nsz Git - cparser/blob - parser.c

   1 /*
   2  * This file is part of cparser.
   3  * Copyright (C) 2007-2008 Matthias Braun <matze@braunis.de>
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; either version 2
   8  * of the License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  18  * 02111-1307, USA.
  19  */
  20 #include <config.h>
  21
  22 #include <assert.h>
  23 #include <stdarg.h>
  24 #include <stdbool.h>
  25
  26 #include "parser.h"
  27 #include "diagnostic.h"
  28 #include "format_check.h"
  29 #include "lexer.h"
  30 #include "symbol_t.h"
  31 #include "token_t.h"
  32 #include "types.h"
  33 #include "type_t.h"
  34 #include "type_hash.h"
  35 #include "ast_t.h"
  36 #include "entity_t.h"
  37 #include "lang_features.h"
  38 #include "walk_statements.h"
  39 #include "warning.h"
  40 #include "adt/bitfiddle.h"
  41 #include "adt/error.h"
  42 #include "adt/array.h"
  43
  44 //#define PRINT_TOKENS
  45 #define MAX_LOOKAHEAD 1
  46
  47 typedef struct {
  48         entity_t           *old_entity;
  49         symbol_t           *symbol;
  50         entity_namespace_t  namespc;
  51 } stack_entry_t;
  52
  53 typedef struct argument_list_t argument_list_t;
  54 struct argument_list_t {
  55         long              argument;
  56         argument_list_t  *next;
  57 };
  58
  59 typedef struct gnu_attribute_t gnu_attribute_t;
  60 struct gnu_attribute_t {
  61         gnu_attribute_kind_t kind;          /**< The kind of the GNU attribute. */
  62         gnu_attribute_t     *next;
  63         bool                 invalid;       /**< Set if this attribute had argument errors, */
  64         bool                 has_arguments; /**< True, if this attribute has arguments. */
  65         union {
  66                 size_t              value;
  67                 string_t            string;
  68                 symbol_t           *symbol;
  69                 long                argument;  /**< Single argument. */
  70                 argument_list_t    *arguments; /**< List of argument expressions. */
  71         } u;
  72 };
  73
  74 typedef struct declaration_specifiers_t  declaration_specifiers_t;
  75 struct declaration_specifiers_t {
  76         source_position_t  source_position;
  77         storage_class_t    storage_class;
  78         unsigned char      alignment;         /**< Alignment, 0 if not set. */
  79         bool               is_inline    : 1;
  80         bool               thread_local : 1;  /**< GCC __thread */
  81         bool               deprecated   : 1;
  82         decl_modifiers_t   modifiers;         /**< declaration modifiers */
  83         gnu_attribute_t   *gnu_attributes;    /**< list of GNU attributes */
  84         const char        *deprecated_string; /**< can be set if declaration was marked deprecated. */
  85         symbol_t          *get_property_sym;  /**< the name of the get property if set. */
  86         symbol_t          *put_property_sym;  /**< the name of the put property if set. */
  87         type_t            *type;
  88 };
  89
  90 /**
  91  * An environment for parsing initializers (and compound literals).
  92  */
  93 typedef struct parse_initializer_env_t {
  94         type_t     *type;   /**< the type of the initializer. In case of an
  95                                  array type with unspecified size this gets
  96                                  adjusted to the actual size. */
  97         entity_t   *entity; /**< the variable that is initialized if any */
  98         bool        must_be_constant;
  99 } parse_initializer_env_t;
 100
 101 /**
 102  * Capture a MS __base extension.
 103  */
 104 typedef struct based_spec_t {
 105         source_position_t  source_position;
 106         variable_t        *base_variable;
 107 } based_spec_t;
 108
 109 typedef entity_t* (*parsed_declaration_func) (entity_t *declaration, bool is_definition);
 110
 111 /** The current token. */
 112 static token_t              token;
 113 /** The lookahead ring-buffer. */
 114 static token_t              lookahead_buffer[MAX_LOOKAHEAD];
 115 /** Position of the next token in the lookahead buffer. */
 116 static size_t               lookahead_bufpos;
 117 static stack_entry_t       *environment_stack = NULL;
 118 static stack_entry_t       *label_stack       = NULL;
 119 static scope_t             *file_scope        = NULL;
 120 static scope_t             *current_scope     = NULL;
 121 /** Point to the current function declaration if inside a function. */
 122 static function_t          *current_function  = NULL;
 123 static entity_t            *current_init_decl = NULL;
 124 static switch_statement_t  *current_switch    = NULL;
 125 static statement_t         *current_loop      = NULL;
 126 static statement_t         *current_parent    = NULL;
 127 static ms_try_statement_t  *current_try       = NULL;
 128 static linkage_kind_t       current_linkage   = LINKAGE_INVALID;
 129 static goto_statement_t    *goto_first        = NULL;
 130 static goto_statement_t   **goto_anchor       = NULL;
 131 static label_statement_t   *label_first       = NULL;
 132 static label_statement_t  **label_anchor      = NULL;
 133 /** current translation unit. */
 134 static translation_unit_t  *unit              = NULL;
 135 /** true if we are in a type property context (evaluation only for type. */
 136 static bool                 in_type_prop      = false;
 137 /** true in we are in a __extension__ context. */
 138 static bool                 in_gcc_extension  = false;
 139 static struct obstack       temp_obst;
 140 static entity_t            *anonymous_entity;
 141 static declaration_t      **incomplete_arrays;
 142
 143
 144 #define PUSH_PARENT(stmt)                          \
 145         statement_t *const prev_parent = current_parent; \
 146         ((void)(current_parent = (stmt)))
 147 #define POP_PARENT ((void)(current_parent = prev_parent))
 148
 149 /** special symbol used for anonymous entities. */
 150 static const symbol_t *sym_anonymous = NULL;
 151
 152 /* symbols for Microsoft extended-decl-modifier */
 153 static const symbol_t *sym_align         = NULL;
 154 static const symbol_t *sym_allocate      = NULL;
 155 static const symbol_t *sym_dllimport     = NULL;
 156 static const symbol_t *sym_dllexport     = NULL;
 157 static const symbol_t *sym_naked         = NULL;
 158 static const symbol_t *sym_noinline      = NULL;
 159 static const symbol_t *sym_returns_twice = NULL;
 160 static const symbol_t *sym_noreturn      = NULL;
 161 static const symbol_t *sym_nothrow       = NULL;
 162 static const symbol_t *sym_novtable      = NULL;
 163 static const symbol_t *sym_property      = NULL;
 164 static const symbol_t *sym_get           = NULL;
 165 static const symbol_t *sym_put           = NULL;
 166 static const symbol_t *sym_selectany     = NULL;
 167 static const symbol_t *sym_thread        = NULL;
 168 static const symbol_t *sym_uuid          = NULL;
 169 static const symbol_t *sym_deprecated    = NULL;
 170 static const symbol_t *sym_restrict      = NULL;
 171 static const symbol_t *sym_noalias       = NULL;
 172
 173 /** The token anchor set */
 174 static unsigned char token_anchor_set[T_LAST_TOKEN];
 175
 176 /** The current source position. */
 177 #define HERE (&token.source_position)
 178
 179 /** true if we are in GCC mode. */
 180 #define GNU_MODE ((c_mode & _GNUC) || in_gcc_extension)
 181
 182 static type_t *type_valist;
 183
 184 static statement_t *parse_compound_statement(bool inside_expression_statement);
 185 static statement_t *parse_statement(void);
 186
 187 static expression_t *parse_sub_expression(precedence_t);
 188 static expression_t *parse_expression(void);
 189 static type_t       *parse_typename(void);
 190 static void          parse_externals(void);
 191 static void          parse_external(void);
 192
 193 static void parse_compound_type_entries(compound_t *compound_declaration);
 194
 195 typedef enum declarator_flags_t {
 196         DECL_FLAGS_NONE             = 0,
 197         DECL_MAY_BE_ABSTRACT        = 1U << 0,
 198         DECL_CREATE_COMPOUND_MEMBER = 1U << 1,
 199         DECL_IS_PARAMETER           = 1U << 2
 200 } declarator_flags_t;
 201
 202 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
 203                                   declarator_flags_t flags);
 204
 205 static entity_t *record_entity(entity_t *entity, bool is_definition);
 206
 207 static void semantic_comparison(binary_expression_t *expression);
 208
 209 static void create_gnu_builtins(void);
 210 static void create_microsoft_intrinsics(void);
 211
 212 #define STORAGE_CLASSES       \
 213         STORAGE_CLASSES_NO_EXTERN \
 214         case T_extern:
 215
 216 #define STORAGE_CLASSES_NO_EXTERN \
 217         case T_typedef:         \
 218         case T_static:          \
 219         case T_auto:            \
 220         case T_register:        \
 221         case T___thread:
 222
 223 #define TYPE_QUALIFIERS     \
 224         case T_const:           \
 225         case T_restrict:        \
 226         case T_volatile:        \
 227         case T_inline:          \
 228         case T__forceinline:    \
 229         case T___attribute__:
 230
 231 #define COMPLEX_SPECIFIERS  \
 232         case T__Complex:
 233 #define IMAGINARY_SPECIFIERS \
 234         case T__Imaginary:
 235
 236 #define TYPE_SPECIFIERS       \
 237         case T__Bool:             \
 238         case T___builtin_va_list: \
 239         case T___typeof__:        \
 240         case T__declspec:         \
 241         case T_bool:              \
 242         case T_char:              \
 243         case T_double:            \
 244         case T_enum:              \
 245         case T_float:             \
 246         case T_int:               \
 247         case T_long:              \
 248         case T_short:             \
 249         case T_signed:            \
 250         case T_struct:            \
 251         case T_union:             \
 252         case T_unsigned:          \
 253         case T_void:              \
 254         case T_wchar_t:           \
 255         COMPLEX_SPECIFIERS        \
 256         IMAGINARY_SPECIFIERS
 257
 258 #define DECLARATION_START   \
 259         STORAGE_CLASSES         \
 260         TYPE_QUALIFIERS         \
 261         TYPE_SPECIFIERS
 262
 263 #define DECLARATION_START_NO_EXTERN \
 264         STORAGE_CLASSES_NO_EXTERN       \
 265         TYPE_QUALIFIERS                 \
 266         TYPE_SPECIFIERS
 267
 268 #define TYPENAME_START      \
 269         TYPE_QUALIFIERS         \
 270         TYPE_SPECIFIERS
 271
 272 #define EXPRESSION_START           \
 273         case '!':                        \
 274         case '&':                        \
 275         case '(':                        \
 276         case '*':                        \
 277         case '+':                        \
 278         case '-':                        \
 279         case '~':                        \
 280         case T_ANDAND:                   \
 281         case T_CHARACTER_CONSTANT:       \
 282         case T_FLOATINGPOINT:            \
 283         case T_INTEGER:                  \
 284         case T_MINUSMINUS:               \
 285         case T_PLUSPLUS:                 \
 286         case T_STRING_LITERAL:           \
 287         case T_WIDE_CHARACTER_CONSTANT:  \
 288         case T_WIDE_STRING_LITERAL:      \
 289         case T___FUNCDNAME__:            \
 290         case T___FUNCSIG__:              \
 291         case T___FUNCTION__:             \
 292         case T___PRETTY_FUNCTION__:      \
 293         case T___alignof__:              \
 294         case T___builtin_classify_type:  \
 295         case T___builtin_constant_p:     \
 296         case T___builtin_isgreater:      \
 297         case T___builtin_isgreaterequal: \
 298         case T___builtin_isless:         \
 299         case T___builtin_islessequal:    \
 300         case T___builtin_islessgreater:  \
 301         case T___builtin_isunordered:    \
 302         case T___builtin_offsetof:       \
 303         case T___builtin_va_arg:         \
 304         case T___builtin_va_start:       \
 305         case T___func__:                 \
 306         case T___noop:                   \
 307         case T__assume:                  \
 308         case T_delete:                   \
 309         case T_false:                    \
 310         case T_sizeof:                   \
 311         case T_throw:                    \
 312         case T_true:
 313
 314 /**
 315  * Allocate an AST node with given size and
 316  * initialize all fields with zero.
 317  */
 318 static void *allocate_ast_zero(size_t size)
 319 {
 320         void *res = allocate_ast(size);
 321         memset(res, 0, size);
 322         return res;
 323 }
 324
 325 /**
 326  * Returns the size of an entity node.
 327  *
 328  * @param kind  the entity kind
 329  */
 330 static size_t get_entity_struct_size(entity_kind_t kind)
 331 {
 332         static const size_t sizes[] = {
 333                 [ENTITY_VARIABLE]        = sizeof(variable_t),
 334                 [ENTITY_PARAMETER]       = sizeof(parameter_t),
 335                 [ENTITY_COMPOUND_MEMBER] = sizeof(compound_member_t),
 336                 [ENTITY_FUNCTION]        = sizeof(function_t),
 337                 [ENTITY_TYPEDEF]         = sizeof(typedef_t),
 338                 [ENTITY_STRUCT]          = sizeof(compound_t),
 339                 [ENTITY_UNION]           = sizeof(compound_t),
 340                 [ENTITY_ENUM]            = sizeof(enum_t),
 341                 [ENTITY_ENUM_VALUE]      = sizeof(enum_value_t),
 342                 [ENTITY_LABEL]           = sizeof(label_t),
 343                 [ENTITY_LOCAL_LABEL]     = sizeof(label_t),
 344                 [ENTITY_NAMESPACE]       = sizeof(namespace_t)
 345         };
 346         assert(kind < lengthof(sizes));
 347         assert(sizes[kind] != 0);
 348         return sizes[kind];
 349 }
 350
 351 /**
 352  * Allocate an entity of given kind and initialize all
 353  * fields with zero.
 354  */
 355 static entity_t *allocate_entity_zero(entity_kind_t kind)
 356 {
 357         size_t    size   = get_entity_struct_size(kind);
 358         entity_t *entity = allocate_ast_zero(size);
 359         entity->kind     = kind;
 360         return entity;
 361 }
 362
 363 /**
 364  * Returns the size of a statement node.
 365  *
 366  * @param kind  the statement kind
 367  */
 368 static size_t get_statement_struct_size(statement_kind_t kind)
 369 {
 370         static const size_t sizes[] = {
 371                 [STATEMENT_INVALID]     = sizeof(invalid_statement_t),
 372                 [STATEMENT_EMPTY]       = sizeof(empty_statement_t),
 373                 [STATEMENT_COMPOUND]    = sizeof(compound_statement_t),
 374                 [STATEMENT_RETURN]      = sizeof(return_statement_t),
 375                 [STATEMENT_DECLARATION] = sizeof(declaration_statement_t),
 376                 [STATEMENT_IF]          = sizeof(if_statement_t),
 377                 [STATEMENT_SWITCH]      = sizeof(switch_statement_t),
 378                 [STATEMENT_EXPRESSION]  = sizeof(expression_statement_t),
 379                 [STATEMENT_CONTINUE]    = sizeof(statement_base_t),
 380                 [STATEMENT_BREAK]       = sizeof(statement_base_t),
 381                 [STATEMENT_GOTO]        = sizeof(goto_statement_t),
 382                 [STATEMENT_LABEL]       = sizeof(label_statement_t),
 383                 [STATEMENT_CASE_LABEL]  = sizeof(case_label_statement_t),
 384                 [STATEMENT_WHILE]       = sizeof(while_statement_t),
 385                 [STATEMENT_DO_WHILE]    = sizeof(do_while_statement_t),
 386                 [STATEMENT_FOR]         = sizeof(for_statement_t),
 387                 [STATEMENT_ASM]         = sizeof(asm_statement_t),
 388                 [STATEMENT_MS_TRY]      = sizeof(ms_try_statement_t),
 389                 [STATEMENT_LEAVE]       = sizeof(leave_statement_t)
 390         };
 391         assert(kind < lengthof(sizes));
 392         assert(sizes[kind] != 0);
 393         return sizes[kind];
 394 }
 395
 396 /**
 397  * Returns the size of an expression node.
 398  *
 399  * @param kind  the expression kind
 400  */
 401 static size_t get_expression_struct_size(expression_kind_t kind)
 402 {
 403         static const size_t sizes[] = {
 404                 [EXPR_INVALID]                    = sizeof(expression_base_t),
 405                 [EXPR_REFERENCE]                  = sizeof(reference_expression_t),
 406                 [EXPR_REFERENCE_ENUM_VALUE]       = sizeof(reference_expression_t),
 407                 [EXPR_CONST]                      = sizeof(const_expression_t),
 408                 [EXPR_CHARACTER_CONSTANT]         = sizeof(const_expression_t),
 409                 [EXPR_WIDE_CHARACTER_CONSTANT]    = sizeof(const_expression_t),
 410                 [EXPR_STRING_LITERAL]             = sizeof(string_literal_expression_t),
 411                 [EXPR_WIDE_STRING_LITERAL]        = sizeof(wide_string_literal_expression_t),
 412                 [EXPR_COMPOUND_LITERAL]           = sizeof(compound_literal_expression_t),
 413                 [EXPR_CALL]                       = sizeof(call_expression_t),
 414                 [EXPR_UNARY_FIRST]                = sizeof(unary_expression_t),
 415                 [EXPR_BINARY_FIRST]               = sizeof(binary_expression_t),
 416                 [EXPR_CONDITIONAL]                = sizeof(conditional_expression_t),
 417                 [EXPR_SELECT]                     = sizeof(select_expression_t),
 418                 [EXPR_ARRAY_ACCESS]               = sizeof(array_access_expression_t),
 419                 [EXPR_SIZEOF]                     = sizeof(typeprop_expression_t),
 420                 [EXPR_ALIGNOF]                    = sizeof(typeprop_expression_t),
 421                 [EXPR_CLASSIFY_TYPE]              = sizeof(classify_type_expression_t),
 422                 [EXPR_FUNCNAME]                   = sizeof(funcname_expression_t),
 423                 [EXPR_BUILTIN_CONSTANT_P]         = sizeof(builtin_constant_expression_t),
 424                 [EXPR_BUILTIN_TYPES_COMPATIBLE_P] = sizeof(builtin_types_compatible_expression_t),
 425                 [EXPR_OFFSETOF]                   = sizeof(offsetof_expression_t),
 426                 [EXPR_VA_START]                   = sizeof(va_start_expression_t),
 427                 [EXPR_VA_ARG]                     = sizeof(va_arg_expression_t),
 428                 [EXPR_STATEMENT]                  = sizeof(statement_expression_t),
 429                 [EXPR_LABEL_ADDRESS]              = sizeof(label_address_expression_t),
 430         };
 431         if (kind >= EXPR_UNARY_FIRST && kind <= EXPR_UNARY_LAST) {
 432                 return sizes[EXPR_UNARY_FIRST];
 433         }
 434         if (kind >= EXPR_BINARY_FIRST && kind <= EXPR_BINARY_LAST) {
 435                 return sizes[EXPR_BINARY_FIRST];
 436         }
 437         assert(kind < lengthof(sizes));
 438         assert(sizes[kind] != 0);
 439         return sizes[kind];
 440 }
 441
 442 /**
 443  * Allocate a statement node of given kind and initialize all
 444  * fields with zero. Sets its source position to the position
 445  * of the current token.
 446  */
 447 static statement_t *allocate_statement_zero(statement_kind_t kind)
 448 {
 449         size_t       size = get_statement_struct_size(kind);
 450         statement_t *res  = allocate_ast_zero(size);
 451
 452         res->base.kind            = kind;
 453         res->base.parent          = current_parent;
 454         res->base.source_position = token.source_position;
 455         return res;
 456 }
 457
 458 /**
 459  * Allocate an expression node of given kind and initialize all
 460  * fields with zero.
 461  */
 462 static expression_t *allocate_expression_zero(expression_kind_t kind)
 463 {
 464         size_t        size = get_expression_struct_size(kind);
 465         expression_t *res  = allocate_ast_zero(size);
 466
 467         res->base.kind            = kind;
 468         res->base.type            = type_error_type;
 469         res->base.source_position = token.source_position;
 470         return res;
 471 }
 472
 473 /**
 474  * Creates a new invalid expression at the source position
 475  * of the current token.
 476  */
 477 static expression_t *create_invalid_expression(void)
 478 {
 479         return allocate_expression_zero(EXPR_INVALID);
 480 }
 481
 482 /**
 483  * Creates a new invalid statement.
 484  */
 485 static statement_t *create_invalid_statement(void)
 486 {
 487         return allocate_statement_zero(STATEMENT_INVALID);
 488 }
 489
 490 /**
 491  * Allocate a new empty statement.
 492  */
 493 static statement_t *create_empty_statement(void)
 494 {
 495         return allocate_statement_zero(STATEMENT_EMPTY);
 496 }
 497
 498 /**
 499  * Returns the size of a type node.
 500  *
 501  * @param kind  the type kind
 502  */
 503 static size_t get_type_struct_size(type_kind_t kind)
 504 {
 505         static const size_t sizes[] = {
 506                 [TYPE_ATOMIC]          = sizeof(atomic_type_t),
 507                 [TYPE_COMPLEX]         = sizeof(complex_type_t),
 508                 [TYPE_IMAGINARY]       = sizeof(imaginary_type_t),
 509                 [TYPE_BITFIELD]        = sizeof(bitfield_type_t),
 510                 [TYPE_COMPOUND_STRUCT] = sizeof(compound_type_t),
 511                 [TYPE_COMPOUND_UNION]  = sizeof(compound_type_t),
 512                 [TYPE_ENUM]            = sizeof(enum_type_t),
 513                 [TYPE_FUNCTION]        = sizeof(function_type_t),
 514                 [TYPE_POINTER]         = sizeof(pointer_type_t),
 515                 [TYPE_ARRAY]           = sizeof(array_type_t),
 516                 [TYPE_BUILTIN]         = sizeof(builtin_type_t),
 517                 [TYPE_TYPEDEF]         = sizeof(typedef_type_t),
 518                 [TYPE_TYPEOF]          = sizeof(typeof_type_t),
 519         };
 520         assert(lengthof(sizes) == (int)TYPE_TYPEOF + 1);
 521         assert(kind <= TYPE_TYPEOF);
 522         assert(sizes[kind] != 0);
 523         return sizes[kind];
 524 }
 525
 526 /**
 527  * Allocate a type node of given kind and initialize all
 528  * fields with zero.
 529  *
 530  * @param kind             type kind to allocate
 531  */
 532 static type_t *allocate_type_zero(type_kind_t kind)
 533 {
 534         size_t  size = get_type_struct_size(kind);
 535         type_t *res  = obstack_alloc(type_obst, size);
 536         memset(res, 0, size);
 537         res->base.kind = kind;
 538
 539         return res;
 540 }
 541
 542 /**
 543  * Returns the size of an initializer node.
 544  *
 545  * @param kind  the initializer kind
 546  */
 547 static size_t get_initializer_size(initializer_kind_t kind)
 548 {
 549         static const size_t sizes[] = {
 550                 [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
 551                 [INITIALIZER_STRING]      = sizeof(initializer_string_t),
 552                 [INITIALIZER_WIDE_STRING] = sizeof(initializer_wide_string_t),
 553                 [INITIALIZER_LIST]        = sizeof(initializer_list_t),
 554                 [INITIALIZER_DESIGNATOR]  = sizeof(initializer_designator_t)
 555         };
 556         assert(kind < lengthof(sizes));
 557         assert(sizes[kind] != 0);
 558         return sizes[kind];
 559 }
 560
 561 /**
 562  * Allocate an initializer node of given kind and initialize all
 563  * fields with zero.
 564  */
 565 static initializer_t *allocate_initializer_zero(initializer_kind_t kind)
 566 {
 567         initializer_t *result = allocate_ast_zero(get_initializer_size(kind));
 568         result->kind          = kind;
 569
 570         return result;
 571 }
 572
 573 /**
 574  * Returns the index of the top element of the environment stack.
 575  */
 576 static size_t environment_top(void)
 577 {
 578         return ARR_LEN(environment_stack);
 579 }
 580
 581 /**
 582  * Returns the index of the top element of the global label stack.
 583  */
 584 static size_t label_top(void)
 585 {
 586         return ARR_LEN(label_stack);
 587 }
 588
 589 /**
 590  * Return the next token.
 591  */
 592 static inline void next_token(void)
 593 {
 594         token                              = lookahead_buffer[lookahead_bufpos];
 595         lookahead_buffer[lookahead_bufpos] = lexer_token;
 596         lexer_next_token();
 597
 598         lookahead_bufpos = (lookahead_bufpos + 1) % MAX_LOOKAHEAD;
 599
 600 #ifdef PRINT_TOKENS
 601         print_token(stderr, &token);
 602         fprintf(stderr, "\n");
 603 #endif
 604 }
 605
 606 /**
 607  * Return the next token with a given lookahead.
 608  */
 609 static inline const token_t *look_ahead(size_t num)
 610 {
 611         assert(0 < num && num <= MAX_LOOKAHEAD);
 612         size_t pos = (lookahead_bufpos + num - 1) % MAX_LOOKAHEAD;
 613         return &lookahead_buffer[pos];
 614 }
 615
 616 /**
 617  * Adds a token type to the token type anchor set (a multi-set).
 618  */
 619 static void add_anchor_token(int token_type)
 620 {
 621         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 622         ++token_anchor_set[token_type];
 623 }
 624
 625 /**
 626  * Set the number of tokens types of the given type
 627  * to zero and return the old count.
 628  */
 629 static int save_and_reset_anchor_state(int token_type)
 630 {
 631         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 632         int count = token_anchor_set[token_type];
 633         token_anchor_set[token_type] = 0;
 634         return count;
 635 }
 636
 637 /**
 638  * Restore the number of token types to the given count.
 639  */
 640 static void restore_anchor_state(int token_type, int count)
 641 {
 642         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 643         token_anchor_set[token_type] = count;
 644 }
 645
 646 /**
 647  * Remove a token type from the token type anchor set (a multi-set).
 648  */
 649 static void rem_anchor_token(int token_type)
 650 {
 651         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 652         assert(token_anchor_set[token_type] != 0);
 653         --token_anchor_set[token_type];
 654 }
 655
 656 /**
 657  * Return true if the token type of the current token is
 658  * in the anchor set.
 659  */
 660 static bool at_anchor(void)
 661 {
 662         if (token.type < 0)
 663                 return false;
 664         return token_anchor_set[token.type];
 665 }
 666
 667 /**
 668  * Eat tokens until a matching token type is found.
 669  */
 670 static void eat_until_matching_token(int type)
 671 {
 672         int end_token;
 673         switch (type) {
 674                 case '(': end_token = ')';  break;
 675                 case '{': end_token = '}';  break;
 676                 case '[': end_token = ']';  break;
 677                 default:  end_token = type; break;
 678         }
 679
 680         unsigned parenthesis_count = 0;
 681         unsigned brace_count       = 0;
 682         unsigned bracket_count     = 0;
 683         while (token.type        != end_token ||
 684                parenthesis_count != 0         ||
 685                brace_count       != 0         ||
 686                bracket_count     != 0) {
 687                 switch (token.type) {
 688                 case T_EOF: return;
 689                 case '(': ++parenthesis_count; break;
 690                 case '{': ++brace_count;       break;
 691                 case '[': ++bracket_count;     break;
 692
 693                 case ')':
 694                         if (parenthesis_count > 0)
 695                                 --parenthesis_count;
 696                         goto check_stop;
 697
 698                 case '}':
 699                         if (brace_count > 0)
 700                                 --brace_count;
 701                         goto check_stop;
 702
 703                 case ']':
 704                         if (bracket_count > 0)
 705                                 --bracket_count;
 706 check_stop:
 707                         if (token.type        == end_token &&
 708                             parenthesis_count == 0         &&
 709                             brace_count       == 0         &&
 710                             bracket_count     == 0)
 711                                 return;
 712                         break;
 713
 714                 default:
 715                         break;
 716                 }
 717                 next_token();
 718         }
 719 }
 720
 721 /**
 722  * Eat input tokens until an anchor is found.
 723  */
 724 static void eat_until_anchor(void)
 725 {
 726         while (token_anchor_set[token.type] == 0) {
 727                 if (token.type == '(' || token.type == '{' || token.type == '[')
 728                         eat_until_matching_token(token.type);
 729                 next_token();
 730         }
 731 }
 732
 733 /**
 734  * Eat a whole block from input tokens.
 735  */
 736 static void eat_block(void)
 737 {
 738         eat_until_matching_token('{');
 739         if (token.type == '}')
 740                 next_token();
 741 }
 742
 743 #define eat(token_type) (assert(token.type == (token_type)), next_token())
 744
 745 /**
 746  * Report a parse error because an expected token was not found.
 747  */
 748 static
 749 #if defined __GNUC__ && __GNUC__ >= 4
 750 __attribute__((sentinel))
 751 #endif
 752 void parse_error_expected(const char *message, ...)
 753 {
 754         if (message != NULL) {
 755                 errorf(HERE, "%s", message);
 756         }
 757         va_list ap;
 758         va_start(ap, message);
 759         errorf(HERE, "got %K, expected %#k", &token, &ap, ", ");
 760         va_end(ap);
 761 }
 762
 763 /**
 764  * Report an incompatible type.
 765  */
 766 static void type_error_incompatible(const char *msg,
 767                 const source_position_t *source_position, type_t *type1, type_t *type2)
 768 {
 769         errorf(source_position, "%s, incompatible types: '%T' - '%T'",
 770                msg, type1, type2);
 771 }
 772
 773 /**
 774  * Expect the current token is the expected token.
 775  * If not, generate an error, eat the current statement,
 776  * and goto the end_error label.
 777  */
 778 #define expect(expected, error_label)                     \
 779         do {                                                  \
 780                 if (UNLIKELY(token.type != (expected))) {         \
 781                         parse_error_expected(NULL, (expected), NULL); \
 782                         add_anchor_token(expected);                   \
 783                         eat_until_anchor();                           \
 784                         if (token.type == expected)                   \
 785                                 next_token();                             \
 786                         rem_anchor_token(expected);                   \
 787                         goto error_label;                             \
 788                 }                                                 \
 789                 next_token();                                     \
 790         } while (0)
 791
 792 /**
 793  * Push a given scope on the scope stack and make it the
 794  * current scope
 795  */
 796 static scope_t *scope_push(scope_t *new_scope)
 797 {
 798         if (current_scope != NULL) {
 799                 new_scope->depth = current_scope->depth + 1;
 800         }
 801
 802         scope_t *old_scope = current_scope;
 803         current_scope      = new_scope;
 804         return old_scope;
 805 }
 806
 807 /**
 808  * Pop the current scope from the scope stack.
 809  */
 810 static void scope_pop(scope_t *old_scope)
 811 {
 812         current_scope = old_scope;
 813 }
 814
 815 /**
 816  * Search an entity by its symbol in a given namespace.
 817  */
 818 static entity_t *get_entity(const symbol_t *const symbol,
 819                             namespace_tag_t namespc)
 820 {
 821         entity_t *entity = symbol->entity;
 822         for (; entity != NULL; entity = entity->base.symbol_next) {
 823                 if (entity->base.namespc == namespc)
 824                         return entity;
 825         }
 826
 827         return NULL;
 828 }
 829
 830 /**
 831  * pushs an entity on the environment stack and links the corresponding symbol
 832  * it.
 833  */
 834 static void stack_push(stack_entry_t **stack_ptr, entity_t *entity)
 835 {
 836         symbol_t           *symbol  = entity->base.symbol;
 837         entity_namespace_t  namespc = entity->base.namespc;
 838         assert(namespc != NAMESPACE_INVALID);
 839
 840         /* replace/add entity into entity list of the symbol */
 841         entity_t **anchor;
 842         entity_t  *iter;
 843         for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 844                 iter = *anchor;
 845                 if (iter == NULL)
 846                         break;
 847
 848                 /* replace an entry? */
 849                 if (iter->base.namespc == namespc) {
 850                         entity->base.symbol_next = iter->base.symbol_next;
 851                         break;
 852                 }
 853         }
 854         *anchor = entity;
 855
 856         /* remember old declaration */
 857         stack_entry_t entry;
 858         entry.symbol     = symbol;
 859         entry.old_entity = iter;
 860         entry.namespc    = namespc;
 861         ARR_APP1(stack_entry_t, *stack_ptr, entry);
 862 }
 863
 864 /**
 865  * Push an entity on the environment stack.
 866  */
 867 static void environment_push(entity_t *entity)
 868 {
 869         assert(entity->base.source_position.input_name != NULL);
 870         assert(entity->base.parent_scope != NULL);
 871         stack_push(&environment_stack, entity);
 872 }
 873
 874 /**
 875  * Push a declaration on the global label stack.
 876  *
 877  * @param declaration  the declaration
 878  */
 879 static void label_push(entity_t *label)
 880 {
 881         /* we abuse the parameters scope as parent for the labels */
 882         label->base.parent_scope = &current_function->parameters;
 883         stack_push(&label_stack, label);
 884 }
 885
 886 /**
 887  * pops symbols from the environment stack until @p new_top is the top element
 888  */
 889 static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
 890 {
 891         stack_entry_t *stack = *stack_ptr;
 892         size_t         top   = ARR_LEN(stack);
 893         size_t         i;
 894
 895         assert(new_top <= top);
 896         if (new_top == top)
 897                 return;
 898
 899         for (i = top; i > new_top; --i) {
 900                 stack_entry_t *entry = &stack[i - 1];
 901
 902                 entity_t           *old_entity = entry->old_entity;
 903                 symbol_t           *symbol     = entry->symbol;
 904                 entity_namespace_t  namespc    = entry->namespc;
 905
 906                 /* replace with old_entity/remove */
 907                 entity_t **anchor;
 908                 entity_t  *iter;
 909                 for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 910                         iter = *anchor;
 911                         assert(iter != NULL);
 912                         /* replace an entry? */
 913                         if (iter->base.namespc == namespc)
 914                                 break;
 915                 }
 916
 917                 /* restore definition from outer scopes (if there was one) */
 918                 if (old_entity != NULL) {
 919                         old_entity->base.symbol_next = iter->base.symbol_next;
 920                         *anchor                      = old_entity;
 921                 } else {
 922                         /* remove entry from list */
 923                         *anchor = iter->base.symbol_next;
 924                 }
 925         }
 926
 927         ARR_SHRINKLEN(*stack_ptr, (int) new_top);
 928 }
 929
 930 /**
 931  * Pop all entries from the environment stack until the new_top
 932  * is reached.
 933  *
 934  * @param new_top  the new stack top
 935  */
 936 static void environment_pop_to(size_t new_top)
 937 {
 938         stack_pop_to(&environment_stack, new_top);
 939 }
 940
 941 /**
 942  * Pop all entries from the global label stack until the new_top
 943  * is reached.
 944  *
 945  * @param new_top  the new stack top
 946  */
 947 static void label_pop_to(size_t new_top)
 948 {
 949         stack_pop_to(&label_stack, new_top);
 950 }
 951
 952 static int get_akind_rank(atomic_type_kind_t akind)
 953 {
 954         return (int) akind;
 955 }
 956
 957 /**
 958  * Return the type rank for an atomic type.
 959  */
 960 static int get_rank(const type_t *type)
 961 {
 962         assert(!is_typeref(type));
 963         if (type->kind == TYPE_ENUM)
 964                 return get_akind_rank(type->enumt.akind);
 965
 966         assert(type->kind == TYPE_ATOMIC);
 967         return get_akind_rank(type->atomic.akind);
 968 }
 969
 970 /**
 971  * Do integer promotion for a given type.
 972  *
 973  * @param type  the type to promote
 974  * @return the promoted type
 975  */
 976 static type_t *promote_integer(type_t *type)
 977 {
 978         if (type->kind == TYPE_BITFIELD)
 979                 type = type->bitfield.base_type;
 980
 981         if (get_rank(type) < get_akind_rank(ATOMIC_TYPE_INT))
 982                 type = type_int;
 983
 984         return type;
 985 }
 986
 987 /**
 988  * Create a cast expression.
 989  *
 990  * @param expression  the expression to cast
 991  * @param dest_type   the destination type
 992  */
 993 static expression_t *create_cast_expression(expression_t *expression,
 994                                             type_t *dest_type)
 995 {
 996         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST_IMPLICIT);
 997
 998         cast->unary.value = expression;
 999         cast->base.type   = dest_type;
1000
1001         return cast;
1002 }
1003
1004 /**
1005  * Check if a given expression represents a null pointer constant.
1006  *
1007  * @param expression  the expression to check
1008  */
1009 static bool is_null_pointer_constant(const expression_t *expression)
1010 {
1011         /* skip void* cast */
1012         if (expression->kind == EXPR_UNARY_CAST ||
1013                         expression->kind == EXPR_UNARY_CAST_IMPLICIT) {
1014                 type_t *const type = skip_typeref(expression->base.type);
1015                 if (types_compatible(type, type_void_ptr))
1016                         expression = expression->unary.value;
1017         }
1018
1019         type_t *const type = skip_typeref(expression->base.type);
1020         return
1021                 is_type_integer(type)              &&
1022                 is_constant_expression(expression) &&
1023                 fold_constant(expression) == 0;
1024 }
1025
1026 /**
1027  * Create an implicit cast expression.
