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 static void create_gnu_builtins(void);
 210 static void create_microsoft_intrinsics(void);
 211
 212 #define STORAGE_CLASSES       \
 213         STORAGE_CLASSES_NO_EXTERN \
 214         case T_extern:
 215
 216 #define STORAGE_CLASSES_NO_EXTERN \
 217         case T_typedef:         \
 218         case T_static:          \
 219         case T_auto:            \
 220         case T_register:        \
 221         case T___thread:
 222
 223 #define TYPE_QUALIFIERS     \
 224         case T_const:           \
 225         case T_restrict:        \
 226         case T_volatile:        \
 227         case T_inline:          \
 228         case T__forceinline:    \
 229         case T___attribute__:
 230
 231 #define COMPLEX_SPECIFIERS  \
 232         case T__Complex:
 233 #define IMAGINARY_SPECIFIERS \
 234         case T__Imaginary:
 235
 236 #define TYPE_SPECIFIERS       \
 237         case T__Bool:             \
 238         case T___builtin_va_list: \
 239         case T___typeof__:        \
 240         case T__declspec:         \
 241         case T_bool:              \
 242         case T_char:              \
 243         case T_double:            \
 244         case T_enum:              \
 245         case T_float:             \
 246         case T_int:               \
 247         case T_long:              \
 248         case T_short:             \
 249         case T_signed:            \
 250         case T_struct:            \
 251         case T_union:             \
 252         case T_unsigned:          \
 253         case T_void:              \
 254         case T_wchar_t:           \
 255         COMPLEX_SPECIFIERS        \
 256         IMAGINARY_SPECIFIERS
 257
 258 #define DECLARATION_START   \
 259         STORAGE_CLASSES         \
 260         TYPE_QUALIFIERS         \
 261         TYPE_SPECIFIERS
 262
 263 #define DECLARATION_START_NO_EXTERN \
 264         STORAGE_CLASSES_NO_EXTERN       \
 265         TYPE_QUALIFIERS                 \
 266         TYPE_SPECIFIERS
 267
 268 #define TYPENAME_START      \
 269         TYPE_QUALIFIERS         \
 270         TYPE_SPECIFIERS
 271
 272 #define EXPRESSION_START           \
 273         case '!':                        \
 274         case '&':                        \
 275         case '(':                        \
 276         case '*':                        \
 277         case '+':                        \
 278         case '-':                        \
 279         case '~':                        \
 280         case T_ANDAND:                   \
 281         case T_CHARACTER_CONSTANT:       \
 282         case T_FLOATINGPOINT:            \
 283         case T_INTEGER:                  \
 284         case T_MINUSMINUS:               \
 285         case T_PLUSPLUS:                 \
 286         case T_STRING_LITERAL:           \
 287         case T_WIDE_CHARACTER_CONSTANT:  \
 288         case T_WIDE_STRING_LITERAL:      \
 289         case T___FUNCDNAME__:            \
 290         case T___FUNCSIG__:              \
 291         case T___FUNCTION__:             \
 292         case T___PRETTY_FUNCTION__:      \
 293         case T___alignof__:              \
 294         case T___builtin_classify_type:  \
 295         case T___builtin_constant_p:     \
 296         case T___builtin_isgreater:      \
 297         case T___builtin_isgreaterequal: \
 298         case T___builtin_isless:         \
 299         case T___builtin_islessequal:    \
 300         case T___builtin_islessgreater:  \
 301         case T___builtin_isunordered:    \
 302         case T___builtin_offsetof:       \
 303         case T___builtin_va_arg:         \
 304         case T___builtin_va_start:       \
 305         case T___func__:                 \
 306         case T___noop:                   \
 307         case T__assume:                  \
 308         case T_delete:                   \
 309         case T_false:                    \
 310         case T_sizeof:                   \
 311         case T_throw:                    \
 312         case T_true:
 313
 314 /**
 315  * Allocate an AST node with given size and
 316  * initialize all fields with zero.
 317  */
 318 static void *allocate_ast_zero(size_t size)
 319 {
 320         void *res = allocate_ast(size);
 321         memset(res, 0, size);
 322         return res;
 323 }
 324
 325 /**
 326  * Returns the size of an entity node.
 327  *
 328  * @param kind  the entity kind
 329  */
 330 static size_t get_entity_struct_size(entity_kind_t kind)
 331 {
 332         static const size_t sizes[] = {
 333                 [ENTITY_VARIABLE]        = sizeof(variable_t),
 334                 [ENTITY_PARAMETER]       = sizeof(parameter_t),
 335                 [ENTITY_COMPOUND_MEMBER] = sizeof(compound_member_t),
 336                 [ENTITY_FUNCTION]        = sizeof(function_t),
 337                 [ENTITY_TYPEDEF]         = sizeof(typedef_t),
 338                 [ENTITY_STRUCT]          = sizeof(compound_t),
 339                 [ENTITY_UNION]           = sizeof(compound_t),
 340                 [ENTITY_ENUM]            = sizeof(enum_t),
 341                 [ENTITY_ENUM_VALUE]      = sizeof(enum_value_t),
 342                 [ENTITY_LABEL]           = sizeof(label_t),
 343                 [ENTITY_LOCAL_LABEL]     = sizeof(label_t),
 344                 [ENTITY_NAMESPACE]       = sizeof(namespace_t)
 345         };
 346         assert(kind < lengthof(sizes));
 347         assert(sizes[kind] != 0);
 348         return sizes[kind];
 349 }
 350
 351 /**
 352  * Allocate an entity of given kind and initialize all
 353  * fields with zero.
 354  */
 355 static entity_t *allocate_entity_zero(entity_kind_t kind)
 356 {
 357         size_t    size   = get_entity_struct_size(kind);
 358         entity_t *entity = allocate_ast_zero(size);
 359         entity->kind     = kind;
 360         return entity;
 361 }
 362
 363 /**
 364  * Returns the size of a statement node.
 365  *
 366  * @param kind  the statement kind
 367  */
 368 static size_t get_statement_struct_size(statement_kind_t kind)
 369 {
 370         static const size_t sizes[] = {
 371                 [STATEMENT_INVALID]     = sizeof(invalid_statement_t),
 372                 [STATEMENT_EMPTY]       = sizeof(empty_statement_t),
 373                 [STATEMENT_COMPOUND]    = sizeof(compound_statement_t),
 374                 [STATEMENT_RETURN]      = sizeof(return_statement_t),
 375                 [STATEMENT_DECLARATION] = sizeof(declaration_statement_t),
 376                 [STATEMENT_IF]          = sizeof(if_statement_t),
 377                 [STATEMENT_SWITCH]      = sizeof(switch_statement_t),
 378                 [STATEMENT_EXPRESSION]  = sizeof(expression_statement_t),
 379                 [STATEMENT_CONTINUE]    = sizeof(statement_base_t),
 380                 [STATEMENT_BREAK]       = sizeof(statement_base_t),
 381                 [STATEMENT_GOTO]        = sizeof(goto_statement_t),
 382                 [STATEMENT_LABEL]       = sizeof(label_statement_t),
 383                 [STATEMENT_CASE_LABEL]  = sizeof(case_label_statement_t),
 384                 [STATEMENT_WHILE]       = sizeof(while_statement_t),
 385                 [STATEMENT_DO_WHILE]    = sizeof(do_while_statement_t),
 386                 [STATEMENT_FOR]         = sizeof(for_statement_t),
 387                 [STATEMENT_ASM]         = sizeof(asm_statement_t),
 388                 [STATEMENT_MS_TRY]      = sizeof(ms_try_statement_t),
 389                 [STATEMENT_LEAVE]       = sizeof(leave_statement_t)
 390         };
 391         assert(kind < lengthof(sizes));
 392         assert(sizes[kind] != 0);
 393         return sizes[kind];
 394 }
 395
 396 /**
 397  * Returns the size of an expression node.
 398  *
 399  * @param kind  the expression kind
 400  */
 401 static size_t get_expression_struct_size(expression_kind_t kind)
 402 {
 403         static const size_t sizes[] = {
 404                 [EXPR_INVALID]                    = sizeof(expression_base_t),
 405                 [EXPR_REFERENCE]                  = sizeof(reference_expression_t),
 406                 [EXPR_REFERENCE_ENUM_VALUE]       = sizeof(reference_expression_t),
 407                 [EXPR_CONST]                      = sizeof(const_expression_t),
 408                 [EXPR_CHARACTER_CONSTANT]         = sizeof(const_expression_t),
 409                 [EXPR_WIDE_CHARACTER_CONSTANT]    = sizeof(const_expression_t),
 410                 [EXPR_STRING_LITERAL]             = sizeof(string_literal_expression_t),
 411                 [EXPR_WIDE_STRING_LITERAL]        = sizeof(wide_string_literal_expression_t),
 412                 [EXPR_COMPOUND_LITERAL]           = sizeof(compound_literal_expression_t),
 413                 [EXPR_CALL]                       = sizeof(call_expression_t),
 414                 [EXPR_UNARY_FIRST]                = sizeof(unary_expression_t),
 415                 [EXPR_BINARY_FIRST]               = sizeof(binary_expression_t),
 416                 [EXPR_CONDITIONAL]                = sizeof(conditional_expression_t),
 417                 [EXPR_SELECT]                     = sizeof(select_expression_t),
 418                 [EXPR_ARRAY_ACCESS]               = sizeof(array_access_expression_t),
 419                 [EXPR_SIZEOF]                     = sizeof(typeprop_expression_t),
 420                 [EXPR_ALIGNOF]                    = sizeof(typeprop_expression_t),
 421                 [EXPR_CLASSIFY_TYPE]              = sizeof(classify_type_expression_t),
 422                 [EXPR_FUNCNAME]                   = sizeof(funcname_expression_t),
 423                 [EXPR_BUILTIN_CONSTANT_P]         = sizeof(builtin_constant_expression_t),
 424                 [EXPR_BUILTIN_TYPES_COMPATIBLE_P] = sizeof(builtin_types_compatible_expression_t),
 425                 [EXPR_OFFSETOF]                   = sizeof(offsetof_expression_t),
 426                 [EXPR_VA_START]                   = sizeof(va_start_expression_t),
 427                 [EXPR_VA_ARG]                     = sizeof(va_arg_expression_t),
 428                 [EXPR_STATEMENT]                  = sizeof(statement_expression_t),
 429                 [EXPR_LABEL_ADDRESS]              = sizeof(label_address_expression_t),
 430         };
 431         if (kind >= EXPR_UNARY_FIRST && kind <= EXPR_UNARY_LAST) {
 432                 return sizes[EXPR_UNARY_FIRST];
 433         }
 434         if (kind >= EXPR_BINARY_FIRST && kind <= EXPR_BINARY_LAST) {
 435                 return sizes[EXPR_BINARY_FIRST];
 436         }
 437         assert(kind < lengthof(sizes));
 438         assert(sizes[kind] != 0);
 439         return sizes[kind];
 440 }
 441
 442 /**
 443  * Allocate a statement node of given kind and initialize all
 444  * fields with zero. Sets its source position to the position
 445  * of the current token.
 446  */
 447 static statement_t *allocate_statement_zero(statement_kind_t kind)
 448 {
 449         size_t       size = get_statement_struct_size(kind);
 450         statement_t *res  = allocate_ast_zero(size);
 451
 452         res->base.kind            = kind;
 453         res->base.parent          = current_parent;
 454         res->base.source_position = token.source_position;
 455         return res;
 456 }
 457
 458 /**
 459  * Allocate an expression node of given kind and initialize all
 460  * fields with zero.
 461  */
 462 static expression_t *allocate_expression_zero(expression_kind_t kind)
 463 {
 464         size_t        size = get_expression_struct_size(kind);
 465         expression_t *res  = allocate_ast_zero(size);
 466
 467         res->base.kind            = kind;
 468         res->base.type            = type_error_type;
 469         res->base.source_position = token.source_position;
 470         return res;
 471 }
 472
 473 /**
 474  * Creates a new invalid expression at the source position
 475  * of the current token.
 476  */
 477 static expression_t *create_invalid_expression(void)
 478 {
 479         return allocate_expression_zero(EXPR_INVALID);
 480 }
 481
 482 /**
 483  * Creates a new invalid statement.
 484  */
 485 static statement_t *create_invalid_statement(void)
 486 {
 487         return allocate_statement_zero(STATEMENT_INVALID);
 488 }
 489
 490 /**
 491  * Allocate a new empty statement.
 492  */
 493 static statement_t *create_empty_statement(void)
 494 {
 495         return allocate_statement_zero(STATEMENT_EMPTY);
 496 }
 497
 498 /**
 499  * Returns the size of a type node.
 500  *
 501  * @param kind  the type kind
 502  */
 503 static size_t get_type_struct_size(type_kind_t kind)
 504 {
 505         static const size_t sizes[] = {
 506                 [TYPE_ATOMIC]          = sizeof(atomic_type_t),
 507                 [TYPE_COMPLEX]         = sizeof(complex_type_t),
 508                 [TYPE_IMAGINARY]       = sizeof(imaginary_type_t),
 509                 [TYPE_BITFIELD]        = sizeof(bitfield_type_t),
 510                 [TYPE_COMPOUND_STRUCT] = sizeof(compound_type_t),
 511                 [TYPE_COMPOUND_UNION]  = sizeof(compound_type_t),
 512                 [TYPE_ENUM]            = sizeof(enum_type_t),
 513                 [TYPE_FUNCTION]        = sizeof(function_type_t),
 514                 [TYPE_POINTER]         = sizeof(pointer_type_t),
 515                 [TYPE_ARRAY]           = sizeof(array_type_t),
 516                 [TYPE_BUILTIN]         = sizeof(builtin_type_t),
 517                 [TYPE_TYPEDEF]         = sizeof(typedef_type_t),
 518                 [TYPE_TYPEOF]          = sizeof(typeof_type_t),
 519         };
 520         assert(lengthof(sizes) == (int)TYPE_TYPEOF + 1);
 521         assert(kind <= TYPE_TYPEOF);
 522         assert(sizes[kind] != 0);
 523         return sizes[kind];
 524 }
 525
 526 /**
 527  * Allocate a type node of given kind and initialize all
 528  * fields with zero.
 529  *
 530  * @param kind             type kind to allocate
 531  */
 532 static type_t *allocate_type_zero(type_kind_t kind)
 533 {
 534         size_t  size = get_type_struct_size(kind);
 535         type_t *res  = obstack_alloc(type_obst, size);
 536         memset(res, 0, size);
 537         res->base.kind = kind;
 538
 539         return res;
 540 }
 541
 542 /**
 543  * Returns the size of an initializer node.
 544  *
 545  * @param kind  the initializer kind
 546  */
 547 static size_t get_initializer_size(initializer_kind_t kind)
 548 {
 549         static const size_t sizes[] = {
 550                 [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
 551                 [INITIALIZER_STRING]      = sizeof(initializer_string_t),
 552                 [INITIALIZER_WIDE_STRING] = sizeof(initializer_wide_string_t),
 553                 [INITIALIZER_LIST]        = sizeof(initializer_list_t),
 554                 [INITIALIZER_DESIGNATOR]  = sizeof(initializer_designator_t)
 555         };
 556         assert(kind < lengthof(sizes));
 557         assert(sizes[kind] != 0);
 558         return sizes[kind];
 559 }
 560
 561 /**
 562  * Allocate an initializer node of given kind and initialize all
 563  * fields with zero.
 564  */
 565 static initializer_t *allocate_initializer_zero(initializer_kind_t kind)
 566 {
 567         initializer_t *result = allocate_ast_zero(get_initializer_size(kind));
 568         result->kind          = kind;
 569
 570         return result;
 571 }
 572
 573 /**
 574  * Returns the index of the top element of the environment stack.
 575  */
 576 static size_t environment_top(void)
 577 {
 578         return ARR_LEN(environment_stack);
 579 }
 580
 581 /**
 582  * Returns the index of the top element of the global label stack.
 583  */
 584 static size_t label_top(void)
 585 {
 586         return ARR_LEN(label_stack);
 587 }
 588
 589 /**
 590  * Return the next token.
 591  */
 592 static inline void next_token(void)
 593 {
 594         token                              = lookahead_buffer[lookahead_bufpos];
 595         lookahead_buffer[lookahead_bufpos] = lexer_token;
 596         lexer_next_token();
 597
 598         lookahead_bufpos = (lookahead_bufpos + 1) % MAX_LOOKAHEAD;
 599
 600 #ifdef PRINT_TOKENS
 601         print_token(stderr, &token);
 602         fprintf(stderr, "\n");
 603 #endif
 604 }
 605
 606 /**
 607  * Return the next token with a given lookahead.
 608  */
 609 static inline const token_t *look_ahead(size_t num)
 610 {
 611         assert(0 < num && num <= MAX_LOOKAHEAD);
 612         size_t pos = (lookahead_bufpos + num - 1) % MAX_LOOKAHEAD;
 613         return &lookahead_buffer[pos];
 614 }
 615
 616 /**
 617  * Adds a token type to the token type anchor set (a multi-set).
 618  */
 619 static void add_anchor_token(int token_type)
 620 {
 621         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 622         ++token_anchor_set[token_type];
 623 }
 624
 625 /**
 626  * Set the number of tokens types of the given type
 627  * to zero and return the old count.
 628  */
 629 static int save_and_reset_anchor_state(int token_type)
 630 {
 631         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 632         int count = token_anchor_set[token_type];
 633         token_anchor_set[token_type] = 0;
 634         return count;
 635 }
 636
 637 /**
 638  * Restore the number of token types to the given count.
 639  */
 640 static void restore_anchor_state(int token_type, int count)
 641 {
 642         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 643         token_anchor_set[token_type] = count;
 644 }
 645
 646 /**
 647  * Remove a token type from the token type anchor set (a multi-set).
 648  */
 649 static void rem_anchor_token(int token_type)
 650 {
 651         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 652         assert(token_anchor_set[token_type] != 0);
 653         --token_anchor_set[token_type];
 654 }
 655
 656 /**
 657  * Return true if the token type of the current token is
 658  * in the anchor set.
 659  */
 660 static bool at_anchor(void)
 661 {
 662         if (token.type < 0)
 663                 return false;
 664         return token_anchor_set[token.type];
 665 }
 666
 667 /**
 668  * Eat tokens until a matching token type is found.
 669  */
 670 static void eat_until_matching_token(int type)
 671 {
 672         int end_token;
 673         switch (type) {
 674                 case '(': end_token = ')';  break;
 675                 case '{': end_token = '}';  break;
 676                 case '[': end_token = ']';  break;
 677                 default:  end_token = type; break;
 678         }
 679
 680         unsigned parenthesis_count = 0;
 681         unsigned brace_count       = 0;
 682         unsigned bracket_count     = 0;
 683         while (token.type        != end_token ||
 684                parenthesis_count != 0         ||
 685                brace_count       != 0         ||
 686                bracket_count     != 0) {
 687                 switch (token.type) {
 688                 case T_EOF: return;
 689                 case '(': ++parenthesis_count; break;
 690                 case '{': ++brace_count;       break;
 691                 case '[': ++bracket_count;     break;
 692
 693                 case ')':
 694                         if (parenthesis_count > 0)
 695                                 --parenthesis_count;
 696                         goto check_stop;
 697
 698                 case '}':
 699                         if (brace_count > 0)
 700                                 --brace_count;
 701                         goto check_stop;
 702
 703                 case ']':
 704                         if (bracket_count > 0)
 705                                 --bracket_count;
 706 check_stop:
 707                         if (token.type        == end_token &&
 708                             parenthesis_count == 0         &&
 709                             brace_count       == 0         &&
 710                             bracket_count     == 0)
 711                                 return;
 712                         break;
 713
 714                 default:
 715                         break;
 716                 }
 717                 next_token();
 718         }
 719 }
 720
 721 /**
 722  * Eat input tokens until an anchor is found.
 723  */
 724 static void eat_until_anchor(void)
 725 {
 726         while (token_anchor_set[token.type] == 0) {
 727                 if (token.type == '(' || token.type == '{' || token.type == '[')
 728                         eat_until_matching_token(token.type);
 729                 next_token();
 730         }
 731 }
 732
 733 /**
 734  * Eat a whole block from input tokens.
 735  */
 736 static void eat_block(void)
 737 {
 738         eat_until_matching_token('{');
 739         if (token.type == '}')
 740                 next_token();
 741 }
 742
 743 #define eat(token_type) (assert(token.type == (token_type)), next_token())
 744
 745 /**
 746  * Report a parse error because an expected token was not found.
 747  */
 748 static
 749 #if defined __GNUC__ && __GNUC__ >= 4
 750 __attribute__((sentinel))
 751 #endif
 752 void parse_error_expected(const char *message, ...)
 753 {
 754         if (message != NULL) {
 755                 errorf(HERE, "%s", message);
 756         }
 757         va_list ap;
 758         va_start(ap, message);
 759         errorf(HERE, "got %K, expected %#k", &token, &ap, ", ");
 760         va_end(ap);
 761 }
 762
 763 /**
 764  * Report an incompatible type.
 765  */
 766 static void type_error_incompatible(const char *msg,
 767                 const source_position_t *source_position, type_t *type1, type_t *type2)
 768 {
 769         errorf(source_position, "%s, incompatible types: '%T' - '%T'",
 770                msg, type1, type2);
 771 }
 772
 773 /**
 774  * Expect the current token is the expected token.
 775  * If not, generate an error, eat the current statement,
 776  * and goto the end_error label.
 777  */
 778 #define expect(expected, error_label)                     \
 779         do {                                                  \
 780                 if (UNLIKELY(token.type != (expected))) {         \
 781                         parse_error_expected(NULL, (expected), NULL); \
 782                         add_anchor_token(expected);                   \
 783                         eat_until_anchor();                           \
 784                         if (token.type == expected)                   \
 785                                 next_token();                             \
 786                         rem_anchor_token(expected);                   \
 787                         goto error_label;                             \
 788                 }                                                 \
 789                 next_token();                                     \
 790         } while (0)
 791
 792 /**
 793  * Push a given scope on the scope stack and make it the
 794  * current scope
 795  */
 796 static scope_t *scope_push(scope_t *new_scope)
 797 {
 798         if (current_scope != NULL) {
 799                 new_scope->depth = current_scope->depth + 1;
 800         }
 801
 802         scope_t *old_scope = current_scope;
 803         current_scope      = new_scope;
 804         return old_scope;
 805 }
 806
 807 /**
 808  * Pop the current scope from the scope stack.
 809  */
 810 static void scope_pop(scope_t *old_scope)
 811 {
 812         current_scope = old_scope;
 813 }
 814
 815 /**
 816  * Search an entity by its symbol in a given namespace.
 817  */
 818 static entity_t *get_entity(const symbol_t *const symbol,
 819                             namespace_tag_t namespc)
 820 {
 821         entity_t *entity = symbol->entity;
 822         for (; entity != NULL; entity = entity->base.symbol_next) {
 823                 if (entity->base.namespc == namespc)
 824                         return entity;
 825         }
 826
 827         return NULL;
 828 }
 829
 830 /**
 831  * pushs an entity on the environment stack and links the corresponding symbol
 832  * it.
 833  */
 834 static void stack_push(stack_entry_t **stack_ptr, entity_t *entity)
 835 {
 836         symbol_t           *symbol  = entity->base.symbol;
 837         entity_namespace_t  namespc = entity->base.namespc;
 838         assert(namespc != NAMESPACE_INVALID);
 839
 840         /* replace/add entity into entity list of the symbol */
 841         entity_t **anchor;
 842         entity_t  *iter;
 843         for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 844                 iter = *anchor;
 845                 if (iter == NULL)
 846                         break;
 847
 848                 /* replace an entry? */
 849                 if (iter->base.namespc == namespc) {
 850                         entity->base.symbol_next = iter->base.symbol_next;
 851                         break;
 852                 }
 853         }
 854         *anchor = entity;
 855
 856         /* remember old declaration */
 857         stack_entry_t entry;
 858         entry.symbol     = symbol;
 859         entry.old_entity = iter;
 860         entry.namespc    = namespc;
 861         ARR_APP1(stack_entry_t, *stack_ptr, entry);
 862 }
 863
 864 /**
 865  * Push an entity on the environment stack.
 866  */
 867 static void environment_push(entity_t *entity)
 868 {
 869         assert(entity->base.source_position.input_name != NULL);
 870         assert(entity->base.parent_scope != NULL);
 871         stack_push(&environment_stack, entity);
 872 }
 873
 874 /**
 875  * Push a declaration on the global label stack.
 876  *
 877  * @param declaration  the declaration
 878  */
 879 static void label_push(entity_t *label)
 880 {
 881         /* we abuse the parameters scope as parent for the labels */
 882         label->base.parent_scope = &current_function->parameters;
 883         stack_push(&label_stack, label);
 884 }
 885
 886 /**
 887  * pops symbols from the environment stack until @p new_top is the top element
 888  */
 889 static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
 890 {
 891         stack_entry_t *stack = *stack_ptr;
 892         size_t         top   = ARR_LEN(stack);
 893         size_t         i;
 894
 895         assert(new_top <= top);
 896         if (new_top == top)
 897                 return;
 898
 899         for (i = top; i > new_top; --i) {
 900                 stack_entry_t *entry = &stack[i - 1];
 901
 902                 entity_t           *old_entity = entry->old_entity;
 903                 symbol_t           *symbol     = entry->symbol;
 904                 entity_namespace_t  namespc    = entry->namespc;
 905
 906                 /* replace with old_entity/remove */
 907                 entity_t **anchor;
 908                 entity_t  *iter;
 909                 for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 910                         iter = *anchor;
 911                         assert(iter != NULL);
 912                         /* replace an entry? */
 913                         if (iter->base.namespc == namespc)
 914                                 break;
 915                 }
 916
 917                 /* restore definition from outer scopes (if there was one) */
 918                 if (old_entity != NULL) {
 919                         old_entity->base.symbol_next = iter->base.symbol_next;
 920                         *anchor                      = old_entity;
 921                 } else {
 922                         /* remove entry from list */
 923                         *anchor = iter->base.symbol_next;
 924                 }
 925         }
 926
 927         ARR_SHRINKLEN(*stack_ptr, (int) new_top);
 928 }
 929
 930 /**
 931  * Pop all entries from the environment stack until the new_top
 932  * is reached.
 933  *
 934  * @param new_top  the new stack top
 935  */
 936 static void environment_pop_to(size_t new_top)
 937 {
 938         stack_pop_to(&environment_stack, new_top);
 939 }
 940
 941 /**
 942  * Pop all entries from the global label stack until the new_top
 943  * is reached.
 944  *
 945  * @param new_top  the new stack top
 946  */
 947 static void label_pop_to(size_t new_top)
 948 {
 949         stack_pop_to(&label_stack, new_top);
 950 }
 951
 952 static int get_akind_rank(atomic_type_kind_t akind)
 953 {
 954         return (int) akind;
 955 }
 956
 957 /**
 958  * Return the type rank for an atomic type.
 959  */
 960 static int get_rank(const type_t *type)
 961 {
 962         assert(!is_typeref(type));
 963         if (type->kind == TYPE_ENUM)
 964                 return get_akind_rank(type->enumt.akind);
 965
 966         assert(type->kind == TYPE_ATOMIC);
 967         return get_akind_rank(type->atomic.akind);
 968 }
 969
 970 /**
 971  * Do integer promotion for a given type.
 972  *
 973  * @param type  the type to promote
 974  * @return the promoted type
 975  */
 976 static type_t *promote_integer(type_t *type)
 977 {
 978         if (type->kind == TYPE_BITFIELD)
 979                 type = type->bitfield.base_type;
 980
 981         if (get_rank(type) < get_akind_rank(ATOMIC_TYPE_INT))
 982                 type = type_int;
 983
 984         return type;
 985 }
 986
 987 /**
 988  * Create a cast expression.
 989  *
 990  * @param expression  the expression to cast
 991  * @param dest_type   the destination type
 992  */
 993 static expression_t *create_cast_expression(expression_t *expression,
 994                                             type_t *dest_type)
 995 {
 996         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST_IMPLICIT);
 997
 998         cast->unary.value = expression;
 999         cast->base.type   = dest_type;
1000
1001         return cast;
1002 }
1003
1004 /**
1005  * Check if a given expression represents a null pointer constant.
1006  *
1007  * @param expression  the expression to check
1008  */
1009 static bool is_null_pointer_constant(const expression_t *expression)
1010 {
1011         /* skip void* cast */
1012         if (expression->kind == EXPR_UNARY_CAST ||
1013                         expression->kind == EXPR_UNARY_CAST_IMPLICIT) {
1014                 type_t *const type = skip_typeref(expression->base.type);
1015                 if (types_compatible(type, type_void_ptr))
1016                         expression = expression->unary.value;
1017         }
1018
1019         type_t *const type = skip_typeref(expression->base.type);
1020         return
1021                 is_type_integer(type)              &&
1022                 is_constant_expression(expression) &&
1023                 fold_constant(expression) == 0;
1024 }
1025
1026 /**
1027  * Create an implicit cast expression.
1028  *
1029  * @param expression  the expression to cast
1030  * @param dest_type   the destination type
1031  */
1032 static expression_t *create_implicit_cast(expression_t *expression,
1033                                           type_t *dest_type)
1034 {
1035         type_t *const source_type = expression->base.type;
1036
1037         if (source_type == dest_type)
1038                 return expression;
1039
1040         return create_cast_expression(expression, dest_type);
1041 }
1042
1043 typedef enum assign_error_t {
1044         ASSIGN_SUCCESS,
1045         ASSIGN_ERROR_INCOMPATIBLE,
1046         ASSIGN_ERROR_POINTER_QUALIFIER_MISSING,
1047         ASSIGN_WARNING_POINTER_INCOMPATIBLE,
1048         ASSIGN_WARNING_POINTER_FROM_INT,
1049         ASSIGN_WARNING_INT_FROM_POINTER
1050 } assign_error_t;
1051
1052 static void report_assign_error(assign_error_t error, type_t *orig_type_left,
1053                                 const expression_t *const right,
1054                                 const char *context,
1055                                 const source_position_t *source_position)
1056 {
1057         type_t *const orig_type_right = right->base.type;
1058         type_t *const type_left       = skip_typeref(orig_type_left);
1059         type_t *const type_right      = skip_typeref(orig_type_right);
1060
1061         switch (error) {
1062         case ASSIGN_SUCCESS:
1063                 return;
1064         case ASSIGN_ERROR_INCOMPATIBLE:
1065                 errorf(source_position,
1066                        "destination type '%T' in %s is incompatible with type '%T'",
1067                        orig_type_left, context, orig_type_right);
1068                 return;
1069
1070         case ASSIGN_ERROR_POINTER_QUALIFIER_MISSING: {
1071                 if (warning.other) {
1072                         type_t *points_to_left  = skip_typeref(type_left->pointer.points_to);
1073                         type_t *points_to_right = skip_typeref(type_right->pointer.points_to);
1074
1075                         /* the left type has all qualifiers from the right type */
1076                         unsigned missing_qualifiers
1077                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
1078                         warningf(source_position,
1079                                         "destination type '%T' in %s from type '%T' lacks qualifiers '%Q' in pointer target type",
1080                                         orig_type_left, context, orig_type_right, missing_qualifiers);
1081                 }
1082                 return;
1083         }
1084
1085         case ASSIGN_WARNING_POINTER_INCOMPATIBLE:
1086                 if (warning.other) {
1087                         warningf(source_position,
1088                                         "destination type '%T' in %s is incompatible with '%E' of type '%T'",
1089                                         orig_type_left, context, right, orig_type_right);
1090                 }
1091                 return;
1092
1093         case ASSIGN_WARNING_POINTER_FROM_INT:
1094                 if (warning.other) {
1095                         warningf(source_position,
1096                                         "%s makes pointer '%T' from integer '%T' without a cast",
1097                                         context, orig_type_left, orig_type_right);
1098                 }
1099                 return;
1100
1101         case ASSIGN_WARNING_INT_FROM_POINTER:
1102                 if (warning.other) {
1103                         warningf(source_position,
1104                                         "%s makes integer '%T' from pointer '%T' without a cast",
1105                                         context, orig_type_left, orig_type_right);
1106                 }
1107                 return;
1108
1109         default:
1110                 panic("invalid error value");
1111         }
1112 }
1113
1114 /** Implements the rules from §6.5.16.1 */
1115 static assign_error_t semantic_assign(type_t *orig_type_left,
1116                                       const expression_t *const right)
1117 {
1118         type_t *const orig_type_right = right->base.type;
1119         type_t *const type_left       = skip_typeref(orig_type_left);
1120         type_t *const type_right      = skip_typeref(orig_type_right);
1121
1122         if (is_type_pointer(type_left)) {
1123                 if (is_null_pointer_constant(right)) {
1124                         return ASSIGN_SUCCESS;
1125                 } else if (is_type_pointer(type_right)) {
1126                         type_t *points_to_left
1127                                 = skip_typeref(type_left->pointer.points_to);
1128                         type_t *points_to_right
1129                                 = skip_typeref(type_right->pointer.points_to);
1130                         assign_error_t res = ASSIGN_SUCCESS;
1131
1132                         /* the left type has all qualifiers from the right type */
1133                         unsigned missing_qualifiers
1134                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
1135                         if (missing_qualifiers != 0) {
1136                                 res = ASSIGN_ERROR_POINTER_QUALIFIER_MISSING;
1137                         }
1138
1139                         points_to_left  = get_unqualified_type(points_to_left);
1140                         points_to_right = get_unqualified_type(points_to_right);
1141
1142                         if (is_type_atomic(points_to_left, ATOMIC_TYPE_VOID))
1143                                 return res;
1144
1145                         if (is_type_atomic(points_to_right, ATOMIC_TYPE_VOID)) {
1146                                 /* ISO/IEC 14882:1998(E) §C.1.2:6 */
1147                                 return c_mode & _CXX ? ASSIGN_ERROR_INCOMPATIBLE : res;
1148                         }
1149
1150                         if (!types_compatible(points_to_left, points_to_right)) {
1151                                 return ASSIGN_WARNING_POINTER_INCOMPATIBLE;
1152                         }
1153
1154                         return res;
1155                 } else if (is_type_integer(type_right)) {
1156                         return ASSIGN_WARNING_POINTER_FROM_INT;
1157                 }
1158         } else if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
1159             (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
1160                 && is_type_pointer(type_right))) {
1161                 return ASSIGN_SUCCESS;
1162         } else if ((is_type_compound(type_left)  && is_type_compound(type_right))
1163                         || (is_type_builtin(type_left) && is_type_builtin(type_right))) {
1164                 type_t *const unqual_type_left  = get_unqualified_type(type_left);
1165                 type_t *const unqual_type_right = get_unqualified_type(type_right);
1166                 if (types_compatible(unqual_type_left, unqual_type_right)) {
1167                         return ASSIGN_SUCCESS;
1168                 }
1169         } else if (is_type_integer(type_left) && is_type_pointer(type_right)) {
1170                 return ASSIGN_WARNING_INT_FROM_POINTER;
1171         }
1172
1173         if (!is_type_valid(type_left) || !is_type_valid(type_right))
1174                 return ASSIGN_SUCCESS;
1175
1176         return ASSIGN_ERROR_INCOMPATIBLE;
1177 }
1178
1179 static expression_t *parse_constant_expression(void)
1180 {
1181         expression_t *result = parse_sub_expression(PREC_CONDITIONAL);
1182
1183         if (!is_constant_expression(result)) {
1184                 errorf(&result->base.source_position,
1185                        "expression '%E' is not constant", result);
1186         }
1187
1188         return result;
1189 }
1190
1191 static expression_t *parse_assignment_expression(void)
1192 {
1193         return parse_sub_expression(PREC_ASSIGNMENT);
1194 }
1195
1196 static string_t parse_string_literals(void)
1197 {
1198         assert(token.type == T_STRING_LITERAL);
1199         string_t result = token.v.string;
1200
1201         next_token();
1202
1203         while (token.type == T_STRING_LITERAL) {
1204                 result = concat_strings(&result, &token.v.string);
1205                 next_token();
1206         }
1207
1208         return result;
1209 }
1210
1211 static const char *const gnu_attribute_names[GNU_AK_LAST] = {
1212         [GNU_AK_CONST]                  = "const",
1213         [GNU_AK_VOLATILE]               = "volatile",
1214         [GNU_AK_CDECL]                  = "cdecl",
1215         [GNU_AK_STDCALL]                = "stdcall",
1216         [GNU_AK_FASTCALL]               = "fastcall",
1217         [GNU_AK_DEPRECATED]             = "deprecated",
1218         [GNU_AK_NOINLINE]               = "noinline",
1219         [GNU_AK_RETURNS_TWICE]          = "returns_twice",
1220         [GNU_AK_NORETURN]               = "noreturn",
1221         [GNU_AK_NAKED]                  = "naked",
1222         [GNU_AK_PURE]                   = "pure",
1223         [GNU_AK_ALWAYS_INLINE]          = "always_inline",
1224         [GNU_AK_MALLOC]                 = "malloc",
1225         [GNU_AK_WEAK]                   = "weak",
1226         [GNU_AK_CONSTRUCTOR]            = "constructor",
1227         [GNU_AK_DESTRUCTOR]             = "destructor",
1228         [GNU_AK_NOTHROW]                = "nothrow",
1229         [GNU_AK_TRANSPARENT_UNION]      = "transparent_union",
1230         [GNU_AK_COMMON]                 = "common",
1231         [GNU_AK_NOCOMMON]               = "nocommon",
1232         [GNU_AK_PACKED]                 = "packed",
1233         [GNU_AK_SHARED]                 = "shared",
1234         [GNU_AK_NOTSHARED]              = "notshared",
1235         [GNU_AK_USED]                   = "used",
1236         [GNU_AK_UNUSED]                 = "unused",
1237         [GNU_AK_NO_INSTRUMENT_FUNCTION] = "no_instrument_function",
1238         [GNU_AK_WARN_UNUSED_RESULT]     = "warn_unused_result",
1239         [GNU_AK_LONGCALL]               = "longcall",
1240         [GNU_AK_SHORTCALL]              = "shortcall",
1241         [GNU_AK_LONG_CALL]              = "long_call",
1242         [GNU_AK_SHORT_CALL]             = "short_call",
1243         [GNU_AK_FUNCTION_VECTOR]        = "function_vector",
1244         [GNU_AK_INTERRUPT]              = "interrupt",
1245         [GNU_AK_INTERRUPT_HANDLER]      = "interrupt_handler",
1246         [GNU_AK_NMI_HANDLER]            = "nmi_handler",
1247         [GNU_AK_NESTING]                = "nesting",
1248         [GNU_AK_NEAR]                   = "near",
1249         [GNU_AK_FAR]                    = "far",
1250         [GNU_AK_SIGNAL]                 = "signal",
1251         [GNU_AK_EIGTHBIT_DATA]          = "eightbit_data",
1252         [GNU_AK_TINY_DATA]              = "tiny_data",
1253         [GNU_AK_SAVEALL]                = "saveall",
1254         [GNU_AK_FLATTEN]                = "flatten",
1255         [GNU_AK_SSEREGPARM]             = "sseregparm",
1256         [GNU_AK_EXTERNALLY_VISIBLE]     = "externally_visible",
1257         [GNU_AK_RETURN_TWICE]           = "return_twice",
1258         [GNU_AK_MAY_ALIAS]              = "may_alias",
1259         [GNU_AK_MS_STRUCT]              = "ms_struct",
1260         [GNU_AK_GCC_STRUCT]             = "gcc_struct",
1261         [GNU_AK_DLLIMPORT]              = "dllimport",
1262         [GNU_AK_DLLEXPORT]              = "dllexport",
1263         [GNU_AK_ALIGNED]                = "aligned",
1264         [GNU_AK_ALIAS]                  = "alias",
1265         [GNU_AK_SECTION]                = "section",
1266         [GNU_AK_FORMAT]                 = "format",
1267         [GNU_AK_FORMAT_ARG]             = "format_arg",
1268         [GNU_AK_WEAKREF]                = "weakref",
1269         [GNU_AK_NONNULL]                = "nonnull",
1270         [GNU_AK_TLS_MODEL]              = "tls_model",
1271         [GNU_AK_VISIBILITY]             = "visibility",
1272         [GNU_AK_REGPARM]                = "regparm",
1273         [GNU_AK_MODE]                   = "mode",
1274         [GNU_AK_MODEL]                  = "model",
1275         [GNU_AK_TRAP_EXIT]              = "trap_exit",
1276         [GNU_AK_SP_SWITCH]              = "sp_switch",
1277         [GNU_AK_SENTINEL]               = "sentinel"
1278 };
1279
1280 /**
1281  * compare two string, ignoring double underscores on the second.
1282  */
1283 static int strcmp_underscore(const char *s1, const char *s2)
1284 {
1285         if (s2[0] == '_' && s2[1] == '_') {
1286                 size_t len2 = strlen(s2);
1287                 size_t len1 = strlen(s1);
1288                 if (len1 == len2-4 && s2[len2-2] == '_' && s2[len2-1] == '_') {
1289                         return strncmp(s1, s2+2, len2-4);
1290                 }
1291         }
1292
1293         return strcmp(s1, s2);
1294 }
1295
1296 /**
1297  * Allocate a new gnu temporal attribute of given kind.
1298  */
1299 static gnu_attribute_t *allocate_gnu_attribute(gnu_attribute_kind_t kind)
1300 {
1301         gnu_attribute_t *attribute = obstack_alloc(&temp_obst, sizeof(*attribute));
1302         attribute->kind            = kind;
1303         attribute->next            = NULL;
1304         attribute->invalid         = false;
1305         attribute->has_arguments   = false;
1306
1307         return attribute;
1308 }
1309
1310 /**
1311  * Parse one constant expression argument of the given attribute.
1312  */
1313 static void parse_gnu_attribute_const_arg(gnu_attribute_t *attribute)
1314 {
1315         expression_t *expression;
1316         add_anchor_token(')');
1317         expression = parse_constant_expression();
1318         rem_anchor_token(')');
1319         expect(')', end_error);
1320         attribute->u.argument = fold_constant(expression);
1321         return;
1322 end_error:
1323         attribute->invalid = true;
1324 }
1325
1326 /**
1327  * Parse a list of constant expressions arguments of the given attribute.
1328  */
1329 static void parse_gnu_attribute_const_arg_list(gnu_attribute_t *attribute)
1330 {
1331         argument_list_t **list = &attribute->u.arguments;
1332         argument_list_t  *entry;
1333         expression_t     *expression;
1334         add_anchor_token(')');
1335         add_anchor_token(',');
1336         while (true) {
1337                 expression = parse_constant_expression();
1338                 entry = obstack_alloc(&temp_obst, sizeof(entry));
1339                 entry->argument = fold_constant(expression);
1340                 entry->next     = NULL;
1341                 *list = entry;
1342                 list = &entry->next;
1343                 if (token.type != ',')
1344                         break;
1345                 next_token();
1346         }
1347         rem_anchor_token(',');
1348         rem_anchor_token(')');
1349         expect(')', end_error);
1350         return;
1351 end_error:
1352         attribute->invalid = true;
1353 }
1354
1355 /**
1356  * Parse one string literal argument of the given attribute.
1357  */
1358 static void parse_gnu_attribute_string_arg(gnu_attribute_t *attribute,
1359                                            string_t *string)
1360 {
1361         add_anchor_token('(');
1362         if (token.type != T_STRING_LITERAL) {
1363                 parse_error_expected("while parsing attribute directive",
1364                                      T_STRING_LITERAL, NULL);
1365                 goto end_error;
1366         }
1367         *string = parse_string_literals();
1368         rem_anchor_token('(');
1369         expect(')', end_error);
1370         return;
1371 end_error:
1372         attribute->invalid = true;
1373 }
1374
1375 /**
1376  * Parse one tls model of the given attribute.
1377  */
1378 static void parse_gnu_attribute_tls_model_arg(gnu_attribute_t *attribute)
1379 {
1380         static const char *const tls_models[] = {
1381                 "global-dynamic",
1382                 "local-dynamic",
1383                 "initial-exec",
1384                 "local-exec"
1385         };
1386         string_t string = { NULL, 0 };
1387         parse_gnu_attribute_string_arg(attribute, &string);
1388         if (string.begin != NULL) {
1389                 for (size_t i = 0; i < 4; ++i) {
1390                         if (strcmp(tls_models[i], string.begin) == 0) {
1391                                 attribute->u.value = i;
1392                                 return;
1393                         }
1394                 }
1395                 errorf(HERE, "'%s' is an unrecognized tls model", string.begin);
1396         }
1397         attribute->invalid = true;
1398 }
1399
1400 /**
1401  * Parse one tls model of the given attribute.
1402  */
1403 static void parse_gnu_attribute_visibility_arg(gnu_attribute_t *attribute)
1404 {
1405         static const char *const visibilities[] = {
1406                 "default",
1407                 "protected",
1408                 "hidden",
1409                 "internal"
1410         };
1411         string_t string = { NULL, 0 };
1412         parse_gnu_attribute_string_arg(attribute, &string);
1413         if (string.begin != NULL) {
1414                 for (size_t i = 0; i < 4; ++i) {
1415                         if (strcmp(visibilities[i], string.begin) == 0) {
1416                                 attribute->u.value = i;
1417                                 return;
1418                         }
1419                 }
1420                 errorf(HERE, "'%s' is an unrecognized visibility", string.begin);
1421         }
1422         attribute->invalid = true;
1423 }
1424
1425 /**
1426  * Parse one (code) model of the given attribute.
1427  */
1428 static void parse_gnu_attribute_model_arg(gnu_attribute_t *attribute)
1429 {
1430         static const char *const visibilities[] = {
1431                 "small",
1432                 "medium",
1433                 "large"
1434         };
1435         string_t string = { NULL, 0 };
1436         parse_gnu_attribute_string_arg(attribute, &string);
1437         if (string.begin != NULL) {
1438                 for (int i = 0; i < 3; ++i) {
1439                         if (strcmp(visibilities[i], string.begin) == 0) {
1440                                 attribute->u.value = i;
1441                                 return;
1442                         }
1443                 }
1444                 errorf(HERE, "'%s' is an unrecognized model", string.begin);
1445         }
1446         attribute->invalid = true;
1447 }
1448
1449 /**
1450  * Parse one mode of the given attribute.
1451  */
1452 static void parse_gnu_attribute_mode_arg(gnu_attribute_t *attribute)
1453 {
1454         add_anchor_token(')');
1455
1456         if (token.type != T_IDENTIFIER) {
1457                 expect(T_IDENTIFIER, end_error);
1458         }
1459
1460         attribute->u.symbol = token.v.symbol;
1461         next_token();
1462
1463         rem_anchor_token(')');
1464         expect(')', end_error);
1465         return;
1466 end_error:
1467         attribute->invalid = true;
1468 }
1469
1470 /**
1471  * Parse one interrupt argument of the given attribute.
1472  */
1473 static void parse_gnu_attribute_interrupt_arg(gnu_attribute_t *attribute)
1474 {
1475         static const char *const interrupts[] = {
1476                 "IRQ",
1477                 "FIQ",
1478                 "SWI",
1479                 "ABORT",
1480                 "UNDEF"
1481         };
1482         string_t string = { NULL, 0 };
1483         parse_gnu_attribute_string_arg(attribute, &string);
1484         if (string.begin != NULL) {
1485                 for (size_t i = 0; i < 5; ++i) {
1486                         if (strcmp(interrupts[i], string.begin) == 0) {
1487                                 attribute->u.value = i;
1488                                 return;
1489                         }
1490                 }
1491                 errorf(HERE, "'%s' is not an interrupt", string.begin);
1492         }
1493         attribute->invalid = true;
1494 }
1495
1496 /**
1497  * Parse ( identifier, const expression, const expression )
1498  */
1499 static void parse_gnu_attribute_format_args(gnu_attribute_t *attribute)
1500 {
1501         static const char *const format_names[] = {
1502                 "printf",
1503                 "scanf",
1504                 "strftime",
1505                 "strfmon"
1506         };
1507         int i;
1508
1509         if (token.type != T_IDENTIFIER) {
1510                 parse_error_expected("while parsing format attribute directive", T_IDENTIFIER, NULL);
1511                 goto end_error;
1512         }
1513         const char *name = token.v.symbol->string;
1514         for (i = 0; i < 4; ++i) {
1515                 if (strcmp_underscore(format_names[i], name) == 0)
1516                         break;
1517         }
1518         if (i >= 4) {
1519                 if (warning.attribute)
1520                         warningf(HERE, "'%s' is an unrecognized format function type", name);
1521         }
1522         next_token();
1523
1524         expect(',', end_error);
1525         add_anchor_token(')');
1526         add_anchor_token(',');
1527         parse_constant_expression();
1528         rem_anchor_token(',');
1529         rem_anchor_token(')');
1530
1531         expect(',', end_error);
1532         add_anchor_token(')');
1533         parse_constant_expression();
1534         rem_anchor_token(')');
1535         expect(')', end_error);
1536         return;
1537 end_error:
1538         attribute->u.value = true;
1539 }
1540
1541 /**
1542  * Check that a given GNU attribute has no arguments.
1543  */
1544 static void check_no_argument(gnu_attribute_t *attribute, const char *name)
1545 {
1546         if (!attribute->has_arguments)
1547                 return;
1548
1549         /* should have no arguments */
1550         errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1551         eat_until_matching_token('(');
1552         /* we have already consumed '(', so we stop before ')', eat it */
1553         eat(')');
1554         attribute->invalid = true;
1555 }
1556
1557 /**
1558  * Parse one GNU attribute.
1559  *
1560  * Note that attribute names can be specified WITH or WITHOUT
1561  * double underscores, ie const or __const__.
