check the semantic restrictions for a div/mod expression.
8857  */
8858 static void semantic_divmod_arithmetic(binary_expression_t *expression) {
8859         semantic_binexpr_arithmetic(expression);
8860         warn_div_by_zero(expression);
8861 }
8862
8863 static void warn_addsub_in_shift(const expression_t *const expr)
8864 {
8865         if (expr->base.parenthesized)
8866                 return;
8867
8868         char op;
8869         switch (expr->kind) {
8870                 case EXPR_BINARY_ADD: op = '+'; break;
8871                 case EXPR_BINARY_SUB: op = '-'; break;
8872                 default:              return;
8873         }
8874
8875         warningf(&expr->base.source_position,
8876                         "suggest parentheses around '%c' inside shift", op);
8877 }
8878
8879 static void semantic_shift_op(binary_expression_t *expression)
8880 {
8881         expression_t *const left            = expression->left;
8882         expression_t *const right           = expression->right;
8883         type_t       *const orig_type_left  = left->base.type;
8884         type_t       *const orig_type_right = right->base.type;
8885         type_t       *      type_left       = skip_typeref(orig_type_left);
8886         type_t       *      type_right      = skip_typeref(orig_type_right);
8887
8888         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8889                 /* TODO: improve error message */
8890                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8891                         errorf(&expression->base.source_position,
8892                                "operands of shift operation must have integer types");
8893                 }
8894                 return;
8895         }
8896
8897         if (warning.parentheses) {
8898                 warn_addsub_in_shift(left);
8899                 warn_addsub_in_shift(right);
8900         }
8901
8902         type_left  = promote_integer(type_left);
8903         type_right = promote_integer(type_right);
8904
8905         expression->left      = create_implicit_cast(left, type_left);
8906         expression->right     = create_implicit_cast(right, type_right);
8907         expression->base.type = type_left;
8908 }
8909
8910 static void semantic_add(binary_expression_t *expression)
8911 {
8912         expression_t *const left            = expression->left;
8913         expression_t *const right           = expression->right;
8914         type_t       *const orig_type_left  = left->base.type;
8915         type_t       *const orig_type_right = right->base.type;
8916         type_t       *const type_left       = skip_typeref(orig_type_left);
8917         type_t       *const type_right      = skip_typeref(orig_type_right);
8918
8919         /* § 6.5.6 */
8920         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8921                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8922                 expression->left  = create_implicit_cast(left, arithmetic_type);
8923                 expression->right = create_implicit_cast(right, arithmetic_type);
8924                 expression->base.type = arithmetic_type;
8925         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8926                 check_pointer_arithmetic(&expression->base.source_position,
8927                                          type_left, orig_type_left);
8928                 expression->base.type = type_left;
8929         } else if (is_type_pointer(type_right) && is_type_integer(type_left)) {
8930                 check_pointer_arithmetic(&expression->base.source_position,
8931                                          type_right, orig_type_right);
8932                 expression->base.type = type_right;
8933         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8934                 errorf(&expression->base.source_position,
8935                        "invalid operands to binary + ('%T', '%T')",
8936                        orig_type_left, orig_type_right);
8937         }
8938 }
8939
8940 static void semantic_sub(binary_expression_t *expression)
8941 {
8942         expression_t            *const left            = expression->left;
8943         expression_t            *const right           = expression->right;
8944         type_t                  *const orig_type_left  = left->base.type;
8945         type_t                  *const orig_type_right = right->base.type;
8946         type_t                  *const type_left       = skip_typeref(orig_type_left);
8947         type_t                  *const type_right      = skip_typeref(orig_type_right);
8948         source_position_t const *const pos             = &expression->base.source_position;
8949
8950         /* § 5.6.5 */
8951         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8952                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8953                 expression->left        = create_implicit_cast(left, arithmetic_type);
8954                 expression->right       = create_implicit_cast(right, arithmetic_type);
8955                 expression->base.type =  arithmetic_type;
8956         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8957                 check_pointer_arithmetic(&expression->base.source_position,
8958                                          type_left, orig_type_left);
8959                 expression->base.type = type_left;
8960         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8961                 type_t *const unqual_left  = get_unqualified_type(skip_typeref(type_left->pointer.points_to));
8962                 type_t *const unqual_right = get_unqualified_type(skip_typeref(type_right->pointer.points_to));
8963                 if (!types_compatible(unqual_left, unqual_right)) {
8964                         errorf(pos,
8965                                "subtracting pointers to incompatible types '%T' and '%T'",
8966                                orig_type_left, orig_type_right);
8967                 } else if (!is_type_object(unqual_left)) {
8968                         if (!is_type_atomic(unqual_left, ATOMIC_TYPE_VOID)) {
8969                                 errorf(pos, "subtracting pointers to non-object types '%T'",
8970                                        orig_type_left);
8971                         } else if (warning.other) {
8972                                 warningf(pos, "subtracting pointers to void");
8973                         }
8974                 }
8975                 expression->base.type = type_ptrdiff_t;
8976         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8977                 errorf(pos, "invalid operands of types '%T' and '%T' to binary '-'",
8978                        orig_type_left, orig_type_right);
8979         }
8980 }
8981
8982 static void warn_string_literal_address(expression_t const* expr)
8983 {
8984         while (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
8985                 expr = expr->unary.value;
8986                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
8987                         return;
8988                 expr = expr->unary.value;
8989         }
8990
8991         if (expr->kind == EXPR_STRING_LITERAL ||
8992             expr->kind == EXPR_WIDE_STRING_LITERAL) {
8993                 warningf(&expr->base.source_position,
8994                         "comparison with string literal results in unspecified behaviour");
8995         }
8996 }
8997
8998 static void warn_comparison_in_comparison(const expression_t *const expr)
8999 {
9000         if (expr->base.parenthesized)
9001                 return;
9002         switch (expr->base.kind) {
9003                 case EXPR_BINARY_LESS:
9004                 case EXPR_BINARY_GREATER:
9005                 case EXPR_BINARY_LESSEQUAL:
9006                 case EXPR_BINARY_GREATEREQUAL:
9007                 case EXPR_BINARY_NOTEQUAL:
9008                 case EXPR_BINARY_EQUAL:
9009                         warningf(&expr->base.source_position,
9010                                         "comparisons like 'x <= y < z' do not have their mathematical meaning");
9011                         break;
9012                 default:
9013                         break;
9014         }
9015 }
9016
9017 static bool maybe_negative(expression_t const *const expr)
9018 {
9019         return
9020                 !is_constant_expression(expr) ||
9021                 fold_constant(expr) < 0;
9022 }
9023
9024 /**
9025  * Check the semantics of comparison expressions.
9026  *
9027  * @param expression   The expression to check.
9028  */
9029 static void semantic_comparison(binary_expression_t *expression)
9030 {
9031         expression_t *left  = expression->left;
9032         expression_t *right = expression->right;
9033
9034         if (warning.address) {
9035                 warn_string_literal_address(left);
9036                 warn_string_literal_address(right);
9037
9038                 expression_t const* const func_left = get_reference_address(left);
9039                 if (func_left != NULL && is_null_pointer_constant(right)) {
9040                         warningf(&expression->base.source_position,
9041                                  "the address of '%Y' will never be NULL",
9042                                  func_left->reference.entity->base.symbol);
9043                 }
9044
9045                 expression_t const* const func_right = get_reference_address(right);
9046                 if (func_right != NULL && is_null_pointer_constant(right)) {
9047                         warningf(&expression->base.source_position,
9048                                  "the address of '%Y' will never be NULL",
9049                                  func_right->reference.entity->base.symbol);
9050                 }
9051         }
9052
9053         if (warning.parentheses) {
9054                 warn_comparison_in_comparison(left);
9055                 warn_comparison_in_comparison(right);
9056         }
9057
9058         type_t *orig_type_left  = left->base.type;
9059         type_t *orig_type_right = right->base.type;
9060         type_t *type_left       = skip_typeref(orig_type_left);
9061         type_t *type_right      = skip_typeref(orig_type_right);
9062
9063         /* TODO non-arithmetic types */
9064         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
9065                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
9066
9067                 /* test for signed vs unsigned compares */
9068                 if (warning.sign_compare && is_type_integer(arithmetic_type)) {
9069                         bool const signed_left  = is_type_signed(type_left);
9070                         bool const signed_right = is_type_signed(type_right);
9071                         if (signed_left != signed_right) {
9072                                 /* FIXME long long needs better const folding magic */
9073                                 /* TODO check whether constant value can be represented by other type */
9074                                 if ((signed_left  && maybe_negative(left)) ||
9075                                                 (signed_right && maybe_negative(right))) {
9076                                         warningf(&expression->base.source_position,
9077                                                         "comparison between signed and unsigned");
9078                                 }
9079                         }
9080                 }
9081
9082                 expression->left        = create_implicit_cast(left, arithmetic_type);
9083                 expression->right       = create_implicit_cast(right, arithmetic_type);
9084                 expression->base.type   = arithmetic_type;
9085                 if (warning.float_equal &&
9086                     (expression->base.kind == EXPR_BINARY_EQUAL ||
9087                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
9088                     is_type_float(arithmetic_type)) {
9089                         warningf(&expression->base.source_position,
9090                                  "comparing floating point with == or != is unsafe");
9091                 }
9092         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
9093                 /* TODO check compatibility */
9094         } else if (is_type_pointer(type_left)) {
9095                 expression->right = create_implicit_cast(right, type_left);
9096         } else if (is_type_pointer(type_right)) {
9097                 expression->left = create_implicit_cast(left, type_right);
9098         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
9099                 type_error_incompatible("invalid operands in comparison",
9100                                         &expression->base.source_position,
9101                                         type_left, type_right);
9102         }
9103         expression->base.type = c_mode & _CXX ? type_bool : type_int;
9104 }
9105
9106 /**
9107  * Checks if a compound type has constant fields.
9108  */
9109 static bool has_const_fields(const compound_type_t *type)
9110 {
9111         compound_t *compound = type->compound;
9112         entity_t   *entry    = compound->members.entities;
9113
9114         for (; entry != NULL; entry = entry->base.next) {
9115                 if (!is_declaration(entry))
9116                         continue;
9117
9118                 const type_t *decl_type = skip_typeref(entry->declaration.type);
9119                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
9120                         return true;
9121         }
9122
9123         return false;
9124 }
9125
9126 static bool is_valid_assignment_lhs(expression_t const* const left)
9127 {
9128         type_t *const orig_type_left = revert_automatic_type_conversion(left);
9129         type_t *const type_left      = skip_typeref(orig_type_left);
9130
9131         if (!is_lvalue(left)) {
9132                 errorf(HERE, "left hand side '%E' of assignment is not an lvalue",
9133                        left);
9134                 return false;
9135         }
9136
9137         if (left->kind == EXPR_REFERENCE
9138                         && left->reference.entity->kind == ENTITY_FUNCTION) {
9139                 errorf(HERE, "cannot assign to function '%E'", left);
9140                 return false;
9141         }
9142
9143         if (is_type_array(type_left)) {
9144                 errorf(HERE, "cannot assign to array '%E'", left);
9145                 return false;
9146         }
9147         if (type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
9148                 errorf(HERE, "assignment to readonly location '%E' (type '%T')", left,
9149                        orig_type_left);
9150                 return false;
9151         }
9152         if (is_type_incomplete(type_left)) {
9153                 errorf(HERE, "left-hand side '%E' of assignment has incomplete type '%T'",
9154                        left, orig_type_left);
9155                 return false;
9156         }
9157         if (is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
9158                 errorf(HERE, "cannot assign to '%E' because compound type '%T' has readonly fields",
9159                        left, orig_type_left);
9160                 return false;
9161         }
9162
9163         return true;
9164 }
9165
9166 static void semantic_arithmetic_assign(binary_expression_t *expression)
9167 {
9168         expression_t *left            = expression->left;
9169         expression_t *right           = expression->right;
9170         type_t       *orig_type_left  = left->base.type;
9171         type_t       *orig_type_right = right->base.type;
9172
9173         if (!is_valid_assignment_lhs(left))
9174                 return;
9175
9176         type_t *type_left  = skip_typeref(orig_type_left);
9177         type_t *type_right = skip_typeref(orig_type_right);
9178
9179         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
9180                 /* TODO: improve error message */
9181                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
9182                         errorf(&expression->base.source_position,
9183                                "operation needs arithmetic types");
9184                 }
9185                 return;
9186         }
9187
9188         /* combined instructions are tricky. We can't create an implicit cast on
9189          * the left side, because we need the uncasted form for the store.