1028  *
1029  * @param expression  the expression to cast
1030  * @param dest_type   the destination type
1031  */
1032 static expression_t *create_implicit_cast(expression_t *expression,
1033                                           type_t *dest_type)
1034 {
1035         type_t *const source_type = expression->base.type;
1036
1037         if (source_type == dest_type)
1038                 return expression;
1039
1040         return create_cast_expression(expression, dest_type);
1041 }
1042
1043 typedef enum assign_error_t {
1044         ASSIGN_SUCCESS,
1045         ASSIGN_ERROR_INCOMPATIBLE,
1046         ASSIGN_ERROR_POINTER_QUALIFIER_MISSING,
1047         ASSIGN_WARNING_POINTER_INCOMPATIBLE,
1048         ASSIGN_WARNING_POINTER_FROM_INT,
1049         ASSIGN_WARNING_INT_FROM_POINTER
1050 } assign_error_t;
1051
1052 static void report_assign_error(assign_error_t error, type_t *orig_type_left,
1053                                 const expression_t *const right,
1054                                 const char *context,
1055                                 const source_position_t *source_position)
1056 {
1057         type_t *const orig_type_right = right->base.type;
1058         type_t *const type_left       = skip_typeref(orig_type_left);
1059         type_t *const type_right      = skip_typeref(orig_type_right);
1060
1061         switch (error) {
1062         case ASSIGN_SUCCESS:
1063                 return;
1064         case ASSIGN_ERROR_INCOMPATIBLE:
1065                 errorf(source_position,
1066                        "destination type '%T' in %s is incompatible with type '%T'",
1067                        orig_type_left, context, orig_type_right);
1068                 return;
1069
1070         case ASSIGN_ERROR_POINTER_QUALIFIER_MISSING: {
1071                 if (warning.other) {
1072                         type_t *points_to_left  = skip_typeref(type_left->pointer.points_to);
1073                         type_t *points_to_right = skip_typeref(type_right->pointer.points_to);
1074
1075                         /* the left type has all qualifiers from the right type */
1076                         unsigned missing_qualifiers
1077                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
1078                         warningf(source_position,
1079                                         "destination type '%T' in %s from type '%T' lacks qualifiers '%Q' in pointer target type",
1080                                         orig_type_left, context, orig_type_right, missing_qualifiers);
1081                 }
1082                 return;
1083         }
1084
1085         case ASSIGN_WARNING_POINTER_INCOMPATIBLE:
1086                 if (warning.other) {
1087                         warningf(source_position,
1088                                         "destination type '%T' in %s is incompatible with '%E' of type '%T'",
1089                                         orig_type_left, context, right, orig_type_right);
1090                 }
1091                 return;
1092
1093         case ASSIGN_WARNING_POINTER_FROM_INT:
1094                 if (warning.other) {
1095                         warningf(source_position,
1096                                         "%s makes pointer '%T' from integer '%T' without a cast",
1097                                         context, orig_type_left, orig_type_right);
1098                 }
1099                 return;
1100
1101         case ASSIGN_WARNING_INT_FROM_POINTER:
1102                 if (warning.other) {
1103                         warningf(source_position,
1104                                         "%s makes integer '%T' from pointer '%T' without a cast",
1105                                         context, orig_type_left, orig_type_right);
1106                 }
1107                 return;
1108
1109         default:
1110                 panic("invalid error value");
1111         }
1112 }
1113
1114 /** Implements the rules from §6.5.16.1 */
1115 static assign_error_t semantic_assign(type_t *orig_type_left,
1116                                       const expression_t *const right)
1117 {
1118         type_t *const orig_type_right = right->base.type;
1119         type_t *const type_left       = skip_typeref(orig_type_left);
1120         type_t *const type_right      = skip_typeref(orig_type_right);
1121
1122         if (is_type_pointer(type_left)) {
1123                 if (is_null_pointer_constant(right)) {
1124                         return ASSIGN_SUCCESS;
1125                 } else if (is_type_pointer(type_right)) {
1126                         type_t *points_to_left
1127                                 = skip_typeref(type_left->pointer.points_to);
1128                         type_t *points_to_right
1129                                 = skip_typeref(type_right->pointer.points_to);
1130                         assign_error_t res = ASSIGN_SUCCESS;
1131
1132                         /* the left type has all qualifiers from the right type */
1133                         unsigned missing_qualifiers
1134                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
1135                         if (missing_qualifiers != 0) {
1136                                 res = ASSIGN_ERROR_POINTER_QUALIFIER_MISSING;
1137                         }
1138
1139                         points_to_left  = get_unqualified_type(points_to_left);
1140                         points_to_right = get_unqualified_type(points_to_right);
1141
1142                         if (is_type_atomic(points_to_left, ATOMIC_TYPE_VOID))
1143                                 return res;
1144
1145                         if (is_type_atomic(points_to_right, ATOMIC_TYPE_VOID)) {
1146                                 /* ISO/IEC 14882:1998(E) §C.1.2:6 */
1147                                 return c_mode & _CXX ? ASSIGN_ERROR_INCOMPATIBLE : res;
1148                         }
1149
1150                         if (!types_compatible(points_to_left, points_to_right)) {
1151                                 return ASSIGN_WARNING_POINTER_INCOMPATIBLE;
1152                         }
1153
1154                         return res;
1155                 } else if (is_type_integer(type_right)) {
1156                         return ASSIGN_WARNING_POINTER_FROM_INT;
1157                 }
1158         } else if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
1159             (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
1160                 && is_type_pointer(type_right))) {
1161                 return ASSIGN_SUCCESS;
1162         } else if ((is_type_compound(type_left)  && is_type_compound(type_right))
1163                         || (is_type_builtin(type_left) && is_type_builtin(type_right))) {
1164                 type_t *const unqual_type_left  = get_unqualified_type(type_left);
1165                 type_t *const unqual_type_right = get_unqualified_type(type_right);
1166                 if (types_compatible(unqual_type_left, unqual_type_right)) {
1167                         return ASSIGN_SUCCESS;
1168                 }
1169         } else if (is_type_integer(type_left) && is_type_pointer(type_right)) {
1170                 return ASSIGN_WARNING_INT_FROM_POINTER;
1171         }
1172
1173         if (!is_type_valid(type_left) || !is_type_valid(type_right))
1174                 return ASSIGN_SUCCESS;
1175
1176         return ASSIGN_ERROR_INCOMPATIBLE;
1177 }
1178
1179 static expression_t *parse_constant_expression(void)
1180 {
1181         expression_t *result = parse_sub_expression(PREC_CONDITIONAL);
1182
1183         if (!is_constant_expression(result)) {
1184                 errorf(&result->base.source_position,
1185                        "expression '%E' is not constant", result);
1186         }
1187
1188         return result;
1189 }
1190
1191 static expression_t *parse_assignment_expression(void)
1192 {
1193         return parse_sub_expression(PREC_ASSIGNMENT);
1194 }
1195
1196 static string_t parse_string_literals(void)
1197 {
1198         assert(token.type == T_STRING_LITERAL);
1199         string_t result = token.v.string;
1200
1201         next_token();
1202
1203         while (token.type == T_STRING_LITERAL) {
1204                 result = concat_strings(&result, &token.v.string);
1205                 next_token();
1206         }
1207
1208         return result;
1209 }
1210
1211 static const char *const gnu_attribute_names[GNU_AK_LAST] = {
1212         [GNU_AK_CONST]                  = "const",
1213         [GNU_AK_VOLATILE]               = "volatile",
1214         [GNU_AK_CDECL]                  = "cdecl",
1215         [GNU_AK_STDCALL]                = "stdcall",
1216         [GNU_AK_FASTCALL]               = "fastcall",
1217         [GNU_AK_DEPRECATED]             = "deprecated",
1218         [GNU_AK_NOINLINE]               = "noinline",
1219         [GNU_AK_RETURNS_TWICE]          = "returns_twice",
1220         [GNU_AK_NORETURN]               = "noreturn",
1221         [GNU_AK_NAKED]                  = "naked",
1222         [GNU_AK_PURE]                   = "pure",
1223         [GNU_AK_ALWAYS_INLINE]          = "always_inline",
1224         [GNU_AK_MALLOC]                 = "malloc",
1225         [GNU_AK_WEAK]                   = "weak",
1226         [GNU_AK_CONSTRUCTOR]            = "constructor",
1227         [GNU_AK_DESTRUCTOR]             = "destructor",
1228         [GNU_AK_NOTHROW]                = "nothrow",
1229         [GNU_AK_TRANSPARENT_UNION]      = "transparent_union",
1230         [GNU_AK_COMMON]                 = "common",
1231         [GNU_AK_NOCOMMON]               = "nocommon",
1232         [GNU_AK_PACKED]                 = "packed",
1233         [GNU_AK_SHARED]                 = "shared",
1234         [GNU_AK_NOTSHARED]              = "notshared",
1235         [GNU_AK_USED]                   = "used",
1236         [GNU_AK_UNUSED]                 = "unused",
1237         [GNU_AK_NO_INSTRUMENT_FUNCTION] = "no_instrument_function",
1238         [GNU_AK_WARN_UNUSED_RESULT]     = "warn_unused_result",
1239         [GNU_AK_LONGCALL]               = "longcall",
1240         [GNU_AK_SHORTCALL]              = "shortcall",
1241         [GNU_AK_LONG_CALL]              = "long_call",
1242         [GNU_AK_SHORT_CALL]             = "short_call",
1243         [GNU_AK_FUNCTION_VECTOR]        = "function_vector",
1244         [GNU_AK_INTERRUPT]              = "interrupt",
1245         [GNU_AK_INTERRUPT_HANDLER]      = "interrupt_handler",
1246         [GNU_AK_NMI_HANDLER]            = "nmi_handler",
1247         [GNU_AK_NESTING]                = "nesting",
1248         [GNU_AK_NEAR]                   = "near",
1249         [GNU_AK_FAR]                    = "far",
1250         [GNU_AK_SIGNAL]                 = "signal",
1251         [GNU_AK_EIGTHBIT_DATA]          = "eightbit_data",
1252         [GNU_AK_TINY_DATA]              = "tiny_data",
1253         [GNU_AK_SAVEALL]                = "saveall",
1254         [GNU_AK_FLATTEN]                = "flatten",
1255         [GNU_AK_SSEREGPARM]             = "sseregparm",
1256         [GNU_AK_EXTERNALLY_VISIBLE]     = "externally_visible",
1257         [GNU_AK_RETURN_TWICE]           = "return_twice",
1258         [GNU_AK_MAY_ALIAS]              = "may_alias",
1259         [GNU_AK_MS_STRUCT]              = "ms_struct",
1260         [GNU_AK_GCC_STRUCT]             = "gcc_struct",
1261         [GNU_AK_DLLIMPORT]              = "dllimport",
1262         [GNU_AK_DLLEXPORT]              = "dllexport",
1263         [GNU_AK_ALIGNED]                = "aligned",
1264         [GNU_AK_ALIAS]                  = "alias",
1265         [GNU_AK_SECTION]                = "section",
1266         [GNU_AK_FORMAT]                 = "format",
1267         [GNU_AK_FORMAT_ARG]             = "format_arg",
1268         [GNU_AK_WEAKREF]                = "weakref",
1269         [GNU_AK_NONNULL]                = "nonnull",
1270         [GNU_AK_TLS_MODEL]              = "tls_model",
1271         [GNU_AK_VISIBILITY]             = "visibility",
1272         [GNU_AK_REGPARM]                = "regparm",
1273         [GNU_AK_MODE]                   = "mode",
1274         [GNU_AK_MODEL]                  = "model",
1275         [GNU_AK_TRAP_EXIT]              = "trap_exit",
1276         [GNU_AK_SP_SWITCH]              = "sp_switch",
1277         [GNU_AK_SENTINEL]               = "sentinel"
1278 };
1279
1280 /**
1281  * compare two string, ignoring double underscores on the second.
1282  */
1283 static int strcmp_underscore(const char *s1, const char *s2)
1284 {
1285         if (s2[0] == '_' && s2[1] == '_') {
1286                 size_t len2 = strlen(s2);
1287                 size_t len1 = strlen(s1);
1288                 if (len1 == len2-4 && s2[len2-2] == '_' && s2[len2-1] == '_') {
1289                         return strncmp(s1, s2+2, len2-4);
1290                 }
1291         }
1292
1293         return strcmp(s1, s2);
1294 }
1295
1296 /**
1297  * Allocate a new gnu temporal attribute of given kind.
1298  */
1299 static gnu_attribute_t *allocate_gnu_attribute(gnu_attribute_kind_t kind)
1300 {
1301         gnu_attribute_t *attribute = obstack_alloc(&temp_obst, sizeof(*attribute));
1302         attribute->kind            = kind;
1303         attribute->next            = NULL;
1304         attribute->invalid         = false;
1305         attribute->has_arguments   = false;
1306
1307         return attribute;
1308 }
1309
1310 /**
1311  * Parse one constant expression argument of the given attribute.
1312  */
1313 static void parse_gnu_attribute_const_arg(gnu_attribute_t *attribute)
1314 {
1315         expression_t *expression;
1316         add_anchor_token(')');
1317         expression = parse_constant_expression();
1318         rem_anchor_token(')');
1319         expect(')', end_error);
1320         attribute->u.argument = fold_constant(expression);
1321         return;
1322 end_error:
1323         attribute->invalid = true;
1324 }
1325
1326 /**
1327  * Parse a list of constant expressions arguments of the given attribute.
1328  */
1329 static void parse_gnu_attribute_const_arg_list(gnu_attribute_t *attribute)
1330 {
1331         argument_list_t **list = &attribute->u.arguments;
1332         argument_list_t  *entry;
1333         expression_t     *expression;
1334         add_anchor_token(')');
1335         add_anchor_token(',');
1336         while (true) {
1337                 expression = parse_constant_expression();
1338                 entry = obstack_alloc(&temp_obst, sizeof(entry));
1339                 entry->argument = fold_constant(expression);
1340                 entry->next     = NULL;
1341                 *list = entry;
1342                 list = &entry->next;
1343                 if (token.type != ',')
1344                         break;
1345                 next_token();
1346         }
1347         rem_anchor_token(',');
1348         rem_anchor_token(')');
1349         expect(')', end_error);
1350         return;
1351 end_error:
1352         attribute->invalid = true;
1353 }
1354
1355 /**
1356  * Parse one string literal argument of the given attribute.
1357  */
1358 static void parse_gnu_attribute_string_arg(gnu_attribute_t *attribute,
1359                                            string_t *string)
1360 {
1361         add_anchor_token('(');
1362         if (token.type != T_STRING_LITERAL) {
1363                 parse_error_expected("while parsing attribute directive",
1364                                      T_STRING_LITERAL, NULL);
1365                 goto end_error;
1366         }
1367         *string = parse_string_literals();
1368         rem_anchor_token('(');
1369         expect(')', end_error);
1370         return;
1371 end_error:
1372         attribute->invalid = true;
1373 }
1374
1375 /**
1376  * Parse one tls model of the given attribute.
1377  */
1378 static void parse_gnu_attribute_tls_model_arg(gnu_attribute_t *attribute)
1379 {
1380         static const char *const tls_models[] = {
1381                 "global-dynamic",
1382                 "local-dynamic",
1383                 "initial-exec",
1384                 "local-exec"
1385         };
1386         string_t string = { NULL, 0 };
1387         parse_gnu_attribute_string_arg(attribute, &string);
1388         if (string.begin != NULL) {
1389                 for (size_t i = 0; i < 4; ++i) {
1390                         if (strcmp(tls_models[i], string.begin) == 0) {
1391                                 attribute->u.value = i;
1392                                 return;
1393                         }
1394                 }
1395                 errorf(HERE, "'%s' is an unrecognized tls model", string.begin);
1396         }
1397         attribute->invalid = true;
1398 }
1399
1400 /**
1401  * Parse one tls model of the given attribute.
1402  */
1403 static void parse_gnu_attribute_visibility_arg(gnu_attribute_t *attribute)
1404 {
1405         static const char *const visibilities[] = {
1406                 "default",
1407                 "protected",
1408                 "hidden",
1409                 "internal"
1410         };
1411         string_t string = { NULL, 0 };
1412         parse_gnu_attribute_string_arg(attribute, &string);
1413         if (string.begin != NULL) {
1414                 for (size_t i = 0; i < 4; ++i) {
1415                         if (strcmp(visibilities[i], string.begin) == 0) {
1416                                 attribute->u.value = i;
1417                                 return;
1418                         }
1419                 }
1420                 errorf(HERE, "'%s' is an unrecognized visibility", string.begin);
1421         }
1422         attribute->invalid = true;
1423 }
1424
1425 /**
1426  * Parse one (code) model of the given attribute.
1427  */
1428 static void parse_gnu_attribute_model_arg(gnu_attribute_t *attribute)
1429 {
1430         static const char *const visibilities[] = {
1431                 "small",
1432                 "medium",
1433                 "large"
1434         };
1435         string_t string = { NULL, 0 };
1436         parse_gnu_attribute_string_arg(attribute, &string);
1437         if (string.begin != NULL) {
1438                 for (int i = 0; i < 3; ++i) {
1439                         if (strcmp(visibilities[i], string.begin) == 0) {
1440                                 attribute->u.value = i;
1441                                 return;
1442                         }
1443                 }
1444                 errorf(HERE, "'%s' is an unrecognized model", string.begin);
1445         }
1446         attribute->invalid = true;
1447 }
1448
1449 /**
1450  * Parse one mode of the given attribute.
1451  */
1452 static void parse_gnu_attribute_mode_arg(gnu_attribute_t *attribute)
1453 {
1454         add_anchor_token(')');
1455
1456         if (token.type != T_IDENTIFIER) {
1457                 expect(T_IDENTIFIER, end_error);
1458         }
1459
1460         attribute->u.symbol = token.v.symbol;
1461         next_token();
1462
1463         rem_anchor_token(')');
1464         expect(')', end_error);
1465         return;
1466 end_error:
1467         attribute->invalid = true;
1468 }
1469
1470 /**
1471  * Parse one interrupt argument of the given attribute.
1472  */
1473 static void parse_gnu_attribute_interrupt_arg(gnu_attribute_t *attribute)
1474 {
1475         static const char *const interrupts[] = {
1476                 "IRQ",
1477                 "FIQ",
1478                 "SWI",
1479                 "ABORT",
1480                 "UNDEF"
1481         };
1482         string_t string = { NULL, 0 };
1483         parse_gnu_attribute_string_arg(attribute, &string);
1484         if (string.begin != NULL) {
1485                 for (size_t i = 0; i < 5; ++i) {
1486                         if (strcmp(interrupts[i], string.begin) == 0) {
1487                                 attribute->u.value = i;
1488                                 return;
1489                         }
1490                 }
1491                 errorf(HERE, "'%s' is not an interrupt", string.begin);
1492         }
1493         attribute->invalid = true;
1494 }
1495
1496 /**
1497  * Parse ( identifier, const expression, const expression )
1498  */
1499 static void parse_gnu_attribute_format_args(gnu_attribute_t *attribute)
1500 {
1501         static const char *const format_names[] = {
1502                 "printf",
1503                 "scanf",
1504                 "strftime",
1505                 "strfmon"
1506         };
1507         int i;
1508
1509         if (token.type != T_IDENTIFIER) {
1510                 parse_error_expected("while parsing format attribute directive", T_IDENTIFIER, NULL);
1511                 goto end_error;
1512         }
1513         const char *name = token.v.symbol->string;
1514         for (i = 0; i < 4; ++i) {
1515                 if (strcmp_underscore(format_names[i], name) == 0)
1516                         break;
1517         }
1518         if (i >= 4) {
1519                 if (warning.attribute)
1520                         warningf(HERE, "'%s' is an unrecognized format function type", name);
1521         }
1522         next_token();
1523
1524         expect(',', end_error);
1525         add_anchor_token(')');
1526         add_anchor_token(',');
1527         parse_constant_expression();
1528         rem_anchor_token(',');
1529         rem_anchor_token(')');
1530
1531         expect(',', end_error);
1532         add_anchor_token(')');
1533         parse_constant_expression();
1534         rem_anchor_token(')');
1535         expect(')', end_error);
1536         return;
1537 end_error:
1538         attribute->u.value = true;
1539 }
1540
1541 /**
1542  * Check that a given GNU attribute has no arguments.
1543  */
1544 static void check_no_argument(gnu_attribute_t *attribute, const char *name)
1545 {
1546         if (!attribute->has_arguments)
1547                 return;
1548
1549         /* should have no arguments */
1550         errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1551         eat_until_matching_token('(');
1552         /* we have already consumed '(', so we stop before ')', eat it */
1553         eat(')');
1554         attribute->invalid = true;
1555 }
1556
1557 /**
1558  * Parse one GNU attribute.
1559  *
1560  * Note that attribute names can be specified WITH or WITHOUT
1561  * double underscores, ie const or __const__.
1562  *
1563  * The following attributes are parsed without arguments
1564  *  const
1565  *  volatile
1566  *  cdecl
1567  *  stdcall
1568  *  fastcall
1569  *  deprecated
1570  *  noinline
1571  *  noreturn
1572  *  naked
1573  *  pure
1574  *  always_inline
1575  *  malloc
1576  *  weak
1577  *  constructor
1578  *  destructor
1579  *  nothrow
1580  *  transparent_union
1581  *  common
1582  *  nocommon
1583  *  packed
1584  *  shared
1585  *  notshared
1586  *  used
1587  *  unused
1588  *  no_instrument_function
1589  *  warn_unused_result
1590  *  longcall
1591  *  shortcall
1592  *  long_call
1593  *  short_call
1594  *  function_vector
1595  *  interrupt_handler
1596  *  nmi_handler
1597  *  nesting
1598  *  near
1599  *  far
1600  *  signal
1601  *  eightbit_data
1602  *  tiny_data
1603  *  saveall
1604  *  flatten
1605  *  sseregparm
1606  *  externally_visible
1607  *  return_twice
1608  *  may_alias
1609  *  ms_struct
1610  *  gcc_struct
1611  *  dllimport
1612  *  dllexport
1613  *
1614  * The following attributes are parsed with arguments
1615  *  aligned( const expression )
1616  *  alias( string literal )
1617  *  section( string literal )
1618  *  format( identifier, const expression, const expression )
1619  *  format_arg( const expression )
1620  *  tls_model( string literal )
1621  *  visibility( string literal )
1622  *  regparm( const expression )
1623  *  model( string leteral )
1624  *  trap_exit( const expression )
1625  *  sp_switch( string literal )
1626  *
1627  * The following attributes might have arguments
1628  *  weak_ref( string literal )
1629  *  non_null( const expression // ',' )
1630  *  interrupt( string literal )
1631  *  sentinel( constant expression )
1632  */
1633 static decl_modifiers_t parse_gnu_attribute(gnu_attribute_t **attributes)
1634 {
1635         gnu_attribute_t *head      = *attributes;
1636         gnu_attribute_t *last      = *attributes;
1637         decl_modifiers_t modifiers = 0;
1638         gnu_attribute_t *attribute;
1639
1640         eat(T___attribute__);
1641         expect('(', end_error);
1642         expect('(', end_error);
1643
1644         if (token.type != ')') {
1645                 /* find the end of the list */
1646                 if (last != NULL) {
1647                         while (last->next != NULL)
1648                                 last = last->next;
1649                 }
1650
1651                 /* non-empty attribute list */
1652                 while (true) {
1653                         const char *name;
1654                         if (token.type == T_const) {
1655                                 name = "const";
1656                         } else if (token.type == T_volatile) {
1657                                 name = "volatile";
1658                         } else if (token.type == T_cdecl) {
1659                                 /* __attribute__((cdecl)), WITH ms mode */
1660                                 name = "cdecl";
1661                         } else if (token.type == T_IDENTIFIER) {
1662                                 const symbol_t *sym = token.v.symbol;
1663                                 name = sym->string;
1664                         } else {
1665                                 parse_error_expected("while parsing GNU attribute", T_IDENTIFIER, NULL);
1666                                 break;
1667                         }
1668
1669                         next_token();
1670
1671                         int i;
1672                         for (i = 0; i < GNU_AK_LAST; ++i) {
1673                                 if (strcmp_underscore(gnu_attribute_names[i], name) == 0)
1674                                         break;
1675                         }
1676                         gnu_attribute_kind_t kind = (gnu_attribute_kind_t)i;
1677
1678                         attribute = NULL;
1679                         if (kind == GNU_AK_LAST) {
1680                                 if (warning.attribute)
1681                                         warningf(HERE, "'%s' attribute directive ignored", name);
1682
1683                                 /* skip possible arguments */
1684                                 if (token.type == '(') {
1685                                         eat_until_matching_token(')');
1686                                 }
1687                         } else {
1688                                 /* check for arguments */
1689                                 attribute = allocate_gnu_attribute(kind);
1690                                 if (token.type == '(') {
1691                                         next_token();
1692                                         if (token.type == ')') {
1693                                                 /* empty args are allowed */
1694                                                 next_token();
1695                                         } else
1696                                                 attribute->has_arguments = true;
1697                                 }
1698
1699                                 switch (kind) {
1700                                 case GNU_AK_VOLATILE:
1701                                 case GNU_AK_NAKED:
1702                                 case GNU_AK_MALLOC:
1703                                 case GNU_AK_WEAK:
1704                                 case GNU_AK_COMMON:
1705                                 case GNU_AK_NOCOMMON:
1706                                 case GNU_AK_SHARED:
1707                                 case GNU_AK_NOTSHARED:
1708                                 case GNU_AK_NO_INSTRUMENT_FUNCTION:
1709                                 case GNU_AK_WARN_UNUSED_RESULT:
1710                                 case GNU_AK_LONGCALL:
1711                                 case GNU_AK_SHORTCALL:
1712                                 case GNU_AK_LONG_CALL:
1713                                 case GNU_AK_SHORT_CALL:
1714                                 case GNU_AK_FUNCTION_VECTOR:
1715                                 case GNU_AK_INTERRUPT_HANDLER:
1716                                 case GNU_AK_NMI_HANDLER:
1717                                 case GNU_AK_NESTING:
1718                                 case GNU_AK_NEAR:
1719                                 case GNU_AK_FAR:
1720                                 case GNU_AK_SIGNAL:
1721                                 case GNU_AK_EIGTHBIT_DATA:
1722                                 case GNU_AK_TINY_DATA:
1723                                 case GNU_AK_SAVEALL:
1724                                 case GNU_AK_FLATTEN:
1725                                 case GNU_AK_SSEREGPARM:
1726                                 case GNU_AK_EXTERNALLY_VISIBLE:
1727                                 case GNU_AK_RETURN_TWICE:
1728                                 case GNU_AK_MAY_ALIAS:
1729                                 case GNU_AK_MS_STRUCT:
1730                                 case GNU_AK_GCC_STRUCT:
1731                                         goto no_arg;
1732
1733                                 case GNU_AK_CDECL:             modifiers |= DM_CDECL;             goto no_arg;
1734                                 case GNU_AK_FASTCALL:          modifiers |= DM_FASTCALL;          goto no_arg;
1735                                 case GNU_AK_STDCALL:           modifiers |= DM_STDCALL;           goto no_arg;
1736                                 case GNU_AK_UNUSED:            modifiers |= DM_UNUSED;            goto no_arg;
1737                                 case GNU_AK_USED:              modifiers |= DM_USED;              goto no_arg;
1738                                 case GNU_AK_PURE:              modifiers |= DM_PURE;              goto no_arg;
1739                                 case GNU_AK_CONST:             modifiers |= DM_CONST;             goto no_arg;
1740                                 case GNU_AK_ALWAYS_INLINE:     modifiers |= DM_FORCEINLINE;       goto no_arg;
1741                                 case GNU_AK_DLLIMPORT:         modifiers |= DM_DLLIMPORT;         goto no_arg;
1742                                 case GNU_AK_DLLEXPORT:         modifiers |= DM_DLLEXPORT;         goto no_arg;
1743                                 case GNU_AK_PACKED:            modifiers |= DM_PACKED;            goto no_arg;
1744                                 case GNU_AK_NOINLINE:          modifiers |= DM_NOINLINE;          goto no_arg;
1745                                 case GNU_AK_RETURNS_TWICE:     modifiers |= DM_RETURNS_TWICE;     goto no_arg;
1746                                 case GNU_AK_NORETURN:          modifiers |= DM_NORETURN;          goto no_arg;
1747                                 case GNU_AK_NOTHROW:           modifiers |= DM_NOTHROW;           goto no_arg;
1748                                 case GNU_AK_TRANSPARENT_UNION: modifiers |= DM_TRANSPARENT_UNION; goto no_arg;
1749                                 case GNU_AK_CONSTRUCTOR:       modifiers |= DM_CONSTRUCTOR;       goto no_arg;
1750                                 case GNU_AK_DESTRUCTOR:        modifiers |= DM_DESTRUCTOR;        goto no_arg;
1751                                 case GNU_AK_DEPRECATED:        modifiers |= DM_DEPRECATED;        goto no_arg;
1752
1753                                 case GNU_AK_ALIGNED:
1754                                         /* __align__ may be used without an argument */
1755                                         if (attribute->has_arguments) {
1756                                                 parse_gnu_attribute_const_arg(attribute);
1757                                         }
1758                                         break;
1759
1760                                 case GNU_AK_FORMAT_ARG:
1761                                 case GNU_AK_REGPARM:
1762                                 case GNU_AK_TRAP_EXIT:
1763                                         if (!attribute->has_arguments) {
1764                                                 /* should have arguments */
1765                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1766                                                 attribute->invalid = true;
1767                                         } else
1768                                                 parse_gnu_attribute_const_arg(attribute);
1769                                         break;
1770                                 case GNU_AK_ALIAS:
1771                                 case GNU_AK_SECTION:
1772                                 case GNU_AK_SP_SWITCH:
1773                                         if (!attribute->has_arguments) {
1774                                                 /* should have arguments */
1775                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1776                                                 attribute->invalid = true;
1777                                         } else
1778                                                 parse_gnu_attribute_string_arg(attribute, &attribute->u.string);
1779                                         break;
1780                                 case GNU_AK_FORMAT:
1781                                         if (!attribute->has_arguments) {
1782                                                 /* should have arguments */
1783                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1784                                                 attribute->invalid = true;
1785                                         } else
1786                                                 parse_gnu_attribute_format_args(attribute);
1787                                         break;
1788                                 case GNU_AK_WEAKREF:
1789                                         /* may have one string argument */
1790                                         if (attribute->has_arguments)
1791                                                 parse_gnu_attribute_string_arg(attribute, &attribute->u.string);
1792                                         break;
1793                                 case GNU_AK_NONNULL:
1794                                         if (attribute->has_arguments)
1795                                                 parse_gnu_attribute_const_arg_list(attribute);
1796                                         break;
1797                                 case GNU_AK_TLS_MODEL:
1798                                         if (!attribute->has_arguments) {
1799                                                 /* should have arguments */
1800                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1801                                         } else
1802                                                 parse_gnu_attribute_tls_model_arg(attribute);
1803                                         break;
1804                                 case GNU_AK_VISIBILITY:
1805                                         if (!attribute->has_arguments) {
1806                                                 /* should have arguments */
1807                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1808                                         } else
1809                                                 parse_gnu_attribute_visibility_arg(attribute);
1810                                         break;
1811                                 case GNU_AK_MODEL:
1812                                         if (!attribute->has_arguments) {
1813                                                 /* should have arguments */
1814                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1815                                         } else {
1816                                                 parse_gnu_attribute_model_arg(attribute);
1817                                         }
1818                                         break;
1819                                 case GNU_AK_MODE:
1820                                         if (!attribute->has_arguments) {
1821                                                 /* should have arguments */
1822                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1823                                         } else {
1824                                                 parse_gnu_attribute_mode_arg(attribute);
1825                                         }
1826                                         break;
1827                                 case GNU_AK_INTERRUPT:
1828                                         /* may have one string argument */
1829                                         if (attribute->has_arguments)
1830                                                 parse_gnu_attribute_interrupt_arg(attribute);
1831                                         break;
1832                                 case GNU_AK_SENTINEL:
1833                                         /* may have one string argument */
1834                                         if (attribute->has_arguments)
1835                                                 parse_gnu_attribute_const_arg(attribute);
1836                                         break;
1837                                 case GNU_AK_LAST:
1838                                         /* already handled */
1839                                         break;
1840
1841 no_arg:
1842                                         check_no_argument(attribute, name);
1843                                 }
1844                         }
1845                         if (attribute != NULL) {
1846                                 if (last != NULL) {
1847                                         last->next = attribute;
1848                                         last       = attribute;
1849                                 } else {
1850                                         head = last = attribute;
1851                                 }
1852                         }
1853
1854                         if (token.type != ',')
1855                                 break;
1856                         next_token();
1857                 }
1858         }
1859         expect(')', end_error);
1860         expect(')', end_error);
1861 end_error:
1862         *attributes = head;
1863
1864         return modifiers;
1865 }
1866
1867 /**
1868  * Parse GNU attributes.
1869  */
1870 static decl_modifiers_t parse_attributes(gnu_attribute_t **attributes)
1871 {
1872         decl_modifiers_t modifiers = 0;
1873
1874         while (true) {
1875                 switch (token.type) {
1876                 case T___attribute__:
1877                         modifiers |= parse_gnu_attribute(attributes);
1878                         continue;
1879
1880                 case T_asm:
1881                         next_token();
1882                         expect('(', end_error);
1883                         if (token.type != T_STRING_LITERAL) {
1884                                 parse_error_expected("while parsing assembler attribute",
1885                                                      T_STRING_LITERAL, NULL);
1886                                 eat_until_matching_token('(');
1887                                 break;
1888                         } else {
1889                                 parse_string_literals();
1890                         }
1891                         expect(')', end_error);
1892                         continue;
1893
1894                 case T_cdecl:     modifiers |= DM_CDECL;    break;
1895                 case T__fastcall: modifiers |= DM_FASTCALL; break;
1896                 case T__stdcall:  modifiers |= DM_STDCALL;  break;
1897
1898                 case T___thiscall:
1899                         /* TODO record modifier */
1900                         if (warning.other)
1901                                 warningf(HERE, "Ignoring declaration modifier %K", &token);
1902                         break;
1903
1904 end_error:
1905                 default: return modifiers;
1906                 }
1907
1908                 next_token();
1909         }
1910 }
1911
1912 static void mark_vars_read(expression_t *expr, entity_t *lhs_ent);
1913
1914 static entity_t *determine_lhs_ent(expression_t *const expr,
1915                                    entity_t *lhs_ent)
1916 {
1917         switch (expr->kind) {
1918                 case EXPR_REFERENCE: {
1919                         entity_t *const entity = expr->reference.entity;
1920                         /* we should only find variables as lvalues... */
1921                         if (entity->base.kind != ENTITY_VARIABLE
1922                                         && entity->base.kind != ENTITY_PARAMETER)
1923                                 return NULL;
1924
1925                         return entity;
1926                 }
1927
1928                 case EXPR_ARRAY_ACCESS: {
1929                         expression_t *const ref = expr->array_access.array_ref;
1930                         entity_t     *      ent = NULL;
1931                         if (is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1932                                 ent     = determine_lhs_ent(ref, lhs_ent);
1933                                 lhs_ent = ent;
1934                         } else {
1935                                 mark_vars_read(expr->select.compound, lhs_ent);
1936                         }
1937                         mark_vars_read(expr->array_access.index, lhs_ent);
1938                         return ent;
1939                 }
1940
1941                 case EXPR_SELECT: {
1942                         if (is_type_compound(skip_typeref(expr->base.type))) {
1943                                 return determine_lhs_ent(expr->select.compound, lhs_ent);
1944                         } else {
1945                                 mark_vars_read(expr->select.compound, lhs_ent);
1946                                 return NULL;
1947                         }
1948                 }
1949
1950                 case EXPR_UNARY_DEREFERENCE: {
1951                         expression_t *const val = expr->unary.value;
1952                         if (val->kind == EXPR_UNARY_TAKE_ADDRESS) {
1953                                 /* *&x is a NOP */
1954                                 return determine_lhs_ent(val->unary.value, lhs_ent);
1955                         } else {
1956                                 mark_vars_read(val, NULL);
1957                                 return NULL;
1958                         }
1959                 }
1960
1961                 default:
1962                         mark_vars_read(expr, NULL);
1963                         return NULL;
1964         }
1965 }
1966
1967 #define ENT_ANY ((entity_t*)-1)
1968
1969 /**
1970  * Mark declarations, which are read.  This is used to detect variables, which
1971  * are never read.
1972  * Example:
1973  * x = x + 1;
1974  *   x is not marked as "read", because it is only read to calculate its own new
1975  *   value.
1976  *
1977  * x += y; y += x;
1978  *   x and y are not detected as "not read", because multiple variables are
1979  *   involved.
1980  */
1981 static void mark_vars_read(expression_t *const expr, entity_t *lhs_ent)
1982 {
1983         switch (expr->kind) {
1984                 case EXPR_REFERENCE: {
1985                         entity_t *const entity = expr->reference.entity;
1986                         if (entity->kind != ENTITY_VARIABLE
1987                                         && entity->kind != ENTITY_PARAMETER)
1988                                 return;
1989
1990                         if (lhs_ent != entity && lhs_ent != ENT_ANY) {
1991                                 if (entity->kind == ENTITY_VARIABLE) {
1992                                         entity->variable.read = true;
1993                                 } else {
1994                                         entity->parameter.read = true;
1995                                 }
1996                         }
1997                         return;
1998                 }
1999
2000                 case EXPR_CALL:
2001                         // TODO respect pure/const
2002                         mark_vars_read(expr->call.function, NULL);
2003                         for (call_argument_t *arg = expr->call.arguments; arg != NULL; arg = arg->next) {
2004                                 mark_vars_read(arg->expression, NULL);
2005                         }
2006                         return;
2007
2008                 case EXPR_CONDITIONAL:
2009                         // TODO lhs_decl should depend on whether true/false have an effect
2010                         mark_vars_read(expr->conditional.condition, NULL);
2011                         if (expr->conditional.true_expression != NULL)
2012                                 mark_vars_read(expr->conditional.true_expression, lhs_ent);
2013                         mark_vars_read(expr->conditional.false_expression, lhs_ent);
2014                         return;
2015
2016                 case EXPR_SELECT:
2017                         if (lhs_ent == ENT_ANY
2018                                         && !is_type_compound(skip_typeref(expr->base.type)))
2019                                 lhs_ent = NULL;
2020                         mark_vars_read(expr->select.compound, lhs_ent);
2021                         return;
2022
2023                 case EXPR_ARRAY_ACCESS: {
2024                         expression_t *const ref = expr->array_access.array_ref;
2025                         mark_vars_read(ref, lhs_ent);
2026                         lhs_ent = determine_lhs_ent(ref, lhs_ent);
2027                         mark_vars_read(expr->array_access.index, lhs_ent);
2028                         return;
2029                 }
2030
2031                 case EXPR_VA_ARG:
2032                         mark_vars_read(expr->va_arge.ap, lhs_ent);
2033                         return;
2034
2035                 case EXPR_UNARY_CAST:
2036                         /* Special case: Use void cast to mark a variable as "read" */
2037                         if (is_type_atomic(skip_typeref(expr->base.type), ATOMIC_TYPE_VOID))
2038                                 lhs_ent = NULL;
2039                         goto unary;
2040
2041
2042                 case EXPR_UNARY_THROW:
2043                         if (expr->unary.value == NULL)
2044                                 return;
2045                         /* FALLTHROUGH */
2046                 case EXPR_UNARY_DEREFERENCE:
2047                 case EXPR_UNARY_DELETE:
2048                 case EXPR_UNARY_DELETE_ARRAY:
2049                         if (lhs_ent == ENT_ANY)
2050                                 lhs_ent = NULL;
2051                         goto unary;
2052
2053                 case EXPR_UNARY_NEGATE:
2054                 case EXPR_UNARY_PLUS:
2055                 case EXPR_UNARY_BITWISE_NEGATE:
2056                 case EXPR_UNARY_NOT:
2057                 case EXPR_UNARY_TAKE_ADDRESS:
2058                 case EXPR_UNARY_POSTFIX_INCREMENT:
2059                 case EXPR_UNARY_POSTFIX_DECREMENT:
2060                 case EXPR_UNARY_PREFIX_INCREMENT:
2061                 case EXPR_UNARY_PREFIX_DECREMENT:
2062                 case EXPR_UNARY_CAST_IMPLICIT:
2063                 case EXPR_UNARY_ASSUME:
2064 unary:
2065                         mark_vars_read(expr->unary.value, lhs_ent);
2066                         return;
2067
2068                 case EXPR_BINARY_ADD:
2069                 case EXPR_BINARY_SUB:
2070                 case EXPR_BINARY_MUL:
2071                 case EXPR_BINARY_DIV:
2072                 case EXPR_BINARY_MOD:
2073                 case EXPR_BINARY_EQUAL:
2074                 case EXPR_BINARY_NOTEQUAL:
2075                 case EXPR_BINARY_LESS:
2076                 case EXPR_BINARY_LESSEQUAL:
2077                 case EXPR_BINARY_GREATER:
2078                 case EXPR_BINARY_GREATEREQUAL:
2079                 case EXPR_BINARY_BITWISE_AND:
2080                 case EXPR_BINARY_BITWISE_OR:
2081                 case EXPR_BINARY_BITWISE_XOR:
2082                 case EXPR_BINARY_LOGICAL_AND:
2083                 case EXPR_BINARY_LOGICAL_OR:
2084                 case EXPR_BINARY_SHIFTLEFT:
2085                 case EXPR_BINARY_SHIFTRIGHT:
2086                 case EXPR_BINARY_COMMA:
2087                 case EXPR_BINARY_ISGREATER:
2088                 case EXPR_BINARY_ISGREATEREQUAL:
2089                 case EXPR_BINARY_ISLESS:
2090                 case EXPR_BINARY_ISLESSEQUAL:
2091                 case EXPR_BINARY_ISLESSGREATER:
2092                 case EXPR_BINARY_ISUNORDERED:
2093                         mark_vars_read(expr->binary.left,  lhs_ent);
2094                         mark_vars_read(expr->binary.right, lhs_ent);
2095                         return;
2096
2097                 case EXPR_BINARY_ASSIGN:
2098                 case EXPR_BINARY_MUL_ASSIGN:
2099                 case EXPR_BINARY_DIV_ASSIGN:
2100                 case EXPR_BINARY_MOD_ASSIGN:
2101                 case EXPR_BINARY_ADD_ASSIGN:
2102                 case EXPR_BINARY_SUB_ASSIGN:
2103                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:
2104                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:
2105                 case EXPR_BINARY_BITWISE_AND_ASSIGN:
2106                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:
2107                 case EXPR_BINARY_BITWISE_OR_ASSIGN: {
2108                         if (lhs_ent == ENT_ANY)
2109                                 lhs_ent = NULL;
2110                         lhs_ent = determine_lhs_ent(expr->binary.left, lhs_ent);
2111                         mark_vars_read(expr->binary.right, lhs_ent);
2112                         return;
2113                 }
2114
2115                 case EXPR_VA_START:
2116                         determine_lhs_ent(expr->va_starte.ap, lhs_ent);
2117                         return;
2118
2119                 case EXPR_UNKNOWN:
2120                 case EXPR_INVALID:
2121                 case EXPR_CONST:
2122                 case EXPR_CHARACTER_CONSTANT:
2123                 case EXPR_WIDE_CHARACTER_CONSTANT:
2124                 case EXPR_STRING_LITERAL:
2125                 case EXPR_WIDE_STRING_LITERAL:
2126                 case EXPR_COMPOUND_LITERAL: // TODO init?