1562  *
1563  * The following attributes are parsed without arguments
1564  *  const
1565  *  volatile
1566  *  cdecl
1567  *  stdcall
1568  *  fastcall
1569  *  deprecated
1570  *  noinline
1571  *  noreturn
1572  *  naked
1573  *  pure
1574  *  always_inline
1575  *  malloc
1576  *  weak
1577  *  constructor
1578  *  destructor
1579  *  nothrow
1580  *  transparent_union
1581  *  common
1582  *  nocommon
1583  *  packed
1584  *  shared
1585  *  notshared
1586  *  used
1587  *  unused
1588  *  no_instrument_function
1589  *  warn_unused_result
1590  *  longcall
1591  *  shortcall
1592  *  long_call
1593  *  short_call
1594  *  function_vector
1595  *  interrupt_handler
1596  *  nmi_handler
1597  *  nesting
1598  *  near
1599  *  far
1600  *  signal
1601  *  eightbit_data
1602  *  tiny_data
1603  *  saveall
1604  *  flatten
1605  *  sseregparm
1606  *  externally_visible
1607  *  return_twice
1608  *  may_alias
1609  *  ms_struct
1610  *  gcc_struct
1611  *  dllimport
1612  *  dllexport
1613  *
1614  * The following attributes are parsed with arguments
1615  *  aligned( const expression )
1616  *  alias( string literal )
1617  *  section( string literal )
1618  *  format( identifier, const expression, const expression )
1619  *  format_arg( const expression )
1620  *  tls_model( string literal )
1621  *  visibility( string literal )
1622  *  regparm( const expression )
1623  *  model( string leteral )
1624  *  trap_exit( const expression )
1625  *  sp_switch( string literal )
1626  *
1627  * The following attributes might have arguments
1628  *  weak_ref( string literal )
1629  *  non_null( const expression // ',' )
1630  *  interrupt( string literal )
1631  *  sentinel( constant expression )
1632  */
1633 static decl_modifiers_t parse_gnu_attribute(gnu_attribute_t **attributes)
1634 {
1635         gnu_attribute_t *head      = *attributes;
1636         gnu_attribute_t *last      = *attributes;
1637         decl_modifiers_t modifiers = 0;
1638         gnu_attribute_t *attribute;
1639
1640         eat(T___attribute__);
1641         expect('(', end_error);
1642         expect('(', end_error);
1643
1644         if (token.type != ')') {
1645                 /* find the end of the list */
1646                 if (last != NULL) {
1647                         while (last->next != NULL)
1648                                 last = last->next;
1649                 }
1650
1651                 /* non-empty attribute list */
1652                 while (true) {
1653                         const char *name;
1654                         if (token.type == T_const) {
1655                                 name = "const";
1656                         } else if (token.type == T_volatile) {
1657                                 name = "volatile";
1658                         } else if (token.type == T_cdecl) {
1659                                 /* __attribute__((cdecl)), WITH ms mode */
1660                                 name = "cdecl";
1661                         } else if (token.type == T_IDENTIFIER) {
1662                                 const symbol_t *sym = token.v.symbol;
1663                                 name = sym->string;
1664                         } else {
1665                                 parse_error_expected("while parsing GNU attribute", T_IDENTIFIER, NULL);
1666                                 break;
1667                         }
1668
1669                         next_token();
1670
1671                         int i;
1672                         for (i = 0; i < GNU_AK_LAST; ++i) {
1673                                 if (strcmp_underscore(gnu_attribute_names[i], name) == 0)
1674                                         break;
1675                         }
1676                         gnu_attribute_kind_t kind = (gnu_attribute_kind_t)i;
1677
1678                         attribute = NULL;
1679                         if (kind == GNU_AK_LAST) {
1680                                 if (warning.attribute)
1681                                         warningf(HERE, "'%s' attribute directive ignored", name);
1682
1683                                 /* skip possible arguments */
1684                                 if (token.type == '(') {
1685                                         eat_until_matching_token(')');
1686                                 }
1687                         } else {
1688                                 /* check for arguments */
1689                                 attribute = allocate_gnu_attribute(kind);
1690                                 if (token.type == '(') {
1691                                         next_token();
1692                                         if (token.type == ')') {
1693                                                 /* empty args are allowed */
1694                                                 next_token();
1695                                         } else
1696                                                 attribute->has_arguments = true;
1697                                 }
1698
1699                                 switch (kind) {
1700                                 case GNU_AK_VOLATILE:
1701                                 case GNU_AK_NAKED:
1702                                 case GNU_AK_MALLOC:
1703                                 case GNU_AK_WEAK:
1704                                 case GNU_AK_COMMON:
1705                                 case GNU_AK_NOCOMMON:
1706                                 case GNU_AK_SHARED:
1707                                 case GNU_AK_NOTSHARED:
1708                                 case GNU_AK_NO_INSTRUMENT_FUNCTION:
1709                                 case GNU_AK_WARN_UNUSED_RESULT:
1710                                 case GNU_AK_LONGCALL:
1711                                 case GNU_AK_SHORTCALL:
1712                                 case GNU_AK_LONG_CALL:
1713                                 case GNU_AK_SHORT_CALL:
1714                                 case GNU_AK_FUNCTION_VECTOR:
1715                                 case GNU_AK_INTERRUPT_HANDLER:
1716                                 case GNU_AK_NMI_HANDLER:
1717                                 case GNU_AK_NESTING:
1718                                 case GNU_AK_NEAR:
1719                                 case GNU_AK_FAR:
1720                                 case GNU_AK_SIGNAL:
1721                                 case GNU_AK_EIGTHBIT_DATA:
1722                                 case GNU_AK_TINY_DATA:
1723                                 case GNU_AK_SAVEALL:
1724                                 case GNU_AK_FLATTEN:
1725                                 case GNU_AK_SSEREGPARM:
1726                                 case GNU_AK_EXTERNALLY_VISIBLE:
1727                                 case GNU_AK_RETURN_TWICE:
1728                                 case GNU_AK_MAY_ALIAS:
1729                                 case GNU_AK_MS_STRUCT:
1730                                 case GNU_AK_GCC_STRUCT:
1731                                         goto no_arg;
1732
1733                                 case GNU_AK_CDECL:             modifiers |= DM_CDECL;             goto no_arg;
1734                                 case GNU_AK_FASTCALL:          modifiers |= DM_FASTCALL;          goto no_arg;
1735                                 case GNU_AK_STDCALL:           modifiers |= DM_STDCALL;           goto no_arg;
1736                                 case GNU_AK_UNUSED:            modifiers |= DM_UNUSED;            goto no_arg;
1737                                 case GNU_AK_USED:              modifiers |= DM_USED;              goto no_arg;
1738                                 case GNU_AK_PURE:              modifiers |= DM_PURE;              goto no_arg;
1739                                 case GNU_AK_CONST:             modifiers |= DM_CONST;             goto no_arg;
1740                                 case GNU_AK_ALWAYS_INLINE:     modifiers |= DM_FORCEINLINE;       goto no_arg;
1741                                 case GNU_AK_DLLIMPORT:         modifiers |= DM_DLLIMPORT;         goto no_arg;
1742                                 case GNU_AK_DLLEXPORT:         modifiers |= DM_DLLEXPORT;         goto no_arg;
1743                                 case GNU_AK_PACKED:            modifiers |= DM_PACKED;            goto no_arg;
1744                                 case GNU_AK_NOINLINE:          modifiers |= DM_NOINLINE;          goto no_arg;
1745                                 case GNU_AK_RETURNS_TWICE:     modifiers |= DM_RETURNS_TWICE;     goto no_arg;
1746                                 case GNU_AK_NORETURN:          modifiers |= DM_NORETURN;          goto no_arg;
1747                                 case GNU_AK_NOTHROW:           modifiers |= DM_NOTHROW;           goto no_arg;
1748                                 case GNU_AK_TRANSPARENT_UNION: modifiers |= DM_TRANSPARENT_UNION; goto no_arg;
1749                                 case GNU_AK_CONSTRUCTOR:       modifiers |= DM_CONSTRUCTOR;       goto no_arg;
1750                                 case GNU_AK_DESTRUCTOR:        modifiers |= DM_DESTRUCTOR;        goto no_arg;
1751                                 case GNU_AK_DEPRECATED:        modifiers |= DM_DEPRECATED;        goto no_arg;
1752
1753                                 case GNU_AK_ALIGNED:
1754                                         /* __align__ may be used without an argument */
1755                                         if (attribute->has_arguments) {
1756                                                 parse_gnu_attribute_const_arg(attribute);
1757                                         }
1758                                         break;
1759
1760                                 case GNU_AK_FORMAT_ARG:
1761                                 case GNU_AK_REGPARM:
1762                                 case GNU_AK_TRAP_EXIT:
1763                                         if (!attribute->has_arguments) {
1764                                                 /* should have arguments */
1765                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1766                                                 attribute->invalid = true;
1767                                         } else
1768                                                 parse_gnu_attribute_const_arg(attribute);
1769                                         break;
1770                                 case GNU_AK_ALIAS:
1771                                 case GNU_AK_SECTION:
1772                                 case GNU_AK_SP_SWITCH:
1773                                         if (!attribute->has_arguments) {
1774                                                 /* should have arguments */
1775                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1776                                                 attribute->invalid = true;
1777                                         } else
1778                                                 parse_gnu_attribute_string_arg(attribute, &attribute->u.string);
1779                                         break;
1780                                 case GNU_AK_FORMAT:
1781                                         if (!attribute->has_arguments) {
1782                                                 /* should have arguments */
1783                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1784                                                 attribute->invalid = true;
1785                                         } else
1786                                                 parse_gnu_attribute_format_args(attribute);
1787                                         break;
1788                                 case GNU_AK_WEAKREF:
1789                                         /* may have one string argument */
1790                                         if (attribute->has_arguments)
1791                                                 parse_gnu_attribute_string_arg(attribute, &attribute->u.string);
1792                                         break;
1793                                 case GNU_AK_NONNULL:
1794                                         if (attribute->has_arguments)
1795                                                 parse_gnu_attribute_const_arg_list(attribute);
1796                                         break;
1797                                 case GNU_AK_TLS_MODEL:
1798                                         if (!attribute->has_arguments) {
1799                                                 /* should have arguments */
1800                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1801                                         } else
1802                                                 parse_gnu_attribute_tls_model_arg(attribute);
1803                                         break;
1804                                 case GNU_AK_VISIBILITY:
1805                                         if (!attribute->has_arguments) {
1806                                                 /* should have arguments */
1807                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1808                                         } else
1809                                                 parse_gnu_attribute_visibility_arg(attribute);
1810                                         break;
1811                                 case GNU_AK_MODEL:
1812                                         if (!attribute->has_arguments) {
1813                                                 /* should have arguments */
1814                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1815                                         } else {
1816                                                 parse_gnu_attribute_model_arg(attribute);
1817                                         }
1818                                         break;
1819                                 case GNU_AK_MODE:
1820                                         if (!attribute->has_arguments) {
1821                                                 /* should have arguments */
1822                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1823                                         } else {
1824                                                 parse_gnu_attribute_mode_arg(attribute);
1825                                         }
1826                                         break;
1827                                 case GNU_AK_INTERRUPT:
1828                                         /* may have one string argument */
1829                                         if (attribute->has_arguments)
1830                                                 parse_gnu_attribute_interrupt_arg(attribute);
1831                                         break;
1832                                 case GNU_AK_SENTINEL:
1833                                         /* may have one string argument */
1834                                         if (attribute->has_arguments)
1835                                                 parse_gnu_attribute_const_arg(attribute);
1836                                         break;
1837                                 case GNU_AK_LAST:
1838                                         /* already handled */
1839                                         break;
1840
1841 no_arg:
1842                                         check_no_argument(attribute, name);
1843                                 }
1844                         }
1845                         if (attribute != NULL) {
1846                                 if (last != NULL) {
1847                                         last->next = attribute;
1848                                         last       = attribute;
1849                                 } else {
1850                                         head = last = attribute;
1851                                 }
1852                         }
1853
1854                         if (token.type != ',')
1855                                 break;
1856                         next_token();
1857                 }
1858         }
1859         expect(')', end_error);
1860         expect(')', end_error);
1861 end_error:
1862         *attributes = head;
1863
1864         return modifiers;
1865 }
1866
1867 /**
1868  * Parse GNU attributes.
1869  */
1870 static decl_modifiers_t parse_attributes(gnu_attribute_t **attributes)
1871 {
1872         decl_modifiers_t modifiers = 0;
1873
1874         while (true) {
1875                 switch (token.type) {
1876                 case T___attribute__:
1877                         modifiers |= parse_gnu_attribute(attributes);
1878                         continue;
1879
1880                 case T_asm:
1881                         next_token();
1882                         expect('(', end_error);
1883                         if (token.type != T_STRING_LITERAL) {
1884                                 parse_error_expected("while parsing assembler attribute",
1885                                                      T_STRING_LITERAL, NULL);
1886                                 eat_until_matching_token('(');
1887                                 break;
1888                         } else {
1889                                 parse_string_literals();
1890                         }
1891                         expect(')', end_error);
1892                         continue;
1893
1894                 case T_cdecl:     modifiers |= DM_CDECL;    break;
1895                 case T__fastcall: modifiers |= DM_FASTCALL; break;
1896                 case T__stdcall:  modifiers |= DM_STDCALL;  break;
1897
1898                 case T___thiscall:
1899                         /* TODO record modifier */
1900                         if (warning.other)
1901                                 warningf(HERE, "Ignoring declaration modifier %K", &token);
1902                         break;
1903
1904 end_error:
1905                 default: return modifiers;
1906                 }
1907
1908                 next_token();
1909         }
1910 }
1911
1912 static void mark_vars_read(expression_t *expr, entity_t *lhs_ent);
1913
1914 static entity_t *determine_lhs_ent(expression_t *const expr,
1915                                    entity_t *lhs_ent)
1916 {
1917         switch (expr->kind) {
1918                 case EXPR_REFERENCE: {
1919                         entity_t *const entity = expr->reference.entity;
1920                         /* we should only find variables as lvalues... */
1921                         if (entity->base.kind != ENTITY_VARIABLE
1922                                         && entity->base.kind != ENTITY_PARAMETER)
1923                                 return NULL;
1924
1925                         return entity;
1926                 }
1927
1928                 case EXPR_ARRAY_ACCESS: {
1929                         expression_t *const ref = expr->array_access.array_ref;
1930                         entity_t     *      ent = NULL;
1931                         if (is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1932                                 ent     = determine_lhs_ent(ref, lhs_ent);
1933                                 lhs_ent = ent;
1934                         } else {
1935                                 mark_vars_read(expr->select.compound, lhs_ent);
1936                         }
1937                         mark_vars_read(expr->array_access.index, lhs_ent);
1938                         return ent;
1939                 }
1940
1941                 case EXPR_SELECT: {
1942                         if (is_type_compound(skip_typeref(expr->base.type))) {
1943                                 return determine_lhs_ent(expr->select.compound, lhs_ent);
1944                         } else {
1945                                 mark_vars_read(expr->select.compound, lhs_ent);
1946                                 return NULL;
1947                         }
1948                 }
1949
1950                 case EXPR_UNARY_DEREFERENCE: {
1951                         expression_t *const val = expr->unary.value;
1952                         if (val->kind == EXPR_UNARY_TAKE_ADDRESS) {
1953                                 /* *&x is a NOP */
1954                                 return determine_lhs_ent(val->unary.value, lhs_ent);
1955                         } else {
1956                                 mark_vars_read(val, NULL);
1957                                 return NULL;
1958                         }
1959                 }
1960
1961                 default:
1962                         mark_vars_read(expr, NULL);
1963                         return NULL;
1964         }
1965 }
1966
1967 #define ENT_ANY ((entity_t*)-1)
1968
1969 /**
1970  * Mark declarations, which are read.  This is used to detect variables, which
1971  * are never read.
1972  * Example:
1973  * x = x + 1;
1974  *   x is not marked as "read", because it is only read to calculate its own new
1975  *   value.
1976  *
1977  * x += y; y += x;
1978  *   x and y are not detected as "not read", because multiple variables are
1979  *   involved.
1980  */
1981 static void mark_vars_read(expression_t *const expr, entity_t *lhs_ent)
1982 {
1983         switch (expr->kind) {
1984                 case EXPR_REFERENCE: {
1985                         entity_t *const entity = expr->reference.entity;
1986                         if (entity->kind != ENTITY_VARIABLE
1987                                         && entity->kind != ENTITY_PARAMETER)
1988                                 return;
1989
1990                         if (lhs_ent != entity && lhs_ent != ENT_ANY) {
1991                                 if (entity->kind == ENTITY_VARIABLE) {
1992                                         entity->variable.read = true;
1993                                 } else {
1994                                         entity->parameter.read = true;
1995                                 }
1996                         }
1997                         return;
1998                 }
1999
2000                 case EXPR_CALL:
2001                         // TODO respect pure/const
2002                         mark_vars_read(expr->call.function, NULL);
2003                         for (call_argument_t *arg = expr->call.arguments; arg != NULL; arg = arg->next) {
2004                                 mark_vars_read(arg->expression, NULL);
2005                         }
2006                         return;
2007
2008                 case EXPR_CONDITIONAL:
2009                         // TODO lhs_decl should depend on whether true/false have an effect
2010                         mark_vars_read(expr->conditional.condition, NULL);
2011                         if (expr->conditional.true_expression != NULL)
2012                                 mark_vars_read(expr->conditional.true_expression, lhs_ent);
2013                         mark_vars_read(expr->conditional.false_expression, lhs_ent);
2014                         return;
2015
2016                 case EXPR_SELECT:
2017                         if (lhs_ent == ENT_ANY
2018                                         && !is_type_compound(skip_typeref(expr->base.type)))
2019                                 lhs_ent = NULL;
2020                         mark_vars_read(expr->select.compound, lhs_ent);
2021                         return;
2022
2023                 case EXPR_ARRAY_ACCESS: {
2024                         expression_t *const ref = expr->array_access.array_ref;
2025                         mark_vars_read(ref, lhs_ent);
2026                         lhs_ent = determine_lhs_ent(ref, lhs_ent);
2027                         mark_vars_read(expr->array_access.index, lhs_ent);
2028                         return;
2029                 }
2030
2031                 case EXPR_VA_ARG:
2032                         mark_vars_read(expr->va_arge.ap, lhs_ent);
2033                         return;
2034
2035                 case EXPR_UNARY_CAST:
2036                         /* Special case: Use void cast to mark a variable as "read" */
2037                         if (is_type_atomic(skip_typeref(expr->base.type), ATOMIC_TYPE_VOID))
2038                                 lhs_ent = NULL;
2039                         goto unary;
2040
2041
2042                 case EXPR_UNARY_THROW:
2043                         if (expr->unary.value == NULL)
2044                                 return;
2045                         /* FALLTHROUGH */
2046                 case EXPR_UNARY_DEREFERENCE:
2047                 case EXPR_UNARY_DELETE:
2048                 case EXPR_UNARY_DELETE_ARRAY:
2049                         if (lhs_ent == ENT_ANY)
2050                                 lhs_ent = NULL;
2051                         goto unary;
2052
2053                 case EXPR_UNARY_NEGATE:
2054                 case EXPR_UNARY_PLUS:
2055                 case EXPR_UNARY_BITWISE_NEGATE:
2056                 case EXPR_UNARY_NOT:
2057                 case EXPR_UNARY_TAKE_ADDRESS:
2058                 case EXPR_UNARY_POSTFIX_INCREMENT:
2059                 case EXPR_UNARY_POSTFIX_DECREMENT:
2060                 case EXPR_UNARY_PREFIX_INCREMENT:
2061                 case EXPR_UNARY_PREFIX_DECREMENT:
2062                 case EXPR_UNARY_CAST_IMPLICIT:
2063                 case EXPR_UNARY_ASSUME:
2064 unary:
2065                         mark_vars_read(expr->unary.value, lhs_ent);
2066                         return;
2067
2068                 case EXPR_BINARY_ADD:
2069                 case EXPR_BINARY_SUB:
2070                 case EXPR_BINARY_MUL:
2071                 case EXPR_BINARY_DIV:
2072                 case EXPR_BINARY_MOD:
2073                 case EXPR_BINARY_EQUAL:
2074                 case EXPR_BINARY_NOTEQUAL:
2075                 case EXPR_BINARY_LESS:
2076                 case EXPR_BINARY_LESSEQUAL:
2077                 case EXPR_BINARY_GREATER:
2078                 case EXPR_BINARY_GREATEREQUAL:
2079                 case EXPR_BINARY_BITWISE_AND:
2080                 case EXPR_BINARY_BITWISE_OR:
2081                 case EXPR_BINARY_BITWISE_XOR:
2082                 case EXPR_BINARY_LOGICAL_AND:
2083                 case EXPR_BINARY_LOGICAL_OR:
2084                 case EXPR_BINARY_SHIFTLEFT:
2085                 case EXPR_BINARY_SHIFTRIGHT:
2086                 case EXPR_BINARY_COMMA:
2087                 case EXPR_BINARY_ISGREATER:
2088                 case EXPR_BINARY_ISGREATEREQUAL:
2089                 case EXPR_BINARY_ISLESS:
2090                 case EXPR_BINARY_ISLESSEQUAL:
2091                 case EXPR_BINARY_ISLESSGREATER:
2092                 case EXPR_BINARY_ISUNORDERED:
2093                         mark_vars_read(expr->binary.left,  lhs_ent);
2094                         mark_vars_read(expr->binary.right, lhs_ent);
2095                         return;
2096
2097                 case EXPR_BINARY_ASSIGN:
2098                 case EXPR_BINARY_MUL_ASSIGN:
2099                 case EXPR_BINARY_DIV_ASSIGN:
2100                 case EXPR_BINARY_MOD_ASSIGN:
2101                 case EXPR_BINARY_ADD_ASSIGN:
2102                 case EXPR_BINARY_SUB_ASSIGN:
2103                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:
2104                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:
2105                 case EXPR_BINARY_BITWISE_AND_ASSIGN:
2106                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:
2107                 case EXPR_BINARY_BITWISE_OR_ASSIGN: {
2108                         if (lhs_ent == ENT_ANY)
2109                                 lhs_ent = NULL;
2110                         lhs_ent = determine_lhs_ent(expr->binary.left, lhs_ent);
2111                         mark_vars_read(expr->binary.right, lhs_ent);
2112                         return;
2113                 }
2114
2115                 case EXPR_VA_START:
2116                         determine_lhs_ent(expr->va_starte.ap, lhs_ent);
2117                         return;
2118
2119                 case EXPR_UNKNOWN:
2120                 case EXPR_INVALID:
2121                 case EXPR_CONST:
2122                 case EXPR_CHARACTER_CONSTANT:
2123                 case EXPR_WIDE_CHARACTER_CONSTANT:
2124                 case EXPR_STRING_LITERAL:
2125                 case EXPR_WIDE_STRING_LITERAL:
2126                 case EXPR_COMPOUND_LITERAL: // TODO init?
2127                 case EXPR_SIZEOF:
2128                 case EXPR_CLASSIFY_TYPE:
2129                 case EXPR_ALIGNOF:
2130                 case EXPR_FUNCNAME:
2131                 case EXPR_BUILTIN_CONSTANT_P:
2132                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
2133                 case EXPR_OFFSETOF:
2134                 case EXPR_STATEMENT: // TODO
2135                 case EXPR_LABEL_ADDRESS:
2136                 case EXPR_REFERENCE_ENUM_VALUE:
2137                         return;
2138         }
2139
2140         panic("unhandled expression");
2141 }
2142
2143 static designator_t *parse_designation(void)
2144 {
2145         designator_t *result = NULL;
2146         designator_t *last   = NULL;
2147
2148         while (true) {
2149                 designator_t *designator;
2150                 switch (token.type) {
2151                 case '[':
2152                         designator = allocate_ast_zero(sizeof(designator[0]));
2153                         designator->source_position = token.source_position;
2154                         next_token();
2155                         add_anchor_token(']');
2156                         designator->array_index = parse_constant_expression();
2157                         rem_anchor_token(']');
2158                         expect(']', end_error);
2159                         break;
2160                 case '.':
2161                         designator = allocate_ast_zero(sizeof(designator[0]));
2162                         designator->source_position = token.source_position;
2163                         next_token();
2164                         if (token.type != T_IDENTIFIER) {
2165                                 parse_error_expected("while parsing designator",
2166                                                      T_IDENTIFIER, NULL);
2167                                 return NULL;
2168                         }
2169                         designator->symbol = token.v.symbol;
2170                         next_token();
2171                         break;
2172                 default:
2173                         expect('=', end_error);
2174                         return result;
2175                 }
2176
2177                 assert(designator != NULL);
2178                 if (last != NULL) {
2179                         last->next = designator;
2180                 } else {
2181                         result = designator;
2182                 }
2183                 last = designator;
2184         }
2185 end_error:
2186         return NULL;
2187 }
2188
2189 static initializer_t *initializer_from_string(array_type_t *type,
2190                                               const string_t *const string)
2191 {
2192         /* TODO: check len vs. size of array type */
2193         (void) type;
2194
2195         initializer_t *initializer = allocate_initializer_zero(INITIALIZER_STRING);
2196         initializer->string.string = *string;
2197
2198         return initializer;
2199 }
2200
2201 static initializer_t *initializer_from_wide_string(array_type_t *const type,
2202                                                    wide_string_t *const string)
2203 {
2204         /* TODO: check len vs. size of array type */
2205         (void) type;
2206
2207         initializer_t *const initializer =
2208                 allocate_initializer_zero(INITIALIZER_WIDE_STRING);
2209         initializer->wide_string.string = *string;
2210
2211         return initializer;
2212 }
2213
2214 /**
2215  * Build an initializer from a given expression.
2216  */
2217 static initializer_t *initializer_from_expression(type_t *orig_type,
2218                                                   expression_t *expression)
2219 {
2220         /* TODO check that expression is a constant expression */
2221
2222         /* §6.7.8.14/15 char array may be initialized by string literals */
2223         type_t *type           = skip_typeref(orig_type);
2224         type_t *expr_type_orig = expression->base.type;
2225         type_t *expr_type      = skip_typeref(expr_type_orig);
2226         if (is_type_array(type) && expr_type->kind == TYPE_POINTER) {
2227                 array_type_t *const array_type   = &type->array;
2228                 type_t       *const element_type = skip_typeref(array_type->element_type);
2229
2230                 if (element_type->kind == TYPE_ATOMIC) {
2231                         atomic_type_kind_t akind = element_type->atomic.akind;
2232                         switch (expression->kind) {
2233                                 case EXPR_STRING_LITERAL:
2234                                         if (akind == ATOMIC_TYPE_CHAR
2235                                                         || akind == ATOMIC_TYPE_SCHAR
2236                                                         || akind == ATOMIC_TYPE_UCHAR) {
2237                                                 return initializer_from_string(array_type,
2238                                                         &expression->string.value);
2239                                         }
2240                                         break;
2241
2242                                 case EXPR_WIDE_STRING_LITERAL: {
2243                                         type_t *bare_wchar_type = skip_typeref(type_wchar_t);
2244                                         if (get_unqualified_type(element_type) == bare_wchar_type) {
2245                                                 return initializer_from_wide_string(array_type,
2246                                                         &expression->wide_string.value);
2247                                         }
2248                                         break;
2249                                 }
2250
2251                                 default:
2252                                         break;
2253                         }
2254                 }
2255         }
2256
2257         assign_error_t error = semantic_assign(type, expression);
2258         if (error == ASSIGN_ERROR_INCOMPATIBLE)
2259                 return NULL;
2260         report_assign_error(error, type, expression, "initializer",
2261                             &expression->base.source_position);
2262
2263         initializer_t *const result = allocate_initializer_zero(INITIALIZER_VALUE);
2264 #if 0
2265         if (type->kind == TYPE_BITFIELD) {
2266                 type = type->bitfield.base_type;
2267         }
2268 #endif
2269         result->value.value = create_implicit_cast(expression, type);
2270
2271         return result;
2272 }
2273
2274 /**
2275  * Checks if a given expression can be used as an constant initializer.
2276  */
2277 static bool is_initializer_constant(const expression_t *expression)
2278 {
2279         return is_constant_expression(expression)
2280                 || is_address_constant(expression);
2281 }
2282
2283 /**
2284  * Parses an scalar initializer.
2285  *
2286  * §6.7.8.11; eat {} without warning
2287  */
2288 static initializer_t *parse_scalar_initializer(type_t *type,
2289                                                bool must_be_constant)
2290 {
2291         /* there might be extra {} hierarchies */
2292         int braces = 0;
2293         if (token.type == '{') {
2294                 if (warning.other)
2295                         warningf(HERE, "extra curly braces around scalar initializer");
2296                 do {
2297                         ++braces;
2298                         next_token();
2299                 } while (token.type == '{');
2300         }
2301
2302         expression_t *expression = parse_assignment_expression();
2303         mark_vars_read(expression, NULL);
2304         if (must_be_constant && !is_initializer_constant(expression)) {
2305                 errorf(&expression->base.source_position,
2306                        "Initialisation expression '%E' is not constant",
2307                        expression);
2308         }
2309
2310         initializer_t *initializer = initializer_from_expression(type, expression);
2311
2312         if (initializer == NULL) {
2313                 errorf(&expression->base.source_position,
2314                        "expression '%E' (type '%T') doesn't match expected type '%T'",
2315                        expression, expression->base.type, type);
2316                 /* TODO */
2317                 return NULL;
2318         }
2319
2320         bool additional_warning_displayed = false;
2321         while (braces > 0) {
2322                 if (token.type == ',') {
2323                         next_token();
2324                 }
2325                 if (token.type != '}') {
2326                         if (!additional_warning_displayed && warning.other) {
2327                                 warningf(HERE, "additional elements in scalar initializer");
2328                                 additional_warning_displayed = true;
2329                         }
2330                 }
2331                 eat_block();
2332                 braces--;
2333         }
2334
2335         return initializer;
2336 }
2337
2338 /**
2339  * An entry in the type path.
2340  */
2341 typedef struct type_path_entry_t type_path_entry_t;
2342 struct type_path_entry_t {
2343         type_t *type;       /**< the upper top type. restored to path->top_tye if this entry is popped. */
2344         union {
2345                 size_t         index;          /**< For array types: the current index. */
2346                 declaration_t *compound_entry; /**< For compound types: the current declaration. */
2347         } v;
2348 };
2349
2350 /**
2351  * A type path expression a position inside compound or array types.
2352  */
2353 typedef struct type_path_t type_path_t;
2354 struct type_path_t {
2355         type_path_entry_t *path;         /**< An flexible array containing the current path. */
2356         type_t            *top_type;     /**< type of the element the path points */
2357         size_t             max_index;    /**< largest index in outermost array */
2358 };
2359
2360 /**
2361  * Prints a type path for debugging.
2362  */
2363 static __attribute__((unused)) void debug_print_type_path(
2364                 const type_path_t *path)
2365 {
2366         size_t len = ARR_LEN(path->path);
2367
2368         for (size_t i = 0; i < len; ++i) {
2369                 const type_path_entry_t *entry = & path->path[i];
2370
2371                 type_t *type = skip_typeref(entry->type);
2372                 if (is_type_compound(type)) {
2373                         /* in gcc mode structs can have no members */
2374                         if (entry->v.compound_entry == NULL) {
2375                                 assert(i == len-1);
2376                                 continue;
2377                         }
2378                         fprintf(stderr, ".%s",
2379                                 entry->v.compound_entry->base.symbol->string);
2380                 } else if (is_type_array(type)) {
2381                         fprintf(stderr, "[%u]", (unsigned) entry->v.index);
2382                 } else {
2383                         fprintf(stderr, "-INVALID-");
2384                 }
2385         }
2386         if (path->top_type != NULL) {
2387                 fprintf(stderr, "  (");
2388                 print_type(path->top_type);
2389                 fprintf(stderr, ")");
2390         }
2391 }
2392
2393 /**
2394  * Return the top type path entry, ie. in a path
2395  * (type).a.b returns the b.
2396  */
2397 static type_path_entry_t *get_type_path_top(const type_path_t *path)
2398 {
2399         size_t len = ARR_LEN(path->path);
2400         assert(len > 0);
2401         return &path->path[len-1];
2402 }
2403
2404 /**
2405  * Enlarge the type path by an (empty) element.
2406  */
2407 static type_path_entry_t *append_to_type_path(type_path_t *path)
2408 {
2409         size_t len = ARR_LEN(path->path);
2410         ARR_RESIZE(type_path_entry_t, path->path, len+1);
2411
2412         type_path_entry_t *result = & path->path[len];
2413         memset(result, 0, sizeof(result[0]));
2414         return result;
2415 }
2416
2417 /**
2418  * Descending into a sub-type. Enter the scope of the current top_type.
2419  */
2420 static void descend_into_subtype(type_path_t *path)
2421 {
2422         type_t *orig_top_type = path->top_type;
2423         type_t *top_type      = skip_typeref(orig_top_type);
2424
2425         type_path_entry_t *top = append_to_type_path(path);
2426         top->type              = top_type;
2427
2428         if (is_type_compound(top_type)) {
2429                 compound_t *compound  = top_type->compound.compound;
2430                 entity_t   *entry     = compound->members.entities;
2431
2432                 if (entry != NULL) {
2433                         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
2434                         top->v.compound_entry = &entry->declaration;
2435                         path->top_type = entry->declaration.type;
2436                 } else {
2437                         path->top_type = NULL;
2438                 }
2439         } else if (is_type_array(top_type)) {
2440                 top->v.index   = 0;
2441                 path->top_type = top_type->array.element_type;
2442         } else {
2443                 assert(!is_type_valid(top_type));
2444         }
2445 }
2446
2447 /**
2448  * Pop an entry from the given type path, ie. returning from
2449  * (type).a.b to (type).a
2450  */
2451 static void ascend_from_subtype(type_path_t *path)
2452 {
2453         type_path_entry_t *top = get_type_path_top(path);
2454
2455         path->top_type = top->type;
2456
2457         size_t len = ARR_LEN(path->path);
2458         ARR_RESIZE(type_path_entry_t, path->path, len-1);
2459 }
2460
2461 /**
2462  * Pop entries from the given type path until the given
2463  * path level is reached.
2464  */
2465 static void ascend_to(type_path_t *path, size_t top_path_level)
2466 {
2467         size_t len = ARR_LEN(path->path);
2468
2469         while (len > top_path_level) {
2470                 ascend_from_subtype(path);
2471                 len = ARR_LEN(path->path);
2472         }
2473 }
2474
2475 static bool walk_designator(type_path_t *path, const designator_t *designator,
2476                             bool used_in_offsetof)
2477 {
2478         for (; designator != NULL; designator = designator->next) {
2479                 type_path_entry_t *top       = get_type_path_top(path);
2480                 type_t            *orig_type = top->type;
2481
2482                 type_t *type = skip_typeref(orig_type);
2483
2484                 if (designator->symbol != NULL) {
2485                         symbol_t *symbol = designator->symbol;
2486                         if (!is_type_compound(type)) {
2487                                 if (is_type_valid(type)) {
2488                                         errorf(&designator->source_position,
2489                                                "'.%Y' designator used for non-compound type '%T'",
2490                                                symbol, orig_type);
2491                                 }
2492
2493                                 top->type             = type_error_type;
2494                                 top->v.compound_entry = NULL;
2495                                 orig_type             = type_error_type;
2496                         } else {
2497                                 compound_t *compound = type->compound.compound;
2498                                 entity_t   *iter     = compound->members.entities;
2499                                 for (; iter != NULL; iter = iter->base.next) {
2500                                         if (iter->base.symbol == symbol) {
2501                                                 break;
2502                                         }
2503                                 }
2504                                 if (iter == NULL) {
2505                                         errorf(&designator->source_position,
2506                                                "'%T' has no member named '%Y'", orig_type, symbol);
2507                                         goto failed;
2508                                 }
2509                                 assert(iter->kind == ENTITY_COMPOUND_MEMBER);
2510                                 if (used_in_offsetof) {
2511                                         type_t *real_type = skip_typeref(iter->declaration.type);
2512                                         if (real_type->kind == TYPE_BITFIELD) {
2513                                                 errorf(&designator->source_position,
2514                                                        "offsetof designator '%Y' may not specify bitfield",
2515                                                        symbol);
2516                                                 goto failed;
2517                                         }
2518                                 }
2519
2520                                 top->type             = orig_type;
2521                                 top->v.compound_entry = &iter->declaration;
2522                                 orig_type             = iter->declaration.type;
2523                         }
2524                 } else {
2525                         expression_t *array_index = designator->array_index;
2526                         assert(designator->array_index != NULL);
2527
2528                         if (!is_type_array(type)) {
2529                                 if (is_type_valid(type)) {
2530                                         errorf(&designator->source_position,
2531                                                "[%E] designator used for non-array type '%T'",
2532                                                array_index, orig_type);
2533                                 }
2534                                 goto failed;
2535                         }
2536
2537                         long index = fold_constant(array_index);
2538                         if (!used_in_offsetof) {
2539                                 if (index < 0) {
2540                                         errorf(&designator->source_position,
2541                                                "array index [%E] must be positive", array_index);
2542                                 } else if (type->array.size_constant) {
2543                                         long array_size = type->array.size;
2544                                         if (index >= array_size) {
2545                                                 errorf(&designator->source_position,
2546                                                        "designator [%E] (%d) exceeds array size %d",
2547                                                        array_index, index, array_size);
2548                                         }
2549                                 }
2550                         }
2551
2552                         top->type    = orig_type;
2553                         top->v.index = (size_t) index;
2554                         orig_type    = type->array.element_type;
2555                 }
2556                 path->top_type = orig_type;
2557
2558                 if (designator->next != NULL) {
2559                         descend_into_subtype(path);
2560                 }
2561         }
2562         return true;
2563
2564 failed:
2565         return false;
2566 }
2567
2568 static void advance_current_object(type_path_t *path, size_t top_path_level)
2569 {
2570         type_path_entry_t *top = get_type_path_top(path);
2571
2572         type_t *type = skip_typeref(top->type);
2573         if (is_type_union(type)) {
2574                 /* in unions only the first element is initialized */
2575                 top->v.compound_entry = NULL;
2576         } else if (is_type_struct(type)) {
2577                 declaration_t *entry = top->v.compound_entry;
2578
2579                 entity_t *next_entity = entry->base.next;
2580                 if (next_entity != NULL) {
2581                         assert(is_declaration(next_entity));
2582                         entry = &next_entity->declaration;
2583                 } else {
2584                         entry = NULL;
2585                 }
2586
2587                 top->v.compound_entry = entry;
2588                 if (entry != NULL) {
2589                         path->top_type = entry->type;
2590                         return;
2591                 }
2592         } else if (is_type_array(type)) {
2593                 assert(is_type_array(type));
2594
2595                 top->v.index++;
2596
2597                 if (!type->array.size_constant || top->v.index < type->array.size) {
2598                         return;
2599                 }
2600         } else {
2601                 assert(!is_type_valid(type));
2602                 return;
2603         }
2604
2605         /* we're past the last member of the current sub-aggregate, try if we
2606          * can ascend in the type hierarchy and continue with another subobject */
2607         size_t len = ARR_LEN(path->path);
2608
2609         if (len > top_path_level) {
2610                 ascend_from_subtype(path);
2611                 advance_current_object(path, top_path_level);
2612         } else {
2613                 path->top_type = NULL;
2614         }
2615 }
2616
2617 /**
2618  * skip until token is found.
2619  */
2620 static void skip_until(int type)
2621 {
2622         while (token.type != type) {
2623                 if (token.type == T_EOF)
2624                         return;
2625                 next_token();
2626         }
2627 }
2628
2629 /**
2630  * skip any {...} blocks until a closing bracket is reached.
2631  */
2632 static void skip_initializers(void)
2633 {
2634         if (token.type == '{')
2635                 next_token();
2636
2637         while (token.type != '}') {
2638                 if (token.type == T_EOF)
2639                         return;
2640                 if (token.type == '{') {
2641                         eat_block();
2642                         continue;
2643                 }
2644                 next_token();
2645         }
2646 }
2647
2648 static initializer_t *create_empty_initializer(void)
2649 {
2650         static initializer_t empty_initializer
2651                 = { .list = { { INITIALIZER_LIST }, 0 } };
2652         return &empty_initializer;
2653 }
2654
2655 /**
2656  * Parse a part of an initialiser for a struct or union,
2657  */
2658 static initializer_t *parse_sub_initializer(type_path_t *path,
2659                 type_t *outer_type, size_t top_path_level,
2660                 parse_initializer_env_t *env)
2661 {
2662         if (token.type == '}') {
2663                 /* empty initializer */
2664                 return create_empty_initializer();
2665         }
2666
2667         type_t *orig_type = path->top_type;
2668         type_t *type      = NULL;
2669
2670         if (orig_type == NULL) {
2671                 /* We are initializing an empty compound. */
2672         } else {
2673                 type = skip_typeref(orig_type);
2674         }
2675
2676         initializer_t **initializers = NEW_ARR_F(initializer_t*, 0);
2677
2678         while (true) {
2679                 designator_t *designator = NULL;
2680                 if (token.type == '.' || token.type == '[') {
2681                         designator = parse_designation();
2682                         goto finish_designator;
2683                 } else if (token.type == T_IDENTIFIER && look_ahead(1)->type == ':') {
2684                         /* GNU-style designator ("identifier: value") */
2685                         designator = allocate_ast_zero(sizeof(designator[0]));
2686                         designator->source_position = token.source_position;
2687                         designator->symbol          = token.v.symbol;
2688                         eat(T_IDENTIFIER);
2689                         eat(':');
2690
2691 finish_designator:
2692                         /* reset path to toplevel, evaluate designator from there */
2693                         ascend_to(path, top_path_level);
2694                         if (!walk_designator(path, designator, false)) {
2695                                 /* can't continue after designation error */
2696                                 goto end_error;
2697                         }
2698
2699                         initializer_t *designator_initializer
2700                                 = allocate_initializer_zero(INITIALIZER_DESIGNATOR);
2701                         designator_initializer->designator.designator = designator;
2702                         ARR_APP1(initializer_t*, initializers, designator_initializer);
2703
2704                         orig_type = path->top_type;
2705                         type      = orig_type != NULL ? skip_typeref(orig_type) : NULL;
2706                 }
2707
2708                 initializer_t *sub;
2709
2710                 if (token.type == '{') {
2711                         if (type != NULL && is_type_scalar(type)) {
2712                                 sub = parse_scalar_initializer(type, env->must_be_constant);
2713                         } else {
2714                                 eat('{');
2715                                 if (type == NULL) {
2716                                         if (env->entity != NULL) {
2717                                                 errorf(HERE,
2718                                                      "extra brace group at end of initializer for '%Y'",
2719                                                      env->entity->base.symbol);
2720                                         } else {
2721                                                 errorf(HERE, "extra brace group at end of initializer");
2722                                         }
2723                                 } else
2724                                         descend_into_subtype(path);
2725
2726                                 add_anchor_token('}');
2727                                 sub = parse_sub_initializer(path, orig_type, top_path_level+1,
2728                                                             env);
2729                                 rem_anchor_token('}');
2730
2731                                 if (type != NULL) {
2732                                         ascend_from_subtype(path);
2733                                         expect('}', end_error);
2734                                 } else {
2735                                         expect('}', end_error);
2736                                         goto error_parse_next;
2737                                 }
2738                         }
2739                 } else {
2740                         /* must be an expression */
2741                         expression_t *expression = parse_assignment_expression();
2742                         mark_vars_read(expression, NULL);
2743
2744                         if (env->must_be_constant && !is_initializer_constant(expression)) {
2745                                 errorf(&expression->base.source_position,
2746                                        "Initialisation expression '%E' is not constant",
2747                                        expression);
2748                         }
2749
2750                         if (type == NULL) {
2751                                 /* we are already outside, ... */
2752                                 type_t *const outer_type_skip = skip_typeref(outer_type);
2753                                 if (is_type_compound(outer_type_skip) &&
2754                                     !outer_type_skip->compound.compound->complete) {
2755                                         goto error_parse_next;
2756                                 }
2757                                 goto error_excess;
2758                         }
2759
2760                         /* handle { "string" } special case */
2761                         if ((expression->kind == EXPR_STRING_LITERAL
2762                                         || expression->kind == EXPR_WIDE_STRING_LITERAL)
2763                                         && outer_type != NULL) {
2764                                 sub = initializer_from_expression(outer_type, expression);
2765                                 if (sub != NULL) {
2766                                         if (token.type == ',') {
2767                                                 next_token();
2768                                         }
2769                                         if (token.type != '}' && warning.other) {
2770                                                 warningf(HERE, "excessive elements in initializer for type '%T'",
2771                                                                  orig_type);
2772                                         }
2773                                         /* TODO: eat , ... */
2774                                         return sub;
2775                                 }
2776                         }
2777
2778                         /* descend into subtypes until expression matches type */
2779                         while (true) {
2780                                 orig_type = path->top_type;
2781                                 type      = skip_typeref(orig_type);
2782
2783                                 sub = initializer_from_expression(orig_type, expression);
2784                                 if (sub != NULL) {
2785                                         break;
2786                                 }
2787                                 if (!is_type_valid(type)) {
2788                                         goto end_error;
2789                                 }
2790                                 if (is_type_scalar(type)) {
2791                                         errorf(&expression->base.source_position,
2792                                                         "expression '%E' doesn't match expected type '%T'",
2793                                                         expression, orig_type);
2794                                         goto end_error;
2795                                 }
2796
2797                                 descend_into_subtype(path);
2798                         }
2799                 }
2800
2801                 /* update largest index of top array */
2802                 const type_path_entry_t *first      = &path->path[0];
2803                 type_t                  *first_type = first->type;
2804                 first_type                          = skip_typeref(first_type);
2805                 if (is_type_array(first_type)) {
2806                         size_t index = first->v.index;
2807                         if (index > path->max_index)
2808                                 path->max_index = index;
2809                 }
2810
2811                 if (type != NULL) {
2812                         /* append to initializers list */
2813                         ARR_APP1(initializer_t*, initializers, sub);
2814                 } else {
2815 error_excess:
2816                         if (warning.other) {
2817                                 if (env->entity != NULL) {
2818                                         warningf(HERE, "excess elements in struct initializer for '%Y'",
2819                                            env->entity->base.symbol);
2820                                 } else {
2821                                         warningf(HERE, "excess elements in struct initializer");
2822                                 }
2823                         }
2824                 }
2825
2826 error_parse_next:
2827                 if (token.type == '}') {
2828                         break;
2829                 }
2830                 expect(',', end_error);
2831                 if (token.type == '}') {
2832                         break;
2833                 }
2834
2835                 if (type != NULL) {
2836                         /* advance to the next declaration if we are not at the end */
2837                         advance_current_object(path, top_path_level);
2838                         orig_type = path->top_type;
2839                         if (orig_type != NULL)
2840                                 type = skip_typeref(orig_type);
2841                         else
2842                                 type = NULL;
2843                 }
2844         }
2845
2846         size_t len  = ARR_LEN(initializers);
2847         size_t size = sizeof(initializer_list_t) + len * sizeof(initializers[0]);
2848         initializer_t *result = allocate_ast_zero(size);
2849         result->kind          = INITIALIZER_LIST;
2850         result->list.len      = len;
2851         memcpy(&result->list.initializers, initializers,
2852                len * sizeof(initializers[0]));
2853
2854         DEL_ARR_F(initializers);
2855         ascend_to(path, top_path_level+1);
2856
2857         return result;
2858
2859 end_error:
2860         skip_initializers();
2861         DEL_ARR_F(initializers);
2862         ascend_to(path, top_path_level+1);
2863         return NULL;
2864 }
2865
2866 /**
2867  * Parses an initializer. Parsers either a compound literal
2868  * (env->declaration == NULL) or an initializer of a declaration.
