nsz Git - cparser/blob - parser.c

   1 /*
   2  * This file is part of cparser.
   3  * Copyright (C) 2007-2008 Matthias Braun <matze@braunis.de>
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; either version 2
   8  * of the License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  18  * 02111-1307, USA.
  19  */
  20 #include <config.h>
  21
  22 #include <assert.h>
  23 #include <stdarg.h>
  24 #include <stdbool.h>
  25
  26 #include "parser.h"
  27 #include "diagnostic.h"
  28 #include "format_check.h"
  29 #include "lexer.h"
  30 #include "symbol_t.h"
  31 #include "token_t.h"
  32 #include "types.h"
  33 #include "type_t.h"
  34 #include "type_hash.h"
  35 #include "ast_t.h"
  36 #include "entity_t.h"
  37 #include "lang_features.h"
  38 #include "walk_statements.h"
  39 #include "warning.h"
  40 #include "adt/bitfiddle.h"
  41 #include "adt/error.h"
  42 #include "adt/array.h"
  43
  44 //#define PRINT_TOKENS
  45 #define MAX_LOOKAHEAD 2
  46
  47 typedef struct {
  48         entity_t           *old_entity;
  49         symbol_t           *symbol;
  50         entity_namespace_t  namespc;
  51 } stack_entry_t;
  52
  53 typedef struct argument_list_t argument_list_t;
  54 struct argument_list_t {
  55         long              argument;
  56         argument_list_t  *next;
  57 };
  58
  59 typedef struct gnu_attribute_t gnu_attribute_t;
  60 struct gnu_attribute_t {
  61         gnu_attribute_kind_t kind;          /**< The kind of the GNU attribute. */
  62         gnu_attribute_t     *next;
  63         bool                 invalid;       /**< Set if this attribute had argument errors, */
  64         bool                 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 int                  lookahead_bufpos;
 117 static stack_entry_t       *environment_stack = NULL;
 118 static stack_entry_t       *label_stack       = NULL;
 119 static scope_t             *file_scope        = NULL;
 120 static scope_t             *current_scope     = NULL;
 121 /** Point to the current function declaration if inside a function. */
 122 static function_t          *current_function  = NULL;
 123 static entity_t            *current_init_decl = NULL;
 124 static switch_statement_t  *current_switch    = NULL;
 125 static statement_t         *current_loop      = NULL;
 126 static statement_t         *current_parent    = NULL;
 127 static ms_try_statement_t  *current_try       = NULL;
 128 static linkage_kind_t       current_linkage   = LINKAGE_INVALID;
 129 static goto_statement_t    *goto_first        = NULL;
 130 static goto_statement_t   **goto_anchor       = NULL;
 131 static label_statement_t   *label_first       = NULL;
 132 static label_statement_t  **label_anchor      = NULL;
 133 /** current translation unit. */
 134 static translation_unit_t  *unit              = NULL;
 135 /** true if we are in a type property context (evaluation only for type. */
 136 static bool                 in_type_prop      = false;
 137 /** true in we are in a __extension__ context. */
 138 static bool                 in_gcc_extension  = false;
 139 static struct obstack       temp_obst;
 140 static entity_t            *anonymous_entity;
 141 static declaration_t      **incomplete_arrays;
 142
 143
 144 #define PUSH_PARENT(stmt)                          \
 145         statement_t *const prev_parent = current_parent; \
 146         ((void)(current_parent = (stmt)))
 147 #define POP_PARENT ((void)(current_parent = prev_parent))
 148
 149 /** special symbol used for anonymous entities. */
 150 static const symbol_t *sym_anonymous = NULL;
 151
 152 /* symbols for Microsoft extended-decl-modifier */
 153 static const symbol_t *sym_align         = NULL;
 154 static const symbol_t *sym_allocate      = NULL;
 155 static const symbol_t *sym_dllimport     = NULL;
 156 static const symbol_t *sym_dllexport     = NULL;
 157 static const symbol_t *sym_naked         = NULL;
 158 static const symbol_t *sym_noinline      = NULL;
 159 static const symbol_t *sym_returns_twice = NULL;
 160 static const symbol_t *sym_noreturn      = NULL;
 161 static const symbol_t *sym_nothrow       = NULL;
 162 static const symbol_t *sym_novtable      = NULL;
 163 static const symbol_t *sym_property      = NULL;
 164 static const symbol_t *sym_get           = NULL;
 165 static const symbol_t *sym_put           = NULL;
 166 static const symbol_t *sym_selectany     = NULL;
 167 static const symbol_t *sym_thread        = NULL;
 168 static const symbol_t *sym_uuid          = NULL;
 169 static const symbol_t *sym_deprecated    = NULL;
 170 static const symbol_t *sym_restrict      = NULL;
 171 static const symbol_t *sym_noalias       = NULL;
 172
 173 /** The token anchor set */
 174 static unsigned char token_anchor_set[T_LAST_TOKEN];
 175
 176 /** The current source position. */
 177 #define HERE (&token.source_position)
 178
 179 /** true if we are in GCC mode. */
 180 #define GNU_MODE ((c_mode & _GNUC) || in_gcc_extension)
 181
 182 static type_t *type_valist;
 183
 184 static statement_t *parse_compound_statement(bool inside_expression_statement);
 185 static statement_t *parse_statement(void);
 186
 187 static expression_t *parse_sub_expression(precedence_t);
 188 static expression_t *parse_expression(void);
 189 static type_t       *parse_typename(void);
 190 static void          parse_externals(void);
 191 static void          parse_external(void);
 192
 193 static void parse_compound_type_entries(compound_t *compound_declaration);
 194
 195 typedef enum declarator_flags_t {
 196         DECL_FLAGS_NONE             = 0,
 197         DECL_MAY_BE_ABSTRACT        = 1U << 0,
 198         DECL_CREATE_COMPOUND_MEMBER = 1U << 1,
 199         DECL_IS_PARAMETER           = 1U << 2
 200 } declarator_flags_t;
 201
 202 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
 203                                   declarator_flags_t flags);
 204
 205 static entity_t *record_entity(entity_t *entity, bool is_definition);
 206
 207 static void semantic_comparison(binary_expression_t *expression);
 208
 209 #define STORAGE_CLASSES       \
 210         STORAGE_CLASSES_NO_EXTERN \
 211         case T_extern:
 212
 213 #define STORAGE_CLASSES_NO_EXTERN \
 214         case T_typedef:         \
 215         case T_static:          \
 216         case T_auto:            \
 217         case T_register:        \
 218         case T___thread:
 219
 220 #define TYPE_QUALIFIERS     \
 221         case T_const:           \
 222         case T_restrict:        \
 223         case T_volatile:        \
 224         case T_inline:          \
 225         case T__forceinline:    \
 226         case T___attribute__:
 227
 228 #define COMPLEX_SPECIFIERS  \
 229         case T__Complex:
 230 #define IMAGINARY_SPECIFIERS \
 231         case T__Imaginary:
 232
 233 #define TYPE_SPECIFIERS       \
 234         case T__Bool:             \
 235         case T___builtin_va_list: \
 236         case T___typeof__:        \
 237         case T__declspec:         \
 238         case T_bool:              \
 239         case T_char:              \
 240         case T_double:            \
 241         case T_enum:              \
 242         case T_float:             \
 243         case T_int:               \
 244         case T_long:              \
 245         case T_short:             \
 246         case T_signed:            \
 247         case T_struct:            \
 248         case T_union:             \
 249         case T_unsigned:          \
 250         case T_void:              \
 251         case T_wchar_t:           \
 252         COMPLEX_SPECIFIERS        \
 253         IMAGINARY_SPECIFIERS
 254
 255 #define DECLARATION_START   \
 256         STORAGE_CLASSES         \
 257         TYPE_QUALIFIERS         \
 258         TYPE_SPECIFIERS
 259
 260 #define DECLARATION_START_NO_EXTERN \
 261         STORAGE_CLASSES_NO_EXTERN       \
 262         TYPE_QUALIFIERS                 \
 263         TYPE_SPECIFIERS
 264
 265 #define TYPENAME_START      \
 266         TYPE_QUALIFIERS         \
 267         TYPE_SPECIFIERS
 268
 269 #define EXPRESSION_START           \
 270         case '!':                        \
 271         case '&':                        \
 272         case '(':                        \
 273         case '*':                        \
 274         case '+':                        \
 275         case '-':                        \
 276         case '~':                        \
 277         case T_ANDAND:                   \
 278         case T_CHARACTER_CONSTANT:       \
 279         case T_FLOATINGPOINT:            \
 280         case T_INTEGER:                  \
 281         case T_MINUSMINUS:               \
 282         case T_PLUSPLUS:                 \
 283         case T_STRING_LITERAL:           \
 284         case T_WIDE_CHARACTER_CONSTANT:  \
 285         case T_WIDE_STRING_LITERAL:      \
 286         case T___FUNCDNAME__:            \
 287         case T___FUNCSIG__:              \
 288         case T___FUNCTION__:             \
 289         case T___PRETTY_FUNCTION__:      \
 290         case T___alignof__:              \
 291         case T___builtin_alloca:         \
 292         case T___builtin_classify_type:  \
 293         case T___builtin_constant_p:     \
 294         case T___builtin_expect:         \
 295         case T___builtin_huge_val:       \
 296         case T___builtin_inf:            \
 297         case T___builtin_inff:           \
 298         case T___builtin_infl:           \
 299         case T___builtin_isgreater:      \
 300         case T___builtin_isgreaterequal: \
 301         case T___builtin_isless:         \
 302         case T___builtin_islessequal:    \
 303         case T___builtin_islessgreater:  \
 304         case T___builtin_isunordered:    \
 305         case T___builtin_nan:            \
 306         case T___builtin_nanf:           \
 307         case T___builtin_nanl:           \
 308         case T___builtin_offsetof:       \
 309         case T___builtin_prefetch:       \
 310         case T___builtin_va_arg:         \
 311         case T___builtin_va_end:         \
 312         case T___builtin_va_start:       \
 313         case T___func__:                 \
 314         case T___noop:                   \
 315         case T__assume:                  \
 316         case T_delete:                   \
 317         case T_false:                    \
 318         case T_sizeof:                   \
 319         case T_throw:                    \
 320         case T_true:
 321
 322 /**
 323  * Allocate an AST node with given size and
 324  * initialize all fields with zero.
 325  */
 326 static void *allocate_ast_zero(size_t size)
 327 {
 328         void *res = allocate_ast(size);
 329         memset(res, 0, size);
 330         return res;
 331 }
 332
 333 /**
 334  * Returns the size of an entity node.
 335  *
 336  * @param kind  the entity kind
 337  */
 338 static size_t get_entity_struct_size(entity_kind_t kind)
 339 {
 340         static const size_t sizes[] = {
 341                 [ENTITY_VARIABLE]        = sizeof(variable_t),
 342                 [ENTITY_PARAMETER]       = sizeof(parameter_t),
 343                 [ENTITY_COMPOUND_MEMBER] = sizeof(compound_member_t),
 344                 [ENTITY_FUNCTION]        = sizeof(function_t),
 345                 [ENTITY_TYPEDEF]         = sizeof(typedef_t),
 346                 [ENTITY_STRUCT]          = sizeof(compound_t),
 347                 [ENTITY_UNION]           = sizeof(compound_t),
 348                 [ENTITY_ENUM]            = sizeof(enum_t),
 349                 [ENTITY_ENUM_VALUE]      = sizeof(enum_value_t),
 350                 [ENTITY_LABEL]           = sizeof(label_t),
 351                 [ENTITY_LOCAL_LABEL]     = sizeof(label_t),
 352                 [ENTITY_NAMESPACE]       = sizeof(namespace_t)
 353         };
 354         assert(kind < sizeof(sizes) / sizeof(sizes[0]));
 355         assert(sizes[kind] != 0);
 356         return sizes[kind];
 357 }
 358
 359 /**
 360  * Allocate an entity of given kind and initialize all
 361  * fields with zero.
 362  */
 363 static entity_t *allocate_entity_zero(entity_kind_t kind)
 364 {
 365         size_t    size   = get_entity_struct_size(kind);
 366         entity_t *entity = allocate_ast_zero(size);
 367         entity->kind     = kind;
 368         return entity;
 369 }
 370
 371 /**
 372  * Returns the size of a statement node.
 373  *
 374  * @param kind  the statement kind
 375  */
 376 static size_t get_statement_struct_size(statement_kind_t kind)
 377 {
 378         static const size_t sizes[] = {
 379                 [STATEMENT_INVALID]     = sizeof(invalid_statement_t),
 380                 [STATEMENT_EMPTY]       = sizeof(empty_statement_t),
 381                 [STATEMENT_COMPOUND]    = sizeof(compound_statement_t),
 382                 [STATEMENT_RETURN]      = sizeof(return_statement_t),
 383                 [STATEMENT_DECLARATION] = sizeof(declaration_statement_t),
 384                 [STATEMENT_IF]          = sizeof(if_statement_t),
 385                 [STATEMENT_SWITCH]      = sizeof(switch_statement_t),
 386                 [STATEMENT_EXPRESSION]  = sizeof(expression_statement_t),
 387                 [STATEMENT_CONTINUE]    = sizeof(statement_base_t),
 388                 [STATEMENT_BREAK]       = sizeof(statement_base_t),
 389                 [STATEMENT_GOTO]        = sizeof(goto_statement_t),
 390                 [STATEMENT_LABEL]       = sizeof(label_statement_t),
 391                 [STATEMENT_CASE_LABEL]  = sizeof(case_label_statement_t),
 392                 [STATEMENT_WHILE]       = sizeof(while_statement_t),
 393                 [STATEMENT_DO_WHILE]    = sizeof(do_while_statement_t),
 394                 [STATEMENT_FOR]         = sizeof(for_statement_t),
 395                 [STATEMENT_ASM]         = sizeof(asm_statement_t),
 396                 [STATEMENT_MS_TRY]      = sizeof(ms_try_statement_t),
 397                 [STATEMENT_LEAVE]       = sizeof(leave_statement_t)
 398         };
 399         assert(kind < sizeof(sizes) / sizeof(sizes[0]));
 400         assert(sizes[kind] != 0);
 401         return sizes[kind];
 402 }
 403
 404 /**
 405  * Returns the size of an expression node.
 406  *
 407  * @param kind  the expression kind
 408  */
 409 static size_t get_expression_struct_size(expression_kind_t kind)
 410 {
 411         static const size_t sizes[] = {
 412                 [EXPR_INVALID]                 = sizeof(expression_base_t),
 413                 [EXPR_REFERENCE]               = sizeof(reference_expression_t),
 414                 [EXPR_REFERENCE_ENUM_VALUE]    = sizeof(reference_expression_t),
 415                 [EXPR_CONST]                   = sizeof(const_expression_t),
 416                 [EXPR_CHARACTER_CONSTANT]      = sizeof(const_expression_t),
 417                 [EXPR_WIDE_CHARACTER_CONSTANT] = sizeof(const_expression_t),
 418                 [EXPR_STRING_LITERAL]          = sizeof(string_literal_expression_t),
 419                 [EXPR_WIDE_STRING_LITERAL]     = sizeof(wide_string_literal_expression_t),
 420                 [EXPR_COMPOUND_LITERAL]        = sizeof(compound_literal_expression_t),
 421                 [EXPR_CALL]                    = sizeof(call_expression_t),
 422                 [EXPR_UNARY_FIRST]             = sizeof(unary_expression_t),
 423                 [EXPR_BINARY_FIRST]            = sizeof(binary_expression_t),
 424                 [EXPR_CONDITIONAL]             = sizeof(conditional_expression_t),
 425                 [EXPR_SELECT]                  = sizeof(select_expression_t),
 426                 [EXPR_ARRAY_ACCESS]            = sizeof(array_access_expression_t),
 427                 [EXPR_SIZEOF]                  = sizeof(typeprop_expression_t),
 428                 [EXPR_ALIGNOF]                 = sizeof(typeprop_expression_t),
 429                 [EXPR_CLASSIFY_TYPE]           = sizeof(classify_type_expression_t),
 430                 [EXPR_FUNCNAME]                = sizeof(funcname_expression_t),
 431                 [EXPR_BUILTIN_SYMBOL]          = sizeof(builtin_symbol_expression_t),
 432                 [EXPR_BUILTIN_CONSTANT_P]      = sizeof(builtin_constant_expression_t),
 433                 [EXPR_BUILTIN_PREFETCH]        = sizeof(builtin_prefetch_expression_t),
 434                 [EXPR_OFFSETOF]                = sizeof(offsetof_expression_t),
 435                 [EXPR_VA_START]                = sizeof(va_start_expression_t),
 436                 [EXPR_VA_ARG]                  = sizeof(va_arg_expression_t),
 437                 [EXPR_STATEMENT]               = sizeof(statement_expression_t),
 438                 [EXPR_LABEL_ADDRESS]           = sizeof(label_address_expression_t),
 439         };
 440         if (kind >= EXPR_UNARY_FIRST && kind <= EXPR_UNARY_LAST) {
 441                 return sizes[EXPR_UNARY_FIRST];
 442         }
 443         if (kind >= EXPR_BINARY_FIRST && kind <= EXPR_BINARY_LAST) {
 444                 return sizes[EXPR_BINARY_FIRST];
 445         }
 446         assert(kind < sizeof(sizes) / sizeof(sizes[0]));
 447         assert(sizes[kind] != 0);
 448         return sizes[kind];
 449 }
 450
 451 /**
 452  * Allocate a statement node of given kind and initialize all
 453  * fields with zero. Sets its source position to the position
 454  * of the current token.
 455  */
 456 static statement_t *allocate_statement_zero(statement_kind_t kind)
 457 {
 458         size_t       size = get_statement_struct_size(kind);
 459         statement_t *res  = allocate_ast_zero(size);
 460
 461         res->base.kind            = kind;
 462         res->base.parent          = current_parent;
 463         res->base.source_position = token.source_position;
 464         return res;
 465 }
 466
 467 /**
 468  * Allocate an expression node of given kind and initialize all
 469  * fields with zero.
 470  */
 471 static expression_t *allocate_expression_zero(expression_kind_t kind)
 472 {
 473         size_t        size = get_expression_struct_size(kind);
 474         expression_t *res  = allocate_ast_zero(size);
 475
 476         res->base.kind            = kind;
 477         res->base.type            = type_error_type;
 478         res->base.source_position = token.source_position;
 479         return res;
 480 }
 481
 482 /**
 483  * Creates a new invalid expression at the source position
 484  * of the current token.
 485  */
 486 static expression_t *create_invalid_expression(void)
 487 {
 488         return allocate_expression_zero(EXPR_INVALID);
 489 }
 490
 491 /**
 492  * Creates a new invalid statement.
 493  */
 494 static statement_t *create_invalid_statement(void)
 495 {
 496         return allocate_statement_zero(STATEMENT_INVALID);
 497 }
 498
 499 /**
 500  * Allocate a new empty statement.
 501  */
 502 static statement_t *create_empty_statement(void)
 503 {
 504         return allocate_statement_zero(STATEMENT_EMPTY);
 505 }
 506
 507 /**
 508  * Returns the size of a type node.
 509  *
 510  * @param kind  the type kind
 511  */
 512 static size_t get_type_struct_size(type_kind_t kind)
 513 {
 514         static const size_t sizes[] = {
 515                 [TYPE_ATOMIC]          = sizeof(atomic_type_t),
 516                 [TYPE_COMPLEX]         = sizeof(complex_type_t),
 517                 [TYPE_IMAGINARY]       = sizeof(imaginary_type_t),
 518                 [TYPE_BITFIELD]        = sizeof(bitfield_type_t),
 519                 [TYPE_COMPOUND_STRUCT] = sizeof(compound_type_t),
 520                 [TYPE_COMPOUND_UNION]  = sizeof(compound_type_t),
 521                 [TYPE_ENUM]            = sizeof(enum_type_t),
 522                 [TYPE_FUNCTION]        = sizeof(function_type_t),
 523                 [TYPE_POINTER]         = sizeof(pointer_type_t),
 524                 [TYPE_ARRAY]           = sizeof(array_type_t),
 525                 [TYPE_BUILTIN]         = sizeof(builtin_type_t),
 526                 [TYPE_TYPEDEF]         = sizeof(typedef_type_t),
 527                 [TYPE_TYPEOF]          = sizeof(typeof_type_t),
 528         };
 529         assert(sizeof(sizes) / sizeof(sizes[0]) == (int) TYPE_TYPEOF + 1);
 530         assert(kind <= TYPE_TYPEOF);
 531         assert(sizes[kind] != 0);
 532         return sizes[kind];
 533 }
 534
 535 /**
 536  * Allocate a type node of given kind and initialize all
 537  * fields with zero.
 538  *
 539  * @param kind             type kind to allocate
 540  */
 541 static type_t *allocate_type_zero(type_kind_t kind)
 542 {
 543         size_t  size = get_type_struct_size(kind);
 544         type_t *res  = obstack_alloc(type_obst, size);
 545         memset(res, 0, size);
 546         res->base.kind = kind;
 547
 548         return res;
 549 }
 550
 551 /**
 552  * Returns the size of an initializer node.
 553  *
 554  * @param kind  the initializer kind
 555  */
 556 static size_t get_initializer_size(initializer_kind_t kind)
 557 {
 558         static const size_t sizes[] = {
 559                 [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
 560                 [INITIALIZER_STRING]      = sizeof(initializer_string_t),
 561                 [INITIALIZER_WIDE_STRING] = sizeof(initializer_wide_string_t),
 562                 [INITIALIZER_LIST]        = sizeof(initializer_list_t),
 563                 [INITIALIZER_DESIGNATOR]  = sizeof(initializer_designator_t)
 564         };
 565         assert(kind < sizeof(sizes) / sizeof(*sizes));
 566         assert(sizes[kind] != 0);
 567         return sizes[kind];
 568 }
 569
 570 /**
 571  * Allocate an initializer node of given kind and initialize all
 572  * fields with zero.
 573  */
 574 static initializer_t *allocate_initializer_zero(initializer_kind_t kind)
 575 {
 576         initializer_t *result = allocate_ast_zero(get_initializer_size(kind));
 577         result->kind          = kind;
 578
 579         return result;
 580 }
 581
 582 /**
 583  * Returns the index of the top element of the environment stack.
 584  */
 585 static size_t environment_top(void)
 586 {
 587         return ARR_LEN(environment_stack);
 588 }
 589
 590 /**
 591  * Returns the index of the top element of the global label stack.
 592  */
 593 static size_t label_top(void)
 594 {
 595         return ARR_LEN(label_stack);
 596 }
 597
 598 /**
 599  * Return the next token.
 600  */
 601 static inline void next_token(void)
 602 {
 603         token                              = lookahead_buffer[lookahead_bufpos];
 604         lookahead_buffer[lookahead_bufpos] = lexer_token;
 605         lexer_next_token();
 606
 607         lookahead_bufpos = (lookahead_bufpos+1) % MAX_LOOKAHEAD;
 608
 609 #ifdef PRINT_TOKENS
 610         print_token(stderr, &token);
 611         fprintf(stderr, "\n");
 612 #endif
 613 }
 614
 615 /**
 616  * Return the next token with a given lookahead.
 617  */
 618 static inline const token_t *look_ahead(int num)
 619 {
 620         assert(num > 0 && num <= MAX_LOOKAHEAD);
 621         int pos = (lookahead_bufpos+num-1) % MAX_LOOKAHEAD;
 622         return &lookahead_buffer[pos];
 623 }
 624
 625 /**
 626  * Adds a token type to the token type anchor set (a multi-set).
 627  */
 628 static void add_anchor_token(int token_type)
 629 {
 630         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 631         ++token_anchor_set[token_type];
 632 }
 633
 634 /**
 635  * Set the number of tokens types of the given type
 636  * to zero and return the old count.
 637  */
 638 static int save_and_reset_anchor_state(int token_type)
 639 {
 640         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 641         int count = token_anchor_set[token_type];
 642         token_anchor_set[token_type] = 0;
 643         return count;
 644 }
 645
 646 /**
 647  * Restore the number of token types to the given count.
 648  */
 649 static void restore_anchor_state(int token_type, int count)
 650 {
 651         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 652         token_anchor_set[token_type] = count;
 653 }
 654
 655 /**
 656  * Remove a token type from the token type anchor set (a multi-set).
 657  */
 658 static void rem_anchor_token(int token_type)
 659 {
 660         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 661         assert(token_anchor_set[token_type] != 0);
 662         --token_anchor_set[token_type];
 663 }
 664
 665 /**
 666  * Return true if the token type of the current token is
 667  * in the anchor set.
 668  */
 669 static bool at_anchor(void)
 670 {
 671         if (token.type < 0)
 672                 return false;
 673         return token_anchor_set[token.type];
 674 }
 675
 676 /**
 677  * Eat tokens until a matching token type is found.
 678  */
 679 static void eat_until_matching_token(int type)
 680 {
 681         int end_token;
 682         switch (type) {
 683                 case '(': end_token = ')';  break;
 684                 case '{': end_token = '}';  break;
 685                 case '[': end_token = ']';  break;
 686                 default:  end_token = type; break;
 687         }
 688
 689         unsigned parenthesis_count = 0;
 690         unsigned brace_count       = 0;
 691         unsigned bracket_count     = 0;
 692         while (token.type        != end_token ||
 693                parenthesis_count != 0         ||
 694                brace_count       != 0         ||
 695                bracket_count     != 0) {
 696                 switch (token.type) {
 697                 case T_EOF: return;
 698                 case '(': ++parenthesis_count; break;
 699                 case '{': ++brace_count;       break;
 700                 case '[': ++bracket_count;     break;
 701
 702                 case ')':
 703                         if (parenthesis_count > 0)
 704                                 --parenthesis_count;
 705                         goto check_stop;
 706
 707                 case '}':
 708                         if (brace_count > 0)
 709                                 --brace_count;
 710                         goto check_stop;
 711
 712                 case ']':
 713                         if (bracket_count > 0)
 714                                 --bracket_count;
 715 check_stop:
 716                         if (token.type        == end_token &&
 717                             parenthesis_count == 0         &&
 718                             brace_count       == 0         &&
 719                             bracket_count     == 0)
 720                                 return;
 721                         break;
 722
 723                 default:
 724                         break;
 725                 }
 726                 next_token();
 727         }
 728 }
 729
 730 /**
 731  * Eat input tokens until an anchor is found.
 732  */
 733 static void eat_until_anchor(void)
 734 {
 735         while (token_anchor_set[token.type] == 0) {
 736                 if (token.type == '(' || token.type == '{' || token.type == '[')
 737                         eat_until_matching_token(token.type);
 738                 next_token();
 739         }
 740 }
 741
 742 /**
 743  * Eat a whole block from input tokens.
 744  */
 745 static void eat_block(void)
 746 {
 747         eat_until_matching_token('{');
 748         if (token.type == '}')
 749                 next_token();
 750 }
 751
 752 #define eat(token_type) (assert(token.type == (token_type)), next_token())
 753
 754 /**
 755  * Report a parse error because an expected token was not found.
 756  */
 757 static
 758 #if defined __GNUC__ && __GNUC__ >= 4
 759 __attribute__((sentinel))
 760 #endif
 761 void parse_error_expected(const char *message, ...)
 762 {
 763         if (message != NULL) {
 764                 errorf(HERE, "%s", message);
 765         }
 766         va_list ap;
 767         va_start(ap, message);
 768         errorf(HERE, "got %K, expected %#k", &token, &ap, ", ");
 769         va_end(ap);
 770 }
 771
 772 /**
 773  * Report an incompatible type.
 774  */
 775 static void type_error_incompatible(const char *msg,
 776                 const source_position_t *source_position, type_t *type1, type_t *type2)
 777 {
 778         errorf(source_position, "%s, incompatible types: '%T' - '%T'",
 779                msg, type1, type2);
 780 }
 781
 782 /**
 783  * Expect the current token is the expected token.
 784  * If not, generate an error, eat the current statement,
 785  * and goto the end_error label.
 786  */
 787 #define expect(expected, error_label)                     \
 788         do {                                                  \
 789                 if (UNLIKELY(token.type != (expected))) {         \
 790                         parse_error_expected(NULL, (expected), NULL); \
 791                         add_anchor_token(expected);                   \
 792                         eat_until_anchor();                           \
 793                         if (token.type == expected)                   \
 794                                 next_token();                             \
 795                         rem_anchor_token(expected);                   \
 796                         goto error_label;                             \
 797                 }                                                 \
 798                 next_token();                                     \
 799         } while (0)
 800
 801 /**
 802  * Push a given scope on the scope stack and make it the
 803  * current scope
 804  */
 805 static scope_t *scope_push(scope_t *new_scope)
 806 {
 807         if (current_scope != NULL) {
 808                 new_scope->depth = current_scope->depth + 1;
 809         }
 810
 811         scope_t *old_scope = current_scope;
 812         current_scope      = new_scope;
 813         return old_scope;
 814 }
 815
 816 /**
 817  * Pop the current scope from the scope stack.
 818  */
 819 static void scope_pop(scope_t *old_scope)
 820 {
 821         current_scope = old_scope;
 822 }
 823
 824 /**
 825  * Search an entity by its symbol in a given namespace.
 826  */
 827 static entity_t *get_entity(const symbol_t *const symbol,
 828                             namespace_tag_t namespc)
 829 {
 830         entity_t *entity = symbol->entity;
 831         for (; entity != NULL; entity = entity->base.symbol_next) {
 832                 if (entity->base.namespc == namespc)
 833                         return entity;
 834         }
 835
 836         return NULL;
 837 }
 838
 839 /**
 840  * pushs an entity on the environment stack and links the corresponding symbol
 841  * it.
 842  */
 843 static void stack_push(stack_entry_t **stack_ptr, entity_t *entity)
 844 {
 845         symbol_t           *symbol  = entity->base.symbol;
 846         entity_namespace_t  namespc = entity->base.namespc;
 847         assert(namespc != NAMESPACE_INVALID);
 848
 849         /* replace/add entity into entity list of the symbol */
 850         entity_t **anchor;
 851         entity_t  *iter;
 852         for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 853                 iter = *anchor;
 854                 if (iter == NULL)
 855                         break;
 856
 857                 /* replace an entry? */
 858                 if (iter->base.namespc == namespc) {
 859                         entity->base.symbol_next = iter->base.symbol_next;
 860                         break;
 861                 }
 862         }
 863         *anchor = entity;
 864
 865         /* remember old declaration */
 866         stack_entry_t entry;
 867         entry.symbol     = symbol;
 868         entry.old_entity = iter;
 869         entry.namespc    = namespc;
 870         ARR_APP1(stack_entry_t, *stack_ptr, entry);
 871 }
 872
 873 /**
 874  * Push an entity on the environment stack.
 875  */
 876 static void environment_push(entity_t *entity)
 877 {
 878         assert(entity->base.source_position.input_name != NULL);
 879         assert(entity->base.parent_scope != NULL);
 880         stack_push(&environment_stack, entity);
 881 }
 882
 883 /**
 884  * Push a declaration on the global label stack.
 885  *
 886  * @param declaration  the declaration
 887  */
 888 static void label_push(entity_t *label)
 889 {
 890         /* we abuse the parameters scope as parent for the labels */
 891         label->base.parent_scope = &current_function->parameters;
 892         stack_push(&label_stack, label);
 893 }
 894
 895 /**
 896  * pops symbols from the environment stack until @p new_top is the top element
 897  */
 898 static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
 899 {
 900         stack_entry_t *stack = *stack_ptr;
 901         size_t         top   = ARR_LEN(stack);
 902         size_t         i;
 903
 904         assert(new_top <= top);
 905         if (new_top == top)
 906                 return;
 907
 908         for (i = top; i > new_top; --i) {
 909                 stack_entry_t *entry = &stack[i - 1];
 910
 911                 entity_t           *old_entity = entry->old_entity;
 912                 symbol_t           *symbol     = entry->symbol;
 913                 entity_namespace_t  namespc    = entry->namespc;
 914
 915                 /* replace with old_entity/remove */
 916                 entity_t **anchor;
 917                 entity_t  *iter;
 918                 for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 919                         iter = *anchor;
 920                         assert(iter != NULL);
 921                         /* replace an entry? */
 922                         if (iter->base.namespc == namespc)
 923                                 break;
 924                 }
 925
 926                 /* restore definition from outer scopes (if there was one) */
 927                 if (old_entity != NULL) {
 928                         old_entity->base.symbol_next = iter->base.symbol_next;
 929                         *anchor                      = old_entity;
 930                 } else {
 931                         /* remove entry from list */
 932                         *anchor = iter->base.symbol_next;
 933                 }
 934         }
 935
 936         ARR_SHRINKLEN(*stack_ptr, (int) new_top);
 937 }
 938
 939 /**
 940  * Pop all entries from the environment stack until the new_top
 941  * is reached.
 942  *
 943  * @param new_top  the new stack top
 944  */
 945 static void environment_pop_to(size_t new_top)
 946 {
 947         stack_pop_to(&environment_stack, new_top);
 948 }
 949
 950 /**
 951  * Pop all entries from the global label stack until the new_top
 952  * is reached.
 953  *
 954  * @param new_top  the new stack top
 955  */
 956 static void label_pop_to(size_t new_top)
 957 {
 958         stack_pop_to(&label_stack, new_top);
 959 }
 960
 961 static int get_akind_rank(atomic_type_kind_t akind)
 962 {
 963         return (int) akind;
 964 }
 965
 966 /**
 967  * Return the type rank for an atomic type.
 968  */
 969 static int get_rank(const type_t *type)
 970 {
 971         assert(!is_typeref(type));
 972         if (type->kind == TYPE_ENUM)
 973                 return get_akind_rank(type->enumt.akind);
 974
 975         assert(type->kind == TYPE_ATOMIC);
 976         return get_akind_rank(type->atomic.akind);
 977 }
 978
 979 /**
 980  * Do integer promotion for a given type.
 981  *
 982  * @param type  the type to promote
 983  * @return the promoted type
 984  */
 985 static type_t *promote_integer(type_t *type)
 986 {
 987         if (type->kind == TYPE_BITFIELD)
 988                 type = type->bitfield.base_type;
 989
 990         if (get_rank(type) < get_akind_rank(ATOMIC_TYPE_INT))
 991                 type = type_int;
 992
 993         return type;
 994 }
 995
 996 /**
 997  * Create a cast expression.
 998  *
 999  * @param expression  the expression to cast
1000  * @param dest_type   the destination type
1001  */
1002 static expression_t *create_cast_expression(expression_t *expression,
1003                                             type_t *dest_type)
1004 {
1005         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST_IMPLICIT);
1006
1007         cast->unary.value = expression;
1008         cast->base.type   = dest_type;
1009
1010         return cast;
1011 }
1012
1013 /**
1014  * Check if a given expression represents a null pointer constant.
1015  *
1016  * @param expression  the expression to check
1017  */
1018 static bool is_null_pointer_constant(const expression_t *expression)
1019 {
1020         /* skip void* cast */
1021         if (expression->kind == EXPR_UNARY_CAST ||
1022                         expression->kind == EXPR_UNARY_CAST_IMPLICIT) {
1023                 type_t *const type = skip_typeref(expression->base.type);
1024                 if (types_compatible(type, type_void_ptr))
1025                         expression = expression->unary.value;
1026         }
1027
1028         type_t *const type = skip_typeref(expression->base.type);
1029         return
1030                 is_type_integer(type)              &&
1031                 is_constant_expression(expression) &&
1032                 fold_constant(expression) == 0;
1033 }
1034
1035 /**
1036  * Create an implicit cast expression.
1037  *
1038  * @param expression  the expression to cast
1039  * @param dest_type   the destination type
1040  */
1041 static expression_t *create_implicit_cast(expression_t *expression,
1042                                           type_t *dest_type)
1043 {
1044         type_t *const source_type = expression->base.type;
1045
1046         if (source_type == dest_type)
1047                 return expression;
1048
1049         return create_cast_expression(expression, dest_type);
1050 }
1051
1052 typedef enum assign_error_t {
1053         ASSIGN_SUCCESS,
1054         ASSIGN_ERROR_INCOMPATIBLE,
1055         ASSIGN_ERROR_POINTER_QUALIFIER_MISSING,
1056         ASSIGN_WARNING_POINTER_INCOMPATIBLE,
1057         ASSIGN_WARNING_POINTER_FROM_INT,
1058         ASSIGN_WARNING_INT_FROM_POINTER
1059 } assign_error_t;
1060
1061 static void report_assign_error(assign_error_t error, type_t *orig_type_left,
1062                                 const expression_t *const right,
1063                                 const char *context,
1064                                 const source_position_t *source_position)
1065 {
1066         type_t *const orig_type_right = right->base.type;
1067         type_t *const type_left       = skip_typeref(orig_type_left);
1068         type_t *const type_right      = skip_typeref(orig_type_right);
1069
1070         switch (error) {
1071         case ASSIGN_SUCCESS:
1072                 return;
1073         case ASSIGN_ERROR_INCOMPATIBLE:
1074                 errorf(source_position,
1075                        "destination type '%T' in %s is incompatible with type '%T'",
1076                        orig_type_left, context, orig_type_right);
1077                 return;
1078
1079         case ASSIGN_ERROR_POINTER_QUALIFIER_MISSING: {
1080                 if (warning.other) {
1081                         type_t *points_to_left  = skip_typeref(type_left->pointer.points_to);
1082                         type_t *points_to_right = skip_typeref(type_right->pointer.points_to);
1083
1084                         /* the left type has all qualifiers from the right type */
1085                         unsigned missing_qualifiers
1086                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
1087                         warningf(source_position,
1088                                         "destination type '%T' in %s from type '%T' lacks qualifiers '%Q' in pointer target type",
1089                                         orig_type_left, context, orig_type_right, missing_qualifiers);
1090                 }
1091                 return;
1092         }
1093
1094         case ASSIGN_WARNING_POINTER_INCOMPATIBLE:
1095                 if (warning.other) {
1096                         warningf(source_position,
1097                                         "destination type '%T' in %s is incompatible with '%E' of type '%T'",
1098                                         orig_type_left, context, right, orig_type_right);
1099                 }
1100                 return;
1101
1102         case ASSIGN_WARNING_POINTER_FROM_INT:
1103                 if (warning.other) {
1104                         warningf(source_position,
1105                                         "%s makes pointer '%T' from integer '%T' without a cast",
1106                                         context, orig_type_left, orig_type_right);
1107                 }
1108                 return;
1109
1110         case ASSIGN_WARNING_INT_FROM_POINTER:
1111                 if (warning.other) {
1112                         warningf(source_position,
1113                                         "%s makes integer '%T' from pointer '%T' without a cast",
1114                                         context, orig_type_left, orig_type_right);
1115                 }
1116                 return;
1117
1118         default:
1119                 panic("invalid error value");
1120         }
1121 }
1122
1123 /** Implements the rules from § 6.5.16.1 */
1124 static assign_error_t semantic_assign(type_t *orig_type_left,
1125                                       const expression_t *const right)
1126 {
1127         type_t *const orig_type_right = right->base.type;
1128         type_t *const type_left       = skip_typeref(orig_type_left);
1129         type_t *const type_right      = skip_typeref(orig_type_right);
1130
1131         if (is_type_pointer(type_left)) {
1132                 if (is_null_pointer_constant(right)) {
1133                         return ASSIGN_SUCCESS;
1134                 } else if (is_type_pointer(type_right)) {
1135                         type_t *points_to_left
1136                                 = skip_typeref(type_left->pointer.points_to);
1137                         type_t *points_to_right
1138                                 = skip_typeref(type_right->pointer.points_to);
1139                         assign_error_t res = ASSIGN_SUCCESS;
1140
1141                         /* the left type has all qualifiers from the right type */
1142                         unsigned missing_qualifiers
1143                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
1144                         if (missing_qualifiers != 0) {
1145                                 res = ASSIGN_ERROR_POINTER_QUALIFIER_MISSING;
1146                         }
1147
1148                         points_to_left  = get_unqualified_type(points_to_left);
1149                         points_to_right = get_unqualified_type(points_to_right);
1150
1151                         if (is_type_atomic(points_to_left, ATOMIC_TYPE_VOID))
1152                                 return res;
1153
1154                         if (is_type_atomic(points_to_right, ATOMIC_TYPE_VOID)) {
1155                                 /* ISO/IEC 14882:1998(E) §C.1.2:6 */
1156                                 return c_mode & _CXX ? ASSIGN_ERROR_INCOMPATIBLE : res;
1157                         }
1158
1159                         if (!types_compatible(points_to_left, points_to_right)) {
1160                                 return ASSIGN_WARNING_POINTER_INCOMPATIBLE;
1161                         }
1162
1163                         return res;
1164                 } else if (is_type_integer(type_right)) {
1165                         return ASSIGN_WARNING_POINTER_FROM_INT;
1166                 }
1167         } else if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
1168             (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
1169                 && is_type_pointer(type_right))) {
1170                 return ASSIGN_SUCCESS;
1171         } else if ((is_type_compound(type_left)  && is_type_compound(type_right))
1172                         || (is_type_builtin(type_left) && is_type_builtin(type_right))) {
1173                 type_t *const unqual_type_left  = get_unqualified_type(type_left);
1174                 type_t *const unqual_type_right = get_unqualified_type(type_right);
1175                 if (types_compatible(unqual_type_left, unqual_type_right)) {
1176                         return ASSIGN_SUCCESS;
1177                 }
1178         } else if (is_type_integer(type_left) && is_type_pointer(type_right)) {
1179                 return ASSIGN_WARNING_INT_FROM_POINTER;
1180         }
1181
1182         if (!is_type_valid(type_left) || !is_type_valid(type_right))
1183                 return ASSIGN_SUCCESS;
1184
1185         return ASSIGN_ERROR_INCOMPATIBLE;
1186 }
1187
1188 static expression_t *parse_constant_expression(void)
1189 {
1190         expression_t *result = parse_sub_expression(PREC_CONDITIONAL);
1191
1192         if (!is_constant_expression(result)) {
1193                 errorf(&result->base.source_position,
1194                        "expression '%E' is not constant", result);
1195         }
1196
1197         return result;
1198 }
1199
1200 static expression_t *parse_assignment_expression(void)
1201 {
1202         return parse_sub_expression(PREC_ASSIGNMENT);
1203 }
1204
1205 static string_t parse_string_literals(void)
1206 {
1207         assert(token.type == T_STRING_LITERAL);
1208         string_t result = token.v.string;
1209
1210         next_token();
1211
1212         while (token.type == T_STRING_LITERAL) {
1213                 result = concat_strings(&result, &token.v.string);
1214                 next_token();
1215         }
1216
1217         return result;
1218 }
1219
1220 static const char *const gnu_attribute_names[GNU_AK_LAST] = {
1221         [GNU_AK_CONST]                  = "const",
1222         [GNU_AK_VOLATILE]               = "volatile",
1223         [GNU_AK_CDECL]                  = "cdecl",
1224         [GNU_AK_STDCALL]                = "stdcall",
1225         [GNU_AK_FASTCALL]               = "fastcall",
1226         [GNU_AK_DEPRECATED]             = "deprecated",
1227         [GNU_AK_NOINLINE]               = "noinline",
1228         [GNU_AK_RETURNS_TWICE]          = "returns_twice",
1229         [GNU_AK_NORETURN]               = "noreturn",
1230         [GNU_AK_NAKED]                  = "naked",
1231         [GNU_AK_PURE]                   = "pure",
1232         [GNU_AK_ALWAYS_INLINE]          = "always_inline",
1233         [GNU_AK_MALLOC]                 = "malloc",
1234         [GNU_AK_WEAK]                   = "weak",
1235         [GNU_AK_CONSTRUCTOR]            = "constructor",
1236         [GNU_AK_DESTRUCTOR]             = "destructor",
1237         [GNU_AK_NOTHROW]                = "nothrow",
1238         [GNU_AK_TRANSPARENT_UNION]      = "transparent_union",
1239         [GNU_AK_COMMON]                 = "common",
1240         [GNU_AK_NOCOMMON]               = "nocommon",
1241         [GNU_AK_PACKED]                 = "packed",
1242         [GNU_AK_SHARED]                 = "shared",
1243         [GNU_AK_NOTSHARED]              = "notshared",
1244         [GNU_AK_USED]                   = "used",
1245         [GNU_AK_UNUSED]                 = "unused",
1246         [GNU_AK_NO_INSTRUMENT_FUNCTION] = "no_instrument_function",
1247         [GNU_AK_WARN_UNUSED_RESULT]     = "warn_unused_result",
1248         [GNU_AK_LONGCALL]               = "longcall",
1249         [GNU_AK_SHORTCALL]              = "shortcall",
1250         [GNU_AK_LONG_CALL]              = "long_call",
1251         [GNU_AK_SHORT_CALL]             = "short_call",
1252         [GNU_AK_FUNCTION_VECTOR]        = "function_vector",
1253         [GNU_AK_INTERRUPT]              = "interrupt",
1254         [GNU_AK_INTERRUPT_HANDLER]      = "interrupt_handler",
1255         [GNU_AK_NMI_HANDLER]            = "nmi_handler",
1256         [GNU_AK_NESTING]                = "nesting",
1257         [GNU_AK_NEAR]                   = "near",
1258         [GNU_AK_FAR]                    = "far",
1259         [GNU_AK_SIGNAL]                 = "signal",
1260         [GNU_AK_EIGTHBIT_DATA]          = "eightbit_data",
1261         [GNU_AK_TINY_DATA]              = "tiny_data",
1262         [GNU_AK_SAVEALL]                = "saveall",
1263         [GNU_AK_FLATTEN]                = "flatten",
1264         [GNU_AK_SSEREGPARM]             = "sseregparm",
1265         [GNU_AK_EXTERNALLY_VISIBLE]     = "externally_visible",
1266         [GNU_AK_RETURN_TWICE]           = "return_twice",
1267         [GNU_AK_MAY_ALIAS]              = "may_alias",
1268         [GNU_AK_MS_STRUCT]              = "ms_struct",
1269         [GNU_AK_GCC_STRUCT]             = "gcc_struct",
1270         [GNU_AK_DLLIMPORT]              = "dllimport",
1271         [GNU_AK_DLLEXPORT]              = "dllexport",
1272         [GNU_AK_ALIGNED]                = "aligned",
1273         [GNU_AK_ALIAS]                  = "alias",
1274         [GNU_AK_SECTION]                = "section",
1275         [GNU_AK_FORMAT]                 = "format",
1276         [GNU_AK_FORMAT_ARG]             = "format_arg",
1277         [GNU_AK_WEAKREF]                = "weakref",
1278         [GNU_AK_NONNULL]                = "nonnull",
1279         [GNU_AK_TLS_MODEL]              = "tls_model",
1280         [GNU_AK_VISIBILITY]             = "visibility",
1281         [GNU_AK_REGPARM]                = "regparm",
1282         [GNU_AK_MODE]                   = "mode",
1283         [GNU_AK_MODEL]                  = "model",
1284         [GNU_AK_TRAP_EXIT]              = "trap_exit",
1285         [GNU_AK_SP_SWITCH]              = "sp_switch",
1286         [GNU_AK_SENTINEL]               = "sentinel"
1287 };
1288
1289 /**
1290  * compare two string, ignoring double underscores on the second.
1291  */
1292 static int strcmp_underscore(const char *s1, const char *s2)
1293 {
1294         if (s2[0] == '_' && s2[1] == '_') {
1295                 size_t len2 = strlen(s2);
1296                 size_t len1 = strlen(s1);
1297                 if (len1 == len2-4 && s2[len2-2] == '_' && s2[len2-1] == '_') {
1298                         return strncmp(s1, s2+2, len2-4);
1299                 }
1300         }
1301
1302         return strcmp(s1, s2);
1303 }
1304
1305 /**
1306  * Allocate a new gnu temporal attribute of given kind.
1307  */
1308 static gnu_attribute_t *allocate_gnu_attribute(gnu_attribute_kind_t kind)
1309 {
1310         gnu_attribute_t *attribute = obstack_alloc(&temp_obst, sizeof(*attribute));
1311         attribute->kind            = kind;
1312         attribute->next            = NULL;
1313         attribute->invalid         = false;
1314         attribute->has_arguments   = false;
1315
1316         return attribute;
1317 }
1318
1319 /**
1320  * Parse one constant expression argument of the given attribute.
1321  */
1322 static void parse_gnu_attribute_const_arg(gnu_attribute_t *attribute)
1323 {
1324         expression_t *expression;
1325         add_anchor_token(')');
1326         expression = parse_constant_expression();
1327         rem_anchor_token(')');
1328         expect(')', end_error);
1329         attribute->u.argument = fold_constant(expression);
1330         return;
1331 end_error:
1332         attribute->invalid = true;
1333 }
1334
1335 /**
1336  * Parse a list of constant expressions arguments of the given attribute.
1337  */
1338 static void parse_gnu_attribute_const_arg_list(gnu_attribute_t *attribute)
1339 {
1340         argument_list_t **list = &attribute->u.arguments;
1341         argument_list_t  *entry;
1342         expression_t     *expression;
1343         add_anchor_token(')');
1344         add_anchor_token(',');
1345         while (true) {
1346                 expression = parse_constant_expression();
1347                 entry = obstack_alloc(&temp_obst, sizeof(entry));
1348                 entry->argument = fold_constant(expression);
1349                 entry->next     = NULL;
1350                 *list = entry;
1351                 list = &entry->next;
1352                 if (token.type != ',')
1353                         break;
1354                 next_token();
1355         }
1356         rem_anchor_token(',');
1357         rem_anchor_token(')');
1358         expect(')', end_error);
1359         return;
1360 end_error:
1361         attribute->invalid = true;
1362 }
1363
1364 /**
1365  * Parse one string literal argument of the given attribute.
1366  */
1367 static void parse_gnu_attribute_string_arg(gnu_attribute_t *attribute,
1368                                            string_t *string)
1369 {
1370         add_anchor_token('(');
1371         if (token.type != T_STRING_LITERAL) {
1372                 parse_error_expected("while parsing attribute directive",
1373                                      T_STRING_LITERAL, NULL);
1374                 goto end_error;
1375         }
1376         *string = parse_string_literals();
1377         rem_anchor_token('(');
1378         expect(')', end_error);
1379         return;
1380 end_error:
1381         attribute->invalid = true;
1382 }
1383
1384 /**
1385  * Parse one tls model of the given attribute.
1386  */
1387 static void parse_gnu_attribute_tls_model_arg(gnu_attribute_t *attribute)
1388 {
1389         static const char *const tls_models[] = {
1390                 "global-dynamic",
1391                 "local-dynamic",
1392                 "initial-exec",
1393                 "local-exec"
1394         };
1395         string_t string = { NULL, 0 };
1396         parse_gnu_attribute_string_arg(attribute, &string);
1397         if (string.begin != NULL) {
1398                 for (size_t i = 0; i < 4; ++i) {
1399                         if (strcmp(tls_models[i], string.begin) == 0) {
1400                                 attribute->u.value = i;
1401                                 return;
1402                         }
1403                 }
1404                 errorf(HERE, "'%s' is an unrecognized tls model", string.begin);
1405         }
1406         attribute->invalid = true;
1407 }
1408
1409 /**
1410  * Parse one tls model of the given attribute.