2127                 case EXPR_SIZEOF:
2128                 case EXPR_CLASSIFY_TYPE:
2129                 case EXPR_ALIGNOF:
2130                 case EXPR_FUNCNAME:
2131                 case EXPR_BUILTIN_CONSTANT_P:
2132                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
2133                 case EXPR_OFFSETOF:
2134                 case EXPR_STATEMENT: // TODO
2135                 case EXPR_LABEL_ADDRESS:
2136                 case EXPR_REFERENCE_ENUM_VALUE:
2137                         return;
2138         }
2139
2140         panic("unhandled expression");
2141 }
2142
2143 static designator_t *parse_designation(void)
2144 {
2145         designator_t *result = NULL;
2146         designator_t *last   = NULL;
2147
2148         while (true) {
2149                 designator_t *designator;
2150                 switch (token.type) {
2151                 case '[':
2152                         designator = allocate_ast_zero(sizeof(designator[0]));
2153                         designator->source_position = token.source_position;
2154                         next_token();
2155                         add_anchor_token(']');
2156                         designator->array_index = parse_constant_expression();
2157                         rem_anchor_token(']');
2158                         expect(']', end_error);
2159                         break;
2160                 case '.':
2161                         designator = allocate_ast_zero(sizeof(designator[0]));
2162                         designator->source_position = token.source_position;
2163                         next_token();
2164                         if (token.type != T_IDENTIFIER) {
2165                                 parse_error_expected("while parsing designator",
2166                                                      T_IDENTIFIER, NULL);
2167                                 return NULL;
2168                         }
2169                         designator->symbol = token.v.symbol;
2170                         next_token();
2171                         break;
2172                 default:
2173                         expect('=', end_error);
2174                         return result;
2175                 }
2176
2177                 assert(designator != NULL);
2178                 if (last != NULL) {
2179                         last->next = designator;
2180                 } else {
2181                         result = designator;
2182                 }
2183                 last = designator;
2184         }
2185 end_error:
2186         return NULL;
2187 }
2188
2189 static initializer_t *initializer_from_string(array_type_t *type,
2190                                               const string_t *const string)
2191 {
2192         /* TODO: check len vs. size of array type */
2193         (void) type;
2194
2195         initializer_t *initializer = allocate_initializer_zero(INITIALIZER_STRING);
2196         initializer->string.string = *string;
2197
2198         return initializer;
2199 }
2200
2201 static initializer_t *initializer_from_wide_string(array_type_t *const type,
2202                                                    wide_string_t *const string)
2203 {
2204         /* TODO: check len vs. size of array type */
2205         (void) type;
2206
2207         initializer_t *const initializer =
2208                 allocate_initializer_zero(INITIALIZER_WIDE_STRING);
2209         initializer->wide_string.string = *string;
2210
2211         return initializer;
2212 }
2213
2214 /**
2215  * Build an initializer from a given expression.
2216  */
2217 static initializer_t *initializer_from_expression(type_t *orig_type,
2218                                                   expression_t *expression)
2219 {
2220         /* TODO check that expression is a constant expression */
2221
2222         /* §6.7.8.14/15 char array may be initialized by string literals */
2223         type_t *type           = skip_typeref(orig_type);
2224         type_t *expr_type_orig = expression->base.type;
2225         type_t *expr_type      = skip_typeref(expr_type_orig);
2226         if (is_type_array(type) && expr_type->kind == TYPE_POINTER) {
2227                 array_type_t *const array_type   = &type->array;
2228                 type_t       *const element_type = skip_typeref(array_type->element_type);
2229
2230                 if (element_type->kind == TYPE_ATOMIC) {
2231                         atomic_type_kind_t akind = element_type->atomic.akind;
2232                         switch (expression->kind) {
2233                                 case EXPR_STRING_LITERAL:
2234                                         if (akind == ATOMIC_TYPE_CHAR
2235                                                         || akind == ATOMIC_TYPE_SCHAR
2236                                                         || akind == ATOMIC_TYPE_UCHAR) {
2237                                                 return initializer_from_string(array_type,
2238                                                         &expression->string.value);
2239                                         }
2240                                         break;
2241
2242                                 case EXPR_WIDE_STRING_LITERAL: {
2243                                         type_t *bare_wchar_type = skip_typeref(type_wchar_t);
2244                                         if (get_unqualified_type(element_type) == bare_wchar_type) {
2245                                                 return initializer_from_wide_string(array_type,
2246                                                         &expression->wide_string.value);
2247                                         }
2248                                         break;
2249                                 }
2250
2251                                 default:
2252                                         break;
2253                         }
2254                 }
2255         }
2256
2257         assign_error_t error = semantic_assign(type, expression);
2258         if (error == ASSIGN_ERROR_INCOMPATIBLE)
2259                 return NULL;
2260         report_assign_error(error, type, expression, "initializer",
2261                             &expression->base.source_position);
2262
2263         initializer_t *const result = allocate_initializer_zero(INITIALIZER_VALUE);
2264 #if 0
2265         if (type->kind == TYPE_BITFIELD) {
2266                 type = type->bitfield.base_type;
2267         }
2268 #endif
2269         result->value.value = create_implicit_cast(expression, type);
2270
2271         return result;
2272 }
2273
2274 /**
2275  * Checks if a given expression can be used as an constant initializer.
2276  */
2277 static bool is_initializer_constant(const expression_t *expression)
2278 {
2279         return is_constant_expression(expression)
2280                 || is_address_constant(expression);
2281 }
2282
2283 /**
2284  * Parses an scalar initializer.
2285  *
2286  * §6.7.8.11; eat {} without warning
2287  */
2288 static initializer_t *parse_scalar_initializer(type_t *type,
2289                                                bool must_be_constant)
2290 {
2291         /* there might be extra {} hierarchies */
2292         int braces = 0;
2293         if (token.type == '{') {
2294                 if (warning.other)
2295                         warningf(HERE, "extra curly braces around scalar initializer");
2296                 do {
2297                         ++braces;
2298                         next_token();
2299                 } while (token.type == '{');
2300         }
2301
2302         expression_t *expression = parse_assignment_expression();
2303         mark_vars_read(expression, NULL);
2304         if (must_be_constant && !is_initializer_constant(expression)) {
2305                 errorf(&expression->base.source_position,
2306                        "Initialisation expression '%E' is not constant",
2307                        expression);
2308         }
2309
2310         initializer_t *initializer = initializer_from_expression(type, expression);
2311
2312         if (initializer == NULL) {
2313                 errorf(&expression->base.source_position,
2314                        "expression '%E' (type '%T') doesn't match expected type '%T'",
2315                        expression, expression->base.type, type);
2316                 /* TODO */
2317                 return NULL;
2318         }
2319
2320         bool additional_warning_displayed = false;
2321         while (braces > 0) {
2322                 if (token.type == ',') {
2323                         next_token();
2324                 }
2325                 if (token.type != '}') {
2326                         if (!additional_warning_displayed && warning.other) {
2327                                 warningf(HERE, "additional elements in scalar initializer");
2328                                 additional_warning_displayed = true;
2329                         }
2330                 }
2331                 eat_block();
2332                 braces--;
2333         }
2334
2335         return initializer;
2336 }
2337
2338 /**
2339  * An entry in the type path.
2340  */
2341 typedef struct type_path_entry_t type_path_entry_t;
2342 struct type_path_entry_t {
2343         type_t *type;       /**< the upper top type. restored to path->top_tye if this entry is popped. */
2344         union {
2345                 size_t         index;          /**< For array types: the current index. */
2346                 declaration_t *compound_entry; /**< For compound types: the current declaration. */
2347         } v;
2348 };
2349
2350 /**
2351  * A type path expression a position inside compound or array types.
2352  */
2353 typedef struct type_path_t type_path_t;
2354 struct type_path_t {
2355         type_path_entry_t *path;         /**< An flexible array containing the current path. */
2356         type_t            *top_type;     /**< type of the element the path points */
2357         size_t             max_index;    /**< largest index in outermost array */
2358 };
2359
2360 /**
2361  * Prints a type path for debugging.
2362  */
2363 static __attribute__((unused)) void debug_print_type_path(
2364                 const type_path_t *path)
2365 {
2366         size_t len = ARR_LEN(path->path);
2367
2368         for (size_t i = 0; i < len; ++i) {
2369                 const type_path_entry_t *entry = & path->path[i];
2370
2371                 type_t *type = skip_typeref(entry->type);
2372                 if (is_type_compound(type)) {
2373                         /* in gcc mode structs can have no members */
2374                         if (entry->v.compound_entry == NULL) {
2375                                 assert(i == len-1);
2376                                 continue;
2377                         }
2378                         fprintf(stderr, ".%s",
2379                                 entry->v.compound_entry->base.symbol->string);
2380                 } else if (is_type_array(type)) {
2381                         fprintf(stderr, "[%u]", (unsigned) entry->v.index);
2382                 } else {
2383                         fprintf(stderr, "-INVALID-");
2384                 }
2385         }
2386         if (path->top_type != NULL) {
2387                 fprintf(stderr, "  (");
2388                 print_type(path->top_type);
2389                 fprintf(stderr, ")");
2390         }
2391 }
2392
2393 /**
2394  * Return the top type path entry, ie. in a path
2395  * (type).a.b returns the b.
2396  */
2397 static type_path_entry_t *get_type_path_top(const type_path_t *path)
2398 {
2399         size_t len = ARR_LEN(path->path);
2400         assert(len > 0);
2401         return &path->path[len-1];
2402 }
2403
2404 /**
2405  * Enlarge the type path by an (empty) element.
2406  */
2407 static type_path_entry_t *append_to_type_path(type_path_t *path)
2408 {
2409         size_t len = ARR_LEN(path->path);
2410         ARR_RESIZE(type_path_entry_t, path->path, len+1);
2411
2412         type_path_entry_t *result = & path->path[len];
2413         memset(result, 0, sizeof(result[0]));
2414         return result;
2415 }
2416
2417 /**
2418  * Descending into a sub-type. Enter the scope of the current top_type.
2419  */
2420 static void descend_into_subtype(type_path_t *path)
2421 {
2422         type_t *orig_top_type = path->top_type;
2423         type_t *top_type      = skip_typeref(orig_top_type);
2424
2425         type_path_entry_t *top = append_to_type_path(path);
2426         top->type              = top_type;
2427
2428         if (is_type_compound(top_type)) {
2429                 compound_t *compound  = top_type->compound.compound;
2430                 entity_t   *entry     = compound->members.entities;
2431
2432                 if (entry != NULL) {
2433                         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
2434                         top->v.compound_entry = &entry->declaration;
2435                         path->top_type = entry->declaration.type;
2436                 } else {
2437                         path->top_type = NULL;
2438                 }
2439         } else if (is_type_array(top_type)) {
2440                 top->v.index   = 0;
2441                 path->top_type = top_type->array.element_type;
2442         } else {
2443                 assert(!is_type_valid(top_type));
2444         }
2445 }
2446
2447 /**
2448  * Pop an entry from the given type path, ie. returning from
2449  * (type).a.b to (type).a
2450  */
2451 static void ascend_from_subtype(type_path_t *path)
2452 {
2453         type_path_entry_t *top = get_type_path_top(path);
2454
2455         path->top_type = top->type;
2456
2457         size_t len = ARR_LEN(path->path);
2458         ARR_RESIZE(type_path_entry_t, path->path, len-1);
2459 }
2460
2461 /**
2462  * Pop entries from the given type path until the given
2463  * path level is reached.
2464  */
2465 static void ascend_to(type_path_t *path, size_t top_path_level)
2466 {
2467         size_t len = ARR_LEN(path->path);
2468
2469         while (len > top_path_level) {
2470                 ascend_from_subtype(path);
2471                 len = ARR_LEN(path->path);
2472         }
2473 }
2474
2475 static bool walk_designator(type_path_t *path, const designator_t *designator,
2476                             bool used_in_offsetof)
2477 {
2478         for (; designator != NULL; designator = designator->next) {
2479                 type_path_entry_t *top       = get_type_path_top(path);
2480                 type_t            *orig_type = top->type;
2481
2482                 type_t *type = skip_typeref(orig_type);
2483
2484                 if (designator->symbol != NULL) {
2485                         symbol_t *symbol = designator->symbol;
2486                         if (!is_type_compound(type)) {
2487                                 if (is_type_valid(type)) {
2488                                         errorf(&designator->source_position,
2489                                                "'.%Y' designator used for non-compound type '%T'",
2490                                                symbol, orig_type);
2491                                 }
2492
2493                                 top->type             = type_error_type;
2494                                 top->v.compound_entry = NULL;
2495                                 orig_type             = type_error_type;
2496                         } else {
2497                                 compound_t *compound = type->compound.compound;
2498                                 entity_t   *iter     = compound->members.entities;
2499                                 for (; iter != NULL; iter = iter->base.next) {
2500                                         if (iter->base.symbol == symbol) {
2501                                                 break;
2502                                         }
2503                                 }
2504                                 if (iter == NULL) {
2505                                         errorf(&designator->source_position,
2506                                                "'%T' has no member named '%Y'", orig_type, symbol);
2507                                         goto failed;
2508                                 }
2509                                 assert(iter->kind == ENTITY_COMPOUND_MEMBER);
2510                                 if (used_in_offsetof) {
2511                                         type_t *real_type = skip_typeref(iter->declaration.type);
2512                                         if (real_type->kind == TYPE_BITFIELD) {
2513                                                 errorf(&designator->source_position,
2514                                                        "offsetof designator '%Y' may not specify bitfield",
2515                                                        symbol);
2516                                                 goto failed;
2517                                         }
2518                                 }
2519
2520                                 top->type             = orig_type;
2521                                 top->v.compound_entry = &iter->declaration;
2522                                 orig_type             = iter->declaration.type;
2523                         }
2524                 } else {
2525                         expression_t *array_index = designator->array_index;
2526                         assert(designator->array_index != NULL);
2527
2528                         if (!is_type_array(type)) {
2529                                 if (is_type_valid(type)) {
2530                                         errorf(&designator->source_position,
2531                                                "[%E] designator used for non-array type '%T'",
2532                                                array_index, orig_type);
2533                                 }
2534                                 goto failed;
2535                         }
2536
2537                         long index = fold_constant(array_index);
2538                         if (!used_in_offsetof) {
2539                                 if (index < 0) {
2540                                         errorf(&designator->source_position,
2541                                                "array index [%E] must be positive", array_index);
2542                                 } else if (type->array.size_constant) {
2543                                         long array_size = type->array.size;
2544                                         if (index >= array_size) {
2545                                                 errorf(&designator->source_position,
2546                                                        "designator [%E] (%d) exceeds array size %d",
2547                                                        array_index, index, array_size);
2548                                         }
2549                                 }
2550                         }
2551
2552                         top->type    = orig_type;
2553                         top->v.index = (size_t) index;
2554                         orig_type    = type->array.element_type;
2555                 }
2556                 path->top_type = orig_type;
2557
2558                 if (designator->next != NULL) {
2559                         descend_into_subtype(path);
2560                 }
2561         }
2562         return true;
2563
2564 failed:
2565         return false;
2566 }
2567
2568 static void advance_current_object(type_path_t *path, size_t top_path_level)
2569 {
2570         type_path_entry_t *top = get_type_path_top(path);
2571
2572         type_t *type = skip_typeref(top->type);
2573         if (is_type_union(type)) {
2574                 /* in unions only the first element is initialized */
2575                 top->v.compound_entry = NULL;
2576         } else if (is_type_struct(type)) {
2577                 declaration_t *entry = top->v.compound_entry;
2578
2579                 entity_t *next_entity = entry->base.next;
2580                 if (next_entity != NULL) {
2581                         assert(is_declaration(next_entity));
2582                         entry = &next_entity->declaration;
2583                 } else {
2584                         entry = NULL;
2585                 }
2586
2587                 top->v.compound_entry = entry;
2588                 if (entry != NULL) {
2589                         path->top_type = entry->type;
2590                         return;
2591                 }
2592         } else if (is_type_array(type)) {
2593                 assert(is_type_array(type));
2594
2595                 top->v.index++;
2596
2597                 if (!type->array.size_constant || top->v.index < type->array.size) {
2598                         return;
2599                 }
2600         } else {
2601                 assert(!is_type_valid(type));
2602                 return;
2603         }
2604
2605         /* we're past the last member of the current sub-aggregate, try if we
2606          * can ascend in the type hierarchy and continue with another subobject */
2607         size_t len = ARR_LEN(path->path);
2608
2609         if (len > top_path_level) {
2610                 ascend_from_subtype(path);
2611                 advance_current_object(path, top_path_level);
2612         } else {
2613                 path->top_type = NULL;
2614         }
2615 }
2616
2617 /**
2618  * skip until token is found.
2619  */
2620 static void skip_until(int type)
2621 {
2622         while (token.type != type) {
2623                 if (token.type == T_EOF)
2624                         return;
2625                 next_token();
2626         }
2627 }
2628
2629 /**
2630  * skip any {...} blocks until a closing bracket is reached.
2631  */
2632 static void skip_initializers(void)
2633 {
2634         if (token.type == '{')
2635                 next_token();
2636
2637         while (token.type != '}') {
2638                 if (token.type == T_EOF)
2639                         return;
2640                 if (token.type == '{') {
2641                         eat_block();
2642                         continue;
2643                 }
2644                 next_token();
2645         }
2646 }
2647
2648 static initializer_t *create_empty_initializer(void)
2649 {
2650         static initializer_t empty_initializer
2651                 = { .list = { { INITIALIZER_LIST }, 0 } };
2652         return &empty_initializer;
2653 }
2654
2655 /**
2656  * Parse a part of an initialiser for a struct or union,
2657  */
2658 static initializer_t *parse_sub_initializer(type_path_t *path,
2659                 type_t *outer_type, size_t top_path_level,
2660                 parse_initializer_env_t *env)
2661 {
2662         if (token.type == '}') {
2663                 /* empty initializer */
2664                 return create_empty_initializer();
2665         }
2666
2667         type_t *orig_type = path->top_type;
2668         type_t *type      = NULL;
2669
2670         if (orig_type == NULL) {
2671                 /* We are initializing an empty compound. */
2672         } else {
2673                 type = skip_typeref(orig_type);
2674         }
2675
2676         initializer_t **initializers = NEW_ARR_F(initializer_t*, 0);
2677
2678         while (true) {
2679                 designator_t *designator = NULL;
2680                 if (token.type == '.' || token.type == '[') {
2681                         designator = parse_designation();
2682                         goto finish_designator;
2683                 } else if (token.type == T_IDENTIFIER && look_ahead(1)->type == ':') {
2684                         /* GNU-style designator ("identifier: value") */
2685                         designator = allocate_ast_zero(sizeof(designator[0]));
2686                         designator->source_position = token.source_position;
2687                         designator->symbol          = token.v.symbol;
2688                         eat(T_IDENTIFIER);
2689                         eat(':');
2690
2691 finish_designator:
2692                         /* reset path to toplevel, evaluate designator from there */
2693                         ascend_to(path, top_path_level);
2694                         if (!walk_designator(path, designator, false)) {
2695                                 /* can't continue after designation error */
2696                                 goto end_error;
2697                         }
2698
2699                         initializer_t *designator_initializer
2700                                 = allocate_initializer_zero(INITIALIZER_DESIGNATOR);
2701                         designator_initializer->designator.designator = designator;
2702                         ARR_APP1(initializer_t*, initializers, designator_initializer);
2703
2704                         orig_type = path->top_type;
2705                         type      = orig_type != NULL ? skip_typeref(orig_type) : NULL;
2706                 }
2707
2708                 initializer_t *sub;
2709
2710                 if (token.type == '{') {
2711                         if (type != NULL && is_type_scalar(type)) {
2712                                 sub = parse_scalar_initializer(type, env->must_be_constant);
2713                         } else {
2714                                 eat('{');
2715                                 if (type == NULL) {
2716                                         if (env->entity != NULL) {
2717                                                 errorf(HERE,
2718                                                      "extra brace group at end of initializer for '%Y'",
2719                                                      env->entity->base.symbol);
2720                                         } else {
2721                                                 errorf(HERE, "extra brace group at end of initializer");
2722                                         }
2723                                 } else
2724                                         descend_into_subtype(path);
2725
2726                                 add_anchor_token('}');
2727                                 sub = parse_sub_initializer(path, orig_type, top_path_level+1,
2728                                                             env);
2729                                 rem_anchor_token('}');
2730
2731                                 if (type != NULL) {
2732                                         ascend_from_subtype(path);
2733                                         expect('}', end_error);
2734                                 } else {
2735                                         expect('}', end_error);
2736                                         goto error_parse_next;
2737                                 }
2738                         }
2739                 } else {
2740                         /* must be an expression */
2741                         expression_t *expression = parse_assignment_expression();
2742                         mark_vars_read(expression, NULL);
2743
2744                         if (env->must_be_constant && !is_initializer_constant(expression)) {
2745                                 errorf(&expression->base.source_position,
2746                                        "Initialisation expression '%E' is not constant",
2747                                        expression);
2748                         }
2749
2750                         if (type == NULL) {
2751                                 /* we are already outside, ... */
2752                                 type_t *const outer_type_skip = skip_typeref(outer_type);
2753                                 if (is_type_compound(outer_type_skip) &&
2754                                     !outer_type_skip->compound.compound->complete) {
2755                                         goto error_parse_next;
2756                                 }
2757                                 goto error_excess;
2758                         }
2759
2760                         /* handle { "string" } special case */
2761                         if ((expression->kind == EXPR_STRING_LITERAL
2762                                         || expression->kind == EXPR_WIDE_STRING_LITERAL)
2763                                         && outer_type != NULL) {
2764                                 sub = initializer_from_expression(outer_type, expression);
2765                                 if (sub != NULL) {
2766                                         if (token.type == ',') {
2767                                                 next_token();
2768                                         }
2769                                         if (token.type != '}' && warning.other) {
2770                                                 warningf(HERE, "excessive elements in initializer for type '%T'",
2771                                                                  orig_type);
2772                                         }
2773                                         /* TODO: eat , ... */
2774                                         return sub;
2775                                 }
2776                         }
2777
2778                         /* descend into subtypes until expression matches type */
2779                         while (true) {
2780                                 orig_type = path->top_type;
2781                                 type      = skip_typeref(orig_type);
2782
2783                                 sub = initializer_from_expression(orig_type, expression);
2784                                 if (sub != NULL) {
2785                                         break;
2786                                 }
2787                                 if (!is_type_valid(type)) {
2788                                         goto end_error;
2789                                 }
2790                                 if (is_type_scalar(type)) {
2791                                         errorf(&expression->base.source_position,
2792                                                         "expression '%E' doesn't match expected type '%T'",
2793                                                         expression, orig_type);
2794                                         goto end_error;
2795                                 }
2796
2797                                 descend_into_subtype(path);
2798                         }
2799                 }
2800
2801                 /* update largest index of top array */
2802                 const type_path_entry_t *first      = &path->path[0];
2803                 type_t                  *first_type = first->type;
2804                 first_type                          = skip_typeref(first_type);
2805                 if (is_type_array(first_type)) {
2806                         size_t index = first->v.index;
2807                         if (index > path->max_index)
2808                                 path->max_index = index;
2809                 }
2810
2811                 if (type != NULL) {
2812                         /* append to initializers list */
2813                         ARR_APP1(initializer_t*, initializers, sub);
2814                 } else {
2815 error_excess:
2816                         if (warning.other) {
2817                                 if (env->entity != NULL) {
2818                                         warningf(HERE, "excess elements in struct initializer for '%Y'",
2819                                            env->entity->base.symbol);
2820                                 } else {
2821                                         warningf(HERE, "excess elements in struct initializer");
2822                                 }
2823                         }
2824                 }
2825
2826 error_parse_next:
2827                 if (token.type == '}') {
2828                         break;
2829                 }
2830                 expect(',', end_error);
2831                 if (token.type == '}') {
2832                         break;
2833                 }
2834
2835                 if (type != NULL) {
2836                         /* advance to the next declaration if we are not at the end */
2837                         advance_current_object(path, top_path_level);
2838                         orig_type = path->top_type;
2839                         if (orig_type != NULL)
2840                                 type = skip_typeref(orig_type);
2841                         else
2842                                 type = NULL;
2843                 }
2844         }
2845
2846         size_t len  = ARR_LEN(initializers);
2847         size_t size = sizeof(initializer_list_t) + len * sizeof(initializers[0]);
2848         initializer_t *result = allocate_ast_zero(size);
2849         result->kind          = INITIALIZER_LIST;
2850         result->list.len      = len;
2851         memcpy(&result->list.initializers, initializers,
2852                len * sizeof(initializers[0]));
2853
2854         DEL_ARR_F(initializers);
2855         ascend_to(path, top_path_level+1);
2856
2857         return result;
2858
2859 end_error:
2860         skip_initializers();
2861         DEL_ARR_F(initializers);
2862         ascend_to(path, top_path_level+1);
2863         return NULL;
2864 }
2865
2866 /**
2867  * Parses an initializer. Parsers either a compound literal
2868  * (env->declaration == NULL) or an initializer of a declaration.
2869  */
2870 static initializer_t *parse_initializer(parse_initializer_env_t *env)
2871 {
2872         type_t        *type      = skip_typeref(env->type);
2873         size_t         max_index = 0xdeadbeaf;   // TODO: Resolve this uninitialized variable problem
2874         initializer_t *result;
2875
2876         if (is_type_scalar(type)) {
2877                 result = parse_scalar_initializer(type, env->must_be_constant);
2878         } else if (token.type == '{') {
2879                 eat('{');
2880
2881                 type_path_t path;
2882                 memset(&path, 0, sizeof(path));
2883                 path.top_type = env->type;
2884                 path.path     = NEW_ARR_F(type_path_entry_t, 0);
2885
2886                 descend_into_subtype(&path);
2887
2888                 add_anchor_token('}');
2889                 result = parse_sub_initializer(&path, env->type, 1, env);
2890                 rem_anchor_token('}');
2891
2892                 max_index = path.max_index;
2893                 DEL_ARR_F(path.path);
2894
2895                 expect('}', end_error);
2896         } else {
2897                 /* parse_scalar_initializer() also works in this case: we simply
2898                  * have an expression without {} around it */
2899                 result = parse_scalar_initializer(type, env->must_be_constant);
2900         }
2901
2902         /* §6.7.8:22 array initializers for arrays with unknown size determine
2903          * the array type size */
2904         if (is_type_array(type) && type->array.size_expression == NULL
2905                         && result != NULL) {
2906                 size_t size;
2907                 switch (result->kind) {
2908                 case INITIALIZER_LIST:
2909                         assert(max_index != 0xdeadbeaf);
2910                         size = max_index + 1;
2911                         break;
2912
2913                 case INITIALIZER_STRING:
2914                         size = result->string.string.size;
2915                         break;
2916
2917                 case INITIALIZER_WIDE_STRING:
2918                         size = result->wide_string.string.size;
2919                         break;
2920
2921                 case INITIALIZER_DESIGNATOR:
2922                 case INITIALIZER_VALUE:
2923                         /* can happen for parse errors */
2924                         size = 0;
2925                         break;
2926
2927                 default:
2928                         internal_errorf(HERE, "invalid initializer type");
2929                 }
2930
2931                 expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
2932                 cnst->base.type          = type_size_t;
2933                 cnst->conste.v.int_value = size;
2934
2935                 type_t *new_type = duplicate_type(type);
2936
2937                 new_type->array.size_expression   = cnst;
2938                 new_type->array.size_constant     = true;
2939                 new_type->array.has_implicit_size = true;
2940                 new_type->array.size              = size;
2941                 env->type = new_type;
2942         }
2943
2944         return result;
2945 end_error:
2946         return NULL;
2947 }
2948
2949 static void append_entity(scope_t *scope, entity_t *entity)
2950 {
2951         if (scope->last_entity != NULL) {
2952                 scope->last_entity->base.next = entity;
2953         } else {
2954                 scope->entities = entity;
2955         }
2956         scope->last_entity = entity;
2957 }
2958
2959
2960 static compound_t *parse_compound_type_specifier(bool is_struct)
2961 {
2962         gnu_attribute_t  *attributes = NULL;
2963         decl_modifiers_t  modifiers  = 0;
2964         if (is_struct) {
2965                 eat(T_struct);
2966         } else {
2967                 eat(T_union);
2968         }
2969
2970         symbol_t   *symbol   = NULL;
2971         compound_t *compound = NULL;
2972
2973         if (token.type == T___attribute__) {
2974                 modifiers |= parse_attributes(&attributes);
2975         }
2976
2977         if (token.type == T_IDENTIFIER) {
2978                 symbol = token.v.symbol;
2979                 next_token();
2980
2981                 namespace_tag_t const namespc =
2982                         is_struct ? NAMESPACE_STRUCT : NAMESPACE_UNION;
2983                 entity_t *entity = get_entity(symbol, namespc);
2984                 if (entity != NULL) {
2985                         assert(entity->kind == (is_struct ? ENTITY_STRUCT : ENTITY_UNION));
2986                         compound = &entity->compound;
2987                         if (compound->base.parent_scope != current_scope &&
2988                             (token.type == '{' || token.type == ';')) {
2989                                 /* we're in an inner scope and have a definition. Shadow
2990                                  * existing definition in outer scope */
2991                                 compound = NULL;
2992                         } else if (compound->complete && token.type == '{') {
2993                                 assert(symbol != NULL);
2994                                 errorf(HERE, "multiple definitions of '%s %Y' (previous definition %P)",
2995                                        is_struct ? "struct" : "union", symbol,
2996                                        &compound->base.source_position);
2997                                 /* clear members in the hope to avoid further errors */
2998                                 compound->members.entities = NULL;
2999                         }
3000                 }
3001         } else if (token.type != '{') {
3002                 if (is_struct) {
3003                         parse_error_expected("while parsing struct type specifier",
3004                                              T_IDENTIFIER, '{', NULL);
3005                 } else {
3006                         parse_error_expected("while parsing union type specifier",
3007                                              T_IDENTIFIER, '{', NULL);
3008                 }
3009
3010                 return NULL;
3011         }
3012
3013         if (compound == NULL) {
3014                 entity_kind_t  kind   = is_struct ? ENTITY_STRUCT : ENTITY_UNION;
3015                 entity_t      *entity = allocate_entity_zero(kind);
3016                 compound              = &entity->compound;
3017
3018                 compound->base.namespc =
3019                         (is_struct ? NAMESPACE_STRUCT : NAMESPACE_UNION);
3020                 compound->base.source_position = token.source_position;
3021                 compound->base.symbol          = symbol;
3022                 compound->base.parent_scope    = current_scope;
3023                 if (symbol != NULL) {
3024                         environment_push(entity);
3025                 }
3026                 append_entity(current_scope, entity);
3027         }
3028
3029         if (token.type == '{') {
3030                 parse_compound_type_entries(compound);
3031                 modifiers |= parse_attributes(&attributes);
3032
3033                 if (symbol == NULL) {
3034                         assert(anonymous_entity == NULL);
3035                         anonymous_entity = (entity_t*)compound;
3036                 }
3037         }
3038
3039         compound->modifiers |= modifiers;
3040         return compound;
3041 }
3042
3043 static void parse_enum_entries(type_t *const enum_type)
3044 {
3045         eat('{');
3046
3047         if (token.type == '}') {
3048                 errorf(HERE, "empty enum not allowed");
3049                 next_token();
3050                 return;
3051         }
3052
3053         add_anchor_token('}');
3054         do {
3055                 if (token.type != T_IDENTIFIER) {
3056                         parse_error_expected("while parsing enum entry", T_IDENTIFIER, NULL);
3057                         eat_block();
3058                         rem_anchor_token('}');
3059                         return;
3060                 }
3061
3062                 entity_t *entity             = allocate_entity_zero(ENTITY_ENUM_VALUE);
3063                 entity->enum_value.enum_type = enum_type;
3064                 entity->base.symbol          = token.v.symbol;
3065                 entity->base.source_position = token.source_position;
3066                 next_token();
3067
3068                 if (token.type == '=') {
3069                         next_token();
3070                         expression_t *value = parse_constant_expression();
3071
3072                         value = create_implicit_cast(value, enum_type);
3073                         entity->enum_value.value = value;
3074
3075                         /* TODO semantic */
3076                 }
3077
3078                 record_entity(entity, false);
3079
3080                 if (token.type != ',')
3081                         break;
3082                 next_token();
3083         } while (token.type != '}');
3084         rem_anchor_token('}');
3085
3086         expect('}', end_error);
3087
3088 end_error:
3089         ;
3090 }
3091
3092 static type_t *parse_enum_specifier(void)
3093 {
3094         gnu_attribute_t *attributes = NULL;
3095         entity_t        *entity;
3096         symbol_t        *symbol;
3097
3098         eat(T_enum);
3099         if (token.type == T_IDENTIFIER) {
3100                 symbol = token.v.symbol;
3101                 next_token();
3102
3103                 entity = get_entity(symbol, NAMESPACE_ENUM);
3104                 if (entity != NULL) {
3105                         assert(entity->kind == ENTITY_ENUM);
3106                         if (entity->base.parent_scope != current_scope &&
3107                                         (token.type == '{' || token.type == ';')) {
3108                                 /* we're in an inner scope and have a definition. Shadow
3109                                  * existing definition in outer scope */
3110                                 entity = NULL;
3111                         } else if (entity->enume.complete && token.type == '{') {
3112                                 errorf(HERE, "multiple definitions of 'enum %Y' (previous definition %P)",
3113                                                 symbol, &entity->base.source_position);
3114                         }
3115                 }
3116         } else if (token.type != '{') {
3117                 parse_error_expected("while parsing enum type specifier",
3118                                      T_IDENTIFIER, '{', NULL);
3119                 return NULL;
3120         } else {
3121                 entity  = NULL;
3122                 symbol  = NULL;
3123         }
3124
3125         if (entity == NULL) {
3126                 entity                       = allocate_entity_zero(ENTITY_ENUM);
3127                 entity->base.namespc         = NAMESPACE_ENUM;
3128                 entity->base.source_position = token.source_position;
3129                 entity->base.symbol          = symbol;
3130                 entity->base.parent_scope    = current_scope;
3131         }
3132
3133         type_t *const type = allocate_type_zero(TYPE_ENUM);
3134         type->enumt.enume  = &entity->enume;
3135         type->enumt.akind  = ATOMIC_TYPE_INT;
3136
3137         if (token.type == '{') {
3138                 if (symbol != NULL) {
3139                         environment_push(entity);
3140                 }
3141                 append_entity(current_scope, entity);
3142                 entity->enume.complete = true;
3143
3144                 parse_enum_entries(type);
3145                 parse_attributes(&attributes);
3146
3147                 if (symbol == NULL) {
3148                         assert(anonymous_entity == NULL);
3149                         anonymous_entity = entity;
3150                 }
3151         } else if (!entity->enume.complete && !(c_mode & _GNUC)) {
3152                 errorf(HERE, "'enum %Y' used before definition (incomplete enums are a GNU extension)",
3153                        symbol);
3154         }
3155
3156         return type;
3157 }
3158
3159 /**
3160  * if a symbol is a typedef to another type, return true
3161  */
3162 static bool is_typedef_symbol(symbol_t *symbol)
3163 {
3164         const entity_t *const entity = get_entity(symbol, NAMESPACE_NORMAL);
3165         return entity != NULL && entity->kind == ENTITY_TYPEDEF;
3166 }
3167
3168 static type_t *parse_typeof(void)
3169 {
3170         eat(T___typeof__);
3171
3172         type_t *type;
3173
3174         expect('(', end_error);
3175         add_anchor_token(')');
3176
3177         expression_t *expression  = NULL;
3178
3179         bool old_type_prop     = in_type_prop;
3180         bool old_gcc_extension = in_gcc_extension;
3181         in_type_prop           = true;
3182
3183         while (token.type == T___extension__) {
3184                 /* This can be a prefix to a typename or an expression. */
3185                 next_token();
3186                 in_gcc_extension = true;
3187         }
3188         switch (token.type) {
3189         case T_IDENTIFIER:
3190                 if (is_typedef_symbol(token.v.symbol)) {
3191                         type = parse_typename();
3192                 } else {
3193                         expression = parse_expression();
3194                         type       = revert_automatic_type_conversion(expression);
3195                 }
3196                 break;
3197
3198         TYPENAME_START
3199                 type = parse_typename();
3200                 break;
3201
3202         default:
3203                 expression = parse_expression();
3204                 type       = expression->base.type;
3205                 break;
3206         }
3207         in_type_prop     = old_type_prop;
3208         in_gcc_extension = old_gcc_extension;
3209
3210         rem_anchor_token(')');
3211         expect(')', end_error);
3212
3213         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF);
3214         typeof_type->typeoft.expression  = expression;
3215         typeof_type->typeoft.typeof_type = type;
3216
3217         return typeof_type;
3218 end_error:
3219         return NULL;
3220 }
3221
3222 typedef enum specifiers_t {
3223         SPECIFIER_SIGNED    = 1 << 0,
3224         SPECIFIER_UNSIGNED  = 1 << 1,
3225         SPECIFIER_LONG      = 1 << 2,
3226         SPECIFIER_INT       = 1 << 3,
3227         SPECIFIER_DOUBLE    = 1 << 4,
3228         SPECIFIER_CHAR      = 1 << 5,
3229         SPECIFIER_WCHAR_T   = 1 << 6,
3230         SPECIFIER_SHORT     = 1 << 7,
3231         SPECIFIER_LONG_LONG = 1 << 8,
3232         SPECIFIER_FLOAT     = 1 << 9,
3233         SPECIFIER_BOOL      = 1 << 10,
3234         SPECIFIER_VOID      = 1 << 11,
3235         SPECIFIER_INT8      = 1 << 12,
3236         SPECIFIER_INT16     = 1 << 13,
3237         SPECIFIER_INT32     = 1 << 14,
3238         SPECIFIER_INT64     = 1 << 15,
3239         SPECIFIER_INT128    = 1 << 16,
3240         SPECIFIER_COMPLEX   = 1 << 17,
3241         SPECIFIER_IMAGINARY = 1 << 18,
3242 } specifiers_t;
3243
3244 static type_t *create_builtin_type(symbol_t *const symbol,
3245                                    type_t *const real_type)
3246 {
3247         type_t *type            = allocate_type_zero(TYPE_BUILTIN);
3248         type->builtin.symbol    = symbol;
3249         type->builtin.real_type = real_type;
3250         return identify_new_type(type);
3251 }
3252
3253 static type_t *get_typedef_type(symbol_t *symbol)
3254 {
3255         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
3256         if (entity == NULL || entity->kind != ENTITY_TYPEDEF)
3257                 return NULL;
3258
3259         type_t *type            = allocate_type_zero(TYPE_TYPEDEF);
3260         type->typedeft.typedefe = &entity->typedefe;
3261
3262         return type;
3263 }
3264
3265 /**
3266  * check for the allowed MS alignment values.