2869  */
2870 static initializer_t *parse_initializer(parse_initializer_env_t *env)
2871 {
2872         type_t        *type      = skip_typeref(env->type);
2873         size_t         max_index = 0xdeadbeaf;   // TODO: Resolve this uninitialized variable problem
2874         initializer_t *result;
2875
2876         if (is_type_scalar(type)) {
2877                 result = parse_scalar_initializer(type, env->must_be_constant);
2878         } else if (token.type == '{') {
2879                 eat('{');
2880
2881                 type_path_t path;
2882                 memset(&path, 0, sizeof(path));
2883                 path.top_type = env->type;
2884                 path.path     = NEW_ARR_F(type_path_entry_t, 0);
2885
2886                 descend_into_subtype(&path);
2887
2888                 add_anchor_token('}');
2889                 result = parse_sub_initializer(&path, env->type, 1, env);
2890                 rem_anchor_token('}');
2891
2892                 max_index = path.max_index;
2893                 DEL_ARR_F(path.path);
2894
2895                 expect('}', end_error);
2896         } else {
2897                 /* parse_scalar_initializer() also works in this case: we simply
2898                  * have an expression without {} around it */
2899                 result = parse_scalar_initializer(type, env->must_be_constant);
2900         }
2901
2902         /* §6.7.8:22 array initializers for arrays with unknown size determine
2903          * the array type size */
2904         if (is_type_array(type) && type->array.size_expression == NULL
2905                         && result != NULL) {
2906                 size_t size;
2907                 switch (result->kind) {
2908                 case INITIALIZER_LIST:
2909                         assert(max_index != 0xdeadbeaf);
2910                         size = max_index + 1;
2911                         break;
2912
2913                 case INITIALIZER_STRING:
2914                         size = result->string.string.size;
2915                         break;
2916
2917                 case INITIALIZER_WIDE_STRING:
2918                         size = result->wide_string.string.size;
2919                         break;
2920
2921                 case INITIALIZER_DESIGNATOR:
2922                 case INITIALIZER_VALUE:
2923                         /* can happen for parse errors */
2924                         size = 0;
2925                         break;
2926
2927                 default:
2928                         internal_errorf(HERE, "invalid initializer type");
2929                 }
2930
2931                 expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
2932                 cnst->base.type          = type_size_t;
2933                 cnst->conste.v.int_value = size;
2934
2935                 type_t *new_type = duplicate_type(type);
2936
2937                 new_type->array.size_expression   = cnst;
2938                 new_type->array.size_constant     = true;
2939                 new_type->array.has_implicit_size = true;
2940                 new_type->array.size              = size;
2941                 env->type = new_type;
2942         }
2943
2944         return result;
2945 end_error:
2946         return NULL;
2947 }
2948
2949 static void append_entity(scope_t *scope, entity_t *entity)
2950 {
2951         if (scope->last_entity != NULL) {
2952                 scope->last_entity->base.next = entity;
2953         } else {
2954                 scope->entities = entity;
2955         }
2956         scope->last_entity = entity;
2957 }
2958
2959
2960 static compound_t *parse_compound_type_specifier(bool is_struct)
2961 {
2962         gnu_attribute_t  *attributes = NULL;
2963         decl_modifiers_t  modifiers  = 0;
2964         if (is_struct) {
2965                 eat(T_struct);
2966         } else {
2967                 eat(T_union);
2968         }
2969
2970         symbol_t   *symbol   = NULL;
2971         compound_t *compound = NULL;
2972
2973         if (token.type == T___attribute__) {
2974                 modifiers |= parse_attributes(&attributes);
2975         }
2976
2977         if (token.type == T_IDENTIFIER) {
2978                 symbol = token.v.symbol;
2979                 next_token();
2980
2981                 namespace_tag_t const namespc =
2982                         is_struct ? NAMESPACE_STRUCT : NAMESPACE_UNION;
2983                 entity_t *entity = get_entity(symbol, namespc);
2984                 if (entity != NULL) {
2985                         assert(entity->kind == (is_struct ? ENTITY_STRUCT : ENTITY_UNION));
2986                         compound = &entity->compound;
2987                         if (compound->base.parent_scope != current_scope &&
2988                             (token.type == '{' || token.type == ';')) {
2989                                 /* we're in an inner scope and have a definition. Shadow
2990                                  * existing definition in outer scope */
2991                                 compound = NULL;
2992                         } else if (compound->complete && token.type == '{') {
2993                                 assert(symbol != NULL);
2994                                 errorf(HERE, "multiple definitions of '%s %Y' (previous definition %P)",
2995                                        is_struct ? "struct" : "union", symbol,
2996                                        &compound->base.source_position);
2997                                 /* clear members in the hope to avoid further errors */
2998                                 compound->members.entities = NULL;
2999                         }
3000                 }
3001         } else if (token.type != '{') {
3002                 if (is_struct) {
3003                         parse_error_expected("while parsing struct type specifier",
3004                                              T_IDENTIFIER, '{', NULL);
3005                 } else {
3006                         parse_error_expected("while parsing union type specifier",
3007                                              T_IDENTIFIER, '{', NULL);
3008                 }
3009
3010                 return NULL;
3011         }
3012
3013         if (compound == NULL) {
3014                 entity_kind_t  kind   = is_struct ? ENTITY_STRUCT : ENTITY_UNION;
3015                 entity_t      *entity = allocate_entity_zero(kind);
3016                 compound              = &entity->compound;
3017
3018                 compound->base.namespc =
3019                         (is_struct ? NAMESPACE_STRUCT : NAMESPACE_UNION);
3020                 compound->base.source_position = token.source_position;
3021                 compound->base.symbol          = symbol;
3022                 compound->base.parent_scope    = current_scope;
3023                 if (symbol != NULL) {
3024                         environment_push(entity);
3025                 }
3026                 append_entity(current_scope, entity);
3027         }
3028
3029         if (token.type == '{') {
3030                 parse_compound_type_entries(compound);
3031                 modifiers |= parse_attributes(&attributes);
3032
3033                 if (symbol == NULL) {
3034                         assert(anonymous_entity == NULL);
3035                         anonymous_entity = (entity_t*)compound;
3036                 }
3037         }
3038
3039         compound->modifiers |= modifiers;
3040         return compound;
3041 }
3042
3043 static void parse_enum_entries(type_t *const enum_type)
3044 {
3045         eat('{');
3046
3047         if (token.type == '}') {
3048                 errorf(HERE, "empty enum not allowed");
3049                 next_token();
3050                 return;
3051         }
3052
3053         add_anchor_token('}');
3054         do {
3055                 if (token.type != T_IDENTIFIER) {
3056                         parse_error_expected("while parsing enum entry", T_IDENTIFIER, NULL);
3057                         eat_block();
3058                         rem_anchor_token('}');
3059                         return;
3060                 }
3061
3062                 entity_t *entity             = allocate_entity_zero(ENTITY_ENUM_VALUE);
3063                 entity->enum_value.enum_type = enum_type;
3064                 entity->base.symbol          = token.v.symbol;
3065                 entity->base.source_position = token.source_position;
3066                 next_token();
3067
3068                 if (token.type == '=') {
3069                         next_token();
3070                         expression_t *value = parse_constant_expression();
3071
3072                         value = create_implicit_cast(value, enum_type);
3073                         entity->enum_value.value = value;
3074
3075                         /* TODO semantic */
3076                 }
3077
3078                 record_entity(entity, false);
3079
3080                 if (token.type != ',')
3081                         break;
3082                 next_token();
3083         } while (token.type != '}');
3084         rem_anchor_token('}');
3085
3086         expect('}', end_error);
3087
3088 end_error:
3089         ;
3090 }
3091
3092 static type_t *parse_enum_specifier(void)
3093 {
3094         gnu_attribute_t *attributes = NULL;
3095         entity_t        *entity;
3096         symbol_t        *symbol;
3097
3098         eat(T_enum);
3099         if (token.type == T_IDENTIFIER) {
3100                 symbol = token.v.symbol;
3101                 next_token();
3102
3103                 entity = get_entity(symbol, NAMESPACE_ENUM);
3104                 if (entity != NULL) {
3105                         assert(entity->kind == ENTITY_ENUM);
3106                         if (entity->base.parent_scope != current_scope &&
3107                                         (token.type == '{' || token.type == ';')) {
3108                                 /* we're in an inner scope and have a definition. Shadow
3109                                  * existing definition in outer scope */
3110                                 entity = NULL;
3111                         } else if (entity->enume.complete && token.type == '{') {
3112                                 errorf(HERE, "multiple definitions of 'enum %Y' (previous definition %P)",
3113                                                 symbol, &entity->base.source_position);
3114                         }
3115                 }
3116         } else if (token.type != '{') {
3117                 parse_error_expected("while parsing enum type specifier",
3118                                      T_IDENTIFIER, '{', NULL);
3119                 return NULL;
3120         } else {
3121                 entity  = NULL;
3122                 symbol  = NULL;
3123         }
3124
3125         if (entity == NULL) {
3126                 entity                       = allocate_entity_zero(ENTITY_ENUM);
3127                 entity->base.namespc         = NAMESPACE_ENUM;
3128                 entity->base.source_position = token.source_position;
3129                 entity->base.symbol          = symbol;
3130                 entity->base.parent_scope    = current_scope;
3131         }
3132
3133         type_t *const type = allocate_type_zero(TYPE_ENUM);
3134         type->enumt.enume  = &entity->enume;
3135         type->enumt.akind  = ATOMIC_TYPE_INT;
3136
3137         if (token.type == '{') {
3138                 if (symbol != NULL) {
3139                         environment_push(entity);
3140                 }
3141                 append_entity(current_scope, entity);
3142                 entity->enume.complete = true;
3143
3144                 parse_enum_entries(type);
3145                 parse_attributes(&attributes);
3146
3147                 if (symbol == NULL) {
3148                         assert(anonymous_entity == NULL);
3149                         anonymous_entity = entity;
3150                 }
3151         } else if (!entity->enume.complete && !(c_mode & _GNUC)) {
3152                 errorf(HERE, "'enum %Y' used before definition (incomplete enums are a GNU extension)",
3153                        symbol);
3154         }
3155
3156         return type;
3157 }
3158
3159 /**
3160  * if a symbol is a typedef to another type, return true
3161  */
3162 static bool is_typedef_symbol(symbol_t *symbol)
3163 {
3164         const entity_t *const entity = get_entity(symbol, NAMESPACE_NORMAL);
3165         return entity != NULL && entity->kind == ENTITY_TYPEDEF;
3166 }
3167
3168 static type_t *parse_typeof(void)
3169 {
3170         eat(T___typeof__);
3171
3172         type_t *type;
3173
3174         expect('(', end_error);
3175         add_anchor_token(')');
3176
3177         expression_t *expression  = NULL;
3178
3179         bool old_type_prop     = in_type_prop;
3180         bool old_gcc_extension = in_gcc_extension;
3181         in_type_prop           = true;
3182
3183         while (token.type == T___extension__) {
3184                 /* This can be a prefix to a typename or an expression. */
3185                 next_token();
3186                 in_gcc_extension = true;
3187         }
3188         switch (token.type) {
3189         case T_IDENTIFIER:
3190                 if (is_typedef_symbol(token.v.symbol)) {
3191                         type = parse_typename();
3192                 } else {
3193                         expression = parse_expression();
3194                         type       = revert_automatic_type_conversion(expression);
3195                 }
3196                 break;
3197
3198         TYPENAME_START
3199                 type = parse_typename();
3200                 break;
3201
3202         default:
3203                 expression = parse_expression();
3204                 type       = expression->base.type;
3205                 break;
3206         }
3207         in_type_prop     = old_type_prop;
3208         in_gcc_extension = old_gcc_extension;
3209
3210         rem_anchor_token(')');
3211         expect(')', end_error);
3212
3213         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF);
3214         typeof_type->typeoft.expression  = expression;
3215         typeof_type->typeoft.typeof_type = type;
3216
3217         return typeof_type;
3218 end_error:
3219         return NULL;
3220 }
3221
3222 typedef enum specifiers_t {
3223         SPECIFIER_SIGNED    = 1 << 0,
3224         SPECIFIER_UNSIGNED  = 1 << 1,
3225         SPECIFIER_LONG      = 1 << 2,
3226         SPECIFIER_INT       = 1 << 3,
3227         SPECIFIER_DOUBLE    = 1 << 4,
3228         SPECIFIER_CHAR      = 1 << 5,
3229         SPECIFIER_WCHAR_T   = 1 << 6,
3230         SPECIFIER_SHORT     = 1 << 7,
3231         SPECIFIER_LONG_LONG = 1 << 8,
3232         SPECIFIER_FLOAT     = 1 << 9,
3233         SPECIFIER_BOOL      = 1 << 10,
3234         SPECIFIER_VOID      = 1 << 11,
3235         SPECIFIER_INT8      = 1 << 12,
3236         SPECIFIER_INT16     = 1 << 13,
3237         SPECIFIER_INT32     = 1 << 14,
3238         SPECIFIER_INT64     = 1 << 15,
3239         SPECIFIER_INT128    = 1 << 16,
3240         SPECIFIER_COMPLEX   = 1 << 17,
3241         SPECIFIER_IMAGINARY = 1 << 18,
3242 } specifiers_t;
3243
3244 static type_t *create_builtin_type(symbol_t *const symbol,
3245                                    type_t *const real_type)
3246 {
3247         type_t *type            = allocate_type_zero(TYPE_BUILTIN);
3248         type->builtin.symbol    = symbol;
3249         type->builtin.real_type = real_type;
3250         return identify_new_type(type);
3251 }
3252
3253 static type_t *get_typedef_type(symbol_t *symbol)
3254 {
3255         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
3256         if (entity == NULL || entity->kind != ENTITY_TYPEDEF)
3257                 return NULL;
3258
3259         type_t *type            = allocate_type_zero(TYPE_TYPEDEF);
3260         type->typedeft.typedefe = &entity->typedefe;
3261
3262         return type;
3263 }
3264
3265 /**
3266  * check for the allowed MS alignment values.
3267  */
3268 static bool check_alignment_value(long long intvalue)
3269 {
3270         if (intvalue < 1 || intvalue > 8192) {
3271                 errorf(HERE, "illegal alignment value");
3272                 return false;
3273         }
3274         unsigned v = (unsigned)intvalue;
3275         for (unsigned i = 1; i <= 8192; i += i) {
3276                 if (i == v)
3277                         return true;
3278         }
3279         errorf(HERE, "alignment must be power of two");
3280         return false;
3281 }
3282
3283 #define DET_MOD(name, tag) do { \
3284         if (*modifiers & tag && warning.other) warningf(HERE, #name " used more than once"); \
3285         *modifiers |= tag; \
3286 } while (0)
3287
3288 static void parse_microsoft_extended_decl_modifier(declaration_specifiers_t *specifiers)
3289 {
3290         decl_modifiers_t *modifiers = &specifiers->modifiers;
3291
3292         while (true) {
3293                 if (token.type == T_restrict) {
3294                         next_token();
3295                         DET_MOD(restrict, DM_RESTRICT);
3296                         goto end_loop;
3297                 } else if (token.type != T_IDENTIFIER)
3298                         break;
3299                 symbol_t *symbol = token.v.symbol;
3300                 if (symbol == sym_align) {
3301                         next_token();
3302                         expect('(', end_error);
3303                         if (token.type != T_INTEGER)
3304                                 goto end_error;
3305                         if (check_alignment_value(token.v.intvalue)) {
3306                                 if (specifiers->alignment != 0 && warning.other)
3307                                         warningf(HERE, "align used more than once");
3308                                 specifiers->alignment = (unsigned char)token.v.intvalue;
3309                         }
3310                         next_token();
3311                         expect(')', end_error);
3312                 } else if (symbol == sym_allocate) {
3313                         next_token();
3314                         expect('(', end_error);
3315                         if (token.type != T_IDENTIFIER)
3316                                 goto end_error;
3317                         (void)token.v.symbol;
3318                         expect(')', end_error);
3319                 } else if (symbol == sym_dllimport) {
3320                         next_token();
3321                         DET_MOD(dllimport, DM_DLLIMPORT);
3322                 } else if (symbol == sym_dllexport) {
3323                         next_token();
3324                         DET_MOD(dllexport, DM_DLLEXPORT);
3325                 } else if (symbol == sym_thread) {
3326                         next_token();
3327                         DET_MOD(thread, DM_THREAD);
3328                 } else if (symbol == sym_naked) {
3329                         next_token();
3330                         DET_MOD(naked, DM_NAKED);
3331                 } else if (symbol == sym_noinline) {
3332                         next_token();
3333                         DET_MOD(noinline, DM_NOINLINE);
3334                 } else if (symbol == sym_returns_twice) {
3335                         next_token();
3336                         DET_MOD(returns_twice, DM_RETURNS_TWICE);
3337                 } else if (symbol == sym_noreturn) {
3338                         next_token();
3339                         DET_MOD(noreturn, DM_NORETURN);
3340                 } else if (symbol == sym_nothrow) {
3341                         next_token();
3342                         DET_MOD(nothrow, DM_NOTHROW);
3343                 } else if (symbol == sym_novtable) {
3344                         next_token();
3345                         DET_MOD(novtable, DM_NOVTABLE);
3346                 } else if (symbol == sym_property) {
3347                         next_token();
3348                         expect('(', end_error);
3349                         for (;;) {
3350                                 bool is_get = false;
3351                                 if (token.type != T_IDENTIFIER)
3352                                         goto end_error;
3353                                 if (token.v.symbol == sym_get) {
3354                                         is_get = true;
3355                                 } else if (token.v.symbol == sym_put) {
3356                                 } else {
3357                                         errorf(HERE, "Bad property name '%Y'", token.v.symbol);
3358                                         goto end_error;
3359                                 }
3360                                 next_token();
3361                                 expect('=', end_error);
3362                                 if (token.type != T_IDENTIFIER)
3363                                         goto end_error;
3364                                 if (is_get) {
3365                                         if (specifiers->get_property_sym != NULL) {
3366                                                 errorf(HERE, "get property name already specified");
3367                                         } else {
3368                                                 specifiers->get_property_sym = token.v.symbol;
3369                                         }
3370                                 } else {
3371                                         if (specifiers->put_property_sym != NULL) {
3372                                                 errorf(HERE, "put property name already specified");
3373                                         } else {
3374                                                 specifiers->put_property_sym = token.v.symbol;
3375                                         }
3376                                 }
3377                                 next_token();
3378                                 if (token.type == ',') {
3379                                         next_token();
3380                                         continue;
3381                                 }
3382                                 break;
3383                         }
3384                         expect(')', end_error);
3385                 } else if (symbol == sym_selectany) {
3386                         next_token();
3387                         DET_MOD(selectany, DM_SELECTANY);
3388                 } else if (symbol == sym_uuid) {
3389                         next_token();
3390                         expect('(', end_error);
3391                         if (token.type != T_STRING_LITERAL)
3392                                 goto end_error;
3393                         next_token();
3394                         expect(')', end_error);
3395                 } else if (symbol == sym_deprecated) {
3396                         next_token();
3397                         if (specifiers->deprecated != 0 && warning.other)
3398                                 warningf(HERE, "deprecated used more than once");
3399                         specifiers->deprecated = true;
3400                         if (token.type == '(') {
3401                                 next_token();
3402                                 if (token.type == T_STRING_LITERAL) {
3403                                         specifiers->deprecated_string = token.v.string.begin;
3404                                         next_token();
3405                                 } else {
3406                                         errorf(HERE, "string literal expected");
3407                                 }
3408                                 expect(')', end_error);
3409                         }
3410                 } else if (symbol == sym_noalias) {
3411                         next_token();
3412                         DET_MOD(noalias, DM_NOALIAS);
3413                 } else {
3414                         if (warning.other)
3415                                 warningf(HERE, "Unknown modifier '%Y' ignored", token.v.symbol);
3416                         next_token();
3417                         if (token.type == '(')
3418                                 skip_until(')');
3419                 }
3420 end_loop:
3421                 if (token.type == ',')
3422                         next_token();
3423         }
3424 end_error:
3425         return;
3426 }
3427
3428 static entity_t *create_error_entity(symbol_t *symbol, entity_kind_tag_t kind)
3429 {
3430         entity_t *entity             = allocate_entity_zero(kind);
3431         entity->base.source_position = *HERE;
3432         entity->base.symbol          = symbol;
3433         if (is_declaration(entity)) {
3434                 entity->declaration.type     = type_error_type;
3435                 entity->declaration.implicit = true;
3436         } else if (kind == ENTITY_TYPEDEF) {
3437                 entity->typedefe.type    = type_error_type;
3438                 entity->typedefe.builtin = true;
3439         }
3440         if (kind != ENTITY_COMPOUND_MEMBER)
3441                 record_entity(entity, false);
3442         return entity;
3443 }
3444
3445 static void parse_microsoft_based(based_spec_t *based_spec)
3446 {
3447         if (token.type != T_IDENTIFIER) {
3448                 parse_error_expected("while parsing __based", T_IDENTIFIER, NULL);
3449                 return;
3450         }
3451         symbol_t *symbol = token.v.symbol;
3452         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
3453
3454         if (entity == NULL || entity->base.kind != ENTITY_VARIABLE) {
3455                 errorf(HERE, "'%Y' is not a variable name.", symbol);
3456                 entity = create_error_entity(symbol, ENTITY_VARIABLE);
3457         } else {
3458                 variable_t *variable = &entity->variable;
3459
3460                 if (based_spec->base_variable != NULL) {
3461                         errorf(HERE, "__based type qualifier specified more than once");
3462                 }
3463                 based_spec->source_position = token.source_position;
3464                 based_spec->base_variable   = variable;
3465
3466                 type_t *const type = variable->base.type;
3467
3468                 if (is_type_valid(type)) {
3469                         if (! is_type_pointer(skip_typeref(type))) {
3470                                 errorf(HERE, "variable in __based modifier must have pointer type instead of '%T'", type);
3471                         }
3472                         if (variable->base.base.parent_scope != file_scope) {
3473                                 errorf(HERE, "a nonstatic local variable may not be used in a __based specification");
3474                         }
3475                 }
3476         }
3477         next_token();
3478 }
3479
3480 /**
3481  * Finish the construction of a struct type by calculating
3482  * its size, offsets, alignment.
3483  */
3484 static void finish_struct_type(compound_type_t *type)
3485 {
3486         assert(type->compound != NULL);
3487
3488         compound_t *compound = type->compound;
3489         if (!compound->complete)
3490                 return;
3491
3492         il_size_t      size           = 0;
3493         il_size_t      offset;
3494         il_alignment_t alignment      = 1;
3495         bool           need_pad       = false;
3496
3497         entity_t *entry = compound->members.entities;
3498         for (; entry != NULL; entry = entry->base.next) {
3499                 if (entry->kind != ENTITY_COMPOUND_MEMBER)
3500                         continue;
3501
3502                 type_t *m_type = skip_typeref(entry->declaration.type);
3503                 if (! is_type_valid(m_type)) {
3504                         /* simply ignore errors here */
3505                         continue;
3506                 }
3507                 il_alignment_t m_alignment = m_type->base.alignment;
3508                 if (m_alignment > alignment)
3509                         alignment = m_alignment;
3510
3511                 offset = (size + m_alignment - 1) & -m_alignment;
3512
3513                 if (offset > size)
3514                         need_pad = true;
3515                 entry->compound_member.offset = offset;
3516                 size = offset + m_type->base.size;
3517         }
3518         if (type->base.alignment != 0) {
3519                 alignment = type->base.alignment;
3520         }
3521
3522         offset = (size + alignment - 1) & -alignment;
3523         if (offset > size)
3524                 need_pad = true;
3525
3526         if (need_pad) {
3527                 if (warning.padded) {
3528                         warningf(&compound->base.source_position, "'%T' needs padding", type);
3529                 }
3530         } else {
3531                 if (compound->modifiers & DM_PACKED && warning.packed) {
3532                         warningf(&compound->base.source_position,
3533                                         "superfluous packed attribute on '%T'", type);
3534                 }
3535         }
3536
3537         type->base.size      = offset;
3538         type->base.alignment = alignment;
3539 }
3540
3541 /**
3542  * Finish the construction of an union type by calculating
3543  * its size and alignment.
3544  */
3545 static void finish_union_type(compound_type_t *type)
3546 {
3547         assert(type->compound != NULL);
3548
3549         compound_t *compound = type->compound;
3550         if (! compound->complete)
3551                 return;
3552
3553         il_size_t      size      = 0;
3554         il_alignment_t alignment = 1;
3555
3556         entity_t *entry = compound->members.entities;
3557         for (; entry != NULL; entry = entry->base.next) {
3558                 if (entry->kind != ENTITY_COMPOUND_MEMBER)
3559                         continue;
3560
3561                 type_t *m_type = skip_typeref(entry->declaration.type);
3562                 if (! is_type_valid(m_type))
3563                         continue;
3564
3565                 entry->compound_member.offset = 0;
3566                 if (m_type->base.size > size)
3567                         size = m_type->base.size;
3568                 if (m_type->base.alignment > alignment)
3569                         alignment = m_type->base.alignment;
3570         }
3571         if (type->base.alignment != 0) {
3572                 alignment = type->base.alignment;
3573         }
3574         size = (size + alignment - 1) & -alignment;
3575         type->base.size      = size;
3576         type->base.alignment = alignment;
3577 }
3578
3579 static type_t *handle_attribute_mode(const gnu_attribute_t *attribute,
3580                                      type_t *orig_type)
3581 {
3582         type_t *type = skip_typeref(orig_type);
3583
3584         /* at least: byte, word, pointer, list of machine modes
3585          * __XXX___ is interpreted as XXX */
3586
3587         /* This isn't really correct, the backend should provide a list of machine
3588          * specific modes (according to gcc philosophy that is...) */
3589         const char         *symbol_str = attribute->u.symbol->string;
3590         bool                sign       = is_type_signed(type);
3591         atomic_type_kind_t  akind;
3592         if (strcmp_underscore("QI",   symbol_str) == 0 ||
3593             strcmp_underscore("byte", symbol_str) == 0) {
3594                 akind = sign ? ATOMIC_TYPE_CHAR : ATOMIC_TYPE_UCHAR;
3595         } else if (strcmp_underscore("HI", symbol_str) == 0) {
3596                 akind = sign ? ATOMIC_TYPE_SHORT : ATOMIC_TYPE_USHORT;
3597         } else if (strcmp_underscore("SI",      symbol_str) == 0
3598                 || strcmp_underscore("word",    symbol_str) == 0
3599                 || strcmp_underscore("pointer", symbol_str) == 0) {
3600                 akind = sign ? ATOMIC_TYPE_INT : ATOMIC_TYPE_UINT;
3601         } else if (strcmp_underscore("DI", symbol_str) == 0) {
3602                 akind = sign ? ATOMIC_TYPE_LONGLONG : ATOMIC_TYPE_ULONGLONG;
3603         } else {
3604                 if (warning.other)
3605                         warningf(HERE, "ignoring unknown mode '%s'", symbol_str);
3606                 return orig_type;
3607         }
3608
3609         if (type->kind == TYPE_ATOMIC) {
3610                 type_t *copy       = duplicate_type(type);
3611                 copy->atomic.akind = akind;
3612                 return identify_new_type(copy);
3613         } else if (type->kind == TYPE_ENUM) {
3614                 type_t *copy      = duplicate_type(type);
3615                 copy->enumt.akind = akind;
3616                 return identify_new_type(copy);
3617         } else if (is_type_pointer(type)) {
3618                 warningf(HERE, "__attribute__((mode)) on pointers not implemented yet (ignored)");
3619                 return type;
3620         }
3621
3622         errorf(HERE, "__attribute__((mode)) only allowed on integer, enum or pointer type");
3623         return orig_type;
3624 }
3625
3626 static type_t *handle_type_attributes(const gnu_attribute_t *attributes,
3627                                       type_t *type)
3628 {
3629         const gnu_attribute_t *attribute = attributes;
3630         for ( ; attribute != NULL; attribute = attribute->next) {
3631                 if (attribute->invalid)
3632                         continue;
3633
3634                 if (attribute->kind == GNU_AK_MODE) {
3635                         type = handle_attribute_mode(attribute, type);
3636                 } else if (attribute->kind == GNU_AK_ALIGNED) {
3637                         int alignment = 32; /* TODO: fill in maximum useful alignment for
3638                                                target machine */
3639                         if (attribute->has_arguments)
3640                                 alignment = attribute->u.argument;
3641
3642                         type_t *copy         = duplicate_type(type);
3643                         copy->base.alignment = attribute->u.argument;
3644                         type                 = identify_new_type(copy);
3645                 }
3646         }
3647
3648         return type;
3649 }
3650
3651 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
3652 {
3653         type_t            *type              = NULL;
3654         type_qualifiers_t  qualifiers        = TYPE_QUALIFIER_NONE;
3655         type_modifiers_t   modifiers         = TYPE_MODIFIER_NONE;
3656         unsigned           type_specifiers   = 0;
3657         bool               newtype           = false;
3658         bool               saw_error         = false;
3659         bool               old_gcc_extension = in_gcc_extension;
3660
3661         specifiers->source_position = token.source_position;
3662
3663         while (true) {
3664                 specifiers->modifiers
3665                         |= parse_attributes(&specifiers->gnu_attributes);
3666
3667                 switch (token.type) {
3668                 /* storage class */
3669 #define MATCH_STORAGE_CLASS(token, class)                                  \
3670                 case token:                                                        \
3671                         if (specifiers->storage_class != STORAGE_CLASS_NONE) {         \
3672                                 errorf(HERE, "multiple storage classes in declaration specifiers"); \
3673                         }                                                              \
3674                         specifiers->storage_class = class;                             \
3675                         if (specifiers->thread_local)                                  \
3676                                 goto check_thread_storage_class;                           \
3677                         next_token();                                                  \
3678                         break;
3679
3680                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
3681                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
3682                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
3683                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
3684                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
3685
3686                 case T__declspec:
3687                         next_token();
3688                         expect('(', end_error);
3689                         add_anchor_token(')');
3690                         parse_microsoft_extended_decl_modifier(specifiers);
3691                         rem_anchor_token(')');
3692                         expect(')', end_error);
3693                         break;
3694
3695                 case T___thread:
3696                         if (specifiers->thread_local) {
3697                                 errorf(HERE, "duplicate '__thread'");
3698                         } else {
3699                                 specifiers->thread_local = true;
3700 check_thread_storage_class:
3701                                 switch (specifiers->storage_class) {
3702                                         case STORAGE_CLASS_EXTERN:
3703                                         case STORAGE_CLASS_NONE:
3704                                         case STORAGE_CLASS_STATIC:
3705                                                 break;
3706
3707                                                 char const* wrong;
3708                                         case STORAGE_CLASS_AUTO:     wrong = "auto";     goto wrong_thread_stoarge_class;
3709                                         case STORAGE_CLASS_REGISTER: wrong = "register"; goto wrong_thread_stoarge_class;
3710                                         case STORAGE_CLASS_TYPEDEF:  wrong = "typedef";  goto wrong_thread_stoarge_class;
3711 wrong_thread_stoarge_class:
3712                                                 errorf(HERE, "'__thread' used with '%s'", wrong);
3713                                                 break;
3714                                 }
3715                         }
3716                         next_token();
3717                         break;
3718
3719                 /* type qualifiers */
3720 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
3721                 case token:                                                     \
3722                         qualifiers |= qualifier;                                    \
3723                         next_token();                                               \
3724                         break
3725
3726                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3727                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3728                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3729                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3730                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3731                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3732                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3733                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3734
3735                 case T___extension__:
3736                         next_token();
3737                         in_gcc_extension = true;
3738                         break;
3739
3740                 /* type specifiers */
3741 #define MATCH_SPECIFIER(token, specifier, name)                         \
3742                 case token:                                                     \
3743                         if (type_specifiers & specifier) {                           \
3744                                 errorf(HERE, "multiple " name " type specifiers given"); \
3745                         } else {                                                    \
3746                                 type_specifiers |= specifier;                           \
3747                         }                                                           \
3748                         next_token();                                               \
3749                         break
3750
3751                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool");
3752                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex");
3753                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary");
3754                 MATCH_SPECIFIER(T__int128,    SPECIFIER_INT128,    "_int128");
3755                 MATCH_SPECIFIER(T__int16,     SPECIFIER_INT16,     "_int16");
3756                 MATCH_SPECIFIER(T__int32,     SPECIFIER_INT32,     "_int32");
3757                 MATCH_SPECIFIER(T__int64,     SPECIFIER_INT64,     "_int64");
3758                 MATCH_SPECIFIER(T__int8,      SPECIFIER_INT8,      "_int8");
3759                 MATCH_SPECIFIER(T_bool,       SPECIFIER_BOOL,      "bool");
3760                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char");
3761                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double");
3762                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float");
3763                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int");
3764                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short");
3765                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed");
3766                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned");
3767                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void");
3768                 MATCH_SPECIFIER(T_wchar_t,    SPECIFIER_WCHAR_T,   "wchar_t");
3769
3770                 case T__forceinline:
3771                         /* only in microsoft mode */
3772                         specifiers->modifiers |= DM_FORCEINLINE;
3773                         /* FALLTHROUGH */
3774
3775                 case T_inline:
3776                         next_token();
3777                         specifiers->is_inline = true;
3778                         break;
3779
3780                 case T_long:
3781                         if (type_specifiers & SPECIFIER_LONG_LONG) {
3782                                 errorf(HERE, "multiple type specifiers given");
3783                         } else if (type_specifiers & SPECIFIER_LONG) {
3784                                 type_specifiers |= SPECIFIER_LONG_LONG;
3785                         } else {
3786                                 type_specifiers |= SPECIFIER_LONG;
3787                         }
3788                         next_token();
3789                         break;
3790
3791                 case T_struct: {
3792                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
3793
3794                         type->compound.compound = parse_compound_type_specifier(true);
3795                         finish_struct_type(&type->compound);
3796                         break;
3797                 }
3798                 case T_union: {
3799                         type = allocate_type_zero(TYPE_COMPOUND_UNION);
3800                         type->compound.compound = parse_compound_type_specifier(false);
3801                         if (type->compound.compound->modifiers & DM_TRANSPARENT_UNION)
3802                                 modifiers |= TYPE_MODIFIER_TRANSPARENT_UNION;
3803                         finish_union_type(&type->compound);
3804                         break;
3805                 }
3806                 case T_enum:
3807                         type = parse_enum_specifier();
3808                         break;
3809                 case T___typeof__:
3810                         type = parse_typeof();
3811                         break;
3812                 case T___builtin_va_list:
3813                         type = duplicate_type(type_valist);
3814                         next_token();
3815                         break;
3816
3817                 case T_IDENTIFIER: {
3818                         /* only parse identifier if we haven't found a type yet */
3819                         if (type != NULL || type_specifiers != 0) {
3820                                 /* Be somewhat resilient to typos like 'unsigned lng* f()' in a
3821                                  * declaration, so it doesn't generate errors about expecting '(' or
3822                                  * '{' later on. */
3823                                 switch (look_ahead(1)->type) {
3824                                         STORAGE_CLASSES
3825                                         TYPE_SPECIFIERS
3826                                         case T_const:
3827                                         case T_restrict:
3828                                         case T_volatile:
3829                                         case T_inline:
3830                                         case T__forceinline: /* ^ DECLARATION_START except for __attribute__ */
3831                                         case T_IDENTIFIER:
3832                                         case '&':
3833                                         case '*':
3834                                                 errorf(HERE, "discarding stray %K in declaration specifier", &token);
3835                                                 next_token();
3836                                                 continue;
3837
3838                                         default:
3839                                                 goto finish_specifiers;
3840                                 }
3841                         }
3842
3843                         type_t *const typedef_type = get_typedef_type(token.v.symbol);
3844                         if (typedef_type == NULL) {
3845                                 /* Be somewhat resilient to typos like 'vodi f()' at the beginning of a
3846                                  * declaration, so it doesn't generate 'implicit int' followed by more
3847                                  * errors later on. */
3848                                 token_type_t const la1_type = (token_type_t)look_ahead(1)->type;
3849                                 switch (la1_type) {
3850                                         DECLARATION_START
3851                                         case T_IDENTIFIER:
3852                                         case '&':
3853                                         case '*': {
3854                                                 errorf(HERE, "%K does not name a type", &token);
3855
3856                                                 entity_t *entity =
3857                                                         create_error_entity(token.v.symbol, ENTITY_TYPEDEF);
3858
3859                                                 type = allocate_type_zero(TYPE_TYPEDEF);
3860                                                 type->typedeft.typedefe = &entity->typedefe;
3861
3862                                                 next_token();
3863                                                 saw_error = true;
3864                                                 if (la1_type == '&' || la1_type == '*')
3865                                                         goto finish_specifiers;
3866                                                 continue;
3867                                         }
3868
3869                                         default:
3870                                                 goto finish_specifiers;
3871                                 }
3872                         }
3873
3874                         next_token();
3875                         type = typedef_type;
3876                         break;
3877                 }
3878
3879                 /* function specifier */
3880                 default:
3881                         goto finish_specifiers;
3882                 }
3883         }
3884
3885 finish_specifiers:
3886         specifiers->modifiers
3887                 |= parse_attributes(&specifiers->gnu_attributes);
3888
3889         in_gcc_extension = old_gcc_extension;
3890
3891         if (type == NULL || (saw_error && type_specifiers != 0)) {
3892                 atomic_type_kind_t atomic_type;
3893
3894                 /* match valid basic types */
3895                 switch (type_specifiers) {
3896                 case SPECIFIER_VOID:
3897                         atomic_type = ATOMIC_TYPE_VOID;
3898                         break;
3899                 case SPECIFIER_WCHAR_T:
3900                         atomic_type = ATOMIC_TYPE_WCHAR_T;
3901                         break;
3902                 case SPECIFIER_CHAR:
3903                         atomic_type = ATOMIC_TYPE_CHAR;
3904                         break;
3905                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
3906                         atomic_type = ATOMIC_TYPE_SCHAR;
3907                         break;
3908                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
3909                         atomic_type = ATOMIC_TYPE_UCHAR;
3910                         break;
3911                 case SPECIFIER_SHORT:
3912                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
3913                 case SPECIFIER_SHORT | SPECIFIER_INT:
3914                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
3915                         atomic_type = ATOMIC_TYPE_SHORT;
3916                         break;
3917                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
3918                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
3919                         atomic_type = ATOMIC_TYPE_USHORT;
3920                         break;
3921                 case SPECIFIER_INT:
3922                 case SPECIFIER_SIGNED:
3923                 case SPECIFIER_SIGNED | SPECIFIER_INT:
3924                         atomic_type = ATOMIC_TYPE_INT;
3925                         break;
3926                 case SPECIFIER_UNSIGNED:
3927                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
3928                         atomic_type = ATOMIC_TYPE_UINT;
3929                         break;
3930                 case SPECIFIER_LONG:
3931                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
3932                 case SPECIFIER_LONG | SPECIFIER_INT:
3933                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
3934                         atomic_type = ATOMIC_TYPE_LONG;
3935                         break;
3936                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
3937                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
3938                         atomic_type = ATOMIC_TYPE_ULONG;
3939                         break;
3940
3941                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3942                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3943                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
3944                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3945                         | SPECIFIER_INT:
3946                         atomic_type = ATOMIC_TYPE_LONGLONG;
3947                         goto warn_about_long_long;
3948
3949                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3950                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3951                         | SPECIFIER_INT:
3952                         atomic_type = ATOMIC_TYPE_ULONGLONG;
3953 warn_about_long_long:
3954                         if (warning.long_long) {
3955                                 warningf(&specifiers->source_position,
3956                                          "ISO C90 does not support 'long long'");
3957                         }
3958                         break;
3959
3960                 case SPECIFIER_UNSIGNED | SPECIFIER_INT8:
3961                         atomic_type = unsigned_int8_type_kind;
3962                         break;
3963
3964                 case SPECIFIER_UNSIGNED | SPECIFIER_INT16:
3965                         atomic_type = unsigned_int16_type_kind;
3966                         break;
3967
3968                 case SPECIFIER_UNSIGNED | SPECIFIER_INT32:
3969                         atomic_type = unsigned_int32_type_kind;
3970                         break;
3971
3972                 case SPECIFIER_UNSIGNED | SPECIFIER_INT64:
3973                         atomic_type = unsigned_int64_type_kind;
3974                         break;
3975
3976                 case SPECIFIER_UNSIGNED | SPECIFIER_INT128:
3977                         atomic_type = unsigned_int128_type_kind;
3978                         break;
3979
3980                 case SPECIFIER_INT8:
3981                 case SPECIFIER_SIGNED | SPECIFIER_INT8:
3982                         atomic_type = int8_type_kind;
3983                         break;
3984
3985                 case SPECIFIER_INT16:
3986                 case SPECIFIER_SIGNED | SPECIFIER_INT16:
3987                         atomic_type = int16_type_kind;
3988                         break;
3989
3990                 case SPECIFIER_INT32:
3991                 case SPECIFIER_SIGNED | SPECIFIER_INT32:
3992                         atomic_type = int32_type_kind;
3993                         break;
3994
3995                 case SPECIFIER_INT64:
3996                 case SPECIFIER_SIGNED | SPECIFIER_INT64:
3997                         atomic_type = int64_type_kind;
3998                         break;
3999
4000                 case SPECIFIER_INT128:
4001                 case SPECIFIER_SIGNED | SPECIFIER_INT128:
4002                         atomic_type = int128_type_kind;
4003                         break;
4004
4005                 case SPECIFIER_FLOAT:
4006                         atomic_type = ATOMIC_TYPE_FLOAT;
4007                         break;
4008                 case SPECIFIER_DOUBLE:
4009                         atomic_type = ATOMIC_TYPE_DOUBLE;
4010                         break;
4011                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
4012                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
4013                         break;
4014                 case SPECIFIER_BOOL:
4015                         atomic_type = ATOMIC_TYPE_BOOL;
4016                         break;
4017                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
4018                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
4019                         atomic_type = ATOMIC_TYPE_FLOAT;
4020                         break;
4021                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
4022                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
4023                         atomic_type = ATOMIC_TYPE_DOUBLE;
4024                         break;
4025                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
4026                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
4027                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
4028                         break;
4029                 default:
4030                         /* invalid specifier combination, give an error message */
4031                         if (type_specifiers == 0) {
4032                                 if (saw_error)
4033                                         goto end_error;
4034
4035                                 /* ISO/IEC 14882:1998(E) §C.1.5:4 */
4036                                 if (!(c_mode & _CXX) && !strict_mode) {
4037                                         if (warning.implicit_int) {
4038                                                 warningf(HERE, "no type specifiers in declaration, using 'int'");
4039                                         }
4040                                         atomic_type = ATOMIC_TYPE_INT;
4041                                         break;
4042                                 } else {
4043                                         errorf(HERE, "no type specifiers given in declaration");
4044                                 }
4045                         } else if ((type_specifiers & SPECIFIER_SIGNED) &&
4046                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
4047                                 errorf(HERE, "signed and unsigned specifiers given");
4048                         } else if (type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
4049                                 errorf(HERE, "only integer types can be signed or unsigned");
4050                         } else {
4051                                 errorf(HERE, "multiple datatypes in declaration");
4052                         }
4053                         goto end_error;
4054                 }
4055
4056                 if (type_specifiers & SPECIFIER_COMPLEX) {
4057                         type                = allocate_type_zero(TYPE_COMPLEX);
4058                         type->complex.akind = atomic_type;
4059                 } else if (type_specifiers & SPECIFIER_IMAGINARY) {
4060                         type                  = allocate_type_zero(TYPE_IMAGINARY);
4061                         type->imaginary.akind = atomic_type;
4062                 } else {
4063                         type                 = allocate_type_zero(TYPE_ATOMIC);
4064                         type->atomic.akind   = atomic_type;
4065                 }
4066                 type->base.alignment = get_atomic_type_alignment(atomic_type);
4067                 unsigned const size  = get_atomic_type_size(atomic_type);
4068                 type->base.size      =
4069                         type_specifiers & SPECIFIER_COMPLEX ? size * 2 : size;
4070                 newtype = true;
4071         } else if (type_specifiers != 0) {
4072                 errorf(HERE, "multiple datatypes in declaration");
4073         }
4074
4075         /* FIXME: check type qualifiers here */
4076
4077         if (specifiers->modifiers & DM_TRANSPARENT_UNION)
4078                 modifiers |= TYPE_MODIFIER_TRANSPARENT_UNION;
4079         type->base.qualifiers = qualifiers;
4080         type->base.modifiers  = modifiers;
4081
4082         if (newtype) {
4083                 type = identify_new_type(type);
4084         } else {
4085                 type = typehash_insert(type);
4086         }
4087
4088         type = handle_type_attributes(specifiers->gnu_attributes, type);
4089         specifiers->type = type;
4090         return;
4091
4092 end_error:
4093         specifiers->type = type_error_type;
4094         return;
4095 }
4096
4097 static type_qualifiers_t parse_type_qualifiers(void)
4098 {
4099         type_qualifiers_t qualifiers = TYPE_QUALIFIER_NONE;
4100
4101         while (true) {
4102                 switch (token.type) {
4103                 /* type qualifiers */
4104                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
4105                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
4106                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
4107                 /* microsoft extended type modifiers */
4108                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
4109                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
4110                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
4111                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
4112                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
4113
4114                 default:
4115                         return qualifiers;
4116                 }
4117         }
4118 }
4119
4120 /**
4121  * Parses an K&R identifier list
4122  */
4123 static void parse_identifier_list(scope_t *scope)
4124 {
4125         do {
4126                 entity_t *entity = allocate_entity_zero(ENTITY_PARAMETER);
4127                 entity->base.source_position = token.source_position;
4128                 entity->base.namespc         = NAMESPACE_NORMAL;
4129                 entity->base.symbol          = token.v.symbol;
4130                 /* a K&R parameter has no type, yet */
4131                 next_token();
4132
4133                 if (scope != NULL)
4134                         append_entity(scope, entity);
4135
4136                 if (token.type != ',') {
4137                         break;
4138                 }
4139                 next_token();
4140         } while (token.type == T_IDENTIFIER);
4141 }
4142
4143 static entity_t *parse_parameter(void)
4144 {
4145         declaration_specifiers_t specifiers;
4146         memset(&specifiers, 0, sizeof(specifiers));
4147
4148         parse_declaration_specifiers(&specifiers);
4149
4150         entity_t *entity = parse_declarator(&specifiers,
4151                         DECL_MAY_BE_ABSTRACT | DECL_IS_PARAMETER);
4152         anonymous_entity = NULL;
4153         return entity;
4154 }
4155
4156 static void semantic_parameter_incomplete(const entity_t *entity)
4157 {
4158         assert(entity->kind == ENTITY_PARAMETER);
4159
4160         /* §6.7.5.3:4  After adjustment, the parameters in a parameter type
4161          *             list in a function declarator that is part of a
4162          *             definition of that function shall not have
4163          *             incomplete type. */
4164         type_t *type = skip_typeref(entity->declaration.type);
4165         if (is_type_incomplete(type)) {
4166                 errorf(&entity->base.source_position,
4167                        "parameter '%Y' has incomplete type '%T'", entity->base.symbol,
4168                        entity->declaration.type);
4169         }
4170 }
4171
4172 /**
4173  * Parses function type parameters (and optionally creates variable_t entities
4174  * for them in a scope)
4175  */
4176 static void parse_parameters(function_type_t *type, scope_t *scope)
4177 {
4178         eat('(');
4179         add_anchor_token(')');
4180         int saved_comma_state = save_and_reset_anchor_state(',');
4181
4182         if (token.type == T_IDENTIFIER &&
4183             !is_typedef_symbol(token.v.symbol)) {
4184                 token_type_t la1_type = (token_type_t)look_ahead(1)->type;
4185                 if (la1_type == ',' || la1_type == ')') {
4186                         type->kr_style_parameters    = true;
4187                         type->unspecified_parameters = true;
4188                         parse_identifier_list(scope);
4189                         goto parameters_finished;
4190                 }
4191         }
4192
4193         if (token.type == ')') {
4194                 /* ISO/IEC 14882:1998(E) §C.1.6:1 */
4195                 if (!(c_mode & _CXX))
4196                         type->unspecified_parameters = true;
4197                 goto parameters_finished;
4198         }
4199
4200         function_parameter_t *parameter;
4201         function_parameter_t *last_parameter = NULL;
4202
4203         while (true) {
4204                 switch (token.type) {
4205                 case T_DOTDOTDOT:
4206                         next_token();
4207                         type->variadic = true;
4208                         goto parameters_finished;
4209
4210                 case T_IDENTIFIER:
4211                 case T___extension__:
4212                 DECLARATION_START
4213                 {
4214                         entity_t *entity = parse_parameter();
4215                         if (entity->kind == ENTITY_TYPEDEF) {
4216                                 errorf(&entity->base.source_position,
4217                                        "typedef not allowed as function parameter");
4218                                 break;
4219                         }
4220                         assert(is_declaration(entity));
4221
4222                         /* func(void) is not a parameter */
4223                         if (last_parameter == NULL
4224                                         && token.type == ')'
4225                                         && entity->base.symbol == NULL
4226                                         && skip_typeref(entity->declaration.type) == type_void) {
4227                                 goto parameters_finished;
4228                         }
4229                         semantic_parameter_incomplete(entity);
4230
4231                         parameter = obstack_alloc(type_obst, sizeof(parameter[0]));
4232                         memset(parameter, 0, sizeof(parameter[0]));
4233                         parameter->type = entity->declaration.type;
4234
4235                         if (scope != NULL) {
4236                                 append_entity(scope, entity);
4237                         }
4238
4239                         if (last_parameter != NULL) {
4240                                 last_parameter->next = parameter;
4241                         } else {
4242                                 type->parameters = parameter;
4243                         }
4244                         last_parameter   = parameter;
4245                         break;
4246                 }
4247
4248                 default:
4249                         goto parameters_finished;
4250                 }
4251                 if (token.type != ',') {
4252                         goto parameters_finished;
4253                 }
4254                 next_token();
4255         }
4256
4257
4258 parameters_finished:
4259         rem_anchor_token(')');
4260         expect(')', end_error);
4261
4262 end_error:
4263         restore_anchor_state(',', saved_comma_state);
4264 }
4265
4266 typedef enum construct_type_kind_t {
4267         CONSTRUCT_INVALID,
4268         CONSTRUCT_POINTER,
4269         CONSTRUCT_REFERENCE,
4270         CONSTRUCT_FUNCTION,
4271         CONSTRUCT_ARRAY
4272 } construct_type_kind_t;
4273
4274 typedef union construct_type_t construct_type_t;
4275
4276 typedef struct construct_type_base_t {
4277         construct_type_kind_t  kind;
4278         construct_type_t      *next;
4279 } construct_type_base_t;
4280
4281 typedef struct parsed_pointer_t {
4282         construct_type_base_t  base;
4283         type_qualifiers_t      type_qualifiers;
4284         variable_t             *base_variable;  /**< MS __based extension. */
4285 } parsed_pointer_t;
4286
4287 typedef struct parsed_reference_t {
4288         construct_type_base_t base;
4289 } parsed_reference_t;
4290
4291 typedef struct construct_function_type_t {
4292         construct_type_base_t  base;
4293         type_t                *function_type;
4294 } construct_function_type_t;
4295
4296 typedef struct parsed_array_t {
4297         construct_type_base_t  base;
4298         type_qualifiers_t      type_qualifiers;
4299         bool                   is_static;
4300         bool                   is_variable;
4301         expression_t          *size;
4302 } parsed_array_t;
4303
4304 union construct_type_t {
4305         construct_type_kind_t     kind;
4306         construct_type_base_t     base;
4307         parsed_pointer_t          pointer;
4308         parsed_reference_t        reference;
4309         construct_function_type_t function;
4310         parsed_array_t            array;
4311 };
4312
4313 static construct_type_t *parse_pointer_declarator(variable_t *base_variable)
4314 {
4315         eat('*');
4316
4317         construct_type_t *cons    = obstack_alloc(&temp_obst, sizeof(cons->pointer));
4318         parsed_pointer_t *pointer = &cons->pointer;
4319         memset(pointer, 0, sizeof(*pointer));
4320         cons->kind               = CONSTRUCT_POINTER;
4321         pointer->type_qualifiers = parse_type_qualifiers();
4322         pointer->base_variable   = base_variable;
4323
4324         return cons;
4325 }
4326
4327 static construct_type_t *parse_reference_declarator(void)
4328 {
4329         eat('&');
4330
4331         construct_type_t   *cons      = obstack_alloc(&temp_obst, sizeof(cons->reference));
4332         parsed_reference_t *reference = &cons->reference;
4333         memset(reference, 0, sizeof(*reference));
4334         cons->kind = CONSTRUCT_REFERENCE;
4335
4336         return cons;
4337 }
4338
4339 static construct_type_t *parse_array_declarator(void)
4340 {
4341         eat('[');
4342         add_anchor_token(']');
4343
4344         construct_type_t *cons  = obstack_alloc(&temp_obst, sizeof(cons->array));
4345         parsed_array_t   *array = &cons->array;
4346         memset(array, 0, sizeof(*array));
4347         cons->kind = CONSTRUCT_ARRAY;
4348
4349         if (token.type == T_static) {
4350                 array->is_static = true;
4351                 next_token();
4352         }
4353
4354         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
4355         if (type_qualifiers != 0) {
4356                 if (token.type == T_static) {
4357                         array->is_static = true;
4358                         next_token();
4359                 }
4360         }
4361         array->type_qualifiers = type_qualifiers;
4362
4363         if (token.type == '*' && look_ahead(1)->type == ']') {
4364                 array->is_variable = true;
4365                 next_token();
4366         } else if (token.type != ']') {
4367                 expression_t *const size = parse_assignment_expression();
4368                 array->size = size;
4369                 mark_vars_read(size, NULL);
4370         }
4371
4372         rem_anchor_token(']');
4373         expect(']', end_error);
4374
4375 end_error:
4376         return cons;
4377 }
4378
4379 static construct_type_t *parse_function_declarator(scope_t *scope,
4380                                                    decl_modifiers_t modifiers)
4381 {
4382         type_t          *type  = allocate_type_zero(TYPE_FUNCTION);
4383         function_type_t *ftype = &type->function;
4384
4385         ftype->linkage = current_linkage;
4386
4387         switch (modifiers & (DM_CDECL | DM_STDCALL | DM_FASTCALL | DM_THISCALL)) {
4388                 case DM_NONE:     break;
4389                 case DM_CDECL:    ftype->calling_convention = CC_CDECL;    break;
4390                 case DM_STDCALL:  ftype->calling_convention = CC_STDCALL;  break;
4391                 case DM_FASTCALL: ftype->calling_convention = CC_FASTCALL; break;
4392                 case DM_THISCALL: ftype->calling_convention = CC_THISCALL; break;
4393
4394                 default:
4395                         errorf(HERE, "multiple calling conventions in declaration");
4396                         break;
4397         }
4398
4399         parse_parameters(ftype, scope);
4400
4401         construct_type_t          *cons     = obstack_alloc(&temp_obst, sizeof(cons->function));
4402         construct_function_type_t *function = &cons->function;
4403         memset(function, 0, sizeof(*function));
4404         cons->kind              = CONSTRUCT_FUNCTION;
4405         function->function_type = type;
4406
4407         return cons;
4408 }
4409
4410 typedef struct parse_declarator_env_t {
4411         decl_modifiers_t   modifiers;
4412         symbol_t          *symbol;
4413         source_position_t  source_position;
4414         scope_t            parameters;
4415 } parse_declarator_env_t;
4416
4417 static construct_type_t *parse_inner_declarator(parse_declarator_env_t *env,
4418                 bool may_be_abstract)
4419 {
4420         /* construct a single linked list of construct_type_t's which describe
4421          * how to construct the final declarator type */
4422         construct_type_t *first      = NULL;
4423         construct_type_t *last       = NULL;
4424         gnu_attribute_t  *attributes = NULL;
4425
4426         decl_modifiers_t modifiers = parse_attributes(&attributes);
4427
4428         /* MS __based extension */
4429         based_spec_t base_spec;
4430         base_spec.base_variable = NULL;
4431
4432         for (;;) {
4433                 construct_type_t *type;
4434                 switch (token.type) {
4435                         case '&':
4436                                 if (!(c_mode & _CXX))
4437                                         errorf(HERE, "references are only available for C++");
4438                                 if (base_spec.base_variable != NULL && warning.other) {
4439                                         warningf(&base_spec.source_position,
4440                                                  "__based does not precede a pointer operator, ignored");
4441                                 }
4442                                 type = parse_reference_declarator();
4443                                 /* consumed */
4444                                 base_spec.base_variable = NULL;
4445                                 break;
4446
4447                         case '*':
4448                                 type = parse_pointer_declarator(base_spec.base_variable);
4449                                 /* consumed */
4450                                 base_spec.base_variable = NULL;
4451                                 break;
4452
4453                         case T__based:
4454                                 next_token();
4455                                 expect('(', end_error);
4456                                 add_anchor_token(')');
4457                                 parse_microsoft_based(&base_spec);
4458                                 rem_anchor_token(')');
4459                                 expect(')', end_error);
4460                                 continue;
4461
4462                         default:
4463                                 goto ptr_operator_end;
4464                 }
4465
4466                 if (last == NULL) {
4467                         first = type;
4468                         last  = type;
4469                 } else {
4470                         last->base.next = type;
4471                         last            = type;
4472                 }
4473
4474                 /* TODO: find out if this is correct */
4475                 modifiers |= parse_attributes(&attributes);
4476         }
4477 ptr_operator_end:
4478         if (base_spec.base_variable != NULL && warning.other) {
4479                 warningf(&base_spec.source_position,
4480                          "__based does not precede a pointer operator, ignored");
4481         }
4482
4483         if (env != NULL) {
4484                 modifiers      |= env->modifiers;
4485                 env->modifiers  = modifiers;
4486         }
4487
4488         construct_type_t *inner_types = NULL;
4489
4490         switch (token.type) {
4491         case T_IDENTIFIER:
4492                 if (env == NULL) {
4493                         errorf(HERE, "no identifier expected in typename");
4494                 } else {
4495                         env->symbol          = token.v.symbol;
4496                         env->source_position = token.source_position;
4497                 }
4498                 next_token();
4499                 break;
4500         case '(':
4501                 /* §6.7.6:2 footnote 126:  Empty parentheses in a type name are
4502                  * interpreted as ``function with no parameter specification'', rather
4503                  * than redundant parentheses around the omitted identifier. */
4504                 if (look_ahead(1)->type != ')') {
4505                         next_token();
4506                         add_anchor_token(')');
4507                         inner_types = parse_inner_declarator(env, may_be_abstract);
4508                         if (inner_types != NULL) {
4509                                 /* All later declarators only modify the return type */
4510                                 env = NULL;
4511                         }
4512                         rem_anchor_token(')');
4513                         expect(')', end_error);
4514                 }
4515                 break;
4516         default:
4517                 if (may_be_abstract)
4518                         break;
4519                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', NULL);
4520                 eat_until_anchor();
4521                 return NULL;
4522         }
4523
4524         construct_type_t *p = last;
4525
4526         while (true) {
4527                 construct_type_t *type;
4528                 switch (token.type) {
4529                 case '(': {
4530                         scope_t *scope = NULL;
4531                         if (env != NULL)
4532                                 scope = &env->parameters;
4533
4534                         type = parse_function_declarator(scope, modifiers);
4535                         break;
4536                 }
4537                 case '[':
4538                         type = parse_array_declarator();
4539                         break;
4540                 default:
4541                         goto declarator_finished;
4542                 }
4543
4544                 /* insert in the middle of the list (behind p) */
4545                 if (p != NULL) {
4546                         type->base.next = p->base.next;
4547                         p->base.next    = type;
4548                 } else {
4549                         type->base.next = first;
4550                         first           = type;
4551                 }
4552                 if (last == p) {
4553                         last = type;
4554                 }
4555         }
4556
4557 declarator_finished:
4558         /* append inner_types at the end of the list, we don't to set last anymore
4559          * as it's not needed anymore */
4560         if (last == NULL) {
4561                 assert(first == NULL);
4562                 first = inner_types;
4563         } else {
4564                 last->base.next = inner_types;
4565         }
4566
4567         return first;
4568 end_error:
4569         return NULL;
4570 }
4571
4572 static void parse_declaration_attributes(entity_t *entity)
4573 {
4574         gnu_attribute_t  *attributes = NULL;
4575         decl_modifiers_t  modifiers  = parse_attributes(&attributes);
4576
4577         if (entity == NULL)
4578                 return;
4579
4580         type_t *type;
4581         if (entity->kind == ENTITY_TYPEDEF) {
4582                 modifiers |= entity->typedefe.modifiers;
4583                 type       = entity->typedefe.type;
4584         } else {
4585                 assert(is_declaration(entity));
4586                 modifiers |= entity->declaration.modifiers;
4587                 type       = entity->declaration.type;
4588         }
4589         if (type == NULL)
4590                 return;
4591
4592         gnu_attribute_t *attribute = attributes;
4593         for ( ; attribute != NULL; attribute = attribute->next) {
4594                 if (attribute->invalid)
4595                         continue;
4596
4597                 if (attribute->kind == GNU_AK_MODE) {
4598                         type = handle_attribute_mode(attribute, type);
4599                 } else if (attribute->kind == GNU_AK_ALIGNED) {
4600                         int alignment = 32; /* TODO: fill in maximum usefull alignment for target machine */
4601                         if (attribute->has_arguments)
4602                                 alignment = attribute->u.argument;
4603
4604                         if (entity->kind == ENTITY_TYPEDEF) {
4605                                 type_t *copy         = duplicate_type(type);
4606                                 copy->base.alignment = attribute->u.argument;
4607                                 type                 = identify_new_type(copy);
4608                         } else if(entity->kind == ENTITY_VARIABLE) {
4609                                 entity->variable.alignment = alignment;
4610                         } else if(entity->kind == ENTITY_COMPOUND_MEMBER) {
4611                                 entity->compound_member.alignment = alignment;
4612                         }
4613                 }
4614         }
4615
4616         type_modifiers_t type_modifiers = type->base.modifiers;
4617         if (modifiers & DM_TRANSPARENT_UNION)
4618                 type_modifiers |= TYPE_MODIFIER_TRANSPARENT_UNION;
4619
4620         if (type->base.modifiers != type_modifiers) {
4621                 type_t *copy         = duplicate_type(type);
4622                 copy->base.modifiers = type_modifiers;
4623                 type                 = identify_new_type(copy);
4624         }
4625
4626         if (entity->kind == ENTITY_TYPEDEF) {
4627                 entity->typedefe.type      = type;
4628                 entity->typedefe.modifiers = modifiers;
4629         } else {
4630                 entity->declaration.type      = type;
4631                 entity->declaration.modifiers = modifiers;
4632         }
4633 }
4634
4635 static type_t *construct_declarator_type(construct_type_t *construct_list, type_t *type)
4636 {
4637         construct_type_t *iter = construct_list;
4638         for (; iter != NULL; iter = iter->base.next) {
4639                 switch (iter->kind) {
4640                 case CONSTRUCT_INVALID:
4641                         break;
4642                 case CONSTRUCT_FUNCTION: {
4643                         construct_function_type_t *function      = &iter->function;
4644                         type_t                    *function_type = function->function_type;
4645
4646                         function_type->function.return_type = type;
4647
4648                         type_t *skipped_return_type = skip_typeref(type);
4649                         /* §6.7.5.3:1 */
4650                         if (is_type_function(skipped_return_type)) {
4651                                 errorf(HERE, "function returning function is not allowed");
4652                         } else if (is_type_array(skipped_return_type)) {
4653                                 errorf(HERE, "function returning array is not allowed");
4654                         } else {
4655                                 if (skipped_return_type->base.qualifiers != 0 && warning.other) {
4656                                         warningf(HERE,
4657                                                 "type qualifiers in return type of function type are meaningless");
4658                                 }
4659                         }
4660
4661                         /* The function type was constructed earlier.  Freeing it here will
4662                          * destroy other types. */
4663                         type = typehash_insert(function_type);
4664                         continue;
4665                 }
4666
4667                 case CONSTRUCT_POINTER: {
4668                         if (is_type_reference(skip_typeref(type)))
4669                                 errorf(HERE, "cannot declare a pointer to reference");
4670
4671                         parsed_pointer_t *pointer = &iter->pointer;
4672                         type = make_based_pointer_type(type, pointer->type_qualifiers, pointer->base_variable);
4673                         continue;
4674                 }
4675
4676                 case CONSTRUCT_REFERENCE:
4677                         if (is_type_reference(skip_typeref(type)))
4678                                 errorf(HERE, "cannot declare a reference to reference");
4679
4680                         type = make_reference_type(type);
4681                         continue;
4682
4683                 case CONSTRUCT_ARRAY: {
4684                         if (is_type_reference(skip_typeref(type)))
4685                                 errorf(HERE, "cannot declare an array of references");
4686
4687                         parsed_array_t *array      = &iter->array;
4688                         type_t         *array_type = allocate_type_zero(TYPE_ARRAY);
4689
4690                         expression_t *size_expression = array->size;
4691                         if (size_expression != NULL) {
4692                                 size_expression
4693                                         = create_implicit_cast(size_expression, type_size_t);
4694                         }
4695
4696                         array_type->base.qualifiers       = array->type_qualifiers;
4697                         array_type->array.element_type    = type;
4698                         array_type->array.is_static       = array->is_static;
4699                         array_type->array.is_variable     = array->is_variable;
4700                         array_type->array.size_expression = size_expression;
4701
4702                         if (size_expression != NULL) {
4703                                 if (is_constant_expression(size_expression)) {
4704                                         array_type->array.size_constant = true;
4705                                         array_type->array.size
4706                                                 = fold_constant(size_expression);
4707                                 } else {
4708                                         array_type->array.is_vla = true;
4709                                 }
4710                         }
4711
4712                         type_t *skipped_type = skip_typeref(type);
4713                         /* §6.7.5.2:1 */
4714                         if (is_type_incomplete(skipped_type)) {
4715                                 errorf(HERE, "array of incomplete type '%T' is not allowed", type);
4716                         } else if (is_type_function(skipped_type)) {
4717                                 errorf(HERE, "array of functions is not allowed");
4718                         }
4719                         type = identify_new_type(array_type);
4720                         continue;
4721                 }
4722                 }
4723                 internal_errorf(HERE, "invalid type construction found");
4724         }
4725
4726         return type;
4727 }
4728
4729 static type_t *automatic_type_conversion(type_t *orig_type);
4730
4731 static type_t *semantic_parameter(const source_position_t *pos,
4732                                   type_t *type,
4733                                   const declaration_specifiers_t *specifiers,
4734                                   symbol_t *symbol)
4735 {
4736         /* §6.7.5.3:7  A declaration of a parameter as ``array of type''
4737          *             shall be adjusted to ``qualified pointer to type'',
4738          *             [...]
