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 1
  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                 has_arguments; /**< True, if this attribute has arguments. */
  65         union {
  66                 size_t              value;
  67                 string_t            string;
  68                 symbol_t           *symbol;
  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 size_t               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 < lengthof(sizes));
 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_IF]          = sizeof(if_statement_t),
 385                 [STATEMENT_SWITCH]      = sizeof(switch_statement_t),
 386                 [STATEMENT_EXPRESSION]  = sizeof(expression_statement_t),
 387                 [STATEMENT_CONTINUE]    = sizeof(statement_base_t),
 388                 [STATEMENT_BREAK]       = sizeof(statement_base_t),
 389                 [STATEMENT_GOTO]        = sizeof(goto_statement_t),
 390                 [STATEMENT_LABEL]       = sizeof(label_statement_t),
 391                 [STATEMENT_CASE_LABEL]  = sizeof(case_label_statement_t),
 392                 [STATEMENT_WHILE]       = sizeof(while_statement_t),
 393                 [STATEMENT_DO_WHILE]    = sizeof(do_while_statement_t),
 394                 [STATEMENT_FOR]         = sizeof(for_statement_t),
 395                 [STATEMENT_ASM]         = sizeof(asm_statement_t),
 396                 [STATEMENT_MS_TRY]      = sizeof(ms_try_statement_t),
 397                 [STATEMENT_LEAVE]       = sizeof(leave_statement_t)
 398         };
 399         assert(kind < lengthof(sizes));
 400         assert(sizes[kind] != 0);
 401         return sizes[kind];
 402 }
 403
 404 /**
 405  * Returns the size of an expression node.
 406  *
 407  * @param kind  the expression kind
 408  */
 409 static size_t get_expression_struct_size(expression_kind_t kind)
 410 {
 411         static const size_t sizes[] = {
 412                 [EXPR_INVALID]                    = sizeof(expression_base_t),
 413                 [EXPR_REFERENCE]                  = sizeof(reference_expression_t),
 414                 [EXPR_REFERENCE_ENUM_VALUE]       = sizeof(reference_expression_t),
 415                 [EXPR_CONST]                      = sizeof(const_expression_t),
 416                 [EXPR_CHARACTER_CONSTANT]         = sizeof(const_expression_t),
 417                 [EXPR_WIDE_CHARACTER_CONSTANT]    = sizeof(const_expression_t),
 418                 [EXPR_STRING_LITERAL]             = sizeof(string_literal_expression_t),
 419                 [EXPR_WIDE_STRING_LITERAL]        = sizeof(wide_string_literal_expression_t),
 420                 [EXPR_COMPOUND_LITERAL]           = sizeof(compound_literal_expression_t),
 421                 [EXPR_CALL]                       = sizeof(call_expression_t),
 422                 [EXPR_UNARY_FIRST]                = sizeof(unary_expression_t),
 423                 [EXPR_BINARY_FIRST]               = sizeof(binary_expression_t),
 424                 [EXPR_CONDITIONAL]                = sizeof(conditional_expression_t),
 425                 [EXPR_SELECT]                     = sizeof(select_expression_t),
 426                 [EXPR_ARRAY_ACCESS]               = sizeof(array_access_expression_t),
 427                 [EXPR_SIZEOF]                     = sizeof(typeprop_expression_t),
 428                 [EXPR_ALIGNOF]                    = sizeof(typeprop_expression_t),
 429                 [EXPR_CLASSIFY_TYPE]              = sizeof(classify_type_expression_t),
 430                 [EXPR_FUNCNAME]                   = sizeof(funcname_expression_t),
 431                 [EXPR_BUILTIN_SYMBOL]             = sizeof(builtin_symbol_expression_t),
 432                 [EXPR_BUILTIN_CONSTANT_P]         = sizeof(builtin_constant_expression_t),
 433                 [EXPR_BUILTIN_TYPES_COMPATIBLE_P] = sizeof(builtin_types_compatible_expression_t),
 434                 [EXPR_OFFSETOF]                   = sizeof(offsetof_expression_t),
 435                 [EXPR_VA_START]                   = sizeof(va_start_expression_t),
 436                 [EXPR_VA_ARG]                     = sizeof(va_arg_expression_t),
 437                 [EXPR_STATEMENT]                  = sizeof(statement_expression_t),
 438                 [EXPR_LABEL_ADDRESS]              = sizeof(label_address_expression_t),
 439         };
 440         if (kind >= EXPR_UNARY_FIRST && kind <= EXPR_UNARY_LAST) {
 441                 return sizes[EXPR_UNARY_FIRST];
 442         }
 443         if (kind >= EXPR_BINARY_FIRST && kind <= EXPR_BINARY_LAST) {
 444                 return sizes[EXPR_BINARY_FIRST];
 445         }
 446         assert(kind < lengthof(sizes));
 447         assert(sizes[kind] != 0);
 448         return sizes[kind];
 449 }
 450
 451 /**
 452  * Allocate a statement node of given kind and initialize all
 453  * fields with zero. Sets its source position to the position
 454  * of the current token.
 455  */
 456 static statement_t *allocate_statement_zero(statement_kind_t kind)
 457 {
 458         size_t       size = get_statement_struct_size(kind);
 459         statement_t *res  = allocate_ast_zero(size);
 460
 461         res->base.kind            = kind;
 462         res->base.parent          = current_parent;
 463         res->base.source_position = token.source_position;
 464         return res;
 465 }
 466
 467 /**
 468  * Allocate an expression node of given kind and initialize all
 469  * fields with zero.
 470  */
 471 static expression_t *allocate_expression_zero(expression_kind_t kind)
 472 {
 473         size_t        size = get_expression_struct_size(kind);
 474         expression_t *res  = allocate_ast_zero(size);
 475
 476         res->base.kind            = kind;
 477         res->base.type            = type_error_type;
 478         res->base.source_position = token.source_position;
 479         return res;
 480 }
 481
 482 /**
 483  * Creates a new invalid expression at the source position
 484  * of the current token.
 485  */
 486 static expression_t *create_invalid_expression(void)
 487 {
 488         return allocate_expression_zero(EXPR_INVALID);
 489 }
 490
 491 /**
 492  * Creates a new invalid statement.
 493  */
 494 static statement_t *create_invalid_statement(void)
 495 {
 496         return allocate_statement_zero(STATEMENT_INVALID);
 497 }
 498
 499 /**
 500  * Allocate a new empty statement.
 501  */
 502 static statement_t *create_empty_statement(void)
 503 {
 504         return allocate_statement_zero(STATEMENT_EMPTY);
 505 }
 506
 507 /**
 508  * Returns the size of a type node.
 509  *
 510  * @param kind  the type kind
 511  */
 512 static size_t get_type_struct_size(type_kind_t kind)
 513 {
 514         static const size_t sizes[] = {
 515                 [TYPE_ATOMIC]          = sizeof(atomic_type_t),
 516                 [TYPE_COMPLEX]         = sizeof(complex_type_t),
 517                 [TYPE_IMAGINARY]       = sizeof(imaginary_type_t),
 518                 [TYPE_BITFIELD]        = sizeof(bitfield_type_t),
 519                 [TYPE_COMPOUND_STRUCT] = sizeof(compound_type_t),
 520                 [TYPE_COMPOUND_UNION]  = sizeof(compound_type_t),
 521                 [TYPE_ENUM]            = sizeof(enum_type_t),
 522                 [TYPE_FUNCTION]        = sizeof(function_type_t),
 523                 [TYPE_POINTER]         = sizeof(pointer_type_t),
 524                 [TYPE_ARRAY]           = sizeof(array_type_t),
 525                 [TYPE_BUILTIN]         = sizeof(builtin_type_t),
 526                 [TYPE_TYPEDEF]         = sizeof(typedef_type_t),
 527                 [TYPE_TYPEOF]          = sizeof(typeof_type_t),
 528         };
 529         assert(lengthof(sizes) == (int)TYPE_TYPEOF + 1);
 530         assert(kind <= TYPE_TYPEOF);
 531         assert(sizes[kind] != 0);
 532         return sizes[kind];
 533 }
 534
 535 /**
 536  * Allocate a type node of given kind and initialize all
 537  * fields with zero.
 538  *
 539  * @param kind             type kind to allocate
 540  */
 541 static type_t *allocate_type_zero(type_kind_t kind)
 542 {
 543         size_t  size = get_type_struct_size(kind);
 544         type_t *res  = obstack_alloc(type_obst, size);
 545         memset(res, 0, size);
 546         res->base.kind = kind;
 547
 548         return res;
 549 }
 550
 551 /**
 552  * Returns the size of an initializer node.
 553  *
 554  * @param kind  the initializer kind
 555  */
 556 static size_t get_initializer_size(initializer_kind_t kind)
 557 {
 558         static const size_t sizes[] = {
 559                 [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
 560                 [INITIALIZER_STRING]      = sizeof(initializer_string_t),
 561                 [INITIALIZER_WIDE_STRING] = sizeof(initializer_wide_string_t),
 562                 [INITIALIZER_LIST]        = sizeof(initializer_list_t),
 563                 [INITIALIZER_DESIGNATOR]  = sizeof(initializer_designator_t)
 564         };
 565         assert(kind < lengthof(sizes));
 566         assert(sizes[kind] != 0);
 567         return sizes[kind];
 568 }
 569
 570 /**
 571  * Allocate an initializer node of given kind and initialize all
 572  * fields with zero.
 573  */
 574 static initializer_t *allocate_initializer_zero(initializer_kind_t kind)
 575 {
 576         initializer_t *result = allocate_ast_zero(get_initializer_size(kind));
 577         result->kind          = kind;
 578
 579         return result;
 580 }
 581
 582 /**
 583  * Returns the index of the top element of the environment stack.
 584  */
 585 static size_t environment_top(void)
 586 {
 587         return ARR_LEN(environment_stack);
 588 }
 589
 590 /**
 591  * Returns the index of the top element of the global label stack.
 592  */
 593 static size_t label_top(void)
 594 {
 595         return ARR_LEN(label_stack);
 596 }
 597
 598 /**
 599  * Return the next token.
 600  */
 601 static inline void next_token(void)
 602 {
 603         token                              = lookahead_buffer[lookahead_bufpos];
 604         lookahead_buffer[lookahead_bufpos] = lexer_token;
 605         lexer_next_token();
 606
 607         lookahead_bufpos = (lookahead_bufpos + 1) % MAX_LOOKAHEAD;
 608
 609 #ifdef PRINT_TOKENS
 610         print_token(stderr, &token);
 611         fprintf(stderr, "\n");
 612 #endif
 613 }
 614
 615 /**
 616  * Return the next token with a given lookahead.
 617  */
 618 static inline const token_t *look_ahead(size_t num)
 619 {
 620         assert(0 < num && num <= MAX_LOOKAHEAD);
 621         size_t pos = (lookahead_bufpos + num - 1) % MAX_LOOKAHEAD;
 622         return &lookahead_buffer[pos];
 623 }
 624
 625 /**
 626  * Adds a token type to the token type anchor set (a multi-set).
 627  */
 628 static void add_anchor_token(int token_type)
 629 {
 630         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 631         ++token_anchor_set[token_type];
 632 }
 633
 634 /**
 635  * Set the number of tokens types of the given type
 636  * to zero and return the old count.
 637  */
 638 static int save_and_reset_anchor_state(int token_type)
 639 {
 640         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 641         int count = token_anchor_set[token_type];
 642         token_anchor_set[token_type] = 0;
 643         return count;
 644 }
 645
 646 /**
 647  * Restore the number of token types to the given count.
 648  */
 649 static void restore_anchor_state(int token_type, int count)
 650 {
 651         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 652         token_anchor_set[token_type] = count;
 653 }
 654
 655 /**
 656  * Remove a token type from the token type anchor set (a multi-set).
 657  */
 658 static void rem_anchor_token(int token_type)
 659 {
 660         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 661         assert(token_anchor_set[token_type] != 0);
 662         --token_anchor_set[token_type];
 663 }
 664
 665 /**
 666  * Return true if the token type of the current token is
 667  * in the anchor set.
 668  */
 669 static bool at_anchor(void)
 670 {
 671         if (token.type < 0)
 672                 return false;
 673         return token_anchor_set[token.type];
 674 }
 675
 676 /**
 677  * Eat tokens until a matching token type is found.
 678  */
 679 static void eat_until_matching_token(int type)
 680 {
 681         int end_token;
 682         switch (type) {
 683                 case '(': end_token = ')';  break;
 684                 case '{': end_token = '}';  break;
 685                 case '[': end_token = ']';  break;
 686                 default:  end_token = type; break;
 687         }
 688
 689         unsigned parenthesis_count = 0;
 690         unsigned brace_count       = 0;
 691         unsigned bracket_count     = 0;
 692         while (token.type        != end_token ||
 693                parenthesis_count != 0         ||
 694                brace_count       != 0         ||
 695                bracket_count     != 0) {
 696                 switch (token.type) {
 697                 case T_EOF: return;
 698                 case '(': ++parenthesis_count; break;
 699                 case '{': ++brace_count;       break;
 700                 case '[': ++bracket_count;     break;
 701
 702                 case ')':
 703                         if (parenthesis_count > 0)
 704                                 --parenthesis_count;
 705                         goto check_stop;
 706
 707                 case '}':
 708                         if (brace_count > 0)
 709                                 --brace_count;
 710                         goto check_stop;
 711
 712                 case ']':
 713                         if (bracket_count > 0)
 714                                 --bracket_count;
 715 check_stop:
 716                         if (token.type        == end_token &&
 717                             parenthesis_count == 0         &&
 718                             brace_count       == 0         &&
 719                             bracket_count     == 0)
 720                                 return;
 721                         break;
 722
 723                 default:
 724                         break;
 725                 }
 726                 next_token();
 727         }
 728 }
 729
 730 /**
 731  * Eat input tokens until an anchor is found.
 732  */
 733 static void eat_until_anchor(void)
 734 {
 735         while (token_anchor_set[token.type] == 0) {
 736                 if (token.type == '(' || token.type == '{' || token.type == '[')
 737                         eat_until_matching_token(token.type);
 738                 next_token();
 739         }
 740 }
 741
 742 /**
 743  * Eat a whole block from input tokens.
 744  */
 745 static void eat_block(void)
 746 {
 747         eat_until_matching_token('{');
 748         if (token.type == '}')
 749                 next_token();
 750 }
 751
 752 #define eat(token_type) (assert(token.type == (token_type)), next_token())
 753
 754 /**
 755  * Report a parse error because an expected token was not found.
 756  */
 757 static
 758 #if defined __GNUC__ && __GNUC__ >= 4
 759 __attribute__((sentinel))
 760 #endif
 761 void parse_error_expected(const char *message, ...)
 762 {
 763         if (message != NULL) {
 764                 errorf(HERE, "%s", message);
 765         }
 766         va_list ap;
 767         va_start(ap, message);
 768         errorf(HERE, "got %K, expected %#k", &token, &ap, ", ");
 769         va_end(ap);
 770 }
 771
 772 /**
 773  * Report an incompatible type.
 774  */
 775 static void type_error_incompatible(const char *msg,
 776                 const source_position_t *source_position, type_t *type1, type_t *type2)
 777 {
 778         errorf(source_position, "%s, incompatible types: '%T' - '%T'",
 779                msg, type1, type2);
 780 }
 781
 782 /**
 783  * Expect the current token is the expected token.
 784  * If not, generate an error, eat the current statement,
 785  * and goto the end_error label.
 786  */
 787 #define expect(expected, error_label)                     \
 788         do {                                                  \
 789                 if (UNLIKELY(token.type != (expected))) {         \
 790                         parse_error_expected(NULL, (expected), NULL); \
 791                         add_anchor_token(expected);                   \
 792                         eat_until_anchor();                           \
 793                         if (token.type == expected)                   \
 794                                 next_token();                             \
 795                         rem_anchor_token(expected);                   \
 796                         goto error_label;                             \
 797                 }                                                 \
 798                 next_token();                                     \
 799         } while (0)
 800
 801 /**
 802  * Push a given scope on the scope stack and make it the
 803  * current scope
 804  */
 805 static scope_t *scope_push(scope_t *new_scope)
 806 {
 807         if (current_scope != NULL) {
 808                 new_scope->depth = current_scope->depth + 1;
 809         }
 810
 811         scope_t *old_scope = current_scope;
 812         current_scope      = new_scope;
 813         return old_scope;
 814 }
 815
 816 /**
 817  * Pop the current scope from the scope stack.
 818  */
 819 static void scope_pop(scope_t *old_scope)
 820 {
 821         current_scope = old_scope;
 822 }
 823
 824 /**
 825  * Search an entity by its symbol in a given namespace.
 826  */
 827 static entity_t *get_entity(const symbol_t *const symbol,
 828                             namespace_tag_t namespc)
 829 {
 830         entity_t *entity = symbol->entity;
 831         for (; entity != NULL; entity = entity->base.symbol_next) {
 832                 if (entity->base.namespc == namespc)
 833                         return entity;
 834         }
 835
 836         return NULL;
 837 }
 838
 839 /**
 840  * pushs an entity on the environment stack and links the corresponding symbol
 841  * it.
 842  */
 843 static void stack_push(stack_entry_t **stack_ptr, entity_t *entity)
 844 {
 845         symbol_t           *symbol  = entity->base.symbol;
 846         entity_namespace_t  namespc = entity->base.namespc;
 847         assert(namespc != NAMESPACE_INVALID);
 848
 849         /* replace/add entity into entity list of the symbol */
 850         entity_t **anchor;
 851         entity_t  *iter;
 852         for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 853                 iter = *anchor;
 854                 if (iter == NULL)
 855                         break;
 856
 857                 /* replace an entry? */
 858                 if (iter->base.namespc == namespc) {
 859                         entity->base.symbol_next = iter->base.symbol_next;
 860                         break;
 861                 }
 862         }
 863         *anchor = entity;
 864
 865         /* remember old declaration */
 866         stack_entry_t entry;
 867         entry.symbol     = symbol;
 868         entry.old_entity = iter;
 869         entry.namespc    = namespc;
 870         ARR_APP1(stack_entry_t, *stack_ptr, entry);
 871 }
 872
 873 /**
 874  * Push an entity on the environment stack.
 875  */
 876 static void environment_push(entity_t *entity)
 877 {
 878         assert(entity->base.source_position.input_name != NULL);
 879         assert(entity->base.parent_scope != NULL);
 880         stack_push(&environment_stack, entity);
 881 }
 882
 883 /**
 884  * Push a declaration on the global label stack.
 885  *
 886  * @param declaration  the declaration
 887  */
 888 static void label_push(entity_t *label)
 889 {
 890         /* we abuse the parameters scope as parent for the labels */
 891         label->base.parent_scope = &current_function->parameters;
 892         stack_push(&label_stack, label);
 893 }
 894
 895 /**
 896  * pops symbols from the environment stack until @p new_top is the top element
 897  */
 898 static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
 899 {
 900         stack_entry_t *stack = *stack_ptr;
 901         size_t         top   = ARR_LEN(stack);
 902         size_t         i;
 903
 904         assert(new_top <= top);
 905         if (new_top == top)
 906                 return;
 907
 908         for (i = top; i > new_top; --i) {
 909                 stack_entry_t *entry = &stack[i - 1];
 910
 911                 entity_t           *old_entity = entry->old_entity;
 912                 symbol_t           *symbol     = entry->symbol;
 913                 entity_namespace_t  namespc    = entry->namespc;
 914
 915                 /* replace with old_entity/remove */
 916                 entity_t **anchor;
 917                 entity_t  *iter;
 918                 for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 919                         iter = *anchor;
 920                         assert(iter != NULL);
 921                         /* replace an entry? */
 922                         if (iter->base.namespc == namespc)
 923                                 break;
 924                 }
 925
 926                 /* restore definition from outer scopes (if there was one) */
 927                 if (old_entity != NULL) {
 928                         old_entity->base.symbol_next = iter->base.symbol_next;
 929                         *anchor                      = old_entity;
 930                 } else {
 931                         /* remove entry from list */
 932                         *anchor = iter->base.symbol_next;
 933                 }
 934         }
 935
 936         ARR_SHRINKLEN(*stack_ptr, (int) new_top);
 937 }
 938
 939 /**
 940  * Pop all entries from the environment stack until the new_top
 941  * is reached.
 942  *
 943  * @param new_top  the new stack top
 944  */
 945 static void environment_pop_to(size_t new_top)
 946 {
 947         stack_pop_to(&environment_stack, new_top);
 948 }
 949
 950 /**
 951  * Pop all entries from the global label stack until the new_top
 952  * is reached.
 953  *
 954  * @param new_top  the new stack top
 955  */
 956 static void label_pop_to(size_t new_top)
 957 {
 958         stack_pop_to(&label_stack, new_top);
 959 }
 960
 961 static int get_akind_rank(atomic_type_kind_t akind)
 962 {
 963         return (int) akind;
 964 }
 965
 966 /**
 967  * Return the type rank for an atomic type.
 968  */
 969 static int get_rank(const type_t *type)
 970 {
 971         assert(!is_typeref(type));
 972         if (type->kind == TYPE_ENUM)
 973                 return get_akind_rank(type->enumt.akind);
 974
 975         assert(type->kind == TYPE_ATOMIC);
 976         return get_akind_rank(type->atomic.akind);
 977 }
 978
 979 /**
 980  * Do integer promotion for a given type.
 981  *
 982  * @param type  the type to promote
 983  * @return the promoted type
 984  */
 985 static type_t *promote_integer(type_t *type)
 986 {
 987         if (type->kind == TYPE_BITFIELD)
 988                 type = type->bitfield.base_type;
 989
 990         if (get_rank(type) < get_akind_rank(ATOMIC_TYPE_INT))
 991                 type = type_int;
 992
 993         return type;
 994 }
 995
 996 /**
 997  * Create a cast expression.
 998  *
 999  * @param expression  the expression to cast
1000  * @param dest_type   the destination type
1001  */
1002 static expression_t *create_cast_expression(expression_t *expression,
1003                                             type_t *dest_type)
1004 {
1005         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST_IMPLICIT);
1006
1007         cast->unary.value = expression;
1008         cast->base.type   = dest_type;
1009
1010         return cast;
1011 }
1012
1013 /**
1014  * Check if a given expression represents a null pointer constant.
1015  *
1016  * @param expression  the expression to check
1017  */
1018 static bool is_null_pointer_constant(const expression_t *expression)
1019 {
1020         /* skip void* cast */
1021         if (expression->kind == EXPR_UNARY_CAST ||
1022                         expression->kind == EXPR_UNARY_CAST_IMPLICIT) {
1023                 type_t *const type = skip_typeref(expression->base.type);
1024                 if (types_compatible(type, type_void_ptr))
1025                         expression = expression->unary.value;
1026         }
1027
1028         type_t *const type = skip_typeref(expression->base.type);
1029         return
1030                 is_type_integer(type)              &&
1031                 is_constant_expression(expression) &&
1032                 fold_constant(expression) == 0;
1033 }
1034
1035 /**
1036  * Create an implicit cast expression.
1037  *
1038  * @param expression  the expression to cast
1039  * @param dest_type   the destination type
1040  */
1041 static expression_t *create_implicit_cast(expression_t *expression,
1042                                           type_t *dest_type)
1043 {
1044         type_t *const source_type = expression->base.type;
1045
1046         if (source_type == dest_type)
1047                 return expression;
1048
1049         return create_cast_expression(expression, dest_type);
1050 }
1051
1052 typedef enum assign_error_t {
1053         ASSIGN_SUCCESS,
1054         ASSIGN_ERROR_INCOMPATIBLE,
1055         ASSIGN_ERROR_POINTER_QUALIFIER_MISSING,
1056         ASSIGN_WARNING_POINTER_INCOMPATIBLE,
1057         ASSIGN_WARNING_POINTER_FROM_INT,
1058         ASSIGN_WARNING_INT_FROM_POINTER
1059 } assign_error_t;
1060
1061 static void report_assign_error(assign_error_t error, type_t *orig_type_left,
1062                                 const expression_t *const right,
1063                                 const char *context,
1064                                 const source_position_t *source_position)
1065 {
1066         type_t *const orig_type_right = right->base.type;
1067         type_t *const type_left       = skip_typeref(orig_type_left);
1068         type_t *const type_right      = skip_typeref(orig_type_right);
1069
1070         switch (error) {
1071         case ASSIGN_SUCCESS:
1072                 return;
1073         case ASSIGN_ERROR_INCOMPATIBLE:
1074                 errorf(source_position,
1075                        "destination type '%T' in %s is incompatible with type '%T'",
1076                        orig_type_left, context, orig_type_right);
1077                 return;
1078
1079         case ASSIGN_ERROR_POINTER_QUALIFIER_MISSING: {
1080                 if (warning.other) {
1081                         type_t *points_to_left  = skip_typeref(type_left->pointer.points_to);
1082                         type_t *points_to_right = skip_typeref(type_right->pointer.points_to);
1083
1084                         /* the left type has all qualifiers from the right type */
1085                         unsigned missing_qualifiers
1086                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
1087                         warningf(source_position,
1088                                         "destination type '%T' in %s from type '%T' lacks qualifiers '%Q' in pointer target type",
1089                                         orig_type_left, context, orig_type_right, missing_qualifiers);
1090                 }
1091                 return;
1092         }
1093
1094         case ASSIGN_WARNING_POINTER_INCOMPATIBLE:
1095                 if (warning.other) {
1096                         warningf(source_position,
1097                                         "destination type '%T' in %s is incompatible with '%E' of type '%T'",
1098                                         orig_type_left, context, right, orig_type_right);
1099                 }
1100                 return;
1101
1102         case ASSIGN_WARNING_POINTER_FROM_INT:
1103                 if (warning.other) {
1104                         warningf(source_position,
1105                                         "%s makes pointer '%T' from integer '%T' without a cast",
1106                                         context, orig_type_left, orig_type_right);
1107                 }
1108                 return;
1109
1110         case ASSIGN_WARNING_INT_FROM_POINTER:
1111                 if (warning.other) {
1112                         warningf(source_position,
1113                                         "%s makes integer '%T' from pointer '%T' without a cast",
1114                                         context, orig_type_left, orig_type_right);
1115                 }
1116                 return;
1117
1118         default:
1119                 panic("invalid error value");
1120         }
1121 }
1122
1123 /** Implements the rules from §6.5.16.1 */
1124 static assign_error_t semantic_assign(type_t *orig_type_left,
1125                                       const expression_t *const right)
1126 {
1127         type_t *const orig_type_right = right->base.type;
1128         type_t *const type_left       = skip_typeref(orig_type_left);
1129         type_t *const type_right      = skip_typeref(orig_type_right);
1130
1131         if (is_type_pointer(type_left)) {
1132                 if (is_null_pointer_constant(right)) {
1133                         return ASSIGN_SUCCESS;
1134                 } else if (is_type_pointer(type_right)) {
1135                         type_t *points_to_left
1136                                 = skip_typeref(type_left->pointer.points_to);
1137                         type_t *points_to_right
1138                                 = skip_typeref(type_right->pointer.points_to);
1139                         assign_error_t res = ASSIGN_SUCCESS;
1140
1141                         /* the left type has all qualifiers from the right type */
1142                         unsigned missing_qualifiers
1143                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
1144                         if (missing_qualifiers != 0) {
1145                                 res = ASSIGN_ERROR_POINTER_QUALIFIER_MISSING;
1146                         }
1147
1148                         points_to_left  = get_unqualified_type(points_to_left);
1149                         points_to_right = get_unqualified_type(points_to_right);
1150
1151                         if (is_type_atomic(points_to_left, ATOMIC_TYPE_VOID))
1152                                 return res;
1153
1154                         if (is_type_atomic(points_to_right, ATOMIC_TYPE_VOID)) {
1155                                 /* ISO/IEC 14882:1998(E) §C.1.2:6 */
1156                                 return c_mode & _CXX ? ASSIGN_ERROR_INCOMPATIBLE : res;
1157                         }
1158
1159                         if (!types_compatible(points_to_left, points_to_right)) {
1160                                 return ASSIGN_WARNING_POINTER_INCOMPATIBLE;
1161                         }
1162
1163                         return res;
1164                 } else if (is_type_integer(type_right)) {
1165                         return ASSIGN_WARNING_POINTER_FROM_INT;
1166                 }
1167         } else if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
1168             (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
1169                 && is_type_pointer(type_right))) {
1170                 return ASSIGN_SUCCESS;
1171         } else if ((is_type_compound(type_left)  && is_type_compound(type_right))
1172                         || (is_type_builtin(type_left) && is_type_builtin(type_right))) {
1173                 type_t *const unqual_type_left  = get_unqualified_type(type_left);
1174                 type_t *const unqual_type_right = get_unqualified_type(type_right);
1175                 if (types_compatible(unqual_type_left, unqual_type_right)) {
1176                         return ASSIGN_SUCCESS;
1177                 }
1178         } else if (is_type_integer(type_left) && is_type_pointer(type_right)) {
1179                 return ASSIGN_WARNING_INT_FROM_POINTER;
1180         }
1181
1182         if (!is_type_valid(type_left) || !is_type_valid(type_right))
1183                 return ASSIGN_SUCCESS;
1184
1185         return ASSIGN_ERROR_INCOMPATIBLE;
1186 }
1187
1188 static expression_t *parse_constant_expression(void)
1189 {
1190         expression_t *result = parse_sub_expression(PREC_CONDITIONAL);
1191
1192         if (!is_constant_expression(result)) {
1193                 errorf(&result->base.source_position,
1194                        "expression '%E' is not constant", result);
1195         }
1196
1197         return result;
1198 }
1199
1200 static expression_t *parse_assignment_expression(void)
1201 {
1202         return parse_sub_expression(PREC_ASSIGNMENT);
1203 }
1204
1205 static string_t parse_string_literals(void)
1206 {
1207         assert(token.type == T_STRING_LITERAL);
1208         string_t result = token.v.string;
1209
1210         next_token();
1211
1212         while (token.type == T_STRING_LITERAL) {
1213                 result = concat_strings(&result, &token.v.string);
1214                 next_token();
1215         }
1216
1217         return result;
1218 }
1219
1220 static const char *const gnu_attribute_names[GNU_AK_LAST] = {
1221         [GNU_AK_CONST]                  = "const",
1222         [GNU_AK_VOLATILE]               = "volatile",
1223         [GNU_AK_CDECL]                  = "cdecl",
1224         [GNU_AK_STDCALL]                = "stdcall",
1225         [GNU_AK_FASTCALL]               = "fastcall",
1226         [GNU_AK_DEPRECATED]             = "deprecated",
1227         [GNU_AK_NOINLINE]               = "noinline",
1228         [GNU_AK_RETURNS_TWICE]          = "returns_twice",
1229         [GNU_AK_NORETURN]               = "noreturn",
1230         [GNU_AK_NAKED]                  = "naked",
1231         [GNU_AK_PURE]                   = "pure",
1232         [GNU_AK_ALWAYS_INLINE]          = "always_inline",
1233         [GNU_AK_MALLOC]                 = "malloc",
1234         [GNU_AK_WEAK]                   = "weak",
1235         [GNU_AK_CONSTRUCTOR]            = "constructor",
1236         [GNU_AK_DESTRUCTOR]             = "destructor",
1237         [GNU_AK_NOTHROW]                = "nothrow",
1238         [GNU_AK_TRANSPARENT_UNION]      = "transparent_union",
1239         [GNU_AK_COMMON]                 = "common",
1240         [GNU_AK_NOCOMMON]               = "nocommon",
1241         [GNU_AK_PACKED]                 = "packed",
1242         [GNU_AK_SHARED]                 = "shared",
1243         [GNU_AK_NOTSHARED]              = "notshared",
1244         [GNU_AK_USED]                   = "used",
1245         [GNU_AK_UNUSED]                 = "unused",
1246         [GNU_AK_NO_INSTRUMENT_FUNCTION] = "no_instrument_function",
1247         [GNU_AK_WARN_UNUSED_RESULT]     = "warn_unused_result",
1248         [GNU_AK_LONGCALL]               = "longcall",
1249         [GNU_AK_SHORTCALL]              = "shortcall",
1250         [GNU_AK_LONG_CALL]              = "long_call",
1251         [GNU_AK_SHORT_CALL]             = "short_call",
1252         [GNU_AK_FUNCTION_VECTOR]        = "function_vector",
1253         [GNU_AK_INTERRUPT]              = "interrupt",
1254         [GNU_AK_INTERRUPT_HANDLER]      = "interrupt_handler",
1255         [GNU_AK_NMI_HANDLER]            = "nmi_handler",
1256         [GNU_AK_NESTING]                = "nesting",
1257         [GNU_AK_NEAR]                   = "near",
1258         [GNU_AK_FAR]                    = "far",
1259         [GNU_AK_SIGNAL]                 = "signal",
1260         [GNU_AK_EIGTHBIT_DATA]          = "eightbit_data",
1261         [GNU_AK_TINY_DATA]              = "tiny_data",
1262         [GNU_AK_SAVEALL]                = "saveall",
1263         [GNU_AK_FLATTEN]                = "flatten",
1264         [GNU_AK_SSEREGPARM]             = "sseregparm",
1265         [GNU_AK_EXTERNALLY_VISIBLE]     = "externally_visible",
1266         [GNU_AK_RETURN_TWICE]           = "return_twice",
1267         [GNU_AK_MAY_ALIAS]              = "may_alias",
1268         [GNU_AK_MS_STRUCT]              = "ms_struct",
1269         [GNU_AK_GCC_STRUCT]             = "gcc_struct",
1270         [GNU_AK_DLLIMPORT]              = "dllimport",
1271         [GNU_AK_DLLEXPORT]              = "dllexport",
1272         [GNU_AK_ALIGNED]                = "aligned",
1273         [GNU_AK_ALIAS]                  = "alias",
1274         [GNU_AK_SECTION]                = "section",
1275         [GNU_AK_FORMAT]                 = "format",
1276         [GNU_AK_FORMAT_ARG]             = "format_arg",
1277         [GNU_AK_WEAKREF]                = "weakref",
1278         [GNU_AK_NONNULL]                = "nonnull",
1279         [GNU_AK_TLS_MODEL]              = "tls_model",
1280         [GNU_AK_VISIBILITY]             = "visibility",
1281         [GNU_AK_REGPARM]                = "regparm",
1282         [GNU_AK_MODE]                   = "mode",
1283         [GNU_AK_MODEL]                  = "model",
1284         [GNU_AK_TRAP_EXIT]              = "trap_exit",
1285         [GNU_AK_SP_SWITCH]              = "sp_switch",
1286         [GNU_AK_SENTINEL]               = "sentinel"
1287 };
1288
1289 /**
1290  * compare two string, ignoring double underscores on the second.
1291  */
1292 static int strcmp_underscore(const char *s1, const char *s2)
1293 {
1294         if (s2[0] == '_' && s2[1] == '_') {
1295                 size_t len2 = strlen(s2);
1296                 size_t len1 = strlen(s1);
1297                 if (len1 == len2-4 && s2[len2-2] == '_' && s2[len2-1] == '_') {
1298                         return strncmp(s1, s2+2, len2-4);
1299                 }
1300         }
1301
1302         return strcmp(s1, s2);
1303 }
1304
1305 /**
1306  * Allocate a new gnu temporal attribute of given kind.
1307  */
1308 static gnu_attribute_t *allocate_gnu_attribute(gnu_attribute_kind_t kind)
1309 {
1310         gnu_attribute_t *attribute = obstack_alloc(&temp_obst, sizeof(*attribute));
1311         attribute->kind            = kind;
1312         attribute->next            = NULL;
1313         attribute->invalid         = false;
1314         attribute->has_arguments   = false;
1315
1316         return attribute;
1317 }
1318
1319 /**
1320  * Parse one constant expression argument of the given attribute.
1321  */
1322 static void parse_gnu_attribute_const_arg(gnu_attribute_t *attribute)
1323 {
1324         expression_t *expression;
1325         add_anchor_token(')');
1326         expression = parse_constant_expression();
1327         rem_anchor_token(')');
1328         expect(')', end_error);
1329         attribute->u.argument = fold_constant(expression);
1330         return;
1331 end_error:
1332         attribute->invalid = true;
1333 }
1334
1335 /**
1336  * Parse a list of constant expressions arguments of the given attribute.
1337  */
1338 static void parse_gnu_attribute_const_arg_list(gnu_attribute_t *attribute)
1339 {
1340         argument_list_t **list = &attribute->u.arguments;
1341         argument_list_t  *entry;
1342         expression_t     *expression;
1343         add_anchor_token(')');
1344         add_anchor_token(',');
1345         while (true) {
1346                 expression = parse_constant_expression();
1347                 entry = obstack_alloc(&temp_obst, sizeof(entry));
1348                 entry->argument = fold_constant(expression);
1349                 entry->next     = NULL;
1350                 *list = entry;
1351                 list = &entry->next;
1352                 if (token.type != ',')
1353                         break;
1354                 next_token();
1355         }
1356         rem_anchor_token(',');
1357         rem_anchor_token(')');
1358         expect(')', end_error);
1359         return;
1360 end_error:
1361         attribute->invalid = true;
1362 }
1363
1364 /**
1365  * Parse one string literal argument of the given attribute.
1366  */
1367 static void parse_gnu_attribute_string_arg(gnu_attribute_t *attribute,
1368                                            string_t *string)
1369 {
1370         add_anchor_token('(');
1371         if (token.type != T_STRING_LITERAL) {
1372                 parse_error_expected("while parsing attribute directive",
1373                                      T_STRING_LITERAL, NULL);
1374                 goto end_error;
1375         }
1376         *string = parse_string_literals();
1377         rem_anchor_token('(');
1378         expect(')', end_error);
1379         return;
1380 end_error:
1381         attribute->invalid = true;
1382 }
1383
1384 /**
1385  * Parse one tls model of the given attribute.
1386  */
1387 static void parse_gnu_attribute_tls_model_arg(gnu_attribute_t *attribute)
1388 {
1389         static const char *const tls_models[] = {
1390                 "global-dynamic",
1391                 "local-dynamic",
1392                 "initial-exec",
1393                 "local-exec"
1394         };
1395         string_t string = { NULL, 0 };
1396         parse_gnu_attribute_string_arg(attribute, &string);
1397         if (string.begin != NULL) {
1398                 for (size_t i = 0; i < 4; ++i) {
1399                         if (strcmp(tls_models[i], string.begin) == 0) {
1400                                 attribute->u.value = i;
1401                                 return;
1402                         }
1403                 }
1404                 errorf(HERE, "'%s' is an unrecognized tls model", string.begin);
1405         }
1406         attribute->invalid = true;
1407 }
1408
1409 /**
1410  * Parse one tls model of the given attribute.
1411  */
1412 static void parse_gnu_attribute_visibility_arg(gnu_attribute_t *attribute)
1413 {
1414         static const char *const visibilities[] = {
1415                 "default",
1416                 "protected",
1417                 "hidden",
1418                 "internal"
1419         };
1420         string_t string = { NULL, 0 };
1421         parse_gnu_attribute_string_arg(attribute, &string);
1422         if (string.begin != NULL) {
1423                 for (size_t i = 0; i < 4; ++i) {
1424                         if (strcmp(visibilities[i], string.begin) == 0) {
1425                                 attribute->u.value = i;
1426                                 return;
1427                         }
1428                 }
1429                 errorf(HERE, "'%s' is an unrecognized visibility", string.begin);
1430         }
1431         attribute->invalid = true;
1432 }
1433
1434 /**
1435  * Parse one (code) model of the given attribute.
1436  */
1437 static void parse_gnu_attribute_model_arg(gnu_attribute_t *attribute)
1438 {
1439         static const char *const visibilities[] = {
1440                 "small",
1441                 "medium",
1442                 "large"
1443         };
1444         string_t string = { NULL, 0 };
1445         parse_gnu_attribute_string_arg(attribute, &string);
1446         if (string.begin != NULL) {
1447                 for (int i = 0; i < 3; ++i) {
1448                         if (strcmp(visibilities[i], string.begin) == 0) {
1449                                 attribute->u.value = i;
1450                                 return;
1451                         }
1452                 }
1453                 errorf(HERE, "'%s' is an unrecognized model", string.begin);
1454         }
1455         attribute->invalid = true;
1456 }
1457
1458 /**
1459  * Parse one mode of the given attribute.
1460  */
1461 static void parse_gnu_attribute_mode_arg(gnu_attribute_t *attribute)
1462 {
1463         add_anchor_token(')');
1464
1465         if (token.type != T_IDENTIFIER) {
1466                 expect(T_IDENTIFIER, end_error);
1467         }
1468
1469         attribute->u.symbol = token.v.symbol;
1470         next_token();
1471
1472         rem_anchor_token(')');
1473         expect(')', end_error);
1474         return;
1475 end_error:
1476         attribute->invalid = true;
1477 }
1478
1479 /**
1480  * Parse one interrupt argument of the given attribute.
1481  */
1482 static void parse_gnu_attribute_interrupt_arg(gnu_attribute_t *attribute)
1483 {
1484         static const char *const interrupts[] = {
1485                 "IRQ",
1486                 "FIQ",
1487                 "SWI",
1488                 "ABORT",
1489                 "UNDEF"
1490         };
1491         string_t string = { NULL, 0 };
1492         parse_gnu_attribute_string_arg(attribute, &string);
1493         if (string.begin != NULL) {
1494                 for (size_t i = 0; i < 5; ++i) {
1495                         if (strcmp(interrupts[i], string.begin) == 0) {
1496                                 attribute->u.value = i;
1497                                 return;
1498                         }
1499                 }
1500                 errorf(HERE, "'%s' is not an interrupt", string.begin);
1501         }
1502         attribute->invalid = true;
1503 }
1504
1505 /**
1506  * Parse ( identifier, const expression, const expression )
1507  */
1508 static void parse_gnu_attribute_format_args(gnu_attribute_t *attribute)
1509 {
1510         static const char *const format_names[] = {
1511                 "printf",
1512                 "scanf",
1513                 "strftime",
1514                 "strfmon"
1515         };
1516         int i;
1517
1518         if (token.type != T_IDENTIFIER) {
1519                 parse_error_expected("while parsing format attribute directive", T_IDENTIFIER, NULL);
1520                 goto end_error;
1521         }
1522         const char *name = token.v.symbol->string;
1523         for (i = 0; i < 4; ++i) {
1524                 if (strcmp_underscore(format_names[i], name) == 0)
1525                         break;
1526         }
1527         if (i >= 4) {
1528                 if (warning.attribute)
1529                         warningf(HERE, "'%s' is an unrecognized format function type", name);
1530         }
1531         next_token();
1532
1533         expect(',', end_error);
1534         add_anchor_token(')');
1535         add_anchor_token(',');
1536         parse_constant_expression();
1537         rem_anchor_token(',');
1538         rem_anchor_token(')');
1539
1540         expect(',', end_error);
1541         add_anchor_token(')');
1542         parse_constant_expression();
1543         rem_anchor_token(')');
1544         expect(')', end_error);
1545         return;
1546 end_error:
1547         attribute->u.value = true;
1548 }
1549
1550 /**
1551  * Check that a given GNU attribute has no arguments.
1552  */
1553 static void check_no_argument(gnu_attribute_t *attribute, const char *name)
1554 {
1555         if (!attribute->has_arguments)
1556                 return;
1557
1558         /* should have no arguments */
1559         errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1560         eat_until_matching_token('(');
1561         /* we have already consumed '(', so we stop before ')', eat it */
1562         eat(')');
1563         attribute->invalid = true;
1564 }
1565
1566 /**
1567  * Parse one GNU attribute.
1568  *
1569  * Note that attribute names can be specified WITH or WITHOUT
1570  * double underscores, ie const or __const__.
1571  *
1572  * The following attributes are parsed without arguments
1573  *  const
1574  *  volatile
1575  *  cdecl
1576  *  stdcall
1577  *  fastcall
1578  *  deprecated
1579  *  noinline
1580  *  noreturn
1581  *  naked
1582  *  pure
1583  *  always_inline
1584  *  malloc
1585  *  weak
1586  *  constructor
1587  *  destructor
1588  *  nothrow
1589  *  transparent_union
1590  *  common
1591  *  nocommon
1592  *  packed
1593  *  shared
1594  *  notshared
1595  *  used
1596  *  unused
1597  *  no_instrument_function
1598  *  warn_unused_result
1599  *  longcall
1600  *  shortcall
1601  *  long_call
1602  *  short_call
1603  *  function_vector
1604  *  interrupt_handler
1605  *  nmi_handler
1606  *  nesting
1607  *  near
1608  *  far
1609  *  signal
1610  *  eightbit_data
1611  *  tiny_data
1612  *  saveall
1613  *  flatten
1614  *  sseregparm
1615  *  externally_visible
1616  *  return_twice
1617  *  may_alias
1618  *  ms_struct
1619  *  gcc_struct
1620  *  dllimport
1621  *  dllexport
1622  *
1623  * The following attributes are parsed with arguments
1624  *  aligned( const expression )
1625  *  alias( string literal )
1626  *  section( string literal )
1627  *  format( identifier, const expression, const expression )
1628  *  format_arg( const expression )
1629  *  tls_model( string literal )
1630  *  visibility( string literal )
1631  *  regparm( const expression )
1632  *  model( string leteral )
1633  *  trap_exit( const expression )
1634  *  sp_switch( string literal )
1635  *
1636  * The following attributes might have arguments
1637  *  weak_ref( string literal )
1638  *  non_null( const expression // ',' )
1639  *  interrupt( string literal )
1640  *  sentinel( constant expression )
1641  */
1642 static decl_modifiers_t parse_gnu_attribute(gnu_attribute_t **attributes)
1643 {
1644         gnu_attribute_t *head      = *attributes;
1645         gnu_attribute_t *last      = *attributes;
1646         decl_modifiers_t modifiers = 0;
1647         gnu_attribute_t *attribute;
1648
1649         eat(T___attribute__);
1650         expect('(', end_error);
1651         expect('(', end_error);
1652
1653         if (token.type != ')') {
1654                 /* find the end of the list */
1655                 if (last != NULL) {
1656                         while (last->next != NULL)
1657                                 last = last->next;
1658                 }
1659
1660                 /* non-empty attribute list */
1661                 while (true) {
1662                         const char *name;
1663                         if (token.type == T_const) {
1664                                 name = "const";
1665                         } else if (token.type == T_volatile) {
1666                                 name = "volatile";
1667                         } else if (token.type == T_cdecl) {
1668                                 /* __attribute__((cdecl)), WITH ms mode */
1669                                 name = "cdecl";
1670                         } else if (token.type == T_IDENTIFIER) {
1671                                 const symbol_t *sym = token.v.symbol;
1672                                 name = sym->string;
1673                         } else {
1674                                 parse_error_expected("while parsing GNU attribute", T_IDENTIFIER, NULL);
1675                                 break;
1676                         }
1677
1678                         next_token();
1679
1680                         int i;
1681                         for (i = 0; i < GNU_AK_LAST; ++i) {
1682                                 if (strcmp_underscore(gnu_attribute_names[i], name) == 0)
1683                                         break;
1684                         }
1685                         gnu_attribute_kind_t kind = (gnu_attribute_kind_t)i;
1686
1687                         attribute = NULL;
1688                         if (kind == GNU_AK_LAST) {
1689                                 if (warning.attribute)
1690                                         warningf(HERE, "'%s' attribute directive ignored", name);
1691
1692                                 /* skip possible arguments */
1693                                 if (token.type == '(') {
1694                                         eat_until_matching_token(')');
1695                                 }
1696                         } else {
1697                                 /* check for arguments */
1698                                 attribute = allocate_gnu_attribute(kind);
1699                                 if (token.type == '(') {
1700                                         next_token();
1701                                         if (token.type == ')') {
1702                                                 /* empty args are allowed */
1703                                                 next_token();
1704                                         } else
1705                                                 attribute->has_arguments = true;
1706                                 }
1707
1708                                 switch (kind) {
1709                                 case GNU_AK_VOLATILE:
1710                                 case GNU_AK_NAKED:
1711                                 case GNU_AK_MALLOC:
1712                                 case GNU_AK_WEAK:
1713                                 case GNU_AK_COMMON:
1714                                 case GNU_AK_NOCOMMON:
1715                                 case GNU_AK_SHARED:
1716                                 case GNU_AK_NOTSHARED:
1717                                 case GNU_AK_NO_INSTRUMENT_FUNCTION:
1718                                 case GNU_AK_WARN_UNUSED_RESULT:
1719                                 case GNU_AK_LONGCALL:
1720                                 case GNU_AK_SHORTCALL:
1721                                 case GNU_AK_LONG_CALL:
1722                                 case GNU_AK_SHORT_CALL:
1723                                 case GNU_AK_FUNCTION_VECTOR:
1724                                 case GNU_AK_INTERRUPT_HANDLER:
1725                                 case GNU_AK_NMI_HANDLER:
1726                                 case GNU_AK_NESTING:
1727                                 case GNU_AK_NEAR:
1728                                 case GNU_AK_FAR:
1729                                 case GNU_AK_SIGNAL:
1730                                 case GNU_AK_EIGTHBIT_DATA:
1731                                 case GNU_AK_TINY_DATA:
1732                                 case GNU_AK_SAVEALL:
1733                                 case GNU_AK_FLATTEN:
1734                                 case GNU_AK_SSEREGPARM:
1735                                 case GNU_AK_EXTERNALLY_VISIBLE:
1736                                 case GNU_AK_RETURN_TWICE:
1737                                 case GNU_AK_MAY_ALIAS:
1738                                 case GNU_AK_MS_STRUCT:
1739                                 case GNU_AK_GCC_STRUCT:
1740                                         goto no_arg;
1741
1742                                 case GNU_AK_CDECL:             modifiers |= DM_CDECL;             goto no_arg;
1743                                 case GNU_AK_FASTCALL:          modifiers |= DM_FASTCALL;          goto no_arg;
1744                                 case GNU_AK_STDCALL:           modifiers |= DM_STDCALL;           goto no_arg;
1745                                 case GNU_AK_UNUSED:            modifiers |= DM_UNUSED;            goto no_arg;
1746                                 case GNU_AK_USED:              modifiers |= DM_USED;              goto no_arg;
1747                                 case GNU_AK_PURE:              modifiers |= DM_PURE;              goto no_arg;
1748                                 case GNU_AK_CONST:             modifiers |= DM_CONST;             goto no_arg;
1749                                 case GNU_AK_ALWAYS_INLINE:     modifiers |= DM_FORCEINLINE;       goto no_arg;
1750                                 case GNU_AK_DLLIMPORT:         modifiers |= DM_DLLIMPORT;         goto no_arg;
1751                                 case GNU_AK_DLLEXPORT:         modifiers |= DM_DLLEXPORT;         goto no_arg;
1752                                 case GNU_AK_PACKED:            modifiers |= DM_PACKED;            goto no_arg;
1753                                 case GNU_AK_NOINLINE:          modifiers |= DM_NOINLINE;          goto no_arg;
1754                                 case GNU_AK_RETURNS_TWICE:     modifiers |= DM_RETURNS_TWICE;     goto no_arg;
1755                                 case GNU_AK_NORETURN:          modifiers |= DM_NORETURN;          goto no_arg;
1756                                 case GNU_AK_NOTHROW:           modifiers |= DM_NOTHROW;           goto no_arg;
1757                                 case GNU_AK_TRANSPARENT_UNION: modifiers |= DM_TRANSPARENT_UNION; goto no_arg;
1758                                 case GNU_AK_CONSTRUCTOR:       modifiers |= DM_CONSTRUCTOR;       goto no_arg;
1759                                 case GNU_AK_DESTRUCTOR:        modifiers |= DM_DESTRUCTOR;        goto no_arg;
1760                                 case GNU_AK_DEPRECATED:        modifiers |= DM_DEPRECATED;        goto no_arg;
1761
1762                                 case GNU_AK_ALIGNED:
1763                                         /* __align__ may be used without an argument */
1764                                         if (attribute->has_arguments) {
1765                                                 parse_gnu_attribute_const_arg(attribute);
1766                                         }
1767                                         break;
1768
1769                                 case GNU_AK_FORMAT_ARG:
1770                                 case GNU_AK_REGPARM:
1771                                 case GNU_AK_TRAP_EXIT:
1772                                         if (!attribute->has_arguments) {
1773                                                 /* should have arguments */
1774                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1775                                                 attribute->invalid = true;
1776                                         } else
1777                                                 parse_gnu_attribute_const_arg(attribute);
1778                                         break;
1779                                 case GNU_AK_ALIAS:
1780                                 case GNU_AK_SECTION:
1781                                 case GNU_AK_SP_SWITCH:
1782                                         if (!attribute->has_arguments) {
1783                                                 /* should have arguments */
1784                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1785                                                 attribute->invalid = true;
1786                                         } else
1787                                                 parse_gnu_attribute_string_arg(attribute, &attribute->u.string);
1788                                         break;
1789                                 case GNU_AK_FORMAT:
1790                                         if (!attribute->has_arguments) {
1791                                                 /* should have arguments */
1792                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1793                                                 attribute->invalid = true;
1794                                         } else
1795                                                 parse_gnu_attribute_format_args(attribute);
1796                                         break;
1797                                 case GNU_AK_WEAKREF:
1798                                         /* may have one string argument */
1799                                         if (attribute->has_arguments)
1800                                                 parse_gnu_attribute_string_arg(attribute, &attribute->u.string);
1801                                         break;
1802                                 case GNU_AK_NONNULL:
1803                                         if (attribute->has_arguments)
1804                                                 parse_gnu_attribute_const_arg_list(attribute);
1805                                         break;
1806                                 case GNU_AK_TLS_MODEL:
1807                                         if (!attribute->has_arguments) {
1808                                                 /* should have arguments */
1809                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1810                                         } else
1811                                                 parse_gnu_attribute_tls_model_arg(attribute);
1812                                         break;
1813                                 case GNU_AK_VISIBILITY:
1814                                         if (!attribute->has_arguments) {
1815                                                 /* should have arguments */
1816                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1817                                         } else
1818                                                 parse_gnu_attribute_visibility_arg(attribute);
1819                                         break;
1820                                 case GNU_AK_MODEL:
1821                                         if (!attribute->has_arguments) {
1822                                                 /* should have arguments */
1823                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1824                                         } else {
1825                                                 parse_gnu_attribute_model_arg(attribute);
1826                                         }
1827                                         break;
1828                                 case GNU_AK_MODE:
1829                                         if (!attribute->has_arguments) {
1830                                                 /* should have arguments */
1831                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1832                                         } else {
1833                                                 parse_gnu_attribute_mode_arg(attribute);
1834                                         }
1835                                         break;
1836                                 case GNU_AK_INTERRUPT:
1837                                         /* may have one string argument */
1838                                         if (attribute->has_arguments)
1839                                                 parse_gnu_attribute_interrupt_arg(attribute);
1840                                         break;
1841                                 case GNU_AK_SENTINEL:
1842                                         /* may have one string argument */
1843                                         if (attribute->has_arguments)
1844                                                 parse_gnu_attribute_const_arg(attribute);
1845                                         break;
1846                                 case GNU_AK_LAST:
1847                                         /* already handled */
1848                                         break;
1849
1850 no_arg:
1851                                         check_no_argument(attribute, name);
1852                                 }
1853                         }
1854                         if (attribute != NULL) {
1855                                 if (last != NULL) {
1856                                         last->next = attribute;
1857                                         last       = attribute;
1858                                 } else {
1859                                         head = last = attribute;
1860                                 }
1861                         }
1862
1863                         if (token.type != ',')
1864                                 break;
1865                         next_token();
1866                 }
1867         }
1868         expect(')', end_error);
1869         expect(')', end_error);
1870 end_error:
1871         *attributes = head;
1872
1873         return modifiers;
1874 }
1875
1876 /**
1877  * Parse GNU attributes.