3267  */
3268 static bool check_alignment_value(long long intvalue)
3269 {
3270         if (intvalue < 1 || intvalue > 8192) {
3271                 errorf(HERE, "illegal alignment value");
3272                 return false;
3273         }
3274         unsigned v = (unsigned)intvalue;
3275         for (unsigned i = 1; i <= 8192; i += i) {
3276                 if (i == v)
3277                         return true;
3278         }
3279         errorf(HERE, "alignment must be power of two");
3280         return false;
3281 }
3282
3283 #define DET_MOD(name, tag) do { \
3284         if (*modifiers & tag && warning.other) warningf(HERE, #name " used more than once"); \
3285         *modifiers |= tag; \
3286 } while (0)
3287
3288 static void parse_microsoft_extended_decl_modifier(declaration_specifiers_t *specifiers)
3289 {
3290         decl_modifiers_t *modifiers = &specifiers->modifiers;
3291
3292         while (true) {
3293                 if (token.type == T_restrict) {
3294                         next_token();
3295                         DET_MOD(restrict, DM_RESTRICT);
3296                         goto end_loop;
3297                 } else if (token.type != T_IDENTIFIER)
3298                         break;
3299                 symbol_t *symbol = token.v.symbol;
3300                 if (symbol == sym_align) {
3301                         next_token();
3302                         expect('(', end_error);
3303                         if (token.type != T_INTEGER)
3304                                 goto end_error;
3305                         if (check_alignment_value(token.v.intvalue)) {
3306                                 if (specifiers->alignment != 0 && warning.other)
3307                                         warningf(HERE, "align used more than once");
3308                                 specifiers->alignment = (unsigned char)token.v.intvalue;
3309                         }
3310                         next_token();
3311                         expect(')', end_error);
3312                 } else if (symbol == sym_allocate) {
3313                         next_token();
3314                         expect('(', end_error);
3315                         if (token.type != T_IDENTIFIER)
3316                                 goto end_error;
3317                         (void)token.v.symbol;
3318                         expect(')', end_error);
3319                 } else if (symbol == sym_dllimport) {
3320                         next_token();
3321                         DET_MOD(dllimport, DM_DLLIMPORT);
3322                 } else if (symbol == sym_dllexport) {
3323                         next_token();
3324                         DET_MOD(dllexport, DM_DLLEXPORT);
3325                 } else if (symbol == sym_thread) {
3326                         next_token();
3327                         DET_MOD(thread, DM_THREAD);
3328                 } else if (symbol == sym_naked) {
3329                         next_token();
3330                         DET_MOD(naked, DM_NAKED);
3331                 } else if (symbol == sym_noinline) {
3332                         next_token();
3333                         DET_MOD(noinline, DM_NOINLINE);
3334                 } else if (symbol == sym_returns_twice) {
3335                         next_token();
3336                         DET_MOD(returns_twice, DM_RETURNS_TWICE);
3337                 } else if (symbol == sym_noreturn) {
3338                         next_token();
3339                         DET_MOD(noreturn, DM_NORETURN);
3340                 } else if (symbol == sym_nothrow) {
3341                         next_token();
3342                         DET_MOD(nothrow, DM_NOTHROW);
3343                 } else if (symbol == sym_novtable) {
3344                         next_token();
3345                         DET_MOD(novtable, DM_NOVTABLE);
3346                 } else if (symbol == sym_property) {
3347                         next_token();
3348                         expect('(', end_error);
3349                         for (;;) {
3350                                 bool is_get = false;
3351                                 if (token.type != T_IDENTIFIER)
3352                                         goto end_error;
3353                                 if (token.v.symbol == sym_get) {
3354                                         is_get = true;
3355                                 } else if (token.v.symbol == sym_put) {
3356                                 } else {
3357                                         errorf(HERE, "Bad property name '%Y'", token.v.symbol);
3358                                         goto end_error;
3359                                 }
3360                                 next_token();
3361                                 expect('=', end_error);
3362                                 if (token.type != T_IDENTIFIER)
3363                                         goto end_error;
3364                                 if (is_get) {
3365                                         if (specifiers->get_property_sym != NULL) {
3366                                                 errorf(HERE, "get property name already specified");
3367                                         } else {
3368                                                 specifiers->get_property_sym = token.v.symbol;
3369                                         }
3370                                 } else {
3371                                         if (specifiers->put_property_sym != NULL) {
3372                                                 errorf(HERE, "put property name already specified");
3373                                         } else {
3374                                                 specifiers->put_property_sym = token.v.symbol;
3375                                         }
3376                                 }
3377                                 next_token();
3378                                 if (token.type == ',') {
3379                                         next_token();
3380                                         continue;
3381                                 }
3382                                 break;
3383                         }
3384                         expect(')', end_error);
3385                 } else if (symbol == sym_selectany) {
3386                         next_token();
3387                         DET_MOD(selectany, DM_SELECTANY);
3388                 } else if (symbol == sym_uuid) {
3389                         next_token();
3390                         expect('(', end_error);
3391                         if (token.type != T_STRING_LITERAL)
3392                                 goto end_error;
3393                         next_token();
3394                         expect(')', end_error);
3395                 } else if (symbol == sym_deprecated) {
3396                         next_token();
3397                         if (specifiers->deprecated != 0 && warning.other)
3398                                 warningf(HERE, "deprecated used more than once");
3399                         specifiers->deprecated = true;
3400                         if (token.type == '(') {
3401                                 next_token();
3402                                 if (token.type == T_STRING_LITERAL) {
3403                                         specifiers->deprecated_string = token.v.string.begin;
3404                                         next_token();
3405                                 } else {
3406                                         errorf(HERE, "string literal expected");
3407                                 }
3408                                 expect(')', end_error);
3409                         }
3410                 } else if (symbol == sym_noalias) {
3411                         next_token();
3412                         DET_MOD(noalias, DM_NOALIAS);
3413                 } else {
3414                         if (warning.other)
3415                                 warningf(HERE, "Unknown modifier '%Y' ignored", token.v.symbol);
3416                         next_token();
3417                         if (token.type == '(')
3418                                 skip_until(')');
3419                 }
3420 end_loop:
3421                 if (token.type == ',')
3422                         next_token();
3423         }
3424 end_error:
3425         return;
3426 }
3427
3428 static entity_t *create_error_entity(symbol_t *symbol, entity_kind_tag_t kind)
3429 {
3430         entity_t *entity             = allocate_entity_zero(kind);
3431         entity->base.source_position = *HERE;
3432         entity->base.symbol          = symbol;
3433         if (is_declaration(entity)) {
3434                 entity->declaration.type     = type_error_type;
3435                 entity->declaration.implicit = true;
3436         } else if (kind == ENTITY_TYPEDEF) {
3437                 entity->typedefe.type    = type_error_type;
3438                 entity->typedefe.builtin = true;
3439         }
3440         if (kind != ENTITY_COMPOUND_MEMBER)
3441                 record_entity(entity, false);
3442         return entity;
3443 }
3444
3445 static void parse_microsoft_based(based_spec_t *based_spec)
3446 {
3447         if (token.type != T_IDENTIFIER) {
3448                 parse_error_expected("while parsing __based", T_IDENTIFIER, NULL);
3449                 return;
3450         }
3451         symbol_t *symbol = token.v.symbol;
3452         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
3453
3454         if (entity == NULL || entity->base.kind != ENTITY_VARIABLE) {
3455                 errorf(HERE, "'%Y' is not a variable name.", symbol);
3456                 entity = create_error_entity(symbol, ENTITY_VARIABLE);
3457         } else {
3458                 variable_t *variable = &entity->variable;
3459
3460                 if (based_spec->base_variable != NULL) {
3461                         errorf(HERE, "__based type qualifier specified more than once");
3462                 }
3463                 based_spec->source_position = token.source_position;
3464                 based_spec->base_variable   = variable;
3465
3466                 type_t *const type = variable->base.type;
3467
3468                 if (is_type_valid(type)) {
3469                         if (! is_type_pointer(skip_typeref(type))) {
3470                                 errorf(HERE, "variable in __based modifier must have pointer type instead of '%T'", type);
3471                         }
3472                         if (variable->base.base.parent_scope != file_scope) {
3473                                 errorf(HERE, "a nonstatic local variable may not be used in a __based specification");
3474                         }
3475                 }
3476         }
3477         next_token();
3478 }
3479
3480 /**
3481  * Finish the construction of a struct type by calculating
3482  * its size, offsets, alignment.
3483  */
3484 static void finish_struct_type(compound_type_t *type)
3485 {
3486         assert(type->compound != NULL);
3487
3488         compound_t *compound = type->compound;
3489         if (!compound->complete)
3490                 return;
3491
3492         il_size_t      size           = 0;
3493         il_size_t      offset;
3494         il_alignment_t alignment      = 1;
3495         bool           need_pad       = false;
3496
3497         entity_t *entry = compound->members.entities;
3498         for (; entry != NULL; entry = entry->base.next) {
3499                 if (entry->kind != ENTITY_COMPOUND_MEMBER)
3500                         continue;
3501
3502                 type_t *m_type = skip_typeref(entry->declaration.type);
3503                 if (! is_type_valid(m_type)) {
3504                         /* simply ignore errors here */
3505                         continue;
3506                 }
3507                 il_alignment_t m_alignment = m_type->base.alignment;
3508                 if (m_alignment > alignment)
3509                         alignment = m_alignment;
3510
3511                 offset = (size + m_alignment - 1) & -m_alignment;
3512
3513                 if (offset > size)
3514                         need_pad = true;
3515                 entry->compound_member.offset = offset;
3516                 size = offset + m_type->base.size;
3517         }
3518         if (type->base.alignment != 0) {
3519                 alignment = type->base.alignment;
3520         }
3521
3522         offset = (size + alignment - 1) & -alignment;
3523         if (offset > size)
3524                 need_pad = true;
3525
3526         if (need_pad) {
3527                 if (warning.padded) {
3528                         warningf(&compound->base.source_position, "'%T' needs padding", type);
3529                 }
3530         } else {
3531                 if (compound->modifiers & DM_PACKED && warning.packed) {
3532                         warningf(&compound->base.source_position,
3533                                         "superfluous packed attribute on '%T'", type);
3534                 }
3535         }
3536
3537         type->base.size      = offset;
3538         type->base.alignment = alignment;
3539 }
3540
3541 /**
3542  * Finish the construction of an union type by calculating
3543  * its size and alignment.
3544  */
3545 static void finish_union_type(compound_type_t *type)
3546 {
3547         assert(type->compound != NULL);
3548
3549         compound_t *compound = type->compound;
3550         if (! compound->complete)
3551                 return;
3552
3553         il_size_t      size      = 0;
3554         il_alignment_t alignment = 1;
3555
3556         entity_t *entry = compound->members.entities;
3557         for (; entry != NULL; entry = entry->base.next) {
3558                 if (entry->kind != ENTITY_COMPOUND_MEMBER)
3559                         continue;
3560
3561                 type_t *m_type = skip_typeref(entry->declaration.type);
3562                 if (! is_type_valid(m_type))
3563                         continue;
3564
3565                 entry->compound_member.offset = 0;
3566                 if (m_type->base.size > size)
3567                         size = m_type->base.size;
3568                 if (m_type->base.alignment > alignment)
3569                         alignment = m_type->base.alignment;
3570         }
3571         if (type->base.alignment != 0) {
3572                 alignment = type->base.alignment;
3573         }
3574         size = (size + alignment - 1) & -alignment;
3575         type->base.size      = size;
3576         type->base.alignment = alignment;
3577 }
3578
3579 static type_t *handle_attribute_mode(const gnu_attribute_t *attribute,
3580                                      type_t *orig_type)
3581 {
3582         type_t *type = skip_typeref(orig_type);
3583
3584         /* at least: byte, word, pointer, list of machine modes
3585          * __XXX___ is interpreted as XXX */
3586
3587         /* This isn't really correct, the backend should provide a list of machine
3588          * specific modes (according to gcc philosophy that is...) */
3589         const char         *symbol_str = attribute->u.symbol->string;
3590         bool                sign       = is_type_signed(type);
3591         atomic_type_kind_t  akind;
3592         if (strcmp_underscore("QI",   symbol_str) == 0 ||
3593             strcmp_underscore("byte", symbol_str) == 0) {
3594                 akind = sign ? ATOMIC_TYPE_CHAR : ATOMIC_TYPE_UCHAR;
3595         } else if (strcmp_underscore("HI", symbol_str) == 0) {
3596                 akind = sign ? ATOMIC_TYPE_SHORT : ATOMIC_TYPE_USHORT;
3597         } else if (strcmp_underscore("SI",      symbol_str) == 0
3598                 || strcmp_underscore("word",    symbol_str) == 0
3599                 || strcmp_underscore("pointer", symbol_str) == 0) {
3600                 akind = sign ? ATOMIC_TYPE_INT : ATOMIC_TYPE_UINT;
3601         } else if (strcmp_underscore("DI", symbol_str) == 0) {
3602                 akind = sign ? ATOMIC_TYPE_LONGLONG : ATOMIC_TYPE_ULONGLONG;
3603         } else {
3604                 if (warning.other)
3605                         warningf(HERE, "ignoring unknown mode '%s'", symbol_str);
3606                 return orig_type;
3607         }
3608
3609         if (type->kind == TYPE_ATOMIC) {
3610                 type_t *copy       = duplicate_type(type);
3611                 copy->atomic.akind = akind;
3612                 return identify_new_type(copy);
3613         } else if (type->kind == TYPE_ENUM) {
3614                 type_t *copy      = duplicate_type(type);
3615                 copy->enumt.akind = akind;
3616                 return identify_new_type(copy);
3617         } else if (is_type_pointer(type)) {
3618                 warningf(HERE, "__attribute__((mode)) on pointers not implemented yet (ignored)");
3619                 return type;
3620         }
3621
3622         errorf(HERE, "__attribute__((mode)) only allowed on integer, enum or pointer type");
3623         return orig_type;
3624 }
3625
3626 static type_t *handle_type_attributes(const gnu_attribute_t *attributes,
3627                                       type_t *type)
3628 {
3629         const gnu_attribute_t *attribute = attributes;
3630         for ( ; attribute != NULL; attribute = attribute->next) {
3631                 if (attribute->invalid)
3632                         continue;
3633
3634                 if (attribute->kind == GNU_AK_MODE) {
3635                         type = handle_attribute_mode(attribute, type);
3636                 } else if (attribute->kind == GNU_AK_ALIGNED) {
3637                         int alignment = 32; /* TODO: fill in maximum useful alignment for
3638                                                target machine */
3639                         if (attribute->has_arguments)
3640                                 alignment = attribute->u.argument;
3641
3642                         type_t *copy         = duplicate_type(type);
3643                         copy->base.alignment = attribute->u.argument;
3644                         type                 = identify_new_type(copy);
3645                 }
3646         }
3647
3648         return type;
3649 }
3650
3651 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
3652 {
3653         type_t            *type              = NULL;
3654         type_qualifiers_t  qualifiers        = TYPE_QUALIFIER_NONE;
3655         type_modifiers_t   modifiers         = TYPE_MODIFIER_NONE;
3656         unsigned           type_specifiers   = 0;
3657         bool               newtype           = false;
3658         bool               saw_error         = false;
3659         bool               old_gcc_extension = in_gcc_extension;
3660
3661         specifiers->source_position = token.source_position;
3662
3663         while (true) {
3664                 specifiers->modifiers
3665                         |= parse_attributes(&specifiers->gnu_attributes);
3666
3667                 switch (token.type) {
3668                 /* storage class */
3669 #define MATCH_STORAGE_CLASS(token, class)                                  \
3670                 case token:                                                        \
3671                         if (specifiers->storage_class != STORAGE_CLASS_NONE) {         \
3672                                 errorf(HERE, "multiple storage classes in declaration specifiers"); \
3673                         }                                                              \
3674                         specifiers->storage_class = class;                             \
3675                         if (specifiers->thread_local)                                  \
3676                                 goto check_thread_storage_class;                           \
3677                         next_token();                                                  \
3678                         break;
3679
3680                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
3681                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
3682                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
3683                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
3684                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
3685
3686                 case T__declspec:
3687                         next_token();
3688                         expect('(', end_error);
3689                         add_anchor_token(')');
3690                         parse_microsoft_extended_decl_modifier(specifiers);
3691                         rem_anchor_token(')');
3692                         expect(')', end_error);
3693                         break;
3694
3695                 case T___thread:
3696                         if (specifiers->thread_local) {
3697                                 errorf(HERE, "duplicate '__thread'");
3698                         } else {
3699                                 specifiers->thread_local = true;
3700 check_thread_storage_class:
3701                                 switch (specifiers->storage_class) {
3702                                         case STORAGE_CLASS_EXTERN:
3703                                         case STORAGE_CLASS_NONE:
3704                                         case STORAGE_CLASS_STATIC:
3705                                                 break;
3706
3707                                                 char const* wrong;
3708                                         case STORAGE_CLASS_AUTO:     wrong = "auto";     goto wrong_thread_stoarge_class;
3709                                         case STORAGE_CLASS_REGISTER: wrong = "register"; goto wrong_thread_stoarge_class;
3710                                         case STORAGE_CLASS_TYPEDEF:  wrong = "typedef";  goto wrong_thread_stoarge_class;
3711 wrong_thread_stoarge_class:
3712                                                 errorf(HERE, "'__thread' used with '%s'", wrong);
3713                                                 break;
3714                                 }
3715                         }
3716                         next_token();
3717                         break;
3718
3719                 /* type qualifiers */
3720 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
3721                 case token:                                                     \
3722                         qualifiers |= qualifier;                                    \
3723                         next_token();                                               \
3724                         break
3725
3726                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3727                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3728                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3729                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3730                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3731                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3732                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3733                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3734
3735                 case T___extension__:
3736                         next_token();
3737                         in_gcc_extension = true;
3738                         break;
3739
3740                 /* type specifiers */
3741 #define MATCH_SPECIFIER(token, specifier, name)                         \
3742                 case token:                                                     \
3743                         if (type_specifiers & specifier) {                           \
3744                                 errorf(HERE, "multiple " name " type specifiers given"); \
3745                         } else {                                                    \
3746                                 type_specifiers |= specifier;                           \
3747                         }                                                           \
3748                         next_token();                                               \
3749                         break
3750
3751                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool");
3752                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex");
3753                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary");
3754                 MATCH_SPECIFIER(T__int128,    SPECIFIER_INT128,    "_int128");
3755                 MATCH_SPECIFIER(T__int16,     SPECIFIER_INT16,     "_int16");
3756                 MATCH_SPECIFIER(T__int32,     SPECIFIER_INT32,     "_int32");
3757                 MATCH_SPECIFIER(T__int64,     SPECIFIER_INT64,     "_int64");
3758                 MATCH_SPECIFIER(T__int8,      SPECIFIER_INT8,      "_int8");
3759                 MATCH_SPECIFIER(T_bool,       SPECIFIER_BOOL,      "bool");
3760                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char");
3761                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double");
3762                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float");
3763                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int");
3764                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short");
3765                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed");
3766                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned");
3767                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void");
3768                 MATCH_SPECIFIER(T_wchar_t,    SPECIFIER_WCHAR_T,   "wchar_t");
3769
3770                 case T__forceinline:
3771                         /* only in microsoft mode */
3772                         specifiers->modifiers |= DM_FORCEINLINE;
3773                         /* FALLTHROUGH */
3774
3775                 case T_inline:
3776                         next_token();
3777                         specifiers->is_inline = true;
3778                         break;
3779
3780                 case T_long:
3781                         if (type_specifiers & SPECIFIER_LONG_LONG) {
3782                                 errorf(HERE, "multiple type specifiers given");
3783                         } else if (type_specifiers & SPECIFIER_LONG) {
3784                                 type_specifiers |= SPECIFIER_LONG_LONG;
3785                         } else {
3786                                 type_specifiers |= SPECIFIER_LONG;
3787                         }
3788                         next_token();
3789                         break;
3790
3791                 case T_struct: {
3792                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
3793
3794                         type->compound.compound = parse_compound_type_specifier(true);
3795                         finish_struct_type(&type->compound);
3796                         break;
3797                 }
3798                 case T_union: {
3799                         type = allocate_type_zero(TYPE_COMPOUND_UNION);
3800                         type->compound.compound = parse_compound_type_specifier(false);
3801                         if (type->compound.compound->modifiers & DM_TRANSPARENT_UNION)
3802                                 modifiers |= TYPE_MODIFIER_TRANSPARENT_UNION;
3803                         finish_union_type(&type->compound);
3804                         break;
3805                 }
3806                 case T_enum:
3807                         type = parse_enum_specifier();
3808                         break;
3809                 case T___typeof__:
3810                         type = parse_typeof();
3811                         break;
3812                 case T___builtin_va_list:
3813                         type = duplicate_type(type_valist);
3814                         next_token();
3815                         break;
3816
3817                 case T_IDENTIFIER: {
3818                         /* only parse identifier if we haven't found a type yet */
3819                         if (type != NULL || type_specifiers != 0) {
3820                                 /* Be somewhat resilient to typos like 'unsigned lng* f()' in a
3821                                  * declaration, so it doesn't generate errors about expecting '(' or
3822                                  * '{' later on. */
3823                                 switch (look_ahead(1)->type) {
3824                                         STORAGE_CLASSES
3825                                         TYPE_SPECIFIERS
3826                                         case T_const:
3827                                         case T_restrict:
3828                                         case T_volatile:
3829                                         case T_inline:
3830                                         case T__forceinline: /* ^ DECLARATION_START except for __attribute__ */
3831                                         case T_IDENTIFIER:
3832                                         case '&':
3833                                         case '*':
3834                                                 errorf(HERE, "discarding stray %K in declaration specifier", &token);
3835                                                 next_token();
3836                                                 continue;
3837
3838                                         default:
3839                                                 goto finish_specifiers;
3840                                 }
3841                         }
3842
3843                         type_t *const typedef_type = get_typedef_type(token.v.symbol);
3844                         if (typedef_type == NULL) {
3845                                 /* Be somewhat resilient to typos like 'vodi f()' at the beginning of a
3846                                  * declaration, so it doesn't generate 'implicit int' followed by more
3847                                  * errors later on. */
3848                                 token_type_t const la1_type = (token_type_t)look_ahead(1)->type;
3849                                 switch (la1_type) {
3850                                         DECLARATION_START
3851                                         case T_IDENTIFIER:
3852                                         case '&':
3853                                         case '*': {
3854                                                 errorf(HERE, "%K does not name a type", &token);
3855
3856                                                 entity_t *entity =
3857                                                         create_error_entity(token.v.symbol, ENTITY_TYPEDEF);
3858
3859                                                 type = allocate_type_zero(TYPE_TYPEDEF);
3860                                                 type->typedeft.typedefe = &entity->typedefe;
3861
3862                                                 next_token();
3863                                                 saw_error = true;
3864                                                 if (la1_type == '&' || la1_type == '*')
3865                                                         goto finish_specifiers;
3866                                                 continue;
3867                                         }
3868
3869                                         default:
3870                                                 goto finish_specifiers;
3871                                 }
3872                         }
3873
3874                         next_token();
3875                         type = typedef_type;
3876                         break;
3877                 }
3878
3879                 /* function specifier */
3880                 default:
3881                         goto finish_specifiers;
3882                 }
3883         }
3884
3885 finish_specifiers:
3886         specifiers->modifiers
3887                 |= parse_attributes(&specifiers->gnu_attributes);
3888
3889         in_gcc_extension = old_gcc_extension;
3890
3891         if (type == NULL || (saw_error && type_specifiers != 0)) {
3892                 atomic_type_kind_t atomic_type;
3893
3894                 /* match valid basic types */
3895                 switch (type_specifiers) {
3896                 case SPECIFIER_VOID:
3897                         atomic_type = ATOMIC_TYPE_VOID;
3898                         break;
3899                 case SPECIFIER_WCHAR_T:
3900                         atomic_type = ATOMIC_TYPE_WCHAR_T;
3901                         break;
3902                 case SPECIFIER_CHAR:
3903                         atomic_type = ATOMIC_TYPE_CHAR;
3904                         break;
3905                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
3906                         atomic_type = ATOMIC_TYPE_SCHAR;
3907                         break;
3908                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
3909                         atomic_type = ATOMIC_TYPE_UCHAR;
3910                         break;
3911                 case SPECIFIER_SHORT:
3912                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
3913                 case SPECIFIER_SHORT | SPECIFIER_INT:
3914                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
3915                         atomic_type = ATOMIC_TYPE_SHORT;
3916                         break;
3917                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
3918                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
3919                         atomic_type = ATOMIC_TYPE_USHORT;
3920                         break;
3921                 case SPECIFIER_INT:
3922                 case SPECIFIER_SIGNED:
3923                 case SPECIFIER_SIGNED | SPECIFIER_INT:
3924                         atomic_type = ATOMIC_TYPE_INT;
3925                         break;
3926                 case SPECIFIER_UNSIGNED:
3927                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
3928                         atomic_type = ATOMIC_TYPE_UINT;
3929                         break;
3930                 case SPECIFIER_LONG:
3931                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
3932                 case SPECIFIER_LONG | SPECIFIER_INT:
3933                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
3934                         atomic_type = ATOMIC_TYPE_LONG;
3935                         break;
3936                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
3937                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
3938                         atomic_type = ATOMIC_TYPE_ULONG;
3939                         break;
3940
3941                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3942                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3943                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
3944                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3945                         | SPECIFIER_INT:
3946                         atomic_type = ATOMIC_TYPE_LONGLONG;
3947                         goto warn_about_long_long;
3948
3949                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3950                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3951                         | SPECIFIER_INT:
3952                         atomic_type = ATOMIC_TYPE_ULONGLONG;
3953 warn_about_long_long:
3954                         if (warning.long_long) {
3955                                 warningf(&specifiers->source_position,
3956                                          "ISO C90 does not support 'long long'");
3957                         }
3958                         break;
3959
3960                 case SPECIFIER_UNSIGNED | SPECIFIER_INT8:
3961                         atomic_type = unsigned_int8_type_kind;
3962                         break;
3963
3964                 case SPECIFIER_UNSIGNED | SPECIFIER_INT16:
3965                         atomic_type = unsigned_int16_type_kind;
3966                         break;
3967
3968                 case SPECIFIER_UNSIGNED | SPECIFIER_INT32:
3969                         atomic_type = unsigned_int32_type_kind;
3970                         break;
3971
3972                 case SPECIFIER_UNSIGNED | SPECIFIER_INT64:
3973                         atomic_type = unsigned_int64_type_kind;
3974                         break;
3975
3976                 case SPECIFIER_UNSIGNED | SPECIFIER_INT128:
3977                         atomic_type = unsigned_int128_type_kind;
3978                         break;
3979
3980                 case SPECIFIER_INT8:
3981                 case SPECIFIER_SIGNED | SPECIFIER_INT8:
3982                         atomic_type = int8_type_kind;
3983                         break;
3984
3985                 case SPECIFIER_INT16:
3986                 case SPECIFIER_SIGNED | SPECIFIER_INT16:
3987                         atomic_type = int16_type_kind;
3988                         break;
3989
3990                 case SPECIFIER_INT32:
3991                 case SPECIFIER_SIGNED | SPECIFIER_INT32:
3992                         atomic_type = int32_type_kind;
3993                         break;
3994
3995                 case SPECIFIER_INT64:
3996                 case SPECIFIER_SIGNED | SPECIFIER_INT64:
3997                         atomic_type = int64_type_kind;
3998                         break;
3999
4000                 case SPECIFIER_INT128:
4001                 case SPECIFIER_SIGNED | SPECIFIER_INT128:
4002                         atomic_type = int128_type_kind;
4003                         break;
4004
4005                 case SPECIFIER_FLOAT:
4006                         atomic_type = ATOMIC_TYPE_FLOAT;
4007                         break;
4008                 case SPECIFIER_DOUBLE:
4009                         atomic_type = ATOMIC_TYPE_DOUBLE;
4010                         break;
4011                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
4012                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
4013                         break;
4014                 case SPECIFIER_BOOL:
4015                         atomic_type = ATOMIC_TYPE_BOOL;
4016                         break;
4017                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
4018                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
4019                         atomic_type = ATOMIC_TYPE_FLOAT;
4020                         break;
4021                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
4022                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
4023                         atomic_type = ATOMIC_TYPE_DOUBLE;
4024                         break;
4025                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
4026                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
4027                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
4028                         break;
4029                 default:
4030                         /* invalid specifier combination, give an error message */
4031                         if (type_specifiers == 0) {
4032                                 if (saw_error)
4033                                         goto end_error;
4034
4035                                 /* ISO/IEC 14882:1998(E) §C.1.5:4 */
4036                                 if (!(c_mode & _CXX) && !strict_mode) {
4037                                         if (warning.implicit_int) {
4038                                                 warningf(HERE, "no type specifiers in declaration, using 'int'");
4039                                         }
4040                                         atomic_type = ATOMIC_TYPE_INT;
4041                                         break;
4042                                 } else {
4043                                         errorf(HERE, "no type specifiers given in declaration");
4044                                 }
4045                         } else if ((type_specifiers & SPECIFIER_SIGNED) &&
4046                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
4047                                 errorf(HERE, "signed and unsigned specifiers given");
4048                         } else if (type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
4049                                 errorf(HERE, "only integer types can be signed or unsigned");
4050                         } else {
4051                                 errorf(HERE, "multiple datatypes in declaration");
4052                         }
4053                         goto end_error;
4054                 }
4055
4056                 if (type_specifiers & SPECIFIER_COMPLEX) {
4057                         type                = allocate_type_zero(TYPE_COMPLEX);
4058                         type->complex.akind = atomic_type;
4059                 } else if (type_specifiers & SPECIFIER_IMAGINARY) {
4060                         type                  = allocate_type_zero(TYPE_IMAGINARY);
4061                         type->imaginary.akind = atomic_type;
4062                 } else {
4063                         type                 = allocate_type_zero(TYPE_ATOMIC);
4064                         type->atomic.akind   = atomic_type;
4065                 }
4066                 type->base.alignment = get_atomic_type_alignment(atomic_type);
4067                 unsigned const size  = get_atomic_type_size(atomic_type);
4068                 type->base.size      =
4069                         type_specifiers & SPECIFIER_COMPLEX ? size * 2 : size;
4070                 newtype = true;
4071         } else if (type_specifiers != 0) {
4072                 errorf(HERE, "multiple datatypes in declaration");
4073         }
4074
4075         /* FIXME: check type qualifiers here */
4076
4077         if (specifiers->modifiers & DM_TRANSPARENT_UNION)
4078                 modifiers |= TYPE_MODIFIER_TRANSPARENT_UNION;
4079         type->base.qualifiers = qualifiers;
4080         type->base.modifiers  = modifiers;
4081
4082         if (newtype) {
4083                 type = identify_new_type(type);
4084         } else {
4085                 type = typehash_insert(type);
4086         }
4087
4088         type = handle_type_attributes(specifiers->gnu_attributes, type);
4089         specifiers->type = type;
4090         return;
4091
4092 end_error:
4093         specifiers->type = type_error_type;
4094         return;
4095 }
4096
4097 static type_qualifiers_t parse_type_qualifiers(void)
4098 {
4099         type_qualifiers_t qualifiers = TYPE_QUALIFIER_NONE;
4100
4101         while (true) {
4102                 switch (token.type) {
4103                 /* type qualifiers */
4104                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
4105                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
4106                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
4107                 /* microsoft extended type modifiers */
4108                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
4109                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
4110                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
4111                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
4112                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
4113
4114                 default:
4115                         return qualifiers;
4116                 }
4117         }
4118 }
4119
4120 /**
4121  * Parses an K&R identifier list
4122  */
4123 static void parse_identifier_list(scope_t *scope)
4124 {
4125         do {
4126                 entity_t *entity = allocate_entity_zero(ENTITY_PARAMETER);
4127                 entity->base.source_position = token.source_position;
4128                 entity->base.namespc         = NAMESPACE_NORMAL;
4129                 entity->base.symbol          = token.v.symbol;
4130                 /* a K&R parameter has no type, yet */
4131                 next_token();
4132
4133                 if (scope != NULL)
4134                         append_entity(scope, entity);
4135
4136                 if (token.type != ',') {
4137                         break;
4138                 }
4139                 next_token();
4140         } while (token.type == T_IDENTIFIER);
4141 }
4142
4143 static entity_t *parse_parameter(void)
4144 {
4145         declaration_specifiers_t specifiers;
4146         memset(&specifiers, 0, sizeof(specifiers));
4147
4148         parse_declaration_specifiers(&specifiers);
4149
4150         entity_t *entity = parse_declarator(&specifiers,
4151                         DECL_MAY_BE_ABSTRACT | DECL_IS_PARAMETER);
4152         anonymous_entity = NULL;
4153         return entity;
4154 }
4155
4156 static void semantic_parameter_incomplete(const entity_t *entity)
4157 {
4158         assert(entity->kind == ENTITY_PARAMETER);
4159
4160         /* §6.7.5.3:4  After adjustment, the parameters in a parameter type
4161          *             list in a function declarator that is part of a
4162          *             definition of that function shall not have
4163          *             incomplete type. */
4164         type_t *type = skip_typeref(entity->declaration.type);
4165         if (is_type_incomplete(type)) {
4166                 errorf(&entity->base.source_position,
4167                        "parameter '%Y' has incomplete type '%T'", entity->base.symbol,
4168                        entity->declaration.type);
4169         }
4170 }
4171
4172 /**
4173  * Parses function type parameters (and optionally creates variable_t entities
4174  * for them in a scope)
4175  */
4176 static void parse_parameters(function_type_t *type, scope_t *scope)
4177 {
4178         eat('(');
4179         add_anchor_token(')');
4180         int saved_comma_state = save_and_reset_anchor_state(',');
4181
4182         if (token.type == T_IDENTIFIER &&
4183             !is_typedef_symbol(token.v.symbol)) {
4184                 token_type_t la1_type = (token_type_t)look_ahead(1)->type;
4185                 if (la1_type == ',' || la1_type == ')') {
4186                         type->kr_style_parameters    = true;
4187                         type->unspecified_parameters = true;
4188                         parse_identifier_list(scope);
4189                         goto parameters_finished;
4190                 }
4191         }
4192
4193         if (token.type == ')') {
4194                 /* ISO/IEC 14882:1998(E) §C.1.6:1 */
4195                 if (!(c_mode & _CXX))
4196                         type->unspecified_parameters = true;
4197                 goto parameters_finished;
4198         }
4199
4200         function_parameter_t *parameter;
4201         function_parameter_t *last_parameter = NULL;
4202
4203         while (true) {
4204                 switch (token.type) {
4205                 case T_DOTDOTDOT:
4206                         next_token();
4207                         type->variadic = true;
4208                         goto parameters_finished;
4209
4210                 case T_IDENTIFIER:
4211                 case T___extension__:
4212                 DECLARATION_START
4213                 {
4214                         entity_t *entity = parse_parameter();
4215                         if (entity->kind == ENTITY_TYPEDEF) {
4216                                 errorf(&entity->base.source_position,
4217                                        "typedef not allowed as function parameter");
4218                                 break;
4219                         }
4220                         assert(is_declaration(entity));
4221
4222                         /* func(void) is not a parameter */
4223                         if (last_parameter == NULL
4224                                         && token.type == ')'
4225                                         && entity->base.symbol == NULL
4226                                         && skip_typeref(entity->declaration.type) == type_void) {
4227                                 goto parameters_finished;
4228                         }
4229                         semantic_parameter_incomplete(entity);
4230
4231                         parameter = obstack_alloc(type_obst, sizeof(parameter[0]));
4232                         memset(parameter, 0, sizeof(parameter[0]));
4233                         parameter->type = entity->declaration.type;
4234
4235                         if (scope != NULL) {
4236                                 append_entity(scope, entity);
4237                         }
4238
4239                         if (last_parameter != NULL) {
4240                                 last_parameter->next = parameter;
4241                         } else {
4242                                 type->parameters = parameter;
4243                         }
4244                         last_parameter   = parameter;
4245                         break;
4246                 }
4247
4248                 default:
4249                         goto parameters_finished;
4250                 }
4251                 if (token.type != ',') {
4252                         goto parameters_finished;
4253                 }
4254                 next_token();
4255         }
4256
4257
4258 parameters_finished:
4259         rem_anchor_token(')');
4260         expect(')', end_error);
4261
4262 end_error:
4263         restore_anchor_state(',', saved_comma_state);
4264 }
4265
4266 typedef enum construct_type_kind_t {
4267         CONSTRUCT_INVALID,
4268         CONSTRUCT_POINTER,
4269         CONSTRUCT_REFERENCE,
4270         CONSTRUCT_FUNCTION,
4271         CONSTRUCT_ARRAY
4272 } construct_type_kind_t;
4273
4274 typedef struct construct_type_t construct_type_t;
4275 struct construct_type_t {
4276         construct_type_kind_t  kind;
4277         construct_type_t      *next;
4278 };
4279
4280 typedef struct parsed_pointer_t parsed_pointer_t;
4281 struct parsed_pointer_t {
4282         construct_type_t  construct_type;
4283         type_qualifiers_t type_qualifiers;
4284         variable_t        *base_variable;  /**< MS __based extension. */
4285 };
4286
4287 typedef struct parsed_reference_t parsed_reference_t;
4288 struct parsed_reference_t {
4289         construct_type_t construct_type;
4290 };
4291
4292 typedef struct construct_function_type_t construct_function_type_t;
4293 struct construct_function_type_t {
4294         construct_type_t  construct_type;
4295         type_t           *function_type;
4296 };
4297
4298 typedef struct parsed_array_t parsed_array_t;
4299 struct parsed_array_t {
4300         construct_type_t  construct_type;
4301         type_qualifiers_t type_qualifiers;
4302         bool              is_static;
4303         bool              is_variable;
4304         expression_t     *size;
4305 };
4306
4307 typedef struct construct_base_type_t construct_base_type_t;
4308 struct construct_base_type_t {
4309         construct_type_t  construct_type;
4310         type_t           *type;
4311 };
4312
4313 static construct_type_t *parse_pointer_declarator(variable_t *base_variable)
4314 {
4315         eat('*');
4316
4317         parsed_pointer_t *pointer = obstack_alloc(&temp_obst, sizeof(pointer[0]));
4318         memset(pointer, 0, sizeof(pointer[0]));
4319         pointer->construct_type.kind = CONSTRUCT_POINTER;
4320         pointer->type_qualifiers     = parse_type_qualifiers();
4321         pointer->base_variable       = base_variable;
4322
4323         return &pointer->construct_type;
4324 }
4325
4326 static construct_type_t *parse_reference_declarator(void)
4327 {
4328         eat('&');
4329
4330         parsed_reference_t *reference = obstack_alloc(&temp_obst, sizeof(reference[0]));
4331         memset(reference, 0, sizeof(reference[0]));
4332         reference->construct_type.kind = CONSTRUCT_REFERENCE;
4333
4334         return (construct_type_t*)reference;
4335 }
4336
4337 static construct_type_t *parse_array_declarator(void)
4338 {
4339         eat('[');
4340         add_anchor_token(']');
4341
4342         parsed_array_t *array = obstack_alloc(&temp_obst, sizeof(array[0]));
4343         memset(array, 0, sizeof(array[0]));
4344         array->construct_type.kind = CONSTRUCT_ARRAY;
4345
4346         if (token.type == T_static) {
4347                 array->is_static = true;
4348                 next_token();
4349         }
4350
4351         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
4352         if (type_qualifiers != 0) {
4353                 if (token.type == T_static) {
4354                         array->is_static = true;
4355                         next_token();
4356                 }
4357         }
4358         array->type_qualifiers = type_qualifiers;
4359
4360         if (token.type == '*' && look_ahead(1)->type == ']') {
4361                 array->is_variable = true;
4362                 next_token();
4363         } else if (token.type != ']') {
4364                 expression_t *const size = parse_assignment_expression();
4365                 array->size = size;
4366                 mark_vars_read(size, NULL);
4367         }
4368
4369         rem_anchor_token(']');
4370         expect(']', end_error);
4371
4372 end_error:
4373         return &array->construct_type;
4374 }
4375
4376 static construct_type_t *parse_function_declarator(scope_t *scope,
4377                                                    decl_modifiers_t modifiers)
4378 {
4379         type_t          *type  = allocate_type_zero(TYPE_FUNCTION);
4380         function_type_t *ftype = &type->function;
4381
4382         ftype->linkage = current_linkage;
4383
4384         switch (modifiers & (DM_CDECL | DM_STDCALL | DM_FASTCALL | DM_THISCALL)) {
4385                 case DM_NONE:     break;
4386                 case DM_CDECL:    ftype->calling_convention = CC_CDECL;    break;
4387                 case DM_STDCALL:  ftype->calling_convention = CC_STDCALL;  break;
4388                 case DM_FASTCALL: ftype->calling_convention = CC_FASTCALL; break;
4389                 case DM_THISCALL: ftype->calling_convention = CC_THISCALL; break;
4390
4391                 default:
4392                         errorf(HERE, "multiple calling conventions in declaration");
4393                         break;
4394         }
4395
4396         parse_parameters(ftype, scope);
4397
4398         construct_function_type_t *construct_function_type =
4399                 obstack_alloc(&temp_obst, sizeof(construct_function_type[0]));
4400         memset(construct_function_type, 0, sizeof(construct_function_type[0]));
4401         construct_function_type->construct_type.kind = CONSTRUCT_FUNCTION;
4402         construct_function_type->function_type       = type;
4403
4404         return &construct_function_type->construct_type;
4405 }
4406
4407 typedef struct parse_declarator_env_t {
4408         decl_modifiers_t   modifiers;
4409         symbol_t          *symbol;
4410         source_position_t  source_position;
4411         scope_t            parameters;
4412 } parse_declarator_env_t;
4413