1411  */
1412 static void parse_gnu_attribute_visibility_arg(gnu_attribute_t *attribute)
1413 {
1414         static const char *const visibilities[] = {
1415                 "default",
1416                 "protected",
1417                 "hidden",
1418                 "internal"
1419         };
1420         string_t string = { NULL, 0 };
1421         parse_gnu_attribute_string_arg(attribute, &string);
1422         if (string.begin != NULL) {
1423                 for (size_t i = 0; i < 4; ++i) {
1424                         if (strcmp(visibilities[i], string.begin) == 0) {
1425                                 attribute->u.value = i;
1426                                 return;
1427                         }
1428                 }
1429                 errorf(HERE, "'%s' is an unrecognized visibility", string.begin);
1430         }
1431         attribute->invalid = true;
1432 }
1433
1434 /**
1435  * Parse one (code) model of the given attribute.
1436  */
1437 static void parse_gnu_attribute_model_arg(gnu_attribute_t *attribute)
1438 {
1439         static const char *const visibilities[] = {
1440                 "small",
1441                 "medium",
1442                 "large"
1443         };
1444         string_t string = { NULL, 0 };
1445         parse_gnu_attribute_string_arg(attribute, &string);
1446         if (string.begin != NULL) {
1447                 for (int i = 0; i < 3; ++i) {
1448                         if (strcmp(visibilities[i], string.begin) == 0) {
1449                                 attribute->u.value = i;
1450                                 return;
1451                         }
1452                 }
1453                 errorf(HERE, "'%s' is an unrecognized model", string.begin);
1454         }
1455         attribute->invalid = true;
1456 }
1457
1458 /**
1459  * Parse one mode of the given attribute.
1460  */
1461 static void parse_gnu_attribute_mode_arg(gnu_attribute_t *attribute)
1462 {
1463         add_anchor_token(')');
1464
1465         if (token.type != T_IDENTIFIER) {
1466                 expect(T_IDENTIFIER, end_error);
1467         }
1468
1469         attribute->u.symbol = token.v.symbol;
1470         next_token();
1471
1472         rem_anchor_token(')');
1473         expect(')', end_error);
1474         return;
1475 end_error:
1476         attribute->invalid = true;
1477 }
1478
1479 /**
1480  * Parse one interrupt argument of the given attribute.
1481  */
1482 static void parse_gnu_attribute_interrupt_arg(gnu_attribute_t *attribute)
1483 {
1484         static const char *const interrupts[] = {
1485                 "IRQ",
1486                 "FIQ",
1487                 "SWI",
1488                 "ABORT",
1489                 "UNDEF"
1490         };
1491         string_t string = { NULL, 0 };
1492         parse_gnu_attribute_string_arg(attribute, &string);
1493         if (string.begin != NULL) {
1494                 for (size_t i = 0; i < 5; ++i) {
1495                         if (strcmp(interrupts[i], string.begin) == 0) {
1496                                 attribute->u.value = i;
1497                                 return;
1498                         }
1499                 }
1500                 errorf(HERE, "'%s' is not an interrupt", string.begin);
1501         }
1502         attribute->invalid = true;
1503 }
1504
1505 /**
1506  * Parse ( identifier, const expression, const expression )
1507  */
1508 static void parse_gnu_attribute_format_args(gnu_attribute_t *attribute)
1509 {
1510         static const char *const format_names[] = {
1511                 "printf",
1512                 "scanf",
1513                 "strftime",
1514                 "strfmon"
1515         };
1516         int i;
1517
1518         if (token.type != T_IDENTIFIER) {
1519                 parse_error_expected("while parsing format attribute directive", T_IDENTIFIER, NULL);
1520                 goto end_error;
1521         }
1522         const char *name = token.v.symbol->string;
1523         for (i = 0; i < 4; ++i) {
1524                 if (strcmp_underscore(format_names[i], name) == 0)
1525                         break;
1526         }
1527         if (i >= 4) {
1528                 if (warning.attribute)
1529                         warningf(HERE, "'%s' is an unrecognized format function type", name);
1530         }
1531         next_token();
1532
1533         expect(',', end_error);
1534         add_anchor_token(')');
1535         add_anchor_token(',');
1536         parse_constant_expression();
1537         rem_anchor_token(',');
1538         rem_anchor_token(')');
1539
1540         expect(',', end_error);
1541         add_anchor_token(')');
1542         parse_constant_expression();
1543         rem_anchor_token(')');
1544         expect(')', end_error);
1545         return;
1546 end_error:
1547         attribute->u.value = true;
1548 }
1549
1550 /**
1551  * Check that a given GNU attribute has no arguments.
1552  */
1553 static void check_no_argument(gnu_attribute_t *attribute, const char *name)
1554 {
1555         if (!attribute->has_arguments)
1556                 return;
1557
1558         /* should have no arguments */
1559         errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1560         eat_until_matching_token('(');
1561         /* we have already consumed '(', so we stop before ')', eat it */
1562         eat(')');
1563         attribute->invalid = true;
1564 }
1565
1566 /**
1567  * Parse one GNU attribute.
1568  *
1569  * Note that attribute names can be specified WITH or WITHOUT
1570  * double underscores, ie const or __const__.
1571  *
1572  * The following attributes are parsed without arguments
1573  *  const
1574  *  volatile
1575  *  cdecl
1576  *  stdcall
1577  *  fastcall
1578  *  deprecated
1579  *  noinline
1580  *  noreturn
1581  *  naked
1582  *  pure
1583  *  always_inline
1584  *  malloc
1585  *  weak
1586  *  constructor
1587  *  destructor
1588  *  nothrow
1589  *  transparent_union
1590  *  common
1591  *  nocommon
1592  *  packed
1593  *  shared
1594  *  notshared
1595  *  used
1596  *  unused
1597  *  no_instrument_function
1598  *  warn_unused_result
1599  *  longcall
1600  *  shortcall
1601  *  long_call
1602  *  short_call
1603  *  function_vector
1604  *  interrupt_handler
1605  *  nmi_handler
1606  *  nesting
1607  *  near
1608  *  far
1609  *  signal
1610  *  eightbit_data
1611  *  tiny_data
1612  *  saveall
1613  *  flatten
1614  *  sseregparm
1615  *  externally_visible
1616  *  return_twice
1617  *  may_alias
1618  *  ms_struct
1619  *  gcc_struct
1620  *  dllimport
1621  *  dllexport
1622  *
1623  * The following attributes are parsed with arguments
1624  *  aligned( const expression )
1625  *  alias( string literal )
1626  *  section( string literal )
1627  *  format( identifier, const expression, const expression )
1628  *  format_arg( const expression )
1629  *  tls_model( string literal )
1630  *  visibility( string literal )
1631  *  regparm( const expression )
1632  *  model( string leteral )
1633  *  trap_exit( const expression )
1634  *  sp_switch( string literal )
1635  *
1636  * The following attributes might have arguments
1637  *  weak_ref( string literal )
1638  *  non_null( const expression // ',' )
1639  *  interrupt( string literal )
1640  *  sentinel( constant expression )
1641  */
1642 static decl_modifiers_t parse_gnu_attribute(gnu_attribute_t **attributes)
1643 {
1644         gnu_attribute_t *head      = *attributes;
1645         gnu_attribute_t *last      = *attributes;
1646         decl_modifiers_t modifiers = 0;
1647         gnu_attribute_t *attribute;
1648
1649         eat(T___attribute__);
1650         expect('(', end_error);
1651         expect('(', end_error);
1652
1653         if (token.type != ')') {
1654                 /* find the end of the list */
1655                 if (last != NULL) {
1656                         while (last->next != NULL)
1657                                 last = last->next;
1658                 }
1659
1660                 /* non-empty attribute list */
1661                 while (true) {
1662                         const char *name;
1663                         if (token.type == T_const) {
1664                                 name = "const";
1665                         } else if (token.type == T_volatile) {
1666                                 name = "volatile";
1667                         } else if (token.type == T_cdecl) {
1668                                 /* __attribute__((cdecl)), WITH ms mode */
1669                                 name = "cdecl";
1670                         } else if (token.type == T_IDENTIFIER) {
1671                                 const symbol_t *sym = token.v.symbol;
1672                                 name = sym->string;
1673                         } else {
1674                                 parse_error_expected("while parsing GNU attribute", T_IDENTIFIER, NULL);
1675                                 break;
1676                         }
1677
1678                         next_token();
1679
1680                         int i;
1681                         for (i = 0; i < GNU_AK_LAST; ++i) {
1682                                 if (strcmp_underscore(gnu_attribute_names[i], name) == 0)
1683                                         break;
1684                         }
1685                         gnu_attribute_kind_t kind = (gnu_attribute_kind_t)i;
1686
1687                         attribute = NULL;
1688                         if (kind == GNU_AK_LAST) {
1689                                 if (warning.attribute)
1690                                         warningf(HERE, "'%s' attribute directive ignored", name);
1691
1692                                 /* skip possible arguments */
1693                                 if (token.type == '(') {
1694                                         eat_until_matching_token(')');
1695                                 }
1696                         } else {
1697                                 /* check for arguments */
1698                                 attribute = allocate_gnu_attribute(kind);
1699                                 if (token.type == '(') {
1700                                         next_token();
1701                                         if (token.type == ')') {
1702                                                 /* empty args are allowed */
1703                                                 next_token();
1704                                         } else
1705                                                 attribute->has_arguments = true;
1706                                 }
1707
1708                                 switch (kind) {
1709                                 case GNU_AK_VOLATILE:
1710                                 case GNU_AK_NAKED:
1711                                 case GNU_AK_MALLOC:
1712                                 case GNU_AK_WEAK:
1713                                 case GNU_AK_COMMON:
1714                                 case GNU_AK_NOCOMMON:
1715                                 case GNU_AK_SHARED:
1716                                 case GNU_AK_NOTSHARED:
1717                                 case GNU_AK_NO_INSTRUMENT_FUNCTION:
1718                                 case GNU_AK_WARN_UNUSED_RESULT:
1719                                 case GNU_AK_LONGCALL:
1720                                 case GNU_AK_SHORTCALL:
1721                                 case GNU_AK_LONG_CALL:
1722                                 case GNU_AK_SHORT_CALL:
1723                                 case GNU_AK_FUNCTION_VECTOR:
1724                                 case GNU_AK_INTERRUPT_HANDLER:
1725                                 case GNU_AK_NMI_HANDLER:
1726                                 case GNU_AK_NESTING:
1727                                 case GNU_AK_NEAR:
1728                                 case GNU_AK_FAR:
1729                                 case GNU_AK_SIGNAL:
1730                                 case GNU_AK_EIGTHBIT_DATA:
1731                                 case GNU_AK_TINY_DATA:
1732                                 case GNU_AK_SAVEALL:
1733                                 case GNU_AK_FLATTEN:
1734                                 case GNU_AK_SSEREGPARM:
1735                                 case GNU_AK_EXTERNALLY_VISIBLE:
1736                                 case GNU_AK_RETURN_TWICE:
1737                                 case GNU_AK_MAY_ALIAS:
1738                                 case GNU_AK_MS_STRUCT:
1739                                 case GNU_AK_GCC_STRUCT:
1740                                         goto no_arg;
1741
1742                                 case GNU_AK_CDECL:             modifiers |= DM_CDECL;             goto no_arg;
1743                                 case GNU_AK_FASTCALL:          modifiers |= DM_FASTCALL;          goto no_arg;
1744                                 case GNU_AK_STDCALL:           modifiers |= DM_STDCALL;           goto no_arg;
1745                                 case GNU_AK_UNUSED:            modifiers |= DM_UNUSED;            goto no_arg;
1746                                 case GNU_AK_USED:              modifiers |= DM_USED;              goto no_arg;
1747                                 case GNU_AK_PURE:              modifiers |= DM_PURE;              goto no_arg;
1748                                 case GNU_AK_CONST:             modifiers |= DM_CONST;             goto no_arg;
1749                                 case GNU_AK_ALWAYS_INLINE:     modifiers |= DM_FORCEINLINE;       goto no_arg;
1750                                 case GNU_AK_DLLIMPORT:         modifiers |= DM_DLLIMPORT;         goto no_arg;
1751                                 case GNU_AK_DLLEXPORT:         modifiers |= DM_DLLEXPORT;         goto no_arg;
1752                                 case GNU_AK_PACKED:            modifiers |= DM_PACKED;            goto no_arg;
1753                                 case GNU_AK_NOINLINE:          modifiers |= DM_NOINLINE;          goto no_arg;
1754                                 case GNU_AK_RETURNS_TWICE:     modifiers |= DM_RETURNS_TWICE;     goto no_arg;
1755                                 case GNU_AK_NORETURN:          modifiers |= DM_NORETURN;          goto no_arg;
1756                                 case GNU_AK_NOTHROW:           modifiers |= DM_NOTHROW;           goto no_arg;
1757                                 case GNU_AK_TRANSPARENT_UNION: modifiers |= DM_TRANSPARENT_UNION; goto no_arg;
1758                                 case GNU_AK_CONSTRUCTOR:       modifiers |= DM_CONSTRUCTOR;       goto no_arg;
1759                                 case GNU_AK_DESTRUCTOR:        modifiers |= DM_DESTRUCTOR;        goto no_arg;
1760                                 case GNU_AK_DEPRECATED:        modifiers |= DM_DEPRECATED;        goto no_arg;
1761
1762                                 case GNU_AK_ALIGNED:
1763                                         /* __align__ may be used without an argument */
1764                                         if (attribute->has_arguments) {
1765                                                 parse_gnu_attribute_const_arg(attribute);
1766                                         }
1767                                         break;
1768
1769                                 case GNU_AK_FORMAT_ARG:
1770                                 case GNU_AK_REGPARM:
1771                                 case GNU_AK_TRAP_EXIT:
1772                                         if (!attribute->has_arguments) {
1773                                                 /* should have arguments */
1774                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1775                                                 attribute->invalid = true;
1776                                         } else
1777                                                 parse_gnu_attribute_const_arg(attribute);
1778                                         break;
1779                                 case GNU_AK_ALIAS:
1780                                 case GNU_AK_SECTION:
1781                                 case GNU_AK_SP_SWITCH:
1782                                         if (!attribute->has_arguments) {
1783                                                 /* should have arguments */
1784                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1785                                                 attribute->invalid = true;
1786                                         } else
1787                                                 parse_gnu_attribute_string_arg(attribute, &attribute->u.string);
1788                                         break;
1789                                 case GNU_AK_FORMAT:
1790                                         if (!attribute->has_arguments) {
1791                                                 /* should have arguments */
1792                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1793                                                 attribute->invalid = true;
1794                                         } else
1795                                                 parse_gnu_attribute_format_args(attribute);
1796                                         break;
1797                                 case GNU_AK_WEAKREF:
1798                                         /* may have one string argument */
1799                                         if (attribute->has_arguments)
1800                                                 parse_gnu_attribute_string_arg(attribute, &attribute->u.string);
1801                                         break;
1802                                 case GNU_AK_NONNULL:
1803                                         if (attribute->has_arguments)
1804                                                 parse_gnu_attribute_const_arg_list(attribute);
1805                                         break;
1806                                 case GNU_AK_TLS_MODEL:
1807                                         if (!attribute->has_arguments) {
1808                                                 /* should have arguments */
1809                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1810                                         } else
1811                                                 parse_gnu_attribute_tls_model_arg(attribute);
1812                                         break;
1813                                 case GNU_AK_VISIBILITY:
1814                                         if (!attribute->has_arguments) {
1815                                                 /* should have arguments */
1816                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1817                                         } else
1818                                                 parse_gnu_attribute_visibility_arg(attribute);
1819                                         break;
1820                                 case GNU_AK_MODEL:
1821                                         if (!attribute->has_arguments) {
1822                                                 /* should have arguments */
1823                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1824                                         } else {
1825                                                 parse_gnu_attribute_model_arg(attribute);
1826                                         }
1827                                         break;
1828                                 case GNU_AK_MODE:
1829                                         if (!attribute->has_arguments) {
1830                                                 /* should have arguments */
1831                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1832                                         } else {
1833                                                 parse_gnu_attribute_mode_arg(attribute);
1834                                         }
1835                                         break;
1836                                 case GNU_AK_INTERRUPT:
1837                                         /* may have one string argument */
1838                                         if (attribute->has_arguments)
1839                                                 parse_gnu_attribute_interrupt_arg(attribute);
1840                                         break;
1841                                 case GNU_AK_SENTINEL:
1842                                         /* may have one string argument */
1843                                         if (attribute->has_arguments)
1844                                                 parse_gnu_attribute_const_arg(attribute);
1845                                         break;
1846                                 case GNU_AK_LAST:
1847                                         /* already handled */
1848                                         break;
1849
1850 no_arg:
1851                                         check_no_argument(attribute, name);
1852                                 }
1853                         }
1854                         if (attribute != NULL) {
1855                                 if (last != NULL) {
1856                                         last->next = attribute;
1857                                         last       = attribute;
1858                                 } else {
1859                                         head = last = attribute;
1860                                 }
1861                         }
1862
1863                         if (token.type != ',')
1864                                 break;
1865                         next_token();
1866                 }
1867         }
1868         expect(')', end_error);
1869         expect(')', end_error);
1870 end_error:
1871         *attributes = head;
1872
1873         return modifiers;
1874 }
1875
1876 /**
1877  * Parse GNU attributes.
1878  */
1879 static decl_modifiers_t parse_attributes(gnu_attribute_t **attributes)
1880 {
1881         decl_modifiers_t modifiers = 0;
1882
1883         while (true) {
1884                 switch (token.type) {
1885                 case T___attribute__:
1886                         modifiers |= parse_gnu_attribute(attributes);
1887                         continue;
1888
1889                 case T_asm:
1890                         next_token();
1891                         expect('(', end_error);
1892                         if (token.type != T_STRING_LITERAL) {
1893                                 parse_error_expected("while parsing assembler attribute",
1894                                                      T_STRING_LITERAL, NULL);
1895                                 eat_until_matching_token('(');
1896                                 break;
1897                         } else {
1898                                 parse_string_literals();
1899                         }
1900                         expect(')', end_error);
1901                         continue;
1902
1903                 case T_cdecl:     modifiers |= DM_CDECL;    break;
1904                 case T__fastcall: modifiers |= DM_FASTCALL; break;
1905                 case T__stdcall:  modifiers |= DM_STDCALL;  break;
1906
1907                 case T___thiscall:
1908                         /* TODO record modifier */
1909                         if (warning.other)
1910                                 warningf(HERE, "Ignoring declaration modifier %K", &token);
1911                         break;
1912
1913 end_error:
1914                 default: return modifiers;
1915                 }
1916
1917                 next_token();
1918         }
1919 }
1920
1921 static void mark_vars_read(expression_t *expr, entity_t *lhs_ent);
1922
1923 static entity_t *determine_lhs_ent(expression_t *const expr,
1924                                    entity_t *lhs_ent)
1925 {
1926         switch (expr->kind) {
1927                 case EXPR_REFERENCE: {
1928                         entity_t *const entity = expr->reference.entity;
1929                         /* we should only find variables as lvalues... */
1930                         if (entity->base.kind != ENTITY_VARIABLE
1931                                         && entity->base.kind != ENTITY_PARAMETER)
1932                                 return NULL;
1933
1934                         return entity;
1935                 }
1936
1937                 case EXPR_ARRAY_ACCESS: {
1938                         expression_t *const ref = expr->array_access.array_ref;
1939                         entity_t     *      ent = NULL;
1940                         if (is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1941                                 ent     = determine_lhs_ent(ref, lhs_ent);
1942                                 lhs_ent = ent;
1943                         } else {
1944                                 mark_vars_read(expr->select.compound, lhs_ent);
1945                         }
1946                         mark_vars_read(expr->array_access.index, lhs_ent);
1947                         return ent;
1948                 }
1949
1950                 case EXPR_SELECT: {
1951                         if (is_type_compound(skip_typeref(expr->base.type))) {
1952                                 return determine_lhs_ent(expr->select.compound, lhs_ent);
1953                         } else {
1954                                 mark_vars_read(expr->select.compound, lhs_ent);
1955                                 return NULL;
1956                         }
1957                 }
1958
1959                 case EXPR_UNARY_DEREFERENCE: {
1960                         expression_t *const val = expr->unary.value;
1961                         if (val->kind == EXPR_UNARY_TAKE_ADDRESS) {
1962                                 /* *&x is a NOP */
1963                                 return determine_lhs_ent(val->unary.value, lhs_ent);
1964                         } else {
1965                                 mark_vars_read(val, NULL);
1966                                 return NULL;
1967                         }
1968                 }
1969
1970                 default:
1971                         mark_vars_read(expr, NULL);
1972                         return NULL;
1973         }
1974 }
1975
1976 #define ENT_ANY ((entity_t*)-1)
1977
1978 /**
1979  * Mark declarations, which are read.  This is used to detect variables, which
1980  * are never read.
1981  * Example:
1982  * x = x + 1;
1983  *   x is not marked as "read", because it is only read to calculate its own new
1984  *   value.
1985  *
1986  * x += y; y += x;
1987  *   x and y are not detected as "not read", because multiple variables are
1988  *   involved.
1989  */
1990 static void mark_vars_read(expression_t *const expr, entity_t *lhs_ent)
1991 {
1992         switch (expr->kind) {
1993                 case EXPR_REFERENCE: {
1994                         entity_t *const entity = expr->reference.entity;
1995                         if (entity->kind != ENTITY_VARIABLE
1996                                         && entity->kind != ENTITY_PARAMETER)
1997                                 return;
1998
1999                         if (lhs_ent != entity && lhs_ent != ENT_ANY) {
2000                                 if (entity->kind == ENTITY_VARIABLE) {
2001                                         entity->variable.read = true;
2002                                 } else {
2003                                         entity->parameter.read = true;
2004                                 }
2005                         }
2006                         return;
2007                 }
2008
2009                 case EXPR_CALL:
2010                         // TODO respect pure/const
2011                         mark_vars_read(expr->call.function, NULL);
2012                         for (call_argument_t *arg = expr->call.arguments; arg != NULL; arg = arg->next) {
2013                                 mark_vars_read(arg->expression, NULL);
2014                         }
2015                         return;
2016
2017                 case EXPR_CONDITIONAL:
2018                         // TODO lhs_decl should depend on whether true/false have an effect
2019                         mark_vars_read(expr->conditional.condition, NULL);
2020                         if (expr->conditional.true_expression != NULL)
2021                                 mark_vars_read(expr->conditional.true_expression, lhs_ent);
2022                         mark_vars_read(expr->conditional.false_expression, lhs_ent);
2023                         return;
2024
2025                 case EXPR_SELECT:
2026                         if (lhs_ent == ENT_ANY
2027                                         && !is_type_compound(skip_typeref(expr->base.type)))
2028                                 lhs_ent = NULL;
2029                         mark_vars_read(expr->select.compound, lhs_ent);
2030                         return;
2031
2032                 case EXPR_ARRAY_ACCESS: {
2033                         expression_t *const ref = expr->array_access.array_ref;
2034                         mark_vars_read(ref, lhs_ent);
2035                         lhs_ent = determine_lhs_ent(ref, lhs_ent);
2036                         mark_vars_read(expr->array_access.index, lhs_ent);
2037                         return;
2038                 }
2039
2040                 case EXPR_VA_ARG:
2041                         mark_vars_read(expr->va_arge.ap, lhs_ent);
2042                         return;
2043
2044                 case EXPR_UNARY_CAST:
2045                         /* Special case: Use void cast to mark a variable as "read" */
2046                         if (is_type_atomic(skip_typeref(expr->base.type), ATOMIC_TYPE_VOID))
2047                                 lhs_ent = NULL;
2048                         goto unary;
2049
2050
2051                 case EXPR_UNARY_THROW:
2052                         if (expr->unary.value == NULL)
2053                                 return;
2054                         /* FALLTHROUGH */
2055                 case EXPR_UNARY_DEREFERENCE:
2056                 case EXPR_UNARY_DELETE:
2057                 case EXPR_UNARY_DELETE_ARRAY:
2058                         if (lhs_ent == ENT_ANY)
2059                                 lhs_ent = NULL;
2060                         goto unary;
2061
2062                 case EXPR_UNARY_NEGATE:
2063                 case EXPR_UNARY_PLUS:
2064                 case EXPR_UNARY_BITWISE_NEGATE:
2065                 case EXPR_UNARY_NOT:
2066                 case EXPR_UNARY_TAKE_ADDRESS:
2067                 case EXPR_UNARY_POSTFIX_INCREMENT:
2068                 case EXPR_UNARY_POSTFIX_DECREMENT:
2069                 case EXPR_UNARY_PREFIX_INCREMENT:
2070                 case EXPR_UNARY_PREFIX_DECREMENT:
2071                 case EXPR_UNARY_CAST_IMPLICIT:
2072                 case EXPR_UNARY_ASSUME:
2073 unary:
2074                         mark_vars_read(expr->unary.value, lhs_ent);
2075                         return;
2076
2077                 case EXPR_BINARY_ADD:
2078                 case EXPR_BINARY_SUB:
2079                 case EXPR_BINARY_MUL:
2080                 case EXPR_BINARY_DIV:
2081                 case EXPR_BINARY_MOD:
2082                 case EXPR_BINARY_EQUAL:
2083                 case EXPR_BINARY_NOTEQUAL:
2084                 case EXPR_BINARY_LESS:
2085                 case EXPR_BINARY_LESSEQUAL:
2086                 case EXPR_BINARY_GREATER:
2087                 case EXPR_BINARY_GREATEREQUAL:
2088                 case EXPR_BINARY_BITWISE_AND:
2089                 case EXPR_BINARY_BITWISE_OR:
2090                 case EXPR_BINARY_BITWISE_XOR:
2091                 case EXPR_BINARY_LOGICAL_AND:
2092                 case EXPR_BINARY_LOGICAL_OR:
2093                 case EXPR_BINARY_SHIFTLEFT:
2094                 case EXPR_BINARY_SHIFTRIGHT:
2095                 case EXPR_BINARY_COMMA:
2096                 case EXPR_BINARY_ISGREATER:
2097                 case EXPR_BINARY_ISGREATEREQUAL:
2098                 case EXPR_BINARY_ISLESS:
2099                 case EXPR_BINARY_ISLESSEQUAL:
2100                 case EXPR_BINARY_ISLESSGREATER:
2101                 case EXPR_BINARY_ISUNORDERED:
2102                         mark_vars_read(expr->binary.left,  lhs_ent);
2103                         mark_vars_read(expr->binary.right, lhs_ent);
2104                         return;
2105
2106                 case EXPR_BINARY_ASSIGN:
2107                 case EXPR_BINARY_MUL_ASSIGN:
2108                 case EXPR_BINARY_DIV_ASSIGN:
2109                 case EXPR_BINARY_MOD_ASSIGN:
2110                 case EXPR_BINARY_ADD_ASSIGN:
2111                 case EXPR_BINARY_SUB_ASSIGN:
2112                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:
2113                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:
2114                 case EXPR_BINARY_BITWISE_AND_ASSIGN:
2115                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:
2116                 case EXPR_BINARY_BITWISE_OR_ASSIGN: {
2117                         if (lhs_ent == ENT_ANY)
2118                                 lhs_ent = NULL;
2119                         lhs_ent = determine_lhs_ent(expr->binary.left, lhs_ent);
2120                         mark_vars_read(expr->binary.right, lhs_ent);
2121                         return;
2122                 }
2123
2124                 case EXPR_VA_START:
2125                         determine_lhs_ent(expr->va_starte.ap, lhs_ent);
2126                         return;
2127
2128                 case EXPR_UNKNOWN:
2129                 case EXPR_INVALID:
2130                 case EXPR_CONST:
2131                 case EXPR_CHARACTER_CONSTANT:
2132                 case EXPR_WIDE_CHARACTER_CONSTANT:
2133                 case EXPR_STRING_LITERAL:
2134                 case EXPR_WIDE_STRING_LITERAL:
2135                 case EXPR_COMPOUND_LITERAL: // TODO init?
2136                 case EXPR_SIZEOF:
2137                 case EXPR_CLASSIFY_TYPE:
2138                 case EXPR_ALIGNOF:
2139                 case EXPR_FUNCNAME:
2140                 case EXPR_BUILTIN_SYMBOL:
2141                 case EXPR_BUILTIN_CONSTANT_P:
2142                 case EXPR_BUILTIN_PREFETCH:
2143                 case EXPR_OFFSETOF:
2144                 case EXPR_STATEMENT: // TODO
2145                 case EXPR_LABEL_ADDRESS:
2146                 case EXPR_REFERENCE_ENUM_VALUE:
2147                         return;
2148         }
2149
2150         panic("unhandled expression");
2151 }
2152
2153 static designator_t *parse_designation(void)
2154 {
2155         designator_t *result = NULL;
2156         designator_t *last   = NULL;
2157
2158         while (true) {
2159                 designator_t *designator;
2160                 switch (token.type) {
2161                 case '[':
2162                         designator = allocate_ast_zero(sizeof(designator[0]));
2163                         designator->source_position = token.source_position;
2164                         next_token();
2165                         add_anchor_token(']');
2166                         designator->array_index = parse_constant_expression();
2167                         rem_anchor_token(']');
2168                         expect(']', end_error);
2169                         break;
2170                 case '.':
2171                         designator = allocate_ast_zero(sizeof(designator[0]));
2172                         designator->source_position = token.source_position;
2173                         next_token();
2174                         if (token.type != T_IDENTIFIER) {
2175                                 parse_error_expected("while parsing designator",
2176                                                      T_IDENTIFIER, NULL);
2177                                 return NULL;
2178                         }
2179                         designator->symbol = token.v.symbol;
2180                         next_token();
2181                         break;
2182                 default:
2183                         expect('=', end_error);
2184                         return result;
2185                 }
2186
2187                 assert(designator != NULL);
2188                 if (last != NULL) {
2189                         last->next = designator;
2190                 } else {
2191                         result = designator;
2192                 }
2193                 last = designator;
2194         }
2195 end_error:
2196         return NULL;
2197 }
2198
2199 static initializer_t *initializer_from_string(array_type_t *type,
2200                                               const string_t *const string)
2201 {
2202         /* TODO: check len vs. size of array type */
2203         (void) type;
2204
2205         initializer_t *initializer = allocate_initializer_zero(INITIALIZER_STRING);
2206         initializer->string.string = *string;
2207
2208         return initializer;
2209 }
2210
2211 static initializer_t *initializer_from_wide_string(array_type_t *const type,
2212                                                    wide_string_t *const string)
2213 {
2214         /* TODO: check len vs. size of array type */
2215         (void) type;
2216
2217         initializer_t *const initializer =
2218                 allocate_initializer_zero(INITIALIZER_WIDE_STRING);
2219         initializer->wide_string.string = *string;
2220
2221         return initializer;
2222 }
2223
2224 /**
2225  * Build an initializer from a given expression.
2226  */
2227 static initializer_t *initializer_from_expression(type_t *orig_type,
2228                                                   expression_t *expression)
2229 {
2230         /* TODO check that expression is a constant expression */
2231
2232         /* § 6.7.8.14/15 char array may be initialized by string literals */
2233         type_t *type           = skip_typeref(orig_type);
2234         type_t *expr_type_orig = expression->base.type;
2235         type_t *expr_type      = skip_typeref(expr_type_orig);
2236         if (is_type_array(type) && expr_type->kind == TYPE_POINTER) {
2237                 array_type_t *const array_type   = &type->array;
2238                 type_t       *const element_type = skip_typeref(array_type->element_type);
2239
2240                 if (element_type->kind == TYPE_ATOMIC) {
2241                         atomic_type_kind_t akind = element_type->atomic.akind;
2242                         switch (expression->kind) {
2243                                 case EXPR_STRING_LITERAL:
2244                                         if (akind == ATOMIC_TYPE_CHAR
2245                                                         || akind == ATOMIC_TYPE_SCHAR
2246                                                         || akind == ATOMIC_TYPE_UCHAR) {
2247                                                 return initializer_from_string(array_type,
2248                                                         &expression->string.value);
2249                                         }
2250                                         break;
2251
2252                                 case EXPR_WIDE_STRING_LITERAL: {
2253                                         type_t *bare_wchar_type = skip_typeref(type_wchar_t);
2254                                         if (get_unqualified_type(element_type) == bare_wchar_type) {
2255                                                 return initializer_from_wide_string(array_type,
2256                                                         &expression->wide_string.value);
2257                                         }
2258                                         break;
2259                                 }
2260
2261                                 default:
2262                                         break;
2263                         }
2264                 }
2265         }
2266
2267         assign_error_t error = semantic_assign(type, expression);
2268         if (error == ASSIGN_ERROR_INCOMPATIBLE)
2269                 return NULL;
2270         report_assign_error(error, type, expression, "initializer",
2271                             &expression->base.source_position);
2272
2273         initializer_t *const result = allocate_initializer_zero(INITIALIZER_VALUE);
2274 #if 0
2275         if (type->kind == TYPE_BITFIELD) {
2276                 type = type->bitfield.base_type;
2277         }
2278 #endif
2279         result->value.value = create_implicit_cast(expression, type);
2280
2281         return result;
2282 }
2283
2284 /**
2285  * Checks if a given expression can be used as an constant initializer.
2286  */
2287 static bool is_initializer_constant(const expression_t *expression)
2288 {
2289         return is_constant_expression(expression)
2290                 || is_address_constant(expression);
2291 }
2292
2293 /**
2294  * Parses an scalar initializer.
2295  *
2296  * § 6.7.8.11; eat {} without warning
2297  */
2298 static initializer_t *parse_scalar_initializer(type_t *type,
2299                                                bool must_be_constant)
2300 {
2301         /* there might be extra {} hierarchies */
2302         int braces = 0;
2303         if (token.type == '{') {
2304                 if (warning.other)
2305                         warningf(HERE, "extra curly braces around scalar initializer");
2306                 do {
2307                         ++braces;
2308                         next_token();
2309                 } while (token.type == '{');
2310         }
2311
2312         expression_t *expression = parse_assignment_expression();
2313         mark_vars_read(expression, NULL);
2314         if (must_be_constant && !is_initializer_constant(expression)) {
2315                 errorf(&expression->base.source_position,
2316                        "Initialisation expression '%E' is not constant",
2317                        expression);
2318         }
2319
2320         initializer_t *initializer = initializer_from_expression(type, expression);
2321
2322         if (initializer == NULL) {
2323                 errorf(&expression->base.source_position,
2324                        "expression '%E' (type '%T') doesn't match expected type '%T'",
2325                        expression, expression->base.type, type);
2326                 /* TODO */
2327                 return NULL;
2328         }
2329
2330         bool additional_warning_displayed = false;
2331         while (braces > 0) {
2332                 if (token.type == ',') {
2333                         next_token();
2334                 }
2335                 if (token.type != '}') {
2336                         if (!additional_warning_displayed && warning.other) {
2337                                 warningf(HERE, "additional elements in scalar initializer");
2338                                 additional_warning_displayed = true;
2339                         }
2340                 }
2341                 eat_block();
2342                 braces--;
2343         }
2344
2345         return initializer;
2346 }
2347
2348 /**
2349  * An entry in the type path.
2350  */
2351 typedef struct type_path_entry_t type_path_entry_t;
2352 struct type_path_entry_t {
2353         type_t *type;       /**< the upper top type. restored to path->top_tye if this entry is popped. */
2354         union {
2355                 size_t         index;          /**< For array types: the current index. */
2356                 declaration_t *compound_entry; /**< For compound types: the current declaration. */
2357         } v;
2358 };
2359
2360 /**
2361  * A type path expression a position inside compound or array types.
2362  */
2363 typedef struct type_path_t type_path_t;
2364 struct type_path_t {
2365         type_path_entry_t *path;         /**< An flexible array containing the current path. */
2366         type_t            *top_type;     /**< type of the element the path points */
2367         size_t             max_index;    /**< largest index in outermost array */
2368 };
2369
2370 /**
2371  * Prints a type path for debugging.
2372  */
2373 static __attribute__((unused)) void debug_print_type_path(
2374                 const type_path_t *path)
2375 {
2376         size_t len = ARR_LEN(path->path);
2377
2378         for (size_t i = 0; i < len; ++i) {
2379                 const type_path_entry_t *entry = & path->path[i];
2380
2381                 type_t *type = skip_typeref(entry->type);
2382                 if (is_type_compound(type)) {
2383                         /* in gcc mode structs can have no members */
2384                         if (entry->v.compound_entry == NULL) {
2385                                 assert(i == len-1);
2386                                 continue;
2387                         }
2388                         fprintf(stderr, ".%s",
2389                                 entry->v.compound_entry->base.symbol->string);
2390                 } else if (is_type_array(type)) {
2391                         fprintf(stderr, "[%u]", (unsigned) entry->v.index);
2392                 } else {
2393                         fprintf(stderr, "-INVALID-");
2394                 }
2395         }
2396         if (path->top_type != NULL) {
2397                 fprintf(stderr, "  (");
2398                 print_type(path->top_type);
2399                 fprintf(stderr, ")");
2400         }
2401 }
2402
2403 /**
2404  * Return the top type path entry, ie. in a path
2405  * (type).a.b returns the b.
2406  */
2407 static type_path_entry_t *get_type_path_top(const type_path_t *path)
2408 {
2409         size_t len = ARR_LEN(path->path);
2410         assert(len > 0);
2411         return &path->path[len-1];
2412 }
2413
2414 /**
2415  * Enlarge the type path by an (empty) element.
2416  */
2417 static type_path_entry_t *append_to_type_path(type_path_t *path)
2418 {
2419         size_t len = ARR_LEN(path->path);
2420         ARR_RESIZE(type_path_entry_t, path->path, len+1);
2421
2422         type_path_entry_t *result = & path->path[len];
2423         memset(result, 0, sizeof(result[0]));
2424         return result;
2425 }
2426
2427 /**
2428  * Descending into a sub-type. Enter the scope of the current top_type.
2429  */
2430 static void descend_into_subtype(type_path_t *path)
2431 {
2432         type_t *orig_top_type = path->top_type;
2433         type_t *top_type      = skip_typeref(orig_top_type);
2434
2435         type_path_entry_t *top = append_to_type_path(path);
2436         top->type              = top_type;
2437
2438         if (is_type_compound(top_type)) {
2439                 compound_t *compound  = top_type->compound.compound;
2440                 entity_t   *entry     = compound->members.entities;
2441
2442                 if (entry != NULL) {
2443                         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
2444                         top->v.compound_entry = &entry->declaration;
2445                         path->top_type = entry->declaration.type;
2446                 } else {
2447                         path->top_type = NULL;
2448                 }
2449         } else if (is_type_array(top_type)) {
2450                 top->v.index   = 0;
2451                 path->top_type = top_type->array.element_type;
2452         } else {
2453                 assert(!is_type_valid(top_type));
2454         }
2455 }
2456
2457 /**
2458  * Pop an entry from the given type path, ie. returning from
2459  * (type).a.b to (type).a
2460  */
2461 static void ascend_from_subtype(type_path_t *path)
2462 {
2463         type_path_entry_t *top = get_type_path_top(path);
2464
2465         path->top_type = top->type;
2466
2467         size_t len = ARR_LEN(path->path);
2468         ARR_RESIZE(type_path_entry_t, path->path, len-1);
2469 }
2470
2471 /**
2472  * Pop entries from the given type path until the given
2473  * path level is reached.
2474  */
2475 static void ascend_to(type_path_t *path, size_t top_path_level)
2476 {
2477         size_t len = ARR_LEN(path->path);
2478
2479         while (len > top_path_level) {
2480                 ascend_from_subtype(path);
2481                 len = ARR_LEN(path->path);
2482         }
2483 }
2484
2485 static bool walk_designator(type_path_t *path, const designator_t *designator,
2486                             bool used_in_offsetof)
2487 {
2488         for (; designator != NULL; designator = designator->next) {
2489                 type_path_entry_t *top       = get_type_path_top(path);
2490                 type_t            *orig_type = top->type;
2491
2492                 type_t *type = skip_typeref(orig_type);
2493
2494                 if (designator->symbol != NULL) {
2495                         symbol_t *symbol = designator->symbol;
2496                         if (!is_type_compound(type)) {
2497                                 if (is_type_valid(type)) {
2498                                         errorf(&designator->source_position,
2499                                                "'.%Y' designator used for non-compound type '%T'",
2500                                                symbol, orig_type);
2501                                 }
2502
2503                                 top->type             = type_error_type;
2504                                 top->v.compound_entry = NULL;
2505                                 orig_type             = type_error_type;
2506                         } else {
2507                                 compound_t *compound = type->compound.compound;
2508                                 entity_t   *iter     = compound->members.entities;
2509                                 for (; iter != NULL; iter = iter->base.next) {
2510                                         if (iter->base.symbol == symbol) {
2511                                                 break;
2512                                         }
2513                                 }
2514                                 if (iter == NULL) {
2515                                         errorf(&designator->source_position,
2516                                                "'%T' has no member named '%Y'", orig_type, symbol);
2517                                         goto failed;
2518                                 }
2519                                 assert(iter->kind == ENTITY_COMPOUND_MEMBER);
2520                                 if (used_in_offsetof) {
2521                                         type_t *real_type = skip_typeref(iter->declaration.type);
2522                                         if (real_type->kind == TYPE_BITFIELD) {
2523                                                 errorf(&designator->source_position,
2524                                                        "offsetof designator '%Y' may not specify bitfield",
2525                                                        symbol);
2526                                                 goto failed;
2527                                         }
2528                                 }
2529
2530                                 top->type             = orig_type;
2531                                 top->v.compound_entry = &iter->declaration;
2532                                 orig_type             = iter->declaration.type;
2533                         }
2534                 } else {
2535                         expression_t *array_index = designator->array_index;
2536                         assert(designator->array_index != NULL);
2537
2538                         if (!is_type_array(type)) {
2539                                 if (is_type_valid(type)) {
2540                                         errorf(&designator->source_position,
2541                                                "[%E] designator used for non-array type '%T'",
2542                                                array_index, orig_type);
2543                                 }
2544                                 goto failed;
2545                         }
2546
2547                         long index = fold_constant(array_index);
2548                         if (!used_in_offsetof) {
2549                                 if (index < 0) {
2550                                         errorf(&designator->source_position,
2551                                                "array index [%E] must be positive", array_index);
2552                                 } else if (type->array.size_constant) {
2553                                         long array_size = type->array.size;
2554                                         if (index >= array_size) {
2555                                                 errorf(&designator->source_position,
2556                                                        "designator [%E] (%d) exceeds array size %d",
2557                                                        array_index, index, array_size);
2558                                         }
2559                                 }
2560                         }
2561
2562                         top->type    = orig_type;
2563                         top->v.index = (size_t) index;
2564                         orig_type    = type->array.element_type;
2565                 }
2566                 path->top_type = orig_type;
2567
2568                 if (designator->next != NULL) {
2569                         descend_into_subtype(path);
2570                 }
2571         }
2572         return true;
2573
2574 failed:
2575         return false;
2576 }
2577
2578 static void advance_current_object(type_path_t *path, size_t top_path_level)
2579 {
2580         type_path_entry_t *top = get_type_path_top(path);
2581
2582         type_t *type = skip_typeref(top->type);
2583         if (is_type_union(type)) {
2584                 /* in unions only the first element is initialized */
2585                 top->v.compound_entry = NULL;
2586         } else if (is_type_struct(type)) {
2587                 declaration_t *entry = top->v.compound_entry;
2588
2589                 entity_t *next_entity = entry->base.next;
2590                 if (next_entity != NULL) {
2591                         assert(is_declaration(next_entity));
2592                         entry = &next_entity->declaration;
2593                 } else {
2594                         entry = NULL;
2595                 }
2596
2597                 top->v.compound_entry = entry;
2598                 if (entry != NULL) {
2599                         path->top_type = entry->type;
2600                         return;
2601                 }
2602         } else if (is_type_array(type)) {
2603                 assert(is_type_array(type));
2604
2605                 top->v.index++;
2606
2607                 if (!type->array.size_constant || top->v.index < type->array.size) {
2608                         return;
2609                 }
2610         } else {
2611                 assert(!is_type_valid(type));
2612                 return;
2613         }
2614
2615         /* we're past the last member of the current sub-aggregate, try if we
2616          * can ascend in the type hierarchy and continue with another subobject */
2617         size_t len = ARR_LEN(path->path);
2618
2619         if (len > top_path_level) {
2620                 ascend_from_subtype(path);
2621                 advance_current_object(path, top_path_level);
2622         } else {
2623                 path->top_type = NULL;
2624         }
2625 }
2626
2627 /**
2628  * skip until token is found.
2629  */
2630 static void skip_until(int type)
2631 {
2632         while (token.type != type) {
2633                 if (token.type == T_EOF)
2634                         return;
2635                 next_token();
2636         }
2637 }
2638
2639 /**
2640  * skip any {...} blocks until a closing bracket is reached.
2641  */
2642 static void skip_initializers(void)
2643 {
2644         if (token.type == '{')
2645                 next_token();
2646
2647         while (token.type != '}') {
2648                 if (token.type == T_EOF)
2649                         return;
2650                 if (token.type == '{') {
2651                         eat_block();
2652                         continue;
2653                 }
2654                 next_token();
2655         }
2656 }
2657
2658 static initializer_t *create_empty_initializer(void)
2659 {
2660         static initializer_t empty_initializer
2661                 = { .list = { { INITIALIZER_LIST }, 0 } };
2662         return &empty_initializer;
2663 }
2664
2665 /**
2666  * Parse a part of an initialiser for a struct or union,
2667  */
2668 static initializer_t *parse_sub_initializer(type_path_t *path,
2669                 type_t *outer_type, size_t top_path_level,
2670                 parse_initializer_env_t *env)
2671 {
2672         if (token.type == '}') {
2673                 /* empty initializer */
2674                 return create_empty_initializer();
2675         }
2676
2677         type_t *orig_type = path->top_type;
2678         type_t *type      = NULL;
2679
2680         if (orig_type == NULL) {
2681                 /* We are initializing an empty compound. */
2682         } else {
2683                 type = skip_typeref(orig_type);
2684         }
2685
2686         initializer_t **initializers = NEW_ARR_F(initializer_t*, 0);
2687
2688         while (true) {
2689                 designator_t *designator = NULL;
2690                 if (token.type == '.' || token.type == '[') {
2691                         designator = parse_designation();
2692                         goto finish_designator;
2693                 } else if (token.type == T_IDENTIFIER && look_ahead(1)->type == ':') {
2694                         /* GNU-style designator ("identifier: value") */
2695                         designator = allocate_ast_zero(sizeof(designator[0]));
2696                         designator->source_position = token.source_position;
2697                         designator->symbol          = token.v.symbol;
2698                         eat(T_IDENTIFIER);
2699                         eat(':');
2700
2701 finish_designator:
2702                         /* reset path to toplevel, evaluate designator from there */
2703                         ascend_to(path, top_path_level);
2704                         if (!walk_designator(path, designator, false)) {
2705                                 /* can't continue after designation error */
2706                                 goto end_error;
2707                         }
2708
2709                         initializer_t *designator_initializer
2710                                 = allocate_initializer_zero(INITIALIZER_DESIGNATOR);
2711                         designator_initializer->designator.designator = designator;
2712                         ARR_APP1(initializer_t*, initializers, designator_initializer);
2713
2714                         orig_type = path->top_type;
2715                         type      = orig_type != NULL ? skip_typeref(orig_type) : NULL;
2716                 }
2717
2718                 initializer_t *sub;
2719
2720                 if (token.type == '{') {
2721                         if (type != NULL && is_type_scalar(type)) {
2722                                 sub = parse_scalar_initializer(type, env->must_be_constant);
2723                         } else {
2724                                 eat('{');
2725                                 if (type == NULL) {
2726                                         if (env->entity != NULL) {
2727                                                 errorf(HERE,
2728                                                      "extra brace group at end of initializer for '%Y'",
2729                                                      env->entity->base.symbol);
2730                                         } else {
2731                                                 errorf(HERE, "extra brace group at end of initializer");
2732                                         }
2733                                 } else
2734                                         descend_into_subtype(path);
2735
2736                                 add_anchor_token('}');
2737                                 sub = parse_sub_initializer(path, orig_type, top_path_level+1,
2738                                                             env);
2739                                 rem_anchor_token('}');
2740
2741                                 if (type != NULL) {
2742                                         ascend_from_subtype(path);
2743                                         expect('}', end_error);
2744                                 } else {
2745                                         expect('}', end_error);
2746                                         goto error_parse_next;
2747                                 }
2748                         }
2749                 } else {
2750                         /* must be an expression */
2751                         expression_t *expression = parse_assignment_expression();
2752                         mark_vars_read(expression, NULL);
2753
2754                         if (env->must_be_constant && !is_initializer_constant(expression)) {
2755                                 errorf(&expression->base.source_position,
2756                                        "Initialisation expression '%E' is not constant",
2757                                        expression);
2758                         }
2759
2760                         if (type == NULL) {
2761                                 /* we are already outside, ... */
2762                                 type_t *const outer_type_skip = skip_typeref(outer_type);
2763                                 if (is_type_compound(outer_type_skip) &&
2764                                     !outer_type_skip->compound.compound->complete) {
2765                                         goto error_parse_next;
2766                                 }
2767                                 goto error_excess;
2768                         }
2769
2770                         /* handle { "string" } special case */
2771                         if ((expression->kind == EXPR_STRING_LITERAL
2772                                         || expression->kind == EXPR_WIDE_STRING_LITERAL)
2773                                         && outer_type != NULL) {
2774                                 sub = initializer_from_expression(outer_type, expression);
2775                                 if (sub != NULL) {
2776                                         if (token.type == ',') {
2777                                                 next_token();
2778                                         }
2779                                         if (token.type != '}' && warning.other) {
2780                                                 warningf(HERE, "excessive elements in initializer for type '%T'",
2781                                                                  orig_type);
2782                                         }
2783                                         /* TODO: eat , ... */
2784                                         return sub;
2785                                 }
2786                         }
2787
2788                         /* descend into subtypes until expression matches type */
2789                         while (true) {
2790                                 orig_type = path->top_type;
2791                                 type      = skip_typeref(orig_type);
2792
2793                                 sub = initializer_from_expression(orig_type, expression);
2794                                 if (sub != NULL) {
2795                                         break;
2796                                 }
2797                                 if (!is_type_valid(type)) {
2798                                         goto end_error;
2799                                 }
2800                                 if (is_type_scalar(type)) {
2801                                         errorf(&expression->base.source_position,
2802                                                         "expression '%E' doesn't match expected type '%T'",
2803                                                         expression, orig_type);
2804                                         goto end_error;
2805                                 }
2806
2807                                 descend_into_subtype(path);
2808                         }
2809                 }
2810
2811                 /* update largest index of top array */
2812                 const type_path_entry_t *first      = &path->path[0];
2813                 type_t                  *first_type = first->type;
2814                 first_type                          = skip_typeref(first_type);
2815                 if (is_type_array(first_type)) {
2816                         size_t index = first->v.index;
2817                         if (index > path->max_index)
2818                                 path->max_index = index;
2819                 }
2820
2821                 if (type != NULL) {
2822                         /* append to initializers list */
2823                         ARR_APP1(initializer_t*, initializers, sub);
2824                 } else {
2825 error_excess:
2826                         if (warning.other) {
2827                                 if (env->entity != NULL) {
2828                                         warningf(HERE, "excess elements in struct initializer for '%Y'",
2829                                            env->entity->base.symbol);
2830                                 } else {
2831                                         warningf(HERE, "excess elements in struct initializer");
2832                                 }
2833                         }
2834                 }
2835
2836 error_parse_next:
2837                 if (token.type == '}') {
2838                         break;
2839                 }
2840                 expect(',', end_error);
2841                 if (token.type == '}') {
2842                         break;
2843                 }
2844
2845                 if (type != NULL) {
2846                         /* advance to the next declaration if we are not at the end */
2847                         advance_current_object(path, top_path_level);
2848                         orig_type = path->top_type;
2849                         if (orig_type != NULL)
2850                                 type = skip_typeref(orig_type);
2851                         else
2852                                 type = NULL;
2853                 }
2854         }
2855
2856         size_t len  = ARR_LEN(initializers);
2857         size_t size = sizeof(initializer_list_t) + len * sizeof(initializers[0]);
2858         initializer_t *result = allocate_ast_zero(size);
2859         result->kind          = INITIALIZER_LIST;
2860         result->list.len      = len;
2861         memcpy(&result->list.initializers, initializers,
2862                len * sizeof(initializers[0]));
2863
2864         DEL_ARR_F(initializers);
2865         ascend_to(path, top_path_level+1);
2866
2867         return result;
2868
2869 end_error:
2870         skip_initializers();
2871         DEL_ARR_F(initializers);
2872         ascend_to(path, top_path_level+1);
2873         return NULL;
2874 }
2875
2876 /**
2877  * Parses an initializer. Parsers either a compound literal
2878  * (env->declaration == NULL) or an initializer of a declaration.