9190          * The ast2firm pass has to know that left_type must be right_type
9191          * for the arithmetic operation and create a cast by itself */
9192         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
9193         expression->right       = create_implicit_cast(right, arithmetic_type);
9194         expression->base.type   = type_left;
9195 }
9196
9197 static void semantic_divmod_assign(binary_expression_t *expression)
9198 {
9199         semantic_arithmetic_assign(expression);
9200         warn_div_by_zero(expression);
9201 }
9202
9203 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
9204 {
9205         expression_t *const left            = expression->left;
9206         expression_t *const right           = expression->right;
9207         type_t       *const orig_type_left  = left->base.type;
9208         type_t       *const orig_type_right = right->base.type;
9209         type_t       *const type_left       = skip_typeref(orig_type_left);
9210         type_t       *const type_right      = skip_typeref(orig_type_right);
9211
9212         if (!is_valid_assignment_lhs(left))
9213                 return;
9214
9215         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
9216                 /* combined instructions are tricky. We can't create an implicit cast on
9217                  * the left side, because we need the uncasted form for the store.
9218                  * The ast2firm pass has to know that left_type must be right_type
9219                  * for the arithmetic operation and create a cast by itself */
9220                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
9221                 expression->right     = create_implicit_cast(right, arithmetic_type);
9222                 expression->base.type = type_left;
9223         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
9224                 check_pointer_arithmetic(&expression->base.source_position,
9225                                          type_left, orig_type_left);
9226                 expression->base.type = type_left;
9227         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
9228                 errorf(&expression->base.source_position,
9229                        "incompatible types '%T' and '%T' in assignment",
9230                        orig_type_left, orig_type_right);
9231         }
9232 }
9233
9234 static void warn_logical_and_within_or(const expression_t *const expr)
9235 {
9236         if (expr->base.kind != EXPR_BINARY_LOGICAL_AND)
9237                 return;
9238         if (expr->base.parenthesized)
9239                 return;
9240         warningf(&expr->base.source_position,
9241                         "suggest parentheses around && within ||");
9242 }
9243
9244 /**
9245  * Check the semantic restrictions of a logical expression.
9246  */
9247 static void semantic_logical_op(binary_expression_t *expression)
9248 {
9249         /* §6.5.13:2  Each of the operands shall have scalar type.
9250          * §6.5.14:2  Each of the operands shall have scalar type. */
9251         semantic_condition(expression->left,   "left operand of logical operator");
9252         semantic_condition(expression->right, "right operand of logical operator");
9253         if (expression->base.kind == EXPR_BINARY_LOGICAL_OR &&
9254                         warning.parentheses) {
9255                 warn_logical_and_within_or(expression->left);
9256                 warn_logical_and_within_or(expression->right);
9257         }
9258         expression->base.type = c_mode & _CXX ? type_bool : type_int;
9259 }
9260
9261 /**
9262  * Check the semantic restrictions of a binary assign expression.
9263  */
9264 static void semantic_binexpr_assign(binary_expression_t *expression)
9265 {
9266         expression_t *left           = expression->left;
9267         type_t       *orig_type_left = left->base.type;
9268
9269         if (!is_valid_assignment_lhs(left))
9270                 return;
9271
9272         assign_error_t error = semantic_assign(orig_type_left, expression->right);
9273         report_assign_error(error, orig_type_left, expression->right,
9274                         "assignment", &left->base.source_position);
9275         expression->right = create_implicit_cast(expression->right, orig_type_left);
9276         expression->base.type = orig_type_left;
9277 }
9278
9279 /**
9280  * Determine if the outermost operation (or parts thereof) of the given
9281  * expression has no effect in order to generate a warning about this fact.
9282  * Therefore in some cases this only examines some of the operands of the
9283  * expression (see comments in the function and examples below).
9284  * Examples:
9285  *   f() + 23;    // warning, because + has no effect
9286  *   x || f();    // no warning, because x controls execution of f()
9287  *   x ? y : f(); // warning, because y has no effect
9288  *   (void)x;     // no warning to be able to suppress the warning
9289  * This function can NOT be used for an "expression has definitely no effect"-
9290  * analysis. */
9291 static bool expression_has_effect(const expression_t *const expr)
9292 {
9293         switch (expr->kind) {
9294                 case EXPR_UNKNOWN:                   break;
9295                 case EXPR_INVALID:                   return true; /* do NOT warn */
9296                 case EXPR_REFERENCE:                 return false;
9297                 case EXPR_REFERENCE_ENUM_VALUE:      return false;
9298                 /* suppress the warning for microsoft __noop operations */
9299                 case EXPR_CONST:                     return expr->conste.is_ms_noop;
9300                 case EXPR_CHARACTER_CONSTANT:        return false;
9301                 case EXPR_WIDE_CHARACTER_CONSTANT:   return false;
9302                 case EXPR_STRING_LITERAL:            return false;
9303                 case EXPR_WIDE_STRING_LITERAL:       return false;
9304                 case EXPR_LABEL_ADDRESS:             return false;
9305
9306                 case EXPR_CALL: {
9307                         const call_expression_t *const call = &expr->call;
9308                         if (call->function->kind != EXPR_BUILTIN_SYMBOL)
9309                                 return true;
9310
9311                         switch (call->function->builtin_symbol.symbol->ID) {
9312                                 case T___builtin_va_end: return true;
9313                                 default:                 return false;
9314                         }
9315                 }
9316
9317                 /* Generate the warning if either the left or right hand side of a
9318                  * conditional expression has no effect */
9319                 case EXPR_CONDITIONAL: {
9320                         const conditional_expression_t *const cond = &expr->conditional;
9321                         return
9322                                 expression_has_effect(cond->true_expression) &&
9323                                 expression_has_effect(cond->false_expression);
9324                 }
9325
9326                 case EXPR_SELECT:                    return false;
9327                 case EXPR_ARRAY_ACCESS:              return false;
9328                 case EXPR_SIZEOF:                    return false;
9329                 case EXPR_CLASSIFY_TYPE:             return false;
9330                 case EXPR_ALIGNOF:                   return false;
9331
9332                 case EXPR_FUNCNAME:                  return false;
9333                 case EXPR_BUILTIN_SYMBOL:            break; /* handled in EXPR_CALL */
9334                 case EXPR_BUILTIN_CONSTANT_P:        return false;
9335                 case EXPR_BUILTIN_PREFETCH:          return true;
9336                 case EXPR_OFFSETOF:                  return false;
9337                 case EXPR_VA_START:                  return true;
9338                 case EXPR_VA_ARG:                    return true;
9339                 case EXPR_STATEMENT:                 return true; // TODO
9340                 case EXPR_COMPOUND_LITERAL:          return false;
9341
9342                 case EXPR_UNARY_NEGATE:              return false;
9343                 case EXPR_UNARY_PLUS:                return false;
9344                 case EXPR_UNARY_BITWISE_NEGATE:      return false;
9345                 case EXPR_UNARY_NOT:                 return false;
9346                 case EXPR_UNARY_DEREFERENCE:         return false;
9347                 case EXPR_UNARY_TAKE_ADDRESS:        return false;
9348                 case EXPR_UNARY_POSTFIX_INCREMENT:   return true;
9349                 case EXPR_UNARY_POSTFIX_DECREMENT:   return true;
9350                 case EXPR_UNARY_PREFIX_INCREMENT:    return true;
9351                 case EXPR_UNARY_PREFIX_DECREMENT:    return true;
9352
9353                 /* Treat void casts as if they have an effect in order to being able to
9354                  * suppress the warning */
9355                 case EXPR_UNARY_CAST: {
9356                         type_t *const type = skip_typeref(expr->base.type);
9357                         return is_type_atomic(type, ATOMIC_TYPE_VOID);
9358                 }
9359
9360                 case EXPR_UNARY_CAST_IMPLICIT:       return true;
9361                 case EXPR_UNARY_ASSUME:              return true;
9362                 case EXPR_UNARY_DELETE:              return true;
9363                 case EXPR_UNARY_DELETE_ARRAY:        return true;
9364                 case EXPR_UNARY_THROW:               return true;
9365
9366                 case EXPR_BINARY_ADD:                return false;
9367                 case EXPR_BINARY_SUB:                return false;
9368                 case EXPR_BINARY_MUL:                return false;
9369                 case EXPR_BINARY_DIV:                return false;
9370                 case EXPR_BINARY_MOD:                return false;
9371                 case EXPR_BINARY_EQUAL:              return false;
9372                 case EXPR_BINARY_NOTEQUAL:           return false;
9373                 case EXPR_BINARY_LESS:               return false;
9374                 case EXPR_BINARY_LESSEQUAL:          return false;
9375                 case EXPR_BINARY_GREATER:            return false;
9376                 case EXPR_BINARY_GREATEREQUAL:       return false;
9377                 case EXPR_BINARY_BITWISE_AND:        return false;
9378                 case EXPR_BINARY_BITWISE_OR:         return false;
9379                 case EXPR_BINARY_BITWISE_XOR:        return false;
9380                 case EXPR_BINARY_SHIFTLEFT:          return false;
9381                 case EXPR_BINARY_SHIFTRIGHT:         return false;
9382                 case EXPR_BINARY_ASSIGN:             return true;
9383                 case EXPR_BINARY_MUL_ASSIGN:         return true;
9384                 case EXPR_BINARY_DIV_ASSIGN:         return true;
9385                 case EXPR_BINARY_MOD_ASSIGN:         return true;
9386                 case EXPR_BINARY_ADD_ASSIGN:         return true;
9387                 case EXPR_BINARY_SUB_ASSIGN:         return true;
9388                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:   return true;
9389                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:  return true;
9390                 case EXPR_BINARY_BITWISE_AND_ASSIGN: return true;
9391                 case EXPR_BINARY_BITWISE_XOR_ASSIGN: return true;
9392                 case EXPR_BINARY_BITWISE_OR_ASSIGN:  return true;
9393
9394                 /* Only examine the right hand side of && and ||, because the left hand
9395                  * side already has the effect of controlling the execution of the right
9396                  * hand side */
9397                 case EXPR_BINARY_LOGICAL_AND:
9398                 case EXPR_BINARY_LOGICAL_OR:
9399                 /* Only examine the right hand side of a comma expression, because the left
9400                  * hand side has a separate warning */
9401                 case EXPR_BINARY_COMMA:
9402                         return expression_has_effect(expr->binary.right);
9403
9404                 case EXPR_BINARY_ISGREATER:          return false;
9405                 case EXPR_BINARY_ISGREATEREQUAL:     return false;
9406                 case EXPR_BINARY_ISLESS:             return false;
9407                 case EXPR_BINARY_ISLESSEQUAL:        return false;
9408                 case EXPR_BINARY_ISLESSGREATER:      return false;
9409                 case EXPR_BINARY_ISUNORDERED:        return false;
9410         }
9411
9412         internal_errorf(HERE, "unexpected expression");
9413 }
9414
9415 static void semantic_comma(binary_expression_t *expression)
9416 {
9417         if (warning.unused_value) {
9418                 const expression_t *const left = expression->left;
9419                 if (!expression_has_effect(left)) {
9420                         warningf(&left->base.source_position,
9421                                  "left-hand operand of comma expression has no effect");
9422                 }
9423         }
9424         expression->base.type = expression->right->base.type;
9425 }
9426
9427 /**
9428  * @param prec_r precedence of the right operand
9429  */
9430 #define CREATE_BINEXPR_PARSER(token_type, binexpression_type, prec_r, sfunc) \
9431 static expression_t *parse_##binexpression_type(expression_t *left)          \
9432 {                                                                            \