4414 static construct_type_t *parse_inner_declarator(parse_declarator_env_t *env,
4415                 bool may_be_abstract)
4416 {
4417         /* construct a single linked list of construct_type_t's which describe
4418          * how to construct the final declarator type */
4419         construct_type_t *first      = NULL;
4420         construct_type_t *last       = NULL;
4421         gnu_attribute_t  *attributes = NULL;
4422
4423         decl_modifiers_t modifiers = parse_attributes(&attributes);
4424
4425         /* MS __based extension */
4426         based_spec_t base_spec;
4427         base_spec.base_variable = NULL;
4428
4429         for (;;) {
4430                 construct_type_t *type;
4431                 switch (token.type) {
4432                         case '&':
4433                                 if (!(c_mode & _CXX))
4434                                         errorf(HERE, "references are only available for C++");
4435                                 if (base_spec.base_variable != NULL && warning.other) {
4436                                         warningf(&base_spec.source_position,
4437                                                  "__based does not precede a pointer operator, ignored");
4438                                 }
4439                                 type = parse_reference_declarator();
4440                                 /* consumed */
4441                                 base_spec.base_variable = NULL;
4442                                 break;
4443
4444                         case '*':
4445                                 type = parse_pointer_declarator(base_spec.base_variable);
4446                                 /* consumed */
4447                                 base_spec.base_variable = NULL;
4448                                 break;
4449
4450                         case T__based:
4451                                 next_token();
4452                                 expect('(', end_error);
4453                                 add_anchor_token(')');
4454                                 parse_microsoft_based(&base_spec);
4455                                 rem_anchor_token(')');
4456                                 expect(')', end_error);
4457                                 continue;
4458
4459                         default:
4460                                 goto ptr_operator_end;
4461                 }
4462
4463                 if (last == NULL) {
4464                         first = type;
4465                         last  = type;
4466                 } else {
4467                         last->next = type;
4468                         last       = type;
4469                 }
4470
4471                 /* TODO: find out if this is correct */
4472                 modifiers |= parse_attributes(&attributes);
4473         }
4474 ptr_operator_end:
4475         if (base_spec.base_variable != NULL && warning.other) {
4476                 warningf(&base_spec.source_position,
4477                          "__based does not precede a pointer operator, ignored");
4478         }
4479
4480         if (env != NULL) {
4481                 modifiers      |= env->modifiers;
4482                 env->modifiers  = modifiers;
4483         }
4484
4485         construct_type_t *inner_types = NULL;
4486
4487         switch (token.type) {
4488         case T_IDENTIFIER:
4489                 if (env == NULL) {
4490                         errorf(HERE, "no identifier expected in typename");
4491                 } else {
4492                         env->symbol          = token.v.symbol;
4493                         env->source_position = token.source_position;
4494                 }
4495                 next_token();
4496                 break;
4497         case '(':
4498                 /* §6.7.6:2 footnote 126:  Empty parentheses in a type name are
4499                  * interpreted as ``function with no parameter specification'', rather
4500                  * than redundant parentheses around the omitted identifier. */
4501                 if (look_ahead(1)->type != ')') {
4502                         next_token();
4503                         add_anchor_token(')');
4504                         inner_types = parse_inner_declarator(env, may_be_abstract);
4505                         if (inner_types != NULL) {
4506                                 /* All later declarators only modify the return type */
4507                                 env = NULL;
4508                         }
4509                         rem_anchor_token(')');
4510                         expect(')', end_error);
4511                 }
4512                 break;
4513         default:
4514                 if (may_be_abstract)
4515                         break;
4516                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', NULL);
4517                 eat_until_anchor();
4518                 return NULL;
4519         }
4520
4521         construct_type_t *p = last;
4522
4523         while (true) {
4524                 construct_type_t *type;
4525                 switch (token.type) {
4526                 case '(': {
4527                         scope_t *scope = NULL;
4528                         if (env != NULL)
4529                                 scope = &env->parameters;
4530
4531                         type = parse_function_declarator(scope, modifiers);
4532                         break;
4533                 }
4534                 case '[':
4535                         type = parse_array_declarator();
4536                         break;
4537                 default:
4538                         goto declarator_finished;
4539                 }
4540
4541                 /* insert in the middle of the list (behind p) */
4542                 if (p != NULL) {
4543                         type->next = p->next;
4544                         p->next    = type;
4545                 } else {
4546                         type->next = first;
4547                         first      = type;
4548                 }
4549                 if (last == p) {
4550                         last = type;
4551                 }
4552         }
4553
4554 declarator_finished:
4555         /* append inner_types at the end of the list, we don't to set last anymore
4556          * as it's not needed anymore */
4557         if (last == NULL) {
4558                 assert(first == NULL);
4559                 first = inner_types;
4560         } else {
4561                 last->next = inner_types;
4562         }
4563
4564         return first;
4565 end_error:
4566         return NULL;
4567 }
4568
4569 static void parse_declaration_attributes(entity_t *entity)
4570 {
4571         gnu_attribute_t  *attributes = NULL;
4572         decl_modifiers_t  modifiers  = parse_attributes(&attributes);
4573
4574         if (entity == NULL)
4575                 return;
4576
4577         type_t *type;
4578         if (entity->kind == ENTITY_TYPEDEF) {
4579                 modifiers |= entity->typedefe.modifiers;
4580                 type       = entity->typedefe.type;
4581         } else {
4582                 assert(is_declaration(entity));
4583                 modifiers |= entity->declaration.modifiers;
4584                 type       = entity->declaration.type;
4585         }
4586         if (type == NULL)
4587                 return;
4588
4589         gnu_attribute_t *attribute = attributes;
4590         for ( ; attribute != NULL; attribute = attribute->next) {
4591                 if (attribute->invalid)
4592                         continue;
4593
4594                 if (attribute->kind == GNU_AK_MODE) {
4595                         type = handle_attribute_mode(attribute, type);
4596                 } else if (attribute->kind == GNU_AK_ALIGNED) {
4597                         int alignment = 32; /* TODO: fill in maximum usefull alignment for target machine */
4598                         if (attribute->has_arguments)
4599                                 alignment = attribute->u.argument;
4600
4601                         if (entity->kind == ENTITY_TYPEDEF) {
4602                                 type_t *copy         = duplicate_type(type);
4603                                 copy->base.alignment = attribute->u.argument;
4604                                 type                 = identify_new_type(copy);
4605                         } else if(entity->kind == ENTITY_VARIABLE) {
4606                                 entity->variable.alignment = alignment;
4607                         } else if(entity->kind == ENTITY_COMPOUND_MEMBER) {
4608                                 entity->compound_member.alignment = alignment;
4609                         }
4610                 }
4611         }
4612
4613         type_modifiers_t type_modifiers = type->base.modifiers;
4614         if (modifiers & DM_TRANSPARENT_UNION)
4615                 type_modifiers |= TYPE_MODIFIER_TRANSPARENT_UNION;
4616
4617         if (type->base.modifiers != type_modifiers) {
4618                 type_t *copy         = duplicate_type(type);
4619                 copy->base.modifiers = type_modifiers;
4620                 type                 = identify_new_type(copy);
4621         }
4622
4623         if (entity->kind == ENTITY_TYPEDEF) {
4624                 entity->typedefe.type      = type;
4625                 entity->typedefe.modifiers = modifiers;
4626         } else {
4627                 entity->declaration.type      = type;
4628                 entity->declaration.modifiers = modifiers;
4629         }
4630 }
4631
4632 static type_t *construct_declarator_type(construct_type_t *construct_list, type_t *type)
4633 {
4634         construct_type_t *iter = construct_list;
4635         for (; iter != NULL; iter = iter->next) {
4636                 switch (iter->kind) {
4637                 case CONSTRUCT_INVALID:
4638                         break;
4639                 case CONSTRUCT_FUNCTION: {
4640                         construct_function_type_t *construct_function_type
4641                                 = (construct_function_type_t*) iter;
4642
4643                         type_t *function_type = construct_function_type->function_type;
4644
4645                         function_type->function.return_type = type;
4646
4647                         type_t *skipped_return_type = skip_typeref(type);
4648                         /* §6.7.5.3:1 */
4649                         if (is_type_function(skipped_return_type)) {
4650                                 errorf(HERE, "function returning function is not allowed");
4651                         } else if (is_type_array(skipped_return_type)) {
4652                                 errorf(HERE, "function returning array is not allowed");
4653                         } else {
4654                                 if (skipped_return_type->base.qualifiers != 0 && warning.other) {
4655                                         warningf(HERE,
4656                                                 "type qualifiers in return type of function type are meaningless");
4657                                 }
4658                         }
4659
4660                         /* The function type was constructed earlier.  Freeing it here will
4661                          * destroy other types. */
4662                         type = typehash_insert(function_type);
4663                         continue;
4664                 }
4665
4666                 case CONSTRUCT_POINTER: {
4667                         if (is_type_reference(skip_typeref(type)))
4668                                 errorf(HERE, "cannot declare a pointer to reference");
4669
4670                         parsed_pointer_t *parsed_pointer = (parsed_pointer_t*) iter;
4671                         type = make_based_pointer_type(type, parsed_pointer->type_qualifiers, parsed_pointer->base_variable);
4672                         continue;
4673                 }
4674
4675                 case CONSTRUCT_REFERENCE:
4676                         if (is_type_reference(skip_typeref(type)))
4677                                 errorf(HERE, "cannot declare a reference to reference");
4678
4679                         type = make_reference_type(type);
4680                         continue;
4681
4682                 case CONSTRUCT_ARRAY: {
4683                         if (is_type_reference(skip_typeref(type)))
4684                                 errorf(HERE, "cannot declare an array of references");
4685
4686                         parsed_array_t *parsed_array  = (parsed_array_t*) iter;
4687                         type_t         *array_type    = allocate_type_zero(TYPE_ARRAY);
4688
4689                         expression_t *size_expression = parsed_array->size;
4690                         if (size_expression != NULL) {
4691                                 size_expression
4692                                         = create_implicit_cast(size_expression, type_size_t);
4693                         }
4694
4695                         array_type->base.qualifiers       = parsed_array->type_qualifiers;
4696                         array_type->array.element_type    = type;
4697                         array_type->array.is_static       = parsed_array->is_static;
4698                         array_type->array.is_variable     = parsed_array->is_variable;
4699                         array_type->array.size_expression = size_expression;
4700
4701                         if (size_expression != NULL) {
4702                                 if (is_constant_expression(size_expression)) {
4703                                         array_type->array.size_constant = true;
4704                                         array_type->array.size
4705                                                 = fold_constant(size_expression);
4706                                 } else {
4707                                         array_type->array.is_vla = true;
4708                                 }
4709                         }
4710
4711                         type_t *skipped_type = skip_typeref(type);
4712                         /* §6.7.5.2:1 */
4713                         if (is_type_incomplete(skipped_type)) {
4714                                 errorf(HERE, "array of incomplete type '%T' is not allowed", type);
4715                         } else if (is_type_function(skipped_type)) {
4716                                 errorf(HERE, "array of functions is not allowed");
4717                         }
4718                         type = identify_new_type(array_type);
4719                         continue;
4720                 }
4721                 }
4722                 internal_errorf(HERE, "invalid type construction found");
4723         }
4724
4725         return type;
4726 }
4727
4728 static type_t *automatic_type_conversion(type_t *orig_type);
4729
4730 static type_t *semantic_parameter(const source_position_t *pos,
4731                                   type_t *type,
4732                                   const declaration_specifiers_t *specifiers,
4733                                   symbol_t *symbol)
4734 {
4735         /* §6.7.5.3:7  A declaration of a parameter as ``array of type''
4736          *             shall be adjusted to ``qualified pointer to type'',
4737          *             [...]
4738          * §6.7.5.3:8  A declaration of a parameter as ``function returning
4739          *             type'' shall be adjusted to ``pointer to function
4740          *             returning type'', as in 6.3.2.1. */
4741         type = automatic_type_conversion(type);
4742
4743         if (specifiers->is_inline && is_type_valid(type)) {
4744                 errorf(pos, "parameter '%Y' declared 'inline'", symbol);
4745         }
4746
4747         /* §6.9.1:6  The declarations in the declaration list shall contain
4748          *           no storage-class specifier other than register and no
4749          *           initializations. */
4750         if (specifiers->thread_local || (
4751                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
4752                         specifiers->storage_class != STORAGE_CLASS_REGISTER)
4753            ) {
4754                 errorf(pos, "invalid storage class for parameter '%Y'", symbol);
4755         }
4756
4757         /* delay test for incomplete type, because we might have (void)
4758          * which is legal but incomplete... */
4759
4760         return type;
4761 }
4762
4763 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
4764                                   declarator_flags_t flags)
4765 {
4766         parse_declarator_env_t env;
4767         memset(&env, 0, sizeof(env));
4768         env.modifiers = specifiers->modifiers;
4769
4770         construct_type_t *construct_type =
4771                 parse_inner_declarator(&env, (flags & DECL_MAY_BE_ABSTRACT) != 0);
4772         type_t           *orig_type      =
4773                 construct_declarator_type(construct_type, specifiers->type);
4774         type_t           *type           = skip_typeref(orig_type);
4775
4776         if (construct_type != NULL) {
4777                 obstack_free(&temp_obst, construct_type);
4778         }
4779
4780         entity_t *entity;
4781         if (specifiers->storage_class == STORAGE_CLASS_TYPEDEF) {
4782                 entity                       = allocate_entity_zero(ENTITY_TYPEDEF);
4783                 entity->base.symbol          = env.symbol;
4784                 entity->base.source_position = env.source_position;
4785                 entity->typedefe.type        = orig_type;
4786
4787                 if (anonymous_entity != NULL) {
4788                         if (is_type_compound(type)) {
4789                                 assert(anonymous_entity->compound.alias == NULL);
4790                                 assert(anonymous_entity->kind == ENTITY_STRUCT ||
4791                                        anonymous_entity->kind == ENTITY_UNION);
4792                                 anonymous_entity->compound.alias = entity;
4793                                 anonymous_entity = NULL;
4794                         } else if (is_type_enum(type)) {
4795                                 assert(anonymous_entity->enume.alias == NULL);
4796                                 assert(anonymous_entity->kind == ENTITY_ENUM);
4797                                 anonymous_entity->enume.alias = entity;
4798                                 anonymous_entity = NULL;
4799                         }
4800                 }
4801         } else {
4802                 /* create a declaration type entity */
4803                 if (flags & DECL_CREATE_COMPOUND_MEMBER) {
4804                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER);
4805
4806                         if (env.symbol != NULL) {
4807                                 if (specifiers->is_inline && is_type_valid(type)) {
4808                                         errorf(&env.source_position,
4809                                                         "compound member '%Y' declared 'inline'", env.symbol);
4810                                 }
4811
4812                                 if (specifiers->thread_local ||
4813                                                 specifiers->storage_class != STORAGE_CLASS_NONE) {
4814                                         errorf(&env.source_position,
4815                                                         "compound member '%Y' must have no storage class",
4816                                                         env.symbol);
4817                                 }
4818                         }
4819                 } else if (flags & DECL_IS_PARAMETER) {
4820                         orig_type = semantic_parameter(&env.source_position, orig_type,
4821                                                        specifiers, env.symbol);
4822
4823                         entity = allocate_entity_zero(ENTITY_PARAMETER);
4824                 } else if (is_type_function(type)) {
4825                         entity = allocate_entity_zero(ENTITY_FUNCTION);
4826
4827                         entity->function.is_inline  = specifiers->is_inline;
4828                         entity->function.parameters = env.parameters;
4829
4830                         if (env.symbol != NULL) {
4831                                 if (specifiers->thread_local || (
4832                                                         specifiers->storage_class != STORAGE_CLASS_EXTERN &&
4833                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
4834                                                         specifiers->storage_class != STORAGE_CLASS_STATIC
4835                                                 )) {
4836                                         errorf(&env.source_position,
4837                                                         "invalid storage class for function '%Y'", env.symbol);
4838                                 }
4839                         }
4840                 } else {
4841                         entity = allocate_entity_zero(ENTITY_VARIABLE);
4842
4843                         entity->variable.get_property_sym = specifiers->get_property_sym;
4844                         entity->variable.put_property_sym = specifiers->put_property_sym;
4845
4846                         entity->variable.thread_local = specifiers->thread_local;
4847
4848                         if (env.symbol != NULL) {
4849                                 if (specifiers->is_inline && is_type_valid(type)) {
4850                                         errorf(&env.source_position,
4851                                                         "variable '%Y' declared 'inline'", env.symbol);
4852                                 }
4853
4854                                 bool invalid_storage_class = false;
4855                                 if (current_scope == file_scope) {
4856                                         if (specifiers->storage_class != STORAGE_CLASS_EXTERN &&
4857                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
4858                                                         specifiers->storage_class != STORAGE_CLASS_STATIC) {
4859                                                 invalid_storage_class = true;
4860                                         }
4861                                 } else {
4862                                         if (specifiers->thread_local &&
4863                                                         specifiers->storage_class == STORAGE_CLASS_NONE) {
4864                                                 invalid_storage_class = true;
4865                                         }
4866                                 }
4867                                 if (invalid_storage_class) {
4868                                         errorf(&env.source_position,
4869                                                         "invalid storage class for variable '%Y'", env.symbol);
4870                                 }
4871                         }
4872                 }
4873
4874                 if (env.symbol != NULL) {
4875                         entity->base.symbol          = env.symbol;
4876                         entity->base.source_position = env.source_position;
4877                 } else {
4878                         entity->base.source_position = specifiers->source_position;
4879                 }
4880                 entity->base.namespc                  = NAMESPACE_NORMAL;
4881                 entity->declaration.type              = orig_type;
4882                 entity->declaration.modifiers         = env.modifiers;
4883                 entity->declaration.deprecated_string = specifiers->deprecated_string;
4884
4885                 storage_class_t storage_class = specifiers->storage_class;
4886                 entity->declaration.declared_storage_class = storage_class;
4887
4888                 if (storage_class == STORAGE_CLASS_NONE && current_scope != file_scope)
4889                         storage_class = STORAGE_CLASS_AUTO;
4890                 entity->declaration.storage_class = storage_class;
4891         }
4892
4893         parse_declaration_attributes(entity);
4894
4895         return entity;
4896 }
4897
4898 static type_t *parse_abstract_declarator(type_t *base_type)
4899 {
4900         construct_type_t *construct_type = parse_inner_declarator(NULL, 1);
4901
4902         type_t *result = construct_declarator_type(construct_type, base_type);
4903         if (construct_type != NULL) {
4904                 obstack_free(&temp_obst, construct_type);
4905         }
4906
4907         return result;
4908 }
4909
4910 /**
4911  * Check if the declaration of main is suspicious.  main should be a
4912  * function with external linkage, returning int, taking either zero
4913  * arguments, two, or three arguments of appropriate types, ie.
4914  *
4915  * int main([ int argc, char **argv [, char **env ] ]).
4916  *
4917  * @param decl    the declaration to check
4918  * @param type    the function type of the declaration
4919  */
4920 static void check_type_of_main(const entity_t *entity)
4921 {
4922         const source_position_t *pos = &entity->base.source_position;
4923         if (entity->kind != ENTITY_FUNCTION) {
4924                 warningf(pos, "'main' is not a function");
4925                 return;
4926         }
4927
4928         if (entity->declaration.storage_class == STORAGE_CLASS_STATIC) {
4929                 warningf(pos, "'main' is normally a non-static function");
4930         }
4931
4932         type_t *type = skip_typeref(entity->declaration.type);
4933         assert(is_type_function(type));
4934
4935         function_type_t *func_type = &type->function;
4936         if (!types_compatible(skip_typeref(func_type->return_type), type_int)) {
4937                 warningf(pos, "return type of 'main' should be 'int', but is '%T'",
4938                          func_type->return_type);
4939         }
4940         const function_parameter_t *parm = func_type->parameters;
4941         if (parm != NULL) {
4942                 type_t *const first_type = parm->type;
4943                 if (!types_compatible(skip_typeref(first_type), type_int)) {
4944                         warningf(pos,
4945                                  "first argument of 'main' should be 'int', but is '%T'",
4946                                  first_type);
4947                 }
4948                 parm = parm->next;
4949                 if (parm != NULL) {
4950                         type_t *const second_type = parm->type;
4951                         if (!types_compatible(skip_typeref(second_type), type_char_ptr_ptr)) {
4952                                 warningf(pos, "second argument of 'main' should be 'char**', but is '%T'", second_type);
4953                         }
4954                         parm = parm->next;
4955                         if (parm != NULL) {
4956                                 type_t *const third_type = parm->type;
4957                                 if (!types_compatible(skip_typeref(third_type), type_char_ptr_ptr)) {
4958                                         warningf(pos, "third argument of 'main' should be 'char**', but is '%T'", third_type);
4959                                 }
4960                                 parm = parm->next;
4961                                 if (parm != NULL)
4962                                         goto warn_arg_count;
4963                         }
4964                 } else {
4965 warn_arg_count:
4966                         warningf(pos, "'main' takes only zero, two or three arguments");
4967                 }
4968         }
4969 }
4970
4971 /**
4972  * Check if a symbol is the equal to "main".
4973  */
4974 static bool is_sym_main(const symbol_t *const sym)
4975 {
4976         return strcmp(sym->string, "main") == 0;
4977 }
4978
4979 static void error_redefined_as_different_kind(const source_position_t *pos,
4980                 const entity_t *old, entity_kind_t new_kind)
4981 {
4982         errorf(pos, "redeclaration of %s '%Y' as %s (declared %P)",
4983                get_entity_kind_name(old->kind), old->base.symbol,
4984                get_entity_kind_name(new_kind), &old->base.source_position);
4985 }
4986
4987 static bool is_error_entity(entity_t *const ent)
4988 {
4989         if (is_declaration(ent)) {
4990                 return is_type_valid(skip_typeref(ent->declaration.type));
4991         } else if (ent->kind == ENTITY_TYPEDEF) {
4992                 return is_type_valid(skip_typeref(ent->typedefe.type));
4993         }
4994         return false;
4995 }
4996
4997 /**
4998  * record entities for the NAMESPACE_NORMAL, and produce error messages/warnings
4999  * for various problems that occur for multiple definitions
5000  */
5001 static entity_t *record_entity(entity_t *entity, const bool is_definition)
5002 {
5003         const symbol_t *const    symbol  = entity->base.symbol;
5004         const namespace_tag_t    namespc = (namespace_tag_t)entity->base.namespc;
5005         const source_position_t *pos     = &entity->base.source_position;
5006
5007         /* can happen in error cases */
5008         if (symbol == NULL)
5009                 return entity;
5010
5011         entity_t *const previous_entity = get_entity(symbol, namespc);
5012         /* pushing the same entity twice will break the stack structure */
5013         assert(previous_entity != entity);
5014
5015         if (entity->kind == ENTITY_FUNCTION) {
5016                 type_t *const orig_type = entity->declaration.type;
5017                 type_t *const type      = skip_typeref(orig_type);
5018
5019                 assert(is_type_function(type));
5020                 if (type->function.unspecified_parameters &&
5021                                 warning.strict_prototypes &&
5022                                 previous_entity == NULL) {
5023                         warningf(pos, "function declaration '%#T' is not a prototype",
5024                                          orig_type, symbol);
5025                 }
5026
5027                 if (warning.main && current_scope == file_scope
5028                                 && is_sym_main(symbol)) {
5029                         check_type_of_main(entity);
5030                 }
5031         }
5032
5033         if (is_declaration(entity) &&
5034                         warning.nested_externs &&
5035                         entity->declaration.storage_class == STORAGE_CLASS_EXTERN &&
5036                         current_scope != file_scope) {
5037                 warningf(pos, "nested extern declaration of '%#T'",
5038                          entity->declaration.type, symbol);
5039         }
5040
5041         if (previous_entity != NULL) {
5042                 if (previous_entity->base.parent_scope == &current_function->parameters &&
5043                                 previous_entity->base.parent_scope->depth + 1 == current_scope->depth) {
5044                         assert(previous_entity->kind == ENTITY_PARAMETER);
5045                         errorf(pos,
5046                                         "declaration '%#T' redeclares the parameter '%#T' (declared %P)",
5047                                         entity->declaration.type, symbol,
5048                                         previous_entity->declaration.type, symbol,
5049                                         &previous_entity->base.source_position);
5050                         goto finish;
5051                 }
5052
5053                 if (previous_entity->base.parent_scope == current_scope) {
5054                         if (previous_entity->kind != entity->kind) {
5055                                 if (!is_error_entity(previous_entity) && !is_error_entity(entity)) {
5056                                         error_redefined_as_different_kind(pos, previous_entity,
5057                                                         entity->kind);
5058                                 }
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 *const 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                                 storage_class_t new_storage_class = decl->storage_class;
5114
5115                                 /* pretend no storage class means extern for function
5116                                  * declarations (except if the previous declaration is neither
5117                                  * none nor extern) */
5118                                 if (entity->kind == ENTITY_FUNCTION) {
5119                                         /* the previous declaration could have unspecified parameters or
5120                                          * be a typedef, so use the new type */
5121                                         if (prev_type->function.unspecified_parameters || is_definition)
5122                                                 prev_decl->type = type;
5123
5124                                         switch (old_storage_class) {
5125                                                 case STORAGE_CLASS_NONE:
5126                                                         old_storage_class = STORAGE_CLASS_EXTERN;
5127                                                         /* FALLTHROUGH */
5128
5129                                                 case STORAGE_CLASS_EXTERN:
5130                                                         if (is_definition) {
5131                                                                 if (warning.missing_prototypes &&
5132                                                                                 prev_type->function.unspecified_parameters &&
5133                                                                                 !is_sym_main(symbol)) {
5134                                                                         warningf(pos, "no previous prototype for '%#T'",
5135                                                                                         orig_type, symbol);
5136                                                                 }
5137                                                         } else if (new_storage_class == STORAGE_CLASS_NONE) {
5138                                                                 new_storage_class = STORAGE_CLASS_EXTERN;
5139                                                         }
5140                                                         break;
5141
5142                                                 default:
5143                                                         break;
5144                                         }
5145                                 } else if (is_type_incomplete(prev_type)) {
5146                                         prev_decl->type = type;
5147                                 }
5148
5149                                 if (old_storage_class == STORAGE_CLASS_EXTERN &&
5150                                                 new_storage_class == STORAGE_CLASS_EXTERN) {
5151 warn_redundant_declaration:
5152                                         if (!is_definition           &&
5153                                                         warning.redundant_decls  &&
5154                                                         is_type_valid(prev_type) &&
5155                                                         strcmp(previous_entity->base.source_position.input_name,
5156                                                                 "<builtin>") != 0) {
5157                                                 warningf(pos,
5158                                                                 "redundant declaration for '%Y' (declared %P)",
5159                                                                 symbol, &previous_entity->base.source_position);
5160                                         }
5161                                 } else if (current_function == NULL) {
5162                                         if (old_storage_class != STORAGE_CLASS_STATIC &&
5163                                                         new_storage_class == STORAGE_CLASS_STATIC) {
5164                                                 errorf(pos,
5165                                                                 "static declaration of '%Y' follows non-static declaration (declared %P)",
5166                                                                 symbol, &previous_entity->base.source_position);
5167                                         } else if (old_storage_class == STORAGE_CLASS_EXTERN) {
5168                                                 prev_decl->storage_class          = STORAGE_CLASS_NONE;
5169                                                 prev_decl->declared_storage_class = STORAGE_CLASS_NONE;
5170                                         } else {
5171                                                 /* ISO/IEC 14882:1998(E) §C.1.2:1 */
5172                                                 if (c_mode & _CXX)
5173                                                         goto error_redeclaration;
5174                                                 goto warn_redundant_declaration;
5175                                         }
5176                                 } else if (is_type_valid(prev_type)) {
5177                                         if (old_storage_class == new_storage_class) {
5178 error_redeclaration:
5179                                                 errorf(pos, "redeclaration of '%Y' (declared %P)",
5180                                                                 symbol, &previous_entity->base.source_position);
5181                                         } else {
5182                                                 errorf(pos,
5183                                                                 "redeclaration of '%Y' with different linkage (declared %P)",
5184                                                                 symbol, &previous_entity->base.source_position);
5185                                         }
5186                                 }
5187                         }
5188
5189                         prev_decl->modifiers |= decl->modifiers;
5190                         if (entity->kind == ENTITY_FUNCTION) {
5191                                 previous_entity->function.is_inline |= entity->function.is_inline;
5192                         }
5193                         return previous_entity;
5194                 }
5195
5196                 if (warning.shadow) {
5197                         warningf(pos, "%s '%Y' shadows %s (declared %P)",
5198                                         get_entity_kind_name(entity->kind), symbol,
5199                                         get_entity_kind_name(previous_entity->kind),
5200                                         &previous_entity->base.source_position);
5201                 }
5202         }
5203
5204         if (entity->kind == ENTITY_FUNCTION) {
5205                 if (is_definition &&
5206                                 entity->declaration.storage_class != STORAGE_CLASS_STATIC) {
5207                         if (warning.missing_prototypes && !is_sym_main(symbol)) {
5208                                 warningf(pos, "no previous prototype for '%#T'",
5209                                          entity->declaration.type, symbol);
5210                         } else if (warning.missing_declarations && !is_sym_main(symbol)) {
5211                                 warningf(pos, "no previous declaration for '%#T'",
5212                                          entity->declaration.type, symbol);
5213                         }
5214                 }
5215         } else if (warning.missing_declarations &&
5216                         entity->kind == ENTITY_VARIABLE &&
5217                         current_scope == file_scope) {
5218                 declaration_t *declaration = &entity->declaration;
5219                 if (declaration->storage_class == STORAGE_CLASS_NONE) {
5220                         warningf(pos, "no previous declaration for '%#T'",
5221                                  declaration->type, symbol);
5222                 }
5223         }
5224
5225 finish:
5226         assert(entity->base.parent_scope == NULL);
5227         assert(current_scope != NULL);
5228
5229         entity->base.parent_scope = current_scope;
5230         entity->base.namespc      = NAMESPACE_NORMAL;
5231         environment_push(entity);
5232         append_entity(current_scope, entity);
5233
5234         return entity;
5235 }
5236
5237 static void parser_error_multiple_definition(entity_t *entity,
5238                 const source_position_t *source_position)
5239 {
5240         errorf(source_position, "multiple definition of '%Y' (declared %P)",
5241                entity->base.symbol, &entity->base.source_position);
5242 }
5243
5244 static bool is_declaration_specifier(const token_t *token,
5245                                      bool only_specifiers_qualifiers)
5246 {
5247         switch (token->type) {
5248                 TYPE_SPECIFIERS
5249                 TYPE_QUALIFIERS
5250                         return true;
5251                 case T_IDENTIFIER:
5252                         return is_typedef_symbol(token->v.symbol);
5253
5254                 case T___extension__:
5255                 STORAGE_CLASSES
5256                         return !only_specifiers_qualifiers;
5257
5258                 default:
5259                         return false;
5260         }
5261 }
5262
5263 static void parse_init_declarator_rest(entity_t *entity)
5264 {
5265         assert(is_declaration(entity));
5266         declaration_t *const declaration = &entity->declaration;
5267
5268         eat('=');
5269
5270         type_t *orig_type = declaration->type;
5271         type_t *type      = skip_typeref(orig_type);
5272
5273         if (entity->kind == ENTITY_VARIABLE
5274                         && entity->variable.initializer != NULL) {
5275                 parser_error_multiple_definition(entity, HERE);
5276         }
5277
5278         bool must_be_constant = false;
5279         if (declaration->storage_class == STORAGE_CLASS_STATIC ||
5280             entity->base.parent_scope  == file_scope) {
5281                 must_be_constant = true;
5282         }
5283
5284         if (is_type_function(type)) {
5285                 errorf(&entity->base.source_position,
5286                        "function '%#T' is initialized like a variable",
5287                        orig_type, entity->base.symbol);
5288                 orig_type = type_error_type;
5289         }
5290
5291         parse_initializer_env_t env;
5292         env.type             = orig_type;
5293         env.must_be_constant = must_be_constant;
5294         env.entity           = entity;
5295         current_init_decl    = entity;
5296
5297         initializer_t *initializer = parse_initializer(&env);
5298         current_init_decl = NULL;
5299
5300         if (entity->kind == ENTITY_VARIABLE) {
5301                 /* §6.7.5:22  array initializers for arrays with unknown size
5302                  * determine the array type size */
5303                 declaration->type            = env.type;
5304                 entity->variable.initializer = initializer;
5305         }
5306 }
5307
5308 /* parse rest of a declaration without any declarator */
5309 static void parse_anonymous_declaration_rest(
5310                 const declaration_specifiers_t *specifiers)
5311 {
5312         eat(';');
5313         anonymous_entity = NULL;
5314
5315         if (warning.other) {
5316                 if (specifiers->storage_class != STORAGE_CLASS_NONE ||
5317                                 specifiers->thread_local) {
5318                         warningf(&specifiers->source_position,
5319                                  "useless storage class in empty declaration");
5320                 }
5321
5322                 type_t *type = specifiers->type;
5323                 switch (type->kind) {
5324                         case TYPE_COMPOUND_STRUCT:
5325                         case TYPE_COMPOUND_UNION: {
5326                                 if (type->compound.compound->base.symbol == NULL) {
5327                                         warningf(&specifiers->source_position,
5328                                                  "unnamed struct/union that defines no instances");
5329                                 }
5330                                 break;
5331                         }
5332
5333                         case TYPE_ENUM:
5334                                 break;
5335
5336                         default:
5337                                 warningf(&specifiers->source_position, "empty declaration");
5338                                 break;
5339                 }
5340         }
5341 }
5342
5343 static void check_variable_type_complete(entity_t *ent)
5344 {
5345         if (ent->kind != ENTITY_VARIABLE)
5346                 return;
5347
5348         /* §6.7:7  If an identifier for an object is declared with no linkage, the
5349          *         type for the object shall be complete [...] */
5350         declaration_t *decl = &ent->declaration;
5351         if (decl->storage_class == STORAGE_CLASS_EXTERN ||
5352                         decl->storage_class == STORAGE_CLASS_STATIC)
5353                 return;
5354
5355         type_t *const orig_type = decl->type;
5356         type_t *const type      = skip_typeref(orig_type);
5357         if (!is_type_incomplete(type))
5358                 return;
5359
5360         /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
5361          * are given length one. */
5362         if (is_type_array(type) && ent->base.parent_scope == file_scope) {
5363                 ARR_APP1(declaration_t*, incomplete_arrays, decl);
5364                 return;
5365         }
5366
5367         errorf(&ent->base.source_position, "variable '%#T' has incomplete type",
5368                         orig_type, ent->base.symbol);
5369 }
5370
5371
5372 static void parse_declaration_rest(entity_t *ndeclaration,
5373                 const declaration_specifiers_t *specifiers,
5374                 parsed_declaration_func         finished_declaration,
5375                 declarator_flags_t              flags)
5376 {
5377         add_anchor_token(';');
5378         add_anchor_token(',');
5379         while (true) {
5380                 entity_t *entity = finished_declaration(ndeclaration, token.type == '=');
5381
5382                 if (token.type == '=') {
5383                         parse_init_declarator_rest(entity);
5384                 } else if (entity->kind == ENTITY_VARIABLE) {
5385                         /* ISO/IEC 14882:1998(E) §8.5.3:3  The initializer can be omitted
5386                          * [...] where the extern specifier is explicitly used. */
5387                         declaration_t *decl = &entity->declaration;
5388                         if (decl->storage_class != STORAGE_CLASS_EXTERN) {
5389                                 type_t *type = decl->type;
5390                                 if (is_type_reference(skip_typeref(type))) {
5391                                         errorf(&entity->base.source_position,
5392                                                         "reference '%#T' must be initialized",
5393                                                         type, entity->base.symbol);
5394                                 }
5395                         }
5396                 }
5397
5398                 check_variable_type_complete(entity);
5399
5400                 if (token.type != ',')
5401                         break;
5402                 eat(',');
5403
5404                 add_anchor_token('=');
5405                 ndeclaration = parse_declarator(specifiers, flags);
5406                 rem_anchor_token('=');
5407         }
5408         expect(';', end_error);
5409
5410 end_error:
5411         anonymous_entity = NULL;
5412         rem_anchor_token(';');
5413         rem_anchor_token(',');
5414 }
5415
5416 static entity_t *finished_kr_declaration(entity_t *entity, bool is_definition)
5417 {
5418         symbol_t *symbol = entity->base.symbol;
5419         if (symbol == NULL) {
5420                 errorf(HERE, "anonymous declaration not valid as function parameter");
5421                 return entity;
5422         }
5423
5424         assert(entity->base.namespc == NAMESPACE_NORMAL);
5425         entity_t *previous_entity = get_entity(symbol, NAMESPACE_NORMAL);
5426         if (previous_entity == NULL
5427                         || previous_entity->base.parent_scope != current_scope) {
5428                 errorf(HERE, "expected declaration of a function parameter, found '%Y'",
5429                        symbol);
5430                 return entity;
5431         }
5432
5433         if (is_definition) {
5434                 errorf(HERE, "parameter '%Y' is initialised", entity->base.symbol);
5435         }
5436
5437         return record_entity(entity, false);
5438 }
5439
5440 static void parse_declaration(parsed_declaration_func finished_declaration,
5441                               declarator_flags_t      flags)
5442 {
5443         declaration_specifiers_t specifiers;
5444         memset(&specifiers, 0, sizeof(specifiers));
5445
5446         add_anchor_token(';');
5447         parse_declaration_specifiers(&specifiers);
5448         rem_anchor_token(';');
5449
5450         if (token.type == ';') {
5451                 parse_anonymous_declaration_rest(&specifiers);
5452         } else {
5453                 entity_t *entity = parse_declarator(&specifiers, flags);
5454                 parse_declaration_rest(entity, &specifiers, finished_declaration, flags);
5455         }
5456 }
5457
5458 static type_t *get_default_promoted_type(type_t *orig_type)
5459 {
5460         type_t *result = orig_type;
5461
5462         type_t *type = skip_typeref(orig_type);
5463         if (is_type_integer(type)) {
5464                 result = promote_integer(type);
5465         } else if (is_type_atomic(type, ATOMIC_TYPE_FLOAT)) {
5466                 result = type_double;
5467         }
5468
5469         return result;
5470 }
5471
5472 static void parse_kr_declaration_list(entity_t *entity)
5473 {
5474         if (entity->kind != ENTITY_FUNCTION)
5475                 return;
5476
5477         type_t *type = skip_typeref(entity->declaration.type);
5478         assert(is_type_function(type));
5479         if (!type->function.kr_style_parameters)
5480                 return;
5481
5482
5483         add_anchor_token('{');
5484
5485         /* push function parameters */
5486         size_t const  top       = environment_top();
5487         scope_t      *old_scope = scope_push(&entity->function.parameters);
5488
5489         entity_t *parameter = entity->function.parameters.entities;
5490         for ( ; parameter != NULL; parameter = parameter->base.next) {
5491                 assert(parameter->base.parent_scope == NULL);
5492                 parameter->base.parent_scope = current_scope;
5493                 environment_push(parameter);
5494         }
5495
5496         /* parse declaration list */
5497         for (;;) {
5498                 switch (token.type) {
5499                         DECLARATION_START
5500                         case T___extension__:
5501                         /* This covers symbols, which are no type, too, and results in
5502                          * better error messages.  The typical cases are misspelled type
5503                          * names and missing includes. */
5504                         case T_IDENTIFIER:
5505                                 parse_declaration(finished_kr_declaration, DECL_IS_PARAMETER);
5506                                 break;
5507                         default:
5508                                 goto decl_list_end;
5509                 }
5510         }
5511 decl_list_end:
5512
5513         /* pop function parameters */
5514         assert(current_scope == &entity->function.parameters);
5515         scope_pop(old_scope);
5516         environment_pop_to(top);
5517
5518         /* update function type */
5519         type_t *new_type = duplicate_type(type);
5520
5521         function_parameter_t *parameters     = NULL;
5522         function_parameter_t *last_parameter = NULL;
5523
5524         parameter = entity->function.parameters.entities;
5525         for (; parameter != NULL; parameter = parameter->base.next) {
5526                 if (parameter->kind != ENTITY_PARAMETER)
5527                         continue;
5528
5529                 type_t *parameter_type = parameter->declaration.type;
5530                 if (parameter_type == NULL) {
5531                         if (strict_mode) {
5532                                 errorf(HERE, "no type specified for function parameter '%Y'",
5533                                        parameter->base.symbol);
5534                         } else {
5535                                 if (warning.implicit_int) {
5536                                         warningf(HERE, "no type specified for function parameter '%Y', using 'int'",
5537                                                  parameter->base.symbol);
5538                                 }
5539                                 parameter_type              = type_int;
5540                                 parameter->declaration.type = parameter_type;
5541                         }
5542                 }
5543
5544                 semantic_parameter_incomplete(parameter);
5545                 parameter_type = parameter->declaration.type;
5546
5547                 /*
5548                  * we need the default promoted types for the function type
5549                  */
5550                 parameter_type = get_default_promoted_type(parameter_type);
5551
5552                 function_parameter_t *function_parameter
5553                         = obstack_alloc(type_obst, sizeof(function_parameter[0]));
5554                 memset(function_parameter, 0, sizeof(function_parameter[0]));
5555
5556                 function_parameter->type = parameter_type;
5557                 if (last_parameter != NULL) {
5558                         last_parameter->next = function_parameter;
5559                 } else {
5560                         parameters = function_parameter;
5561                 }
5562                 last_parameter = function_parameter;
5563         }
5564
5565         /* §6.9.1.7: A K&R style parameter list does NOT act as a function
5566          * prototype */
5567         new_type->function.parameters             = parameters;
5568         new_type->function.unspecified_parameters = true;
5569
5570         new_type = identify_new_type(new_type);
5571
5572         entity->declaration.type = new_type;
5573
5574         rem_anchor_token('{');
5575 }
5576
5577 static bool first_err = true;
5578
5579 /**
5580  * When called with first_err set, prints the name of the current function,
5581  * else does noting.