2879  */
2880 static initializer_t *parse_initializer(parse_initializer_env_t *env)
2881 {
2882         type_t        *type      = skip_typeref(env->type);
2883         size_t         max_index = 0xdeadbeaf;   // TODO: Resolve this uninitialized variable problem
2884         initializer_t *result;
2885
2886         if (is_type_scalar(type)) {
2887                 result = parse_scalar_initializer(type, env->must_be_constant);
2888         } else if (token.type == '{') {
2889                 eat('{');
2890
2891                 type_path_t path;
2892                 memset(&path, 0, sizeof(path));
2893                 path.top_type = env->type;
2894                 path.path     = NEW_ARR_F(type_path_entry_t, 0);
2895
2896                 descend_into_subtype(&path);
2897
2898                 add_anchor_token('}');
2899                 result = parse_sub_initializer(&path, env->type, 1, env);
2900                 rem_anchor_token('}');
2901
2902                 max_index = path.max_index;
2903                 DEL_ARR_F(path.path);
2904
2905                 expect('}', end_error);
2906         } else {
2907                 /* parse_scalar_initializer() also works in this case: we simply
2908                  * have an expression without {} around it */
2909                 result = parse_scalar_initializer(type, env->must_be_constant);
2910         }
2911
2912         /* § 6.7.8:22 array initializers for arrays with unknown size determine
2913          * the array type size */
2914         if (is_type_array(type) && type->array.size_expression == NULL
2915                         && result != NULL) {
2916                 size_t size;
2917                 switch (result->kind) {
2918                 case INITIALIZER_LIST:
2919                         assert(max_index != 0xdeadbeaf);
2920                         size = max_index + 1;
2921                         break;
2922
2923                 case INITIALIZER_STRING:
2924                         size = result->string.string.size;
2925                         break;
2926
2927                 case INITIALIZER_WIDE_STRING:
2928                         size = result->wide_string.string.size;
2929                         break;
2930
2931                 case INITIALIZER_DESIGNATOR:
2932                 case INITIALIZER_VALUE:
2933                         /* can happen for parse errors */
2934                         size = 0;
2935                         break;
2936
2937                 default:
2938                         internal_errorf(HERE, "invalid initializer type");
2939                 }
2940
2941                 expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
2942                 cnst->base.type          = type_size_t;
2943                 cnst->conste.v.int_value = size;
2944
2945                 type_t *new_type = duplicate_type(type);
2946
2947                 new_type->array.size_expression   = cnst;
2948                 new_type->array.size_constant     = true;
2949                 new_type->array.has_implicit_size = true;
2950                 new_type->array.size              = size;
2951                 env->type = new_type;
2952         }
2953
2954         return result;
2955 end_error:
2956         return NULL;
2957 }
2958
2959 static void append_entity(scope_t *scope, entity_t *entity)
2960 {
2961         if (scope->last_entity != NULL) {
2962                 scope->last_entity->base.next = entity;
2963         } else {
2964                 scope->entities = entity;
2965         }
2966         scope->last_entity = entity;
2967 }
2968
2969
2970 static compound_t *parse_compound_type_specifier(bool is_struct)
2971 {
2972         gnu_attribute_t  *attributes = NULL;
2973         decl_modifiers_t  modifiers  = 0;
2974         if (is_struct) {
2975                 eat(T_struct);
2976         } else {
2977                 eat(T_union);
2978         }
2979
2980         symbol_t   *symbol   = NULL;
2981         compound_t *compound = NULL;
2982
2983         if (token.type == T___attribute__) {
2984                 modifiers |= parse_attributes(&attributes);
2985         }
2986
2987         if (token.type == T_IDENTIFIER) {
2988                 symbol = token.v.symbol;
2989                 next_token();
2990
2991                 namespace_tag_t const namespc =
2992                         is_struct ? NAMESPACE_STRUCT : NAMESPACE_UNION;
2993                 entity_t *entity = get_entity(symbol, namespc);
2994                 if (entity != NULL) {
2995                         assert(entity->kind == (is_struct ? ENTITY_STRUCT : ENTITY_UNION));
2996                         compound = &entity->compound;
2997                         if (compound->base.parent_scope != current_scope &&
2998                             (token.type == '{' || token.type == ';')) {
2999                                 /* we're in an inner scope and have a definition. Shadow
3000                                  * existing definition in outer scope */
3001                                 compound = NULL;
3002                         } else if (compound->complete && token.type == '{') {
3003                                 assert(symbol != NULL);
3004                                 errorf(HERE, "multiple definitions of '%s %Y' (previous definition %P)",
3005                                        is_struct ? "struct" : "union", symbol,
3006                                        &compound->base.source_position);
3007                                 /* clear members in the hope to avoid further errors */
3008                                 compound->members.entities = NULL;
3009                         }
3010                 }
3011         } else if (token.type != '{') {
3012                 if (is_struct) {
3013                         parse_error_expected("while parsing struct type specifier",
3014                                              T_IDENTIFIER, '{', NULL);
3015                 } else {
3016                         parse_error_expected("while parsing union type specifier",
3017                                              T_IDENTIFIER, '{', NULL);
3018                 }
3019
3020                 return NULL;
3021         }
3022
3023         if (compound == NULL) {
3024                 entity_kind_t  kind   = is_struct ? ENTITY_STRUCT : ENTITY_UNION;
3025                 entity_t      *entity = allocate_entity_zero(kind);
3026                 compound              = &entity->compound;
3027
3028                 compound->base.namespc =
3029                         (is_struct ? NAMESPACE_STRUCT : NAMESPACE_UNION);
3030                 compound->base.source_position = token.source_position;
3031                 compound->base.symbol          = symbol;
3032                 compound->base.parent_scope    = current_scope;
3033                 if (symbol != NULL) {
3034                         environment_push(entity);
3035                 }
3036                 append_entity(current_scope, entity);
3037         }
3038
3039         if (token.type == '{') {
3040                 parse_compound_type_entries(compound);
3041                 modifiers |= parse_attributes(&attributes);
3042
3043                 if (symbol == NULL) {
3044                         assert(anonymous_entity == NULL);
3045                         anonymous_entity = (entity_t*)compound;
3046                 }
3047         }
3048
3049         compound->modifiers |= modifiers;
3050         return compound;
3051 }
3052
3053 static void parse_enum_entries(type_t *const enum_type)
3054 {
3055         eat('{');
3056
3057         if (token.type == '}') {
3058                 errorf(HERE, "empty enum not allowed");
3059                 next_token();
3060                 return;
3061         }
3062
3063         add_anchor_token('}');
3064         do {
3065                 if (token.type != T_IDENTIFIER) {
3066                         parse_error_expected("while parsing enum entry", T_IDENTIFIER, NULL);
3067                         eat_block();
3068                         rem_anchor_token('}');
3069                         return;
3070                 }
3071
3072                 entity_t *entity             = allocate_entity_zero(ENTITY_ENUM_VALUE);
3073                 entity->enum_value.enum_type = enum_type;
3074                 entity->base.symbol          = token.v.symbol;
3075                 entity->base.source_position = token.source_position;
3076                 next_token();
3077
3078                 if (token.type == '=') {
3079                         next_token();
3080                         expression_t *value = parse_constant_expression();
3081
3082                         value = create_implicit_cast(value, enum_type);
3083                         entity->enum_value.value = value;
3084
3085                         /* TODO semantic */
3086                 }
3087
3088                 record_entity(entity, false);
3089
3090                 if (token.type != ',')
3091                         break;
3092                 next_token();
3093         } while (token.type != '}');
3094         rem_anchor_token('}');
3095
3096         expect('}', end_error);
3097
3098 end_error:
3099         ;
3100 }
3101
3102 static type_t *parse_enum_specifier(void)
3103 {
3104         gnu_attribute_t *attributes = NULL;
3105         entity_t        *entity;
3106         symbol_t        *symbol;
3107
3108         eat(T_enum);
3109         if (token.type == T_IDENTIFIER) {
3110                 symbol = token.v.symbol;
3111                 next_token();
3112
3113                 entity = get_entity(symbol, NAMESPACE_ENUM);
3114                 if (entity != NULL) {
3115                         assert(entity->kind == ENTITY_ENUM);
3116                         if (entity->base.parent_scope != current_scope &&
3117                                         (token.type == '{' || token.type == ';')) {
3118                                 /* we're in an inner scope and have a definition. Shadow
3119                                  * existing definition in outer scope */
3120                                 entity = NULL;
3121                         } else if (entity->enume.complete && token.type == '{') {
3122                                 errorf(HERE, "multiple definitions of 'enum %Y' (previous definition %P)",
3123                                                 symbol, &entity->base.source_position);
3124                         }
3125                 }
3126         } else if (token.type != '{') {
3127                 parse_error_expected("while parsing enum type specifier",
3128                                      T_IDENTIFIER, '{', NULL);
3129                 return NULL;
3130         } else {
3131                 entity  = NULL;
3132                 symbol  = NULL;
3133         }
3134
3135         if (entity == NULL) {
3136                 entity                       = allocate_entity_zero(ENTITY_ENUM);
3137                 entity->base.namespc         = NAMESPACE_ENUM;
3138                 entity->base.source_position = token.source_position;
3139                 entity->base.symbol          = symbol;
3140                 entity->base.parent_scope    = current_scope;
3141         }
3142
3143         type_t *const type = allocate_type_zero(TYPE_ENUM);
3144         type->enumt.enume  = &entity->enume;
3145         type->enumt.akind  = ATOMIC_TYPE_INT;
3146
3147         if (token.type == '{') {
3148                 if (symbol != NULL) {
3149                         environment_push(entity);
3150                 }
3151                 append_entity(current_scope, entity);
3152                 entity->enume.complete = true;
3153
3154                 parse_enum_entries(type);
3155                 parse_attributes(&attributes);
3156
3157                 if (symbol == NULL) {
3158                         assert(anonymous_entity == NULL);
3159                         anonymous_entity = entity;
3160                 }
3161         } else if (!entity->enume.complete && !(c_mode & _GNUC)) {
3162                 errorf(HERE, "'enum %Y' used before definition (incomplete enums are a GNU extension)",
3163                        symbol);
3164         }
3165
3166         return type;
3167 }
3168
3169 /**
3170  * if a symbol is a typedef to another type, return true
3171  */
3172 static bool is_typedef_symbol(symbol_t *symbol)
3173 {
3174         const entity_t *const entity = get_entity(symbol, NAMESPACE_NORMAL);
3175         return entity != NULL && entity->kind == ENTITY_TYPEDEF;
3176 }
3177
3178 static type_t *parse_typeof(void)
3179 {
3180         eat(T___typeof__);
3181
3182         type_t *type;
3183
3184         expect('(', end_error);
3185         add_anchor_token(')');
3186
3187         expression_t *expression  = NULL;
3188
3189         bool old_type_prop     = in_type_prop;
3190         bool old_gcc_extension = in_gcc_extension;
3191         in_type_prop           = true;
3192
3193         while (token.type == T___extension__) {
3194                 /* This can be a prefix to a typename or an expression. */
3195                 next_token();
3196                 in_gcc_extension = true;
3197         }
3198         switch (token.type) {
3199         case T_IDENTIFIER:
3200                 if (is_typedef_symbol(token.v.symbol)) {
3201                         type = parse_typename();
3202                 } else {
3203                         expression = parse_expression();
3204                         type       = expression->base.type;
3205                 }
3206                 break;
3207
3208         TYPENAME_START
3209                 type = parse_typename();
3210                 break;
3211
3212         default:
3213                 expression = parse_expression();
3214                 type       = expression->base.type;
3215                 break;
3216         }
3217         in_type_prop     = old_type_prop;
3218         in_gcc_extension = old_gcc_extension;
3219
3220         rem_anchor_token(')');
3221         expect(')', end_error);
3222
3223         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF);
3224         typeof_type->typeoft.expression  = expression;
3225         typeof_type->typeoft.typeof_type = type;
3226
3227         return typeof_type;
3228 end_error:
3229         return NULL;
3230 }
3231
3232 typedef enum specifiers_t {
3233         SPECIFIER_SIGNED    = 1 << 0,
3234         SPECIFIER_UNSIGNED  = 1 << 1,
3235         SPECIFIER_LONG      = 1 << 2,
3236         SPECIFIER_INT       = 1 << 3,
3237         SPECIFIER_DOUBLE    = 1 << 4,
3238         SPECIFIER_CHAR      = 1 << 5,
3239         SPECIFIER_WCHAR_T   = 1 << 6,
3240         SPECIFIER_SHORT     = 1 << 7,
3241         SPECIFIER_LONG_LONG = 1 << 8,
3242         SPECIFIER_FLOAT     = 1 << 9,
3243         SPECIFIER_BOOL      = 1 << 10,
3244         SPECIFIER_VOID      = 1 << 11,
3245         SPECIFIER_INT8      = 1 << 12,
3246         SPECIFIER_INT16     = 1 << 13,
3247         SPECIFIER_INT32     = 1 << 14,
3248         SPECIFIER_INT64     = 1 << 15,
3249         SPECIFIER_INT128    = 1 << 16,
3250         SPECIFIER_COMPLEX   = 1 << 17,
3251         SPECIFIER_IMAGINARY = 1 << 18,
3252 } specifiers_t;
3253
3254 static type_t *create_builtin_type(symbol_t *const symbol,
3255                                    type_t *const real_type)
3256 {
3257         type_t *type            = allocate_type_zero(TYPE_BUILTIN);
3258         type->builtin.symbol    = symbol;
3259         type->builtin.real_type = real_type;
3260         return identify_new_type(type);
3261 }
3262
3263 static type_t *get_typedef_type(symbol_t *symbol)
3264 {
3265         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
3266         if (entity == NULL || entity->kind != ENTITY_TYPEDEF)
3267                 return NULL;
3268
3269         type_t *type            = allocate_type_zero(TYPE_TYPEDEF);
3270         type->typedeft.typedefe = &entity->typedefe;
3271
3272         return type;
3273 }
3274
3275 /**
3276  * check for the allowed MS alignment values.
3277  */
3278 static bool check_alignment_value(long long intvalue)
3279 {
3280         if (intvalue < 1 || intvalue > 8192) {
3281                 errorf(HERE, "illegal alignment value");
3282                 return false;
3283         }
3284         unsigned v = (unsigned)intvalue;
3285         for (unsigned i = 1; i <= 8192; i += i) {
3286                 if (i == v)
3287                         return true;
3288         }
3289         errorf(HERE, "alignment must be power of two");
3290         return false;
3291 }
3292
3293 #define DET_MOD(name, tag) do { \
3294         if (*modifiers & tag && warning.other) warningf(HERE, #name " used more than once"); \
3295         *modifiers |= tag; \
3296 } while (0)
3297
3298 static void parse_microsoft_extended_decl_modifier(declaration_specifiers_t *specifiers)
3299 {
3300         decl_modifiers_t *modifiers = &specifiers->modifiers;
3301
3302         while (true) {
3303                 if (token.type == T_restrict) {
3304                         next_token();
3305                         DET_MOD(restrict, DM_RESTRICT);
3306                         goto end_loop;
3307                 } else if (token.type != T_IDENTIFIER)
3308                         break;
3309                 symbol_t *symbol = token.v.symbol;
3310                 if (symbol == sym_align) {
3311                         next_token();
3312                         expect('(', end_error);
3313                         if (token.type != T_INTEGER)
3314                                 goto end_error;
3315                         if (check_alignment_value(token.v.intvalue)) {
3316                                 if (specifiers->alignment != 0 && warning.other)
3317                                         warningf(HERE, "align used more than once");
3318                                 specifiers->alignment = (unsigned char)token.v.intvalue;
3319                         }
3320                         next_token();
3321                         expect(')', end_error);
3322                 } else if (symbol == sym_allocate) {
3323                         next_token();
3324                         expect('(', end_error);
3325                         if (token.type != T_IDENTIFIER)
3326                                 goto end_error;
3327                         (void)token.v.symbol;
3328                         expect(')', end_error);
3329                 } else if (symbol == sym_dllimport) {
3330                         next_token();
3331                         DET_MOD(dllimport, DM_DLLIMPORT);
3332                 } else if (symbol == sym_dllexport) {
3333                         next_token();
3334                         DET_MOD(dllexport, DM_DLLEXPORT);
3335                 } else if (symbol == sym_thread) {
3336                         next_token();
3337                         DET_MOD(thread, DM_THREAD);
3338                 } else if (symbol == sym_naked) {
3339                         next_token();
3340                         DET_MOD(naked, DM_NAKED);
3341                 } else if (symbol == sym_noinline) {
3342                         next_token();
3343                         DET_MOD(noinline, DM_NOINLINE);
3344                 } else if (symbol == sym_returns_twice) {
3345                         next_token();
3346                         DET_MOD(returns_twice, DM_RETURNS_TWICE);
3347                 } else if (symbol == sym_noreturn) {
3348                         next_token();
3349                         DET_MOD(noreturn, DM_NORETURN);
3350                 } else if (symbol == sym_nothrow) {
3351                         next_token();
3352                         DET_MOD(nothrow, DM_NOTHROW);
3353                 } else if (symbol == sym_novtable) {
3354                         next_token();
3355                         DET_MOD(novtable, DM_NOVTABLE);
3356                 } else if (symbol == sym_property) {
3357                         next_token();
3358                         expect('(', end_error);
3359                         for (;;) {
3360                                 bool is_get = false;
3361                                 if (token.type != T_IDENTIFIER)
3362                                         goto end_error;
3363                                 if (token.v.symbol == sym_get) {
3364                                         is_get = true;
3365                                 } else if (token.v.symbol == sym_put) {
3366                                 } else {
3367                                         errorf(HERE, "Bad property name '%Y'", token.v.symbol);
3368                                         goto end_error;
3369                                 }
3370                                 next_token();
3371                                 expect('=', end_error);
3372                                 if (token.type != T_IDENTIFIER)
3373                                         goto end_error;
3374                                 if (is_get) {
3375                                         if (specifiers->get_property_sym != NULL) {
3376                                                 errorf(HERE, "get property name already specified");
3377                                         } else {
3378                                                 specifiers->get_property_sym = token.v.symbol;
3379                                         }
3380                                 } else {
3381                                         if (specifiers->put_property_sym != NULL) {
3382                                                 errorf(HERE, "put property name already specified");
3383                                         } else {
3384                                                 specifiers->put_property_sym = token.v.symbol;
3385                                         }
3386                                 }
3387                                 next_token();
3388                                 if (token.type == ',') {
3389                                         next_token();
3390                                         continue;
3391                                 }
3392                                 break;
3393                         }
3394                         expect(')', end_error);
3395                 } else if (symbol == sym_selectany) {
3396                         next_token();
3397                         DET_MOD(selectany, DM_SELECTANY);
3398                 } else if (symbol == sym_uuid) {
3399                         next_token();
3400                         expect('(', end_error);
3401                         if (token.type != T_STRING_LITERAL)
3402                                 goto end_error;
3403                         next_token();
3404                         expect(')', end_error);
3405                 } else if (symbol == sym_deprecated) {
3406                         next_token();
3407                         if (specifiers->deprecated != 0 && warning.other)
3408                                 warningf(HERE, "deprecated used more than once");
3409                         specifiers->deprecated = true;
3410                         if (token.type == '(') {
3411                                 next_token();
3412                                 if (token.type == T_STRING_LITERAL) {
3413                                         specifiers->deprecated_string = token.v.string.begin;
3414                                         next_token();
3415                                 } else {
3416                                         errorf(HERE, "string literal expected");
3417                                 }
3418                                 expect(')', end_error);
3419                         }
3420                 } else if (symbol == sym_noalias) {
3421                         next_token();
3422                         DET_MOD(noalias, DM_NOALIAS);
3423                 } else {
3424                         if (warning.other)
3425                                 warningf(HERE, "Unknown modifier '%Y' ignored", token.v.symbol);
3426                         next_token();
3427                         if (token.type == '(')
3428                                 skip_until(')');
3429                 }
3430 end_loop:
3431                 if (token.type == ',')
3432                         next_token();
3433         }
3434 end_error:
3435         return;
3436 }
3437
3438 static entity_t *create_error_entity(symbol_t *symbol, entity_kind_tag_t kind)
3439 {
3440         entity_t *entity             = allocate_entity_zero(kind);
3441         entity->base.source_position = *HERE;
3442         entity->base.symbol          = symbol;
3443         if (is_declaration(entity)) {
3444                 entity->declaration.type     = type_error_type;
3445                 entity->declaration.implicit = true;
3446         } else if (kind == ENTITY_TYPEDEF) {
3447                 entity->typedefe.type    = type_error_type;
3448                 entity->typedefe.builtin = true;
3449         }
3450         if (kind != ENTITY_COMPOUND_MEMBER)
3451                 record_entity(entity, false);
3452         return entity;
3453 }
3454
3455 static void parse_microsoft_based(based_spec_t *based_spec)
3456 {
3457         if (token.type != T_IDENTIFIER) {
3458                 parse_error_expected("while parsing __based", T_IDENTIFIER, NULL);
3459                 return;
3460         }
3461         symbol_t *symbol = token.v.symbol;
3462         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
3463
3464         if (entity == NULL || entity->base.kind != ENTITY_VARIABLE) {
3465                 errorf(HERE, "'%Y' is not a variable name.", symbol);
3466                 entity = create_error_entity(symbol, ENTITY_VARIABLE);
3467         } else {
3468                 variable_t *variable = &entity->variable;
3469
3470                 if (based_spec->base_variable != NULL) {
3471                         errorf(HERE, "__based type qualifier specified more than once");
3472                 }
3473                 based_spec->source_position = token.source_position;
3474                 based_spec->base_variable   = variable;
3475
3476                 type_t *const type = variable->base.type;
3477
3478                 if (is_type_valid(type)) {
3479                         if (! is_type_pointer(skip_typeref(type))) {
3480                                 errorf(HERE, "variable in __based modifier must have pointer type instead of '%T'", type);
3481                         }
3482                         if (variable->base.base.parent_scope != file_scope) {
3483                                 errorf(HERE, "a nonstatic local variable may not be used in a __based specification");
3484                         }
3485                 }
3486         }
3487         next_token();
3488 }
3489
3490 /**
3491  * Finish the construction of a struct type by calculating
3492  * its size, offsets, alignment.
3493  */
3494 static void finish_struct_type(compound_type_t *type)
3495 {
3496         assert(type->compound != NULL);
3497
3498         compound_t *compound = type->compound;
3499         if (!compound->complete)
3500                 return;
3501
3502         il_size_t      size           = 0;
3503         il_size_t      offset;
3504         il_alignment_t alignment      = 1;
3505         bool           need_pad       = false;
3506
3507         entity_t *entry = compound->members.entities;
3508         for (; entry != NULL; entry = entry->base.next) {
3509                 if (entry->kind != ENTITY_COMPOUND_MEMBER)
3510                         continue;
3511
3512                 type_t *m_type = skip_typeref(entry->declaration.type);
3513                 if (! is_type_valid(m_type)) {
3514                         /* simply ignore errors here */
3515                         continue;
3516                 }
3517                 il_alignment_t m_alignment = m_type->base.alignment;
3518                 if (m_alignment > alignment)
3519                         alignment = m_alignment;
3520
3521                 offset = (size + m_alignment - 1) & -m_alignment;
3522
3523                 if (offset > size)
3524                         need_pad = true;
3525                 entry->compound_member.offset = offset;
3526                 size = offset + m_type->base.size;
3527         }
3528         if (type->base.alignment != 0) {
3529                 alignment = type->base.alignment;
3530         }
3531
3532         offset = (size + alignment - 1) & -alignment;
3533         if (offset > size)
3534                 need_pad = true;
3535
3536         if (need_pad) {
3537                 if (warning.padded) {
3538                         warningf(&compound->base.source_position, "'%T' needs padding", type);
3539                 }
3540         } else {
3541                 if (compound->modifiers & DM_PACKED && warning.packed) {
3542                         warningf(&compound->base.source_position,
3543                                         "superfluous packed attribute on '%T'", type);
3544                 }
3545         }
3546
3547         type->base.size      = offset;
3548         type->base.alignment = alignment;
3549 }
3550
3551 /**
3552  * Finish the construction of an union type by calculating
3553  * its size and alignment.
3554  */
3555 static void finish_union_type(compound_type_t *type)
3556 {
3557         assert(type->compound != NULL);
3558
3559         compound_t *compound = type->compound;
3560         if (! compound->complete)
3561                 return;
3562
3563         il_size_t      size      = 0;
3564         il_alignment_t alignment = 1;
3565
3566         entity_t *entry = compound->members.entities;
3567         for (; entry != NULL; entry = entry->base.next) {
3568                 if (entry->kind != ENTITY_COMPOUND_MEMBER)
3569                         continue;
3570
3571                 type_t *m_type = skip_typeref(entry->declaration.type);
3572                 if (! is_type_valid(m_type))
3573                         continue;
3574
3575                 entry->compound_member.offset = 0;
3576                 if (m_type->base.size > size)
3577                         size = m_type->base.size;
3578                 if (m_type->base.alignment > alignment)
3579                         alignment = m_type->base.alignment;
3580         }
3581         if (type->base.alignment != 0) {
3582                 alignment = type->base.alignment;
3583         }
3584         size = (size + alignment - 1) & -alignment;
3585         type->base.size      = size;
3586         type->base.alignment = alignment;
3587 }
3588
3589 static type_t *handle_attribute_mode(const gnu_attribute_t *attribute,
3590                                      type_t *orig_type)
3591 {
3592         type_t *type = skip_typeref(orig_type);
3593
3594         /* at least: byte, word, pointer, list of machine modes
3595          * __XXX___ is interpreted as XXX */
3596
3597         /* This isn't really correct, the backend should provide a list of machine
3598          * specific modes (according to gcc philosophy that is...) */
3599         const char         *symbol_str = attribute->u.symbol->string;
3600         bool                sign       = is_type_signed(type);
3601         atomic_type_kind_t  akind;
3602         if (strcmp_underscore("QI",   symbol_str) == 0 ||
3603             strcmp_underscore("byte", symbol_str) == 0) {
3604                 akind = sign ? ATOMIC_TYPE_CHAR : ATOMIC_TYPE_UCHAR;
3605         } else if (strcmp_underscore("HI", symbol_str) == 0) {
3606                 akind = sign ? ATOMIC_TYPE_SHORT : ATOMIC_TYPE_USHORT;
3607         } else if (strcmp_underscore("SI",      symbol_str) == 0
3608                 || strcmp_underscore("word",    symbol_str) == 0
3609                 || strcmp_underscore("pointer", symbol_str) == 0) {
3610                 akind = sign ? ATOMIC_TYPE_INT : ATOMIC_TYPE_UINT;
3611         } else if (strcmp_underscore("DI", symbol_str) == 0) {
3612                 akind = sign ? ATOMIC_TYPE_LONGLONG : ATOMIC_TYPE_ULONGLONG;
3613         } else {
3614                 if (warning.other)
3615                         warningf(HERE, "ignoring unknown mode '%s'", symbol_str);
3616                 return orig_type;
3617         }
3618
3619         if (type->kind == TYPE_ATOMIC) {
3620                 type_t *copy       = duplicate_type(type);
3621                 copy->atomic.akind = akind;
3622                 return identify_new_type(copy);
3623         } else if (type->kind == TYPE_ENUM) {
3624                 type_t *copy      = duplicate_type(type);
3625                 copy->enumt.akind = akind;
3626                 return identify_new_type(copy);
3627         } else if (is_type_pointer(type)) {
3628                 warningf(HERE, "__attribute__((mode)) on pointers not implemented yet (ignored)");
3629                 return type;
3630         }
3631
3632         errorf(HERE, "__attribute__((mode)) only allowed on integer, enum or pointer type");
3633         return orig_type;
3634 }
3635
3636 static type_t *handle_type_attributes(const gnu_attribute_t *attributes,
3637                                       type_t *type)
3638 {
3639         const gnu_attribute_t *attribute = attributes;
3640         for ( ; attribute != NULL; attribute = attribute->next) {
3641                 if (attribute->invalid)
3642                         continue;
3643
3644                 if (attribute->kind == GNU_AK_MODE) {
3645                         type = handle_attribute_mode(attribute, type);
3646                 } else if (attribute->kind == GNU_AK_ALIGNED) {
3647                         int alignment = 32; /* TODO: fill in maximum useful alignment for
3648                                                target machine */
3649                         if (attribute->has_arguments)
3650                                 alignment = attribute->u.argument;
3651
3652                         type_t *copy         = duplicate_type(type);
3653                         copy->base.alignment = attribute->u.argument;
3654                         type                 = identify_new_type(copy);
3655                 }
3656         }
3657
3658         return type;
3659 }
3660
3661 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
3662 {
3663         type_t            *type              = NULL;
3664         type_qualifiers_t  qualifiers        = TYPE_QUALIFIER_NONE;
3665         type_modifiers_t   modifiers         = TYPE_MODIFIER_NONE;
3666         unsigned           type_specifiers   = 0;
3667         bool               newtype           = false;
3668         bool               saw_error         = false;
3669         bool               old_gcc_extension = in_gcc_extension;
3670
3671         specifiers->source_position = token.source_position;
3672
3673         while (true) {
3674                 specifiers->modifiers
3675                         |= parse_attributes(&specifiers->gnu_attributes);
3676
3677                 switch (token.type) {
3678                 /* storage class */
3679 #define MATCH_STORAGE_CLASS(token, class)                                  \
3680                 case token:                                                        \
3681                         if (specifiers->storage_class != STORAGE_CLASS_NONE) {         \
3682                                 errorf(HERE, "multiple storage classes in declaration specifiers"); \
3683                         }                                                              \
3684                         specifiers->storage_class = class;                             \
3685                         if (specifiers->thread_local)                                  \
3686                                 goto check_thread_storage_class;                           \
3687                         next_token();                                                  \
3688                         break;
3689
3690                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
3691                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
3692                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
3693                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
3694                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
3695
3696                 case T__declspec:
3697                         next_token();
3698                         expect('(', end_error);
3699                         add_anchor_token(')');
3700                         parse_microsoft_extended_decl_modifier(specifiers);
3701                         rem_anchor_token(')');
3702                         expect(')', end_error);
3703                         break;
3704
3705                 case T___thread:
3706                         if (specifiers->thread_local) {
3707                                 errorf(HERE, "duplicate '__thread'");
3708                         } else {
3709                                 specifiers->thread_local = true;
3710 check_thread_storage_class:
3711                                 switch (specifiers->storage_class) {
3712                                         case STORAGE_CLASS_EXTERN:
3713                                         case STORAGE_CLASS_NONE:
3714                                         case STORAGE_CLASS_STATIC:
3715                                                 break;
3716
3717                                                 char const* wrong;
3718                                         case STORAGE_CLASS_AUTO:     wrong = "auto";     goto wrong_thread_stoarge_class;
3719                                         case STORAGE_CLASS_REGISTER: wrong = "register"; goto wrong_thread_stoarge_class;
3720                                         case STORAGE_CLASS_TYPEDEF:  wrong = "typedef";  goto wrong_thread_stoarge_class;
3721 wrong_thread_stoarge_class:
3722                                                 errorf(HERE, "'__thread' used with '%s'", wrong);
3723                                                 break;
3724                                 }
3725                         }
3726                         next_token();
3727                         break;
3728
3729                 /* type qualifiers */
3730 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
3731                 case token:                                                     \
3732                         qualifiers |= qualifier;                                    \
3733                         next_token();                                               \
3734                         break
3735
3736                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3737                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3738                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3739                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3740                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3741                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3742                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3743                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3744
3745                 case T___extension__:
3746                         next_token();
3747                         in_gcc_extension = true;
3748                         break;
3749
3750                 /* type specifiers */
3751 #define MATCH_SPECIFIER(token, specifier, name)                         \
3752                 case token:                                                     \
3753                         if (type_specifiers & specifier) {                           \
3754                                 errorf(HERE, "multiple " name " type specifiers given"); \
3755                         } else {                                                    \
3756                                 type_specifiers |= specifier;                           \
3757                         }                                                           \
3758                         next_token();                                               \
3759                         break
3760
3761                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool");
3762                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex");
3763                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary");
3764                 MATCH_SPECIFIER(T__int128,    SPECIFIER_INT128,    "_int128");
3765                 MATCH_SPECIFIER(T__int16,     SPECIFIER_INT16,     "_int16");
3766                 MATCH_SPECIFIER(T__int32,     SPECIFIER_INT32,     "_int32");
3767                 MATCH_SPECIFIER(T__int64,     SPECIFIER_INT64,     "_int64");
3768                 MATCH_SPECIFIER(T__int8,      SPECIFIER_INT8,      "_int8");
3769                 MATCH_SPECIFIER(T_bool,       SPECIFIER_BOOL,      "bool");
3770                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char");
3771                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double");
3772                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float");
3773                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int");
3774                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short");
3775                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed");
3776                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned");
3777                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void");
3778                 MATCH_SPECIFIER(T_wchar_t,    SPECIFIER_WCHAR_T,   "wchar_t");
3779
3780                 case T__forceinline:
3781                         /* only in microsoft mode */
3782                         specifiers->modifiers |= DM_FORCEINLINE;
3783                         /* FALLTHROUGH */
3784
3785                 case T_inline:
3786                         next_token();
3787                         specifiers->is_inline = true;
3788                         break;
3789
3790                 case T_long:
3791                         if (type_specifiers & SPECIFIER_LONG_LONG) {
3792                                 errorf(HERE, "multiple type specifiers given");
3793                         } else if (type_specifiers & SPECIFIER_LONG) {
3794                                 type_specifiers |= SPECIFIER_LONG_LONG;
3795                         } else {
3796                                 type_specifiers |= SPECIFIER_LONG;
3797                         }
3798                         next_token();
3799                         break;
3800
3801                 case T_struct: {
3802                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
3803
3804                         type->compound.compound = parse_compound_type_specifier(true);
3805                         finish_struct_type(&type->compound);
3806                         break;
3807                 }
3808                 case T_union: {
3809                         type = allocate_type_zero(TYPE_COMPOUND_UNION);
3810                         type->compound.compound = parse_compound_type_specifier(false);
3811                         if (type->compound.compound->modifiers & DM_TRANSPARENT_UNION)
3812                                 modifiers |= TYPE_MODIFIER_TRANSPARENT_UNION;
3813                         finish_union_type(&type->compound);
3814                         break;
3815                 }
3816                 case T_enum:
3817                         type = parse_enum_specifier();
3818                         break;
3819                 case T___typeof__:
3820                         type = parse_typeof();
3821                         break;
3822                 case T___builtin_va_list:
3823                         type = duplicate_type(type_valist);
3824                         next_token();
3825                         break;
3826
3827                 case T_IDENTIFIER: {
3828                         /* only parse identifier if we haven't found a type yet */
3829                         if (type != NULL || type_specifiers != 0) {
3830                                 /* Be somewhat resilient to typos like 'unsigned lng* f()' in a
3831                                  * declaration, so it doesn't generate errors about expecting '(' or
3832                                  * '{' later on. */
3833                                 switch (look_ahead(1)->type) {
3834                                         STORAGE_CLASSES
3835                                         TYPE_SPECIFIERS
3836                                         case T_const:
3837                                         case T_restrict:
3838                                         case T_volatile:
3839                                         case T_inline:
3840                                         case T__forceinline: /* ^ DECLARATION_START except for __attribute__ */
3841                                         case T_IDENTIFIER:
3842                                         case '&':
3843                                         case '*':
3844                                                 errorf(HERE, "discarding stray %K in declaration specifier", &token);
3845                                                 next_token();
3846                                                 continue;
3847
3848                                         default:
3849                                                 goto finish_specifiers;
3850                                 }
3851                         }
3852
3853                         type_t *const typedef_type = get_typedef_type(token.v.symbol);
3854                         if (typedef_type == NULL) {
3855                                 /* Be somewhat resilient to typos like 'vodi f()' at the beginning of a
3856                                  * declaration, so it doesn't generate 'implicit int' followed by more
3857                                  * errors later on. */
3858                                 token_type_t const la1_type = (token_type_t)look_ahead(1)->type;
3859                                 switch (la1_type) {
3860                                         DECLARATION_START
3861                                         case T_IDENTIFIER:
3862                                         case '&':
3863                                         case '*': {
3864                                                 errorf(HERE, "%K does not name a type", &token);
3865
3866                                                 entity_t *entity =
3867                                                         create_error_entity(token.v.symbol, ENTITY_TYPEDEF);
3868
3869                                                 type = allocate_type_zero(TYPE_TYPEDEF);
3870                                                 type->typedeft.typedefe = &entity->typedefe;
3871
3872                                                 next_token();
3873                                                 saw_error = true;
3874                                                 if (la1_type == '&' || la1_type == '*')
3875                                                         goto finish_specifiers;
3876                                                 continue;
3877                                         }
3878
3879                                         default:
3880                                                 goto finish_specifiers;
3881                                 }
3882                         }
3883
3884                         next_token();
3885                         type = typedef_type;
3886                         break;
3887                 }
3888
3889                 /* function specifier */
3890                 default:
3891                         goto finish_specifiers;
3892                 }
3893         }
3894
3895 finish_specifiers:
3896         specifiers->modifiers
3897                 |= parse_attributes(&specifiers->gnu_attributes);
3898
3899         in_gcc_extension = old_gcc_extension;
3900
3901         if (type == NULL || (saw_error && type_specifiers != 0)) {
3902                 atomic_type_kind_t atomic_type;
3903
3904                 /* match valid basic types */
3905                 switch (type_specifiers) {
3906                 case SPECIFIER_VOID:
3907                         atomic_type = ATOMIC_TYPE_VOID;
3908                         break;
3909                 case SPECIFIER_WCHAR_T:
3910                         atomic_type = ATOMIC_TYPE_WCHAR_T;
3911                         break;
3912                 case SPECIFIER_CHAR:
3913                         atomic_type = ATOMIC_TYPE_CHAR;
3914                         break;
3915                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
3916                         atomic_type = ATOMIC_TYPE_SCHAR;
3917                         break;
3918                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
3919                         atomic_type = ATOMIC_TYPE_UCHAR;
3920                         break;
3921                 case SPECIFIER_SHORT:
3922                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
3923                 case SPECIFIER_SHORT | SPECIFIER_INT:
3924                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
3925                         atomic_type = ATOMIC_TYPE_SHORT;
3926                         break;
3927                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
3928                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
3929                         atomic_type = ATOMIC_TYPE_USHORT;
3930                         break;
3931                 case SPECIFIER_INT:
3932                 case SPECIFIER_SIGNED:
3933                 case SPECIFIER_SIGNED | SPECIFIER_INT:
3934                         atomic_type = ATOMIC_TYPE_INT;
3935                         break;
3936                 case SPECIFIER_UNSIGNED:
3937                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
3938                         atomic_type = ATOMIC_TYPE_UINT;
3939                         break;
3940                 case SPECIFIER_LONG:
3941                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
3942                 case SPECIFIER_LONG | SPECIFIER_INT:
3943                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
3944                         atomic_type = ATOMIC_TYPE_LONG;
3945                         break;
3946                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
3947                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
3948                         atomic_type = ATOMIC_TYPE_ULONG;
3949                         break;
3950
3951                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3952                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3953                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
3954                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3955                         | SPECIFIER_INT:
3956                         atomic_type = ATOMIC_TYPE_LONGLONG;
3957                         goto warn_about_long_long;
3958
3959                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3960                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3961                         | SPECIFIER_INT:
3962                         atomic_type = ATOMIC_TYPE_ULONGLONG;
3963 warn_about_long_long:
3964                         if (warning.long_long) {
3965                                 warningf(&specifiers->source_position,
3966                                          "ISO C90 does not support 'long long'");
3967                         }
3968                         break;
3969
3970                 case SPECIFIER_UNSIGNED | SPECIFIER_INT8:
3971                         atomic_type = unsigned_int8_type_kind;
3972                         break;
3973
3974                 case SPECIFIER_UNSIGNED | SPECIFIER_INT16:
3975                         atomic_type = unsigned_int16_type_kind;
3976                         break;
3977
3978                 case SPECIFIER_UNSIGNED | SPECIFIER_INT32:
3979                         atomic_type = unsigned_int32_type_kind;
3980                         break;
3981
3982                 case SPECIFIER_UNSIGNED | SPECIFIER_INT64:
3983                         atomic_type = unsigned_int64_type_kind;
3984                         break;
3985
3986                 case SPECIFIER_UNSIGNED | SPECIFIER_INT128:
3987                         atomic_type = unsigned_int128_type_kind;
3988                         break;
3989
3990                 case SPECIFIER_INT8:
3991                 case SPECIFIER_SIGNED | SPECIFIER_INT8:
3992                         atomic_type = int8_type_kind;
3993                         break;
3994
3995                 case SPECIFIER_INT16:
3996                 case SPECIFIER_SIGNED | SPECIFIER_INT16:
3997                         atomic_type = int16_type_kind;
3998                         break;
3999
4000                 case SPECIFIER_INT32:
4001                 case SPECIFIER_SIGNED | SPECIFIER_INT32:
4002                         atomic_type = int32_type_kind;
4003                         break;
4004
4005                 case SPECIFIER_INT64:
4006                 case SPECIFIER_SIGNED | SPECIFIER_INT64:
4007                         atomic_type = int64_type_kind;
4008                         break;
4009
4010                 case SPECIFIER_INT128:
4011                 case SPECIFIER_SIGNED | SPECIFIER_INT128:
4012                         atomic_type = int128_type_kind;
4013                         break;
4014
4015                 case SPECIFIER_FLOAT:
4016                         atomic_type = ATOMIC_TYPE_FLOAT;
4017                         break;
4018                 case SPECIFIER_DOUBLE:
4019                         atomic_type = ATOMIC_TYPE_DOUBLE;
4020                         break;
4021                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
4022                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
4023                         break;
4024                 case SPECIFIER_BOOL:
4025                         atomic_type = ATOMIC_TYPE_BOOL;
4026                         break;
4027                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
4028                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
4029                         atomic_type = ATOMIC_TYPE_FLOAT;
4030                         break;
4031                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
4032                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
4033                         atomic_type = ATOMIC_TYPE_DOUBLE;
4034                         break;
4035                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
4036                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
4037                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
4038                         break;
4039                 default:
4040                         /* invalid specifier combination, give an error message */
4041                         if (type_specifiers == 0) {
4042                                 if (saw_error)
4043                                         goto end_error;
4044
4045                                 /* ISO/IEC 14882:1998(E) §C.1.5:4 */
4046                                 if (!(c_mode & _CXX) && !strict_mode) {
4047                                         if (warning.implicit_int) {
4048                                                 warningf(HERE, "no type specifiers in declaration, using 'int'");
4049                                         }
4050                                         atomic_type = ATOMIC_TYPE_INT;
4051                                         break;
4052                                 } else {
4053                                         errorf(HERE, "no type specifiers given in declaration");
4054                                 }
4055                         } else if ((type_specifiers & SPECIFIER_SIGNED) &&
4056                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
4057                                 errorf(HERE, "signed and unsigned specifiers given");
4058                         } else if (type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
4059                                 errorf(HERE, "only integer types can be signed or unsigned");
4060                         } else {
4061                                 errorf(HERE, "multiple datatypes in declaration");
4062                         }
4063                         goto end_error;
4064                 }
4065
4066                 if (type_specifiers & SPECIFIER_COMPLEX) {
4067                         type                = allocate_type_zero(TYPE_COMPLEX);
4068                         type->complex.akind = atomic_type;
4069                 } else if (type_specifiers & SPECIFIER_IMAGINARY) {
4070                         type                  = allocate_type_zero(TYPE_IMAGINARY);
4071                         type->imaginary.akind = atomic_type;
4072                 } else {
4073                         type                 = allocate_type_zero(TYPE_ATOMIC);
4074                         type->atomic.akind   = atomic_type;
4075                 }
4076                 type->base.alignment = get_atomic_type_alignment(atomic_type);
4077                 unsigned const size  = get_atomic_type_size(atomic_type);
4078                 type->base.size      =
4079                         type_specifiers & SPECIFIER_COMPLEX ? size * 2 : size;
4080                 newtype = true;
4081         } else if (type_specifiers != 0) {
4082                 errorf(HERE, "multiple datatypes in declaration");
4083         }
4084
4085         /* FIXME: check type qualifiers here */
4086
4087         if (specifiers->modifiers & DM_TRANSPARENT_UNION)
4088                 modifiers |= TYPE_MODIFIER_TRANSPARENT_UNION;
4089         type->base.qualifiers = qualifiers;
4090         type->base.modifiers  = modifiers;
4091
4092         type = identify_new_type(type);
4093
4094         type = handle_type_attributes(specifiers->gnu_attributes, type);
4095         specifiers->type = type;
4096         return;
4097
4098 end_error:
4099         specifiers->type = type_error_type;
4100         return;
4101 }
4102
4103 static type_qualifiers_t parse_type_qualifiers(void)
4104 {
4105         type_qualifiers_t qualifiers = TYPE_QUALIFIER_NONE;
4106
4107         while (true) {
4108                 switch (token.type) {
4109                 /* type qualifiers */
4110                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
4111                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
4112                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
4113                 /* microsoft extended type modifiers */
4114                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
4115                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
4116                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
4117                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
4118                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
4119
4120                 default:
4121                         return qualifiers;
4122                 }
4123         }
4124 }
4125
4126 /**
4127  * Parses an K&R identifier list
4128  */
4129 static void parse_identifier_list(scope_t *scope)
4130 {
4131         do {
4132                 entity_t *entity = allocate_entity_zero(ENTITY_PARAMETER);
4133                 entity->base.source_position = token.source_position;
4134                 entity->base.namespc         = NAMESPACE_NORMAL;
4135                 entity->base.symbol          = token.v.symbol;
4136                 /* a K&R parameter has no type, yet */
4137                 next_token();
4138
4139                 if (scope != NULL)
4140                         append_entity(scope, entity);
4141
4142                 if (token.type != ',') {
4143                         break;
4144                 }
4145                 next_token();
4146         } while (token.type == T_IDENTIFIER);
4147 }
4148
4149 static entity_t *parse_parameter(void)
4150 {
4151         declaration_specifiers_t specifiers;
4152         memset(&specifiers, 0, sizeof(specifiers));
4153
4154         parse_declaration_specifiers(&specifiers);
4155
4156         entity_t *entity = parse_declarator(&specifiers,
4157                         DECL_MAY_BE_ABSTRACT | DECL_IS_PARAMETER);
4158         anonymous_entity = NULL;
4159         return entity;
4160 }
4161
4162 static void semantic_parameter_incomplete(const entity_t *entity)
4163 {
4164         assert(entity->kind == ENTITY_PARAMETER);
4165
4166         /* §6.7.5.3:4  After adjustment, the parameters in a parameter type
4167          *             list in a function declarator that is part of a
4168          *             definition of that function shall not have
4169          *             incomplete type. */
4170         type_t *type = skip_typeref(entity->declaration.type);
4171         if (is_type_incomplete(type)) {
4172                 errorf(&entity->base.source_position,
4173                        "parameter '%Y' has incomplete type '%T'", entity->base.symbol,
4174                        entity->declaration.type);
4175         }
4176 }
4177
4178 /**
4179  * Parses function type parameters (and optionally creates variable_t entities
4180  * for them in a scope)
4181  */
4182 static void parse_parameters(function_type_t *type, scope_t *scope)
4183 {
4184         eat('(');
4185         add_anchor_token(')');
4186         int saved_comma_state = save_and_reset_anchor_state(',');
4187
4188         if (token.type == T_IDENTIFIER &&
4189             !is_typedef_symbol(token.v.symbol)) {
4190                 token_type_t la1_type = (token_type_t)look_ahead(1)->type;
4191                 if (la1_type == ',' || la1_type == ')') {
4192                         type->kr_style_parameters    = true;
4193                         type->unspecified_parameters = true;
4194                         parse_identifier_list(scope);
4195                         goto parameters_finished;
4196                 }
4197         }
4198
4199         if (token.type == ')') {
4200                 /* ISO/IEC 14882:1998(E) §C.1.6:1 */
4201                 if (!(c_mode & _CXX))
4202                         type->unspecified_parameters = true;
4203                 goto parameters_finished;
4204         }
4205
4206         function_parameter_t *parameter;
4207         function_parameter_t *last_parameter = NULL;
4208
4209         while (true) {
4210                 switch (token.type) {
4211                 case T_DOTDOTDOT:
4212                         next_token();
4213                         type->variadic = true;
4214                         goto parameters_finished;
4215
4216                 case T_IDENTIFIER:
4217                 case T___extension__:
4218                 DECLARATION_START
4219                 {
4220                         entity_t *entity = parse_parameter();
4221                         if (entity->kind == ENTITY_TYPEDEF) {
4222                                 errorf(&entity->base.source_position,
4223                                        "typedef not allowed as function parameter");
4224                                 break;
4225                         }
4226                         assert(is_declaration(entity));
4227
4228                         /* func(void) is not a parameter */
4229                         if (last_parameter == NULL
4230                                         && token.type == ')'
4231                                         && entity->base.symbol == NULL
4232                                         && skip_typeref(entity->declaration.type) == type_void) {
4233                                 goto parameters_finished;
4234                         }
4235                         semantic_parameter_incomplete(entity);
4236
4237                         parameter = obstack_alloc(type_obst, sizeof(parameter[0]));
4238                         memset(parameter, 0, sizeof(parameter[0]));
4239                         parameter->type = entity->declaration.type;
4240
4241                         if (scope != NULL) {
4242                                 append_entity(scope, entity);
4243                         }
4244
4245                         if (last_parameter != NULL) {