4739          * §6.7.5.3:8  A declaration of a parameter as ``function returning
4740          *             type'' shall be adjusted to ``pointer to function
4741          *             returning type'', as in 6.3.2.1. */
4742         type = automatic_type_conversion(type);
4743
4744         if (specifiers->is_inline && is_type_valid(type)) {
4745                 errorf(pos, "parameter '%Y' declared 'inline'", symbol);
4746         }
4747
4748         /* §6.9.1:6  The declarations in the declaration list shall contain
4749          *           no storage-class specifier other than register and no
4750          *           initializations. */
4751         if (specifiers->thread_local || (
4752                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
4753                         specifiers->storage_class != STORAGE_CLASS_REGISTER)
4754            ) {
4755                 errorf(pos, "invalid storage class for parameter '%Y'", symbol);
4756         }
4757
4758         /* delay test for incomplete type, because we might have (void)
4759          * which is legal but incomplete... */
4760
4761         return type;
4762 }
4763
4764 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
4765                                   declarator_flags_t flags)
4766 {
4767         parse_declarator_env_t env;
4768         memset(&env, 0, sizeof(env));
4769         env.modifiers = specifiers->modifiers;
4770
4771         construct_type_t *construct_type =
4772                 parse_inner_declarator(&env, (flags & DECL_MAY_BE_ABSTRACT) != 0);
4773         type_t           *orig_type      =
4774                 construct_declarator_type(construct_type, specifiers->type);
4775         type_t           *type           = skip_typeref(orig_type);
4776
4777         if (construct_type != NULL) {
4778                 obstack_free(&temp_obst, construct_type);
4779         }
4780
4781         entity_t *entity;
4782         if (specifiers->storage_class == STORAGE_CLASS_TYPEDEF) {
4783                 entity                       = allocate_entity_zero(ENTITY_TYPEDEF);
4784                 entity->base.symbol          = env.symbol;
4785                 entity->base.source_position = env.source_position;
4786                 entity->typedefe.type        = orig_type;
4787
4788                 if (anonymous_entity != NULL) {
4789                         if (is_type_compound(type)) {
4790                                 assert(anonymous_entity->compound.alias == NULL);
4791                                 assert(anonymous_entity->kind == ENTITY_STRUCT ||
4792                                        anonymous_entity->kind == ENTITY_UNION);
4793                                 anonymous_entity->compound.alias = entity;
4794                                 anonymous_entity = NULL;
4795                         } else if (is_type_enum(type)) {
4796                                 assert(anonymous_entity->enume.alias == NULL);
4797                                 assert(anonymous_entity->kind == ENTITY_ENUM);
4798                                 anonymous_entity->enume.alias = entity;
4799                                 anonymous_entity = NULL;
4800                         }
4801                 }
4802         } else {
4803                 /* create a declaration type entity */
4804                 if (flags & DECL_CREATE_COMPOUND_MEMBER) {
4805                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER);
4806
4807                         if (env.symbol != NULL) {
4808                                 if (specifiers->is_inline && is_type_valid(type)) {
4809                                         errorf(&env.source_position,
4810                                                         "compound member '%Y' declared 'inline'", env.symbol);
4811                                 }
4812
4813                                 if (specifiers->thread_local ||
4814                                                 specifiers->storage_class != STORAGE_CLASS_NONE) {
4815                                         errorf(&env.source_position,
4816                                                         "compound member '%Y' must have no storage class",
4817                                                         env.symbol);
4818                                 }
4819                         }
4820                 } else if (flags & DECL_IS_PARAMETER) {
4821                         orig_type = semantic_parameter(&env.source_position, orig_type,
4822                                                        specifiers, env.symbol);
4823
4824                         entity = allocate_entity_zero(ENTITY_PARAMETER);
4825                 } else if (is_type_function(type)) {
4826                         entity = allocate_entity_zero(ENTITY_FUNCTION);
4827
4828                         entity->function.is_inline  = specifiers->is_inline;
4829                         entity->function.parameters = env.parameters;
4830
4831                         if (env.symbol != NULL) {
4832                                 if (specifiers->thread_local || (
4833                                                         specifiers->storage_class != STORAGE_CLASS_EXTERN &&
4834                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
4835                                                         specifiers->storage_class != STORAGE_CLASS_STATIC
4836                                                 )) {
4837                                         errorf(&env.source_position,
4838                                                         "invalid storage class for function '%Y'", env.symbol);
4839                                 }
4840                         }
4841                 } else {
4842                         entity = allocate_entity_zero(ENTITY_VARIABLE);
4843
4844                         entity->variable.get_property_sym = specifiers->get_property_sym;
4845                         entity->variable.put_property_sym = specifiers->put_property_sym;
4846
4847                         entity->variable.thread_local = specifiers->thread_local;
4848
4849                         if (env.symbol != NULL) {
4850                                 if (specifiers->is_inline && is_type_valid(type)) {
4851                                         errorf(&env.source_position,
4852                                                         "variable '%Y' declared 'inline'", env.symbol);
4853                                 }
4854
4855                                 bool invalid_storage_class = false;
4856                                 if (current_scope == file_scope) {
4857                                         if (specifiers->storage_class != STORAGE_CLASS_EXTERN &&
4858                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
4859                                                         specifiers->storage_class != STORAGE_CLASS_STATIC) {
4860                                                 invalid_storage_class = true;
4861                                         }
4862                                 } else {
4863                                         if (specifiers->thread_local &&
4864                                                         specifiers->storage_class == STORAGE_CLASS_NONE) {
4865                                                 invalid_storage_class = true;
4866                                         }
4867                                 }
4868                                 if (invalid_storage_class) {
4869                                         errorf(&env.source_position,
4870                                                         "invalid storage class for variable '%Y'", env.symbol);
4871                                 }
4872                         }
4873                 }
4874
4875                 if (env.symbol != NULL) {
4876                         entity->base.symbol          = env.symbol;
4877                         entity->base.source_position = env.source_position;
4878                 } else {
4879                         entity->base.source_position = specifiers->source_position;
4880                 }
4881                 entity->base.namespc                  = NAMESPACE_NORMAL;
4882                 entity->declaration.type              = orig_type;
4883                 entity->declaration.modifiers         = env.modifiers;
4884                 entity->declaration.deprecated_string = specifiers->deprecated_string;
4885
4886                 storage_class_t storage_class = specifiers->storage_class;
4887                 entity->declaration.declared_storage_class = storage_class;
4888
4889                 if (storage_class == STORAGE_CLASS_NONE && current_scope != file_scope)
4890                         storage_class = STORAGE_CLASS_AUTO;
4891                 entity->declaration.storage_class = storage_class;
4892         }
4893
4894         parse_declaration_attributes(entity);
4895
4896         return entity;
4897 }
4898
4899 static type_t *parse_abstract_declarator(type_t *base_type)
4900 {
4901         construct_type_t *construct_type = parse_inner_declarator(NULL, 1);
4902
4903         type_t *result = construct_declarator_type(construct_type, base_type);
4904         if (construct_type != NULL) {
4905                 obstack_free(&temp_obst, construct_type);
4906         }
4907
4908         return result;
4909 }
4910
4911 /**
4912  * Check if the declaration of main is suspicious.  main should be a
4913  * function with external linkage, returning int, taking either zero
4914  * arguments, two, or three arguments of appropriate types, ie.
4915  *
4916  * int main([ int argc, char **argv [, char **env ] ]).
4917  *
4918  * @param decl    the declaration to check
4919  * @param type    the function type of the declaration
4920  */
4921 static void check_type_of_main(const entity_t *entity)
4922 {
4923         const source_position_t *pos = &entity->base.source_position;
4924         if (entity->kind != ENTITY_FUNCTION) {
4925                 warningf(pos, "'main' is not a function");
4926                 return;
4927         }
4928
4929         if (entity->declaration.storage_class == STORAGE_CLASS_STATIC) {
4930                 warningf(pos, "'main' is normally a non-static function");
4931         }
4932
4933         type_t *type = skip_typeref(entity->declaration.type);
4934         assert(is_type_function(type));
4935
4936         function_type_t *func_type = &type->function;
4937         if (!types_compatible(skip_typeref(func_type->return_type), type_int)) {
4938                 warningf(pos, "return type of 'main' should be 'int', but is '%T'",
4939                          func_type->return_type);
4940         }
4941         const function_parameter_t *parm = func_type->parameters;
4942         if (parm != NULL) {
4943                 type_t *const first_type = parm->type;
4944                 if (!types_compatible(skip_typeref(first_type), type_int)) {
4945                         warningf(pos,
4946                                  "first argument of 'main' should be 'int', but is '%T'",
4947                                  first_type);
4948                 }
4949                 parm = parm->next;
4950                 if (parm != NULL) {
4951                         type_t *const second_type = parm->type;
4952                         if (!types_compatible(skip_typeref(second_type), type_char_ptr_ptr)) {
4953                                 warningf(pos, "second argument of 'main' should be 'char**', but is '%T'", second_type);
4954                         }
4955                         parm = parm->next;
4956                         if (parm != NULL) {
4957                                 type_t *const third_type = parm->type;
4958                                 if (!types_compatible(skip_typeref(third_type), type_char_ptr_ptr)) {
4959                                         warningf(pos, "third argument of 'main' should be 'char**', but is '%T'", third_type);
4960                                 }
4961                                 parm = parm->next;
4962                                 if (parm != NULL)
4963                                         goto warn_arg_count;
4964                         }
4965                 } else {
4966 warn_arg_count:
4967                         warningf(pos, "'main' takes only zero, two or three arguments");
4968                 }
4969         }
4970 }
4971
4972 /**
4973  * Check if a symbol is the equal to "main".
4974  */
4975 static bool is_sym_main(const symbol_t *const sym)
4976 {
4977         return strcmp(sym->string, "main") == 0;
4978 }
4979
4980 static void error_redefined_as_different_kind(const source_position_t *pos,
4981                 const entity_t *old, entity_kind_t new_kind)
4982 {
4983         errorf(pos, "redeclaration of %s '%Y' as %s (declared %P)",
4984                get_entity_kind_name(old->kind), old->base.symbol,
4985                get_entity_kind_name(new_kind), &old->base.source_position);
4986 }
4987
4988 static bool is_error_entity(entity_t *const ent)
4989 {
4990         if (is_declaration(ent)) {
4991                 return is_type_valid(skip_typeref(ent->declaration.type));
4992         } else if (ent->kind == ENTITY_TYPEDEF) {
4993                 return is_type_valid(skip_typeref(ent->typedefe.type));
4994         }
4995         return false;
4996 }
4997
4998 /**
4999  * record entities for the NAMESPACE_NORMAL, and produce error messages/warnings
5000  * for various problems that occur for multiple definitions
5001  */
5002 static entity_t *record_entity(entity_t *entity, const bool is_definition)
5003 {
5004         const symbol_t *const    symbol  = entity->base.symbol;
5005         const namespace_tag_t    namespc = (namespace_tag_t)entity->base.namespc;
5006         const source_position_t *pos     = &entity->base.source_position;
5007
5008         /* can happen in error cases */
5009         if (symbol == NULL)
5010                 return entity;
5011
5012         entity_t *const previous_entity = get_entity(symbol, namespc);
5013         /* pushing the same entity twice will break the stack structure */
5014         assert(previous_entity != entity);
5015
5016         if (entity->kind == ENTITY_FUNCTION) {
5017                 type_t *const orig_type = entity->declaration.type;
5018                 type_t *const type      = skip_typeref(orig_type);
5019
5020                 assert(is_type_function(type));
5021                 if (type->function.unspecified_parameters &&
5022                                 warning.strict_prototypes &&
5023                                 previous_entity == NULL) {
5024                         warningf(pos, "function declaration '%#T' is not a prototype",
5025                                          orig_type, symbol);
5026                 }
5027
5028                 if (warning.main && current_scope == file_scope
5029                                 && is_sym_main(symbol)) {
5030                         check_type_of_main(entity);
5031                 }
5032         }
5033
5034         if (is_declaration(entity) &&
5035                         warning.nested_externs &&
5036                         entity->declaration.storage_class == STORAGE_CLASS_EXTERN &&
5037                         current_scope != file_scope) {
5038                 warningf(pos, "nested extern declaration of '%#T'",
5039                          entity->declaration.type, symbol);
5040         }
5041
5042         if (previous_entity != NULL) {
5043                 if (previous_entity->base.parent_scope == &current_function->parameters &&
5044                                 previous_entity->base.parent_scope->depth + 1 == current_scope->depth) {
5045                         assert(previous_entity->kind == ENTITY_PARAMETER);
5046                         errorf(pos,
5047                                         "declaration '%#T' redeclares the parameter '%#T' (declared %P)",
5048                                         entity->declaration.type, symbol,
5049                                         previous_entity->declaration.type, symbol,
5050                                         &previous_entity->base.source_position);
5051                         goto finish;
5052                 }
5053
5054                 if (previous_entity->base.parent_scope == current_scope) {
5055                         if (previous_entity->kind != entity->kind) {
5056                                 if (!is_error_entity(previous_entity) && !is_error_entity(entity)) {
5057                                         error_redefined_as_different_kind(pos, previous_entity,
5058                                                         entity->kind);
5059                                 }
5060                                 goto finish;
5061                         }
5062                         if (previous_entity->kind == ENTITY_ENUM_VALUE) {
5063                                 errorf(pos, "redeclaration of enum entry '%Y' (declared %P)",
5064                                                 symbol, &previous_entity->base.source_position);
5065                                 goto finish;
5066                         }
5067                         if (previous_entity->kind == ENTITY_TYPEDEF) {
5068                                 /* TODO: C++ allows this for exactly the same type */
5069                                 errorf(pos, "redefinition of typedef '%Y' (declared %P)",
5070                                                 symbol, &previous_entity->base.source_position);
5071                                 goto finish;
5072                         }
5073
5074                         /* at this point we should have only VARIABLES or FUNCTIONS */
5075                         assert(is_declaration(previous_entity) && is_declaration(entity));
5076
5077                         declaration_t *const prev_decl = &previous_entity->declaration;
5078                         declaration_t *const decl      = &entity->declaration;
5079
5080                         /* can happen for K&R style declarations */
5081                         if (prev_decl->type       == NULL             &&
5082                                         previous_entity->kind == ENTITY_PARAMETER &&
5083                                         entity->kind          == ENTITY_PARAMETER) {
5084                                 prev_decl->type                   = decl->type;
5085                                 prev_decl->storage_class          = decl->storage_class;
5086                                 prev_decl->declared_storage_class = decl->declared_storage_class;
5087                                 prev_decl->modifiers              = decl->modifiers;
5088                                 prev_decl->deprecated_string      = decl->deprecated_string;
5089                                 return previous_entity;
5090                         }
5091
5092                         type_t *const orig_type = decl->type;
5093                         assert(orig_type != NULL);
5094                         type_t *const type      = skip_typeref(orig_type);
5095                         type_t *const prev_type = skip_typeref(prev_decl->type);
5096
5097                         if (!types_compatible(type, prev_type)) {
5098                                 errorf(pos,
5099                                                 "declaration '%#T' is incompatible with '%#T' (declared %P)",
5100                                                 orig_type, symbol, prev_decl->type, symbol,
5101                                                 &previous_entity->base.source_position);
5102                         } else {
5103                                 unsigned old_storage_class = prev_decl->storage_class;
5104                                 if (warning.redundant_decls               &&
5105                                                 is_definition                     &&
5106                                                 !prev_decl->used                  &&
5107                                                 !(prev_decl->modifiers & DM_USED) &&
5108                                                 prev_decl->storage_class == STORAGE_CLASS_STATIC) {
5109                                         warningf(&previous_entity->base.source_position,
5110                                                         "unnecessary static forward declaration for '%#T'",
5111                                                         prev_decl->type, symbol);
5112                                 }
5113
5114                                 storage_class_t new_storage_class = decl->storage_class;
5115
5116                                 /* pretend no storage class means extern for function
5117                                  * declarations (except if the previous declaration is neither
5118                                  * none nor extern) */
5119                                 if (entity->kind == ENTITY_FUNCTION) {
5120                                         /* the previous declaration could have unspecified parameters or
5121                                          * be a typedef, so use the new type */
5122                                         if (prev_type->function.unspecified_parameters || is_definition)
5123                                                 prev_decl->type = type;
5124
5125                                         switch (old_storage_class) {
5126                                                 case STORAGE_CLASS_NONE:
5127                                                         old_storage_class = STORAGE_CLASS_EXTERN;
5128                                                         /* FALLTHROUGH */
5129
5130                                                 case STORAGE_CLASS_EXTERN:
5131                                                         if (is_definition) {
5132                                                                 if (warning.missing_prototypes &&
5133                                                                                 prev_type->function.unspecified_parameters &&
5134                                                                                 !is_sym_main(symbol)) {
5135                                                                         warningf(pos, "no previous prototype for '%#T'",
5136                                                                                         orig_type, symbol);
5137                                                                 }
5138                                                         } else if (new_storage_class == STORAGE_CLASS_NONE) {
5139                                                                 new_storage_class = STORAGE_CLASS_EXTERN;
5140                                                         }
5141                                                         break;
5142
5143                                                 default:
5144                                                         break;
5145                                         }
5146                                 } else if (is_type_incomplete(prev_type)) {
5147                                         prev_decl->type = type;
5148                                 }
5149
5150                                 if (old_storage_class == STORAGE_CLASS_EXTERN &&
5151                                                 new_storage_class == STORAGE_CLASS_EXTERN) {
5152 warn_redundant_declaration:
5153                                         if (!is_definition           &&
5154                                                         warning.redundant_decls  &&
5155                                                         is_type_valid(prev_type) &&
5156                                                         strcmp(previous_entity->base.source_position.input_name,
5157                                                                 "<builtin>") != 0) {
5158                                                 warningf(pos,
5159                                                                 "redundant declaration for '%Y' (declared %P)",
5160                                                                 symbol, &previous_entity->base.source_position);
5161                                         }
5162                                 } else if (current_function == NULL) {
5163                                         if (old_storage_class != STORAGE_CLASS_STATIC &&
5164                                                         new_storage_class == STORAGE_CLASS_STATIC) {
5165                                                 errorf(pos,
5166                                                                 "static declaration of '%Y' follows non-static declaration (declared %P)",
5167                                                                 symbol, &previous_entity->base.source_position);
5168                                         } else if (old_storage_class == STORAGE_CLASS_EXTERN) {
5169                                                 prev_decl->storage_class          = STORAGE_CLASS_NONE;
5170                                                 prev_decl->declared_storage_class = STORAGE_CLASS_NONE;
5171                                         } else {
5172                                                 /* ISO/IEC 14882:1998(E) §C.1.2:1 */
5173                                                 if (c_mode & _CXX)
5174                                                         goto error_redeclaration;
5175                                                 goto warn_redundant_declaration;
5176                                         }
5177                                 } else if (is_type_valid(prev_type)) {
5178                                         if (old_storage_class == new_storage_class) {
5179 error_redeclaration:
5180                                                 errorf(pos, "redeclaration of '%Y' (declared %P)",
5181                                                                 symbol, &previous_entity->base.source_position);
5182                                         } else {
5183                                                 errorf(pos,
5184                                                                 "redeclaration of '%Y' with different linkage (declared %P)",
5185                                                                 symbol, &previous_entity->base.source_position);
5186                                         }
5187                                 }
5188                         }
5189
5190                         prev_decl->modifiers |= decl->modifiers;
5191                         if (entity->kind == ENTITY_FUNCTION) {
5192                                 previous_entity->function.is_inline |= entity->function.is_inline;
5193                         }
5194                         return previous_entity;
5195                 }
5196
5197                 if (warning.shadow) {
5198                         warningf(pos, "%s '%Y' shadows %s (declared %P)",
5199                                         get_entity_kind_name(entity->kind), symbol,
5200                                         get_entity_kind_name(previous_entity->kind),
5201                                         &previous_entity->base.source_position);
5202                 }
5203         }
5204
5205         if (entity->kind == ENTITY_FUNCTION) {
5206                 if (is_definition &&
5207                                 entity->declaration.storage_class != STORAGE_CLASS_STATIC) {
5208                         if (warning.missing_prototypes && !is_sym_main(symbol)) {
5209                                 warningf(pos, "no previous prototype for '%#T'",
5210                                          entity->declaration.type, symbol);
5211                         } else if (warning.missing_declarations && !is_sym_main(symbol)) {
5212                                 warningf(pos, "no previous declaration for '%#T'",
5213                                          entity->declaration.type, symbol);
5214                         }
5215                 }
5216         } else if (warning.missing_declarations &&
5217                         entity->kind == ENTITY_VARIABLE &&
5218                         current_scope == file_scope) {
5219                 declaration_t *declaration = &entity->declaration;
5220                 if (declaration->storage_class == STORAGE_CLASS_NONE) {
5221                         warningf(pos, "no previous declaration for '%#T'",
5222                                  declaration->type, symbol);
5223                 }
5224         }
5225
5226 finish:
5227         assert(entity->base.parent_scope == NULL);
5228         assert(current_scope != NULL);
5229
5230         entity->base.parent_scope = current_scope;
5231         entity->base.namespc      = NAMESPACE_NORMAL;
5232         environment_push(entity);
5233         append_entity(current_scope, entity);
5234
5235         return entity;
5236 }
5237
5238 static void parser_error_multiple_definition(entity_t *entity,
5239                 const source_position_t *source_position)
5240 {
5241         errorf(source_position, "multiple definition of '%Y' (declared %P)",
5242                entity->base.symbol, &entity->base.source_position);
5243 }
5244
5245 static bool is_declaration_specifier(const token_t *token,
5246                                      bool only_specifiers_qualifiers)
5247 {
5248         switch (token->type) {
5249                 TYPE_SPECIFIERS
5250                 TYPE_QUALIFIERS
5251                         return true;
5252                 case T_IDENTIFIER:
5253                         return is_typedef_symbol(token->v.symbol);
5254
5255                 case T___extension__:
5256                 STORAGE_CLASSES
5257                         return !only_specifiers_qualifiers;
5258
5259                 default:
5260                         return false;
5261         }
5262 }
5263
5264 static void parse_init_declarator_rest(entity_t *entity)
5265 {
5266         assert(is_declaration(entity));
5267         declaration_t *const declaration = &entity->declaration;
5268
5269         eat('=');
5270
5271         type_t *orig_type = declaration->type;
5272         type_t *type      = skip_typeref(orig_type);
5273
5274         if (entity->kind == ENTITY_VARIABLE
5275                         && entity->variable.initializer != NULL) {
5276                 parser_error_multiple_definition(entity, HERE);
5277         }
5278
5279         bool must_be_constant = false;
5280         if (declaration->storage_class == STORAGE_CLASS_STATIC ||
5281             entity->base.parent_scope  == file_scope) {
5282                 must_be_constant = true;
5283         }
5284
5285         if (is_type_function(type)) {
5286                 errorf(&entity->base.source_position,
5287                        "function '%#T' is initialized like a variable",
5288                        orig_type, entity->base.symbol);
5289                 orig_type = type_error_type;
5290         }
5291
5292         parse_initializer_env_t env;
5293         env.type             = orig_type;
5294         env.must_be_constant = must_be_constant;
5295         env.entity           = entity;
5296         current_init_decl    = entity;
5297
5298         initializer_t *initializer = parse_initializer(&env);
5299         current_init_decl = NULL;
5300
5301         if (entity->kind == ENTITY_VARIABLE) {
5302                 /* §6.7.5:22  array initializers for arrays with unknown size
5303                  * determine the array type size */
5304                 declaration->type            = env.type;
5305                 entity->variable.initializer = initializer;
5306         }
5307 }
5308
5309 /* parse rest of a declaration without any declarator */
5310 static void parse_anonymous_declaration_rest(
5311                 const declaration_specifiers_t *specifiers)
5312 {
5313         eat(';');
5314         anonymous_entity = NULL;
5315
5316         if (warning.other) {
5317                 if (specifiers->storage_class != STORAGE_CLASS_NONE ||
5318                                 specifiers->thread_local) {
5319                         warningf(&specifiers->source_position,
5320                                  "useless storage class in empty declaration");
5321                 }
5322
5323                 type_t *type = specifiers->type;
5324                 switch (type->kind) {
5325                         case TYPE_COMPOUND_STRUCT:
5326                         case TYPE_COMPOUND_UNION: {
5327                                 if (type->compound.compound->base.symbol == NULL) {
5328                                         warningf(&specifiers->source_position,
5329                                                  "unnamed struct/union that defines no instances");
5330                                 }
5331                                 break;
5332                         }
5333
5334                         case TYPE_ENUM:
5335                                 break;
5336
5337                         default:
5338                                 warningf(&specifiers->source_position, "empty declaration");
5339                                 break;
5340                 }
5341         }
5342 }
5343
5344 static void check_variable_type_complete(entity_t *ent)
5345 {
5346         if (ent->kind != ENTITY_VARIABLE)
5347                 return;
5348
5349         /* §6.7:7  If an identifier for an object is declared with no linkage, the
5350          *         type for the object shall be complete [...] */
5351         declaration_t *decl = &ent->declaration;
5352         if (decl->storage_class == STORAGE_CLASS_EXTERN ||
5353                         decl->storage_class == STORAGE_CLASS_STATIC)
5354                 return;
5355
5356         type_t *const orig_type = decl->type;
5357         type_t *const type      = skip_typeref(orig_type);
5358         if (!is_type_incomplete(type))
5359                 return;
5360
5361         /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
5362          * are given length one. */
5363         if (is_type_array(type) && ent->base.parent_scope == file_scope) {
5364                 ARR_APP1(declaration_t*, incomplete_arrays, decl);
5365                 return;
5366         }
5367
5368         errorf(&ent->base.source_position, "variable '%#T' has incomplete type",
5369                         orig_type, ent->base.symbol);
5370 }
5371
5372
5373 static void parse_declaration_rest(entity_t *ndeclaration,
5374                 const declaration_specifiers_t *specifiers,
5375                 parsed_declaration_func         finished_declaration,
5376                 declarator_flags_t              flags)
5377 {
5378         add_anchor_token(';');
5379         add_anchor_token(',');
5380         while (true) {
5381                 entity_t *entity = finished_declaration(ndeclaration, token.type == '=');
5382
5383                 if (token.type == '=') {
5384                         parse_init_declarator_rest(entity);
5385                 } else if (entity->kind == ENTITY_VARIABLE) {
5386                         /* ISO/IEC 14882:1998(E) §8.5.3:3  The initializer can be omitted
5387                          * [...] where the extern specifier is explicitly used. */
5388                         declaration_t *decl = &entity->declaration;
5389                         if (decl->storage_class != STORAGE_CLASS_EXTERN) {
5390                                 type_t *type = decl->type;
5391                                 if (is_type_reference(skip_typeref(type))) {
5392                                         errorf(&entity->base.source_position,
5393                                                         "reference '%#T' must be initialized",
5394                                                         type, entity->base.symbol);
5395                                 }
5396                         }
5397                 }
5398
5399                 check_variable_type_complete(entity);
5400
5401                 if (token.type != ',')
5402                         break;
5403                 eat(',');
5404
5405                 add_anchor_token('=');
5406                 ndeclaration = parse_declarator(specifiers, flags);
5407                 rem_anchor_token('=');
5408         }
5409         expect(';', end_error);
5410
5411 end_error:
5412         anonymous_entity = NULL;
5413         rem_anchor_token(';');
5414         rem_anchor_token(',');
5415 }
5416
5417 static entity_t *finished_kr_declaration(entity_t *entity, bool is_definition)
5418 {
5419         symbol_t *symbol = entity->base.symbol;
5420         if (symbol == NULL) {
5421                 errorf(HERE, "anonymous declaration not valid as function parameter");
5422                 return entity;
5423         }
5424
5425         assert(entity->base.namespc == NAMESPACE_NORMAL);
5426         entity_t *previous_entity = get_entity(symbol, NAMESPACE_NORMAL);
5427         if (previous_entity == NULL
5428                         || previous_entity->base.parent_scope != current_scope) {
5429                 errorf(HERE, "expected declaration of a function parameter, found '%Y'",
5430                        symbol);
5431                 return entity;
5432         }
5433
5434         if (is_definition) {
5435                 errorf(HERE, "parameter '%Y' is initialised", entity->base.symbol);
5436         }
5437
5438         return record_entity(entity, false);
5439 }
5440
5441 static void parse_declaration(parsed_declaration_func finished_declaration,
5442                               declarator_flags_t      flags)
5443 {
5444         declaration_specifiers_t specifiers;
5445         memset(&specifiers, 0, sizeof(specifiers));
5446
5447         add_anchor_token(';');
5448         parse_declaration_specifiers(&specifiers);
5449         rem_anchor_token(';');
5450
5451         if (token.type == ';') {
5452                 parse_anonymous_declaration_rest(&specifiers);
5453         } else {
5454                 entity_t *entity = parse_declarator(&specifiers, flags);
5455                 parse_declaration_rest(entity, &specifiers, finished_declaration, flags);
5456         }
5457 }
5458
5459 static type_t *get_default_promoted_type(type_t *orig_type)
5460 {
5461         type_t *result = orig_type;
5462
5463         type_t *type = skip_typeref(orig_type);
5464         if (is_type_integer(type)) {
5465                 result = promote_integer(type);
5466         } else if (is_type_atomic(type, ATOMIC_TYPE_FLOAT)) {
5467                 result = type_double;
5468         }
5469
5470         return result;
5471 }
5472
5473 static void parse_kr_declaration_list(entity_t *entity)
5474 {
5475         if (entity->kind != ENTITY_FUNCTION)
5476                 return;
5477
5478         type_t *type = skip_typeref(entity->declaration.type);
5479         assert(is_type_function(type));
5480         if (!type->function.kr_style_parameters)
5481                 return;
5482
5483
5484         add_anchor_token('{');
5485
5486         /* push function parameters */
5487         size_t const  top       = environment_top();
5488         scope_t      *old_scope = scope_push(&entity->function.parameters);
5489
5490         entity_t *parameter = entity->function.parameters.entities;
5491         for ( ; parameter != NULL; parameter = parameter->base.next) {
5492                 assert(parameter->base.parent_scope == NULL);
5493                 parameter->base.parent_scope = current_scope;
5494                 environment_push(parameter);
5495         }
5496
5497         /* parse declaration list */
5498         for (;;) {
5499                 switch (token.type) {
5500                         DECLARATION_START
5501                         case T___extension__:
5502                         /* This covers symbols, which are no type, too, and results in
5503                          * better error messages.  The typical cases are misspelled type
5504                          * names and missing includes. */
5505                         case T_IDENTIFIER:
5506                                 parse_declaration(finished_kr_declaration, DECL_IS_PARAMETER);
5507                                 break;
5508                         default:
5509                                 goto decl_list_end;
5510                 }
5511         }
5512 decl_list_end:
5513
5514         /* pop function parameters */
5515         assert(current_scope == &entity->function.parameters);
5516         scope_pop(old_scope);
5517         environment_pop_to(top);
5518
5519         /* update function type */
5520         type_t *new_type = duplicate_type(type);
5521
5522         function_parameter_t *parameters     = NULL;
5523         function_parameter_t *last_parameter = NULL;
5524
5525         parameter = entity->function.parameters.entities;
5526         for (; parameter != NULL; parameter = parameter->base.next) {
5527                 if (parameter->kind != ENTITY_PARAMETER)
5528                         continue;
5529
5530                 type_t *parameter_type = parameter->declaration.type;
5531                 if (parameter_type == NULL) {
5532                         if (strict_mode) {
5533                                 errorf(HERE, "no type specified for function parameter '%Y'",
5534                                        parameter->base.symbol);
5535                         } else {
5536                                 if (warning.implicit_int) {
5537                                         warningf(HERE, "no type specified for function parameter '%Y', using 'int'",
5538                                                  parameter->base.symbol);
5539                                 }
5540                                 parameter_type              = type_int;
5541                                 parameter->declaration.type = parameter_type;
5542                         }
5543                 }
5544
5545                 semantic_parameter_incomplete(parameter);
5546                 parameter_type = parameter->declaration.type;
5547
5548                 /*
5549                  * we need the default promoted types for the function type
5550                  */
5551                 parameter_type = get_default_promoted_type(parameter_type);
5552
5553                 function_parameter_t *function_parameter
5554                         = obstack_alloc(type_obst, sizeof(function_parameter[0]));
5555                 memset(function_parameter, 0, sizeof(function_parameter[0]));
5556
5557                 function_parameter->type = parameter_type;
5558                 if (last_parameter != NULL) {
5559                         last_parameter->next = function_parameter;
5560                 } else {
5561                         parameters = function_parameter;
5562                 }
5563                 last_parameter = function_parameter;
5564         }
5565
5566         /* §6.9.1.7: A K&R style parameter list does NOT act as a function
5567          * prototype */
5568         new_type->function.parameters             = parameters;
5569         new_type->function.unspecified_parameters = true;
5570
5571         new_type = identify_new_type(new_type);
5572
5573         entity->declaration.type = new_type;
5574
5575         rem_anchor_token('{');
5576 }
5577
5578 static bool first_err = true;
5579
5580 /**
5581  * When called with first_err set, prints the name of the current function,
5582  * else does noting.
5583  */
5584 static void print_in_function(void)
5585 {
5586         if (first_err) {
5587                 first_err = false;
5588                 diagnosticf("%s: In function '%Y':\n",
5589                             current_function->base.base.source_position.input_name,
5590                             current_function->base.base.symbol);
5591         }
5592 }
5593
5594 /**
5595  * Check if all labels are defined in the current function.
5596  * Check if all labels are used in the current function.
5597  */
5598 static void check_labels(void)
5599 {
5600         for (const goto_statement_t *goto_statement = goto_first;
5601             goto_statement != NULL;
5602             goto_statement = goto_statement->next) {
5603                 /* skip computed gotos */
5604                 if (goto_statement->expression != NULL)
5605                         continue;
5606
5607                 label_t *label = goto_statement->label;
5608
5609                 label->used = true;
5610                 if (label->base.source_position.input_name == NULL) {
5611                         print_in_function();
5612                         errorf(&goto_statement->base.source_position,
5613                                "label '%Y' used but not defined", label->base.symbol);
5614                  }
5615         }
5616
5617         if (warning.unused_label) {
5618                 for (const label_statement_t *label_statement = label_first;
5619                          label_statement != NULL;
5620                          label_statement = label_statement->next) {
5621                         label_t *label = label_statement->label;
5622
5623                         if (! label->used) {
5624                                 print_in_function();
5625                                 warningf(&label_statement->base.source_position,
5626                                          "label '%Y' defined but not used", label->base.symbol);
5627                         }
5628                 }
5629         }
5630 }
5631
5632 static void warn_unused_entity(entity_t *entity, entity_t *last)
5633 {
5634         entity_t const *const end = last != NULL ? last->base.next : NULL;
5635         for (; entity != end; entity = entity->base.next) {
5636                 if (!is_declaration(entity))
5637                         continue;
5638
5639                 declaration_t *declaration = &entity->declaration;
5640                 if (declaration->implicit)
5641                         continue;
5642
5643                 if (!declaration->used) {
5644                         print_in_function();
5645                         const char *what = get_entity_kind_name(entity->kind);
5646                         warningf(&entity->base.source_position, "%s '%Y' is unused",
5647                                  what, entity->base.symbol);
5648                 } else if (entity->kind == ENTITY_VARIABLE && !entity->variable.read) {
5649                         print_in_function();
5650                         const char *what = get_entity_kind_name(entity->kind);
5651                         warningf(&entity->base.source_position, "%s '%Y' is never read",
5652                                  what, entity->base.symbol);
5653                 }
5654         }
5655 }
5656
5657 static void check_unused_variables(statement_t *const stmt, void *const env)
5658 {
5659         (void)env;
5660
5661         switch (stmt->kind) {
5662                 case STATEMENT_DECLARATION: {
5663                         declaration_statement_t const *const decls = &stmt->declaration;
5664                         warn_unused_entity(decls->declarations_begin,
5665                                            decls->declarations_end);
5666                         return;
5667                 }
5668
5669                 case STATEMENT_FOR:
5670                         warn_unused_entity(stmt->fors.scope.entities, NULL);
5671                         return;
5672
5673                 default:
5674                         return;
5675         }
5676 }
5677
5678 /**
5679  * Check declarations of current_function for unused entities.