5582  */
5583 static void print_in_function(void)
5584 {
5585         if (first_err) {
5586                 first_err = false;
5587                 diagnosticf("%s: In function '%Y':\n",
5588                             current_function->base.base.source_position.input_name,
5589                             current_function->base.base.symbol);
5590         }
5591 }
5592
5593 /**
5594  * Check if all labels are defined in the current function.
5595  * Check if all labels are used in the current function.
5596  */
5597 static void check_labels(void)
5598 {
5599         for (const goto_statement_t *goto_statement = goto_first;
5600             goto_statement != NULL;
5601             goto_statement = goto_statement->next) {
5602                 /* skip computed gotos */
5603                 if (goto_statement->expression != NULL)
5604                         continue;
5605
5606                 label_t *label = goto_statement->label;
5607
5608                 label->used = true;
5609                 if (label->base.source_position.input_name == NULL) {
5610                         print_in_function();
5611                         errorf(&goto_statement->base.source_position,
5612                                "label '%Y' used but not defined", label->base.symbol);
5613                  }
5614         }
5615
5616         if (warning.unused_label) {
5617                 for (const label_statement_t *label_statement = label_first;
5618                          label_statement != NULL;
5619                          label_statement = label_statement->next) {
5620                         label_t *label = label_statement->label;
5621
5622                         if (! label->used) {
5623                                 print_in_function();
5624                                 warningf(&label_statement->base.source_position,
5625                                          "label '%Y' defined but not used", label->base.symbol);
5626                         }
5627                 }
5628         }
5629 }
5630
5631 static void warn_unused_entity(entity_t *entity, entity_t *last)
5632 {
5633         entity_t const *const end = last != NULL ? last->base.next : NULL;
5634         for (; entity != end; entity = entity->base.next) {
5635                 if (!is_declaration(entity))
5636                         continue;
5637
5638                 declaration_t *declaration = &entity->declaration;
5639                 if (declaration->implicit)
5640                         continue;
5641
5642                 if (!declaration->used) {
5643                         print_in_function();
5644                         const char *what = get_entity_kind_name(entity->kind);
5645                         warningf(&entity->base.source_position, "%s '%Y' is unused",
5646                                  what, entity->base.symbol);
5647                 } else if (entity->kind == ENTITY_VARIABLE && !entity->variable.read) {
5648                         print_in_function();
5649                         const char *what = get_entity_kind_name(entity->kind);
5650                         warningf(&entity->base.source_position, "%s '%Y' is never read",
5651                                  what, entity->base.symbol);
5652                 }
5653         }
5654 }
5655
5656 static void check_unused_variables(statement_t *const stmt, void *const env)
5657 {
5658         (void)env;
5659
5660         switch (stmt->kind) {
5661                 case STATEMENT_DECLARATION: {
5662                         declaration_statement_t const *const decls = &stmt->declaration;
5663                         warn_unused_entity(decls->declarations_begin,
5664                                            decls->declarations_end);
5665                         return;
5666                 }
5667
5668                 case STATEMENT_FOR:
5669                         warn_unused_entity(stmt->fors.scope.entities, NULL);
5670                         return;
5671
5672                 default:
5673                         return;
5674         }
5675 }
5676
5677 /**
5678  * Check declarations of current_function for unused entities.
5679  */
5680 static void check_declarations(void)
5681 {
5682         if (warning.unused_parameter) {
5683                 const scope_t *scope = &current_function->parameters;
5684
5685                 /* do not issue unused warnings for main */
5686                 if (!is_sym_main(current_function->base.base.symbol)) {
5687                         warn_unused_entity(scope->entities, NULL);
5688                 }
5689         }
5690         if (warning.unused_variable) {
5691                 walk_statements(current_function->statement, check_unused_variables,
5692                                 NULL);
5693         }
5694 }
5695
5696 static int determine_truth(expression_t const* const cond)
5697 {
5698         return
5699                 !is_constant_expression(cond) ? 0 :
5700                 fold_constant(cond) != 0      ? 1 :
5701                 -1;
5702 }
5703
5704 static void check_reachable(statement_t *);
5705 static bool reaches_end;
5706
5707 static bool expression_returns(expression_t const *const expr)
5708 {
5709         switch (expr->kind) {
5710                 case EXPR_CALL: {
5711                         expression_t const *const func = expr->call.function;
5712                         if (func->kind == EXPR_REFERENCE) {
5713                                 entity_t *entity = func->reference.entity;
5714                                 if (entity->kind == ENTITY_FUNCTION
5715                                                 && entity->declaration.modifiers & DM_NORETURN)
5716                                         return false;
5717                         }
5718
5719                         if (!expression_returns(func))
5720                                 return false;
5721
5722                         for (call_argument_t const* arg = expr->call.arguments; arg != NULL; arg = arg->next) {
5723                                 if (!expression_returns(arg->expression))
5724                                         return false;
5725                         }
5726
5727                         return true;
5728                 }
5729
5730                 case EXPR_REFERENCE:
5731                 case EXPR_REFERENCE_ENUM_VALUE:
5732                 case EXPR_CONST:
5733                 case EXPR_CHARACTER_CONSTANT:
5734                 case EXPR_WIDE_CHARACTER_CONSTANT:
5735                 case EXPR_STRING_LITERAL:
5736                 case EXPR_WIDE_STRING_LITERAL:
5737                 case EXPR_COMPOUND_LITERAL: // TODO descend into initialisers
5738                 case EXPR_LABEL_ADDRESS:
5739                 case EXPR_CLASSIFY_TYPE:
5740                 case EXPR_SIZEOF: // TODO handle obscure VLA case
5741                 case EXPR_ALIGNOF:
5742                 case EXPR_FUNCNAME:
5743                 case EXPR_BUILTIN_CONSTANT_P:
5744                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
5745                 case EXPR_OFFSETOF:
5746                 case EXPR_INVALID:
5747                         return true;
5748
5749                 case EXPR_STATEMENT: {
5750                         bool old_reaches_end = reaches_end;
5751                         reaches_end = false;
5752                         check_reachable(expr->statement.statement);
5753                         bool returns = reaches_end;
5754                         reaches_end = old_reaches_end;
5755                         return returns;
5756                 }
5757
5758                 case EXPR_CONDITIONAL:
5759                         // TODO handle constant expression
5760
5761                         if (!expression_returns(expr->conditional.condition))
5762                                 return false;
5763
5764                         if (expr->conditional.true_expression != NULL
5765                                         && expression_returns(expr->conditional.true_expression))
5766                                 return true;
5767
5768                         return expression_returns(expr->conditional.false_expression);
5769
5770                 case EXPR_SELECT:
5771                         return expression_returns(expr->select.compound);
5772
5773                 case EXPR_ARRAY_ACCESS:
5774                         return
5775                                 expression_returns(expr->array_access.array_ref) &&
5776                                 expression_returns(expr->array_access.index);
5777
5778                 case EXPR_VA_START:
5779                         return expression_returns(expr->va_starte.ap);
5780
5781                 case EXPR_VA_ARG:
5782                         return expression_returns(expr->va_arge.ap);
5783
5784                 EXPR_UNARY_CASES_MANDATORY
5785                         return expression_returns(expr->unary.value);
5786
5787                 case EXPR_UNARY_THROW:
5788                         return false;
5789
5790                 EXPR_BINARY_CASES
5791                         // TODO handle constant lhs of && and ||
5792                         return
5793                                 expression_returns(expr->binary.left) &&
5794                                 expression_returns(expr->binary.right);
5795
5796                 case EXPR_UNKNOWN:
5797                         break;
5798         }
5799
5800         panic("unhandled expression");
5801 }
5802
5803 static bool initializer_returns(initializer_t const *const init)
5804 {
5805         switch (init->kind) {
5806                 case INITIALIZER_VALUE:
5807                         return expression_returns(init->value.value);
5808
5809                 case INITIALIZER_LIST: {
5810                         initializer_t * const*       i       = init->list.initializers;
5811                         initializer_t * const* const end     = i + init->list.len;
5812                         bool                         returns = true;
5813                         for (; i != end; ++i) {
5814                                 if (!initializer_returns(*i))
5815                                         returns = false;
5816                         }
5817                         return returns;
5818                 }
5819
5820                 case INITIALIZER_STRING:
5821                 case INITIALIZER_WIDE_STRING:
5822                 case INITIALIZER_DESIGNATOR: // designators have no payload
5823                         return true;
5824         }
5825         panic("unhandled initializer");
5826 }
5827
5828 static bool noreturn_candidate;
5829
5830 static void check_reachable(statement_t *const stmt)
5831 {
5832         if (stmt->base.reachable)
5833                 return;
5834         if (stmt->kind != STATEMENT_DO_WHILE)
5835                 stmt->base.reachable = true;
5836
5837         statement_t *last = stmt;
5838         statement_t *next;
5839         switch (stmt->kind) {
5840                 case STATEMENT_INVALID:
5841                 case STATEMENT_EMPTY:
5842                 case STATEMENT_ASM:
5843                         next = stmt->base.next;
5844                         break;
5845
5846                 case STATEMENT_DECLARATION: {
5847                         declaration_statement_t const *const decl = &stmt->declaration;
5848                         entity_t                const *      ent  = decl->declarations_begin;
5849                         entity_t                const *const last = decl->declarations_end;
5850                         if (ent != NULL) {
5851                                 for (;; ent = ent->base.next) {
5852                                         if (ent->kind                 == ENTITY_VARIABLE &&
5853                                                         ent->variable.initializer != NULL            &&
5854                                                         !initializer_returns(ent->variable.initializer)) {
5855                                                 return;
5856                                         }
5857                                         if (ent == last)
5858                                                 break;
5859                                 }
5860                         }
5861                         next = stmt->base.next;
5862                         break;
5863                 }
5864
5865                 case STATEMENT_COMPOUND:
5866                         next = stmt->compound.statements;
5867                         if (next == NULL)
5868                                 next = stmt->base.next;
5869                         break;
5870
5871                 case STATEMENT_RETURN: {
5872                         expression_t const *const val = stmt->returns.value;
5873                         if (val == NULL || expression_returns(val))
5874                                 noreturn_candidate = false;
5875                         return;
5876                 }
5877
5878                 case STATEMENT_IF: {
5879                         if_statement_t const *const ifs  = &stmt->ifs;
5880                         expression_t   const *const cond = ifs->condition;
5881
5882                         if (!expression_returns(cond))
5883                                 return;
5884
5885                         int const val = determine_truth(cond);
5886
5887                         if (val >= 0)
5888                                 check_reachable(ifs->true_statement);
5889
5890                         if (val > 0)
5891                                 return;
5892
5893                         if (ifs->false_statement != NULL) {
5894                                 check_reachable(ifs->false_statement);
5895                                 return;
5896                         }
5897
5898                         next = stmt->base.next;
5899                         break;
5900                 }
5901
5902                 case STATEMENT_SWITCH: {
5903                         switch_statement_t const *const switchs = &stmt->switchs;
5904                         expression_t       const *const expr    = switchs->expression;
5905
5906                         if (!expression_returns(expr))
5907                                 return;
5908
5909                         if (is_constant_expression(expr)) {
5910                                 long                    const val      = fold_constant(expr);
5911                                 case_label_statement_t *      defaults = NULL;
5912                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
5913                                         if (i->expression == NULL) {
5914                                                 defaults = i;
5915                                                 continue;
5916                                         }
5917
5918                                         if (i->first_case <= val && val <= i->last_case) {
5919                                                 check_reachable((statement_t*)i);
5920                                                 return;
5921                                         }
5922                                 }
5923
5924                                 if (defaults != NULL) {
5925                                         check_reachable((statement_t*)defaults);
5926                                         return;
5927                                 }
5928                         } else {
5929                                 bool has_default = false;
5930                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
5931                                         if (i->expression == NULL)
5932                                                 has_default = true;
5933
5934                                         check_reachable((statement_t*)i);
5935                                 }
5936
5937                                 if (has_default)
5938                                         return;
5939                         }
5940
5941                         next = stmt->base.next;
5942                         break;
5943                 }
5944
5945                 case STATEMENT_EXPRESSION: {
5946                         /* Check for noreturn function call */
5947                         expression_t const *const expr = stmt->expression.expression;
5948                         if (!expression_returns(expr))
5949                                 return;
5950
5951                         next = stmt->base.next;
5952                         break;
5953                 }
5954
5955                 case STATEMENT_CONTINUE: {
5956                         statement_t *parent = stmt;
5957                         for (;;) {
5958                                 parent = parent->base.parent;
5959                                 if (parent == NULL) /* continue not within loop */
5960                                         return;
5961
5962                                 next = parent;
5963                                 switch (parent->kind) {
5964                                         case STATEMENT_WHILE:    goto continue_while;
5965                                         case STATEMENT_DO_WHILE: goto continue_do_while;
5966                                         case STATEMENT_FOR:      goto continue_for;
5967
5968                                         default: break;
5969                                 }
5970                         }
5971                 }
5972
5973                 case STATEMENT_BREAK: {
5974                         statement_t *parent = stmt;
5975                         for (;;) {
5976                                 parent = parent->base.parent;
5977                                 if (parent == NULL) /* break not within loop/switch */
5978                                         return;
5979
5980                                 switch (parent->kind) {
5981                                         case STATEMENT_SWITCH:
5982                                         case STATEMENT_WHILE:
5983                                         case STATEMENT_DO_WHILE:
5984                                         case STATEMENT_FOR:
5985                                                 last = parent;
5986                                                 next = parent->base.next;
5987                                                 goto found_break_parent;
5988
5989                                         default: break;
5990                                 }
5991                         }
5992 found_break_parent:
5993                         break;
5994                 }
5995
5996                 case STATEMENT_GOTO:
5997                         if (stmt->gotos.expression) {
5998                                 if (!expression_returns(stmt->gotos.expression))
5999                                         return;
6000
6001                                 statement_t *parent = stmt->base.parent;
6002                                 if (parent == NULL) /* top level goto */
6003                                         return;
6004                                 next = parent;
6005                         } else {
6006                                 next = stmt->gotos.label->statement;
6007                                 if (next == NULL) /* missing label */
6008                                         return;
6009                         }
6010                         break;
6011
6012                 case STATEMENT_LABEL:
6013                         next = stmt->label.statement;
6014                         break;
6015
6016                 case STATEMENT_CASE_LABEL:
6017                         next = stmt->case_label.statement;
6018                         break;
6019
6020                 case STATEMENT_WHILE: {
6021                         while_statement_t const *const whiles = &stmt->whiles;
6022                         expression_t      const *const cond   = whiles->condition;
6023
6024                         if (!expression_returns(cond))
6025                                 return;
6026
6027                         int const val = determine_truth(cond);
6028
6029                         if (val >= 0)
6030                                 check_reachable(whiles->body);
6031
6032                         if (val > 0)
6033                                 return;
6034
6035                         next = stmt->base.next;
6036                         break;
6037                 }
6038
6039                 case STATEMENT_DO_WHILE:
6040                         next = stmt->do_while.body;
6041                         break;
6042
6043                 case STATEMENT_FOR: {
6044                         for_statement_t *const fors = &stmt->fors;
6045
6046                         if (fors->condition_reachable)
6047                                 return;
6048                         fors->condition_reachable = true;
6049
6050                         expression_t const *const cond = fors->condition;
6051
6052                         int val;
6053                         if (cond == NULL) {
6054                                 val = 1;
6055                         } else if (expression_returns(cond)) {
6056                                 val = determine_truth(cond);
6057                         } else {
6058                                 return;
6059                         }
6060
6061                         if (val >= 0)
6062                                 check_reachable(fors->body);
6063
6064                         if (val > 0)
6065                                 return;
6066
6067                         next = stmt->base.next;
6068                         break;
6069                 }
6070
6071                 case STATEMENT_MS_TRY: {
6072                         ms_try_statement_t const *const ms_try = &stmt->ms_try;
6073                         check_reachable(ms_try->try_statement);
6074                         next = ms_try->final_statement;
6075                         break;
6076                 }
6077
6078                 case STATEMENT_LEAVE: {
6079                         statement_t *parent = stmt;
6080                         for (;;) {
6081                                 parent = parent->base.parent;
6082                                 if (parent == NULL) /* __leave not within __try */
6083                                         return;
6084
6085                                 if (parent->kind == STATEMENT_MS_TRY) {
6086                                         last = parent;
6087                                         next = parent->ms_try.final_statement;
6088                                         break;
6089                                 }
6090                         }
6091                         break;
6092                 }
6093
6094                 default:
6095                         panic("invalid statement kind");
6096         }
6097
6098         while (next == NULL) {
6099                 next = last->base.parent;
6100                 if (next == NULL) {
6101                         noreturn_candidate = false;
6102
6103                         type_t *const type = skip_typeref(current_function->base.type);
6104                         assert(is_type_function(type));
6105                         type_t *const ret  = skip_typeref(type->function.return_type);
6106                         if (warning.return_type                    &&
6107                             !is_type_atomic(ret, ATOMIC_TYPE_VOID) &&
6108                             is_type_valid(ret)                     &&
6109                             !is_sym_main(current_function->base.base.symbol)) {
6110                                 warningf(&stmt->base.source_position,
6111                                          "control reaches end of non-void function");
6112                         }
6113                         return;
6114                 }
6115
6116                 switch (next->kind) {
6117                         case STATEMENT_INVALID:
6118                         case STATEMENT_EMPTY:
6119                         case STATEMENT_DECLARATION:
6120                         case STATEMENT_EXPRESSION:
6121                         case STATEMENT_ASM:
6122                         case STATEMENT_RETURN:
6123                         case STATEMENT_CONTINUE:
6124                         case STATEMENT_BREAK:
6125                         case STATEMENT_GOTO:
6126                         case STATEMENT_LEAVE:
6127                                 panic("invalid control flow in function");
6128
6129                         case STATEMENT_COMPOUND:
6130                                 if (next->compound.stmt_expr) {
6131                                         reaches_end = true;
6132                                         return;
6133                                 }
6134                                 /* FALLTHROUGH */
6135                         case STATEMENT_IF:
6136                         case STATEMENT_SWITCH:
6137                         case STATEMENT_LABEL:
6138                         case STATEMENT_CASE_LABEL:
6139                                 last = next;
6140                                 next = next->base.next;
6141                                 break;
6142
6143                         case STATEMENT_WHILE: {
6144 continue_while:
6145                                 if (next->base.reachable)
6146                                         return;
6147                                 next->base.reachable = true;
6148
6149                                 while_statement_t const *const whiles = &next->whiles;
6150                                 expression_t      const *const cond   = whiles->condition;
6151
6152                                 if (!expression_returns(cond))
6153                                         return;
6154
6155                                 int const val = determine_truth(cond);
6156
6157                                 if (val >= 0)
6158                                         check_reachable(whiles->body);
6159
6160                                 if (val > 0)
6161                                         return;
6162
6163                                 last = next;
6164                                 next = next->base.next;
6165                                 break;
6166                         }
6167
6168                         case STATEMENT_DO_WHILE: {
6169 continue_do_while:
6170                                 if (next->base.reachable)
6171                                         return;
6172                                 next->base.reachable = true;
6173
6174                                 do_while_statement_t const *const dw   = &next->do_while;
6175                                 expression_t         const *const cond = dw->condition;
6176
6177                                 if (!expression_returns(cond))
6178                                         return;
6179
6180                                 int const val = determine_truth(cond);
6181
6182                                 if (val >= 0)
6183                                         check_reachable(dw->body);
6184
6185                                 if (val > 0)
6186                                         return;
6187
6188                                 last = next;
6189                                 next = next->base.next;
6190                                 break;
6191                         }
6192
6193                         case STATEMENT_FOR: {
6194 continue_for:;
6195                                 for_statement_t *const fors = &next->fors;
6196
6197                                 fors->step_reachable = true;
6198
6199                                 if (fors->condition_reachable)
6200                                         return;
6201                                 fors->condition_reachable = true;
6202
6203                                 expression_t const *const cond = fors->condition;
6204
6205                                 int val;
6206                                 if (cond == NULL) {
6207                                         val = 1;
6208                                 } else if (expression_returns(cond)) {
6209                                         val = determine_truth(cond);
6210                                 } else {
6211                                         return;
6212                                 }
6213
6214                                 if (val >= 0)
6215                                         check_reachable(fors->body);
6216
6217                                 if (val > 0)
6218                                         return;
6219
6220                                 last = next;
6221                                 next = next->base.next;
6222                                 break;
6223                         }
6224
6225                         case STATEMENT_MS_TRY:
6226                                 last = next;
6227                                 next = next->ms_try.final_statement;
6228                                 break;
6229                 }
6230         }
6231
6232         check_reachable(next);
6233 }
6234
6235 static void check_unreachable(statement_t* const stmt, void *const env)
6236 {
6237         (void)env;
6238
6239         switch (stmt->kind) {
6240                 case STATEMENT_DO_WHILE:
6241                         if (!stmt->base.reachable) {
6242                                 expression_t const *const cond = stmt->do_while.condition;
6243                                 if (determine_truth(cond) >= 0) {
6244                                         warningf(&cond->base.source_position,
6245                                                  "condition of do-while-loop is unreachable");
6246                                 }
6247                         }
6248                         return;
6249
6250                 case STATEMENT_FOR: {
6251                         for_statement_t const* const fors = &stmt->fors;
6252
6253                         // if init and step are unreachable, cond is unreachable, too
6254                         if (!stmt->base.reachable && !fors->step_reachable) {
6255                                 warningf(&stmt->base.source_position, "statement is unreachable");
6256                         } else {
6257                                 if (!stmt->base.reachable && fors->initialisation != NULL) {
6258                                         warningf(&fors->initialisation->base.source_position,
6259                                                  "initialisation of for-statement is unreachable");
6260                                 }
6261
6262                                 if (!fors->condition_reachable && fors->condition != NULL) {
6263                                         warningf(&fors->condition->base.source_position,
6264                                                  "condition of for-statement is unreachable");
6265                                 }
6266
6267                                 if (!fors->step_reachable && fors->step != NULL) {
6268                                         warningf(&fors->step->base.source_position,
6269                                                  "step of for-statement is unreachable");
6270                                 }
6271                         }
6272                         return;
6273                 }
6274
6275                 case STATEMENT_COMPOUND:
6276                         if (stmt->compound.statements != NULL)
6277                                 return;
6278                         goto warn_unreachable;
6279
6280                 case STATEMENT_DECLARATION: {
6281                         /* Only warn if there is at least one declarator with an initializer.
6282                          * This typically occurs in switch statements. */
6283                         declaration_statement_t const *const decl = &stmt->declaration;
6284                         entity_t                const *      ent  = decl->declarations_begin;
6285                         entity_t                const *const last = decl->declarations_end;
6286                         if (ent != NULL) {
6287                                 for (;; ent = ent->base.next) {
6288                                         if (ent->kind                 == ENTITY_VARIABLE &&
6289                                                         ent->variable.initializer != NULL) {
6290                                                 goto warn_unreachable;
6291                                         }
6292                                         if (ent == last)
6293                                                 return;
6294                                 }
6295                         }
6296                 }
6297
6298                 default:
6299 warn_unreachable:
6300                         if (!stmt->base.reachable)
6301                                 warningf(&stmt->base.source_position, "statement is unreachable");
6302                         return;
6303         }
6304 }
6305
6306 static void parse_external_declaration(void)
6307 {
6308         /* function-definitions and declarations both start with declaration
6309          * specifiers */
6310         declaration_specifiers_t specifiers;
6311         memset(&specifiers, 0, sizeof(specifiers));
6312
6313         add_anchor_token(';');
6314         parse_declaration_specifiers(&specifiers);
6315         rem_anchor_token(';');
6316
6317         /* must be a declaration */
6318         if (token.type == ';') {
6319                 parse_anonymous_declaration_rest(&specifiers);
6320                 return;
6321         }
6322
6323         add_anchor_token(',');
6324         add_anchor_token('=');
6325         add_anchor_token(';');
6326         add_anchor_token('{');
6327
6328         /* declarator is common to both function-definitions and declarations */
6329         entity_t *ndeclaration = parse_declarator(&specifiers, DECL_FLAGS_NONE);
6330
6331         rem_anchor_token('{');
6332         rem_anchor_token(';');
6333         rem_anchor_token('=');
6334         rem_anchor_token(',');
6335
6336         /* must be a declaration */
6337         switch (token.type) {
6338                 case ',':
6339                 case ';':
6340                 case '=':
6341                         parse_declaration_rest(ndeclaration, &specifiers, record_entity,
6342                                         DECL_FLAGS_NONE);
6343                         return;
6344         }
6345
6346         /* must be a function definition */
6347         parse_kr_declaration_list(ndeclaration);
6348
6349         if (token.type != '{') {
6350                 parse_error_expected("while parsing function definition", '{', NULL);
6351                 eat_until_matching_token(';');
6352                 return;
6353         }
6354
6355         assert(is_declaration(ndeclaration));
6356         type_t *const orig_type = ndeclaration->declaration.type;
6357         type_t *      type      = skip_typeref(orig_type);
6358
6359         if (!is_type_function(type)) {
6360                 if (is_type_valid(type)) {
6361                         errorf(HERE, "declarator '%#T' has a body but is not a function type",
6362                                type, ndeclaration->base.symbol);
6363                 }
6364                 eat_block();
6365                 return;
6366         } else if (is_typeref(orig_type)) {
6367                 /* §6.9.1:2 */
6368                 errorf(&ndeclaration->base.source_position,
6369                                 "type of function definition '%#T' is a typedef",
6370                                 orig_type, ndeclaration->base.symbol);
6371         }
6372
6373         if (warning.aggregate_return &&
6374             is_type_compound(skip_typeref(type->function.return_type))) {
6375                 warningf(HERE, "function '%Y' returns an aggregate",
6376                          ndeclaration->base.symbol);
6377         }
6378         if (warning.traditional && !type->function.unspecified_parameters) {
6379                 warningf(HERE, "traditional C rejects ISO C style function definition of function '%Y'",
6380                         ndeclaration->base.symbol);
6381         }
6382         if (warning.old_style_definition && type->function.unspecified_parameters) {
6383                 warningf(HERE, "old-style function definition '%Y'",
6384                         ndeclaration->base.symbol);
6385         }
6386
6387         /* §6.7.5.3:14 a function definition with () means no
6388          * parameters (and not unspecified parameters) */
6389         if (type->function.unspecified_parameters &&
6390                         type->function.parameters == NULL     &&
6391                         !type->function.kr_style_parameters) {
6392                 type_t *copy                          = duplicate_type(type);
6393                 copy->function.unspecified_parameters = false;
6394                 type                                  = identify_new_type(copy);
6395
6396                 ndeclaration->declaration.type = type;
6397         }
6398
6399         entity_t *const entity = record_entity(ndeclaration, true);
6400         assert(entity->kind == ENTITY_FUNCTION);
6401         assert(ndeclaration->kind == ENTITY_FUNCTION);
6402
6403         function_t *function = &entity->function;
6404         if (ndeclaration != entity) {
6405                 function->parameters = ndeclaration->function.parameters;
6406         }
6407         assert(is_declaration(entity));
6408         type = skip_typeref(entity->declaration.type);
6409
6410         /* push function parameters and switch scope */
6411         size_t const  top       = environment_top();
6412         scope_t      *old_scope = scope_push(&function->parameters);
6413
6414         entity_t *parameter = function->parameters.entities;
6415         for (; parameter != NULL; parameter = parameter->base.next) {
6416                 if (parameter->base.parent_scope == &ndeclaration->function.parameters) {
6417                         parameter->base.parent_scope = current_scope;
6418                 }
6419                 assert(parameter->base.parent_scope == NULL
6420                                 || parameter->base.parent_scope == current_scope);
6421                 parameter->base.parent_scope = current_scope;
6422                 if (parameter->base.symbol == NULL) {
6423                         errorf(&parameter->base.source_position, "parameter name omitted");
6424                         continue;
6425                 }
6426                 environment_push(parameter);
6427         }
6428
6429         if (function->statement != NULL) {
6430                 parser_error_multiple_definition(entity, HERE);
6431                 eat_block();
6432         } else {
6433                 /* parse function body */
6434                 int         label_stack_top      = label_top();
6435                 function_t *old_current_function = current_function;
6436                 current_function                 = function;
6437                 current_parent                   = NULL;
6438
6439                 goto_first   = NULL;
6440                 goto_anchor  = &goto_first;
6441                 label_first  = NULL;
6442                 label_anchor = &label_first;
6443
6444                 statement_t *const body = parse_compound_statement(false);
6445                 function->statement = body;
6446                 first_err = true;
6447                 check_labels();
6448                 check_declarations();
6449                 if (warning.return_type      ||
6450                     warning.unreachable_code ||
6451                     (warning.missing_noreturn
6452                      && !(function->base.modifiers & DM_NORETURN))) {
6453                         noreturn_candidate = true;
6454                         check_reachable(body);
6455                         if (warning.unreachable_code)
6456                                 walk_statements(body, check_unreachable, NULL);
6457                         if (warning.missing_noreturn &&
6458                             noreturn_candidate       &&
6459                             !(function->base.modifiers & DM_NORETURN)) {
6460                                 warningf(&body->base.source_position,
6461                                          "function '%#T' is candidate for attribute 'noreturn'",
6462                                          type, entity->base.symbol);
6463                         }
6464                 }
6465
6466                 assert(current_parent   == NULL);
6467                 assert(current_function == function);
6468                 current_function = old_current_function;
6469                 label_pop_to(label_stack_top);
6470         }
6471
6472         assert(current_scope == &function->parameters);
6473         scope_pop(old_scope);
6474         environment_pop_to(top);
6475 }
6476
6477 static type_t *make_bitfield_type(type_t *base_type, expression_t *size,
6478                                   source_position_t *source_position,
6479                                   const symbol_t *symbol)
6480 {
6481         type_t *type = allocate_type_zero(TYPE_BITFIELD);
6482
6483         type->bitfield.base_type       = base_type;
6484         type->bitfield.size_expression = size;
6485
6486         il_size_t bit_size;
6487         type_t *skipped_type = skip_typeref(base_type);
6488         if (!is_type_integer(skipped_type)) {
6489                 errorf(HERE, "bitfield base type '%T' is not an integer type",
6490                         base_type);
6491                 bit_size = 0;
6492         } else {
6493                 bit_size = skipped_type->base.size * 8;
6494         }
6495
6496         if (is_constant_expression(size)) {
6497                 long v = fold_constant(size);
6498
6499                 if (v < 0) {
6500                         errorf(source_position, "negative width in bit-field '%Y'", symbol);
6501                 } else if (v == 0) {
6502                         errorf(source_position, "zero width for bit-field '%Y'", symbol);
6503                 } else if (bit_size > 0 && (il_size_t)v > bit_size) {
6504                         errorf(source_position, "width of '%Y' exceeds its type", symbol);
6505                 } else {
6506                         type->bitfield.bit_size = v;
6507                 }
6508         }
6509
6510         return type;
6511 }
6512
6513 static entity_t *find_compound_entry(compound_t *compound, symbol_t *symbol)
6514 {
6515         entity_t *iter = compound->members.entities;
6516         for (; iter != NULL; iter = iter->base.next) {
6517                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
6518                         continue;
6519
6520                 if (iter->base.symbol == symbol) {
6521                         return iter;
6522                 } else if (iter->base.symbol == NULL) {
6523                         type_t *type = skip_typeref(iter->declaration.type);
6524                         if (is_type_compound(type)) {
6525                                 entity_t *result
6526                                         = find_compound_entry(type->compound.compound, symbol);
6527                                 if (result != NULL)
6528                                         return result;
6529                         }
6530                         continue;
6531                 }
6532         }
6533
6534         return NULL;
6535 }
6536
6537 static void parse_compound_declarators(compound_t *compound,
6538                 const declaration_specifiers_t *specifiers)
6539 {
6540         while (true) {
6541                 entity_t *entity;
6542
6543                 if (token.type == ':') {
6544                         source_position_t source_position = *HERE;
6545                         next_token();
6546
6547                         type_t *base_type = specifiers->type;
6548                         expression_t *size = parse_constant_expression();
6549
6550                         type_t *type = make_bitfield_type(base_type, size,
6551                                         &source_position, sym_anonymous);
6552
6553                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER);
6554                         entity->base.namespc                       = NAMESPACE_NORMAL;
6555                         entity->base.source_position               = source_position;
6556                         entity->declaration.declared_storage_class = STORAGE_CLASS_NONE;
6557                         entity->declaration.storage_class          = STORAGE_CLASS_NONE;
6558                         entity->declaration.modifiers              = specifiers->modifiers;
6559                         entity->declaration.type                   = type;
6560                         append_entity(&compound->members, entity);
6561                 } else {
6562                         entity = parse_declarator(specifiers,
6563                                         DECL_MAY_BE_ABSTRACT | DECL_CREATE_COMPOUND_MEMBER);
6564                         if (entity->kind == ENTITY_TYPEDEF) {
6565                                 errorf(&entity->base.source_position,
6566                                                 "typedef not allowed as compound member");
6567                         } else {
6568                                 assert(entity->kind == ENTITY_COMPOUND_MEMBER);
6569
6570                                 /* make sure we don't define a symbol multiple times */
6571                                 symbol_t *symbol = entity->base.symbol;
6572                                 if (symbol != NULL) {
6573                                         entity_t *prev = find_compound_entry(compound, symbol);
6574                                         if (prev != NULL) {
6575                                                 errorf(&entity->base.source_position,
6576                                                                 "multiple declarations of symbol '%Y' (declared %P)",
6577                                                                 symbol, &prev->base.source_position);
6578                                         }
6579                                 }
6580
6581                                 if (token.type == ':') {
6582                                         source_position_t source_position = *HERE;
6583                                         next_token();
6584                                         expression_t *size = parse_constant_expression();
6585
6586                                         type_t *type          = entity->declaration.type;
6587                                         type_t *bitfield_type = make_bitfield_type(type, size,
6588                                                         &source_position, entity->base.symbol);
6589                                         entity->declaration.type = bitfield_type;
6590                                 } else {
6591                                         type_t *orig_type = entity->declaration.type;
6592                                         type_t *type      = skip_typeref(orig_type);
6593                                         if (is_type_function(type)) {
6594                                                 errorf(&entity->base.source_position,
6595                                                                 "compound member '%Y' must not have function type '%T'",
6596                                                                 entity->base.symbol, orig_type);
6597                                         } else if (is_type_incomplete(type)) {
6598                                                 /* §6.7.2.1:16 flexible array member */
6599                                                 if (!is_type_array(type)       ||
6600                                                                 token.type          != ';' ||
6601                                                                 look_ahead(1)->type != '}') {
6602                                                         errorf(&entity->base.source_position,
6603                                                                         "compound member '%Y' has incomplete type '%T'",
6604                                                                         entity->base.symbol, orig_type);
6605                                                 }
6606                                         }
6607                                 }
6608
6609                                 append_entity(&compound->members, entity);
6610                         }
6611                 }
6612
6613                 if (token.type != ',')
6614                         break;
6615                 next_token();
6616         }
6617         expect(';', end_error);
6618
6619 end_error:
6620         anonymous_entity = NULL;
6621 }
6622
6623 static void parse_compound_type_entries(compound_t *compound)
6624 {
6625         eat('{');
6626         add_anchor_token('}');
6627
6628         while (token.type != '}') {
6629                 if (token.type == T_EOF) {
6630                         errorf(HERE, "EOF while parsing struct");
6631                         break;
6632                 }
6633                 declaration_specifiers_t specifiers;
6634                 memset(&specifiers, 0, sizeof(specifiers));
6635                 parse_declaration_specifiers(&specifiers);
6636
6637                 parse_compound_declarators(compound, &specifiers);
6638         }
6639         rem_anchor_token('}');
6640         next_token();
6641
6642         /* §6.7.2.1:7 */
6643         compound->complete = true;
6644 }
6645
6646 static type_t *parse_typename(void)
6647 {
6648         declaration_specifiers_t specifiers;
6649         memset(&specifiers, 0, sizeof(specifiers));
6650         parse_declaration_specifiers(&specifiers);
6651         if (specifiers.storage_class != STORAGE_CLASS_NONE ||
6652                         specifiers.thread_local) {
6653                 /* TODO: improve error message, user does probably not know what a
6654                  * storage class is...