4246                                 last_parameter->next = parameter;
4247                         } else {
4248                                 type->parameters = parameter;
4249                         }
4250                         last_parameter   = parameter;
4251                         break;
4252                 }
4253
4254                 default:
4255                         goto parameters_finished;
4256                 }
4257                 if (token.type != ',') {
4258                         goto parameters_finished;
4259                 }
4260                 next_token();
4261         }
4262
4263
4264 parameters_finished:
4265         rem_anchor_token(')');
4266         expect(')', end_error);
4267
4268 end_error:
4269         restore_anchor_state(',', saved_comma_state);
4270 }
4271
4272 typedef enum construct_type_kind_t {
4273         CONSTRUCT_INVALID,
4274         CONSTRUCT_POINTER,
4275         CONSTRUCT_REFERENCE,
4276         CONSTRUCT_FUNCTION,
4277         CONSTRUCT_ARRAY
4278 } construct_type_kind_t;
4279
4280 typedef struct construct_type_t construct_type_t;
4281 struct construct_type_t {
4282         construct_type_kind_t  kind;
4283         construct_type_t      *next;
4284 };
4285
4286 typedef struct parsed_pointer_t parsed_pointer_t;
4287 struct parsed_pointer_t {
4288         construct_type_t  construct_type;
4289         type_qualifiers_t type_qualifiers;
4290         variable_t        *base_variable;  /**< MS __based extension. */
4291 };
4292
4293 typedef struct parsed_reference_t parsed_reference_t;
4294 struct parsed_reference_t {
4295         construct_type_t construct_type;
4296 };
4297
4298 typedef struct construct_function_type_t construct_function_type_t;
4299 struct construct_function_type_t {
4300         construct_type_t  construct_type;
4301         type_t           *function_type;
4302 };
4303
4304 typedef struct parsed_array_t parsed_array_t;
4305 struct parsed_array_t {
4306         construct_type_t  construct_type;
4307         type_qualifiers_t type_qualifiers;
4308         bool              is_static;
4309         bool              is_variable;
4310         expression_t     *size;
4311 };
4312
4313 typedef struct construct_base_type_t construct_base_type_t;
4314 struct construct_base_type_t {
4315         construct_type_t  construct_type;
4316         type_t           *type;
4317 };
4318
4319 static construct_type_t *parse_pointer_declarator(variable_t *base_variable)
4320 {
4321         eat('*');
4322
4323         parsed_pointer_t *pointer = obstack_alloc(&temp_obst, sizeof(pointer[0]));
4324         memset(pointer, 0, sizeof(pointer[0]));
4325         pointer->construct_type.kind = CONSTRUCT_POINTER;
4326         pointer->type_qualifiers     = parse_type_qualifiers();
4327         pointer->base_variable       = base_variable;
4328
4329         return &pointer->construct_type;
4330 }
4331
4332 static construct_type_t *parse_reference_declarator(void)
4333 {
4334         eat('&');
4335
4336         parsed_reference_t *reference = obstack_alloc(&temp_obst, sizeof(reference[0]));
4337         memset(reference, 0, sizeof(reference[0]));
4338         reference->construct_type.kind = CONSTRUCT_REFERENCE;
4339
4340         return (construct_type_t*)reference;
4341 }
4342
4343 static construct_type_t *parse_array_declarator(void)
4344 {
4345         eat('[');
4346         add_anchor_token(']');
4347
4348         parsed_array_t *array = obstack_alloc(&temp_obst, sizeof(array[0]));
4349         memset(array, 0, sizeof(array[0]));
4350         array->construct_type.kind = CONSTRUCT_ARRAY;
4351
4352         if (token.type == T_static) {
4353                 array->is_static = true;
4354                 next_token();
4355         }
4356
4357         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
4358         if (type_qualifiers != 0) {
4359                 if (token.type == T_static) {
4360                         array->is_static = true;
4361                         next_token();
4362                 }
4363         }
4364         array->type_qualifiers = type_qualifiers;
4365
4366         if (token.type == '*' && look_ahead(1)->type == ']') {
4367                 array->is_variable = true;
4368                 next_token();
4369         } else if (token.type != ']') {
4370                 expression_t *const size = parse_assignment_expression();
4371                 array->size = size;
4372                 mark_vars_read(size, NULL);
4373         }
4374
4375         rem_anchor_token(']');
4376         expect(']', end_error);
4377
4378 end_error:
4379         return &array->construct_type;
4380 }
4381
4382 static construct_type_t *parse_function_declarator(scope_t *scope,
4383                                                    decl_modifiers_t modifiers)
4384 {
4385         type_t          *type  = allocate_type_zero(TYPE_FUNCTION);
4386         function_type_t *ftype = &type->function;
4387
4388         ftype->linkage = current_linkage;
4389
4390         switch (modifiers & (DM_CDECL | DM_STDCALL | DM_FASTCALL | DM_THISCALL)) {
4391                 case DM_NONE:     break;
4392                 case DM_CDECL:    ftype->calling_convention = CC_CDECL;    break;
4393                 case DM_STDCALL:  ftype->calling_convention = CC_STDCALL;  break;
4394                 case DM_FASTCALL: ftype->calling_convention = CC_FASTCALL; break;
4395                 case DM_THISCALL: ftype->calling_convention = CC_THISCALL; break;
4396
4397                 default:
4398                         errorf(HERE, "multiple calling conventions in declaration");
4399                         break;
4400         }
4401
4402         parse_parameters(ftype, scope);
4403
4404         construct_function_type_t *construct_function_type =
4405                 obstack_alloc(&temp_obst, sizeof(construct_function_type[0]));
4406         memset(construct_function_type, 0, sizeof(construct_function_type[0]));
4407         construct_function_type->construct_type.kind = CONSTRUCT_FUNCTION;
4408         construct_function_type->function_type       = type;
4409
4410         return &construct_function_type->construct_type;
4411 }
4412
4413 typedef struct parse_declarator_env_t {
4414         decl_modifiers_t   modifiers;
4415         symbol_t          *symbol;
4416         source_position_t  source_position;
4417         scope_t            parameters;
4418 } parse_declarator_env_t;
4419
4420 static construct_type_t *parse_inner_declarator(parse_declarator_env_t *env,
4421                 bool may_be_abstract)
4422 {
4423         /* construct a single linked list of construct_type_t's which describe
4424          * how to construct the final declarator type */
4425         construct_type_t *first      = NULL;
4426         construct_type_t *last       = NULL;
4427         gnu_attribute_t  *attributes = NULL;
4428
4429         decl_modifiers_t modifiers = parse_attributes(&attributes);
4430
4431         /* MS __based extension */
4432         based_spec_t base_spec;
4433         base_spec.base_variable = NULL;
4434
4435         for (;;) {
4436                 construct_type_t *type;
4437                 switch (token.type) {
4438                         case '&':
4439                                 if (!(c_mode & _CXX))
4440                                         errorf(HERE, "references are only available for C++");
4441                                 if (base_spec.base_variable != NULL && warning.other) {
4442                                         warningf(&base_spec.source_position,
4443                                                  "__based does not precede a pointer operator, ignored");
4444                                 }
4445                                 type = parse_reference_declarator();
4446                                 /* consumed */
4447                                 base_spec.base_variable = NULL;
4448                                 break;
4449
4450                         case '*':
4451                                 type = parse_pointer_declarator(base_spec.base_variable);
4452                                 /* consumed */
4453                                 base_spec.base_variable = NULL;
4454                                 break;
4455
4456                         case T__based:
4457                                 next_token();
4458                                 expect('(', end_error);
4459                                 add_anchor_token(')');
4460                                 parse_microsoft_based(&base_spec);
4461                                 rem_anchor_token(')');
4462                                 expect(')', end_error);
4463                                 continue;
4464
4465                         default:
4466                                 goto ptr_operator_end;
4467                 }
4468
4469                 if (last == NULL) {
4470                         first = type;
4471                         last  = type;
4472                 } else {
4473                         last->next = type;
4474                         last       = type;
4475                 }
4476
4477                 /* TODO: find out if this is correct */
4478                 modifiers |= parse_attributes(&attributes);
4479         }
4480 ptr_operator_end:
4481         if (base_spec.base_variable != NULL && warning.other) {
4482                 warningf(&base_spec.source_position,
4483                          "__based does not precede a pointer operator, ignored");
4484         }
4485
4486         if (env != NULL) {
4487                 modifiers      |= env->modifiers;
4488                 env->modifiers  = modifiers;
4489         }
4490
4491         construct_type_t *inner_types = NULL;
4492
4493         switch (token.type) {
4494         case T_IDENTIFIER:
4495                 if (env == NULL) {
4496                         errorf(HERE, "no identifier expected in typename");
4497                 } else {
4498                         env->symbol          = token.v.symbol;
4499                         env->source_position = token.source_position;
4500                 }
4501                 next_token();
4502                 break;
4503         case '(':
4504                 /* §6.7.6:2 footnote 126:  Empty parentheses in a type name are
4505                  * interpreted as ``function with no parameter specification'', rather
4506                  * than redundant parentheses around the omitted identifier. */
4507                 if (look_ahead(1)->type != ')') {
4508                         next_token();
4509                         add_anchor_token(')');
4510                         inner_types = parse_inner_declarator(env, may_be_abstract);
4511                         if (inner_types != NULL) {
4512                                 /* All later declarators only modify the return type */
4513                                 env = NULL;
4514                         }
4515                         rem_anchor_token(')');
4516                         expect(')', end_error);
4517                 }
4518                 break;
4519         default:
4520                 if (may_be_abstract)
4521                         break;
4522                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', NULL);
4523                 eat_until_anchor();
4524                 return NULL;
4525         }
4526
4527         construct_type_t *p = last;
4528
4529         while (true) {
4530                 construct_type_t *type;
4531                 switch (token.type) {
4532                 case '(': {
4533                         scope_t *scope = NULL;
4534                         if (env != NULL)
4535                                 scope = &env->parameters;
4536
4537                         type = parse_function_declarator(scope, modifiers);
4538                         break;
4539                 }
4540                 case '[':
4541                         type = parse_array_declarator();
4542                         break;
4543                 default:
4544                         goto declarator_finished;
4545                 }
4546
4547                 /* insert in the middle of the list (behind p) */
4548                 if (p != NULL) {
4549                         type->next = p->next;
4550                         p->next    = type;
4551                 } else {
4552                         type->next = first;
4553                         first      = type;
4554                 }
4555                 if (last == p) {
4556                         last = type;
4557                 }
4558         }
4559
4560 declarator_finished:
4561         /* append inner_types at the end of the list, we don't to set last anymore
4562          * as it's not needed anymore */
4563         if (last == NULL) {
4564                 assert(first == NULL);
4565                 first = inner_types;
4566         } else {
4567                 last->next = inner_types;
4568         }
4569
4570         return first;
4571 end_error:
4572         return NULL;
4573 }
4574
4575 static void parse_declaration_attributes(entity_t *entity)
4576 {
4577         gnu_attribute_t  *attributes = NULL;
4578         decl_modifiers_t  modifiers  = parse_attributes(&attributes);
4579
4580         if (entity == NULL)
4581                 return;
4582
4583         type_t *type;
4584         if (entity->kind == ENTITY_TYPEDEF) {
4585                 modifiers |= entity->typedefe.modifiers;
4586                 type       = entity->typedefe.type;
4587         } else {
4588                 assert(is_declaration(entity));
4589                 modifiers |= entity->declaration.modifiers;
4590                 type       = entity->declaration.type;
4591         }
4592         if (type == NULL)
4593                 return;
4594
4595         gnu_attribute_t *attribute = attributes;
4596         for ( ; attribute != NULL; attribute = attribute->next) {
4597                 if (attribute->invalid)
4598                         continue;
4599
4600                 if (attribute->kind == GNU_AK_MODE) {
4601                         type = handle_attribute_mode(attribute, type);
4602                 } else if (attribute->kind == GNU_AK_ALIGNED) {
4603                         int alignment = 32; /* TODO: fill in maximum usefull alignment for target machine */
4604                         if (attribute->has_arguments)
4605                                 alignment = attribute->u.argument;
4606
4607                         if (entity->kind == ENTITY_TYPEDEF) {
4608                                 type_t *copy         = duplicate_type(type);
4609                                 copy->base.alignment = attribute->u.argument;
4610                                 type                 = identify_new_type(copy);
4611                         } else if(entity->kind == ENTITY_VARIABLE) {
4612                                 entity->variable.alignment = alignment;
4613                         } else if(entity->kind == ENTITY_COMPOUND_MEMBER) {
4614                                 entity->compound_member.alignment = alignment;
4615                         }
4616                 }
4617         }
4618
4619         type_modifiers_t type_modifiers = type->base.modifiers;
4620         if (modifiers & DM_TRANSPARENT_UNION)
4621                 type_modifiers |= TYPE_MODIFIER_TRANSPARENT_UNION;
4622
4623         if (type->base.modifiers != type_modifiers) {
4624                 type_t *copy         = duplicate_type(type);
4625                 copy->base.modifiers = type_modifiers;
4626                 type                 = identify_new_type(copy);
4627         }
4628
4629         if (entity->kind == ENTITY_TYPEDEF) {
4630                 entity->typedefe.type      = type;
4631                 entity->typedefe.modifiers = modifiers;
4632         } else {
4633                 entity->declaration.type      = type;
4634                 entity->declaration.modifiers = modifiers;
4635         }
4636 }
4637
4638 static type_t *construct_declarator_type(construct_type_t *construct_list, type_t *type)
4639 {
4640         construct_type_t *iter = construct_list;
4641         for (; iter != NULL; iter = iter->next) {
4642                 switch (iter->kind) {
4643                 case CONSTRUCT_INVALID:
4644                         internal_errorf(HERE, "invalid type construction found");
4645                 case CONSTRUCT_FUNCTION: {
4646                         construct_function_type_t *construct_function_type
4647                                 = (construct_function_type_t*) iter;
4648
4649                         type_t *function_type = construct_function_type->function_type;
4650
4651                         function_type->function.return_type = type;
4652
4653                         type_t *skipped_return_type = skip_typeref(type);
4654                         /* §6.7.5.3:1 */
4655                         if (is_type_function(skipped_return_type)) {
4656                                 errorf(HERE, "function returning function is not allowed");
4657                         } else if (is_type_array(skipped_return_type)) {
4658                                 errorf(HERE, "function returning array is not allowed");
4659                         } else {
4660                                 if (skipped_return_type->base.qualifiers != 0 && warning.other) {
4661                                         warningf(HERE,
4662                                                 "type qualifiers in return type of function type are meaningless");
4663                                 }
4664                         }
4665
4666                         type = function_type;
4667                         break;
4668                 }
4669
4670                 case CONSTRUCT_POINTER: {
4671                         if (is_type_reference(skip_typeref(type)))
4672                                 errorf(HERE, "cannot declare a pointer to reference");
4673
4674                         parsed_pointer_t *parsed_pointer = (parsed_pointer_t*) iter;
4675                         type = make_based_pointer_type(type, parsed_pointer->type_qualifiers, parsed_pointer->base_variable);
4676                         continue;
4677                 }
4678
4679                 case CONSTRUCT_REFERENCE:
4680                         if (is_type_reference(skip_typeref(type)))
4681                                 errorf(HERE, "cannot declare a reference to reference");
4682
4683                         type = make_reference_type(type);
4684                         continue;
4685
4686                 case CONSTRUCT_ARRAY: {
4687                         if (is_type_reference(skip_typeref(type)))
4688                                 errorf(HERE, "cannot declare an array of references");
4689
4690                         parsed_array_t *parsed_array  = (parsed_array_t*) iter;
4691                         type_t         *array_type    = allocate_type_zero(TYPE_ARRAY);
4692
4693                         expression_t *size_expression = parsed_array->size;
4694                         if (size_expression != NULL) {
4695                                 size_expression
4696                                         = create_implicit_cast(size_expression, type_size_t);
4697                         }
4698
4699                         array_type->base.qualifiers       = parsed_array->type_qualifiers;
4700                         array_type->array.element_type    = type;
4701                         array_type->array.is_static       = parsed_array->is_static;
4702                         array_type->array.is_variable     = parsed_array->is_variable;
4703                         array_type->array.size_expression = size_expression;
4704
4705                         if (size_expression != NULL) {
4706                                 if (is_constant_expression(size_expression)) {
4707                                         array_type->array.size_constant = true;
4708                                         array_type->array.size
4709                                                 = fold_constant(size_expression);
4710                                 } else {
4711                                         array_type->array.is_vla = true;
4712                                 }
4713                         }
4714
4715                         type_t *skipped_type = skip_typeref(type);
4716                         /* §6.7.5.2:1 */
4717                         if (is_type_incomplete(skipped_type)) {
4718                                 errorf(HERE, "array of incomplete type '%T' is not allowed", type);
4719                         } else if (is_type_function(skipped_type)) {
4720                                 errorf(HERE, "array of functions is not allowed");
4721                         }
4722                         type = array_type;
4723                         break;
4724                 }
4725                 }
4726
4727                 /* The function type was constructed earlier.  Freeing it here will
4728                  * destroy other types. */
4729                 if (iter->kind == CONSTRUCT_FUNCTION) {
4730                         type = typehash_insert(type);
4731                 } else {
4732                         type = identify_new_type(type);
4733                 }
4734         }
4735
4736         return type;
4737 }
4738
4739 static type_t *automatic_type_conversion(type_t *orig_type);
4740
4741 static type_t *semantic_parameter(const source_position_t *pos,
4742                                   type_t *type,
4743                                   const declaration_specifiers_t *specifiers,
4744                                   symbol_t *symbol)
4745 {
4746         /* §6.7.5.3:7  A declaration of a parameter as ``array of type''
4747          *             shall be adjusted to ``qualified pointer to type'',
4748          *             [...]
4749          * §6.7.5.3:8  A declaration of a parameter as ``function returning
4750          *             type'' shall be adjusted to ``pointer to function
4751          *             returning type'', as in 6.3.2.1. */
4752         type = automatic_type_conversion(type);
4753
4754         if (specifiers->is_inline && is_type_valid(type)) {
4755                 errorf(pos, "parameter '%Y' declared 'inline'", symbol);
4756         }
4757
4758         /* §6.9.1:6  The declarations in the declaration list shall contain
4759          *           no storage-class specifier other than register and no
4760          *           initializations. */
4761         if (specifiers->thread_local || (
4762                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
4763                         specifiers->storage_class != STORAGE_CLASS_REGISTER)
4764            ) {
4765                 errorf(pos, "invalid storage class for parameter '%Y'", symbol);
4766         }
4767
4768         /* delay test for incomplete type, because we might have (void)
4769          * which is legal but incomplete... */
4770
4771         return type;
4772 }
4773
4774 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
4775                                   declarator_flags_t flags)
4776 {
4777         parse_declarator_env_t env;
4778         memset(&env, 0, sizeof(env));
4779         env.modifiers = specifiers->modifiers;
4780
4781         construct_type_t *construct_type =
4782                 parse_inner_declarator(&env, (flags & DECL_MAY_BE_ABSTRACT) != 0);
4783         type_t           *orig_type      =
4784                 construct_declarator_type(construct_type, specifiers->type);
4785         type_t           *type           = skip_typeref(orig_type);
4786
4787         if (construct_type != NULL) {
4788                 obstack_free(&temp_obst, construct_type);
4789         }
4790
4791         entity_t *entity;
4792         if (specifiers->storage_class == STORAGE_CLASS_TYPEDEF) {
4793                 entity                       = allocate_entity_zero(ENTITY_TYPEDEF);
4794                 entity->base.symbol          = env.symbol;
4795                 entity->base.source_position = env.source_position;
4796                 entity->typedefe.type        = orig_type;
4797
4798                 if (anonymous_entity != NULL) {
4799                         if (is_type_compound(type)) {
4800                                 assert(anonymous_entity->compound.alias == NULL);
4801                                 assert(anonymous_entity->kind == ENTITY_STRUCT ||
4802                                        anonymous_entity->kind == ENTITY_UNION);
4803                                 anonymous_entity->compound.alias = entity;
4804                                 anonymous_entity = NULL;
4805                         } else if (is_type_enum(type)) {
4806                                 assert(anonymous_entity->enume.alias == NULL);
4807                                 assert(anonymous_entity->kind == ENTITY_ENUM);
4808                                 anonymous_entity->enume.alias = entity;
4809                                 anonymous_entity = NULL;
4810                         }
4811                 }
4812         } else {
4813                 /* create a declaration type entity */
4814                 if (flags & DECL_CREATE_COMPOUND_MEMBER) {
4815                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER);
4816
4817                         if (env.symbol != NULL) {
4818                                 if (specifiers->is_inline && is_type_valid(type)) {
4819                                         errorf(&env.source_position,
4820                                                         "compound member '%Y' declared 'inline'", env.symbol);
4821                                 }
4822
4823                                 if (specifiers->thread_local ||
4824                                                 specifiers->storage_class != STORAGE_CLASS_NONE) {
4825                                         errorf(&env.source_position,
4826                                                         "compound member '%Y' must have no storage class",
4827                                                         env.symbol);
4828                                 }
4829                         }
4830                 } else if (flags & DECL_IS_PARAMETER) {
4831                         orig_type = semantic_parameter(&env.source_position, orig_type,
4832                                                        specifiers, env.symbol);
4833
4834                         entity = allocate_entity_zero(ENTITY_PARAMETER);
4835                 } else if (is_type_function(type)) {
4836                         entity = allocate_entity_zero(ENTITY_FUNCTION);
4837
4838                         entity->function.is_inline  = specifiers->is_inline;
4839                         entity->function.parameters = env.parameters;
4840
4841                         if (env.symbol != NULL) {
4842                                 if (specifiers->thread_local || (
4843                                                         specifiers->storage_class != STORAGE_CLASS_EXTERN &&
4844                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
4845                                                         specifiers->storage_class != STORAGE_CLASS_STATIC
4846                                                 )) {
4847                                         errorf(&env.source_position,
4848                                                         "invalid storage class for function '%Y'", env.symbol);
4849                                 }
4850                         }
4851                 } else {
4852                         entity = allocate_entity_zero(ENTITY_VARIABLE);
4853
4854                         entity->variable.get_property_sym = specifiers->get_property_sym;
4855                         entity->variable.put_property_sym = specifiers->put_property_sym;
4856
4857                         entity->variable.thread_local = specifiers->thread_local;
4858
4859                         if (env.symbol != NULL) {
4860                                 if (specifiers->is_inline && is_type_valid(type)) {
4861                                         errorf(&env.source_position,
4862                                                         "variable '%Y' declared 'inline'", env.symbol);
4863                                 }
4864
4865                                 bool invalid_storage_class = false;
4866                                 if (current_scope == file_scope) {
4867                                         if (specifiers->storage_class != STORAGE_CLASS_EXTERN &&
4868                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
4869                                                         specifiers->storage_class != STORAGE_CLASS_STATIC) {
4870                                                 invalid_storage_class = true;
4871                                         }
4872                                 } else {
4873                                         if (specifiers->thread_local &&
4874                                                         specifiers->storage_class == STORAGE_CLASS_NONE) {
4875                                                 invalid_storage_class = true;
4876                                         }
4877                                 }
4878                                 if (invalid_storage_class) {
4879                                         errorf(&env.source_position,
4880                                                         "invalid storage class for variable '%Y'", env.symbol);
4881                                 }
4882                         }
4883                 }
4884
4885                 if (env.symbol != NULL) {
4886                         entity->base.symbol          = env.symbol;
4887                         entity->base.source_position = env.source_position;
4888                 } else {
4889                         entity->base.source_position = specifiers->source_position;
4890                 }
4891                 entity->base.namespc                  = NAMESPACE_NORMAL;
4892                 entity->declaration.type              = orig_type;
4893                 entity->declaration.modifiers         = env.modifiers;
4894                 entity->declaration.deprecated_string = specifiers->deprecated_string;
4895
4896                 storage_class_t storage_class = specifiers->storage_class;
4897                 entity->declaration.declared_storage_class = storage_class;
4898
4899                 if (storage_class == STORAGE_CLASS_NONE && current_scope != file_scope)
4900                         storage_class = STORAGE_CLASS_AUTO;
4901                 entity->declaration.storage_class = storage_class;
4902         }
4903
4904         parse_declaration_attributes(entity);
4905
4906         return entity;
4907 }
4908
4909 static type_t *parse_abstract_declarator(type_t *base_type)
4910 {
4911         construct_type_t *construct_type = parse_inner_declarator(NULL, 1);
4912
4913         type_t *result = construct_declarator_type(construct_type, base_type);
4914         if (construct_type != NULL) {
4915                 obstack_free(&temp_obst, construct_type);
4916         }
4917
4918         return result;
4919 }
4920
4921 /**
4922  * Check if the declaration of main is suspicious.  main should be a
4923  * function with external linkage, returning int, taking either zero
4924  * arguments, two, or three arguments of appropriate types, ie.
4925  *
4926  * int main([ int argc, char **argv [, char **env ] ]).
4927  *
4928  * @param decl    the declaration to check
4929  * @param type    the function type of the declaration
4930  */
4931 static void check_type_of_main(const entity_t *entity)
4932 {
4933         const source_position_t *pos = &entity->base.source_position;
4934         if (entity->kind != ENTITY_FUNCTION) {
4935                 warningf(pos, "'main' is not a function");
4936                 return;
4937         }
4938
4939         if (entity->declaration.storage_class == STORAGE_CLASS_STATIC) {
4940                 warningf(pos, "'main' is normally a non-static function");
4941         }
4942
4943         type_t *type = skip_typeref(entity->declaration.type);
4944         assert(is_type_function(type));
4945
4946         function_type_t *func_type = &type->function;
4947         if (!types_compatible(skip_typeref(func_type->return_type), type_int)) {
4948                 warningf(pos, "return type of 'main' should be 'int', but is '%T'",
4949                          func_type->return_type);
4950         }
4951         const function_parameter_t *parm = func_type->parameters;
4952         if (parm != NULL) {
4953                 type_t *const first_type = parm->type;
4954                 if (!types_compatible(skip_typeref(first_type), type_int)) {
4955                         warningf(pos,
4956                                  "first argument of 'main' should be 'int', but is '%T'",
4957                                  first_type);
4958                 }
4959                 parm = parm->next;
4960                 if (parm != NULL) {
4961                         type_t *const second_type = parm->type;
4962                         if (!types_compatible(skip_typeref(second_type), type_char_ptr_ptr)) {
4963                                 warningf(pos, "second argument of 'main' should be 'char**', but is '%T'", second_type);
4964                         }
4965                         parm = parm->next;
4966                         if (parm != NULL) {
4967                                 type_t *const third_type = parm->type;
4968                                 if (!types_compatible(skip_typeref(third_type), type_char_ptr_ptr)) {
4969                                         warningf(pos, "third argument of 'main' should be 'char**', but is '%T'", third_type);
4970                                 }
4971                                 parm = parm->next;
4972                                 if (parm != NULL)
4973                                         goto warn_arg_count;
4974                         }
4975                 } else {
4976 warn_arg_count:
4977                         warningf(pos, "'main' takes only zero, two or three arguments");
4978                 }
4979         }
4980 }
4981
4982 /**
4983  * Check if a symbol is the equal to "main".
4984  */
4985 static bool is_sym_main(const symbol_t *const sym)
4986 {
4987         return strcmp(sym->string, "main") == 0;
4988 }
4989
4990 static void error_redefined_as_different_kind(const source_position_t *pos,
4991                 const entity_t *old, entity_kind_t new_kind)
4992 {
4993         errorf(pos, "redeclaration of %s '%Y' as %s (declared %P)",
4994                get_entity_kind_name(old->kind), old->base.symbol,
4995                get_entity_kind_name(new_kind), &old->base.source_position);
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 *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                         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 != NULL &&
5055                         previous_entity->base.parent_scope == current_scope) {
5056                 if (previous_entity->kind != entity->kind) {
5057                         error_redefined_as_different_kind(pos, previous_entity,
5058                                                           entity->kind);
5059                         goto finish;
5060                 }
5061                 if (previous_entity->kind == ENTITY_ENUM_VALUE) {
5062                         errorf(pos, "redeclaration of enum entry '%Y' (declared %P)",
5063                                    symbol, &previous_entity->base.source_position);
5064                         goto finish;
5065                 }
5066                 if (previous_entity->kind == ENTITY_TYPEDEF) {
5067                         /* TODO: C++ allows this for exactly the same type */
5068                         errorf(pos, "redefinition of typedef '%Y' (declared %P)",
5069                                symbol, &previous_entity->base.source_position);
5070                         goto finish;
5071                 }
5072
5073                 /* at this point we should have only VARIABLES or FUNCTIONS */
5074                 assert(is_declaration(previous_entity) && is_declaration(entity));
5075
5076                 declaration_t *const prev_decl = &previous_entity->declaration;
5077                 declaration_t *const decl      = &entity->declaration;
5078
5079                 /* can happen for K&R style declarations */
5080                 if (prev_decl->type       == NULL             &&
5081                                 previous_entity->kind == ENTITY_PARAMETER &&
5082                                 entity->kind          == ENTITY_PARAMETER) {
5083                         prev_decl->type                   = decl->type;
5084                         prev_decl->storage_class          = decl->storage_class;
5085                         prev_decl->declared_storage_class = decl->declared_storage_class;
5086                         prev_decl->modifiers              = decl->modifiers;
5087                         prev_decl->deprecated_string      = decl->deprecated_string;
5088                         return previous_entity;
5089                 }
5090
5091                 type_t *const orig_type = decl->type;
5092                 assert(orig_type != NULL);
5093                 type_t *const type      = skip_typeref(orig_type);
5094                 type_t *      prev_type = skip_typeref(prev_decl->type);
5095
5096                 if (!types_compatible(type, prev_type)) {
5097                         errorf(pos,
5098                                    "declaration '%#T' is incompatible with '%#T' (declared %P)",
5099                                    orig_type, symbol, prev_decl->type, symbol,
5100                                    &previous_entity->base.source_position);
5101                 } else {
5102                         unsigned old_storage_class = prev_decl->storage_class;
5103                         if (warning.redundant_decls               &&
5104                                         is_definition                     &&
5105                                         !prev_decl->used                  &&
5106                                         !(prev_decl->modifiers & DM_USED) &&
5107                                         prev_decl->storage_class == STORAGE_CLASS_STATIC) {
5108                                 warningf(&previous_entity->base.source_position,
5109                                          "unnecessary static forward declaration for '%#T'",
5110                                          prev_decl->type, symbol);
5111                         }
5112
5113                         unsigned new_storage_class = decl->storage_class;
5114                         if (is_type_incomplete(prev_type)) {
5115                                 prev_decl->type = type;
5116                                 prev_type       = type;
5117                         }
5118
5119                         /* pretend no storage class means extern for function
5120                          * declarations (except if the previous declaration is neither
5121                          * none nor extern) */
5122                         if (entity->kind == ENTITY_FUNCTION) {
5123                                 if (prev_type->function.unspecified_parameters) {
5124                                         prev_decl->type = type;
5125                                         prev_type       = type;
5126                                 }
5127
5128                                 switch (old_storage_class) {
5129                                 case STORAGE_CLASS_NONE:
5130                                         old_storage_class = STORAGE_CLASS_EXTERN;
5131                                         /* FALLTHROUGH */
5132
5133                                 case STORAGE_CLASS_EXTERN:
5134                                         if (is_definition) {
5135                                                 if (warning.missing_prototypes &&
5136                                                     prev_type->function.unspecified_parameters &&
5137                                                     !is_sym_main(symbol)) {
5138                                                         warningf(pos, "no previous prototype for '%#T'",
5139                                                                          orig_type, symbol);
5140                                                 }
5141                                         } else if (new_storage_class == STORAGE_CLASS_NONE) {
5142                                                 new_storage_class = STORAGE_CLASS_EXTERN;
5143                                         }
5144                                         break;
5145
5146                                 default:
5147                                         break;
5148                                 }
5149                         }
5150
5151                         if (old_storage_class == STORAGE_CLASS_EXTERN &&
5152                                         new_storage_class == STORAGE_CLASS_EXTERN) {
5153 warn_redundant_declaration:
5154                                 if (!is_definition           &&
5155                                     warning.redundant_decls  &&
5156                                     is_type_valid(prev_type) &&
5157                                     strcmp(previous_entity->base.source_position.input_name,
5158                                            "<builtin>") != 0) {
5159                                         warningf(pos,
5160                                                  "redundant declaration for '%Y' (declared %P)",
5161                                                  symbol, &previous_entity->base.source_position);
5162                                 }
5163                         } else if (current_function == NULL) {
5164                                 if (old_storage_class != STORAGE_CLASS_STATIC &&
5165                                     new_storage_class == STORAGE_CLASS_STATIC) {
5166                                         errorf(pos,
5167                                                "static declaration of '%Y' follows non-static declaration (declared %P)",
5168                                                symbol, &previous_entity->base.source_position);
5169                                 } else if (old_storage_class == STORAGE_CLASS_EXTERN) {
5170                                         prev_decl->storage_class          = STORAGE_CLASS_NONE;
5171                                         prev_decl->declared_storage_class = STORAGE_CLASS_NONE;
5172                                 } else {
5173                                         /* ISO/IEC 14882:1998(E) §C.1.2:1 */
5174                                         if (c_mode & _CXX)
5175                                                 goto error_redeclaration;
5176                                         goto warn_redundant_declaration;
5177                                 }
5178                         } else if (is_type_valid(prev_type)) {
5179                                 if (old_storage_class == new_storage_class) {
5180 error_redeclaration:
5181                                         errorf(pos, "redeclaration of '%Y' (declared %P)",
5182                                                symbol, &previous_entity->base.source_position);
5183                                 } else {
5184                                         errorf(pos,
5185                                                "redeclaration of '%Y' with different linkage (declared %P)",
5186                                                symbol, &previous_entity->base.source_position);
5187                                 }
5188                         }
5189                 }
5190
5191                 prev_decl->modifiers |= decl->modifiers;
5192                 if (entity->kind == ENTITY_FUNCTION) {
5193                         previous_entity->function.is_inline |= entity->function.is_inline;
5194                 }
5195                 return previous_entity;
5196         }
5197
5198         if (entity->kind == ENTITY_FUNCTION) {
5199                 if (is_definition &&
5200                                 entity->declaration.storage_class != STORAGE_CLASS_STATIC) {
5201                         if (warning.missing_prototypes && !is_sym_main(symbol)) {
5202                                 warningf(pos, "no previous prototype for '%#T'",
5203                                          entity->declaration.type, symbol);
5204                         } else if (warning.missing_declarations && !is_sym_main(symbol)) {
5205                                 warningf(pos, "no previous declaration for '%#T'",
5206                                          entity->declaration.type, symbol);
5207                         }
5208                 }
5209         } else if (warning.missing_declarations &&
5210                         entity->kind == ENTITY_VARIABLE &&
5211                         current_scope == file_scope) {
5212                 declaration_t *declaration = &entity->declaration;
5213                 if (declaration->storage_class == STORAGE_CLASS_NONE) {
5214                         warningf(pos, "no previous declaration for '%#T'",
5215                                  declaration->type, symbol);
5216                 }
5217         }
5218
5219 finish:
5220         assert(entity->base.parent_scope == NULL);
5221         assert(current_scope != NULL);
5222
5223         entity->base.parent_scope = current_scope;
5224         entity->base.namespc      = NAMESPACE_NORMAL;
5225         environment_push(entity);
5226         append_entity(current_scope, entity);
5227
5228         return entity;
5229 }
5230
5231 static void parser_error_multiple_definition(entity_t *entity,
5232                 const source_position_t *source_position)
5233 {
5234         errorf(source_position, "multiple definition of '%Y' (declared %P)",
5235                entity->base.symbol, &entity->base.source_position);
5236 }
5237
5238 static bool is_declaration_specifier(const token_t *token,
5239                                      bool only_specifiers_qualifiers)
5240 {
5241         switch (token->type) {
5242                 TYPE_SPECIFIERS
5243                 TYPE_QUALIFIERS
5244                         return true;
5245                 case T_IDENTIFIER:
5246                         return is_typedef_symbol(token->v.symbol);
5247
5248                 case T___extension__:
5249                 STORAGE_CLASSES
5250                         return !only_specifiers_qualifiers;
5251
5252                 default:
5253                         return false;
5254         }
5255 }
5256
5257 static void parse_init_declarator_rest(entity_t *entity)
5258 {
5259         assert(is_declaration(entity));
5260         declaration_t *const declaration = &entity->declaration;
5261
5262         eat('=');
5263
5264         type_t *orig_type = declaration->type;
5265         type_t *type      = skip_typeref(orig_type);
5266
5267         if (entity->kind == ENTITY_VARIABLE
5268                         && entity->variable.initializer != NULL) {
5269                 parser_error_multiple_definition(entity, HERE);
5270         }
5271
5272         bool must_be_constant = false;
5273         if (declaration->storage_class == STORAGE_CLASS_STATIC ||
5274             entity->base.parent_scope  == file_scope) {
5275                 must_be_constant = true;
5276         }
5277
5278         if (is_type_function(type)) {
5279                 errorf(&entity->base.source_position,
5280                        "function '%#T' is initialized like a variable",
5281                        orig_type, entity->base.symbol);
5282                 orig_type = type_error_type;
5283         }
5284
5285         parse_initializer_env_t env;
5286         env.type             = orig_type;
5287         env.must_be_constant = must_be_constant;
5288         env.entity           = entity;
5289         current_init_decl    = entity;
5290
5291         initializer_t *initializer = parse_initializer(&env);
5292         current_init_decl = NULL;
5293
5294         if (entity->kind == ENTITY_VARIABLE) {
5295                 /* § 6.7.5:22  array initializers for arrays with unknown size
5296                  * determine the array type size */
5297                 declaration->type            = env.type;
5298                 entity->variable.initializer = initializer;
5299         }
5300 }
5301
5302 /* parse rest of a declaration without any declarator */
5303 static void parse_anonymous_declaration_rest(
5304                 const declaration_specifiers_t *specifiers)
5305 {
5306         eat(';');
5307         anonymous_entity = NULL;
5308
5309         if (warning.other) {
5310                 if (specifiers->storage_class != STORAGE_CLASS_NONE ||
5311                                 specifiers->thread_local) {
5312                         warningf(&specifiers->source_position,
5313                                  "useless storage class in empty declaration");
5314                 }
5315
5316                 type_t *type = specifiers->type;
5317                 switch (type->kind) {
5318                         case TYPE_COMPOUND_STRUCT:
5319                         case TYPE_COMPOUND_UNION: {
5320                                 if (type->compound.compound->base.symbol == NULL) {
5321                                         warningf(&specifiers->source_position,
5322                                                  "unnamed struct/union that defines no instances");
5323                                 }
5324                                 break;
5325                         }
5326
5327                         case TYPE_ENUM:
5328                                 break;
5329
5330                         default:
5331                                 warningf(&specifiers->source_position, "empty declaration");
5332                                 break;
5333                 }
5334         }
5335 }
5336
5337 static void check_variable_type_complete(entity_t *ent)
5338 {
5339         if (ent->kind != ENTITY_VARIABLE)
5340                 return;
5341
5342         /* §6.7:7  If an identifier for an object is declared with no linkage, the
5343          *         type for the object shall be complete [...] */
5344         declaration_t *decl = &ent->declaration;
5345         if (decl->storage_class != STORAGE_CLASS_NONE)
5346                 return;
5347
5348         type_t *const orig_type = decl->type;
5349         type_t *const type      = skip_typeref(orig_type);
5350         if (!is_type_incomplete(type))
5351                 return;
5352
5353         /* GCC allows global arrays without size and assigns them a length of one,
5354          * if no different declaration follows */
5355         if (is_type_array(type) &&
5356                         c_mode & _GNUC      &&
5357                         ent->base.parent_scope == file_scope) {
5358                 ARR_APP1(declaration_t*, incomplete_arrays, decl);
5359                 return;
5360         }
5361
5362         errorf(&ent->base.source_position, "variable '%#T' has incomplete type",
5363                         orig_type, ent->base.symbol);
5364 }
5365
5366
5367 static void parse_declaration_rest(entity_t *ndeclaration,
5368                 const declaration_specifiers_t *specifiers,
5369                 parsed_declaration_func         finished_declaration,
5370                 declarator_flags_t              flags)
5371 {
5372         add_anchor_token(';');
5373         add_anchor_token(',');
5374         while (true) {
5375                 entity_t *entity = finished_declaration(ndeclaration, token.type == '=');
5376
5377                 if (token.type == '=') {
5378                         parse_init_declarator_rest(entity);
5379                 } else if (entity->kind == ENTITY_VARIABLE) {
5380                         /* ISO/IEC 14882:1998(E) §8.5.3:3  The initializer can be omitted
5381                          * [...] where the extern specifier is explicitly used. */
5382                         declaration_t *decl = &entity->declaration;
5383                         if (decl->storage_class != STORAGE_CLASS_EXTERN) {
5384                                 type_t *type = decl->type;
5385                                 if (is_type_reference(skip_typeref(type))) {
5386                                         errorf(&entity->base.source_position,
5387                                                         "reference '%#T' must be initialized",
5388                                                         type, entity->base.symbol);
5389                                 }
5390                         }
5391                 }
5392
5393                 check_variable_type_complete(entity);
5394
5395                 if (token.type != ',')
5396                         break;
5397                 eat(',');
5398
5399                 add_anchor_token('=');
5400                 ndeclaration = parse_declarator(specifiers, flags);
5401                 rem_anchor_token('=');
5402         }
5403         expect(';', end_error);
5404
5405 end_error:
5406         anonymous_entity = NULL;
5407         rem_anchor_token(';');
5408         rem_anchor_token(',');
5409 }
5410
5411 static entity_t *finished_kr_declaration(entity_t *entity, bool is_definition)
5412 {
5413         symbol_t *symbol = entity->base.symbol;
5414         if (symbol == NULL) {
5415                 errorf(HERE, "anonymous declaration not valid as function parameter");
5416                 return entity;
5417         }
5418
5419         assert(entity->base.namespc == NAMESPACE_NORMAL);
5420         entity_t *previous_entity = get_entity(symbol, NAMESPACE_NORMAL);
5421         if (previous_entity == NULL
5422                         || previous_entity->base.parent_scope != current_scope) {
5423                 errorf(HERE, "expected declaration of a function parameter, found '%Y'",
5424                        symbol);
5425                 return entity;
5426         }
5427
5428         if (is_definition) {
5429                 errorf(HERE, "parameter '%Y' is initialised", entity->base.symbol);
5430         }
5431
5432         return record_entity(entity, false);
5433 }
5434
5435 static void parse_declaration(parsed_declaration_func finished_declaration,
5436                               declarator_flags_t      flags)
5437 {
5438         declaration_specifiers_t specifiers;
5439         memset(&specifiers, 0, sizeof(specifiers));
5440
5441         add_anchor_token(';');
5442         parse_declaration_specifiers(&specifiers);
5443         rem_anchor_token(';');
5444
5445         if (token.type == ';') {
5446                 parse_anonymous_declaration_rest(&specifiers);
5447         } else {
5448                 entity_t *entity = parse_declarator(&specifiers, flags);
5449                 parse_declaration_rest(entity, &specifiers, finished_declaration, flags);
5450         }
5451 }
5452
5453 static type_t *get_default_promoted_type(type_t *orig_type)
5454 {
5455         type_t *result = orig_type;
5456
5457         type_t *type = skip_typeref(orig_type);
5458         if (is_type_integer(type)) {
5459                 result = promote_integer(type);
5460         } else if (type == type_float) {
5461                 result = type_double;
5462         }
5463
5464         return result;
5465 }
5466
5467 static void parse_kr_declaration_list(entity_t *entity)
5468 {
5469         if (entity->kind != ENTITY_FUNCTION)
5470                 return;
5471
5472         type_t *type = skip_typeref(entity->declaration.type);
5473         assert(is_type_function(type));
5474         if (!type->function.kr_style_parameters)
5475                 return;
5476
5477
5478         add_anchor_token('{');
5479
5480         /* push function parameters */
5481         size_t const  top       = environment_top();
5482         scope_t      *old_scope = scope_push(&entity->function.parameters);
5483
5484         entity_t *parameter = entity->function.parameters.entities;
5485         for ( ; parameter != NULL; parameter = parameter->base.next) {
5486                 assert(parameter->base.parent_scope == NULL);
5487                 parameter->base.parent_scope = current_scope;
5488                 environment_push(parameter);
5489         }
5490
5491         /* parse declaration list */
5492         for (;;) {
5493                 switch (token.type) {
5494                         DECLARATION_START
5495                         case T___extension__:
5496                         /* This covers symbols, which are no type, too, and results in
5497                          * better error messages.  The typical cases are misspelled type
5498                          * names and missing includes. */
5499                         case T_IDENTIFIER:
5500                                 parse_declaration(finished_kr_declaration, DECL_IS_PARAMETER);
5501                                 break;
5502                         default:
5503                                 goto decl_list_end;
5504                 }
5505         }
5506 decl_list_end:
5507
5508         /* pop function parameters */
5509         assert(current_scope == &entity->function.parameters);
5510         scope_pop(old_scope);
5511         environment_pop_to(top);
5512
5513         /* update function type */
5514         type_t *new_type = duplicate_type(type);
5515
5516         function_parameter_t *parameters     = NULL;
5517         function_parameter_t *last_parameter = NULL;
5518
5519         parameter = entity->function.parameters.entities;
5520         for (; parameter != NULL; parameter = parameter->base.next) {
5521                 type_t *parameter_type = parameter->declaration.type;
5522                 if (parameter_type == NULL) {
5523                         if (strict_mode) {
5524                                 errorf(HERE, "no type specified for function parameter '%Y'",
5525                                        parameter->base.symbol);
5526                         } else {
5527                                 if (warning.implicit_int) {
5528                                         warningf(HERE, "no type specified for function parameter '%Y', using 'int'",
5529                                                  parameter->base.symbol);
5530                                 }
5531                                 parameter_type              = type_int;
5532                                 parameter->declaration.type = parameter_type;
5533                         }
5534                 }
5535
5536                 semantic_parameter_incomplete(parameter);
5537                 parameter_type = parameter->declaration.type;
5538
5539                 /*
5540                  * we need the default promoted types for the function type
5541                  */
5542                 parameter_type = get_default_promoted_type(parameter_type);
5543
5544                 function_parameter_t *function_parameter
5545                         = obstack_alloc(type_obst, sizeof(function_parameter[0]));
5546                 memset(function_parameter, 0, sizeof(function_parameter[0]));
5547
5548                 function_parameter->type = parameter_type;
5549                 if (last_parameter != NULL) {
5550                         last_parameter->next = function_parameter;
5551                 } else {
5552                         parameters = function_parameter;
5553                 }
5554                 last_parameter = function_parameter;
5555         }
5556
5557         /* § 6.9.1.7: A K&R style parameter list does NOT act as a function
5558          * prototype */
5559         new_type->function.parameters             = parameters;
5560         new_type->function.unspecified_parameters = true;
5561
5562         new_type = identify_new_type(new_type);
5563
5564         entity->declaration.type = new_type;
5565
5566         rem_anchor_token('{');
5567 }
5568
5569 static bool first_err = true;
5570
5571 /**
5572  * When called with first_err set, prints the name of the current function,
5573  * else does noting.
5574  */
5575 static void print_in_function(void)
5576 {
5577         if (first_err) {
5578                 first_err = false;
5579                 diagnosticf("%s: In function '%Y':\n",
5580                             current_function->base.base.source_position.input_name,
5581                             current_function->base.base.symbol);
5582         }
5583 }
5584
5585 /**
5586  * Check if all labels are defined in the current function.
5587  * Check if all labels are used in the current function.
5588  */
5589 static void check_labels(void)
5590 {
5591         for (const goto_statement_t *goto_statement = goto_first;
5592             goto_statement != NULL;
5593             goto_statement = goto_statement->next) {
5594                 /* skip computed gotos */
5595                 if (goto_statement->expression != NULL)
5596                         continue;
5597
5598                 label_t *label = goto_statement->label;
5599
5600                 label->used = true;
5601                 if (label->base.source_position.input_name == NULL) {
5602                         print_in_function();
5603                         errorf(&goto_statement->base.source_position,
5604                                "label '%Y' used but not defined", label->base.symbol);
5605                  }
5606         }
5607
5608         if (warning.unused_label) {
5609                 for (const label_statement_t *label_statement = label_first;
5610                          label_statement != NULL;
5611                          label_statement = label_statement->next) {
5612                         label_t *label = label_statement->label;
5613
5614                         if (! label->used) {
5615                                 print_in_function();
5616                                 warningf(&label_statement->base.source_position,
5617                                          "label '%Y' defined but not used", label->base.symbol);
5618                         }
5619                 }
5620         }
5621 }
5622
5623 static void warn_unused_entity(entity_t *entity, entity_t *last)
5624 {
5625         entity_t const *const end = last != NULL ? last->base.next : NULL;
5626         for (; entity != end; entity = entity->base.next) {
5627                 if (!is_declaration(entity))
5628                         continue;
5629
5630                 declaration_t *declaration = &entity->declaration;
5631                 if (declaration->implicit)
5632                         continue;
5633
5634                 if (!declaration->used) {
5635                         print_in_function();
5636                         const char *what = get_entity_kind_name(entity->kind);
5637                         warningf(&entity->base.source_position, "%s '%Y' is unused",
5638                                  what, entity->base.symbol);
5639                 } else if (entity->kind == ENTITY_VARIABLE && !entity->variable.read) {
5640                         print_in_function();
5641                         const char *what = get_entity_kind_name(entity->kind);
5642                         warningf(&entity->base.source_position, "%s '%Y' is never read",
5643                                  what, entity->base.symbol);
5644                 }
5645         }
5646 }
5647
5648 static void check_unused_variables(statement_t *const stmt, void *const env)
5649 {
5650         (void)env;
5651
5652         switch (stmt->kind) {
5653                 case STATEMENT_DECLARATION: {
5654                         declaration_statement_t const *const decls = &stmt->declaration;
5655                         warn_unused_entity(decls->declarations_begin,
5656                                            decls->declarations_end);
5657                         return;
5658                 }
5659
5660                 case STATEMENT_FOR:
5661                         warn_unused_entity(stmt->fors.scope.entities, NULL);
5662                         return;
5663
5664                 default:
5665                         return;
5666         }
5667 }
5668
5669 /**
5670  * Check declarations of current_function for unused entities.