9433         expression_t *binexpr = allocate_expression_zero(binexpression_type);    \
9434         binexpr->binary.left  = left;                                            \
9435         eat(token_type);                                                         \
9436                                                                              \
9437         expression_t *right = parse_sub_expression(prec_r);                      \
9438                                                                              \
9439         binexpr->binary.right = right;                                           \
9440         sfunc(&binexpr->binary);                                                 \
9441                                                                              \
9442         return binexpr;                                                          \
9443 }
9444
9445 CREATE_BINEXPR_PARSER('*',                    EXPR_BINARY_MUL,                PREC_CAST,           semantic_binexpr_arithmetic)
9446 CREATE_BINEXPR_PARSER('/',                    EXPR_BINARY_DIV,                PREC_CAST,           semantic_divmod_arithmetic)
9447 CREATE_BINEXPR_PARSER('%',                    EXPR_BINARY_MOD,                PREC_CAST,           semantic_divmod_arithmetic)
9448 CREATE_BINEXPR_PARSER('+',                    EXPR_BINARY_ADD,                PREC_MULTIPLICATIVE, semantic_add)
9449 CREATE_BINEXPR_PARSER('-',                    EXPR_BINARY_SUB,                PREC_MULTIPLICATIVE, semantic_sub)
9450 CREATE_BINEXPR_PARSER(T_LESSLESS,             EXPR_BINARY_SHIFTLEFT,          PREC_ADDITIVE,       semantic_shift_op)
9451 CREATE_BINEXPR_PARSER(T_GREATERGREATER,       EXPR_BINARY_SHIFTRIGHT,         PREC_ADDITIVE,       semantic_shift_op)
9452 CREATE_BINEXPR_PARSER('<',                    EXPR_BINARY_LESS,               PREC_SHIFT,          semantic_comparison)
9453 CREATE_BINEXPR_PARSER('>',                    EXPR_BINARY_GREATER,            PREC_SHIFT,          semantic_comparison)
9454 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,          PREC_SHIFT,          semantic_comparison)
9455 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,       PREC_SHIFT,          semantic_comparison)
9456 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,           PREC_RELATIONAL,     semantic_comparison)
9457 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,              PREC_RELATIONAL,     semantic_comparison)
9458 CREATE_BINEXPR_PARSER('&',                    EXPR_BINARY_BITWISE_AND,        PREC_EQUALITY,       semantic_binexpr_arithmetic)
9459 CREATE_BINEXPR_PARSER('^',                    EXPR_BINARY_BITWISE_XOR,        PREC_AND,            semantic_binexpr_arithmetic)
9460 CREATE_BINEXPR_PARSER('|',                    EXPR_BINARY_BITWISE_OR,         PREC_XOR,            semantic_binexpr_arithmetic)
9461 CREATE_BINEXPR_PARSER(T_ANDAND,               EXPR_BINARY_LOGICAL_AND,        PREC_OR,             semantic_logical_op)
9462 CREATE_BINEXPR_PARSER(T_PIPEPIPE,             EXPR_BINARY_LOGICAL_OR,         PREC_LOGICAL_AND,    semantic_logical_op)
9463 CREATE_BINEXPR_PARSER('=',                    EXPR_BINARY_ASSIGN,             PREC_ASSIGNMENT,     semantic_binexpr_assign)
9464 CREATE_BINEXPR_PARSER(T_PLUSEQUAL,            EXPR_BINARY_ADD_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
9465 CREATE_BINEXPR_PARSER(T_MINUSEQUAL,           EXPR_BINARY_SUB_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
9466 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL,        EXPR_BINARY_MUL_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9467 CREATE_BINEXPR_PARSER(T_SLASHEQUAL,           EXPR_BINARY_DIV_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
9468 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL,         EXPR_BINARY_MOD_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
9469 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL,        EXPR_BINARY_SHIFTLEFT_ASSIGN,   PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9470 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL,  EXPR_BINARY_SHIFTRIGHT_ASSIGN,  PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9471 CREATE_BINEXPR_PARSER(T_ANDEQUAL,             EXPR_BINARY_BITWISE_AND_ASSIGN, PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9472 CREATE_BINEXPR_PARSER(T_PIPEEQUAL,            EXPR_BINARY_BITWISE_OR_ASSIGN,  PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9473 CREATE_BINEXPR_PARSER(T_CARETEQUAL,           EXPR_BINARY_BITWISE_XOR_ASSIGN, PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9474 CREATE_BINEXPR_PARSER(',',                    EXPR_BINARY_COMMA,              PREC_ASSIGNMENT,     semantic_comma)
9475
9476
9477 static expression_t *parse_sub_expression(precedence_t precedence)
9478 {
9479         if (token.type < 0) {
9480                 return expected_expression_error();
9481         }
9482
9483         expression_parser_function_t *parser
9484                 = &expression_parsers[token.type];
9485         source_position_t             source_position = token.source_position;
9486         expression_t                 *left;
9487
9488         if (parser->parser != NULL) {
9489                 left = parser->parser();
9490         } else {
9491                 left = parse_primary_expression();
9492         }
9493         assert(left != NULL);
9494         left->base.source_position = source_position;
9495
9496         while (true) {
9497                 if (token.type < 0) {
9498                         return expected_expression_error();
9499                 }
9500
9501                 parser = &expression_parsers[token.type];
9502                 if (parser->infix_parser == NULL)
9503                         break;
9504                 if (parser->infix_precedence < precedence)
9505                         break;
9506
9507                 left = parser->infix_parser(left);
9508
9509                 assert(left != NULL);
9510                 assert(left->kind != EXPR_UNKNOWN);
9511                 left->base.source_position = source_position;
9512         }
9513
9514         return left;
9515 }
9516
9517 /**
9518  * Parse an expression.
9519  */
9520 static expression_t *parse_expression(void)
9521 {
9522         return parse_sub_expression(PREC_EXPRESSION);
9523 }
9524
9525 /**
9526  * Register a parser for a prefix-like operator.
9527  *
9528  * @param parser      the parser function
9529  * @param token_type  the token type of the prefix token
9530  */
9531 static void register_expression_parser(parse_expression_function parser,
9532                                        int token_type)
9533 {
9534         expression_parser_function_t *entry = &expression_parsers[token_type];
9535
9536         if (entry->parser != NULL) {
9537                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
9538                 panic("trying to register multiple expression parsers for a token");
9539         }
9540         entry->parser = parser;
9541 }
9542
9543 /**
9544  * Register a parser for an infix operator with given precedence.
9545  *
9546  * @param parser      the parser function
9547  * @param token_type  the token type of the infix operator
9548  * @param precedence  the precedence of the operator
9549  */
9550 static void register_infix_parser(parse_expression_infix_function parser,
9551                 int token_type, precedence_t precedence)
9552 {
9553         expression_parser_function_t *entry = &expression_parsers[token_type];
9554
9555         if (entry->infix_parser != NULL) {
9556                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
9557                 panic("trying to register multiple infix expression parsers for a "
9558                       "token");
9559         }
9560         entry->infix_parser     = parser;
9561         entry->infix_precedence = precedence;
9562 }
9563
9564 /**
9565  * Initialize the expression parsers.
9566  */
9567 static void init_expression_parsers(void)
9568 {
9569         memset(&expression_parsers, 0, sizeof(expression_parsers));
9570
9571         register_infix_parser(parse_array_expression,               '[',                    PREC_POSTFIX);
9572         register_infix_parser(parse_call_expression,                '(',                    PREC_POSTFIX);
9573         register_infix_parser(parse_select_expression,              '.',                    PREC_POSTFIX);
9574         register_infix_parser(parse_select_expression,              T_MINUSGREATER,         PREC_POSTFIX);
9575         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,   T_PLUSPLUS,             PREC_POSTFIX);
9576         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,   T_MINUSMINUS,           PREC_POSTFIX);
9577         register_infix_parser(parse_EXPR_BINARY_MUL,                '*',                    PREC_MULTIPLICATIVE);
9578         register_infix_parser(parse_EXPR_BINARY_DIV,                '/',                    PREC_MULTIPLICATIVE);
9579         register_infix_parser(parse_EXPR_BINARY_MOD,                '%',                    PREC_MULTIPLICATIVE);
9580         register_infix_parser(parse_EXPR_BINARY_ADD,                '+',                    PREC_ADDITIVE);
9581         register_infix_parser(parse_EXPR_BINARY_SUB,                '-',                    PREC_ADDITIVE);
9582         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,          T_LESSLESS,             PREC_SHIFT);
9583         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,         T_GREATERGREATER,       PREC_SHIFT);
9584         register_infix_parser(parse_EXPR_BINARY_LESS,               '<',                    PREC_RELATIONAL);
9585         register_infix_parser(parse_EXPR_BINARY_GREATER,            '>',                    PREC_RELATIONAL);
9586         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,          T_LESSEQUAL,            PREC_RELATIONAL);
9587         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL,       T_GREATEREQUAL,         PREC_RELATIONAL);
9588         register_infix_parser(parse_EXPR_BINARY_EQUAL,              T_EQUALEQUAL,           PREC_EQUALITY);
9589         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,           T_EXCLAMATIONMARKEQUAL, PREC_EQUALITY);
9590         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,        '&',                    PREC_AND);
9591         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,        '^',                    PREC_XOR);
9592         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,         '|',                    PREC_OR);
9593         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,        T_ANDAND,               PREC_LOGICAL_AND);
9594         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,         T_PIPEPIPE,             PREC_LOGICAL_OR);
9595         register_infix_parser(parse_conditional_expression,         '?',                    PREC_CONDITIONAL);
9596         register_infix_parser(parse_EXPR_BINARY_ASSIGN,             '=',                    PREC_ASSIGNMENT);
9597         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,         T_PLUSEQUAL,            PREC_ASSIGNMENT);
9598         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,         T_MINUSEQUAL,           PREC_ASSIGNMENT);
9599         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,         T_ASTERISKEQUAL,        PREC_ASSIGNMENT);
9600         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,         T_SLASHEQUAL,           PREC_ASSIGNMENT);
9601         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,         T_PERCENTEQUAL,         PREC_ASSIGNMENT);
9602         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,   T_LESSLESSEQUAL,        PREC_ASSIGNMENT);
9603         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,  T_GREATERGREATEREQUAL,  PREC_ASSIGNMENT);
9604         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN, T_ANDEQUAL,             PREC_ASSIGNMENT);
9605         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,  T_PIPEEQUAL,            PREC_ASSIGNMENT);
9606         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN, T_CARETEQUAL,           PREC_ASSIGNMENT);
9607         register_infix_parser(parse_EXPR_BINARY_COMMA,              ',',                    PREC_EXPRESSION);
9608
9609         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-');
9610         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+');
9611         register_expression_parser(parse_EXPR_UNARY_NOT,              '!');
9612         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~');
9613         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*');
9614         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&');
9615         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT, T_PLUSPLUS);
9616         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT, T_MINUSMINUS);
9617         register_expression_parser(parse_sizeof,                      T_sizeof);
9618         register_expression_parser(parse_alignof,                     T___alignof__);
9619         register_expression_parser(parse_extension,                   T___extension__);
9620         register_expression_parser(parse_builtin_classify_type,       T___builtin_classify_type);
9621         register_expression_parser(parse_delete,                      T_delete);
9622         register_expression_parser(parse_throw,                       T_throw);
9623 }
9624
9625 /**
9626  * Parse a asm statement arguments specification.