6655                  */
6656                 errorf(HERE, "typename may not have a storage class");
6657         }
6658
6659         type_t *result = parse_abstract_declarator(specifiers.type);
6660
6661         return result;
6662 }
6663
6664
6665
6666
6667 typedef expression_t* (*parse_expression_function)(void);
6668 typedef expression_t* (*parse_expression_infix_function)(expression_t *left);
6669
6670 typedef struct expression_parser_function_t expression_parser_function_t;
6671 struct expression_parser_function_t {
6672         parse_expression_function        parser;
6673         precedence_t                     infix_precedence;
6674         parse_expression_infix_function  infix_parser;
6675 };
6676
6677 expression_parser_function_t expression_parsers[T_LAST_TOKEN];
6678
6679 /**
6680  * Prints an error message if an expression was expected but not read
6681  */
6682 static expression_t *expected_expression_error(void)
6683 {
6684         /* skip the error message if the error token was read */
6685         if (token.type != T_ERROR) {
6686                 errorf(HERE, "expected expression, got token %K", &token);
6687         }
6688         next_token();
6689
6690         return create_invalid_expression();
6691 }
6692
6693 /**
6694  * Parse a string constant.
6695  */
6696 static expression_t *parse_string_const(void)
6697 {
6698         wide_string_t wres;
6699         if (token.type == T_STRING_LITERAL) {
6700                 string_t res = token.v.string;
6701                 next_token();
6702                 while (token.type == T_STRING_LITERAL) {
6703                         res = concat_strings(&res, &token.v.string);
6704                         next_token();
6705                 }
6706                 if (token.type != T_WIDE_STRING_LITERAL) {
6707                         expression_t *const cnst = allocate_expression_zero(EXPR_STRING_LITERAL);
6708                         /* note: that we use type_char_ptr here, which is already the
6709                          * automatic converted type. revert_automatic_type_conversion
6710                          * will construct the array type */
6711                         cnst->base.type    = warning.write_strings ? type_const_char_ptr : type_char_ptr;
6712                         cnst->string.value = res;
6713                         return cnst;
6714                 }
6715
6716                 wres = concat_string_wide_string(&res, &token.v.wide_string);
6717         } else {
6718                 wres = token.v.wide_string;
6719         }
6720         next_token();
6721
6722         for (;;) {
6723                 switch (token.type) {
6724                         case T_WIDE_STRING_LITERAL:
6725                                 wres = concat_wide_strings(&wres, &token.v.wide_string);
6726                                 break;
6727
6728                         case T_STRING_LITERAL:
6729                                 wres = concat_wide_string_string(&wres, &token.v.string);
6730                                 break;
6731
6732                         default: {
6733                                 expression_t *const cnst = allocate_expression_zero(EXPR_WIDE_STRING_LITERAL);
6734                                 cnst->base.type         = warning.write_strings ? type_const_wchar_t_ptr : type_wchar_t_ptr;
6735                                 cnst->wide_string.value = wres;
6736                                 return cnst;
6737                         }
6738                 }
6739                 next_token();
6740         }
6741 }
6742
6743 /**
6744  * Parse a boolean constant.
6745  */
6746 static expression_t *parse_bool_const(bool value)
6747 {
6748         expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
6749         cnst->base.type          = type_bool;
6750         cnst->conste.v.int_value = value;
6751
6752         next_token();
6753
6754         return cnst;
6755 }
6756
6757 /**
6758  * Parse an integer constant.
6759  */
6760 static expression_t *parse_int_const(void)
6761 {
6762         expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
6763         cnst->base.type          = token.datatype;
6764         cnst->conste.v.int_value = token.v.intvalue;
6765
6766         next_token();
6767
6768         return cnst;
6769 }
6770
6771 /**
6772  * Parse a character constant.
6773  */
6774 static expression_t *parse_character_constant(void)
6775 {
6776         expression_t *cnst = allocate_expression_zero(EXPR_CHARACTER_CONSTANT);
6777         cnst->base.type          = token.datatype;
6778         cnst->conste.v.character = token.v.string;
6779
6780         if (cnst->conste.v.character.size != 1) {
6781                 if (!GNU_MODE) {
6782                         errorf(HERE, "more than 1 character in character constant");
6783                 } else if (warning.multichar) {
6784                         warningf(HERE, "multi-character character constant");
6785                 }
6786         }
6787         next_token();
6788
6789         return cnst;
6790 }
6791
6792 /**
6793  * Parse a wide character constant.
6794  */
6795 static expression_t *parse_wide_character_constant(void)
6796 {
6797         expression_t *cnst = allocate_expression_zero(EXPR_WIDE_CHARACTER_CONSTANT);
6798         cnst->base.type               = token.datatype;
6799         cnst->conste.v.wide_character = token.v.wide_string;
6800
6801         if (cnst->conste.v.wide_character.size != 1) {
6802                 if (!GNU_MODE) {
6803                         errorf(HERE, "more than 1 character in character constant");
6804                 } else if (warning.multichar) {
6805                         warningf(HERE, "multi-character character constant");
6806                 }
6807         }
6808         next_token();
6809
6810         return cnst;
6811 }
6812
6813 /**
6814  * Parse a float constant.
6815  */
6816 static expression_t *parse_float_const(void)
6817 {
6818         expression_t *cnst         = allocate_expression_zero(EXPR_CONST);
6819         cnst->base.type            = token.datatype;
6820         cnst->conste.v.float_value = token.v.floatvalue;
6821
6822         next_token();
6823
6824         return cnst;
6825 }
6826
6827 static entity_t *create_implicit_function(symbol_t *symbol,
6828                 const source_position_t *source_position)
6829 {
6830         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
6831         ntype->function.return_type            = type_int;
6832         ntype->function.unspecified_parameters = true;
6833         ntype->function.linkage                = LINKAGE_C;
6834         type_t *type                           = identify_new_type(ntype);
6835
6836         entity_t *entity = allocate_entity_zero(ENTITY_FUNCTION);
6837         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
6838         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
6839         entity->declaration.type                   = type;
6840         entity->declaration.implicit               = true;
6841         entity->base.symbol                        = symbol;
6842         entity->base.source_position               = *source_position;
6843
6844         bool strict_prototypes_old = warning.strict_prototypes;
6845         warning.strict_prototypes  = false;
6846         record_entity(entity, false);
6847         warning.strict_prototypes = strict_prototypes_old;
6848
6849         return entity;
6850 }
6851
6852 /**
6853  * Creates a return_type (func)(argument_type) function type if not
6854  * already exists.
6855  */
6856 static type_t *make_function_2_type(type_t *return_type, type_t *argument_type1,
6857                                     type_t *argument_type2)
6858 {
6859         function_parameter_t *parameter2
6860                 = obstack_alloc(type_obst, sizeof(parameter2[0]));
6861         memset(parameter2, 0, sizeof(parameter2[0]));
6862         parameter2->type = argument_type2;
6863
6864         function_parameter_t *parameter1
6865                 = obstack_alloc(type_obst, sizeof(parameter1[0]));
6866         memset(parameter1, 0, sizeof(parameter1[0]));
6867         parameter1->type = argument_type1;
6868         parameter1->next = parameter2;
6869
6870         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6871         type->function.return_type = return_type;
6872         type->function.parameters  = parameter1;
6873
6874         return identify_new_type(type);
6875 }
6876
6877 /**
6878  * Creates a return_type (func)(argument_type) function type if not
6879  * already exists.
6880  *
6881  * @param return_type    the return type
6882  * @param argument_type  the argument type
6883  */
6884 static type_t *make_function_1_type(type_t *return_type, type_t *argument_type)
6885 {
6886         function_parameter_t *parameter
6887                 = obstack_alloc(type_obst, sizeof(parameter[0]));
6888         memset(parameter, 0, sizeof(parameter[0]));
6889         parameter->type = argument_type;
6890
6891         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6892         type->function.return_type = return_type;
6893         type->function.parameters  = parameter;
6894
6895         return identify_new_type(type);
6896 }
6897
6898 static type_t *make_function_1_type_variadic(type_t *return_type, type_t *argument_type)
6899 {
6900         type_t *res = make_function_1_type(return_type, argument_type);
6901         res->function.variadic = 1;
6902         return res;
6903 }
6904
6905 /**
6906  * Creates a return_type (func)(void) function type if not
6907  * already exists.
6908  *
6909  * @param return_type    the return type
6910  */
6911 static type_t *make_function_0_type(type_t *return_type)
6912 {
6913         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6914         type->function.return_type = return_type;
6915         type->function.parameters  = NULL;
6916
6917         return identify_new_type(type);
6918 }
6919
6920 /**
6921  * Creates a NO_RETURN return_type (func)(void) function type if not
6922  * already exists.
6923  *
6924  * @param return_type    the return type
6925  */
6926 static type_t *make_function_0_type_noreturn(type_t *return_type)
6927 {
6928         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6929         type->function.return_type = return_type;
6930         type->function.parameters  = NULL;
6931         type->function.base.modifiers |= DM_NORETURN;
6932         return type;
6933
6934         return identify_new_type(type);
6935 }
6936
6937 /**
6938  * Performs automatic type cast as described in §6.3.2.1.
6939  *
6940  * @param orig_type  the original type
6941  */
6942 static type_t *automatic_type_conversion(type_t *orig_type)
6943 {
6944         type_t *type = skip_typeref(orig_type);
6945         if (is_type_array(type)) {
6946                 array_type_t *array_type   = &type->array;
6947                 type_t       *element_type = array_type->element_type;
6948                 unsigned      qualifiers   = array_type->base.qualifiers;
6949
6950                 return make_pointer_type(element_type, qualifiers);
6951         }
6952
6953         if (is_type_function(type)) {
6954                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
6955         }
6956
6957         return orig_type;
6958 }
6959
6960 /**
6961  * reverts the automatic casts of array to pointer types and function
6962  * to function-pointer types as defined §6.3.2.1
6963  */
6964 type_t *revert_automatic_type_conversion(const expression_t *expression)
6965 {
6966         switch (expression->kind) {
6967                 case EXPR_REFERENCE: {
6968                         entity_t *entity = expression->reference.entity;
6969                         if (is_declaration(entity)) {
6970                                 return entity->declaration.type;
6971                         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6972                                 return entity->enum_value.enum_type;
6973                         } else {
6974                                 panic("no declaration or enum in reference");
6975                         }
6976                 }
6977
6978                 case EXPR_SELECT: {
6979                         entity_t *entity = expression->select.compound_entry;
6980                         assert(is_declaration(entity));
6981                         type_t   *type   = entity->declaration.type;
6982                         return get_qualified_type(type,
6983                                         expression->base.type->base.qualifiers);
6984                 }
6985
6986                 case EXPR_UNARY_DEREFERENCE: {
6987                         const expression_t *const value = expression->unary.value;
6988                         type_t             *const type  = skip_typeref(value->base.type);
6989                         if (!is_type_pointer(type))
6990                                 return type_error_type;
6991                         return type->pointer.points_to;
6992                 }
6993
6994                 case EXPR_ARRAY_ACCESS: {
6995                         const expression_t *array_ref = expression->array_access.array_ref;
6996                         type_t             *type_left = skip_typeref(array_ref->base.type);
6997                         if (!is_type_pointer(type_left))
6998                                 return type_error_type;
6999                         return type_left->pointer.points_to;
7000                 }
7001
7002                 case EXPR_STRING_LITERAL: {
7003                         size_t size = expression->string.value.size;
7004                         return make_array_type(type_char, size, TYPE_QUALIFIER_NONE);
7005                 }
7006
7007                 case EXPR_WIDE_STRING_LITERAL: {
7008                         size_t size = expression->wide_string.value.size;
7009                         return make_array_type(type_wchar_t, size, TYPE_QUALIFIER_NONE);
7010                 }
7011
7012                 case EXPR_COMPOUND_LITERAL:
7013                         return expression->compound_literal.type;
7014
7015                 default:
7016                         return expression->base.type;
7017         }
7018 }
7019
7020 static expression_t *parse_reference(void)
7021 {
7022         symbol_t *const symbol = token.v.symbol;
7023
7024         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
7025
7026         if (entity == NULL) {
7027                 if (!strict_mode && look_ahead(1)->type == '(') {
7028                         /* an implicitly declared function */
7029                         if (warning.error_implicit_function_declaration) {
7030                                 errorf(HERE, "implicit declaration of function '%Y'", symbol);
7031                         } else if (warning.implicit_function_declaration) {
7032                                 warningf(HERE, "implicit declaration of function '%Y'", symbol);
7033                         }
7034
7035                         entity = create_implicit_function(symbol, HERE);
7036                 } else {
7037                         errorf(HERE, "unknown identifier '%Y' found.", symbol);
7038                         entity = create_error_entity(symbol, ENTITY_VARIABLE);
7039                 }
7040         }
7041
7042         type_t *orig_type;
7043
7044         if (is_declaration(entity)) {
7045                 orig_type = entity->declaration.type;
7046         } else if (entity->kind == ENTITY_ENUM_VALUE) {
7047                 orig_type = entity->enum_value.enum_type;
7048         } else if (entity->kind == ENTITY_TYPEDEF) {
7049                 errorf(HERE, "encountered typedef name '%Y' while parsing expression",
7050                         symbol);
7051                 next_token();
7052                 return create_invalid_expression();
7053         } else {
7054                 panic("expected declaration or enum value in reference");
7055         }
7056
7057         /* we always do the auto-type conversions; the & and sizeof parser contains
7058          * code to revert this! */
7059         type_t *type = automatic_type_conversion(orig_type);
7060
7061         expression_kind_t kind = EXPR_REFERENCE;
7062         if (entity->kind == ENTITY_ENUM_VALUE)
7063                 kind = EXPR_REFERENCE_ENUM_VALUE;
7064
7065         expression_t *expression     = allocate_expression_zero(kind);
7066         expression->reference.entity = entity;
7067         expression->base.type        = type;
7068
7069         /* this declaration is used */
7070         if (is_declaration(entity)) {
7071                 entity->declaration.used = true;
7072         }
7073
7074         if (entity->base.parent_scope != file_scope
7075                 && entity->base.parent_scope->depth < current_function->parameters.depth
7076                 && is_type_valid(orig_type) && !is_type_function(orig_type)) {
7077                 if (entity->kind == ENTITY_VARIABLE) {
7078                         /* access of a variable from an outer function */
7079                         entity->variable.address_taken = true;
7080                 } else if (entity->kind == ENTITY_PARAMETER) {
7081                         entity->parameter.address_taken = true;
7082                 }
7083                 current_function->need_closure = true;
7084         }
7085
7086         /* check for deprecated functions */
7087         if (warning.deprecated_declarations
7088                 && is_declaration(entity)
7089                 && entity->declaration.modifiers & DM_DEPRECATED) {
7090                 declaration_t *declaration = &entity->declaration;
7091
7092                 char const *const prefix = entity->kind == ENTITY_FUNCTION ?
7093                         "function" : "variable";
7094
7095                 if (declaration->deprecated_string != NULL) {
7096                         warningf(HERE, "%s '%Y' is deprecated (declared %P): \"%s\"",
7097                                  prefix, entity->base.symbol, &entity->base.source_position,
7098                                  declaration->deprecated_string);
7099                 } else {
7100                         warningf(HERE, "%s '%Y' is deprecated (declared %P)", prefix,
7101                                  entity->base.symbol, &entity->base.source_position);
7102                 }
7103         }
7104
7105         if (warning.init_self && entity == current_init_decl && !in_type_prop
7106             && entity->kind == ENTITY_VARIABLE) {
7107                 current_init_decl = NULL;
7108                 warningf(HERE, "variable '%#T' is initialized by itself",
7109                          entity->declaration.type, entity->base.symbol);
7110         }
7111
7112         next_token();
7113         return expression;
7114 }
7115
7116 static bool semantic_cast(expression_t *cast)
7117 {
7118         expression_t            *expression      = cast->unary.value;
7119         type_t                  *orig_dest_type  = cast->base.type;
7120         type_t                  *orig_type_right = expression->base.type;
7121         type_t            const *dst_type        = skip_typeref(orig_dest_type);
7122         type_t            const *src_type        = skip_typeref(orig_type_right);
7123         source_position_t const *pos             = &cast->base.source_position;
7124
7125         /* §6.5.4 A (void) cast is explicitly permitted, more for documentation than for utility. */
7126         if (dst_type == type_void)
7127                 return true;
7128
7129         /* only integer and pointer can be casted to pointer */
7130         if (is_type_pointer(dst_type)  &&
7131             !is_type_pointer(src_type) &&
7132             !is_type_integer(src_type) &&
7133             is_type_valid(src_type)) {
7134                 errorf(pos, "cannot convert type '%T' to a pointer type", orig_type_right);
7135                 return false;
7136         }
7137
7138         if (!is_type_scalar(dst_type) && is_type_valid(dst_type)) {
7139                 errorf(pos, "conversion to non-scalar type '%T' requested", orig_dest_type);
7140                 return false;
7141         }
7142
7143         if (!is_type_scalar(src_type) && is_type_valid(src_type)) {
7144                 errorf(pos, "conversion from non-scalar type '%T' requested", orig_type_right);
7145                 return false;
7146         }
7147
7148         if (warning.cast_qual &&
7149             is_type_pointer(src_type) &&
7150             is_type_pointer(dst_type)) {
7151                 type_t *src = skip_typeref(src_type->pointer.points_to);
7152                 type_t *dst = skip_typeref(dst_type->pointer.points_to);
7153                 unsigned missing_qualifiers =
7154                         src->base.qualifiers & ~dst->base.qualifiers;
7155                 if (missing_qualifiers != 0) {
7156                         warningf(pos,
7157                                  "cast discards qualifiers '%Q' in pointer target type of '%T'",
7158                                  missing_qualifiers, orig_type_right);
7159                 }
7160         }
7161         return true;
7162 }
7163
7164 static expression_t *parse_compound_literal(type_t *type)
7165 {
7166         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
7167
7168         parse_initializer_env_t env;
7169         env.type             = type;
7170         env.entity           = NULL;
7171         env.must_be_constant = false;
7172         initializer_t *initializer = parse_initializer(&env);
7173         type = env.type;
7174
7175         expression->compound_literal.initializer = initializer;
7176         expression->compound_literal.type        = type;
7177         expression->base.type                    = automatic_type_conversion(type);
7178
7179         return expression;
7180 }
7181
7182 /**
7183  * Parse a cast expression.
7184  */
7185 static expression_t *parse_cast(void)
7186 {
7187         add_anchor_token(')');
7188
7189         source_position_t source_position = token.source_position;
7190
7191         type_t *type = parse_typename();
7192
7193         rem_anchor_token(')');
7194         expect(')', end_error);
7195
7196         if (token.type == '{') {
7197                 return parse_compound_literal(type);
7198         }
7199
7200         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
7201         cast->base.source_position = source_position;
7202
7203         expression_t *value = parse_sub_expression(PREC_CAST);
7204         cast->base.type   = type;
7205         cast->unary.value = value;
7206
7207         if (! semantic_cast(cast)) {
7208                 /* TODO: record the error in the AST. else it is impossible to detect it */
7209         }
7210
7211         return cast;
7212 end_error:
7213         return create_invalid_expression();
7214 }
7215
7216 /**
7217  * Parse a statement expression.
7218  */
7219 static expression_t *parse_statement_expression(void)
7220 {
7221         add_anchor_token(')');
7222
7223         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
7224
7225         statement_t *statement          = parse_compound_statement(true);
7226         statement->compound.stmt_expr   = true;
7227         expression->statement.statement = statement;
7228
7229         /* find last statement and use its type */
7230         type_t *type = type_void;
7231         const statement_t *stmt = statement->compound.statements;
7232         if (stmt != NULL) {
7233                 while (stmt->base.next != NULL)
7234                         stmt = stmt->base.next;
7235
7236                 if (stmt->kind == STATEMENT_EXPRESSION) {
7237                         type = stmt->expression.expression->base.type;
7238                 }
7239         } else if (warning.other) {
7240                 warningf(&expression->base.source_position, "empty statement expression ({})");
7241         }
7242         expression->base.type = type;
7243
7244         rem_anchor_token(')');
7245         expect(')', end_error);
7246
7247 end_error:
7248         return expression;
7249 }
7250
7251 /**
7252  * Parse a parenthesized expression.
7253  */
7254 static expression_t *parse_parenthesized_expression(void)
7255 {
7256         eat('(');
7257
7258         switch (token.type) {
7259         case '{':
7260                 /* gcc extension: a statement expression */
7261                 return parse_statement_expression();
7262
7263         TYPE_QUALIFIERS
7264         TYPE_SPECIFIERS
7265                 return parse_cast();
7266         case T_IDENTIFIER:
7267                 if (is_typedef_symbol(token.v.symbol)) {
7268                         return parse_cast();
7269                 }
7270         }
7271
7272         add_anchor_token(')');
7273         expression_t *result = parse_expression();
7274         result->base.parenthesized = true;
7275         rem_anchor_token(')');
7276         expect(')', end_error);
7277
7278 end_error:
7279         return result;
7280 }
7281
7282 static expression_t *parse_function_keyword(void)
7283 {
7284         /* TODO */
7285
7286         if (current_function == NULL) {
7287                 errorf(HERE, "'__func__' used outside of a function");
7288         }
7289
7290         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
7291         expression->base.type     = type_char_ptr;
7292         expression->funcname.kind = FUNCNAME_FUNCTION;
7293
7294         next_token();
7295
7296         return expression;
7297 }
7298
7299 static expression_t *parse_pretty_function_keyword(void)
7300 {
7301         if (current_function == NULL) {
7302                 errorf(HERE, "'__PRETTY_FUNCTION__' used outside of a function");
7303         }
7304
7305         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
7306         expression->base.type     = type_char_ptr;
7307         expression->funcname.kind = FUNCNAME_PRETTY_FUNCTION;
7308
7309         eat(T___PRETTY_FUNCTION__);
7310
7311         return expression;
7312 }
7313
7314 static expression_t *parse_funcsig_keyword(void)
7315 {
7316         if (current_function == NULL) {
7317                 errorf(HERE, "'__FUNCSIG__' used outside of a function");
7318         }
7319
7320         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
7321         expression->base.type     = type_char_ptr;
7322         expression->funcname.kind = FUNCNAME_FUNCSIG;
7323
7324         eat(T___FUNCSIG__);
7325
7326         return expression;
7327 }
7328
7329 static expression_t *parse_funcdname_keyword(void)
7330 {
7331         if (current_function == NULL) {
7332                 errorf(HERE, "'__FUNCDNAME__' used outside of a function");
7333         }
7334
7335         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
7336         expression->base.type     = type_char_ptr;
7337         expression->funcname.kind = FUNCNAME_FUNCDNAME;
7338
7339         eat(T___FUNCDNAME__);
7340
7341         return expression;
7342 }
7343
7344 static designator_t *parse_designator(void)
7345 {
7346         designator_t *result    = allocate_ast_zero(sizeof(result[0]));
7347         result->source_position = *HERE;
7348
7349         if (token.type != T_IDENTIFIER) {
7350                 parse_error_expected("while parsing member designator",
7351                                      T_IDENTIFIER, NULL);
7352                 return NULL;
7353         }
7354         result->symbol = token.v.symbol;
7355         next_token();
7356
7357         designator_t *last_designator = result;
7358         while (true) {
7359                 if (token.type == '.') {
7360                         next_token();
7361                         if (token.type != T_IDENTIFIER) {
7362                                 parse_error_expected("while parsing member designator",
7363                                                      T_IDENTIFIER, NULL);
7364                                 return NULL;
7365                         }
7366                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
7367                         designator->source_position = *HERE;
7368                         designator->symbol          = token.v.symbol;
7369                         next_token();
7370
7371                         last_designator->next = designator;
7372                         last_designator       = designator;
7373                         continue;
7374                 }
7375                 if (token.type == '[') {
7376                         next_token();
7377                         add_anchor_token(']');
7378                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
7379                         designator->source_position = *HERE;
7380                         designator->array_index     = parse_expression();
7381                         rem_anchor_token(']');
7382                         expect(']', end_error);
7383                         if (designator->array_index == NULL) {
7384                                 return NULL;
7385                         }
7386
7387                         last_designator->next = designator;
7388                         last_designator       = designator;
7389                         continue;
7390                 }
7391                 break;
7392         }
7393
7394         return result;
7395 end_error:
7396         return NULL;
7397 }
7398
7399 /**
7400  * Parse the __builtin_offsetof() expression.
7401  */
7402 static expression_t *parse_offsetof(void)
7403 {
7404         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
7405         expression->base.type    = type_size_t;
7406
7407         eat(T___builtin_offsetof);
7408
7409         expect('(', end_error);
7410         add_anchor_token(',');
7411         type_t *type = parse_typename();
7412         rem_anchor_token(',');
7413         expect(',', end_error);
7414         add_anchor_token(')');
7415         designator_t *designator = parse_designator();
7416         rem_anchor_token(')');
7417         expect(')', end_error);
7418
7419         expression->offsetofe.type       = type;
7420         expression->offsetofe.designator = designator;
7421
7422         type_path_t path;
7423         memset(&path, 0, sizeof(path));
7424         path.top_type = type;
7425         path.path     = NEW_ARR_F(type_path_entry_t, 0);
7426
7427         descend_into_subtype(&path);
7428
7429         if (!walk_designator(&path, designator, true)) {
7430                 return create_invalid_expression();
7431         }
7432
7433         DEL_ARR_F(path.path);
7434
7435         return expression;
7436 end_error:
7437         return create_invalid_expression();
7438 }
7439
7440 /**
7441  * Parses a _builtin_va_start() expression.
7442  */
7443 static expression_t *parse_va_start(void)
7444 {
7445         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
7446
7447         eat(T___builtin_va_start);
7448
7449         expect('(', end_error);
7450         add_anchor_token(',');
7451         expression->va_starte.ap = parse_assignment_expression();
7452         rem_anchor_token(',');
7453         expect(',', end_error);
7454         expression_t *const expr = parse_assignment_expression();
7455         if (expr->kind == EXPR_REFERENCE) {
7456                 entity_t *const entity = expr->reference.entity;
7457                 if (entity->base.parent_scope != &current_function->parameters
7458                                 || entity->base.next != NULL
7459                                 || entity->kind != ENTITY_PARAMETER) {
7460                         errorf(&expr->base.source_position,
7461                                "second argument of 'va_start' must be last parameter of the current function");
7462                 } else {
7463                         expression->va_starte.parameter = &entity->variable;
7464                 }
7465                 expect(')', end_error);
7466                 return expression;
7467         }
7468         expect(')', end_error);
7469 end_error:
7470         return create_invalid_expression();
7471 }
7472
7473 /**
7474  * Parses a _builtin_va_arg() expression.
7475  */
7476 static expression_t *parse_va_arg(void)
7477 {
7478         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
7479
7480         eat(T___builtin_va_arg);
7481
7482         expect('(', end_error);
7483         expression->va_arge.ap = parse_assignment_expression();
7484         expect(',', end_error);
7485         expression->base.type = parse_typename();
7486         expect(')', end_error);
7487
7488         return expression;
7489 end_error:
7490         return create_invalid_expression();
7491 }
7492
7493 /**
7494  * Parses a __builtin_constant_p() expression.
7495  */
7496 static expression_t *parse_builtin_constant(void)
7497 {
7498         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
7499
7500         eat(T___builtin_constant_p);
7501
7502         expect('(', end_error);
7503         add_anchor_token(')');
7504         expression->builtin_constant.value = parse_assignment_expression();
7505         rem_anchor_token(')');
7506         expect(')', end_error);
7507         expression->base.type = type_int;
7508
7509         return expression;
7510 end_error:
7511         return create_invalid_expression();
7512 }
7513
7514 /**
7515  * Parses a __builtin_types_compatible_p() expression.
7516  */
7517 static expression_t *parse_builtin_types_compatible(void)
7518 {
7519         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_TYPES_COMPATIBLE_P);
7520
7521         eat(T___builtin_types_compatible_p);
7522
7523         expect('(', end_error);
7524         add_anchor_token(')');
7525         add_anchor_token(',');
7526         expression->builtin_types_compatible.left = parse_typename();
7527         rem_anchor_token(',');
7528         expect(',', end_error);
7529         expression->builtin_types_compatible.right = parse_typename();
7530         rem_anchor_token(')');
7531         expect(')', end_error);
7532         expression->base.type = type_int;
7533
7534         return expression;
7535 end_error:
7536         return create_invalid_expression();
7537 }
7538
7539 /**
7540  * Parses a __builtin_is_*() compare expression.
7541  */
7542 static expression_t *parse_compare_builtin(void)
7543 {
7544         expression_t *expression;
7545
7546         switch (token.type) {
7547         case T___builtin_isgreater:
7548                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATER);
7549                 break;
7550         case T___builtin_isgreaterequal:
7551                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATEREQUAL);
7552                 break;
7553         case T___builtin_isless:
7554                 expression = allocate_expression_zero(EXPR_BINARY_ISLESS);
7555                 break;
7556         case T___builtin_islessequal:
7557                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSEQUAL);
7558                 break;
7559         case T___builtin_islessgreater:
7560                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSGREATER);
7561                 break;
7562         case T___builtin_isunordered:
7563                 expression = allocate_expression_zero(EXPR_BINARY_ISUNORDERED);
7564                 break;
7565         default:
7566                 internal_errorf(HERE, "invalid compare builtin found");
7567         }
7568         expression->base.source_position = *HERE;
7569         next_token();
7570
7571         expect('(', end_error);
7572         expression->binary.left = parse_assignment_expression();
7573         expect(',', end_error);
7574         expression->binary.right = parse_assignment_expression();
7575         expect(')', end_error);
7576
7577         type_t *const orig_type_left  = expression->binary.left->base.type;
7578         type_t *const orig_type_right = expression->binary.right->base.type;
7579
7580         type_t *const type_left  = skip_typeref(orig_type_left);
7581         type_t *const type_right = skip_typeref(orig_type_right);
7582         if (!is_type_float(type_left) && !is_type_float(type_right)) {
7583                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7584                         type_error_incompatible("invalid operands in comparison",
7585                                 &expression->base.source_position, orig_type_left, orig_type_right);
7586                 }
7587         } else {
7588                 semantic_comparison(&expression->binary);
7589         }
7590
7591         return expression;
7592 end_error:
7593         return create_invalid_expression();
7594 }
7595
7596 #if 0
7597 /**
7598  * Parses a __builtin_expect(, end_error) expression.
7599  */
7600 static expression_t *parse_builtin_expect(void, end_error)
7601 {
7602         expression_t *expression
7603                 = allocate_expression_zero(EXPR_BINARY_BUILTIN_EXPECT);
7604
7605         eat(T___builtin_expect);
7606
7607         expect('(', end_error);
7608         expression->binary.left = parse_assignment_expression();
7609         expect(',', end_error);
7610         expression->binary.right = parse_constant_expression();
7611         expect(')', end_error);
7612
7613         expression->base.type = expression->binary.left->base.type;
7614
7615         return expression;
7616 end_error:
7617         return create_invalid_expression();
7618 }
7619 #endif
7620
7621 /**
7622  * Parses a MS assume() expression.
7623  */
7624 static expression_t *parse_assume(void)
7625 {
7626         expression_t *expression = allocate_expression_zero(EXPR_UNARY_ASSUME);
7627
7628         eat(T__assume);
7629
7630         expect('(', end_error);
7631         add_anchor_token(')');
7632         expression->unary.value = parse_assignment_expression();
7633         rem_anchor_token(')');
7634         expect(')', end_error);
7635
7636         expression->base.type = type_void;
7637         return expression;
7638 end_error:
7639         return create_invalid_expression();
7640 }
7641
7642 /**
7643  * Return the declaration for a given label symbol or create a new one.
7644  *
7645  * @param symbol  the symbol of the label
7646  */
7647 static label_t *get_label(symbol_t *symbol)
7648 {
7649         entity_t *label;
7650         assert(current_function != NULL);
7651
7652         label = get_entity(symbol, NAMESPACE_LABEL);
7653         /* if we found a local label, we already created the declaration */
7654         if (label != NULL && label->kind == ENTITY_LOCAL_LABEL) {
7655                 if (label->base.parent_scope != current_scope) {
7656                         assert(label->base.parent_scope->depth < current_scope->depth);
7657                         current_function->goto_to_outer = true;
7658                 }
7659                 return &label->label;
7660         }
7661
7662         label = get_entity(symbol, NAMESPACE_LABEL);
7663         /* if we found a label in the same function, then we already created the
7664          * declaration */
7665         if (label != NULL
7666                         && label->base.parent_scope == &current_function->parameters) {
7667                 return &label->label;
7668         }
7669
7670         /* otherwise we need to create a new one */
7671         label               = allocate_entity_zero(ENTITY_LABEL);
7672         label->base.namespc = NAMESPACE_LABEL;
7673         label->base.symbol  = symbol;
7674
7675         label_push(label);
7676
7677         return &label->label;
7678 }
7679
7680 /**
7681  * Parses a GNU && label address expression.
7682  */
7683 static expression_t *parse_label_address(void)
7684 {
7685         source_position_t source_position = token.source_position;
7686         eat(T_ANDAND);
7687         if (token.type != T_IDENTIFIER) {
7688                 parse_error_expected("while parsing label address", T_IDENTIFIER, NULL);
7689                 goto end_error;
7690         }
7691         symbol_t *symbol = token.v.symbol;
7692         next_token();
7693
7694         label_t *label       = get_label(symbol);
7695         label->used          = true;
7696         label->address_taken = true;
7697
7698         expression_t *expression = allocate_expression_zero(EXPR_LABEL_ADDRESS);
7699         expression->base.source_position = source_position;
7700
7701         /* label address is threaten as a void pointer */
7702         expression->base.type           = type_void_ptr;
7703         expression->label_address.label = label;
7704         return expression;
7705 end_error:
7706         return create_invalid_expression();
7707 }
7708
7709 /**
7710  * Parse a microsoft __noop expression.
7711  */
7712 static expression_t *parse_noop_expression(void)
7713 {
7714         /* the result is a (int)0 */
7715         expression_t *cnst         = allocate_expression_zero(EXPR_CONST);
7716         cnst->base.type            = type_int;
7717         cnst->conste.v.int_value   = 0;
7718         cnst->conste.is_ms_noop    = true;
7719
7720         eat(T___noop);
7721
7722         if (token.type == '(') {
7723                 /* parse arguments */
7724                 eat('(');
7725                 add_anchor_token(')');
7726                 add_anchor_token(',');
7727
7728                 if (token.type != ')') {
7729                         while (true) {
7730                                 (void)parse_assignment_expression();
7731                                 if (token.type != ',')
7732                                         break;
7733                                 next_token();
7734                         }
7735                 }
7736         }
7737         rem_anchor_token(',');
7738         rem_anchor_token(')');
7739         expect(')', end_error);
7740
7741 end_error:
7742         return cnst;
7743 }
7744
7745 /**
7746  * Parses a primary expression.
7747  */
7748 static expression_t *parse_primary_expression(void)
7749 {
7750         switch (token.type) {
7751                 case T_false:                        return parse_bool_const(false);
7752                 case T_true:                         return parse_bool_const(true);
7753                 case T_INTEGER:                      return parse_int_const();
7754                 case T_CHARACTER_CONSTANT:           return parse_character_constant();
7755                 case T_WIDE_CHARACTER_CONSTANT:      return parse_wide_character_constant();
7756                 case T_FLOATINGPOINT:                return parse_float_const();
7757                 case T_STRING_LITERAL:
7758                 case T_WIDE_STRING_LITERAL:          return parse_string_const();
7759                 case T_IDENTIFIER:                   return parse_reference();
7760                 case T___FUNCTION__:
7761                 case T___func__:                     return parse_function_keyword();
7762                 case T___PRETTY_FUNCTION__:          return parse_pretty_function_keyword();
7763                 case T___FUNCSIG__:                  return parse_funcsig_keyword();
7764                 case T___FUNCDNAME__:                return parse_funcdname_keyword();
7765                 case T___builtin_offsetof:           return parse_offsetof();
7766                 case T___builtin_va_start:           return parse_va_start();
7767                 case T___builtin_va_arg:             return parse_va_arg();
7768                 case T___builtin_isgreater:
7769                 case T___builtin_isgreaterequal:
7770                 case T___builtin_isless:
7771                 case T___builtin_islessequal:
7772                 case T___builtin_islessgreater:
7773                 case T___builtin_isunordered:        return parse_compare_builtin();
7774                 case T___builtin_constant_p:         return parse_builtin_constant();
7775                 case T___builtin_types_compatible_p: return parse_builtin_types_compatible();
7776                 case T__assume:                      return parse_assume();
7777                 case T_ANDAND:
7778                         if (GNU_MODE)
7779                                 return parse_label_address();
7780                         break;
7781
7782                 case '(':                            return parse_parenthesized_expression();
7783                 case T___noop:                       return parse_noop_expression();
7784         }
7785
7786         errorf(HERE, "unexpected token %K, expected an expression", &token);
7787         return create_invalid_expression();
7788 }
7789
7790 /**
7791  * Check if the expression has the character type and issue a warning then.