5680  */
5681 static void check_declarations(void)
5682 {
5683         if (warning.unused_parameter) {
5684                 const scope_t *scope = &current_function->parameters;
5685
5686                 /* do not issue unused warnings for main */
5687                 if (!is_sym_main(current_function->base.base.symbol)) {
5688                         warn_unused_entity(scope->entities, NULL);
5689                 }
5690         }
5691         if (warning.unused_variable) {
5692                 walk_statements(current_function->statement, check_unused_variables,
5693                                 NULL);
5694         }
5695 }
5696
5697 static int determine_truth(expression_t const* const cond)
5698 {
5699         return
5700                 !is_constant_expression(cond) ? 0 :
5701                 fold_constant(cond) != 0      ? 1 :
5702                 -1;
5703 }
5704
5705 static void check_reachable(statement_t *);
5706 static bool reaches_end;
5707
5708 static bool expression_returns(expression_t const *const expr)
5709 {
5710         switch (expr->kind) {
5711                 case EXPR_CALL: {
5712                         expression_t const *const func = expr->call.function;
5713                         if (func->kind == EXPR_REFERENCE) {
5714                                 entity_t *entity = func->reference.entity;
5715                                 if (entity->kind == ENTITY_FUNCTION
5716                                                 && entity->declaration.modifiers & DM_NORETURN)
5717                                         return false;
5718                         }
5719
5720                         if (!expression_returns(func))
5721                                 return false;
5722
5723                         for (call_argument_t const* arg = expr->call.arguments; arg != NULL; arg = arg->next) {
5724                                 if (!expression_returns(arg->expression))
5725                                         return false;
5726                         }
5727
5728                         return true;
5729                 }
5730
5731                 case EXPR_REFERENCE:
5732                 case EXPR_REFERENCE_ENUM_VALUE:
5733                 case EXPR_CONST:
5734                 case EXPR_CHARACTER_CONSTANT:
5735                 case EXPR_WIDE_CHARACTER_CONSTANT:
5736                 case EXPR_STRING_LITERAL:
5737                 case EXPR_WIDE_STRING_LITERAL:
5738                 case EXPR_COMPOUND_LITERAL: // TODO descend into initialisers
5739                 case EXPR_LABEL_ADDRESS:
5740                 case EXPR_CLASSIFY_TYPE:
5741                 case EXPR_SIZEOF: // TODO handle obscure VLA case
5742                 case EXPR_ALIGNOF:
5743                 case EXPR_FUNCNAME:
5744                 case EXPR_BUILTIN_CONSTANT_P:
5745                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
5746                 case EXPR_OFFSETOF:
5747                 case EXPR_INVALID:
5748                         return true;
5749
5750                 case EXPR_STATEMENT: {
5751                         bool old_reaches_end = reaches_end;
5752                         reaches_end = false;
5753                         check_reachable(expr->statement.statement);
5754                         bool returns = reaches_end;
5755                         reaches_end = old_reaches_end;
5756                         return returns;
5757                 }
5758
5759                 case EXPR_CONDITIONAL:
5760                         // TODO handle constant expression
5761
5762                         if (!expression_returns(expr->conditional.condition))
5763                                 return false;
5764
5765                         if (expr->conditional.true_expression != NULL
5766                                         && expression_returns(expr->conditional.true_expression))
5767                                 return true;
5768
5769                         return expression_returns(expr->conditional.false_expression);
5770
5771                 case EXPR_SELECT:
5772                         return expression_returns(expr->select.compound);
5773
5774                 case EXPR_ARRAY_ACCESS:
5775                         return
5776                                 expression_returns(expr->array_access.array_ref) &&
5777                                 expression_returns(expr->array_access.index);
5778
5779                 case EXPR_VA_START:
5780                         return expression_returns(expr->va_starte.ap);
5781
5782                 case EXPR_VA_ARG:
5783                         return expression_returns(expr->va_arge.ap);
5784
5785                 EXPR_UNARY_CASES_MANDATORY
5786                         return expression_returns(expr->unary.value);
5787
5788                 case EXPR_UNARY_THROW:
5789                         return false;
5790
5791                 EXPR_BINARY_CASES
5792                         // TODO handle constant lhs of && and ||
5793                         return
5794                                 expression_returns(expr->binary.left) &&
5795                                 expression_returns(expr->binary.right);
5796
5797                 case EXPR_UNKNOWN:
5798                         break;
5799         }
5800
5801         panic("unhandled expression");
5802 }
5803
5804 static bool initializer_returns(initializer_t const *const init)
5805 {
5806         switch (init->kind) {
5807                 case INITIALIZER_VALUE:
5808                         return expression_returns(init->value.value);
5809
5810                 case INITIALIZER_LIST: {
5811                         initializer_t * const*       i       = init->list.initializers;
5812                         initializer_t * const* const end     = i + init->list.len;
5813                         bool                         returns = true;
5814                         for (; i != end; ++i) {
5815                                 if (!initializer_returns(*i))
5816                                         returns = false;
5817                         }
5818                         return returns;
5819                 }
5820
5821                 case INITIALIZER_STRING:
5822                 case INITIALIZER_WIDE_STRING:
5823                 case INITIALIZER_DESIGNATOR: // designators have no payload
5824                         return true;
5825         }
5826         panic("unhandled initializer");
5827 }
5828
5829 static bool noreturn_candidate;
5830
5831 static void check_reachable(statement_t *const stmt)
5832 {
5833         if (stmt->base.reachable)
5834                 return;
5835         if (stmt->kind != STATEMENT_DO_WHILE)
5836                 stmt->base.reachable = true;
5837
5838         statement_t *last = stmt;
5839         statement_t *next;
5840         switch (stmt->kind) {
5841                 case STATEMENT_INVALID:
5842                 case STATEMENT_EMPTY:
5843                 case STATEMENT_ASM:
5844                         next = stmt->base.next;
5845                         break;
5846
5847                 case STATEMENT_DECLARATION: {
5848                         declaration_statement_t const *const decl = &stmt->declaration;
5849                         entity_t                const *      ent  = decl->declarations_begin;
5850                         entity_t                const *const last = decl->declarations_end;
5851                         if (ent != NULL) {
5852                                 for (;; ent = ent->base.next) {
5853                                         if (ent->kind                 == ENTITY_VARIABLE &&
5854                                                         ent->variable.initializer != NULL            &&
5855                                                         !initializer_returns(ent->variable.initializer)) {
5856                                                 return;
5857                                         }
5858                                         if (ent == last)
5859                                                 break;
5860                                 }
5861                         }
5862                         next = stmt->base.next;
5863                         break;
5864                 }
5865
5866                 case STATEMENT_COMPOUND:
5867                         next = stmt->compound.statements;
5868                         if (next == NULL)
5869                                 next = stmt->base.next;
5870                         break;
5871
5872                 case STATEMENT_RETURN: {
5873                         expression_t const *const val = stmt->returns.value;
5874                         if (val == NULL || expression_returns(val))
5875                                 noreturn_candidate = false;
5876                         return;
5877                 }
5878
5879                 case STATEMENT_IF: {
5880                         if_statement_t const *const ifs  = &stmt->ifs;
5881                         expression_t   const *const cond = ifs->condition;
5882
5883                         if (!expression_returns(cond))
5884                                 return;
5885
5886                         int const val = determine_truth(cond);
5887
5888                         if (val >= 0)
5889                                 check_reachable(ifs->true_statement);
5890
5891                         if (val > 0)
5892                                 return;
5893
5894                         if (ifs->false_statement != NULL) {
5895                                 check_reachable(ifs->false_statement);
5896                                 return;
5897                         }
5898
5899                         next = stmt->base.next;
5900                         break;
5901                 }
5902
5903                 case STATEMENT_SWITCH: {
5904                         switch_statement_t const *const switchs = &stmt->switchs;
5905                         expression_t       const *const expr    = switchs->expression;
5906
5907                         if (!expression_returns(expr))
5908                                 return;
5909
5910                         if (is_constant_expression(expr)) {
5911                                 long                    const val      = fold_constant(expr);
5912                                 case_label_statement_t *      defaults = NULL;
5913                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
5914                                         if (i->expression == NULL) {
5915                                                 defaults = i;
5916                                                 continue;
5917                                         }
5918
5919                                         if (i->first_case <= val && val <= i->last_case) {
5920                                                 check_reachable((statement_t*)i);
5921                                                 return;
5922                                         }
5923                                 }
5924
5925                                 if (defaults != NULL) {
5926                                         check_reachable((statement_t*)defaults);
5927                                         return;
5928                                 }
5929                         } else {
5930                                 bool has_default = false;
5931                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
5932                                         if (i->expression == NULL)
5933                                                 has_default = true;
5934
5935                                         check_reachable((statement_t*)i);
5936                                 }
5937
5938                                 if (has_default)
5939                                         return;
5940                         }
5941
5942                         next = stmt->base.next;
5943                         break;
5944                 }
5945
5946                 case STATEMENT_EXPRESSION: {
5947                         /* Check for noreturn function call */
5948                         expression_t const *const expr = stmt->expression.expression;
5949                         if (!expression_returns(expr))
5950                                 return;
5951
5952                         next = stmt->base.next;
5953                         break;
5954                 }
5955
5956                 case STATEMENT_CONTINUE: {
5957                         statement_t *parent = stmt;
5958                         for (;;) {
5959                                 parent = parent->base.parent;
5960                                 if (parent == NULL) /* continue not within loop */
5961                                         return;
5962
5963                                 next = parent;
5964                                 switch (parent->kind) {
5965                                         case STATEMENT_WHILE:    goto continue_while;
5966                                         case STATEMENT_DO_WHILE: goto continue_do_while;
5967                                         case STATEMENT_FOR:      goto continue_for;
5968
5969                                         default: break;
5970                                 }
5971                         }
5972                 }
5973
5974                 case STATEMENT_BREAK: {
5975                         statement_t *parent = stmt;
5976                         for (;;) {
5977                                 parent = parent->base.parent;
5978                                 if (parent == NULL) /* break not within loop/switch */
5979                                         return;
5980
5981                                 switch (parent->kind) {
5982                                         case STATEMENT_SWITCH:
5983                                         case STATEMENT_WHILE:
5984                                         case STATEMENT_DO_WHILE:
5985                                         case STATEMENT_FOR:
5986                                                 last = parent;
5987                                                 next = parent->base.next;
5988                                                 goto found_break_parent;
5989
5990                                         default: break;
5991                                 }
5992                         }
5993 found_break_parent:
5994                         break;
5995                 }
5996
5997                 case STATEMENT_GOTO:
5998                         if (stmt->gotos.expression) {
5999                                 if (!expression_returns(stmt->gotos.expression))
6000                                         return;
6001
6002                                 statement_t *parent = stmt->base.parent;
6003                                 if (parent == NULL) /* top level goto */
6004                                         return;
6005                                 next = parent;
6006                         } else {
6007                                 next = stmt->gotos.label->statement;
6008                                 if (next == NULL) /* missing label */
6009                                         return;
6010                         }
6011                         break;
6012
6013                 case STATEMENT_LABEL:
6014                         next = stmt->label.statement;
6015                         break;
6016
6017                 case STATEMENT_CASE_LABEL:
6018                         next = stmt->case_label.statement;
6019                         break;
6020
6021                 case STATEMENT_WHILE: {
6022                         while_statement_t const *const whiles = &stmt->whiles;
6023                         expression_t      const *const cond   = whiles->condition;
6024
6025                         if (!expression_returns(cond))
6026                                 return;
6027
6028                         int const val = determine_truth(cond);
6029
6030                         if (val >= 0)
6031                                 check_reachable(whiles->body);
6032
6033                         if (val > 0)
6034                                 return;
6035
6036                         next = stmt->base.next;
6037                         break;
6038                 }
6039
6040                 case STATEMENT_DO_WHILE:
6041                         next = stmt->do_while.body;
6042                         break;
6043
6044                 case STATEMENT_FOR: {
6045                         for_statement_t *const fors = &stmt->fors;
6046
6047                         if (fors->condition_reachable)
6048                                 return;
6049                         fors->condition_reachable = true;
6050
6051                         expression_t const *const cond = fors->condition;
6052
6053                         int val;
6054                         if (cond == NULL) {
6055                                 val = 1;
6056                         } else if (expression_returns(cond)) {
6057                                 val = determine_truth(cond);
6058                         } else {
6059                                 return;
6060                         }
6061
6062                         if (val >= 0)
6063                                 check_reachable(fors->body);
6064
6065                         if (val > 0)
6066                                 return;
6067
6068                         next = stmt->base.next;
6069                         break;
6070                 }
6071
6072                 case STATEMENT_MS_TRY: {
6073                         ms_try_statement_t const *const ms_try = &stmt->ms_try;
6074                         check_reachable(ms_try->try_statement);
6075                         next = ms_try->final_statement;
6076                         break;
6077                 }
6078
6079                 case STATEMENT_LEAVE: {
6080                         statement_t *parent = stmt;
6081                         for (;;) {
6082                                 parent = parent->base.parent;
6083                                 if (parent == NULL) /* __leave not within __try */
6084                                         return;
6085
6086                                 if (parent->kind == STATEMENT_MS_TRY) {
6087                                         last = parent;
6088                                         next = parent->ms_try.final_statement;
6089                                         break;
6090                                 }
6091                         }
6092                         break;
6093                 }
6094
6095                 default:
6096                         panic("invalid statement kind");
6097         }
6098
6099         while (next == NULL) {
6100                 next = last->base.parent;
6101                 if (next == NULL) {
6102                         noreturn_candidate = false;
6103
6104                         type_t *const type = skip_typeref(current_function->base.type);
6105                         assert(is_type_function(type));
6106                         type_t *const ret  = skip_typeref(type->function.return_type);
6107                         if (warning.return_type                    &&
6108                             !is_type_atomic(ret, ATOMIC_TYPE_VOID) &&
6109                             is_type_valid(ret)                     &&
6110                             !is_sym_main(current_function->base.base.symbol)) {
6111                                 warningf(&stmt->base.source_position,
6112                                          "control reaches end of non-void function");
6113                         }
6114                         return;
6115                 }
6116
6117                 switch (next->kind) {
6118                         case STATEMENT_INVALID:
6119                         case STATEMENT_EMPTY:
6120                         case STATEMENT_DECLARATION:
6121                         case STATEMENT_EXPRESSION:
6122                         case STATEMENT_ASM:
6123                         case STATEMENT_RETURN:
6124                         case STATEMENT_CONTINUE:
6125                         case STATEMENT_BREAK:
6126                         case STATEMENT_GOTO:
6127                         case STATEMENT_LEAVE:
6128                                 panic("invalid control flow in function");
6129
6130                         case STATEMENT_COMPOUND:
6131                                 if (next->compound.stmt_expr) {
6132                                         reaches_end = true;
6133                                         return;
6134                                 }
6135                                 /* FALLTHROUGH */
6136                         case STATEMENT_IF:
6137                         case STATEMENT_SWITCH:
6138                         case STATEMENT_LABEL:
6139                         case STATEMENT_CASE_LABEL:
6140                                 last = next;
6141                                 next = next->base.next;
6142                                 break;
6143
6144                         case STATEMENT_WHILE: {
6145 continue_while:
6146                                 if (next->base.reachable)
6147                                         return;
6148                                 next->base.reachable = true;
6149
6150                                 while_statement_t const *const whiles = &next->whiles;
6151                                 expression_t      const *const cond   = whiles->condition;
6152
6153                                 if (!expression_returns(cond))
6154                                         return;
6155
6156                                 int const val = determine_truth(cond);
6157
6158                                 if (val >= 0)
6159                                         check_reachable(whiles->body);
6160
6161                                 if (val > 0)
6162                                         return;
6163
6164                                 last = next;
6165                                 next = next->base.next;
6166                                 break;
6167                         }
6168
6169                         case STATEMENT_DO_WHILE: {
6170 continue_do_while:
6171                                 if (next->base.reachable)
6172                                         return;
6173                                 next->base.reachable = true;
6174
6175                                 do_while_statement_t const *const dw   = &next->do_while;
6176                                 expression_t         const *const cond = dw->condition;
6177
6178                                 if (!expression_returns(cond))
6179                                         return;
6180
6181                                 int const val = determine_truth(cond);
6182
6183                                 if (val >= 0)
6184                                         check_reachable(dw->body);
6185
6186                                 if (val > 0)
6187                                         return;
6188
6189                                 last = next;
6190                                 next = next->base.next;
6191                                 break;
6192                         }
6193
6194                         case STATEMENT_FOR: {
6195 continue_for:;
6196                                 for_statement_t *const fors = &next->fors;
6197
6198                                 fors->step_reachable = true;
6199
6200                                 if (fors->condition_reachable)
6201                                         return;
6202                                 fors->condition_reachable = true;
6203
6204                                 expression_t const *const cond = fors->condition;
6205
6206                                 int val;
6207                                 if (cond == NULL) {
6208                                         val = 1;
6209                                 } else if (expression_returns(cond)) {
6210                                         val = determine_truth(cond);
6211                                 } else {
6212                                         return;
6213                                 }
6214
6215                                 if (val >= 0)
6216                                         check_reachable(fors->body);
6217
6218                                 if (val > 0)
6219                                         return;
6220
6221                                 last = next;
6222                                 next = next->base.next;
6223                                 break;
6224                         }
6225
6226                         case STATEMENT_MS_TRY:
6227                                 last = next;
6228                                 next = next->ms_try.final_statement;
6229                                 break;
6230                 }
6231         }
6232
6233         check_reachable(next);
6234 }
6235
6236 static void check_unreachable(statement_t* const stmt, void *const env)
6237 {
6238         (void)env;
6239
6240         switch (stmt->kind) {
6241                 case STATEMENT_DO_WHILE:
6242                         if (!stmt->base.reachable) {
6243                                 expression_t const *const cond = stmt->do_while.condition;
6244                                 if (determine_truth(cond) >= 0) {
6245                                         warningf(&cond->base.source_position,
6246                                                  "condition of do-while-loop is unreachable");
6247                                 }
6248                         }
6249                         return;
6250
6251                 case STATEMENT_FOR: {
6252                         for_statement_t const* const fors = &stmt->fors;
6253
6254                         // if init and step are unreachable, cond is unreachable, too
6255                         if (!stmt->base.reachable && !fors->step_reachable) {
6256                                 warningf(&stmt->base.source_position, "statement is unreachable");
6257                         } else {
6258                                 if (!stmt->base.reachable && fors->initialisation != NULL) {
6259                                         warningf(&fors->initialisation->base.source_position,
6260                                                  "initialisation of for-statement is unreachable");
6261                                 }
6262
6263                                 if (!fors->condition_reachable && fors->condition != NULL) {
6264                                         warningf(&fors->condition->base.source_position,
6265                                                  "condition of for-statement is unreachable");
6266                                 }
6267
6268                                 if (!fors->step_reachable && fors->step != NULL) {
6269                                         warningf(&fors->step->base.source_position,
6270                                                  "step of for-statement is unreachable");
6271                                 }
6272                         }
6273                         return;
6274                 }
6275
6276                 case STATEMENT_COMPOUND:
6277                         if (stmt->compound.statements != NULL)
6278                                 return;
6279                         goto warn_unreachable;
6280
6281                 case STATEMENT_DECLARATION: {
6282                         /* Only warn if there is at least one declarator with an initializer.
6283                          * This typically occurs in switch statements. */
6284                         declaration_statement_t const *const decl = &stmt->declaration;
6285                         entity_t                const *      ent  = decl->declarations_begin;
6286                         entity_t                const *const last = decl->declarations_end;
6287                         if (ent != NULL) {
6288                                 for (;; ent = ent->base.next) {
6289                                         if (ent->kind                 == ENTITY_VARIABLE &&
6290                                                         ent->variable.initializer != NULL) {
6291                                                 goto warn_unreachable;
6292                                         }
6293                                         if (ent == last)
6294                                                 return;
6295                                 }
6296                         }
6297                 }
6298
6299                 default:
6300 warn_unreachable:
6301                         if (!stmt->base.reachable)
6302                                 warningf(&stmt->base.source_position, "statement is unreachable");
6303                         return;
6304         }
6305 }
6306
6307 static void parse_external_declaration(void)
6308 {
6309         /* function-definitions and declarations both start with declaration
6310          * specifiers */
6311         declaration_specifiers_t specifiers;
6312         memset(&specifiers, 0, sizeof(specifiers));
6313
6314         add_anchor_token(';');
6315         parse_declaration_specifiers(&specifiers);
6316         rem_anchor_token(';');
6317
6318         /* must be a declaration */
6319         if (token.type == ';') {
6320                 parse_anonymous_declaration_rest(&specifiers);
6321                 return;
6322         }
6323
6324         add_anchor_token(',');
6325         add_anchor_token('=');
6326         add_anchor_token(';');
6327         add_anchor_token('{');
6328
6329         /* declarator is common to both function-definitions and declarations */
6330         entity_t *ndeclaration = parse_declarator(&specifiers, DECL_FLAGS_NONE);
6331
6332         rem_anchor_token('{');
6333         rem_anchor_token(';');
6334         rem_anchor_token('=');
6335         rem_anchor_token(',');
6336
6337         /* must be a declaration */
6338         switch (token.type) {
6339                 case ',':
6340                 case ';':
6341                 case '=':
6342                         parse_declaration_rest(ndeclaration, &specifiers, record_entity,
6343                                         DECL_FLAGS_NONE);
6344                         return;
6345         }
6346
6347         /* must be a function definition */
6348         parse_kr_declaration_list(ndeclaration);
6349
6350         if (token.type != '{') {
6351                 parse_error_expected("while parsing function definition", '{', NULL);
6352                 eat_until_matching_token(';');
6353                 return;
6354         }
6355
6356         assert(is_declaration(ndeclaration));
6357         type_t *const orig_type = ndeclaration->declaration.type;
6358         type_t *      type      = skip_typeref(orig_type);
6359
6360         if (!is_type_function(type)) {
6361                 if (is_type_valid(type)) {
6362                         errorf(HERE, "declarator '%#T' has a body but is not a function type",
6363                                type, ndeclaration->base.symbol);
6364                 }
6365                 eat_block();
6366                 return;
6367         } else if (is_typeref(orig_type)) {
6368                 /* §6.9.1:2 */
6369                 errorf(&ndeclaration->base.source_position,
6370                                 "type of function definition '%#T' is a typedef",
6371                                 orig_type, ndeclaration->base.symbol);
6372         }
6373
6374         if (warning.aggregate_return &&
6375             is_type_compound(skip_typeref(type->function.return_type))) {
6376                 warningf(HERE, "function '%Y' returns an aggregate",
6377                          ndeclaration->base.symbol);
6378         }
6379         if (warning.traditional && !type->function.unspecified_parameters) {
6380                 warningf(HERE, "traditional C rejects ISO C style function definition of function '%Y'",
6381                         ndeclaration->base.symbol);
6382         }
6383         if (warning.old_style_definition && type->function.unspecified_parameters) {
6384                 warningf(HERE, "old-style function definition '%Y'",
6385                         ndeclaration->base.symbol);
6386         }
6387
6388         /* §6.7.5.3:14 a function definition with () means no
6389          * parameters (and not unspecified parameters) */
6390         if (type->function.unspecified_parameters &&
6391                         type->function.parameters == NULL     &&
6392                         !type->function.kr_style_parameters) {
6393                 type_t *copy                          = duplicate_type(type);
6394                 copy->function.unspecified_parameters = false;
6395                 type                                  = identify_new_type(copy);
6396
6397                 ndeclaration->declaration.type = type;
6398         }
6399
6400         entity_t *const entity = record_entity(ndeclaration, true);
6401         assert(entity->kind == ENTITY_FUNCTION);
6402         assert(ndeclaration->kind == ENTITY_FUNCTION);
6403
6404         function_t *function = &entity->function;
6405         if (ndeclaration != entity) {
6406                 function->parameters = ndeclaration->function.parameters;
6407         }
6408         assert(is_declaration(entity));
6409         type = skip_typeref(entity->declaration.type);
6410
6411         /* push function parameters and switch scope */
6412         size_t const  top       = environment_top();
6413         scope_t      *old_scope = scope_push(&function->parameters);
6414
6415         entity_t *parameter = function->parameters.entities;
6416         for (; parameter != NULL; parameter = parameter->base.next) {
6417                 if (parameter->base.parent_scope == &ndeclaration->function.parameters) {
6418                         parameter->base.parent_scope = current_scope;
6419                 }
6420                 assert(parameter->base.parent_scope == NULL
6421                                 || parameter->base.parent_scope == current_scope);
6422                 parameter->base.parent_scope = current_scope;
6423                 if (parameter->base.symbol == NULL) {
6424                         errorf(&parameter->base.source_position, "parameter name omitted");
6425                         continue;
6426                 }
6427                 environment_push(parameter);
6428         }
6429
6430         if (function->statement != NULL) {
6431                 parser_error_multiple_definition(entity, HERE);
6432                 eat_block();
6433         } else {
6434                 /* parse function body */
6435                 int         label_stack_top      = label_top();
6436                 function_t *old_current_function = current_function;
6437                 current_function                 = function;
6438                 current_parent                   = NULL;
6439
6440                 goto_first   = NULL;
6441                 goto_anchor  = &goto_first;
6442                 label_first  = NULL;
6443                 label_anchor = &label_first;
6444
6445                 statement_t *const body = parse_compound_statement(false);
6446                 function->statement = body;
6447                 first_err = true;
6448                 check_labels();
6449                 check_declarations();
6450                 if (warning.return_type      ||
6451                     warning.unreachable_code ||
6452                     (warning.missing_noreturn
6453                      && !(function->base.modifiers & DM_NORETURN))) {
6454                         noreturn_candidate = true;
6455                         check_reachable(body);
6456                         if (warning.unreachable_code)
6457                                 walk_statements(body, check_unreachable, NULL);
6458                         if (warning.missing_noreturn &&
6459                             noreturn_candidate       &&
6460                             !(function->base.modifiers & DM_NORETURN)) {
6461                                 warningf(&body->base.source_position,
6462                                          "function '%#T' is candidate for attribute 'noreturn'",
6463                                          type, entity->base.symbol);
6464                         }
6465                 }
6466
6467                 assert(current_parent   == NULL);
6468                 assert(current_function == function);
6469                 current_function = old_current_function;
6470                 label_pop_to(label_stack_top);
6471         }
6472
6473         assert(current_scope == &function->parameters);
6474         scope_pop(old_scope);
6475         environment_pop_to(top);
6476 }
6477
6478 static type_t *make_bitfield_type(type_t *base_type, expression_t *size,
6479                                   source_position_t *source_position,
6480                                   const symbol_t *symbol)
6481 {
6482         type_t *type = allocate_type_zero(TYPE_BITFIELD);
6483
6484         type->bitfield.base_type       = base_type;
6485         type->bitfield.size_expression = size;
6486
6487         il_size_t bit_size;
6488         type_t *skipped_type = skip_typeref(base_type);
6489         if (!is_type_integer(skipped_type)) {
6490                 errorf(HERE, "bitfield base type '%T' is not an integer type",
6491                         base_type);
6492                 bit_size = 0;
6493         } else {
6494                 bit_size = skipped_type->base.size * 8;
6495         }
6496
6497         if (is_constant_expression(size)) {
6498                 long v = fold_constant(size);
6499
6500                 if (v < 0) {
6501                         errorf(source_position, "negative width in bit-field '%Y'", symbol);
6502                 } else if (v == 0) {
6503                         errorf(source_position, "zero width for bit-field '%Y'", symbol);
6504                 } else if (bit_size > 0 && (il_size_t)v > bit_size) {
6505                         errorf(source_position, "width of '%Y' exceeds its type", symbol);
6506                 } else {
6507                         type->bitfield.bit_size = v;
6508                 }
6509         }
6510
6511         return type;
6512 }
6513
6514 static entity_t *find_compound_entry(compound_t *compound, symbol_t *symbol)
6515 {
6516         entity_t *iter = compound->members.entities;
6517         for (; iter != NULL; iter = iter->base.next) {
6518                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
6519                         continue;
6520
6521                 if (iter->base.symbol == symbol) {
6522                         return iter;
6523                 } else if (iter->base.symbol == NULL) {
6524                         type_t *type = skip_typeref(iter->declaration.type);
6525                         if (is_type_compound(type)) {
6526                                 entity_t *result
6527                                         = find_compound_entry(type->compound.compound, symbol);
6528                                 if (result != NULL)
6529                                         return result;
6530                         }
6531                         continue;
6532                 }
6533         }
6534
6535         return NULL;
6536 }
6537
6538 static void parse_compound_declarators(compound_t *compound,
6539                 const declaration_specifiers_t *specifiers)
6540 {
6541         while (true) {
6542                 entity_t *entity;
6543
6544                 if (token.type == ':') {
6545                         source_position_t source_position = *HERE;
6546                         next_token();
6547
6548                         type_t *base_type = specifiers->type;
6549                         expression_t *size = parse_constant_expression();
6550
6551                         type_t *type = make_bitfield_type(base_type, size,
6552                                         &source_position, sym_anonymous);
6553
6554                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER);
6555                         entity->base.namespc                       = NAMESPACE_NORMAL;
6556                         entity->base.source_position               = source_position;
6557                         entity->declaration.declared_storage_class = STORAGE_CLASS_NONE;
6558                         entity->declaration.storage_class          = STORAGE_CLASS_NONE;
6559                         entity->declaration.modifiers              = specifiers->modifiers;
6560                         entity->declaration.type                   = type;
6561                         append_entity(&compound->members, entity);
6562                 } else {
6563                         entity = parse_declarator(specifiers,
6564                                         DECL_MAY_BE_ABSTRACT | DECL_CREATE_COMPOUND_MEMBER);
6565                         if (entity->kind == ENTITY_TYPEDEF) {
6566                                 errorf(&entity->base.source_position,
6567                                                 "typedef not allowed as compound member");
6568                         } else {
6569                                 assert(entity->kind == ENTITY_COMPOUND_MEMBER);
6570
6571                                 /* make sure we don't define a symbol multiple times */
6572                                 symbol_t *symbol = entity->base.symbol;
6573                                 if (symbol != NULL) {
6574                                         entity_t *prev = find_compound_entry(compound, symbol);
6575                                         if (prev != NULL) {
6576                                                 errorf(&entity->base.source_position,
6577                                                                 "multiple declarations of symbol '%Y' (declared %P)",
6578                                                                 symbol, &prev->base.source_position);
6579                                         }
6580                                 }
6581
6582                                 if (token.type == ':') {
6583                                         source_position_t source_position = *HERE;
6584                                         next_token();
6585                                         expression_t *size = parse_constant_expression();
6586
6587                                         type_t *type          = entity->declaration.type;
6588                                         type_t *bitfield_type = make_bitfield_type(type, size,
6589                                                         &source_position, entity->base.symbol);
6590                                         entity->declaration.type = bitfield_type;
6591                                 } else {
6592                                         type_t *orig_type = entity->declaration.type;
6593                                         type_t *type      = skip_typeref(orig_type);
6594                                         if (is_type_function(type)) {
6595                                                 errorf(&entity->base.source_position,
6596                                                                 "compound member '%Y' must not have function type '%T'",
6597                                                                 entity->base.symbol, orig_type);
6598                                         } else if (is_type_incomplete(type)) {
6599                                                 /* §6.7.2.1:16 flexible array member */
6600                                                 if (!is_type_array(type)       ||
6601                                                                 token.type          != ';' ||
6602                                                                 look_ahead(1)->type != '}') {
6603                                                         errorf(&entity->base.source_position,
6604                                                                         "compound member '%Y' has incomplete type '%T'",
6605                                                                         entity->base.symbol, orig_type);
6606                                                 }
6607                                         }
6608                                 }
6609
6610                                 append_entity(&compound->members, entity);
6611                         }
6612                 }
6613
6614                 if (token.type != ',')
6615                         break;
6616                 next_token();
6617         }
6618         expect(';', end_error);
6619
6620 end_error:
6621         anonymous_entity = NULL;
6622 }
6623
6624 static void parse_compound_type_entries(compound_t *compound)
6625 {
6626         eat('{');
6627         add_anchor_token('}');
6628
6629         while (token.type != '}') {
6630                 if (token.type == T_EOF) {
6631                         errorf(HERE, "EOF while parsing struct");
6632                         break;
6633                 }
6634                 declaration_specifiers_t specifiers;
6635                 memset(&specifiers, 0, sizeof(specifiers));
6636                 parse_declaration_specifiers(&specifiers);
6637
6638                 parse_compound_declarators(compound, &specifiers);
6639         }
6640         rem_anchor_token('}');
6641         next_token();
6642
6643         /* §6.7.2.1:7 */
6644         compound->complete = true;
6645 }
6646
6647 static type_t *parse_typename(void)
6648 {
6649         declaration_specifiers_t specifiers;
6650         memset(&specifiers, 0, sizeof(specifiers));
6651         parse_declaration_specifiers(&specifiers);
6652         if (specifiers.storage_class != STORAGE_CLASS_NONE ||
6653                         specifiers.thread_local) {
6654                 /* TODO: improve error message, user does probably not know what a
6655                  * storage class is...
6656                  */
6657                 errorf(HERE, "typename may not have a storage class");
6658         }
6659
6660         type_t *result = parse_abstract_declarator(specifiers.type);
6661
6662         return result;
6663 }
6664
6665
6666
6667
6668 typedef expression_t* (*parse_expression_function)(void);
6669 typedef expression_t* (*parse_expression_infix_function)(expression_t *left);
6670
6671 typedef struct expression_parser_function_t expression_parser_function_t;
6672 struct expression_parser_function_t {
6673         parse_expression_function        parser;
6674         precedence_t                     infix_precedence;
6675         parse_expression_infix_function  infix_parser;
6676 };
6677
6678 expression_parser_function_t expression_parsers[T_LAST_TOKEN];
6679
6680 /**
6681  * Prints an error message if an expression was expected but not read
6682  */
6683 static expression_t *expected_expression_error(void)
6684 {
6685         /* skip the error message if the error token was read */
6686         if (token.type != T_ERROR) {
6687                 errorf(HERE, "expected expression, got token %K", &token);
6688         }
6689         next_token();
6690
6691         return create_invalid_expression();
6692 }
6693
6694 /**
6695  * Parse a string constant.
6696  */
6697 static expression_t *parse_string_const(void)
6698 {
6699         wide_string_t wres;
6700         if (token.type == T_STRING_LITERAL) {
6701                 string_t res = token.v.string;
6702                 next_token();
6703                 while (token.type == T_STRING_LITERAL) {
6704                         res = concat_strings(&res, &token.v.string);
6705                         next_token();
6706                 }
6707                 if (token.type != T_WIDE_STRING_LITERAL) {
6708                         expression_t *const cnst = allocate_expression_zero(EXPR_STRING_LITERAL);
6709                         /* note: that we use type_char_ptr here, which is already the
6710                          * automatic converted type. revert_automatic_type_conversion
6711                          * will construct the array type */
6712                         cnst->base.type    = warning.write_strings ? type_const_char_ptr : type_char_ptr;
6713                         cnst->string.value = res;
6714                         return cnst;
6715                 }
6716
6717                 wres = concat_string_wide_string(&res, &token.v.wide_string);
6718         } else {
6719                 wres = token.v.wide_string;
6720         }
6721         next_token();
6722
6723         for (;;) {
6724                 switch (token.type) {
6725                         case T_WIDE_STRING_LITERAL:
6726                                 wres = concat_wide_strings(&wres, &token.v.wide_string);
6727                                 break;
6728
6729                         case T_STRING_LITERAL:
6730                                 wres = concat_wide_string_string(&wres, &token.v.string);
6731                                 break;
6732
6733                         default: {
6734                                 expression_t *const cnst = allocate_expression_zero(EXPR_WIDE_STRING_LITERAL);
6735                                 cnst->base.type         = warning.write_strings ? type_const_wchar_t_ptr : type_wchar_t_ptr;
6736                                 cnst->wide_string.value = wres;
6737                                 return cnst;
6738                         }
6739                 }
6740                 next_token();
6741         }
6742 }
6743
6744 /**
6745  * Parse a boolean constant.
6746  */
6747 static expression_t *parse_bool_const(bool value)
6748 {
6749         expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
6750         cnst->base.type          = type_bool;
6751         cnst->conste.v.int_value = value;
6752
6753         next_token();
6754
6755         return cnst;
6756 }
6757
6758 /**
6759  * Parse an integer constant.
6760  */
6761 static expression_t *parse_int_const(void)
6762 {
6763         expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
6764         cnst->base.type          = token.datatype;
6765         cnst->conste.v.int_value = token.v.intvalue;
6766
6767         next_token();
6768
6769         return cnst;
6770 }
6771
6772 /**
6773  * Parse a character constant.
6774  */
6775 static expression_t *parse_character_constant(void)
6776 {
6777         expression_t *cnst = allocate_expression_zero(EXPR_CHARACTER_CONSTANT);
6778         cnst->base.type          = token.datatype;
6779         cnst->conste.v.character = token.v.string;
6780
6781         if (cnst->conste.v.character.size != 1) {
6782                 if (!GNU_MODE) {
6783                         errorf(HERE, "more than 1 character in character constant");
6784                 } else if (warning.multichar) {
6785                         warningf(HERE, "multi-character character constant");
6786                 }
6787         }
6788         next_token();
6789
6790         return cnst;
6791 }
6792
6793 /**
6794  * Parse a wide character constant.
6795  */
6796 static expression_t *parse_wide_character_constant(void)
6797 {
6798         expression_t *cnst = allocate_expression_zero(EXPR_WIDE_CHARACTER_CONSTANT);
6799         cnst->base.type               = token.datatype;
6800         cnst->conste.v.wide_character = token.v.wide_string;
6801
6802         if (cnst->conste.v.wide_character.size != 1) {
6803                 if (!GNU_MODE) {
6804                         errorf(HERE, "more than 1 character in character constant");
6805                 } else if (warning.multichar) {
6806                         warningf(HERE, "multi-character character constant");
6807                 }
6808         }
6809         next_token();
6810
6811         return cnst;
6812 }
6813
6814 /**
6815  * Parse a float constant.
6816  */
6817 static expression_t *parse_float_const(void)
6818 {
6819         expression_t *cnst         = allocate_expression_zero(EXPR_CONST);
6820         cnst->base.type            = token.datatype;
6821         cnst->conste.v.float_value = token.v.floatvalue;
6822
6823         next_token();
6824
6825         return cnst;
6826 }
6827
6828 static entity_t *create_implicit_function(symbol_t *symbol,
6829                 const source_position_t *source_position)
6830 {
6831         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
6832         ntype->function.return_type            = type_int;
6833         ntype->function.unspecified_parameters = true;
6834         ntype->function.linkage                = LINKAGE_C;
6835         type_t *type                           = identify_new_type(ntype);
6836
6837         entity_t *entity = allocate_entity_zero(ENTITY_FUNCTION);
6838         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
6839         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
6840         entity->declaration.type                   = type;
6841         entity->declaration.implicit               = true;
6842         entity->base.symbol                        = symbol;
6843         entity->base.source_position               = *source_position;
6844
6845         bool strict_prototypes_old = warning.strict_prototypes;
6846         warning.strict_prototypes  = false;
6847         record_entity(entity, false);
6848         warning.strict_prototypes = strict_prototypes_old;
6849
6850         return entity;
6851 }
6852
6853 /**
6854  * Creates a return_type (func)(argument_type) function type if not
6855  * already exists.
6856  */
6857 static type_t *make_function_2_type(type_t *return_type, type_t *argument_type1,
6858                                     type_t *argument_type2)
6859 {
6860         function_parameter_t *parameter2
6861                 = obstack_alloc(type_obst, sizeof(parameter2[0]));
6862         memset(parameter2, 0, sizeof(parameter2[0]));
6863         parameter2->type = argument_type2;
6864
6865         function_parameter_t *parameter1
6866                 = obstack_alloc(type_obst, sizeof(parameter1[0]));
6867         memset(parameter1, 0, sizeof(parameter1[0]));
6868         parameter1->type = argument_type1;
6869         parameter1->next = parameter2;
6870
6871         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6872         type->function.return_type = return_type;
6873         type->function.parameters  = parameter1;
6874
6875         return identify_new_type(type);
6876 }
6877
6878 /**
6879  * Creates a return_type (func)(argument_type) function type if not
6880  * already exists.
6881  *
6882  * @param return_type    the return type
6883  * @param argument_type  the argument type
6884  */
6885 static type_t *make_function_1_type(type_t *return_type, type_t *argument_type)
6886 {
6887         function_parameter_t *parameter
6888                 = obstack_alloc(type_obst, sizeof(parameter[0]));
6889         memset(parameter, 0, sizeof(parameter[0]));
6890         parameter->type = argument_type;
6891
6892         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6893         type->function.return_type = return_type;
6894         type->function.parameters  = parameter;
6895
6896         return identify_new_type(type);
6897 }
6898
6899 static type_t *make_function_1_type_variadic(type_t *return_type, type_t *argument_type)
6900 {
6901         type_t *res = make_function_1_type(return_type, argument_type);
6902         res->function.variadic = 1;
6903         return res;
6904 }
6905
6906 /**
6907  * Creates a return_type (func)(void) function type if not
6908  * already exists.
6909  *
6910  * @param return_type    the return type
6911  */
6912 static type_t *make_function_0_type(type_t *return_type)
6913 {
6914         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6915         type->function.return_type = return_type;
6916         type->function.parameters  = NULL;
6917
6918         return identify_new_type(type);
6919 }
6920
6921 /**
6922  * Creates a NO_RETURN return_type (func)(void) function type if not
6923  * already exists.
6924  *
6925  * @param return_type    the return type
6926  */
6927 static type_t *make_function_0_type_noreturn(type_t *return_type)
6928 {
6929         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6930         type->function.return_type = return_type;
6931         type->function.parameters  = NULL;
6932         type->function.base.modifiers |= DM_NORETURN;
6933         return type;
6934
6935         return identify_new_type(type);
6936 }
6937
6938 /**
6939  * Performs automatic type cast as described in §6.3.2.1.
6940  *
6941  * @param orig_type  the original type
6942  */
6943 static type_t *automatic_type_conversion(type_t *orig_type)
6944 {
6945         type_t *type = skip_typeref(orig_type);
6946         if (is_type_array(type)) {
6947                 array_type_t *array_type   = &type->array;
6948                 type_t       *element_type = array_type->element_type;
6949                 unsigned      qualifiers   = array_type->base.qualifiers;
6950
6951                 return make_pointer_type(element_type, qualifiers);
6952         }
6953
6954         if (is_type_function(type)) {
6955                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
6956         }
6957
6958         return orig_type;
6959 }
6960
6961 /**
6962  * reverts the automatic casts of array to pointer types and function
6963  * to function-pointer types as defined §6.3.2.1
6964  */
6965 type_t *revert_automatic_type_conversion(const expression_t *expression)
6966 {
6967         switch (expression->kind) {
6968                 case EXPR_REFERENCE: {
6969                         entity_t *entity = expression->reference.entity;
6970                         if (is_declaration(entity)) {
6971                                 return entity->declaration.type;
6972                         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6973                                 return entity->enum_value.enum_type;
6974                         } else {
6975                                 panic("no declaration or enum in reference");
6976                         }
6977                 }
6978
6979                 case EXPR_SELECT: {
6980                         entity_t *entity = expression->select.compound_entry;
6981                         assert(is_declaration(entity));
6982                         type_t   *type   = entity->declaration.type;
6983                         return get_qualified_type(type,
6984                                         expression->base.type->base.qualifiers);
6985                 }
6986
6987                 case EXPR_UNARY_DEREFERENCE: {
6988                         const expression_t *const value = expression->unary.value;
6989                         type_t             *const type  = skip_typeref(value->base.type);
6990                         if (!is_type_pointer(type))
6991                                 return type_error_type;
6992                         return type->pointer.points_to;
6993                 }
6994
6995                 case EXPR_ARRAY_ACCESS: {
6996                         const expression_t *array_ref = expression->array_access.array_ref;
6997                         type_t             *type_left = skip_typeref(array_ref->base.type);
6998                         if (!is_type_pointer(type_left))
6999                                 return type_error_type;
7000                         return type_left->pointer.points_to;
7001                 }
7002
7003                 case EXPR_STRING_LITERAL: {
7004                         size_t size = expression->string.value.size;
7005                         return make_array_type(type_char, size, TYPE_QUALIFIER_NONE);
7006                 }
7007
7008                 case EXPR_WIDE_STRING_LITERAL: {
7009                         size_t size = expression->wide_string.value.size;
7010                         return make_array_type(type_wchar_t, size, TYPE_QUALIFIER_NONE);
7011                 }
7012
7013                 case EXPR_COMPOUND_LITERAL:
7014                         return expression->compound_literal.type;
7015
7016                 default:
7017                         return expression->base.type;
7018         }
7019 }
7020
7021 static expression_t *parse_reference(void)
7022 {
7023         symbol_t *const symbol = token.v.symbol;
7024
7025         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
7026
7027         if (entity == NULL) {
7028                 if (!strict_mode && look_ahead(1)->type == '(') {
7029                         /* an implicitly declared function */
7030                         if (warning.error_implicit_function_declaration) {
7031                                 errorf(HERE, "implicit declaration of function '%Y'", symbol);
7032                         } else if (warning.implicit_function_declaration) {
7033                                 warningf(HERE, "implicit declaration of function '%Y'", symbol);
7034                         }
7035
7036                         entity = create_implicit_function(symbol, HERE);
7037                 } else {
7038                         errorf(HERE, "unknown identifier '%Y' found.", symbol);
7039                         entity = create_error_entity(symbol, ENTITY_VARIABLE);
7040                 }
7041         }
7042
7043         type_t *orig_type;
7044
7045         if (is_declaration(entity)) {
7046                 orig_type = entity->declaration.type;
7047         } else if (entity->kind == ENTITY_ENUM_VALUE) {
7048                 orig_type = entity->enum_value.enum_type;
7049         } else if (entity->kind == ENTITY_TYPEDEF) {
7050                 errorf(HERE, "encountered typedef name '%Y' while parsing expression",
7051                         symbol);
7052                 next_token();
7053                 return create_invalid_expression();
7054         } else {
7055                 panic("expected declaration or enum value in reference");
7056         }
7057
7058         /* we always do the auto-type conversions; the & and sizeof parser contains
7059          * code to revert this! */
7060         type_t *type = automatic_type_conversion(orig_type);
7061
7062         expression_kind_t kind = EXPR_REFERENCE;
7063         if (entity->kind == ENTITY_ENUM_VALUE)
7064                 kind = EXPR_REFERENCE_ENUM_VALUE;
7065
7066         expression_t *expression     = allocate_expression_zero(kind);
7067         expression->reference.entity = entity;
7068         expression->base.type        = type;
7069
7070         /* this declaration is used */
7071         if (is_declaration(entity)) {
7072                 entity->declaration.used = true;
7073         }
7074
7075         if (entity->base.parent_scope != file_scope
7076                 && entity->base.parent_scope->depth < current_function->parameters.depth
7077                 && is_type_valid(orig_type) && !is_type_function(orig_type)) {
7078                 if (entity->kind == ENTITY_VARIABLE) {
7079                         /* access of a variable from an outer function */
7080                         entity->variable.address_taken = true;
7081                 } else if (entity->kind == ENTITY_PARAMETER) {
7082                         entity->parameter.address_taken = true;
7083                 }
7084                 current_function->need_closure = true;
7085         }
7086
7087         /* check for deprecated functions */
7088         if (warning.deprecated_declarations
7089                 && is_declaration(entity)
7090                 && entity->declaration.modifiers & DM_DEPRECATED) {
7091                 declaration_t *declaration = &entity->declaration;
7092
7093                 char const *const prefix = entity->kind == ENTITY_FUNCTION ?
7094                         "function" : "variable";
7095
7096                 if (declaration->deprecated_string != NULL) {
7097                         warningf(HERE, "%s '%Y' is deprecated (declared %P): \"%s\"",
7098                                  prefix, entity->base.symbol, &entity->base.source_position,
7099                                  declaration->deprecated_string);
7100                 } else {
7101                         warningf(HERE, "%s '%Y' is deprecated (declared %P)", prefix,
7102                                  entity->base.symbol, &entity->base.source_position);
7103                 }
7104         }
7105
7106         if (warning.init_self && entity == current_init_decl && !in_type_prop
7107             && entity->kind == ENTITY_VARIABLE) {
7108                 current_init_decl = NULL;
7109                 warningf(HERE, "variable '%#T' is initialized by itself",
7110                          entity->declaration.type, entity->base.symbol);
7111         }
7112
7113         next_token();
7114         return expression;
7115 }
7116
7117 static bool semantic_cast(expression_t *cast)
7118 {
7119         expression_t            *expression      = cast->unary.value;
7120         type_t                  *orig_dest_type  = cast->base.type;
7121         type_t                  *orig_type_right = expression->base.type;
7122         type_t            const *dst_type        = skip_typeref(orig_dest_type);
7123         type_t            const *src_type        = skip_typeref(orig_type_right);
7124         source_position_t const *pos             = &cast->base.source_position;
7125
7126         /* §6.5.4 A (void) cast is explicitly permitted, more for documentation than for utility. */
7127         if (dst_type == type_void)
7128                 return true;
7129
7130         /* only integer and pointer can be casted to pointer */
7131         if (is_type_pointer(dst_type)  &&
7132             !is_type_pointer(src_type) &&
7133             !is_type_integer(src_type) &&
7134             is_type_valid(src_type)) {
7135                 errorf(pos, "cannot convert type '%T' to a pointer type", orig_type_right);
7136                 return false;
7137         }
7138
7139         if (!is_type_scalar(dst_type) && is_type_valid(dst_type)) {
7140                 errorf(pos, "conversion to non-scalar type '%T' requested", orig_dest_type);
7141                 return false;
7142         }
7143
7144         if (!is_type_scalar(src_type) && is_type_valid(src_type)) {
7145                 errorf(pos, "conversion from non-scalar type '%T' requested", orig_type_right);
7146                 return false;
7147         }
7148
7149         if (warning.cast_qual &&
7150             is_type_pointer(src_type) &&
7151             is_type_pointer(dst_type)) {
7152                 type_t *src = skip_typeref(src_type->pointer.points_to);
7153                 type_t *dst = skip_typeref(dst_type->pointer.points_to);
7154                 unsigned missing_qualifiers =
7155                         src->base.qualifiers & ~dst->base.qualifiers;
7156                 if (missing_qualifiers != 0) {
7157                         warningf(pos,
7158                                  "cast discards qualifiers '%Q' in pointer target type of '%T'",
7159                                  missing_qualifiers, orig_type_right);
7160                 }
7161         }
7162         return true;
7163 }
7164
7165 static expression_t *parse_compound_literal(type_t *type)
7166 {
7167         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
7168
7169         parse_initializer_env_t env;
7170         env.type             = type;
7171         env.entity           = NULL;
7172         env.must_be_constant = false;
7173         initializer_t *initializer = parse_initializer(&env);
7174         type = env.type;
7175
7176         expression->compound_literal.initializer = initializer;
7177         expression->compound_literal.type        = type;
7178         expression->base.type                    = automatic_type_conversion(type);
7179
7180         return expression;
7181 }
7182
7183 /**
7184  * Parse a cast expression.
7185  */
7186 static expression_t *parse_cast(void)
7187 {
7188         add_anchor_token(')');
7189
7190         source_position_t source_position = token.source_position;
7191
7192         type_t *type = parse_typename();
7193
7194         rem_anchor_token(')');
7195         expect(')', end_error);
7196
7197         if (token.type == '{') {
7198                 return parse_compound_literal(type);
7199         }
7200
7201         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
7202         cast->base.source_position = source_position;
7203
7204         expression_t *value = parse_sub_expression(PREC_CAST);
7205         cast->base.type   = type;
7206         cast->unary.value = value;
7207
7208         if (! semantic_cast(cast)) {
7209                 /* TODO: record the error in the AST. else it is impossible to detect it */
7210         }
7211
7212         return cast;
7213 end_error:
7214         return create_invalid_expression();
7215 }
7216
7217 /**
7218  * Parse a statement expression.
7219  */
7220 static expression_t *parse_statement_expression(void)
7221 {
7222         add_anchor_token(')');
7223
7224         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
7225
7226         statement_t *statement          = parse_compound_statement(true);
7227         statement->compound.stmt_expr   = true;
7228         expression->statement.statement = statement;
7229
7230         /* find last statement and use its type */
7231         type_t *type = type_void;
7232         const statement_t *stmt = statement->compound.statements;
7233         if (stmt != NULL) {
7234                 while (stmt->base.next != NULL)
7235                         stmt = stmt->base.next;
7236
7237                 if (stmt->kind == STATEMENT_EXPRESSION) {
7238                         type = stmt->expression.expression->base.type;
7239                 }
7240         } else if (warning.other) {
7241                 warningf(&expression->base.source_position, "empty statement expression ({})");
7242         }
7243         expression->base.type = type;
7244
7245         rem_anchor_token(')');
7246         expect(')', end_error);
7247
7248 end_error:
7249         return expression;
7250 }
7251
7252 /**
7253  * Parse a parenthesized expression.
7254  */
7255 static expression_t *parse_parenthesized_expression(void)
7256 {
7257         eat('(');
7258
7259         switch (token.type) {
7260         case '{':
7261                 /* gcc extension: a statement expression */
7262                 return parse_statement_expression();
7263
7264         TYPE_QUALIFIERS
7265         TYPE_SPECIFIERS
7266                 return parse_cast();
7267         case T_IDENTIFIER:
7268                 if (is_typedef_symbol(token.v.symbol)) {
7269                         return parse_cast();
7270                 }
7271         }
7272
7273         add_anchor_token(')');
7274         expression_t *result = parse_expression();
7275         result->base.parenthesized = true;
7276         rem_anchor_token(')');
7277         expect(')', end_error);
7278
7279 end_error:
7280         return result;
7281 }
7282
7283 static expression_t *parse_function_keyword(void)
7284 {
7285         /* TODO */
7286
7287         if (current_function == NULL) {
7288                 errorf(HERE, "'__func__' used outside of a function");
7289         }
7290
7291         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
7292         expression->base.type     = type_char_ptr;
7293         expression->funcname.kind = FUNCNAME_FUNCTION;
7294
7295         next_token();
7296
7297         return expression;
7298 }
7299
7300 static expression_t *parse_pretty_function_keyword(void)
7301 {
7302         if (current_function == NULL) {
7303                 errorf(HERE, "'__PRETTY_FUNCTION__' used outside of a function");
7304         }
7305
7306         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
7307         expression->base.type     = type_char_ptr;
7308         expression->funcname.kind = FUNCNAME_PRETTY_FUNCTION;
7309
7310         eat(T___PRETTY_FUNCTION__);
7311
7312         return expression;
7313 }
7314
7315 static expression_t *parse_funcsig_keyword(void)
7316 {
7317         if (current_function == NULL) {
7318                 errorf(HERE, "'__FUNCSIG__' used outside of a function");
7319         }
7320
7321         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
7322         expression->base.type     = type_char_ptr;
7323         expression->funcname.kind = FUNCNAME_FUNCSIG;
7324
7325         eat(T___FUNCSIG__);
7326
7327         return expression;
7328 }
7329
7330 static expression_t *parse_funcdname_keyword(void)
7331 {
7332         if (current_function == NULL) {
7333                 errorf(HERE, "'__FUNCDNAME__' used outside of a function");
7334         }
7335
7336         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
7337         expression->base.type     = type_char_ptr;
7338         expression->funcname.kind = FUNCNAME_FUNCDNAME;
7339
7340         eat(T___FUNCDNAME__);
7341
7342         return expression;
7343 }
7344
7345 static designator_t *parse_designator(void)
7346 {
7347         designator_t *result    = allocate_ast_zero(sizeof(result[0]));
7348         result->source_position = *HERE;
7349
7350         if (token.type != T_IDENTIFIER) {
7351                 parse_error_expected("while parsing member designator",
7352                                      T_IDENTIFIER, NULL);
7353                 return NULL;
7354         }
7355         result->symbol = token.v.symbol;
7356         next_token();
7357
7358         designator_t *last_designator = result;
7359         while (true) {
7360                 if (token.type == '.') {
7361                         next_token();
7362                         if (token.type != T_IDENTIFIER) {
7363                                 parse_error_expected("while parsing member designator",
7364                                                      T_IDENTIFIER, NULL);
7365                                 return NULL;
7366                         }
7367                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
7368                         designator->source_position = *HERE;
7369                         designator->symbol          = token.v.symbol;
7370                         next_token();
7371
7372                         last_designator->next = designator;
7373                         last_designator       = designator;
7374                         continue;
7375                 }
7376                 if (token.type == '[') {
7377                         next_token();
7378                         add_anchor_token(']');
7379                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
7380                         designator->source_position = *HERE;
7381                         designator->array_index     = parse_expression();
7382                         rem_anchor_token(']');
7383                         expect(']', end_error);
7384                         if (designator->array_index == NULL) {
7385                                 return NULL;
7386                         }
7387
7388                         last_designator->next = designator;
7389                         last_designator       = designator;
7390                         continue;
7391                 }
7392                 break;
7393         }
7394
7395         return result;
7396 end_error:
7397         return NULL;
7398 }
7399
7400 /**
7401  * Parse the __builtin_offsetof() expression.