1878  */
1879 static decl_modifiers_t parse_attributes(gnu_attribute_t **attributes)
1880 {
1881         decl_modifiers_t modifiers = 0;
1882
1883         while (true) {
1884                 switch (token.type) {
1885                 case T___attribute__:
1886                         modifiers |= parse_gnu_attribute(attributes);
1887                         continue;
1888
1889                 case T_asm:
1890                         next_token();
1891                         expect('(', end_error);
1892                         if (token.type != T_STRING_LITERAL) {
1893                                 parse_error_expected("while parsing assembler attribute",
1894                                                      T_STRING_LITERAL, NULL);
1895                                 eat_until_matching_token('(');
1896                                 break;
1897                         } else {
1898                                 parse_string_literals();
1899                         }
1900                         expect(')', end_error);
1901                         continue;
1902
1903                 case T_cdecl:     modifiers |= DM_CDECL;    break;
1904                 case T__fastcall: modifiers |= DM_FASTCALL; break;
1905                 case T__stdcall:  modifiers |= DM_STDCALL;  break;
1906
1907                 case T___thiscall:
1908                         /* TODO record modifier */
1909                         if (warning.other)
1910                                 warningf(HERE, "Ignoring declaration modifier %K", &token);
1911                         break;
1912
1913 end_error:
1914                 default: return modifiers;
1915                 }
1916
1917                 next_token();
1918         }
1919 }
1920
1921 static void mark_vars_read(expression_t *expr, entity_t *lhs_ent);
1922
1923 static entity_t *determine_lhs_ent(expression_t *const expr,
1924                                    entity_t *lhs_ent)
1925 {
1926         switch (expr->kind) {
1927                 case EXPR_REFERENCE: {
1928                         entity_t *const entity = expr->reference.entity;
1929                         /* we should only find variables as lvalues... */
1930                         if (entity->base.kind != ENTITY_VARIABLE
1931                                         && entity->base.kind != ENTITY_PARAMETER)
1932                                 return NULL;
1933
1934                         return entity;
1935                 }
1936
1937                 case EXPR_ARRAY_ACCESS: {
1938                         expression_t *const ref = expr->array_access.array_ref;
1939                         entity_t     *      ent = NULL;
1940                         if (is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1941                                 ent     = determine_lhs_ent(ref, lhs_ent);
1942                                 lhs_ent = ent;
1943                         } else {
1944                                 mark_vars_read(expr->select.compound, lhs_ent);
1945                         }
1946                         mark_vars_read(expr->array_access.index, lhs_ent);
1947                         return ent;
1948                 }
1949
1950                 case EXPR_SELECT: {
1951                         if (is_type_compound(skip_typeref(expr->base.type))) {
1952                                 return determine_lhs_ent(expr->select.compound, lhs_ent);
1953                         } else {
1954                                 mark_vars_read(expr->select.compound, lhs_ent);
1955                                 return NULL;
1956                         }
1957                 }
1958
1959                 case EXPR_UNARY_DEREFERENCE: {
1960                         expression_t *const val = expr->unary.value;
1961                         if (val->kind == EXPR_UNARY_TAKE_ADDRESS) {
1962                                 /* *&x is a NOP */
1963                                 return determine_lhs_ent(val->unary.value, lhs_ent);
1964                         } else {
1965                                 mark_vars_read(val, NULL);
1966                                 return NULL;
1967                         }
1968                 }
1969
1970                 default:
1971                         mark_vars_read(expr, NULL);
1972                         return NULL;
1973         }
1974 }
1975
1976 #define ENT_ANY ((entity_t*)-1)
1977
1978 /**
1979  * Mark declarations, which are read.  This is used to detect variables, which
1980  * are never read.
1981  * Example:
1982  * x = x + 1;
1983  *   x is not marked as "read", because it is only read to calculate its own new
1984  *   value.
1985  *
1986  * x += y; y += x;
1987  *   x and y are not detected as "not read", because multiple variables are
1988  *   involved.
1989  */
1990 static void mark_vars_read(expression_t *const expr, entity_t *lhs_ent)
1991 {
1992         switch (expr->kind) {
1993                 case EXPR_REFERENCE: {
1994                         entity_t *const entity = expr->reference.entity;
1995                         if (entity->kind != ENTITY_VARIABLE
1996                                         && entity->kind != ENTITY_PARAMETER)
1997                                 return;
1998
1999                         if (lhs_ent != entity && lhs_ent != ENT_ANY) {
2000                                 if (entity->kind == ENTITY_VARIABLE) {
2001                                         entity->variable.read = true;
2002                                 } else {
2003                                         entity->parameter.read = true;
2004                                 }
2005                         }
2006                         return;
2007                 }
2008
2009                 case EXPR_CALL:
2010                         // TODO respect pure/const
2011                         mark_vars_read(expr->call.function, NULL);
2012                         for (call_argument_t *arg = expr->call.arguments; arg != NULL; arg = arg->next) {
2013                                 mark_vars_read(arg->expression, NULL);
2014                         }
2015                         return;
2016
2017                 case EXPR_CONDITIONAL:
2018                         // TODO lhs_decl should depend on whether true/false have an effect
2019                         mark_vars_read(expr->conditional.condition, NULL);
2020                         if (expr->conditional.true_expression != NULL)
2021                                 mark_vars_read(expr->conditional.true_expression, lhs_ent);
2022                         mark_vars_read(expr->conditional.false_expression, lhs_ent);
2023                         return;
2024
2025                 case EXPR_SELECT:
2026                         if (lhs_ent == ENT_ANY
2027                                         && !is_type_compound(skip_typeref(expr->base.type)))
2028                                 lhs_ent = NULL;
2029                         mark_vars_read(expr->select.compound, lhs_ent);
2030                         return;
2031
2032                 case EXPR_ARRAY_ACCESS: {
2033                         expression_t *const ref = expr->array_access.array_ref;
2034                         mark_vars_read(ref, lhs_ent);
2035                         lhs_ent = determine_lhs_ent(ref, lhs_ent);
2036                         mark_vars_read(expr->array_access.index, lhs_ent);
2037                         return;
2038                 }
2039
2040                 case EXPR_VA_ARG:
2041                         mark_vars_read(expr->va_arge.ap, lhs_ent);
2042                         return;
2043
2044                 case EXPR_UNARY_CAST:
2045                         /* Special case: Use void cast to mark a variable as "read" */
2046                         if (is_type_atomic(skip_typeref(expr->base.type), ATOMIC_TYPE_VOID))
2047                                 lhs_ent = NULL;
2048                         goto unary;
2049
2050
2051                 case EXPR_UNARY_THROW:
2052                         if (expr->unary.value == NULL)
2053                                 return;
2054                         /* FALLTHROUGH */
2055                 case EXPR_UNARY_DEREFERENCE:
2056                 case EXPR_UNARY_DELETE:
2057                 case EXPR_UNARY_DELETE_ARRAY:
2058                         if (lhs_ent == ENT_ANY)
2059                                 lhs_ent = NULL;
2060                         goto unary;
2061
2062                 case EXPR_UNARY_NEGATE:
2063                 case EXPR_UNARY_PLUS:
2064                 case EXPR_UNARY_BITWISE_NEGATE:
2065                 case EXPR_UNARY_NOT:
2066                 case EXPR_UNARY_TAKE_ADDRESS:
2067                 case EXPR_UNARY_POSTFIX_INCREMENT:
2068                 case EXPR_UNARY_POSTFIX_DECREMENT:
2069                 case EXPR_UNARY_PREFIX_INCREMENT:
2070                 case EXPR_UNARY_PREFIX_DECREMENT:
2071                 case EXPR_UNARY_CAST_IMPLICIT:
2072                 case EXPR_UNARY_ASSUME:
2073 unary:
2074                         mark_vars_read(expr->unary.value, lhs_ent);
2075                         return;
2076
2077                 case EXPR_BINARY_ADD:
2078                 case EXPR_BINARY_SUB:
2079                 case EXPR_BINARY_MUL:
2080                 case EXPR_BINARY_DIV:
2081                 case EXPR_BINARY_MOD:
2082                 case EXPR_BINARY_EQUAL:
2083                 case EXPR_BINARY_NOTEQUAL:
2084                 case EXPR_BINARY_LESS:
2085                 case EXPR_BINARY_LESSEQUAL:
2086                 case EXPR_BINARY_GREATER:
2087                 case EXPR_BINARY_GREATEREQUAL:
2088                 case EXPR_BINARY_BITWISE_AND:
2089                 case EXPR_BINARY_BITWISE_OR:
2090                 case EXPR_BINARY_BITWISE_XOR:
2091                 case EXPR_BINARY_LOGICAL_AND:
2092                 case EXPR_BINARY_LOGICAL_OR:
2093                 case EXPR_BINARY_SHIFTLEFT:
2094                 case EXPR_BINARY_SHIFTRIGHT:
2095                 case EXPR_BINARY_COMMA:
2096                 case EXPR_BINARY_ISGREATER:
2097                 case EXPR_BINARY_ISGREATEREQUAL:
2098                 case EXPR_BINARY_ISLESS:
2099                 case EXPR_BINARY_ISLESSEQUAL:
2100                 case EXPR_BINARY_ISLESSGREATER:
2101                 case EXPR_BINARY_ISUNORDERED:
2102                         mark_vars_read(expr->binary.left,  lhs_ent);
2103                         mark_vars_read(expr->binary.right, lhs_ent);
2104                         return;
2105
2106                 case EXPR_BINARY_ASSIGN:
2107                 case EXPR_BINARY_MUL_ASSIGN:
2108                 case EXPR_BINARY_DIV_ASSIGN:
2109                 case EXPR_BINARY_MOD_ASSIGN:
2110                 case EXPR_BINARY_ADD_ASSIGN:
2111                 case EXPR_BINARY_SUB_ASSIGN:
2112                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:
2113                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:
2114                 case EXPR_BINARY_BITWISE_AND_ASSIGN:
2115                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:
2116                 case EXPR_BINARY_BITWISE_OR_ASSIGN: {
2117                         if (lhs_ent == ENT_ANY)
2118                                 lhs_ent = NULL;
2119                         lhs_ent = determine_lhs_ent(expr->binary.left, lhs_ent);
2120                         mark_vars_read(expr->binary.right, lhs_ent);
2121                         return;
2122                 }
2123
2124                 case EXPR_VA_START:
2125                         determine_lhs_ent(expr->va_starte.ap, lhs_ent);
2126                         return;
2127
2128                 case EXPR_UNKNOWN:
2129                 case EXPR_INVALID:
2130                 case EXPR_CONST:
2131                 case EXPR_CHARACTER_CONSTANT:
2132                 case EXPR_WIDE_CHARACTER_CONSTANT:
2133                 case EXPR_STRING_LITERAL:
2134                 case EXPR_WIDE_STRING_LITERAL:
2135                 case EXPR_COMPOUND_LITERAL: // TODO init?
2136                 case EXPR_SIZEOF:
2137                 case EXPR_CLASSIFY_TYPE:
2138                 case EXPR_ALIGNOF:
2139                 case EXPR_FUNCNAME:
2140                 case EXPR_BUILTIN_SYMBOL:
2141                 case EXPR_BUILTIN_CONSTANT_P:
2142                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
2143                 case EXPR_OFFSETOF:
2144                 case EXPR_STATEMENT: // TODO
2145                 case EXPR_LABEL_ADDRESS:
2146                 case EXPR_REFERENCE_ENUM_VALUE:
2147                         return;
2148         }
2149
2150         panic("unhandled expression");
2151 }
2152
2153 static designator_t *parse_designation(void)
2154 {
2155         designator_t *result = NULL;
2156         designator_t *last   = NULL;
2157
2158         while (true) {
2159                 designator_t *designator;
2160                 switch (token.type) {
2161                 case '[':
2162                         designator = allocate_ast_zero(sizeof(designator[0]));
2163                         designator->source_position = token.source_position;
2164                         next_token();
2165                         add_anchor_token(']');
2166                         designator->array_index = parse_constant_expression();
2167                         rem_anchor_token(']');
2168                         expect(']', end_error);
2169                         break;
2170                 case '.':
2171                         designator = allocate_ast_zero(sizeof(designator[0]));
2172                         designator->source_position = token.source_position;
2173                         next_token();
2174                         if (token.type != T_IDENTIFIER) {
2175                                 parse_error_expected("while parsing designator",
2176                                                      T_IDENTIFIER, NULL);
2177                                 return NULL;
2178                         }
2179                         designator->symbol = token.v.symbol;
2180                         next_token();
2181                         break;
2182                 default:
2183                         expect('=', end_error);
2184                         return result;
2185                 }
2186
2187                 assert(designator != NULL);
2188                 if (last != NULL) {
2189                         last->next = designator;
2190                 } else {
2191                         result = designator;
2192                 }
2193                 last = designator;
2194         }
2195 end_error:
2196         return NULL;
2197 }
2198
2199 static initializer_t *initializer_from_string(array_type_t *type,
2200                                               const string_t *const string)
2201 {
2202         /* TODO: check len vs. size of array type */
2203         (void) type;
2204
2205         initializer_t *initializer = allocate_initializer_zero(INITIALIZER_STRING);
2206         initializer->string.string = *string;
2207
2208         return initializer;
2209 }
2210
2211 static initializer_t *initializer_from_wide_string(array_type_t *const type,
2212                                                    wide_string_t *const string)
2213 {
2214         /* TODO: check len vs. size of array type */
2215         (void) type;
2216
2217         initializer_t *const initializer =
2218                 allocate_initializer_zero(INITIALIZER_WIDE_STRING);
2219         initializer->wide_string.string = *string;
2220
2221         return initializer;
2222 }
2223
2224 /**
2225  * Build an initializer from a given expression.
2226  */
2227 static initializer_t *initializer_from_expression(type_t *orig_type,
2228                                                   expression_t *expression)
2229 {
2230         /* TODO check that expression is a constant expression */
2231
2232         /* §6.7.8.14/15 char array may be initialized by string literals */
2233         type_t *type           = skip_typeref(orig_type);
2234         type_t *expr_type_orig = expression->base.type;
2235         type_t *expr_type      = skip_typeref(expr_type_orig);
2236         if (is_type_array(type) && expr_type->kind == TYPE_POINTER) {
2237                 array_type_t *const array_type   = &type->array;
2238                 type_t       *const element_type = skip_typeref(array_type->element_type);
2239
2240                 if (element_type->kind == TYPE_ATOMIC) {
2241                         atomic_type_kind_t akind = element_type->atomic.akind;
2242                         switch (expression->kind) {
2243                                 case EXPR_STRING_LITERAL:
2244                                         if (akind == ATOMIC_TYPE_CHAR
2245                                                         || akind == ATOMIC_TYPE_SCHAR
2246                                                         || akind == ATOMIC_TYPE_UCHAR) {
2247                                                 return initializer_from_string(array_type,
2248                                                         &expression->string.value);
2249                                         }
2250                                         break;
2251
2252                                 case EXPR_WIDE_STRING_LITERAL: {
2253                                         type_t *bare_wchar_type = skip_typeref(type_wchar_t);
2254                                         if (get_unqualified_type(element_type) == bare_wchar_type) {
2255                                                 return initializer_from_wide_string(array_type,
2256                                                         &expression->wide_string.value);
2257                                         }
2258                                         break;
2259                                 }
2260
2261                                 default:
2262                                         break;
2263                         }
2264                 }
2265         }
2266
2267         assign_error_t error = semantic_assign(type, expression);
2268         if (error == ASSIGN_ERROR_INCOMPATIBLE)
2269                 return NULL;
2270         report_assign_error(error, type, expression, "initializer",
2271                             &expression->base.source_position);
2272
2273         initializer_t *const result = allocate_initializer_zero(INITIALIZER_VALUE);
2274 #if 0
2275         if (type->kind == TYPE_BITFIELD) {
2276                 type = type->bitfield.base_type;
2277         }
2278 #endif
2279         result->value.value = create_implicit_cast(expression, type);
2280
2281         return result;
2282 }
2283
2284 /**
2285  * Checks if a given expression can be used as an constant initializer.
2286  */
2287 static bool is_initializer_constant(const expression_t *expression)
2288 {
2289         return is_constant_expression(expression)
2290                 || is_address_constant(expression);
2291 }
2292
2293 /**
2294  * Parses an scalar initializer.
2295  *
2296  * §6.7.8.11; eat {} without warning
2297  */
2298 static initializer_t *parse_scalar_initializer(type_t *type,
2299                                                bool must_be_constant)
2300 {
2301         /* there might be extra {} hierarchies */
2302         int braces = 0;
2303         if (token.type == '{') {
2304                 if (warning.other)
2305                         warningf(HERE, "extra curly braces around scalar initializer");
2306                 do {
2307                         ++braces;
2308                         next_token();
2309                 } while (token.type == '{');
2310         }
2311
2312         expression_t *expression = parse_assignment_expression();
2313         mark_vars_read(expression, NULL);
2314         if (must_be_constant && !is_initializer_constant(expression)) {
2315                 errorf(&expression->base.source_position,
2316                        "Initialisation expression '%E' is not constant",
2317                        expression);
2318         }
2319
2320         initializer_t *initializer = initializer_from_expression(type, expression);
2321
2322         if (initializer == NULL) {
2323                 errorf(&expression->base.source_position,
2324                        "expression '%E' (type '%T') doesn't match expected type '%T'",
2325                        expression, expression->base.type, type);
2326                 /* TODO */
2327                 return NULL;
2328         }
2329
2330         bool additional_warning_displayed = false;
2331         while (braces > 0) {
2332                 if (token.type == ',') {
2333                         next_token();
2334                 }
2335                 if (token.type != '}') {
2336                         if (!additional_warning_displayed && warning.other) {
2337                                 warningf(HERE, "additional elements in scalar initializer");
2338                                 additional_warning_displayed = true;
2339                         }
2340                 }
2341                 eat_block();
2342                 braces--;
2343         }
2344
2345         return initializer;
2346 }
2347
2348 /**
2349  * An entry in the type path.
2350  */
2351 typedef struct type_path_entry_t type_path_entry_t;
2352 struct type_path_entry_t {
2353         type_t *type;       /**< the upper top type. restored to path->top_tye if this entry is popped. */
2354         union {
2355                 size_t         index;          /**< For array types: the current index. */
2356                 declaration_t *compound_entry; /**< For compound types: the current declaration. */
2357         } v;
2358 };
2359
2360 /**
2361  * A type path expression a position inside compound or array types.
2362  */
2363 typedef struct type_path_t type_path_t;
2364 struct type_path_t {
2365         type_path_entry_t *path;         /**< An flexible array containing the current path. */
2366         type_t            *top_type;     /**< type of the element the path points */
2367         size_t             max_index;    /**< largest index in outermost array */
2368 };
2369
2370 /**
2371  * Prints a type path for debugging.
2372  */
2373 static __attribute__((unused)) void debug_print_type_path(
2374                 const type_path_t *path)
2375 {
2376         size_t len = ARR_LEN(path->path);
2377
2378         for (size_t i = 0; i < len; ++i) {
2379                 const type_path_entry_t *entry = & path->path[i];
2380
2381                 type_t *type = skip_typeref(entry->type);
2382                 if (is_type_compound(type)) {
2383                         /* in gcc mode structs can have no members */
2384                         if (entry->v.compound_entry == NULL) {
2385                                 assert(i == len-1);
2386                                 continue;
2387                         }
2388                         fprintf(stderr, ".%s",
2389                                 entry->v.compound_entry->base.symbol->string);
2390                 } else if (is_type_array(type)) {
2391                         fprintf(stderr, "[%u]", (unsigned) entry->v.index);
2392                 } else {
2393                         fprintf(stderr, "-INVALID-");
2394                 }
2395         }
2396         if (path->top_type != NULL) {
2397                 fprintf(stderr, "  (");
2398                 print_type(path->top_type);
2399                 fprintf(stderr, ")");
2400         }
2401 }
2402
2403 /**
2404  * Return the top type path entry, ie. in a path
2405  * (type).a.b returns the b.
2406  */
2407 static type_path_entry_t *get_type_path_top(const type_path_t *path)
2408 {
2409         size_t len = ARR_LEN(path->path);
2410         assert(len > 0);
2411         return &path->path[len-1];
2412 }
2413
2414 /**
2415  * Enlarge the type path by an (empty) element.
2416  */
2417 static type_path_entry_t *append_to_type_path(type_path_t *path)
2418 {
2419         size_t len = ARR_LEN(path->path);
2420         ARR_RESIZE(type_path_entry_t, path->path, len+1);
2421
2422         type_path_entry_t *result = & path->path[len];
2423         memset(result, 0, sizeof(result[0]));
2424         return result;
2425 }
2426
2427 /**
2428  * Descending into a sub-type. Enter the scope of the current top_type.
2429  */
2430 static void descend_into_subtype(type_path_t *path)
2431 {
2432         type_t *orig_top_type = path->top_type;
2433         type_t *top_type      = skip_typeref(orig_top_type);
2434
2435         type_path_entry_t *top = append_to_type_path(path);
2436         top->type              = top_type;
2437
2438         if (is_type_compound(top_type)) {
2439                 compound_t *compound  = top_type->compound.compound;
2440                 entity_t   *entry     = compound->members.entities;
2441
2442                 if (entry != NULL) {
2443                         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
2444                         top->v.compound_entry = &entry->declaration;
2445                         path->top_type = entry->declaration.type;
2446                 } else {
2447                         path->top_type = NULL;
2448                 }
2449         } else if (is_type_array(top_type)) {
2450                 top->v.index   = 0;
2451                 path->top_type = top_type->array.element_type;
2452         } else {
2453                 assert(!is_type_valid(top_type));
2454         }
2455 }
2456
2457 /**
2458  * Pop an entry from the given type path, ie. returning from
2459  * (type).a.b to (type).a
2460  */
2461 static void ascend_from_subtype(type_path_t *path)
2462 {
2463         type_path_entry_t *top = get_type_path_top(path);
2464
2465         path->top_type = top->type;
2466
2467         size_t len = ARR_LEN(path->path);
2468         ARR_RESIZE(type_path_entry_t, path->path, len-1);
2469 }
2470
2471 /**
2472  * Pop entries from the given type path until the given
2473  * path level is reached.
2474  */
2475 static void ascend_to(type_path_t *path, size_t top_path_level)
2476 {
2477         size_t len = ARR_LEN(path->path);
2478
2479         while (len > top_path_level) {
2480                 ascend_from_subtype(path);
2481                 len = ARR_LEN(path->path);
2482         }
2483 }
2484
2485 static bool walk_designator(type_path_t *path, const designator_t *designator,
2486                             bool used_in_offsetof)
2487 {
2488         for (; designator != NULL; designator = designator->next) {
2489                 type_path_entry_t *top       = get_type_path_top(path);
2490                 type_t            *orig_type = top->type;
2491
2492                 type_t *type = skip_typeref(orig_type);
2493
2494                 if (designator->symbol != NULL) {
2495                         symbol_t *symbol = designator->symbol;
2496                         if (!is_type_compound(type)) {
2497                                 if (is_type_valid(type)) {
2498                                         errorf(&designator->source_position,
2499                                                "'.%Y' designator used for non-compound type '%T'",
2500                                                symbol, orig_type);
2501                                 }
2502
2503                                 top->type             = type_error_type;
2504                                 top->v.compound_entry = NULL;
2505                                 orig_type             = type_error_type;
2506                         } else {
2507                                 compound_t *compound = type->compound.compound;
2508                                 entity_t   *iter     = compound->members.entities;
2509                                 for (; iter != NULL; iter = iter->base.next) {
2510                                         if (iter->base.symbol == symbol) {
2511                                                 break;
2512                                         }
2513                                 }
2514                                 if (iter == NULL) {
2515                                         errorf(&designator->source_position,
2516                                                "'%T' has no member named '%Y'", orig_type, symbol);
2517                                         goto failed;
2518                                 }
2519                                 assert(iter->kind == ENTITY_COMPOUND_MEMBER);
2520                                 if (used_in_offsetof) {
2521                                         type_t *real_type = skip_typeref(iter->declaration.type);
2522                                         if (real_type->kind == TYPE_BITFIELD) {
2523                                                 errorf(&designator->source_position,
2524                                                        "offsetof designator '%Y' may not specify bitfield",
2525                                                        symbol);
2526                                                 goto failed;
2527                                         }
2528                                 }
2529
2530                                 top->type             = orig_type;
2531                                 top->v.compound_entry = &iter->declaration;
2532                                 orig_type             = iter->declaration.type;
2533                         }
2534                 } else {
2535                         expression_t *array_index = designator->array_index;
2536                         assert(designator->array_index != NULL);
2537
2538                         if (!is_type_array(type)) {
2539                                 if (is_type_valid(type)) {
2540                                         errorf(&designator->source_position,
2541                                                "[%E] designator used for non-array type '%T'",
2542                                                array_index, orig_type);
2543                                 }
2544                                 goto failed;
2545                         }
2546
2547                         long index = fold_constant(array_index);
2548                         if (!used_in_offsetof) {
2549                                 if (index < 0) {
2550                                         errorf(&designator->source_position,
2551                                                "array index [%E] must be positive", array_index);
2552                                 } else if (type->array.size_constant) {
2553                                         long array_size = type->array.size;
2554                                         if (index >= array_size) {
2555                                                 errorf(&designator->source_position,
2556                                                        "designator [%E] (%d) exceeds array size %d",
2557                                                        array_index, index, array_size);
2558                                         }
2559                                 }
2560                         }
2561
2562                         top->type    = orig_type;
2563                         top->v.index = (size_t) index;
2564                         orig_type    = type->array.element_type;
2565                 }
2566                 path->top_type = orig_type;
2567
2568                 if (designator->next != NULL) {
2569                         descend_into_subtype(path);
2570                 }
2571         }
2572         return true;
2573
2574 failed:
2575         return false;
2576 }
2577
2578 static void advance_current_object(type_path_t *path, size_t top_path_level)
2579 {
2580         type_path_entry_t *top = get_type_path_top(path);
2581
2582         type_t *type = skip_typeref(top->type);
2583         if (is_type_union(type)) {
2584                 /* in unions only the first element is initialized */
2585                 top->v.compound_entry = NULL;
2586         } else if (is_type_struct(type)) {
2587                 declaration_t *entry = top->v.compound_entry;
2588
2589                 entity_t *next_entity = entry->base.next;
2590                 if (next_entity != NULL) {
2591                         assert(is_declaration(next_entity));
2592                         entry = &next_entity->declaration;
2593                 } else {
2594                         entry = NULL;
2595                 }
2596
2597                 top->v.compound_entry = entry;
2598                 if (entry != NULL) {
2599                         path->top_type = entry->type;
2600                         return;
2601                 }
2602         } else if (is_type_array(type)) {
2603                 assert(is_type_array(type));
2604
2605                 top->v.index++;
2606
2607                 if (!type->array.size_constant || top->v.index < type->array.size) {
2608                         return;
2609                 }
2610         } else {
2611                 assert(!is_type_valid(type));
2612                 return;
2613         }
2614
2615         /* we're past the last member of the current sub-aggregate, try if we
2616          * can ascend in the type hierarchy and continue with another subobject */
2617         size_t len = ARR_LEN(path->path);
2618
2619         if (len > top_path_level) {
2620                 ascend_from_subtype(path);
2621                 advance_current_object(path, top_path_level);
2622         } else {
2623                 path->top_type = NULL;
2624         }
2625 }
2626
2627 /**
2628  * skip until token is found.
2629  */
2630 static void skip_until(int type)
2631 {
2632         while (token.type != type) {
2633                 if (token.type == T_EOF)
2634                         return;
2635                 next_token();
2636         }
2637 }
2638
2639 /**
2640  * skip any {...} blocks until a closing bracket is reached.
2641  */
2642 static void skip_initializers(void)
2643 {
2644         if (token.type == '{')
2645                 next_token();
2646
2647         while (token.type != '}') {
2648                 if (token.type == T_EOF)
2649                         return;
2650                 if (token.type == '{') {
2651                         eat_block();
2652                         continue;
2653                 }
2654                 next_token();
2655         }
2656 }
2657
2658 static initializer_t *create_empty_initializer(void)
2659 {
2660         static initializer_t empty_initializer
2661                 = { .list = { { INITIALIZER_LIST }, 0 } };
2662         return &empty_initializer;
2663 }
2664
2665 /**
2666  * Parse a part of an initialiser for a struct or union,
2667  */
2668 static initializer_t *parse_sub_initializer(type_path_t *path,
2669                 type_t *outer_type, size_t top_path_level,
2670                 parse_initializer_env_t *env)
2671 {
2672         if (token.type == '}') {
2673                 /* empty initializer */
2674                 return create_empty_initializer();
2675         }
2676
2677         type_t *orig_type = path->top_type;
2678         type_t *type      = NULL;
2679
2680         if (orig_type == NULL) {
2681                 /* We are initializing an empty compound. */
2682         } else {
2683                 type = skip_typeref(orig_type);
2684         }
2685
2686         initializer_t **initializers = NEW_ARR_F(initializer_t*, 0);
2687
2688         while (true) {
2689                 designator_t *designator = NULL;
2690                 if (token.type == '.' || token.type == '[') {
2691                         designator = parse_designation();
2692                         goto finish_designator;
2693                 } else if (token.type == T_IDENTIFIER && look_ahead(1)->type == ':') {
2694                         /* GNU-style designator ("identifier: value") */
2695                         designator = allocate_ast_zero(sizeof(designator[0]));
2696                         designator->source_position = token.source_position;
2697                         designator->symbol          = token.v.symbol;
2698                         eat(T_IDENTIFIER);
2699                         eat(':');
2700
2701 finish_designator:
2702                         /* reset path to toplevel, evaluate designator from there */
2703                         ascend_to(path, top_path_level);
2704                         if (!walk_designator(path, designator, false)) {
2705                                 /* can't continue after designation error */
2706                                 goto end_error;
2707                         }
2708
2709                         initializer_t *designator_initializer
2710                                 = allocate_initializer_zero(INITIALIZER_DESIGNATOR);
2711                         designator_initializer->designator.designator = designator;
2712                         ARR_APP1(initializer_t*, initializers, designator_initializer);
2713
2714                         orig_type = path->top_type;
2715                         type      = orig_type != NULL ? skip_typeref(orig_type) : NULL;
2716                 }
2717
2718                 initializer_t *sub;
2719
2720                 if (token.type == '{') {
2721                         if (type != NULL && is_type_scalar(type)) {
2722                                 sub = parse_scalar_initializer(type, env->must_be_constant);
2723                         } else {
2724                                 eat('{');
2725                                 if (type == NULL) {
2726                                         if (env->entity != NULL) {
2727                                                 errorf(HERE,
2728                                                      "extra brace group at end of initializer for '%Y'",
2729                                                      env->entity->base.symbol);
2730                                         } else {
2731                                                 errorf(HERE, "extra brace group at end of initializer");
2732                                         }
2733                                 } else
2734                                         descend_into_subtype(path);
2735
2736                                 add_anchor_token('}');
2737                                 sub = parse_sub_initializer(path, orig_type, top_path_level+1,
2738                                                             env);
2739                                 rem_anchor_token('}');
2740
2741                                 if (type != NULL) {
2742                                         ascend_from_subtype(path);
2743                                         expect('}', end_error);
2744                                 } else {
2745                                         expect('}', end_error);
2746                                         goto error_parse_next;
2747                                 }
2748                         }
2749                 } else {
2750                         /* must be an expression */
2751                         expression_t *expression = parse_assignment_expression();
2752                         mark_vars_read(expression, NULL);
2753
2754                         if (env->must_be_constant && !is_initializer_constant(expression)) {
2755                                 errorf(&expression->base.source_position,
2756                                        "Initialisation expression '%E' is not constant",
2757                                        expression);
2758                         }
2759
2760                         if (type == NULL) {
2761                                 /* we are already outside, ... */
2762                                 type_t *const outer_type_skip = skip_typeref(outer_type);
2763                                 if (is_type_compound(outer_type_skip) &&
2764                                     !outer_type_skip->compound.compound->complete) {
2765                                         goto error_parse_next;
2766                                 }
2767                                 goto error_excess;
2768                         }
2769
2770                         /* handle { "string" } special case */
2771                         if ((expression->kind == EXPR_STRING_LITERAL
2772                                         || expression->kind == EXPR_WIDE_STRING_LITERAL)
2773                                         && outer_type != NULL) {
2774                                 sub = initializer_from_expression(outer_type, expression);
2775                                 if (sub != NULL) {
2776                                         if (token.type == ',') {
2777                                                 next_token();
2778                                         }
2779                                         if (token.type != '}' && warning.other) {
2780                                                 warningf(HERE, "excessive elements in initializer for type '%T'",
2781                                                                  orig_type);
2782                                         }
2783                                         /* TODO: eat , ... */
2784                                         return sub;
2785                                 }
2786                         }
2787
2788                         /* descend into subtypes until expression matches type */
2789                         while (true) {
2790                                 orig_type = path->top_type;
2791                                 type      = skip_typeref(orig_type);
2792
2793                                 sub = initializer_from_expression(orig_type, expression);
2794                                 if (sub != NULL) {
2795                                         break;
2796                                 }
2797                                 if (!is_type_valid(type)) {
2798                                         goto end_error;
2799                                 }
2800                                 if (is_type_scalar(type)) {
2801                                         errorf(&expression->base.source_position,
2802                                                         "expression '%E' doesn't match expected type '%T'",
2803                                                         expression, orig_type);
2804                                         goto end_error;
2805                                 }
2806
2807                                 descend_into_subtype(path);
2808                         }
2809                 }
2810
2811                 /* update largest index of top array */
2812                 const type_path_entry_t *first      = &path->path[0];
2813                 type_t                  *first_type = first->type;
2814                 first_type                          = skip_typeref(first_type);
2815                 if (is_type_array(first_type)) {
2816                         size_t index = first->v.index;
2817                         if (index > path->max_index)
2818                                 path->max_index = index;
2819                 }
2820
2821                 if (type != NULL) {
2822                         /* append to initializers list */
2823                         ARR_APP1(initializer_t*, initializers, sub);
2824                 } else {
2825 error_excess:
2826                         if (warning.other) {
2827                                 if (env->entity != NULL) {
2828                                         warningf(HERE, "excess elements in struct initializer for '%Y'",
2829                                            env->entity->base.symbol);
2830                                 } else {
2831                                         warningf(HERE, "excess elements in struct initializer");
2832                                 }
2833                         }
2834                 }
2835
2836 error_parse_next:
2837                 if (token.type == '}') {
2838                         break;
2839                 }
2840                 expect(',', end_error);
2841                 if (token.type == '}') {
2842                         break;
2843                 }
2844
2845                 if (type != NULL) {
2846                         /* advance to the next declaration if we are not at the end */
2847                         advance_current_object(path, top_path_level);
2848                         orig_type = path->top_type;
2849                         if (orig_type != NULL)
2850                                 type = skip_typeref(orig_type);
2851                         else
2852                                 type = NULL;
2853                 }
2854         }
2855
2856         size_t len  = ARR_LEN(initializers);
2857         size_t size = sizeof(initializer_list_t) + len * sizeof(initializers[0]);
2858         initializer_t *result = allocate_ast_zero(size);
2859         result->kind          = INITIALIZER_LIST;
2860         result->list.len      = len;
2861         memcpy(&result->list.initializers, initializers,
2862                len * sizeof(initializers[0]));
2863
2864         DEL_ARR_F(initializers);
2865         ascend_to(path, top_path_level+1);
2866
2867         return result;
2868
2869 end_error:
2870         skip_initializers();
2871         DEL_ARR_F(initializers);
2872         ascend_to(path, top_path_level+1);
2873         return NULL;
2874 }
2875
2876 /**
2877  * Parses an initializer. Parsers either a compound literal
2878  * (env->declaration == NULL) or an initializer of a declaration.
2879  */
2880 static initializer_t *parse_initializer(parse_initializer_env_t *env)
2881 {
2882         type_t        *type      = skip_typeref(env->type);
2883         size_t         max_index = 0xdeadbeaf;   // TODO: Resolve this uninitialized variable problem
2884         initializer_t *result;
2885
2886         if (is_type_scalar(type)) {
2887                 result = parse_scalar_initializer(type, env->must_be_constant);
2888         } else if (token.type == '{') {
2889                 eat('{');
2890
2891                 type_path_t path;
2892                 memset(&path, 0, sizeof(path));
2893                 path.top_type = env->type;
2894                 path.path     = NEW_ARR_F(type_path_entry_t, 0);
2895
2896                 descend_into_subtype(&path);
2897
2898                 add_anchor_token('}');
2899                 result = parse_sub_initializer(&path, env->type, 1, env);
2900                 rem_anchor_token('}');
2901
2902                 max_index = path.max_index;
2903                 DEL_ARR_F(path.path);
2904
2905                 expect('}', end_error);
2906         } else {
2907                 /* parse_scalar_initializer() also works in this case: we simply
2908                  * have an expression without {} around it */
2909                 result = parse_scalar_initializer(type, env->must_be_constant);
2910         }
2911
2912         /* §6.7.8:22 array initializers for arrays with unknown size determine
2913          * the array type size */
2914         if (is_type_array(type) && type->array.size_expression == NULL
2915                         && result != NULL) {
2916                 size_t size;
2917                 switch (result->kind) {
2918                 case INITIALIZER_LIST:
2919                         assert(max_index != 0xdeadbeaf);
2920                         size = max_index + 1;
2921                         break;
2922
2923                 case INITIALIZER_STRING:
2924                         size = result->string.string.size;
2925                         break;
2926
2927                 case INITIALIZER_WIDE_STRING:
2928                         size = result->wide_string.string.size;
2929                         break;
2930
2931                 case INITIALIZER_DESIGNATOR:
2932                 case INITIALIZER_VALUE:
2933                         /* can happen for parse errors */
2934                         size = 0;
2935                         break;
2936
2937                 default:
2938                         internal_errorf(HERE, "invalid initializer type");
2939                 }
2940
2941                 expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
2942                 cnst->base.type          = type_size_t;
2943                 cnst->conste.v.int_value = size;
2944
2945                 type_t *new_type = duplicate_type(type);
2946
2947                 new_type->array.size_expression   = cnst;
2948                 new_type->array.size_constant     = true;
2949                 new_type->array.has_implicit_size = true;
2950                 new_type->array.size              = size;
2951                 env->type = new_type;
2952         }
2953
2954         return result;
2955 end_error:
2956         return NULL;
2957 }
2958
2959 static void append_entity(scope_t *scope, entity_t *entity)
2960 {
2961         if (scope->last_entity != NULL) {
2962                 scope->last_entity->base.next = entity;
2963         } else {
2964                 scope->entities = entity;
2965         }
2966         scope->last_entity = entity;
2967 }
2968
2969
2970 static compound_t *parse_compound_type_specifier(bool is_struct)
2971 {
2972         gnu_attribute_t  *attributes = NULL;
2973         decl_modifiers_t  modifiers  = 0;
2974         if (is_struct) {
2975                 eat(T_struct);
2976         } else {
2977                 eat(T_union);
2978         }
2979
2980         symbol_t   *symbol   = NULL;
2981         compound_t *compound = NULL;
2982
2983         if (token.type == T___attribute__) {
2984                 modifiers |= parse_attributes(&attributes);
2985         }
2986
2987         if (token.type == T_IDENTIFIER) {
2988                 symbol = token.v.symbol;
2989                 next_token();
2990
2991                 namespace_tag_t const namespc =
2992                         is_struct ? NAMESPACE_STRUCT : NAMESPACE_UNION;
2993                 entity_t *entity = get_entity(symbol, namespc);
2994                 if (entity != NULL) {
2995                         assert(entity->kind == (is_struct ? ENTITY_STRUCT : ENTITY_UNION));
2996                         compound = &entity->compound;
2997                         if (compound->base.parent_scope != current_scope &&
2998                             (token.type == '{' || token.type == ';')) {
2999                                 /* we're in an inner scope and have a definition. Shadow
3000                                  * existing definition in outer scope */
3001                                 compound = NULL;
3002                         } else if (compound->complete && token.type == '{') {
3003                                 assert(symbol != NULL);
3004                                 errorf(HERE, "multiple definitions of '%s %Y' (previous definition %P)",
3005                                        is_struct ? "struct" : "union", symbol,
3006                                        &compound->base.source_position);
3007                                 /* clear members in the hope to avoid further errors */
3008                                 compound->members.entities = NULL;
3009                         }
3010                 }
3011         } else if (token.type != '{') {
3012                 if (is_struct) {
3013                         parse_error_expected("while parsing struct type specifier",
3014                                              T_IDENTIFIER, '{', NULL);
3015                 } else {
3016                         parse_error_expected("while parsing union type specifier",
3017                                              T_IDENTIFIER, '{', NULL);
3018                 }
3019
3020                 return NULL;
3021         }
3022
3023         if (compound == NULL) {
3024                 entity_kind_t  kind   = is_struct ? ENTITY_STRUCT : ENTITY_UNION;
3025                 entity_t      *entity = allocate_entity_zero(kind);
3026                 compound              = &entity->compound;
3027
3028                 compound->base.namespc =
3029                         (is_struct ? NAMESPACE_STRUCT : NAMESPACE_UNION);
3030                 compound->base.source_position = token.source_position;
3031                 compound->base.symbol          = symbol;
3032                 compound->base.parent_scope    = current_scope;
3033                 if (symbol != NULL) {
3034                         environment_push(entity);
3035                 }
3036                 append_entity(current_scope, entity);
3037         }
3038
3039         if (token.type == '{') {
3040                 parse_compound_type_entries(compound);
3041                 modifiers |= parse_attributes(&attributes);
3042
3043                 if (symbol == NULL) {
3044                         assert(anonymous_entity == NULL);
3045                         anonymous_entity = (entity_t*)compound;
3046                 }
3047         }
3048
3049         compound->modifiers |= modifiers;
3050         return compound;
3051 }
3052
3053 static void parse_enum_entries(type_t *const enum_type)
3054 {
3055         eat('{');
3056
3057         if (token.type == '}') {
3058                 errorf(HERE, "empty enum not allowed");
3059                 next_token();
3060                 return;
3061         }
3062
3063         add_anchor_token('}');
3064         do {
3065                 if (token.type != T_IDENTIFIER) {
3066                         parse_error_expected("while parsing enum entry", T_IDENTIFIER, NULL);
3067                         eat_block();
3068                         rem_anchor_token('}');
3069                         return;
3070                 }
3071
3072                 entity_t *entity             = allocate_entity_zero(ENTITY_ENUM_VALUE);
3073                 entity->enum_value.enum_type = enum_type;
3074                 entity->base.symbol          = token.v.symbol;
3075                 entity->base.source_position = token.source_position;
3076                 next_token();
3077
3078                 if (token.type == '=') {
3079                         next_token();
3080                         expression_t *value = parse_constant_expression();
3081
3082                         value = create_implicit_cast(value, enum_type);
3083                         entity->enum_value.value = value;
3084
3085                         /* TODO semantic */
3086                 }
3087
3088                 record_entity(entity, false);
3089
3090                 if (token.type != ',')
3091                         break;
3092                 next_token();
3093         } while (token.type != '}');
3094         rem_anchor_token('}');
3095
3096         expect('}', end_error);
3097
3098 end_error:
3099         ;
3100 }
3101
3102 static type_t *parse_enum_specifier(void)
3103 {
3104         gnu_attribute_t *attributes = NULL;
3105         entity_t        *entity;
3106         symbol_t        *symbol;
3107
3108         eat(T_enum);
3109         if (token.type == T_IDENTIFIER) {
3110                 symbol = token.v.symbol;
3111                 next_token();
3112
3113                 entity = get_entity(symbol, NAMESPACE_ENUM);
3114                 if (entity != NULL) {
3115                         assert(entity->kind == ENTITY_ENUM);
3116                         if (entity->base.parent_scope != current_scope &&
3117                                         (token.type == '{' || token.type == ';')) {
3118                                 /* we're in an inner scope and have a definition. Shadow
3119                                  * existing definition in outer scope */
3120                                 entity = NULL;
3121                         } else if (entity->enume.complete && token.type == '{') {
3122                                 errorf(HERE, "multiple definitions of 'enum %Y' (previous definition %P)",
3123                                                 symbol, &entity->base.source_position);
3124                         }
3125                 }
3126         } else if (token.type != '{') {
3127                 parse_error_expected("while parsing enum type specifier",
3128                                      T_IDENTIFIER, '{', NULL);
3129                 return NULL;
3130         } else {
3131                 entity  = NULL;
3132                 symbol  = NULL;
3133         }
3134
3135         if (entity == NULL) {
3136                 entity                       = allocate_entity_zero(ENTITY_ENUM);
3137                 entity->base.namespc         = NAMESPACE_ENUM;
3138                 entity->base.source_position = token.source_position;
3139                 entity->base.symbol          = symbol;
3140                 entity->base.parent_scope    = current_scope;
3141         }
3142
3143         type_t *const type = allocate_type_zero(TYPE_ENUM);
3144         type->enumt.enume  = &entity->enume;
3145         type->enumt.akind  = ATOMIC_TYPE_INT;
3146
3147         if (token.type == '{') {
3148                 if (symbol != NULL) {
3149                         environment_push(entity);
3150                 }
3151                 append_entity(current_scope, entity);
3152                 entity->enume.complete = true;
3153
3154                 parse_enum_entries(type);
3155                 parse_attributes(&attributes);
3156
3157                 if (symbol == NULL) {
3158                         assert(anonymous_entity == NULL);
3159                         anonymous_entity = entity;
3160                 }
3161         } else if (!entity->enume.complete && !(c_mode & _GNUC)) {
3162                 errorf(HERE, "'enum %Y' used before definition (incomplete enums are a GNU extension)",
3163                        symbol);
3164         }
3165
3166         return type;
3167 }
3168
3169 /**
3170  * if a symbol is a typedef to another type, return true
3171  */
3172 static bool is_typedef_symbol(symbol_t *symbol)
3173 {
3174         const entity_t *const entity = get_entity(symbol, NAMESPACE_NORMAL);
3175         return entity != NULL && entity->kind == ENTITY_TYPEDEF;
3176 }
3177
3178 static type_t *parse_typeof(void)
3179 {
3180         eat(T___typeof__);
3181
3182         type_t *type;
3183
3184         expect('(', end_error);
3185         add_anchor_token(')');
3186
3187         expression_t *expression  = NULL;
3188
3189         bool old_type_prop     = in_type_prop;
3190         bool old_gcc_extension = in_gcc_extension;
3191         in_type_prop           = true;
3192
3193         while (token.type == T___extension__) {
3194                 /* This can be a prefix to a typename or an expression. */
3195                 next_token();
3196                 in_gcc_extension = true;
3197         }
3198         switch (token.type) {
3199         case T_IDENTIFIER:
3200                 if (is_typedef_symbol(token.v.symbol)) {
3201                         type = parse_typename();
3202                 } else {
3203                         expression = parse_expression();
3204                         type       = revert_automatic_type_conversion(expression);
3205                 }
3206                 break;
3207
3208         TYPENAME_START
3209                 type = parse_typename();
3210                 break;
3211
3212         default:
3213                 expression = parse_expression();
3214                 type       = expression->base.type;
3215                 break;
3216         }
3217         in_type_prop     = old_type_prop;
3218         in_gcc_extension = old_gcc_extension;
3219
3220         rem_anchor_token(')');
3221         expect(')', end_error);
3222
3223         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF);
3224         typeof_type->typeoft.expression  = expression;
3225         typeof_type->typeoft.typeof_type = type;
3226
3227         return typeof_type;
3228 end_error:
3229         return NULL;
3230 }
3231
3232 typedef enum specifiers_t {
3233         SPECIFIER_SIGNED    = 1 << 0,
3234         SPECIFIER_UNSIGNED  = 1 << 1,
3235         SPECIFIER_LONG      = 1 << 2,
3236         SPECIFIER_INT       = 1 << 3,
3237         SPECIFIER_DOUBLE    = 1 << 4,
3238         SPECIFIER_CHAR      = 1 << 5,
3239         SPECIFIER_WCHAR_T   = 1 << 6,
3240         SPECIFIER_SHORT     = 1 << 7,
3241         SPECIFIER_LONG_LONG = 1 << 8,
3242         SPECIFIER_FLOAT     = 1 << 9,
3243         SPECIFIER_BOOL      = 1 << 10,
3244         SPECIFIER_VOID      = 1 << 11,
3245         SPECIFIER_INT8      = 1 << 12,
3246         SPECIFIER_INT16     = 1 << 13,
3247         SPECIFIER_INT32     = 1 << 14,
3248         SPECIFIER_INT64     = 1 << 15,
3249         SPECIFIER_INT128    = 1 << 16,
3250         SPECIFIER_COMPLEX   = 1 << 17,
3251         SPECIFIER_IMAGINARY = 1 << 18,
3252 } specifiers_t;
3253
3254 static type_t *create_builtin_type(symbol_t *const symbol,
3255                                    type_t *const real_type)
3256 {
3257         type_t *type            = allocate_type_zero(TYPE_BUILTIN);
3258         type->builtin.symbol    = symbol;
3259         type->builtin.real_type = real_type;
3260         return identify_new_type(type);
3261 }
3262
3263 static type_t *get_typedef_type(symbol_t *symbol)
3264 {
3265         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
3266         if (entity == NULL || entity->kind != ENTITY_TYPEDEF)
3267                 return NULL;
3268
3269         type_t *type            = allocate_type_zero(TYPE_TYPEDEF);
3270         type->typedeft.typedefe = &entity->typedefe;
3271
3272         return type;
3273 }
3274
3275 /**
3276  * check for the allowed MS alignment values.