9627  */
9628 static asm_argument_t *parse_asm_arguments(bool is_out)
9629 {
9630         asm_argument_t  *result = NULL;
9631         asm_argument_t **anchor = &result;
9632
9633         while (token.type == T_STRING_LITERAL || token.type == '[') {
9634                 asm_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
9635                 memset(argument, 0, sizeof(argument[0]));
9636
9637                 if (token.type == '[') {
9638                         eat('[');
9639                         if (token.type != T_IDENTIFIER) {
9640                                 parse_error_expected("while parsing asm argument",
9641                                                      T_IDENTIFIER, NULL);
9642                                 return NULL;
9643                         }
9644                         argument->symbol = token.v.symbol;
9645
9646                         expect(']', end_error);
9647                 }
9648
9649                 argument->constraints = parse_string_literals();
9650                 expect('(', end_error);
9651                 add_anchor_token(')');
9652                 expression_t *expression = parse_expression();
9653                 rem_anchor_token(')');
9654                 if (is_out) {
9655                         /* Ugly GCC stuff: Allow lvalue casts.  Skip casts, when they do not
9656                          * change size or type representation (e.g. int -> long is ok, but
9657                          * int -> float is not) */
9658                         if (expression->kind == EXPR_UNARY_CAST) {
9659                                 type_t      *const type = expression->base.type;
9660                                 type_kind_t  const kind = type->kind;
9661                                 if (kind == TYPE_ATOMIC || kind == TYPE_POINTER) {
9662                                         unsigned flags;
9663                                         unsigned size;
9664                                         if (kind == TYPE_ATOMIC) {
9665                                                 atomic_type_kind_t const akind = type->atomic.akind;
9666                                                 flags = get_atomic_type_flags(akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
9667                                                 size  = get_atomic_type_size(akind);
9668                                         } else {
9669                                                 flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
9670                                                 size  = get_atomic_type_size(get_intptr_kind());
9671                                         }
9672
9673                                         do {
9674                                                 expression_t *const value      = expression->unary.value;
9675                                                 type_t       *const value_type = value->base.type;
9676                                                 type_kind_t   const value_kind = value_type->kind;
9677
9678                                                 unsigned value_flags;
9679                                                 unsigned value_size;
9680                                                 if (value_kind == TYPE_ATOMIC) {
9681                                                         atomic_type_kind_t const value_akind = value_type->atomic.akind;
9682                                                         value_flags = get_atomic_type_flags(value_akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
9683                                                         value_size  = get_atomic_type_size(value_akind);
9684                                                 } else if (value_kind == TYPE_POINTER) {
9685                                                         value_flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
9686                                                         value_size  = get_atomic_type_size(get_intptr_kind());
9687                                                 } else {
9688                                                         break;
9689                                                 }
9690
9691                                                 if (value_flags != flags || value_size != size)
9692                                                         break;
9693
9694                                                 expression = value;
9695                                         } while (expression->kind == EXPR_UNARY_CAST);
9696                                 }
9697                         }
9698
9699                         if (!is_lvalue(expression)) {
9700                                 errorf(&expression->base.source_position,
9701                                        "asm output argument is not an lvalue");
9702                         }
9703
9704                         if (argument->constraints.begin[0] == '+')
9705                                 mark_vars_read(expression, NULL);
9706                 } else {
9707                         mark_vars_read(expression, NULL);
9708                 }
9709                 argument->expression = expression;
9710                 expect(')', end_error);
9711
9712                 set_address_taken(expression, true);
9713
9714                 *anchor = argument;
9715                 anchor  = &argument->next;
9716
9717                 if (token.type != ',')
9718                         break;
9719                 eat(',');
9720         }
9721
9722         return result;
9723 end_error:
9724         return NULL;
9725 }
9726
9727 /**
9728  * Parse a asm statement clobber specification.
9729  */
9730 static asm_clobber_t *parse_asm_clobbers(void)
9731 {
9732         asm_clobber_t *result = NULL;
9733         asm_clobber_t *last   = NULL;
9734
9735         while (token.type == T_STRING_LITERAL) {
9736                 asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
9737                 clobber->clobber       = parse_string_literals();
9738
9739                 if (last != NULL) {
9740                         last->next = clobber;
9741                 } else {
9742                         result = clobber;
9743                 }
9744                 last = clobber;
9745
9746                 if (token.type != ',')
9747                         break;
9748                 eat(',');
9749         }
9750
9751         return result;
9752 }
9753
9754 /**
9755  * Parse an asm statement.
9756  */
9757 static statement_t *parse_asm_statement(void)
9758 {
9759         statement_t     *statement     = allocate_statement_zero(STATEMENT_ASM);
9760         asm_statement_t *asm_statement = &statement->asms;
9761
9762         eat(T_asm);
9763
9764         if (token.type == T_volatile) {
9765                 next_token();
9766                 asm_statement->is_volatile = true;
9767         }
9768
9769         expect('(', end_error);
9770         add_anchor_token(')');
9771         add_anchor_token(':');
9772         asm_statement->asm_text = parse_string_literals();
9773
9774         if (token.type != ':') {
9775                 rem_anchor_token(':');
9776                 goto end_of_asm;
9777         }
9778         eat(':');
9779
9780         asm_statement->outputs = parse_asm_arguments(true);
9781         if (token.type != ':') {
9782                 rem_anchor_token(':');
9783                 goto end_of_asm;
9784         }
9785         eat(':');
9786
9787         asm_statement->inputs = parse_asm_arguments(false);
9788         if (token.type != ':') {
9789                 rem_anchor_token(':');
9790                 goto end_of_asm;
9791         }
9792         rem_anchor_token(':');
9793         eat(':');
9794
9795         asm_statement->clobbers = parse_asm_clobbers();
9796
9797 end_of_asm:
9798         rem_anchor_token(')');
9799         expect(')', end_error);
9800         expect(';', end_error);
9801
9802         if (asm_statement->outputs == NULL) {
9803                 /* GCC: An 'asm' instruction without any output operands will be treated
9804                  * identically to a volatile 'asm' instruction. */
9805                 asm_statement->is_volatile = true;
9806         }
9807
9808         return statement;
9809 end_error:
9810         return create_invalid_statement();
9811 }
9812
9813 /**
9814  * Parse a case statement.
9815  */
9816 static statement_t *parse_case_statement(void)
9817 {
9818         statement_t       *const statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9819         source_position_t *const pos       = &statement->base.source_position;
9820
9821         eat(T_case);
9822
9823         expression_t *const expression   = parse_expression();
9824         statement->case_label.expression = expression;
9825         if (!is_constant_expression(expression)) {
9826                 /* This check does not prevent the error message in all cases of an
9827                  * prior error while parsing the expression.  At least it catches the
9828                  * common case of a mistyped enum entry. */
9829                 if (is_type_valid(skip_typeref(expression->base.type))) {
9830                         errorf(pos, "case label does not reduce to an integer constant");
9831                 }
9832                 statement->case_label.is_bad = true;
9833         } else {
9834                 long const val = fold_constant(expression);
9835                 statement->case_label.first_case = val;
9836                 statement->case_label.last_case  = val;
9837         }
9838
9839         if (GNU_MODE) {
9840                 if (token.type == T_DOTDOTDOT) {
9841                         next_token();
9842                         expression_t *const end_range   = parse_expression();
9843                         statement->case_label.end_range = end_range;
9844                         if (!is_constant_expression(end_range)) {
9845                                 /* This check does not prevent the error message in all cases of an
9846                                  * prior error while parsing the expression.  At least it catches the
9847                                  * common case of a mistyped enum entry. */
9848                                 if (is_type_valid(skip_typeref(end_range->base.type))) {
9849                                         errorf(pos, "case range does not reduce to an integer constant");
9850                                 }
9851                                 statement->case_label.is_bad = true;
9852                         } else {
9853                                 long const val = fold_constant(end_range);
9854                                 statement->case_label.last_case = val;
9855
9856                                 if (warning.other && val < statement->case_label.first_case) {
9857                                         statement->case_label.is_empty_range = true;
9858                                         warningf(pos, "empty range specified");
9859                                 }
9860                         }
9861                 }
9862         }
9863
9864         PUSH_PARENT(statement);
9865
9866         expect(':', end_error);
9867 end_error:
9868
9869         if (current_switch != NULL) {
9870                 if (! statement->case_label.is_bad) {
9871                         /* Check for duplicate case values */
9872                         case_label_statement_t *c = &statement->case_label;
9873                         for (case_label_statement_t *l = current_switch->first_case; l != NULL; l = l->next) {
9874                                 if (l->is_bad || l->is_empty_range || l->expression == NULL)
9875                                         continue;
9876
9877                                 if (c->last_case < l->first_case || c->first_case > l->last_case)
9878                                         continue;
9879
9880                                 errorf(pos, "duplicate case value (previously used %P)",
9881                                        &l->base.source_position);
9882                                 break;
9883                         }
9884                 }
9885                 /* link all cases into the switch statement */
9886                 if (current_switch->last_case == NULL) {
9887                         current_switch->first_case      = &statement->case_label;
9888                 } else {
9889                         current_switch->last_case->next = &statement->case_label;
9890                 }
9891                 current_switch->last_case = &statement->case_label;
9892         } else {
9893                 errorf(pos, "case label not within a switch statement");
9894         }
9895
9896         statement_t *const inner_stmt = parse_statement();
9897         statement->case_label.statement = inner_stmt;
9898         if (inner_stmt->kind == STATEMENT_DECLARATION) {
9899                 errorf(&inner_stmt->base.source_position, "declaration after case label");
9900         }
9901
9902         POP_PARENT;
9903         return statement;
9904 }
9905
9906 /**
9907  * Parse a default statement.
9908  */
9909 static statement_t *parse_default_statement(void)
9910 {
9911         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9912
9913         eat(T_default);
9914
9915         PUSH_PARENT(statement);
9916
9917         expect(':', end_error);
9918         if (current_switch != NULL) {
9919                 const case_label_statement_t *def_label = current_switch->default_label;
9920                 if (def_label != NULL) {
9921                         errorf(HERE, "multiple default labels in one switch (previous declared %P)",
9922                                &def_label->base.source_position);
9923                 } else {
9924                         current_switch->default_label = &statement->case_label;
9925
9926                         /* link all cases into the switch statement */
9927                         if (current_switch->last_case == NULL) {
9928                                 current_switch->first_case      = &statement->case_label;
9929                         } else {
9930                                 current_switch->last_case->next = &statement->case_label;
9931                         }
9932                         current_switch->last_case = &statement->case_label;
9933                 }
9934         } else {
9935                 errorf(&statement->base.source_position,
9936                         "'default' label not within a switch statement");
9937         }
9938
9939         statement_t *const inner_stmt = parse_statement();
9940         statement->case_label.statement = inner_stmt;
9941         if (inner_stmt->kind == STATEMENT_DECLARATION) {
9942                 errorf(&inner_stmt->base.source_position, "declaration after default label");
9943         }
9944
9945         POP_PARENT;
9946         return statement;
9947 end_error:
9948         POP_PARENT;
9949         return create_invalid_statement();
9950 }
9951
9952 /**
9953  * Parse a label statement.
9954  */
9955 static statement_t *parse_label_statement(void)
9956 {
9957         assert(token.type == T_IDENTIFIER);
9958         symbol_t *symbol = token.v.symbol;
9959         label_t  *label  = get_label(symbol);
9960
9961         statement_t *const statement = allocate_statement_zero(STATEMENT_LABEL);
9962         statement->label.label       = label;
9963
9964         next_token();
9965
9966         PUSH_PARENT(statement);
9967
9968         /* if statement is already set then the label is defined twice,
9969          * otherwise it was just mentioned in a goto/local label declaration so far
9970          */
9971         if (label->statement != NULL) {
9972                 errorf(HERE, "duplicate label '%Y' (declared %P)",
9973                        symbol, &label->base.source_position);
9974         } else {
9975                 label->base.source_position = token.source_position;
9976                 label->statement            = statement;
9977         }
9978
9979         eat(':');
9980
9981         if (token.type == '}') {
9982                 /* TODO only warn? */
9983                 if (warning.other && false) {
9984                         warningf(HERE, "label at end of compound statement");
9985                         statement->label.statement = create_empty_statement();
9986                 } else {
9987                         errorf(HERE, "label at end of compound statement");
9988                         statement->label.statement = create_invalid_statement();
9989                 }
9990         } else if (token.type == ';') {
9991                 /* Eat an empty statement here, to avoid the warning about an empty
9992                  * statement after a label.  label:; is commonly used to have a label
9993                  * before a closing brace. */
9994                 statement->label.statement = create_empty_statement();
9995                 next_token();
9996         } else {
9997                 statement_t *const inner_stmt = parse_statement();
9998                 statement->label.statement = inner_stmt;
9999                 if (inner_stmt->kind == STATEMENT_DECLARATION) {
10000                         errorf(&inner_stmt->base.source_position, "declaration after label");
10001                 }
10002         }
10003
10004         /* remember the labels in a list for later checking */
10005         *label_anchor = &statement->label;
10006         label_anchor  = &statement->label.next;
10007
10008         POP_PARENT;
10009         return statement;
10010 }
10011
10012 /**
10013  * Parse an if statement.