7402  */
7403 static expression_t *parse_offsetof(void)
7404 {
7405         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
7406         expression->base.type    = type_size_t;
7407
7408         eat(T___builtin_offsetof);
7409
7410         expect('(', end_error);
7411         add_anchor_token(',');
7412         type_t *type = parse_typename();
7413         rem_anchor_token(',');
7414         expect(',', end_error);
7415         add_anchor_token(')');
7416         designator_t *designator = parse_designator();
7417         rem_anchor_token(')');
7418         expect(')', end_error);
7419
7420         expression->offsetofe.type       = type;
7421         expression->offsetofe.designator = designator;
7422
7423         type_path_t path;
7424         memset(&path, 0, sizeof(path));
7425         path.top_type = type;
7426         path.path     = NEW_ARR_F(type_path_entry_t, 0);
7427
7428         descend_into_subtype(&path);
7429
7430         if (!walk_designator(&path, designator, true)) {
7431                 return create_invalid_expression();
7432         }
7433
7434         DEL_ARR_F(path.path);
7435
7436         return expression;
7437 end_error:
7438         return create_invalid_expression();
7439 }
7440
7441 /**
7442  * Parses a _builtin_va_start() expression.
7443  */
7444 static expression_t *parse_va_start(void)
7445 {
7446         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
7447
7448         eat(T___builtin_va_start);
7449
7450         expect('(', end_error);
7451         add_anchor_token(',');
7452         expression->va_starte.ap = parse_assignment_expression();
7453         rem_anchor_token(',');
7454         expect(',', end_error);
7455         expression_t *const expr = parse_assignment_expression();
7456         if (expr->kind == EXPR_REFERENCE) {
7457                 entity_t *const entity = expr->reference.entity;
7458                 if (entity->base.parent_scope != &current_function->parameters
7459                                 || entity->base.next != NULL
7460                                 || entity->kind != ENTITY_PARAMETER) {
7461                         errorf(&expr->base.source_position,
7462                                "second argument of 'va_start' must be last parameter of the current function");
7463                 } else {
7464                         expression->va_starte.parameter = &entity->variable;
7465                 }
7466                 expect(')', end_error);
7467                 return expression;
7468         }
7469         expect(')', end_error);
7470 end_error:
7471         return create_invalid_expression();
7472 }
7473
7474 /**
7475  * Parses a _builtin_va_arg() expression.
7476  */
7477 static expression_t *parse_va_arg(void)
7478 {
7479         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
7480
7481         eat(T___builtin_va_arg);
7482
7483         expect('(', end_error);
7484         expression->va_arge.ap = parse_assignment_expression();
7485         expect(',', end_error);
7486         expression->base.type = parse_typename();
7487         expect(')', end_error);
7488
7489         return expression;
7490 end_error:
7491         return create_invalid_expression();
7492 }
7493
7494 /**
7495  * Parses a __builtin_constant_p() expression.
7496  */
7497 static expression_t *parse_builtin_constant(void)
7498 {
7499         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
7500
7501         eat(T___builtin_constant_p);
7502
7503         expect('(', end_error);
7504         add_anchor_token(')');
7505         expression->builtin_constant.value = parse_assignment_expression();
7506         rem_anchor_token(')');
7507         expect(')', end_error);
7508         expression->base.type = type_int;
7509
7510         return expression;
7511 end_error:
7512         return create_invalid_expression();
7513 }
7514
7515 /**
7516  * Parses a __builtin_types_compatible_p() expression.
7517  */
7518 static expression_t *parse_builtin_types_compatible(void)
7519 {
7520         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_TYPES_COMPATIBLE_P);
7521
7522         eat(T___builtin_types_compatible_p);
7523
7524         expect('(', end_error);
7525         add_anchor_token(')');
7526         add_anchor_token(',');
7527         expression->builtin_types_compatible.left = parse_typename();
7528         rem_anchor_token(',');
7529         expect(',', end_error);
7530         expression->builtin_types_compatible.right = parse_typename();
7531         rem_anchor_token(')');
7532         expect(')', end_error);
7533         expression->base.type = type_int;
7534
7535         return expression;
7536 end_error:
7537         return create_invalid_expression();
7538 }
7539
7540 /**
7541  * Parses a __builtin_is_*() compare expression.
7542  */
7543 static expression_t *parse_compare_builtin(void)
7544 {
7545         expression_t *expression;
7546
7547         switch (token.type) {
7548         case T___builtin_isgreater:
7549                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATER);
7550                 break;
7551         case T___builtin_isgreaterequal:
7552                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATEREQUAL);
7553                 break;
7554         case T___builtin_isless:
7555                 expression = allocate_expression_zero(EXPR_BINARY_ISLESS);
7556                 break;
7557         case T___builtin_islessequal:
7558                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSEQUAL);
7559                 break;
7560         case T___builtin_islessgreater:
7561                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSGREATER);
7562                 break;
7563         case T___builtin_isunordered:
7564                 expression = allocate_expression_zero(EXPR_BINARY_ISUNORDERED);
7565                 break;
7566         default:
7567                 internal_errorf(HERE, "invalid compare builtin found");
7568         }
7569         expression->base.source_position = *HERE;
7570         next_token();
7571
7572         expect('(', end_error);
7573         expression->binary.left = parse_assignment_expression();
7574         expect(',', end_error);
7575         expression->binary.right = parse_assignment_expression();
7576         expect(')', end_error);
7577
7578         type_t *const orig_type_left  = expression->binary.left->base.type;
7579         type_t *const orig_type_right = expression->binary.right->base.type;
7580
7581         type_t *const type_left  = skip_typeref(orig_type_left);
7582         type_t *const type_right = skip_typeref(orig_type_right);
7583         if (!is_type_float(type_left) && !is_type_float(type_right)) {
7584                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7585                         type_error_incompatible("invalid operands in comparison",
7586                                 &expression->base.source_position, orig_type_left, orig_type_right);
7587                 }
7588         } else {
7589                 semantic_comparison(&expression->binary);
7590         }
7591
7592         return expression;
7593 end_error:
7594         return create_invalid_expression();
7595 }
7596
7597 #if 0
7598 /**
7599  * Parses a __builtin_expect(, end_error) expression.
7600  */
7601 static expression_t *parse_builtin_expect(void, end_error)
7602 {
7603         expression_t *expression
7604                 = allocate_expression_zero(EXPR_BINARY_BUILTIN_EXPECT);
7605
7606         eat(T___builtin_expect);
7607
7608         expect('(', end_error);
7609         expression->binary.left = parse_assignment_expression();
7610         expect(',', end_error);
7611         expression->binary.right = parse_constant_expression();
7612         expect(')', end_error);
7613
7614         expression->base.type = expression->binary.left->base.type;
7615
7616         return expression;
7617 end_error:
7618         return create_invalid_expression();
7619 }
7620 #endif
7621
7622 /**
7623  * Parses a MS assume() expression.
7624  */
7625 static expression_t *parse_assume(void)
7626 {
7627         expression_t *expression = allocate_expression_zero(EXPR_UNARY_ASSUME);
7628
7629         eat(T__assume);
7630
7631         expect('(', end_error);
7632         add_anchor_token(')');
7633         expression->unary.value = parse_assignment_expression();
7634         rem_anchor_token(')');
7635         expect(')', end_error);
7636
7637         expression->base.type = type_void;
7638         return expression;
7639 end_error:
7640         return create_invalid_expression();
7641 }
7642
7643 /**
7644  * Return the declaration for a given label symbol or create a new one.
7645  *
7646  * @param symbol  the symbol of the label
7647  */
7648 static label_t *get_label(symbol_t *symbol)
7649 {
7650         entity_t *label;
7651         assert(current_function != NULL);
7652
7653         label = get_entity(symbol, NAMESPACE_LABEL);
7654         /* if we found a local label, we already created the declaration */
7655         if (label != NULL && label->kind == ENTITY_LOCAL_LABEL) {
7656                 if (label->base.parent_scope != current_scope) {
7657                         assert(label->base.parent_scope->depth < current_scope->depth);
7658                         current_function->goto_to_outer = true;
7659                 }
7660                 return &label->label;
7661         }
7662
7663         label = get_entity(symbol, NAMESPACE_LABEL);
7664         /* if we found a label in the same function, then we already created the
7665          * declaration */
7666         if (label != NULL
7667                         && label->base.parent_scope == &current_function->parameters) {
7668                 return &label->label;
7669         }
7670
7671         /* otherwise we need to create a new one */
7672         label               = allocate_entity_zero(ENTITY_LABEL);
7673         label->base.namespc = NAMESPACE_LABEL;
7674         label->base.symbol  = symbol;
7675
7676         label_push(label);
7677
7678         return &label->label;
7679 }
7680
7681 /**
7682  * Parses a GNU && label address expression.
7683  */
7684 static expression_t *parse_label_address(void)
7685 {
7686         source_position_t source_position = token.source_position;
7687         eat(T_ANDAND);
7688         if (token.type != T_IDENTIFIER) {
7689                 parse_error_expected("while parsing label address", T_IDENTIFIER, NULL);
7690                 goto end_error;
7691         }
7692         symbol_t *symbol = token.v.symbol;
7693         next_token();
7694
7695         label_t *label       = get_label(symbol);
7696         label->used          = true;
7697         label->address_taken = true;
7698
7699         expression_t *expression = allocate_expression_zero(EXPR_LABEL_ADDRESS);
7700         expression->base.source_position = source_position;
7701
7702         /* label address is threaten as a void pointer */
7703         expression->base.type           = type_void_ptr;
7704         expression->label_address.label = label;
7705         return expression;
7706 end_error:
7707         return create_invalid_expression();
7708 }
7709
7710 /**
7711  * Parse a microsoft __noop expression.
7712  */
7713 static expression_t *parse_noop_expression(void)
7714 {
7715         /* the result is a (int)0 */
7716         expression_t *cnst         = allocate_expression_zero(EXPR_CONST);
7717         cnst->base.type            = type_int;
7718         cnst->conste.v.int_value   = 0;
7719         cnst->conste.is_ms_noop    = true;
7720
7721         eat(T___noop);
7722
7723         if (token.type == '(') {
7724                 /* parse arguments */
7725                 eat('(');
7726                 add_anchor_token(')');
7727                 add_anchor_token(',');
7728
7729                 if (token.type != ')') {
7730                         while (true) {
7731                                 (void)parse_assignment_expression();
7732                                 if (token.type != ',')
7733                                         break;
7734                                 next_token();
7735                         }
7736                 }
7737         }
7738         rem_anchor_token(',');
7739         rem_anchor_token(')');
7740         expect(')', end_error);
7741
7742 end_error:
7743         return cnst;
7744 }
7745
7746 /**
7747  * Parses a primary expression.
7748  */
7749 static expression_t *parse_primary_expression(void)
7750 {
7751         switch (token.type) {
7752                 case T_false:                        return parse_bool_const(false);
7753                 case T_true:                         return parse_bool_const(true);
7754                 case T_INTEGER:                      return parse_int_const();
7755                 case T_CHARACTER_CONSTANT:           return parse_character_constant();
7756                 case T_WIDE_CHARACTER_CONSTANT:      return parse_wide_character_constant();
7757                 case T_FLOATINGPOINT:                return parse_float_const();
7758                 case T_STRING_LITERAL:
7759                 case T_WIDE_STRING_LITERAL:          return parse_string_const();
7760                 case T_IDENTIFIER:                   return parse_reference();
7761                 case T___FUNCTION__:
7762                 case T___func__:                     return parse_function_keyword();
7763                 case T___PRETTY_FUNCTION__:          return parse_pretty_function_keyword();
7764                 case T___FUNCSIG__:                  return parse_funcsig_keyword();
7765                 case T___FUNCDNAME__:                return parse_funcdname_keyword();
7766                 case T___builtin_offsetof:           return parse_offsetof();
7767                 case T___builtin_va_start:           return parse_va_start();
7768                 case T___builtin_va_arg:             return parse_va_arg();
7769                 case T___builtin_isgreater:
7770                 case T___builtin_isgreaterequal:
7771                 case T___builtin_isless:
7772                 case T___builtin_islessequal:
7773                 case T___builtin_islessgreater:
7774                 case T___builtin_isunordered:        return parse_compare_builtin();
7775                 case T___builtin_constant_p:         return parse_builtin_constant();
7776                 case T___builtin_types_compatible_p: return parse_builtin_types_compatible();
7777                 case T__assume:                      return parse_assume();
7778                 case T_ANDAND:
7779                         if (GNU_MODE)
7780                                 return parse_label_address();
7781                         break;
7782
7783                 case '(':                            return parse_parenthesized_expression();
7784                 case T___noop:                       return parse_noop_expression();
7785         }
7786
7787         errorf(HERE, "unexpected token %K, expected an expression", &token);
7788         return create_invalid_expression();
7789 }
7790
7791 /**
7792  * Check if the expression has the character type and issue a warning then.
7793  */
7794 static void check_for_char_index_type(const expression_t *expression)
7795 {
7796         type_t       *const type      = expression->base.type;
7797         const type_t *const base_type = skip_typeref(type);
7798
7799         if (is_type_atomic(base_type, ATOMIC_TYPE_CHAR) &&
7800                         warning.char_subscripts) {
7801                 warningf(&expression->base.source_position,
7802                          "array subscript has type '%T'", type);
7803         }
7804 }
7805
7806 static expression_t *parse_array_expression(expression_t *left)
7807 {
7808         expression_t *expression = allocate_expression_zero(EXPR_ARRAY_ACCESS);
7809
7810         eat('[');
7811         add_anchor_token(']');
7812
7813         expression_t *inside = parse_expression();
7814
7815         type_t *const orig_type_left   = left->base.type;
7816         type_t *const orig_type_inside = inside->base.type;
7817
7818         type_t *const type_left   = skip_typeref(orig_type_left);
7819         type_t *const type_inside = skip_typeref(orig_type_inside);
7820
7821         type_t                    *return_type;
7822         array_access_expression_t *array_access = &expression->array_access;
7823         if (is_type_pointer(type_left)) {
7824                 return_type             = type_left->pointer.points_to;
7825                 array_access->array_ref = left;
7826                 array_access->index     = inside;
7827                 check_for_char_index_type(inside);
7828         } else if (is_type_pointer(type_inside)) {
7829                 return_type             = type_inside->pointer.points_to;
7830                 array_access->array_ref = inside;
7831                 array_access->index     = left;
7832                 array_access->flipped   = true;
7833                 check_for_char_index_type(left);
7834         } else {
7835                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
7836                         errorf(HERE,
7837                                 "array access on object with non-pointer types '%T', '%T'",
7838                                 orig_type_left, orig_type_inside);
7839                 }
7840                 return_type             = type_error_type;
7841                 array_access->array_ref = left;
7842                 array_access->index     = inside;
7843         }
7844
7845         expression->base.type = automatic_type_conversion(return_type);
7846
7847         rem_anchor_token(']');
7848         expect(']', end_error);
7849 end_error:
7850         return expression;
7851 }
7852
7853 static expression_t *parse_typeprop(expression_kind_t const kind)
7854 {
7855         expression_t  *tp_expression = allocate_expression_zero(kind);
7856         tp_expression->base.type     = type_size_t;
7857
7858         eat(kind == EXPR_SIZEOF ? T_sizeof : T___alignof__);
7859
7860         /* we only refer to a type property, mark this case */
7861         bool old     = in_type_prop;
7862         in_type_prop = true;
7863
7864         type_t       *orig_type;
7865         expression_t *expression;
7866         if (token.type == '(' && is_declaration_specifier(look_ahead(1), true)) {
7867                 next_token();
7868                 add_anchor_token(')');
7869                 orig_type = parse_typename();
7870                 rem_anchor_token(')');
7871                 expect(')', end_error);
7872
7873                 if (token.type == '{') {
7874                         /* It was not sizeof(type) after all.  It is sizeof of an expression
7875                          * starting with a compound literal */
7876                         expression = parse_compound_literal(orig_type);
7877                         goto typeprop_expression;
7878                 }
7879         } else {
7880                 expression = parse_sub_expression(PREC_UNARY);
7881
7882 typeprop_expression:
7883                 tp_expression->typeprop.tp_expression = expression;
7884
7885                 orig_type = revert_automatic_type_conversion(expression);
7886                 expression->base.type = orig_type;
7887         }
7888
7889         tp_expression->typeprop.type   = orig_type;
7890         type_t const* const type       = skip_typeref(orig_type);
7891         char   const* const wrong_type =
7892                 GNU_MODE && is_type_atomic(type, ATOMIC_TYPE_VOID) ? NULL                  :
7893                 is_type_incomplete(type)                           ? "incomplete"          :
7894                 type->kind == TYPE_FUNCTION                        ? "function designator" :
7895                 type->kind == TYPE_BITFIELD                        ? "bitfield"            :
7896                 NULL;
7897         if (wrong_type != NULL) {
7898                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
7899                 errorf(&tp_expression->base.source_position,
7900                                 "operand of %s expression must not be of %s type '%T'",
7901                                 what, wrong_type, orig_type);
7902         }
7903
7904 end_error:
7905         in_type_prop = old;
7906         return tp_expression;
7907 }
7908
7909 static expression_t *parse_sizeof(void)
7910 {
7911         return parse_typeprop(EXPR_SIZEOF);
7912 }
7913
7914 static expression_t *parse_alignof(void)
7915 {
7916         return parse_typeprop(EXPR_ALIGNOF);
7917 }
7918
7919 static expression_t *parse_select_expression(expression_t *compound)
7920 {
7921         expression_t *select    = allocate_expression_zero(EXPR_SELECT);
7922         select->select.compound = compound;
7923
7924         assert(token.type == '.' || token.type == T_MINUSGREATER);
7925         bool is_pointer = (token.type == T_MINUSGREATER);
7926         next_token();
7927
7928         if (token.type != T_IDENTIFIER) {
7929                 parse_error_expected("while parsing select", T_IDENTIFIER, NULL);
7930                 return select;
7931         }
7932         symbol_t *symbol = token.v.symbol;
7933         next_token();
7934
7935         type_t *const orig_type = compound->base.type;
7936         type_t *const type      = skip_typeref(orig_type);
7937
7938         type_t *type_left;
7939         bool    saw_error = false;
7940         if (is_type_pointer(type)) {
7941                 if (!is_pointer) {
7942                         errorf(HERE,
7943                                "request for member '%Y' in something not a struct or union, but '%T'",
7944                                symbol, orig_type);
7945                         saw_error = true;
7946                 }
7947                 type_left = skip_typeref(type->pointer.points_to);
7948         } else {
7949                 if (is_pointer && is_type_valid(type)) {
7950                         errorf(HERE, "left hand side of '->' is not a pointer, but '%T'", orig_type);
7951                         saw_error = true;
7952                 }
7953                 type_left = type;
7954         }
7955
7956         entity_t *entry;
7957         if (type_left->kind == TYPE_COMPOUND_STRUCT ||
7958             type_left->kind == TYPE_COMPOUND_UNION) {
7959                 compound_t *compound = type_left->compound.compound;
7960
7961                 if (!compound->complete) {
7962                         errorf(HERE, "request for member '%Y' of incomplete type '%T'",
7963                                symbol, type_left);
7964                         goto create_error_entry;
7965                 }
7966
7967                 entry = find_compound_entry(compound, symbol);
7968                 if (entry == NULL) {
7969                         errorf(HERE, "'%T' has no member named '%Y'", orig_type, symbol);
7970                         goto create_error_entry;
7971                 }
7972         } else {
7973                 if (is_type_valid(type_left) && !saw_error) {
7974                         errorf(HERE,
7975                                "request for member '%Y' in something not a struct or union, but '%T'",
7976                                symbol, type_left);
7977                 }
7978 create_error_entry:
7979                 entry = create_error_entity(symbol, ENTITY_COMPOUND_MEMBER);
7980         }
7981
7982         assert(is_declaration(entry));
7983         select->select.compound_entry = entry;
7984
7985         type_t *entry_type = entry->declaration.type;
7986         type_t *res_type
7987                 = get_qualified_type(entry_type, type_left->base.qualifiers);
7988
7989         /* we always do the auto-type conversions; the & and sizeof parser contains
7990          * code to revert this! */
7991         select->base.type = automatic_type_conversion(res_type);
7992
7993         type_t *skipped = skip_typeref(res_type);
7994         if (skipped->kind == TYPE_BITFIELD) {
7995                 select->base.type = skipped->bitfield.base_type;
7996         }
7997
7998         return select;
7999 }
8000
8001 static void check_call_argument(const function_parameter_t *parameter,
8002                                 call_argument_t *argument, unsigned pos)
8003 {
8004         type_t         *expected_type      = parameter->type;
8005         type_t         *expected_type_skip = skip_typeref(expected_type);
8006         assign_error_t  error              = ASSIGN_ERROR_INCOMPATIBLE;
8007         expression_t   *arg_expr           = argument->expression;
8008         type_t         *arg_type           = skip_typeref(arg_expr->base.type);
8009
8010         /* handle transparent union gnu extension */
8011         if (is_type_union(expected_type_skip)
8012                         && (expected_type_skip->base.modifiers
8013                                 & TYPE_MODIFIER_TRANSPARENT_UNION)) {
8014                 compound_t *union_decl  = expected_type_skip->compound.compound;
8015                 type_t     *best_type   = NULL;
8016                 entity_t   *entry       = union_decl->members.entities;
8017                 for ( ; entry != NULL; entry = entry->base.next) {
8018                         assert(is_declaration(entry));
8019                         type_t *decl_type = entry->declaration.type;
8020                         error = semantic_assign(decl_type, arg_expr);
8021                         if (error == ASSIGN_ERROR_INCOMPATIBLE
8022                                 || error == ASSIGN_ERROR_POINTER_QUALIFIER_MISSING)
8023                                 continue;
8024
8025                         if (error == ASSIGN_SUCCESS) {
8026                                 best_type = decl_type;
8027                         } else if (best_type == NULL) {
8028                                 best_type = decl_type;
8029                         }
8030                 }
8031
8032                 if (best_type != NULL) {
8033                         expected_type = best_type;
8034                 }
8035         }
8036
8037         error                = semantic_assign(expected_type, arg_expr);
8038         argument->expression = create_implicit_cast(argument->expression,
8039                                                     expected_type);
8040
8041         if (error != ASSIGN_SUCCESS) {
8042                 /* report exact scope in error messages (like "in argument 3") */
8043                 char buf[64];
8044                 snprintf(buf, sizeof(buf), "call argument %u", pos);
8045                 report_assign_error(error, expected_type, arg_expr,     buf,
8046                                                         &arg_expr->base.source_position);
8047         } else if (warning.traditional || warning.conversion) {
8048                 type_t *const promoted_type = get_default_promoted_type(arg_type);
8049                 if (!types_compatible(expected_type_skip, promoted_type) &&
8050                     !types_compatible(expected_type_skip, type_void_ptr) &&
8051                     !types_compatible(type_void_ptr,      promoted_type)) {
8052                         /* Deliberately show the skipped types in this warning */
8053                         warningf(&arg_expr->base.source_position,
8054                                 "passing call argument %u as '%T' rather than '%T' due to prototype",
8055                                 pos, expected_type_skip, promoted_type);
8056                 }
8057         }
8058 }
8059
8060 /**
8061  * Handle the semantic restrictions of builtin calls
8062  */
8063 static void handle_builtin_argument_restrictions(call_expression_t *call) {
8064         switch (call->function->reference.entity->function.btk) {
8065                 case bk_gnu_builtin_return_address:
8066                 case bk_gnu_builtin_frame_address: {
8067                         /* argument must be constant */
8068                         call_argument_t *argument = call->arguments;
8069
8070                         if (! is_constant_expression(argument->expression)) {
8071                                 errorf(&call->base.source_position,
8072                                        "argument of '%Y' must be a constant expression",
8073                                        call->function->reference.entity->base.symbol);
8074                         }
8075                         break;
8076                 }
8077                 case bk_gnu_builtin_prefetch: {
8078                         /* second and third argument must be constant if existent */
8079                         call_argument_t *rw = call->arguments->next;
8080                         call_argument_t *locality = NULL;
8081
8082                         if (rw != NULL) {
8083                                 if (! is_constant_expression(rw->expression)) {
8084                                         errorf(&call->base.source_position,
8085                                                "second argument of '%Y' must be a constant expression",
8086                                                call->function->reference.entity->base.symbol);
8087                                 }
8088                                 locality = rw->next;
8089                         }
8090                         if (locality != NULL) {
8091                                 if (! is_constant_expression(locality->expression)) {
8092                                         errorf(&call->base.source_position,
8093                                                "third argument of '%Y' must be a constant expression",
8094                                                call->function->reference.entity->base.symbol);
8095                                 }
8096                                 locality = rw->next;
8097                         }
8098                         break;
8099                 }
8100                 default:
8101                         break;
8102         }
8103 }
8104
8105 /**
8106  * Parse a call expression, ie. expression '( ... )'.
8107  *
8108  * @param expression  the function address
8109  */
8110 static expression_t *parse_call_expression(expression_t *expression)
8111 {
8112         expression_t      *result = allocate_expression_zero(EXPR_CALL);
8113         call_expression_t *call   = &result->call;
8114         call->function            = expression;
8115
8116         type_t *const orig_type = expression->base.type;
8117         type_t *const type      = skip_typeref(orig_type);
8118
8119         function_type_t *function_type = NULL;
8120         if (is_type_pointer(type)) {
8121                 type_t *const to_type = skip_typeref(type->pointer.points_to);
8122
8123                 if (is_type_function(to_type)) {
8124                         function_type   = &to_type->function;
8125                         call->base.type = function_type->return_type;
8126                 }
8127         }
8128
8129         if (function_type == NULL && is_type_valid(type)) {
8130                 errorf(HERE, "called object '%E' (type '%T') is not a pointer to a function", expression, orig_type);
8131         }
8132
8133         /* parse arguments */
8134         eat('(');
8135         add_anchor_token(')');
8136         add_anchor_token(',');
8137
8138         if (token.type != ')') {
8139                 call_argument_t *last_argument = NULL;
8140
8141                 while (true) {
8142                         call_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
8143
8144                         argument->expression = parse_assignment_expression();
8145                         if (last_argument == NULL) {
8146                                 call->arguments = argument;
8147                         } else {
8148                                 last_argument->next = argument;
8149                         }
8150                         last_argument = argument;
8151
8152                         if (token.type != ',')
8153                                 break;
8154                         next_token();
8155                 }
8156         }
8157         rem_anchor_token(',');
8158         rem_anchor_token(')');
8159         expect(')', end_error);
8160
8161         if (function_type == NULL)
8162                 return result;
8163
8164         function_parameter_t *parameter = function_type->parameters;
8165         call_argument_t      *argument  = call->arguments;
8166         if (!function_type->unspecified_parameters) {
8167                 for (unsigned pos = 0; parameter != NULL && argument != NULL;
8168                                 parameter = parameter->next, argument = argument->next) {
8169                         check_call_argument(parameter, argument, ++pos);
8170                 }
8171
8172                 if (parameter != NULL) {
8173                         errorf(HERE, "too few arguments to function '%E'", expression);
8174                 } else if (argument != NULL && !function_type->variadic) {
8175                         errorf(HERE, "too many arguments to function '%E'", expression);
8176                 }
8177         }
8178
8179         /* do default promotion */
8180         for (; argument != NULL; argument = argument->next) {
8181                 type_t *type = argument->expression->base.type;
8182
8183                 type = get_default_promoted_type(type);
8184
8185                 argument->expression
8186                         = create_implicit_cast(argument->expression, type);
8187         }
8188
8189         check_format(&result->call);
8190
8191         if (warning.aggregate_return &&
8192             is_type_compound(skip_typeref(function_type->return_type))) {
8193                 warningf(&result->base.source_position,
8194                          "function call has aggregate value");
8195         }
8196
8197         if (call->function->kind == EXPR_REFERENCE) {
8198                 reference_expression_t *reference = &call->function->reference;
8199                 if (reference->entity->kind == ENTITY_FUNCTION &&
8200                     reference->entity->function.btk != bk_none)
8201                         handle_builtin_argument_restrictions(call);
8202         }
8203
8204 end_error:
8205         return result;
8206 }
8207
8208 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
8209
8210 static bool same_compound_type(const type_t *type1, const type_t *type2)
8211 {
8212         return
8213                 is_type_compound(type1) &&
8214                 type1->kind == type2->kind &&
8215                 type1->compound.compound == type2->compound.compound;
8216 }
8217
8218 static expression_t const *get_reference_address(expression_t const *expr)
8219 {
8220         bool regular_take_address = true;
8221         for (;;) {
8222                 if (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
8223                         expr = expr->unary.value;
8224                 } else {
8225                         regular_take_address = false;
8226                 }
8227
8228                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
8229                         break;
8230
8231                 expr = expr->unary.value;
8232         }
8233
8234         if (expr->kind != EXPR_REFERENCE)
8235                 return NULL;
8236
8237         /* special case for functions which are automatically converted to a
8238          * pointer to function without an extra TAKE_ADDRESS operation */
8239         if (!regular_take_address &&
8240                         expr->reference.entity->kind != ENTITY_FUNCTION) {
8241                 return NULL;
8242         }
8243
8244         return expr;
8245 }
8246
8247 static void warn_reference_address_as_bool(expression_t const* expr)
8248 {
8249         if (!warning.address)
8250                 return;
8251
8252         expr = get_reference_address(expr);
8253         if (expr != NULL) {
8254                 warningf(&expr->base.source_position,
8255                          "the address of '%Y' will always evaluate as 'true'",
8256                          expr->reference.entity->base.symbol);
8257         }
8258 }
8259
8260 static void warn_assignment_in_condition(const expression_t *const expr)
8261 {
8262         if (!warning.parentheses)
8263                 return;
8264         if (expr->base.kind != EXPR_BINARY_ASSIGN)
8265                 return;
8266         if (expr->base.parenthesized)
8267                 return;
8268         warningf(&expr->base.source_position,
8269                         "suggest parentheses around assignment used as truth value");
8270 }
8271
8272 static void semantic_condition(expression_t const *const expr,
8273                                char const *const context)
8274 {
8275         type_t *const type = skip_typeref(expr->base.type);
8276         if (is_type_scalar(type)) {
8277                 warn_reference_address_as_bool(expr);
8278                 warn_assignment_in_condition(expr);
8279         } else if (is_type_valid(type)) {
8280                 errorf(&expr->base.source_position,
8281                                 "%s must have scalar type", context);
8282         }
8283 }
8284
8285 /**
8286  * Parse a conditional expression, ie. 'expression ? ... : ...'.
8287  *
8288  * @param expression  the conditional expression
8289  */
8290 static expression_t *parse_conditional_expression(expression_t *expression)
8291 {
8292         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
8293
8294         conditional_expression_t *conditional = &result->conditional;
8295         conditional->condition                = expression;
8296
8297         eat('?');
8298         add_anchor_token(':');
8299
8300         /* §6.5.15:2  The first operand shall have scalar type. */
8301         semantic_condition(expression, "condition of conditional operator");
8302
8303         expression_t *true_expression = expression;
8304         bool          gnu_cond = false;
8305         if (GNU_MODE && token.type == ':') {
8306                 gnu_cond = true;
8307         } else {
8308                 true_expression = parse_expression();
8309         }
8310         rem_anchor_token(':');
8311         expect(':', end_error);
8312 end_error:;
8313         expression_t *false_expression =
8314                 parse_sub_expression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
8315
8316         type_t *const orig_true_type  = true_expression->base.type;
8317         type_t *const orig_false_type = false_expression->base.type;
8318         type_t *const true_type       = skip_typeref(orig_true_type);
8319         type_t *const false_type      = skip_typeref(orig_false_type);
8320
8321         /* 6.5.15.3 */
8322         type_t *result_type;
8323         if (is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
8324                         is_type_atomic(false_type, ATOMIC_TYPE_VOID)) {
8325                 /* ISO/IEC 14882:1998(E) §5.16:2 */
8326                 if (true_expression->kind == EXPR_UNARY_THROW) {
8327                         result_type = false_type;
8328                 } else if (false_expression->kind == EXPR_UNARY_THROW) {
8329                         result_type = true_type;
8330                 } else {
8331                         if (warning.other && (
8332                                                 !is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
8333                                                 !is_type_atomic(false_type, ATOMIC_TYPE_VOID)
8334                                         )) {
8335                                 warningf(&conditional->base.source_position,
8336                                                 "ISO C forbids conditional expression with only one void side");
8337                         }
8338                         result_type = type_void;
8339                 }
8340         } else if (is_type_arithmetic(true_type)
8341                    && is_type_arithmetic(false_type)) {
8342                 result_type = semantic_arithmetic(true_type, false_type);
8343
8344                 true_expression  = create_implicit_cast(true_expression, result_type);
8345                 false_expression = create_implicit_cast(false_expression, result_type);
8346
8347                 conditional->true_expression  = true_expression;
8348                 conditional->false_expression = false_expression;
8349                 conditional->base.type        = result_type;
8350         } else if (same_compound_type(true_type, false_type)) {
8351                 /* just take 1 of the 2 types */
8352                 result_type = true_type;
8353         } else if (is_type_pointer(true_type) || is_type_pointer(false_type)) {
8354                 type_t *pointer_type;
8355                 type_t *other_type;
8356                 expression_t *other_expression;
8357                 if (is_type_pointer(true_type) &&
8358                                 (!is_type_pointer(false_type) || is_null_pointer_constant(false_expression))) {
8359                         pointer_type     = true_type;
8360                         other_type       = false_type;
8361                         other_expression = false_expression;
8362                 } else {
8363                         pointer_type     = false_type;
8364                         other_type       = true_type;
8365                         other_expression = true_expression;
8366                 }
8367
8368                 if (is_null_pointer_constant(other_expression)) {
8369                         result_type = pointer_type;
8370                 } else if (is_type_pointer(other_type)) {
8371                         type_t *to1 = skip_typeref(pointer_type->pointer.points_to);
8372                         type_t *to2 = skip_typeref(other_type->pointer.points_to);
8373
8374                         type_t *to;
8375                         if (is_type_atomic(to1, ATOMIC_TYPE_VOID) ||
8376                             is_type_atomic(to2, ATOMIC_TYPE_VOID)) {
8377                                 to = type_void;
8378                         } else if (types_compatible(get_unqualified_type(to1),
8379                                                     get_unqualified_type(to2))) {
8380                                 to = to1;
8381                         } else {
8382                                 if (warning.other) {
8383                                         warningf(&conditional->base.source_position,
8384                                                         "pointer types '%T' and '%T' in conditional expression are incompatible",
8385                                                         true_type, false_type);
8386                                 }
8387                                 to = type_void;
8388                         }
8389
8390                         type_t *const type =
8391                                 get_qualified_type(to, to1->base.qualifiers | to2->base.qualifiers);
8392                         result_type = make_pointer_type(type, TYPE_QUALIFIER_NONE);
8393                 } else if (is_type_integer(other_type)) {
8394                         if (warning.other) {
8395                                 warningf(&conditional->base.source_position,
8396                                                 "pointer/integer type mismatch in conditional expression ('%T' and '%T')", true_type, false_type);
8397                         }
8398                         result_type = pointer_type;
8399                 } else {
8400                         if (is_type_valid(other_type)) {
8401                                 type_error_incompatible("while parsing conditional",
8402                                                 &expression->base.source_position, true_type, false_type);
8403                         }
8404                         result_type = type_error_type;
8405                 }
8406         } else {
8407                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
8408                         type_error_incompatible("while parsing conditional",
8409                                                 &conditional->base.source_position, true_type,
8410                                                 false_type);
8411                 }
8412                 result_type = type_error_type;
8413         }
8414
8415         conditional->true_expression
8416                 = gnu_cond ? NULL : create_implicit_cast(true_expression, result_type);
8417         conditional->false_expression
8418                 = create_implicit_cast(false_expression, result_type);
8419         conditional->base.type = result_type;
8420         return result;
8421 }
8422
8423 /**
8424  * Parse an extension expression.
8425  */
8426 static expression_t *parse_extension(void)
8427 {
8428         eat(T___extension__);
8429
8430         bool old_gcc_extension   = in_gcc_extension;
8431         in_gcc_extension         = true;
8432         expression_t *expression = parse_sub_expression(PREC_UNARY);
8433         in_gcc_extension         = old_gcc_extension;
8434         return expression;
8435 }
8436
8437 /**
8438  * Parse a __builtin_classify_type() expression.
8439  */
8440 static expression_t *parse_builtin_classify_type(void)
8441 {
8442         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
8443         result->base.type    = type_int;
8444
8445         eat(T___builtin_classify_type);
8446
8447         expect('(', end_error);
8448         add_anchor_token(')');
8449         expression_t *expression = parse_expression();
8450         rem_anchor_token(')');
8451         expect(')', end_error);
8452         result->classify_type.type_expression = expression;
8453
8454         return result;
8455 end_error:
8456         return create_invalid_expression();
8457 }
8458
8459 /**
8460  * Parse a delete expression
8461  * ISO/IEC 14882:1998(E) §5.3.5
8462  */
8463 static expression_t *parse_delete(void)
8464 {
8465         expression_t *const result = allocate_expression_zero(EXPR_UNARY_DELETE);
8466         result->base.type          = type_void;
8467
8468         eat(T_delete);
8469
8470         if (token.type == '[') {
8471                 next_token();
8472                 result->kind = EXPR_UNARY_DELETE_ARRAY;
8473                 expect(']', end_error);
8474 end_error:;
8475         }
8476
8477         expression_t *const value = parse_sub_expression(PREC_CAST);
8478         result->unary.value = value;
8479
8480         type_t *const type = skip_typeref(value->base.type);
8481         if (!is_type_pointer(type)) {
8482                 if (is_type_valid(type)) {
8483                         errorf(&value->base.source_position,
8484                                         "operand of delete must have pointer type");
8485                 }
8486         } else if (warning.other &&
8487                         is_type_atomic(skip_typeref(type->pointer.points_to), ATOMIC_TYPE_VOID)) {
8488                 warningf(&value->base.source_position,
8489                                 "deleting 'void*' is undefined");
8490         }
8491
8492         return result;
8493 }
8494
8495 /**
8496  * Parse a throw expression
8497  * ISO/IEC 14882:1998(E) §15:1
8498  */
8499 static expression_t *parse_throw(void)
8500 {
8501         expression_t *const result = allocate_expression_zero(EXPR_UNARY_THROW);
8502         result->base.type          = type_void;
8503
8504         eat(T_throw);
8505
8506         expression_t *value = NULL;
8507         switch (token.type) {
8508                 EXPRESSION_START {
8509                         value = parse_assignment_expression();
8510                         /* ISO/IEC 14882:1998(E) §15.1:3 */
8511                         type_t *const orig_type = value->base.type;
8512                         type_t *const type      = skip_typeref(orig_type);
8513                         if (is_type_incomplete(type)) {
8514                                 errorf(&value->base.source_position,
8515                                                 "cannot throw object of incomplete type '%T'", orig_type);
8516                         } else if (is_type_pointer(type)) {
8517                                 type_t *const points_to = skip_typeref(type->pointer.points_to);
8518                                 if (is_type_incomplete(points_to) &&
8519                                                 !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
8520                                         errorf(&value->base.source_position,
8521                                                         "cannot throw pointer to incomplete type '%T'", orig_type);
8522                                 }
8523                         }
8524                 }
8525
8526                 default:
8527                         break;
8528         }
8529         result->unary.value = value;
8530
8531         return result;
8532 }
8533
8534 static bool check_pointer_arithmetic(const source_position_t *source_position,
8535                                      type_t *pointer_type,
8536                                      type_t *orig_pointer_type)
8537 {
8538         type_t *points_to = pointer_type->pointer.points_to;
8539         points_to = skip_typeref(points_to);
8540
8541         if (is_type_incomplete(points_to)) {
8542                 if (!GNU_MODE || !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
8543                         errorf(source_position,
8544                                "arithmetic with pointer to incomplete type '%T' not allowed",
8545                                orig_pointer_type);
8546                         return false;
8547                 } else if (warning.pointer_arith) {
8548                         warningf(source_position,
8549                                  "pointer of type '%T' used in arithmetic",
8550                                  orig_pointer_type);
8551                 }
8552         } else if (is_type_function(points_to)) {
8553                 if (!GNU_MODE) {
8554                         errorf(source_position,
8555                                "arithmetic with pointer to function type '%T' not allowed",
8556                                orig_pointer_type);
8557                         return false;
8558                 } else if (warning.pointer_arith) {
8559                         warningf(source_position,
8560                                  "pointer to a function '%T' used in arithmetic",
8561                                  orig_pointer_type);
8562                 }
8563         }
8564         return true;
8565 }
8566
8567 static bool is_lvalue(const expression_t *expression)
8568 {
8569         /* TODO: doesn't seem to be consistent with §6.3.2.1:1 */
8570         switch (expression->kind) {
8571         case EXPR_ARRAY_ACCESS:
8572         case EXPR_COMPOUND_LITERAL:
8573         case EXPR_REFERENCE:
8574         case EXPR_SELECT:
8575         case EXPR_UNARY_DEREFERENCE:
8576                 return true;
8577
8578         default: {
8579           type_t *type = skip_typeref(expression->base.type);
8580           return
8581                 /* ISO/IEC 14882:1998(E) §3.10:3 */
8582                 is_type_reference(type) ||
8583                 /* Claim it is an lvalue, if the type is invalid.  There was a parse
8584                  * error before, which maybe prevented properly recognizing it as
8585                  * lvalue. */
8586                 !is_type_valid(type);
8587         }
8588         }
8589 }
8590
8591 static void semantic_incdec(unary_expression_t *expression)
8592 {
8593         type_t *const orig_type = expression->value->base.type;
8594         type_t *const type      = skip_typeref(orig_type);
8595         if (is_type_pointer(type)) {
8596                 if (!check_pointer_arithmetic(&expression->base.source_position,
8597                                               type, orig_type)) {
8598                         return;
8599                 }
8600         } else if (!is_type_real(type) && is_type_valid(type)) {
8601                 /* TODO: improve error message */
8602                 errorf(&expression->base.source_position,
8603                        "operation needs an arithmetic or pointer type");
8604                 return;
8605         }
8606         if (!is_lvalue(expression->value)) {
8607                 /* TODO: improve error message */
8608                 errorf(&expression->base.source_position, "lvalue required as operand");
8609         }
8610         expression->base.type = orig_type;
8611 }
8612
8613 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
8614 {
8615         type_t *const orig_type = expression->value->base.type;
8616         type_t *const type      = skip_typeref(orig_type);
8617         if (!is_type_arithmetic(type)) {
8618                 if (is_type_valid(type)) {
8619                         /* TODO: improve error message */
8620                         errorf(&expression->base.source_position,
8621                                 "operation needs an arithmetic type");
8622                 }
8623                 return;
8624         }
8625
8626         expression->base.type = orig_type;
8627 }
8628
8629 static void semantic_unexpr_plus(unary_expression_t *expression)
8630 {
8631         semantic_unexpr_arithmetic(expression);
8632         if (warning.traditional)
8633                 warningf(&expression->base.source_position,
8634                         "traditional C rejects the unary plus operator");
8635 }
8636
8637 static void semantic_not(unary_expression_t *expression)
8638 {
8639         /* §6.5.3.3:1  The operand [...] of the ! operator, scalar type. */
8640         semantic_condition(expression->value, "operand of !");
8641         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8642 }
8643
8644 static void semantic_unexpr_integer(unary_expression_t *expression)
8645 {
8646         type_t *const orig_type = expression->value->base.type;
8647         type_t *const type      = skip_typeref(orig_type);
8648         if (!is_type_integer(type)) {
8649                 if (is_type_valid(type)) {
8650                         errorf(&expression->base.source_position,
8651                                "operand of ~ must be of integer type");
8652                 }
8653                 return;
8654         }
8655
8656         expression->base.type = orig_type;
8657 }
8658
8659 static void semantic_dereference(unary_expression_t *expression)
8660 {
8661         type_t *const orig_type = expression->value->base.type;
8662         type_t *const type      = skip_typeref(orig_type);
8663         if (!is_type_pointer(type)) {
8664                 if (is_type_valid(type)) {
8665                         errorf(&expression->base.source_position,
8666                                "Unary '*' needs pointer or array type, but type '%T' given", orig_type);
8667                 }
8668                 return;
8669         }
8670
8671         type_t *result_type   = type->pointer.points_to;
8672         result_type           = automatic_type_conversion(result_type);
8673         expression->base.type = result_type;
8674 }
8675
8676 /**
8677  * Record that an address is taken (expression represents an lvalue).
8678  *
8679  * @param expression       the expression
8680  * @param may_be_register  if true, the expression might be an register
8681  */
8682 static void set_address_taken(expression_t *expression, bool may_be_register)
8683 {
8684         if (expression->kind != EXPR_REFERENCE)
8685                 return;
8686
8687         entity_t *const entity = expression->reference.entity;
8688
8689         if (entity->kind != ENTITY_VARIABLE && entity->kind != ENTITY_PARAMETER)
8690                 return;
8691
8692         if (entity->declaration.storage_class == STORAGE_CLASS_REGISTER
8693                         && !may_be_register) {
8694                 errorf(&expression->base.source_position,
8695                                 "address of register %s '%Y' requested",
8696                                 get_entity_kind_name(entity->kind),     entity->base.symbol);
8697         }
8698
8699         if (entity->kind == ENTITY_VARIABLE) {
8700                 entity->variable.address_taken = true;
8701         } else {
8702                 assert(entity->kind == ENTITY_PARAMETER);
8703                 entity->parameter.address_taken = true;
8704         }
8705 }
8706
8707 /**
8708  * Check the semantic of the address taken expression.
8709  */
8710 static void semantic_take_addr(unary_expression_t *expression)
8711 {
8712         expression_t *value = expression->value;
8713         value->base.type    = revert_automatic_type_conversion(value);
8714
8715         type_t *orig_type = value->base.type;
8716         type_t *type      = skip_typeref(orig_type);
8717         if (!is_type_valid(type))
8718                 return;
8719
8720         /* §6.5.3.2 */
8721         if (!is_lvalue(value)) {
8722                 errorf(&expression->base.source_position, "'&' requires an lvalue");
8723         }
8724         if (type->kind == TYPE_BITFIELD) {
8725                 errorf(&expression->base.source_position,
8726                        "'&' not allowed on object with bitfield type '%T'",
8727                        type);
8728         }
8729
8730         set_address_taken(value, false);
8731
8732         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
8733 }
8734
8735 #define CREATE_UNARY_EXPRESSION_PARSER(token_type, unexpression_type, sfunc) \
8736 static expression_t *parse_##unexpression_type(void)                         \
8737 {                                                                            \
8738         expression_t *unary_expression                                           \
8739                 = allocate_expression_zero(unexpression_type);                       \
8740         eat(token_type);                                                         \
8741         unary_expression->unary.value = parse_sub_expression(PREC_UNARY);        \
8742                                                                                  \
8743         sfunc(&unary_expression->unary);                                         \
8744                                                                                  \
8745         return unary_expression;                                                 \
8746 }
8747
8748 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
8749                                semantic_unexpr_arithmetic)
8750 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
8751                                semantic_unexpr_plus)
8752 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
8753                                semantic_not)
8754 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
8755                                semantic_dereference)
8756 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
8757                                semantic_take_addr)
8758 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
8759                                semantic_unexpr_integer)
8760 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
8761                                semantic_incdec)
8762 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
8763                                semantic_incdec)
8764
8765 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_type, unexpression_type, \
8766                                                sfunc)                         \
8767 static expression_t *parse_##unexpression_type(expression_t *left)            \
8768 {                                                                             \
8769         expression_t *unary_expression                                            \
8770                 = allocate_expression_zero(unexpression_type);                        \
8771         eat(token_type);                                                          \
8772         unary_expression->unary.value = left;                                     \
8773                                                                                   \
8774         sfunc(&unary_expression->unary);                                          \
8775                                                                               \
8776         return unary_expression;                                                  \
8777 }
8778
8779 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
8780                                        EXPR_UNARY_POSTFIX_INCREMENT,
8781                                        semantic_incdec)
8782 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
8783                                        EXPR_UNARY_POSTFIX_DECREMENT,
8784                                        semantic_incdec)
8785
8786 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
8787 {
8788         /* TODO: handle complex + imaginary types */
8789
8790         type_left  = get_unqualified_type(type_left);
8791         type_right = get_unqualified_type(type_right);
8792
8793         /* §6.3.1.8 Usual arithmetic conversions */
8794         if (type_left == type_long_double || type_right == type_long_double) {
8795                 return type_long_double;
8796         } else if (type_left == type_double || type_right == type_double) {
8797                 return type_double;
8798         } else if (type_left == type_float || type_right == type_float) {
8799                 return type_float;
8800         }
8801
8802         type_left  = promote_integer(type_left);
8803         type_right = promote_integer(type_right);
8804
8805         if (type_left == type_right)
8806                 return type_left;
8807
8808         bool const signed_left  = is_type_signed(type_left);
8809         bool const signed_right = is_type_signed(type_right);
8810         int const  rank_left    = get_rank(type_left);
8811         int const  rank_right   = get_rank(type_right);
8812
8813         if (signed_left == signed_right)
8814                 return rank_left >= rank_right ? type_left : type_right;
8815
8816         int     s_rank;
8817         int     u_rank;
8818         type_t *s_type;
8819         type_t *u_type;
8820         if (signed_left) {
8821                 s_rank = rank_left;
8822                 s_type = type_left;
8823                 u_rank = rank_right;
8824                 u_type = type_right;
8825         } else {
8826                 s_rank = rank_right;
8827                 s_type = type_right;
8828                 u_rank = rank_left;
8829                 u_type = type_left;
8830         }
8831
8832         if (u_rank >= s_rank)
8833                 return u_type;
8834
8835         /* casting rank to atomic_type_kind is a bit hacky, but makes things
8836          * easier here... */
8837         if (get_atomic_type_size((atomic_type_kind_t) s_rank)
8838                         > get_atomic_type_size((atomic_type_kind_t) u_rank))
8839                 return s_type;
8840
8841         switch (s_rank) {
8842                 case ATOMIC_TYPE_INT:      return type_unsigned_int;
8843                 case ATOMIC_TYPE_LONG:     return type_unsigned_long;
8844                 case ATOMIC_TYPE_LONGLONG: return type_unsigned_long_long;
8845
8846                 default: panic("invalid atomic type");
8847         }
8848 }
8849
8850 /**
8851  * Check the semantic restrictions for a binary expression.
8852  */
8853 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
8854 {
8855         expression_t *const left            = expression->left;
8856         expression_t *const right           = expression->right;
8857         type_t       *const orig_type_left  = left->base.type;
8858         type_t       *const orig_type_right = right->base.type;
8859         type_t       *const type_left       = skip_typeref(orig_type_left);
8860         type_t       *const type_right      = skip_typeref(orig_type_right);
8861
8862         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8863                 /* TODO: improve error message */
8864                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8865                         errorf(&expression->base.source_position,
8866                                "operation needs arithmetic types");
8867                 }
8868                 return;
8869         }
8870
8871         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8872         expression->left      = create_implicit_cast(left, arithmetic_type);
8873         expression->right     = create_implicit_cast(right, arithmetic_type);
8874         expression->base.type = arithmetic_type;
8875 }
8876
8877 static void warn_div_by_zero(binary_expression_t const *const expression)
8878 {
8879         if (!warning.div_by_zero ||
8880             !is_type_integer(expression->base.type))
8881                 return;
8882
8883         expression_t const *const right = expression->right;
8884         /* The type of the right operand can be different for /= */
8885         if (is_type_integer(right->base.type) &&
8886             is_constant_expression(right)     &&
8887             fold_constant(right) == 0) {
8888                 warningf(&expression->base.source_position, "division by zero");
8889         }
8890 }
8891
8892 /**
8893  * Check the semantic restrictions for a div/mod expression.