3277  */
3278 static bool check_alignment_value(long long intvalue)
3279 {
3280         if (intvalue < 1 || intvalue > 8192) {
3281                 errorf(HERE, "illegal alignment value");
3282                 return false;
3283         }
3284         unsigned v = (unsigned)intvalue;
3285         for (unsigned i = 1; i <= 8192; i += i) {
3286                 if (i == v)
3287                         return true;
3288         }
3289         errorf(HERE, "alignment must be power of two");
3290         return false;
3291 }
3292
3293 #define DET_MOD(name, tag) do { \
3294         if (*modifiers & tag && warning.other) warningf(HERE, #name " used more than once"); \
3295         *modifiers |= tag; \
3296 } while (0)
3297
3298 static void parse_microsoft_extended_decl_modifier(declaration_specifiers_t *specifiers)
3299 {
3300         decl_modifiers_t *modifiers = &specifiers->modifiers;
3301
3302         while (true) {
3303                 if (token.type == T_restrict) {
3304                         next_token();
3305                         DET_MOD(restrict, DM_RESTRICT);
3306                         goto end_loop;
3307                 } else if (token.type != T_IDENTIFIER)
3308                         break;
3309                 symbol_t *symbol = token.v.symbol;
3310                 if (symbol == sym_align) {
3311                         next_token();
3312                         expect('(', end_error);
3313                         if (token.type != T_INTEGER)
3314                                 goto end_error;
3315                         if (check_alignment_value(token.v.intvalue)) {
3316                                 if (specifiers->alignment != 0 && warning.other)
3317                                         warningf(HERE, "align used more than once");
3318                                 specifiers->alignment = (unsigned char)token.v.intvalue;
3319                         }
3320                         next_token();
3321                         expect(')', end_error);
3322                 } else if (symbol == sym_allocate) {
3323                         next_token();
3324                         expect('(', end_error);
3325                         if (token.type != T_IDENTIFIER)
3326                                 goto end_error;
3327                         (void)token.v.symbol;
3328                         expect(')', end_error);
3329                 } else if (symbol == sym_dllimport) {
3330                         next_token();
3331                         DET_MOD(dllimport, DM_DLLIMPORT);
3332                 } else if (symbol == sym_dllexport) {
3333                         next_token();
3334                         DET_MOD(dllexport, DM_DLLEXPORT);
3335                 } else if (symbol == sym_thread) {
3336                         next_token();
3337                         DET_MOD(thread, DM_THREAD);
3338                 } else if (symbol == sym_naked) {
3339                         next_token();
3340                         DET_MOD(naked, DM_NAKED);
3341                 } else if (symbol == sym_noinline) {
3342                         next_token();
3343                         DET_MOD(noinline, DM_NOINLINE);
3344                 } else if (symbol == sym_returns_twice) {
3345                         next_token();
3346                         DET_MOD(returns_twice, DM_RETURNS_TWICE);
3347                 } else if (symbol == sym_noreturn) {
3348                         next_token();
3349                         DET_MOD(noreturn, DM_NORETURN);
3350                 } else if (symbol == sym_nothrow) {
3351                         next_token();
3352                         DET_MOD(nothrow, DM_NOTHROW);
3353                 } else if (symbol == sym_novtable) {
3354                         next_token();
3355                         DET_MOD(novtable, DM_NOVTABLE);
3356                 } else if (symbol == sym_property) {
3357                         next_token();
3358                         expect('(', end_error);
3359                         for (;;) {
3360                                 bool is_get = false;
3361                                 if (token.type != T_IDENTIFIER)
3362                                         goto end_error;
3363                                 if (token.v.symbol == sym_get) {
3364                                         is_get = true;
3365                                 } else if (token.v.symbol == sym_put) {
3366                                 } else {
3367                                         errorf(HERE, "Bad property name '%Y'", token.v.symbol);
3368                                         goto end_error;
3369                                 }
3370                                 next_token();
3371                                 expect('=', end_error);
3372                                 if (token.type != T_IDENTIFIER)
3373                                         goto end_error;
3374                                 if (is_get) {
3375                                         if (specifiers->get_property_sym != NULL) {
3376                                                 errorf(HERE, "get property name already specified");
3377                                         } else {
3378                                                 specifiers->get_property_sym = token.v.symbol;
3379                                         }
3380                                 } else {
3381                                         if (specifiers->put_property_sym != NULL) {
3382                                                 errorf(HERE, "put property name already specified");
3383                                         } else {
3384                                                 specifiers->put_property_sym = token.v.symbol;
3385                                         }
3386                                 }
3387                                 next_token();
3388                                 if (token.type == ',') {
3389                                         next_token();
3390                                         continue;
3391                                 }
3392                                 break;
3393                         }
3394                         expect(')', end_error);
3395                 } else if (symbol == sym_selectany) {
3396                         next_token();
3397                         DET_MOD(selectany, DM_SELECTANY);
3398                 } else if (symbol == sym_uuid) {
3399                         next_token();
3400                         expect('(', end_error);
3401                         if (token.type != T_STRING_LITERAL)
3402                                 goto end_error;
3403                         next_token();
3404                         expect(')', end_error);
3405                 } else if (symbol == sym_deprecated) {
3406                         next_token();
3407                         if (specifiers->deprecated != 0 && warning.other)
3408                                 warningf(HERE, "deprecated used more than once");
3409                         specifiers->deprecated = true;
3410                         if (token.type == '(') {
3411                                 next_token();
3412                                 if (token.type == T_STRING_LITERAL) {
3413                                         specifiers->deprecated_string = token.v.string.begin;
3414                                         next_token();
3415                                 } else {
3416                                         errorf(HERE, "string literal expected");
3417                                 }
3418                                 expect(')', end_error);
3419                         }
3420                 } else if (symbol == sym_noalias) {
3421                         next_token();
3422                         DET_MOD(noalias, DM_NOALIAS);
3423                 } else {
3424                         if (warning.other)
3425                                 warningf(HERE, "Unknown modifier '%Y' ignored", token.v.symbol);
3426                         next_token();
3427                         if (token.type == '(')
3428                                 skip_until(')');
3429                 }
3430 end_loop:
3431                 if (token.type == ',')
3432                         next_token();
3433         }
3434 end_error:
3435         return;
3436 }
3437
3438 static entity_t *create_error_entity(symbol_t *symbol, entity_kind_tag_t kind)
3439 {
3440         entity_t *entity             = allocate_entity_zero(kind);
3441         entity->base.source_position = *HERE;
3442         entity->base.symbol          = symbol;
3443         if (is_declaration(entity)) {
3444                 entity->declaration.type     = type_error_type;
3445                 entity->declaration.implicit = true;
3446         } else if (kind == ENTITY_TYPEDEF) {
3447                 entity->typedefe.type    = type_error_type;
3448                 entity->typedefe.builtin = true;
3449         }
3450         if (kind != ENTITY_COMPOUND_MEMBER)
3451                 record_entity(entity, false);
3452         return entity;
3453 }
3454
3455 static void parse_microsoft_based(based_spec_t *based_spec)
3456 {
3457         if (token.type != T_IDENTIFIER) {
3458                 parse_error_expected("while parsing __based", T_IDENTIFIER, NULL);
3459                 return;
3460         }
3461         symbol_t *symbol = token.v.symbol;
3462         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
3463
3464         if (entity == NULL || entity->base.kind != ENTITY_VARIABLE) {
3465                 errorf(HERE, "'%Y' is not a variable name.", symbol);
3466                 entity = create_error_entity(symbol, ENTITY_VARIABLE);
3467         } else {
3468                 variable_t *variable = &entity->variable;
3469
3470                 if (based_spec->base_variable != NULL) {
3471                         errorf(HERE, "__based type qualifier specified more than once");
3472                 }
3473                 based_spec->source_position = token.source_position;
3474                 based_spec->base_variable   = variable;
3475
3476                 type_t *const type = variable->base.type;
3477
3478                 if (is_type_valid(type)) {
3479                         if (! is_type_pointer(skip_typeref(type))) {
3480                                 errorf(HERE, "variable in __based modifier must have pointer type instead of '%T'", type);
3481                         }
3482                         if (variable->base.base.parent_scope != file_scope) {
3483                                 errorf(HERE, "a nonstatic local variable may not be used in a __based specification");
3484                         }
3485                 }
3486         }
3487         next_token();
3488 }
3489
3490 /**
3491  * Finish the construction of a struct type by calculating
3492  * its size, offsets, alignment.
3493  */
3494 static void finish_struct_type(compound_type_t *type)
3495 {
3496         assert(type->compound != NULL);
3497
3498         compound_t *compound = type->compound;
3499         if (!compound->complete)
3500                 return;
3501
3502         il_size_t      size           = 0;
3503         il_size_t      offset;
3504         il_alignment_t alignment      = 1;
3505         bool           need_pad       = false;
3506
3507         entity_t *entry = compound->members.entities;
3508         for (; entry != NULL; entry = entry->base.next) {
3509                 if (entry->kind != ENTITY_COMPOUND_MEMBER)
3510                         continue;
3511
3512                 type_t *m_type = skip_typeref(entry->declaration.type);
3513                 if (! is_type_valid(m_type)) {
3514                         /* simply ignore errors here */
3515                         continue;
3516                 }
3517                 il_alignment_t m_alignment = m_type->base.alignment;
3518                 if (m_alignment > alignment)
3519                         alignment = m_alignment;
3520
3521                 offset = (size + m_alignment - 1) & -m_alignment;
3522
3523                 if (offset > size)
3524                         need_pad = true;
3525                 entry->compound_member.offset = offset;
3526                 size = offset + m_type->base.size;
3527         }
3528         if (type->base.alignment != 0) {
3529                 alignment = type->base.alignment;
3530         }
3531
3532         offset = (size + alignment - 1) & -alignment;
3533         if (offset > size)
3534                 need_pad = true;
3535
3536         if (need_pad) {
3537                 if (warning.padded) {
3538                         warningf(&compound->base.source_position, "'%T' needs padding", type);
3539                 }
3540         } else {
3541                 if (compound->modifiers & DM_PACKED && warning.packed) {
3542                         warningf(&compound->base.source_position,
3543                                         "superfluous packed attribute on '%T'", type);
3544                 }
3545         }
3546
3547         type->base.size      = offset;
3548         type->base.alignment = alignment;
3549 }
3550
3551 /**
3552  * Finish the construction of an union type by calculating
3553  * its size and alignment.
3554  */
3555 static void finish_union_type(compound_type_t *type)
3556 {
3557         assert(type->compound != NULL);
3558
3559         compound_t *compound = type->compound;
3560         if (! compound->complete)
3561                 return;
3562
3563         il_size_t      size      = 0;
3564         il_alignment_t alignment = 1;
3565
3566         entity_t *entry = compound->members.entities;
3567         for (; entry != NULL; entry = entry->base.next) {
3568                 if (entry->kind != ENTITY_COMPOUND_MEMBER)
3569                         continue;
3570
3571                 type_t *m_type = skip_typeref(entry->declaration.type);
3572                 if (! is_type_valid(m_type))
3573                         continue;
3574
3575                 entry->compound_member.offset = 0;
3576                 if (m_type->base.size > size)
3577                         size = m_type->base.size;
3578                 if (m_type->base.alignment > alignment)
3579                         alignment = m_type->base.alignment;
3580         }
3581         if (type->base.alignment != 0) {
3582                 alignment = type->base.alignment;
3583         }
3584         size = (size + alignment - 1) & -alignment;
3585         type->base.size      = size;
3586         type->base.alignment = alignment;
3587 }
3588
3589 static type_t *handle_attribute_mode(const gnu_attribute_t *attribute,
3590                                      type_t *orig_type)
3591 {
3592         type_t *type = skip_typeref(orig_type);
3593
3594         /* at least: byte, word, pointer, list of machine modes
3595          * __XXX___ is interpreted as XXX */
3596
3597         /* This isn't really correct, the backend should provide a list of machine
3598          * specific modes (according to gcc philosophy that is...) */
3599         const char         *symbol_str = attribute->u.symbol->string;
3600         bool                sign       = is_type_signed(type);
3601         atomic_type_kind_t  akind;
3602         if (strcmp_underscore("QI",   symbol_str) == 0 ||
3603             strcmp_underscore("byte", symbol_str) == 0) {
3604                 akind = sign ? ATOMIC_TYPE_CHAR : ATOMIC_TYPE_UCHAR;
3605         } else if (strcmp_underscore("HI", symbol_str) == 0) {
3606                 akind = sign ? ATOMIC_TYPE_SHORT : ATOMIC_TYPE_USHORT;
3607         } else if (strcmp_underscore("SI",      symbol_str) == 0
3608                 || strcmp_underscore("word",    symbol_str) == 0
3609                 || strcmp_underscore("pointer", symbol_str) == 0) {
3610                 akind = sign ? ATOMIC_TYPE_INT : ATOMIC_TYPE_UINT;
3611         } else if (strcmp_underscore("DI", symbol_str) == 0) {
3612                 akind = sign ? ATOMIC_TYPE_LONGLONG : ATOMIC_TYPE_ULONGLONG;
3613         } else {
3614                 if (warning.other)
3615                         warningf(HERE, "ignoring unknown mode '%s'", symbol_str);
3616                 return orig_type;
3617         }
3618
3619         if (type->kind == TYPE_ATOMIC) {
3620                 type_t *copy       = duplicate_type(type);
3621                 copy->atomic.akind = akind;
3622                 return identify_new_type(copy);
3623         } else if (type->kind == TYPE_ENUM) {
3624                 type_t *copy      = duplicate_type(type);
3625                 copy->enumt.akind = akind;
3626                 return identify_new_type(copy);
3627         } else if (is_type_pointer(type)) {
3628                 warningf(HERE, "__attribute__((mode)) on pointers not implemented yet (ignored)");
3629                 return type;
3630         }
3631
3632         errorf(HERE, "__attribute__((mode)) only allowed on integer, enum or pointer type");
3633         return orig_type;
3634 }
3635
3636 static type_t *handle_type_attributes(const gnu_attribute_t *attributes,
3637                                       type_t *type)
3638 {
3639         const gnu_attribute_t *attribute = attributes;
3640         for ( ; attribute != NULL; attribute = attribute->next) {
3641                 if (attribute->invalid)
3642                         continue;
3643
3644                 if (attribute->kind == GNU_AK_MODE) {
3645                         type = handle_attribute_mode(attribute, type);
3646                 } else if (attribute->kind == GNU_AK_ALIGNED) {
3647                         int alignment = 32; /* TODO: fill in maximum useful alignment for
3648                                                target machine */
3649                         if (attribute->has_arguments)
3650                                 alignment = attribute->u.argument;
3651
3652                         type_t *copy         = duplicate_type(type);
3653                         copy->base.alignment = attribute->u.argument;
3654                         type                 = identify_new_type(copy);
3655                 }
3656         }
3657
3658         return type;
3659 }
3660
3661 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
3662 {
3663         type_t            *type              = NULL;
3664         type_qualifiers_t  qualifiers        = TYPE_QUALIFIER_NONE;
3665         type_modifiers_t   modifiers         = TYPE_MODIFIER_NONE;
3666         unsigned           type_specifiers   = 0;
3667         bool               newtype           = false;
3668         bool               saw_error         = false;
3669         bool               old_gcc_extension = in_gcc_extension;
3670
3671         specifiers->source_position = token.source_position;
3672
3673         while (true) {
3674                 specifiers->modifiers
3675                         |= parse_attributes(&specifiers->gnu_attributes);
3676
3677                 switch (token.type) {
3678                 /* storage class */
3679 #define MATCH_STORAGE_CLASS(token, class)                                  \
3680                 case token:                                                        \
3681                         if (specifiers->storage_class != STORAGE_CLASS_NONE) {         \
3682                                 errorf(HERE, "multiple storage classes in declaration specifiers"); \
3683                         }                                                              \
3684                         specifiers->storage_class = class;                             \
3685                         if (specifiers->thread_local)                                  \
3686                                 goto check_thread_storage_class;                           \
3687                         next_token();                                                  \
3688                         break;
3689
3690                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
3691                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
3692                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
3693                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
3694                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
3695
3696                 case T__declspec:
3697                         next_token();
3698                         expect('(', end_error);
3699                         add_anchor_token(')');
3700                         parse_microsoft_extended_decl_modifier(specifiers);
3701                         rem_anchor_token(')');
3702                         expect(')', end_error);
3703                         break;
3704
3705                 case T___thread:
3706                         if (specifiers->thread_local) {
3707                                 errorf(HERE, "duplicate '__thread'");
3708                         } else {
3709                                 specifiers->thread_local = true;
3710 check_thread_storage_class:
3711                                 switch (specifiers->storage_class) {
3712                                         case STORAGE_CLASS_EXTERN:
3713                                         case STORAGE_CLASS_NONE:
3714                                         case STORAGE_CLASS_STATIC:
3715                                                 break;
3716
3717                                                 char const* wrong;
3718                                         case STORAGE_CLASS_AUTO:     wrong = "auto";     goto wrong_thread_stoarge_class;
3719                                         case STORAGE_CLASS_REGISTER: wrong = "register"; goto wrong_thread_stoarge_class;
3720                                         case STORAGE_CLASS_TYPEDEF:  wrong = "typedef";  goto wrong_thread_stoarge_class;
3721 wrong_thread_stoarge_class:
3722                                                 errorf(HERE, "'__thread' used with '%s'", wrong);
3723                                                 break;
3724                                 }
3725                         }
3726                         next_token();
3727                         break;
3728
3729                 /* type qualifiers */
3730 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
3731                 case token:                                                     \
3732                         qualifiers |= qualifier;                                    \
3733                         next_token();                                               \
3734                         break
3735
3736                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3737                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3738                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3739                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3740                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3741                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3742                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3743                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3744
3745                 case T___extension__:
3746                         next_token();
3747                         in_gcc_extension = true;
3748                         break;
3749
3750                 /* type specifiers */
3751 #define MATCH_SPECIFIER(token, specifier, name)                         \
3752                 case token:                                                     \
3753                         if (type_specifiers & specifier) {                           \
3754                                 errorf(HERE, "multiple " name " type specifiers given"); \
3755                         } else {                                                    \
3756                                 type_specifiers |= specifier;                           \
3757                         }                                                           \
3758                         next_token();                                               \
3759                         break
3760
3761                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool");
3762                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex");
3763                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary");
3764                 MATCH_SPECIFIER(T__int128,    SPECIFIER_INT128,    "_int128");
3765                 MATCH_SPECIFIER(T__int16,     SPECIFIER_INT16,     "_int16");
3766                 MATCH_SPECIFIER(T__int32,     SPECIFIER_INT32,     "_int32");
3767                 MATCH_SPECIFIER(T__int64,     SPECIFIER_INT64,     "_int64");
3768                 MATCH_SPECIFIER(T__int8,      SPECIFIER_INT8,      "_int8");
3769                 MATCH_SPECIFIER(T_bool,       SPECIFIER_BOOL,      "bool");
3770                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char");
3771                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double");
3772                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float");
3773                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int");
3774                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short");
3775                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed");
3776                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned");
3777                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void");
3778                 MATCH_SPECIFIER(T_wchar_t,    SPECIFIER_WCHAR_T,   "wchar_t");
3779
3780                 case T__forceinline:
3781                         /* only in microsoft mode */
3782                         specifiers->modifiers |= DM_FORCEINLINE;
3783                         /* FALLTHROUGH */
3784
3785                 case T_inline:
3786                         next_token();
3787                         specifiers->is_inline = true;
3788                         break;
3789
3790                 case T_long:
3791                         if (type_specifiers & SPECIFIER_LONG_LONG) {
3792                                 errorf(HERE, "multiple type specifiers given");
3793                         } else if (type_specifiers & SPECIFIER_LONG) {
3794                                 type_specifiers |= SPECIFIER_LONG_LONG;
3795                         } else {
3796                                 type_specifiers |= SPECIFIER_LONG;
3797                         }
3798                         next_token();
3799                         break;
3800
3801                 case T_struct: {
3802                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
3803
3804                         type->compound.compound = parse_compound_type_specifier(true);
3805                         finish_struct_type(&type->compound);
3806                         break;
3807                 }
3808                 case T_union: {
3809                         type = allocate_type_zero(TYPE_COMPOUND_UNION);
3810                         type->compound.compound = parse_compound_type_specifier(false);
3811                         if (type->compound.compound->modifiers & DM_TRANSPARENT_UNION)
3812                                 modifiers |= TYPE_MODIFIER_TRANSPARENT_UNION;
3813                         finish_union_type(&type->compound);
3814                         break;
3815                 }
3816                 case T_enum:
3817                         type = parse_enum_specifier();
3818                         break;
3819                 case T___typeof__:
3820                         type = parse_typeof();
3821                         break;
3822                 case T___builtin_va_list:
3823                         type = duplicate_type(type_valist);
3824                         next_token();
3825                         break;
3826
3827                 case T_IDENTIFIER: {
3828                         /* only parse identifier if we haven't found a type yet */
3829                         if (type != NULL || type_specifiers != 0) {
3830                                 /* Be somewhat resilient to typos like 'unsigned lng* f()' in a
3831                                  * declaration, so it doesn't generate errors about expecting '(' or
3832                                  * '{' later on. */
3833                                 switch (look_ahead(1)->type) {
3834                                         STORAGE_CLASSES
3835                                         TYPE_SPECIFIERS
3836                                         case T_const:
3837                                         case T_restrict:
3838                                         case T_volatile:
3839                                         case T_inline:
3840                                         case T__forceinline: /* ^ DECLARATION_START except for __attribute__ */
3841                                         case T_IDENTIFIER:
3842                                         case '&':
3843                                         case '*':
3844                                                 errorf(HERE, "discarding stray %K in declaration specifier", &token);
3845                                                 next_token();
3846                                                 continue;
3847
3848                                         default:
3849                                                 goto finish_specifiers;
3850                                 }
3851                         }
3852
3853                         type_t *const typedef_type = get_typedef_type(token.v.symbol);
3854                         if (typedef_type == NULL) {
3855                                 /* Be somewhat resilient to typos like 'vodi f()' at the beginning of a
3856                                  * declaration, so it doesn't generate 'implicit int' followed by more
3857                                  * errors later on. */
3858                                 token_type_t const la1_type = (token_type_t)look_ahead(1)->type;
3859                                 switch (la1_type) {
3860                                         DECLARATION_START
3861                                         case T_IDENTIFIER:
3862                                         case '&':
3863                                         case '*': {
3864                                                 errorf(HERE, "%K does not name a type", &token);
3865
3866                                                 entity_t *entity =
3867                                                         create_error_entity(token.v.symbol, ENTITY_TYPEDEF);
3868
3869                                                 type = allocate_type_zero(TYPE_TYPEDEF);
3870                                                 type->typedeft.typedefe = &entity->typedefe;
3871
3872                                                 next_token();
3873                                                 saw_error = true;
3874                                                 if (la1_type == '&' || la1_type == '*')
3875                                                         goto finish_specifiers;
3876                                                 continue;
3877                                         }
3878
3879                                         default:
3880                                                 goto finish_specifiers;
3881                                 }
3882                         }
3883
3884                         next_token();
3885                         type = typedef_type;
3886                         break;
3887                 }
3888
3889                 /* function specifier */
3890                 default:
3891                         goto finish_specifiers;
3892                 }
3893         }
3894
3895 finish_specifiers:
3896         specifiers->modifiers
3897                 |= parse_attributes(&specifiers->gnu_attributes);
3898
3899         in_gcc_extension = old_gcc_extension;
3900
3901         if (type == NULL || (saw_error && type_specifiers != 0)) {
3902                 atomic_type_kind_t atomic_type;
3903
3904                 /* match valid basic types */
3905                 switch (type_specifiers) {
3906                 case SPECIFIER_VOID:
3907                         atomic_type = ATOMIC_TYPE_VOID;
3908                         break;
3909                 case SPECIFIER_WCHAR_T:
3910                         atomic_type = ATOMIC_TYPE_WCHAR_T;
3911                         break;
3912                 case SPECIFIER_CHAR:
3913                         atomic_type = ATOMIC_TYPE_CHAR;
3914                         break;
3915                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
3916                         atomic_type = ATOMIC_TYPE_SCHAR;
3917                         break;
3918                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
3919                         atomic_type = ATOMIC_TYPE_UCHAR;
3920                         break;
3921                 case SPECIFIER_SHORT:
3922                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
3923                 case SPECIFIER_SHORT | SPECIFIER_INT:
3924                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
3925                         atomic_type = ATOMIC_TYPE_SHORT;
3926                         break;
3927                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
3928                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
3929                         atomic_type = ATOMIC_TYPE_USHORT;
3930                         break;
3931                 case SPECIFIER_INT:
3932                 case SPECIFIER_SIGNED:
3933                 case SPECIFIER_SIGNED | SPECIFIER_INT:
3934                         atomic_type = ATOMIC_TYPE_INT;
3935                         break;
3936                 case SPECIFIER_UNSIGNED:
3937                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
3938                         atomic_type = ATOMIC_TYPE_UINT;
3939                         break;
3940                 case SPECIFIER_LONG:
3941                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
3942                 case SPECIFIER_LONG | SPECIFIER_INT:
3943                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
3944                         atomic_type = ATOMIC_TYPE_LONG;
3945                         break;
3946                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
3947                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
3948                         atomic_type = ATOMIC_TYPE_ULONG;
3949                         break;
3950
3951                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3952                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3953                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
3954                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3955                         | SPECIFIER_INT:
3956                         atomic_type = ATOMIC_TYPE_LONGLONG;
3957                         goto warn_about_long_long;
3958
3959                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3960                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3961                         | SPECIFIER_INT:
3962                         atomic_type = ATOMIC_TYPE_ULONGLONG;
3963 warn_about_long_long:
3964                         if (warning.long_long) {
3965                                 warningf(&specifiers->source_position,
3966                                          "ISO C90 does not support 'long long'");
3967                         }
3968                         break;
3969
3970                 case SPECIFIER_UNSIGNED | SPECIFIER_INT8:
3971                         atomic_type = unsigned_int8_type_kind;
3972                         break;
3973
3974                 case SPECIFIER_UNSIGNED | SPECIFIER_INT16:
3975                         atomic_type = unsigned_int16_type_kind;
3976                         break;
3977
3978                 case SPECIFIER_UNSIGNED | SPECIFIER_INT32:
3979                         atomic_type = unsigned_int32_type_kind;
3980                         break;
3981
3982                 case SPECIFIER_UNSIGNED | SPECIFIER_INT64:
3983                         atomic_type = unsigned_int64_type_kind;
3984                         break;
3985
3986                 case SPECIFIER_UNSIGNED | SPECIFIER_INT128:
3987                         atomic_type = unsigned_int128_type_kind;
3988                         break;
3989
3990                 case SPECIFIER_INT8:
3991                 case SPECIFIER_SIGNED | SPECIFIER_INT8:
3992                         atomic_type = int8_type_kind;
3993                         break;
3994
3995                 case SPECIFIER_INT16:
3996                 case SPECIFIER_SIGNED | SPECIFIER_INT16:
3997                         atomic_type = int16_type_kind;
3998                         break;
3999
4000                 case SPECIFIER_INT32:
4001                 case SPECIFIER_SIGNED | SPECIFIER_INT32:
4002                         atomic_type = int32_type_kind;
4003                         break;
4004
4005                 case SPECIFIER_INT64:
4006                 case SPECIFIER_SIGNED | SPECIFIER_INT64:
4007                         atomic_type = int64_type_kind;
4008                         break;
4009
4010                 case SPECIFIER_INT128:
4011                 case SPECIFIER_SIGNED | SPECIFIER_INT128:
4012                         atomic_type = int128_type_kind;
4013                         break;
4014
4015                 case SPECIFIER_FLOAT:
4016                         atomic_type = ATOMIC_TYPE_FLOAT;
4017                         break;
4018                 case SPECIFIER_DOUBLE:
4019                         atomic_type = ATOMIC_TYPE_DOUBLE;
4020                         break;
4021                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
4022                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
4023                         break;
4024                 case SPECIFIER_BOOL:
4025                         atomic_type = ATOMIC_TYPE_BOOL;
4026                         break;
4027                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
4028                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
4029                         atomic_type = ATOMIC_TYPE_FLOAT;
4030                         break;
4031                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
4032                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
4033                         atomic_type = ATOMIC_TYPE_DOUBLE;
4034                         break;
4035                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
4036                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
4037                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
4038                         break;
4039                 default:
4040                         /* invalid specifier combination, give an error message */
4041                         if (type_specifiers == 0) {
4042                                 if (saw_error)
4043                                         goto end_error;
4044
4045                                 /* ISO/IEC 14882:1998(E) §C.1.5:4 */
4046                                 if (!(c_mode & _CXX) && !strict_mode) {
4047                                         if (warning.implicit_int) {
4048                                                 warningf(HERE, "no type specifiers in declaration, using 'int'");
4049                                         }
4050                                         atomic_type = ATOMIC_TYPE_INT;
4051                                         break;
4052                                 } else {
4053                                         errorf(HERE, "no type specifiers given in declaration");
4054                                 }
4055                         } else if ((type_specifiers & SPECIFIER_SIGNED) &&
4056                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
4057                                 errorf(HERE, "signed and unsigned specifiers given");
4058                         } else if (type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
4059                                 errorf(HERE, "only integer types can be signed or unsigned");
4060                         } else {
4061                                 errorf(HERE, "multiple datatypes in declaration");
4062                         }
4063                         goto end_error;
4064                 }
4065
4066                 if (type_specifiers & SPECIFIER_COMPLEX) {
4067                         type                = allocate_type_zero(TYPE_COMPLEX);
4068                         type->complex.akind = atomic_type;
4069                 } else if (type_specifiers & SPECIFIER_IMAGINARY) {
4070                         type                  = allocate_type_zero(TYPE_IMAGINARY);
4071                         type->imaginary.akind = atomic_type;
4072                 } else {
4073                         type                 = allocate_type_zero(TYPE_ATOMIC);
4074                         type->atomic.akind   = atomic_type;
4075                 }
4076                 type->base.alignment = get_atomic_type_alignment(atomic_type);
4077                 unsigned const size  = get_atomic_type_size(atomic_type);
4078                 type->base.size      =
4079                         type_specifiers & SPECIFIER_COMPLEX ? size * 2 : size;
4080                 newtype = true;
4081         } else if (type_specifiers != 0) {
4082                 errorf(HERE, "multiple datatypes in declaration");
4083         }
4084
4085         /* FIXME: check type qualifiers here */
4086
4087         if (specifiers->modifiers & DM_TRANSPARENT_UNION)
4088                 modifiers |= TYPE_MODIFIER_TRANSPARENT_UNION;
4089         type->base.qualifiers = qualifiers;
4090         type->base.modifiers  = modifiers;
4091
4092         if (newtype) {
4093                 type = identify_new_type(type);
4094         } else {
4095                 type = typehash_insert(type);
4096         }
4097
4098         type = handle_type_attributes(specifiers->gnu_attributes, type);
4099         specifiers->type = type;
4100         return;
4101
4102 end_error:
4103         specifiers->type = type_error_type;
4104         return;
4105 }
4106
4107 static type_qualifiers_t parse_type_qualifiers(void)
4108 {
4109         type_qualifiers_t qualifiers = TYPE_QUALIFIER_NONE;
4110
4111         while (true) {
4112                 switch (token.type) {
4113                 /* type qualifiers */
4114                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
4115                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
4116                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
4117                 /* microsoft extended type modifiers */
4118                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
4119                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
4120                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
4121                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
4122                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
4123
4124                 default:
4125                         return qualifiers;
4126                 }
4127         }
4128 }
4129
4130 /**
4131  * Parses an K&R identifier list
4132  */
4133 static void parse_identifier_list(scope_t *scope)
4134 {
4135         do {
4136                 entity_t *entity = allocate_entity_zero(ENTITY_PARAMETER);
4137                 entity->base.source_position = token.source_position;
4138                 entity->base.namespc         = NAMESPACE_NORMAL;
4139                 entity->base.symbol          = token.v.symbol;
4140                 /* a K&R parameter has no type, yet */
4141                 next_token();
4142
4143                 if (scope != NULL)
4144                         append_entity(scope, entity);
4145
4146                 if (token.type != ',') {
4147                         break;
4148                 }
4149                 next_token();
4150         } while (token.type == T_IDENTIFIER);
4151 }
4152
4153 static entity_t *parse_parameter(void)
4154 {
4155         declaration_specifiers_t specifiers;
4156         memset(&specifiers, 0, sizeof(specifiers));
4157
4158         parse_declaration_specifiers(&specifiers);
4159
4160         entity_t *entity = parse_declarator(&specifiers,
4161                         DECL_MAY_BE_ABSTRACT | DECL_IS_PARAMETER);
4162         anonymous_entity = NULL;
4163         return entity;
4164 }
4165
4166 static void semantic_parameter_incomplete(const entity_t *entity)
4167 {
4168         assert(entity->kind == ENTITY_PARAMETER);
4169
4170         /* §6.7.5.3:4  After adjustment, the parameters in a parameter type
4171          *             list in a function declarator that is part of a
4172          *             definition of that function shall not have
4173          *             incomplete type. */
4174         type_t *type = skip_typeref(entity->declaration.type);
4175         if (is_type_incomplete(type)) {
4176                 errorf(&entity->base.source_position,
4177                        "parameter '%Y' has incomplete type '%T'", entity->base.symbol,
4178                        entity->declaration.type);
4179         }
4180 }
4181
4182 /**
4183  * Parses function type parameters (and optionally creates variable_t entities
4184  * for them in a scope)
4185  */
4186 static void parse_parameters(function_type_t *type, scope_t *scope)
4187 {
4188         eat('(');
4189         add_anchor_token(')');
4190         int saved_comma_state = save_and_reset_anchor_state(',');
4191
4192         if (token.type == T_IDENTIFIER &&
4193             !is_typedef_symbol(token.v.symbol)) {
4194                 token_type_t la1_type = (token_type_t)look_ahead(1)->type;
4195                 if (la1_type == ',' || la1_type == ')') {
4196                         type->kr_style_parameters    = true;
4197                         type->unspecified_parameters = true;
4198                         parse_identifier_list(scope);
4199                         goto parameters_finished;
4200                 }
4201         }
4202
4203         if (token.type == ')') {
4204                 /* ISO/IEC 14882:1998(E) §C.1.6:1 */
4205                 if (!(c_mode & _CXX))
4206                         type->unspecified_parameters = true;
4207                 goto parameters_finished;
4208         }
4209
4210         function_parameter_t *parameter;
4211         function_parameter_t *last_parameter = NULL;
4212
4213         while (true) {
4214                 switch (token.type) {
4215                 case T_DOTDOTDOT:
4216                         next_token();
4217                         type->variadic = true;
4218                         goto parameters_finished;
4219
4220                 case T_IDENTIFIER:
4221                 case T___extension__:
4222                 DECLARATION_START
4223                 {
4224                         entity_t *entity = parse_parameter();
4225                         if (entity->kind == ENTITY_TYPEDEF) {
4226                                 errorf(&entity->base.source_position,
4227                                        "typedef not allowed as function parameter");
4228                                 break;
4229                         }
4230                         assert(is_declaration(entity));
4231
4232                         /* func(void) is not a parameter */
4233                         if (last_parameter == NULL
4234                                         && token.type == ')'
4235                                         && entity->base.symbol == NULL
4236                                         && skip_typeref(entity->declaration.type) == type_void) {
4237                                 goto parameters_finished;
4238                         }
4239                         semantic_parameter_incomplete(entity);
4240
4241                         parameter = obstack_alloc(type_obst, sizeof(parameter[0]));
4242                         memset(parameter, 0, sizeof(parameter[0]));
4243                         parameter->type = entity->declaration.type;
4244
4245                         if (scope != NULL) {
4246                                 append_entity(scope, entity);
4247                         }
4248
4249                         if (last_parameter != NULL) {
4250                                 last_parameter->next = parameter;
4251                         } else {
4252                                 type->parameters = parameter;
4253                         }
4254                         last_parameter   = parameter;
4255                         break;
4256                 }
4257
4258                 default:
4259                         goto parameters_finished;
4260                 }
4261                 if (token.type != ',') {
4262                         goto parameters_finished;
4263                 }
4264                 next_token();
4265         }
4266
4267
4268 parameters_finished:
4269         rem_anchor_token(')');
4270         expect(')', end_error);
4271
4272 end_error:
4273         restore_anchor_state(',', saved_comma_state);
4274 }
4275
4276 typedef enum construct_type_kind_t {
4277         CONSTRUCT_INVALID,
4278         CONSTRUCT_POINTER,
4279         CONSTRUCT_REFERENCE,
4280         CONSTRUCT_FUNCTION,
4281         CONSTRUCT_ARRAY
4282 } construct_type_kind_t;
4283
4284 typedef struct construct_type_t construct_type_t;
4285 struct construct_type_t {
4286         construct_type_kind_t  kind;
4287         construct_type_t      *next;
4288 };
4289
4290 typedef struct parsed_pointer_t parsed_pointer_t;
4291 struct parsed_pointer_t {
4292         construct_type_t  construct_type;
4293         type_qualifiers_t type_qualifiers;
4294         variable_t        *base_variable;  /**< MS __based extension. */
4295 };
4296
4297 typedef struct parsed_reference_t parsed_reference_t;
4298 struct parsed_reference_t {
4299         construct_type_t construct_type;
4300 };
4301
4302 typedef struct construct_function_type_t construct_function_type_t;
4303 struct construct_function_type_t {
4304         construct_type_t  construct_type;
4305         type_t           *function_type;
4306 };
4307
4308 typedef struct parsed_array_t parsed_array_t;
4309 struct parsed_array_t {
4310         construct_type_t  construct_type;
4311         type_qualifiers_t type_qualifiers;
4312         bool              is_static;
4313         bool              is_variable;
4314         expression_t     *size;
4315 };
4316
4317 typedef struct construct_base_type_t construct_base_type_t;
4318 struct construct_base_type_t {
4319         construct_type_t  construct_type;
4320         type_t           *type;
4321 };
4322
4323 static construct_type_t *parse_pointer_declarator(variable_t *base_variable)
4324 {
4325         eat('*');
4326
4327         parsed_pointer_t *pointer = obstack_alloc(&temp_obst, sizeof(pointer[0]));
4328         memset(pointer, 0, sizeof(pointer[0]));
4329         pointer->construct_type.kind = CONSTRUCT_POINTER;
4330         pointer->type_qualifiers     = parse_type_qualifiers();
4331         pointer->base_variable       = base_variable;
4332
4333         return &pointer->construct_type;
4334 }
4335
4336 static construct_type_t *parse_reference_declarator(void)
4337 {
4338         eat('&');
4339
4340         parsed_reference_t *reference = obstack_alloc(&temp_obst, sizeof(reference[0]));
4341         memset(reference, 0, sizeof(reference[0]));
4342         reference->construct_type.kind = CONSTRUCT_REFERENCE;
4343
4344         return (construct_type_t*)reference;
4345 }
4346
4347 static construct_type_t *parse_array_declarator(void)
4348 {
4349         eat('[');
4350         add_anchor_token(']');
4351
4352         parsed_array_t *array = obstack_alloc(&temp_obst, sizeof(array[0]));
4353         memset(array, 0, sizeof(array[0]));
4354         array->construct_type.kind = CONSTRUCT_ARRAY;
4355
4356         if (token.type == T_static) {
4357                 array->is_static = true;
4358                 next_token();
4359         }
4360
4361         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
4362         if (type_qualifiers != 0) {
4363                 if (token.type == T_static) {
4364                         array->is_static = true;
4365                         next_token();
4366                 }
4367         }
4368         array->type_qualifiers = type_qualifiers;
4369
4370         if (token.type == '*' && look_ahead(1)->type == ']') {
4371                 array->is_variable = true;
4372                 next_token();
4373         } else if (token.type != ']') {
4374                 expression_t *const size = parse_assignment_expression();
4375                 array->size = size;
4376                 mark_vars_read(size, NULL);
4377         }
4378
4379         rem_anchor_token(']');
4380         expect(']', end_error);
4381
4382 end_error:
4383         return &array->construct_type;
4384 }
4385
4386 static construct_type_t *parse_function_declarator(scope_t *scope,
4387                                                    decl_modifiers_t modifiers)
4388 {
4389         type_t          *type  = allocate_type_zero(TYPE_FUNCTION);
4390         function_type_t *ftype = &type->function;
4391
4392         ftype->linkage = current_linkage;
4393
4394         switch (modifiers & (DM_CDECL | DM_STDCALL | DM_FASTCALL | DM_THISCALL)) {
4395                 case DM_NONE:     break;
4396                 case DM_CDECL:    ftype->calling_convention = CC_CDECL;    break;
4397                 case DM_STDCALL:  ftype->calling_convention = CC_STDCALL;  break;
4398                 case DM_FASTCALL: ftype->calling_convention = CC_FASTCALL; break;
4399                 case DM_THISCALL: ftype->calling_convention = CC_THISCALL; break;
4400
4401                 default:
4402                         errorf(HERE, "multiple calling conventions in declaration");
4403                         break;
4404         }
4405
4406         parse_parameters(ftype, scope);
4407
4408         construct_function_type_t *construct_function_type =
4409                 obstack_alloc(&temp_obst, sizeof(construct_function_type[0]));
4410         memset(construct_function_type, 0, sizeof(construct_function_type[0]));
4411         construct_function_type->construct_type.kind = CONSTRUCT_FUNCTION;
4412         construct_function_type->function_type       = type;
4413
4414         return &construct_function_type->construct_type;
4415 }
4416
4417 typedef struct parse_declarator_env_t {
4418         decl_modifiers_t   modifiers;
4419         symbol_t          *symbol;
4420         source_position_t  source_position;
4421         scope_t            parameters;
4422 } parse_declarator_env_t;
4423
4424 static construct_type_t *parse_inner_declarator(parse_declarator_env_t *env,
4425                 bool may_be_abstract)
4426 {
4427         /* construct a single linked list of construct_type_t's which describe
4428          * how to construct the final declarator type */
4429         construct_type_t *first      = NULL;
4430         construct_type_t *last       = NULL;
4431         gnu_attribute_t  *attributes = NULL;
4432
4433         decl_modifiers_t modifiers = parse_attributes(&attributes);
4434
4435         /* MS __based extension */
4436         based_spec_t base_spec;
4437         base_spec.base_variable = NULL;
4438
4439         for (;;) {
4440                 construct_type_t *type;
4441                 switch (token.type) {
4442                         case '&':
4443                                 if (!(c_mode & _CXX))
4444                                         errorf(HERE, "references are only available for C++");
4445                                 if (base_spec.base_variable != NULL && warning.other) {
4446                                         warningf(&base_spec.source_position,
4447                                                  "__based does not precede a pointer operator, ignored");
4448                                 }
4449                                 type = parse_reference_declarator();
4450                                 /* consumed */
4451                                 base_spec.base_variable = NULL;
4452                                 break;
4453
4454                         case '*':
4455                                 type = parse_pointer_declarator(base_spec.base_variable);
4456                                 /* consumed */
4457                                 base_spec.base_variable = NULL;
4458                                 break;
4459
4460                         case T__based:
4461                                 next_token();
4462                                 expect('(', end_error);
4463                                 add_anchor_token(')');
4464                                 parse_microsoft_based(&base_spec);
4465                                 rem_anchor_token(')');
4466                                 expect(')', end_error);
4467                                 continue;
4468
4469                         default:
4470                                 goto ptr_operator_end;
4471                 }
4472
4473                 if (last == NULL) {
4474                         first = type;
4475                         last  = type;
4476                 } else {
4477                         last->next = type;
4478                         last       = type;
4479                 }
4480
4481                 /* TODO: find out if this is correct */
4482                 modifiers |= parse_attributes(&attributes);
4483         }
4484 ptr_operator_end:
4485         if (base_spec.base_variable != NULL && warning.other) {
4486                 warningf(&base_spec.source_position,
4487                          "__based does not precede a pointer operator, ignored");
4488         }
4489
4490         if (env != NULL) {
4491                 modifiers      |= env->modifiers;
4492                 env->modifiers  = modifiers;
4493         }
4494
4495         construct_type_t *inner_types = NULL;
4496
4497         switch (token.type) {
4498         case T_IDENTIFIER:
4499                 if (env == NULL) {
4500                         errorf(HERE, "no identifier expected in typename");
4501                 } else {
4502                         env->symbol          = token.v.symbol;
4503                         env->source_position = token.source_position;
4504                 }
4505                 next_token();
4506                 break;
4507         case '(':
4508                 /* §6.7.6:2 footnote 126:  Empty parentheses in a type name are
4509                  * interpreted as ``function with no parameter specification'', rather
4510                  * than redundant parentheses around the omitted identifier. */
4511                 if (look_ahead(1)->type != ')') {
4512                         next_token();
4513                         add_anchor_token(')');
4514                         inner_types = parse_inner_declarator(env, may_be_abstract);
4515                         if (inner_types != NULL) {
4516                                 /* All later declarators only modify the return type */
4517                                 env = NULL;
4518                         }
4519                         rem_anchor_token(')');
4520                         expect(')', end_error);
4521                 }
4522                 break;
4523         default:
4524                 if (may_be_abstract)
4525                         break;
4526                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', NULL);
4527                 eat_until_anchor();
4528                 return NULL;
4529         }
4530
4531         construct_type_t *p = last;
4532
4533         while (true) {
4534                 construct_type_t *type;
4535                 switch (token.type) {
4536                 case '(': {
4537                         scope_t *scope = NULL;
4538                         if (env != NULL)
4539                                 scope = &env->parameters;
4540
4541                         type = parse_function_declarator(scope, modifiers);
4542                         break;
4543                 }
4544                 case '[':
4545                         type = parse_array_declarator();
4546                         break;
4547                 default:
4548                         goto declarator_finished;
4549                 }
4550
4551                 /* insert in the middle of the list (behind p) */
4552                 if (p != NULL) {
4553                         type->next = p->next;
4554                         p->next    = type;
4555                 } else {
4556                         type->next = first;
4557                         first      = type;
4558                 }
4559                 if (last == p) {
4560                         last = type;
4561                 }
4562         }
4563
4564 declarator_finished:
4565         /* append inner_types at the end of the list, we don't to set last anymore
4566          * as it's not needed anymore */
4567         if (last == NULL) {
4568                 assert(first == NULL);
4569                 first = inner_types;
4570         } else {
4571                 last->next = inner_types;
4572         }
4573
4574         return first;
4575 end_error:
4576         return NULL;
4577 }
4578
4579 static void parse_declaration_attributes(entity_t *entity)
4580 {
4581         gnu_attribute_t  *attributes = NULL;
4582         decl_modifiers_t  modifiers  = parse_attributes(&attributes);
4583
4584         if (entity == NULL)
4585                 return;
4586
4587         type_t *type;
4588         if (entity->kind == ENTITY_TYPEDEF) {
4589                 modifiers |= entity->typedefe.modifiers;
4590                 type       = entity->typedefe.type;
4591         } else {
4592                 assert(is_declaration(entity));
4593                 modifiers |= entity->declaration.modifiers;
4594                 type       = entity->declaration.type;
4595         }
4596         if (type == NULL)
4597                 return;
4598
4599         gnu_attribute_t *attribute = attributes;
4600         for ( ; attribute != NULL; attribute = attribute->next) {
4601                 if (attribute->invalid)
4602                         continue;
4603
4604                 if (attribute->kind == GNU_AK_MODE) {
4605                         type = handle_attribute_mode(attribute, type);
4606                 } else if (attribute->kind == GNU_AK_ALIGNED) {
4607                         int alignment = 32; /* TODO: fill in maximum usefull alignment for target machine */
4608                         if (attribute->has_arguments)
4609                                 alignment = attribute->u.argument;
4610
4611                         if (entity->kind == ENTITY_TYPEDEF) {
4612                                 type_t *copy         = duplicate_type(type);
4613                                 copy->base.alignment = attribute->u.argument;
4614                                 type                 = identify_new_type(copy);
4615                         } else if(entity->kind == ENTITY_VARIABLE) {
4616                                 entity->variable.alignment = alignment;
4617                         } else if(entity->kind == ENTITY_COMPOUND_MEMBER) {
4618                                 entity->compound_member.alignment = alignment;
4619                         }
4620                 }
4621         }
4622
4623         type_modifiers_t type_modifiers = type->base.modifiers;
4624         if (modifiers & DM_TRANSPARENT_UNION)
4625                 type_modifiers |= TYPE_MODIFIER_TRANSPARENT_UNION;
4626
4627         if (type->base.modifiers != type_modifiers) {
4628                 type_t *copy         = duplicate_type(type);
4629                 copy->base.modifiers = type_modifiers;
4630                 type                 = identify_new_type(copy);
4631         }
4632
4633         if (entity->kind == ENTITY_TYPEDEF) {
4634                 entity->typedefe.type      = type;
4635                 entity->typedefe.modifiers = modifiers;
4636         } else {
4637                 entity->declaration.type      = type;
4638                 entity->declaration.modifiers = modifiers;
4639         }
4640 }
4641
4642 static type_t *construct_declarator_type(construct_type_t *construct_list, type_t *type)
4643 {
4644         construct_type_t *iter = construct_list;
4645         for (; iter != NULL; iter = iter->next) {
4646                 switch (iter->kind) {
4647                 case CONSTRUCT_INVALID:
4648                         internal_errorf(HERE, "invalid type construction found");
4649                 case CONSTRUCT_FUNCTION: {
4650                         construct_function_type_t *construct_function_type
4651                                 = (construct_function_type_t*) iter;
4652
4653                         type_t *function_type = construct_function_type->function_type;
4654
4655                         function_type->function.return_type = type;
4656
4657                         type_t *skipped_return_type = skip_typeref(type);
4658                         /* §6.7.5.3:1 */
4659                         if (is_type_function(skipped_return_type)) {
4660                                 errorf(HERE, "function returning function is not allowed");
4661                         } else if (is_type_array(skipped_return_type)) {
4662                                 errorf(HERE, "function returning array is not allowed");
4663                         } else {
4664                                 if (skipped_return_type->base.qualifiers != 0 && warning.other) {
4665                                         warningf(HERE,
4666                                                 "type qualifiers in return type of function type are meaningless");
4667                                 }
4668                         }
4669
4670                         type = function_type;
4671                         break;
4672                 }
4673
4674                 case CONSTRUCT_POINTER: {
4675                         if (is_type_reference(skip_typeref(type)))
4676                                 errorf(HERE, "cannot declare a pointer to reference");
4677
4678                         parsed_pointer_t *parsed_pointer = (parsed_pointer_t*) iter;
4679                         type = make_based_pointer_type(type, parsed_pointer->type_qualifiers, parsed_pointer->base_variable);
4680                         continue;
4681                 }
4682
4683                 case CONSTRUCT_REFERENCE:
4684                         if (is_type_reference(skip_typeref(type)))
4685                                 errorf(HERE, "cannot declare a reference to reference");
4686
4687                         type = make_reference_type(type);
4688                         continue;
4689
4690                 case CONSTRUCT_ARRAY: {
4691                         if (is_type_reference(skip_typeref(type)))
4692                                 errorf(HERE, "cannot declare an array of references");
4693
4694                         parsed_array_t *parsed_array  = (parsed_array_t*) iter;
4695                         type_t         *array_type    = allocate_type_zero(TYPE_ARRAY);
4696
4697                         expression_t *size_expression = parsed_array->size;
4698                         if (size_expression != NULL) {
4699                                 size_expression
4700                                         = create_implicit_cast(size_expression, type_size_t);
4701                         }
4702
4703                         array_type->base.qualifiers       = parsed_array->type_qualifiers;
4704                         array_type->array.element_type    = type;
4705                         array_type->array.is_static       = parsed_array->is_static;
4706                         array_type->array.is_variable     = parsed_array->is_variable;
4707                         array_type->array.size_expression = size_expression;
4708
4709                         if (size_expression != NULL) {
4710                                 if (is_constant_expression(size_expression)) {
4711                                         array_type->array.size_constant = true;
4712                                         array_type->array.size
4713                                                 = fold_constant(size_expression);
4714                                 } else {
4715                                         array_type->array.is_vla = true;
4716                                 }
4717                         }
4718
4719                         type_t *skipped_type = skip_typeref(type);
4720                         /* §6.7.5.2:1 */
4721                         if (is_type_incomplete(skipped_type)) {
4722                                 errorf(HERE, "array of incomplete type '%T' is not allowed", type);
4723                         } else if (is_type_function(skipped_type)) {
4724                                 errorf(HERE, "array of functions is not allowed");
4725                         }
4726                         type = array_type;
4727                         break;
4728                 }
4729                 }
4730
4731                 /* The function type was constructed earlier.  Freeing it here will
4732                  * destroy other types. */
4733                 if (iter->kind == CONSTRUCT_FUNCTION) {
4734                         type = typehash_insert(type);
4735                 } else {
4736                         type = identify_new_type(type);
4737                 }
4738         }
4739
4740         return type;
4741 }
4742
4743 static type_t *automatic_type_conversion(type_t *orig_type);
4744
4745 static type_t *semantic_parameter(const source_position_t *pos,
4746                                   type_t *type,
4747                                   const declaration_specifiers_t *specifiers,
4748                                   symbol_t *symbol)
4749 {
4750         /* §6.7.5.3:7  A declaration of a parameter as ``array of type''
4751          *             shall be adjusted to ``qualified pointer to type'',
4752          *             [...]