5671  */
5672 static void check_declarations(void)
5673 {
5674         if (warning.unused_parameter) {
5675                 const scope_t *scope = &current_function->parameters;
5676
5677                 /* do not issue unused warnings for main */
5678                 if (!is_sym_main(current_function->base.base.symbol)) {
5679                         warn_unused_entity(scope->entities, NULL);
5680                 }
5681         }
5682         if (warning.unused_variable) {
5683                 walk_statements(current_function->statement, check_unused_variables,
5684                                 NULL);
5685         }
5686 }
5687
5688 static int determine_truth(expression_t const* const cond)
5689 {
5690         return
5691                 !is_constant_expression(cond) ? 0 :
5692                 fold_constant(cond) != 0      ? 1 :
5693                 -1;
5694 }
5695
5696 static void check_reachable(statement_t *);
5697 static bool reaches_end;
5698
5699 static bool expression_returns(expression_t const *const expr)
5700 {
5701         switch (expr->kind) {
5702                 case EXPR_CALL: {
5703                         expression_t const *const func = expr->call.function;
5704                         if (func->kind == EXPR_REFERENCE) {
5705                                 entity_t *entity = func->reference.entity;
5706                                 if (entity->kind == ENTITY_FUNCTION
5707                                                 && entity->declaration.modifiers & DM_NORETURN)
5708                                         return false;
5709                         }
5710
5711                         if (!expression_returns(func))
5712                                 return false;
5713
5714                         for (call_argument_t const* arg = expr->call.arguments; arg != NULL; arg = arg->next) {
5715                                 if (!expression_returns(arg->expression))
5716                                         return false;
5717                         }
5718
5719                         return true;
5720                 }
5721
5722                 case EXPR_REFERENCE:
5723                 case EXPR_REFERENCE_ENUM_VALUE:
5724                 case EXPR_CONST:
5725                 case EXPR_CHARACTER_CONSTANT:
5726                 case EXPR_WIDE_CHARACTER_CONSTANT:
5727                 case EXPR_STRING_LITERAL:
5728                 case EXPR_WIDE_STRING_LITERAL:
5729                 case EXPR_COMPOUND_LITERAL: // TODO descend into initialisers
5730                 case EXPR_LABEL_ADDRESS:
5731                 case EXPR_CLASSIFY_TYPE:
5732                 case EXPR_SIZEOF: // TODO handle obscure VLA case
5733                 case EXPR_ALIGNOF:
5734                 case EXPR_FUNCNAME:
5735                 case EXPR_BUILTIN_SYMBOL:
5736                 case EXPR_BUILTIN_CONSTANT_P:
5737                 case EXPR_BUILTIN_PREFETCH:
5738                 case EXPR_OFFSETOF:
5739                 case EXPR_INVALID:
5740                         return true;
5741
5742                 case EXPR_STATEMENT: {
5743                         bool old_reaches_end = reaches_end;
5744                         reaches_end = false;
5745                         check_reachable(expr->statement.statement);
5746                         bool returns = reaches_end;
5747                         reaches_end = old_reaches_end;
5748                         return returns;
5749                 }
5750
5751                 case EXPR_CONDITIONAL:
5752                         // TODO handle constant expression
5753
5754                         if (!expression_returns(expr->conditional.condition))
5755                                 return false;
5756
5757                         if (expr->conditional.true_expression != NULL
5758                                         && expression_returns(expr->conditional.true_expression))
5759                                 return true;
5760
5761                         return expression_returns(expr->conditional.false_expression);
5762
5763                 case EXPR_SELECT:
5764                         return expression_returns(expr->select.compound);
5765
5766                 case EXPR_ARRAY_ACCESS:
5767                         return
5768                                 expression_returns(expr->array_access.array_ref) &&
5769                                 expression_returns(expr->array_access.index);
5770
5771                 case EXPR_VA_START:
5772                         return expression_returns(expr->va_starte.ap);
5773
5774                 case EXPR_VA_ARG:
5775                         return expression_returns(expr->va_arge.ap);
5776
5777                 EXPR_UNARY_CASES_MANDATORY
5778                         return expression_returns(expr->unary.value);
5779
5780                 case EXPR_UNARY_THROW:
5781                         return false;
5782
5783                 EXPR_BINARY_CASES
5784                         // TODO handle constant lhs of && and ||
5785                         return
5786                                 expression_returns(expr->binary.left) &&
5787                                 expression_returns(expr->binary.right);
5788
5789                 case EXPR_UNKNOWN:
5790                         break;
5791         }
5792
5793         panic("unhandled expression");
5794 }
5795
5796 static bool initializer_returns(initializer_t const *const init)
5797 {
5798         switch (init->kind) {
5799                 case INITIALIZER_VALUE:
5800                         return expression_returns(init->value.value);
5801
5802                 case INITIALIZER_LIST: {
5803                         initializer_t * const*       i       = init->list.initializers;
5804                         initializer_t * const* const end     = i + init->list.len;
5805                         bool                         returns = true;
5806                         for (; i != end; ++i) {
5807                                 if (!initializer_returns(*i))
5808                                         returns = false;
5809                         }
5810                         return returns;
5811                 }
5812
5813                 case INITIALIZER_STRING:
5814                 case INITIALIZER_WIDE_STRING:
5815                 case INITIALIZER_DESIGNATOR: // designators have no payload
5816                         return true;
5817         }
5818         panic("unhandled initializer");
5819 }
5820
5821 static bool noreturn_candidate;
5822
5823 static void check_reachable(statement_t *const stmt)
5824 {
5825         if (stmt->base.reachable)
5826                 return;
5827         if (stmt->kind != STATEMENT_DO_WHILE)
5828                 stmt->base.reachable = true;
5829
5830         statement_t *last = stmt;
5831         statement_t *next;
5832         switch (stmt->kind) {
5833                 case STATEMENT_INVALID:
5834                 case STATEMENT_EMPTY:
5835                 case STATEMENT_ASM:
5836                         next = stmt->base.next;
5837                         break;
5838
5839                 case STATEMENT_DECLARATION: {
5840                         declaration_statement_t const *const decl = &stmt->declaration;
5841                         entity_t                const *      ent  = decl->declarations_begin;
5842                         entity_t                const *const last = decl->declarations_end;
5843                         if (ent != NULL) {
5844                                 for (;; ent = ent->base.next) {
5845                                         if (ent->kind                 == ENTITY_VARIABLE &&
5846                                                         ent->variable.initializer != NULL            &&
5847                                                         !initializer_returns(ent->variable.initializer)) {
5848                                                 return;
5849                                         }
5850                                         if (ent == last)
5851                                                 break;
5852                                 }
5853                         }
5854                         next = stmt->base.next;
5855                         break;
5856                 }
5857
5858                 case STATEMENT_COMPOUND:
5859                         next = stmt->compound.statements;
5860                         if (next == NULL)
5861                                 next = stmt->base.next;
5862                         break;
5863
5864                 case STATEMENT_RETURN: {
5865                         expression_t const *const val = stmt->returns.value;
5866                         if (val == NULL || expression_returns(val))
5867                                 noreturn_candidate = false;
5868                         return;
5869                 }
5870
5871                 case STATEMENT_IF: {
5872                         if_statement_t const *const ifs  = &stmt->ifs;
5873                         expression_t   const *const cond = ifs->condition;
5874
5875                         if (!expression_returns(cond))
5876                                 return;
5877
5878                         int const val = determine_truth(cond);
5879
5880                         if (val >= 0)
5881                                 check_reachable(ifs->true_statement);
5882
5883                         if (val > 0)
5884                                 return;
5885
5886                         if (ifs->false_statement != NULL) {
5887                                 check_reachable(ifs->false_statement);
5888                                 return;
5889                         }
5890
5891                         next = stmt->base.next;
5892                         break;
5893                 }
5894
5895                 case STATEMENT_SWITCH: {
5896                         switch_statement_t const *const switchs = &stmt->switchs;
5897                         expression_t       const *const expr    = switchs->expression;
5898
5899                         if (!expression_returns(expr))
5900                                 return;
5901
5902                         if (is_constant_expression(expr)) {
5903                                 long                    const val      = fold_constant(expr);
5904                                 case_label_statement_t *      defaults = NULL;
5905                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
5906                                         if (i->expression == NULL) {
5907                                                 defaults = i;
5908                                                 continue;
5909                                         }
5910
5911                                         if (i->first_case <= val && val <= i->last_case) {
5912                                                 check_reachable((statement_t*)i);
5913                                                 return;
5914                                         }
5915                                 }
5916
5917                                 if (defaults != NULL) {
5918                                         check_reachable((statement_t*)defaults);
5919                                         return;
5920                                 }
5921                         } else {
5922                                 bool has_default = false;
5923                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
5924                                         if (i->expression == NULL)
5925                                                 has_default = true;
5926
5927                                         check_reachable((statement_t*)i);
5928                                 }
5929
5930                                 if (has_default)
5931                                         return;
5932                         }
5933
5934                         next = stmt->base.next;
5935                         break;
5936                 }
5937
5938                 case STATEMENT_EXPRESSION: {
5939                         /* Check for noreturn function call */
5940                         expression_t const *const expr = stmt->expression.expression;
5941                         if (!expression_returns(expr))
5942                                 return;
5943
5944                         next = stmt->base.next;
5945                         break;
5946                 }
5947
5948                 case STATEMENT_CONTINUE: {
5949                         statement_t *parent = stmt;
5950                         for (;;) {
5951                                 parent = parent->base.parent;
5952                                 if (parent == NULL) /* continue not within loop */
5953                                         return;
5954
5955                                 next = parent;
5956                                 switch (parent->kind) {
5957                                         case STATEMENT_WHILE:    goto continue_while;
5958                                         case STATEMENT_DO_WHILE: goto continue_do_while;
5959                                         case STATEMENT_FOR:      goto continue_for;
5960
5961                                         default: break;
5962                                 }
5963                         }
5964                 }
5965
5966                 case STATEMENT_BREAK: {
5967                         statement_t *parent = stmt;
5968                         for (;;) {
5969                                 parent = parent->base.parent;
5970                                 if (parent == NULL) /* break not within loop/switch */
5971                                         return;
5972
5973                                 switch (parent->kind) {
5974                                         case STATEMENT_SWITCH:
5975                                         case STATEMENT_WHILE:
5976                                         case STATEMENT_DO_WHILE:
5977                                         case STATEMENT_FOR:
5978                                                 last = parent;
5979                                                 next = parent->base.next;
5980                                                 goto found_break_parent;
5981
5982                                         default: break;
5983                                 }
5984                         }
5985 found_break_parent:
5986                         break;
5987                 }
5988
5989                 case STATEMENT_GOTO:
5990                         if (stmt->gotos.expression) {
5991                                 if (!expression_returns(stmt->gotos.expression))
5992                                         return;
5993
5994                                 statement_t *parent = stmt->base.parent;
5995                                 if (parent == NULL) /* top level goto */
5996                                         return;
5997                                 next = parent;
5998                         } else {
5999                                 next = stmt->gotos.label->statement;
6000                                 if (next == NULL) /* missing label */
6001                                         return;
6002                         }
6003                         break;
6004
6005                 case STATEMENT_LABEL:
6006                         next = stmt->label.statement;
6007                         break;
6008
6009                 case STATEMENT_CASE_LABEL:
6010                         next = stmt->case_label.statement;
6011                         break;
6012
6013                 case STATEMENT_WHILE: {
6014                         while_statement_t const *const whiles = &stmt->whiles;
6015                         expression_t      const *const cond   = whiles->condition;
6016
6017                         if (!expression_returns(cond))
6018                                 return;
6019
6020                         int const val = determine_truth(cond);
6021
6022                         if (val >= 0)
6023                                 check_reachable(whiles->body);
6024
6025                         if (val > 0)
6026                                 return;
6027
6028                         next = stmt->base.next;
6029                         break;
6030                 }
6031
6032                 case STATEMENT_DO_WHILE:
6033                         next = stmt->do_while.body;
6034                         break;
6035
6036                 case STATEMENT_FOR: {
6037                         for_statement_t *const fors = &stmt->fors;
6038
6039                         if (fors->condition_reachable)
6040                                 return;
6041                         fors->condition_reachable = true;
6042
6043                         expression_t const *const cond = fors->condition;
6044
6045                         int val;
6046                         if (cond == NULL) {
6047                                 val = 1;
6048                         } else if (expression_returns(cond)) {
6049                                 val = determine_truth(cond);
6050                         } else {
6051                                 return;
6052                         }
6053
6054                         if (val >= 0)
6055                                 check_reachable(fors->body);
6056
6057                         if (val > 0)
6058                                 return;
6059
6060                         next = stmt->base.next;
6061                         break;
6062                 }
6063
6064                 case STATEMENT_MS_TRY: {
6065                         ms_try_statement_t const *const ms_try = &stmt->ms_try;
6066                         check_reachable(ms_try->try_statement);
6067                         next = ms_try->final_statement;
6068                         break;
6069                 }
6070
6071                 case STATEMENT_LEAVE: {
6072                         statement_t *parent = stmt;
6073                         for (;;) {
6074                                 parent = parent->base.parent;
6075                                 if (parent == NULL) /* __leave not within __try */
6076                                         return;
6077
6078                                 if (parent->kind == STATEMENT_MS_TRY) {
6079                                         last = parent;
6080                                         next = parent->ms_try.final_statement;
6081                                         break;
6082                                 }
6083                         }
6084                         break;
6085                 }
6086
6087                 default:
6088                         panic("invalid statement kind");
6089         }
6090
6091         while (next == NULL) {
6092                 next = last->base.parent;
6093                 if (next == NULL) {
6094                         noreturn_candidate = false;
6095
6096                         type_t *const type = current_function->base.type;
6097                         assert(is_type_function(type));
6098                         type_t *const ret  = skip_typeref(type->function.return_type);
6099                         if (warning.return_type                    &&
6100                             !is_type_atomic(ret, ATOMIC_TYPE_VOID) &&
6101                             is_type_valid(ret)                     &&
6102                             !is_sym_main(current_function->base.base.symbol)) {
6103                                 warningf(&stmt->base.source_position,
6104                                          "control reaches end of non-void function");
6105                         }
6106                         return;
6107                 }
6108
6109                 switch (next->kind) {
6110                         case STATEMENT_INVALID:
6111                         case STATEMENT_EMPTY:
6112                         case STATEMENT_DECLARATION:
6113                         case STATEMENT_EXPRESSION:
6114                         case STATEMENT_ASM:
6115                         case STATEMENT_RETURN:
6116                         case STATEMENT_CONTINUE:
6117                         case STATEMENT_BREAK:
6118                         case STATEMENT_GOTO:
6119                         case STATEMENT_LEAVE:
6120                                 panic("invalid control flow in function");
6121
6122                         case STATEMENT_COMPOUND:
6123                                 if (next->compound.stmt_expr) {
6124                                         reaches_end = true;
6125                                         return;
6126                                 }
6127                                 /* FALLTHROUGH */
6128                         case STATEMENT_IF:
6129                         case STATEMENT_SWITCH:
6130                         case STATEMENT_LABEL:
6131                         case STATEMENT_CASE_LABEL:
6132                                 last = next;
6133                                 next = next->base.next;
6134                                 break;
6135
6136                         case STATEMENT_WHILE: {
6137 continue_while:
6138                                 if (next->base.reachable)
6139                                         return;
6140                                 next->base.reachable = true;
6141
6142                                 while_statement_t const *const whiles = &next->whiles;
6143                                 expression_t      const *const cond   = whiles->condition;
6144
6145                                 if (!expression_returns(cond))
6146                                         return;
6147
6148                                 int const val = determine_truth(cond);
6149
6150                                 if (val >= 0)
6151                                         check_reachable(whiles->body);
6152
6153                                 if (val > 0)
6154                                         return;
6155
6156                                 last = next;
6157                                 next = next->base.next;
6158                                 break;
6159                         }
6160
6161                         case STATEMENT_DO_WHILE: {
6162 continue_do_while:
6163                                 if (next->base.reachable)
6164                                         return;
6165                                 next->base.reachable = true;
6166
6167                                 do_while_statement_t const *const dw   = &next->do_while;
6168                                 expression_t         const *const cond = dw->condition;
6169
6170                                 if (!expression_returns(cond))
6171                                         return;
6172
6173                                 int const val = determine_truth(cond);
6174
6175                                 if (val >= 0)
6176                                         check_reachable(dw->body);
6177
6178                                 if (val > 0)
6179                                         return;
6180
6181                                 last = next;
6182                                 next = next->base.next;
6183                                 break;
6184                         }
6185
6186                         case STATEMENT_FOR: {
6187 continue_for:;
6188                                 for_statement_t *const fors = &next->fors;
6189
6190                                 fors->step_reachable = true;
6191
6192                                 if (fors->condition_reachable)
6193                                         return;
6194                                 fors->condition_reachable = true;
6195
6196                                 expression_t const *const cond = fors->condition;
6197
6198                                 int val;
6199                                 if (cond == NULL) {
6200                                         val = 1;
6201                                 } else if (expression_returns(cond)) {
6202                                         val = determine_truth(cond);
6203                                 } else {
6204                                         return;
6205                                 }
6206
6207                                 if (val >= 0)
6208                                         check_reachable(fors->body);
6209
6210                                 if (val > 0)
6211                                         return;
6212
6213                                 last = next;
6214                                 next = next->base.next;
6215                                 break;
6216                         }
6217
6218                         case STATEMENT_MS_TRY:
6219                                 last = next;
6220                                 next = next->ms_try.final_statement;
6221                                 break;
6222                 }
6223         }
6224
6225         check_reachable(next);
6226 }
6227
6228 static void check_unreachable(statement_t* const stmt, void *const env)
6229 {
6230         (void)env;
6231
6232         switch (stmt->kind) {
6233                 case STATEMENT_DO_WHILE:
6234                         if (!stmt->base.reachable) {
6235                                 expression_t const *const cond = stmt->do_while.condition;
6236                                 if (determine_truth(cond) >= 0) {
6237                                         warningf(&cond->base.source_position,
6238                                                  "condition of do-while-loop is unreachable");
6239                                 }
6240                         }
6241                         return;
6242
6243                 case STATEMENT_FOR: {
6244                         for_statement_t const* const fors = &stmt->fors;
6245
6246                         // if init and step are unreachable, cond is unreachable, too
6247                         if (!stmt->base.reachable && !fors->step_reachable) {
6248                                 warningf(&stmt->base.source_position, "statement is unreachable");
6249                         } else {
6250                                 if (!stmt->base.reachable && fors->initialisation != NULL) {
6251                                         warningf(&fors->initialisation->base.source_position,
6252                                                  "initialisation of for-statement is unreachable");
6253                                 }
6254
6255                                 if (!fors->condition_reachable && fors->condition != NULL) {
6256                                         warningf(&fors->condition->base.source_position,
6257                                                  "condition of for-statement is unreachable");
6258                                 }
6259
6260                                 if (!fors->step_reachable && fors->step != NULL) {
6261                                         warningf(&fors->step->base.source_position,
6262                                                  "step of for-statement is unreachable");
6263                                 }
6264                         }
6265                         return;
6266                 }
6267
6268                 case STATEMENT_COMPOUND:
6269                         if (stmt->compound.statements != NULL)
6270                                 return;
6271                         goto warn_unreachable;
6272
6273                 case STATEMENT_DECLARATION: {
6274                         /* Only warn if there is at least one declarator with an initializer.
6275                          * This typically occurs in switch statements. */
6276                         declaration_statement_t const *const decl = &stmt->declaration;
6277                         entity_t                const *      ent  = decl->declarations_begin;
6278                         entity_t                const *const last = decl->declarations_end;
6279                         if (ent != NULL) {
6280                                 for (;; ent = ent->base.next) {
6281                                         if (ent->kind                 == ENTITY_VARIABLE &&
6282                                                         ent->variable.initializer != NULL) {
6283                                                 goto warn_unreachable;
6284                                         }
6285                                         if (ent == last)
6286                                                 return;
6287                                 }
6288                         }
6289                 }
6290
6291                 default:
6292 warn_unreachable:
6293                         if (!stmt->base.reachable)
6294                                 warningf(&stmt->base.source_position, "statement is unreachable");
6295                         return;
6296         }
6297 }
6298
6299 static void parse_external_declaration(void)
6300 {
6301         /* function-definitions and declarations both start with declaration
6302          * specifiers */
6303         declaration_specifiers_t specifiers;
6304         memset(&specifiers, 0, sizeof(specifiers));
6305
6306         add_anchor_token(';');
6307         parse_declaration_specifiers(&specifiers);
6308         rem_anchor_token(';');
6309
6310         /* must be a declaration */
6311         if (token.type == ';') {
6312                 parse_anonymous_declaration_rest(&specifiers);
6313                 return;
6314         }
6315
6316         add_anchor_token(',');
6317         add_anchor_token('=');
6318         add_anchor_token(';');
6319         add_anchor_token('{');
6320
6321         /* declarator is common to both function-definitions and declarations */
6322         entity_t *ndeclaration = parse_declarator(&specifiers, DECL_FLAGS_NONE);
6323
6324         rem_anchor_token('{');
6325         rem_anchor_token(';');
6326         rem_anchor_token('=');
6327         rem_anchor_token(',');
6328
6329         /* must be a declaration */
6330         switch (token.type) {
6331                 case ',':
6332                 case ';':
6333                 case '=':
6334                         parse_declaration_rest(ndeclaration, &specifiers, record_entity,
6335                                         DECL_FLAGS_NONE);
6336                         return;
6337         }
6338
6339         /* must be a function definition */
6340         parse_kr_declaration_list(ndeclaration);
6341
6342         if (token.type != '{') {
6343                 parse_error_expected("while parsing function definition", '{', NULL);
6344                 eat_until_matching_token(';');
6345                 return;
6346         }
6347
6348         assert(is_declaration(ndeclaration));
6349         type_t *type = skip_typeref(ndeclaration->declaration.type);
6350
6351         if (!is_type_function(type)) {
6352                 if (is_type_valid(type)) {
6353                         errorf(HERE, "declarator '%#T' has a body but is not a function type",
6354                                type, ndeclaration->base.symbol);
6355                 }
6356                 eat_block();
6357                 return;
6358         }
6359
6360         if (warning.aggregate_return &&
6361             is_type_compound(skip_typeref(type->function.return_type))) {
6362                 warningf(HERE, "function '%Y' returns an aggregate",
6363                          ndeclaration->base.symbol);
6364         }
6365         if (warning.traditional && !type->function.unspecified_parameters) {
6366                 warningf(HERE, "traditional C rejects ISO C style function definition of function '%Y'",
6367                         ndeclaration->base.symbol);
6368         }
6369         if (warning.old_style_definition && type->function.unspecified_parameters) {
6370                 warningf(HERE, "old-style function definition '%Y'",
6371                         ndeclaration->base.symbol);
6372         }
6373
6374         /* § 6.7.5.3:14 a function definition with () means no
6375          * parameters (and not unspecified parameters) */
6376         if (type->function.unspecified_parameters &&
6377                         type->function.parameters == NULL     &&
6378                         !type->function.kr_style_parameters) {
6379                 type_t *copy                          = duplicate_type(type);
6380                 copy->function.unspecified_parameters = false;
6381                 type                                  = identify_new_type(copy);
6382
6383                 ndeclaration->declaration.type = type;
6384         }
6385
6386         entity_t *const entity = record_entity(ndeclaration, true);
6387         assert(entity->kind == ENTITY_FUNCTION);
6388         assert(ndeclaration->kind == ENTITY_FUNCTION);
6389
6390         function_t *function = &entity->function;
6391         if (ndeclaration != entity) {
6392                 function->parameters = ndeclaration->function.parameters;
6393         }
6394         assert(is_declaration(entity));
6395         type = skip_typeref(entity->declaration.type);
6396
6397         /* push function parameters and switch scope */
6398         size_t const  top       = environment_top();
6399         scope_t      *old_scope = scope_push(&function->parameters);
6400
6401         entity_t *parameter = function->parameters.entities;
6402         for (; parameter != NULL; parameter = parameter->base.next) {
6403                 if (parameter->base.parent_scope == &ndeclaration->function.parameters) {
6404                         parameter->base.parent_scope = current_scope;
6405                 }
6406                 assert(parameter->base.parent_scope == NULL
6407                                 || parameter->base.parent_scope == current_scope);
6408                 parameter->base.parent_scope = current_scope;
6409                 if (parameter->base.symbol == NULL) {
6410                         errorf(&parameter->base.source_position, "parameter name omitted");
6411                         continue;
6412                 }
6413                 environment_push(parameter);
6414         }
6415
6416         if (function->statement != NULL) {
6417                 parser_error_multiple_definition(entity, HERE);
6418                 eat_block();
6419         } else {
6420                 /* parse function body */
6421                 int         label_stack_top      = label_top();
6422                 function_t *old_current_function = current_function;
6423                 current_function                 = function;
6424                 current_parent                   = NULL;
6425
6426                 goto_first   = NULL;
6427                 goto_anchor  = &goto_first;
6428                 label_first  = NULL;
6429                 label_anchor = &label_first;
6430
6431                 statement_t *const body = parse_compound_statement(false);
6432                 function->statement = body;
6433                 first_err = true;
6434                 check_labels();
6435                 check_declarations();
6436                 if (warning.return_type      ||
6437                     warning.unreachable_code ||
6438                     (warning.missing_noreturn
6439                      && !(function->base.modifiers & DM_NORETURN))) {
6440                         noreturn_candidate = true;
6441                         check_reachable(body);
6442                         if (warning.unreachable_code)
6443                                 walk_statements(body, check_unreachable, NULL);
6444                         if (warning.missing_noreturn &&
6445                             noreturn_candidate       &&
6446                             !(function->base.modifiers & DM_NORETURN)) {
6447                                 warningf(&body->base.source_position,
6448                                          "function '%#T' is candidate for attribute 'noreturn'",
6449                                          type, entity->base.symbol);
6450                         }
6451                 }
6452
6453                 assert(current_parent   == NULL);
6454                 assert(current_function == function);
6455                 current_function = old_current_function;
6456                 label_pop_to(label_stack_top);
6457         }
6458
6459         assert(current_scope == &function->parameters);
6460         scope_pop(old_scope);
6461         environment_pop_to(top);
6462 }
6463
6464 static type_t *make_bitfield_type(type_t *base_type, expression_t *size,
6465                                   source_position_t *source_position,
6466                                   const symbol_t *symbol)
6467 {
6468         type_t *type = allocate_type_zero(TYPE_BITFIELD);
6469
6470         type->bitfield.base_type       = base_type;
6471         type->bitfield.size_expression = size;
6472
6473         il_size_t bit_size;
6474         type_t *skipped_type = skip_typeref(base_type);
6475         if (!is_type_integer(skipped_type)) {
6476                 errorf(HERE, "bitfield base type '%T' is not an integer type",
6477                         base_type);
6478                 bit_size = 0;
6479         } else {
6480                 bit_size = skipped_type->base.size * 8;
6481         }
6482
6483         if (is_constant_expression(size)) {
6484                 long v = fold_constant(size);
6485
6486                 if (v < 0) {
6487                         errorf(source_position, "negative width in bit-field '%Y'", symbol);
6488                 } else if (v == 0) {
6489                         errorf(source_position, "zero width for bit-field '%Y'", symbol);
6490                 } else if (bit_size > 0 && (il_size_t)v > bit_size) {
6491                         errorf(source_position, "width of '%Y' exceeds its type", symbol);
6492                 } else {
6493                         type->bitfield.bit_size = v;
6494                 }
6495         }
6496
6497         return type;
6498 }
6499
6500 static entity_t *find_compound_entry(compound_t *compound, symbol_t *symbol)
6501 {
6502         entity_t *iter = compound->members.entities;
6503         for (; iter != NULL; iter = iter->base.next) {
6504                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
6505                         continue;
6506
6507                 if (iter->base.symbol == symbol) {
6508                         return iter;
6509                 } else if (iter->base.symbol == NULL) {
6510                         type_t *type = skip_typeref(iter->declaration.type);
6511                         if (is_type_compound(type)) {
6512                                 entity_t *result
6513                                         = find_compound_entry(type->compound.compound, symbol);
6514                                 if (result != NULL)
6515                                         return result;
6516                         }
6517                         continue;
6518                 }
6519         }
6520
6521         return NULL;
6522 }
6523
6524 static void parse_compound_declarators(compound_t *compound,
6525                 const declaration_specifiers_t *specifiers)
6526 {
6527         while (true) {
6528                 entity_t *entity;
6529
6530                 if (token.type == ':') {
6531                         source_position_t source_position = *HERE;
6532                         next_token();
6533
6534                         type_t *base_type = specifiers->type;
6535                         expression_t *size = parse_constant_expression();
6536
6537                         type_t *type = make_bitfield_type(base_type, size,
6538                                         &source_position, sym_anonymous);
6539
6540                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER);
6541                         entity->base.namespc                       = NAMESPACE_NORMAL;
6542                         entity->base.source_position               = source_position;
6543                         entity->declaration.declared_storage_class = STORAGE_CLASS_NONE;
6544                         entity->declaration.storage_class          = STORAGE_CLASS_NONE;
6545                         entity->declaration.modifiers              = specifiers->modifiers;
6546                         entity->declaration.type                   = type;
6547                         append_entity(&compound->members, entity);
6548                 } else {
6549                         entity = parse_declarator(specifiers,
6550                                         DECL_MAY_BE_ABSTRACT | DECL_CREATE_COMPOUND_MEMBER);
6551                         if (entity->kind == ENTITY_TYPEDEF) {
6552                                 errorf(&entity->base.source_position,
6553                                                 "typedef not allowed as compound member");
6554                         } else {
6555                                 assert(entity->kind == ENTITY_COMPOUND_MEMBER);
6556
6557                                 /* make sure we don't define a symbol multiple times */
6558                                 symbol_t *symbol = entity->base.symbol;
6559                                 if (symbol != NULL) {
6560                                         entity_t *prev = find_compound_entry(compound, symbol);
6561                                         if (prev != NULL) {
6562                                                 errorf(&entity->base.source_position,
6563                                                                 "multiple declarations of symbol '%Y' (declared %P)",
6564                                                                 symbol, &prev->base.source_position);
6565                                         }
6566                                 }
6567
6568                                 if (token.type == ':') {
6569                                         source_position_t source_position = *HERE;
6570                                         next_token();
6571                                         expression_t *size = parse_constant_expression();
6572
6573                                         type_t *type          = entity->declaration.type;
6574                                         type_t *bitfield_type = make_bitfield_type(type, size,
6575                                                         &source_position, entity->base.symbol);
6576                                         entity->declaration.type = bitfield_type;
6577                                 } else {
6578                                         type_t *orig_type = entity->declaration.type;
6579                                         type_t *type      = skip_typeref(orig_type);
6580                                         if (is_type_function(type)) {
6581                                                 errorf(&entity->base.source_position,
6582                                                                 "compound member '%Y' must not have function type '%T'",
6583                                                                 entity->base.symbol, orig_type);
6584                                         } else if (is_type_incomplete(type)) {
6585                                                 /* §6.7.2.1:16 flexible array member */
6586                                                 if (is_type_array(type) &&
6587                                                                 token.type == ';'   &&
6588                                                                 look_ahead(1)->type == '}') {
6589                                                         compound->has_flexible_member = true;
6590                                                 } else {
6591                                                         errorf(&entity->base.source_position,
6592                                                                         "compound member '%Y' has incomplete type '%T'",
6593                                                                         entity->base.symbol, orig_type);
6594                                                 }
6595                                         }
6596                                 }
6597
6598                                 append_entity(&compound->members, entity);
6599                         }
6600                 }
6601
6602                 if (token.type != ',')
6603                         break;
6604                 next_token();
6605         }
6606         expect(';', end_error);
6607
6608 end_error:
6609         anonymous_entity = NULL;
6610 }
6611
6612 static void parse_compound_type_entries(compound_t *compound)
6613 {
6614         eat('{');
6615         add_anchor_token('}');
6616
6617         while (token.type != '}') {
6618                 if (token.type == T_EOF) {
6619                         errorf(HERE, "EOF while parsing struct");
6620                         break;
6621                 }
6622                 declaration_specifiers_t specifiers;
6623                 memset(&specifiers, 0, sizeof(specifiers));
6624                 parse_declaration_specifiers(&specifiers);
6625
6626                 parse_compound_declarators(compound, &specifiers);
6627         }
6628         rem_anchor_token('}');
6629         next_token();
6630
6631         /* §6.7.2.1:7 */
6632         compound->complete = true;
6633 }
6634
6635 static type_t *parse_typename(void)
6636 {
6637         declaration_specifiers_t specifiers;
6638         memset(&specifiers, 0, sizeof(specifiers));
6639         parse_declaration_specifiers(&specifiers);
6640         if (specifiers.storage_class != STORAGE_CLASS_NONE ||
6641                         specifiers.thread_local) {
6642                 /* TODO: improve error message, user does probably not know what a
6643                  * storage class is...
6644                  */
6645                 errorf(HERE, "typename may not have a storage class");
6646         }
6647
6648         type_t *result = parse_abstract_declarator(specifiers.type);
6649
6650         return result;
6651 }
6652
6653
6654
6655
6656 typedef expression_t* (*parse_expression_function)(void);
6657 typedef expression_t* (*parse_expression_infix_function)(expression_t *left);
6658
6659 typedef struct expression_parser_function_t expression_parser_function_t;
6660 struct expression_parser_function_t {
6661         parse_expression_function        parser;
6662         precedence_t                     infix_precedence;
6663         parse_expression_infix_function  infix_parser;
6664 };
6665
6666 expression_parser_function_t expression_parsers[T_LAST_TOKEN];
6667
6668 /**
6669  * Prints an error message if an expression was expected but not read
6670  */
6671 static expression_t *expected_expression_error(void)
6672 {
6673         /* skip the error message if the error token was read */
6674         if (token.type != T_ERROR) {
6675                 errorf(HERE, "expected expression, got token %K", &token);
6676         }
6677         next_token();
6678
6679         return create_invalid_expression();
6680 }
6681
6682 /**
6683  * Parse a string constant.
6684  */
6685 static expression_t *parse_string_const(void)
6686 {
6687         wide_string_t wres;
6688         if (token.type == T_STRING_LITERAL) {
6689                 string_t res = token.v.string;
6690                 next_token();
6691                 while (token.type == T_STRING_LITERAL) {
6692                         res = concat_strings(&res, &token.v.string);
6693                         next_token();
6694                 }
6695                 if (token.type != T_WIDE_STRING_LITERAL) {
6696                         expression_t *const cnst = allocate_expression_zero(EXPR_STRING_LITERAL);
6697                         /* note: that we use type_char_ptr here, which is already the
6698                          * automatic converted type. revert_automatic_type_conversion
6699                          * will construct the array type */
6700                         cnst->base.type    = warning.write_strings ? type_const_char_ptr : type_char_ptr;
6701                         cnst->string.value = res;
6702                         return cnst;
6703                 }
6704
6705                 wres = concat_string_wide_string(&res, &token.v.wide_string);
6706         } else {
6707                 wres = token.v.wide_string;
6708         }
6709         next_token();
6710
6711         for (;;) {
6712                 switch (token.type) {
6713                         case T_WIDE_STRING_LITERAL:
6714                                 wres = concat_wide_strings(&wres, &token.v.wide_string);
6715                                 break;
6716
6717                         case T_STRING_LITERAL:
6718                                 wres = concat_wide_string_string(&wres, &token.v.string);
6719                                 break;
6720
6721                         default: {
6722                                 expression_t *const cnst = allocate_expression_zero(EXPR_WIDE_STRING_LITERAL);
6723                                 cnst->base.type         = warning.write_strings ? type_const_wchar_t_ptr : type_wchar_t_ptr;
6724                                 cnst->wide_string.value = wres;
6725                                 return cnst;
6726                         }
6727                 }
6728                 next_token();
6729         }
6730 }
6731
6732 /**
6733  * Parse a boolean constant.
6734  */
6735 static expression_t *parse_bool_const(bool value)
6736 {
6737         expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
6738         cnst->base.type          = type_bool;
6739         cnst->conste.v.int_value = value;
6740
6741         next_token();
6742
6743         return cnst;
6744 }
6745
6746 /**
6747  * Parse an integer constant.
6748  */
6749 static expression_t *parse_int_const(void)
6750 {
6751         expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
6752         cnst->base.type          = token.datatype;
6753         cnst->conste.v.int_value = token.v.intvalue;
6754
6755         next_token();
6756
6757         return cnst;
6758 }
6759
6760 /**
6761  * Parse a character constant.
6762  */
6763 static expression_t *parse_character_constant(void)
6764 {
6765         expression_t *cnst = allocate_expression_zero(EXPR_CHARACTER_CONSTANT);
6766         cnst->base.type          = token.datatype;
6767         cnst->conste.v.character = token.v.string;
6768
6769         if (cnst->conste.v.character.size != 1) {
6770                 if (!GNU_MODE) {
6771                         errorf(HERE, "more than 1 character in character constant");
6772                 } else if (warning.multichar) {
6773                         warningf(HERE, "multi-character character constant");
6774                 }
6775         }
6776         next_token();
6777
6778         return cnst;
6779 }
6780
6781 /**
6782  * Parse a wide character constant.
6783  */
6784 static expression_t *parse_wide_character_constant(void)
6785 {
6786         expression_t *cnst = allocate_expression_zero(EXPR_WIDE_CHARACTER_CONSTANT);
6787         cnst->base.type               = token.datatype;
6788         cnst->conste.v.wide_character = token.v.wide_string;
6789
6790         if (cnst->conste.v.wide_character.size != 1) {
6791                 if (!GNU_MODE) {
6792                         errorf(HERE, "more than 1 character in character constant");
6793                 } else if (warning.multichar) {
6794                         warningf(HERE, "multi-character character constant");
6795                 }
6796         }
6797         next_token();
6798
6799         return cnst;
6800 }
6801
6802 /**
6803  * Parse a float constant.
6804  */
6805 static expression_t *parse_float_const(void)
6806 {
6807         expression_t *cnst         = allocate_expression_zero(EXPR_CONST);
6808         cnst->base.type            = token.datatype;
6809         cnst->conste.v.float_value = token.v.floatvalue;
6810
6811         next_token();
6812
6813         return cnst;
6814 }
6815
6816 static entity_t *create_implicit_function(symbol_t *symbol,
6817                 const source_position_t *source_position)
6818 {
6819         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
6820         ntype->function.return_type            = type_int;
6821         ntype->function.unspecified_parameters = true;
6822         ntype->function.linkage                = LINKAGE_C;
6823         type_t *type                           = identify_new_type(ntype);
6824
6825         entity_t *entity = allocate_entity_zero(ENTITY_FUNCTION);
6826         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
6827         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
6828         entity->declaration.type                   = type;
6829         entity->declaration.implicit               = true;
6830         entity->base.symbol                        = symbol;
6831         entity->base.source_position               = *source_position;
6832
6833         bool strict_prototypes_old = warning.strict_prototypes;
6834         warning.strict_prototypes  = false;
6835         record_entity(entity, false);
6836         warning.strict_prototypes = strict_prototypes_old;
6837
6838         return entity;
6839 }
6840
6841 /**
6842  * Creates a return_type (func)(argument_type) function type if not
6843  * already exists.
6844  */
6845 static type_t *make_function_2_type(type_t *return_type, type_t *argument_type1,
6846                                     type_t *argument_type2)
6847 {
6848         function_parameter_t *parameter2
6849                 = obstack_alloc(type_obst, sizeof(parameter2[0]));
6850         memset(parameter2, 0, sizeof(parameter2[0]));
6851         parameter2->type = argument_type2;
6852
6853         function_parameter_t *parameter1
6854                 = obstack_alloc(type_obst, sizeof(parameter1[0]));
6855         memset(parameter1, 0, sizeof(parameter1[0]));
6856         parameter1->type = argument_type1;
6857         parameter1->next = parameter2;
6858
6859         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6860         type->function.return_type = return_type;
6861         type->function.parameters  = parameter1;
6862
6863         return identify_new_type(type);
6864 }
6865
6866 /**
6867  * Creates a return_type (func)(argument_type) function type if not
6868  * already exists.
6869  *
6870  * @param return_type    the return type
6871  * @param argument_type  the argument type
6872  */
6873 static type_t *make_function_1_type(type_t *return_type, type_t *argument_type)
6874 {
6875         function_parameter_t *parameter
6876                 = obstack_alloc(type_obst, sizeof(parameter[0]));
6877         memset(parameter, 0, sizeof(parameter[0]));
6878         parameter->type = argument_type;
6879
6880         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6881         type->function.return_type = return_type;
6882         type->function.parameters  = parameter;
6883
6884         return identify_new_type(type);
6885 }
6886
6887 static type_t *make_function_0_type(type_t *return_type)
6888 {
6889         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6890         type->function.return_type = return_type;
6891         type->function.parameters  = NULL;
6892
6893         return identify_new_type(type);
6894 }
6895
6896 /**
6897  * Creates a function type for some function like builtins.
6898  *
6899  * @param symbol   the symbol describing the builtin
6900  */
6901 static type_t *get_builtin_symbol_type(symbol_t *symbol)
6902 {
6903         switch (symbol->ID) {
6904         case T___builtin_alloca:
6905                 return make_function_1_type(type_void_ptr, type_size_t);
6906         case T___builtin_huge_val:
6907                 return make_function_0_type(type_double);
6908         case T___builtin_inf:
6909                 return make_function_0_type(type_double);
6910         case T___builtin_inff:
6911                 return make_function_0_type(type_float);
6912         case T___builtin_infl:
6913                 return make_function_0_type(type_long_double);
6914         case T___builtin_nan:
6915                 return make_function_1_type(type_double, type_char_ptr);
6916         case T___builtin_nanf:
6917                 return make_function_1_type(type_float, type_char_ptr);
6918         case T___builtin_nanl:
6919                 return make_function_1_type(type_long_double, type_char_ptr);
6920         case T___builtin_va_end:
6921                 return make_function_1_type(type_void, type_valist);
6922         case T___builtin_expect:
6923                 return make_function_2_type(type_long, type_long, type_long);
6924         default:
6925                 internal_errorf(HERE, "not implemented builtin identifier found");
6926         }
6927 }
6928
6929 /**
6930  * Performs automatic type cast as described in § 6.3.2.1.
6931  *
6932  * @param orig_type  the original type
6933  */
6934 static type_t *automatic_type_conversion(type_t *orig_type)
6935 {
6936         type_t *type = skip_typeref(orig_type);
6937         if (is_type_array(type)) {
6938                 array_type_t *array_type   = &type->array;
6939                 type_t       *element_type = array_type->element_type;
6940                 unsigned      qualifiers   = array_type->base.qualifiers;
6941
6942                 return make_pointer_type(element_type, qualifiers);
6943         }
6944
6945         if (is_type_function(type)) {
6946                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
6947         }
6948
6949         return orig_type;
6950 }
6951
6952 /**
6953  * reverts the automatic casts of array to pointer types and function
6954  * to function-pointer types as defined § 6.3.2.1
6955  */
6956 type_t *revert_automatic_type_conversion(const expression_t *expression)
6957 {
6958         switch (expression->kind) {
6959                 case EXPR_REFERENCE: {
6960                         entity_t *entity = expression->reference.entity;
6961                         if (is_declaration(entity)) {
6962                                 return entity->declaration.type;
6963                         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6964                                 return entity->enum_value.enum_type;
6965                         } else {
6966                                 panic("no declaration or enum in reference");
6967                         }
6968                 }
6969
6970                 case EXPR_SELECT: {
6971                         entity_t *entity = expression->select.compound_entry;
6972                         assert(is_declaration(entity));
6973                         type_t   *type   = entity->declaration.type;
6974                         return get_qualified_type(type,
6975                                         expression->base.type->base.qualifiers);
6976                 }
6977
6978                 case EXPR_UNARY_DEREFERENCE: {
6979                         const expression_t *const value = expression->unary.value;
6980                         type_t             *const type  = skip_typeref(value->base.type);
6981                         if (!is_type_pointer(type))
6982                                 return type_error_type;
6983                         return type->pointer.points_to;
6984                 }
6985
6986                 case EXPR_BUILTIN_SYMBOL:
6987                         return get_builtin_symbol_type(expression->builtin_symbol.symbol);
6988
6989                 case EXPR_ARRAY_ACCESS: {
6990                         const expression_t *array_ref = expression->array_access.array_ref;
6991                         type_t             *type_left = skip_typeref(array_ref->base.type);
6992                         if (!is_type_pointer(type_left))
6993                                 return type_error_type;
6994                         return type_left->pointer.points_to;
6995                 }
6996
6997                 case EXPR_STRING_LITERAL: {
6998                         size_t size = expression->string.value.size;
6999                         return make_array_type(type_char, size, TYPE_QUALIFIER_NONE);
7000                 }
7001
7002                 case EXPR_WIDE_STRING_LITERAL: {
7003                         size_t size = expression->wide_string.value.size;
7004                         return make_array_type(type_wchar_t, size, TYPE_QUALIFIER_NONE);
7005                 }
7006
7007                 case EXPR_COMPOUND_LITERAL:
7008                         return expression->compound_literal.type;
7009
7010                 default:
7011                         return expression->base.type;
7012         }
7013 }
7014
7015 static expression_t *parse_reference(void)
7016 {
7017         symbol_t *const symbol = token.v.symbol;
7018
7019         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
7020
7021         if (entity == NULL) {
7022                 if (!strict_mode && look_ahead(1)->type == '(') {
7023                         /* an implicitly declared function */
7024                         if (warning.error_implicit_function_declaration) {
7025                                 errorf(HERE, "implicit declaration of function '%Y'", symbol);
7026                         } else if (warning.implicit_function_declaration) {
7027                                 warningf(HERE, "implicit declaration of function '%Y'", symbol);
7028                         }
7029
7030                         entity = create_implicit_function(symbol, HERE);
7031                 } else {
7032                         errorf(HERE, "unknown identifier '%Y' found.", symbol);
7033                         entity = create_error_entity(symbol, ENTITY_VARIABLE);
7034                 }
7035         }
7036
7037         type_t *orig_type;
7038
7039         if (is_declaration(entity)) {
7040                 orig_type = entity->declaration.type;
7041         } else if (entity->kind == ENTITY_ENUM_VALUE) {
7042                 orig_type = entity->enum_value.enum_type;
7043         } else if (entity->kind == ENTITY_TYPEDEF) {
7044                 errorf(HERE, "encountered typedef name '%Y' while parsing expression",
7045                         symbol);
7046                 next_token();
7047                 return create_invalid_expression();
7048         } else {
7049                 panic("expected declaration or enum value in reference");
7050         }
7051
7052         /* we always do the auto-type conversions; the & and sizeof parser contains
7053          * code to revert this! */
7054         type_t *type = automatic_type_conversion(orig_type);
7055
7056         expression_kind_t kind = EXPR_REFERENCE;
7057         if (entity->kind == ENTITY_ENUM_VALUE)
7058                 kind = EXPR_REFERENCE_ENUM_VALUE;
7059
7060         expression_t *expression     = allocate_expression_zero(kind);
7061         expression->reference.entity = entity;
7062         expression->base.type        = type;
7063
7064         /* this declaration is used */
7065         if (is_declaration(entity)) {
7066                 entity->declaration.used = true;
7067         }
7068
7069         if (entity->base.parent_scope != file_scope
7070                 && entity->base.parent_scope->depth < current_function->parameters.depth
7071                 && is_type_valid(orig_type) && !is_type_function(orig_type)) {
7072                 if (entity->kind == ENTITY_VARIABLE) {
7073                         /* access of a variable from an outer function */
7074                         entity->variable.address_taken = true;
7075                 } else if (entity->kind == ENTITY_PARAMETER) {
7076                         entity->parameter.address_taken = true;
7077                 }
7078                 current_function->need_closure = true;
7079         }
7080
7081         /* check for deprecated functions */
7082         if (warning.deprecated_declarations
7083                 && is_declaration(entity)
7084                 && entity->declaration.modifiers & DM_DEPRECATED) {
7085                 declaration_t *declaration = &entity->declaration;
7086
7087                 char const *const prefix = entity->kind == ENTITY_FUNCTION ?
7088                         "function" : "variable";
7089
7090                 if (declaration->deprecated_string != NULL) {
7091                         warningf(HERE, "%s '%Y' is deprecated (declared %P): \"%s\"",
7092                                  prefix, entity->base.symbol, &entity->base.source_position,
7093                                  declaration->deprecated_string);
7094                 } else {
7095                         warningf(HERE, "%s '%Y' is deprecated (declared %P)", prefix,
7096                                  entity->base.symbol, &entity->base.source_position);
7097                 }
7098         }
7099
7100         if (warning.init_self && entity == current_init_decl && !in_type_prop
7101             && entity->kind == ENTITY_VARIABLE) {
7102                 current_init_decl = NULL;
7103                 warningf(HERE, "variable '%#T' is initialized by itself",
7104                          entity->declaration.type, entity->base.symbol);
7105         }
7106
7107         next_token();
7108         return expression;
7109 }
7110
7111 static bool semantic_cast(expression_t *cast)
7112 {
7113         expression_t            *expression      = cast->unary.value;
7114         type_t                  *orig_dest_type  = cast->base.type;
7115         type_t                  *orig_type_right = expression->base.type;
7116         type_t            const *dst_type        = skip_typeref(orig_dest_type);
7117         type_t            const *src_type        = skip_typeref(orig_type_right);
7118         source_position_t const *pos             = &cast->base.source_position;
7119
7120         /* §6.5.4 A (void) cast is explicitly permitted, more for documentation than for utility. */
7121         if (dst_type == type_void)
7122                 return true;
7123
7124         /* only integer and pointer can be casted to pointer */
7125         if (is_type_pointer(dst_type)  &&
7126             !is_type_pointer(src_type) &&
7127             !is_type_integer(src_type) &&
7128             is_type_valid(src_type)) {
7129                 errorf(pos, "cannot convert type '%T' to a pointer type", orig_type_right);
7130                 return false;
7131         }
7132
7133         if (!is_type_scalar(dst_type) && is_type_valid(dst_type)) {
7134                 errorf(pos, "conversion to non-scalar type '%T' requested", orig_dest_type);
7135                 return false;
7136         }
7137
7138         if (!is_type_scalar(src_type) && is_type_valid(src_type)) {
7139                 errorf(pos, "conversion from non-scalar type '%T' requested", orig_type_right);
7140                 return false;
7141         }
7142
7143         if (warning.cast_qual &&
7144             is_type_pointer(src_type) &&
7145             is_type_pointer(dst_type)) {
7146                 type_t *src = skip_typeref(src_type->pointer.points_to);
7147                 type_t *dst = skip_typeref(dst_type->pointer.points_to);
7148                 unsigned missing_qualifiers =
7149                         src->base.qualifiers & ~dst->base.qualifiers;
7150                 if (missing_qualifiers != 0) {
7151                         warningf(pos,
7152                                  "cast discards qualifiers '%Q' in pointer target type of '%T'",
7153                                  missing_qualifiers, orig_type_right);
7154                 }
7155         }
7156         return true;
7157 }
7158
7159 static expression_t *parse_compound_literal(type_t *type)
7160 {
7161         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
7162
7163         parse_initializer_env_t env;
7164         env.type             = type;
7165         env.entity           = NULL;
7166         env.must_be_constant = false;
7167         initializer_t *initializer = parse_initializer(&env);
7168         type = env.type;
7169
7170         expression->compound_literal.initializer = initializer;
7171         expression->compound_literal.type        = type;
7172         expression->base.type                    = automatic_type_conversion(type);
7173
7174         return expression;
7175 }
7176
7177 /**
7178  * Parse a cast expression.