8894  */
8895 static void semantic_divmod_arithmetic(binary_expression_t *expression)
8896 {
8897         semantic_binexpr_arithmetic(expression);
8898         warn_div_by_zero(expression);
8899 }
8900
8901 static void warn_addsub_in_shift(const expression_t *const expr)
8902 {
8903         if (expr->base.parenthesized)
8904                 return;
8905
8906         char op;
8907         switch (expr->kind) {
8908                 case EXPR_BINARY_ADD: op = '+'; break;
8909                 case EXPR_BINARY_SUB: op = '-'; break;
8910                 default:              return;
8911         }
8912
8913         warningf(&expr->base.source_position,
8914                         "suggest parentheses around '%c' inside shift", op);
8915 }
8916
8917 static void semantic_shift_op(binary_expression_t *expression)
8918 {
8919         expression_t *const left            = expression->left;
8920         expression_t *const right           = expression->right;
8921         type_t       *const orig_type_left  = left->base.type;
8922         type_t       *const orig_type_right = right->base.type;
8923         type_t       *      type_left       = skip_typeref(orig_type_left);
8924         type_t       *      type_right      = skip_typeref(orig_type_right);
8925
8926         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8927                 /* TODO: improve error message */
8928                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8929                         errorf(&expression->base.source_position,
8930                                "operands of shift operation must have integer types");
8931                 }
8932                 return;
8933         }
8934
8935         if (warning.parentheses) {
8936                 warn_addsub_in_shift(left);
8937                 warn_addsub_in_shift(right);
8938         }
8939
8940         type_left  = promote_integer(type_left);
8941         type_right = promote_integer(type_right);
8942
8943         expression->left      = create_implicit_cast(left, type_left);
8944         expression->right     = create_implicit_cast(right, type_right);
8945         expression->base.type = type_left;
8946 }
8947
8948 static void semantic_add(binary_expression_t *expression)
8949 {
8950         expression_t *const left            = expression->left;
8951         expression_t *const right           = expression->right;
8952         type_t       *const orig_type_left  = left->base.type;
8953         type_t       *const orig_type_right = right->base.type;
8954         type_t       *const type_left       = skip_typeref(orig_type_left);
8955         type_t       *const type_right      = skip_typeref(orig_type_right);
8956
8957         /* §6.5.6 */
8958         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8959                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8960                 expression->left  = create_implicit_cast(left, arithmetic_type);
8961                 expression->right = create_implicit_cast(right, arithmetic_type);
8962                 expression->base.type = arithmetic_type;
8963         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8964                 check_pointer_arithmetic(&expression->base.source_position,
8965                                          type_left, orig_type_left);
8966                 expression->base.type = type_left;
8967         } else if (is_type_pointer(type_right) && is_type_integer(type_left)) {
8968                 check_pointer_arithmetic(&expression->base.source_position,
8969                                          type_right, orig_type_right);
8970                 expression->base.type = type_right;
8971         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8972                 errorf(&expression->base.source_position,
8973                        "invalid operands to binary + ('%T', '%T')",
8974                        orig_type_left, orig_type_right);
8975         }
8976 }
8977
8978 static void semantic_sub(binary_expression_t *expression)
8979 {
8980         expression_t            *const left            = expression->left;
8981         expression_t            *const right           = expression->right;
8982         type_t                  *const orig_type_left  = left->base.type;
8983         type_t                  *const orig_type_right = right->base.type;
8984         type_t                  *const type_left       = skip_typeref(orig_type_left);
8985         type_t                  *const type_right      = skip_typeref(orig_type_right);
8986         source_position_t const *const pos             = &expression->base.source_position;
8987
8988         /* §5.6.5 */
8989         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8990                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8991                 expression->left        = create_implicit_cast(left, arithmetic_type);
8992                 expression->right       = create_implicit_cast(right, arithmetic_type);
8993                 expression->base.type =  arithmetic_type;
8994         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8995                 check_pointer_arithmetic(&expression->base.source_position,
8996                                          type_left, orig_type_left);
8997                 expression->base.type = type_left;
8998         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8999                 type_t *const unqual_left  = get_unqualified_type(skip_typeref(type_left->pointer.points_to));
9000                 type_t *const unqual_right = get_unqualified_type(skip_typeref(type_right->pointer.points_to));
9001                 if (!types_compatible(unqual_left, unqual_right)) {
9002                         errorf(pos,
9003                                "subtracting pointers to incompatible types '%T' and '%T'",
9004                                orig_type_left, orig_type_right);
9005                 } else if (!is_type_object(unqual_left)) {
9006                         if (!is_type_atomic(unqual_left, ATOMIC_TYPE_VOID)) {
9007                                 errorf(pos, "subtracting pointers to non-object types '%T'",
9008                                        orig_type_left);
9009                         } else if (warning.other) {
9010                                 warningf(pos, "subtracting pointers to void");
9011                         }
9012                 }
9013                 expression->base.type = type_ptrdiff_t;
9014         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
9015                 errorf(pos, "invalid operands of types '%T' and '%T' to binary '-'",
9016                        orig_type_left, orig_type_right);
9017         }
9018 }
9019
9020 static void warn_string_literal_address(expression_t const* expr)
9021 {
9022         while (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
9023                 expr = expr->unary.value;
9024                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
9025                         return;
9026                 expr = expr->unary.value;
9027         }
9028
9029         if (expr->kind == EXPR_STRING_LITERAL ||
9030             expr->kind == EXPR_WIDE_STRING_LITERAL) {
9031                 warningf(&expr->base.source_position,
9032                         "comparison with string literal results in unspecified behaviour");
9033         }
9034 }
9035
9036 static void warn_comparison_in_comparison(const expression_t *const expr)
9037 {
9038         if (expr->base.parenthesized)
9039                 return;
9040         switch (expr->base.kind) {
9041                 case EXPR_BINARY_LESS:
9042                 case EXPR_BINARY_GREATER:
9043                 case EXPR_BINARY_LESSEQUAL:
9044                 case EXPR_BINARY_GREATEREQUAL:
9045                 case EXPR_BINARY_NOTEQUAL:
9046                 case EXPR_BINARY_EQUAL:
9047                         warningf(&expr->base.source_position,
9048                                         "comparisons like 'x <= y < z' do not have their mathematical meaning");
9049                         break;
9050                 default:
9051                         break;
9052         }
9053 }
9054
9055 static bool maybe_negative(expression_t const *const expr)
9056 {
9057         return
9058                 !is_constant_expression(expr) ||
9059                 fold_constant(expr) < 0;
9060 }
9061
9062 /**
9063  * Check the semantics of comparison expressions.
9064  *
9065  * @param expression   The expression to check.
9066  */
9067 static void semantic_comparison(binary_expression_t *expression)
9068 {
9069         expression_t *left  = expression->left;
9070         expression_t *right = expression->right;
9071
9072         if (warning.address) {
9073                 warn_string_literal_address(left);
9074                 warn_string_literal_address(right);
9075
9076                 expression_t const* const func_left = get_reference_address(left);
9077                 if (func_left != NULL && is_null_pointer_constant(right)) {
9078                         warningf(&expression->base.source_position,
9079                                  "the address of '%Y' will never be NULL",
9080                                  func_left->reference.entity->base.symbol);
9081                 }
9082
9083                 expression_t const* const func_right = get_reference_address(right);
9084                 if (func_right != NULL && is_null_pointer_constant(right)) {
9085                         warningf(&expression->base.source_position,
9086                                  "the address of '%Y' will never be NULL",
9087                                  func_right->reference.entity->base.symbol);
9088                 }
9089         }
9090
9091         if (warning.parentheses) {
9092                 warn_comparison_in_comparison(left);
9093                 warn_comparison_in_comparison(right);
9094         }
9095
9096         type_t *orig_type_left  = left->base.type;
9097         type_t *orig_type_right = right->base.type;
9098         type_t *type_left       = skip_typeref(orig_type_left);
9099         type_t *type_right      = skip_typeref(orig_type_right);
9100
9101         /* TODO non-arithmetic types */
9102         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
9103                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
9104
9105                 /* test for signed vs unsigned compares */
9106                 if (warning.sign_compare && is_type_integer(arithmetic_type)) {
9107                         bool const signed_left  = is_type_signed(type_left);
9108                         bool const signed_right = is_type_signed(type_right);
9109                         if (signed_left != signed_right) {
9110                                 /* FIXME long long needs better const folding magic */
9111                                 /* TODO check whether constant value can be represented by other type */
9112                                 if ((signed_left  && maybe_negative(left)) ||
9113                                                 (signed_right && maybe_negative(right))) {
9114                                         warningf(&expression->base.source_position,
9115                                                         "comparison between signed and unsigned");
9116                                 }
9117                         }
9118                 }
9119
9120                 expression->left        = create_implicit_cast(left, arithmetic_type);
9121                 expression->right       = create_implicit_cast(right, arithmetic_type);
9122                 expression->base.type   = arithmetic_type;
9123                 if (warning.float_equal &&
9124                     (expression->base.kind == EXPR_BINARY_EQUAL ||
9125                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
9126                     is_type_float(arithmetic_type)) {
9127                         warningf(&expression->base.source_position,
9128                                  "comparing floating point with == or != is unsafe");
9129                 }
9130         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
9131                 /* TODO check compatibility */
9132         } else if (is_type_pointer(type_left)) {
9133                 expression->right = create_implicit_cast(right, type_left);
9134         } else if (is_type_pointer(type_right)) {
9135                 expression->left = create_implicit_cast(left, type_right);
9136         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
9137                 type_error_incompatible("invalid operands in comparison",
9138                                         &expression->base.source_position,
9139                                         type_left, type_right);
9140         }
9141         expression->base.type = c_mode & _CXX ? type_bool : type_int;
9142 }
9143
9144 /**
9145  * Checks if a compound type has constant fields.
9146  */
9147 static bool has_const_fields(const compound_type_t *type)
9148 {
9149         compound_t *compound = type->compound;
9150         entity_t   *entry    = compound->members.entities;
9151
9152         for (; entry != NULL; entry = entry->base.next) {
9153                 if (!is_declaration(entry))
9154                         continue;
9155
9156                 const type_t *decl_type = skip_typeref(entry->declaration.type);
9157                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
9158                         return true;
9159         }
9160
9161         return false;
9162 }
9163
9164 static bool is_valid_assignment_lhs(expression_t const* const left)
9165 {
9166         type_t *const orig_type_left = revert_automatic_type_conversion(left);
9167         type_t *const type_left      = skip_typeref(orig_type_left);
9168
9169         if (!is_lvalue(left)) {
9170                 errorf(HERE, "left hand side '%E' of assignment is not an lvalue",
9171                        left);
9172                 return false;
9173         }
9174
9175         if (left->kind == EXPR_REFERENCE
9176                         && left->reference.entity->kind == ENTITY_FUNCTION) {
9177                 errorf(HERE, "cannot assign to function '%E'", left);
9178                 return false;
9179         }
9180
9181         if (is_type_array(type_left)) {
9182                 errorf(HERE, "cannot assign to array '%E'", left);
9183                 return false;
9184         }
9185         if (type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
9186                 errorf(HERE, "assignment to readonly location '%E' (type '%T')", left,
9187                        orig_type_left);
9188                 return false;
9189         }
9190         if (is_type_incomplete(type_left)) {
9191                 errorf(HERE, "left-hand side '%E' of assignment has incomplete type '%T'",
9192                        left, orig_type_left);
9193                 return false;
9194         }
9195         if (is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
9196                 errorf(HERE, "cannot assign to '%E' because compound type '%T' has readonly fields",
9197                        left, orig_type_left);
9198                 return false;
9199         }
9200
9201         return true;
9202 }
9203
9204 static void semantic_arithmetic_assign(binary_expression_t *expression)
9205 {
9206         expression_t *left            = expression->left;
9207         expression_t *right           = expression->right;
9208         type_t       *orig_type_left  = left->base.type;
9209         type_t       *orig_type_right = right->base.type;
9210
9211         if (!is_valid_assignment_lhs(left))
9212                 return;
9213
9214         type_t *type_left  = skip_typeref(orig_type_left);
9215         type_t *type_right = skip_typeref(orig_type_right);
9216
9217         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
9218                 /* TODO: improve error message */
9219                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
9220                         errorf(&expression->base.source_position,
9221                                "operation needs arithmetic types");
9222                 }
9223                 return;
9224         }
9225
9226         /* combined instructions are tricky. We can't create an implicit cast on
9227          * the left side, because we need the uncasted form for the store.
9228          * The ast2firm pass has to know that left_type must be right_type
9229          * for the arithmetic operation and create a cast by itself */
9230         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
9231         expression->right       = create_implicit_cast(right, arithmetic_type);
9232         expression->base.type   = type_left;
9233 }
9234
9235 static void semantic_divmod_assign(binary_expression_t *expression)
9236 {
9237         semantic_arithmetic_assign(expression);
9238         warn_div_by_zero(expression);
9239 }
9240
9241 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
9242 {
9243         expression_t *const left            = expression->left;
9244         expression_t *const right           = expression->right;
9245         type_t       *const orig_type_left  = left->base.type;
9246         type_t       *const orig_type_right = right->base.type;
9247         type_t       *const type_left       = skip_typeref(orig_type_left);
9248         type_t       *const type_right      = skip_typeref(orig_type_right);
9249
9250         if (!is_valid_assignment_lhs(left))
9251                 return;
9252
9253         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
9254                 /* combined instructions are tricky. We can't create an implicit cast on
9255                  * the left side, because we need the uncasted form for the store.
9256                  * The ast2firm pass has to know that left_type must be right_type
9257                  * for the arithmetic operation and create a cast by itself */
9258                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
9259                 expression->right     = create_implicit_cast(right, arithmetic_type);
9260                 expression->base.type = type_left;
9261         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
9262                 check_pointer_arithmetic(&expression->base.source_position,
9263                                          type_left, orig_type_left);
9264                 expression->base.type = type_left;
9265         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
9266                 errorf(&expression->base.source_position,
9267                        "incompatible types '%T' and '%T' in assignment",
9268                        orig_type_left, orig_type_right);
9269         }
9270 }
9271
9272 static void warn_logical_and_within_or(const expression_t *const expr)
9273 {
9274         if (expr->base.kind != EXPR_BINARY_LOGICAL_AND)
9275                 return;
9276         if (expr->base.parenthesized)
9277                 return;
9278         warningf(&expr->base.source_position,
9279                         "suggest parentheses around && within ||");
9280 }
9281
9282 /**
9283  * Check the semantic restrictions of a logical expression.
9284  */
9285 static void semantic_logical_op(binary_expression_t *expression)
9286 {
9287         /* §6.5.13:2  Each of the operands shall have scalar type.
9288          * §6.5.14:2  Each of the operands shall have scalar type. */
9289         semantic_condition(expression->left,   "left operand of logical operator");
9290         semantic_condition(expression->right, "right operand of logical operator");
9291         if (expression->base.kind == EXPR_BINARY_LOGICAL_OR &&
9292                         warning.parentheses) {
9293                 warn_logical_and_within_or(expression->left);
9294                 warn_logical_and_within_or(expression->right);
9295         }
9296         expression->base.type = c_mode & _CXX ? type_bool : type_int;
9297 }
9298
9299 /**
9300  * Check the semantic restrictions of a binary assign expression.
9301  */
9302 static void semantic_binexpr_assign(binary_expression_t *expression)
9303 {
9304         expression_t *left           = expression->left;
9305         type_t       *orig_type_left = left->base.type;
9306
9307         if (!is_valid_assignment_lhs(left))
9308                 return;
9309
9310         assign_error_t error = semantic_assign(orig_type_left, expression->right);
9311         report_assign_error(error, orig_type_left, expression->right,
9312                         "assignment", &left->base.source_position);
9313         expression->right = create_implicit_cast(expression->right, orig_type_left);
9314         expression->base.type = orig_type_left;
9315 }
9316
9317 /**
9318  * Determine if the outermost operation (or parts thereof) of the given
9319  * expression has no effect in order to generate a warning about this fact.
9320  * Therefore in some cases this only examines some of the operands of the
9321  * expression (see comments in the function and examples below).
9322  * Examples:
9323  *   f() + 23;    // warning, because + has no effect
9324  *   x || f();    // no warning, because x controls execution of f()
9325  *   x ? y : f(); // warning, because y has no effect
9326  *   (void)x;     // no warning to be able to suppress the warning
9327  * This function can NOT be used for an "expression has definitely no effect"-
9328  * analysis. */
9329 static bool expression_has_effect(const expression_t *const expr)
9330 {
9331         switch (expr->kind) {
9332                 case EXPR_UNKNOWN:                    break;
9333                 case EXPR_INVALID:                    return true; /* do NOT warn */
9334                 case EXPR_REFERENCE:                  return false;
9335                 case EXPR_REFERENCE_ENUM_VALUE:       return false;
9336                 /* suppress the warning for microsoft __noop operations */
9337                 case EXPR_CONST:                      return expr->conste.is_ms_noop;
9338                 case EXPR_CHARACTER_CONSTANT:         return false;
9339                 case EXPR_WIDE_CHARACTER_CONSTANT:    return false;
9340                 case EXPR_STRING_LITERAL:             return false;
9341                 case EXPR_WIDE_STRING_LITERAL:        return false;
9342                 case EXPR_LABEL_ADDRESS:              return false;
9343
9344                 case EXPR_CALL: {
9345                         const call_expression_t *const call = &expr->call;
9346                         if (call->function->kind != EXPR_REFERENCE)
9347                                 return true;
9348
9349                         switch (call->function->reference.entity->function.btk) {
9350                                 /* FIXME: which builtins have no effect? */
9351                                 default:                      return true;
9352                         }
9353                 }
9354
9355                 /* Generate the warning if either the left or right hand side of a
9356                  * conditional expression has no effect */
9357                 case EXPR_CONDITIONAL: {
9358                         conditional_expression_t const *const cond = &expr->conditional;
9359                         expression_t             const *const t    = cond->true_expression;
9360                         return
9361                                 (t == NULL || expression_has_effect(t)) &&
9362                                 expression_has_effect(cond->false_expression);
9363                 }
9364
9365                 case EXPR_SELECT:                     return false;
9366                 case EXPR_ARRAY_ACCESS:               return false;
9367                 case EXPR_SIZEOF:                     return false;
9368                 case EXPR_CLASSIFY_TYPE:              return false;
9369                 case EXPR_ALIGNOF:                    return false;
9370
9371                 case EXPR_FUNCNAME:                   return false;
9372                 case EXPR_BUILTIN_CONSTANT_P:         return false;
9373                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P: return false;
9374                 case EXPR_OFFSETOF:                   return false;
9375                 case EXPR_VA_START:                   return true;
9376                 case EXPR_VA_ARG:                     return true;
9377                 case EXPR_STATEMENT:                  return true; // TODO
9378                 case EXPR_COMPOUND_LITERAL:           return false;
9379
9380                 case EXPR_UNARY_NEGATE:               return false;
9381                 case EXPR_UNARY_PLUS:                 return false;
9382                 case EXPR_UNARY_BITWISE_NEGATE:       return false;
9383                 case EXPR_UNARY_NOT:                  return false;
9384                 case EXPR_UNARY_DEREFERENCE:          return false;
9385                 case EXPR_UNARY_TAKE_ADDRESS:         return false;
9386                 case EXPR_UNARY_POSTFIX_INCREMENT:    return true;
9387                 case EXPR_UNARY_POSTFIX_DECREMENT:    return true;
9388                 case EXPR_UNARY_PREFIX_INCREMENT:     return true;
9389                 case EXPR_UNARY_PREFIX_DECREMENT:     return true;
9390
9391                 /* Treat void casts as if they have an effect in order to being able to
9392                  * suppress the warning */
9393                 case EXPR_UNARY_CAST: {
9394                         type_t *const type = skip_typeref(expr->base.type);
9395                         return is_type_atomic(type, ATOMIC_TYPE_VOID);
9396                 }
9397
9398                 case EXPR_UNARY_CAST_IMPLICIT:        return true;
9399                 case EXPR_UNARY_ASSUME:               return true;
9400                 case EXPR_UNARY_DELETE:               return true;
9401                 case EXPR_UNARY_DELETE_ARRAY:         return true;
9402                 case EXPR_UNARY_THROW:                return true;
9403
9404                 case EXPR_BINARY_ADD:                 return false;
9405                 case EXPR_BINARY_SUB:                 return false;
9406                 case EXPR_BINARY_MUL:                 return false;
9407                 case EXPR_BINARY_DIV:                 return false;
9408                 case EXPR_BINARY_MOD:                 return false;
9409                 case EXPR_BINARY_EQUAL:               return false;
9410                 case EXPR_BINARY_NOTEQUAL:            return false;
9411                 case EXPR_BINARY_LESS:                return false;
9412                 case EXPR_BINARY_LESSEQUAL:           return false;
9413                 case EXPR_BINARY_GREATER:             return false;
9414                 case EXPR_BINARY_GREATEREQUAL:        return false;
9415                 case EXPR_BINARY_BITWISE_AND:         return false;
9416                 case EXPR_BINARY_BITWISE_OR:          return false;
9417                 case EXPR_BINARY_BITWISE_XOR:         return false;
9418                 case EXPR_BINARY_SHIFTLEFT:           return false;
9419                 case EXPR_BINARY_SHIFTRIGHT:          return false;
9420                 case EXPR_BINARY_ASSIGN:              return true;
9421                 case EXPR_BINARY_MUL_ASSIGN:          return true;
9422                 case EXPR_BINARY_DIV_ASSIGN:          return true;
9423                 case EXPR_BINARY_MOD_ASSIGN:          return true;
9424                 case EXPR_BINARY_ADD_ASSIGN:          return true;
9425                 case EXPR_BINARY_SUB_ASSIGN:          return true;
9426                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:    return true;
9427                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:   return true;
9428                 case EXPR_BINARY_BITWISE_AND_ASSIGN:  return true;
9429                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:  return true;
9430                 case EXPR_BINARY_BITWISE_OR_ASSIGN:   return true;
9431
9432                 /* Only examine the right hand side of && and ||, because the left hand
9433                  * side already has the effect of controlling the execution of the right
9434                  * hand side */
9435                 case EXPR_BINARY_LOGICAL_AND:
9436                 case EXPR_BINARY_LOGICAL_OR:
9437                 /* Only examine the right hand side of a comma expression, because the left
9438                  * hand side has a separate warning */
9439                 case EXPR_BINARY_COMMA:
9440                         return expression_has_effect(expr->binary.right);
9441
9442                 case EXPR_BINARY_ISGREATER:           return false;
9443                 case EXPR_BINARY_ISGREATEREQUAL:      return false;
9444                 case EXPR_BINARY_ISLESS:              return false;
9445                 case EXPR_BINARY_ISLESSEQUAL:         return false;
9446                 case EXPR_BINARY_ISLESSGREATER:       return false;
9447                 case EXPR_BINARY_ISUNORDERED:         return false;
9448         }
9449
9450         internal_errorf(HERE, "unexpected expression");
9451 }
9452
9453 static void semantic_comma(binary_expression_t *expression)
9454 {
9455         if (warning.unused_value) {
9456                 const expression_t *const left = expression->left;
9457                 if (!expression_has_effect(left)) {
9458                         warningf(&left->base.source_position,
9459                                  "left-hand operand of comma expression has no effect");
9460                 }
9461         }
9462         expression->base.type = expression->right->base.type;
9463 }
9464
9465 /**
9466  * @param prec_r precedence of the right operand
9467  */
9468 #define CREATE_BINEXPR_PARSER(token_type, binexpression_type, prec_r, sfunc) \
9469 static expression_t *parse_##binexpression_type(expression_t *left)          \
9470 {                                                                            \
9471         expression_t *binexpr = allocate_expression_zero(binexpression_type);    \
9472         binexpr->binary.left  = left;                                            \
9473         eat(token_type);                                                         \
9474                                                                              \
9475         expression_t *right = parse_sub_expression(prec_r);                      \
9476                                                                              \
9477         binexpr->binary.right = right;                                           \
9478         sfunc(&binexpr->binary);                                                 \
9479                                                                              \
9480         return binexpr;                                                          \
9481 }
9482
9483 CREATE_BINEXPR_PARSER('*',                    EXPR_BINARY_MUL,                PREC_CAST,           semantic_binexpr_arithmetic)
9484 CREATE_BINEXPR_PARSER('/',                    EXPR_BINARY_DIV,                PREC_CAST,           semantic_divmod_arithmetic)
9485 CREATE_BINEXPR_PARSER('%',                    EXPR_BINARY_MOD,                PREC_CAST,           semantic_divmod_arithmetic)
9486 CREATE_BINEXPR_PARSER('+',                    EXPR_BINARY_ADD,                PREC_MULTIPLICATIVE, semantic_add)
9487 CREATE_BINEXPR_PARSER('-',                    EXPR_BINARY_SUB,                PREC_MULTIPLICATIVE, semantic_sub)
9488 CREATE_BINEXPR_PARSER(T_LESSLESS,             EXPR_BINARY_SHIFTLEFT,          PREC_ADDITIVE,       semantic_shift_op)
9489 CREATE_BINEXPR_PARSER(T_GREATERGREATER,       EXPR_BINARY_SHIFTRIGHT,         PREC_ADDITIVE,       semantic_shift_op)
9490 CREATE_BINEXPR_PARSER('<',                    EXPR_BINARY_LESS,               PREC_SHIFT,          semantic_comparison)
9491 CREATE_BINEXPR_PARSER('>',                    EXPR_BINARY_GREATER,            PREC_SHIFT,          semantic_comparison)
9492 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,          PREC_SHIFT,          semantic_comparison)
9493 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,       PREC_SHIFT,          semantic_comparison)
9494 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,           PREC_RELATIONAL,     semantic_comparison)
9495 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,              PREC_RELATIONAL,     semantic_comparison)
9496 CREATE_BINEXPR_PARSER('&',                    EXPR_BINARY_BITWISE_AND,        PREC_EQUALITY,       semantic_binexpr_arithmetic)
9497 CREATE_BINEXPR_PARSER('^',                    EXPR_BINARY_BITWISE_XOR,        PREC_AND,            semantic_binexpr_arithmetic)
9498 CREATE_BINEXPR_PARSER('|',                    EXPR_BINARY_BITWISE_OR,         PREC_XOR,            semantic_binexpr_arithmetic)
9499 CREATE_BINEXPR_PARSER(T_ANDAND,               EXPR_BINARY_LOGICAL_AND,        PREC_OR,             semantic_logical_op)
9500 CREATE_BINEXPR_PARSER(T_PIPEPIPE,             EXPR_BINARY_LOGICAL_OR,         PREC_LOGICAL_AND,    semantic_logical_op)
9501 CREATE_BINEXPR_PARSER('=',                    EXPR_BINARY_ASSIGN,             PREC_ASSIGNMENT,     semantic_binexpr_assign)
9502 CREATE_BINEXPR_PARSER(T_PLUSEQUAL,            EXPR_BINARY_ADD_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
9503 CREATE_BINEXPR_PARSER(T_MINUSEQUAL,           EXPR_BINARY_SUB_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
9504 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL,        EXPR_BINARY_MUL_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9505 CREATE_BINEXPR_PARSER(T_SLASHEQUAL,           EXPR_BINARY_DIV_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
9506 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL,         EXPR_BINARY_MOD_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
9507 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL,        EXPR_BINARY_SHIFTLEFT_ASSIGN,   PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9508 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL,  EXPR_BINARY_SHIFTRIGHT_ASSIGN,  PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9509 CREATE_BINEXPR_PARSER(T_ANDEQUAL,             EXPR_BINARY_BITWISE_AND_ASSIGN, PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9510 CREATE_BINEXPR_PARSER(T_PIPEEQUAL,            EXPR_BINARY_BITWISE_OR_ASSIGN,  PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9511 CREATE_BINEXPR_PARSER(T_CARETEQUAL,           EXPR_BINARY_BITWISE_XOR_ASSIGN, PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9512 CREATE_BINEXPR_PARSER(',',                    EXPR_BINARY_COMMA,              PREC_ASSIGNMENT,     semantic_comma)
9513
9514
9515 static expression_t *parse_sub_expression(precedence_t precedence)
9516 {
9517         if (token.type < 0) {
9518                 return expected_expression_error();
9519         }
9520
9521         expression_parser_function_t *parser
9522                 = &expression_parsers[token.type];
9523         source_position_t             source_position = token.source_position;
9524         expression_t                 *left;
9525
9526         if (parser->parser != NULL) {
9527                 left = parser->parser();
9528         } else {
9529                 left = parse_primary_expression();
9530         }
9531         assert(left != NULL);
9532         left->base.source_position = source_position;
9533
9534         while (true) {
9535                 if (token.type < 0) {
9536                         return expected_expression_error();
9537                 }
9538
9539                 parser = &expression_parsers[token.type];
9540                 if (parser->infix_parser == NULL)
9541                         break;
9542                 if (parser->infix_precedence < precedence)
9543                         break;
9544
9545                 left = parser->infix_parser(left);
9546
9547                 assert(left != NULL);
9548                 assert(left->kind != EXPR_UNKNOWN);
9549                 left->base.source_position = source_position;
9550         }
9551
9552         return left;
9553 }
9554
9555 /**
9556  * Parse an expression.
9557  */
9558 static expression_t *parse_expression(void)
9559 {
9560         return parse_sub_expression(PREC_EXPRESSION);
9561 }
9562
9563 /**
9564  * Register a parser for a prefix-like operator.
9565  *
9566  * @param parser      the parser function
9567  * @param token_type  the token type of the prefix token
9568  */
9569 static void register_expression_parser(parse_expression_function parser,
9570                                        int token_type)
9571 {
9572         expression_parser_function_t *entry = &expression_parsers[token_type];
9573
9574         if (entry->parser != NULL) {
9575                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
9576                 panic("trying to register multiple expression parsers for a token");
9577         }
9578         entry->parser = parser;
9579 }
9580
9581 /**
9582  * Register a parser for an infix operator with given precedence.
9583  *
9584  * @param parser      the parser function
9585  * @param token_type  the token type of the infix operator
9586  * @param precedence  the precedence of the operator
9587  */
9588 static void register_infix_parser(parse_expression_infix_function parser,
9589                 int token_type, precedence_t precedence)
9590 {
9591         expression_parser_function_t *entry = &expression_parsers[token_type];
9592
9593         if (entry->infix_parser != NULL) {
9594                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
9595                 panic("trying to register multiple infix expression parsers for a "
9596                       "token");
9597         }
9598         entry->infix_parser     = parser;
9599         entry->infix_precedence = precedence;
9600 }
9601
9602 /**
9603  * Initialize the expression parsers.
9604  */
9605 static void init_expression_parsers(void)
9606 {
9607         memset(&expression_parsers, 0, sizeof(expression_parsers));
9608
9609         register_infix_parser(parse_array_expression,               '[',                    PREC_POSTFIX);
9610         register_infix_parser(parse_call_expression,                '(',                    PREC_POSTFIX);
9611         register_infix_parser(parse_select_expression,              '.',                    PREC_POSTFIX);
9612         register_infix_parser(parse_select_expression,              T_MINUSGREATER,         PREC_POSTFIX);
9613         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,   T_PLUSPLUS,             PREC_POSTFIX);
9614         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,   T_MINUSMINUS,           PREC_POSTFIX);
9615         register_infix_parser(parse_EXPR_BINARY_MUL,                '*',                    PREC_MULTIPLICATIVE);
9616         register_infix_parser(parse_EXPR_BINARY_DIV,                '/',                    PREC_MULTIPLICATIVE);
9617         register_infix_parser(parse_EXPR_BINARY_MOD,                '%',                    PREC_MULTIPLICATIVE);
9618         register_infix_parser(parse_EXPR_BINARY_ADD,                '+',                    PREC_ADDITIVE);
9619         register_infix_parser(parse_EXPR_BINARY_SUB,                '-',                    PREC_ADDITIVE);
9620         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,          T_LESSLESS,             PREC_SHIFT);
9621         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,         T_GREATERGREATER,       PREC_SHIFT);
9622         register_infix_parser(parse_EXPR_BINARY_LESS,               '<',                    PREC_RELATIONAL);
9623         register_infix_parser(parse_EXPR_BINARY_GREATER,            '>',                    PREC_RELATIONAL);
9624         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,          T_LESSEQUAL,            PREC_RELATIONAL);
9625         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL,       T_GREATEREQUAL,         PREC_RELATIONAL);
9626         register_infix_parser(parse_EXPR_BINARY_EQUAL,              T_EQUALEQUAL,           PREC_EQUALITY);
9627         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,           T_EXCLAMATIONMARKEQUAL, PREC_EQUALITY);
9628         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,        '&',                    PREC_AND);
9629         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,        '^',                    PREC_XOR);
9630         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,         '|',                    PREC_OR);
9631         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,        T_ANDAND,               PREC_LOGICAL_AND);
9632         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,         T_PIPEPIPE,             PREC_LOGICAL_OR);
9633         register_infix_parser(parse_conditional_expression,         '?',                    PREC_CONDITIONAL);
9634         register_infix_parser(parse_EXPR_BINARY_ASSIGN,             '=',                    PREC_ASSIGNMENT);
9635         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,         T_PLUSEQUAL,            PREC_ASSIGNMENT);
9636         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,         T_MINUSEQUAL,           PREC_ASSIGNMENT);
9637         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,         T_ASTERISKEQUAL,        PREC_ASSIGNMENT);
9638         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,         T_SLASHEQUAL,           PREC_ASSIGNMENT);
9639         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,         T_PERCENTEQUAL,         PREC_ASSIGNMENT);
9640         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,   T_LESSLESSEQUAL,        PREC_ASSIGNMENT);
9641         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,  T_GREATERGREATEREQUAL,  PREC_ASSIGNMENT);
9642         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN, T_ANDEQUAL,             PREC_ASSIGNMENT);
9643         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,  T_PIPEEQUAL,            PREC_ASSIGNMENT);
9644         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN, T_CARETEQUAL,           PREC_ASSIGNMENT);
9645         register_infix_parser(parse_EXPR_BINARY_COMMA,              ',',                    PREC_EXPRESSION);
9646
9647         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-');
9648         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+');
9649         register_expression_parser(parse_EXPR_UNARY_NOT,              '!');
9650         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~');
9651         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*');
9652         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&');
9653         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT, T_PLUSPLUS);
9654         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT, T_MINUSMINUS);
9655         register_expression_parser(parse_sizeof,                      T_sizeof);
9656         register_expression_parser(parse_alignof,                     T___alignof__);
9657         register_expression_parser(parse_extension,                   T___extension__);
9658         register_expression_parser(parse_builtin_classify_type,       T___builtin_classify_type);
9659         register_expression_parser(parse_delete,                      T_delete);
9660         register_expression_parser(parse_throw,                       T_throw);
9661 }
9662
9663 /**
9664  * Parse a asm statement arguments specification.
9665  */
9666 static asm_argument_t *parse_asm_arguments(bool is_out)
9667 {
9668         asm_argument_t  *result = NULL;
9669         asm_argument_t **anchor = &result;
9670
9671         while (token.type == T_STRING_LITERAL || token.type == '[') {
9672                 asm_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
9673                 memset(argument, 0, sizeof(argument[0]));
9674
9675                 if (token.type == '[') {
9676                         eat('[');
9677                         if (token.type != T_IDENTIFIER) {
9678                                 parse_error_expected("while parsing asm argument",
9679                                                      T_IDENTIFIER, NULL);
9680                                 return NULL;
9681                         }
9682                         argument->symbol = token.v.symbol;
9683
9684                         expect(']', end_error);
9685                 }
9686
9687                 argument->constraints = parse_string_literals();
9688                 expect('(', end_error);
9689                 add_anchor_token(')');
9690                 expression_t *expression = parse_expression();
9691                 rem_anchor_token(')');
9692                 if (is_out) {
9693                         /* Ugly GCC stuff: Allow lvalue casts.  Skip casts, when they do not
9694                          * change size or type representation (e.g. int -> long is ok, but
9695                          * int -> float is not) */
9696                         if (expression->kind == EXPR_UNARY_CAST) {
9697                                 type_t      *const type = expression->base.type;
9698                                 type_kind_t  const kind = type->kind;
9699                                 if (kind == TYPE_ATOMIC || kind == TYPE_POINTER) {
9700                                         unsigned flags;
9701                                         unsigned size;
9702                                         if (kind == TYPE_ATOMIC) {
9703                                                 atomic_type_kind_t const akind = type->atomic.akind;
9704                                                 flags = get_atomic_type_flags(akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
9705                                                 size  = get_atomic_type_size(akind);
9706                                         } else {
9707                                                 flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
9708                                                 size  = get_atomic_type_size(get_intptr_kind());
9709                                         }
9710
9711                                         do {
9712                                                 expression_t *const value      = expression->unary.value;
9713                                                 type_t       *const value_type = value->base.type;
9714                                                 type_kind_t   const value_kind = value_type->kind;
9715
9716                                                 unsigned value_flags;
9717                                                 unsigned value_size;
9718                                                 if (value_kind == TYPE_ATOMIC) {
9719                                                         atomic_type_kind_t const value_akind = value_type->atomic.akind;
9720                                                         value_flags = get_atomic_type_flags(value_akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
9721                                                         value_size  = get_atomic_type_size(value_akind);
9722                                                 } else if (value_kind == TYPE_POINTER) {
9723                                                         value_flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
9724                                                         value_size  = get_atomic_type_size(get_intptr_kind());
9725                                                 } else {
9726                                                         break;
9727                                                 }
9728
9729                                                 if (value_flags != flags || value_size != size)
9730                                                         break;
9731
9732                                                 expression = value;
9733                                         } while (expression->kind == EXPR_UNARY_CAST);
9734                                 }
9735                         }
9736
9737                         if (!is_lvalue(expression)) {
9738                                 errorf(&expression->base.source_position,
9739                                        "asm output argument is not an lvalue");
9740                         }
9741
9742                         if (argument->constraints.begin[0] == '+')
9743                                 mark_vars_read(expression, NULL);
9744                 } else {
9745                         mark_vars_read(expression, NULL);
9746                 }
9747                 argument->expression = expression;
9748                 expect(')', end_error);
9749
9750                 set_address_taken(expression, true);
9751
9752                 *anchor = argument;
9753                 anchor  = &argument->next;
9754
9755                 if (token.type != ',')
9756                         break;
9757                 eat(',');
9758         }
9759
9760         return result;
9761 end_error:
9762         return NULL;
9763 }
9764
9765 /**
9766  * Parse a asm statement clobber specification.
9767  */
9768 static asm_clobber_t *parse_asm_clobbers(void)
9769 {
9770         asm_clobber_t *result = NULL;
9771         asm_clobber_t *last   = NULL;
9772
9773         while (token.type == T_STRING_LITERAL) {
9774                 asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
9775                 clobber->clobber       = parse_string_literals();
9776
9777                 if (last != NULL) {
9778                         last->next = clobber;
9779                 } else {
9780                         result = clobber;
9781                 }
9782                 last = clobber;
9783
9784                 if (token.type != ',')
9785                         break;
9786                 eat(',');
9787         }
9788
9789         return result;
9790 }
9791
9792 /**
9793  * Parse an asm statement.
9794  */
9795 static statement_t *parse_asm_statement(void)
9796 {
9797         statement_t     *statement     = allocate_statement_zero(STATEMENT_ASM);
9798         asm_statement_t *asm_statement = &statement->asms;
9799
9800         eat(T_asm);
9801
9802         if (token.type == T_volatile) {
9803                 next_token();
9804                 asm_statement->is_volatile = true;
9805         }
9806
9807         expect('(', end_error);
9808         add_anchor_token(')');
9809         add_anchor_token(':');
9810         asm_statement->asm_text = parse_string_literals();
9811
9812         if (token.type != ':') {
9813                 rem_anchor_token(':');
9814                 goto end_of_asm;
9815         }
9816         eat(':');
9817
9818         asm_statement->outputs = parse_asm_arguments(true);
9819         if (token.type != ':') {
9820                 rem_anchor_token(':');
9821                 goto end_of_asm;
9822         }
9823         eat(':');
9824
9825         asm_statement->inputs = parse_asm_arguments(false);
9826         if (token.type != ':') {
9827                 rem_anchor_token(':');
9828                 goto end_of_asm;
9829         }
9830         rem_anchor_token(':');
9831         eat(':');
9832
9833         asm_statement->clobbers = parse_asm_clobbers();
9834
9835 end_of_asm:
9836         rem_anchor_token(')');
9837         expect(')', end_error);
9838         expect(';', end_error);
9839
9840         if (asm_statement->outputs == NULL) {
9841                 /* GCC: An 'asm' instruction without any output operands will be treated
9842                  * identically to a volatile 'asm' instruction. */
9843                 asm_statement->is_volatile = true;
9844         }
9845
9846         return statement;
9847 end_error:
9848         return create_invalid_statement();
9849 }
9850
9851 /**
9852  * Parse a case statement.
9853  */
9854 static statement_t *parse_case_statement(void)
9855 {
9856         statement_t       *const statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9857         source_position_t *const pos       = &statement->base.source_position;
9858
9859         eat(T_case);
9860
9861         expression_t *const expression   = parse_expression();
9862         statement->case_label.expression = expression;
9863         if (!is_constant_expression(expression)) {
9864                 /* This check does not prevent the error message in all cases of an
9865                  * prior error while parsing the expression.  At least it catches the
9866                  * common case of a mistyped enum entry. */
9867                 if (is_type_valid(skip_typeref(expression->base.type))) {
9868                         errorf(pos, "case label does not reduce to an integer constant");
9869                 }
9870                 statement->case_label.is_bad = true;
9871         } else {
9872                 long const val = fold_constant(expression);
9873                 statement->case_label.first_case = val;
9874                 statement->case_label.last_case  = val;
9875         }
9876
9877         if (GNU_MODE) {
9878                 if (token.type == T_DOTDOTDOT) {
9879                         next_token();
9880                         expression_t *const end_range   = parse_expression();
9881                         statement->case_label.end_range = end_range;
9882                         if (!is_constant_expression(end_range)) {
9883                                 /* This check does not prevent the error message in all cases of an
9884                                  * prior error while parsing the expression.  At least it catches the
9885                                  * common case of a mistyped enum entry. */
9886                                 if (is_type_valid(skip_typeref(end_range->base.type))) {
9887                                         errorf(pos, "case range does not reduce to an integer constant");
9888                                 }
9889                                 statement->case_label.is_bad = true;
9890                         } else {
9891                                 long const val = fold_constant(end_range);
9892                                 statement->case_label.last_case = val;
9893
9894                                 if (warning.other && val < statement->case_label.first_case) {
9895                                         statement->case_label.is_empty_range = true;
9896                                         warningf(pos, "empty range specified");
9897                                 }
9898                         }
9899                 }
9900         }
9901
9902         PUSH_PARENT(statement);
9903
9904         expect(':', end_error);
9905 end_error:
9906
9907         if (current_switch != NULL) {
9908                 if (! statement->case_label.is_bad) {
9909                         /* Check for duplicate case values */
9910                         case_label_statement_t *c = &statement->case_label;
9911                         for (case_label_statement_t *l = current_switch->first_case; l != NULL; l = l->next) {
9912                                 if (l->is_bad || l->is_empty_range || l->expression == NULL)
9913                                         continue;
9914
9915                                 if (c->last_case < l->first_case || c->first_case > l->last_case)
9916                                         continue;
9917
9918                                 errorf(pos, "duplicate case value (previously used %P)",
9919                                        &l->base.source_position);
9920                                 break;
9921                         }
9922                 }
9923                 /* link all cases into the switch statement */
9924                 if (current_switch->last_case == NULL) {
9925                         current_switch->first_case      = &statement->case_label;
9926                 } else {
9927                         current_switch->last_case->next = &statement->case_label;
9928                 }
9929                 current_switch->last_case = &statement->case_label;
9930         } else {
9931                 errorf(pos, "case label not within a switch statement");
9932         }
9933
9934         statement_t *const inner_stmt = parse_statement();
9935         statement->case_label.statement = inner_stmt;
9936         if (inner_stmt->kind == STATEMENT_DECLARATION) {
9937                 errorf(&inner_stmt->base.source_position, "declaration after case label");
9938         }
9939
9940         POP_PARENT;
9941         return statement;
9942 }
9943
9944 /**
9945  * Parse a default statement.
9946  */
9947 static statement_t *parse_default_statement(void)
9948 {
9949         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9950
9951         eat(T_default);
9952
9953         PUSH_PARENT(statement);
9954
9955         expect(':', end_error);
9956         if (current_switch != NULL) {
9957                 const case_label_statement_t *def_label = current_switch->default_label;
9958                 if (def_label != NULL) {
9959                         errorf(HERE, "multiple default labels in one switch (previous declared %P)",
9960                                &def_label->base.source_position);
9961                 } else {
9962                         current_switch->default_label = &statement->case_label;
9963
9964                         /* link all cases into the switch statement */
9965                         if (current_switch->last_case == NULL) {
9966                                 current_switch->first_case      = &statement->case_label;
9967                         } else {
9968                                 current_switch->last_case->next = &statement->case_label;
9969                         }
9970                         current_switch->last_case = &statement->case_label;
9971                 }
9972         } else {
9973                 errorf(&statement->base.source_position,
9974                         "'default' label not within a switch statement");
9975         }
9976
9977         statement_t *const inner_stmt = parse_statement();
9978         statement->case_label.statement = inner_stmt;
9979         if (inner_stmt->kind == STATEMENT_DECLARATION) {
9980                 errorf(&inner_stmt->base.source_position, "declaration after default label");
9981         }
9982
9983         POP_PARENT;
9984         return statement;
9985 end_error:
9986         POP_PARENT;
9987         return create_invalid_statement();
9988 }
9989
9990 /**
9991  * Parse a label statement.
9992  */
9993 static statement_t *parse_label_statement(void)
9994 {
9995         assert(token.type == T_IDENTIFIER);
9996         symbol_t *symbol = token.v.symbol;
9997         label_t  *label  = get_label(symbol);
9998
9999         statement_t *const statement = allocate_statement_zero(STATEMENT_LABEL);
10000         statement->label.label       = label;
10001
10002         next_token();
10003
10004         PUSH_PARENT(statement);
10005
10006         /* if statement is already set then the label is defined twice,
10007          * otherwise it was just mentioned in a goto/local label declaration so far
10008          */
10009         if (label->statement != NULL) {
10010                 errorf(HERE, "duplicate label '%Y' (declared %P)",
10011                        symbol, &label->base.source_position);
10012         } else {
10013                 label->base.source_position = token.source_position;
10014                 label->statement            = statement;
10015         }
10016
10017         eat(':');
10018
10019         if (token.type == '}') {
10020                 /* TODO only warn? */
10021                 if (warning.other && false) {
10022                         warningf(HERE, "label at end of compound statement");
10023                         statement->label.statement = create_empty_statement();
10024                 } else {
10025                         errorf(HERE, "label at end of compound statement");
10026                         statement->label.statement = create_invalid_statement();
10027                 }
10028         } else if (token.type == ';') {
10029                 /* Eat an empty statement here, to avoid the warning about an empty
10030                  * statement after a label.  label:; is commonly used to have a label
10031                  * before a closing brace. */
10032                 statement->label.statement = create_empty_statement();
10033                 next_token();
10034         } else {
10035                 statement_t *const inner_stmt = parse_statement();
10036                 statement->label.statement = inner_stmt;
10037                 if (inner_stmt->kind == STATEMENT_DECLARATION) {
10038                         errorf(&inner_stmt->base.source_position, "declaration after label");
10039                 }
10040         }
10041
10042         /* remember the labels in a list for later checking */
10043         *label_anchor = &statement->label;
10044         label_anchor  = &statement->label.next;
10045
10046         POP_PARENT;
10047         return statement;
10048 }
10049
10050 /**
10051  * Parse an if statement.
10052  */
10053 static statement_t *parse_if(void)
10054 {
10055         statement_t *statement = allocate_statement_zero(STATEMENT_IF);
10056
10057         eat(T_if);
10058
10059         PUSH_PARENT(statement);
10060
10061         add_anchor_token('{');
10062
10063         expect('(', end_error);
10064         add_anchor_token(')');
10065         expression_t *const expr = parse_expression();
10066         statement->ifs.condition = expr;
10067         /* §6.8.4.1:1  The controlling expression of an if statement shall have
10068          *             scalar type. */
10069         semantic_condition(expr, "condition of 'if'-statment");
10070         mark_vars_read(expr, NULL);
10071         rem_anchor_token(')');
10072         expect(')', end_error);
10073
10074 end_error:
10075         rem_anchor_token('{');
10076
10077         add_anchor_token(T_else);
10078         statement_t *const true_stmt = parse_statement();
10079         statement->ifs.true_statement = true_stmt;
10080         rem_anchor_token(T_else);
10081
10082         if (token.type == T_else) {
10083                 next_token();
10084                 statement->ifs.false_statement = parse_statement();
10085         } else if (warning.parentheses &&
10086                         true_stmt->kind == STATEMENT_IF &&
10087                         true_stmt->ifs.false_statement != NULL) {
10088                 warningf(&true_stmt->base.source_position,
10089                                 "suggest explicit braces to avoid ambiguous 'else'");
10090         }
10091
10092         POP_PARENT;
10093         return statement;
10094 }
10095
10096 /**
10097  * Check that all enums are handled in a switch.
10098  *
10099  * @param statement  the switch statement to check
10100  */
10101 static void check_enum_cases(const switch_statement_t *statement)
10102 {
10103         const type_t *type = skip_typeref(statement->expression->base.type);
10104         if (! is_type_enum(type))
10105                 return;
10106         const enum_type_t *enumt = &type->enumt;
10107
10108         /* if we have a default, no warnings */
10109         if (statement->default_label != NULL)
10110                 return;
10111
10112         /* FIXME: calculation of value should be done while parsing */
10113         /* TODO: quadratic algorithm here. Change to an n log n one */
10114         long            last_value = -1;
10115         const entity_t *entry      = enumt->enume->base.next;
10116         for (; entry != NULL && entry->kind == ENTITY_ENUM_VALUE;
10117              entry = entry->base.next) {
10118                 const expression_t *expression = entry->enum_value.value;
10119                 long                value      = expression != NULL ? fold_constant(expression) : last_value + 1;
10120                 bool                found      = false;
10121                 for (const case_label_statement_t *l = statement->first_case; l != NULL; l = l->next) {
10122                         if (l->expression == NULL)
10123                                 continue;
10124                         if (l->first_case <= value && value <= l->last_case) {
10125                                 found = true;
10126                                 break;
10127                         }
10128                 }
10129                 if (! found) {
10130                         warningf(&statement->base.source_position,
10131                                  "enumeration value '%Y' not handled in switch",
10132                                  entry->base.symbol);
10133                 }
10134                 last_value = value;
10135         }
10136 }
10137
10138 /**
10139  * Parse a switch statement.