4753          * §6.7.5.3:8  A declaration of a parameter as ``function returning
4754          *             type'' shall be adjusted to ``pointer to function
4755          *             returning type'', as in 6.3.2.1. */
4756         type = automatic_type_conversion(type);
4757
4758         if (specifiers->is_inline && is_type_valid(type)) {
4759                 errorf(pos, "parameter '%Y' declared 'inline'", symbol);
4760         }
4761
4762         /* §6.9.1:6  The declarations in the declaration list shall contain
4763          *           no storage-class specifier other than register and no
4764          *           initializations. */
4765         if (specifiers->thread_local || (
4766                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
4767                         specifiers->storage_class != STORAGE_CLASS_REGISTER)
4768            ) {
4769                 errorf(pos, "invalid storage class for parameter '%Y'", symbol);
4770         }
4771
4772         /* delay test for incomplete type, because we might have (void)
4773          * which is legal but incomplete... */
4774
4775         return type;
4776 }
4777
4778 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
4779                                   declarator_flags_t flags)
4780 {
4781         parse_declarator_env_t env;
4782         memset(&env, 0, sizeof(env));
4783         env.modifiers = specifiers->modifiers;
4784
4785         construct_type_t *construct_type =
4786                 parse_inner_declarator(&env, (flags & DECL_MAY_BE_ABSTRACT) != 0);
4787         type_t           *orig_type      =
4788                 construct_declarator_type(construct_type, specifiers->type);
4789         type_t           *type           = skip_typeref(orig_type);
4790
4791         if (construct_type != NULL) {
4792                 obstack_free(&temp_obst, construct_type);
4793         }
4794
4795         entity_t *entity;
4796         if (specifiers->storage_class == STORAGE_CLASS_TYPEDEF) {
4797                 entity                       = allocate_entity_zero(ENTITY_TYPEDEF);
4798                 entity->base.symbol          = env.symbol;
4799                 entity->base.source_position = env.source_position;
4800                 entity->typedefe.type        = orig_type;
4801
4802                 if (anonymous_entity != NULL) {
4803                         if (is_type_compound(type)) {
4804                                 assert(anonymous_entity->compound.alias == NULL);
4805                                 assert(anonymous_entity->kind == ENTITY_STRUCT ||
4806                                        anonymous_entity->kind == ENTITY_UNION);
4807                                 anonymous_entity->compound.alias = entity;
4808                                 anonymous_entity = NULL;
4809                         } else if (is_type_enum(type)) {
4810                                 assert(anonymous_entity->enume.alias == NULL);
4811                                 assert(anonymous_entity->kind == ENTITY_ENUM);
4812                                 anonymous_entity->enume.alias = entity;
4813                                 anonymous_entity = NULL;
4814                         }
4815                 }
4816         } else {
4817                 /* create a declaration type entity */
4818                 if (flags & DECL_CREATE_COMPOUND_MEMBER) {
4819                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER);
4820
4821                         if (env.symbol != NULL) {
4822                                 if (specifiers->is_inline && is_type_valid(type)) {
4823                                         errorf(&env.source_position,
4824                                                         "compound member '%Y' declared 'inline'", env.symbol);
4825                                 }
4826
4827                                 if (specifiers->thread_local ||
4828                                                 specifiers->storage_class != STORAGE_CLASS_NONE) {
4829                                         errorf(&env.source_position,
4830                                                         "compound member '%Y' must have no storage class",
4831                                                         env.symbol);
4832                                 }
4833                         }
4834                 } else if (flags & DECL_IS_PARAMETER) {
4835                         orig_type = semantic_parameter(&env.source_position, orig_type,
4836                                                        specifiers, env.symbol);
4837
4838                         entity = allocate_entity_zero(ENTITY_PARAMETER);
4839                 } else if (is_type_function(type)) {
4840                         entity = allocate_entity_zero(ENTITY_FUNCTION);
4841
4842                         entity->function.is_inline  = specifiers->is_inline;
4843                         entity->function.parameters = env.parameters;
4844
4845                         if (env.symbol != NULL) {
4846                                 if (specifiers->thread_local || (
4847                                                         specifiers->storage_class != STORAGE_CLASS_EXTERN &&
4848                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
4849                                                         specifiers->storage_class != STORAGE_CLASS_STATIC
4850                                                 )) {
4851                                         errorf(&env.source_position,
4852                                                         "invalid storage class for function '%Y'", env.symbol);
4853                                 }
4854                         }
4855                 } else {
4856                         entity = allocate_entity_zero(ENTITY_VARIABLE);
4857
4858                         entity->variable.get_property_sym = specifiers->get_property_sym;
4859                         entity->variable.put_property_sym = specifiers->put_property_sym;
4860
4861                         entity->variable.thread_local = specifiers->thread_local;
4862
4863                         if (env.symbol != NULL) {
4864                                 if (specifiers->is_inline && is_type_valid(type)) {
4865                                         errorf(&env.source_position,
4866                                                         "variable '%Y' declared 'inline'", env.symbol);
4867                                 }
4868
4869                                 bool invalid_storage_class = false;
4870                                 if (current_scope == file_scope) {
4871                                         if (specifiers->storage_class != STORAGE_CLASS_EXTERN &&
4872                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
4873                                                         specifiers->storage_class != STORAGE_CLASS_STATIC) {
4874                                                 invalid_storage_class = true;
4875                                         }
4876                                 } else {
4877                                         if (specifiers->thread_local &&
4878                                                         specifiers->storage_class == STORAGE_CLASS_NONE) {
4879                                                 invalid_storage_class = true;
4880                                         }
4881                                 }
4882                                 if (invalid_storage_class) {
4883                                         errorf(&env.source_position,
4884                                                         "invalid storage class for variable '%Y'", env.symbol);
4885                                 }
4886                         }
4887                 }
4888
4889                 if (env.symbol != NULL) {
4890                         entity->base.symbol          = env.symbol;
4891                         entity->base.source_position = env.source_position;
4892                 } else {
4893                         entity->base.source_position = specifiers->source_position;
4894                 }
4895                 entity->base.namespc                  = NAMESPACE_NORMAL;
4896                 entity->declaration.type              = orig_type;
4897                 entity->declaration.modifiers         = env.modifiers;
4898                 entity->declaration.deprecated_string = specifiers->deprecated_string;
4899
4900                 storage_class_t storage_class = specifiers->storage_class;
4901                 entity->declaration.declared_storage_class = storage_class;
4902
4903                 if (storage_class == STORAGE_CLASS_NONE && current_scope != file_scope)
4904                         storage_class = STORAGE_CLASS_AUTO;
4905                 entity->declaration.storage_class = storage_class;
4906         }
4907
4908         parse_declaration_attributes(entity);
4909
4910         return entity;
4911 }
4912
4913 static type_t *parse_abstract_declarator(type_t *base_type)
4914 {
4915         construct_type_t *construct_type = parse_inner_declarator(NULL, 1);
4916
4917         type_t *result = construct_declarator_type(construct_type, base_type);
4918         if (construct_type != NULL) {
4919                 obstack_free(&temp_obst, construct_type);
4920         }
4921
4922         return result;
4923 }
4924
4925 /**
4926  * Check if the declaration of main is suspicious.  main should be a
4927  * function with external linkage, returning int, taking either zero
4928  * arguments, two, or three arguments of appropriate types, ie.
4929  *
4930  * int main([ int argc, char **argv [, char **env ] ]).
4931  *
4932  * @param decl    the declaration to check
4933  * @param type    the function type of the declaration
4934  */
4935 static void check_type_of_main(const entity_t *entity)
4936 {
4937         const source_position_t *pos = &entity->base.source_position;
4938         if (entity->kind != ENTITY_FUNCTION) {
4939                 warningf(pos, "'main' is not a function");
4940                 return;
4941         }
4942
4943         if (entity->declaration.storage_class == STORAGE_CLASS_STATIC) {
4944                 warningf(pos, "'main' is normally a non-static function");
4945         }
4946
4947         type_t *type = skip_typeref(entity->declaration.type);
4948         assert(is_type_function(type));
4949
4950         function_type_t *func_type = &type->function;
4951         if (!types_compatible(skip_typeref(func_type->return_type), type_int)) {
4952                 warningf(pos, "return type of 'main' should be 'int', but is '%T'",
4953                          func_type->return_type);
4954         }
4955         const function_parameter_t *parm = func_type->parameters;
4956         if (parm != NULL) {
4957                 type_t *const first_type = parm->type;
4958                 if (!types_compatible(skip_typeref(first_type), type_int)) {
4959                         warningf(pos,
4960                                  "first argument of 'main' should be 'int', but is '%T'",
4961                                  first_type);
4962                 }
4963                 parm = parm->next;
4964                 if (parm != NULL) {
4965                         type_t *const second_type = parm->type;
4966                         if (!types_compatible(skip_typeref(second_type), type_char_ptr_ptr)) {
4967                                 warningf(pos, "second argument of 'main' should be 'char**', but is '%T'", second_type);
4968                         }
4969                         parm = parm->next;
4970                         if (parm != NULL) {
4971                                 type_t *const third_type = parm->type;
4972                                 if (!types_compatible(skip_typeref(third_type), type_char_ptr_ptr)) {
4973                                         warningf(pos, "third argument of 'main' should be 'char**', but is '%T'", third_type);
4974                                 }
4975                                 parm = parm->next;
4976                                 if (parm != NULL)
4977                                         goto warn_arg_count;
4978                         }
4979                 } else {
4980 warn_arg_count:
4981                         warningf(pos, "'main' takes only zero, two or three arguments");
4982                 }
4983         }
4984 }
4985
4986 /**
4987  * Check if a symbol is the equal to "main".
4988  */
4989 static bool is_sym_main(const symbol_t *const sym)
4990 {
4991         return strcmp(sym->string, "main") == 0;
4992 }
4993
4994 static void error_redefined_as_different_kind(const source_position_t *pos,
4995                 const entity_t *old, entity_kind_t new_kind)
4996 {
4997         errorf(pos, "redeclaration of %s '%Y' as %s (declared %P)",
4998                get_entity_kind_name(old->kind), old->base.symbol,
4999                get_entity_kind_name(new_kind), &old->base.source_position);
5000 }
5001
5002 static bool is_error_entity(entity_t *const ent)
5003 {
5004         if (is_declaration(ent)) {
5005                 return is_type_valid(skip_typeref(ent->declaration.type));
5006         } else if (ent->kind == ENTITY_TYPEDEF) {
5007                 return is_type_valid(skip_typeref(ent->typedefe.type));
5008         }
5009         return false;
5010 }
5011
5012 /**
5013  * record entities for the NAMESPACE_NORMAL, and produce error messages/warnings
5014  * for various problems that occur for multiple definitions
5015  */
5016 static entity_t *record_entity(entity_t *entity, const bool is_definition)
5017 {
5018         const symbol_t *const    symbol  = entity->base.symbol;
5019         const namespace_tag_t    namespc = (namespace_tag_t)entity->base.namespc;
5020         const source_position_t *pos     = &entity->base.source_position;
5021
5022         /* can happen in error cases */
5023         if (symbol == NULL)
5024                 return entity;
5025
5026         entity_t *previous_entity = get_entity(symbol, namespc);
5027         /* pushing the same entity twice will break the stack structure */
5028         assert(previous_entity != entity);
5029
5030         if (entity->kind == ENTITY_FUNCTION) {
5031                 type_t *const orig_type = entity->declaration.type;
5032                 type_t *const type      = skip_typeref(orig_type);
5033
5034                 assert(is_type_function(type));
5035                 if (type->function.unspecified_parameters &&
5036                                 warning.strict_prototypes &&
5037                                 previous_entity == NULL) {
5038                         warningf(pos, "function declaration '%#T' is not a prototype",
5039                                          orig_type, symbol);
5040                 }
5041
5042                 if (warning.main && current_scope == file_scope
5043                                 && is_sym_main(symbol)) {
5044                         check_type_of_main(entity);
5045                 }
5046         }
5047
5048         if (is_declaration(entity) &&
5049                         warning.nested_externs &&
5050                         entity->declaration.storage_class == STORAGE_CLASS_EXTERN &&
5051                         current_scope != file_scope) {
5052                 warningf(pos, "nested extern declaration of '%#T'",
5053                          entity->declaration.type, symbol);
5054         }
5055
5056         if (previous_entity != NULL &&
5057                         previous_entity->base.parent_scope == &current_function->parameters &&
5058                         previous_entity->base.parent_scope->depth + 1 == current_scope->depth) {
5059                 assert(previous_entity->kind == ENTITY_PARAMETER);
5060                 errorf(pos,
5061                        "declaration '%#T' redeclares the parameter '%#T' (declared %P)",
5062                                          entity->declaration.type, symbol,
5063                                          previous_entity->declaration.type, symbol,
5064                                          &previous_entity->base.source_position);
5065                 goto finish;
5066         }
5067
5068         if (previous_entity != NULL &&
5069                         previous_entity->base.parent_scope == current_scope) {
5070                 if (previous_entity->kind != entity->kind) {
5071                         if (!is_error_entity(previous_entity) && !is_error_entity(entity)) {
5072                                 error_redefined_as_different_kind(pos, previous_entity,
5073                                                 entity->kind);
5074                         }
5075                         goto finish;
5076                 }
5077                 if (previous_entity->kind == ENTITY_ENUM_VALUE) {
5078                         errorf(pos, "redeclaration of enum entry '%Y' (declared %P)",
5079                                    symbol, &previous_entity->base.source_position);
5080                         goto finish;
5081                 }
5082                 if (previous_entity->kind == ENTITY_TYPEDEF) {
5083                         /* TODO: C++ allows this for exactly the same type */
5084                         errorf(pos, "redefinition of typedef '%Y' (declared %P)",
5085                                symbol, &previous_entity->base.source_position);
5086                         goto finish;
5087                 }
5088
5089                 /* at this point we should have only VARIABLES or FUNCTIONS */
5090                 assert(is_declaration(previous_entity) && is_declaration(entity));
5091
5092                 declaration_t *const prev_decl = &previous_entity->declaration;
5093                 declaration_t *const decl      = &entity->declaration;
5094
5095                 /* can happen for K&R style declarations */
5096                 if (prev_decl->type       == NULL             &&
5097                                 previous_entity->kind == ENTITY_PARAMETER &&
5098                                 entity->kind          == ENTITY_PARAMETER) {
5099                         prev_decl->type                   = decl->type;
5100                         prev_decl->storage_class          = decl->storage_class;
5101                         prev_decl->declared_storage_class = decl->declared_storage_class;
5102                         prev_decl->modifiers              = decl->modifiers;
5103                         prev_decl->deprecated_string      = decl->deprecated_string;
5104                         return previous_entity;
5105                 }
5106
5107                 type_t *const orig_type = decl->type;
5108                 assert(orig_type != NULL);
5109                 type_t *const type      = skip_typeref(orig_type);
5110                 type_t *const prev_type = skip_typeref(prev_decl->type);
5111
5112                 if (!types_compatible(type, prev_type)) {
5113                         errorf(pos,
5114                                    "declaration '%#T' is incompatible with '%#T' (declared %P)",
5115                                    orig_type, symbol, prev_decl->type, symbol,
5116                                    &previous_entity->base.source_position);
5117                 } else {
5118                         unsigned old_storage_class = prev_decl->storage_class;
5119                         if (warning.redundant_decls               &&
5120                                         is_definition                     &&
5121                                         !prev_decl->used                  &&
5122                                         !(prev_decl->modifiers & DM_USED) &&
5123                                         prev_decl->storage_class == STORAGE_CLASS_STATIC) {
5124                                 warningf(&previous_entity->base.source_position,
5125                                          "unnecessary static forward declaration for '%#T'",
5126                                          prev_decl->type, symbol);
5127                         }
5128
5129                         storage_class_t new_storage_class = decl->storage_class;
5130
5131                         /* pretend no storage class means extern for function
5132                          * declarations (except if the previous declaration is neither
5133                          * none nor extern) */
5134                         if (entity->kind == ENTITY_FUNCTION) {
5135                                 /* the previous declaration could have unspecified parameters or
5136                                  * be a typedef, so use the new type */
5137                                 if (prev_type->function.unspecified_parameters || is_definition)
5138                                         prev_decl->type = type;
5139
5140                                 switch (old_storage_class) {
5141                                 case STORAGE_CLASS_NONE:
5142                                         old_storage_class = STORAGE_CLASS_EXTERN;
5143                                         /* FALLTHROUGH */
5144
5145                                 case STORAGE_CLASS_EXTERN:
5146                                         if (is_definition) {
5147                                                 if (warning.missing_prototypes &&
5148                                                     prev_type->function.unspecified_parameters &&
5149                                                     !is_sym_main(symbol)) {
5150                                                         warningf(pos, "no previous prototype for '%#T'",
5151                                                                          orig_type, symbol);
5152                                                 }
5153                                         } else if (new_storage_class == STORAGE_CLASS_NONE) {
5154                                                 new_storage_class = STORAGE_CLASS_EXTERN;
5155                                         }
5156                                         break;
5157
5158                                 default:
5159                                         break;
5160                                 }
5161                         } else if (is_type_incomplete(prev_type)) {
5162                                 prev_decl->type = type;
5163                         }
5164
5165                         if (old_storage_class == STORAGE_CLASS_EXTERN &&
5166                                         new_storage_class == STORAGE_CLASS_EXTERN) {
5167 warn_redundant_declaration:
5168                                 if (!is_definition           &&
5169                                     warning.redundant_decls  &&
5170                                     is_type_valid(prev_type) &&
5171                                     strcmp(previous_entity->base.source_position.input_name,
5172                                            "<builtin>") != 0) {
5173                                         warningf(pos,
5174                                                  "redundant declaration for '%Y' (declared %P)",
5175                                                  symbol, &previous_entity->base.source_position);
5176                                 }
5177                         } else if (current_function == NULL) {
5178                                 if (old_storage_class != STORAGE_CLASS_STATIC &&
5179                                     new_storage_class == STORAGE_CLASS_STATIC) {
5180                                         errorf(pos,
5181                                                "static declaration of '%Y' follows non-static declaration (declared %P)",
5182                                                symbol, &previous_entity->base.source_position);
5183                                 } else if (old_storage_class == STORAGE_CLASS_EXTERN) {
5184                                         prev_decl->storage_class          = STORAGE_CLASS_NONE;
5185                                         prev_decl->declared_storage_class = STORAGE_CLASS_NONE;
5186                                 } else {
5187                                         /* ISO/IEC 14882:1998(E) §C.1.2:1 */
5188                                         if (c_mode & _CXX)
5189                                                 goto error_redeclaration;
5190                                         goto warn_redundant_declaration;
5191                                 }
5192                         } else if (is_type_valid(prev_type)) {
5193                                 if (old_storage_class == new_storage_class) {
5194 error_redeclaration:
5195                                         errorf(pos, "redeclaration of '%Y' (declared %P)",
5196                                                symbol, &previous_entity->base.source_position);
5197                                 } else {
5198                                         errorf(pos,
5199                                                "redeclaration of '%Y' with different linkage (declared %P)",
5200                                                symbol, &previous_entity->base.source_position);
5201                                 }
5202                         }
5203                 }
5204
5205                 prev_decl->modifiers |= decl->modifiers;
5206                 if (entity->kind == ENTITY_FUNCTION) {
5207                         previous_entity->function.is_inline |= entity->function.is_inline;
5208                 }
5209                 return previous_entity;
5210         }
5211
5212         if (entity->kind == ENTITY_FUNCTION) {
5213                 if (is_definition &&
5214                                 entity->declaration.storage_class != STORAGE_CLASS_STATIC) {
5215                         if (warning.missing_prototypes && !is_sym_main(symbol)) {
5216                                 warningf(pos, "no previous prototype for '%#T'",
5217                                          entity->declaration.type, symbol);
5218                         } else if (warning.missing_declarations && !is_sym_main(symbol)) {
5219                                 warningf(pos, "no previous declaration for '%#T'",
5220                                          entity->declaration.type, symbol);
5221                         }
5222                 }
5223         } else if (warning.missing_declarations &&
5224                         entity->kind == ENTITY_VARIABLE &&
5225                         current_scope == file_scope) {
5226                 declaration_t *declaration = &entity->declaration;
5227                 if (declaration->storage_class == STORAGE_CLASS_NONE) {
5228                         warningf(pos, "no previous declaration for '%#T'",
5229                                  declaration->type, symbol);
5230                 }
5231         }
5232
5233 finish:
5234         assert(entity->base.parent_scope == NULL);
5235         assert(current_scope != NULL);
5236
5237         entity->base.parent_scope = current_scope;
5238         entity->base.namespc      = NAMESPACE_NORMAL;
5239         environment_push(entity);
5240         append_entity(current_scope, entity);
5241
5242         return entity;
5243 }
5244
5245 static void parser_error_multiple_definition(entity_t *entity,
5246                 const source_position_t *source_position)
5247 {
5248         errorf(source_position, "multiple definition of '%Y' (declared %P)",
5249                entity->base.symbol, &entity->base.source_position);
5250 }
5251
5252 static bool is_declaration_specifier(const token_t *token,
5253                                      bool only_specifiers_qualifiers)
5254 {
5255         switch (token->type) {
5256                 TYPE_SPECIFIERS
5257                 TYPE_QUALIFIERS
5258                         return true;
5259                 case T_IDENTIFIER:
5260                         return is_typedef_symbol(token->v.symbol);
5261
5262                 case T___extension__:
5263                 STORAGE_CLASSES
5264                         return !only_specifiers_qualifiers;
5265
5266                 default:
5267                         return false;
5268         }
5269 }
5270
5271 static void parse_init_declarator_rest(entity_t *entity)
5272 {
5273         assert(is_declaration(entity));
5274         declaration_t *const declaration = &entity->declaration;
5275
5276         eat('=');
5277
5278         type_t *orig_type = declaration->type;
5279         type_t *type      = skip_typeref(orig_type);
5280
5281         if (entity->kind == ENTITY_VARIABLE
5282                         && entity->variable.initializer != NULL) {
5283                 parser_error_multiple_definition(entity, HERE);
5284         }
5285
5286         bool must_be_constant = false;
5287         if (declaration->storage_class == STORAGE_CLASS_STATIC ||
5288             entity->base.parent_scope  == file_scope) {
5289                 must_be_constant = true;
5290         }
5291
5292         if (is_type_function(type)) {
5293                 errorf(&entity->base.source_position,
5294                        "function '%#T' is initialized like a variable",
5295                        orig_type, entity->base.symbol);
5296                 orig_type = type_error_type;
5297         }
5298
5299         parse_initializer_env_t env;
5300         env.type             = orig_type;
5301         env.must_be_constant = must_be_constant;
5302         env.entity           = entity;
5303         current_init_decl    = entity;
5304
5305         initializer_t *initializer = parse_initializer(&env);
5306         current_init_decl = NULL;
5307
5308         if (entity->kind == ENTITY_VARIABLE) {
5309                 /* §6.7.5:22  array initializers for arrays with unknown size
5310                  * determine the array type size */
5311                 declaration->type            = env.type;
5312                 entity->variable.initializer = initializer;
5313         }
5314 }
5315
5316 /* parse rest of a declaration without any declarator */
5317 static void parse_anonymous_declaration_rest(
5318                 const declaration_specifiers_t *specifiers)
5319 {
5320         eat(';');
5321         anonymous_entity = NULL;
5322
5323         if (warning.other) {
5324                 if (specifiers->storage_class != STORAGE_CLASS_NONE ||
5325                                 specifiers->thread_local) {
5326                         warningf(&specifiers->source_position,
5327                                  "useless storage class in empty declaration");
5328                 }
5329
5330                 type_t *type = specifiers->type;
5331                 switch (type->kind) {
5332                         case TYPE_COMPOUND_STRUCT:
5333                         case TYPE_COMPOUND_UNION: {
5334                                 if (type->compound.compound->base.symbol == NULL) {
5335                                         warningf(&specifiers->source_position,
5336                                                  "unnamed struct/union that defines no instances");
5337                                 }
5338                                 break;
5339                         }
5340
5341                         case TYPE_ENUM:
5342                                 break;
5343
5344                         default:
5345                                 warningf(&specifiers->source_position, "empty declaration");
5346                                 break;
5347                 }
5348         }
5349 }
5350
5351 static void check_variable_type_complete(entity_t *ent)
5352 {
5353         if (ent->kind != ENTITY_VARIABLE)
5354                 return;
5355
5356         /* §6.7:7  If an identifier for an object is declared with no linkage, the
5357          *         type for the object shall be complete [...] */
5358         declaration_t *decl = &ent->declaration;
5359         if (decl->storage_class != STORAGE_CLASS_NONE)
5360                 return;
5361
5362         type_t *const orig_type = decl->type;
5363         type_t *const type      = skip_typeref(orig_type);
5364         if (!is_type_incomplete(type))
5365                 return;
5366
5367         /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
5368          * are given length one. */
5369         if (is_type_array(type) && ent->base.parent_scope == file_scope) {
5370                 ARR_APP1(declaration_t*, incomplete_arrays, decl);
5371                 return;
5372         }
5373
5374         errorf(&ent->base.source_position, "variable '%#T' has incomplete type",
5375                         orig_type, ent->base.symbol);
5376 }
5377
5378
5379 static void parse_declaration_rest(entity_t *ndeclaration,
5380                 const declaration_specifiers_t *specifiers,
5381                 parsed_declaration_func         finished_declaration,
5382                 declarator_flags_t              flags)
5383 {
5384         add_anchor_token(';');
5385         add_anchor_token(',');
5386         while (true) {
5387                 entity_t *entity = finished_declaration(ndeclaration, token.type == '=');
5388
5389                 if (token.type == '=') {
5390                         parse_init_declarator_rest(entity);
5391                 } else if (entity->kind == ENTITY_VARIABLE) {
5392                         /* ISO/IEC 14882:1998(E) §8.5.3:3  The initializer can be omitted
5393                          * [...] where the extern specifier is explicitly used. */
5394                         declaration_t *decl = &entity->declaration;
5395                         if (decl->storage_class != STORAGE_CLASS_EXTERN) {
5396                                 type_t *type = decl->type;
5397                                 if (is_type_reference(skip_typeref(type))) {
5398                                         errorf(&entity->base.source_position,
5399                                                         "reference '%#T' must be initialized",
5400                                                         type, entity->base.symbol);
5401                                 }
5402                         }
5403                 }
5404
5405                 check_variable_type_complete(entity);
5406
5407                 if (token.type != ',')
5408                         break;
5409                 eat(',');
5410
5411                 add_anchor_token('=');
5412                 ndeclaration = parse_declarator(specifiers, flags);
5413                 rem_anchor_token('=');
5414         }
5415         expect(';', end_error);
5416
5417 end_error:
5418         anonymous_entity = NULL;
5419         rem_anchor_token(';');
5420         rem_anchor_token(',');
5421 }
5422
5423 static entity_t *finished_kr_declaration(entity_t *entity, bool is_definition)
5424 {
5425         symbol_t *symbol = entity->base.symbol;
5426         if (symbol == NULL) {
5427                 errorf(HERE, "anonymous declaration not valid as function parameter");
5428                 return entity;
5429         }
5430
5431         assert(entity->base.namespc == NAMESPACE_NORMAL);
5432         entity_t *previous_entity = get_entity(symbol, NAMESPACE_NORMAL);
5433         if (previous_entity == NULL
5434                         || previous_entity->base.parent_scope != current_scope) {
5435                 errorf(HERE, "expected declaration of a function parameter, found '%Y'",
5436                        symbol);
5437                 return entity;
5438         }
5439
5440         if (is_definition) {
5441                 errorf(HERE, "parameter '%Y' is initialised", entity->base.symbol);
5442         }
5443
5444         return record_entity(entity, false);
5445 }
5446
5447 static void parse_declaration(parsed_declaration_func finished_declaration,
5448                               declarator_flags_t      flags)
5449 {
5450         declaration_specifiers_t specifiers;
5451         memset(&specifiers, 0, sizeof(specifiers));
5452
5453         add_anchor_token(';');
5454         parse_declaration_specifiers(&specifiers);
5455         rem_anchor_token(';');
5456
5457         if (token.type == ';') {
5458                 parse_anonymous_declaration_rest(&specifiers);
5459         } else {
5460                 entity_t *entity = parse_declarator(&specifiers, flags);
5461                 parse_declaration_rest(entity, &specifiers, finished_declaration, flags);
5462         }
5463 }
5464
5465 static type_t *get_default_promoted_type(type_t *orig_type)
5466 {
5467         type_t *result = orig_type;
5468
5469         type_t *type = skip_typeref(orig_type);
5470         if (is_type_integer(type)) {
5471                 result = promote_integer(type);
5472         } else if (type == type_float) {
5473                 result = type_double;
5474         }
5475
5476         return result;
5477 }
5478
5479 static void parse_kr_declaration_list(entity_t *entity)
5480 {
5481         if (entity->kind != ENTITY_FUNCTION)
5482                 return;
5483
5484         type_t *type = skip_typeref(entity->declaration.type);
5485         assert(is_type_function(type));
5486         if (!type->function.kr_style_parameters)
5487                 return;
5488
5489
5490         add_anchor_token('{');
5491
5492         /* push function parameters */
5493         size_t const  top       = environment_top();
5494         scope_t      *old_scope = scope_push(&entity->function.parameters);
5495
5496         entity_t *parameter = entity->function.parameters.entities;
5497         for ( ; parameter != NULL; parameter = parameter->base.next) {
5498                 assert(parameter->base.parent_scope == NULL);
5499                 parameter->base.parent_scope = current_scope;
5500                 environment_push(parameter);
5501         }
5502
5503         /* parse declaration list */
5504         for (;;) {
5505                 switch (token.type) {
5506                         DECLARATION_START
5507                         case T___extension__:
5508                         /* This covers symbols, which are no type, too, and results in
5509                          * better error messages.  The typical cases are misspelled type
5510                          * names and missing includes. */
5511                         case T_IDENTIFIER:
5512                                 parse_declaration(finished_kr_declaration, DECL_IS_PARAMETER);
5513                                 break;
5514                         default:
5515                                 goto decl_list_end;
5516                 }
5517         }
5518 decl_list_end:
5519
5520         /* pop function parameters */
5521         assert(current_scope == &entity->function.parameters);
5522         scope_pop(old_scope);
5523         environment_pop_to(top);
5524
5525         /* update function type */
5526         type_t *new_type = duplicate_type(type);
5527
5528         function_parameter_t *parameters     = NULL;
5529         function_parameter_t *last_parameter = NULL;
5530
5531         parameter = entity->function.parameters.entities;
5532         for (; parameter != NULL; parameter = parameter->base.next) {
5533                 if (parameter->kind != ENTITY_PARAMETER)
5534                         continue;
5535
5536                 type_t *parameter_type = parameter->declaration.type;
5537                 if (parameter_type == NULL) {
5538                         if (strict_mode) {
5539                                 errorf(HERE, "no type specified for function parameter '%Y'",
5540                                        parameter->base.symbol);
5541                         } else {
5542                                 if (warning.implicit_int) {
5543                                         warningf(HERE, "no type specified for function parameter '%Y', using 'int'",
5544                                                  parameter->base.symbol);
5545                                 }
5546                                 parameter_type              = type_int;
5547                                 parameter->declaration.type = parameter_type;
5548                         }
5549                 }
5550
5551                 semantic_parameter_incomplete(parameter);
5552                 parameter_type = parameter->declaration.type;
5553
5554                 /*
5555                  * we need the default promoted types for the function type
5556                  */
5557                 parameter_type = get_default_promoted_type(parameter_type);
5558
5559                 function_parameter_t *function_parameter
5560                         = obstack_alloc(type_obst, sizeof(function_parameter[0]));
5561                 memset(function_parameter, 0, sizeof(function_parameter[0]));
5562
5563                 function_parameter->type = parameter_type;
5564                 if (last_parameter != NULL) {
5565                         last_parameter->next = function_parameter;
5566                 } else {
5567                         parameters = function_parameter;
5568                 }
5569                 last_parameter = function_parameter;
5570         }
5571
5572         /* §6.9.1.7: A K&R style parameter list does NOT act as a function
5573          * prototype */
5574         new_type->function.parameters             = parameters;
5575         new_type->function.unspecified_parameters = true;
5576
5577         new_type = identify_new_type(new_type);
5578
5579         entity->declaration.type = new_type;
5580
5581         rem_anchor_token('{');
5582 }
5583
5584 static bool first_err = true;
5585
5586 /**
5587  * When called with first_err set, prints the name of the current function,
5588  * else does noting.
5589  */
5590 static void print_in_function(void)
5591 {
5592         if (first_err) {
5593                 first_err = false;
5594                 diagnosticf("%s: In function '%Y':\n",
5595                             current_function->base.base.source_position.input_name,
5596                             current_function->base.base.symbol);
5597         }
5598 }
5599
5600 /**
5601  * Check if all labels are defined in the current function.
5602  * Check if all labels are used in the current function.
5603  */
5604 static void check_labels(void)
5605 {
5606         for (const goto_statement_t *goto_statement = goto_first;
5607             goto_statement != NULL;
5608             goto_statement = goto_statement->next) {
5609                 /* skip computed gotos */
5610                 if (goto_statement->expression != NULL)
5611                         continue;
5612
5613                 label_t *label = goto_statement->label;
5614
5615                 label->used = true;
5616                 if (label->base.source_position.input_name == NULL) {
5617                         print_in_function();
5618                         errorf(&goto_statement->base.source_position,
5619                                "label '%Y' used but not defined", label->base.symbol);
5620                  }
5621         }
5622
5623         if (warning.unused_label) {
5624                 for (const label_statement_t *label_statement = label_first;
5625                          label_statement != NULL;
5626                          label_statement = label_statement->next) {
5627                         label_t *label = label_statement->label;
5628
5629                         if (! label->used) {
5630                                 print_in_function();
5631                                 warningf(&label_statement->base.source_position,
5632                                          "label '%Y' defined but not used", label->base.symbol);
5633                         }
5634                 }
5635         }
5636 }
5637
5638 static void warn_unused_entity(entity_t *entity, entity_t *last)
5639 {
5640         entity_t const *const end = last != NULL ? last->base.next : NULL;
5641         for (; entity != end; entity = entity->base.next) {
5642                 if (!is_declaration(entity))
5643                         continue;
5644
5645                 declaration_t *declaration = &entity->declaration;
5646                 if (declaration->implicit)
5647                         continue;
5648
5649                 if (!declaration->used) {
5650                         print_in_function();
5651                         const char *what = get_entity_kind_name(entity->kind);
5652                         warningf(&entity->base.source_position, "%s '%Y' is unused",
5653                                  what, entity->base.symbol);
5654                 } else if (entity->kind == ENTITY_VARIABLE && !entity->variable.read) {
5655                         print_in_function();
5656                         const char *what = get_entity_kind_name(entity->kind);
5657                         warningf(&entity->base.source_position, "%s '%Y' is never read",
5658                                  what, entity->base.symbol);
5659                 }
5660         }
5661 }
5662
5663 static void check_unused_variables(statement_t *const stmt, void *const env)
5664 {
5665         (void)env;
5666
5667         switch (stmt->kind) {
5668                 case STATEMENT_DECLARATION: {
5669                         declaration_statement_t const *const decls = &stmt->declaration;
5670                         warn_unused_entity(decls->declarations_begin,
5671                                            decls->declarations_end);
5672                         return;
5673                 }
5674
5675                 case STATEMENT_FOR:
5676                         warn_unused_entity(stmt->fors.scope.entities, NULL);
5677                         return;
5678
5679                 default:
5680                         return;
5681         }
5682 }
5683
5684 /**
5685  * Check declarations of current_function for unused entities.