10014  */
10015 static statement_t *parse_if(void)
10016 {
10017         statement_t *statement = allocate_statement_zero(STATEMENT_IF);
10018
10019         eat(T_if);
10020
10021         PUSH_PARENT(statement);
10022
10023         add_anchor_token('{');
10024
10025         expect('(', end_error);
10026         add_anchor_token(')');
10027         expression_t *const expr = parse_expression();
10028         statement->ifs.condition = expr;
10029         /* §6.8.4.1:1  The controlling expression of an if statement shall have
10030          *             scalar type. */
10031         semantic_condition(expr, "condition of 'if'-statment");
10032         mark_vars_read(expr, NULL);
10033         rem_anchor_token(')');
10034         expect(')', end_error);
10035
10036 end_error:
10037         rem_anchor_token('{');
10038
10039         add_anchor_token(T_else);
10040         statement_t *const true_stmt = parse_statement();
10041         statement->ifs.true_statement = true_stmt;
10042         rem_anchor_token(T_else);
10043
10044         if (token.type == T_else) {
10045                 next_token();
10046                 statement->ifs.false_statement = parse_statement();
10047         } else if (warning.parentheses &&
10048                         true_stmt->kind == STATEMENT_IF &&
10049                         true_stmt->ifs.false_statement != NULL) {
10050                 warningf(&true_stmt->base.source_position,
10051                                 "suggest explicit braces to avoid ambiguous 'else'");
10052         }
10053
10054         POP_PARENT;
10055         return statement;
10056 }
10057
10058 /**
10059  * Check that all enums are handled in a switch.
10060  *
10061  * @param statement  the switch statement to check
10062  */
10063 static void check_enum_cases(const switch_statement_t *statement) {
10064         const type_t *type = skip_typeref(statement->expression->base.type);
10065         if (! is_type_enum(type))
10066                 return;
10067         const enum_type_t *enumt = &type->enumt;
10068
10069         /* if we have a default, no warnings */
10070         if (statement->default_label != NULL)
10071                 return;
10072
10073         /* FIXME: calculation of value should be done while parsing */
10074         /* TODO: quadratic algorithm here. Change to an n log n one */
10075         long            last_value = -1;
10076         const entity_t *entry      = enumt->enume->base.next;
10077         for (; entry != NULL && entry->kind == ENTITY_ENUM_VALUE;
10078              entry = entry->base.next) {
10079                 const expression_t *expression = entry->enum_value.value;
10080                 long                value      = expression != NULL ? fold_constant(expression) : last_value + 1;
10081                 bool                found      = false;
10082                 for (const case_label_statement_t *l = statement->first_case; l != NULL; l = l->next) {
10083                         if (l->expression == NULL)
10084                                 continue;
10085                         if (l->first_case <= value && value <= l->last_case) {
10086                                 found = true;
10087                                 break;
10088                         }
10089                 }
10090                 if (! found) {
10091                         warningf(&statement->base.source_position,
10092                                  "enumeration value '%Y' not handled in switch",
10093                                  entry->base.symbol);
10094                 }
10095                 last_value = value;
10096         }
10097 }
10098
10099 /**
10100  * Parse a switch statement.
10101  */
10102 static statement_t *parse_switch(void)
10103 {
10104         statement_t *statement = allocate_statement_zero(STATEMENT_SWITCH);
10105
10106         eat(T_switch);
10107
10108         PUSH_PARENT(statement);
10109
10110         expect('(', end_error);
10111         add_anchor_token(')');
10112         expression_t *const expr = parse_expression();
10113         mark_vars_read(expr, NULL);
10114         type_t       *      type = skip_typeref(expr->base.type);
10115         if (is_type_integer(type)) {
10116                 type = promote_integer(type);
10117                 if (warning.traditional) {
10118                         if (get_rank(type) >= get_akind_rank(ATOMIC_TYPE_LONG)) {
10119                                 warningf(&expr->base.source_position,
10120                                         "'%T' switch expression not converted to '%T' in ISO C",
10121                                         type, type_int);
10122                         }
10123                 }
10124         } else if (is_type_valid(type)) {
10125                 errorf(&expr->base.source_position,
10126                        "switch quantity is not an integer, but '%T'", type);
10127                 type = type_error_type;
10128         }
10129         statement->switchs.expression = create_implicit_cast(expr, type);
10130         expect(')', end_error);
10131         rem_anchor_token(')');
10132
10133         switch_statement_t *rem = current_switch;
10134         current_switch          = &statement->switchs;
10135         statement->switchs.body = parse_statement();
10136         current_switch          = rem;
10137
10138         if (warning.switch_default &&
10139             statement->switchs.default_label == NULL) {
10140                 warningf(&statement->base.source_position, "switch has no default case");
10141         }
10142         if (warning.switch_enum)
10143                 check_enum_cases(&statement->switchs);
10144
10145         POP_PARENT;
10146         return statement;
10147 end_error:
10148         POP_PARENT;
10149         return create_invalid_statement();
10150 }
10151
10152 static statement_t *parse_loop_body(statement_t *const loop)
10153 {
10154         statement_t *const rem = current_loop;
10155         current_loop = loop;
10156
10157         statement_t *const body = parse_statement();
10158
10159         current_loop = rem;
10160         return body;
10161 }
10162
10163 /**
10164  * Parse a while statement.
10165  */
10166 static statement_t *parse_while(void)
10167 {
10168         statement_t *statement = allocate_statement_zero(STATEMENT_WHILE);
10169
10170         eat(T_while);
10171
10172         PUSH_PARENT(statement);
10173
10174         expect('(', end_error);
10175         add_anchor_token(')');
10176         expression_t *const cond = parse_expression();
10177         statement->whiles.condition = cond;
10178         /* §6.8.5:2    The controlling expression of an iteration statement shall
10179          *             have scalar type. */
10180         semantic_condition(cond, "condition of 'while'-statement");
10181         mark_vars_read(cond, NULL);
10182         rem_anchor_token(')');
10183         expect(')', end_error);
10184
10185         statement->whiles.body = parse_loop_body(statement);
10186
10187         POP_PARENT;
10188         return statement;
10189 end_error:
10190         POP_PARENT;
10191         return create_invalid_statement();
10192 }
10193
10194 /**
10195  * Parse a do statement.
10196  */
10197 static statement_t *parse_do(void)
10198 {
10199         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
10200
10201         eat(T_do);
10202
10203         PUSH_PARENT(statement);
10204
10205         add_anchor_token(T_while);
10206         statement->do_while.body = parse_loop_body(statement);
10207         rem_anchor_token(T_while);
10208
10209         expect(T_while, end_error);
10210         expect('(', end_error);
10211         add_anchor_token(')');
10212         expression_t *const cond = parse_expression();
10213         statement->do_while.condition = cond;
10214         /* §6.8.5:2    The controlling expression of an iteration statement shall
10215          *             have scalar type. */
10216         semantic_condition(cond, "condition of 'do-while'-statement");
10217         mark_vars_read(cond, NULL);
10218         rem_anchor_token(')');
10219         expect(')', end_error);
10220         expect(';', end_error);
10221
10222         POP_PARENT;
10223         return statement;
10224 end_error:
10225         POP_PARENT;
10226         return create_invalid_statement();
10227 }
10228
10229 /**
10230  * Parse a for statement.
10231  */
10232 static statement_t *parse_for(void)
10233 {
10234         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
10235
10236         eat(T_for);
10237
10238         expect('(', end_error1);
10239         add_anchor_token(')');
10240
10241         PUSH_PARENT(statement);
10242
10243         size_t const  top       = environment_top();
10244         scope_t      *old_scope = scope_push(&statement->fors.scope);
10245
10246         if (token.type == ';') {
10247                 next_token();
10248         } else if (is_declaration_specifier(&token, false)) {
10249                 parse_declaration(record_entity, DECL_FLAGS_NONE);
10250         } else {
10251                 add_anchor_token(';');
10252                 expression_t *const init = parse_expression();
10253                 statement->fors.initialisation = init;
10254                 mark_vars_read(init, ENT_ANY);
10255                 if (warning.unused_value && !expression_has_effect(init)) {
10256                         warningf(&init->base.source_position,
10257                                         "initialisation of 'for'-statement has no effect");
10258                 }
10259                 rem_anchor_token(';');
10260                 expect(';', end_error2);
10261         }
10262
10263         if (token.type != ';') {
10264                 add_anchor_token(';');
10265                 expression_t *const cond = parse_expression();
10266                 statement->fors.condition = cond;
10267                 /* §6.8.5:2    The controlling expression of an iteration statement
10268                  *             shall have scalar type. */
10269                 semantic_condition(cond, "condition of 'for'-statement");
10270                 mark_vars_read(cond, NULL);
10271                 rem_anchor_token(';');
10272         }
10273         expect(';', end_error2);
10274         if (token.type != ')') {
10275                 expression_t *const step = parse_expression();
10276                 statement->fors.step = step;
10277                 mark_vars_read(step, ENT_ANY);
10278                 if (warning.unused_value && !expression_has_effect(step)) {
10279                         warningf(&step->base.source_position,
10280                                  "step of 'for'-statement has no effect");
10281                 }
10282         }
10283         expect(')', end_error2);
10284         rem_anchor_token(')');
10285         statement->fors.body = parse_loop_body(statement);
10286
10287         assert(current_scope == &statement->fors.scope);
10288         scope_pop(old_scope);
10289         environment_pop_to(top);
10290
10291         POP_PARENT;
10292         return statement;
10293
10294 end_error2:
10295         POP_PARENT;
10296         rem_anchor_token(')');
10297         assert(current_scope == &statement->fors.scope);
10298         scope_pop(old_scope);
10299         environment_pop_to(top);
10300         /* fallthrough */
10301
10302 end_error1:
10303         return create_invalid_statement();
10304 }
10305
10306 /**
10307  * Parse a goto statement.
10308  */
10309 static statement_t *parse_goto(void)
10310 {
10311         statement_t *statement = allocate_statement_zero(STATEMENT_GOTO);
10312         eat(T_goto);
10313
10314         if (GNU_MODE && token.type == '*') {
10315                 next_token();
10316                 expression_t *expression = parse_expression();
10317                 mark_vars_read(expression, NULL);
10318
10319                 /* Argh: although documentation says the expression must be of type void*,
10320                  * gcc accepts anything that can be casted into void* without error */
10321                 type_t *type = expression->base.type;
10322
10323                 if (type != type_error_type) {
10324                         if (!is_type_pointer(type) && !is_type_integer(type)) {
10325                                 errorf(&expression->base.source_position,
10326                                         "cannot convert to a pointer type");
10327                         } else if (warning.other && type != type_void_ptr) {
10328                                 warningf(&expression->base.source_position,
10329                                         "type of computed goto expression should be 'void*' not '%T'", type);
10330                         }
10331                         expression = create_implicit_cast(expression, type_void_ptr);
10332                 }
10333
10334                 statement->gotos.expression = expression;
10335         } else {
10336                 if (token.type != T_IDENTIFIER) {
10337                         if (GNU_MODE)
10338                                 parse_error_expected("while parsing goto", T_IDENTIFIER, '*', NULL);
10339                         else
10340                                 parse_error_expected("while parsing goto", T_IDENTIFIER, NULL);
10341                         eat_until_anchor();
10342                         goto end_error;
10343                 }
10344                 symbol_t *symbol = token.v.symbol;
10345                 next_token();
10346
10347                 statement->gotos.label = get_label(symbol);
10348         }
10349
10350         /* remember the goto's in a list for later checking */
10351         *goto_anchor = &statement->gotos;
10352         goto_anchor  = &statement->gotos.next;
10353
10354         expect(';', end_error);
10355
10356         return statement;
10357 end_error:
10358         return create_invalid_statement();
10359 }
10360
10361 /**
10362  * Parse a continue statement.
10363  */
10364 static statement_t *parse_continue(void)
10365 {
10366         if (current_loop == NULL) {
10367                 errorf(HERE, "continue statement not within loop");
10368         }
10369
10370         statement_t *statement = allocate_statement_zero(STATEMENT_CONTINUE);
10371
10372         eat(T_continue);
10373         expect(';', end_error);
10374
10375 end_error:
10376         return statement;
10377 }
10378
10379 /**
10380  * Parse a break statement.
10381  */
10382 static statement_t *parse_break(void)
10383 {
10384         if (current_switch == NULL && current_loop == NULL) {
10385                 errorf(HERE, "break statement not within loop or switch");
10386         }
10387
10388         statement_t *statement = allocate_statement_zero(STATEMENT_BREAK);
10389
10390         eat(T_break);
10391         expect(';', end_error);
10392
10393 end_error:
10394         return statement;
10395 }
10396
10397 /**
10398  * Parse a __leave statement.