7179  */
7180 static expression_t *parse_cast(void)
7181 {
7182         add_anchor_token(')');
7183
7184         source_position_t source_position = token.source_position;
7185
7186         type_t *type = parse_typename();
7187
7188         rem_anchor_token(')');
7189         expect(')', end_error);
7190
7191         if (token.type == '{') {
7192                 return parse_compound_literal(type);
7193         }
7194
7195         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
7196         cast->base.source_position = source_position;
7197
7198         expression_t *value = parse_sub_expression(PREC_CAST);
7199         cast->base.type   = type;
7200         cast->unary.value = value;
7201
7202         if (! semantic_cast(cast)) {
7203                 /* TODO: record the error in the AST. else it is impossible to detect it */
7204         }
7205
7206         return cast;
7207 end_error:
7208         return create_invalid_expression();
7209 }
7210
7211 /**
7212  * Parse a statement expression.
7213  */
7214 static expression_t *parse_statement_expression(void)
7215 {
7216         add_anchor_token(')');
7217
7218         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
7219
7220         statement_t *statement          = parse_compound_statement(true);
7221         statement->compound.stmt_expr   = true;
7222         expression->statement.statement = statement;
7223
7224         /* find last statement and use its type */
7225         type_t *type = type_void;
7226         const statement_t *stmt = statement->compound.statements;
7227         if (stmt != NULL) {
7228                 while (stmt->base.next != NULL)
7229                         stmt = stmt->base.next;
7230
7231                 if (stmt->kind == STATEMENT_EXPRESSION) {
7232                         type = stmt->expression.expression->base.type;
7233                 }
7234         } else if (warning.other) {
7235                 warningf(&expression->base.source_position, "empty statement expression ({})");
7236         }
7237         expression->base.type = type;
7238
7239         rem_anchor_token(')');
7240         expect(')', end_error);
7241
7242 end_error:
7243         return expression;
7244 }
7245
7246 /**
7247  * Parse a parenthesized expression.
7248  */
7249 static expression_t *parse_parenthesized_expression(void)
7250 {
7251         eat('(');
7252
7253         switch (token.type) {
7254         case '{':
7255                 /* gcc extension: a statement expression */
7256                 return parse_statement_expression();
7257
7258         TYPE_QUALIFIERS
7259         TYPE_SPECIFIERS
7260                 return parse_cast();
7261         case T_IDENTIFIER:
7262                 if (is_typedef_symbol(token.v.symbol)) {
7263                         return parse_cast();
7264                 }
7265         }
7266
7267         add_anchor_token(')');
7268         expression_t *result = parse_expression();
7269         result->base.parenthesized = true;
7270         rem_anchor_token(')');
7271         expect(')', end_error);
7272
7273 end_error:
7274         return result;
7275 }
7276
7277 static expression_t *parse_function_keyword(void)
7278 {
7279         /* TODO */
7280
7281         if (current_function == NULL) {
7282                 errorf(HERE, "'__func__' used outside of a function");
7283         }
7284
7285         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
7286         expression->base.type     = type_char_ptr;
7287         expression->funcname.kind = FUNCNAME_FUNCTION;
7288
7289         next_token();
7290
7291         return expression;
7292 }
7293
7294 static expression_t *parse_pretty_function_keyword(void)
7295 {
7296         if (current_function == NULL) {
7297                 errorf(HERE, "'__PRETTY_FUNCTION__' used outside of a function");
7298         }
7299
7300         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
7301         expression->base.type     = type_char_ptr;
7302         expression->funcname.kind = FUNCNAME_PRETTY_FUNCTION;
7303
7304         eat(T___PRETTY_FUNCTION__);
7305
7306         return expression;
7307 }
7308
7309 static expression_t *parse_funcsig_keyword(void)
7310 {
7311         if (current_function == NULL) {
7312                 errorf(HERE, "'__FUNCSIG__' used outside of a function");
7313         }
7314
7315         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
7316         expression->base.type     = type_char_ptr;
7317         expression->funcname.kind = FUNCNAME_FUNCSIG;
7318
7319         eat(T___FUNCSIG__);
7320
7321         return expression;
7322 }
7323
7324 static expression_t *parse_funcdname_keyword(void)
7325 {
7326         if (current_function == NULL) {
7327                 errorf(HERE, "'__FUNCDNAME__' used outside of a function");
7328         }
7329
7330         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
7331         expression->base.type     = type_char_ptr;
7332         expression->funcname.kind = FUNCNAME_FUNCDNAME;
7333
7334         eat(T___FUNCDNAME__);
7335
7336         return expression;
7337 }
7338
7339 static designator_t *parse_designator(void)
7340 {
7341         designator_t *result    = allocate_ast_zero(sizeof(result[0]));
7342         result->source_position = *HERE;
7343
7344         if (token.type != T_IDENTIFIER) {
7345                 parse_error_expected("while parsing member designator",
7346                                      T_IDENTIFIER, NULL);
7347                 return NULL;
7348         }
7349         result->symbol = token.v.symbol;
7350         next_token();
7351
7352         designator_t *last_designator = result;
7353         while (true) {
7354                 if (token.type == '.') {
7355                         next_token();
7356                         if (token.type != T_IDENTIFIER) {
7357                                 parse_error_expected("while parsing member designator",
7358                                                      T_IDENTIFIER, NULL);
7359                                 return NULL;
7360                         }
7361                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
7362                         designator->source_position = *HERE;
7363                         designator->symbol          = token.v.symbol;
7364                         next_token();
7365
7366                         last_designator->next = designator;
7367                         last_designator       = designator;
7368                         continue;
7369                 }
7370                 if (token.type == '[') {
7371                         next_token();
7372                         add_anchor_token(']');
7373                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
7374                         designator->source_position = *HERE;
7375                         designator->array_index     = parse_expression();
7376                         rem_anchor_token(']');
7377                         expect(']', end_error);
7378                         if (designator->array_index == NULL) {
7379                                 return NULL;
7380                         }
7381
7382                         last_designator->next = designator;
7383                         last_designator       = designator;
7384                         continue;
7385                 }
7386                 break;
7387         }
7388
7389         return result;
7390 end_error:
7391         return NULL;
7392 }
7393
7394 /**
7395  * Parse the __builtin_offsetof() expression.
7396  */
7397 static expression_t *parse_offsetof(void)
7398 {
7399         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
7400         expression->base.type    = type_size_t;
7401
7402         eat(T___builtin_offsetof);
7403
7404         expect('(', end_error);
7405         add_anchor_token(',');
7406         type_t *type = parse_typename();
7407         rem_anchor_token(',');
7408         expect(',', end_error);
7409         add_anchor_token(')');
7410         designator_t *designator = parse_designator();
7411         rem_anchor_token(')');
7412         expect(')', end_error);
7413
7414         expression->offsetofe.type       = type;
7415         expression->offsetofe.designator = designator;
7416
7417         type_path_t path;
7418         memset(&path, 0, sizeof(path));
7419         path.top_type = type;
7420         path.path     = NEW_ARR_F(type_path_entry_t, 0);
7421
7422         descend_into_subtype(&path);
7423
7424         if (!walk_designator(&path, designator, true)) {
7425                 return create_invalid_expression();
7426         }
7427
7428         DEL_ARR_F(path.path);
7429
7430         return expression;
7431 end_error:
7432         return create_invalid_expression();
7433 }
7434
7435 /**
7436  * Parses a _builtin_va_start() expression.
7437  */
7438 static expression_t *parse_va_start(void)
7439 {
7440         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
7441
7442         eat(T___builtin_va_start);
7443
7444         expect('(', end_error);
7445         add_anchor_token(',');
7446         expression->va_starte.ap = parse_assignment_expression();
7447         rem_anchor_token(',');
7448         expect(',', end_error);
7449         expression_t *const expr = parse_assignment_expression();
7450         if (expr->kind == EXPR_REFERENCE) {
7451                 entity_t *const entity = expr->reference.entity;
7452                 if (entity->base.parent_scope != &current_function->parameters
7453                                 || entity->base.next != NULL
7454                                 || entity->kind != ENTITY_PARAMETER) {
7455                         errorf(&expr->base.source_position,
7456                                "second argument of 'va_start' must be last parameter of the current function");
7457                 } else {
7458                         expression->va_starte.parameter = &entity->variable;
7459                 }
7460                 expect(')', end_error);
7461                 return expression;
7462         }
7463         expect(')', end_error);
7464 end_error:
7465         return create_invalid_expression();
7466 }
7467
7468 /**
7469  * Parses a _builtin_va_arg() expression.
7470  */
7471 static expression_t *parse_va_arg(void)
7472 {
7473         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
7474
7475         eat(T___builtin_va_arg);
7476
7477         expect('(', end_error);
7478         expression->va_arge.ap = parse_assignment_expression();
7479         expect(',', end_error);
7480         expression->base.type = parse_typename();
7481         expect(')', end_error);
7482
7483         return expression;
7484 end_error:
7485         return create_invalid_expression();
7486 }
7487
7488 static expression_t *parse_builtin_symbol(void)
7489 {
7490         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_SYMBOL);
7491
7492         symbol_t *symbol = token.v.symbol;
7493
7494         expression->builtin_symbol.symbol = symbol;
7495         next_token();
7496
7497         type_t *type = get_builtin_symbol_type(symbol);
7498         type = automatic_type_conversion(type);
7499
7500         expression->base.type = type;
7501         return expression;
7502 }
7503
7504 /**
7505  * Parses a __builtin_constant() expression.
7506  */
7507 static expression_t *parse_builtin_constant(void)
7508 {
7509         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
7510
7511         eat(T___builtin_constant_p);
7512
7513         expect('(', end_error);
7514         add_anchor_token(')');
7515         expression->builtin_constant.value = parse_assignment_expression();
7516         rem_anchor_token(')');
7517         expect(')', end_error);
7518         expression->base.type = type_int;
7519
7520         return expression;
7521 end_error:
7522         return create_invalid_expression();
7523 }
7524
7525 /**
7526  * Parses a __builtin_prefetch() expression.
7527  */
7528 static expression_t *parse_builtin_prefetch(void)
7529 {
7530         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_PREFETCH);
7531
7532         eat(T___builtin_prefetch);
7533
7534         expect('(', end_error);
7535         add_anchor_token(')');
7536         expression->builtin_prefetch.adr = parse_assignment_expression();
7537         if (token.type == ',') {
7538                 next_token();
7539                 expression->builtin_prefetch.rw = parse_assignment_expression();
7540         }
7541         if (token.type == ',') {
7542                 next_token();
7543                 expression->builtin_prefetch.locality = parse_assignment_expression();
7544         }
7545         rem_anchor_token(')');
7546         expect(')', end_error);
7547         expression->base.type = type_void;
7548
7549         return expression;
7550 end_error:
7551         return create_invalid_expression();
7552 }
7553
7554 /**
7555  * Parses a __builtin_is_*() compare expression.
7556  */
7557 static expression_t *parse_compare_builtin(void)
7558 {
7559         expression_t *expression;
7560
7561         switch (token.type) {
7562         case T___builtin_isgreater:
7563                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATER);
7564                 break;
7565         case T___builtin_isgreaterequal:
7566                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATEREQUAL);
7567                 break;
7568         case T___builtin_isless:
7569                 expression = allocate_expression_zero(EXPR_BINARY_ISLESS);
7570                 break;
7571         case T___builtin_islessequal:
7572                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSEQUAL);
7573                 break;
7574         case T___builtin_islessgreater:
7575                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSGREATER);
7576                 break;
7577         case T___builtin_isunordered:
7578                 expression = allocate_expression_zero(EXPR_BINARY_ISUNORDERED);
7579                 break;
7580         default:
7581                 internal_errorf(HERE, "invalid compare builtin found");
7582         }
7583         expression->base.source_position = *HERE;
7584         next_token();
7585
7586         expect('(', end_error);
7587         expression->binary.left = parse_assignment_expression();
7588         expect(',', end_error);
7589         expression->binary.right = parse_assignment_expression();
7590         expect(')', end_error);
7591
7592         type_t *const orig_type_left  = expression->binary.left->base.type;
7593         type_t *const orig_type_right = expression->binary.right->base.type;
7594
7595         type_t *const type_left  = skip_typeref(orig_type_left);
7596         type_t *const type_right = skip_typeref(orig_type_right);
7597         if (!is_type_float(type_left) && !is_type_float(type_right)) {
7598                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7599                         type_error_incompatible("invalid operands in comparison",
7600                                 &expression->base.source_position, orig_type_left, orig_type_right);
7601                 }
7602         } else {
7603                 semantic_comparison(&expression->binary);
7604         }
7605
7606         return expression;
7607 end_error:
7608         return create_invalid_expression();
7609 }
7610
7611 #if 0
7612 /**
7613  * Parses a __builtin_expect(, end_error) expression.
7614  */
7615 static expression_t *parse_builtin_expect(void, end_error)
7616 {
7617         expression_t *expression
7618                 = allocate_expression_zero(EXPR_BINARY_BUILTIN_EXPECT);
7619
7620         eat(T___builtin_expect);
7621
7622         expect('(', end_error);
7623         expression->binary.left = parse_assignment_expression();
7624         expect(',', end_error);
7625         expression->binary.right = parse_constant_expression();
7626         expect(')', end_error);
7627
7628         expression->base.type = expression->binary.left->base.type;
7629
7630         return expression;
7631 end_error:
7632         return create_invalid_expression();
7633 }
7634 #endif
7635
7636 /**
7637  * Parses a MS assume() expression.
7638  */
7639 static expression_t *parse_assume(void)
7640 {
7641         expression_t *expression = allocate_expression_zero(EXPR_UNARY_ASSUME);
7642
7643         eat(T__assume);
7644
7645         expect('(', end_error);
7646         add_anchor_token(')');
7647         expression->unary.value = parse_assignment_expression();
7648         rem_anchor_token(')');
7649         expect(')', end_error);
7650
7651         expression->base.type = type_void;
7652         return expression;
7653 end_error:
7654         return create_invalid_expression();
7655 }
7656
7657 /**
7658  * Return the declaration for a given label symbol or create a new one.
7659  *
7660  * @param symbol  the symbol of the label
7661  */
7662 static label_t *get_label(symbol_t *symbol)
7663 {
7664         entity_t *label;
7665         assert(current_function != NULL);
7666
7667         label = get_entity(symbol, NAMESPACE_LABEL);
7668         /* if we found a local label, we already created the declaration */
7669         if (label != NULL && label->kind == ENTITY_LOCAL_LABEL) {
7670                 if (label->base.parent_scope != current_scope) {
7671                         assert(label->base.parent_scope->depth < current_scope->depth);
7672                         current_function->goto_to_outer = true;
7673                 }
7674                 return &label->label;
7675         }
7676
7677         label = get_entity(symbol, NAMESPACE_LABEL);
7678         /* if we found a label in the same function, then we already created the
7679          * declaration */
7680         if (label != NULL
7681                         && label->base.parent_scope == &current_function->parameters) {
7682                 return &label->label;
7683         }
7684
7685         /* otherwise we need to create a new one */
7686         label               = allocate_entity_zero(ENTITY_LABEL);
7687         label->base.namespc = NAMESPACE_LABEL;
7688         label->base.symbol  = symbol;
7689
7690         label_push(label);
7691
7692         return &label->label;
7693 }
7694
7695 /**
7696  * Parses a GNU && label address expression.
7697  */
7698 static expression_t *parse_label_address(void)
7699 {
7700         source_position_t source_position = token.source_position;
7701         eat(T_ANDAND);
7702         if (token.type != T_IDENTIFIER) {
7703                 parse_error_expected("while parsing label address", T_IDENTIFIER, NULL);
7704                 goto end_error;
7705         }
7706         symbol_t *symbol = token.v.symbol;
7707         next_token();
7708
7709         label_t *label       = get_label(symbol);
7710         label->used          = true;
7711         label->address_taken = true;
7712
7713         expression_t *expression = allocate_expression_zero(EXPR_LABEL_ADDRESS);
7714         expression->base.source_position = source_position;
7715
7716         /* label address is threaten as a void pointer */
7717         expression->base.type           = type_void_ptr;
7718         expression->label_address.label = label;
7719         return expression;
7720 end_error:
7721         return create_invalid_expression();
7722 }
7723
7724 /**
7725  * Parse a microsoft __noop expression.
7726  */
7727 static expression_t *parse_noop_expression(void)
7728 {
7729         /* the result is a (int)0 */
7730         expression_t *cnst         = allocate_expression_zero(EXPR_CONST);
7731         cnst->base.type            = type_int;
7732         cnst->conste.v.int_value   = 0;
7733         cnst->conste.is_ms_noop    = true;
7734
7735         eat(T___noop);
7736
7737         if (token.type == '(') {
7738                 /* parse arguments */
7739                 eat('(');
7740                 add_anchor_token(')');
7741                 add_anchor_token(',');
7742
7743                 if (token.type != ')') {
7744                         while (true) {
7745                                 (void)parse_assignment_expression();
7746                                 if (token.type != ',')
7747                                         break;
7748                                 next_token();
7749                         }
7750                 }
7751         }
7752         rem_anchor_token(',');
7753         rem_anchor_token(')');
7754         expect(')', end_error);
7755
7756 end_error:
7757         return cnst;
7758 }
7759
7760 /**
7761  * Parses a primary expression.
7762  */
7763 static expression_t *parse_primary_expression(void)
7764 {
7765         switch (token.type) {
7766                 case T_false:                    return parse_bool_const(false);
7767                 case T_true:                     return parse_bool_const(true);
7768                 case T_INTEGER:                  return parse_int_const();
7769                 case T_CHARACTER_CONSTANT:       return parse_character_constant();
7770                 case T_WIDE_CHARACTER_CONSTANT:  return parse_wide_character_constant();
7771                 case T_FLOATINGPOINT:            return parse_float_const();
7772                 case T_STRING_LITERAL:
7773                 case T_WIDE_STRING_LITERAL:      return parse_string_const();
7774                 case T_IDENTIFIER:               return parse_reference();
7775                 case T___FUNCTION__:
7776                 case T___func__:                 return parse_function_keyword();
7777                 case T___PRETTY_FUNCTION__:      return parse_pretty_function_keyword();
7778                 case T___FUNCSIG__:              return parse_funcsig_keyword();
7779                 case T___FUNCDNAME__:            return parse_funcdname_keyword();
7780                 case T___builtin_offsetof:       return parse_offsetof();
7781                 case T___builtin_va_start:       return parse_va_start();
7782                 case T___builtin_va_arg:         return parse_va_arg();
7783                 case T___builtin_expect:
7784                 case T___builtin_alloca:
7785                 case T___builtin_inf:
7786                 case T___builtin_inff:
7787                 case T___builtin_infl:
7788                 case T___builtin_nan:
7789                 case T___builtin_nanf:
7790                 case T___builtin_nanl:
7791                 case T___builtin_huge_val:
7792                 case T___builtin_va_end:         return parse_builtin_symbol();
7793                 case T___builtin_isgreater:
7794                 case T___builtin_isgreaterequal:
7795                 case T___builtin_isless:
7796                 case T___builtin_islessequal:
7797                 case T___builtin_islessgreater:
7798                 case T___builtin_isunordered:    return parse_compare_builtin();
7799                 case T___builtin_constant_p:     return parse_builtin_constant();
7800                 case T___builtin_prefetch:       return parse_builtin_prefetch();
7801                 case T__assume:                  return parse_assume();
7802                 case T_ANDAND:
7803                         if (GNU_MODE)
7804                                 return parse_label_address();
7805                         break;
7806
7807                 case '(':                        return parse_parenthesized_expression();
7808                 case T___noop:                   return parse_noop_expression();
7809         }
7810
7811         errorf(HERE, "unexpected token %K, expected an expression", &token);
7812         return create_invalid_expression();
7813 }
7814
7815 /**
7816  * Check if the expression has the character type and issue a warning then.
7817  */
7818 static void check_for_char_index_type(const expression_t *expression)
7819 {
7820         type_t       *const type      = expression->base.type;
7821         const type_t *const base_type = skip_typeref(type);
7822
7823         if (is_type_atomic(base_type, ATOMIC_TYPE_CHAR) &&
7824                         warning.char_subscripts) {
7825                 warningf(&expression->base.source_position,
7826                          "array subscript has type '%T'", type);
7827         }
7828 }
7829
7830 static expression_t *parse_array_expression(expression_t *left)
7831 {
7832         expression_t *expression = allocate_expression_zero(EXPR_ARRAY_ACCESS);
7833
7834         eat('[');
7835         add_anchor_token(']');
7836
7837         expression_t *inside = parse_expression();
7838
7839         type_t *const orig_type_left   = left->base.type;
7840         type_t *const orig_type_inside = inside->base.type;
7841
7842         type_t *const type_left   = skip_typeref(orig_type_left);
7843         type_t *const type_inside = skip_typeref(orig_type_inside);
7844
7845         type_t                    *return_type;
7846         array_access_expression_t *array_access = &expression->array_access;
7847         if (is_type_pointer(type_left)) {
7848                 return_type             = type_left->pointer.points_to;
7849                 array_access->array_ref = left;
7850                 array_access->index     = inside;
7851                 check_for_char_index_type(inside);
7852         } else if (is_type_pointer(type_inside)) {
7853                 return_type             = type_inside->pointer.points_to;
7854                 array_access->array_ref = inside;
7855                 array_access->index     = left;
7856                 array_access->flipped   = true;
7857                 check_for_char_index_type(left);
7858         } else {
7859                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
7860                         errorf(HERE,
7861                                 "array access on object with non-pointer types '%T', '%T'",
7862                                 orig_type_left, orig_type_inside);
7863                 }
7864                 return_type             = type_error_type;
7865                 array_access->array_ref = left;
7866                 array_access->index     = inside;
7867         }
7868
7869         expression->base.type = automatic_type_conversion(return_type);
7870
7871         rem_anchor_token(']');
7872         expect(']', end_error);
7873 end_error:
7874         return expression;
7875 }
7876
7877 static expression_t *parse_typeprop(expression_kind_t const kind)
7878 {
7879         expression_t  *tp_expression = allocate_expression_zero(kind);
7880         tp_expression->base.type     = type_size_t;
7881
7882         eat(kind == EXPR_SIZEOF ? T_sizeof : T___alignof__);
7883
7884         /* we only refer to a type property, mark this case */
7885         bool old     = in_type_prop;
7886         in_type_prop = true;
7887
7888         type_t       *orig_type;
7889         expression_t *expression;
7890         if (token.type == '(' && is_declaration_specifier(look_ahead(1), true)) {
7891                 next_token();
7892                 add_anchor_token(')');
7893                 orig_type = parse_typename();
7894                 rem_anchor_token(')');
7895                 expect(')', end_error);
7896
7897                 if (token.type == '{') {
7898                         /* It was not sizeof(type) after all.  It is sizeof of an expression
7899                          * starting with a compound literal */
7900                         expression = parse_compound_literal(orig_type);
7901                         goto typeprop_expression;
7902                 }
7903         } else {
7904                 expression = parse_sub_expression(PREC_UNARY);
7905
7906 typeprop_expression:
7907                 tp_expression->typeprop.tp_expression = expression;
7908
7909                 orig_type = revert_automatic_type_conversion(expression);
7910                 expression->base.type = orig_type;
7911         }
7912
7913         tp_expression->typeprop.type   = orig_type;
7914         type_t const* const type       = skip_typeref(orig_type);
7915         char   const* const wrong_type =
7916                 GNU_MODE && is_type_atomic(type, ATOMIC_TYPE_VOID) ? NULL                  :
7917                 is_type_incomplete(type)                           ? "incomplete"          :
7918                 type->kind == TYPE_FUNCTION                        ? "function designator" :
7919                 type->kind == TYPE_BITFIELD                        ? "bitfield"            :
7920                 NULL;
7921         if (wrong_type != NULL) {
7922                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
7923                 errorf(&tp_expression->base.source_position,
7924                                 "operand of %s expression must not be of %s type '%T'",
7925                                 what, wrong_type, orig_type);
7926         }
7927
7928 end_error:
7929         in_type_prop = old;
7930         return tp_expression;
7931 }
7932
7933 static expression_t *parse_sizeof(void)
7934 {
7935         return parse_typeprop(EXPR_SIZEOF);
7936 }
7937
7938 static expression_t *parse_alignof(void)
7939 {
7940         return parse_typeprop(EXPR_ALIGNOF);
7941 }
7942
7943 static expression_t *parse_select_expression(expression_t *compound)
7944 {
7945         expression_t *select    = allocate_expression_zero(EXPR_SELECT);
7946         select->select.compound = compound;
7947
7948         assert(token.type == '.' || token.type == T_MINUSGREATER);
7949         bool is_pointer = (token.type == T_MINUSGREATER);
7950         next_token();
7951
7952         if (token.type != T_IDENTIFIER) {
7953                 parse_error_expected("while parsing select", T_IDENTIFIER, NULL);
7954                 return select;
7955         }
7956         symbol_t *symbol = token.v.symbol;
7957         next_token();
7958
7959         type_t *const orig_type = compound->base.type;
7960         type_t *const type      = skip_typeref(orig_type);
7961
7962         type_t *type_left;
7963         bool    saw_error = false;
7964         if (is_type_pointer(type)) {
7965                 if (!is_pointer) {
7966                         errorf(HERE,
7967                                "request for member '%Y' in something not a struct or union, but '%T'",
7968                                symbol, orig_type);
7969                         saw_error = true;
7970                 }
7971                 type_left = skip_typeref(type->pointer.points_to);
7972         } else {
7973                 if (is_pointer && is_type_valid(type)) {
7974                         errorf(HERE, "left hand side of '->' is not a pointer, but '%T'", orig_type);
7975                         saw_error = true;
7976                 }
7977                 type_left = type;
7978         }
7979
7980         entity_t *entry;
7981         if (type_left->kind == TYPE_COMPOUND_STRUCT ||
7982             type_left->kind == TYPE_COMPOUND_UNION) {
7983                 compound_t *compound = type_left->compound.compound;
7984
7985                 if (!compound->complete) {
7986                         errorf(HERE, "request for member '%Y' of incomplete type '%T'",
7987                                symbol, type_left);
7988                         goto create_error_entry;
7989                 }
7990
7991                 entry = find_compound_entry(compound, symbol);
7992                 if (entry == NULL) {
7993                         errorf(HERE, "'%T' has no member named '%Y'", orig_type, symbol);
7994                         goto create_error_entry;
7995                 }
7996         } else {
7997                 if (is_type_valid(type_left) && !saw_error) {
7998                         errorf(HERE,
7999                                "request for member '%Y' in something not a struct or union, but '%T'",
8000                                symbol, type_left);
8001                 }
8002 create_error_entry:
8003                 entry = create_error_entity(symbol, ENTITY_COMPOUND_MEMBER);
8004         }
8005
8006         assert(is_declaration(entry));
8007         select->select.compound_entry = entry;
8008
8009         type_t *entry_type = entry->declaration.type;
8010         type_t *res_type
8011                 = get_qualified_type(entry_type, type_left->base.qualifiers);
8012
8013         /* we always do the auto-type conversions; the & and sizeof parser contains
8014          * code to revert this! */
8015         select->base.type = automatic_type_conversion(res_type);
8016
8017         type_t *skipped = skip_typeref(res_type);
8018         if (skipped->kind == TYPE_BITFIELD) {
8019                 select->base.type = skipped->bitfield.base_type;
8020         }
8021
8022         return select;
8023 }
8024
8025 static void check_call_argument(const function_parameter_t *parameter,
8026                                 call_argument_t *argument, unsigned pos)
8027 {
8028         type_t         *expected_type      = parameter->type;
8029         type_t         *expected_type_skip = skip_typeref(expected_type);
8030         assign_error_t  error              = ASSIGN_ERROR_INCOMPATIBLE;
8031         expression_t   *arg_expr           = argument->expression;
8032         type_t         *arg_type           = skip_typeref(arg_expr->base.type);
8033
8034         /* handle transparent union gnu extension */
8035         if (is_type_union(expected_type_skip)
8036                         && (expected_type_skip->base.modifiers
8037                                 & TYPE_MODIFIER_TRANSPARENT_UNION)) {
8038                 compound_t *union_decl  = expected_type_skip->compound.compound;
8039                 type_t     *best_type   = NULL;
8040                 entity_t   *entry       = union_decl->members.entities;
8041                 for ( ; entry != NULL; entry = entry->base.next) {
8042                         assert(is_declaration(entry));
8043                         type_t *decl_type = entry->declaration.type;
8044                         error = semantic_assign(decl_type, arg_expr);
8045                         if (error == ASSIGN_ERROR_INCOMPATIBLE
8046                                 || error == ASSIGN_ERROR_POINTER_QUALIFIER_MISSING)
8047                                 continue;
8048
8049                         if (error == ASSIGN_SUCCESS) {
8050                                 best_type = decl_type;
8051                         } else if (best_type == NULL) {
8052                                 best_type = decl_type;
8053                         }
8054                 }
8055
8056                 if (best_type != NULL) {
8057                         expected_type = best_type;
8058                 }
8059         }
8060
8061         error                = semantic_assign(expected_type, arg_expr);
8062         argument->expression = create_implicit_cast(argument->expression,
8063                                                     expected_type);
8064
8065         if (error != ASSIGN_SUCCESS) {
8066                 /* report exact scope in error messages (like "in argument 3") */
8067                 char buf[64];
8068                 snprintf(buf, sizeof(buf), "call argument %u", pos);
8069                 report_assign_error(error, expected_type, arg_expr,     buf,
8070                                                         &arg_expr->base.source_position);
8071         } else if (warning.traditional || warning.conversion) {
8072                 type_t *const promoted_type = get_default_promoted_type(arg_type);
8073                 if (!types_compatible(expected_type_skip, promoted_type) &&
8074                     !types_compatible(expected_type_skip, type_void_ptr) &&
8075                     !types_compatible(type_void_ptr,      promoted_type)) {
8076                         /* Deliberately show the skipped types in this warning */
8077                         warningf(&arg_expr->base.source_position,
8078                                 "passing call argument %u as '%T' rather than '%T' due to prototype",
8079                                 pos, expected_type_skip, promoted_type);
8080                 }
8081         }
8082 }
8083
8084 /**
8085  * Parse a call expression, ie. expression '( ... )'.
8086  *
8087  * @param expression  the function address
8088  */
8089 static expression_t *parse_call_expression(expression_t *expression)
8090 {
8091         expression_t      *result = allocate_expression_zero(EXPR_CALL);
8092         call_expression_t *call   = &result->call;
8093         call->function            = expression;
8094
8095         type_t *const orig_type = expression->base.type;
8096         type_t *const type      = skip_typeref(orig_type);
8097
8098         function_type_t *function_type = NULL;
8099         if (is_type_pointer(type)) {
8100                 type_t *const to_type = skip_typeref(type->pointer.points_to);
8101
8102                 if (is_type_function(to_type)) {
8103                         function_type   = &to_type->function;
8104                         call->base.type = function_type->return_type;
8105                 }
8106         }
8107
8108         if (function_type == NULL && is_type_valid(type)) {
8109                 errorf(HERE, "called object '%E' (type '%T') is not a pointer to a function", expression, orig_type);
8110         }
8111
8112         /* parse arguments */
8113         eat('(');
8114         add_anchor_token(')');
8115         add_anchor_token(',');
8116
8117         if (token.type != ')') {
8118                 call_argument_t *last_argument = NULL;
8119
8120                 while (true) {
8121                         call_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
8122
8123                         argument->expression = parse_assignment_expression();
8124                         if (last_argument == NULL) {
8125                                 call->arguments = argument;
8126                         } else {
8127                                 last_argument->next = argument;
8128                         }
8129                         last_argument = argument;
8130
8131                         if (token.type != ',')
8132                                 break;
8133                         next_token();
8134                 }
8135         }
8136         rem_anchor_token(',');
8137         rem_anchor_token(')');
8138         expect(')', end_error);
8139
8140         if (function_type == NULL)
8141                 return result;
8142
8143         function_parameter_t *parameter = function_type->parameters;
8144         call_argument_t      *argument  = call->arguments;
8145         if (!function_type->unspecified_parameters) {
8146                 for (unsigned pos = 0; parameter != NULL && argument != NULL;
8147                                 parameter = parameter->next, argument = argument->next) {
8148                         check_call_argument(parameter, argument, ++pos);
8149                 }
8150
8151                 if (parameter != NULL) {
8152                         errorf(HERE, "too few arguments to function '%E'", expression);
8153                 } else if (argument != NULL && !function_type->variadic) {
8154                         errorf(HERE, "too many arguments to function '%E'", expression);
8155                 }
8156         }
8157
8158         /* do default promotion */
8159         for (; argument != NULL; argument = argument->next) {
8160                 type_t *type = argument->expression->base.type;
8161
8162                 type = get_default_promoted_type(type);
8163
8164                 argument->expression
8165                         = create_implicit_cast(argument->expression, type);
8166         }
8167
8168         check_format(&result->call);
8169
8170         if (warning.aggregate_return &&
8171             is_type_compound(skip_typeref(function_type->return_type))) {
8172                 warningf(&result->base.source_position,
8173                          "function call has aggregate value");
8174         }
8175
8176 end_error:
8177         return result;
8178 }
8179
8180 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
8181
8182 static bool same_compound_type(const type_t *type1, const type_t *type2)
8183 {
8184         return
8185                 is_type_compound(type1) &&
8186                 type1->kind == type2->kind &&
8187                 type1->compound.compound == type2->compound.compound;
8188 }
8189
8190 static expression_t const *get_reference_address(expression_t const *expr)
8191 {
8192         bool regular_take_address = true;
8193         for (;;) {
8194                 if (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
8195                         expr = expr->unary.value;
8196                 } else {
8197                         regular_take_address = false;
8198                 }
8199
8200                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
8201                         break;
8202
8203                 expr = expr->unary.value;
8204         }
8205
8206         if (expr->kind != EXPR_REFERENCE)
8207                 return NULL;
8208
8209         /* special case for functions which are automatically converted to a
8210          * pointer to function without an extra TAKE_ADDRESS operation */
8211         if (!regular_take_address &&
8212                         expr->reference.entity->kind != ENTITY_FUNCTION) {
8213                 return NULL;
8214         }
8215
8216         return expr;
8217 }
8218
8219 static void warn_reference_address_as_bool(expression_t const* expr)
8220 {
8221         if (!warning.address)
8222                 return;
8223
8224         expr = get_reference_address(expr);
8225         if (expr != NULL) {
8226                 warningf(&expr->base.source_position,
8227                          "the address of '%Y' will always evaluate as 'true'",
8228                          expr->reference.entity->base.symbol);
8229         }
8230 }
8231
8232 static void warn_assignment_in_condition(const expression_t *const expr)
8233 {
8234         if (!warning.parentheses)
8235                 return;
8236         if (expr->base.kind != EXPR_BINARY_ASSIGN)
8237                 return;
8238         if (expr->base.parenthesized)
8239                 return;
8240         warningf(&expr->base.source_position,
8241                         "suggest parentheses around assignment used as truth value");
8242 }
8243
8244 static void semantic_condition(expression_t const *const expr,
8245                                char const *const context)
8246 {
8247         type_t *const type = skip_typeref(expr->base.type);
8248         if (is_type_scalar(type)) {
8249                 warn_reference_address_as_bool(expr);
8250                 warn_assignment_in_condition(expr);
8251         } else if (is_type_valid(type)) {
8252                 errorf(&expr->base.source_position,
8253                                 "%s must have scalar type", context);
8254         }
8255 }
8256
8257 /**
8258  * Parse a conditional expression, ie. 'expression ? ... : ...'.
8259  *
8260  * @param expression  the conditional expression
8261  */
8262 static expression_t *parse_conditional_expression(expression_t *expression)
8263 {
8264         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
8265
8266         conditional_expression_t *conditional = &result->conditional;
8267         conditional->condition                = expression;
8268
8269         eat('?');
8270         add_anchor_token(':');
8271
8272         /* §6.5.15:2  The first operand shall have scalar type. */
8273         semantic_condition(expression, "condition of conditional operator");
8274
8275         expression_t *true_expression = expression;
8276         bool          gnu_cond = false;
8277         if (GNU_MODE && token.type == ':') {
8278                 gnu_cond = true;
8279         } else {
8280                 true_expression = parse_expression();
8281         }
8282         rem_anchor_token(':');
8283         expect(':', end_error);
8284 end_error:;
8285         expression_t *false_expression =
8286                 parse_sub_expression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
8287
8288         type_t *const orig_true_type  = true_expression->base.type;
8289         type_t *const orig_false_type = false_expression->base.type;
8290         type_t *const true_type       = skip_typeref(orig_true_type);
8291         type_t *const false_type      = skip_typeref(orig_false_type);
8292
8293         /* 6.5.15.3 */
8294         type_t *result_type;
8295         if (is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
8296                         is_type_atomic(false_type, ATOMIC_TYPE_VOID)) {
8297                 /* ISO/IEC 14882:1998(E) §5.16:2 */
8298                 if (true_expression->kind == EXPR_UNARY_THROW) {
8299                         result_type = false_type;
8300                 } else if (false_expression->kind == EXPR_UNARY_THROW) {
8301                         result_type = true_type;
8302                 } else {
8303                         if (warning.other && (
8304                                                 !is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
8305                                                 !is_type_atomic(false_type, ATOMIC_TYPE_VOID)
8306                                         )) {
8307                                 warningf(&conditional->base.source_position,
8308                                                 "ISO C forbids conditional expression with only one void side");
8309                         }
8310                         result_type = type_void;
8311                 }
8312         } else if (is_type_arithmetic(true_type)
8313                    && is_type_arithmetic(false_type)) {
8314                 result_type = semantic_arithmetic(true_type, false_type);
8315
8316                 true_expression  = create_implicit_cast(true_expression, result_type);
8317                 false_expression = create_implicit_cast(false_expression, result_type);
8318
8319                 conditional->true_expression  = true_expression;
8320                 conditional->false_expression = false_expression;
8321                 conditional->base.type        = result_type;
8322         } else if (same_compound_type(true_type, false_type)) {
8323                 /* just take 1 of the 2 types */
8324                 result_type = true_type;
8325         } else if (is_type_pointer(true_type) || is_type_pointer(false_type)) {
8326                 type_t *pointer_type;
8327                 type_t *other_type;
8328                 expression_t *other_expression;
8329                 if (is_type_pointer(true_type) &&
8330                                 (!is_type_pointer(false_type) || is_null_pointer_constant(false_expression))) {
8331                         pointer_type     = true_type;
8332                         other_type       = false_type;
8333                         other_expression = false_expression;
8334                 } else {
8335                         pointer_type     = false_type;
8336                         other_type       = true_type;
8337                         other_expression = true_expression;
8338                 }
8339
8340                 if (is_null_pointer_constant(other_expression)) {
8341                         result_type = pointer_type;
8342                 } else if (is_type_pointer(other_type)) {
8343                         type_t *to1 = skip_typeref(pointer_type->pointer.points_to);
8344                         type_t *to2 = skip_typeref(other_type->pointer.points_to);
8345
8346                         type_t *to;
8347                         if (is_type_atomic(to1, ATOMIC_TYPE_VOID) ||
8348                             is_type_atomic(to2, ATOMIC_TYPE_VOID)) {
8349                                 to = type_void;
8350                         } else if (types_compatible(get_unqualified_type(to1),
8351                                                     get_unqualified_type(to2))) {
8352                                 to = to1;
8353                         } else {
8354                                 if (warning.other) {
8355                                         warningf(&conditional->base.source_position,
8356                                                         "pointer types '%T' and '%T' in conditional expression are incompatible",
8357                                                         true_type, false_type);
8358                                 }
8359                                 to = type_void;
8360                         }
8361
8362                         type_t *const type =
8363                                 get_qualified_type(to, to1->base.qualifiers | to2->base.qualifiers);
8364                         result_type = make_pointer_type(type, TYPE_QUALIFIER_NONE);
8365                 } else if (is_type_integer(other_type)) {
8366                         if (warning.other) {
8367                                 warningf(&conditional->base.source_position,
8368                                                 "pointer/integer type mismatch in conditional expression ('%T' and '%T')", true_type, false_type);
8369                         }
8370                         result_type = pointer_type;
8371                 } else {
8372                         if (is_type_valid(other_type)) {
8373                                 type_error_incompatible("while parsing conditional",
8374                                                 &expression->base.source_position, true_type, false_type);
8375                         }
8376                         result_type = type_error_type;
8377                 }
8378         } else {
8379                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
8380                         type_error_incompatible("while parsing conditional",
8381                                                 &conditional->base.source_position, true_type,
8382                                                 false_type);
8383                 }
8384                 result_type = type_error_type;
8385         }
8386
8387         conditional->true_expression
8388                 = gnu_cond ? NULL : create_implicit_cast(true_expression, result_type);
8389         conditional->false_expression
8390                 = create_implicit_cast(false_expression, result_type);
8391         conditional->base.type = result_type;
8392         return result;
8393 }
8394
8395 /**
8396  * Parse an extension expression.
8397  */
8398 static expression_t *parse_extension(void)
8399 {
8400         eat(T___extension__);
8401
8402         bool old_gcc_extension   = in_gcc_extension;
8403         in_gcc_extension         = true;
8404         expression_t *expression = parse_sub_expression(PREC_UNARY);
8405         in_gcc_extension         = old_gcc_extension;
8406         return expression;
8407 }
8408
8409 /**
8410  * Parse a __builtin_classify_type() expression.
8411  */
8412 static expression_t *parse_builtin_classify_type(void)
8413 {
8414         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
8415         result->base.type    = type_int;
8416
8417         eat(T___builtin_classify_type);
8418
8419         expect('(', end_error);
8420         add_anchor_token(')');
8421         expression_t *expression = parse_expression();
8422         rem_anchor_token(')');
8423         expect(')', end_error);
8424         result->classify_type.type_expression = expression;
8425
8426         return result;
8427 end_error:
8428         return create_invalid_expression();
8429 }
8430
8431 /**
8432  * Parse a delete expression
8433  * ISO/IEC 14882:1998(E) §5.3.5
8434  */
8435 static expression_t *parse_delete(void)
8436 {
8437         expression_t *const result = allocate_expression_zero(EXPR_UNARY_DELETE);
8438         result->base.type          = type_void;
8439
8440         eat(T_delete);
8441
8442         if (token.type == '[') {
8443                 next_token();
8444                 result->kind = EXPR_UNARY_DELETE_ARRAY;
8445                 expect(']', end_error);
8446 end_error:;
8447         }
8448
8449         expression_t *const value = parse_sub_expression(PREC_CAST);
8450         result->unary.value = value;
8451
8452         type_t *const type = skip_typeref(value->base.type);
8453         if (!is_type_pointer(type)) {
8454                 if (is_type_valid(type)) {
8455                         errorf(&value->base.source_position,
8456                                         "operand of delete must have pointer type");
8457                 }
8458         } else if (warning.other &&
8459                         is_type_atomic(skip_typeref(type->pointer.points_to), ATOMIC_TYPE_VOID)) {
8460                 warningf(&value->base.source_position,
8461                                 "deleting 'void*' is undefined");
8462         }
8463
8464         return result;
8465 }
8466
8467 /**
8468  * Parse a throw expression
8469  * ISO/IEC 14882:1998(E) §15:1
8470  */
8471 static expression_t *parse_throw(void)
8472 {
8473         expression_t *const result = allocate_expression_zero(EXPR_UNARY_THROW);
8474         result->base.type          = type_void;
8475
8476         eat(T_throw);
8477
8478         expression_t *value = NULL;
8479         switch (token.type) {
8480                 EXPRESSION_START {
8481                         value = parse_assignment_expression();
8482                         /* ISO/IEC 14882:1998(E) §15.1:3 */
8483                         type_t *const orig_type = value->base.type;
8484                         type_t *const type      = skip_typeref(orig_type);
8485                         if (is_type_incomplete(type)) {
8486                                 errorf(&value->base.source_position,
8487                                                 "cannot throw object of incomplete type '%T'", orig_type);
8488                         } else if (is_type_pointer(type)) {
8489                                 type_t *const points_to = skip_typeref(type->pointer.points_to);
8490                                 if (is_type_incomplete(points_to) &&
8491                                                 !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
8492                                         errorf(&value->base.source_position,
8493                                                         "cannot throw pointer to incomplete type '%T'", orig_type);
8494                                 }
8495                         }
8496                 }
8497
8498                 default:
8499                         break;
8500         }
8501         result->unary.value = value;
8502
8503         return result;
8504 }
8505
8506 static bool check_pointer_arithmetic(const source_position_t *source_position,
8507                                      type_t *pointer_type,
8508                                      type_t *orig_pointer_type)
8509 {
8510         type_t *points_to = pointer_type->pointer.points_to;
8511         points_to = skip_typeref(points_to);
8512
8513         if (is_type_incomplete(points_to)) {
8514                 if (!GNU_MODE || !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
8515                         errorf(source_position,
8516                                "arithmetic with pointer to incomplete type '%T' not allowed",
8517                                orig_pointer_type);
8518                         return false;
8519                 } else if (warning.pointer_arith) {
8520                         warningf(source_position,
8521                                  "pointer of type '%T' used in arithmetic",
8522                                  orig_pointer_type);
8523                 }
8524         } else if (is_type_function(points_to)) {
8525                 if (!GNU_MODE) {
8526                         errorf(source_position,
8527                                "arithmetic with pointer to function type '%T' not allowed",
8528                                orig_pointer_type);
8529                         return false;
8530                 } else if (warning.pointer_arith) {
8531                         warningf(source_position,
8532                                  "pointer to a function '%T' used in arithmetic",
8533                                  orig_pointer_type);
8534                 }
8535         }
8536         return true;
8537 }
8538
8539 static bool is_lvalue(const expression_t *expression)
8540 {
8541         /* TODO: doesn't seem to be consistent with §6.3.2.1:1 */
8542         switch (expression->kind) {
8543         case EXPR_ARRAY_ACCESS:
8544         case EXPR_COMPOUND_LITERAL:
8545         case EXPR_REFERENCE:
8546         case EXPR_SELECT:
8547         case EXPR_UNARY_DEREFERENCE:
8548                 return true;
8549
8550         default: {
8551           type_t *type = skip_typeref(expression->base.type);
8552           return
8553                 /* ISO/IEC 14882:1998(E) §3.10:3 */
8554                 is_type_reference(type) ||
8555                 /* Claim it is an lvalue, if the type is invalid.  There was a parse
8556                  * error before, which maybe prevented properly recognizing it as
8557                  * lvalue. */
8558                 !is_type_valid(type);
8559         }
8560         }
8561 }
8562
8563 static void semantic_incdec(unary_expression_t *expression)
8564 {
8565         type_t *const orig_type = expression->value->base.type;
8566         type_t *const type      = skip_typeref(orig_type);
8567         if (is_type_pointer(type)) {
8568                 if (!check_pointer_arithmetic(&expression->base.source_position,
8569                                               type, orig_type)) {
8570                         return;
8571                 }
8572         } else if (!is_type_real(type) && is_type_valid(type)) {
8573                 /* TODO: improve error message */
8574                 errorf(&expression->base.source_position,
8575                        "operation needs an arithmetic or pointer type");
8576                 return;
8577         }
8578         if (!is_lvalue(expression->value)) {
8579                 /* TODO: improve error message */
8580                 errorf(&expression->base.source_position, "lvalue required as operand");
8581         }
8582         expression->base.type = orig_type;
8583 }
8584
8585 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
8586 {
8587         type_t *const orig_type = expression->value->base.type;
8588         type_t *const type      = skip_typeref(orig_type);
8589         if (!is_type_arithmetic(type)) {
8590                 if (is_type_valid(type)) {
8591                         /* TODO: improve error message */
8592                         errorf(&expression->base.source_position,
8593                                 "operation needs an arithmetic type");
8594                 }
8595                 return;
8596         }
8597
8598         expression->base.type = orig_type;
8599 }
8600
8601 static void semantic_unexpr_plus(unary_expression_t *expression)
8602 {
8603         semantic_unexpr_arithmetic(expression);
8604         if (warning.traditional)
8605                 warningf(&expression->base.source_position,
8606                         "traditional C rejects the unary plus operator");
8607 }
8608
8609 static void semantic_not(unary_expression_t *expression)
8610 {
8611         /* §6.5.3.3:1  The operand [...] of the ! operator, scalar type. */
8612         semantic_condition(expression->value, "operand of !");
8613         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8614 }
8615
8616 static void semantic_unexpr_integer(unary_expression_t *expression)
8617 {
8618         type_t *const orig_type = expression->value->base.type;
8619         type_t *const type      = skip_typeref(orig_type);
8620         if (!is_type_integer(type)) {
8621                 if (is_type_valid(type)) {
8622                         errorf(&expression->base.source_position,
8623                                "operand of ~ must be of integer type");
8624                 }
8625                 return;
8626         }
8627
8628         expression->base.type = orig_type;
8629 }
8630
8631 static void semantic_dereference(unary_expression_t *expression)
8632 {
8633         type_t *const orig_type = expression->value->base.type;
8634         type_t *const type      = skip_typeref(orig_type);
8635         if (!is_type_pointer(type)) {
8636                 if (is_type_valid(type)) {
8637                         errorf(&expression->base.source_position,
8638                                "Unary '*' needs pointer or array type, but type '%T' given", orig_type);
8639                 }
8640                 return;
8641         }
8642
8643         type_t *result_type   = type->pointer.points_to;
8644         result_type           = automatic_type_conversion(result_type);
8645         expression->base.type = result_type;
8646 }
8647
8648 /**
8649  * Record that an address is taken (expression represents an lvalue).
8650  *
8651  * @param expression       the expression
8652  * @param may_be_register  if true, the expression might be an register
8653  */
8654 static void set_address_taken(expression_t *expression, bool may_be_register)
8655 {
8656         if (expression->kind != EXPR_REFERENCE)
8657                 return;
8658
8659         entity_t *const entity = expression->reference.entity;
8660
8661         if (entity->kind != ENTITY_VARIABLE && entity->kind != ENTITY_PARAMETER)
8662                 return;
8663
8664         if (entity->declaration.storage_class == STORAGE_CLASS_REGISTER
8665                         && !may_be_register) {
8666                 errorf(&expression->base.source_position,
8667                                 "address of register %s '%Y' requested",
8668                                 get_entity_kind_name(entity->kind),     entity->base.symbol);
8669         }
8670
8671         if (entity->kind == ENTITY_VARIABLE) {
8672                 entity->variable.address_taken = true;
8673         } else {
8674                 assert(entity->kind == ENTITY_PARAMETER);
8675                 entity->parameter.address_taken = true;
8676         }
8677 }
8678
8679 /**
8680  * Check the semantic of the address taken expression.