5686  */
5687 static void check_declarations(void)
5688 {
5689         if (warning.unused_parameter) {
5690                 const scope_t *scope = &current_function->parameters;
5691
5692                 /* do not issue unused warnings for main */
5693                 if (!is_sym_main(current_function->base.base.symbol)) {
5694                         warn_unused_entity(scope->entities, NULL);
5695                 }
5696         }
5697         if (warning.unused_variable) {
5698                 walk_statements(current_function->statement, check_unused_variables,
5699                                 NULL);
5700         }
5701 }
5702
5703 static int determine_truth(expression_t const* const cond)
5704 {
5705         return
5706                 !is_constant_expression(cond) ? 0 :
5707                 fold_constant(cond) != 0      ? 1 :
5708                 -1;
5709 }
5710
5711 static void check_reachable(statement_t *);
5712 static bool reaches_end;
5713
5714 static bool expression_returns(expression_t const *const expr)
5715 {
5716         switch (expr->kind) {
5717                 case EXPR_CALL: {
5718                         expression_t const *const func = expr->call.function;
5719                         if (func->kind == EXPR_REFERENCE) {
5720                                 entity_t *entity = func->reference.entity;
5721                                 if (entity->kind == ENTITY_FUNCTION
5722                                                 && entity->declaration.modifiers & DM_NORETURN)
5723                                         return false;
5724                         }
5725
5726                         if (!expression_returns(func))
5727                                 return false;
5728
5729                         for (call_argument_t const* arg = expr->call.arguments; arg != NULL; arg = arg->next) {
5730                                 if (!expression_returns(arg->expression))
5731                                         return false;
5732                         }
5733
5734                         return true;
5735                 }
5736
5737                 case EXPR_REFERENCE:
5738                 case EXPR_REFERENCE_ENUM_VALUE:
5739                 case EXPR_CONST:
5740                 case EXPR_CHARACTER_CONSTANT:
5741                 case EXPR_WIDE_CHARACTER_CONSTANT:
5742                 case EXPR_STRING_LITERAL:
5743                 case EXPR_WIDE_STRING_LITERAL:
5744                 case EXPR_COMPOUND_LITERAL: // TODO descend into initialisers
5745                 case EXPR_LABEL_ADDRESS:
5746                 case EXPR_CLASSIFY_TYPE:
5747                 case EXPR_SIZEOF: // TODO handle obscure VLA case
5748                 case EXPR_ALIGNOF:
5749                 case EXPR_FUNCNAME:
5750                 case EXPR_BUILTIN_SYMBOL:
5751                 case EXPR_BUILTIN_CONSTANT_P:
5752                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
5753                 case EXPR_OFFSETOF:
5754                 case EXPR_INVALID:
5755                         return true;
5756
5757                 case EXPR_STATEMENT: {
5758                         bool old_reaches_end = reaches_end;
5759                         reaches_end = false;
5760                         check_reachable(expr->statement.statement);
5761                         bool returns = reaches_end;
5762                         reaches_end = old_reaches_end;
5763                         return returns;
5764                 }
5765
5766                 case EXPR_CONDITIONAL:
5767                         // TODO handle constant expression
5768
5769                         if (!expression_returns(expr->conditional.condition))
5770                                 return false;
5771
5772                         if (expr->conditional.true_expression != NULL
5773                                         && expression_returns(expr->conditional.true_expression))
5774                                 return true;
5775
5776                         return expression_returns(expr->conditional.false_expression);
5777
5778                 case EXPR_SELECT:
5779                         return expression_returns(expr->select.compound);
5780
5781                 case EXPR_ARRAY_ACCESS:
5782                         return
5783                                 expression_returns(expr->array_access.array_ref) &&
5784                                 expression_returns(expr->array_access.index);
5785
5786                 case EXPR_VA_START:
5787                         return expression_returns(expr->va_starte.ap);
5788
5789                 case EXPR_VA_ARG:
5790                         return expression_returns(expr->va_arge.ap);
5791
5792                 EXPR_UNARY_CASES_MANDATORY
5793                         return expression_returns(expr->unary.value);
5794
5795                 case EXPR_UNARY_THROW:
5796                         return false;
5797
5798                 EXPR_BINARY_CASES
5799                         // TODO handle constant lhs of && and ||
5800                         return
5801                                 expression_returns(expr->binary.left) &&
5802                                 expression_returns(expr->binary.right);
5803
5804                 case EXPR_UNKNOWN:
5805                         break;
5806         }
5807
5808         panic("unhandled expression");
5809 }
5810
5811 static bool initializer_returns(initializer_t const *const init)
5812 {
5813         switch (init->kind) {
5814                 case INITIALIZER_VALUE:
5815                         return expression_returns(init->value.value);
5816
5817                 case INITIALIZER_LIST: {
5818                         initializer_t * const*       i       = init->list.initializers;
5819                         initializer_t * const* const end     = i + init->list.len;
5820                         bool                         returns = true;
5821                         for (; i != end; ++i) {
5822                                 if (!initializer_returns(*i))
5823                                         returns = false;
5824                         }
5825                         return returns;
5826                 }
5827
5828                 case INITIALIZER_STRING:
5829                 case INITIALIZER_WIDE_STRING:
5830                 case INITIALIZER_DESIGNATOR: // designators have no payload
5831                         return true;
5832         }
5833         panic("unhandled initializer");
5834 }
5835
5836 static bool noreturn_candidate;
5837
5838 static void check_reachable(statement_t *const stmt)
5839 {
5840         if (stmt->base.reachable)
5841                 return;
5842         if (stmt->kind != STATEMENT_DO_WHILE)
5843                 stmt->base.reachable = true;
5844
5845         statement_t *last = stmt;
5846         statement_t *next;
5847         switch (stmt->kind) {
5848                 case STATEMENT_INVALID:
5849                 case STATEMENT_EMPTY:
5850                 case STATEMENT_ASM:
5851                         next = stmt->base.next;
5852                         break;
5853
5854                 case STATEMENT_DECLARATION: {
5855                         declaration_statement_t const *const decl = &stmt->declaration;
5856                         entity_t                const *      ent  = decl->declarations_begin;
5857                         entity_t                const *const last = decl->declarations_end;
5858                         if (ent != NULL) {
5859                                 for (;; ent = ent->base.next) {
5860                                         if (ent->kind                 == ENTITY_VARIABLE &&
5861                                                         ent->variable.initializer != NULL            &&
5862                                                         !initializer_returns(ent->variable.initializer)) {
5863                                                 return;
5864                                         }
5865                                         if (ent == last)
5866                                                 break;
5867                                 }
5868                         }
5869                         next = stmt->base.next;
5870                         break;
5871                 }
5872
5873                 case STATEMENT_COMPOUND:
5874                         next = stmt->compound.statements;
5875                         if (next == NULL)
5876                                 next = stmt->base.next;
5877                         break;
5878
5879                 case STATEMENT_RETURN: {
5880                         expression_t const *const val = stmt->returns.value;
5881                         if (val == NULL || expression_returns(val))
5882                                 noreturn_candidate = false;
5883                         return;
5884                 }
5885
5886                 case STATEMENT_IF: {
5887                         if_statement_t const *const ifs  = &stmt->ifs;
5888                         expression_t   const *const cond = ifs->condition;
5889
5890                         if (!expression_returns(cond))
5891                                 return;
5892
5893                         int const val = determine_truth(cond);
5894
5895                         if (val >= 0)
5896                                 check_reachable(ifs->true_statement);
5897
5898                         if (val > 0)
5899                                 return;
5900
5901                         if (ifs->false_statement != NULL) {
5902                                 check_reachable(ifs->false_statement);
5903                                 return;
5904                         }
5905
5906                         next = stmt->base.next;
5907                         break;
5908                 }
5909
5910                 case STATEMENT_SWITCH: {
5911                         switch_statement_t const *const switchs = &stmt->switchs;
5912                         expression_t       const *const expr    = switchs->expression;
5913
5914                         if (!expression_returns(expr))
5915                                 return;
5916
5917                         if (is_constant_expression(expr)) {
5918                                 long                    const val      = fold_constant(expr);
5919                                 case_label_statement_t *      defaults = NULL;
5920                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
5921                                         if (i->expression == NULL) {
5922                                                 defaults = i;
5923                                                 continue;
5924                                         }
5925
5926                                         if (i->first_case <= val && val <= i->last_case) {
5927                                                 check_reachable((statement_t*)i);
5928                                                 return;
5929                                         }
5930                                 }
5931
5932                                 if (defaults != NULL) {
5933                                         check_reachable((statement_t*)defaults);
5934                                         return;
5935                                 }
5936                         } else {
5937                                 bool has_default = false;
5938                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
5939                                         if (i->expression == NULL)
5940                                                 has_default = true;
5941
5942                                         check_reachable((statement_t*)i);
5943                                 }
5944
5945                                 if (has_default)
5946                                         return;
5947                         }
5948
5949                         next = stmt->base.next;
5950                         break;
5951                 }
5952
5953                 case STATEMENT_EXPRESSION: {
5954                         /* Check for noreturn function call */
5955                         expression_t const *const expr = stmt->expression.expression;
5956                         if (!expression_returns(expr))
5957                                 return;
5958
5959                         next = stmt->base.next;
5960                         break;
5961                 }
5962
5963                 case STATEMENT_CONTINUE: {
5964                         statement_t *parent = stmt;
5965                         for (;;) {
5966                                 parent = parent->base.parent;
5967                                 if (parent == NULL) /* continue not within loop */
5968                                         return;
5969
5970                                 next = parent;
5971                                 switch (parent->kind) {
5972                                         case STATEMENT_WHILE:    goto continue_while;
5973                                         case STATEMENT_DO_WHILE: goto continue_do_while;
5974                                         case STATEMENT_FOR:      goto continue_for;
5975
5976                                         default: break;
5977                                 }
5978                         }
5979                 }
5980
5981                 case STATEMENT_BREAK: {
5982                         statement_t *parent = stmt;
5983                         for (;;) {
5984                                 parent = parent->base.parent;
5985                                 if (parent == NULL) /* break not within loop/switch */
5986                                         return;
5987
5988                                 switch (parent->kind) {
5989                                         case STATEMENT_SWITCH:
5990                                         case STATEMENT_WHILE:
5991                                         case STATEMENT_DO_WHILE:
5992                                         case STATEMENT_FOR:
5993                                                 last = parent;
5994                                                 next = parent->base.next;
5995                                                 goto found_break_parent;
5996
5997                                         default: break;
5998                                 }
5999                         }
6000 found_break_parent:
6001                         break;
6002                 }
6003
6004                 case STATEMENT_GOTO:
6005                         if (stmt->gotos.expression) {
6006                                 if (!expression_returns(stmt->gotos.expression))
6007                                         return;
6008
6009                                 statement_t *parent = stmt->base.parent;
6010                                 if (parent == NULL) /* top level goto */
6011                                         return;
6012                                 next = parent;
6013                         } else {
6014                                 next = stmt->gotos.label->statement;
6015                                 if (next == NULL) /* missing label */
6016                                         return;
6017                         }
6018                         break;
6019
6020                 case STATEMENT_LABEL:
6021                         next = stmt->label.statement;
6022                         break;
6023
6024                 case STATEMENT_CASE_LABEL:
6025                         next = stmt->case_label.statement;
6026                         break;
6027
6028                 case STATEMENT_WHILE: {
6029                         while_statement_t const *const whiles = &stmt->whiles;
6030                         expression_t      const *const cond   = whiles->condition;
6031
6032                         if (!expression_returns(cond))
6033                                 return;
6034
6035                         int const val = determine_truth(cond);
6036
6037                         if (val >= 0)
6038                                 check_reachable(whiles->body);
6039
6040                         if (val > 0)
6041                                 return;
6042
6043                         next = stmt->base.next;
6044                         break;
6045                 }
6046
6047                 case STATEMENT_DO_WHILE:
6048                         next = stmt->do_while.body;
6049                         break;
6050
6051                 case STATEMENT_FOR: {
6052                         for_statement_t *const fors = &stmt->fors;
6053
6054                         if (fors->condition_reachable)
6055                                 return;
6056                         fors->condition_reachable = true;
6057
6058                         expression_t const *const cond = fors->condition;
6059
6060                         int val;
6061                         if (cond == NULL) {
6062                                 val = 1;
6063                         } else if (expression_returns(cond)) {
6064                                 val = determine_truth(cond);
6065                         } else {
6066                                 return;
6067                         }
6068
6069                         if (val >= 0)
6070                                 check_reachable(fors->body);
6071
6072                         if (val > 0)
6073                                 return;
6074
6075                         next = stmt->base.next;
6076                         break;
6077                 }
6078
6079                 case STATEMENT_MS_TRY: {
6080                         ms_try_statement_t const *const ms_try = &stmt->ms_try;
6081                         check_reachable(ms_try->try_statement);
6082                         next = ms_try->final_statement;
6083                         break;
6084                 }
6085
6086                 case STATEMENT_LEAVE: {
6087                         statement_t *parent = stmt;
6088                         for (;;) {
6089                                 parent = parent->base.parent;
6090                                 if (parent == NULL) /* __leave not within __try */
6091                                         return;
6092
6093                                 if (parent->kind == STATEMENT_MS_TRY) {
6094                                         last = parent;
6095                                         next = parent->ms_try.final_statement;
6096                                         break;
6097                                 }
6098                         }
6099                         break;
6100                 }
6101
6102                 default:
6103                         panic("invalid statement kind");
6104         }
6105
6106         while (next == NULL) {
6107                 next = last->base.parent;
6108                 if (next == NULL) {
6109                         noreturn_candidate = false;
6110
6111                         type_t *const type = skip_typeref(current_function->base.type);
6112                         assert(is_type_function(type));
6113                         type_t *const ret  = skip_typeref(type->function.return_type);
6114                         if (warning.return_type                    &&
6115                             !is_type_atomic(ret, ATOMIC_TYPE_VOID) &&
6116                             is_type_valid(ret)                     &&
6117                             !is_sym_main(current_function->base.base.symbol)) {
6118                                 warningf(&stmt->base.source_position,
6119                                          "control reaches end of non-void function");
6120                         }
6121                         return;
6122                 }
6123
6124                 switch (next->kind) {
6125                         case STATEMENT_INVALID:
6126                         case STATEMENT_EMPTY:
6127                         case STATEMENT_DECLARATION:
6128                         case STATEMENT_EXPRESSION:
6129                         case STATEMENT_ASM:
6130                         case STATEMENT_RETURN:
6131                         case STATEMENT_CONTINUE:
6132                         case STATEMENT_BREAK:
6133                         case STATEMENT_GOTO:
6134                         case STATEMENT_LEAVE:
6135                                 panic("invalid control flow in function");
6136
6137                         case STATEMENT_COMPOUND:
6138                                 if (next->compound.stmt_expr) {
6139                                         reaches_end = true;
6140                                         return;
6141                                 }
6142                                 /* FALLTHROUGH */
6143                         case STATEMENT_IF:
6144                         case STATEMENT_SWITCH:
6145                         case STATEMENT_LABEL:
6146                         case STATEMENT_CASE_LABEL:
6147                                 last = next;
6148                                 next = next->base.next;
6149                                 break;
6150
6151                         case STATEMENT_WHILE: {
6152 continue_while:
6153                                 if (next->base.reachable)
6154                                         return;
6155                                 next->base.reachable = true;
6156
6157                                 while_statement_t const *const whiles = &next->whiles;
6158                                 expression_t      const *const cond   = whiles->condition;
6159
6160                                 if (!expression_returns(cond))
6161                                         return;
6162
6163                                 int const val = determine_truth(cond);
6164
6165                                 if (val >= 0)
6166                                         check_reachable(whiles->body);
6167
6168                                 if (val > 0)
6169                                         return;
6170
6171                                 last = next;
6172                                 next = next->base.next;
6173                                 break;
6174                         }
6175
6176                         case STATEMENT_DO_WHILE: {
6177 continue_do_while:
6178                                 if (next->base.reachable)
6179                                         return;
6180                                 next->base.reachable = true;
6181
6182                                 do_while_statement_t const *const dw   = &next->do_while;
6183                                 expression_t         const *const cond = dw->condition;
6184
6185                                 if (!expression_returns(cond))
6186                                         return;
6187
6188                                 int const val = determine_truth(cond);
6189
6190                                 if (val >= 0)
6191                                         check_reachable(dw->body);
6192
6193                                 if (val > 0)
6194                                         return;
6195
6196                                 last = next;
6197                                 next = next->base.next;
6198                                 break;
6199                         }
6200
6201                         case STATEMENT_FOR: {
6202 continue_for:;
6203                                 for_statement_t *const fors = &next->fors;
6204
6205                                 fors->step_reachable = true;
6206
6207                                 if (fors->condition_reachable)
6208                                         return;
6209                                 fors->condition_reachable = true;
6210
6211                                 expression_t const *const cond = fors->condition;
6212
6213                                 int val;
6214                                 if (cond == NULL) {
6215                                         val = 1;
6216                                 } else if (expression_returns(cond)) {
6217                                         val = determine_truth(cond);
6218                                 } else {
6219                                         return;
6220                                 }
6221
6222                                 if (val >= 0)
6223                                         check_reachable(fors->body);
6224
6225                                 if (val > 0)
6226                                         return;
6227
6228                                 last = next;
6229                                 next = next->base.next;
6230                                 break;
6231                         }
6232
6233                         case STATEMENT_MS_TRY:
6234                                 last = next;
6235                                 next = next->ms_try.final_statement;
6236                                 break;
6237                 }
6238         }
6239
6240         check_reachable(next);
6241 }
6242
6243 static void check_unreachable(statement_t* const stmt, void *const env)
6244 {
6245         (void)env;
6246
6247         switch (stmt->kind) {
6248                 case STATEMENT_DO_WHILE:
6249                         if (!stmt->base.reachable) {
6250                                 expression_t const *const cond = stmt->do_while.condition;
6251                                 if (determine_truth(cond) >= 0) {
6252                                         warningf(&cond->base.source_position,
6253                                                  "condition of do-while-loop is unreachable");
6254                                 }
6255                         }
6256                         return;
6257
6258                 case STATEMENT_FOR: {
6259                         for_statement_t const* const fors = &stmt->fors;
6260
6261                         // if init and step are unreachable, cond is unreachable, too
6262                         if (!stmt->base.reachable && !fors->step_reachable) {
6263                                 warningf(&stmt->base.source_position, "statement is unreachable");
6264                         } else {
6265                                 if (!stmt->base.reachable && fors->initialisation != NULL) {
6266                                         warningf(&fors->initialisation->base.source_position,
6267                                                  "initialisation of for-statement is unreachable");
6268                                 }
6269
6270                                 if (!fors->condition_reachable && fors->condition != NULL) {
6271                                         warningf(&fors->condition->base.source_position,
6272                                                  "condition of for-statement is unreachable");
6273                                 }
6274
6275                                 if (!fors->step_reachable && fors->step != NULL) {
6276                                         warningf(&fors->step->base.source_position,
6277                                                  "step of for-statement is unreachable");
6278                                 }
6279                         }
6280                         return;
6281                 }
6282
6283                 case STATEMENT_COMPOUND:
6284                         if (stmt->compound.statements != NULL)
6285                                 return;
6286                         goto warn_unreachable;
6287
6288                 case STATEMENT_DECLARATION: {
6289                         /* Only warn if there is at least one declarator with an initializer.
6290                          * This typically occurs in switch statements. */
6291                         declaration_statement_t const *const decl = &stmt->declaration;
6292                         entity_t                const *      ent  = decl->declarations_begin;
6293                         entity_t                const *const last = decl->declarations_end;
6294                         if (ent != NULL) {
6295                                 for (;; ent = ent->base.next) {
6296                                         if (ent->kind                 == ENTITY_VARIABLE &&
6297                                                         ent->variable.initializer != NULL) {
6298                                                 goto warn_unreachable;
6299                                         }
6300                                         if (ent == last)
6301                                                 return;
6302                                 }
6303                         }
6304                 }
6305
6306                 default:
6307 warn_unreachable:
6308                         if (!stmt->base.reachable)
6309                                 warningf(&stmt->base.source_position, "statement is unreachable");
6310                         return;
6311         }
6312 }
6313
6314 static void parse_external_declaration(void)
6315 {
6316         /* function-definitions and declarations both start with declaration
6317          * specifiers */
6318         declaration_specifiers_t specifiers;
6319         memset(&specifiers, 0, sizeof(specifiers));
6320
6321         add_anchor_token(';');
6322         parse_declaration_specifiers(&specifiers);
6323         rem_anchor_token(';');
6324
6325         /* must be a declaration */
6326         if (token.type == ';') {
6327                 parse_anonymous_declaration_rest(&specifiers);
6328                 return;
6329         }
6330
6331         add_anchor_token(',');
6332         add_anchor_token('=');
6333         add_anchor_token(';');
6334         add_anchor_token('{');
6335
6336         /* declarator is common to both function-definitions and declarations */
6337         entity_t *ndeclaration = parse_declarator(&specifiers, DECL_FLAGS_NONE);
6338
6339         rem_anchor_token('{');
6340         rem_anchor_token(';');
6341         rem_anchor_token('=');
6342         rem_anchor_token(',');
6343
6344         /* must be a declaration */
6345         switch (token.type) {
6346                 case ',':
6347                 case ';':
6348                 case '=':
6349                         parse_declaration_rest(ndeclaration, &specifiers, record_entity,
6350                                         DECL_FLAGS_NONE);
6351                         return;
6352         }
6353
6354         /* must be a function definition */
6355         parse_kr_declaration_list(ndeclaration);
6356
6357         if (token.type != '{') {
6358                 parse_error_expected("while parsing function definition", '{', NULL);
6359                 eat_until_matching_token(';');
6360                 return;
6361         }
6362
6363         assert(is_declaration(ndeclaration));
6364         type_t *const orig_type = ndeclaration->declaration.type;
6365         type_t *      type      = skip_typeref(orig_type);
6366
6367         if (!is_type_function(type)) {
6368                 if (is_type_valid(type)) {
6369                         errorf(HERE, "declarator '%#T' has a body but is not a function type",
6370                                type, ndeclaration->base.symbol);
6371                 }
6372                 eat_block();
6373                 return;
6374         } else if (is_typeref(orig_type)) {
6375                 /* §6.9.1:2 */
6376                 errorf(&ndeclaration->base.source_position,
6377                                 "type of function definition '%#T' is a typedef",
6378                                 orig_type, ndeclaration->base.symbol);
6379         }
6380
6381         if (warning.aggregate_return &&
6382             is_type_compound(skip_typeref(type->function.return_type))) {
6383                 warningf(HERE, "function '%Y' returns an aggregate",
6384                          ndeclaration->base.symbol);
6385         }
6386         if (warning.traditional && !type->function.unspecified_parameters) {
6387                 warningf(HERE, "traditional C rejects ISO C style function definition of function '%Y'",
6388                         ndeclaration->base.symbol);
6389         }
6390         if (warning.old_style_definition && type->function.unspecified_parameters) {
6391                 warningf(HERE, "old-style function definition '%Y'",
6392                         ndeclaration->base.symbol);
6393         }
6394
6395         /* §6.7.5.3:14 a function definition with () means no
6396          * parameters (and not unspecified parameters) */
6397         if (type->function.unspecified_parameters &&
6398                         type->function.parameters == NULL     &&
6399                         !type->function.kr_style_parameters) {
6400                 type_t *copy                          = duplicate_type(type);
6401                 copy->function.unspecified_parameters = false;
6402                 type                                  = identify_new_type(copy);
6403
6404                 ndeclaration->declaration.type = type;
6405         }
6406
6407         entity_t *const entity = record_entity(ndeclaration, true);
6408         assert(entity->kind == ENTITY_FUNCTION);
6409         assert(ndeclaration->kind == ENTITY_FUNCTION);
6410
6411         function_t *function = &entity->function;
6412         if (ndeclaration != entity) {
6413                 function->parameters = ndeclaration->function.parameters;
6414         }
6415         assert(is_declaration(entity));
6416         type = skip_typeref(entity->declaration.type);
6417
6418         /* push function parameters and switch scope */
6419         size_t const  top       = environment_top();
6420         scope_t      *old_scope = scope_push(&function->parameters);
6421
6422         entity_t *parameter = function->parameters.entities;
6423         for (; parameter != NULL; parameter = parameter->base.next) {
6424                 if (parameter->base.parent_scope == &ndeclaration->function.parameters) {
6425                         parameter->base.parent_scope = current_scope;
6426                 }
6427                 assert(parameter->base.parent_scope == NULL
6428                                 || parameter->base.parent_scope == current_scope);
6429                 parameter->base.parent_scope = current_scope;
6430                 if (parameter->base.symbol == NULL) {
6431                         errorf(&parameter->base.source_position, "parameter name omitted");
6432                         continue;
6433                 }
6434                 environment_push(parameter);
6435         }
6436
6437         if (function->statement != NULL) {
6438                 parser_error_multiple_definition(entity, HERE);
6439                 eat_block();
6440         } else {
6441                 /* parse function body */
6442                 int         label_stack_top      = label_top();
6443                 function_t *old_current_function = current_function;
6444                 current_function                 = function;
6445                 current_parent                   = NULL;
6446
6447                 goto_first   = NULL;
6448                 goto_anchor  = &goto_first;
6449                 label_first  = NULL;
6450                 label_anchor = &label_first;
6451
6452                 statement_t *const body = parse_compound_statement(false);
6453                 function->statement = body;
6454                 first_err = true;
6455                 check_labels();
6456                 check_declarations();
6457                 if (warning.return_type      ||
6458                     warning.unreachable_code ||
6459                     (warning.missing_noreturn
6460                      && !(function->base.modifiers & DM_NORETURN))) {
6461                         noreturn_candidate = true;
6462                         check_reachable(body);
6463                         if (warning.unreachable_code)
6464                                 walk_statements(body, check_unreachable, NULL);
6465                         if (warning.missing_noreturn &&
6466                             noreturn_candidate       &&
6467                             !(function->base.modifiers & DM_NORETURN)) {
6468                                 warningf(&body->base.source_position,
6469                                          "function '%#T' is candidate for attribute 'noreturn'",
6470                                          type, entity->base.symbol);
6471                         }
6472                 }
6473
6474                 assert(current_parent   == NULL);
6475                 assert(current_function == function);
6476                 current_function = old_current_function;
6477                 label_pop_to(label_stack_top);
6478         }
6479
6480         assert(current_scope == &function->parameters);
6481         scope_pop(old_scope);
6482         environment_pop_to(top);
6483 }
6484
6485 static type_t *make_bitfield_type(type_t *base_type, expression_t *size,
6486                                   source_position_t *source_position,
6487                                   const symbol_t *symbol)
6488 {
6489         type_t *type = allocate_type_zero(TYPE_BITFIELD);
6490
6491         type->bitfield.base_type       = base_type;
6492         type->bitfield.size_expression = size;
6493
6494         il_size_t bit_size;
6495         type_t *skipped_type = skip_typeref(base_type);
6496         if (!is_type_integer(skipped_type)) {
6497                 errorf(HERE, "bitfield base type '%T' is not an integer type",
6498                         base_type);
6499                 bit_size = 0;
6500         } else {
6501                 bit_size = skipped_type->base.size * 8;
6502         }
6503
6504         if (is_constant_expression(size)) {
6505                 long v = fold_constant(size);
6506
6507                 if (v < 0) {
6508                         errorf(source_position, "negative width in bit-field '%Y'", symbol);
6509                 } else if (v == 0) {
6510                         errorf(source_position, "zero width for bit-field '%Y'", symbol);
6511                 } else if (bit_size > 0 && (il_size_t)v > bit_size) {
6512                         errorf(source_position, "width of '%Y' exceeds its type", symbol);
6513                 } else {
6514                         type->bitfield.bit_size = v;
6515                 }
6516         }
6517
6518         return type;
6519 }
6520
6521 static entity_t *find_compound_entry(compound_t *compound, symbol_t *symbol)
6522 {
6523         entity_t *iter = compound->members.entities;
6524         for (; iter != NULL; iter = iter->base.next) {
6525                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
6526                         continue;
6527
6528                 if (iter->base.symbol == symbol) {
6529                         return iter;
6530                 } else if (iter->base.symbol == NULL) {
6531                         type_t *type = skip_typeref(iter->declaration.type);
6532                         if (is_type_compound(type)) {
6533                                 entity_t *result
6534                                         = find_compound_entry(type->compound.compound, symbol);
6535                                 if (result != NULL)
6536                                         return result;
6537                         }
6538                         continue;
6539                 }
6540         }
6541
6542         return NULL;
6543 }
6544
6545 static void parse_compound_declarators(compound_t *compound,
6546                 const declaration_specifiers_t *specifiers)
6547 {
6548         while (true) {
6549                 entity_t *entity;
6550
6551                 if (token.type == ':') {
6552                         source_position_t source_position = *HERE;
6553                         next_token();
6554
6555                         type_t *base_type = specifiers->type;
6556                         expression_t *size = parse_constant_expression();
6557
6558                         type_t *type = make_bitfield_type(base_type, size,
6559                                         &source_position, sym_anonymous);
6560
6561                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER);
6562                         entity->base.namespc                       = NAMESPACE_NORMAL;
6563                         entity->base.source_position               = source_position;
6564                         entity->declaration.declared_storage_class = STORAGE_CLASS_NONE;
6565                         entity->declaration.storage_class          = STORAGE_CLASS_NONE;
6566                         entity->declaration.modifiers              = specifiers->modifiers;
6567                         entity->declaration.type                   = type;
6568                         append_entity(&compound->members, entity);
6569                 } else {
6570                         entity = parse_declarator(specifiers,
6571                                         DECL_MAY_BE_ABSTRACT | DECL_CREATE_COMPOUND_MEMBER);
6572                         if (entity->kind == ENTITY_TYPEDEF) {
6573                                 errorf(&entity->base.source_position,
6574                                                 "typedef not allowed as compound member");
6575                         } else {
6576                                 assert(entity->kind == ENTITY_COMPOUND_MEMBER);
6577
6578                                 /* make sure we don't define a symbol multiple times */
6579                                 symbol_t *symbol = entity->base.symbol;
6580                                 if (symbol != NULL) {
6581                                         entity_t *prev = find_compound_entry(compound, symbol);
6582                                         if (prev != NULL) {
6583                                                 errorf(&entity->base.source_position,
6584                                                                 "multiple declarations of symbol '%Y' (declared %P)",
6585                                                                 symbol, &prev->base.source_position);
6586                                         }
6587                                 }
6588
6589                                 if (token.type == ':') {
6590                                         source_position_t source_position = *HERE;
6591                                         next_token();
6592                                         expression_t *size = parse_constant_expression();
6593
6594                                         type_t *type          = entity->declaration.type;
6595                                         type_t *bitfield_type = make_bitfield_type(type, size,
6596                                                         &source_position, entity->base.symbol);
6597                                         entity->declaration.type = bitfield_type;
6598                                 } else {
6599                                         type_t *orig_type = entity->declaration.type;
6600                                         type_t *type      = skip_typeref(orig_type);
6601                                         if (is_type_function(type)) {
6602                                                 errorf(&entity->base.source_position,
6603                                                                 "compound member '%Y' must not have function type '%T'",
6604                                                                 entity->base.symbol, orig_type);
6605                                         } else if (is_type_incomplete(type)) {
6606                                                 /* §6.7.2.1:16 flexible array member */
6607                                                 if (is_type_array(type) &&
6608                                                                 token.type == ';'   &&
6609                                                                 look_ahead(1)->type == '}') {
6610                                                         compound->has_flexible_member = true;
6611                                                 } else {
6612                                                         errorf(&entity->base.source_position,
6613                                                                         "compound member '%Y' has incomplete type '%T'",
6614                                                                         entity->base.symbol, orig_type);
6615                                                 }
6616                                         }
6617                                 }
6618
6619                                 append_entity(&compound->members, entity);
6620                         }
6621                 }
6622
6623                 if (token.type != ',')
6624                         break;
6625                 next_token();
6626         }
6627         expect(';', end_error);
6628
6629 end_error:
6630         anonymous_entity = NULL;
6631 }
6632
6633 static void parse_compound_type_entries(compound_t *compound)
6634 {
6635         eat('{');
6636         add_anchor_token('}');
6637
6638         while (token.type != '}') {
6639                 if (token.type == T_EOF) {
6640                         errorf(HERE, "EOF while parsing struct");
6641                         break;
6642                 }
6643                 declaration_specifiers_t specifiers;
6644                 memset(&specifiers, 0, sizeof(specifiers));
6645                 parse_declaration_specifiers(&specifiers);
6646
6647                 parse_compound_declarators(compound, &specifiers);
6648         }
6649         rem_anchor_token('}');
6650         next_token();
6651
6652         /* §6.7.2.1:7 */
6653         compound->complete = true;
6654 }
6655
6656 static type_t *parse_typename(void)
6657 {
6658         declaration_specifiers_t specifiers;
6659         memset(&specifiers, 0, sizeof(specifiers));
6660         parse_declaration_specifiers(&specifiers);
6661         if (specifiers.storage_class != STORAGE_CLASS_NONE ||
6662                         specifiers.thread_local) {
6663                 /* TODO: improve error message, user does probably not know what a
6664                  * storage class is...
6665                  */
6666                 errorf(HERE, "typename may not have a storage class");
6667         }
6668
6669         type_t *result = parse_abstract_declarator(specifiers.type);
6670
6671         return result;
6672 }
6673
6674
6675
6676
6677 typedef expression_t* (*parse_expression_function)(void);
6678 typedef expression_t* (*parse_expression_infix_function)(expression_t *left);
6679
6680 typedef struct expression_parser_function_t expression_parser_function_t;
6681 struct expression_parser_function_t {
6682         parse_expression_function        parser;
6683         precedence_t                     infix_precedence;
6684         parse_expression_infix_function  infix_parser;
6685 };
6686
6687 expression_parser_function_t expression_parsers[T_LAST_TOKEN];
6688
6689 /**
6690  * Prints an error message if an expression was expected but not read
6691  */
6692 static expression_t *expected_expression_error(void)
6693 {
6694         /* skip the error message if the error token was read */
6695         if (token.type != T_ERROR) {
6696                 errorf(HERE, "expected expression, got token %K", &token);
6697         }
6698         next_token();
6699
6700         return create_invalid_expression();
6701 }
6702
6703 /**
6704  * Parse a string constant.
6705  */
6706 static expression_t *parse_string_const(void)
6707 {
6708         wide_string_t wres;
6709         if (token.type == T_STRING_LITERAL) {
6710                 string_t res = token.v.string;
6711                 next_token();
6712                 while (token.type == T_STRING_LITERAL) {
6713                         res = concat_strings(&res, &token.v.string);
6714                         next_token();
6715                 }
6716                 if (token.type != T_WIDE_STRING_LITERAL) {
6717                         expression_t *const cnst = allocate_expression_zero(EXPR_STRING_LITERAL);
6718                         /* note: that we use type_char_ptr here, which is already the
6719                          * automatic converted type. revert_automatic_type_conversion
6720                          * will construct the array type */
6721                         cnst->base.type    = warning.write_strings ? type_const_char_ptr : type_char_ptr;
6722                         cnst->string.value = res;
6723                         return cnst;
6724                 }
6725
6726                 wres = concat_string_wide_string(&res, &token.v.wide_string);
6727         } else {
6728                 wres = token.v.wide_string;
6729         }
6730         next_token();
6731
6732         for (;;) {
6733                 switch (token.type) {
6734                         case T_WIDE_STRING_LITERAL:
6735                                 wres = concat_wide_strings(&wres, &token.v.wide_string);
6736                                 break;
6737
6738                         case T_STRING_LITERAL:
6739                                 wres = concat_wide_string_string(&wres, &token.v.string);
6740                                 break;
6741
6742                         default: {
6743                                 expression_t *const cnst = allocate_expression_zero(EXPR_WIDE_STRING_LITERAL);
6744                                 cnst->base.type         = warning.write_strings ? type_const_wchar_t_ptr : type_wchar_t_ptr;
6745                                 cnst->wide_string.value = wres;
6746                                 return cnst;
6747                         }
6748                 }
6749                 next_token();
6750         }
6751 }
6752
6753 /**
6754  * Parse a boolean constant.
6755  */
6756 static expression_t *parse_bool_const(bool value)
6757 {
6758         expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
6759         cnst->base.type          = type_bool;
6760         cnst->conste.v.int_value = value;
6761
6762         next_token();
6763
6764         return cnst;
6765 }
6766
6767 /**
6768  * Parse an integer constant.
6769  */
6770 static expression_t *parse_int_const(void)
6771 {
6772         expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
6773         cnst->base.type          = token.datatype;
6774         cnst->conste.v.int_value = token.v.intvalue;
6775
6776         next_token();
6777
6778         return cnst;
6779 }
6780
6781 /**
6782  * Parse a character constant.
6783  */
6784 static expression_t *parse_character_constant(void)
6785 {
6786         expression_t *cnst = allocate_expression_zero(EXPR_CHARACTER_CONSTANT);
6787         cnst->base.type          = token.datatype;
6788         cnst->conste.v.character = token.v.string;
6789
6790         if (cnst->conste.v.character.size != 1) {
6791                 if (!GNU_MODE) {
6792                         errorf(HERE, "more than 1 character in character constant");
6793                 } else if (warning.multichar) {
6794                         warningf(HERE, "multi-character character constant");
6795                 }
6796         }
6797         next_token();
6798
6799         return cnst;
6800 }
6801
6802 /**
6803  * Parse a wide character constant.
6804  */
6805 static expression_t *parse_wide_character_constant(void)
6806 {
6807         expression_t *cnst = allocate_expression_zero(EXPR_WIDE_CHARACTER_CONSTANT);
6808         cnst->base.type               = token.datatype;
6809         cnst->conste.v.wide_character = token.v.wide_string;
6810
6811         if (cnst->conste.v.wide_character.size != 1) {
6812                 if (!GNU_MODE) {
6813                         errorf(HERE, "more than 1 character in character constant");
6814                 } else if (warning.multichar) {
6815                         warningf(HERE, "multi-character character constant");
6816                 }
6817         }
6818         next_token();
6819
6820         return cnst;
6821 }
6822
6823 /**
6824  * Parse a float constant.
6825  */
6826 static expression_t *parse_float_const(void)
6827 {
6828         expression_t *cnst         = allocate_expression_zero(EXPR_CONST);
6829         cnst->base.type            = token.datatype;
6830         cnst->conste.v.float_value = token.v.floatvalue;
6831
6832         next_token();
6833
6834         return cnst;
6835 }
6836
6837 static entity_t *create_implicit_function(symbol_t *symbol,
6838                 const source_position_t *source_position)
6839 {
6840         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
6841         ntype->function.return_type            = type_int;
6842         ntype->function.unspecified_parameters = true;
6843         ntype->function.linkage                = LINKAGE_C;
6844         type_t *type                           = identify_new_type(ntype);
6845
6846         entity_t *entity = allocate_entity_zero(ENTITY_FUNCTION);
6847         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
6848         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
6849         entity->declaration.type                   = type;
6850         entity->declaration.implicit               = true;
6851         entity->base.symbol                        = symbol;
6852         entity->base.source_position               = *source_position;
6853
6854         bool strict_prototypes_old = warning.strict_prototypes;
6855         warning.strict_prototypes  = false;
6856         record_entity(entity, false);
6857         warning.strict_prototypes = strict_prototypes_old;
6858
6859         return entity;
6860 }
6861
6862 /**
6863  * Creates a return_type (func)(argument_type) function type if not
6864  * already exists.
6865  */
6866 static type_t *make_function_2_type(type_t *return_type, type_t *argument_type1,
6867                                     type_t *argument_type2)
6868 {
6869         function_parameter_t *parameter2
6870                 = obstack_alloc(type_obst, sizeof(parameter2[0]));
6871         memset(parameter2, 0, sizeof(parameter2[0]));
6872         parameter2->type = argument_type2;
6873
6874         function_parameter_t *parameter1
6875                 = obstack_alloc(type_obst, sizeof(parameter1[0]));
6876         memset(parameter1, 0, sizeof(parameter1[0]));
6877         parameter1->type = argument_type1;
6878         parameter1->next = parameter2;
6879
6880         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6881         type->function.return_type = return_type;
6882         type->function.parameters  = parameter1;
6883
6884         return identify_new_type(type);
6885 }
6886
6887 /**
6888  * Creates a return_type (func)(argument_type) function type if not
6889  * already exists.
6890  *
6891  * @param return_type    the return type
6892  * @param argument_type  the argument type
6893  */
6894 static type_t *make_function_1_type(type_t *return_type, type_t *argument_type)
6895 {
6896         function_parameter_t *parameter
6897                 = obstack_alloc(type_obst, sizeof(parameter[0]));
6898         memset(parameter, 0, sizeof(parameter[0]));
6899         parameter->type = argument_type;
6900
6901         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6902         type->function.return_type = return_type;
6903         type->function.parameters  = parameter;
6904
6905         return identify_new_type(type);
6906 }
6907
6908 static type_t *make_function_1_type_variadic(type_t *return_type, type_t *argument_type)
6909 {
6910         type_t *res = make_function_1_type(return_type, argument_type);
6911         res->function.variadic = 1;
6912         return res;
6913 }
6914
6915 /**
6916  * Creates a return_type (func)(void) function type if not
6917  * already exists.
6918  *
6919  * @param return_type    the return type
6920  */
6921 static type_t *make_function_0_type(type_t *return_type)
6922 {
6923         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6924         type->function.return_type = return_type;
6925         type->function.parameters  = NULL;
6926
6927         return identify_new_type(type);
6928 }
6929
6930 /**
6931  * Creates a function type for some function like builtins.
6932  *
6933  * @param symbol   the symbol describing the builtin
6934  */
6935 static type_t *get_builtin_symbol_type(symbol_t *symbol)
6936 {
6937         switch (symbol->ID) {
6938         case T___builtin_alloca:
6939                 return make_function_1_type(type_void_ptr, type_size_t);
6940         case T___builtin_huge_val:
6941                 return make_function_0_type(type_double);
6942         case T___builtin_inf:
6943                 return make_function_0_type(type_double);
6944         case T___builtin_inff:
6945                 return make_function_0_type(type_float);
6946         case T___builtin_infl:
6947                 return make_function_0_type(type_long_double);
6948         case T___builtin_nan:
6949                 return make_function_1_type(type_double, type_char_ptr);
6950         case T___builtin_nanf:
6951                 return make_function_1_type(type_float, type_char_ptr);
6952         case T___builtin_nanl:
6953                 return make_function_1_type(type_long_double, type_char_ptr);
6954         case T___builtin_va_end:
6955                 return make_function_1_type(type_void, type_valist);
6956         case T___builtin_expect:
6957                 return make_function_2_type(type_long, type_long, type_long);
6958         case T___builtin_return_address:
6959         case T___builtin_frame_address:
6960                 return make_function_1_type(type_void_ptr, type_unsigned_int);
6961         case T___builtin_prefetch:
6962                 return make_function_1_type_variadic(type_float, type_void_ptr);
6963         default:
6964                 internal_errorf(HERE, "not implemented builtin identifier found");
6965         }
6966 }
6967
6968 /**
6969  * Performs automatic type cast as described in §6.3.2.1.
6970  *
6971  * @param orig_type  the original type
6972  */
6973 static type_t *automatic_type_conversion(type_t *orig_type)
6974 {
6975         type_t *type = skip_typeref(orig_type);
6976         if (is_type_array(type)) {
6977                 array_type_t *array_type   = &type->array;
6978                 type_t       *element_type = array_type->element_type;
6979                 unsigned      qualifiers   = array_type->base.qualifiers;
6980
6981                 return make_pointer_type(element_type, qualifiers);
6982         }
6983
6984         if (is_type_function(type)) {
6985                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
6986         }
6987
6988         return orig_type;
6989 }
6990
6991 /**
6992  * reverts the automatic casts of array to pointer types and function
6993  * to function-pointer types as defined §6.3.2.1
6994  */
6995 type_t *revert_automatic_type_conversion(const expression_t *expression)
6996 {
6997         switch (expression->kind) {
6998                 case EXPR_REFERENCE: {
6999                         entity_t *entity = expression->reference.entity;
7000                         if (is_declaration(entity)) {
7001                                 return entity->declaration.type;
7002                         } else if (entity->kind == ENTITY_ENUM_VALUE) {
7003                                 return entity->enum_value.enum_type;
7004                         } else {
7005                                 panic("no declaration or enum in reference");
7006                         }
7007                 }
7008
7009                 case EXPR_SELECT: {
7010                         entity_t *entity = expression->select.compound_entry;
7011                         assert(is_declaration(entity));
7012                         type_t   *type   = entity->declaration.type;
7013                         return get_qualified_type(type,
7014                                         expression->base.type->base.qualifiers);
7015                 }
7016
7017                 case EXPR_UNARY_DEREFERENCE: {
7018                         const expression_t *const value = expression->unary.value;
7019                         type_t             *const type  = skip_typeref(value->base.type);
7020                         if (!is_type_pointer(type))
7021                                 return type_error_type;
7022                         return type->pointer.points_to;
7023                 }
7024
7025                 case EXPR_BUILTIN_SYMBOL:
7026                         return get_builtin_symbol_type(expression->builtin_symbol.symbol);
7027
7028                 case EXPR_ARRAY_ACCESS: {
7029                         const expression_t *array_ref = expression->array_access.array_ref;
7030                         type_t             *type_left = skip_typeref(array_ref->base.type);
7031                         if (!is_type_pointer(type_left))
7032                                 return type_error_type;
7033                         return type_left->pointer.points_to;
7034                 }
7035
7036                 case EXPR_STRING_LITERAL: {
7037                         size_t size = expression->string.value.size;
7038                         return make_array_type(type_char, size, TYPE_QUALIFIER_NONE);
7039                 }
7040
7041                 case EXPR_WIDE_STRING_LITERAL: {
7042                         size_t size = expression->wide_string.value.size;
7043                         return make_array_type(type_wchar_t, size, TYPE_QUALIFIER_NONE);
7044                 }
7045
7046                 case EXPR_COMPOUND_LITERAL:
7047                         return expression->compound_literal.type;
7048
7049                 default:
7050                         return expression->base.type;
7051         }
7052 }
7053
7054 static expression_t *parse_reference(void)
7055 {
7056         symbol_t *const symbol = token.v.symbol;
7057
7058         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
7059
7060         if (entity == NULL) {
7061                 if (!strict_mode && look_ahead(1)->type == '(') {
7062                         /* an implicitly declared function */
7063                         if (warning.error_implicit_function_declaration) {
7064                                 errorf(HERE, "implicit declaration of function '%Y'", symbol);
7065                         } else if (warning.implicit_function_declaration) {
7066                                 warningf(HERE, "implicit declaration of function '%Y'", symbol);
7067                         }
7068
7069                         entity = create_implicit_function(symbol, HERE);
7070                 } else {
7071                         errorf(HERE, "unknown identifier '%Y' found.", symbol);
7072                         entity = create_error_entity(symbol, ENTITY_VARIABLE);
7073                 }
7074         }
7075
7076         type_t *orig_type;
7077
7078         if (is_declaration(entity)) {
7079                 orig_type = entity->declaration.type;
7080         } else if (entity->kind == ENTITY_ENUM_VALUE) {
7081                 orig_type = entity->enum_value.enum_type;
7082         } else if (entity->kind == ENTITY_TYPEDEF) {
7083                 errorf(HERE, "encountered typedef name '%Y' while parsing expression",
7084                         symbol);
7085                 next_token();
7086                 return create_invalid_expression();
7087         } else {
7088                 panic("expected declaration or enum value in reference");
7089         }
7090
7091         /* we always do the auto-type conversions; the & and sizeof parser contains
7092          * code to revert this! */
7093         type_t *type = automatic_type_conversion(orig_type);
7094
7095         expression_kind_t kind = EXPR_REFERENCE;
7096         if (entity->kind == ENTITY_ENUM_VALUE)
7097                 kind = EXPR_REFERENCE_ENUM_VALUE;
7098
7099         expression_t *expression     = allocate_expression_zero(kind);
7100         expression->reference.entity = entity;
7101         expression->base.type        = type;
7102
7103         /* this declaration is used */
7104         if (is_declaration(entity)) {
7105                 entity->declaration.used = true;
7106         }
7107
7108         if (entity->base.parent_scope != file_scope
7109                 && entity->base.parent_scope->depth < current_function->parameters.depth
7110                 && is_type_valid(orig_type) && !is_type_function(orig_type)) {
7111                 if (entity->kind == ENTITY_VARIABLE) {
7112                         /* access of a variable from an outer function */
7113                         entity->variable.address_taken = true;
7114                 } else if (entity->kind == ENTITY_PARAMETER) {
7115                         entity->parameter.address_taken = true;
7116                 }
7117                 current_function->need_closure = true;
7118         }
7119
7120         /* check for deprecated functions */
7121         if (warning.deprecated_declarations
7122                 && is_declaration(entity)
7123                 && entity->declaration.modifiers & DM_DEPRECATED) {
7124                 declaration_t *declaration = &entity->declaration;
7125
7126                 char const *const prefix = entity->kind == ENTITY_FUNCTION ?
7127                         "function" : "variable";
7128
7129                 if (declaration->deprecated_string != NULL) {
7130                         warningf(HERE, "%s '%Y' is deprecated (declared %P): \"%s\"",
7131                                  prefix, entity->base.symbol, &entity->base.source_position,
7132                                  declaration->deprecated_string);
7133                 } else {
7134                         warningf(HERE, "%s '%Y' is deprecated (declared %P)", prefix,
7135                                  entity->base.symbol, &entity->base.source_position);
7136                 }
7137         }
7138
7139         if (warning.init_self && entity == current_init_decl && !in_type_prop
7140             && entity->kind == ENTITY_VARIABLE) {
7141                 current_init_decl = NULL;
7142                 warningf(HERE, "variable '%#T' is initialized by itself",
7143                          entity->declaration.type, entity->base.symbol);
7144         }
7145
7146         next_token();
7147         return expression;
7148 }
7149
7150 static bool semantic_cast(expression_t *cast)
7151 {
7152         expression_t            *expression      = cast->unary.value;
7153         type_t                  *orig_dest_type  = cast->base.type;
7154         type_t                  *orig_type_right = expression->base.type;
7155         type_t            const *dst_type        = skip_typeref(orig_dest_type);
7156         type_t            const *src_type        = skip_typeref(orig_type_right);
7157         source_position_t const *pos             = &cast->base.source_position;
7158
7159         /* §6.5.4 A (void) cast is explicitly permitted, more for documentation than for utility. */
7160         if (dst_type == type_void)
7161                 return true;
7162
7163         /* only integer and pointer can be casted to pointer */
7164         if (is_type_pointer(dst_type)  &&
7165             !is_type_pointer(src_type) &&
7166             !is_type_integer(src_type) &&
7167             is_type_valid(src_type)) {
7168                 errorf(pos, "cannot convert type '%T' to a pointer type", orig_type_right);
7169                 return false;
7170         }
7171
7172         if (!is_type_scalar(dst_type) && is_type_valid(dst_type)) {
7173                 errorf(pos, "conversion to non-scalar type '%T' requested", orig_dest_type);
7174                 return false;
7175         }
7176
7177         if (!is_type_scalar(src_type) && is_type_valid(src_type)) {
7178                 errorf(pos, "conversion from non-scalar type '%T' requested", orig_type_right);
7179                 return false;
7180         }
7181
7182         if (warning.cast_qual &&
7183             is_type_pointer(src_type) &&
7184             is_type_pointer(dst_type)) {
7185                 type_t *src = skip_typeref(src_type->pointer.points_to);
7186                 type_t *dst = skip_typeref(dst_type->pointer.points_to);
7187                 unsigned missing_qualifiers =
7188                         src->base.qualifiers & ~dst->base.qualifiers;
7189                 if (missing_qualifiers != 0) {
7190                         warningf(pos,
7191                                  "cast discards qualifiers '%Q' in pointer target type of '%T'",
7192                                  missing_qualifiers, orig_type_right);
7193                 }
7194         }
7195         return true;
7196 }
7197
7198 static expression_t *parse_compound_literal(type_t *type)
7199 {
7200         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
7201
7202         parse_initializer_env_t env;
7203         env.type             = type;
7204         env.entity           = NULL;
7205         env.must_be_constant = false;
7206         initializer_t *initializer = parse_initializer(&env);
7207         type = env.type;
7208
7209         expression->compound_literal.initializer = initializer;
7210         expression->compound_literal.type        = type;
7211         expression->base.type                    = automatic_type_conversion(type);
7212
7213         return expression;
7214 }
7215
7216 /**
7217  * Parse a cast expression.
7218  */
7219 static expression_t *parse_cast(void)
7220 {
7221         add_anchor_token(')');
7222
7223         source_position_t source_position = token.source_position;
7224
7225         type_t *type = parse_typename();
7226
7227         rem_anchor_token(')');
7228         expect(')', end_error);
7229
7230         if (token.type == '{') {
7231                 return parse_compound_literal(type);
7232         }
7233
7234         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
7235         cast->base.source_position = source_position;
7236
7237         expression_t *value = parse_sub_expression(PREC_CAST);
7238         cast->base.type   = type;
7239         cast->unary.value = value;
7240
7241         if (! semantic_cast(cast)) {
7242                 /* TODO: record the error in the AST. else it is impossible to detect it */
7243         }
7244
7245         return cast;
7246 end_error:
7247         return create_invalid_expression();
7248 }
7249
7250 /**
7251  * Parse a statement expression.
7252  */
7253 static expression_t *parse_statement_expression(void)
7254 {
7255         add_anchor_token(')');
7256
7257         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
7258
7259         statement_t *statement          = parse_compound_statement(true);
7260         statement->compound.stmt_expr   = true;
7261         expression->statement.statement = statement;
7262
7263         /* find last statement and use its type */
7264         type_t *type = type_void;
7265         const statement_t *stmt = statement->compound.statements;
7266         if (stmt != NULL) {
7267                 while (stmt->base.next != NULL)
7268                         stmt = stmt->base.next;
7269
7270                 if (stmt->kind == STATEMENT_EXPRESSION) {
7271                         type = stmt->expression.expression->base.type;
7272                 }
7273         } else if (warning.other) {
7274                 warningf(&expression->base.source_position, "empty statement expression ({})");
7275         }
7276         expression->base.type = type;
7277
7278         rem_anchor_token(')');
7279         expect(')', end_error);
7280
7281 end_error:
7282         return expression;
7283 }
7284
7285 /**
7286  * Parse a parenthesized expression.
7287  */
7288 static expression_t *parse_parenthesized_expression(void)
7289 {
7290         eat('(');
7291
7292         switch (token.type) {
7293         case '{':
7294                 /* gcc extension: a statement expression */
7295                 return parse_statement_expression();
7296
7297         TYPE_QUALIFIERS
7298         TYPE_SPECIFIERS
7299                 return parse_cast();
7300         case T_IDENTIFIER:
7301                 if (is_typedef_symbol(token.v.symbol)) {
7302                         return parse_cast();
7303                 }
7304         }
7305
7306         add_anchor_token(')');
7307         expression_t *result = parse_expression();
7308         result->base.parenthesized = true;
7309         rem_anchor_token(')');
7310         expect(')', end_error);
7311
7312 end_error:
7313         return result;
7314 }
7315
7316 static expression_t *parse_function_keyword(void)
7317 {
7318         /* TODO */
7319
7320         if (current_function == NULL) {
7321                 errorf(HERE, "'__func__' used outside of a function");
7322         }
7323
7324         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
7325         expression->base.type     = type_char_ptr;
7326         expression->funcname.kind = FUNCNAME_FUNCTION;
7327
7328         next_token();
7329
7330         return expression;
7331 }
7332
7333 static expression_t *parse_pretty_function_keyword(void)
7334 {
7335         if (current_function == NULL) {
7336                 errorf(HERE, "'__PRETTY_FUNCTION__' used outside of a function");
7337         }
7338
7339         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
7340         expression->base.type     = type_char_ptr;
7341         expression->funcname.kind = FUNCNAME_PRETTY_FUNCTION;
7342
7343         eat(T___PRETTY_FUNCTION__);
7344
7345         return expression;
7346 }
7347
7348 static expression_t *parse_funcsig_keyword(void)
7349 {
7350         if (current_function == NULL) {
7351                 errorf(HERE, "'__FUNCSIG__' used outside of a function");
7352         }
7353
7354         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
7355         expression->base.type     = type_char_ptr;
7356         expression->funcname.kind = FUNCNAME_FUNCSIG;
7357
7358         eat(T___FUNCSIG__);
7359
7360         return expression;
7361 }
7362
7363 static expression_t *parse_funcdname_keyword(void)
7364 {
7365         if (current_function == NULL) {
7366                 errorf(HERE, "'__FUNCDNAME__' used outside of a function");
7367         }
7368
7369         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
7370         expression->base.type     = type_char_ptr;
7371         expression->funcname.kind = FUNCNAME_FUNCDNAME;
7372
7373         eat(T___FUNCDNAME__);
7374
7375         return expression;
7376 }
7377
7378 static designator_t *parse_designator(void)
7379 {
7380         designator_t *result    = allocate_ast_zero(sizeof(result[0]));
7381         result->source_position = *HERE;
7382
7383         if (token.type != T_IDENTIFIER) {
7384                 parse_error_expected("while parsing member designator",
7385                                      T_IDENTIFIER, NULL);
7386                 return NULL;
7387         }
7388         result->symbol = token.v.symbol;
7389         next_token();
7390
7391         designator_t *last_designator = result;
7392         while (true) {
7393                 if (token.type == '.') {
7394                         next_token();
7395                         if (token.type != T_IDENTIFIER) {
7396                                 parse_error_expected("while parsing member designator",
7397                                                      T_IDENTIFIER, NULL);
7398                                 return NULL;
7399                         }
7400                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
7401                         designator->source_position = *HERE;
7402                         designator->symbol          = token.v.symbol;
7403                         next_token();
7404
7405                         last_designator->next = designator;
7406                         last_designator       = designator;
7407                         continue;
7408                 }
7409                 if (token.type == '[') {
7410                         next_token();
7411                         add_anchor_token(']');
7412                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
7413                         designator->source_position = *HERE;
7414                         designator->array_index     = parse_expression();
7415                         rem_anchor_token(']');
7416                         expect(']', end_error);
7417                         if (designator->array_index == NULL) {
7418                                 return NULL;
7419                         }
7420
7421                         last_designator->next = designator;
7422                         last_designator       = designator;
7423                         continue;
7424                 }
7425                 break;
7426         }
7427
7428         return result;
7429 end_error:
7430         return NULL;
7431 }
7432
7433 /**
7434  * Parse the __builtin_offsetof() expression.