10140  */
10141 static statement_t *parse_switch(void)
10142 {
10143         statement_t *statement = allocate_statement_zero(STATEMENT_SWITCH);
10144
10145         eat(T_switch);
10146
10147         PUSH_PARENT(statement);
10148
10149         expect('(', end_error);
10150         add_anchor_token(')');
10151         expression_t *const expr = parse_expression();
10152         mark_vars_read(expr, NULL);
10153         type_t       *      type = skip_typeref(expr->base.type);
10154         if (is_type_integer(type)) {
10155                 type = promote_integer(type);
10156                 if (warning.traditional) {
10157                         if (get_rank(type) >= get_akind_rank(ATOMIC_TYPE_LONG)) {
10158                                 warningf(&expr->base.source_position,
10159                                         "'%T' switch expression not converted to '%T' in ISO C",
10160                                         type, type_int);
10161                         }
10162                 }
10163         } else if (is_type_valid(type)) {
10164                 errorf(&expr->base.source_position,
10165                        "switch quantity is not an integer, but '%T'", type);
10166                 type = type_error_type;
10167         }
10168         statement->switchs.expression = create_implicit_cast(expr, type);
10169         expect(')', end_error);
10170         rem_anchor_token(')');
10171
10172         switch_statement_t *rem = current_switch;
10173         current_switch          = &statement->switchs;
10174         statement->switchs.body = parse_statement();
10175         current_switch          = rem;
10176
10177         if (warning.switch_default &&
10178             statement->switchs.default_label == NULL) {
10179                 warningf(&statement->base.source_position, "switch has no default case");
10180         }
10181         if (warning.switch_enum)
10182                 check_enum_cases(&statement->switchs);
10183
10184         POP_PARENT;
10185         return statement;
10186 end_error:
10187         POP_PARENT;
10188         return create_invalid_statement();
10189 }
10190
10191 static statement_t *parse_loop_body(statement_t *const loop)
10192 {
10193         statement_t *const rem = current_loop;
10194         current_loop = loop;
10195
10196         statement_t *const body = parse_statement();
10197
10198         current_loop = rem;
10199         return body;
10200 }
10201
10202 /**
10203  * Parse a while statement.
10204  */
10205 static statement_t *parse_while(void)
10206 {
10207         statement_t *statement = allocate_statement_zero(STATEMENT_WHILE);
10208
10209         eat(T_while);
10210
10211         PUSH_PARENT(statement);
10212
10213         expect('(', end_error);
10214         add_anchor_token(')');
10215         expression_t *const cond = parse_expression();
10216         statement->whiles.condition = cond;
10217         /* §6.8.5:2    The controlling expression of an iteration statement shall
10218          *             have scalar type. */
10219         semantic_condition(cond, "condition of 'while'-statement");
10220         mark_vars_read(cond, NULL);
10221         rem_anchor_token(')');
10222         expect(')', end_error);
10223
10224         statement->whiles.body = parse_loop_body(statement);
10225
10226         POP_PARENT;
10227         return statement;
10228 end_error:
10229         POP_PARENT;
10230         return create_invalid_statement();
10231 }
10232
10233 /**
10234  * Parse a do statement.
10235  */
10236 static statement_t *parse_do(void)
10237 {
10238         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
10239
10240         eat(T_do);
10241
10242         PUSH_PARENT(statement);
10243
10244         add_anchor_token(T_while);
10245         statement->do_while.body = parse_loop_body(statement);
10246         rem_anchor_token(T_while);
10247
10248         expect(T_while, end_error);
10249         expect('(', end_error);
10250         add_anchor_token(')');
10251         expression_t *const cond = parse_expression();
10252         statement->do_while.condition = cond;
10253         /* §6.8.5:2    The controlling expression of an iteration statement shall
10254          *             have scalar type. */
10255         semantic_condition(cond, "condition of 'do-while'-statement");
10256         mark_vars_read(cond, NULL);
10257         rem_anchor_token(')');
10258         expect(')', end_error);
10259         expect(';', end_error);
10260
10261         POP_PARENT;
10262         return statement;
10263 end_error:
10264         POP_PARENT;
10265         return create_invalid_statement();
10266 }
10267
10268 /**
10269  * Parse a for statement.
10270  */
10271 static statement_t *parse_for(void)
10272 {
10273         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
10274
10275         eat(T_for);
10276
10277         expect('(', end_error1);
10278         add_anchor_token(')');
10279
10280         PUSH_PARENT(statement);
10281
10282         size_t const  top       = environment_top();
10283         scope_t      *old_scope = scope_push(&statement->fors.scope);
10284
10285         if (token.type == ';') {
10286                 next_token();
10287         } else if (is_declaration_specifier(&token, false)) {
10288                 parse_declaration(record_entity, DECL_FLAGS_NONE);
10289         } else {
10290                 add_anchor_token(';');
10291                 expression_t *const init = parse_expression();
10292                 statement->fors.initialisation = init;
10293                 mark_vars_read(init, ENT_ANY);
10294                 if (warning.unused_value && !expression_has_effect(init)) {
10295                         warningf(&init->base.source_position,
10296                                         "initialisation of 'for'-statement has no effect");
10297                 }
10298                 rem_anchor_token(';');
10299                 expect(';', end_error2);
10300         }
10301
10302         if (token.type != ';') {
10303                 add_anchor_token(';');
10304                 expression_t *const cond = parse_expression();
10305                 statement->fors.condition = cond;
10306                 /* §6.8.5:2    The controlling expression of an iteration statement
10307                  *             shall have scalar type. */
10308                 semantic_condition(cond, "condition of 'for'-statement");
10309                 mark_vars_read(cond, NULL);
10310                 rem_anchor_token(';');
10311         }
10312         expect(';', end_error2);
10313         if (token.type != ')') {
10314                 expression_t *const step = parse_expression();
10315                 statement->fors.step = step;
10316                 mark_vars_read(step, ENT_ANY);
10317                 if (warning.unused_value && !expression_has_effect(step)) {
10318                         warningf(&step->base.source_position,
10319                                  "step of 'for'-statement has no effect");
10320                 }
10321         }
10322         expect(')', end_error2);
10323         rem_anchor_token(')');
10324         statement->fors.body = parse_loop_body(statement);
10325
10326         assert(current_scope == &statement->fors.scope);
10327         scope_pop(old_scope);
10328         environment_pop_to(top);
10329
10330         POP_PARENT;
10331         return statement;
10332
10333 end_error2:
10334         POP_PARENT;
10335         rem_anchor_token(')');
10336         assert(current_scope == &statement->fors.scope);
10337         scope_pop(old_scope);
10338         environment_pop_to(top);
10339         /* fallthrough */
10340
10341 end_error1:
10342         return create_invalid_statement();
10343 }
10344
10345 /**
10346  * Parse a goto statement.
10347  */
10348 static statement_t *parse_goto(void)
10349 {
10350         statement_t *statement = allocate_statement_zero(STATEMENT_GOTO);
10351         eat(T_goto);
10352
10353         if (GNU_MODE && token.type == '*') {
10354                 next_token();
10355                 expression_t *expression = parse_expression();
10356                 mark_vars_read(expression, NULL);
10357
10358                 /* Argh: although documentation says the expression must be of type void*,
10359                  * gcc accepts anything that can be casted into void* without error */
10360                 type_t *type = expression->base.type;
10361
10362                 if (type != type_error_type) {
10363                         if (!is_type_pointer(type) && !is_type_integer(type)) {
10364                                 errorf(&expression->base.source_position,
10365                                         "cannot convert to a pointer type");
10366                         } else if (warning.other && type != type_void_ptr) {
10367                                 warningf(&expression->base.source_position,
10368                                         "type of computed goto expression should be 'void*' not '%T'", type);
10369                         }
10370                         expression = create_implicit_cast(expression, type_void_ptr);
10371                 }
10372
10373                 statement->gotos.expression = expression;
10374         } else {
10375                 if (token.type != T_IDENTIFIER) {
10376                         if (GNU_MODE)
10377                                 parse_error_expected("while parsing goto", T_IDENTIFIER, '*', NULL);
10378                         else
10379                                 parse_error_expected("while parsing goto", T_IDENTIFIER, NULL);
10380                         eat_until_anchor();
10381                         goto end_error;
10382                 }
10383                 symbol_t *symbol = token.v.symbol;
10384                 next_token();
10385
10386                 statement->gotos.label = get_label(symbol);
10387         }
10388
10389         /* remember the goto's in a list for later checking */
10390         *goto_anchor = &statement->gotos;
10391         goto_anchor  = &statement->gotos.next;
10392
10393         expect(';', end_error);
10394
10395         return statement;
10396 end_error:
10397         return create_invalid_statement();
10398 }
10399
10400 /**
10401  * Parse a continue statement.
10402  */
10403 static statement_t *parse_continue(void)
10404 {
10405         if (current_loop == NULL) {
10406                 errorf(HERE, "continue statement not within loop");
10407         }
10408
10409         statement_t *statement = allocate_statement_zero(STATEMENT_CONTINUE);
10410
10411         eat(T_continue);
10412         expect(';', end_error);
10413
10414 end_error:
10415         return statement;
10416 }
10417
10418 /**
10419  * Parse a break statement.
10420  */
10421 static statement_t *parse_break(void)
10422 {
10423         if (current_switch == NULL && current_loop == NULL) {
10424                 errorf(HERE, "break statement not within loop or switch");
10425         }
10426
10427         statement_t *statement = allocate_statement_zero(STATEMENT_BREAK);
10428
10429         eat(T_break);
10430         expect(';', end_error);
10431
10432 end_error:
10433         return statement;
10434 }
10435
10436 /**
10437  * Parse a __leave statement.
10438  */
10439 static statement_t *parse_leave_statement(void)
10440 {
10441         if (current_try == NULL) {
10442                 errorf(HERE, "__leave statement not within __try");
10443         }
10444
10445         statement_t *statement = allocate_statement_zero(STATEMENT_LEAVE);
10446
10447         eat(T___leave);
10448         expect(';', end_error);
10449
10450 end_error:
10451         return statement;
10452 }
10453
10454 /**
10455  * Check if a given entity represents a local variable.
10456  */
10457 static bool is_local_variable(const entity_t *entity)
10458 {
10459         if (entity->kind != ENTITY_VARIABLE)
10460                 return false;
10461
10462         switch ((storage_class_tag_t) entity->declaration.storage_class) {
10463         case STORAGE_CLASS_AUTO:
10464         case STORAGE_CLASS_REGISTER: {
10465                 const type_t *type = skip_typeref(entity->declaration.type);
10466                 if (is_type_function(type)) {
10467                         return false;
10468                 } else {
10469                         return true;
10470                 }
10471         }
10472         default:
10473                 return false;
10474         }
10475 }
10476
10477 /**
10478  * Check if a given expression represents a local variable.
10479  */
10480 static bool expression_is_local_variable(const expression_t *expression)
10481 {
10482         if (expression->base.kind != EXPR_REFERENCE) {
10483                 return false;
10484         }
10485         const entity_t *entity = expression->reference.entity;
10486         return is_local_variable(entity);
10487 }
10488
10489 /**
10490  * Check if a given expression represents a local variable and
10491  * return its declaration then, else return NULL.
10492  */
10493 entity_t *expression_is_variable(const expression_t *expression)
10494 {
10495         if (expression->base.kind != EXPR_REFERENCE) {
10496                 return NULL;
10497         }
10498         entity_t *entity = expression->reference.entity;
10499         if (entity->kind != ENTITY_VARIABLE)
10500                 return NULL;
10501
10502         return entity;
10503 }
10504
10505 /**
10506  * Parse a return statement.
10507  */
10508 static statement_t *parse_return(void)
10509 {
10510         eat(T_return);
10511
10512         statement_t *statement = allocate_statement_zero(STATEMENT_RETURN);
10513
10514         expression_t *return_value = NULL;
10515         if (token.type != ';') {
10516                 return_value = parse_expression();
10517                 mark_vars_read(return_value, NULL);
10518         }
10519
10520         const type_t *const func_type = skip_typeref(current_function->base.type);
10521         assert(is_type_function(func_type));
10522         type_t *const return_type = skip_typeref(func_type->function.return_type);
10523
10524         source_position_t const *const pos = &statement->base.source_position;
10525         if (return_value != NULL) {
10526                 type_t *return_value_type = skip_typeref(return_value->base.type);
10527
10528                 if (is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
10529                         if (is_type_atomic(return_value_type, ATOMIC_TYPE_VOID)) {
10530                                 /* ISO/IEC 14882:1998(E) §6.6.3:2 */
10531                                 /* Only warn in C mode, because GCC does the same */
10532                                 if (c_mode & _CXX || strict_mode) {
10533                                         errorf(pos,
10534                                                         "'return' with a value, in function returning 'void'");
10535                                 } else if (warning.other) {
10536                                         warningf(pos,
10537                                                         "'return' with a value, in function returning 'void'");
10538                                 }
10539                         } else if (!(c_mode & _CXX)) { /* ISO/IEC 14882:1998(E) §6.6.3:3 */
10540                                 /* Only warn in C mode, because GCC does the same */
10541                                 if (strict_mode) {
10542                                         errorf(pos,
10543                                                         "'return' with expression in function return 'void'");
10544                                 } else if (warning.other) {
10545                                         warningf(pos,
10546                                                         "'return' with expression in function return 'void'");
10547                                 }
10548                         }
10549                 } else {
10550                         assign_error_t error = semantic_assign(return_type, return_value);
10551                         report_assign_error(error, return_type, return_value, "'return'",
10552                                         pos);
10553                 }
10554                 return_value = create_implicit_cast(return_value, return_type);
10555                 /* check for returning address of a local var */
10556                 if (warning.other && return_value != NULL
10557                                 && return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
10558                         const expression_t *expression = return_value->unary.value;
10559                         if (expression_is_local_variable(expression)) {
10560                                 warningf(pos, "function returns address of local variable");
10561                         }
10562                 }
10563         } else if (warning.other && !is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
10564                 /* ISO/IEC 14882:1998(E) §6.6.3:3 */
10565                 if (c_mode & _CXX || strict_mode) {
10566                         errorf(pos,
10567                                         "'return' without value, in function returning non-void");
10568                 } else {
10569                         warningf(pos,
10570                                         "'return' without value, in function returning non-void");
10571                 }
10572         }
10573         statement->returns.value = return_value;
10574
10575         expect(';', end_error);
10576
10577 end_error:
10578         return statement;
10579 }
10580
10581 /**
10582  * Parse a declaration statement.
10583  */
10584 static statement_t *parse_declaration_statement(void)
10585 {
10586         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
10587
10588         entity_t *before = current_scope->last_entity;
10589         if (GNU_MODE) {
10590                 parse_external_declaration();
10591         } else {
10592                 parse_declaration(record_entity, DECL_FLAGS_NONE);
10593         }
10594
10595         declaration_statement_t *const decl  = &statement->declaration;
10596         entity_t                *const begin =
10597                 before != NULL ? before->base.next : current_scope->entities;
10598         decl->declarations_begin = begin;
10599         decl->declarations_end   = begin != NULL ? current_scope->last_entity : NULL;
10600
10601         return statement;
10602 }
10603
10604 /**
10605  * Parse an expression statement, ie. expr ';'.
10606  */
10607 static statement_t *parse_expression_statement(void)
10608 {
10609         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10610
10611         expression_t *const expr         = parse_expression();
10612         statement->expression.expression = expr;
10613         mark_vars_read(expr, ENT_ANY);
10614
10615         expect(';', end_error);
10616
10617 end_error:
10618         return statement;
10619 }
10620
10621 /**
10622  * Parse a microsoft __try { } __finally { } or
10623  * __try{ } __except() { }
10624  */
10625 static statement_t *parse_ms_try_statment(void)
10626 {
10627         statement_t *statement = allocate_statement_zero(STATEMENT_MS_TRY);
10628         eat(T___try);
10629
10630         PUSH_PARENT(statement);
10631
10632         ms_try_statement_t *rem = current_try;
10633         current_try = &statement->ms_try;
10634         statement->ms_try.try_statement = parse_compound_statement(false);
10635         current_try = rem;
10636
10637         POP_PARENT;
10638
10639         if (token.type == T___except) {
10640                 eat(T___except);
10641                 expect('(', end_error);
10642                 add_anchor_token(')');
10643                 expression_t *const expr = parse_expression();
10644                 mark_vars_read(expr, NULL);
10645                 type_t       *      type = skip_typeref(expr->base.type);
10646                 if (is_type_integer(type)) {
10647                         type = promote_integer(type);
10648                 } else if (is_type_valid(type)) {
10649                         errorf(&expr->base.source_position,
10650                                "__expect expression is not an integer, but '%T'", type);
10651                         type = type_error_type;
10652                 }
10653                 statement->ms_try.except_expression = create_implicit_cast(expr, type);
10654                 rem_anchor_token(')');
10655                 expect(')', end_error);
10656                 statement->ms_try.final_statement = parse_compound_statement(false);
10657         } else if (token.type == T__finally) {
10658                 eat(T___finally);
10659                 statement->ms_try.final_statement = parse_compound_statement(false);
10660         } else {
10661                 parse_error_expected("while parsing __try statement", T___except, T___finally, NULL);
10662                 return create_invalid_statement();
10663         }
10664         return statement;
10665 end_error:
10666         return create_invalid_statement();
10667 }
10668
10669 static statement_t *parse_empty_statement(void)
10670 {
10671         if (warning.empty_statement) {
10672                 warningf(HERE, "statement is empty");
10673         }
10674         statement_t *const statement = create_empty_statement();
10675         eat(';');
10676         return statement;
10677 }
10678
10679 static statement_t *parse_local_label_declaration(void)
10680 {
10681         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
10682
10683         eat(T___label__);
10684
10685         entity_t *begin = NULL, *end = NULL;
10686
10687         while (true) {
10688                 if (token.type != T_IDENTIFIER) {
10689                         parse_error_expected("while parsing local label declaration",
10690                                 T_IDENTIFIER, NULL);
10691                         goto end_error;
10692                 }
10693                 symbol_t *symbol = token.v.symbol;
10694                 entity_t *entity = get_entity(symbol, NAMESPACE_LABEL);
10695                 if (entity != NULL && entity->base.parent_scope == current_scope) {
10696                         errorf(HERE, "multiple definitions of '__label__ %Y' (previous definition %P)",
10697                                symbol, &entity->base.source_position);
10698                 } else {
10699                         entity = allocate_entity_zero(ENTITY_LOCAL_LABEL);
10700
10701                         entity->base.parent_scope    = current_scope;
10702                         entity->base.namespc         = NAMESPACE_LABEL;
10703                         entity->base.source_position = token.source_position;
10704                         entity->base.symbol          = symbol;
10705
10706                         if (end != NULL)
10707                                 end->base.next = entity;
10708                         end = entity;
10709                         if (begin == NULL)
10710                                 begin = entity;
10711
10712                         environment_push(entity);
10713                 }
10714                 next_token();
10715
10716                 if (token.type != ',')
10717                         break;
10718                 next_token();
10719         }
10720         eat(';');
10721 end_error:
10722         statement->declaration.declarations_begin = begin;
10723         statement->declaration.declarations_end   = end;
10724         return statement;
10725 }
10726
10727 static void parse_namespace_definition(void)
10728 {
10729         eat(T_namespace);
10730
10731         entity_t *entity = NULL;
10732         symbol_t *symbol = NULL;
10733
10734         if (token.type == T_IDENTIFIER) {
10735                 symbol = token.v.symbol;
10736                 next_token();
10737
10738                 entity = get_entity(symbol, NAMESPACE_NORMAL);
10739                 if (entity       != NULL             &&
10740                                 entity->kind != ENTITY_NAMESPACE &&
10741                                 entity->base.parent_scope == current_scope) {
10742                         if (!is_error_entity(entity)) {
10743                                 error_redefined_as_different_kind(&token.source_position,
10744                                                 entity, ENTITY_NAMESPACE);
10745                         }
10746                         entity = NULL;
10747                 }
10748         }
10749
10750         if (entity == NULL) {
10751                 entity                       = allocate_entity_zero(ENTITY_NAMESPACE);
10752                 entity->base.symbol          = symbol;
10753                 entity->base.source_position = token.source_position;
10754                 entity->base.namespc         = NAMESPACE_NORMAL;
10755                 entity->base.parent_scope    = current_scope;
10756         }
10757
10758         if (token.type == '=') {
10759                 /* TODO: parse namespace alias */
10760                 panic("namespace alias definition not supported yet");
10761         }
10762
10763         environment_push(entity);
10764         append_entity(current_scope, entity);
10765
10766         size_t const  top       = environment_top();
10767         scope_t      *old_scope = scope_push(&entity->namespacee.members);
10768
10769         expect('{', end_error);
10770         parse_externals();
10771         expect('}', end_error);
10772
10773 end_error:
10774         assert(current_scope == &entity->namespacee.members);
10775         scope_pop(old_scope);
10776         environment_pop_to(top);
10777 }
10778
10779 /**
10780  * Parse a statement.
10781  * There's also parse_statement() which additionally checks for
10782  * "statement has no effect" warnings
10783  */
10784 static statement_t *intern_parse_statement(void)
10785 {
10786         statement_t *statement = NULL;
10787
10788         /* declaration or statement */
10789         add_anchor_token(';');
10790         switch (token.type) {
10791         case T_IDENTIFIER: {
10792                 token_type_t la1_type = (token_type_t)look_ahead(1)->type;
10793                 if (la1_type == ':') {
10794                         statement = parse_label_statement();
10795                 } else if (is_typedef_symbol(token.v.symbol)) {
10796                         statement = parse_declaration_statement();
10797                 } else {
10798                         /* it's an identifier, the grammar says this must be an
10799                          * expression statement. However it is common that users mistype
10800                          * declaration types, so we guess a bit here to improve robustness
10801                          * for incorrect programs */
10802                         switch (la1_type) {
10803                         case '&':
10804                         case '*':
10805                                 if (get_entity(token.v.symbol, NAMESPACE_NORMAL) != NULL)
10806                                         goto expression_statment;
10807                                 /* FALLTHROUGH */
10808
10809                         DECLARATION_START
10810                         case T_IDENTIFIER:
10811                                 statement = parse_declaration_statement();
10812                                 break;
10813
10814                         default:
10815 expression_statment:
10816                                 statement = parse_expression_statement();
10817                                 break;
10818                         }
10819                 }
10820                 break;
10821         }
10822
10823         case T___extension__:
10824                 /* This can be a prefix to a declaration or an expression statement.
10825                  * We simply eat it now and parse the rest with tail recursion. */
10826                 do {
10827                         next_token();
10828                 } while (token.type == T___extension__);
10829                 bool old_gcc_extension = in_gcc_extension;
10830                 in_gcc_extension       = true;
10831                 statement = intern_parse_statement();
10832                 in_gcc_extension = old_gcc_extension;
10833                 break;
10834
10835         DECLARATION_START
10836                 statement = parse_declaration_statement();
10837                 break;
10838
10839         case T___label__:
10840                 statement = parse_local_label_declaration();
10841                 break;
10842
10843         case ';':         statement = parse_empty_statement();         break;
10844         case '{':         statement = parse_compound_statement(false); break;
10845         case T___leave:   statement = parse_leave_statement();         break;
10846         case T___try:     statement = parse_ms_try_statment();         break;
10847         case T_asm:       statement = parse_asm_statement();           break;
10848         case T_break:     statement = parse_break();                   break;
10849         case T_case:      statement = parse_case_statement();          break;
10850         case T_continue:  statement = parse_continue();                break;
10851         case T_default:   statement = parse_default_statement();       break;
10852         case T_do:        statement = parse_do();                      break;
10853         case T_for:       statement = parse_for();                     break;
10854         case T_goto:      statement = parse_goto();                    break;
10855         case T_if:        statement = parse_if();                      break;
10856         case T_return:    statement = parse_return();                  break;
10857         case T_switch:    statement = parse_switch();                  break;
10858         case T_while:     statement = parse_while();                   break;
10859
10860         EXPRESSION_START
10861                 statement = parse_expression_statement();
10862                 break;
10863
10864         default:
10865                 errorf(HERE, "unexpected token %K while parsing statement", &token);
10866                 statement = create_invalid_statement();
10867                 if (!at_anchor())
10868                         next_token();
10869                 break;
10870         }
10871         rem_anchor_token(';');
10872
10873         assert(statement != NULL
10874                         && statement->base.source_position.input_name != NULL);
10875
10876         return statement;
10877 }
10878
10879 /**
10880  * parse a statement and emits "statement has no effect" warning if needed
10881  * (This is really a wrapper around intern_parse_statement with check for 1
10882  *  single warning. It is needed, because for statement expressions we have
10883  *  to avoid the warning on the last statement)
10884  */
10885 static statement_t *parse_statement(void)
10886 {
10887         statement_t *statement = intern_parse_statement();
10888
10889         if (statement->kind == STATEMENT_EXPRESSION && warning.unused_value) {
10890                 expression_t *expression = statement->expression.expression;
10891                 if (!expression_has_effect(expression)) {
10892                         warningf(&expression->base.source_position,
10893                                         "statement has no effect");
10894                 }
10895         }
10896
10897         return statement;
10898 }
10899
10900 /**
10901  * Parse a compound statement.
10902  */
10903 static statement_t *parse_compound_statement(bool inside_expression_statement)
10904 {
10905         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
10906
10907         PUSH_PARENT(statement);
10908
10909         eat('{');
10910         add_anchor_token('}');
10911         /* tokens, which can start a statement */
10912         /* TODO MS, __builtin_FOO */
10913         add_anchor_token('!');
10914         add_anchor_token('&');
10915         add_anchor_token('(');
10916         add_anchor_token('*');
10917         add_anchor_token('+');
10918         add_anchor_token('-');
10919         add_anchor_token('{');
10920         add_anchor_token('~');
10921         add_anchor_token(T_CHARACTER_CONSTANT);
10922         add_anchor_token(T_COLONCOLON);
10923         add_anchor_token(T_FLOATINGPOINT);
10924         add_anchor_token(T_IDENTIFIER);
10925         add_anchor_token(T_INTEGER);
10926         add_anchor_token(T_MINUSMINUS);
10927         add_anchor_token(T_PLUSPLUS);
10928         add_anchor_token(T_STRING_LITERAL);
10929         add_anchor_token(T_WIDE_CHARACTER_CONSTANT);
10930         add_anchor_token(T_WIDE_STRING_LITERAL);
10931         add_anchor_token(T__Bool);
10932         add_anchor_token(T__Complex);
10933         add_anchor_token(T__Imaginary);
10934         add_anchor_token(T___FUNCTION__);
10935         add_anchor_token(T___PRETTY_FUNCTION__);
10936         add_anchor_token(T___alignof__);
10937         add_anchor_token(T___attribute__);
10938         add_anchor_token(T___builtin_va_start);
10939         add_anchor_token(T___extension__);
10940         add_anchor_token(T___func__);
10941         add_anchor_token(T___imag__);
10942         add_anchor_token(T___label__);
10943         add_anchor_token(T___real__);
10944         add_anchor_token(T___thread);
10945         add_anchor_token(T_asm);
10946         add_anchor_token(T_auto);
10947         add_anchor_token(T_bool);
10948         add_anchor_token(T_break);
10949         add_anchor_token(T_case);
10950         add_anchor_token(T_char);
10951         add_anchor_token(T_class);
10952         add_anchor_token(T_const);
10953         add_anchor_token(T_const_cast);
10954         add_anchor_token(T_continue);
10955         add_anchor_token(T_default);
10956         add_anchor_token(T_delete);
10957         add_anchor_token(T_double);
10958         add_anchor_token(T_do);
10959         add_anchor_token(T_dynamic_cast);
10960         add_anchor_token(T_enum);
10961         add_anchor_token(T_extern);
10962         add_anchor_token(T_false);
10963         add_anchor_token(T_float);
10964         add_anchor_token(T_for);
10965         add_anchor_token(T_goto);
10966         add_anchor_token(T_if);
10967         add_anchor_token(T_inline);
10968         add_anchor_token(T_int);
10969         add_anchor_token(T_long);
10970         add_anchor_token(T_new);
10971         add_anchor_token(T_operator);
10972         add_anchor_token(T_register);
10973         add_anchor_token(T_reinterpret_cast);
10974         add_anchor_token(T_restrict);
10975         add_anchor_token(T_return);
10976         add_anchor_token(T_short);
10977         add_anchor_token(T_signed);
10978         add_anchor_token(T_sizeof);
10979         add_anchor_token(T_static);
10980         add_anchor_token(T_static_cast);
10981         add_anchor_token(T_struct);
10982         add_anchor_token(T_switch);
10983         add_anchor_token(T_template);
10984         add_anchor_token(T_this);
10985         add_anchor_token(T_throw);
10986         add_anchor_token(T_true);
10987         add_anchor_token(T_try);
10988         add_anchor_token(T_typedef);
10989         add_anchor_token(T_typeid);
10990         add_anchor_token(T_typename);
10991         add_anchor_token(T_typeof);
10992         add_anchor_token(T_union);
10993         add_anchor_token(T_unsigned);
10994         add_anchor_token(T_using);
10995         add_anchor_token(T_void);
10996         add_anchor_token(T_volatile);
10997         add_anchor_token(T_wchar_t);
10998         add_anchor_token(T_while);
10999
11000         size_t const  top       = environment_top();
11001         scope_t      *old_scope = scope_push(&statement->compound.scope);
11002
11003         statement_t **anchor            = &statement->compound.statements;
11004         bool          only_decls_so_far = true;
11005         while (token.type != '}') {
11006                 if (token.type == T_EOF) {
11007                         errorf(&statement->base.source_position,
11008                                "EOF while parsing compound statement");
11009                         break;
11010                 }
11011                 statement_t *sub_statement = intern_parse_statement();
11012                 if (is_invalid_statement(sub_statement)) {
11013                         /* an error occurred. if we are at an anchor, return */
11014                         if (at_anchor())
11015                                 goto end_error;
11016                         continue;
11017                 }
11018
11019                 if (warning.declaration_after_statement) {
11020                         if (sub_statement->kind != STATEMENT_DECLARATION) {
11021                                 only_decls_so_far = false;
11022                         } else if (!only_decls_so_far) {
11023                                 warningf(&sub_statement->base.source_position,
11024                                          "ISO C90 forbids mixed declarations and code");
11025                         }
11026                 }
11027
11028                 *anchor = sub_statement;
11029
11030                 while (sub_statement->base.next != NULL)
11031                         sub_statement = sub_statement->base.next;
11032
11033                 anchor = &sub_statement->base.next;
11034         }
11035         next_token();
11036
11037         /* look over all statements again to produce no effect warnings */
11038         if (warning.unused_value) {
11039                 statement_t *sub_statement = statement->compound.statements;
11040                 for (; sub_statement != NULL; sub_statement = sub_statement->base.next) {
11041                         if (sub_statement->kind != STATEMENT_EXPRESSION)
11042                                 continue;
11043                         /* don't emit a warning for the last expression in an expression
11044                          * statement as it has always an effect */
11045                         if (inside_expression_statement && sub_statement->base.next == NULL)
11046                                 continue;
11047
11048                         expression_t *expression = sub_statement->expression.expression;
11049                         if (!expression_has_effect(expression)) {
11050                                 warningf(&expression->base.source_position,
11051                                          "statement has no effect");
11052                         }
11053                 }
11054         }
11055
11056 end_error:
11057         rem_anchor_token(T_while);
11058         rem_anchor_token(T_wchar_t);
11059         rem_anchor_token(T_volatile);
11060         rem_anchor_token(T_void);
11061         rem_anchor_token(T_using);
11062         rem_anchor_token(T_unsigned);
11063         rem_anchor_token(T_union);
11064         rem_anchor_token(T_typeof);
11065         rem_anchor_token(T_typename);
11066         rem_anchor_token(T_typeid);
11067         rem_anchor_token(T_typedef);
11068         rem_anchor_token(T_try);
11069         rem_anchor_token(T_true);
11070         rem_anchor_token(T_throw);
11071         rem_anchor_token(T_this);
11072         rem_anchor_token(T_template);
11073         rem_anchor_token(T_switch);
11074         rem_anchor_token(T_struct);
11075         rem_anchor_token(T_static_cast);
11076         rem_anchor_token(T_static);
11077         rem_anchor_token(T_sizeof);
11078         rem_anchor_token(T_signed);
11079         rem_anchor_token(T_short);
11080         rem_anchor_token(T_return);
11081         rem_anchor_token(T_restrict);
11082         rem_anchor_token(T_reinterpret_cast);
11083         rem_anchor_token(T_register);
11084         rem_anchor_token(T_operator);
11085         rem_anchor_token(T_new);
11086         rem_anchor_token(T_long);
11087         rem_anchor_token(T_int);
11088         rem_anchor_token(T_inline);
11089         rem_anchor_token(T_if);
11090         rem_anchor_token(T_goto);
11091         rem_anchor_token(T_for);
11092         rem_anchor_token(T_float);
11093         rem_anchor_token(T_false);
11094         rem_anchor_token(T_extern);
11095         rem_anchor_token(T_enum);
11096         rem_anchor_token(T_dynamic_cast);
11097         rem_anchor_token(T_do);
11098         rem_anchor_token(T_double);
11099         rem_anchor_token(T_delete);
11100         rem_anchor_token(T_default);
11101         rem_anchor_token(T_continue);
11102         rem_anchor_token(T_const_cast);
11103         rem_anchor_token(T_const);
11104         rem_anchor_token(T_class);
11105         rem_anchor_token(T_char);
11106         rem_anchor_token(T_case);
11107         rem_anchor_token(T_break);
11108         rem_anchor_token(T_bool);
11109         rem_anchor_token(T_auto);
11110         rem_anchor_token(T_asm);
11111         rem_anchor_token(T___thread);
11112         rem_anchor_token(T___real__);
11113         rem_anchor_token(T___label__);
11114         rem_anchor_token(T___imag__);
11115         rem_anchor_token(T___func__);
11116         rem_anchor_token(T___extension__);
11117         rem_anchor_token(T___builtin_va_start);
11118         rem_anchor_token(T___attribute__);
11119         rem_anchor_token(T___alignof__);
11120         rem_anchor_token(T___PRETTY_FUNCTION__);
11121         rem_anchor_token(T___FUNCTION__);
11122         rem_anchor_token(T__Imaginary);
11123         rem_anchor_token(T__Complex);
11124         rem_anchor_token(T__Bool);
11125         rem_anchor_token(T_WIDE_STRING_LITERAL);
11126         rem_anchor_token(T_WIDE_CHARACTER_CONSTANT);
11127         rem_anchor_token(T_STRING_LITERAL);
11128         rem_anchor_token(T_PLUSPLUS);
11129         rem_anchor_token(T_MINUSMINUS);
11130         rem_anchor_token(T_INTEGER);
11131         rem_anchor_token(T_IDENTIFIER);
11132         rem_anchor_token(T_FLOATINGPOINT);
11133         rem_anchor_token(T_COLONCOLON);
11134         rem_anchor_token(T_CHARACTER_CONSTANT);
11135         rem_anchor_token('~');
11136         rem_anchor_token('{');
11137         rem_anchor_token('-');
11138         rem_anchor_token('+');
11139         rem_anchor_token('*');
11140         rem_anchor_token('(');
11141         rem_anchor_token('&');
11142         rem_anchor_token('!');
11143         rem_anchor_token('}');
11144         assert(current_scope == &statement->compound.scope);
11145         scope_pop(old_scope);
11146         environment_pop_to(top);
11147
11148         POP_PARENT;
11149         return statement;
11150 }
11151
11152 /**
11153  * Check for unused global static functions and variables
11154  */
11155 static void check_unused_globals(void)
11156 {
11157         if (!warning.unused_function && !warning.unused_variable)
11158                 return;
11159
11160         for (const entity_t *entity = file_scope->entities; entity != NULL;
11161              entity = entity->base.next) {
11162                 if (!is_declaration(entity))
11163                         continue;
11164
11165                 const declaration_t *declaration = &entity->declaration;
11166                 if (declaration->used                  ||
11167                     declaration->modifiers & DM_UNUSED ||
11168                     declaration->modifiers & DM_USED   ||
11169                     declaration->storage_class != STORAGE_CLASS_STATIC)
11170                         continue;
11171
11172                 type_t *const type = declaration->type;
11173                 const char *s;
11174                 if (entity->kind == ENTITY_FUNCTION) {
11175                         /* inhibit warning for static inline functions */
11176                         if (entity->function.is_inline)
11177                                 continue;
11178
11179                         s = entity->function.statement != NULL ? "defined" : "declared";
11180                 } else {
11181                         s = "defined";
11182                 }
11183
11184                 warningf(&declaration->base.source_position, "'%#T' %s but not used",
11185                         type, declaration->base.symbol, s);
11186         }
11187 }
11188
11189 static void parse_global_asm(void)
11190 {
11191         statement_t *statement = allocate_statement_zero(STATEMENT_ASM);
11192
11193         eat(T_asm);
11194         expect('(', end_error);
11195
11196         statement->asms.asm_text = parse_string_literals();
11197         statement->base.next     = unit->global_asm;
11198         unit->global_asm         = statement;
11199
11200         expect(')', end_error);
11201         expect(';', end_error);
11202
11203 end_error:;
11204 }
11205
11206 static void parse_linkage_specification(void)
11207 {
11208         eat(T_extern);
11209         assert(token.type == T_STRING_LITERAL);
11210
11211         const char *linkage = parse_string_literals().begin;
11212
11213         linkage_kind_t old_linkage = current_linkage;
11214         linkage_kind_t new_linkage;
11215         if (strcmp(linkage, "C") == 0) {
11216                 new_linkage = LINKAGE_C;
11217         } else if (strcmp(linkage, "C++") == 0) {
11218                 new_linkage = LINKAGE_CXX;
11219         } else {
11220                 errorf(HERE, "linkage string \"%s\" not recognized", linkage);
11221                 new_linkage = LINKAGE_INVALID;
11222         }
11223         current_linkage = new_linkage;
11224
11225         if (token.type == '{') {
11226                 next_token();
11227                 parse_externals();
11228                 expect('}', end_error);
11229         } else {
11230                 parse_external();
11231         }
11232
11233 end_error:
11234         assert(current_linkage == new_linkage);
11235         current_linkage = old_linkage;
11236 }
11237
11238 static void parse_external(void)
11239 {
11240         switch (token.type) {
11241                 DECLARATION_START_NO_EXTERN
11242                 case T_IDENTIFIER:
11243                 case T___extension__:
11244                 /* tokens below are for implicit int */
11245                 case '&': /* & x; -> int& x; (and error later, because C++ has no
11246                              implicit int) */
11247                 case '*': /* * x; -> int* x; */
11248                 case '(': /* (x); -> int (x); */
11249                         parse_external_declaration();
11250                         return;
11251
11252                 case T_extern:
11253                         if (look_ahead(1)->type == T_STRING_LITERAL) {
11254                                 parse_linkage_specification();
11255                         } else {
11256                                 parse_external_declaration();
11257                         }
11258                         return;
11259
11260                 case T_asm:
11261                         parse_global_asm();
11262                         return;
11263
11264                 case T_namespace:
11265                         parse_namespace_definition();
11266                         return;
11267
11268                 case ';':
11269                         if (!strict_mode) {
11270                                 if (warning.other)
11271                                         warningf(HERE, "stray ';' outside of function");
11272                                 next_token();
11273                                 return;
11274                         }
11275                         /* FALLTHROUGH */
11276
11277                 default:
11278                         errorf(HERE, "stray %K outside of function", &token);
11279                         if (token.type == '(' || token.type == '{' || token.type == '[')
11280                                 eat_until_matching_token(token.type);
11281                         next_token();
11282                         return;
11283         }
11284 }
11285
11286 static void parse_externals(void)
11287 {
11288         add_anchor_token('}');
11289         add_anchor_token(T_EOF);
11290
11291 #ifndef NDEBUG
11292         unsigned char token_anchor_copy[T_LAST_TOKEN];
11293         memcpy(token_anchor_copy, token_anchor_set, sizeof(token_anchor_copy));
11294 #endif
11295
11296         while (token.type != T_EOF && token.type != '}') {
11297 #ifndef NDEBUG
11298                 bool anchor_leak = false;
11299                 for (int i = 0; i != T_LAST_TOKEN; ++i) {
11300                         unsigned char count = token_anchor_set[i] - token_anchor_copy[i];
11301                         if (count != 0) {
11302                                 errorf(HERE, "Leaked anchor token %k %d times", i, count);
11303                                 anchor_leak = true;
11304                         }
11305                 }
11306                 if (in_gcc_extension) {
11307                         errorf(HERE, "Leaked __extension__");
11308                         anchor_leak = true;
11309                 }
11310
11311                 if (anchor_leak)
11312                         abort();
11313 #endif
11314
11315                 parse_external();
11316         }
11317
11318         rem_anchor_token(T_EOF);
11319         rem_anchor_token('}');
11320 }
11321
11322 /**
11323  * Parse a translation unit.
11324  */
11325 static void parse_translation_unit(void)
11326 {
11327         add_anchor_token(T_EOF);
11328
11329         while (true) {
11330                 parse_externals();
11331
11332                 if (token.type == T_EOF)
11333                         break;
11334
11335                 errorf(HERE, "stray %K outside of function", &token);
11336                 if (token.type == '(' || token.type == '{' || token.type == '[')
11337                         eat_until_matching_token(token.type);
11338                 next_token();
11339         }
11340 }
11341
11342 /**
11343  * Parse the input.
11344  *
11345  * @return  the translation unit or NULL if errors occurred.
11346  */
11347 void start_parsing(void)
11348 {
11349         environment_stack = NEW_ARR_F(stack_entry_t, 0);
11350         label_stack       = NEW_ARR_F(stack_entry_t, 0);
11351         diagnostic_count  = 0;
11352         error_count       = 0;
11353         warning_count     = 0;
11354
11355         type_set_output(stderr);
11356         ast_set_output(stderr);
11357
11358         assert(unit == NULL);
11359         unit = allocate_ast_zero(sizeof(unit[0]));
11360
11361         assert(file_scope == NULL);
11362         file_scope = &unit->scope;
11363
11364         assert(current_scope == NULL);
11365         scope_push(&unit->scope);
11366
11367         create_gnu_builtins();
11368         if (c_mode & _MS)
11369                 create_microsoft_intrinsics();
11370 }
11371
11372 translation_unit_t *finish_parsing(void)
11373 {
11374         assert(current_scope == &unit->scope);
11375         scope_pop(NULL);
11376
11377         assert(file_scope == &unit->scope);
11378         check_unused_globals();
11379         file_scope = NULL;
11380
11381         DEL_ARR_F(environment_stack);
11382         DEL_ARR_F(label_stack);
11383
11384         translation_unit_t *result = unit;
11385         unit = NULL;
11386         return result;
11387 }
11388
11389 /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
11390  * are given length one. */
11391 static void complete_incomplete_arrays(void)
11392 {
11393         size_t n = ARR_LEN(incomplete_arrays);
11394         for (size_t i = 0; i != n; ++i) {
11395                 declaration_t *const decl      = incomplete_arrays[i];
11396                 type_t        *const orig_type = decl->type;
11397                 type_t        *const type      = skip_typeref(orig_type);
11398
11399                 if (!is_type_incomplete(type))
11400                         continue;
11401
11402                 if (warning.other) {
11403                         warningf(&decl->base.source_position,
11404                                         "array '%#T' assumed to have one element",
11405                                         orig_type, decl->base.symbol);
11406                 }
11407
11408                 type_t *const new_type = duplicate_type(type);
11409                 new_type->array.size_constant     = true;
11410                 new_type->array.has_implicit_size = true;
11411                 new_type->array.size              = 1;
11412
11413                 type_t *const result = identify_new_type(new_type);
11414
11415                 decl->type = result;
11416         }
11417 }
11418
11419 void parse(void)
11420 {
11421         lookahead_bufpos = 0;
11422         for (int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
11423                 next_token();
11424         }
11425         current_linkage   = c_mode & _CXX ? LINKAGE_CXX : LINKAGE_C;
11426         incomplete_arrays = NEW_ARR_F(declaration_t*, 0);
11427         parse_translation_unit();
11428         complete_incomplete_arrays();
11429         DEL_ARR_F(incomplete_arrays);
11430         incomplete_arrays = NULL;
11431 }
11432
11433 /**
11434  * create a builtin function.
11435  */
11436 static entity_t *create_builtin_function(builtin_kind_t kind, const char *name, type_t *function_type)
11437 {
11438         symbol_t *symbol = symbol_table_insert(name);
11439         entity_t *entity = allocate_entity_zero(ENTITY_FUNCTION);
11440         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
11441         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
11442         entity->declaration.type                   = function_type;
11443         entity->declaration.implicit               = true;
11444         entity->base.symbol                        = symbol;
11445         entity->base.source_position               = builtin_source_position;
11446
11447         entity->function.btk                       = kind;
11448
11449         record_entity(entity, /*is_definition=*/false);
11450         return entity;
11451 }
11452
11453
11454 /**
11455  * Create predefined gnu builtins.
11456  */
11457 static void create_gnu_builtins(void)
11458 {
11459 #define GNU_BUILTIN(a, b) create_builtin_function(bk_gnu_builtin_##a, "__builtin_" #a, b)
11460
11461         GNU_BUILTIN(alloca,         make_function_1_type(type_void_ptr, type_size_t));
11462         GNU_BUILTIN(huge_val,       make_function_0_type(type_double));
11463         GNU_BUILTIN(inf,            make_function_0_type(type_double));
11464         GNU_BUILTIN(inff,           make_function_0_type(type_float));
11465         GNU_BUILTIN(infl,           make_function_0_type(type_long_double));
11466         GNU_BUILTIN(nan,            make_function_1_type(type_double, type_char_ptr));
11467         GNU_BUILTIN(nanf,           make_function_1_type(type_float, type_char_ptr));
11468         GNU_BUILTIN(nanl,           make_function_1_type(type_long_double, type_char_ptr));
11469         GNU_BUILTIN(va_end,         make_function_1_type(type_void, type_valist));
11470         GNU_BUILTIN(expect,         make_function_2_type(type_long, type_long, type_long));
11471         GNU_BUILTIN(return_address, make_function_1_type(type_void_ptr, type_unsigned_int));
11472         GNU_BUILTIN(frame_address,  make_function_1_type(type_void_ptr, type_unsigned_int));
11473         GNU_BUILTIN(ffs,            make_function_1_type(type_int, type_unsigned_int));
11474         GNU_BUILTIN(clz,            make_function_1_type(type_int, type_unsigned_int));
11475         GNU_BUILTIN(ctz,            make_function_1_type(type_int, type_unsigned_int));
11476         GNU_BUILTIN(popcount,       make_function_1_type(type_int, type_unsigned_int));
11477         GNU_BUILTIN(parity,         make_function_1_type(type_int, type_unsigned_int));
11478         GNU_BUILTIN(prefetch,       make_function_1_type_variadic(type_float, type_void_ptr));
11479         GNU_BUILTIN(trap,           make_function_0_type_noreturn(type_void));
11480
11481 #undef GNU_BUILTIN
11482 }
11483
11484 /**
11485  * Create predefined MS intrinsics.
11486  */
11487 static void create_microsoft_intrinsics(void)
11488 {
11489 #define MS_BUILTIN(a, b) create_builtin_function(bk_ms##a, #a, b)
11490
11491         /* intrinsics for all architectures */
11492         MS_BUILTIN(_rotl,                  make_function_2_type(type_unsigned_int,   type_unsigned_int, type_int));
11493         MS_BUILTIN(_rotr,                  make_function_2_type(type_unsigned_int,   type_unsigned_int, type_int));
11494         MS_BUILTIN(_rotl64,                make_function_2_type(type_unsigned_int64, type_unsigned_int64, type_int));
11495         MS_BUILTIN(_rotr64,                make_function_2_type(type_unsigned_int64, type_unsigned_int64, type_int));
11496         MS_BUILTIN(_byteswap_ushort,       make_function_1_type(type_unsigned_short, type_unsigned_short));
11497         MS_BUILTIN(_byteswap_ulong,        make_function_1_type(type_unsigned_long,  type_unsigned_long));
11498         MS_BUILTIN(_byteswap_uint64,       make_function_1_type(type_unsigned_int64, type_unsigned_int64));
11499
11500         MS_BUILTIN(__debugbreak,    make_function_0_type(type_void));
11501         MS_BUILTIN(_ReturnAddress,  make_function_0_type(type_void_ptr));
11502         MS_BUILTIN(__popcount,      make_function_1_type(type_unsigned_int, type_unsigned_int));
11503
11504         /* x86/x64 only */
11505         MS_BUILTIN(_enable,                make_function_0_type(type_void));
11506         MS_BUILTIN(_disable,               make_function_0_type(type_void));
11507         MS_BUILTIN(__inbyte,               make_function_1_type(type_unsigned_char, type_unsigned_short));
11508         MS_BUILTIN(__inword,               make_function_1_type(type_unsigned_short, type_unsigned_short));
11509         MS_BUILTIN(__indword,              make_function_1_type(type_unsigned_long, type_unsigned_short));
11510         MS_BUILTIN(__outbyte,              make_function_2_type(type_void, type_unsigned_short, type_unsigned_char));
11511         MS_BUILTIN(__outword,              make_function_2_type(type_void, type_unsigned_short, type_unsigned_short));
11512         MS_BUILTIN(__outdword,             make_function_2_type(type_void, type_unsigned_short, type_unsigned_long));
11513         MS_BUILTIN(__ud2,                  make_function_0_type_noreturn(type_void));
11514         MS_BUILTIN(_BitScanForward,        make_function_2_type(type_unsigned_char, type_unsigned_long_ptr, type_unsigned_long));
11515         MS_BUILTIN(_BitScanReverse,        make_function_2_type(type_unsigned_char, type_unsigned_long_ptr, type_unsigned_long));
11516         MS_BUILTIN(_InterlockedExchange,   make_function_2_type(type_long, type_long_ptr, type_long));
11517         MS_BUILTIN(_InterlockedExchange64, make_function_2_type(type_int64, type_int64_ptr, type_int64));
11518
11519         if (machine_size <= 32) {
11520                 MS_BUILTIN(__readeflags,           make_function_0_type(type_unsigned_int));
11521                 MS_BUILTIN(__writeeflags,          make_function_1_type(type_void, type_unsigned_int));
11522         } else {
11523                 MS_BUILTIN(__readeflags,           make_function_0_type(type_unsigned_int64));
11524                 MS_BUILTIN(__writeeflags,          make_function_1_type(type_void, type_unsigned_int64));
11525         }
11526
11527 #undef MS_BUILTIN
11528 }
11529
11530 /**
11531  * Initialize the parser.
11532  */
11533 void init_parser(void)
11534 {
11535         sym_anonymous = symbol_table_insert("<anonymous>");
11536
11537         if (c_mode & _MS) {
11538                 /* add predefined symbols for extended-decl-modifier */
11539                 sym_align         = symbol_table_insert("align");
11540                 sym_allocate      = symbol_table_insert("allocate");
11541                 sym_dllimport     = symbol_table_insert("dllimport");
11542                 sym_dllexport     = symbol_table_insert("dllexport");
11543                 sym_naked         = symbol_table_insert("naked");
11544                 sym_noinline      = symbol_table_insert("noinline");
11545                 sym_returns_twice = symbol_table_insert("returns_twice");
11546                 sym_noreturn      = symbol_table_insert("noreturn");
11547                 sym_nothrow       = symbol_table_insert("nothrow");
11548                 sym_novtable      = symbol_table_insert("novtable");
11549                 sym_property      = symbol_table_insert("property");
11550                 sym_get           = symbol_table_insert("get");
11551                 sym_put           = symbol_table_insert("put");
11552                 sym_selectany     = symbol_table_insert("selectany");
11553                 sym_thread        = symbol_table_insert("thread");
11554                 sym_uuid          = symbol_table_insert("uuid");
11555                 sym_deprecated    = symbol_table_insert("deprecated");
11556                 sym_restrict      = symbol_table_insert("restrict");
11557                 sym_noalias       = symbol_table_insert("noalias");
11558         }
11559         memset(token_anchor_set, 0, sizeof(token_anchor_set));
11560
11561         init_expression_parsers();
11562         obstack_init(&temp_obst);
11563
11564         symbol_t *const va_list_sym = symbol_table_insert("__builtin_va_list");
11565         type_valist = create_builtin_type(va_list_sym, type_void_ptr);
11566 }
11567
11568 /**
11569  * Terminate the parser.
11570  */
11571 void exit_parser(void)
11572 {
11573         obstack_free(&temp_obst, NULL);
11574 }