10399  */
10400 static statement_t *parse_leave_statement(void)
10401 {
10402         if (current_try == NULL) {
10403                 errorf(HERE, "__leave statement not within __try");
10404         }
10405
10406         statement_t *statement = allocate_statement_zero(STATEMENT_LEAVE);
10407
10408         eat(T___leave);
10409         expect(';', end_error);
10410
10411 end_error:
10412         return statement;
10413 }
10414
10415 /**
10416  * Check if a given entity represents a local variable.
10417  */
10418 static bool is_local_variable(const entity_t *entity)
10419 {
10420         if (entity->kind != ENTITY_VARIABLE)
10421                 return false;
10422
10423         switch ((storage_class_tag_t) entity->declaration.storage_class) {
10424         case STORAGE_CLASS_AUTO:
10425         case STORAGE_CLASS_REGISTER: {
10426                 const type_t *type = skip_typeref(entity->declaration.type);
10427                 if (is_type_function(type)) {
10428                         return false;
10429                 } else {
10430                         return true;
10431                 }
10432         }
10433         default:
10434                 return false;
10435         }
10436 }
10437
10438 /**
10439  * Check if a given expression represents a local variable.
10440  */
10441 static bool expression_is_local_variable(const expression_t *expression)
10442 {
10443         if (expression->base.kind != EXPR_REFERENCE) {
10444                 return false;
10445         }
10446         const entity_t *entity = expression->reference.entity;
10447         return is_local_variable(entity);
10448 }
10449
10450 /**
10451  * Check if a given expression represents a local variable and
10452  * return its declaration then, else return NULL.
10453  */
10454 entity_t *expression_is_variable(const expression_t *expression)
10455 {
10456         if (expression->base.kind != EXPR_REFERENCE) {
10457                 return NULL;
10458         }
10459         entity_t *entity = expression->reference.entity;
10460         if (entity->kind != ENTITY_VARIABLE)
10461                 return NULL;
10462
10463         return entity;
10464 }
10465
10466 /**
10467  * Parse a return statement.
10468  */
10469 static statement_t *parse_return(void)
10470 {
10471         eat(T_return);
10472
10473         statement_t *statement = allocate_statement_zero(STATEMENT_RETURN);
10474
10475         expression_t *return_value = NULL;
10476         if (token.type != ';') {
10477                 return_value = parse_expression();
10478                 mark_vars_read(return_value, NULL);
10479         }
10480
10481         const type_t *const func_type = skip_typeref(current_function->base.type);
10482         assert(is_type_function(func_type));
10483         type_t *const return_type = skip_typeref(func_type->function.return_type);
10484
10485         source_position_t const *const pos = &statement->base.source_position;
10486         if (return_value != NULL) {
10487                 type_t *return_value_type = skip_typeref(return_value->base.type);
10488
10489                 if (is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
10490                         if (is_type_atomic(return_value_type, ATOMIC_TYPE_VOID)) {
10491                                 /* ISO/IEC 14882:1998(E) §6.6.3:2 */
10492                                 /* Only warn in C mode, because GCC does the same */
10493                                 if (c_mode & _CXX || strict_mode) {
10494                                         errorf(pos,
10495                                                         "'return' with a value, in function returning 'void'");
10496                                 } else if (warning.other) {
10497                                         warningf(pos,
10498                                                         "'return' with a value, in function returning 'void'");
10499                                 }
10500                         } else if (!(c_mode & _CXX)) { /* ISO/IEC 14882:1998(E) §6.6.3:3 */
10501                                 /* Only warn in C mode, because GCC does the same */
10502                                 if (strict_mode) {
10503                                         errorf(pos,
10504                                                         "'return' with expression in function return 'void'");
10505                                 } else if (warning.other) {
10506                                         warningf(pos,
10507                                                         "'return' with expression in function return 'void'");
10508                                 }
10509                         }
10510                 } else {
10511                         assign_error_t error = semantic_assign(return_type, return_value);
10512                         report_assign_error(error, return_type, return_value, "'return'",
10513                                         pos);
10514                 }
10515                 return_value = create_implicit_cast(return_value, return_type);
10516                 /* check for returning address of a local var */
10517                 if (warning.other && return_value != NULL
10518                                 && return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
10519                         const expression_t *expression = return_value->unary.value;
10520                         if (expression_is_local_variable(expression)) {
10521                                 warningf(pos, "function returns address of local variable");
10522                         }
10523                 }
10524         } else if (warning.other && !is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
10525                 /* ISO/IEC 14882:1998(E) §6.6.3:3 */
10526                 if (c_mode & _CXX || strict_mode) {
10527                         errorf(pos,
10528                                         "'return' without value, in function returning non-void");
10529                 } else {
10530                         warningf(pos,
10531                                         "'return' without value, in function returning non-void");
10532                 }
10533         }
10534         statement->returns.value = return_value;
10535
10536         expect(';', end_error);
10537
10538 end_error:
10539         return statement;
10540 }
10541
10542 /**
10543  * Parse a declaration statement.
10544  */
10545 static statement_t *parse_declaration_statement(void)
10546 {
10547         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
10548
10549         entity_t *before = current_scope->last_entity;
10550         if (GNU_MODE) {
10551                 parse_external_declaration();
10552         } else {
10553                 parse_declaration(record_entity, DECL_FLAGS_NONE);
10554         }
10555
10556         if (before == NULL) {
10557                 statement->declaration.declarations_begin = current_scope->entities;
10558         } else {
10559                 statement->declaration.declarations_begin = before->base.next;
10560         }
10561         statement->declaration.declarations_end = current_scope->last_entity;
10562
10563         return statement;
10564 }
10565
10566 /**
10567  * Parse an expression statement, ie. expr ';'.
10568  */
10569 static statement_t *parse_expression_statement(void)
10570 {
10571         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10572
10573         expression_t *const expr         = parse_expression();
10574         statement->expression.expression = expr;
10575         mark_vars_read(expr, ENT_ANY);
10576
10577         expect(';', end_error);
10578
10579 end_error:
10580         return statement;
10581 }
10582
10583 /**
10584  * Parse a microsoft __try { } __finally { } or
10585  * __try{ } __except() { }
10586  */
10587 static statement_t *parse_ms_try_statment(void)
10588 {
10589         statement_t *statement = allocate_statement_zero(STATEMENT_MS_TRY);
10590         eat(T___try);
10591
10592         PUSH_PARENT(statement);
10593
10594         ms_try_statement_t *rem = current_try;
10595         current_try = &statement->ms_try;
10596         statement->ms_try.try_statement = parse_compound_statement(false);
10597         current_try = rem;
10598
10599         POP_PARENT;
10600
10601         if (token.type == T___except) {
10602                 eat(T___except);
10603                 expect('(', end_error);
10604                 add_anchor_token(')');
10605                 expression_t *const expr = parse_expression();
10606                 mark_vars_read(expr, NULL);
10607                 type_t       *      type = skip_typeref(expr->base.type);
10608                 if (is_type_integer(type)) {
10609                         type = promote_integer(type);
10610                 } else if (is_type_valid(type)) {
10611                         errorf(&expr->base.source_position,
10612                                "__expect expression is not an integer, but '%T'", type);
10613                         type = type_error_type;
10614                 }
10615                 statement->ms_try.except_expression = create_implicit_cast(expr, type);
10616                 rem_anchor_token(')');
10617                 expect(')', end_error);
10618                 statement->ms_try.final_statement = parse_compound_statement(false);
10619         } else if (token.type == T__finally) {
10620                 eat(T___finally);
10621                 statement->ms_try.final_statement = parse_compound_statement(false);
10622         } else {
10623                 parse_error_expected("while parsing __try statement", T___except, T___finally, NULL);
10624                 return create_invalid_statement();
10625         }
10626         return statement;
10627 end_error:
10628         return create_invalid_statement();
10629 }
10630
10631 static statement_t *parse_empty_statement(void)
10632 {
10633         if (warning.empty_statement) {
10634                 warningf(HERE, "statement is empty");
10635         }
10636         statement_t *const statement = create_empty_statement();
10637         eat(';');
10638         return statement;
10639 }
10640
10641 static statement_t *parse_local_label_declaration(void)
10642 {
10643         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
10644
10645         eat(T___label__);
10646
10647         entity_t *begin = NULL, *end = NULL;
10648
10649         while (true) {
10650                 if (token.type != T_IDENTIFIER) {
10651                         parse_error_expected("while parsing local label declaration",
10652                                 T_IDENTIFIER, NULL);
10653                         goto end_error;
10654                 }
10655                 symbol_t *symbol = token.v.symbol;
10656                 entity_t *entity = get_entity(symbol, NAMESPACE_LABEL);
10657                 if (entity != NULL && entity->base.parent_scope == current_scope) {
10658                         errorf(HERE, "multiple definitions of '__label__ %Y' (previous definition %P)",
10659                                symbol, &entity->base.source_position);
10660                 } else {
10661                         entity = allocate_entity_zero(ENTITY_LOCAL_LABEL);
10662
10663                         entity->base.parent_scope    = current_scope;
10664                         entity->base.namespc         = NAMESPACE_LABEL;
10665                         entity->base.source_position = token.source_position;
10666                         entity->base.symbol          = symbol;
10667
10668                         if (end != NULL)
10669                                 end->base.next = entity;
10670                         end = entity;
10671                         if (begin == NULL)
10672                                 begin = entity;
10673
10674                         environment_push(entity);
10675                 }
10676                 next_token();
10677
10678                 if (token.type != ',')
10679                         break;
10680                 next_token();
10681         }
10682         eat(';');
10683 end_error:
10684         statement->declaration.declarations_begin = begin;
10685         statement->declaration.declarations_end   = end;
10686         return statement;
10687 }
10688
10689 static void parse_namespace_definition(void)
10690 {
10691         eat(T_namespace);
10692
10693         entity_t *entity = NULL;
10694         symbol_t *symbol = NULL;
10695
10696         if (token.type == T_IDENTIFIER) {
10697                 symbol = token.v.symbol;
10698                 next_token();
10699
10700                 entity = get_entity(symbol, NAMESPACE_NORMAL);
10701                 if (entity != NULL && entity->kind != ENTITY_NAMESPACE
10702                                 && entity->base.parent_scope == current_scope) {
10703                         error_redefined_as_different_kind(&token.source_position,
10704                                                           entity, ENTITY_NAMESPACE);
10705                         entity = NULL;
10706                 }
10707         }
10708
10709         if (entity == NULL) {
10710                 entity                       = allocate_entity_zero(ENTITY_NAMESPACE);
10711                 entity->base.symbol          = symbol;
10712                 entity->base.source_position = token.source_position;
10713                 entity->base.namespc         = NAMESPACE_NORMAL;
10714                 entity->base.parent_scope    = current_scope;
10715         }
10716
10717         if (token.type == '=') {
10718                 /* TODO: parse namespace alias */
10719                 panic("namespace alias definition not supported yet");
10720         }
10721
10722         environment_push(entity);
10723         append_entity(current_scope, entity);
10724
10725         size_t const  top       = environment_top();
10726         scope_t      *old_scope = scope_push(&entity->namespacee.members);
10727
10728         expect('{', end_error);
10729         parse_externals();
10730         expect('}', end_error);
10731
10732 end_error:
10733         assert(current_scope == &entity->namespacee.members);
10734         scope_pop(old_scope);
10735         environment_pop_to(top);
10736 }
10737
10738 /**
10739  * Parse a statement.
10740  * There's also parse_statement() which additionally checks for
10741  * "statement has no effect" warnings
10742  */
10743 static statement_t *intern_parse_statement(void)
10744 {
10745         statement_t *statement = NULL;
10746
10747         /* declaration or statement */
10748         add_anchor_token(';');
10749         switch (token.type) {
10750         case T_IDENTIFIER: {
10751                 token_type_t la1_type = (token_type_t)look_ahead(1)->type;
10752                 if (la1_type == ':') {
10753                         statement = parse_label_statement();
10754                 } else if (is_typedef_symbol(token.v.symbol)) {
10755                         statement = parse_declaration_statement();
10756                 } else {
10757                         /* it's an identifier, the grammar says this must be an
10758                          * expression statement. However it is common that users mistype
10759                          * declaration types, so we guess a bit here to improve robustness
10760                          * for incorrect programs */
10761                         switch (la1_type) {
10762                         case '&':
10763                         case '*':
10764                                 if (get_entity(token.v.symbol, NAMESPACE_NORMAL) != NULL)
10765                                         goto expression_statment;
10766                                 /* FALLTHROUGH */
10767
10768                         DECLARATION_START
10769                         case T_IDENTIFIER:
10770                                 statement = parse_declaration_statement();
10771                                 break;
10772
10773                         default:
10774 expression_statment:
10775                                 statement = parse_expression_statement();
10776                                 break;
10777                         }
10778                 }
10779                 break;
10780         }
10781
10782         case T___extension__:
10783                 /* This can be a prefix to a declaration or an expression statement.