7435  */
7436 static expression_t *parse_offsetof(void)
7437 {
7438         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
7439         expression->base.type    = type_size_t;
7440
7441         eat(T___builtin_offsetof);
7442
7443         expect('(', end_error);
7444         add_anchor_token(',');
7445         type_t *type = parse_typename();
7446         rem_anchor_token(',');
7447         expect(',', end_error);
7448         add_anchor_token(')');
7449         designator_t *designator = parse_designator();
7450         rem_anchor_token(')');
7451         expect(')', end_error);
7452
7453         expression->offsetofe.type       = type;
7454         expression->offsetofe.designator = designator;
7455
7456         type_path_t path;
7457         memset(&path, 0, sizeof(path));
7458         path.top_type = type;
7459         path.path     = NEW_ARR_F(type_path_entry_t, 0);
7460
7461         descend_into_subtype(&path);
7462
7463         if (!walk_designator(&path, designator, true)) {
7464                 return create_invalid_expression();
7465         }
7466
7467         DEL_ARR_F(path.path);
7468
7469         return expression;
7470 end_error:
7471         return create_invalid_expression();
7472 }
7473
7474 /**
7475  * Parses a _builtin_va_start() expression.
7476  */
7477 static expression_t *parse_va_start(void)
7478 {
7479         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
7480
7481         eat(T___builtin_va_start);
7482
7483         expect('(', end_error);
7484         add_anchor_token(',');
7485         expression->va_starte.ap = parse_assignment_expression();
7486         rem_anchor_token(',');
7487         expect(',', end_error);
7488         expression_t *const expr = parse_assignment_expression();
7489         if (expr->kind == EXPR_REFERENCE) {
7490                 entity_t *const entity = expr->reference.entity;
7491                 if (entity->base.parent_scope != &current_function->parameters
7492                                 || entity->base.next != NULL
7493                                 || entity->kind != ENTITY_PARAMETER) {
7494                         errorf(&expr->base.source_position,
7495                                "second argument of 'va_start' must be last parameter of the current function");
7496                 } else {
7497                         expression->va_starte.parameter = &entity->variable;
7498                 }
7499                 expect(')', end_error);
7500                 return expression;
7501         }
7502         expect(')', end_error);
7503 end_error:
7504         return create_invalid_expression();
7505 }
7506
7507 /**
7508  * Parses a _builtin_va_arg() expression.
7509  */
7510 static expression_t *parse_va_arg(void)
7511 {
7512         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
7513
7514         eat(T___builtin_va_arg);
7515
7516         expect('(', end_error);
7517         expression->va_arge.ap = parse_assignment_expression();
7518         expect(',', end_error);
7519         expression->base.type = parse_typename();
7520         expect(')', end_error);
7521
7522         return expression;
7523 end_error:
7524         return create_invalid_expression();
7525 }
7526
7527 static expression_t *parse_builtin_symbol(void)
7528 {
7529         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_SYMBOL);
7530
7531         symbol_t *symbol = token.v.symbol;
7532
7533         expression->builtin_symbol.symbol = symbol;
7534         next_token();
7535
7536         type_t *type = get_builtin_symbol_type(symbol);
7537         type = automatic_type_conversion(type);
7538
7539         expression->base.type = type;
7540         return expression;
7541 }
7542
7543 /**
7544  * Parses a __builtin_constant_p() expression.
7545  */
7546 static expression_t *parse_builtin_constant(void)
7547 {
7548         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
7549
7550         eat(T___builtin_constant_p);
7551
7552         expect('(', end_error);
7553         add_anchor_token(')');
7554         expression->builtin_constant.value = parse_assignment_expression();
7555         rem_anchor_token(')');
7556         expect(')', end_error);
7557         expression->base.type = type_int;
7558
7559         return expression;
7560 end_error:
7561         return create_invalid_expression();
7562 }
7563
7564 /**
7565  * Parses a __builtin_types_compatible_p() expression.
7566  */
7567 static expression_t *parse_builtin_types_compatible(void)
7568 {
7569         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_TYPES_COMPATIBLE_P);
7570
7571         eat(T___builtin_types_compatible_p);
7572
7573         expect('(', end_error);
7574         add_anchor_token(')');
7575         add_anchor_token(',');
7576         expression->builtin_types_compatible.left = parse_typename();
7577         rem_anchor_token(',');
7578         expect(',', end_error);
7579         expression->builtin_types_compatible.right = parse_typename();
7580         rem_anchor_token(')');
7581         expect(')', end_error);
7582         expression->base.type = type_int;
7583
7584         return expression;
7585 end_error:
7586         return create_invalid_expression();
7587 }
7588
7589 /**
7590  * Parses a __builtin_is_*() compare expression.
7591  */
7592 static expression_t *parse_compare_builtin(void)
7593 {
7594         expression_t *expression;
7595
7596         switch (token.type) {
7597         case T___builtin_isgreater:
7598                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATER);
7599                 break;
7600         case T___builtin_isgreaterequal:
7601                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATEREQUAL);
7602                 break;
7603         case T___builtin_isless:
7604                 expression = allocate_expression_zero(EXPR_BINARY_ISLESS);
7605                 break;
7606         case T___builtin_islessequal:
7607                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSEQUAL);
7608                 break;
7609         case T___builtin_islessgreater:
7610                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSGREATER);
7611                 break;
7612         case T___builtin_isunordered:
7613                 expression = allocate_expression_zero(EXPR_BINARY_ISUNORDERED);
7614                 break;
7615         default:
7616                 internal_errorf(HERE, "invalid compare builtin found");
7617         }
7618         expression->base.source_position = *HERE;
7619         next_token();
7620
7621         expect('(', end_error);
7622         expression->binary.left = parse_assignment_expression();
7623         expect(',', end_error);
7624         expression->binary.right = parse_assignment_expression();
7625         expect(')', end_error);
7626
7627         type_t *const orig_type_left  = expression->binary.left->base.type;
7628         type_t *const orig_type_right = expression->binary.right->base.type;
7629
7630         type_t *const type_left  = skip_typeref(orig_type_left);
7631         type_t *const type_right = skip_typeref(orig_type_right);
7632         if (!is_type_float(type_left) && !is_type_float(type_right)) {
7633                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7634                         type_error_incompatible("invalid operands in comparison",
7635                                 &expression->base.source_position, orig_type_left, orig_type_right);
7636                 }
7637         } else {
7638                 semantic_comparison(&expression->binary);
7639         }
7640
7641         return expression;
7642 end_error:
7643         return create_invalid_expression();
7644 }
7645
7646 #if 0
7647 /**
7648  * Parses a __builtin_expect(, end_error) expression.
7649  */
7650 static expression_t *parse_builtin_expect(void, end_error)
7651 {
7652         expression_t *expression
7653                 = allocate_expression_zero(EXPR_BINARY_BUILTIN_EXPECT);
7654
7655         eat(T___builtin_expect);
7656
7657         expect('(', end_error);
7658         expression->binary.left = parse_assignment_expression();
7659         expect(',', end_error);
7660         expression->binary.right = parse_constant_expression();
7661         expect(')', end_error);
7662
7663         expression->base.type = expression->binary.left->base.type;
7664
7665         return expression;
7666 end_error:
7667         return create_invalid_expression();
7668 }
7669 #endif
7670
7671 /**
7672  * Parses a MS assume() expression.
7673  */
7674 static expression_t *parse_assume(void)
7675 {
7676         expression_t *expression = allocate_expression_zero(EXPR_UNARY_ASSUME);
7677
7678         eat(T__assume);
7679
7680         expect('(', end_error);
7681         add_anchor_token(')');
7682         expression->unary.value = parse_assignment_expression();
7683         rem_anchor_token(')');
7684         expect(')', end_error);
7685
7686         expression->base.type = type_void;
7687         return expression;
7688 end_error:
7689         return create_invalid_expression();
7690 }
7691
7692 /**
7693  * Return the declaration for a given label symbol or create a new one.
7694  *
7695  * @param symbol  the symbol of the label
7696  */
7697 static label_t *get_label(symbol_t *symbol)
7698 {
7699         entity_t *label;
7700         assert(current_function != NULL);
7701
7702         label = get_entity(symbol, NAMESPACE_LABEL);
7703         /* if we found a local label, we already created the declaration */
7704         if (label != NULL && label->kind == ENTITY_LOCAL_LABEL) {
7705                 if (label->base.parent_scope != current_scope) {
7706                         assert(label->base.parent_scope->depth < current_scope->depth);
7707                         current_function->goto_to_outer = true;
7708                 }
7709                 return &label->label;
7710         }
7711
7712         label = get_entity(symbol, NAMESPACE_LABEL);
7713         /* if we found a label in the same function, then we already created the
7714          * declaration */
7715         if (label != NULL
7716                         && label->base.parent_scope == &current_function->parameters) {
7717                 return &label->label;
7718         }
7719
7720         /* otherwise we need to create a new one */
7721         label               = allocate_entity_zero(ENTITY_LABEL);
7722         label->base.namespc = NAMESPACE_LABEL;
7723         label->base.symbol  = symbol;
7724
7725         label_push(label);
7726
7727         return &label->label;
7728 }
7729
7730 /**
7731  * Parses a GNU && label address expression.
7732  */
7733 static expression_t *parse_label_address(void)
7734 {
7735         source_position_t source_position = token.source_position;
7736         eat(T_ANDAND);
7737         if (token.type != T_IDENTIFIER) {
7738                 parse_error_expected("while parsing label address", T_IDENTIFIER, NULL);
7739                 goto end_error;
7740         }
7741         symbol_t *symbol = token.v.symbol;
7742         next_token();
7743
7744         label_t *label       = get_label(symbol);
7745         label->used          = true;
7746         label->address_taken = true;
7747
7748         expression_t *expression = allocate_expression_zero(EXPR_LABEL_ADDRESS);
7749         expression->base.source_position = source_position;
7750
7751         /* label address is threaten as a void pointer */
7752         expression->base.type           = type_void_ptr;
7753         expression->label_address.label = label;
7754         return expression;
7755 end_error:
7756         return create_invalid_expression();
7757 }
7758
7759 /**
7760  * Parse a microsoft __noop expression.
7761  */
7762 static expression_t *parse_noop_expression(void)
7763 {
7764         /* the result is a (int)0 */
7765         expression_t *cnst         = allocate_expression_zero(EXPR_CONST);
7766         cnst->base.type            = type_int;
7767         cnst->conste.v.int_value   = 0;
7768         cnst->conste.is_ms_noop    = true;
7769
7770         eat(T___noop);
7771
7772         if (token.type == '(') {
7773                 /* parse arguments */
7774                 eat('(');
7775                 add_anchor_token(')');
7776                 add_anchor_token(',');
7777
7778                 if (token.type != ')') {
7779                         while (true) {
7780                                 (void)parse_assignment_expression();
7781                                 if (token.type != ',')
7782                                         break;
7783                                 next_token();
7784                         }
7785                 }
7786         }
7787         rem_anchor_token(',');
7788         rem_anchor_token(')');
7789         expect(')', end_error);
7790
7791 end_error:
7792         return cnst;
7793 }
7794
7795 /**
7796  * Parses a primary expression.
7797  */
7798 static expression_t *parse_primary_expression(void)
7799 {
7800         switch (token.type) {
7801                 case T_false:                        return parse_bool_const(false);
7802                 case T_true:                         return parse_bool_const(true);
7803                 case T_INTEGER:                      return parse_int_const();
7804                 case T_CHARACTER_CONSTANT:           return parse_character_constant();
7805                 case T_WIDE_CHARACTER_CONSTANT:      return parse_wide_character_constant();
7806                 case T_FLOATINGPOINT:                return parse_float_const();
7807                 case T_STRING_LITERAL:
7808                 case T_WIDE_STRING_LITERAL:          return parse_string_const();
7809                 case T_IDENTIFIER:                   return parse_reference();
7810                 case T___FUNCTION__:
7811                 case T___func__:                     return parse_function_keyword();
7812                 case T___PRETTY_FUNCTION__:          return parse_pretty_function_keyword();
7813                 case T___FUNCSIG__:                  return parse_funcsig_keyword();
7814                 case T___FUNCDNAME__:                return parse_funcdname_keyword();
7815                 case T___builtin_offsetof:           return parse_offsetof();
7816                 case T___builtin_va_start:           return parse_va_start();
7817                 case T___builtin_va_arg:             return parse_va_arg();
7818                 case T___builtin_expect:
7819                 case T___builtin_alloca:
7820                 case T___builtin_inf:
7821                 case T___builtin_inff:
7822                 case T___builtin_infl:
7823                 case T___builtin_nan:
7824                 case T___builtin_nanf:
7825                 case T___builtin_nanl:
7826                 case T___builtin_huge_val:
7827                 case T___builtin_va_end:
7828                 case T___builtin_return_address:
7829                 case T___builtin_frame_address:
7830                 case T___builtin_prefetch:           return parse_builtin_symbol();
7831                 case T___builtin_isgreater:
7832                 case T___builtin_isgreaterequal:
7833                 case T___builtin_isless:
7834                 case T___builtin_islessequal:
7835                 case T___builtin_islessgreater:
7836                 case T___builtin_isunordered:        return parse_compare_builtin();
7837                 case T___builtin_constant_p:         return parse_builtin_constant();
7838                 case T___builtin_types_compatible_p: return parse_builtin_types_compatible();
7839                 case T__assume:                      return parse_assume();
7840                 case T_ANDAND:
7841                         if (GNU_MODE)
7842                                 return parse_label_address();
7843                         break;
7844
7845                 case '(':                            return parse_parenthesized_expression();
7846                 case T___noop:                       return parse_noop_expression();
7847         }
7848
7849         errorf(HERE, "unexpected token %K, expected an expression", &token);
7850         return create_invalid_expression();
7851 }
7852
7853 /**
7854  * Check if the expression has the character type and issue a warning then.
7855  */
7856 static void check_for_char_index_type(const expression_t *expression)
7857 {
7858         type_t       *const type      = expression->base.type;
7859         const type_t *const base_type = skip_typeref(type);
7860
7861         if (is_type_atomic(base_type, ATOMIC_TYPE_CHAR) &&
7862                         warning.char_subscripts) {
7863                 warningf(&expression->base.source_position,
7864                          "array subscript has type '%T'", type);
7865         }
7866 }
7867
7868 static expression_t *parse_array_expression(expression_t *left)
7869 {
7870         expression_t *expression = allocate_expression_zero(EXPR_ARRAY_ACCESS);
7871
7872         eat('[');
7873         add_anchor_token(']');
7874
7875         expression_t *inside = parse_expression();
7876
7877         type_t *const orig_type_left   = left->base.type;
7878         type_t *const orig_type_inside = inside->base.type;
7879
7880         type_t *const type_left   = skip_typeref(orig_type_left);
7881         type_t *const type_inside = skip_typeref(orig_type_inside);
7882
7883         type_t                    *return_type;
7884         array_access_expression_t *array_access = &expression->array_access;
7885         if (is_type_pointer(type_left)) {
7886                 return_type             = type_left->pointer.points_to;
7887                 array_access->array_ref = left;
7888                 array_access->index     = inside;
7889                 check_for_char_index_type(inside);
7890         } else if (is_type_pointer(type_inside)) {
7891                 return_type             = type_inside->pointer.points_to;
7892                 array_access->array_ref = inside;
7893                 array_access->index     = left;
7894                 array_access->flipped   = true;
7895                 check_for_char_index_type(left);
7896         } else {
7897                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
7898                         errorf(HERE,
7899                                 "array access on object with non-pointer types '%T', '%T'",
7900                                 orig_type_left, orig_type_inside);
7901                 }
7902                 return_type             = type_error_type;
7903                 array_access->array_ref = left;
7904                 array_access->index     = inside;
7905         }
7906
7907         expression->base.type = automatic_type_conversion(return_type);
7908
7909         rem_anchor_token(']');
7910         expect(']', end_error);
7911 end_error:
7912         return expression;
7913 }
7914
7915 static expression_t *parse_typeprop(expression_kind_t const kind)
7916 {
7917         expression_t  *tp_expression = allocate_expression_zero(kind);
7918         tp_expression->base.type     = type_size_t;
7919
7920         eat(kind == EXPR_SIZEOF ? T_sizeof : T___alignof__);
7921
7922         /* we only refer to a type property, mark this case */
7923         bool old     = in_type_prop;
7924         in_type_prop = true;
7925
7926         type_t       *orig_type;
7927         expression_t *expression;
7928         if (token.type == '(' && is_declaration_specifier(look_ahead(1), true)) {
7929                 next_token();
7930                 add_anchor_token(')');
7931                 orig_type = parse_typename();
7932                 rem_anchor_token(')');
7933                 expect(')', end_error);
7934
7935                 if (token.type == '{') {
7936                         /* It was not sizeof(type) after all.  It is sizeof of an expression
7937                          * starting with a compound literal */
7938                         expression = parse_compound_literal(orig_type);
7939                         goto typeprop_expression;
7940                 }
7941         } else {
7942                 expression = parse_sub_expression(PREC_UNARY);
7943
7944 typeprop_expression:
7945                 tp_expression->typeprop.tp_expression = expression;
7946
7947                 orig_type = revert_automatic_type_conversion(expression);
7948                 expression->base.type = orig_type;
7949         }
7950
7951         tp_expression->typeprop.type   = orig_type;
7952         type_t const* const type       = skip_typeref(orig_type);
7953         char   const* const wrong_type =
7954                 GNU_MODE && is_type_atomic(type, ATOMIC_TYPE_VOID) ? NULL                  :
7955                 is_type_incomplete(type)                           ? "incomplete"          :
7956                 type->kind == TYPE_FUNCTION                        ? "function designator" :
7957                 type->kind == TYPE_BITFIELD                        ? "bitfield"            :
7958                 NULL;
7959         if (wrong_type != NULL) {
7960                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
7961                 errorf(&tp_expression->base.source_position,
7962                                 "operand of %s expression must not be of %s type '%T'",
7963                                 what, wrong_type, orig_type);
7964         }
7965
7966 end_error:
7967         in_type_prop = old;
7968         return tp_expression;
7969 }
7970
7971 static expression_t *parse_sizeof(void)
7972 {
7973         return parse_typeprop(EXPR_SIZEOF);
7974 }
7975
7976 static expression_t *parse_alignof(void)
7977 {
7978         return parse_typeprop(EXPR_ALIGNOF);
7979 }
7980
7981 static expression_t *parse_select_expression(expression_t *compound)
7982 {
7983         expression_t *select    = allocate_expression_zero(EXPR_SELECT);
7984         select->select.compound = compound;
7985
7986         assert(token.type == '.' || token.type == T_MINUSGREATER);
7987         bool is_pointer = (token.type == T_MINUSGREATER);
7988         next_token();
7989
7990         if (token.type != T_IDENTIFIER) {
7991                 parse_error_expected("while parsing select", T_IDENTIFIER, NULL);
7992                 return select;
7993         }
7994         symbol_t *symbol = token.v.symbol;
7995         next_token();
7996
7997         type_t *const orig_type = compound->base.type;
7998         type_t *const type      = skip_typeref(orig_type);
7999
8000         type_t *type_left;
8001         bool    saw_error = false;
8002         if (is_type_pointer(type)) {
8003                 if (!is_pointer) {
8004                         errorf(HERE,
8005                                "request for member '%Y' in something not a struct or union, but '%T'",
8006                                symbol, orig_type);
8007                         saw_error = true;
8008                 }
8009                 type_left = skip_typeref(type->pointer.points_to);
8010         } else {
8011                 if (is_pointer && is_type_valid(type)) {
8012                         errorf(HERE, "left hand side of '->' is not a pointer, but '%T'", orig_type);
8013                         saw_error = true;
8014                 }
8015                 type_left = type;
8016         }
8017
8018         entity_t *entry;
8019         if (type_left->kind == TYPE_COMPOUND_STRUCT ||
8020             type_left->kind == TYPE_COMPOUND_UNION) {
8021                 compound_t *compound = type_left->compound.compound;
8022
8023                 if (!compound->complete) {
8024                         errorf(HERE, "request for member '%Y' of incomplete type '%T'",
8025                                symbol, type_left);
8026                         goto create_error_entry;
8027                 }
8028
8029                 entry = find_compound_entry(compound, symbol);
8030                 if (entry == NULL) {
8031                         errorf(HERE, "'%T' has no member named '%Y'", orig_type, symbol);
8032                         goto create_error_entry;
8033                 }
8034         } else {
8035                 if (is_type_valid(type_left) && !saw_error) {
8036                         errorf(HERE,
8037                                "request for member '%Y' in something not a struct or union, but '%T'",
8038                                symbol, type_left);
8039                 }
8040 create_error_entry:
8041                 entry = create_error_entity(symbol, ENTITY_COMPOUND_MEMBER);
8042         }
8043
8044         assert(is_declaration(entry));
8045         select->select.compound_entry = entry;
8046
8047         type_t *entry_type = entry->declaration.type;
8048         type_t *res_type
8049                 = get_qualified_type(entry_type, type_left->base.qualifiers);
8050
8051         /* we always do the auto-type conversions; the & and sizeof parser contains
8052          * code to revert this! */
8053         select->base.type = automatic_type_conversion(res_type);
8054
8055         type_t *skipped = skip_typeref(res_type);
8056         if (skipped->kind == TYPE_BITFIELD) {
8057                 select->base.type = skipped->bitfield.base_type;
8058         }
8059
8060         return select;
8061 }
8062
8063 static void check_call_argument(const function_parameter_t *parameter,
8064                                 call_argument_t *argument, unsigned pos)
8065 {
8066         type_t         *expected_type      = parameter->type;
8067         type_t         *expected_type_skip = skip_typeref(expected_type);
8068         assign_error_t  error              = ASSIGN_ERROR_INCOMPATIBLE;
8069         expression_t   *arg_expr           = argument->expression;
8070         type_t         *arg_type           = skip_typeref(arg_expr->base.type);
8071
8072         /* handle transparent union gnu extension */
8073         if (is_type_union(expected_type_skip)
8074                         && (expected_type_skip->base.modifiers
8075                                 & TYPE_MODIFIER_TRANSPARENT_UNION)) {
8076                 compound_t *union_decl  = expected_type_skip->compound.compound;
8077                 type_t     *best_type   = NULL;
8078                 entity_t   *entry       = union_decl->members.entities;
8079                 for ( ; entry != NULL; entry = entry->base.next) {
8080                         assert(is_declaration(entry));
8081                         type_t *decl_type = entry->declaration.type;
8082                         error = semantic_assign(decl_type, arg_expr);
8083                         if (error == ASSIGN_ERROR_INCOMPATIBLE
8084                                 || error == ASSIGN_ERROR_POINTER_QUALIFIER_MISSING)
8085                                 continue;
8086
8087                         if (error == ASSIGN_SUCCESS) {
8088                                 best_type = decl_type;
8089                         } else if (best_type == NULL) {
8090                                 best_type = decl_type;
8091                         }
8092                 }
8093
8094                 if (best_type != NULL) {
8095                         expected_type = best_type;
8096                 }
8097         }
8098
8099         error                = semantic_assign(expected_type, arg_expr);
8100         argument->expression = create_implicit_cast(argument->expression,
8101                                                     expected_type);
8102
8103         if (error != ASSIGN_SUCCESS) {
8104                 /* report exact scope in error messages (like "in argument 3") */
8105                 char buf[64];
8106                 snprintf(buf, sizeof(buf), "call argument %u", pos);
8107                 report_assign_error(error, expected_type, arg_expr,     buf,
8108                                                         &arg_expr->base.source_position);
8109         } else if (warning.traditional || warning.conversion) {
8110                 type_t *const promoted_type = get_default_promoted_type(arg_type);
8111                 if (!types_compatible(expected_type_skip, promoted_type) &&
8112                     !types_compatible(expected_type_skip, type_void_ptr) &&
8113                     !types_compatible(type_void_ptr,      promoted_type)) {
8114                         /* Deliberately show the skipped types in this warning */
8115                         warningf(&arg_expr->base.source_position,
8116                                 "passing call argument %u as '%T' rather than '%T' due to prototype",
8117                                 pos, expected_type_skip, promoted_type);
8118                 }
8119         }
8120 }
8121
8122 /**
8123  * Handle the semantic restrictions of builtin calls
8124  */
8125 static void handle_builtin_argument_restrictions(call_expression_t *call) {
8126         switch (call->function->builtin_symbol.symbol->ID) {
8127                 case T___builtin_return_address:
8128                 case T___builtin_frame_address: {
8129                         /* argument must be constant */
8130                         call_argument_t *argument = call->arguments;
8131
8132                         if (! is_constant_expression(argument->expression)) {
8133                                 errorf(&call->base.source_position,
8134                                        "argument of '%Y' must be a constant expression",
8135                                        call->function->builtin_symbol.symbol);
8136                         }
8137                         break;
8138                 }
8139                 case T___builtin_prefetch: {
8140                         /* second and third argument must be constant if existant */
8141                         call_argument_t *rw = call->arguments->next;
8142                         call_argument_t *locality = NULL;
8143
8144                         if (rw != NULL) {
8145                                 if (! is_constant_expression(rw->expression)) {
8146                                         errorf(&call->base.source_position,
8147                                                "second argument of '%Y' must be a constant expression",
8148                                                call->function->builtin_symbol.symbol);
8149                                 }
8150                                 locality = rw->next;
8151                         }
8152                         if (locality != NULL) {
8153                                 if (! is_constant_expression(locality->expression)) {
8154                                         errorf(&call->base.source_position,
8155                                                "third argument of '%Y' must be a constant expression",
8156                                                call->function->builtin_symbol.symbol);
8157                                 }
8158                                 locality = rw->next;
8159                         }
8160                         break;
8161                 }
8162                 default:
8163                         break;
8164         }
8165 }
8166
8167 /**
8168  * Parse a call expression, ie. expression '( ... )'.
8169  *
8170  * @param expression  the function address
8171  */
8172 static expression_t *parse_call_expression(expression_t *expression)
8173 {
8174         expression_t      *result = allocate_expression_zero(EXPR_CALL);
8175         call_expression_t *call   = &result->call;
8176         call->function            = expression;
8177
8178         type_t *const orig_type = expression->base.type;
8179         type_t *const type      = skip_typeref(orig_type);
8180
8181         function_type_t *function_type = NULL;
8182         if (is_type_pointer(type)) {
8183                 type_t *const to_type = skip_typeref(type->pointer.points_to);
8184
8185                 if (is_type_function(to_type)) {
8186                         function_type   = &to_type->function;
8187                         call->base.type = function_type->return_type;
8188                 }
8189         }
8190
8191         if (function_type == NULL && is_type_valid(type)) {
8192                 errorf(HERE, "called object '%E' (type '%T') is not a pointer to a function", expression, orig_type);
8193         }
8194
8195         /* parse arguments */
8196         eat('(');
8197         add_anchor_token(')');
8198         add_anchor_token(',');
8199
8200         if (token.type != ')') {
8201                 call_argument_t *last_argument = NULL;
8202
8203                 while (true) {
8204                         call_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
8205
8206                         argument->expression = parse_assignment_expression();
8207                         if (last_argument == NULL) {
8208                                 call->arguments = argument;
8209                         } else {
8210                                 last_argument->next = argument;
8211                         }
8212                         last_argument = argument;
8213
8214                         if (token.type != ',')
8215                                 break;
8216                         next_token();
8217                 }
8218         }
8219         rem_anchor_token(',');
8220         rem_anchor_token(')');
8221         expect(')', end_error);
8222
8223         if (function_type == NULL)
8224                 return result;
8225
8226         function_parameter_t *parameter = function_type->parameters;
8227         call_argument_t      *argument  = call->arguments;
8228         if (!function_type->unspecified_parameters) {
8229                 for (unsigned pos = 0; parameter != NULL && argument != NULL;
8230                                 parameter = parameter->next, argument = argument->next) {
8231                         check_call_argument(parameter, argument, ++pos);
8232                 }
8233
8234                 if (parameter != NULL) {
8235                         errorf(HERE, "too few arguments to function '%E'", expression);
8236                 } else if (argument != NULL && !function_type->variadic) {
8237                         errorf(HERE, "too many arguments to function '%E'", expression);
8238                 }
8239         }
8240
8241         /* do default promotion */
8242         for (; argument != NULL; argument = argument->next) {
8243                 type_t *type = argument->expression->base.type;
8244
8245                 type = get_default_promoted_type(type);
8246
8247                 argument->expression
8248                         = create_implicit_cast(argument->expression, type);
8249         }
8250
8251         check_format(&result->call);
8252
8253         if (warning.aggregate_return &&
8254             is_type_compound(skip_typeref(function_type->return_type))) {
8255                 warningf(&result->base.source_position,
8256                          "function call has aggregate value");
8257         }
8258
8259         if (call->function->kind == EXPR_BUILTIN_SYMBOL) {
8260                 handle_builtin_argument_restrictions(&result->call);
8261         }
8262
8263 end_error:
8264         return result;
8265 }
8266
8267 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
8268
8269 static bool same_compound_type(const type_t *type1, const type_t *type2)
8270 {
8271         return
8272                 is_type_compound(type1) &&
8273                 type1->kind == type2->kind &&
8274                 type1->compound.compound == type2->compound.compound;
8275 }
8276
8277 static expression_t const *get_reference_address(expression_t const *expr)
8278 {
8279         bool regular_take_address = true;
8280         for (;;) {
8281                 if (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
8282                         expr = expr->unary.value;
8283                 } else {
8284                         regular_take_address = false;
8285                 }
8286
8287                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
8288                         break;
8289
8290                 expr = expr->unary.value;
8291         }
8292
8293         if (expr->kind != EXPR_REFERENCE)
8294                 return NULL;
8295
8296         /* special case for functions which are automatically converted to a
8297          * pointer to function without an extra TAKE_ADDRESS operation */
8298         if (!regular_take_address &&
8299                         expr->reference.entity->kind != ENTITY_FUNCTION) {
8300                 return NULL;
8301         }
8302
8303         return expr;
8304 }
8305
8306 static void warn_reference_address_as_bool(expression_t const* expr)
8307 {
8308         if (!warning.address)
8309                 return;
8310
8311         expr = get_reference_address(expr);
8312         if (expr != NULL) {
8313                 warningf(&expr->base.source_position,
8314                          "the address of '%Y' will always evaluate as 'true'",
8315                          expr->reference.entity->base.symbol);
8316         }
8317 }
8318
8319 static void warn_assignment_in_condition(const expression_t *const expr)
8320 {
8321         if (!warning.parentheses)
8322                 return;
8323         if (expr->base.kind != EXPR_BINARY_ASSIGN)
8324                 return;
8325         if (expr->base.parenthesized)
8326                 return;
8327         warningf(&expr->base.source_position,
8328                         "suggest parentheses around assignment used as truth value");
8329 }
8330
8331 static void semantic_condition(expression_t const *const expr,
8332                                char const *const context)
8333 {
8334         type_t *const type = skip_typeref(expr->base.type);
8335         if (is_type_scalar(type)) {
8336                 warn_reference_address_as_bool(expr);
8337                 warn_assignment_in_condition(expr);
8338         } else if (is_type_valid(type)) {
8339                 errorf(&expr->base.source_position,
8340                                 "%s must have scalar type", context);
8341         }
8342 }
8343
8344 /**
8345  * Parse a conditional expression, ie. 'expression ? ... : ...'.
8346  *
8347  * @param expression  the conditional expression
8348  */
8349 static expression_t *parse_conditional_expression(expression_t *expression)
8350 {
8351         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
8352
8353         conditional_expression_t *conditional = &result->conditional;
8354         conditional->condition                = expression;
8355
8356         eat('?');
8357         add_anchor_token(':');
8358
8359         /* §6.5.15:2  The first operand shall have scalar type. */
8360         semantic_condition(expression, "condition of conditional operator");
8361
8362         expression_t *true_expression = expression;
8363         bool          gnu_cond = false;
8364         if (GNU_MODE && token.type == ':') {
8365                 gnu_cond = true;
8366         } else {
8367                 true_expression = parse_expression();
8368         }
8369         rem_anchor_token(':');
8370         expect(':', end_error);
8371 end_error:;
8372         expression_t *false_expression =
8373                 parse_sub_expression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
8374
8375         type_t *const orig_true_type  = true_expression->base.type;
8376         type_t *const orig_false_type = false_expression->base.type;
8377         type_t *const true_type       = skip_typeref(orig_true_type);
8378         type_t *const false_type      = skip_typeref(orig_false_type);
8379
8380         /* 6.5.15.3 */
8381         type_t *result_type;
8382         if (is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
8383                         is_type_atomic(false_type, ATOMIC_TYPE_VOID)) {
8384                 /* ISO/IEC 14882:1998(E) §5.16:2 */
8385                 if (true_expression->kind == EXPR_UNARY_THROW) {
8386                         result_type = false_type;
8387                 } else if (false_expression->kind == EXPR_UNARY_THROW) {
8388                         result_type = true_type;
8389                 } else {
8390                         if (warning.other && (
8391                                                 !is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
8392                                                 !is_type_atomic(false_type, ATOMIC_TYPE_VOID)
8393                                         )) {
8394                                 warningf(&conditional->base.source_position,
8395                                                 "ISO C forbids conditional expression with only one void side");
8396                         }
8397                         result_type = type_void;
8398                 }
8399         } else if (is_type_arithmetic(true_type)
8400                    && is_type_arithmetic(false_type)) {
8401                 result_type = semantic_arithmetic(true_type, false_type);
8402
8403                 true_expression  = create_implicit_cast(true_expression, result_type);
8404                 false_expression = create_implicit_cast(false_expression, result_type);
8405
8406                 conditional->true_expression  = true_expression;
8407                 conditional->false_expression = false_expression;
8408                 conditional->base.type        = result_type;
8409         } else if (same_compound_type(true_type, false_type)) {
8410                 /* just take 1 of the 2 types */
8411                 result_type = true_type;
8412         } else if (is_type_pointer(true_type) || is_type_pointer(false_type)) {
8413                 type_t *pointer_type;
8414                 type_t *other_type;
8415                 expression_t *other_expression;
8416                 if (is_type_pointer(true_type) &&
8417                                 (!is_type_pointer(false_type) || is_null_pointer_constant(false_expression))) {
8418                         pointer_type     = true_type;
8419                         other_type       = false_type;
8420                         other_expression = false_expression;
8421                 } else {
8422                         pointer_type     = false_type;
8423                         other_type       = true_type;
8424                         other_expression = true_expression;
8425                 }
8426
8427                 if (is_null_pointer_constant(other_expression)) {
8428                         result_type = pointer_type;
8429                 } else if (is_type_pointer(other_type)) {
8430                         type_t *to1 = skip_typeref(pointer_type->pointer.points_to);
8431                         type_t *to2 = skip_typeref(other_type->pointer.points_to);
8432
8433                         type_t *to;
8434                         if (is_type_atomic(to1, ATOMIC_TYPE_VOID) ||
8435                             is_type_atomic(to2, ATOMIC_TYPE_VOID)) {
8436                                 to = type_void;
8437                         } else if (types_compatible(get_unqualified_type(to1),
8438                                                     get_unqualified_type(to2))) {
8439                                 to = to1;
8440                         } else {
8441                                 if (warning.other) {
8442                                         warningf(&conditional->base.source_position,
8443                                                         "pointer types '%T' and '%T' in conditional expression are incompatible",
8444                                                         true_type, false_type);
8445                                 }
8446                                 to = type_void;
8447                         }
8448
8449                         type_t *const type =
8450                                 get_qualified_type(to, to1->base.qualifiers | to2->base.qualifiers);
8451                         result_type = make_pointer_type(type, TYPE_QUALIFIER_NONE);
8452                 } else if (is_type_integer(other_type)) {
8453                         if (warning.other) {
8454                                 warningf(&conditional->base.source_position,
8455                                                 "pointer/integer type mismatch in conditional expression ('%T' and '%T')", true_type, false_type);
8456                         }
8457                         result_type = pointer_type;
8458                 } else {
8459                         if (is_type_valid(other_type)) {
8460                                 type_error_incompatible("while parsing conditional",
8461                                                 &expression->base.source_position, true_type, false_type);
8462                         }
8463                         result_type = type_error_type;
8464                 }
8465         } else {
8466                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
8467                         type_error_incompatible("while parsing conditional",
8468                                                 &conditional->base.source_position, true_type,
8469                                                 false_type);
8470                 }
8471                 result_type = type_error_type;
8472         }
8473
8474         conditional->true_expression
8475                 = gnu_cond ? NULL : create_implicit_cast(true_expression, result_type);
8476         conditional->false_expression
8477                 = create_implicit_cast(false_expression, result_type);
8478         conditional->base.type = result_type;
8479         return result;
8480 }
8481
8482 /**
8483  * Parse an extension expression.
8484  */
8485 static expression_t *parse_extension(void)
8486 {
8487         eat(T___extension__);
8488
8489         bool old_gcc_extension   = in_gcc_extension;
8490         in_gcc_extension         = true;
8491         expression_t *expression = parse_sub_expression(PREC_UNARY);
8492         in_gcc_extension         = old_gcc_extension;
8493         return expression;
8494 }
8495
8496 /**
8497  * Parse a __builtin_classify_type() expression.
8498  */
8499 static expression_t *parse_builtin_classify_type(void)
8500 {
8501         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
8502         result->base.type    = type_int;
8503
8504         eat(T___builtin_classify_type);
8505
8506         expect('(', end_error);
8507         add_anchor_token(')');
8508         expression_t *expression = parse_expression();
8509         rem_anchor_token(')');
8510         expect(')', end_error);
8511         result->classify_type.type_expression = expression;
8512
8513         return result;
8514 end_error:
8515         return create_invalid_expression();
8516 }
8517
8518 /**
8519  * Parse a delete expression
8520  * ISO/IEC 14882:1998(E) §5.3.5
8521  */
8522 static expression_t *parse_delete(void)
8523 {
8524         expression_t *const result = allocate_expression_zero(EXPR_UNARY_DELETE);
8525         result->base.type          = type_void;
8526
8527         eat(T_delete);
8528
8529         if (token.type == '[') {
8530                 next_token();
8531                 result->kind = EXPR_UNARY_DELETE_ARRAY;
8532                 expect(']', end_error);
8533 end_error:;
8534         }
8535
8536         expression_t *const value = parse_sub_expression(PREC_CAST);
8537         result->unary.value = value;
8538
8539         type_t *const type = skip_typeref(value->base.type);
8540         if (!is_type_pointer(type)) {
8541                 if (is_type_valid(type)) {
8542                         errorf(&value->base.source_position,
8543                                         "operand of delete must have pointer type");
8544                 }
8545         } else if (warning.other &&
8546                         is_type_atomic(skip_typeref(type->pointer.points_to), ATOMIC_TYPE_VOID)) {
8547                 warningf(&value->base.source_position,
8548                                 "deleting 'void*' is undefined");
8549         }
8550
8551         return result;
8552 }
8553
8554 /**
8555  * Parse a throw expression
8556  * ISO/IEC 14882:1998(E) §15:1
8557  */
8558 static expression_t *parse_throw(void)
8559 {
8560         expression_t *const result = allocate_expression_zero(EXPR_UNARY_THROW);
8561         result->base.type          = type_void;
8562
8563         eat(T_throw);
8564
8565         expression_t *value = NULL;
8566         switch (token.type) {
8567                 EXPRESSION_START {
8568                         value = parse_assignment_expression();
8569                         /* ISO/IEC 14882:1998(E) §15.1:3 */
8570                         type_t *const orig_type = value->base.type;
8571                         type_t *const type      = skip_typeref(orig_type);
8572                         if (is_type_incomplete(type)) {
8573                                 errorf(&value->base.source_position,
8574                                                 "cannot throw object of incomplete type '%T'", orig_type);
8575                         } else if (is_type_pointer(type)) {
8576                                 type_t *const points_to = skip_typeref(type->pointer.points_to);
8577                                 if (is_type_incomplete(points_to) &&
8578                                                 !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
8579                                         errorf(&value->base.source_position,
8580                                                         "cannot throw pointer to incomplete type '%T'", orig_type);
8581                                 }
8582                         }
8583                 }
8584
8585                 default:
8586                         break;
8587         }
8588         result->unary.value = value;
8589
8590         return result;
8591 }
8592
8593 static bool check_pointer_arithmetic(const source_position_t *source_position,
8594                                      type_t *pointer_type,
8595                                      type_t *orig_pointer_type)
8596 {
8597         type_t *points_to = pointer_type->pointer.points_to;
8598         points_to = skip_typeref(points_to);
8599
8600         if (is_type_incomplete(points_to)) {
8601                 if (!GNU_MODE || !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
8602                         errorf(source_position,
8603                                "arithmetic with pointer to incomplete type '%T' not allowed",
8604                                orig_pointer_type);
8605                         return false;
8606                 } else if (warning.pointer_arith) {
8607                         warningf(source_position,
8608                                  "pointer of type '%T' used in arithmetic",
8609                                  orig_pointer_type);
8610                 }
8611         } else if (is_type_function(points_to)) {
8612                 if (!GNU_MODE) {
8613                         errorf(source_position,
8614                                "arithmetic with pointer to function type '%T' not allowed",
8615                                orig_pointer_type);
8616                         return false;
8617                 } else if (warning.pointer_arith) {
8618                         warningf(source_position,
8619                                  "pointer to a function '%T' used in arithmetic",
8620                                  orig_pointer_type);
8621                 }
8622         }
8623         return true;
8624 }
8625
8626 static bool is_lvalue(const expression_t *expression)
8627 {
8628         /* TODO: doesn't seem to be consistent with §6.3.2.1:1 */
8629         switch (expression->kind) {
8630         case EXPR_ARRAY_ACCESS:
8631         case EXPR_COMPOUND_LITERAL:
8632         case EXPR_REFERENCE:
8633         case EXPR_SELECT:
8634         case EXPR_UNARY_DEREFERENCE:
8635                 return true;
8636
8637         default: {
8638           type_t *type = skip_typeref(expression->base.type);
8639           return
8640                 /* ISO/IEC 14882:1998(E) §3.10:3 */
8641                 is_type_reference(type) ||
8642                 /* Claim it is an lvalue, if the type is invalid.  There was a parse
8643                  * error before, which maybe prevented properly recognizing it as
8644                  * lvalue. */
8645                 !is_type_valid(type);
8646         }
8647         }
8648 }
8649
8650 static void semantic_incdec(unary_expression_t *expression)
8651 {
8652         type_t *const orig_type = expression->value->base.type;
8653         type_t *const type      = skip_typeref(orig_type);
8654         if (is_type_pointer(type)) {
8655                 if (!check_pointer_arithmetic(&expression->base.source_position,
8656                                               type, orig_type)) {
8657                         return;
8658                 }
8659         } else if (!is_type_real(type) && is_type_valid(type)) {
8660                 /* TODO: improve error message */
8661                 errorf(&expression->base.source_position,
8662                        "operation needs an arithmetic or pointer type");
8663                 return;
8664         }
8665         if (!is_lvalue(expression->value)) {
8666                 /* TODO: improve error message */
8667                 errorf(&expression->base.source_position, "lvalue required as operand");
8668         }
8669         expression->base.type = orig_type;
8670 }
8671
8672 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
8673 {
8674         type_t *const orig_type = expression->value->base.type;
8675         type_t *const type      = skip_typeref(orig_type);
8676         if (!is_type_arithmetic(type)) {
8677                 if (is_type_valid(type)) {
8678                         /* TODO: improve error message */
8679                         errorf(&expression->base.source_position,
8680                                 "operation needs an arithmetic type");
8681                 }
8682                 return;
8683         }
8684
8685         expression->base.type = orig_type;
8686 }
8687
8688 static void semantic_unexpr_plus(unary_expression_t *expression)
8689 {
8690         semantic_unexpr_arithmetic(expression);
8691         if (warning.traditional)
8692                 warningf(&expression->base.source_position,
8693                         "traditional C rejects the unary plus operator");
8694 }
8695
8696 static void semantic_not(unary_expression_t *expression)
8697 {
8698         /* §6.5.3.3:1  The operand [...] of the ! operator, scalar type. */
8699         semantic_condition(expression->value, "operand of !");
8700         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8701 }
8702
8703 static void semantic_unexpr_integer(unary_expression_t *expression)
8704 {
8705         type_t *const orig_type = expression->value->base.type;
8706         type_t *const type      = skip_typeref(orig_type);
8707         if (!is_type_integer(type)) {
8708                 if (is_type_valid(type)) {
8709                         errorf(&expression->base.source_position,
8710                                "operand of ~ must be of integer type");
8711                 }
8712                 return;
8713         }
8714
8715         expression->base.type = orig_type;
8716 }
8717
8718 static void semantic_dereference(unary_expression_t *expression)
8719 {
8720         type_t *const orig_type = expression->value->base.type;
8721         type_t *const type      = skip_typeref(orig_type);
8722         if (!is_type_pointer(type)) {
8723                 if (is_type_valid(type)) {
8724                         errorf(&expression->base.source_position,
8725                                "Unary '*' needs pointer or array type, but type '%T' given", orig_type);
8726                 }
8727                 return;
8728         }
8729
8730         type_t *result_type   = type->pointer.points_to;
8731         result_type           = automatic_type_conversion(result_type);
8732         expression->base.type = result_type;
8733 }
8734
8735 /**
8736  * Record that an address is taken (expression represents an lvalue).
8737  *
8738  * @param expression       the expression
8739  * @param may_be_register  if true, the expression might be an register
8740  */
8741 static void set_address_taken(expression_t *expression, bool may_be_register)
8742 {
8743         if (expression->kind != EXPR_REFERENCE)
8744                 return;
8745
8746         entity_t *const entity = expression->reference.entity;
8747
8748         if (entity->kind != ENTITY_VARIABLE && entity->kind != ENTITY_PARAMETER)
8749                 return;
8750
8751         if (entity->declaration.storage_class == STORAGE_CLASS_REGISTER
8752                         && !may_be_register) {
8753                 errorf(&expression->base.source_position,
8754                                 "address of register %s '%Y' requested",
8755                                 get_entity_kind_name(entity->kind),     entity->base.symbol);
8756         }
8757
8758         if (entity->kind == ENTITY_VARIABLE) {
8759                 entity->variable.address_taken = true;
8760         } else {
8761                 assert(entity->kind == ENTITY_PARAMETER);
8762                 entity->parameter.address_taken = true;
8763         }
8764 }
8765
8766 /**
8767  * Check the semantic of the address taken expression.
8768  */
8769 static void semantic_take_addr(unary_expression_t *expression)
8770 {
8771         expression_t *value = expression->value;
8772         value->base.type    = revert_automatic_type_conversion(value);
8773
8774         type_t *orig_type = value->base.type;
8775         type_t *type      = skip_typeref(orig_type);
8776         if (!is_type_valid(type))
8777                 return;
8778
8779         /* §6.5.3.2 */
8780         if (!is_lvalue(value)) {
8781                 errorf(&expression->base.source_position, "'&' requires an lvalue");
8782         }
8783         if (type->kind == TYPE_BITFIELD) {
8784                 errorf(&expression->base.source_position,
8785                        "'&' not allowed on object with bitfield type '%T'",
8786                        type);
8787         }
8788
8789         set_address_taken(value, false);
8790
8791         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
8792 }
8793
8794 #define CREATE_UNARY_EXPRESSION_PARSER(token_type, unexpression_type, sfunc) \
8795 static expression_t *parse_##unexpression_type(void)                         \
8796 {                                                                            \
8797         expression_t *unary_expression                                           \
8798                 = allocate_expression_zero(unexpression_type);                       \
8799         eat(token_type);                                                         \
8800         unary_expression->unary.value = parse_sub_expression(PREC_UNARY);        \
8801                                                                                  \
8802         sfunc(&unary_expression->unary);                                         \
8803                                                                                  \
8804         return unary_expression;                                                 \
8805 }
8806
8807 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
8808                                semantic_unexpr_arithmetic)
8809 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
8810                                semantic_unexpr_plus)
8811 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
8812                                semantic_not)
8813 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
8814                                semantic_dereference)
8815 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
8816                                semantic_take_addr)
8817 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
8818                                semantic_unexpr_integer)
8819 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
8820                                semantic_incdec)
8821 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
8822                                semantic_incdec)
8823
8824 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_type, unexpression_type, \
8825                                                sfunc)                         \
8826 static expression_t *parse_##unexpression_type(expression_t *left)            \
8827 {                                                                             \
8828         expression_t *unary_expression                                            \
8829                 = allocate_expression_zero(unexpression_type);                        \
8830         eat(token_type);                                                          \
8831         unary_expression->unary.value = left;                                     \
8832                                                                                   \
8833         sfunc(&unary_expression->unary);                                          \
8834                                                                               \
8835         return unary_expression;                                                  \
8836 }
8837
8838 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
8839                                        EXPR_UNARY_POSTFIX_INCREMENT,
8840                                        semantic_incdec)
8841 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
8842                                        EXPR_UNARY_POSTFIX_DECREMENT,
8843                                        semantic_incdec)
8844
8845 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
8846 {
8847         /* TODO: handle complex + imaginary types */
8848
8849         type_left  = get_unqualified_type(type_left);
8850         type_right = get_unqualified_type(type_right);
8851
8852         /* §6.3.1.8 Usual arithmetic conversions */
8853         if (type_left == type_long_double || type_right == type_long_double) {
8854                 return type_long_double;
8855         } else if (type_left == type_double || type_right == type_double) {
8856                 return type_double;
8857         } else if (type_left == type_float || type_right == type_float) {
8858                 return type_float;
8859         }
8860
8861         type_left  = promote_integer(type_left);
8862         type_right = promote_integer(type_right);
8863
8864         if (type_left == type_right)
8865                 return type_left;
8866
8867         bool const signed_left  = is_type_signed(type_left);
8868         bool const signed_right = is_type_signed(type_right);
8869         int const  rank_left    = get_rank(type_left);
8870         int const  rank_right   = get_rank(type_right);
8871
8872         if (signed_left == signed_right)
8873                 return rank_left >= rank_right ? type_left : type_right;
8874
8875         int     s_rank;
8876         int     u_rank;
8877         type_t *s_type;
8878         type_t *u_type;
8879         if (signed_left) {
8880                 s_rank = rank_left;
8881                 s_type = type_left;
8882                 u_rank = rank_right;
8883                 u_type = type_right;
8884         } else {
8885                 s_rank = rank_right;
8886                 s_type = type_right;
8887                 u_rank = rank_left;
8888                 u_type = type_left;
8889         }
8890
8891         if (u_rank >= s_rank)
8892                 return u_type;
8893
8894         /* casting rank to atomic_type_kind is a bit hacky, but makes things
8895          * easier here... */
8896         if (get_atomic_type_size((atomic_type_kind_t) s_rank)
8897                         > get_atomic_type_size((atomic_type_kind_t) u_rank))
8898                 return s_type;
8899
8900         switch (s_rank) {
8901                 case ATOMIC_TYPE_INT:      return type_unsigned_int;
8902                 case ATOMIC_TYPE_LONG:     return type_unsigned_long;
8903                 case ATOMIC_TYPE_LONGLONG: return type_unsigned_long_long;
8904
8905                 default: panic("invalid atomic type");
8906         }
8907 }
8908
8909 /**
8910  * Check the semantic restrictions for a binary expression.