8681  */
8682 static void semantic_take_addr(unary_expression_t *expression)
8683 {
8684         expression_t *value = expression->value;
8685         value->base.type    = revert_automatic_type_conversion(value);
8686
8687         type_t *orig_type = value->base.type;
8688         type_t *type      = skip_typeref(orig_type);
8689         if (!is_type_valid(type))
8690                 return;
8691
8692         /* §6.5.3.2 */
8693         if (!is_lvalue(value)) {
8694                 errorf(&expression->base.source_position, "'&' requires an lvalue");
8695         }
8696         if (type->kind == TYPE_BITFIELD) {
8697                 errorf(&expression->base.source_position,
8698                        "'&' not allowed on object with bitfield type '%T'",
8699                        type);
8700         }
8701
8702         set_address_taken(value, false);
8703
8704         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
8705 }
8706
8707 #define CREATE_UNARY_EXPRESSION_PARSER(token_type, unexpression_type, sfunc) \
8708 static expression_t *parse_##unexpression_type(void)                         \
8709 {                                                                            \
8710         expression_t *unary_expression                                           \
8711                 = allocate_expression_zero(unexpression_type);                       \
8712         eat(token_type);                                                         \
8713         unary_expression->unary.value = parse_sub_expression(PREC_UNARY);        \
8714                                                                                  \
8715         sfunc(&unary_expression->unary);                                         \
8716                                                                                  \
8717         return unary_expression;                                                 \
8718 }
8719
8720 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
8721                                semantic_unexpr_arithmetic)
8722 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
8723                                semantic_unexpr_plus)
8724 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
8725                                semantic_not)
8726 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
8727                                semantic_dereference)
8728 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
8729                                semantic_take_addr)
8730 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
8731                                semantic_unexpr_integer)
8732 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
8733                                semantic_incdec)
8734 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
8735                                semantic_incdec)
8736
8737 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_type, unexpression_type, \
8738                                                sfunc)                         \
8739 static expression_t *parse_##unexpression_type(expression_t *left)            \
8740 {                                                                             \
8741         expression_t *unary_expression                                            \
8742                 = allocate_expression_zero(unexpression_type);                        \
8743         eat(token_type);                                                          \
8744         unary_expression->unary.value = left;                                     \
8745                                                                                   \
8746         sfunc(&unary_expression->unary);                                          \
8747                                                                               \
8748         return unary_expression;                                                  \
8749 }
8750
8751 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
8752                                        EXPR_UNARY_POSTFIX_INCREMENT,
8753                                        semantic_incdec)
8754 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
8755                                        EXPR_UNARY_POSTFIX_DECREMENT,
8756                                        semantic_incdec)
8757
8758 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
8759 {
8760         /* TODO: handle complex + imaginary types */
8761
8762         type_left  = get_unqualified_type(type_left);
8763         type_right = get_unqualified_type(type_right);
8764
8765         /* § 6.3.1.8 Usual arithmetic conversions */
8766         if (type_left == type_long_double || type_right == type_long_double) {
8767                 return type_long_double;
8768         } else if (type_left == type_double || type_right == type_double) {
8769                 return type_double;
8770         } else if (type_left == type_float || type_right == type_float) {
8771                 return type_float;
8772         }
8773
8774         type_left  = promote_integer(type_left);
8775         type_right = promote_integer(type_right);
8776
8777         if (type_left == type_right)
8778                 return type_left;
8779
8780         bool const signed_left  = is_type_signed(type_left);
8781         bool const signed_right = is_type_signed(type_right);
8782         int const  rank_left    = get_rank(type_left);
8783         int const  rank_right   = get_rank(type_right);
8784
8785         if (signed_left == signed_right)
8786                 return rank_left >= rank_right ? type_left : type_right;
8787
8788         int     s_rank;
8789         int     u_rank;
8790         type_t *s_type;
8791         type_t *u_type;
8792         if (signed_left) {
8793                 s_rank = rank_left;
8794                 s_type = type_left;
8795                 u_rank = rank_right;
8796                 u_type = type_right;
8797         } else {
8798                 s_rank = rank_right;
8799                 s_type = type_right;
8800                 u_rank = rank_left;
8801                 u_type = type_left;
8802         }
8803
8804         if (u_rank >= s_rank)
8805                 return u_type;
8806
8807         /* casting rank to atomic_type_kind is a bit hacky, but makes things
8808          * easier here... */
8809         if (get_atomic_type_size((atomic_type_kind_t) s_rank)
8810                         > get_atomic_type_size((atomic_type_kind_t) u_rank))
8811                 return s_type;
8812
8813         switch (s_rank) {
8814                 case ATOMIC_TYPE_INT:      return type_unsigned_int;
8815                 case ATOMIC_TYPE_LONG:     return type_unsigned_long;
8816                 case ATOMIC_TYPE_LONGLONG: return type_unsigned_long_long;
8817
8818                 default: panic("invalid atomic type");
8819         }
8820 }
8821
8822 /**
8823  * Check the semantic restrictions for a binary expression.
8824  */
8825 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
8826 {
8827         expression_t *const left            = expression->left;
8828         expression_t *const right           = expression->right;
8829         type_t       *const orig_type_left  = left->base.type;
8830         type_t       *const orig_type_right = right->base.type;
8831         type_t       *const type_left       = skip_typeref(orig_type_left);
8832         type_t       *const type_right      = skip_typeref(orig_type_right);
8833
8834         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8835                 /* TODO: improve error message */
8836                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8837                         errorf(&expression->base.source_position,
8838                                "operation needs arithmetic types");
8839                 }
8840                 return;
8841         }
8842
8843         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8844         expression->left      = create_implicit_cast(left, arithmetic_type);
8845         expression->right     = create_implicit_cast(right, arithmetic_type);
8846         expression->base.type = arithmetic_type;
8847 }
8848
8849 static void warn_div_by_zero(binary_expression_t const *const expression)
8850 {
8851         if (!warning.div_by_zero ||
8852             !is_type_integer(expression->base.type))
8853                 return;
8854
8855         expression_t const *const right = expression->right;
8856         /* The type of the right operand can be different for /= */
8857         if (is_type_integer(right->base.type) &&
8858             is_constant_expression(right)     &&
8859             fold_constant(right) == 0) {
8860                 warningf(&expression->base.source_position, "division by zero");
8861         }
8862 }
8863
8864 /**
8865  * Check the semantic restrictions for a div/mod expression.
8866  */
8867 static void semantic_divmod_arithmetic(binary_expression_t *expression) {
8868         semantic_binexpr_arithmetic(expression);
8869         warn_div_by_zero(expression);
8870 }
8871
8872 static void warn_addsub_in_shift(const expression_t *const expr)
8873 {
8874         if (expr->base.parenthesized)
8875                 return;
8876
8877         char op;
8878         switch (expr->kind) {
8879                 case EXPR_BINARY_ADD: op = '+'; break;
8880                 case EXPR_BINARY_SUB: op = '-'; break;
8881                 default:              return;
8882         }
8883
8884         warningf(&expr->base.source_position,
8885                         "suggest parentheses around '%c' inside shift", op);
8886 }
8887
8888 static void semantic_shift_op(binary_expression_t *expression)
8889 {
8890         expression_t *const left            = expression->left;
8891         expression_t *const right           = expression->right;
8892         type_t       *const orig_type_left  = left->base.type;
8893         type_t       *const orig_type_right = right->base.type;
8894         type_t       *      type_left       = skip_typeref(orig_type_left);
8895         type_t       *      type_right      = skip_typeref(orig_type_right);
8896
8897         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8898                 /* TODO: improve error message */
8899                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8900                         errorf(&expression->base.source_position,
8901                                "operands of shift operation must have integer types");
8902                 }
8903                 return;
8904         }
8905
8906         if (warning.parentheses) {
8907                 warn_addsub_in_shift(left);
8908                 warn_addsub_in_shift(right);
8909         }
8910
8911         type_left  = promote_integer(type_left);
8912         type_right = promote_integer(type_right);
8913
8914         expression->left      = create_implicit_cast(left, type_left);
8915         expression->right     = create_implicit_cast(right, type_right);
8916         expression->base.type = type_left;
8917 }
8918
8919 static void semantic_add(binary_expression_t *expression)
8920 {
8921         expression_t *const left            = expression->left;
8922         expression_t *const right           = expression->right;
8923         type_t       *const orig_type_left  = left->base.type;
8924         type_t       *const orig_type_right = right->base.type;
8925         type_t       *const type_left       = skip_typeref(orig_type_left);
8926         type_t       *const type_right      = skip_typeref(orig_type_right);
8927
8928         /* § 6.5.6 */
8929         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8930                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8931                 expression->left  = create_implicit_cast(left, arithmetic_type);
8932                 expression->right = create_implicit_cast(right, arithmetic_type);
8933                 expression->base.type = arithmetic_type;
8934         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8935                 check_pointer_arithmetic(&expression->base.source_position,
8936                                          type_left, orig_type_left);
8937                 expression->base.type = type_left;
8938         } else if (is_type_pointer(type_right) && is_type_integer(type_left)) {
8939                 check_pointer_arithmetic(&expression->base.source_position,
8940                                          type_right, orig_type_right);
8941                 expression->base.type = type_right;
8942         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8943                 errorf(&expression->base.source_position,
8944                        "invalid operands to binary + ('%T', '%T')",
8945                        orig_type_left, orig_type_right);
8946         }
8947 }
8948
8949 static void semantic_sub(binary_expression_t *expression)
8950 {
8951         expression_t            *const left            = expression->left;
8952         expression_t            *const right           = expression->right;
8953         type_t                  *const orig_type_left  = left->base.type;
8954         type_t                  *const orig_type_right = right->base.type;
8955         type_t                  *const type_left       = skip_typeref(orig_type_left);
8956         type_t                  *const type_right      = skip_typeref(orig_type_right);
8957         source_position_t const *const pos             = &expression->base.source_position;
8958
8959         /* § 5.6.5 */
8960         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8961                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8962                 expression->left        = create_implicit_cast(left, arithmetic_type);
8963                 expression->right       = create_implicit_cast(right, arithmetic_type);
8964                 expression->base.type =  arithmetic_type;
8965         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8966                 check_pointer_arithmetic(&expression->base.source_position,
8967                                          type_left, orig_type_left);
8968                 expression->base.type = type_left;
8969         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8970                 type_t *const unqual_left  = get_unqualified_type(skip_typeref(type_left->pointer.points_to));
8971                 type_t *const unqual_right = get_unqualified_type(skip_typeref(type_right->pointer.points_to));
8972                 if (!types_compatible(unqual_left, unqual_right)) {
8973                         errorf(pos,
8974                                "subtracting pointers to incompatible types '%T' and '%T'",
8975                                orig_type_left, orig_type_right);
8976                 } else if (!is_type_object(unqual_left)) {
8977                         if (!is_type_atomic(unqual_left, ATOMIC_TYPE_VOID)) {
8978                                 errorf(pos, "subtracting pointers to non-object types '%T'",
8979                                        orig_type_left);
8980                         } else if (warning.other) {
8981                                 warningf(pos, "subtracting pointers to void");
8982                         }
8983                 }
8984                 expression->base.type = type_ptrdiff_t;
8985         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8986                 errorf(pos, "invalid operands of types '%T' and '%T' to binary '-'",
8987                        orig_type_left, orig_type_right);
8988         }
8989 }
8990
8991 static void warn_string_literal_address(expression_t const* expr)
8992 {
8993         while (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
8994                 expr = expr->unary.value;
8995                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
8996                         return;
8997                 expr = expr->unary.value;
8998         }
8999
9000         if (expr->kind == EXPR_STRING_LITERAL ||
9001             expr->kind == EXPR_WIDE_STRING_LITERAL) {
9002                 warningf(&expr->base.source_position,
9003                         "comparison with string literal results in unspecified behaviour");
9004         }
9005 }
9006
9007 static void warn_comparison_in_comparison(const expression_t *const expr)
9008 {
9009         if (expr->base.parenthesized)
9010                 return;
9011         switch (expr->base.kind) {
9012                 case EXPR_BINARY_LESS:
9013                 case EXPR_BINARY_GREATER:
9014                 case EXPR_BINARY_LESSEQUAL:
9015                 case EXPR_BINARY_GREATEREQUAL:
9016                 case EXPR_BINARY_NOTEQUAL:
9017                 case EXPR_BINARY_EQUAL:
9018                         warningf(&expr->base.source_position,
9019                                         "comparisons like 'x <= y < z' do not have their mathematical meaning");
9020                         break;
9021                 default:
9022                         break;
9023         }
9024 }
9025
9026 static bool maybe_negative(expression_t const *const expr)
9027 {
9028         return
9029                 !is_constant_expression(expr) ||
9030                 fold_constant(expr) < 0;
9031 }
9032
9033 /**
9034  * Check the semantics of comparison expressions.
9035  *
9036  * @param expression   The expression to check.
9037  */
9038 static void semantic_comparison(binary_expression_t *expression)
9039 {
9040         expression_t *left  = expression->left;
9041         expression_t *right = expression->right;
9042
9043         if (warning.address) {
9044                 warn_string_literal_address(left);
9045                 warn_string_literal_address(right);
9046
9047                 expression_t const* const func_left = get_reference_address(left);
9048                 if (func_left != NULL && is_null_pointer_constant(right)) {
9049                         warningf(&expression->base.source_position,
9050                                  "the address of '%Y' will never be NULL",
9051                                  func_left->reference.entity->base.symbol);
9052                 }
9053
9054                 expression_t const* const func_right = get_reference_address(right);
9055                 if (func_right != NULL && is_null_pointer_constant(right)) {
9056                         warningf(&expression->base.source_position,
9057                                  "the address of '%Y' will never be NULL",
9058                                  func_right->reference.entity->base.symbol);
9059                 }
9060         }
9061
9062         if (warning.parentheses) {
9063                 warn_comparison_in_comparison(left);
9064                 warn_comparison_in_comparison(right);
9065         }
9066
9067         type_t *orig_type_left  = left->base.type;
9068         type_t *orig_type_right = right->base.type;
9069         type_t *type_left       = skip_typeref(orig_type_left);
9070         type_t *type_right      = skip_typeref(orig_type_right);
9071
9072         /* TODO non-arithmetic types */
9073         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
9074                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
9075
9076                 /* test for signed vs unsigned compares */
9077                 if (warning.sign_compare && is_type_integer(arithmetic_type)) {
9078                         bool const signed_left  = is_type_signed(type_left);
9079                         bool const signed_right = is_type_signed(type_right);
9080                         if (signed_left != signed_right) {
9081                                 /* FIXME long long needs better const folding magic */
9082                                 /* TODO check whether constant value can be represented by other type */
9083                                 if ((signed_left  && maybe_negative(left)) ||
9084                                                 (signed_right && maybe_negative(right))) {
9085                                         warningf(&expression->base.source_position,
9086                                                         "comparison between signed and unsigned");
9087                                 }
9088                         }
9089                 }
9090
9091                 expression->left        = create_implicit_cast(left, arithmetic_type);
9092                 expression->right       = create_implicit_cast(right, arithmetic_type);
9093                 expression->base.type   = arithmetic_type;
9094                 if (warning.float_equal &&
9095                     (expression->base.kind == EXPR_BINARY_EQUAL ||
9096                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
9097                     is_type_float(arithmetic_type)) {
9098                         warningf(&expression->base.source_position,
9099                                  "comparing floating point with == or != is unsafe");
9100                 }
9101         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
9102                 /* TODO check compatibility */
9103         } else if (is_type_pointer(type_left)) {
9104                 expression->right = create_implicit_cast(right, type_left);
9105         } else if (is_type_pointer(type_right)) {
9106                 expression->left = create_implicit_cast(left, type_right);
9107         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
9108                 type_error_incompatible("invalid operands in comparison",
9109                                         &expression->base.source_position,
9110                                         type_left, type_right);
9111         }
9112         expression->base.type = c_mode & _CXX ? type_bool : type_int;
9113 }
9114
9115 /**
9116  * Checks if a compound type has constant fields.
9117  */
9118 static bool has_const_fields(const compound_type_t *type)
9119 {
9120         compound_t *compound = type->compound;
9121         entity_t   *entry    = compound->members.entities;
9122
9123         for (; entry != NULL; entry = entry->base.next) {
9124                 if (!is_declaration(entry))
9125                         continue;
9126
9127                 const type_t *decl_type = skip_typeref(entry->declaration.type);
9128                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
9129                         return true;
9130         }
9131
9132         return false;
9133 }
9134
9135 static bool is_valid_assignment_lhs(expression_t const* const left)
9136 {
9137         type_t *const orig_type_left = revert_automatic_type_conversion(left);
9138         type_t *const type_left      = skip_typeref(orig_type_left);
9139
9140         if (!is_lvalue(left)) {
9141                 errorf(HERE, "left hand side '%E' of assignment is not an lvalue",
9142                        left);
9143                 return false;
9144         }
9145
9146         if (left->kind == EXPR_REFERENCE
9147                         && left->reference.entity->kind == ENTITY_FUNCTION) {
9148                 errorf(HERE, "cannot assign to function '%E'", left);
9149                 return false;
9150         }
9151
9152         if (is_type_array(type_left)) {
9153                 errorf(HERE, "cannot assign to array '%E'", left);
9154                 return false;
9155         }
9156         if (type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
9157                 errorf(HERE, "assignment to readonly location '%E' (type '%T')", left,
9158                        orig_type_left);
9159                 return false;
9160         }
9161         if (is_type_incomplete(type_left)) {
9162                 errorf(HERE, "left-hand side '%E' of assignment has incomplete type '%T'",
9163                        left, orig_type_left);
9164                 return false;
9165         }
9166         if (is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
9167                 errorf(HERE, "cannot assign to '%E' because compound type '%T' has readonly fields",
9168                        left, orig_type_left);
9169                 return false;
9170         }
9171
9172         return true;
9173 }
9174
9175 static void semantic_arithmetic_assign(binary_expression_t *expression)
9176 {
9177         expression_t *left            = expression->left;
9178         expression_t *right           = expression->right;
9179         type_t       *orig_type_left  = left->base.type;
9180         type_t       *orig_type_right = right->base.type;
9181
9182         if (!is_valid_assignment_lhs(left))
9183                 return;
9184
9185         type_t *type_left  = skip_typeref(orig_type_left);
9186         type_t *type_right = skip_typeref(orig_type_right);
9187
9188         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
9189                 /* TODO: improve error message */
9190                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
9191                         errorf(&expression->base.source_position,
9192                                "operation needs arithmetic types");
9193                 }
9194                 return;
9195         }
9196
9197         /* combined instructions are tricky. We can't create an implicit cast on
9198          * the left side, because we need the uncasted form for the store.
9199          * The ast2firm pass has to know that left_type must be right_type
9200          * for the arithmetic operation and create a cast by itself */
9201         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
9202         expression->right       = create_implicit_cast(right, arithmetic_type);
9203         expression->base.type   = type_left;
9204 }
9205
9206 static void semantic_divmod_assign(binary_expression_t *expression)
9207 {
9208         semantic_arithmetic_assign(expression);
9209         warn_div_by_zero(expression);
9210 }
9211
9212 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
9213 {
9214         expression_t *const left            = expression->left;
9215         expression_t *const right           = expression->right;
9216         type_t       *const orig_type_left  = left->base.type;
9217         type_t       *const orig_type_right = right->base.type;
9218         type_t       *const type_left       = skip_typeref(orig_type_left);
9219         type_t       *const type_right      = skip_typeref(orig_type_right);
9220
9221         if (!is_valid_assignment_lhs(left))
9222                 return;
9223
9224         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
9225                 /* combined instructions are tricky. We can't create an implicit cast on
9226                  * the left side, because we need the uncasted form for the store.
9227                  * The ast2firm pass has to know that left_type must be right_type
9228                  * for the arithmetic operation and create a cast by itself */
9229                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
9230                 expression->right     = create_implicit_cast(right, arithmetic_type);
9231                 expression->base.type = type_left;
9232         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
9233                 check_pointer_arithmetic(&expression->base.source_position,
9234                                          type_left, orig_type_left);
9235                 expression->base.type = type_left;
9236         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
9237                 errorf(&expression->base.source_position,
9238                        "incompatible types '%T' and '%T' in assignment",
9239                        orig_type_left, orig_type_right);
9240         }
9241 }
9242
9243 static void warn_logical_and_within_or(const expression_t *const expr)
9244 {
9245         if (expr->base.kind != EXPR_BINARY_LOGICAL_AND)
9246                 return;
9247         if (expr->base.parenthesized)
9248                 return;
9249         warningf(&expr->base.source_position,
9250                         "suggest parentheses around && within ||");
9251 }
9252
9253 /**
9254  * Check the semantic restrictions of a logical expression.
9255  */
9256 static void semantic_logical_op(binary_expression_t *expression)
9257 {
9258         /* §6.5.13:2  Each of the operands shall have scalar type.
9259          * §6.5.14:2  Each of the operands shall have scalar type. */
9260         semantic_condition(expression->left,   "left operand of logical operator");
9261         semantic_condition(expression->right, "right operand of logical operator");
9262         if (expression->base.kind == EXPR_BINARY_LOGICAL_OR &&
9263                         warning.parentheses) {
9264                 warn_logical_and_within_or(expression->left);
9265                 warn_logical_and_within_or(expression->right);
9266         }
9267         expression->base.type = c_mode & _CXX ? type_bool : type_int;
9268 }
9269
9270 /**
9271  * Check the semantic restrictions of a binary assign expression.
9272  */
9273 static void semantic_binexpr_assign(binary_expression_t *expression)
9274 {
9275         expression_t *left           = expression->left;
9276         type_t       *orig_type_left = left->base.type;
9277
9278         if (!is_valid_assignment_lhs(left))
9279                 return;
9280
9281         assign_error_t error = semantic_assign(orig_type_left, expression->right);
9282         report_assign_error(error, orig_type_left, expression->right,
9283                         "assignment", &left->base.source_position);
9284         expression->right = create_implicit_cast(expression->right, orig_type_left);
9285         expression->base.type = orig_type_left;
9286 }
9287
9288 /**
9289  * Determine if the outermost operation (or parts thereof) of the given
9290  * expression has no effect in order to generate a warning about this fact.
9291  * Therefore in some cases this only examines some of the operands of the
9292  * expression (see comments in the function and examples below).
9293  * Examples:
9294  *   f() + 23;    // warning, because + has no effect
9295  *   x || f();    // no warning, because x controls execution of f()
9296  *   x ? y : f(); // warning, because y has no effect
9297  *   (void)x;     // no warning to be able to suppress the warning
9298  * This function can NOT be used for an "expression has definitely no effect"-
9299  * analysis. */
9300 static bool expression_has_effect(const expression_t *const expr)
9301 {
9302         switch (expr->kind) {
9303                 case EXPR_UNKNOWN:                   break;
9304                 case EXPR_INVALID:                   return true; /* do NOT warn */
9305                 case EXPR_REFERENCE:                 return false;
9306                 case EXPR_REFERENCE_ENUM_VALUE:      return false;
9307                 /* suppress the warning for microsoft __noop operations */
9308                 case EXPR_CONST:                     return expr->conste.is_ms_noop;
9309                 case EXPR_CHARACTER_CONSTANT:        return false;
9310                 case EXPR_WIDE_CHARACTER_CONSTANT:   return false;
9311                 case EXPR_STRING_LITERAL:            return false;
9312                 case EXPR_WIDE_STRING_LITERAL:       return false;
9313                 case EXPR_LABEL_ADDRESS:             return false;
9314
9315                 case EXPR_CALL: {
9316                         const call_expression_t *const call = &expr->call;
9317                         if (call->function->kind != EXPR_BUILTIN_SYMBOL)
9318                                 return true;
9319
9320                         switch (call->function->builtin_symbol.symbol->ID) {
9321                                 case T___builtin_va_end: return true;
9322                                 default:                 return false;
9323                         }
9324                 }
9325
9326                 /* Generate the warning if either the left or right hand side of a
9327                  * conditional expression has no effect */
9328                 case EXPR_CONDITIONAL: {
9329                         const conditional_expression_t *const cond = &expr->conditional;
9330                         return
9331                                 expression_has_effect(cond->true_expression) &&
9332                                 expression_has_effect(cond->false_expression);
9333                 }
9334
9335                 case EXPR_SELECT:                    return false;
9336                 case EXPR_ARRAY_ACCESS:              return false;
9337                 case EXPR_SIZEOF:                    return false;
9338                 case EXPR_CLASSIFY_TYPE:             return false;
9339                 case EXPR_ALIGNOF:                   return false;
9340
9341                 case EXPR_FUNCNAME:                  return false;
9342                 case EXPR_BUILTIN_SYMBOL:            break; /* handled in EXPR_CALL */
9343                 case EXPR_BUILTIN_CONSTANT_P:        return false;
9344                 case EXPR_BUILTIN_PREFETCH:          return true;
9345                 case EXPR_OFFSETOF:                  return false;
9346                 case EXPR_VA_START:                  return true;
9347                 case EXPR_VA_ARG:                    return true;
9348                 case EXPR_STATEMENT:                 return true; // TODO
9349                 case EXPR_COMPOUND_LITERAL:          return false;
9350
9351                 case EXPR_UNARY_NEGATE:              return false;
9352                 case EXPR_UNARY_PLUS:                return false;
9353                 case EXPR_UNARY_BITWISE_NEGATE:      return false;
9354                 case EXPR_UNARY_NOT:                 return false;
9355                 case EXPR_UNARY_DEREFERENCE:         return false;
9356                 case EXPR_UNARY_TAKE_ADDRESS:        return false;
9357                 case EXPR_UNARY_POSTFIX_INCREMENT:   return true;
9358                 case EXPR_UNARY_POSTFIX_DECREMENT:   return true;
9359                 case EXPR_UNARY_PREFIX_INCREMENT:    return true;
9360                 case EXPR_UNARY_PREFIX_DECREMENT:    return true;
9361
9362                 /* Treat void casts as if they have an effect in order to being able to
9363                  * suppress the warning */
9364                 case EXPR_UNARY_CAST: {
9365                         type_t *const type = skip_typeref(expr->base.type);
9366                         return is_type_atomic(type, ATOMIC_TYPE_VOID);
9367                 }
9368
9369                 case EXPR_UNARY_CAST_IMPLICIT:       return true;
9370                 case EXPR_UNARY_ASSUME:              return true;
9371                 case EXPR_UNARY_DELETE:              return true;
9372                 case EXPR_UNARY_DELETE_ARRAY:        return true;
9373                 case EXPR_UNARY_THROW:               return true;
9374
9375                 case EXPR_BINARY_ADD:                return false;
9376                 case EXPR_BINARY_SUB:                return false;
9377                 case EXPR_BINARY_MUL:                return false;
9378                 case EXPR_BINARY_DIV:                return false;
9379                 case EXPR_BINARY_MOD:                return false;
9380                 case EXPR_BINARY_EQUAL:              return false;
9381                 case EXPR_BINARY_NOTEQUAL:           return false;
9382                 case EXPR_BINARY_LESS:               return false;
9383                 case EXPR_BINARY_LESSEQUAL:          return false;
9384                 case EXPR_BINARY_GREATER:            return false;
9385                 case EXPR_BINARY_GREATEREQUAL:       return false;
9386                 case EXPR_BINARY_BITWISE_AND:        return false;
9387                 case EXPR_BINARY_BITWISE_OR:         return false;
9388                 case EXPR_BINARY_BITWISE_XOR:        return false;
9389                 case EXPR_BINARY_SHIFTLEFT:          return false;
9390                 case EXPR_BINARY_SHIFTRIGHT:         return false;
9391                 case EXPR_BINARY_ASSIGN:             return true;
9392                 case EXPR_BINARY_MUL_ASSIGN:         return true;
9393                 case EXPR_BINARY_DIV_ASSIGN:         return true;
9394                 case EXPR_BINARY_MOD_ASSIGN:         return true;
9395                 case EXPR_BINARY_ADD_ASSIGN:         return true;
9396                 case EXPR_BINARY_SUB_ASSIGN:         return true;
9397                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:   return true;
9398                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:  return true;
9399                 case EXPR_BINARY_BITWISE_AND_ASSIGN: return true;
9400                 case EXPR_BINARY_BITWISE_XOR_ASSIGN: return true;
9401                 case EXPR_BINARY_BITWISE_OR_ASSIGN:  return true;
9402
9403                 /* Only examine the right hand side of && and ||, because the left hand
9404                  * side already has the effect of controlling the execution of the right
9405                  * hand side */
9406                 case EXPR_BINARY_LOGICAL_AND:
9407                 case EXPR_BINARY_LOGICAL_OR:
9408                 /* Only examine the right hand side of a comma expression, because the left
9409                  * hand side has a separate warning */
9410                 case EXPR_BINARY_COMMA:
9411                         return expression_has_effect(expr->binary.right);
9412
9413                 case EXPR_BINARY_ISGREATER:          return false;
9414                 case EXPR_BINARY_ISGREATEREQUAL:     return false;
9415                 case EXPR_BINARY_ISLESS:             return false;
9416                 case EXPR_BINARY_ISLESSEQUAL:        return false;
9417                 case EXPR_BINARY_ISLESSGREATER:      return false;
9418                 case EXPR_BINARY_ISUNORDERED:        return false;
9419         }
9420
9421         internal_errorf(HERE, "unexpected expression");
9422 }
9423
9424 static void semantic_comma(binary_expression_t *expression)
9425 {
9426         if (warning.unused_value) {
9427                 const expression_t *const left = expression->left;
9428                 if (!expression_has_effect(left)) {
9429                         warningf(&left->base.source_position,
9430                                  "left-hand operand of comma expression has no effect");
9431                 }
9432         }
9433         expression->base.type = expression->right->base.type;
9434 }
9435
9436 /**
9437  * @param prec_r precedence of the right operand
9438  */
9439 #define CREATE_BINEXPR_PARSER(token_type, binexpression_type, prec_r, sfunc) \
9440 static expression_t *parse_##binexpression_type(expression_t *left)          \
9441 {                                                                            \
9442         expression_t *binexpr = allocate_expression_zero(binexpression_type);    \
9443         binexpr->binary.left  = left;                                            \
9444         eat(token_type);                                                         \
9445                                                                              \
9446         expression_t *right = parse_sub_expression(prec_r);                      \
9447                                                                              \
9448         binexpr->binary.right = right;                                           \
9449         sfunc(&binexpr->binary);                                                 \
9450                                                                              \
9451         return binexpr;                                                          \
9452 }
9453
9454 CREATE_BINEXPR_PARSER('*',                    EXPR_BINARY_MUL,                PREC_CAST,           semantic_binexpr_arithmetic)
9455 CREATE_BINEXPR_PARSER('/',                    EXPR_BINARY_DIV,                PREC_CAST,           semantic_divmod_arithmetic)
9456 CREATE_BINEXPR_PARSER('%',                    EXPR_BINARY_MOD,                PREC_CAST,           semantic_divmod_arithmetic)
9457 CREATE_BINEXPR_PARSER('+',                    EXPR_BINARY_ADD,                PREC_MULTIPLICATIVE, semantic_add)
9458 CREATE_BINEXPR_PARSER('-',                    EXPR_BINARY_SUB,                PREC_MULTIPLICATIVE, semantic_sub)
9459 CREATE_BINEXPR_PARSER(T_LESSLESS,             EXPR_BINARY_SHIFTLEFT,          PREC_ADDITIVE,       semantic_shift_op)
9460 CREATE_BINEXPR_PARSER(T_GREATERGREATER,       EXPR_BINARY_SHIFTRIGHT,         PREC_ADDITIVE,       semantic_shift_op)
9461 CREATE_BINEXPR_PARSER('<',                    EXPR_BINARY_LESS,               PREC_SHIFT,          semantic_comparison)
9462 CREATE_BINEXPR_PARSER('>',                    EXPR_BINARY_GREATER,            PREC_SHIFT,          semantic_comparison)
9463 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,          PREC_SHIFT,          semantic_comparison)
9464 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,       PREC_SHIFT,          semantic_comparison)
9465 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,           PREC_RELATIONAL,     semantic_comparison)
9466 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,              PREC_RELATIONAL,     semantic_comparison)
9467 CREATE_BINEXPR_PARSER('&',                    EXPR_BINARY_BITWISE_AND,        PREC_EQUALITY,       semantic_binexpr_arithmetic)
9468 CREATE_BINEXPR_PARSER('^',                    EXPR_BINARY_BITWISE_XOR,        PREC_AND,            semantic_binexpr_arithmetic)
9469 CREATE_BINEXPR_PARSER('|',                    EXPR_BINARY_BITWISE_OR,         PREC_XOR,            semantic_binexpr_arithmetic)
9470 CREATE_BINEXPR_PARSER(T_ANDAND,               EXPR_BINARY_LOGICAL_AND,        PREC_OR,             semantic_logical_op)
9471 CREATE_BINEXPR_PARSER(T_PIPEPIPE,             EXPR_BINARY_LOGICAL_OR,         PREC_LOGICAL_AND,    semantic_logical_op)
9472 CREATE_BINEXPR_PARSER('=',                    EXPR_BINARY_ASSIGN,             PREC_ASSIGNMENT,     semantic_binexpr_assign)
9473 CREATE_BINEXPR_PARSER(T_PLUSEQUAL,            EXPR_BINARY_ADD_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
9474 CREATE_BINEXPR_PARSER(T_MINUSEQUAL,           EXPR_BINARY_SUB_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
9475 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL,        EXPR_BINARY_MUL_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9476 CREATE_BINEXPR_PARSER(T_SLASHEQUAL,           EXPR_BINARY_DIV_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
9477 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL,         EXPR_BINARY_MOD_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
9478 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL,        EXPR_BINARY_SHIFTLEFT_ASSIGN,   PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9479 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL,  EXPR_BINARY_SHIFTRIGHT_ASSIGN,  PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9480 CREATE_BINEXPR_PARSER(T_ANDEQUAL,             EXPR_BINARY_BITWISE_AND_ASSIGN, PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9481 CREATE_BINEXPR_PARSER(T_PIPEEQUAL,            EXPR_BINARY_BITWISE_OR_ASSIGN,  PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9482 CREATE_BINEXPR_PARSER(T_CARETEQUAL,           EXPR_BINARY_BITWISE_XOR_ASSIGN, PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9483 CREATE_BINEXPR_PARSER(',',                    EXPR_BINARY_COMMA,              PREC_ASSIGNMENT,     semantic_comma)
9484
9485
9486 static expression_t *parse_sub_expression(precedence_t precedence)
9487 {
9488         if (token.type < 0) {
9489                 return expected_expression_error();
9490         }
9491
9492         expression_parser_function_t *parser
9493                 = &expression_parsers[token.type];
9494         source_position_t             source_position = token.source_position;
9495         expression_t                 *left;
9496
9497         if (parser->parser != NULL) {
9498                 left = parser->parser();
9499         } else {
9500                 left = parse_primary_expression();
9501         }
9502         assert(left != NULL);
9503         left->base.source_position = source_position;
9504
9505         while (true) {
9506                 if (token.type < 0) {
9507                         return expected_expression_error();
9508                 }
9509
9510                 parser = &expression_parsers[token.type];
9511                 if (parser->infix_parser == NULL)
9512                         break;
9513                 if (parser->infix_precedence < precedence)
9514                         break;
9515
9516                 left = parser->infix_parser(left);
9517
9518                 assert(left != NULL);
9519                 assert(left->kind != EXPR_UNKNOWN);
9520                 left->base.source_position = source_position;
9521         }
9522
9523         return left;
9524 }
9525
9526 /**
9527  * Parse an expression.
9528  */
9529 static expression_t *parse_expression(void)
9530 {
9531         return parse_sub_expression(PREC_EXPRESSION);
9532 }
9533
9534 /**
9535  * Register a parser for a prefix-like operator.
9536  *
9537  * @param parser      the parser function
9538  * @param token_type  the token type of the prefix token
9539  */
9540 static void register_expression_parser(parse_expression_function parser,
9541                                        int token_type)
9542 {
9543         expression_parser_function_t *entry = &expression_parsers[token_type];
9544
9545         if (entry->parser != NULL) {
9546                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
9547                 panic("trying to register multiple expression parsers for a token");
9548         }
9549         entry->parser = parser;
9550 }
9551
9552 /**
9553  * Register a parser for an infix operator with given precedence.
9554  *
9555  * @param parser      the parser function
9556  * @param token_type  the token type of the infix operator
9557  * @param precedence  the precedence of the operator
9558  */
9559 static void register_infix_parser(parse_expression_infix_function parser,
9560                 int token_type, precedence_t precedence)
9561 {
9562         expression_parser_function_t *entry = &expression_parsers[token_type];
9563
9564         if (entry->infix_parser != NULL) {
9565                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
9566                 panic("trying to register multiple infix expression parsers for a "
9567                       "token");
9568         }
9569         entry->infix_parser     = parser;
9570         entry->infix_precedence = precedence;
9571 }
9572
9573 /**
9574  * Initialize the expression parsers.
9575  */
9576 static void init_expression_parsers(void)
9577 {
9578         memset(&expression_parsers, 0, sizeof(expression_parsers));
9579
9580         register_infix_parser(parse_array_expression,               '[',                    PREC_POSTFIX);
9581         register_infix_parser(parse_call_expression,                '(',                    PREC_POSTFIX);
9582         register_infix_parser(parse_select_expression,              '.',                    PREC_POSTFIX);
9583         register_infix_parser(parse_select_expression,              T_MINUSGREATER,         PREC_POSTFIX);
9584         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,   T_PLUSPLUS,             PREC_POSTFIX);
9585         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,   T_MINUSMINUS,           PREC_POSTFIX);
9586         register_infix_parser(parse_EXPR_BINARY_MUL,                '*',                    PREC_MULTIPLICATIVE);
9587         register_infix_parser(parse_EXPR_BINARY_DIV,                '/',                    PREC_MULTIPLICATIVE);
9588         register_infix_parser(parse_EXPR_BINARY_MOD,                '%',                    PREC_MULTIPLICATIVE);
9589         register_infix_parser(parse_EXPR_BINARY_ADD,                '+',                    PREC_ADDITIVE);
9590         register_infix_parser(parse_EXPR_BINARY_SUB,                '-',                    PREC_ADDITIVE);
9591         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,          T_LESSLESS,             PREC_SHIFT);
9592         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,         T_GREATERGREATER,       PREC_SHIFT);
9593         register_infix_parser(parse_EXPR_BINARY_LESS,               '<',                    PREC_RELATIONAL);
9594         register_infix_parser(parse_EXPR_BINARY_GREATER,            '>',                    PREC_RELATIONAL);
9595         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,          T_LESSEQUAL,            PREC_RELATIONAL);
9596         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL,       T_GREATEREQUAL,         PREC_RELATIONAL);
9597         register_infix_parser(parse_EXPR_BINARY_EQUAL,              T_EQUALEQUAL,           PREC_EQUALITY);
9598         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,           T_EXCLAMATIONMARKEQUAL, PREC_EQUALITY);
9599         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,        '&',                    PREC_AND);
9600         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,        '^',                    PREC_XOR);
9601         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,         '|',                    PREC_OR);
9602         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,        T_ANDAND,               PREC_LOGICAL_AND);
9603         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,         T_PIPEPIPE,             PREC_LOGICAL_OR);
9604         register_infix_parser(parse_conditional_expression,         '?',                    PREC_CONDITIONAL);
9605         register_infix_parser(parse_EXPR_BINARY_ASSIGN,             '=',                    PREC_ASSIGNMENT);
9606         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,         T_PLUSEQUAL,            PREC_ASSIGNMENT);
9607         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,         T_MINUSEQUAL,           PREC_ASSIGNMENT);
9608         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,         T_ASTERISKEQUAL,        PREC_ASSIGNMENT);
9609         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,         T_SLASHEQUAL,           PREC_ASSIGNMENT);
9610         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,         T_PERCENTEQUAL,         PREC_ASSIGNMENT);
9611         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,   T_LESSLESSEQUAL,        PREC_ASSIGNMENT);
9612         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,  T_GREATERGREATEREQUAL,  PREC_ASSIGNMENT);
9613         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN, T_ANDEQUAL,             PREC_ASSIGNMENT);
9614         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,  T_PIPEEQUAL,            PREC_ASSIGNMENT);
9615         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN, T_CARETEQUAL,           PREC_ASSIGNMENT);
9616         register_infix_parser(parse_EXPR_BINARY_COMMA,              ',',                    PREC_EXPRESSION);
9617
9618         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-');
9619         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+');
9620         register_expression_parser(parse_EXPR_UNARY_NOT,              '!');
9621         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~');
9622         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*');
9623         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&');
9624         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT, T_PLUSPLUS);
9625         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT, T_MINUSMINUS);
9626         register_expression_parser(parse_sizeof,                      T_sizeof);
9627         register_expression_parser(parse_alignof,                     T___alignof__);
9628         register_expression_parser(parse_extension,                   T___extension__);
9629         register_expression_parser(parse_builtin_classify_type,       T___builtin_classify_type);
9630         register_expression_parser(parse_delete,                      T_delete);
9631         register_expression_parser(parse_throw,                       T_throw);
9632 }
9633
9634 /**
9635  * Parse a asm statement arguments specification.
9636  */
9637 static asm_argument_t *parse_asm_arguments(bool is_out)
9638 {
9639         asm_argument_t  *result = NULL;
9640         asm_argument_t **anchor = &result;
9641
9642         while (token.type == T_STRING_LITERAL || token.type == '[') {
9643                 asm_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
9644                 memset(argument, 0, sizeof(argument[0]));
9645
9646                 if (token.type == '[') {
9647                         eat('[');
9648                         if (token.type != T_IDENTIFIER) {
9649                                 parse_error_expected("while parsing asm argument",
9650                                                      T_IDENTIFIER, NULL);
9651                                 return NULL;
9652                         }
9653                         argument->symbol = token.v.symbol;
9654
9655                         expect(']', end_error);
9656                 }
9657
9658                 argument->constraints = parse_string_literals();
9659                 expect('(', end_error);
9660                 add_anchor_token(')');
9661                 expression_t *expression = parse_expression();
9662                 rem_anchor_token(')');
9663                 if (is_out) {
9664                         /* Ugly GCC stuff: Allow lvalue casts.  Skip casts, when they do not
9665                          * change size or type representation (e.g. int -> long is ok, but
9666                          * int -> float is not) */
9667                         if (expression->kind == EXPR_UNARY_CAST) {
9668                                 type_t      *const type = expression->base.type;
9669                                 type_kind_t  const kind = type->kind;
9670                                 if (kind == TYPE_ATOMIC || kind == TYPE_POINTER) {
9671                                         unsigned flags;
9672                                         unsigned size;
9673                                         if (kind == TYPE_ATOMIC) {
9674                                                 atomic_type_kind_t const akind = type->atomic.akind;
9675                                                 flags = get_atomic_type_flags(akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
9676                                                 size  = get_atomic_type_size(akind);
9677                                         } else {
9678                                                 flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
9679                                                 size  = get_atomic_type_size(get_intptr_kind());
9680                                         }
9681
9682                                         do {
9683                                                 expression_t *const value      = expression->unary.value;
9684                                                 type_t       *const value_type = value->base.type;
9685                                                 type_kind_t   const value_kind = value_type->kind;
9686
9687                                                 unsigned value_flags;
9688                                                 unsigned value_size;
9689                                                 if (value_kind == TYPE_ATOMIC) {
9690                                                         atomic_type_kind_t const value_akind = value_type->atomic.akind;
9691                                                         value_flags = get_atomic_type_flags(value_akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
9692                                                         value_size  = get_atomic_type_size(value_akind);
9693                                                 } else if (value_kind == TYPE_POINTER) {
9694                                                         value_flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
9695                                                         value_size  = get_atomic_type_size(get_intptr_kind());
9696                                                 } else {
9697                                                         break;
9698                                                 }
9699
9700                                                 if (value_flags != flags || value_size != size)
9701                                                         break;
9702
9703                                                 expression = value;
9704                                         } while (expression->kind == EXPR_UNARY_CAST);
9705                                 }
9706                         }
9707
9708                         if (!is_lvalue(expression)) {
9709                                 errorf(&expression->base.source_position,
9710                                        "asm output argument is not an lvalue");
9711                         }
9712
9713                         if (argument->constraints.begin[0] == '+')
9714                                 mark_vars_read(expression, NULL);
9715                 } else {
9716                         mark_vars_read(expression, NULL);
9717                 }
9718                 argument->expression = expression;
9719                 expect(')', end_error);
9720
9721                 set_address_taken(expression, true);
9722
9723                 *anchor = argument;
9724                 anchor  = &argument->next;
9725
9726                 if (token.type != ',')
9727                         break;
9728                 eat(',');
9729         }
9730
9731         return result;
9732 end_error:
9733         return NULL;
9734 }
9735
9736 /**
9737  * Parse a asm statement clobber specification.
9738  */
9739 static asm_clobber_t *parse_asm_clobbers(void)
9740 {
9741         asm_clobber_t *result = NULL;
9742         asm_clobber_t *last   = NULL;
9743
9744         while (token.type == T_STRING_LITERAL) {
9745                 asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
9746                 clobber->clobber       = parse_string_literals();
9747
9748                 if (last != NULL) {
9749                         last->next = clobber;
9750                 } else {
9751                         result = clobber;
9752                 }
9753                 last = clobber;
9754
9755                 if (token.type != ',')
9756                         break;
9757                 eat(',');
9758         }
9759
9760         return result;
9761 }
9762
9763 /**
9764  * Parse an asm statement.
9765  */
9766 static statement_t *parse_asm_statement(void)
9767 {
9768         statement_t     *statement     = allocate_statement_zero(STATEMENT_ASM);
9769         asm_statement_t *asm_statement = &statement->asms;
9770
9771         eat(T_asm);
9772
9773         if (token.type == T_volatile) {
9774                 next_token();
9775                 asm_statement->is_volatile = true;
9776         }
9777
9778         expect('(', end_error);
9779         add_anchor_token(')');
9780         add_anchor_token(':');
9781         asm_statement->asm_text = parse_string_literals();
9782
9783         if (token.type != ':') {
9784                 rem_anchor_token(':');
9785                 goto end_of_asm;
9786         }
9787         eat(':');
9788
9789         asm_statement->outputs = parse_asm_arguments(true);
9790         if (token.type != ':') {
9791                 rem_anchor_token(':');
9792                 goto end_of_asm;
9793         }
9794         eat(':');
9795
9796         asm_statement->inputs = parse_asm_arguments(false);
9797         if (token.type != ':') {
9798                 rem_anchor_token(':');
9799                 goto end_of_asm;
9800         }
9801         rem_anchor_token(':');
9802         eat(':');
9803
9804         asm_statement->clobbers = parse_asm_clobbers();
9805
9806 end_of_asm:
9807         rem_anchor_token(')');
9808         expect(')', end_error);
9809         expect(';', end_error);
9810
9811         if (asm_statement->outputs == NULL) {
9812                 /* GCC: An 'asm' instruction without any output operands will be treated
9813                  * identically to a volatile 'asm' instruction. */
9814                 asm_statement->is_volatile = true;
9815         }
9816
9817         return statement;
9818 end_error:
9819         return create_invalid_statement();
9820 }
9821
9822 /**
9823  * Parse a case statement.
9824  */
9825 static statement_t *parse_case_statement(void)
9826 {
9827         statement_t       *const statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9828         source_position_t *const pos       = &statement->base.source_position;
9829
9830         eat(T_case);
9831
9832         expression_t *const expression   = parse_expression();
9833         statement->case_label.expression = expression;
9834         if (!is_constant_expression(expression)) {
9835                 /* This check does not prevent the error message in all cases of an
9836                  * prior error while parsing the expression.  At least it catches the
9837                  * common case of a mistyped enum entry. */
9838                 if (is_type_valid(skip_typeref(expression->base.type))) {
9839                         errorf(pos, "case label does not reduce to an integer constant");
9840                 }
9841                 statement->case_label.is_bad = true;
9842         } else {
9843                 long const val = fold_constant(expression);
9844                 statement->case_label.first_case = val;
9845                 statement->case_label.last_case  = val;
9846         }
9847
9848         if (GNU_MODE) {
9849                 if (token.type == T_DOTDOTDOT) {
9850                         next_token();
9851                         expression_t *const end_range   = parse_expression();
9852                         statement->case_label.end_range = end_range;
9853                         if (!is_constant_expression(end_range)) {
9854                                 /* This check does not prevent the error message in all cases of an
9855                                  * prior error while parsing the expression.  At least it catches the
9856                                  * common case of a mistyped enum entry. */
9857                                 if (is_type_valid(skip_typeref(end_range->base.type))) {
9858                                         errorf(pos, "case range does not reduce to an integer constant");
9859                                 }
9860                                 statement->case_label.is_bad = true;
9861                         } else {
9862                                 long const val = fold_constant(end_range);
9863                                 statement->case_label.last_case = val;
9864
9865                                 if (warning.other && val < statement->case_label.first_case) {
9866                                         statement->case_label.is_empty_range = true;
9867                                         warningf(pos, "empty range specified");
9868                                 }
9869                         }
9870                 }
9871         }
9872
9873         PUSH_PARENT(statement);
9874
9875         expect(':', end_error);
9876 end_error:
9877
9878         if (current_switch != NULL) {
9879                 if (! statement->case_label.is_bad) {
9880                         /* Check for duplicate case values */
9881                         case_label_statement_t *c = &statement->case_label;
9882                         for (case_label_statement_t *l = current_switch->first_case; l != NULL; l = l->next) {
9883                                 if (l->is_bad || l->is_empty_range || l->expression == NULL)
9884                                         continue;
9885
9886                                 if (c->last_case < l->first_case || c->first_case > l->last_case)
9887                                         continue;
9888
9889                                 errorf(pos, "duplicate case value (previously used %P)",
9890                                        &l->base.source_position);
9891                                 break;
9892                         }
9893                 }
9894                 /* link all cases into the switch statement */
9895                 if (current_switch->last_case == NULL) {
9896                         current_switch->first_case      = &statement->case_label;
9897                 } else {
9898                         current_switch->last_case->next = &statement->case_label;
9899                 }
9900                 current_switch->last_case = &statement->case_label;
9901         } else {
9902                 errorf(pos, "case label not within a switch statement");
9903         }
9904
9905         statement_t *const inner_stmt = parse_statement();
9906         statement->case_label.statement = inner_stmt;
9907         if (inner_stmt->kind == STATEMENT_DECLARATION) {
9908                 errorf(&inner_stmt->base.source_position, "declaration after case label");
9909         }
9910
9911         POP_PARENT;
9912         return statement;
9913 }
9914
9915 /**
9916  * Parse a default statement.
9917  */
9918 static statement_t *parse_default_statement(void)
9919 {
9920         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9921
9922         eat(T_default);
9923
9924         PUSH_PARENT(statement);
9925
9926         expect(':', end_error);
9927         if (current_switch != NULL) {
9928                 const case_label_statement_t *def_label = current_switch->default_label;
9929                 if (def_label != NULL) {
9930                         errorf(HERE, "multiple default labels in one switch (previous declared %P)",
9931                                &def_label->base.source_position);
9932                 } else {
9933                         current_switch->default_label = &statement->case_label;
9934
9935                         /* link all cases into the switch statement */
9936                         if (current_switch->last_case == NULL) {
9937                                 current_switch->first_case      = &statement->case_label;
9938                         } else {
9939                                 current_switch->last_case->next = &statement->case_label;
9940                         }
9941                         current_switch->last_case = &statement->case_label;
9942                 }
9943         } else {
9944                 errorf(&statement->base.source_position,
9945                         "'default' label not within a switch statement");
9946         }
9947
9948         statement_t *const inner_stmt = parse_statement();
9949         statement->case_label.statement = inner_stmt;
9950         if (inner_stmt->kind == STATEMENT_DECLARATION) {
9951                 errorf(&inner_stmt->base.source_position, "declaration after default label");
9952         }
9953
9954         POP_PARENT;
9955         return statement;
9956 end_error:
9957         POP_PARENT;
9958         return create_invalid_statement();
9959 }
9960
9961 /**
9962  * Parse a label statement.