10784                  * We simply eat it now and parse the rest with tail recursion. */
10785                 do {
10786                         next_token();
10787                 } while (token.type == T___extension__);
10788                 bool old_gcc_extension = in_gcc_extension;
10789                 in_gcc_extension       = true;
10790                 statement = intern_parse_statement();
10791                 in_gcc_extension = old_gcc_extension;
10792                 break;
10793
10794         DECLARATION_START
10795                 statement = parse_declaration_statement();
10796                 break;
10797
10798         case T___label__:
10799                 statement = parse_local_label_declaration();
10800                 break;
10801
10802         case ';':         statement = parse_empty_statement();         break;
10803         case '{':         statement = parse_compound_statement(false); break;
10804         case T___leave:   statement = parse_leave_statement();         break;
10805         case T___try:     statement = parse_ms_try_statment();         break;
10806         case T_asm:       statement = parse_asm_statement();           break;
10807         case T_break:     statement = parse_break();                   break;
10808         case T_case:      statement = parse_case_statement();          break;
10809         case T_continue:  statement = parse_continue();                break;
10810         case T_default:   statement = parse_default_statement();       break;
10811         case T_do:        statement = parse_do();                      break;
10812         case T_for:       statement = parse_for();                     break;
10813         case T_goto:      statement = parse_goto();                    break;
10814         case T_if:        statement = parse_if();                      break;
10815         case T_return:    statement = parse_return();                  break;
10816         case T_switch:    statement = parse_switch();                  break;
10817         case T_while:     statement = parse_while();                   break;
10818
10819         EXPRESSION_START
10820                 statement = parse_expression_statement();
10821                 break;
10822
10823         default:
10824                 errorf(HERE, "unexpected token %K while parsing statement", &token);
10825                 statement = create_invalid_statement();
10826                 if (!at_anchor())
10827                         next_token();
10828                 break;
10829         }
10830         rem_anchor_token(';');
10831
10832         assert(statement != NULL
10833                         && statement->base.source_position.input_name != NULL);
10834
10835         return statement;
10836 }
10837
10838 /**
10839  * parse a statement and emits "statement has no effect" warning if needed
10840  * (This is really a wrapper around intern_parse_statement with check for 1
10841  *  single warning. It is needed, because for statement expressions we have
10842  *  to avoid the warning on the last statement)
10843  */
10844 static statement_t *parse_statement(void)
10845 {
10846         statement_t *statement = intern_parse_statement();
10847
10848         if (statement->kind == STATEMENT_EXPRESSION && warning.unused_value) {
10849                 expression_t *expression = statement->expression.expression;
10850                 if (!expression_has_effect(expression)) {
10851                         warningf(&expression->base.source_position,
10852                                         "statement has no effect");
10853                 }
10854         }
10855
10856         return statement;
10857 }
10858
10859 /**
10860  * Parse a compound statement.
10861  */
10862 static statement_t *parse_compound_statement(bool inside_expression_statement)
10863 {
10864         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
10865
10866         PUSH_PARENT(statement);
10867
10868         eat('{');
10869         add_anchor_token('}');
10870         /* tokens, which can start a statement */
10871         /* TODO MS, __builtin_FOO */
10872         add_anchor_token('!');
10873         add_anchor_token('&');
10874         add_anchor_token('(');
10875         add_anchor_token('*');
10876         add_anchor_token('+');
10877         add_anchor_token('-');
10878         add_anchor_token('{');
10879         add_anchor_token('~');
10880         add_anchor_token(T_CHARACTER_CONSTANT);
10881         add_anchor_token(T_COLONCOLON);
10882         add_anchor_token(T_FLOATINGPOINT);
10883         add_anchor_token(T_IDENTIFIER);
10884         add_anchor_token(T_INTEGER);
10885         add_anchor_token(T_MINUSMINUS);
10886         add_anchor_token(T_PLUSPLUS);
10887         add_anchor_token(T_STRING_LITERAL);
10888         add_anchor_token(T_WIDE_CHARACTER_CONSTANT);
10889         add_anchor_token(T_WIDE_STRING_LITERAL);
10890         add_anchor_token(T__Bool);
10891         add_anchor_token(T__Complex);
10892         add_anchor_token(T__Imaginary);
10893         add_anchor_token(T___FUNCTION__);
10894         add_anchor_token(T___PRETTY_FUNCTION__);
10895         add_anchor_token(T___alignof__);
10896         add_anchor_token(T___attribute__);
10897         add_anchor_token(T___builtin_va_start);
10898         add_anchor_token(T___extension__);
10899         add_anchor_token(T___func__);
10900         add_anchor_token(T___imag__);
10901         add_anchor_token(T___label__);
10902         add_anchor_token(T___real__);
10903         add_anchor_token(T___thread);
10904         add_anchor_token(T_asm);
10905         add_anchor_token(T_auto);
10906         add_anchor_token(T_bool);
10907         add_anchor_token(T_break);
10908         add_anchor_token(T_case);
10909         add_anchor_token(T_char);
10910         add_anchor_token(T_class);
10911         add_anchor_token(T_const);
10912         add_anchor_token(T_const_cast);
10913         add_anchor_token(T_continue);
10914         add_anchor_token(T_default);
10915         add_anchor_token(T_delete);
10916         add_anchor_token(T_double);
10917         add_anchor_token(T_do);
10918         add_anchor_token(T_dynamic_cast);
10919         add_anchor_token(T_enum);
10920         add_anchor_token(T_extern);
10921         add_anchor_token(T_false);
10922         add_anchor_token(T_float);
10923         add_anchor_token(T_for);
10924         add_anchor_token(T_goto);
10925         add_anchor_token(T_if);
10926         add_anchor_token(T_inline);
10927         add_anchor_token(T_int);
10928         add_anchor_token(T_long);
10929         add_anchor_token(T_new);
10930         add_anchor_token(T_operator);
10931         add_anchor_token(T_register);
10932         add_anchor_token(T_reinterpret_cast);
10933         add_anchor_token(T_restrict);
10934         add_anchor_token(T_return);
10935         add_anchor_token(T_short);
10936         add_anchor_token(T_signed);
10937         add_anchor_token(T_sizeof);
10938         add_anchor_token(T_static);
10939         add_anchor_token(T_static_cast);
10940         add_anchor_token(T_struct);
10941         add_anchor_token(T_switch);
10942         add_anchor_token(T_template);
10943         add_anchor_token(T_this);
10944         add_anchor_token(T_throw);
10945         add_anchor_token(T_true);
10946         add_anchor_token(T_try);
10947         add_anchor_token(T_typedef);
10948         add_anchor_token(T_typeid);
10949         add_anchor_token(T_typename);
10950         add_anchor_token(T_typeof);
10951         add_anchor_token(T_union);
10952         add_anchor_token(T_unsigned);
10953         add_anchor_token(T_using);
10954         add_anchor_token(T_void);
10955         add_anchor_token(T_volatile);
10956         add_anchor_token(T_wchar_t);
10957         add_anchor_token(T_while);
10958
10959         size_t const  top       = environment_top();
10960         scope_t      *old_scope = scope_push(&statement->compound.scope);
10961
10962         statement_t **anchor            = &statement->compound.statements;
10963         bool          only_decls_so_far = true;
10964         while (token.type != '}') {
10965                 if (token.type == T_EOF) {
10966                         errorf(&statement->base.source_position,
10967                                "EOF while parsing compound statement");
10968                         break;
10969                 }
10970                 statement_t *sub_statement = intern_parse_statement();
10971                 if (is_invalid_statement(sub_statement)) {
10972                         /* an error occurred. if we are at an anchor, return */
10973                         if (at_anchor())
10974                                 goto end_error;
10975                         continue;
10976                 }
10977
10978                 if (warning.declaration_after_statement) {
10979                         if (sub_statement->kind != STATEMENT_DECLARATION) {
10980                                 only_decls_so_far = false;
10981                         } else if (!only_decls_so_far) {
10982                                 warningf(&sub_statement->base.source_position,
10983                                          "ISO C90 forbids mixed declarations and code");
10984                         }
10985                 }
10986
10987                 *anchor = sub_statement;
10988
10989                 while (sub_statement->base.next != NULL)
10990                         sub_statement = sub_statement->base.next;
10991
10992                 anchor = &sub_statement->base.next;
10993         }
10994         next_token();
10995
10996         /* look over all statements again to produce no effect warnings */
10997         if (warning.unused_value) {
10998                 statement_t *sub_statement = statement->compound.statements;
10999                 for (; sub_statement != NULL; sub_statement = sub_statement->base.next) {
11000                         if (sub_statement->kind != STATEMENT_EXPRESSION)
11001                                 continue;
11002                         /* don't emit a warning for the last expression in an expression
11003                          * statement as it has always an effect */
11004                         if (inside_expression_statement && sub_statement->base.next == NULL)
11005                                 continue;
11006
11007                         expression_t *expression = sub_statement->expression.expression;
11008                         if (!expression_has_effect(expression)) {
11009                                 warningf(&expression->base.source_position,
11010                                          "statement has no effect");
11011                         }
11012                 }
11013         }
11014
11015 end_error:
11016         rem_anchor_token(T_while);
11017         rem_anchor_token(T_wchar_t);
11018         rem_anchor_token(T_volatile);
11019         rem_anchor_token(T_void);
11020         rem_anchor_token(T_using);
11021         rem_anchor_token(T_unsigned);
11022         rem_anchor_token(T_union);
11023         rem_anchor_token(T_typeof);
11024         rem_anchor_token(T_typename);
11025         rem_anchor_token(T_typeid);
11026         rem_anchor_token(T_typedef);
11027         rem_anchor_token(T_try);
11028         rem_anchor_token(T_true);
11029         rem_anchor_token(T_throw);
11030         rem_anchor_token(T_this);
11031         rem_anchor_token(T_template);
11032         rem_anchor_token(T_switch);
11033         rem_anchor_token(T_struct);
11034         rem_anchor_token(T_static_cast);
11035         rem_anchor_token(T_static);
11036         rem_anchor_token(T_sizeof);
11037         rem_anchor_token(T_signed);
11038         rem_anchor_token(T_short);
11039         rem_anchor_token(T_return);
11040         rem_anchor_token(T_restrict);
11041         rem_anchor_token(T_reinterpret_cast);
11042         rem_anchor_token(T_register);
11043         rem_anchor_token(T_operator);
11044         rem_anchor_token(T_new);
11045         rem_anchor_token(T_long);
11046         rem_anchor_token(T_int);
11047         rem_anchor_token(T_inline);
11048         rem_anchor_token(T_if);
11049         rem_anchor_token(T_goto);
11050         rem_anchor_token(T_for);
11051         rem_anchor_token(T_float);
11052         rem_anchor_token(T_false);
11053         rem_anchor_token(T_extern);
11054         rem_anchor_token(T_enum);
11055         rem_anchor_token(T_dynamic_cast);
11056         rem_anchor_token(T_do);
11057         rem_anchor_token(T_double);
11058         rem_anchor_token(T_delete);
11059         rem_anchor_token(T_default);
11060         rem_anchor_token(T_continue);
11061         rem_anchor_token(T_const_cast);
11062         rem_anchor_token(T_const);
11063         rem_anchor_token(T_class);
11064         rem_anchor_token(T_char);
11065         rem_anchor_token(T_case);
11066         rem_anchor_token(T_break);
11067         rem_anchor_token(T_bool);
11068         rem_anchor_token(T_auto);
11069         rem_anchor_token(T_asm);
11070         rem_anchor_token(T___thread);
11071         rem_anchor_token(T___real__);
11072         rem_anchor_token(T___label__);
11073         rem_anchor_token(T___imag__);
11074         rem_anchor_token(T___func__);
11075         rem_anchor_token(T___extension__);
11076         rem_anchor_token(T___builtin_va_start);
11077         rem_anchor_token(T___attribute__);
11078         rem_anchor_token(T___alignof__);
11079         rem_anchor_token(T___PRETTY_FUNCTION__);
11080         rem_anchor_token(T___FUNCTION__);
11081         rem_anchor_token(T__Imaginary);
11082         rem_anchor_token(T__Complex);
11083         rem_anchor_token(T__Bool);