8911  */
8912 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
8913 {
8914         expression_t *const left            = expression->left;
8915         expression_t *const right           = expression->right;
8916         type_t       *const orig_type_left  = left->base.type;
8917         type_t       *const orig_type_right = right->base.type;
8918         type_t       *const type_left       = skip_typeref(orig_type_left);
8919         type_t       *const type_right      = skip_typeref(orig_type_right);
8920
8921         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8922                 /* TODO: improve error message */
8923                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8924                         errorf(&expression->base.source_position,
8925                                "operation needs arithmetic types");
8926                 }
8927                 return;
8928         }
8929
8930         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8931         expression->left      = create_implicit_cast(left, arithmetic_type);
8932         expression->right     = create_implicit_cast(right, arithmetic_type);
8933         expression->base.type = arithmetic_type;
8934 }
8935
8936 static void warn_div_by_zero(binary_expression_t const *const expression)
8937 {
8938         if (!warning.div_by_zero ||
8939             !is_type_integer(expression->base.type))
8940                 return;
8941
8942         expression_t const *const right = expression->right;
8943         /* The type of the right operand can be different for /= */
8944         if (is_type_integer(right->base.type) &&
8945             is_constant_expression(right)     &&
8946             fold_constant(right) == 0) {
8947                 warningf(&expression->base.source_position, "division by zero");
8948         }
8949 }
8950
8951 /**
8952  * Check the semantic restrictions for a div/mod expression.
8953  */
8954 static void semantic_divmod_arithmetic(binary_expression_t *expression)
8955 {
8956         semantic_binexpr_arithmetic(expression);
8957         warn_div_by_zero(expression);
8958 }
8959
8960 static void warn_addsub_in_shift(const expression_t *const expr)
8961 {
8962         if (expr->base.parenthesized)
8963                 return;
8964
8965         char op;
8966         switch (expr->kind) {
8967                 case EXPR_BINARY_ADD: op = '+'; break;
8968                 case EXPR_BINARY_SUB: op = '-'; break;
8969                 default:              return;
8970         }
8971
8972         warningf(&expr->base.source_position,
8973                         "suggest parentheses around '%c' inside shift", op);
8974 }
8975
8976 static void semantic_shift_op(binary_expression_t *expression)
8977 {
8978         expression_t *const left            = expression->left;
8979         expression_t *const right           = expression->right;
8980         type_t       *const orig_type_left  = left->base.type;
8981         type_t       *const orig_type_right = right->base.type;
8982         type_t       *      type_left       = skip_typeref(orig_type_left);
8983         type_t       *      type_right      = skip_typeref(orig_type_right);
8984
8985         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8986                 /* TODO: improve error message */
8987                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8988                         errorf(&expression->base.source_position,
8989                                "operands of shift operation must have integer types");
8990                 }
8991                 return;
8992         }
8993
8994         if (warning.parentheses) {
8995                 warn_addsub_in_shift(left);
8996                 warn_addsub_in_shift(right);
8997         }
8998
8999         type_left  = promote_integer(type_left);
9000         type_right = promote_integer(type_right);
9001
9002         expression->left      = create_implicit_cast(left, type_left);
9003         expression->right     = create_implicit_cast(right, type_right);
9004         expression->base.type = type_left;
9005 }
9006
9007 static void semantic_add(binary_expression_t *expression)
9008 {
9009         expression_t *const left            = expression->left;
9010         expression_t *const right           = expression->right;
9011         type_t       *const orig_type_left  = left->base.type;
9012         type_t       *const orig_type_right = right->base.type;
9013         type_t       *const type_left       = skip_typeref(orig_type_left);
9014         type_t       *const type_right      = skip_typeref(orig_type_right);
9015
9016         /* §6.5.6 */
9017         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
9018                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
9019                 expression->left  = create_implicit_cast(left, arithmetic_type);
9020                 expression->right = create_implicit_cast(right, arithmetic_type);
9021                 expression->base.type = arithmetic_type;
9022         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
9023                 check_pointer_arithmetic(&expression->base.source_position,
9024                                          type_left, orig_type_left);
9025                 expression->base.type = type_left;
9026         } else if (is_type_pointer(type_right) && is_type_integer(type_left)) {
9027                 check_pointer_arithmetic(&expression->base.source_position,
9028                                          type_right, orig_type_right);
9029                 expression->base.type = type_right;
9030         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
9031                 errorf(&expression->base.source_position,
9032                        "invalid operands to binary + ('%T', '%T')",
9033                        orig_type_left, orig_type_right);
9034         }
9035 }
9036
9037 static void semantic_sub(binary_expression_t *expression)
9038 {
9039         expression_t            *const left            = expression->left;
9040         expression_t            *const right           = expression->right;
9041         type_t                  *const orig_type_left  = left->base.type;
9042         type_t                  *const orig_type_right = right->base.type;
9043         type_t                  *const type_left       = skip_typeref(orig_type_left);
9044         type_t                  *const type_right      = skip_typeref(orig_type_right);
9045         source_position_t const *const pos             = &expression->base.source_position;
9046
9047         /* §5.6.5 */
9048         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
9049                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
9050                 expression->left        = create_implicit_cast(left, arithmetic_type);
9051                 expression->right       = create_implicit_cast(right, arithmetic_type);
9052                 expression->base.type =  arithmetic_type;
9053         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
9054                 check_pointer_arithmetic(&expression->base.source_position,
9055                                          type_left, orig_type_left);
9056                 expression->base.type = type_left;
9057         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
9058                 type_t *const unqual_left  = get_unqualified_type(skip_typeref(type_left->pointer.points_to));
9059                 type_t *const unqual_right = get_unqualified_type(skip_typeref(type_right->pointer.points_to));
9060                 if (!types_compatible(unqual_left, unqual_right)) {
9061                         errorf(pos,
9062                                "subtracting pointers to incompatible types '%T' and '%T'",
9063                                orig_type_left, orig_type_right);
9064                 } else if (!is_type_object(unqual_left)) {
9065                         if (!is_type_atomic(unqual_left, ATOMIC_TYPE_VOID)) {
9066                                 errorf(pos, "subtracting pointers to non-object types '%T'",
9067                                        orig_type_left);
9068                         } else if (warning.other) {
9069                                 warningf(pos, "subtracting pointers to void");
9070                         }
9071                 }
9072                 expression->base.type = type_ptrdiff_t;
9073         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
9074                 errorf(pos, "invalid operands of types '%T' and '%T' to binary '-'",
9075                        orig_type_left, orig_type_right);
9076         }
9077 }
9078
9079 static void warn_string_literal_address(expression_t const* expr)
9080 {
9081         while (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
9082                 expr = expr->unary.value;
9083                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
9084                         return;
9085                 expr = expr->unary.value;
9086         }
9087
9088         if (expr->kind == EXPR_STRING_LITERAL ||
9089             expr->kind == EXPR_WIDE_STRING_LITERAL) {
9090                 warningf(&expr->base.source_position,
9091                         "comparison with string literal results in unspecified behaviour");
9092         }
9093 }
9094
9095 static void warn_comparison_in_comparison(const expression_t *const expr)
9096 {
9097         if (expr->base.parenthesized)
9098                 return;
9099         switch (expr->base.kind) {
9100                 case EXPR_BINARY_LESS:
9101                 case EXPR_BINARY_GREATER:
9102                 case EXPR_BINARY_LESSEQUAL:
9103                 case EXPR_BINARY_GREATEREQUAL:
9104                 case EXPR_BINARY_NOTEQUAL:
9105                 case EXPR_BINARY_EQUAL:
9106                         warningf(&expr->base.source_position,
9107                                         "comparisons like 'x <= y < z' do not have their mathematical meaning");
9108                         break;
9109                 default:
9110                         break;
9111         }
9112 }
9113
9114 static bool maybe_negative(expression_t const *const expr)
9115 {
9116         return
9117                 !is_constant_expression(expr) ||
9118                 fold_constant(expr) < 0;
9119 }
9120
9121 /**
9122  * Check the semantics of comparison expressions.
9123  *
9124  * @param expression   The expression to check.
9125  */
9126 static void semantic_comparison(binary_expression_t *expression)
9127 {
9128         expression_t *left  = expression->left;
9129         expression_t *right = expression->right;
9130
9131         if (warning.address) {
9132                 warn_string_literal_address(left);
9133                 warn_string_literal_address(right);
9134
9135                 expression_t const* const func_left = get_reference_address(left);
9136                 if (func_left != NULL && is_null_pointer_constant(right)) {
9137                         warningf(&expression->base.source_position,
9138                                  "the address of '%Y' will never be NULL",
9139                                  func_left->reference.entity->base.symbol);
9140                 }
9141
9142                 expression_t const* const func_right = get_reference_address(right);
9143                 if (func_right != NULL && is_null_pointer_constant(right)) {
9144                         warningf(&expression->base.source_position,
9145                                  "the address of '%Y' will never be NULL",
9146                                  func_right->reference.entity->base.symbol);
9147                 }
9148         }
9149
9150         if (warning.parentheses) {
9151                 warn_comparison_in_comparison(left);
9152                 warn_comparison_in_comparison(right);
9153         }
9154
9155         type_t *orig_type_left  = left->base.type;
9156         type_t *orig_type_right = right->base.type;
9157         type_t *type_left       = skip_typeref(orig_type_left);
9158         type_t *type_right      = skip_typeref(orig_type_right);
9159
9160         /* TODO non-arithmetic types */
9161         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
9162                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
9163
9164                 /* test for signed vs unsigned compares */
9165                 if (warning.sign_compare && is_type_integer(arithmetic_type)) {
9166                         bool const signed_left  = is_type_signed(type_left);
9167                         bool const signed_right = is_type_signed(type_right);
9168                         if (signed_left != signed_right) {
9169                                 /* FIXME long long needs better const folding magic */
9170                                 /* TODO check whether constant value can be represented by other type */
9171                                 if ((signed_left  && maybe_negative(left)) ||
9172                                                 (signed_right && maybe_negative(right))) {
9173                                         warningf(&expression->base.source_position,
9174                                                         "comparison between signed and unsigned");
9175                                 }
9176                         }
9177                 }
9178
9179                 expression->left        = create_implicit_cast(left, arithmetic_type);
9180                 expression->right       = create_implicit_cast(right, arithmetic_type);
9181                 expression->base.type   = arithmetic_type;
9182                 if (warning.float_equal &&
9183                     (expression->base.kind == EXPR_BINARY_EQUAL ||
9184                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
9185                     is_type_float(arithmetic_type)) {
9186                         warningf(&expression->base.source_position,
9187                                  "comparing floating point with == or != is unsafe");
9188                 }
9189         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
9190                 /* TODO check compatibility */
9191         } else if (is_type_pointer(type_left)) {
9192                 expression->right = create_implicit_cast(right, type_left);
9193         } else if (is_type_pointer(type_right)) {
9194                 expression->left = create_implicit_cast(left, type_right);
9195         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
9196                 type_error_incompatible("invalid operands in comparison",
9197                                         &expression->base.source_position,
9198                                         type_left, type_right);
9199         }
9200         expression->base.type = c_mode & _CXX ? type_bool : type_int;
9201 }
9202
9203 /**
9204  * Checks if a compound type has constant fields.
9205  */
9206 static bool has_const_fields(const compound_type_t *type)
9207 {
9208         compound_t *compound = type->compound;
9209         entity_t   *entry    = compound->members.entities;
9210
9211         for (; entry != NULL; entry = entry->base.next) {
9212                 if (!is_declaration(entry))
9213                         continue;
9214
9215                 const type_t *decl_type = skip_typeref(entry->declaration.type);
9216                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
9217                         return true;
9218         }
9219
9220         return false;
9221 }
9222
9223 static bool is_valid_assignment_lhs(expression_t const* const left)
9224 {
9225         type_t *const orig_type_left = revert_automatic_type_conversion(left);
9226         type_t *const type_left      = skip_typeref(orig_type_left);
9227
9228         if (!is_lvalue(left)) {
9229                 errorf(HERE, "left hand side '%E' of assignment is not an lvalue",
9230                        left);
9231                 return false;
9232         }
9233
9234         if (left->kind == EXPR_REFERENCE
9235                         && left->reference.entity->kind == ENTITY_FUNCTION) {
9236                 errorf(HERE, "cannot assign to function '%E'", left);
9237                 return false;
9238         }
9239
9240         if (is_type_array(type_left)) {
9241                 errorf(HERE, "cannot assign to array '%E'", left);
9242                 return false;
9243         }
9244         if (type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
9245                 errorf(HERE, "assignment to readonly location '%E' (type '%T')", left,
9246                        orig_type_left);
9247                 return false;
9248         }
9249         if (is_type_incomplete(type_left)) {
9250                 errorf(HERE, "left-hand side '%E' of assignment has incomplete type '%T'",
9251                        left, orig_type_left);
9252                 return false;
9253         }
9254         if (is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
9255                 errorf(HERE, "cannot assign to '%E' because compound type '%T' has readonly fields",
9256                        left, orig_type_left);
9257                 return false;
9258         }
9259
9260         return true;
9261 }
9262
9263 static void semantic_arithmetic_assign(binary_expression_t *expression)
9264 {
9265         expression_t *left            = expression->left;
9266         expression_t *right           = expression->right;
9267         type_t       *orig_type_left  = left->base.type;
9268         type_t       *orig_type_right = right->base.type;
9269
9270         if (!is_valid_assignment_lhs(left))
9271                 return;
9272
9273         type_t *type_left  = skip_typeref(orig_type_left);
9274         type_t *type_right = skip_typeref(orig_type_right);
9275
9276         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
9277                 /* TODO: improve error message */
9278                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
9279                         errorf(&expression->base.source_position,
9280                                "operation needs arithmetic types");
9281                 }
9282                 return;
9283         }
9284
9285         /* combined instructions are tricky. We can't create an implicit cast on
9286          * the left side, because we need the uncasted form for the store.
9287          * The ast2firm pass has to know that left_type must be right_type
9288          * for the arithmetic operation and create a cast by itself */
9289         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
9290         expression->right       = create_implicit_cast(right, arithmetic_type);
9291         expression->base.type   = type_left;
9292 }
9293
9294 static void semantic_divmod_assign(binary_expression_t *expression)
9295 {
9296         semantic_arithmetic_assign(expression);
9297         warn_div_by_zero(expression);
9298 }
9299
9300 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
9301 {
9302         expression_t *const left            = expression->left;
9303         expression_t *const right           = expression->right;
9304         type_t       *const orig_type_left  = left->base.type;
9305         type_t       *const orig_type_right = right->base.type;
9306         type_t       *const type_left       = skip_typeref(orig_type_left);
9307         type_t       *const type_right      = skip_typeref(orig_type_right);
9308
9309         if (!is_valid_assignment_lhs(left))
9310                 return;
9311
9312         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
9313                 /* combined instructions are tricky. We can't create an implicit cast on
9314                  * the left side, because we need the uncasted form for the store.
9315                  * The ast2firm pass has to know that left_type must be right_type
9316                  * for the arithmetic operation and create a cast by itself */
9317                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
9318                 expression->right     = create_implicit_cast(right, arithmetic_type);
9319                 expression->base.type = type_left;
9320         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
9321                 check_pointer_arithmetic(&expression->base.source_position,
9322                                          type_left, orig_type_left);
9323                 expression->base.type = type_left;
9324         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
9325                 errorf(&expression->base.source_position,
9326                        "incompatible types '%T' and '%T' in assignment",
9327                        orig_type_left, orig_type_right);
9328         }
9329 }
9330
9331 static void warn_logical_and_within_or(const expression_t *const expr)
9332 {
9333         if (expr->base.kind != EXPR_BINARY_LOGICAL_AND)
9334                 return;
9335         if (expr->base.parenthesized)
9336                 return;
9337         warningf(&expr->base.source_position,
9338                         "suggest parentheses around && within ||");
9339 }
9340
9341 /**
9342  * Check the semantic restrictions of a logical expression.
9343  */
9344 static void semantic_logical_op(binary_expression_t *expression)
9345 {
9346         /* §6.5.13:2  Each of the operands shall have scalar type.
9347          * §6.5.14:2  Each of the operands shall have scalar type. */
9348         semantic_condition(expression->left,   "left operand of logical operator");
9349         semantic_condition(expression->right, "right operand of logical operator");
9350         if (expression->base.kind == EXPR_BINARY_LOGICAL_OR &&
9351                         warning.parentheses) {
9352                 warn_logical_and_within_or(expression->left);
9353                 warn_logical_and_within_or(expression->right);
9354         }
9355         expression->base.type = c_mode & _CXX ? type_bool : type_int;
9356 }
9357
9358 /**
9359  * Check the semantic restrictions of a binary assign expression.
9360  */
9361 static void semantic_binexpr_assign(binary_expression_t *expression)
9362 {
9363         expression_t *left           = expression->left;
9364         type_t       *orig_type_left = left->base.type;
9365
9366         if (!is_valid_assignment_lhs(left))
9367                 return;
9368
9369         assign_error_t error = semantic_assign(orig_type_left, expression->right);
9370         report_assign_error(error, orig_type_left, expression->right,
9371                         "assignment", &left->base.source_position);
9372         expression->right = create_implicit_cast(expression->right, orig_type_left);
9373         expression->base.type = orig_type_left;
9374 }
9375
9376 /**
9377  * Determine if the outermost operation (or parts thereof) of the given
9378  * expression has no effect in order to generate a warning about this fact.
9379  * Therefore in some cases this only examines some of the operands of the
9380  * expression (see comments in the function and examples below).
9381  * Examples:
9382  *   f() + 23;    // warning, because + has no effect
9383  *   x || f();    // no warning, because x controls execution of f()
9384  *   x ? y : f(); // warning, because y has no effect
9385  *   (void)x;     // no warning to be able to suppress the warning
9386  * This function can NOT be used for an "expression has definitely no effect"-
9387  * analysis. */
9388 static bool expression_has_effect(const expression_t *const expr)
9389 {
9390         switch (expr->kind) {
9391                 case EXPR_UNKNOWN:                    break;
9392                 case EXPR_INVALID:                    return true; /* do NOT warn */
9393                 case EXPR_REFERENCE:                  return false;
9394                 case EXPR_REFERENCE_ENUM_VALUE:       return false;
9395                 /* suppress the warning for microsoft __noop operations */
9396                 case EXPR_CONST:                      return expr->conste.is_ms_noop;
9397                 case EXPR_CHARACTER_CONSTANT:         return false;
9398                 case EXPR_WIDE_CHARACTER_CONSTANT:    return false;
9399                 case EXPR_STRING_LITERAL:             return false;
9400                 case EXPR_WIDE_STRING_LITERAL:        return false;
9401                 case EXPR_LABEL_ADDRESS:              return false;
9402
9403                 case EXPR_CALL: {
9404                         const call_expression_t *const call = &expr->call;
9405                         if (call->function->kind != EXPR_BUILTIN_SYMBOL)
9406                                 return true;
9407
9408                         switch (call->function->builtin_symbol.symbol->ID) {
9409                                 case T___builtin_prefetch:
9410                                 case T___builtin_va_end:   return true;
9411                                 default:                   return false;
9412                         }
9413                 }
9414
9415                 /* Generate the warning if either the left or right hand side of a
9416                  * conditional expression has no effect */
9417                 case EXPR_CONDITIONAL: {
9418                         conditional_expression_t const *const cond = &expr->conditional;
9419                         expression_t             const *const t    = cond->true_expression;
9420                         return
9421                                 (t == NULL || expression_has_effect(t)) &&
9422                                 expression_has_effect(cond->false_expression);
9423                 }
9424
9425                 case EXPR_SELECT:                     return false;
9426                 case EXPR_ARRAY_ACCESS:               return false;
9427                 case EXPR_SIZEOF:                     return false;
9428                 case EXPR_CLASSIFY_TYPE:              return false;
9429                 case EXPR_ALIGNOF:                    return false;
9430
9431                 case EXPR_FUNCNAME:                   return false;
9432                 case EXPR_BUILTIN_SYMBOL:             break; /* handled in EXPR_CALL */
9433                 case EXPR_BUILTIN_CONSTANT_P:         return false;
9434                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P: return false;
9435                 case EXPR_OFFSETOF:                   return false;
9436                 case EXPR_VA_START:                   return true;
9437                 case EXPR_VA_ARG:                     return true;
9438                 case EXPR_STATEMENT:                  return true; // TODO
9439                 case EXPR_COMPOUND_LITERAL:           return false;
9440
9441                 case EXPR_UNARY_NEGATE:               return false;
9442                 case EXPR_UNARY_PLUS:                 return false;
9443                 case EXPR_UNARY_BITWISE_NEGATE:       return false;
9444                 case EXPR_UNARY_NOT:                  return false;
9445                 case EXPR_UNARY_DEREFERENCE:          return false;
9446                 case EXPR_UNARY_TAKE_ADDRESS:         return false;
9447                 case EXPR_UNARY_POSTFIX_INCREMENT:    return true;
9448                 case EXPR_UNARY_POSTFIX_DECREMENT:    return true;
9449                 case EXPR_UNARY_PREFIX_INCREMENT:     return true;
9450                 case EXPR_UNARY_PREFIX_DECREMENT:     return true;
9451
9452                 /* Treat void casts as if they have an effect in order to being able to
9453                  * suppress the warning */
9454                 case EXPR_UNARY_CAST: {
9455                         type_t *const type = skip_typeref(expr->base.type);
9456                         return is_type_atomic(type, ATOMIC_TYPE_VOID);
9457                 }
9458
9459                 case EXPR_UNARY_CAST_IMPLICIT:        return true;
9460                 case EXPR_UNARY_ASSUME:               return true;
9461                 case EXPR_UNARY_DELETE:               return true;
9462                 case EXPR_UNARY_DELETE_ARRAY:         return true;
9463                 case EXPR_UNARY_THROW:                return true;
9464
9465                 case EXPR_BINARY_ADD:                 return false;
9466                 case EXPR_BINARY_SUB:                 return false;
9467                 case EXPR_BINARY_MUL:                 return false;
9468                 case EXPR_BINARY_DIV:                 return false;
9469                 case EXPR_BINARY_MOD:                 return false;
9470                 case EXPR_BINARY_EQUAL:               return false;
9471                 case EXPR_BINARY_NOTEQUAL:            return false;
9472                 case EXPR_BINARY_LESS:                return false;
9473                 case EXPR_BINARY_LESSEQUAL:           return false;
9474                 case EXPR_BINARY_GREATER:             return false;
9475                 case EXPR_BINARY_GREATEREQUAL:        return false;
9476                 case EXPR_BINARY_BITWISE_AND:         return false;
9477                 case EXPR_BINARY_BITWISE_OR:          return false;
9478                 case EXPR_BINARY_BITWISE_XOR:         return false;
9479                 case EXPR_BINARY_SHIFTLEFT:           return false;
9480                 case EXPR_BINARY_SHIFTRIGHT:          return false;
9481                 case EXPR_BINARY_ASSIGN:              return true;
9482                 case EXPR_BINARY_MUL_ASSIGN:          return true;
9483                 case EXPR_BINARY_DIV_ASSIGN:          return true;
9484                 case EXPR_BINARY_MOD_ASSIGN:          return true;
9485                 case EXPR_BINARY_ADD_ASSIGN:          return true;
9486                 case EXPR_BINARY_SUB_ASSIGN:          return true;
9487                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:    return true;
9488                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:   return true;
9489                 case EXPR_BINARY_BITWISE_AND_ASSIGN:  return true;
9490                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:  return true;
9491                 case EXPR_BINARY_BITWISE_OR_ASSIGN:   return true;
9492
9493                 /* Only examine the right hand side of && and ||, because the left hand
9494                  * side already has the effect of controlling the execution of the right
9495                  * hand side */
9496                 case EXPR_BINARY_LOGICAL_AND:
9497                 case EXPR_BINARY_LOGICAL_OR:
9498                 /* Only examine the right hand side of a comma expression, because the left
9499                  * hand side has a separate warning */
9500                 case EXPR_BINARY_COMMA:
9501                         return expression_has_effect(expr->binary.right);
9502
9503                 case EXPR_BINARY_ISGREATER:           return false;
9504                 case EXPR_BINARY_ISGREATEREQUAL:      return false;
9505                 case EXPR_BINARY_ISLESS:              return false;
9506                 case EXPR_BINARY_ISLESSEQUAL:         return false;
9507                 case EXPR_BINARY_ISLESSGREATER:       return false;
9508                 case EXPR_BINARY_ISUNORDERED:         return false;
9509         }
9510
9511         internal_errorf(HERE, "unexpected expression");
9512 }
9513
9514 static void semantic_comma(binary_expression_t *expression)
9515 {
9516         if (warning.unused_value) {
9517                 const expression_t *const left = expression->left;
9518                 if (!expression_has_effect(left)) {
9519                         warningf(&left->base.source_position,
9520                                  "left-hand operand of comma expression has no effect");
9521                 }
9522         }
9523         expression->base.type = expression->right->base.type;
9524 }
9525
9526 /**
9527  * @param prec_r precedence of the right operand
9528  */
9529 #define CREATE_BINEXPR_PARSER(token_type, binexpression_type, prec_r, sfunc) \
9530 static expression_t *parse_##binexpression_type(expression_t *left)          \
9531 {                                                                            \
9532         expression_t *binexpr = allocate_expression_zero(binexpression_type);    \
9533         binexpr->binary.left  = left;                                            \
9534         eat(token_type);                                                         \
9535                                                                              \
9536         expression_t *right = parse_sub_expression(prec_r);                      \
9537                                                                              \
9538         binexpr->binary.right = right;                                           \
9539         sfunc(&binexpr->binary);                                                 \
9540                                                                              \
9541         return binexpr;                                                          \
9542 }
9543
9544 CREATE_BINEXPR_PARSER('*',                    EXPR_BINARY_MUL,                PREC_CAST,           semantic_binexpr_arithmetic)
9545 CREATE_BINEXPR_PARSER('/',                    EXPR_BINARY_DIV,                PREC_CAST,           semantic_divmod_arithmetic)
9546 CREATE_BINEXPR_PARSER('%',                    EXPR_BINARY_MOD,                PREC_CAST,           semantic_divmod_arithmetic)
9547 CREATE_BINEXPR_PARSER('+',                    EXPR_BINARY_ADD,                PREC_MULTIPLICATIVE, semantic_add)
9548 CREATE_BINEXPR_PARSER('-',                    EXPR_BINARY_SUB,                PREC_MULTIPLICATIVE, semantic_sub)
9549 CREATE_BINEXPR_PARSER(T_LESSLESS,             EXPR_BINARY_SHIFTLEFT,          PREC_ADDITIVE,       semantic_shift_op)
9550 CREATE_BINEXPR_PARSER(T_GREATERGREATER,       EXPR_BINARY_SHIFTRIGHT,         PREC_ADDITIVE,       semantic_shift_op)
9551 CREATE_BINEXPR_PARSER('<',                    EXPR_BINARY_LESS,               PREC_SHIFT,          semantic_comparison)
9552 CREATE_BINEXPR_PARSER('>',                    EXPR_BINARY_GREATER,            PREC_SHIFT,          semantic_comparison)
9553 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,          PREC_SHIFT,          semantic_comparison)
9554 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,       PREC_SHIFT,          semantic_comparison)
9555 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,           PREC_RELATIONAL,     semantic_comparison)
9556 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,              PREC_RELATIONAL,     semantic_comparison)
9557 CREATE_BINEXPR_PARSER('&',                    EXPR_BINARY_BITWISE_AND,        PREC_EQUALITY,       semantic_binexpr_arithmetic)
9558 CREATE_BINEXPR_PARSER('^',                    EXPR_BINARY_BITWISE_XOR,        PREC_AND,            semantic_binexpr_arithmetic)
9559 CREATE_BINEXPR_PARSER('|',                    EXPR_BINARY_BITWISE_OR,         PREC_XOR,            semantic_binexpr_arithmetic)
9560 CREATE_BINEXPR_PARSER(T_ANDAND,               EXPR_BINARY_LOGICAL_AND,        PREC_OR,             semantic_logical_op)
9561 CREATE_BINEXPR_PARSER(T_PIPEPIPE,             EXPR_BINARY_LOGICAL_OR,         PREC_LOGICAL_AND,    semantic_logical_op)
9562 CREATE_BINEXPR_PARSER('=',                    EXPR_BINARY_ASSIGN,             PREC_ASSIGNMENT,     semantic_binexpr_assign)
9563 CREATE_BINEXPR_PARSER(T_PLUSEQUAL,            EXPR_BINARY_ADD_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
9564 CREATE_BINEXPR_PARSER(T_MINUSEQUAL,           EXPR_BINARY_SUB_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
9565 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL,        EXPR_BINARY_MUL_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9566 CREATE_BINEXPR_PARSER(T_SLASHEQUAL,           EXPR_BINARY_DIV_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
9567 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL,         EXPR_BINARY_MOD_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
9568 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL,        EXPR_BINARY_SHIFTLEFT_ASSIGN,   PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9569 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL,  EXPR_BINARY_SHIFTRIGHT_ASSIGN,  PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9570 CREATE_BINEXPR_PARSER(T_ANDEQUAL,             EXPR_BINARY_BITWISE_AND_ASSIGN, PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9571 CREATE_BINEXPR_PARSER(T_PIPEEQUAL,            EXPR_BINARY_BITWISE_OR_ASSIGN,  PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9572 CREATE_BINEXPR_PARSER(T_CARETEQUAL,           EXPR_BINARY_BITWISE_XOR_ASSIGN, PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9573 CREATE_BINEXPR_PARSER(',',                    EXPR_BINARY_COMMA,              PREC_ASSIGNMENT,     semantic_comma)
9574
9575
9576 static expression_t *parse_sub_expression(precedence_t precedence)
9577 {
9578         if (token.type < 0) {
9579                 return expected_expression_error();
9580         }
9581
9582         expression_parser_function_t *parser
9583                 = &expression_parsers[token.type];
9584         source_position_t             source_position = token.source_position;
9585         expression_t                 *left;
9586
9587         if (parser->parser != NULL) {
9588                 left = parser->parser();
9589         } else {
9590                 left = parse_primary_expression();
9591         }
9592         assert(left != NULL);
9593         left->base.source_position = source_position;
9594
9595         while (true) {
9596                 if (token.type < 0) {
9597                         return expected_expression_error();
9598                 }
9599
9600                 parser = &expression_parsers[token.type];
9601                 if (parser->infix_parser == NULL)
9602                         break;
9603                 if (parser->infix_precedence < precedence)
9604                         break;
9605
9606                 left = parser->infix_parser(left);
9607
9608                 assert(left != NULL);
9609                 assert(left->kind != EXPR_UNKNOWN);
9610                 left->base.source_position = source_position;
9611         }
9612
9613         return left;
9614 }
9615
9616 /**
9617  * Parse an expression.
9618  */
9619 static expression_t *parse_expression(void)
9620 {
9621         return parse_sub_expression(PREC_EXPRESSION);
9622 }
9623
9624 /**
9625  * Register a parser for a prefix-like operator.
9626  *
9627  * @param parser      the parser function
9628  * @param token_type  the token type of the prefix token
9629  */
9630 static void register_expression_parser(parse_expression_function parser,
9631                                        int token_type)
9632 {
9633         expression_parser_function_t *entry = &expression_parsers[token_type];
9634
9635         if (entry->parser != NULL) {
9636                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
9637                 panic("trying to register multiple expression parsers for a token");
9638         }
9639         entry->parser = parser;
9640 }
9641
9642 /**
9643  * Register a parser for an infix operator with given precedence.
9644  *
9645  * @param parser      the parser function
9646  * @param token_type  the token type of the infix operator
9647  * @param precedence  the precedence of the operator
9648  */
9649 static void register_infix_parser(parse_expression_infix_function parser,
9650                 int token_type, precedence_t precedence)
9651 {
9652         expression_parser_function_t *entry = &expression_parsers[token_type];
9653
9654         if (entry->infix_parser != NULL) {
9655                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
9656                 panic("trying to register multiple infix expression parsers for a "
9657                       "token");
9658         }
9659         entry->infix_parser     = parser;
9660         entry->infix_precedence = precedence;
9661 }
9662
9663 /**
9664  * Initialize the expression parsers.
9665  */
9666 static void init_expression_parsers(void)
9667 {
9668         memset(&expression_parsers, 0, sizeof(expression_parsers));
9669
9670         register_infix_parser(parse_array_expression,               '[',                    PREC_POSTFIX);
9671         register_infix_parser(parse_call_expression,                '(',                    PREC_POSTFIX);
9672         register_infix_parser(parse_select_expression,              '.',                    PREC_POSTFIX);
9673         register_infix_parser(parse_select_expression,              T_MINUSGREATER,         PREC_POSTFIX);
9674         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,   T_PLUSPLUS,             PREC_POSTFIX);
9675         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,   T_MINUSMINUS,           PREC_POSTFIX);
9676         register_infix_parser(parse_EXPR_BINARY_MUL,                '*',                    PREC_MULTIPLICATIVE);
9677         register_infix_parser(parse_EXPR_BINARY_DIV,                '/',                    PREC_MULTIPLICATIVE);
9678         register_infix_parser(parse_EXPR_BINARY_MOD,                '%',                    PREC_MULTIPLICATIVE);
9679         register_infix_parser(parse_EXPR_BINARY_ADD,                '+',                    PREC_ADDITIVE);
9680         register_infix_parser(parse_EXPR_BINARY_SUB,                '-',                    PREC_ADDITIVE);
9681         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,          T_LESSLESS,             PREC_SHIFT);
9682         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,         T_GREATERGREATER,       PREC_SHIFT);
9683         register_infix_parser(parse_EXPR_BINARY_LESS,               '<',                    PREC_RELATIONAL);
9684         register_infix_parser(parse_EXPR_BINARY_GREATER,            '>',                    PREC_RELATIONAL);
9685         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,          T_LESSEQUAL,            PREC_RELATIONAL);
9686         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL,       T_GREATEREQUAL,         PREC_RELATIONAL);
9687         register_infix_parser(parse_EXPR_BINARY_EQUAL,              T_EQUALEQUAL,           PREC_EQUALITY);
9688         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,           T_EXCLAMATIONMARKEQUAL, PREC_EQUALITY);
9689         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,        '&',                    PREC_AND);
9690         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,        '^',                    PREC_XOR);
9691         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,         '|',                    PREC_OR);
9692         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,        T_ANDAND,               PREC_LOGICAL_AND);
9693         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,         T_PIPEPIPE,             PREC_LOGICAL_OR);
9694         register_infix_parser(parse_conditional_expression,         '?',                    PREC_CONDITIONAL);
9695         register_infix_parser(parse_EXPR_BINARY_ASSIGN,             '=',                    PREC_ASSIGNMENT);
9696         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,         T_PLUSEQUAL,            PREC_ASSIGNMENT);
9697         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,         T_MINUSEQUAL,           PREC_ASSIGNMENT);
9698         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,         T_ASTERISKEQUAL,        PREC_ASSIGNMENT);
9699         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,         T_SLASHEQUAL,           PREC_ASSIGNMENT);
9700         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,         T_PERCENTEQUAL,         PREC_ASSIGNMENT);
9701         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,   T_LESSLESSEQUAL,        PREC_ASSIGNMENT);
9702         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,  T_GREATERGREATEREQUAL,  PREC_ASSIGNMENT);
9703         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN, T_ANDEQUAL,             PREC_ASSIGNMENT);
9704         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,  T_PIPEEQUAL,            PREC_ASSIGNMENT);
9705         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN, T_CARETEQUAL,           PREC_ASSIGNMENT);
9706         register_infix_parser(parse_EXPR_BINARY_COMMA,              ',',                    PREC_EXPRESSION);
9707
9708         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-');
9709         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+');
9710         register_expression_parser(parse_EXPR_UNARY_NOT,              '!');
9711         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~');
9712         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*');
9713         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&');
9714         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT, T_PLUSPLUS);
9715         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT, T_MINUSMINUS);
9716         register_expression_parser(parse_sizeof,                      T_sizeof);
9717         register_expression_parser(parse_alignof,                     T___alignof__);
9718         register_expression_parser(parse_extension,                   T___extension__);
9719         register_expression_parser(parse_builtin_classify_type,       T___builtin_classify_type);
9720         register_expression_parser(parse_delete,                      T_delete);
9721         register_expression_parser(parse_throw,                       T_throw);
9722 }
9723
9724 /**
9725  * Parse a asm statement arguments specification.
9726  */
9727 static asm_argument_t *parse_asm_arguments(bool is_out)
9728 {
9729         asm_argument_t  *result = NULL;
9730         asm_argument_t **anchor = &result;
9731
9732         while (token.type == T_STRING_LITERAL || token.type == '[') {
9733                 asm_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
9734                 memset(argument, 0, sizeof(argument[0]));
9735
9736                 if (token.type == '[') {
9737                         eat('[');
9738                         if (token.type != T_IDENTIFIER) {
9739                                 parse_error_expected("while parsing asm argument",
9740                                                      T_IDENTIFIER, NULL);
9741                                 return NULL;
9742                         }
9743                         argument->symbol = token.v.symbol;
9744
9745                         expect(']', end_error);
9746                 }
9747
9748                 argument->constraints = parse_string_literals();
9749                 expect('(', end_error);
9750                 add_anchor_token(')');
9751                 expression_t *expression = parse_expression();
9752                 rem_anchor_token(')');
9753                 if (is_out) {
9754                         /* Ugly GCC stuff: Allow lvalue casts.  Skip casts, when they do not
9755                          * change size or type representation (e.g. int -> long is ok, but
9756                          * int -> float is not) */
9757                         if (expression->kind == EXPR_UNARY_CAST) {
9758                                 type_t      *const type = expression->base.type;
9759                                 type_kind_t  const kind = type->kind;
9760                                 if (kind == TYPE_ATOMIC || kind == TYPE_POINTER) {
9761                                         unsigned flags;
9762                                         unsigned size;
9763                                         if (kind == TYPE_ATOMIC) {
9764                                                 atomic_type_kind_t const akind = type->atomic.akind;
9765                                                 flags = get_atomic_type_flags(akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
9766                                                 size  = get_atomic_type_size(akind);
9767                                         } else {
9768                                                 flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
9769                                                 size  = get_atomic_type_size(get_intptr_kind());
9770                                         }
9771
9772                                         do {
9773                                                 expression_t *const value      = expression->unary.value;
9774                                                 type_t       *const value_type = value->base.type;
9775                                                 type_kind_t   const value_kind = value_type->kind;
9776
9777                                                 unsigned value_flags;
9778                                                 unsigned value_size;
9779                                                 if (value_kind == TYPE_ATOMIC) {
9780                                                         atomic_type_kind_t const value_akind = value_type->atomic.akind;
9781                                                         value_flags = get_atomic_type_flags(value_akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
9782                                                         value_size  = get_atomic_type_size(value_akind);
9783                                                 } else if (value_kind == TYPE_POINTER) {
9784                                                         value_flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
9785                                                         value_size  = get_atomic_type_size(get_intptr_kind());
9786                                                 } else {
9787                                                         break;
9788                                                 }
9789
9790                                                 if (value_flags != flags || value_size != size)
9791                                                         break;
9792
9793                                                 expression = value;
9794                                         } while (expression->kind == EXPR_UNARY_CAST);
9795                                 }
9796                         }
9797
9798                         if (!is_lvalue(expression)) {
9799                                 errorf(&expression->base.source_position,
9800                                        "asm output argument is not an lvalue");
9801                         }
9802
9803                         if (argument->constraints.begin[0] == '+')
9804                                 mark_vars_read(expression, NULL);
9805                 } else {
9806                         mark_vars_read(expression, NULL);
9807                 }
9808                 argument->expression = expression;
9809                 expect(')', end_error);
9810
9811                 set_address_taken(expression, true);
9812
9813                 *anchor = argument;
9814                 anchor  = &argument->next;
9815
9816                 if (token.type != ',')
9817                         break;
9818                 eat(',');
9819         }
9820
9821         return result;
9822 end_error:
9823         return NULL;
9824 }
9825
9826 /**
9827  * Parse a asm statement clobber specification.
9828  */
9829 static asm_clobber_t *parse_asm_clobbers(void)
9830 {
9831         asm_clobber_t *result = NULL;
9832         asm_clobber_t *last   = NULL;
9833
9834         while (token.type == T_STRING_LITERAL) {
9835                 asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
9836                 clobber->clobber       = parse_string_literals();
9837
9838                 if (last != NULL) {
9839                         last->next = clobber;
9840                 } else {
9841                         result = clobber;
9842                 }
9843                 last = clobber;
9844
9845                 if (token.type != ',')
9846                         break;
9847                 eat(',');
9848         }
9849
9850         return result;
9851 }
9852
9853 /**
9854  * Parse an asm statement.
9855  */
9856 static statement_t *parse_asm_statement(void)
9857 {
9858         statement_t     *statement     = allocate_statement_zero(STATEMENT_ASM);
9859         asm_statement_t *asm_statement = &statement->asms;
9860
9861         eat(T_asm);
9862
9863         if (token.type == T_volatile) {
9864                 next_token();
9865                 asm_statement->is_volatile = true;
9866         }
9867
9868         expect('(', end_error);
9869         add_anchor_token(')');
9870         add_anchor_token(':');
9871         asm_statement->asm_text = parse_string_literals();
9872
9873         if (token.type != ':') {
9874                 rem_anchor_token(':');
9875                 goto end_of_asm;
9876         }
9877         eat(':');
9878
9879         asm_statement->outputs = parse_asm_arguments(true);
9880         if (token.type != ':') {
9881                 rem_anchor_token(':');
9882                 goto end_of_asm;
9883         }
9884         eat(':');
9885
9886         asm_statement->inputs = parse_asm_arguments(false);
9887         if (token.type != ':') {
9888                 rem_anchor_token(':');
9889                 goto end_of_asm;
9890         }
9891         rem_anchor_token(':');
9892         eat(':');
9893
9894         asm_statement->clobbers = parse_asm_clobbers();
9895
9896 end_of_asm:
9897         rem_anchor_token(')');
9898         expect(')', end_error);
9899         expect(';', end_error);
9900
9901         if (asm_statement->outputs == NULL) {
9902                 /* GCC: An 'asm' instruction without any output operands will be treated
9903                  * identically to a volatile 'asm' instruction. */
9904                 asm_statement->is_volatile = true;
9905         }
9906
9907         return statement;
9908 end_error:
9909         return create_invalid_statement();
9910 }
9911
9912 /**
9913  * Parse a case statement.
9914  */
9915 static statement_t *parse_case_statement(void)
9916 {
9917         statement_t       *const statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9918         source_position_t *const pos       = &statement->base.source_position;
9919
9920         eat(T_case);
9921
9922         expression_t *const expression   = parse_expression();
9923         statement->case_label.expression = expression;
9924         if (!is_constant_expression(expression)) {
9925                 /* This check does not prevent the error message in all cases of an
9926                  * prior error while parsing the expression.  At least it catches the
9927                  * common case of a mistyped enum entry. */
9928                 if (is_type_valid(skip_typeref(expression->base.type))) {
9929                         errorf(pos, "case label does not reduce to an integer constant");
9930                 }
9931                 statement->case_label.is_bad = true;
9932         } else {
9933                 long const val = fold_constant(expression);
9934                 statement->case_label.first_case = val;
9935                 statement->case_label.last_case  = val;
9936         }
9937
9938         if (GNU_MODE) {
9939                 if (token.type == T_DOTDOTDOT) {
9940                         next_token();
9941                         expression_t *const end_range   = parse_expression();
9942                         statement->case_label.end_range = end_range;
9943                         if (!is_constant_expression(end_range)) {
9944                                 /* This check does not prevent the error message in all cases of an
9945                                  * prior error while parsing the expression.  At least it catches the
9946                                  * common case of a mistyped enum entry. */
9947                                 if (is_type_valid(skip_typeref(end_range->base.type))) {
9948                                         errorf(pos, "case range does not reduce to an integer constant");
9949                                 }
9950                                 statement->case_label.is_bad = true;
9951                         } else {
9952                                 long const val = fold_constant(end_range);
9953                                 statement->case_label.last_case = val;
9954
9955                                 if (warning.other && val < statement->case_label.first_case) {
9956                                         statement->case_label.is_empty_range = true;
9957                                         warningf(pos, "empty range specified");
9958                                 }
9959                         }
9960                 }
9961         }
9962
9963         PUSH_PARENT(statement);
9964
9965         expect(':', end_error);
9966 end_error:
9967
9968         if (current_switch != NULL) {
9969                 if (! statement->case_label.is_bad) {
9970                         /* Check for duplicate case values */
9971                         case_label_statement_t *c = &statement->case_label;
9972                         for (case_label_statement_t *l = current_switch->first_case; l != NULL; l = l->next) {
9973                                 if (l->is_bad || l->is_empty_range || l->expression == NULL)
9974                                         continue;
9975
9976                                 if (c->last_case < l->first_case || c->first_case > l->last_case)
9977                                         continue;
9978
9979                                 errorf(pos, "duplicate case value (previously used %P)",
9980                                        &l->base.source_position);
9981                                 break;
9982                         }
9983                 }
9984                 /* link all cases into the switch statement */
9985                 if (current_switch->last_case == NULL) {
9986                         current_switch->first_case      = &statement->case_label;
9987                 } else {
9988                         current_switch->last_case->next = &statement->case_label;
9989                 }
9990                 current_switch->last_case = &statement->case_label;
9991         } else {
9992                 errorf(pos, "case label not within a switch statement");
9993         }
9994
9995         statement_t *const inner_stmt = parse_statement();
9996         statement->case_label.statement = inner_stmt;
9997         if (inner_stmt->kind == STATEMENT_DECLARATION) {
9998                 errorf(&inner_stmt->base.source_position, "declaration after case label");
9999         }
10000
10001         POP_PARENT;
10002         return statement;
10003 }
10004
10005 /**
10006  * Parse a default statement.
10007  */
10008 static statement_t *parse_default_statement(void)
10009 {
10010         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
10011
10012         eat(T_default);
10013
10014         PUSH_PARENT(statement);
10015
10016         expect(':', end_error);
10017         if (current_switch != NULL) {
10018                 const case_label_statement_t *def_label = current_switch->default_label;
10019                 if (def_label != NULL) {
10020                         errorf(HERE, "multiple default labels in one switch (previous declared %P)",
10021                                &def_label->base.source_position);
10022                 } else {
10023                         current_switch->default_label = &statement->case_label;
10024
10025                         /* link all cases into the switch statement */
10026                         if (current_switch->last_case == NULL) {
10027                                 current_switch->first_case      = &statement->case_label;
10028                         } else {
10029                                 current_switch->last_case->next = &statement->case_label;
10030                         }
10031                         current_switch->last_case = &statement->case_label;
10032                 }
10033         } else {
10034                 errorf(&statement->base.source_position,
10035                         "'default' label not within a switch statement");
10036         }
10037
10038         statement_t *const inner_stmt = parse_statement();
10039         statement->case_label.statement = inner_stmt;
10040         if (inner_stmt->kind == STATEMENT_DECLARATION) {
10041                 errorf(&inner_stmt->base.source_position, "declaration after default label");
10042         }
10043
10044         POP_PARENT;
10045         return statement;
10046 end_error:
10047         POP_PARENT;
10048         return create_invalid_statement();
10049 }
10050
10051 /**
10052  * Parse a label statement.