9963  */
9964 static statement_t *parse_label_statement(void)
9965 {
9966         assert(token.type == T_IDENTIFIER);
9967         symbol_t *symbol = token.v.symbol;
9968         label_t  *label  = get_label(symbol);
9969
9970         statement_t *const statement = allocate_statement_zero(STATEMENT_LABEL);
9971         statement->label.label       = label;
9972
9973         next_token();
9974
9975         PUSH_PARENT(statement);
9976
9977         /* if statement is already set then the label is defined twice,
9978          * otherwise it was just mentioned in a goto/local label declaration so far
9979          */
9980         if (label->statement != NULL) {
9981                 errorf(HERE, "duplicate label '%Y' (declared %P)",
9982                        symbol, &label->base.source_position);
9983         } else {
9984                 label->base.source_position = token.source_position;
9985                 label->statement            = statement;
9986         }
9987
9988         eat(':');
9989
9990         if (token.type == '}') {
9991                 /* TODO only warn? */
9992                 if (warning.other && false) {
9993                         warningf(HERE, "label at end of compound statement");
9994                         statement->label.statement = create_empty_statement();
9995                 } else {
9996                         errorf(HERE, "label at end of compound statement");
9997                         statement->label.statement = create_invalid_statement();
9998                 }
9999         } else if (token.type == ';') {
10000                 /* Eat an empty statement here, to avoid the warning about an empty
10001                  * statement after a label.  label:; is commonly used to have a label
10002                  * before a closing brace. */
10003                 statement->label.statement = create_empty_statement();
10004                 next_token();
10005         } else {
10006                 statement_t *const inner_stmt = parse_statement();
10007                 statement->label.statement = inner_stmt;
10008                 if (inner_stmt->kind == STATEMENT_DECLARATION) {
10009                         errorf(&inner_stmt->base.source_position, "declaration after label");
10010                 }
10011         }
10012
10013         /* remember the labels in a list for later checking */
10014         *label_anchor = &statement->label;
10015         label_anchor  = &statement->label.next;
10016
10017         POP_PARENT;
10018         return statement;
10019 }
10020
10021 /**
10022  * Parse an if statement.
10023  */
10024 static statement_t *parse_if(void)
10025 {
10026         statement_t *statement = allocate_statement_zero(STATEMENT_IF);
10027
10028         eat(T_if);
10029
10030         PUSH_PARENT(statement);
10031
10032         add_anchor_token('{');
10033
10034         expect('(', end_error);
10035         add_anchor_token(')');
10036         expression_t *const expr = parse_expression();
10037         statement->ifs.condition = expr;
10038         /* §6.8.4.1:1  The controlling expression of an if statement shall have
10039          *             scalar type. */
10040         semantic_condition(expr, "condition of 'if'-statment");
10041         mark_vars_read(expr, NULL);
10042         rem_anchor_token(')');
10043         expect(')', end_error);
10044
10045 end_error:
10046         rem_anchor_token('{');
10047
10048         add_anchor_token(T_else);
10049         statement_t *const true_stmt = parse_statement();
10050         statement->ifs.true_statement = true_stmt;
10051         rem_anchor_token(T_else);
10052
10053         if (token.type == T_else) {
10054                 next_token();
10055                 statement->ifs.false_statement = parse_statement();
10056         } else if (warning.parentheses &&
10057                         true_stmt->kind == STATEMENT_IF &&
10058                         true_stmt->ifs.false_statement != NULL) {
10059                 warningf(&true_stmt->base.source_position,
10060                                 "suggest explicit braces to avoid ambiguous 'else'");
10061         }
10062
10063         POP_PARENT;
10064         return statement;
10065 }
10066
10067 /**
10068  * Check that all enums are handled in a switch.
10069  *
10070  * @param statement  the switch statement to check
10071  */
10072 static void check_enum_cases(const switch_statement_t *statement) {
10073         const type_t *type = skip_typeref(statement->expression->base.type);
10074         if (! is_type_enum(type))
10075                 return;
10076         const enum_type_t *enumt = &type->enumt;
10077
10078         /* if we have a default, no warnings */
10079         if (statement->default_label != NULL)
10080                 return;
10081
10082         /* FIXME: calculation of value should be done while parsing */
10083         /* TODO: quadratic algorithm here. Change to an n log n one */
10084         long            last_value = -1;
10085         const entity_t *entry      = enumt->enume->base.next;
10086         for (; entry != NULL && entry->kind == ENTITY_ENUM_VALUE;
10087              entry = entry->base.next) {
10088                 const expression_t *expression = entry->enum_value.value;
10089                 long                value      = expression != NULL ? fold_constant(expression) : last_value + 1;
10090                 bool                found      = false;
10091                 for (const case_label_statement_t *l = statement->first_case; l != NULL; l = l->next) {
10092                         if (l->expression == NULL)
10093                                 continue;
10094                         if (l->first_case <= value && value <= l->last_case) {
10095                                 found = true;
10096                                 break;
10097                         }
10098                 }
10099                 if (! found) {
10100                         warningf(&statement->base.source_position,
10101                                  "enumeration value '%Y' not handled in switch",
10102                                  entry->base.symbol);
10103                 }
10104                 last_value = value;
10105         }
10106 }
10107
10108 /**
10109  * Parse a switch statement.
10110  */
10111 static statement_t *parse_switch(void)
10112 {
10113         statement_t *statement = allocate_statement_zero(STATEMENT_SWITCH);
10114
10115         eat(T_switch);
10116
10117         PUSH_PARENT(statement);
10118
10119         expect('(', end_error);
10120         add_anchor_token(')');
10121         expression_t *const expr = parse_expression();
10122         mark_vars_read(expr, NULL);
10123         type_t       *      type = skip_typeref(expr->base.type);
10124         if (is_type_integer(type)) {
10125                 type = promote_integer(type);
10126                 if (warning.traditional) {
10127                         if (get_rank(type) >= get_akind_rank(ATOMIC_TYPE_LONG)) {
10128                                 warningf(&expr->base.source_position,
10129                                         "'%T' switch expression not converted to '%T' in ISO C",
10130                                         type, type_int);
10131                         }
10132                 }
10133         } else if (is_type_valid(type)) {
10134                 errorf(&expr->base.source_position,
10135                        "switch quantity is not an integer, but '%T'", type);
10136                 type = type_error_type;
10137         }
10138         statement->switchs.expression = create_implicit_cast(expr, type);
10139         expect(')', end_error);
10140         rem_anchor_token(')');
10141
10142         switch_statement_t *rem = current_switch;
10143         current_switch          = &statement->switchs;
10144         statement->switchs.body = parse_statement();
10145         current_switch          = rem;
10146
10147         if (warning.switch_default &&
10148             statement->switchs.default_label == NULL) {
10149                 warningf(&statement->base.source_position, "switch has no default case");
10150         }
10151         if (warning.switch_enum)
10152                 check_enum_cases(&statement->switchs);
10153
10154         POP_PARENT;
10155         return statement;
10156 end_error:
10157         POP_PARENT;
10158         return create_invalid_statement();
10159 }
10160
10161 static statement_t *parse_loop_body(statement_t *const loop)
10162 {
10163         statement_t *const rem = current_loop;
10164         current_loop = loop;
10165
10166         statement_t *const body = parse_statement();
10167
10168         current_loop = rem;
10169         return body;
10170 }
10171
10172 /**
10173  * Parse a while statement.
10174  */
10175 static statement_t *parse_while(void)
10176 {
10177         statement_t *statement = allocate_statement_zero(STATEMENT_WHILE);
10178
10179         eat(T_while);
10180
10181         PUSH_PARENT(statement);
10182
10183         expect('(', end_error);
10184         add_anchor_token(')');
10185         expression_t *const cond = parse_expression();
10186         statement->whiles.condition = cond;
10187         /* §6.8.5:2    The controlling expression of an iteration statement shall
10188          *             have scalar type. */
10189         semantic_condition(cond, "condition of 'while'-statement");
10190         mark_vars_read(cond, NULL);
10191         rem_anchor_token(')');
10192         expect(')', end_error);
10193
10194         statement->whiles.body = parse_loop_body(statement);
10195
10196         POP_PARENT;
10197         return statement;
10198 end_error:
10199         POP_PARENT;
10200         return create_invalid_statement();
10201 }
10202
10203 /**
10204  * Parse a do statement.
10205  */
10206 static statement_t *parse_do(void)
10207 {
10208         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
10209
10210         eat(T_do);
10211
10212         PUSH_PARENT(statement);
10213
10214         add_anchor_token(T_while);
10215         statement->do_while.body = parse_loop_body(statement);
10216         rem_anchor_token(T_while);
10217
10218         expect(T_while, end_error);
10219         expect('(', end_error);
10220         add_anchor_token(')');
10221         expression_t *const cond = parse_expression();
10222         statement->do_while.condition = cond;
10223         /* §6.8.5:2    The controlling expression of an iteration statement shall
10224          *             have scalar type. */
10225         semantic_condition(cond, "condition of 'do-while'-statement");
10226         mark_vars_read(cond, NULL);
10227         rem_anchor_token(')');
10228         expect(')', end_error);
10229         expect(';', end_error);
10230
10231         POP_PARENT;
10232         return statement;
10233 end_error:
10234         POP_PARENT;
10235         return create_invalid_statement();
10236 }
10237
10238 /**
10239  * Parse a for statement.
10240  */
10241 static statement_t *parse_for(void)
10242 {
10243         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
10244
10245         eat(T_for);
10246
10247         expect('(', end_error1);
10248         add_anchor_token(')');
10249
10250         PUSH_PARENT(statement);
10251
10252         size_t const  top       = environment_top();
10253         scope_t      *old_scope = scope_push(&statement->fors.scope);
10254
10255         if (token.type == ';') {
10256                 next_token();
10257         } else if (is_declaration_specifier(&token, false)) {
10258                 parse_declaration(record_entity, DECL_FLAGS_NONE);
10259         } else {
10260                 add_anchor_token(';');
10261                 expression_t *const init = parse_expression();
10262                 statement->fors.initialisation = init;
10263                 mark_vars_read(init, ENT_ANY);
10264                 if (warning.unused_value && !expression_has_effect(init)) {
10265                         warningf(&init->base.source_position,
10266                                         "initialisation of 'for'-statement has no effect");
10267                 }
10268                 rem_anchor_token(';');
10269                 expect(';', end_error2);
10270         }
10271
10272         if (token.type != ';') {
10273                 add_anchor_token(';');
10274                 expression_t *const cond = parse_expression();
10275                 statement->fors.condition = cond;
10276                 /* §6.8.5:2    The controlling expression of an iteration statement
10277                  *             shall have scalar type. */
10278                 semantic_condition(cond, "condition of 'for'-statement");
10279                 mark_vars_read(cond, NULL);
10280                 rem_anchor_token(';');
10281         }
10282         expect(';', end_error2);
10283         if (token.type != ')') {
10284                 expression_t *const step = parse_expression();
10285                 statement->fors.step = step;
10286                 mark_vars_read(step, ENT_ANY);
10287                 if (warning.unused_value && !expression_has_effect(step)) {
10288                         warningf(&step->base.source_position,
10289                                  "step of 'for'-statement has no effect");
10290                 }
10291         }
10292         expect(')', end_error2);
10293         rem_anchor_token(')');
10294         statement->fors.body = parse_loop_body(statement);
10295
10296         assert(current_scope == &statement->fors.scope);
10297         scope_pop(old_scope);
10298         environment_pop_to(top);
10299
10300         POP_PARENT;
10301         return statement;
10302
10303 end_error2:
10304         POP_PARENT;
10305         rem_anchor_token(')');
10306         assert(current_scope == &statement->fors.scope);
10307         scope_pop(old_scope);
10308         environment_pop_to(top);
10309         /* fallthrough */
10310
10311 end_error1:
10312         return create_invalid_statement();
10313 }
10314
10315 /**
10316  * Parse a goto statement.
10317  */
10318 static statement_t *parse_goto(void)
10319 {
10320         statement_t *statement = allocate_statement_zero(STATEMENT_GOTO);
10321         eat(T_goto);
10322
10323         if (GNU_MODE && token.type == '*') {
10324                 next_token();
10325                 expression_t *expression = parse_expression();
10326                 mark_vars_read(expression, NULL);
10327
10328                 /* Argh: although documentation says the expression must be of type void*,
10329                  * gcc accepts anything that can be casted into void* without error */
10330                 type_t *type = expression->base.type;
10331
10332                 if (type != type_error_type) {
10333                         if (!is_type_pointer(type) && !is_type_integer(type)) {
10334                                 errorf(&expression->base.source_position,
10335                                         "cannot convert to a pointer type");
10336                         } else if (warning.other && type != type_void_ptr) {
10337                                 warningf(&expression->base.source_position,
10338                                         "type of computed goto expression should be 'void*' not '%T'", type);
10339                         }
10340                         expression = create_implicit_cast(expression, type_void_ptr);
10341                 }
10342
10343                 statement->gotos.expression = expression;
10344         } else {
10345                 if (token.type != T_IDENTIFIER) {
10346                         if (GNU_MODE)
10347                                 parse_error_expected("while parsing goto", T_IDENTIFIER, '*', NULL);
10348                         else
10349                                 parse_error_expected("while parsing goto", T_IDENTIFIER, NULL);
10350                         eat_until_anchor();
10351                         goto end_error;
10352                 }
10353                 symbol_t *symbol = token.v.symbol;
10354                 next_token();
10355
10356                 statement->gotos.label = get_label(symbol);
10357         }
10358
10359         /* remember the goto's in a list for later checking */
10360         *goto_anchor = &statement->gotos;
10361         goto_anchor  = &statement->gotos.next;
10362
10363         expect(';', end_error);
10364
10365         return statement;
10366 end_error:
10367         return create_invalid_statement();
10368 }
10369
10370 /**
10371  * Parse a continue statement.
10372  */
10373 static statement_t *parse_continue(void)
10374 {
10375         if (current_loop == NULL) {
10376                 errorf(HERE, "continue statement not within loop");
10377         }
10378
10379         statement_t *statement = allocate_statement_zero(STATEMENT_CONTINUE);
10380
10381         eat(T_continue);
10382         expect(';', end_error);
10383
10384 end_error:
10385         return statement;
10386 }
10387
10388 /**
10389  * Parse a break statement.
10390  */
10391 static statement_t *parse_break(void)
10392 {
10393         if (current_switch == NULL && current_loop == NULL) {
10394                 errorf(HERE, "break statement not within loop or switch");
10395         }
10396
10397         statement_t *statement = allocate_statement_zero(STATEMENT_BREAK);
10398
10399         eat(T_break);
10400         expect(';', end_error);
10401
10402 end_error:
10403         return statement;
10404 }
10405
10406 /**
10407  * Parse a __leave statement.
10408  */
10409 static statement_t *parse_leave_statement(void)
10410 {
10411         if (current_try == NULL) {
10412                 errorf(HERE, "__leave statement not within __try");
10413         }
10414
10415         statement_t *statement = allocate_statement_zero(STATEMENT_LEAVE);
10416
10417         eat(T___leave);
10418         expect(';', end_error);
10419
10420 end_error:
10421         return statement;
10422 }
10423
10424 /**
10425  * Check if a given entity represents a local variable.
10426  */
10427 static bool is_local_variable(const entity_t *entity)
10428 {
10429         if (entity->kind != ENTITY_VARIABLE)
10430                 return false;
10431
10432         switch ((storage_class_tag_t) entity->declaration.storage_class) {
10433         case STORAGE_CLASS_AUTO:
10434         case STORAGE_CLASS_REGISTER: {
10435                 const type_t *type = skip_typeref(entity->declaration.type);
10436                 if (is_type_function(type)) {
10437                         return false;
10438                 } else {
10439                         return true;
10440                 }
10441         }
10442         default:
10443                 return false;
10444         }
10445 }
10446
10447 /**
10448  * Check if a given expression represents a local variable.
10449  */
10450 static bool expression_is_local_variable(const expression_t *expression)
10451 {
10452         if (expression->base.kind != EXPR_REFERENCE) {
10453                 return false;
10454         }
10455         const entity_t *entity = expression->reference.entity;
10456         return is_local_variable(entity);
10457 }
10458
10459 /**
10460  * Check if a given expression represents a local variable and
10461  * return its declaration then, else return NULL.
10462  */
10463 entity_t *expression_is_variable(const expression_t *expression)
10464 {
10465         if (expression->base.kind != EXPR_REFERENCE) {
10466                 return NULL;
10467         }
10468         entity_t *entity = expression->reference.entity;
10469         if (entity->kind != ENTITY_VARIABLE)
10470                 return NULL;
10471
10472         return entity;
10473 }
10474
10475 /**
10476  * Parse a return statement.
10477  */
10478 static statement_t *parse_return(void)
10479 {
10480         eat(T_return);
10481
10482         statement_t *statement = allocate_statement_zero(STATEMENT_RETURN);
10483
10484         expression_t *return_value = NULL;
10485         if (token.type != ';') {
10486                 return_value = parse_expression();
10487                 mark_vars_read(return_value, NULL);
10488         }
10489
10490         const type_t *const func_type = skip_typeref(current_function->base.type);
10491         assert(is_type_function(func_type));
10492         type_t *const return_type = skip_typeref(func_type->function.return_type);
10493
10494         source_position_t const *const pos = &statement->base.source_position;
10495         if (return_value != NULL) {
10496                 type_t *return_value_type = skip_typeref(return_value->base.type);
10497
10498                 if (is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
10499                         if (is_type_atomic(return_value_type, ATOMIC_TYPE_VOID)) {
10500                                 /* ISO/IEC 14882:1998(E) §6.6.3:2 */
10501                                 /* Only warn in C mode, because GCC does the same */
10502                                 if (c_mode & _CXX || strict_mode) {
10503                                         errorf(pos,
10504                                                         "'return' with a value, in function returning 'void'");
10505                                 } else if (warning.other) {
10506                                         warningf(pos,
10507                                                         "'return' with a value, in function returning 'void'");
10508                                 }
10509                         } else if (!(c_mode & _CXX)) { /* ISO/IEC 14882:1998(E) §6.6.3:3 */
10510                                 /* Only warn in C mode, because GCC does the same */
10511                                 if (strict_mode) {
10512                                         errorf(pos,
10513                                                         "'return' with expression in function return 'void'");
10514                                 } else if (warning.other) {
10515                                         warningf(pos,
10516                                                         "'return' with expression in function return 'void'");
10517                                 }
10518                         }
10519                 } else {
10520                         assign_error_t error = semantic_assign(return_type, return_value);
10521                         report_assign_error(error, return_type, return_value, "'return'",
10522                                         pos);
10523                 }
10524                 return_value = create_implicit_cast(return_value, return_type);
10525                 /* check for returning address of a local var */
10526                 if (warning.other && return_value != NULL
10527                                 && return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
10528                         const expression_t *expression = return_value->unary.value;
10529                         if (expression_is_local_variable(expression)) {
10530                                 warningf(pos, "function returns address of local variable");
10531                         }
10532                 }
10533         } else if (warning.other && !is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
10534                 /* ISO/IEC 14882:1998(E) §6.6.3:3 */
10535                 if (c_mode & _CXX || strict_mode) {
10536                         errorf(pos,
10537                                         "'return' without value, in function returning non-void");
10538                 } else {
10539                         warningf(pos,
10540                                         "'return' without value, in function returning non-void");
10541                 }
10542         }
10543         statement->returns.value = return_value;
10544
10545         expect(';', end_error);
10546
10547 end_error:
10548         return statement;
10549 }
10550
10551 /**
10552  * Parse a declaration statement.
10553  */
10554 static statement_t *parse_declaration_statement(void)
10555 {
10556         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
10557
10558         entity_t *before = current_scope->last_entity;
10559         if (GNU_MODE) {
10560                 parse_external_declaration();
10561         } else {
10562                 parse_declaration(record_entity, DECL_FLAGS_NONE);
10563         }
10564
10565         if (before == NULL) {
10566                 statement->declaration.declarations_begin = current_scope->entities;
10567         } else {
10568                 statement->declaration.declarations_begin = before->base.next;
10569         }
10570         statement->declaration.declarations_end = current_scope->last_entity;
10571
10572         return statement;
10573 }
10574
10575 /**
10576  * Parse an expression statement, ie. expr ';'.
10577  */
10578 static statement_t *parse_expression_statement(void)
10579 {
10580         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10581
10582         expression_t *const expr         = parse_expression();
10583         statement->expression.expression = expr;
10584         mark_vars_read(expr, ENT_ANY);
10585
10586         expect(';', end_error);
10587
10588 end_error:
10589         return statement;
10590 }
10591
10592 /**
10593  * Parse a microsoft __try { } __finally { } or
10594  * __try{ } __except() { }
10595  */
10596 static statement_t *parse_ms_try_statment(void)
10597 {
10598         statement_t *statement = allocate_statement_zero(STATEMENT_MS_TRY);
10599         eat(T___try);
10600
10601         PUSH_PARENT(statement);
10602
10603         ms_try_statement_t *rem = current_try;
10604         current_try = &statement->ms_try;
10605         statement->ms_try.try_statement = parse_compound_statement(false);
10606         current_try = rem;
10607
10608         POP_PARENT;
10609
10610         if (token.type == T___except) {
10611                 eat(T___except);
10612                 expect('(', end_error);
10613                 add_anchor_token(')');
10614                 expression_t *const expr = parse_expression();
10615                 mark_vars_read(expr, NULL);
10616                 type_t       *      type = skip_typeref(expr->base.type);
10617                 if (is_type_integer(type)) {
10618                         type = promote_integer(type);
10619                 } else if (is_type_valid(type)) {
10620                         errorf(&expr->base.source_position,
10621                                "__expect expression is not an integer, but '%T'", type);
10622                         type = type_error_type;
10623                 }
10624                 statement->ms_try.except_expression = create_implicit_cast(expr, type);
10625                 rem_anchor_token(')');
10626                 expect(')', end_error);
10627                 statement->ms_try.final_statement = parse_compound_statement(false);
10628         } else if (token.type == T__finally) {
10629                 eat(T___finally);
10630                 statement->ms_try.final_statement = parse_compound_statement(false);
10631         } else {
10632                 parse_error_expected("while parsing __try statement", T___except, T___finally, NULL);
10633                 return create_invalid_statement();
10634         }
10635         return statement;
10636 end_error:
10637         return create_invalid_statement();
10638 }
10639
10640 static statement_t *parse_empty_statement(void)
10641 {
10642         if (warning.empty_statement) {
10643                 warningf(HERE, "statement is empty");
10644         }
10645         statement_t *const statement = create_empty_statement();
10646         eat(';');
10647         return statement;
10648 }
10649
10650 static statement_t *parse_local_label_declaration(void)
10651 {
10652         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
10653
10654         eat(T___label__);
10655
10656         entity_t *begin = NULL, *end = NULL;
10657
10658         while (true) {
10659                 if (token.type != T_IDENTIFIER) {
10660                         parse_error_expected("while parsing local label declaration",
10661                                 T_IDENTIFIER, NULL);
10662                         goto end_error;
10663                 }
10664                 symbol_t *symbol = token.v.symbol;
10665                 entity_t *entity = get_entity(symbol, NAMESPACE_LABEL);
10666                 if (entity != NULL && entity->base.parent_scope == current_scope) {
10667                         errorf(HERE, "multiple definitions of '__label__ %Y' (previous definition %P)",
10668                                symbol, &entity->base.source_position);
10669                 } else {
10670                         entity = allocate_entity_zero(ENTITY_LOCAL_LABEL);
10671
10672                         entity->base.parent_scope    = current_scope;
10673                         entity->base.namespc         = NAMESPACE_LABEL;
10674                         entity->base.source_position = token.source_position;
10675                         entity->base.symbol          = symbol;
10676
10677                         if (end != NULL)
10678                                 end->base.next = entity;
10679                         end = entity;
10680                         if (begin == NULL)
10681                                 begin = entity;
10682
10683                         environment_push(entity);
10684                 }
10685                 next_token();
10686
10687                 if (token.type != ',')
10688                         break;
10689                 next_token();
10690         }
10691         eat(';');
10692 end_error:
10693         statement->declaration.declarations_begin = begin;
10694         statement->declaration.declarations_end   = end;
10695         return statement;
10696 }
10697
10698 static void parse_namespace_definition(void)
10699 {
10700         eat(T_namespace);
10701
10702         entity_t *entity = NULL;
10703         symbol_t *symbol = NULL;
10704
10705         if (token.type == T_IDENTIFIER) {
10706                 symbol = token.v.symbol;
10707                 next_token();
10708
10709                 entity = get_entity(symbol, NAMESPACE_NORMAL);
10710                 if (entity != NULL && entity->kind != ENTITY_NAMESPACE
10711                                 && entity->base.parent_scope == current_scope) {
10712                         error_redefined_as_different_kind(&token.source_position,
10713                                                           entity, ENTITY_NAMESPACE);
10714                         entity = NULL;
10715                 }
10716         }
10717
10718         if (entity == NULL) {
10719                 entity                       = allocate_entity_zero(ENTITY_NAMESPACE);
10720                 entity->base.symbol          = symbol;
10721                 entity->base.source_position = token.source_position;
10722                 entity->base.namespc         = NAMESPACE_NORMAL;
10723                 entity->base.parent_scope    = current_scope;
10724         }
10725
10726         if (token.type == '=') {
10727                 /* TODO: parse namespace alias */
10728                 panic("namespace alias definition not supported yet");
10729         }
10730
10731         environment_push(entity);
10732         append_entity(current_scope, entity);
10733
10734         size_t const  top       = environment_top();
10735         scope_t      *old_scope = scope_push(&entity->namespacee.members);
10736
10737         expect('{', end_error);
10738         parse_externals();
10739         expect('}', end_error);
10740
10741 end_error:
10742         assert(current_scope == &entity->namespacee.members);
10743         scope_pop(old_scope);
10744         environment_pop_to(top);
10745 }
10746
10747 /**
10748  * Parse a statement.
10749  * There's also parse_statement() which additionally checks for
10750  * "statement has no effect" warnings
10751  */
10752 static statement_t *intern_parse_statement(void)
10753 {
10754         statement_t *statement = NULL;
10755
10756         /* declaration or statement */
10757         add_anchor_token(';');
10758         switch (token.type) {
10759         case T_IDENTIFIER: {
10760                 token_type_t la1_type = (token_type_t)look_ahead(1)->type;
10761                 if (la1_type == ':') {
10762                         statement = parse_label_statement();
10763                 } else if (is_typedef_symbol(token.v.symbol)) {
10764                         statement = parse_declaration_statement();
10765                 } else {
10766                         /* it's an identifier, the grammar says this must be an
10767                          * expression statement. However it is common that users mistype
10768                          * declaration types, so we guess a bit here to improve robustness
10769                          * for incorrect programs */
10770                         switch (la1_type) {
10771                         case '&':
10772                         case '*':
10773                                 if (get_entity(token.v.symbol, NAMESPACE_NORMAL) != NULL)
10774                                         goto expression_statment;
10775                                 /* FALLTHROUGH */
10776
10777                         DECLARATION_START
10778                         case T_IDENTIFIER:
10779                                 statement = parse_declaration_statement();
10780                                 break;
10781
10782                         default:
10783 expression_statment:
10784                                 statement = parse_expression_statement();
10785                                 break;
10786                         }
10787                 }
10788                 break;
10789         }
10790
10791         case T___extension__:
10792                 /* This can be a prefix to a declaration or an expression statement.
10793                  * We simply eat it now and parse the rest with tail recursion. */
10794                 do {
10795                         next_token();
10796                 } while (token.type == T___extension__);
10797                 bool old_gcc_extension = in_gcc_extension;
10798                 in_gcc_extension       = true;
10799                 statement = intern_parse_statement();
10800                 in_gcc_extension = old_gcc_extension;
10801                 break;
10802
10803         DECLARATION_START
10804                 statement = parse_declaration_statement();
10805                 break;
10806
10807         case T___label__:
10808                 statement = parse_local_label_declaration();
10809                 break;
10810
10811         case ';':         statement = parse_empty_statement();         break;
10812         case '{':         statement = parse_compound_statement(false); break;
10813         case T___leave:   statement = parse_leave_statement();         break;
10814         case T___try:     statement = parse_ms_try_statment();         break;
10815         case T_asm:       statement = parse_asm_statement();           break;
10816         case T_break:     statement = parse_break();                   break;
10817         case T_case:      statement = parse_case_statement();          break;
10818         case T_continue:  statement = parse_continue();                break;
10819         case T_default:   statement = parse_default_statement();       break;
10820         case T_do:        statement = parse_do();                      break;
10821         case T_for:       statement = parse_for();                     break;
10822         case T_goto:      statement = parse_goto();                    break;
10823         case T_if:        statement = parse_if();                      break;
10824         case T_return:    statement = parse_return();                  break;
10825         case T_switch:    statement = parse_switch();                  break;
10826         case T_while:     statement = parse_while();                   break;
10827
10828         EXPRESSION_START
10829                 statement = parse_expression_statement();
10830                 break;
10831
10832         default:
10833                 errorf(HERE, "unexpected token %K while parsing statement", &token);
10834                 statement = create_invalid_statement();
10835                 if (!at_anchor())
10836                         next_token();
10837                 break;
10838         }
10839         rem_anchor_token(';');
10840
10841         assert(statement != NULL
10842                         && statement->base.source_position.input_name != NULL);
10843
10844         return statement;
10845 }
10846
10847 /**
10848  * parse a statement and emits "statement has no effect" warning if needed
10849  * (This is really a wrapper around intern_parse_statement with check for 1
10850  *  single warning. It is needed, because for statement expressions we have
10851  *  to avoid the warning on the last statement)
10852  */
10853 static statement_t *parse_statement(void)
10854 {
10855         statement_t *statement = intern_parse_statement();
10856
10857         if (statement->kind == STATEMENT_EXPRESSION && warning.unused_value) {
10858                 expression_t *expression = statement->expression.expression;
10859                 if (!expression_has_effect(expression)) {
10860                         warningf(&expression->base.source_position,
10861                                         "statement has no effect");
10862                 }
10863         }
10864
10865         return statement;
10866 }
10867
10868 /**
10869  * Parse a compound statement.
10870  */
10871 static statement_t *parse_compound_statement(bool inside_expression_statement)
10872 {
10873         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
10874
10875         PUSH_PARENT(statement);
10876
10877         eat('{');
10878         add_anchor_token('}');
10879         /* tokens, which can start a statement */
10880         /* TODO MS, __builtin_FOO */
10881         add_anchor_token('!');
10882         add_anchor_token('&');
10883         add_anchor_token('(');
10884         add_anchor_token('*');
10885         add_anchor_token('+');
10886         add_anchor_token('-');
10887         add_anchor_token('{');
10888         add_anchor_token('~');
10889         add_anchor_token(T_CHARACTER_CONSTANT);
10890         add_anchor_token(T_COLONCOLON);
10891         add_anchor_token(T_FLOATINGPOINT);
10892         add_anchor_token(T_IDENTIFIER);
10893         add_anchor_token(T_INTEGER);
10894         add_anchor_token(T_MINUSMINUS);
10895         add_anchor_token(T_PLUSPLUS);
10896         add_anchor_token(T_STRING_LITERAL);
10897         add_anchor_token(T_WIDE_CHARACTER_CONSTANT);
10898         add_anchor_token(T_WIDE_STRING_LITERAL);
10899         add_anchor_token(T__Bool);
10900         add_anchor_token(T__Complex);
10901         add_anchor_token(T__Imaginary);
10902         add_anchor_token(T___FUNCTION__);
10903         add_anchor_token(T___PRETTY_FUNCTION__);
10904         add_anchor_token(T___alignof__);
10905         add_anchor_token(T___attribute__);
10906         add_anchor_token(T___builtin_va_start);
10907         add_anchor_token(T___extension__);
10908         add_anchor_token(T___func__);
10909         add_anchor_token(T___imag__);
10910         add_anchor_token(T___label__);
10911         add_anchor_token(T___real__);
10912         add_anchor_token(T___thread);
10913         add_anchor_token(T_asm);
10914         add_anchor_token(T_auto);
10915         add_anchor_token(T_bool);
10916         add_anchor_token(T_break);
10917         add_anchor_token(T_case);
10918         add_anchor_token(T_char);
10919         add_anchor_token(T_class);
10920         add_anchor_token(T_const);
10921         add_anchor_token(T_const_cast);
10922         add_anchor_token(T_continue);
10923         add_anchor_token(T_default);
10924         add_anchor_token(T_delete);
10925         add_anchor_token(T_double);
10926         add_anchor_token(T_do);
10927         add_anchor_token(T_dynamic_cast);
10928         add_anchor_token(T_enum);
10929         add_anchor_token(T_extern);
10930         add_anchor_token(T_false);
10931         add_anchor_token(T_float);
10932         add_anchor_token(T_for);
10933         add_anchor_token(T_goto);
10934         add_anchor_token(T_if);
10935         add_anchor_token(T_inline);
10936         add_anchor_token(T_int);
10937         add_anchor_token(T_long);
10938         add_anchor_token(T_new);
10939         add_anchor_token(T_operator);
10940         add_anchor_token(T_register);
10941         add_anchor_token(T_reinterpret_cast);
10942         add_anchor_token(T_restrict);
10943         add_anchor_token(T_return);
10944         add_anchor_token(T_short);
10945         add_anchor_token(T_signed);
10946         add_anchor_token(T_sizeof);
10947         add_anchor_token(T_static);
10948         add_anchor_token(T_static_cast);
10949         add_anchor_token(T_struct);
10950         add_anchor_token(T_switch);
10951         add_anchor_token(T_template);
10952         add_anchor_token(T_this);
10953         add_anchor_token(T_throw);
10954         add_anchor_token(T_true);
10955         add_anchor_token(T_try);
10956         add_anchor_token(T_typedef);
10957         add_anchor_token(T_typeid);
10958         add_anchor_token(T_typename);
10959         add_anchor_token(T_typeof);
10960         add_anchor_token(T_union);
10961         add_anchor_token(T_unsigned);
10962         add_anchor_token(T_using);
10963         add_anchor_token(T_void);
10964         add_anchor_token(T_volatile);
10965         add_anchor_token(T_wchar_t);
10966         add_anchor_token(T_while);
10967
10968         size_t const  top       = environment_top();
10969         scope_t      *old_scope = scope_push(&statement->compound.scope);
10970
10971         statement_t **anchor            = &statement->compound.statements;
10972         bool          only_decls_so_far = true;
10973         while (token.type != '}') {
10974                 if (token.type == T_EOF) {
10975                         errorf(&statement->base.source_position,
10976                                "EOF while parsing compound statement");
10977                         break;
10978                 }
10979                 statement_t *sub_statement = intern_parse_statement();
10980                 if (is_invalid_statement(sub_statement)) {
10981                         /* an error occurred. if we are at an anchor, return */
10982                         if (at_anchor())
10983                                 goto end_error;
10984                         continue;
10985                 }
10986
10987                 if (warning.declaration_after_statement) {
10988                         if (sub_statement->kind != STATEMENT_DECLARATION) {
10989                                 only_decls_so_far = false;
10990                         } else if (!only_decls_so_far) {
10991                                 warningf(&sub_statement->base.source_position,
10992                                          "ISO C90 forbids mixed declarations and code");
10993                         }
10994                 }
10995
10996                 *anchor = sub_statement;
10997
10998                 while (sub_statement->base.next != NULL)
10999                         sub_statement = sub_statement->base.next;
11000
11001                 anchor = &sub_statement->base.next;
11002         }
11003         next_token();
11004
11005         /* look over all statements again to produce no effect warnings */
11006         if (warning.unused_value) {
11007                 statement_t *sub_statement = statement->compound.statements;
11008                 for (; sub_statement != NULL; sub_statement = sub_statement->base.next) {
11009                         if (sub_statement->kind != STATEMENT_EXPRESSION)
11010                                 continue;
11011                         /* don't emit a warning for the last expression in an expression
11012                          * statement as it has always an effect */
11013                         if (inside_expression_statement && sub_statement->base.next == NULL)
11014                                 continue;
11015
11016                         expression_t *expression = sub_statement->expression.expression;
11017                         if (!expression_has_effect(expression)) {
11018                                 warningf(&expression->base.source_position,
11019                                          "statement has no effect");
11020                         }
11021                 }
11022         }
11023
11024 end_error:
11025         rem_anchor_token(T_while);
11026         rem_anchor_token(T_wchar_t);
11027         rem_anchor_token(T_volatile);
11028         rem_anchor_token(T_void);
11029         rem_anchor_token(T_using);
11030         rem_anchor_token(T_unsigned);
11031         rem_anchor_token(T_union);
11032         rem_anchor_token(T_typeof);
11033         rem_anchor_token(T_typename);
11034         rem_anchor_token(T_typeid);
11035         rem_anchor_token(T_typedef);
11036         rem_anchor_token(T_try);
11037         rem_anchor_token(T_true);
11038         rem_anchor_token(T_throw);
11039         rem_anchor_token(T_this);
11040         rem_anchor_token(T_template);
11041         rem_anchor_token(T_switch);
11042         rem_anchor_token(T_struct);
11043         rem_anchor_token(T_static_cast);
11044         rem_anchor_token(T_static);
11045         rem_anchor_token(T_sizeof);
11046         rem_anchor_token(T_signed);
11047         rem_anchor_token(T_short);
11048         rem_anchor_token(T_return);
11049         rem_anchor_token(T_restrict);
11050         rem_anchor_token(T_reinterpret_cast);
11051         rem_anchor_token(T_register);
11052         rem_anchor_token(T_operator);
11053         rem_anchor_token(T_new);
11054         rem_anchor_token(T_long);
11055         rem_anchor_token(T_int);
11056         rem_anchor_token(T_inline);
11057         rem_anchor_token(T_if);
11058         rem_anchor_token(T_goto);
11059         rem_anchor_token(T_for);
11060         rem_anchor_token(T_float);
11061         rem_anchor_token(T_false);
11062         rem_anchor_token(T_extern);
11063         rem_anchor_token(T_enum);
11064         rem_anchor_token(T_dynamic_cast);
11065         rem_anchor_token(T_do);
11066         rem_anchor_token(T_double);
11067         rem_anchor_token(T_delete);
11068         rem_anchor_token(T_default);
11069         rem_anchor_token(T_continue);
11070         rem_anchor_token(T_const_cast);
11071         rem_anchor_token(T_const);
11072         rem_anchor_token(T_class);
11073         rem_anchor_token(T_char);
11074         rem_anchor_token(T_case);
11075         rem_anchor_token(T_break);
11076         rem_anchor_token(T_bool);
11077         rem_anchor_token(T_auto);
11078         rem_anchor_token(T_asm);
11079         rem_anchor_token(T___thread);
11080         rem_anchor_token(T___real__);
11081         rem_anchor_token(T___label__);
11082         rem_anchor_token(T___imag__);
11083         rem_anchor_token(T___func__);
11084         rem_anchor_token(T___extension__);
11085         rem_anchor_token(T___builtin_va_start);
11086         rem_anchor_token(T___attribute__);
11087         rem_anchor_token(T___alignof__);
11088         rem_anchor_token(T___PRETTY_FUNCTION__);
11089         rem_anchor_token(T___FUNCTION__);
11090         rem_anchor_token(T__Imaginary);
11091         rem_anchor_token(T__Complex);
11092         rem_anchor_token(T__Bool);
11093         rem_anchor_token(T_WIDE_STRING_LITERAL);
11094         rem_anchor_token(T_WIDE_CHARACTER_CONSTANT);
11095         rem_anchor_token(T_STRING_LITERAL);
11096         rem_anchor_token(T_PLUSPLUS);
11097         rem_anchor_token(T_MINUSMINUS);
11098         rem_anchor_token(T_INTEGER);
11099         rem_anchor_token(T_IDENTIFIER);
11100         rem_anchor_token(T_FLOATINGPOINT);
11101         rem_anchor_token(T_COLONCOLON);
11102         rem_anchor_token(T_CHARACTER_CONSTANT);
11103         rem_anchor_token('~');
11104         rem_anchor_token('{');
11105         rem_anchor_token('-');
11106         rem_anchor_token('+');
11107         rem_anchor_token('*');
11108         rem_anchor_token('(');
11109         rem_anchor_token('&');
11110         rem_anchor_token('!');
11111         rem_anchor_token('}');
11112         assert(current_scope == &statement->compound.scope);
11113         scope_pop(old_scope);
11114         environment_pop_to(top);
11115
11116         POP_PARENT;
11117         return statement;
11118 }
11119
11120 /**
11121  * Check for unused global static functions and variables
11122  */
11123 static void check_unused_globals(void)
11124 {
11125         if (!warning.unused_function && !warning.unused_variable)
11126                 return;
11127
11128         for (const entity_t *entity = file_scope->entities; entity != NULL;
11129              entity = entity->base.next) {
11130                 if (!is_declaration(entity))
11131                         continue;
11132
11133                 const declaration_t *declaration = &entity->declaration;
11134                 if (declaration->used                  ||
11135                     declaration->modifiers & DM_UNUSED ||
11136                     declaration->modifiers & DM_USED   ||
11137                     declaration->storage_class != STORAGE_CLASS_STATIC)
11138                         continue;
11139
11140                 type_t *const type = declaration->type;
11141                 const char *s;
11142                 if (entity->kind == ENTITY_FUNCTION) {
11143                         /* inhibit warning for static inline functions */
11144                         if (entity->function.is_inline)
11145                                 continue;
11146
11147                         s = entity->function.statement != NULL ? "defined" : "declared";
11148                 } else {
11149                         s = "defined";
11150                 }
11151
11152                 warningf(&declaration->base.source_position, "'%#T' %s but not used",
11153                         type, declaration->base.symbol, s);
11154         }
11155 }
11156
11157 static void parse_global_asm(void)
11158 {
11159         statement_t *statement = allocate_statement_zero(STATEMENT_ASM);
11160
11161         eat(T_asm);
11162         expect('(', end_error);
11163
11164         statement->asms.asm_text = parse_string_literals();
11165         statement->base.next     = unit->global_asm;
11166         unit->global_asm         = statement;
11167
11168         expect(')', end_error);
11169         expect(';', end_error);
11170
11171 end_error:;
11172 }
11173
11174 static void parse_linkage_specification(void)
11175 {
11176         eat(T_extern);
11177         assert(token.type == T_STRING_LITERAL);
11178
11179         const char *linkage = parse_string_literals().begin;
11180
11181         linkage_kind_t old_linkage = current_linkage;
11182         linkage_kind_t new_linkage;
11183         if (strcmp(linkage, "C") == 0) {
11184                 new_linkage = LINKAGE_C;
11185         } else if (strcmp(linkage, "C++") == 0) {
11186                 new_linkage = LINKAGE_CXX;
11187         } else {
11188                 errorf(HERE, "linkage string \"%s\" not recognized", linkage);
11189                 new_linkage = LINKAGE_INVALID;
11190         }
11191         current_linkage = new_linkage;
11192
11193         if (token.type == '{') {
11194                 next_token();
11195                 parse_externals();
11196                 expect('}', end_error);
11197         } else {
11198                 parse_external();
11199         }
11200
11201 end_error:
11202         assert(current_linkage == new_linkage);
11203         current_linkage = old_linkage;
11204 }
11205
11206 static void parse_external(void)
11207 {
11208         switch (token.type) {
11209                 DECLARATION_START_NO_EXTERN
11210                 case T_IDENTIFIER:
11211                 case T___extension__:
11212                 /* tokens below are for implicit int */
11213                 case '&': /* & x; -> int& x; (and error later, because C++ has no
11214                              implicit int) */
11215                 case '*': /* * x; -> int* x; */
11216                 case '(': /* (x); -> int (x); */
11217                         parse_external_declaration();
11218                         return;
11219
11220                 case T_extern:
11221                         if (look_ahead(1)->type == T_STRING_LITERAL) {
11222                                 parse_linkage_specification();
11223                         } else {
11224                                 parse_external_declaration();
11225                         }
11226                         return;
11227
11228                 case T_asm:
11229                         parse_global_asm();
11230                         return;
11231
11232                 case T_namespace:
11233                         parse_namespace_definition();
11234                         return;
11235
11236                 case ';':
11237                         if (!strict_mode) {
11238                                 if (warning.other)
11239                                         warningf(HERE, "stray ';' outside of function");
11240                                 next_token();
11241                                 return;
11242                         }
11243                         /* FALLTHROUGH */
11244
11245                 default:
11246                         errorf(HERE, "stray %K outside of function", &token);
11247                         if (token.type == '(' || token.type == '{' || token.type == '[')
11248                                 eat_until_matching_token(token.type);
11249                         next_token();
11250                         return;
11251         }
11252 }
11253
11254 static void parse_externals(void)
11255 {
11256         add_anchor_token('}');
11257         add_anchor_token(T_EOF);
11258
11259 #ifndef NDEBUG
11260         unsigned char token_anchor_copy[T_LAST_TOKEN];
11261         memcpy(token_anchor_copy, token_anchor_set, sizeof(token_anchor_copy));
11262 #endif
11263
11264         while (token.type != T_EOF && token.type != '}') {
11265 #ifndef NDEBUG
11266                 bool anchor_leak = false;
11267                 for (int i = 0; i != T_LAST_TOKEN; ++i) {
11268                         unsigned char count = token_anchor_set[i] - token_anchor_copy[i];
11269                         if (count != 0) {
11270                                 errorf(HERE, "Leaked anchor token %k %d times", i, count);
11271                                 anchor_leak = true;
11272                         }
11273                 }
11274                 if (in_gcc_extension) {
11275                         errorf(HERE, "Leaked __extension__");
11276                         anchor_leak = true;
11277                 }
11278
11279                 if (anchor_leak)
11280                         abort();
11281 #endif
11282
11283                 parse_external();
11284         }
11285
11286         rem_anchor_token(T_EOF);
11287         rem_anchor_token('}');
11288 }
11289
11290 /**
11291  * Parse a translation unit.
11292  */
11293 static void parse_translation_unit(void)
11294 {
11295         add_anchor_token(T_EOF);
11296
11297         while (true) {
11298                 parse_externals();
11299
11300                 if (token.type == T_EOF)
11301                         break;
11302
11303                 errorf(HERE, "stray %K outside of function", &token);
11304                 if (token.type == '(' || token.type == '{' || token.type == '[')
11305                         eat_until_matching_token(token.type);
11306                 next_token();
11307         }
11308 }
11309
11310 /**
11311  * Parse the input.
11312  *
11313  * @return  the translation unit or NULL if errors occurred.
11314  */
11315 void start_parsing(void)
11316 {
11317         environment_stack = NEW_ARR_F(stack_entry_t, 0);
11318         label_stack       = NEW_ARR_F(stack_entry_t, 0);
11319         diagnostic_count  = 0;
11320         error_count       = 0;
11321         warning_count     = 0;
11322
11323         type_set_output(stderr);
11324         ast_set_output(stderr);
11325
11326         assert(unit == NULL);
11327         unit = allocate_ast_zero(sizeof(unit[0]));
11328
11329         assert(file_scope == NULL);
11330         file_scope = &unit->scope;
11331
11332         assert(current_scope == NULL);
11333         scope_push(&unit->scope);
11334 }
11335
11336 translation_unit_t *finish_parsing(void)
11337 {
11338         assert(current_scope == &unit->scope);
11339         scope_pop(NULL);
11340
11341         assert(file_scope == &unit->scope);
11342         check_unused_globals();
11343         file_scope = NULL;
11344
11345         DEL_ARR_F(environment_stack);
11346         DEL_ARR_F(label_stack);
11347
11348         translation_unit_t *result = unit;
11349         unit = NULL;
11350         return result;
11351 }
11352
11353 /* GCC allows global arrays without size and assigns them a length of one,
11354  * if no different declaration follows */
11355 static void complete_incomplete_arrays(void)
11356 {
11357         size_t n = ARR_LEN(incomplete_arrays);
11358         for (size_t i = 0; i != n; ++i) {
11359                 declaration_t *const decl      = incomplete_arrays[i];
11360                 type_t        *const orig_type = decl->type;
11361                 type_t        *const type      = skip_typeref(orig_type);
11362
11363                 if (!is_type_incomplete(type))
11364                         continue;
11365
11366                 if (warning.other) {
11367                         warningf(&decl->base.source_position,
11368                                         "array '%#T' assumed to have one element",
11369                                         orig_type, decl->base.symbol);
11370                 }
11371
11372                 type_t *const new_type = duplicate_type(type);
11373                 new_type->array.size_constant     = true;
11374                 new_type->array.has_implicit_size = true;
11375                 new_type->array.size              = 1;
11376
11377                 type_t *const result = identify_new_type(new_type);
11378
11379                 decl->type = result;
11380         }
11381 }
11382
11383 void parse(void)
11384 {
11385         lookahead_bufpos = 0;
11386         for (int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
11387                 next_token();
11388         }
11389         current_linkage   = c_mode & _CXX ? LINKAGE_CXX : LINKAGE_C;
11390         incomplete_arrays = NEW_ARR_F(declaration_t*, 0);
11391         parse_translation_unit();
11392         complete_incomplete_arrays();
11393         DEL_ARR_F(incomplete_arrays);
11394         incomplete_arrays = NULL;
11395 }
11396
11397 /**
11398  * Initialize the parser.
11399  */
11400 void init_parser(void)
11401 {
11402         sym_anonymous = symbol_table_insert("<anonymous>");
11403
11404         if (c_mode & _MS) {
11405                 /* add predefined symbols for extended-decl-modifier */
11406                 sym_align         = symbol_table_insert("align");
11407                 sym_allocate      = symbol_table_insert("allocate");
11408                 sym_dllimport     = symbol_table_insert("dllimport");
11409                 sym_dllexport     = symbol_table_insert("dllexport");
11410                 sym_naked         = symbol_table_insert("naked");
11411                 sym_noinline      = symbol_table_insert("noinline");
11412                 sym_returns_twice = symbol_table_insert("returns_twice");
11413                 sym_noreturn      = symbol_table_insert("noreturn");
11414                 sym_nothrow       = symbol_table_insert("nothrow");
11415                 sym_novtable      = symbol_table_insert("novtable");
11416                 sym_property      = symbol_table_insert("property");
11417                 sym_get           = symbol_table_insert("get");
11418                 sym_put           = symbol_table_insert("put");
11419                 sym_selectany     = symbol_table_insert("selectany");
11420                 sym_thread        = symbol_table_insert("thread");
11421                 sym_uuid          = symbol_table_insert("uuid");
11422                 sym_deprecated    = symbol_table_insert("deprecated");
11423                 sym_restrict      = symbol_table_insert("restrict");
11424                 sym_noalias       = symbol_table_insert("noalias");
11425         }
11426         memset(token_anchor_set, 0, sizeof(token_anchor_set));
11427
11428         init_expression_parsers();
11429         obstack_init(&temp_obst);
11430
11431         symbol_t *const va_list_sym = symbol_table_insert("__builtin_va_list");
11432         type_valist = create_builtin_type(va_list_sym, type_void_ptr);
11433 }
11434
11435 /**
11436  * Terminate the parser.
11437  */
11438 void exit_parser(void)
11439 {
11440         obstack_free(&temp_obst, NULL);
11441 }