11084         rem_anchor_token(T_WIDE_STRING_LITERAL);
11085         rem_anchor_token(T_WIDE_CHARACTER_CONSTANT);
11086         rem_anchor_token(T_STRING_LITERAL);
11087         rem_anchor_token(T_PLUSPLUS);
11088         rem_anchor_token(T_MINUSMINUS);
11089         rem_anchor_token(T_INTEGER);
11090         rem_anchor_token(T_IDENTIFIER);
11091         rem_anchor_token(T_FLOATINGPOINT);
11092         rem_anchor_token(T_COLONCOLON);
11093         rem_anchor_token(T_CHARACTER_CONSTANT);
11094         rem_anchor_token('~');
11095         rem_anchor_token('{');
11096         rem_anchor_token('-');
11097         rem_anchor_token('+');
11098         rem_anchor_token('*');
11099         rem_anchor_token('(');
11100         rem_anchor_token('&');
11101         rem_anchor_token('!');
11102         rem_anchor_token('}');
11103         assert(current_scope == &statement->compound.scope);
11104         scope_pop(old_scope);
11105         environment_pop_to(top);
11106
11107         POP_PARENT;
11108         return statement;
11109 }
11110
11111 /**
11112  * Check for unused global static functions and variables
11113  */
11114 static void check_unused_globals(void)
11115 {
11116         if (!warning.unused_function && !warning.unused_variable)
11117                 return;
11118
11119         for (const entity_t *entity = file_scope->entities; entity != NULL;
11120              entity = entity->base.next) {
11121                 if (!is_declaration(entity))
11122                         continue;
11123
11124                 const declaration_t *declaration = &entity->declaration;
11125                 if (declaration->used                  ||
11126                     declaration->modifiers & DM_UNUSED ||
11127                     declaration->modifiers & DM_USED   ||
11128                     declaration->storage_class != STORAGE_CLASS_STATIC)
11129                         continue;
11130
11131                 type_t *const type = declaration->type;
11132                 const char *s;
11133                 if (entity->kind == ENTITY_FUNCTION) {
11134                         /* inhibit warning for static inline functions */
11135                         if (entity->function.is_inline)
11136                                 continue;
11137
11138                         s = entity->function.statement != NULL ? "defined" : "declared";
11139                 } else {
11140                         s = "defined";
11141                 }
11142
11143                 warningf(&declaration->base.source_position, "'%#T' %s but not used",
11144                         type, declaration->base.symbol, s);
11145         }
11146 }
11147
11148 static void parse_global_asm(void)
11149 {
11150         statement_t *statement = allocate_statement_zero(STATEMENT_ASM);
11151
11152         eat(T_asm);
11153         expect('(', end_error);
11154
11155         statement->asms.asm_text = parse_string_literals();
11156         statement->base.next     = unit->global_asm;
11157         unit->global_asm         = statement;
11158
11159         expect(')', end_error);
11160         expect(';', end_error);
11161
11162 end_error:;
11163 }
11164
11165 static void parse_linkage_specification(void)
11166 {
11167         eat(T_extern);
11168         assert(token.type == T_STRING_LITERAL);
11169
11170         const char *linkage = parse_string_literals().begin;
11171
11172         linkage_kind_t old_linkage = current_linkage;
11173         linkage_kind_t new_linkage;
11174         if (strcmp(linkage, "C") == 0) {
11175                 new_linkage = LINKAGE_C;
11176         } else if (strcmp(linkage, "C++") == 0) {
11177                 new_linkage = LINKAGE_CXX;
11178         } else {
11179                 errorf(HERE, "linkage string \"%s\" not recognized", linkage);
11180                 new_linkage = LINKAGE_INVALID;
11181         }
11182         current_linkage = new_linkage;
11183
11184         if (token.type == '{') {
11185                 next_token();
11186                 parse_externals();
11187                 expect('}', end_error);
11188         } else {
11189                 parse_external();
11190         }
11191
11192 end_error:
11193         assert(current_linkage == new_linkage);
11194         current_linkage = old_linkage;
11195 }
11196
11197 static void parse_external(void)
11198 {
11199         switch (token.type) {
11200                 DECLARATION_START_NO_EXTERN
11201                 case T_IDENTIFIER:
11202                 case T___extension__:
11203                 /* tokens below are for implicit int */
11204                 case '&': /* & x; -> int& x; (and error later, because C++ has no
11205                              implicit int) */
11206                 case '*': /* * x; -> int* x; */
11207                 case '(': /* (x); -> int (x); */
11208                         parse_external_declaration();
11209                         return;
11210
11211                 case T_extern:
11212                         if (look_ahead(1)->type == T_STRING_LITERAL) {
11213                                 parse_linkage_specification();
11214                         } else {
11215                                 parse_external_declaration();
11216                         }
11217                         return;
11218
11219                 case T_asm:
11220                         parse_global_asm();
11221                         return;
11222
11223                 case T_namespace:
11224                         parse_namespace_definition();
11225                         return;
11226
11227                 case ';':
11228                         if (!strict_mode) {
11229                                 if (warning.other)
11230                                         warningf(HERE, "stray ';' outside of function");
11231                                 next_token();
11232                                 return;
11233                         }
11234                         /* FALLTHROUGH */
11235
11236                 default:
11237                         errorf(HERE, "stray %K outside of function", &token);
11238                         if (token.type == '(' || token.type == '{' || token.type == '[')
11239                                 eat_until_matching_token(token.type);
11240                         next_token();
11241                         return;
11242         }
11243 }
11244
11245 static void parse_externals(void)
11246 {
11247         add_anchor_token('}');
11248         add_anchor_token(T_EOF);
11249
11250 #ifndef NDEBUG
11251         unsigned char token_anchor_copy[T_LAST_TOKEN];
11252         memcpy(token_anchor_copy, token_anchor_set, sizeof(token_anchor_copy));
11253 #endif
11254
11255         while (token.type != T_EOF && token.type != '}') {
11256 #ifndef NDEBUG
11257                 bool anchor_leak = false;
11258                 for (int i = 0; i != T_LAST_TOKEN; ++i) {
11259                         unsigned char count = token_anchor_set[i] - token_anchor_copy[i];
11260                         if (count != 0) {
11261                                 errorf(HERE, "Leaked anchor token %k %d times", i, count);
11262                                 anchor_leak = true;
11263                         }
11264                 }
11265                 if (in_gcc_extension) {
11266                         errorf(HERE, "Leaked __extension__");
11267                         anchor_leak = true;
11268                 }
11269
11270                 if (anchor_leak)
11271                         abort();
11272 #endif
11273
11274                 parse_external();
11275         }
11276
11277         rem_anchor_token(T_EOF);
11278         rem_anchor_token('}');
11279 }
11280
11281 /**
11282  * Parse a translation unit.
11283  */
11284 static void parse_translation_unit(void)
11285 {
11286         add_anchor_token(T_EOF);
11287
11288         while (true) {
11289                 parse_externals();
11290
11291                 if (token.type == T_EOF)
11292                         break;
11293
11294                 errorf(HERE, "stray %K outside of function", &token);
11295                 if (token.type == '(' || token.type == '{' || token.type == '[')
11296                         eat_until_matching_token(token.type);
11297                 next_token();
11298         }
11299 }
11300
11301 /**
11302  * Parse the input.
11303  *
11304  * @return  the translation unit or NULL if errors occurred.
11305  */
11306 void start_parsing(void)
11307 {
11308         environment_stack = NEW_ARR_F(stack_entry_t, 0);
11309         label_stack       = NEW_ARR_F(stack_entry_t, 0);
11310         diagnostic_count  = 0;
11311         error_count       = 0;
11312         warning_count     = 0;
11313
11314         type_set_output(stderr);
11315         ast_set_output(stderr);
11316
11317         assert(unit == NULL);
11318         unit = allocate_ast_zero(sizeof(unit[0]));
11319
11320         assert(file_scope == NULL);
11321         file_scope = &unit->scope;
11322
11323         assert(current_scope == NULL);
11324         scope_push(&unit->scope);
11325 }
11326
11327 translation_unit_t *finish_parsing(void)
11328 {
11329         assert(current_scope == &unit->scope);
11330         scope_pop(NULL);
11331
11332         assert(file_scope == &unit->scope);
11333         check_unused_globals();
11334         file_scope = NULL;
11335
11336         DEL_ARR_F(environment_stack);
11337         DEL_ARR_F(label_stack);
11338
11339         translation_unit_t *result = unit;
11340         unit = NULL;
11341         return result;
11342 }
11343
11344 /* GCC allows global arrays without size and assigns them a length of one,
11345  * if no different declaration follows */
11346 static void complete_incomplete_arrays(void)
11347 {
11348         size_t n = ARR_LEN(incomplete_arrays);
11349         for (size_t i = 0; i != n; ++i) {
11350                 declaration_t *const decl      = incomplete_arrays[i];
11351                 type_t        *const orig_type = decl->type;
11352                 type_t        *const type      = skip_typeref(orig_type);
11353
11354                 if (!is_type_incomplete(type))
11355                         continue;
11356
11357                 if (warning.other) {
11358                         warningf(&decl->base.source_position,
11359                                         "array '%#T' assumed to have one element",
11360                                         orig_type, decl->base.symbol);
11361                 }
11362
11363                 type_t *const new_type = duplicate_type(type);
11364                 new_type->array.size_constant     = true;
11365                 new_type->array.has_implicit_size = true;
11366                 new_type->array.size              = 1;
11367
11368                 type_t *const result = typehash_insert(new_type);
11369                 if (type != result)
11370                         free_type(type);
11371
11372                 decl->type = result;
11373         }
11374 }
11375
11376 void parse(void)
11377 {
11378         lookahead_bufpos = 0;
11379         for (int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
11380                 next_token();
11381         }
11382         current_linkage   = c_mode & _CXX ? LINKAGE_CXX : LINKAGE_C;
11383         incomplete_arrays = NEW_ARR_F(declaration_t*, 0);
11384         parse_translation_unit();
11385         complete_incomplete_arrays();
11386         DEL_ARR_F(incomplete_arrays);
11387         incomplete_arrays = NULL;
11388 }
11389
11390 /**
11391  * Initialize the parser.
11392  */
11393 void init_parser(void)
11394 {
11395         sym_anonymous = symbol_table_insert("<anonymous>");
11396
11397         if (c_mode & _MS) {
11398                 /* add predefined symbols for extended-decl-modifier */
11399                 sym_align         = symbol_table_insert("align");
11400                 sym_allocate      = symbol_table_insert("allocate");
11401                 sym_dllimport     = symbol_table_insert("dllimport");
11402                 sym_dllexport     = symbol_table_insert("dllexport");
11403                 sym_naked         = symbol_table_insert("naked");
11404                 sym_noinline      = symbol_table_insert("noinline");
11405                 sym_returns_twice = symbol_table_insert("returns_twice");
11406                 sym_noreturn      = symbol_table_insert("noreturn");
11407                 sym_nothrow       = symbol_table_insert("nothrow");
11408                 sym_novtable      = symbol_table_insert("novtable");
11409                 sym_property      = symbol_table_insert("property");
11410                 sym_get           = symbol_table_insert("get");
11411                 sym_put           = symbol_table_insert("put");
11412                 sym_selectany     = symbol_table_insert("selectany");
11413                 sym_thread        = symbol_table_insert("thread");
11414                 sym_uuid          = symbol_table_insert("uuid");
11415                 sym_deprecated    = symbol_table_insert("deprecated");
11416                 sym_restrict      = symbol_table_insert("restrict");
11417                 sym_noalias       = symbol_table_insert("noalias");
11418         }
11419         memset(token_anchor_set, 0, sizeof(token_anchor_set));
11420
11421         init_expression_parsers();
11422         obstack_init(&temp_obst);
11423
11424         symbol_t *const va_list_sym = symbol_table_insert("__builtin_va_list");
11425         type_valist = create_builtin_type(va_list_sym, type_void_ptr);
11426 }
11427
11428 /**
11429  * Terminate the parser.
11430  */
11431 void exit_parser(void)
11432 {
11433         obstack_free(&temp_obst, NULL);
11434 }