10053  */
10054 static statement_t *parse_label_statement(void)
10055 {
10056         assert(token.type == T_IDENTIFIER);
10057         symbol_t *symbol = token.v.symbol;
10058         label_t  *label  = get_label(symbol);
10059
10060         statement_t *const statement = allocate_statement_zero(STATEMENT_LABEL);
10061         statement->label.label       = label;
10062
10063         next_token();
10064
10065         PUSH_PARENT(statement);
10066
10067         /* if statement is already set then the label is defined twice,
10068          * otherwise it was just mentioned in a goto/local label declaration so far
10069          */
10070         if (label->statement != NULL) {
10071                 errorf(HERE, "duplicate label '%Y' (declared %P)",
10072                        symbol, &label->base.source_position);
10073         } else {
10074                 label->base.source_position = token.source_position;
10075                 label->statement            = statement;
10076         }
10077
10078         eat(':');
10079
10080         if (token.type == '}') {
10081                 /* TODO only warn? */
10082                 if (warning.other && false) {
10083                         warningf(HERE, "label at end of compound statement");
10084                         statement->label.statement = create_empty_statement();
10085                 } else {
10086                         errorf(HERE, "label at end of compound statement");
10087                         statement->label.statement = create_invalid_statement();
10088                 }
10089         } else if (token.type == ';') {
10090                 /* Eat an empty statement here, to avoid the warning about an empty
10091                  * statement after a label.  label:; is commonly used to have a label
10092                  * before a closing brace. */
10093                 statement->label.statement = create_empty_statement();
10094                 next_token();
10095         } else {
10096                 statement_t *const inner_stmt = parse_statement();
10097                 statement->label.statement = inner_stmt;
10098                 if (inner_stmt->kind == STATEMENT_DECLARATION) {
10099                         errorf(&inner_stmt->base.source_position, "declaration after label");
10100                 }
10101         }
10102
10103         /* remember the labels in a list for later checking */
10104         *label_anchor = &statement->label;
10105         label_anchor  = &statement->label.next;
10106
10107         POP_PARENT;
10108         return statement;
10109 }
10110
10111 /**
10112  * Parse an if statement.
10113  */
10114 static statement_t *parse_if(void)
10115 {
10116         statement_t *statement = allocate_statement_zero(STATEMENT_IF);
10117
10118         eat(T_if);
10119
10120         PUSH_PARENT(statement);
10121
10122         add_anchor_token('{');
10123
10124         expect('(', end_error);
10125         add_anchor_token(')');
10126         expression_t *const expr = parse_expression();
10127         statement->ifs.condition = expr;
10128         /* §6.8.4.1:1  The controlling expression of an if statement shall have
10129          *             scalar type. */
10130         semantic_condition(expr, "condition of 'if'-statment");
10131         mark_vars_read(expr, NULL);
10132         rem_anchor_token(')');
10133         expect(')', end_error);
10134
10135 end_error:
10136         rem_anchor_token('{');
10137
10138         add_anchor_token(T_else);
10139         statement_t *const true_stmt = parse_statement();
10140         statement->ifs.true_statement = true_stmt;
10141         rem_anchor_token(T_else);
10142
10143         if (token.type == T_else) {
10144                 next_token();
10145                 statement->ifs.false_statement = parse_statement();
10146         } else if (warning.parentheses &&
10147                         true_stmt->kind == STATEMENT_IF &&
10148                         true_stmt->ifs.false_statement != NULL) {
10149                 warningf(&true_stmt->base.source_position,
10150                                 "suggest explicit braces to avoid ambiguous 'else'");
10151         }
10152
10153         POP_PARENT;
10154         return statement;
10155 }
10156
10157 /**
10158  * Check that all enums are handled in a switch.
10159  *
10160  * @param statement  the switch statement to check
10161  */
10162 static void check_enum_cases(const switch_statement_t *statement)
10163 {
10164         const type_t *type = skip_typeref(statement->expression->base.type);
10165         if (! is_type_enum(type))
10166                 return;
10167         const enum_type_t *enumt = &type->enumt;
10168
10169         /* if we have a default, no warnings */
10170         if (statement->default_label != NULL)
10171                 return;
10172
10173         /* FIXME: calculation of value should be done while parsing */
10174         /* TODO: quadratic algorithm here. Change to an n log n one */
10175         long            last_value = -1;
10176         const entity_t *entry      = enumt->enume->base.next;
10177         for (; entry != NULL && entry->kind == ENTITY_ENUM_VALUE;
10178              entry = entry->base.next) {
10179                 const expression_t *expression = entry->enum_value.value;
10180                 long                value      = expression != NULL ? fold_constant(expression) : last_value + 1;
10181                 bool                found      = false;
10182                 for (const case_label_statement_t *l = statement->first_case; l != NULL; l = l->next) {
10183                         if (l->expression == NULL)
10184                                 continue;
10185                         if (l->first_case <= value && value <= l->last_case) {
10186                                 found = true;
10187                                 break;
10188                         }
10189                 }
10190                 if (! found) {
10191                         warningf(&statement->base.source_position,
10192                                  "enumeration value '%Y' not handled in switch",
10193                                  entry->base.symbol);
10194                 }
10195                 last_value = value;
10196         }
10197 }
10198
10199 /**
10200  * Parse a switch statement.
10201  */
10202 static statement_t *parse_switch(void)
10203 {
10204         statement_t *statement = allocate_statement_zero(STATEMENT_SWITCH);
10205
10206         eat(T_switch);
10207
10208         PUSH_PARENT(statement);
10209
10210         expect('(', end_error);
10211         add_anchor_token(')');
10212         expression_t *const expr = parse_expression();
10213         mark_vars_read(expr, NULL);
10214         type_t       *      type = skip_typeref(expr->base.type);
10215         if (is_type_integer(type)) {
10216                 type = promote_integer(type);
10217                 if (warning.traditional) {
10218                         if (get_rank(type) >= get_akind_rank(ATOMIC_TYPE_LONG)) {
10219                                 warningf(&expr->base.source_position,
10220                                         "'%T' switch expression not converted to '%T' in ISO C",
10221                                         type, type_int);
10222                         }
10223                 }
10224         } else if (is_type_valid(type)) {
10225                 errorf(&expr->base.source_position,
10226                        "switch quantity is not an integer, but '%T'", type);
10227                 type = type_error_type;
10228         }
10229         statement->switchs.expression = create_implicit_cast(expr, type);
10230         expect(')', end_error);
10231         rem_anchor_token(')');
10232
10233         switch_statement_t *rem = current_switch;
10234         current_switch          = &statement->switchs;
10235         statement->switchs.body = parse_statement();
10236         current_switch          = rem;
10237
10238         if (warning.switch_default &&
10239             statement->switchs.default_label == NULL) {
10240                 warningf(&statement->base.source_position, "switch has no default case");
10241         }
10242         if (warning.switch_enum)
10243                 check_enum_cases(&statement->switchs);
10244
10245         POP_PARENT;
10246         return statement;
10247 end_error:
10248         POP_PARENT;
10249         return create_invalid_statement();
10250 }
10251
10252 static statement_t *parse_loop_body(statement_t *const loop)
10253 {
10254         statement_t *const rem = current_loop;
10255         current_loop = loop;
10256
10257         statement_t *const body = parse_statement();
10258
10259         current_loop = rem;
10260         return body;
10261 }
10262
10263 /**
10264  * Parse a while statement.
10265  */
10266 static statement_t *parse_while(void)
10267 {
10268         statement_t *statement = allocate_statement_zero(STATEMENT_WHILE);
10269
10270         eat(T_while);
10271
10272         PUSH_PARENT(statement);
10273
10274         expect('(', end_error);
10275         add_anchor_token(')');
10276         expression_t *const cond = parse_expression();
10277         statement->whiles.condition = cond;
10278         /* §6.8.5:2    The controlling expression of an iteration statement shall
10279          *             have scalar type. */
10280         semantic_condition(cond, "condition of 'while'-statement");
10281         mark_vars_read(cond, NULL);
10282         rem_anchor_token(')');
10283         expect(')', end_error);
10284
10285         statement->whiles.body = parse_loop_body(statement);
10286
10287         POP_PARENT;
10288         return statement;
10289 end_error:
10290         POP_PARENT;
10291         return create_invalid_statement();
10292 }
10293
10294 /**
10295  * Parse a do statement.
10296  */
10297 static statement_t *parse_do(void)
10298 {
10299         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
10300
10301         eat(T_do);
10302
10303         PUSH_PARENT(statement);
10304
10305         add_anchor_token(T_while);
10306         statement->do_while.body = parse_loop_body(statement);
10307         rem_anchor_token(T_while);
10308
10309         expect(T_while, end_error);
10310         expect('(', end_error);
10311         add_anchor_token(')');
10312         expression_t *const cond = parse_expression();
10313         statement->do_while.condition = cond;
10314         /* §6.8.5:2    The controlling expression of an iteration statement shall
10315          *             have scalar type. */
10316         semantic_condition(cond, "condition of 'do-while'-statement");
10317         mark_vars_read(cond, NULL);
10318         rem_anchor_token(')');
10319         expect(')', end_error);
10320         expect(';', end_error);
10321
10322         POP_PARENT;
10323         return statement;
10324 end_error:
10325         POP_PARENT;
10326         return create_invalid_statement();
10327 }
10328
10329 /**
10330  * Parse a for statement.
10331  */
10332 static statement_t *parse_for(void)
10333 {
10334         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
10335
10336         eat(T_for);
10337
10338         expect('(', end_error1);
10339         add_anchor_token(')');
10340
10341         PUSH_PARENT(statement);
10342
10343         size_t const  top       = environment_top();
10344         scope_t      *old_scope = scope_push(&statement->fors.scope);
10345
10346         if (token.type == ';') {
10347                 next_token();
10348         } else if (is_declaration_specifier(&token, false)) {
10349                 parse_declaration(record_entity, DECL_FLAGS_NONE);
10350         } else {
10351                 add_anchor_token(';');
10352                 expression_t *const init = parse_expression();
10353                 statement->fors.initialisation = init;
10354                 mark_vars_read(init, ENT_ANY);
10355                 if (warning.unused_value && !expression_has_effect(init)) {
10356                         warningf(&init->base.source_position,
10357                                         "initialisation of 'for'-statement has no effect");
10358                 }
10359                 rem_anchor_token(';');
10360                 expect(';', end_error2);
10361         }
10362
10363         if (token.type != ';') {
10364                 add_anchor_token(';');
10365                 expression_t *const cond = parse_expression();
10366                 statement->fors.condition = cond;
10367                 /* §6.8.5:2    The controlling expression of an iteration statement
10368                  *             shall have scalar type. */
10369                 semantic_condition(cond, "condition of 'for'-statement");
10370                 mark_vars_read(cond, NULL);
10371                 rem_anchor_token(';');
10372         }
10373         expect(';', end_error2);
10374         if (token.type != ')') {
10375                 expression_t *const step = parse_expression();
10376                 statement->fors.step = step;
10377                 mark_vars_read(step, ENT_ANY);
10378                 if (warning.unused_value && !expression_has_effect(step)) {
10379                         warningf(&step->base.source_position,
10380                                  "step of 'for'-statement has no effect");
10381                 }
10382         }
10383         expect(')', end_error2);
10384         rem_anchor_token(')');
10385         statement->fors.body = parse_loop_body(statement);
10386
10387         assert(current_scope == &statement->fors.scope);
10388         scope_pop(old_scope);
10389         environment_pop_to(top);
10390
10391         POP_PARENT;
10392         return statement;
10393
10394 end_error2:
10395         POP_PARENT;
10396         rem_anchor_token(')');
10397         assert(current_scope == &statement->fors.scope);
10398         scope_pop(old_scope);
10399         environment_pop_to(top);
10400         /* fallthrough */
10401
10402 end_error1:
10403         return create_invalid_statement();
10404 }
10405
10406 /**
10407  * Parse a goto statement.
10408  */
10409 static statement_t *parse_goto(void)
10410 {
10411         statement_t *statement = allocate_statement_zero(STATEMENT_GOTO);
10412         eat(T_goto);
10413
10414         if (GNU_MODE && token.type == '*') {
10415                 next_token();
10416                 expression_t *expression = parse_expression();
10417                 mark_vars_read(expression, NULL);
10418
10419                 /* Argh: although documentation says the expression must be of type void*,
10420                  * gcc accepts anything that can be casted into void* without error */
10421                 type_t *type = expression->base.type;
10422
10423                 if (type != type_error_type) {
10424                         if (!is_type_pointer(type) && !is_type_integer(type)) {
10425                                 errorf(&expression->base.source_position,
10426                                         "cannot convert to a pointer type");
10427                         } else if (warning.other && type != type_void_ptr) {
10428                                 warningf(&expression->base.source_position,
10429                                         "type of computed goto expression should be 'void*' not '%T'", type);
10430                         }
10431                         expression = create_implicit_cast(expression, type_void_ptr);
10432                 }
10433
10434                 statement->gotos.expression = expression;
10435         } else {
10436                 if (token.type != T_IDENTIFIER) {
10437                         if (GNU_MODE)
10438                                 parse_error_expected("while parsing goto", T_IDENTIFIER, '*', NULL);
10439                         else
10440                                 parse_error_expected("while parsing goto", T_IDENTIFIER, NULL);
10441                         eat_until_anchor();
10442                         goto end_error;
10443                 }
10444                 symbol_t *symbol = token.v.symbol;
10445                 next_token();
10446
10447                 statement->gotos.label = get_label(symbol);
10448         }
10449
10450         /* remember the goto's in a list for later checking */
10451         *goto_anchor = &statement->gotos;
10452         goto_anchor  = &statement->gotos.next;
10453
10454         expect(';', end_error);
10455
10456         return statement;
10457 end_error:
10458         return create_invalid_statement();
10459 }
10460
10461 /**
10462  * Parse a continue statement.
10463  */
10464 static statement_t *parse_continue(void)
10465 {
10466         if (current_loop == NULL) {
10467                 errorf(HERE, "continue statement not within loop");
10468         }
10469
10470         statement_t *statement = allocate_statement_zero(STATEMENT_CONTINUE);
10471
10472         eat(T_continue);
10473         expect(';', end_error);
10474
10475 end_error:
10476         return statement;
10477 }
10478
10479 /**
10480  * Parse a break statement.
10481  */
10482 static statement_t *parse_break(void)
10483 {
10484         if (current_switch == NULL && current_loop == NULL) {
10485                 errorf(HERE, "break statement not within loop or switch");
10486         }
10487
10488         statement_t *statement = allocate_statement_zero(STATEMENT_BREAK);
10489
10490         eat(T_break);
10491         expect(';', end_error);
10492
10493 end_error:
10494         return statement;
10495 }
10496
10497 /**
10498  * Parse a __leave statement.
10499  */
10500 static statement_t *parse_leave_statement(void)
10501 {
10502         if (current_try == NULL) {
10503                 errorf(HERE, "__leave statement not within __try");
10504         }
10505
10506         statement_t *statement = allocate_statement_zero(STATEMENT_LEAVE);
10507
10508         eat(T___leave);
10509         expect(';', end_error);
10510
10511 end_error:
10512         return statement;
10513 }
10514
10515 /**
10516  * Check if a given entity represents a local variable.
10517  */
10518 static bool is_local_variable(const entity_t *entity)
10519 {
10520         if (entity->kind != ENTITY_VARIABLE)
10521                 return false;
10522
10523         switch ((storage_class_tag_t) entity->declaration.storage_class) {
10524         case STORAGE_CLASS_AUTO:
10525         case STORAGE_CLASS_REGISTER: {
10526                 const type_t *type = skip_typeref(entity->declaration.type);
10527                 if (is_type_function(type)) {
10528                         return false;
10529                 } else {
10530                         return true;
10531                 }
10532         }
10533         default:
10534                 return false;
10535         }
10536 }
10537
10538 /**
10539  * Check if a given expression represents a local variable.
10540  */
10541 static bool expression_is_local_variable(const expression_t *expression)
10542 {
10543         if (expression->base.kind != EXPR_REFERENCE) {
10544                 return false;
10545         }
10546         const entity_t *entity = expression->reference.entity;
10547         return is_local_variable(entity);
10548 }
10549
10550 /**
10551  * Check if a given expression represents a local variable and
10552  * return its declaration then, else return NULL.
10553  */
10554 entity_t *expression_is_variable(const expression_t *expression)
10555 {
10556         if (expression->base.kind != EXPR_REFERENCE) {
10557                 return NULL;
10558         }
10559         entity_t *entity = expression->reference.entity;
10560         if (entity->kind != ENTITY_VARIABLE)
10561                 return NULL;
10562
10563         return entity;
10564 }
10565
10566 /**
10567  * Parse a return statement.
10568  */
10569 static statement_t *parse_return(void)
10570 {
10571         eat(T_return);
10572
10573         statement_t *statement = allocate_statement_zero(STATEMENT_RETURN);
10574
10575         expression_t *return_value = NULL;
10576         if (token.type != ';') {
10577                 return_value = parse_expression();
10578                 mark_vars_read(return_value, NULL);
10579         }
10580
10581         const type_t *const func_type = skip_typeref(current_function->base.type);
10582         assert(is_type_function(func_type));
10583         type_t *const return_type = skip_typeref(func_type->function.return_type);
10584
10585         source_position_t const *const pos = &statement->base.source_position;
10586         if (return_value != NULL) {
10587                 type_t *return_value_type = skip_typeref(return_value->base.type);
10588
10589                 if (is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
10590                         if (is_type_atomic(return_value_type, ATOMIC_TYPE_VOID)) {
10591                                 /* ISO/IEC 14882:1998(E) §6.6.3:2 */
10592                                 /* Only warn in C mode, because GCC does the same */
10593                                 if (c_mode & _CXX || strict_mode) {
10594                                         errorf(pos,
10595                                                         "'return' with a value, in function returning 'void'");
10596                                 } else if (warning.other) {
10597                                         warningf(pos,
10598                                                         "'return' with a value, in function returning 'void'");
10599                                 }
10600                         } else if (!(c_mode & _CXX)) { /* ISO/IEC 14882:1998(E) §6.6.3:3 */
10601                                 /* Only warn in C mode, because GCC does the same */
10602                                 if (strict_mode) {
10603                                         errorf(pos,
10604                                                         "'return' with expression in function return 'void'");
10605                                 } else if (warning.other) {
10606                                         warningf(pos,
10607                                                         "'return' with expression in function return 'void'");
10608                                 }
10609                         }
10610                 } else {
10611                         assign_error_t error = semantic_assign(return_type, return_value);
10612                         report_assign_error(error, return_type, return_value, "'return'",
10613                                         pos);
10614                 }
10615                 return_value = create_implicit_cast(return_value, return_type);
10616                 /* check for returning address of a local var */
10617                 if (warning.other && return_value != NULL
10618                                 && return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
10619                         const expression_t *expression = return_value->unary.value;
10620                         if (expression_is_local_variable(expression)) {
10621                                 warningf(pos, "function returns address of local variable");
10622                         }
10623                 }
10624         } else if (warning.other && !is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
10625                 /* ISO/IEC 14882:1998(E) §6.6.3:3 */
10626                 if (c_mode & _CXX || strict_mode) {
10627                         errorf(pos,
10628                                         "'return' without value, in function returning non-void");
10629                 } else {
10630                         warningf(pos,
10631                                         "'return' without value, in function returning non-void");
10632                 }
10633         }
10634         statement->returns.value = return_value;
10635
10636         expect(';', end_error);
10637
10638 end_error:
10639         return statement;
10640 }
10641
10642 /**
10643  * Parse a declaration statement.
10644  */
10645 static statement_t *parse_declaration_statement(void)
10646 {
10647         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
10648
10649         entity_t *before = current_scope->last_entity;
10650         if (GNU_MODE) {
10651                 parse_external_declaration();
10652         } else {
10653                 parse_declaration(record_entity, DECL_FLAGS_NONE);
10654         }
10655
10656         declaration_statement_t *const decl  = &statement->declaration;
10657         entity_t                *const begin =
10658                 before != NULL ? before->base.next : current_scope->entities;
10659         decl->declarations_begin = begin;
10660         decl->declarations_end   = begin != NULL ? current_scope->last_entity : NULL;
10661
10662         return statement;
10663 }
10664
10665 /**
10666  * Parse an expression statement, ie. expr ';'.
10667  */
10668 static statement_t *parse_expression_statement(void)
10669 {
10670         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10671
10672         expression_t *const expr         = parse_expression();
10673         statement->expression.expression = expr;
10674         mark_vars_read(expr, ENT_ANY);
10675
10676         expect(';', end_error);
10677
10678 end_error:
10679         return statement;
10680 }
10681
10682 /**
10683  * Parse a microsoft __try { } __finally { } or
10684  * __try{ } __except() { }
10685  */
10686 static statement_t *parse_ms_try_statment(void)
10687 {
10688         statement_t *statement = allocate_statement_zero(STATEMENT_MS_TRY);
10689         eat(T___try);
10690
10691         PUSH_PARENT(statement);
10692
10693         ms_try_statement_t *rem = current_try;
10694         current_try = &statement->ms_try;
10695         statement->ms_try.try_statement = parse_compound_statement(false);
10696         current_try = rem;
10697
10698         POP_PARENT;
10699
10700         if (token.type == T___except) {
10701                 eat(T___except);
10702                 expect('(', end_error);
10703                 add_anchor_token(')');
10704                 expression_t *const expr = parse_expression();
10705                 mark_vars_read(expr, NULL);
10706                 type_t       *      type = skip_typeref(expr->base.type);
10707                 if (is_type_integer(type)) {
10708                         type = promote_integer(type);
10709                 } else if (is_type_valid(type)) {
10710                         errorf(&expr->base.source_position,
10711                                "__expect expression is not an integer, but '%T'", type);
10712                         type = type_error_type;
10713                 }
10714                 statement->ms_try.except_expression = create_implicit_cast(expr, type);
10715                 rem_anchor_token(')');
10716                 expect(')', end_error);
10717                 statement->ms_try.final_statement = parse_compound_statement(false);
10718         } else if (token.type == T__finally) {
10719                 eat(T___finally);
10720                 statement->ms_try.final_statement = parse_compound_statement(false);
10721         } else {
10722                 parse_error_expected("while parsing __try statement", T___except, T___finally, NULL);
10723                 return create_invalid_statement();
10724         }
10725         return statement;
10726 end_error:
10727         return create_invalid_statement();
10728 }
10729
10730 static statement_t *parse_empty_statement(void)
10731 {
10732         if (warning.empty_statement) {
10733                 warningf(HERE, "statement is empty");
10734         }
10735         statement_t *const statement = create_empty_statement();
10736         eat(';');
10737         return statement;
10738 }
10739
10740 static statement_t *parse_local_label_declaration(void)
10741 {
10742         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
10743
10744         eat(T___label__);
10745
10746         entity_t *begin = NULL, *end = NULL;
10747
10748         while (true) {
10749                 if (token.type != T_IDENTIFIER) {
10750                         parse_error_expected("while parsing local label declaration",
10751                                 T_IDENTIFIER, NULL);
10752                         goto end_error;
10753                 }
10754                 symbol_t *symbol = token.v.symbol;
10755                 entity_t *entity = get_entity(symbol, NAMESPACE_LABEL);
10756                 if (entity != NULL && entity->base.parent_scope == current_scope) {
10757                         errorf(HERE, "multiple definitions of '__label__ %Y' (previous definition %P)",
10758                                symbol, &entity->base.source_position);
10759                 } else {
10760                         entity = allocate_entity_zero(ENTITY_LOCAL_LABEL);
10761
10762                         entity->base.parent_scope    = current_scope;
10763                         entity->base.namespc         = NAMESPACE_LABEL;
10764                         entity->base.source_position = token.source_position;
10765                         entity->base.symbol          = symbol;
10766
10767                         if (end != NULL)
10768                                 end->base.next = entity;
10769                         end = entity;
10770                         if (begin == NULL)
10771                                 begin = entity;
10772
10773                         environment_push(entity);
10774                 }
10775                 next_token();
10776
10777                 if (token.type != ',')
10778                         break;
10779                 next_token();
10780         }
10781         eat(';');
10782 end_error:
10783         statement->declaration.declarations_begin = begin;
10784         statement->declaration.declarations_end   = end;
10785         return statement;
10786 }
10787
10788 static void parse_namespace_definition(void)
10789 {
10790         eat(T_namespace);
10791
10792         entity_t *entity = NULL;
10793         symbol_t *symbol = NULL;
10794
10795         if (token.type == T_IDENTIFIER) {
10796                 symbol = token.v.symbol;
10797                 next_token();
10798
10799                 entity = get_entity(symbol, NAMESPACE_NORMAL);
10800                 if (entity       != NULL             &&
10801                                 entity->kind != ENTITY_NAMESPACE &&
10802                                 entity->base.parent_scope == current_scope) {
10803                         if (!is_error_entity(entity)) {
10804                                 error_redefined_as_different_kind(&token.source_position,
10805                                                 entity, ENTITY_NAMESPACE);
10806                         }
10807                         entity = NULL;
10808                 }
10809         }
10810
10811         if (entity == NULL) {
10812                 entity                       = allocate_entity_zero(ENTITY_NAMESPACE);
10813                 entity->base.symbol          = symbol;
10814                 entity->base.source_position = token.source_position;
10815                 entity->base.namespc         = NAMESPACE_NORMAL;
10816                 entity->base.parent_scope    = current_scope;
10817         }
10818
10819         if (token.type == '=') {
10820                 /* TODO: parse namespace alias */
10821                 panic("namespace alias definition not supported yet");
10822         }
10823
10824         environment_push(entity);
10825         append_entity(current_scope, entity);
10826
10827         size_t const  top       = environment_top();
10828         scope_t      *old_scope = scope_push(&entity->namespacee.members);
10829
10830         expect('{', end_error);
10831         parse_externals();
10832         expect('}', end_error);
10833
10834 end_error:
10835         assert(current_scope == &entity->namespacee.members);
10836         scope_pop(old_scope);
10837         environment_pop_to(top);
10838 }
10839
10840 /**
10841  * Parse a statement.
10842  * There's also parse_statement() which additionally checks for
10843  * "statement has no effect" warnings
10844  */
10845 static statement_t *intern_parse_statement(void)
10846 {
10847         statement_t *statement = NULL;
10848
10849         /* declaration or statement */
10850         add_anchor_token(';');
10851         switch (token.type) {
10852         case T_IDENTIFIER: {
10853                 token_type_t la1_type = (token_type_t)look_ahead(1)->type;
10854                 if (la1_type == ':') {
10855                         statement = parse_label_statement();
10856                 } else if (is_typedef_symbol(token.v.symbol)) {
10857                         statement = parse_declaration_statement();
10858                 } else {
10859                         /* it's an identifier, the grammar says this must be an
10860                          * expression statement. However it is common that users mistype
10861                          * declaration types, so we guess a bit here to improve robustness
10862                          * for incorrect programs */
10863                         switch (la1_type) {
10864                         case '&':
10865                         case '*':
10866                                 if (get_entity(token.v.symbol, NAMESPACE_NORMAL) != NULL)
10867                                         goto expression_statment;
10868                                 /* FALLTHROUGH */
10869
10870                         DECLARATION_START
10871                         case T_IDENTIFIER:
10872                                 statement = parse_declaration_statement();
10873                                 break;
10874
10875                         default:
10876 expression_statment:
10877                                 statement = parse_expression_statement();
10878                                 break;
10879                         }
10880                 }
10881                 break;
10882         }
10883
10884         case T___extension__:
10885                 /* This can be a prefix to a declaration or an expression statement.
10886                  * We simply eat it now and parse the rest with tail recursion. */
10887                 do {
10888                         next_token();
10889                 } while (token.type == T___extension__);
10890                 bool old_gcc_extension = in_gcc_extension;
10891                 in_gcc_extension       = true;
10892                 statement = intern_parse_statement();
10893                 in_gcc_extension = old_gcc_extension;
10894                 break;
10895
10896         DECLARATION_START
10897                 statement = parse_declaration_statement();
10898                 break;
10899
10900         case T___label__:
10901                 statement = parse_local_label_declaration();
10902                 break;
10903
10904         case ';':         statement = parse_empty_statement();         break;
10905         case '{':         statement = parse_compound_statement(false); break;
10906         case T___leave:   statement = parse_leave_statement();         break;
10907         case T___try:     statement = parse_ms_try_statment();         break;
10908         case T_asm:       statement = parse_asm_statement();           break;
10909         case T_break:     statement = parse_break();                   break;
10910         case T_case:      statement = parse_case_statement();          break;
10911         case T_continue:  statement = parse_continue();                break;
10912         case T_default:   statement = parse_default_statement();       break;
10913         case T_do:        statement = parse_do();                      break;
10914         case T_for:       statement = parse_for();                     break;
10915         case T_goto:      statement = parse_goto();                    break;
10916         case T_if:        statement = parse_if();                      break;
10917         case T_return:    statement = parse_return();                  break;
10918         case T_switch:    statement = parse_switch();                  break;
10919         case T_while:     statement = parse_while();                   break;
10920
10921         EXPRESSION_START
10922                 statement = parse_expression_statement();
10923                 break;
10924
10925         default:
10926                 errorf(HERE, "unexpected token %K while parsing statement", &token);
10927                 statement = create_invalid_statement();
10928                 if (!at_anchor())
10929                         next_token();
10930                 break;
10931         }
10932         rem_anchor_token(';');
10933
10934         assert(statement != NULL
10935                         && statement->base.source_position.input_name != NULL);
10936
10937         return statement;
10938 }
10939
10940 /**
10941  * parse a statement and emits "statement has no effect" warning if needed
10942  * (This is really a wrapper around intern_parse_statement with check for 1
10943  *  single warning. It is needed, because for statement expressions we have
10944  *  to avoid the warning on the last statement)
10945  */
10946 static statement_t *parse_statement(void)
10947 {
10948         statement_t *statement = intern_parse_statement();
10949
10950         if (statement->kind == STATEMENT_EXPRESSION && warning.unused_value) {
10951                 expression_t *expression = statement->expression.expression;
10952                 if (!expression_has_effect(expression)) {
10953                         warningf(&expression->base.source_position,
10954                                         "statement has no effect");
10955                 }
10956         }
10957
10958         return statement;
10959 }
10960
10961 /**
10962  * Parse a compound statement.
10963  */
10964 static statement_t *parse_compound_statement(bool inside_expression_statement)
10965 {
10966         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
10967
10968         PUSH_PARENT(statement);
10969
10970         eat('{');
10971         add_anchor_token('}');
10972         /* tokens, which can start a statement */
10973         /* TODO MS, __builtin_FOO */
10974         add_anchor_token('!');
10975         add_anchor_token('&');
10976         add_anchor_token('(');
10977         add_anchor_token('*');
10978         add_anchor_token('+');
10979         add_anchor_token('-');
10980         add_anchor_token('{');
10981         add_anchor_token('~');
10982         add_anchor_token(T_CHARACTER_CONSTANT);
10983         add_anchor_token(T_COLONCOLON);
10984         add_anchor_token(T_FLOATINGPOINT);
10985         add_anchor_token(T_IDENTIFIER);
10986         add_anchor_token(T_INTEGER);
10987         add_anchor_token(T_MINUSMINUS);
10988         add_anchor_token(T_PLUSPLUS);
10989         add_anchor_token(T_STRING_LITERAL);
10990         add_anchor_token(T_WIDE_CHARACTER_CONSTANT);
10991         add_anchor_token(T_WIDE_STRING_LITERAL);
10992         add_anchor_token(T__Bool);
10993         add_anchor_token(T__Complex);
10994         add_anchor_token(T__Imaginary);
10995         add_anchor_token(T___FUNCTION__);
10996         add_anchor_token(T___PRETTY_FUNCTION__);
10997         add_anchor_token(T___alignof__);
10998         add_anchor_token(T___attribute__);
10999         add_anchor_token(T___builtin_va_start);
11000         add_anchor_token(T___extension__);
11001         add_anchor_token(T___func__);
11002         add_anchor_token(T___imag__);
11003         add_anchor_token(T___label__);
11004         add_anchor_token(T___real__);
11005         add_anchor_token(T___thread);
11006         add_anchor_token(T_asm);
11007         add_anchor_token(T_auto);
11008         add_anchor_token(T_bool);
11009         add_anchor_token(T_break);
11010         add_anchor_token(T_case);
11011         add_anchor_token(T_char);
11012         add_anchor_token(T_class);
11013         add_anchor_token(T_const);
11014         add_anchor_token(T_const_cast);
11015         add_anchor_token(T_continue);
11016         add_anchor_token(T_default);
11017         add_anchor_token(T_delete);
11018         add_anchor_token(T_double);
11019         add_anchor_token(T_do);
11020         add_anchor_token(T_dynamic_cast);
11021         add_anchor_token(T_enum);
11022         add_anchor_token(T_extern);
11023         add_anchor_token(T_false);
11024         add_anchor_token(T_float);
11025         add_anchor_token(T_for);
11026         add_anchor_token(T_goto);
11027         add_anchor_token(T_if);
11028         add_anchor_token(T_inline);
11029         add_anchor_token(T_int);
11030         add_anchor_token(T_long);
11031         add_anchor_token(T_new);
11032         add_anchor_token(T_operator);
11033         add_anchor_token(T_register);
11034         add_anchor_token(T_reinterpret_cast);
11035         add_anchor_token(T_restrict);
11036         add_anchor_token(T_return);
11037         add_anchor_token(T_short);
11038         add_anchor_token(T_signed);
11039         add_anchor_token(T_sizeof);
11040         add_anchor_token(T_static);
11041         add_anchor_token(T_static_cast);
11042         add_anchor_token(T_struct);
11043         add_anchor_token(T_switch);
11044         add_anchor_token(T_template);
11045         add_anchor_token(T_this);
11046         add_anchor_token(T_throw);
11047         add_anchor_token(T_true);
11048         add_anchor_token(T_try);
11049         add_anchor_token(T_typedef);
11050         add_anchor_token(T_typeid);
11051         add_anchor_token(T_typename);
11052         add_anchor_token(T_typeof);
11053         add_anchor_token(T_union);
11054         add_anchor_token(T_unsigned);
11055         add_anchor_token(T_using);
11056         add_anchor_token(T_void);
11057         add_anchor_token(T_volatile);
11058         add_anchor_token(T_wchar_t);
11059         add_anchor_token(T_while);
11060
11061         size_t const  top       = environment_top();
11062         scope_t      *old_scope = scope_push(&statement->compound.scope);
11063
11064         statement_t **anchor            = &statement->compound.statements;
11065         bool          only_decls_so_far = true;
11066         while (token.type != '}') {
11067                 if (token.type == T_EOF) {
11068                         errorf(&statement->base.source_position,
11069                                "EOF while parsing compound statement");
11070                         break;
11071                 }
11072                 statement_t *sub_statement = intern_parse_statement();
11073                 if (is_invalid_statement(sub_statement)) {
11074                         /* an error occurred. if we are at an anchor, return */
11075                         if (at_anchor())
11076                                 goto end_error;
11077                         continue;
11078                 }
11079
11080                 if (warning.declaration_after_statement) {
11081                         if (sub_statement->kind != STATEMENT_DECLARATION) {
11082                                 only_decls_so_far = false;
11083                         } else if (!only_decls_so_far) {
11084                                 warningf(&sub_statement->base.source_position,
11085                                          "ISO C90 forbids mixed declarations and code");
11086                         }
11087                 }
11088
11089                 *anchor = sub_statement;
11090
11091                 while (sub_statement->base.next != NULL)
11092                         sub_statement = sub_statement->base.next;
11093
11094                 anchor = &sub_statement->base.next;
11095         }
11096         next_token();
11097
11098         /* look over all statements again to produce no effect warnings */
11099         if (warning.unused_value) {
11100                 statement_t *sub_statement = statement->compound.statements;
11101                 for (; sub_statement != NULL; sub_statement = sub_statement->base.next) {
11102                         if (sub_statement->kind != STATEMENT_EXPRESSION)
11103                                 continue;
11104                         /* don't emit a warning for the last expression in an expression
11105                          * statement as it has always an effect */
11106                         if (inside_expression_statement && sub_statement->base.next == NULL)
11107                                 continue;
11108
11109                         expression_t *expression = sub_statement->expression.expression;
11110                         if (!expression_has_effect(expression)) {
11111                                 warningf(&expression->base.source_position,
11112                                          "statement has no effect");
11113                         }
11114                 }
11115         }
11116
11117 end_error:
11118         rem_anchor_token(T_while);
11119         rem_anchor_token(T_wchar_t);
11120         rem_anchor_token(T_volatile);
11121         rem_anchor_token(T_void);
11122         rem_anchor_token(T_using);
11123         rem_anchor_token(T_unsigned);
11124         rem_anchor_token(T_union);
11125         rem_anchor_token(T_typeof);
11126         rem_anchor_token(T_typename);
11127         rem_anchor_token(T_typeid);
11128         rem_anchor_token(T_typedef);
11129         rem_anchor_token(T_try);
11130         rem_anchor_token(T_true);
11131         rem_anchor_token(T_throw);
11132         rem_anchor_token(T_this);
11133         rem_anchor_token(T_template);
11134         rem_anchor_token(T_switch);
11135         rem_anchor_token(T_struct);
11136         rem_anchor_token(T_static_cast);
11137         rem_anchor_token(T_static);
11138         rem_anchor_token(T_sizeof);
11139         rem_anchor_token(T_signed);
11140         rem_anchor_token(T_short);
11141         rem_anchor_token(T_return);
11142         rem_anchor_token(T_restrict);
11143         rem_anchor_token(T_reinterpret_cast);
11144         rem_anchor_token(T_register);
11145         rem_anchor_token(T_operator);
11146         rem_anchor_token(T_new);
11147         rem_anchor_token(T_long);
11148         rem_anchor_token(T_int);
11149         rem_anchor_token(T_inline);
11150         rem_anchor_token(T_if);
11151         rem_anchor_token(T_goto);
11152         rem_anchor_token(T_for);
11153         rem_anchor_token(T_float);
11154         rem_anchor_token(T_false);
11155         rem_anchor_token(T_extern);
11156         rem_anchor_token(T_enum);
11157         rem_anchor_token(T_dynamic_cast);
11158         rem_anchor_token(T_do);
11159         rem_anchor_token(T_double);
11160         rem_anchor_token(T_delete);
11161         rem_anchor_token(T_default);
11162         rem_anchor_token(T_continue);
11163         rem_anchor_token(T_const_cast);
11164         rem_anchor_token(T_const);
11165         rem_anchor_token(T_class);
11166         rem_anchor_token(T_char);
11167         rem_anchor_token(T_case);
11168         rem_anchor_token(T_break);
11169         rem_anchor_token(T_bool);
11170         rem_anchor_token(T_auto);
11171         rem_anchor_token(T_asm);
11172         rem_anchor_token(T___thread);
11173         rem_anchor_token(T___real__);
11174         rem_anchor_token(T___label__);
11175         rem_anchor_token(T___imag__);
11176         rem_anchor_token(T___func__);
11177         rem_anchor_token(T___extension__);
11178         rem_anchor_token(T___builtin_va_start);
11179         rem_anchor_token(T___attribute__);
11180         rem_anchor_token(T___alignof__);
11181         rem_anchor_token(T___PRETTY_FUNCTION__);
11182         rem_anchor_token(T___FUNCTION__);
11183         rem_anchor_token(T__Imaginary);
11184         rem_anchor_token(T__Complex);
11185         rem_anchor_token(T__Bool);
11186         rem_anchor_token(T_WIDE_STRING_LITERAL);
11187         rem_anchor_token(T_WIDE_CHARACTER_CONSTANT);
11188         rem_anchor_token(T_STRING_LITERAL);
11189         rem_anchor_token(T_PLUSPLUS);
11190         rem_anchor_token(T_MINUSMINUS);
11191         rem_anchor_token(T_INTEGER);
11192         rem_anchor_token(T_IDENTIFIER);
11193         rem_anchor_token(T_FLOATINGPOINT);
11194         rem_anchor_token(T_COLONCOLON);
11195         rem_anchor_token(T_CHARACTER_CONSTANT);
11196         rem_anchor_token('~');
11197         rem_anchor_token('{');
11198         rem_anchor_token('-');
11199         rem_anchor_token('+');
11200         rem_anchor_token('*');
11201         rem_anchor_token('(');
11202         rem_anchor_token('&');
11203         rem_anchor_token('!');
11204         rem_anchor_token('}');
11205         assert(current_scope == &statement->compound.scope);
11206         scope_pop(old_scope);
11207         environment_pop_to(top);
11208
11209         POP_PARENT;
11210         return statement;
11211 }
11212
11213 /**
11214  * Check for unused global static functions and variables
11215  */
11216 static void check_unused_globals(void)
11217 {
11218         if (!warning.unused_function && !warning.unused_variable)
11219                 return;
11220
11221         for (const entity_t *entity = file_scope->entities; entity != NULL;
11222              entity = entity->base.next) {
11223                 if (!is_declaration(entity))
11224                         continue;
11225
11226                 const declaration_t *declaration = &entity->declaration;
11227                 if (declaration->used                  ||
11228                     declaration->modifiers & DM_UNUSED ||
11229                     declaration->modifiers & DM_USED   ||
11230                     declaration->storage_class != STORAGE_CLASS_STATIC)
11231                         continue;
11232
11233                 type_t *const type = declaration->type;
11234                 const char *s;
11235                 if (entity->kind == ENTITY_FUNCTION) {
11236                         /* inhibit warning for static inline functions */
11237                         if (entity->function.is_inline)
11238                                 continue;
11239
11240                         s = entity->function.statement != NULL ? "defined" : "declared";
11241                 } else {
11242                         s = "defined";
11243                 }
11244
11245                 warningf(&declaration->base.source_position, "'%#T' %s but not used",
11246                         type, declaration->base.symbol, s);
11247         }
11248 }
11249
11250 static void parse_global_asm(void)
11251 {
11252         statement_t *statement = allocate_statement_zero(STATEMENT_ASM);
11253
11254         eat(T_asm);
11255         expect('(', end_error);
11256
11257         statement->asms.asm_text = parse_string_literals();
11258         statement->base.next     = unit->global_asm;
11259         unit->global_asm         = statement;
11260
11261         expect(')', end_error);
11262         expect(';', end_error);
11263
11264 end_error:;
11265 }
11266
11267 static void parse_linkage_specification(void)
11268 {
11269         eat(T_extern);
11270         assert(token.type == T_STRING_LITERAL);
11271
11272         const char *linkage = parse_string_literals().begin;
11273
11274         linkage_kind_t old_linkage = current_linkage;
11275         linkage_kind_t new_linkage;
11276         if (strcmp(linkage, "C") == 0) {
11277                 new_linkage = LINKAGE_C;
11278         } else if (strcmp(linkage, "C++") == 0) {
11279                 new_linkage = LINKAGE_CXX;
11280         } else {
11281                 errorf(HERE, "linkage string \"%s\" not recognized", linkage);
11282                 new_linkage = LINKAGE_INVALID;
11283         }
11284         current_linkage = new_linkage;
11285
11286         if (token.type == '{') {
11287                 next_token();
11288                 parse_externals();
11289                 expect('}', end_error);
11290         } else {
11291                 parse_external();
11292         }
11293
11294 end_error:
11295         assert(current_linkage == new_linkage);
11296         current_linkage = old_linkage;
11297 }
11298
11299 static void parse_external(void)
11300 {
11301         switch (token.type) {
11302                 DECLARATION_START_NO_EXTERN
11303                 case T_IDENTIFIER:
11304                 case T___extension__:
11305                 /* tokens below are for implicit int */
11306                 case '&': /* & x; -> int& x; (and error later, because C++ has no
11307                              implicit int) */
11308                 case '*': /* * x; -> int* x; */
11309                 case '(': /* (x); -> int (x); */
11310                         parse_external_declaration();
11311                         return;
11312
11313                 case T_extern:
11314                         if (look_ahead(1)->type == T_STRING_LITERAL) {
11315                                 parse_linkage_specification();
11316                         } else {
11317                                 parse_external_declaration();
11318                         }
11319                         return;
11320
11321                 case T_asm:
11322                         parse_global_asm();
11323                         return;
11324
11325                 case T_namespace:
11326                         parse_namespace_definition();
11327                         return;
11328
11329                 case ';':
11330                         if (!strict_mode) {
11331                                 if (warning.other)
11332                                         warningf(HERE, "stray ';' outside of function");
11333                                 next_token();
11334                                 return;
11335                         }
11336                         /* FALLTHROUGH */
11337
11338                 default:
11339                         errorf(HERE, "stray %K outside of function", &token);
11340                         if (token.type == '(' || token.type == '{' || token.type == '[')
11341                                 eat_until_matching_token(token.type);
11342                         next_token();
11343                         return;
11344         }
11345 }
11346
11347 static void parse_externals(void)
11348 {
11349         add_anchor_token('}');
11350         add_anchor_token(T_EOF);
11351
11352 #ifndef NDEBUG
11353         unsigned char token_anchor_copy[T_LAST_TOKEN];
11354         memcpy(token_anchor_copy, token_anchor_set, sizeof(token_anchor_copy));
11355 #endif
11356
11357         while (token.type != T_EOF && token.type != '}') {
11358 #ifndef NDEBUG
11359                 bool anchor_leak = false;
11360                 for (int i = 0; i != T_LAST_TOKEN; ++i) {
11361                         unsigned char count = token_anchor_set[i] - token_anchor_copy[i];
11362                         if (count != 0) {
11363                                 errorf(HERE, "Leaked anchor token %k %d times", i, count);
11364                                 anchor_leak = true;
11365                         }
11366                 }
11367                 if (in_gcc_extension) {
11368                         errorf(HERE, "Leaked __extension__");
11369                         anchor_leak = true;
11370                 }
11371
11372                 if (anchor_leak)
11373                         abort();
11374 #endif
11375
11376                 parse_external();
11377         }
11378
11379         rem_anchor_token(T_EOF);
11380         rem_anchor_token('}');
11381 }
11382
11383 /**
11384  * Parse a translation unit.
11385  */
11386 static void parse_translation_unit(void)
11387 {
11388         add_anchor_token(T_EOF);
11389
11390         while (true) {
11391                 parse_externals();
11392
11393                 if (token.type == T_EOF)
11394                         break;
11395
11396                 errorf(HERE, "stray %K outside of function", &token);
11397                 if (token.type == '(' || token.type == '{' || token.type == '[')
11398                         eat_until_matching_token(token.type);
11399                 next_token();
11400         }
11401 }
11402
11403 /**
11404  * Parse the input.
11405  *
11406  * @return  the translation unit or NULL if errors occurred.
11407  */
11408 void start_parsing(void)
11409 {
11410         environment_stack = NEW_ARR_F(stack_entry_t, 0);
11411         label_stack       = NEW_ARR_F(stack_entry_t, 0);
11412         diagnostic_count  = 0;
11413         error_count       = 0;
11414         warning_count     = 0;
11415
11416         type_set_output(stderr);
11417         ast_set_output(stderr);
11418
11419         assert(unit == NULL);
11420         unit = allocate_ast_zero(sizeof(unit[0]));
11421
11422         assert(file_scope == NULL);
11423         file_scope = &unit->scope;
11424
11425         assert(current_scope == NULL);
11426         scope_push(&unit->scope);
11427 }
11428
11429 translation_unit_t *finish_parsing(void)
11430 {
11431         assert(current_scope == &unit->scope);
11432         scope_pop(NULL);
11433
11434         assert(file_scope == &unit->scope);
11435         check_unused_globals();
11436         file_scope = NULL;
11437
11438         DEL_ARR_F(environment_stack);
11439         DEL_ARR_F(label_stack);
11440
11441         translation_unit_t *result = unit;
11442         unit = NULL;
11443         return result;
11444 }
11445
11446 /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
11447  * are given length one. */
11448 static void complete_incomplete_arrays(void)
11449 {
11450         size_t n = ARR_LEN(incomplete_arrays);
11451         for (size_t i = 0; i != n; ++i) {
11452                 declaration_t *const decl      = incomplete_arrays[i];
11453                 type_t        *const orig_type = decl->type;
11454                 type_t        *const type      = skip_typeref(orig_type);
11455
11456                 if (!is_type_incomplete(type))
11457                         continue;
11458
11459                 if (warning.other) {
11460                         warningf(&decl->base.source_position,
11461                                         "array '%#T' assumed to have one element",
11462                                         orig_type, decl->base.symbol);
11463                 }
11464
11465                 type_t *const new_type = duplicate_type(type);
11466                 new_type->array.size_constant     = true;
11467                 new_type->array.has_implicit_size = true;
11468                 new_type->array.size              = 1;
11469
11470                 type_t *const result = identify_new_type(new_type);
11471
11472                 decl->type = result;
11473         }
11474 }
11475
11476 void parse(void)
11477 {
11478         lookahead_bufpos = 0;
11479         for (int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
11480                 next_token();
11481         }
11482         current_linkage   = c_mode & _CXX ? LINKAGE_CXX : LINKAGE_C;
11483         incomplete_arrays = NEW_ARR_F(declaration_t*, 0);
11484         parse_translation_unit();
11485         complete_incomplete_arrays();
11486         DEL_ARR_F(incomplete_arrays);
11487         incomplete_arrays = NULL;
11488 }
11489
11490 /**
11491  * Initialize the parser.
11492  */
11493 void init_parser(void)
11494 {
11495         sym_anonymous = symbol_table_insert("<anonymous>");
11496
11497         if (c_mode & _MS) {
11498                 /* add predefined symbols for extended-decl-modifier */
11499                 sym_align         = symbol_table_insert("align");
11500                 sym_allocate      = symbol_table_insert("allocate");
11501                 sym_dllimport     = symbol_table_insert("dllimport");
11502                 sym_dllexport     = symbol_table_insert("dllexport");
11503                 sym_naked         = symbol_table_insert("naked");
11504                 sym_noinline      = symbol_table_insert("noinline");
11505                 sym_returns_twice = symbol_table_insert("returns_twice");
11506                 sym_noreturn      = symbol_table_insert("noreturn");
11507                 sym_nothrow       = symbol_table_insert("nothrow");
11508                 sym_novtable      = symbol_table_insert("novtable");
11509                 sym_property      = symbol_table_insert("property");
11510                 sym_get           = symbol_table_insert("get");
11511                 sym_put           = symbol_table_insert("put");
11512                 sym_selectany     = symbol_table_insert("selectany");
11513                 sym_thread        = symbol_table_insert("thread");
11514                 sym_uuid          = symbol_table_insert("uuid");
11515                 sym_deprecated    = symbol_table_insert("deprecated");
11516                 sym_restrict      = symbol_table_insert("restrict");
11517                 sym_noalias       = symbol_table_insert("noalias");
11518         }
11519         memset(token_anchor_set, 0, sizeof(token_anchor_set));
11520
11521         init_expression_parsers();
11522         obstack_init(&temp_obst);
11523
11524         symbol_t *const va_list_sym = symbol_table_insert("__builtin_va_list");
11525         type_valist = create_builtin_type(va_list_sym, type_void_ptr);
11526 }
11527
11528 /**
11529  * Terminate the parser.
11530  */
11531 void exit_parser(void)
11532 {
11533         obstack_free(&temp_obst, NULL);
11534 }