7792  */
7793 static void check_for_char_index_type(const expression_t *expression)
7794 {
7795         type_t       *const type      = expression->base.type;
7796         const type_t *const base_type = skip_typeref(type);
7797
7798         if (is_type_atomic(base_type, ATOMIC_TYPE_CHAR) &&
7799                         warning.char_subscripts) {
7800                 warningf(&expression->base.source_position,
7801                          "array subscript has type '%T'", type);
7802         }
7803 }
7804
7805 static expression_t *parse_array_expression(expression_t *left)
7806 {
7807         expression_t *expression = allocate_expression_zero(EXPR_ARRAY_ACCESS);
7808
7809         eat('[');
7810         add_anchor_token(']');
7811
7812         expression_t *inside = parse_expression();
7813
7814         type_t *const orig_type_left   = left->base.type;
7815         type_t *const orig_type_inside = inside->base.type;
7816
7817         type_t *const type_left   = skip_typeref(orig_type_left);
7818         type_t *const type_inside = skip_typeref(orig_type_inside);
7819
7820         type_t                    *return_type;
7821         array_access_expression_t *array_access = &expression->array_access;
7822         if (is_type_pointer(type_left)) {
7823                 return_type             = type_left->pointer.points_to;
7824                 array_access->array_ref = left;
7825                 array_access->index     = inside;
7826                 check_for_char_index_type(inside);
7827         } else if (is_type_pointer(type_inside)) {
7828                 return_type             = type_inside->pointer.points_to;
7829                 array_access->array_ref = inside;
7830                 array_access->index     = left;
7831                 array_access->flipped   = true;
7832                 check_for_char_index_type(left);
7833         } else {
7834                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
7835                         errorf(HERE,
7836                                 "array access on object with non-pointer types '%T', '%T'",
7837                                 orig_type_left, orig_type_inside);
7838                 }
7839                 return_type             = type_error_type;
7840                 array_access->array_ref = left;
7841                 array_access->index     = inside;
7842         }
7843
7844         expression->base.type = automatic_type_conversion(return_type);
7845
7846         rem_anchor_token(']');
7847         expect(']', end_error);
7848 end_error:
7849         return expression;
7850 }
7851
7852 static expression_t *parse_typeprop(expression_kind_t const kind)
7853 {
7854         expression_t  *tp_expression = allocate_expression_zero(kind);
7855         tp_expression->base.type     = type_size_t;
7856
7857         eat(kind == EXPR_SIZEOF ? T_sizeof : T___alignof__);
7858
7859         /* we only refer to a type property, mark this case */
7860         bool old     = in_type_prop;
7861         in_type_prop = true;
7862
7863         type_t       *orig_type;
7864         expression_t *expression;
7865         if (token.type == '(' && is_declaration_specifier(look_ahead(1), true)) {
7866                 next_token();
7867                 add_anchor_token(')');
7868                 orig_type = parse_typename();
7869                 rem_anchor_token(')');
7870                 expect(')', end_error);
7871
7872                 if (token.type == '{') {
7873                         /* It was not sizeof(type) after all.  It is sizeof of an expression
7874                          * starting with a compound literal */
7875                         expression = parse_compound_literal(orig_type);
7876                         goto typeprop_expression;
7877                 }
7878         } else {
7879                 expression = parse_sub_expression(PREC_UNARY);
7880
7881 typeprop_expression:
7882                 tp_expression->typeprop.tp_expression = expression;
7883
7884                 orig_type = revert_automatic_type_conversion(expression);
7885                 expression->base.type = orig_type;
7886         }
7887
7888         tp_expression->typeprop.type   = orig_type;
7889         type_t const* const type       = skip_typeref(orig_type);
7890         char   const* const wrong_type =
7891                 GNU_MODE && is_type_atomic(type, ATOMIC_TYPE_VOID) ? NULL                  :
7892                 is_type_incomplete(type)                           ? "incomplete"          :
7893                 type->kind == TYPE_FUNCTION                        ? "function designator" :
7894                 type->kind == TYPE_BITFIELD                        ? "bitfield"            :
7895                 NULL;
7896         if (wrong_type != NULL) {
7897                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
7898                 errorf(&tp_expression->base.source_position,
7899                                 "operand of %s expression must not be of %s type '%T'",
7900                                 what, wrong_type, orig_type);
7901         }
7902
7903 end_error:
7904         in_type_prop = old;
7905         return tp_expression;
7906 }
7907
7908 static expression_t *parse_sizeof(void)
7909 {
7910         return parse_typeprop(EXPR_SIZEOF);
7911 }
7912
7913 static expression_t *parse_alignof(void)
7914 {
7915         return parse_typeprop(EXPR_ALIGNOF);
7916 }
7917
7918 static expression_t *parse_select_expression(expression_t *compound)
7919 {
7920         expression_t *select    = allocate_expression_zero(EXPR_SELECT);
7921         select->select.compound = compound;
7922
7923         assert(token.type == '.' || token.type == T_MINUSGREATER);
7924         bool is_pointer = (token.type == T_MINUSGREATER);
7925         next_token();
7926
7927         if (token.type != T_IDENTIFIER) {
7928                 parse_error_expected("while parsing select", T_IDENTIFIER, NULL);
7929                 return select;
7930         }
7931         symbol_t *symbol = token.v.symbol;
7932         next_token();
7933
7934         type_t *const orig_type = compound->base.type;
7935         type_t *const type      = skip_typeref(orig_type);
7936
7937         type_t *type_left;
7938         bool    saw_error = false;
7939         if (is_type_pointer(type)) {
7940                 if (!is_pointer) {
7941                         errorf(HERE,
7942                                "request for member '%Y' in something not a struct or union, but '%T'",
7943                                symbol, orig_type);
7944                         saw_error = true;
7945                 }
7946                 type_left = skip_typeref(type->pointer.points_to);
7947         } else {
7948                 if (is_pointer && is_type_valid(type)) {
7949                         errorf(HERE, "left hand side of '->' is not a pointer, but '%T'", orig_type);
7950                         saw_error = true;
7951                 }
7952                 type_left = type;
7953         }
7954
7955         entity_t *entry;
7956         if (type_left->kind == TYPE_COMPOUND_STRUCT ||
7957             type_left->kind == TYPE_COMPOUND_UNION) {
7958                 compound_t *compound = type_left->compound.compound;
7959
7960                 if (!compound->complete) {
7961                         errorf(HERE, "request for member '%Y' of incomplete type '%T'",
7962                                symbol, type_left);
7963                         goto create_error_entry;
7964                 }
7965
7966                 entry = find_compound_entry(compound, symbol);
7967                 if (entry == NULL) {
7968                         errorf(HERE, "'%T' has no member named '%Y'", orig_type, symbol);
7969                         goto create_error_entry;
7970                 }
7971         } else {
7972                 if (is_type_valid(type_left) && !saw_error) {
7973                         errorf(HERE,
7974                                "request for member '%Y' in something not a struct or union, but '%T'",
7975                                symbol, type_left);
7976                 }
7977 create_error_entry:
7978                 entry = create_error_entity(symbol, ENTITY_COMPOUND_MEMBER);
7979         }
7980
7981         assert(is_declaration(entry));
7982         select->select.compound_entry = entry;
7983
7984         type_t *entry_type = entry->declaration.type;
7985         type_t *res_type
7986                 = get_qualified_type(entry_type, type_left->base.qualifiers);
7987
7988         /* we always do the auto-type conversions; the & and sizeof parser contains
7989          * code to revert this! */
7990         select->base.type = automatic_type_conversion(res_type);
7991
7992         type_t *skipped = skip_typeref(res_type);
7993         if (skipped->kind == TYPE_BITFIELD) {
7994                 select->base.type = skipped->bitfield.base_type;
7995         }
7996
7997         return select;
7998 }
7999
8000 static void check_call_argument(const function_parameter_t *parameter,
8001                                 call_argument_t *argument, unsigned pos)
8002 {
8003         type_t         *expected_type      = parameter->type;
8004         type_t         *expected_type_skip = skip_typeref(expected_type);
8005         assign_error_t  error              = ASSIGN_ERROR_INCOMPATIBLE;
8006         expression_t   *arg_expr           = argument->expression;
8007         type_t         *arg_type           = skip_typeref(arg_expr->base.type);
8008
8009         /* handle transparent union gnu extension */
8010         if (is_type_union(expected_type_skip)
8011                         && (expected_type_skip->base.modifiers
8012                                 & TYPE_MODIFIER_TRANSPARENT_UNION)) {
8013                 compound_t *union_decl  = expected_type_skip->compound.compound;
8014                 type_t     *best_type   = NULL;
8015                 entity_t   *entry       = union_decl->members.entities;
8016                 for ( ; entry != NULL; entry = entry->base.next) {
8017                         assert(is_declaration(entry));
8018                         type_t *decl_type = entry->declaration.type;
8019                         error = semantic_assign(decl_type, arg_expr);
8020                         if (error == ASSIGN_ERROR_INCOMPATIBLE
8021                                 || error == ASSIGN_ERROR_POINTER_QUALIFIER_MISSING)
8022                                 continue;
8023
8024                         if (error == ASSIGN_SUCCESS) {
8025                                 best_type = decl_type;
8026                         } else if (best_type == NULL) {
8027                                 best_type = decl_type;
8028                         }
8029                 }
8030
8031                 if (best_type != NULL) {
8032                         expected_type = best_type;
8033                 }
8034         }
8035
8036         error                = semantic_assign(expected_type, arg_expr);
8037         argument->expression = create_implicit_cast(argument->expression,
8038                                                     expected_type);
8039
8040         if (error != ASSIGN_SUCCESS) {
8041                 /* report exact scope in error messages (like "in argument 3") */
8042                 char buf[64];
8043                 snprintf(buf, sizeof(buf), "call argument %u", pos);
8044                 report_assign_error(error, expected_type, arg_expr,     buf,
8045                                                         &arg_expr->base.source_position);
8046         } else if (warning.traditional || warning.conversion) {
8047                 type_t *const promoted_type = get_default_promoted_type(arg_type);
8048                 if (!types_compatible(expected_type_skip, promoted_type) &&
8049                     !types_compatible(expected_type_skip, type_void_ptr) &&
8050                     !types_compatible(type_void_ptr,      promoted_type)) {
8051                         /* Deliberately show the skipped types in this warning */
8052                         warningf(&arg_expr->base.source_position,
8053                                 "passing call argument %u as '%T' rather than '%T' due to prototype",
8054                                 pos, expected_type_skip, promoted_type);
8055                 }
8056         }
8057 }
8058
8059 /**
8060  * Handle the semantic restrictions of builtin calls
8061  */
8062 static void handle_builtin_argument_restrictions(call_expression_t *call) {
8063         switch (call->function->reference.entity->function.btk) {
8064                 case bk_gnu_builtin_return_address:
8065                 case bk_gnu_builtin_frame_address: {
8066                         /* argument must be constant */
8067                         call_argument_t *argument = call->arguments;
8068
8069                         if (! is_constant_expression(argument->expression)) {
8070                                 errorf(&call->base.source_position,
8071                                        "argument of '%Y' must be a constant expression",
8072                                        call->function->reference.entity->base.symbol);
8073                         }
8074                         break;
8075                 }
8076                 case bk_gnu_builtin_prefetch: {
8077                         /* second and third argument must be constant if existent */
8078                         call_argument_t *rw = call->arguments->next;
8079                         call_argument_t *locality = NULL;
8080
8081                         if (rw != NULL) {
8082                                 if (! is_constant_expression(rw->expression)) {
8083                                         errorf(&call->base.source_position,
8084                                                "second argument of '%Y' must be a constant expression",
8085                                                call->function->reference.entity->base.symbol);
8086                                 }
8087                                 locality = rw->next;
8088                         }
8089                         if (locality != NULL) {
8090                                 if (! is_constant_expression(locality->expression)) {
8091                                         errorf(&call->base.source_position,
8092                                                "third argument of '%Y' must be a constant expression",
8093                                                call->function->reference.entity->base.symbol);
8094                                 }
8095                                 locality = rw->next;
8096                         }
8097                         break;
8098                 }
8099                 default:
8100                         break;
8101         }
8102 }
8103
8104 /**
8105  * Parse a call expression, ie. expression '( ... )'.
8106  *
8107  * @param expression  the function address
8108  */
8109 static expression_t *parse_call_expression(expression_t *expression)
8110 {
8111         expression_t      *result = allocate_expression_zero(EXPR_CALL);
8112         call_expression_t *call   = &result->call;
8113         call->function            = expression;
8114
8115         type_t *const orig_type = expression->base.type;
8116         type_t *const type      = skip_typeref(orig_type);
8117
8118         function_type_t *function_type = NULL;
8119         if (is_type_pointer(type)) {
8120                 type_t *const to_type = skip_typeref(type->pointer.points_to);
8121
8122                 if (is_type_function(to_type)) {
8123                         function_type   = &to_type->function;
8124                         call->base.type = function_type->return_type;
8125                 }
8126         }
8127
8128         if (function_type == NULL && is_type_valid(type)) {
8129                 errorf(HERE, "called object '%E' (type '%T') is not a pointer to a function", expression, orig_type);
8130         }
8131
8132         /* parse arguments */
8133         eat('(');
8134         add_anchor_token(')');
8135         add_anchor_token(',');
8136
8137         if (token.type != ')') {
8138                 call_argument_t *last_argument = NULL;
8139
8140                 while (true) {
8141                         call_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
8142
8143                         argument->expression = parse_assignment_expression();
8144                         if (last_argument == NULL) {
8145                                 call->arguments = argument;
8146                         } else {
8147                                 last_argument->next = argument;
8148                         }
8149                         last_argument = argument;
8150
8151                         if (token.type != ',')
8152                                 break;
8153                         next_token();
8154                 }
8155         }
8156         rem_anchor_token(',');
8157         rem_anchor_token(')');
8158         expect(')', end_error);
8159
8160         if (function_type == NULL)
8161                 return result;
8162
8163         function_parameter_t *parameter = function_type->parameters;
8164         call_argument_t      *argument  = call->arguments;
8165         if (!function_type->unspecified_parameters) {
8166                 for (unsigned pos = 0; parameter != NULL && argument != NULL;
8167                                 parameter = parameter->next, argument = argument->next) {
8168                         check_call_argument(parameter, argument, ++pos);
8169                 }
8170
8171                 if (parameter != NULL) {
8172                         errorf(HERE, "too few arguments to function '%E'", expression);
8173                 } else if (argument != NULL && !function_type->variadic) {
8174                         errorf(HERE, "too many arguments to function '%E'", expression);
8175                 }
8176         }
8177
8178         /* do default promotion */
8179         for (; argument != NULL; argument = argument->next) {
8180                 type_t *type = argument->expression->base.type;
8181
8182                 type = get_default_promoted_type(type);
8183
8184                 argument->expression
8185                         = create_implicit_cast(argument->expression, type);
8186         }
8187
8188         check_format(&result->call);
8189
8190         if (warning.aggregate_return &&
8191             is_type_compound(skip_typeref(function_type->return_type))) {
8192                 warningf(&result->base.source_position,
8193                          "function call has aggregate value");
8194         }
8195
8196         if (call->function->kind == EXPR_REFERENCE) {
8197                 reference_expression_t *reference = &call->function->reference;
8198                 if (reference->entity->kind == ENTITY_FUNCTION &&
8199                     reference->entity->function.btk != bk_none)
8200                         handle_builtin_argument_restrictions(call);
8201         }
8202
8203 end_error:
8204         return result;
8205 }
8206
8207 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
8208
8209 static bool same_compound_type(const type_t *type1, const type_t *type2)
8210 {
8211         return
8212                 is_type_compound(type1) &&
8213                 type1->kind == type2->kind &&
8214                 type1->compound.compound == type2->compound.compound;
8215 }
8216
8217 static expression_t const *get_reference_address(expression_t const *expr)
8218 {
8219         bool regular_take_address = true;
8220         for (;;) {
8221                 if (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
8222                         expr = expr->unary.value;
8223                 } else {
8224                         regular_take_address = false;
8225                 }
8226
8227                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
8228                         break;
8229
8230                 expr = expr->unary.value;
8231         }
8232
8233         if (expr->kind != EXPR_REFERENCE)
8234                 return NULL;
8235
8236         /* special case for functions which are automatically converted to a
8237          * pointer to function without an extra TAKE_ADDRESS operation */
8238         if (!regular_take_address &&
8239                         expr->reference.entity->kind != ENTITY_FUNCTION) {
8240                 return NULL;
8241         }
8242
8243         return expr;
8244 }
8245
8246 static void warn_reference_address_as_bool(expression_t const* expr)
8247 {
8248         if (!warning.address)
8249                 return;
8250
8251         expr = get_reference_address(expr);
8252         if (expr != NULL) {
8253                 warningf(&expr->base.source_position,
8254                          "the address of '%Y' will always evaluate as 'true'",
8255                          expr->reference.entity->base.symbol);
8256         }
8257 }
8258
8259 static void warn_assignment_in_condition(const expression_t *const expr)
8260 {
8261         if (!warning.parentheses)
8262                 return;
8263         if (expr->base.kind != EXPR_BINARY_ASSIGN)
8264                 return;
8265         if (expr->base.parenthesized)
8266                 return;
8267         warningf(&expr->base.source_position,
8268                         "suggest parentheses around assignment used as truth value");
8269 }
8270
8271 static void semantic_condition(expression_t const *const expr,
8272                                char const *const context)
8273 {
8274         type_t *const type = skip_typeref(expr->base.type);
8275         if (is_type_scalar(type)) {
8276                 warn_reference_address_as_bool(expr);
8277                 warn_assignment_in_condition(expr);
8278         } else if (is_type_valid(type)) {
8279                 errorf(&expr->base.source_position,
8280                                 "%s must have scalar type", context);
8281         }
8282 }
8283
8284 /**
8285  * Parse a conditional expression, ie. 'expression ? ... : ...'.
8286  *
8287  * @param expression  the conditional expression
8288  */
8289 static expression_t *parse_conditional_expression(expression_t *expression)
8290 {
8291         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
8292
8293         conditional_expression_t *conditional = &result->conditional;
8294         conditional->condition                = expression;
8295
8296         eat('?');
8297         add_anchor_token(':');
8298
8299         /* §6.5.15:2  The first operand shall have scalar type. */
8300         semantic_condition(expression, "condition of conditional operator");
8301
8302         expression_t *true_expression = expression;
8303         bool          gnu_cond = false;
8304         if (GNU_MODE && token.type == ':') {
8305                 gnu_cond = true;
8306         } else {
8307                 true_expression = parse_expression();
8308         }
8309         rem_anchor_token(':');
8310         expect(':', end_error);
8311 end_error:;
8312         expression_t *false_expression =
8313                 parse_sub_expression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
8314
8315         type_t *const orig_true_type  = true_expression->base.type;
8316         type_t *const orig_false_type = false_expression->base.type;
8317         type_t *const true_type       = skip_typeref(orig_true_type);
8318         type_t *const false_type      = skip_typeref(orig_false_type);
8319
8320         /* 6.5.15.3 */
8321         type_t *result_type;
8322         if (is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
8323                         is_type_atomic(false_type, ATOMIC_TYPE_VOID)) {
8324                 /* ISO/IEC 14882:1998(E) §5.16:2 */
8325                 if (true_expression->kind == EXPR_UNARY_THROW) {
8326                         result_type = false_type;
8327                 } else if (false_expression->kind == EXPR_UNARY_THROW) {
8328                         result_type = true_type;
8329                 } else {
8330                         if (warning.other && (
8331                                                 !is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
8332                                                 !is_type_atomic(false_type, ATOMIC_TYPE_VOID)
8333                                         )) {
8334                                 warningf(&conditional->base.source_position,
8335                                                 "ISO C forbids conditional expression with only one void side");
8336                         }
8337                         result_type = type_void;
8338                 }
8339         } else if (is_type_arithmetic(true_type)
8340                    && is_type_arithmetic(false_type)) {
8341                 result_type = semantic_arithmetic(true_type, false_type);
8342
8343                 true_expression  = create_implicit_cast(true_expression, result_type);
8344                 false_expression = create_implicit_cast(false_expression, result_type);
8345
8346                 conditional->true_expression  = true_expression;
8347                 conditional->false_expression = false_expression;
8348                 conditional->base.type        = result_type;
8349         } else if (same_compound_type(true_type, false_type)) {
8350                 /* just take 1 of the 2 types */
8351                 result_type = true_type;
8352         } else if (is_type_pointer(true_type) || is_type_pointer(false_type)) {
8353                 type_t *pointer_type;
8354                 type_t *other_type;
8355                 expression_t *other_expression;
8356                 if (is_type_pointer(true_type) &&
8357                                 (!is_type_pointer(false_type) || is_null_pointer_constant(false_expression))) {
8358                         pointer_type     = true_type;
8359                         other_type       = false_type;
8360                         other_expression = false_expression;
8361                 } else {
8362                         pointer_type     = false_type;
8363                         other_type       = true_type;
8364                         other_expression = true_expression;
8365                 }
8366
8367                 if (is_null_pointer_constant(other_expression)) {
8368                         result_type = pointer_type;
8369                 } else if (is_type_pointer(other_type)) {
8370                         type_t *to1 = skip_typeref(pointer_type->pointer.points_to);
8371                         type_t *to2 = skip_typeref(other_type->pointer.points_to);
8372
8373                         type_t *to;
8374                         if (is_type_atomic(to1, ATOMIC_TYPE_VOID) ||
8375                             is_type_atomic(to2, ATOMIC_TYPE_VOID)) {
8376                                 to = type_void;
8377                         } else if (types_compatible(get_unqualified_type(to1),
8378                                                     get_unqualified_type(to2))) {
8379                                 to = to1;
8380                         } else {
8381                                 if (warning.other) {
8382                                         warningf(&conditional->base.source_position,
8383                                                         "pointer types '%T' and '%T' in conditional expression are incompatible",
8384                                                         true_type, false_type);
8385                                 }
8386                                 to = type_void;
8387                         }
8388
8389                         type_t *const type =
8390                                 get_qualified_type(to, to1->base.qualifiers | to2->base.qualifiers);
8391                         result_type = make_pointer_type(type, TYPE_QUALIFIER_NONE);
8392                 } else if (is_type_integer(other_type)) {
8393                         if (warning.other) {
8394                                 warningf(&conditional->base.source_position,
8395                                                 "pointer/integer type mismatch in conditional expression ('%T' and '%T')", true_type, false_type);
8396                         }
8397                         result_type = pointer_type;
8398                 } else {
8399                         if (is_type_valid(other_type)) {
8400                                 type_error_incompatible("while parsing conditional",
8401                                                 &expression->base.source_position, true_type, false_type);
8402                         }
8403                         result_type = type_error_type;
8404                 }
8405         } else {
8406                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
8407                         type_error_incompatible("while parsing conditional",
8408                                                 &conditional->base.source_position, true_type,
8409                                                 false_type);
8410                 }
8411                 result_type = type_error_type;
8412         }
8413
8414         conditional->true_expression
8415                 = gnu_cond ? NULL : create_implicit_cast(true_expression, result_type);
8416         conditional->false_expression
8417                 = create_implicit_cast(false_expression, result_type);
8418         conditional->base.type = result_type;
8419         return result;
8420 }
8421
8422 /**
8423  * Parse an extension expression.
8424  */
8425 static expression_t *parse_extension(void)
8426 {
8427         eat(T___extension__);
8428
8429         bool old_gcc_extension   = in_gcc_extension;
8430         in_gcc_extension         = true;
8431         expression_t *expression = parse_sub_expression(PREC_UNARY);
8432         in_gcc_extension         = old_gcc_extension;
8433         return expression;
8434 }
8435
8436 /**
8437  * Parse a __builtin_classify_type() expression.
8438  */
8439 static expression_t *parse_builtin_classify_type(void)
8440 {
8441         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
8442         result->base.type    = type_int;
8443
8444         eat(T___builtin_classify_type);
8445
8446         expect('(', end_error);
8447         add_anchor_token(')');
8448         expression_t *expression = parse_expression();
8449         rem_anchor_token(')');
8450         expect(')', end_error);
8451         result->classify_type.type_expression = expression;
8452
8453         return result;
8454 end_error:
8455         return create_invalid_expression();
8456 }
8457
8458 /**
8459  * Parse a delete expression
8460  * ISO/IEC 14882:1998(E) §5.3.5
8461  */
8462 static expression_t *parse_delete(void)
8463 {
8464         expression_t *const result = allocate_expression_zero(EXPR_UNARY_DELETE);
8465         result->base.type          = type_void;
8466
8467         eat(T_delete);
8468
8469         if (token.type == '[') {
8470                 next_token();
8471                 result->kind = EXPR_UNARY_DELETE_ARRAY;
8472                 expect(']', end_error);
8473 end_error:;
8474         }
8475
8476         expression_t *const value = parse_sub_expression(PREC_CAST);
8477         result->unary.value = value;
8478
8479         type_t *const type = skip_typeref(value->base.type);
8480         if (!is_type_pointer(type)) {
8481                 if (is_type_valid(type)) {
8482                         errorf(&value->base.source_position,
8483                                         "operand of delete must have pointer type");
8484                 }
8485         } else if (warning.other &&
8486                         is_type_atomic(skip_typeref(type->pointer.points_to), ATOMIC_TYPE_VOID)) {
8487                 warningf(&value->base.source_position,
8488                                 "deleting 'void*' is undefined");
8489         }
8490
8491         return result;
8492 }
8493
8494 /**
8495  * Parse a throw expression
8496  * ISO/IEC 14882:1998(E) §15:1
8497  */
8498 static expression_t *parse_throw(void)
8499 {
8500         expression_t *const result = allocate_expression_zero(EXPR_UNARY_THROW);
8501         result->base.type          = type_void;
8502
8503         eat(T_throw);
8504
8505         expression_t *value = NULL;
8506         switch (token.type) {
8507                 EXPRESSION_START {
8508                         value = parse_assignment_expression();
8509                         /* ISO/IEC 14882:1998(E) §15.1:3 */
8510                         type_t *const orig_type = value->base.type;
8511                         type_t *const type      = skip_typeref(orig_type);
8512                         if (is_type_incomplete(type)) {
8513                                 errorf(&value->base.source_position,
8514                                                 "cannot throw object of incomplete type '%T'", orig_type);
8515                         } else if (is_type_pointer(type)) {
8516                                 type_t *const points_to = skip_typeref(type->pointer.points_to);
8517                                 if (is_type_incomplete(points_to) &&
8518                                                 !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
8519                                         errorf(&value->base.source_position,
8520                                                         "cannot throw pointer to incomplete type '%T'", orig_type);
8521                                 }
8522                         }
8523                 }
8524
8525                 default:
8526                         break;
8527         }
8528         result->unary.value = value;
8529
8530         return result;
8531 }
8532
8533 static bool check_pointer_arithmetic(const source_position_t *source_position,
8534                                      type_t *pointer_type,
8535                                      type_t *orig_pointer_type)
8536 {
8537         type_t *points_to = pointer_type->pointer.points_to;
8538         points_to = skip_typeref(points_to);
8539
8540         if (is_type_incomplete(points_to)) {
8541                 if (!GNU_MODE || !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
8542                         errorf(source_position,
8543                                "arithmetic with pointer to incomplete type '%T' not allowed",
8544                                orig_pointer_type);
8545                         return false;
8546                 } else if (warning.pointer_arith) {
8547                         warningf(source_position,
8548                                  "pointer of type '%T' used in arithmetic",
8549                                  orig_pointer_type);
8550                 }
8551         } else if (is_type_function(points_to)) {
8552                 if (!GNU_MODE) {
8553                         errorf(source_position,
8554                                "arithmetic with pointer to function type '%T' not allowed",
8555                                orig_pointer_type);
8556                         return false;
8557                 } else if (warning.pointer_arith) {
8558                         warningf(source_position,
8559                                  "pointer to a function '%T' used in arithmetic",
8560                                  orig_pointer_type);
8561                 }
8562         }
8563         return true;
8564 }
8565
8566 static bool is_lvalue(const expression_t *expression)
8567 {
8568         /* TODO: doesn't seem to be consistent with §6.3.2.1:1 */
8569         switch (expression->kind) {
8570         case EXPR_ARRAY_ACCESS:
8571         case EXPR_COMPOUND_LITERAL:
8572         case EXPR_REFERENCE:
8573         case EXPR_SELECT:
8574         case EXPR_UNARY_DEREFERENCE:
8575                 return true;
8576
8577         default: {
8578           type_t *type = skip_typeref(expression->base.type);
8579           return
8580                 /* ISO/IEC 14882:1998(E) §3.10:3 */
8581                 is_type_reference(type) ||
8582                 /* Claim it is an lvalue, if the type is invalid.  There was a parse
8583                  * error before, which maybe prevented properly recognizing it as
8584                  * lvalue. */
8585                 !is_type_valid(type);
8586         }
8587         }
8588 }
8589
8590 static void semantic_incdec(unary_expression_t *expression)
8591 {
8592         type_t *const orig_type = expression->value->base.type;
8593         type_t *const type      = skip_typeref(orig_type);
8594         if (is_type_pointer(type)) {
8595                 if (!check_pointer_arithmetic(&expression->base.source_position,
8596                                               type, orig_type)) {
8597                         return;
8598                 }
8599         } else if (!is_type_real(type) && is_type_valid(type)) {
8600                 /* TODO: improve error message */
8601                 errorf(&expression->base.source_position,
8602                        "operation needs an arithmetic or pointer type");
8603                 return;
8604         }
8605         if (!is_lvalue(expression->value)) {
8606                 /* TODO: improve error message */
8607                 errorf(&expression->base.source_position, "lvalue required as operand");
8608         }
8609         expression->base.type = orig_type;
8610 }
8611
8612 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
8613 {
8614         type_t *const orig_type = expression->value->base.type;
8615         type_t *const type      = skip_typeref(orig_type);
8616         if (!is_type_arithmetic(type)) {
8617                 if (is_type_valid(type)) {
8618                         /* TODO: improve error message */
8619                         errorf(&expression->base.source_position,
8620                                 "operation needs an arithmetic type");
8621                 }
8622                 return;
8623         }
8624
8625         expression->base.type = orig_type;
8626 }
8627
8628 static void semantic_unexpr_plus(unary_expression_t *expression)
8629 {
8630         semantic_unexpr_arithmetic(expression);
8631         if (warning.traditional)
8632                 warningf(&expression->base.source_position,
8633                         "traditional C rejects the unary plus operator");
8634 }
8635
8636 static void semantic_not(unary_expression_t *expression)
8637 {
8638         /* §6.5.3.3:1  The operand [...] of the ! operator, scalar type. */
8639         semantic_condition(expression->value, "operand of !");
8640         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8641 }
8642
8643 static void semantic_unexpr_integer(unary_expression_t *expression)
8644 {
8645         type_t *const orig_type = expression->value->base.type;
8646         type_t *const type      = skip_typeref(orig_type);
8647         if (!is_type_integer(type)) {
8648                 if (is_type_valid(type)) {
8649                         errorf(&expression->base.source_position,
8650                                "operand of ~ must be of integer type");
8651                 }
8652                 return;
8653         }
8654
8655         expression->base.type = orig_type;
8656 }
8657
8658 static void semantic_dereference(unary_expression_t *expression)
8659 {
8660         type_t *const orig_type = expression->value->base.type;
8661         type_t *const type      = skip_typeref(orig_type);
8662         if (!is_type_pointer(type)) {
8663                 if (is_type_valid(type)) {
8664                         errorf(&expression->base.source_position,
8665                                "Unary '*' needs pointer or array type, but type '%T' given", orig_type);
8666                 }
8667                 return;
8668         }
8669
8670         type_t *result_type   = type->pointer.points_to;
8671         result_type           = automatic_type_conversion(result_type);
8672         expression->base.type = result_type;
8673 }
8674
8675 /**
8676  * Record that an address is taken (expression represents an lvalue).
8677  *
8678  * @param expression       the expression
8679  * @param may_be_register  if true, the expression might be an register
8680  */
8681 static void set_address_taken(expression_t *expression, bool may_be_register)
8682 {
8683         if (expression->kind != EXPR_REFERENCE)
8684                 return;
8685
8686         entity_t *const entity = expression->reference.entity;
8687
8688         if (entity->kind != ENTITY_VARIABLE && entity->kind != ENTITY_PARAMETER)
8689                 return;
8690
8691         if (entity->declaration.storage_class == STORAGE_CLASS_REGISTER
8692                         && !may_be_register) {
8693                 errorf(&expression->base.source_position,
8694                                 "address of register %s '%Y' requested",
8695                                 get_entity_kind_name(entity->kind),     entity->base.symbol);
8696         }
8697
8698         if (entity->kind == ENTITY_VARIABLE) {
8699                 entity->variable.address_taken = true;
8700         } else {
8701                 assert(entity->kind == ENTITY_PARAMETER);
8702                 entity->parameter.address_taken = true;
8703         }
8704 }
8705
8706 /**
8707  * Check the semantic of the address taken expression.
8708  */
8709 static void semantic_take_addr(unary_expression_t *expression)
8710 {
8711         expression_t *value = expression->value;
8712         value->base.type    = revert_automatic_type_conversion(value);
8713
8714         type_t *orig_type = value->base.type;
8715         type_t *type      = skip_typeref(orig_type);
8716         if (!is_type_valid(type))
8717                 return;
8718
8719         /* §6.5.3.2 */
8720         if (!is_lvalue(value)) {
8721                 errorf(&expression->base.source_position, "'&' requires an lvalue");
8722         }
8723         if (type->kind == TYPE_BITFIELD) {
8724                 errorf(&expression->base.source_position,
8725                        "'&' not allowed on object with bitfield type '%T'",
8726                        type);
8727         }
8728
8729         set_address_taken(value, false);
8730
8731         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
8732 }
8733
8734 #define CREATE_UNARY_EXPRESSION_PARSER(token_type, unexpression_type, sfunc) \
8735 static expression_t *parse_##unexpression_type(void)                         \
8736 {                                                                            \
8737         expression_t *unary_expression                                           \
8738                 = allocate_expression_zero(unexpression_type);                       \
8739         eat(token_type);                                                         \
8740         unary_expression->unary.value = parse_sub_expression(PREC_UNARY);        \
8741                                                                                  \
8742         sfunc(&unary_expression->unary);                                         \
8743                                                                                  \
8744         return unary_expression;                                                 \
8745 }
8746
8747 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
8748                                semantic_unexpr_arithmetic)
8749 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
8750                                semantic_unexpr_plus)
8751 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
8752                                semantic_not)
8753 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
8754                                semantic_dereference)
8755 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
8756                                semantic_take_addr)
8757 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
8758                                semantic_unexpr_integer)
8759 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
8760                                semantic_incdec)
8761 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
8762                                semantic_incdec)
8763
8764 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_type, unexpression_type, \
8765                                                sfunc)                         \
8766 static expression_t *parse_##unexpression_type(expression_t *left)            \
8767 {                                                                             \
8768         expression_t *unary_expression                                            \
8769                 = allocate_expression_zero(unexpression_type);                        \
8770         eat(token_type);                                                          \
8771         unary_expression->unary.value = left;                                     \
8772                                                                                   \
8773         sfunc(&unary_expression->unary);                                          \
8774                                                                               \
8775         return unary_expression;                                                  \
8776 }
8777
8778 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
8779                                        EXPR_UNARY_POSTFIX_INCREMENT,
8780                                        semantic_incdec)
8781 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
8782                                        EXPR_UNARY_POSTFIX_DECREMENT,
8783                                        semantic_incdec)
8784
8785 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
8786 {
8787         /* TODO: handle complex + imaginary types */
8788
8789         type_left  = get_unqualified_type(type_left);
8790         type_right = get_unqualified_type(type_right);
8791
8792         /* §6.3.1.8 Usual arithmetic conversions */
8793         if (type_left == type_long_double || type_right == type_long_double) {
8794                 return type_long_double;
8795         } else if (type_left == type_double || type_right == type_double) {
8796                 return type_double;
8797         } else if (type_left == type_float || type_right == type_float) {
8798                 return type_float;
8799         }
8800
8801         type_left  = promote_integer(type_left);
8802         type_right = promote_integer(type_right);
8803
8804         if (type_left == type_right)
8805                 return type_left;
8806
8807         bool const signed_left  = is_type_signed(type_left);
8808         bool const signed_right = is_type_signed(type_right);
8809         int const  rank_left    = get_rank(type_left);
8810         int const  rank_right   = get_rank(type_right);
8811
8812         if (signed_left == signed_right)
8813                 return rank_left >= rank_right ? type_left : type_right;
8814
8815         int     s_rank;
8816         int     u_rank;
8817         type_t *s_type;
8818         type_t *u_type;
8819         if (signed_left) {
8820                 s_rank = rank_left;
8821                 s_type = type_left;
8822                 u_rank = rank_right;
8823                 u_type = type_right;
8824         } else {
8825                 s_rank = rank_right;
8826                 s_type = type_right;
8827                 u_rank = rank_left;
8828                 u_type = type_left;
8829         }
8830
8831         if (u_rank >= s_rank)
8832                 return u_type;
8833
8834         /* casting rank to atomic_type_kind is a bit hacky, but makes things
8835          * easier here... */
8836         if (get_atomic_type_size((atomic_type_kind_t) s_rank)
8837                         > get_atomic_type_size((atomic_type_kind_t) u_rank))
8838                 return s_type;
8839
8840         switch (s_rank) {
8841                 case ATOMIC_TYPE_INT:      return type_unsigned_int;
8842                 case ATOMIC_TYPE_LONG:     return type_unsigned_long;
8843                 case ATOMIC_TYPE_LONGLONG: return type_unsigned_long_long;
8844
8845                 default: panic("invalid atomic type");
8846         }
8847 }
8848
8849 /**
8850  * Check the semantic restrictions for a binary expression.
8851  */
8852 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
8853 {
8854         expression_t *const left            = expression->left;
8855         expression_t *const right           = expression->right;
8856         type_t       *const orig_type_left  = left->base.type;
8857         type_t       *const orig_type_right = right->base.type;
8858         type_t       *const type_left       = skip_typeref(orig_type_left);
8859         type_t       *const type_right      = skip_typeref(orig_type_right);
8860
8861         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8862                 /* TODO: improve error message */
8863                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8864                         errorf(&expression->base.source_position,
8865                                "operation needs arithmetic types");
8866                 }
8867                 return;
8868         }
8869
8870         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8871         expression->left      = create_implicit_cast(left, arithmetic_type);
8872         expression->right     = create_implicit_cast(right, arithmetic_type);
8873         expression->base.type = arithmetic_type;
8874 }
8875
8876 static void warn_div_by_zero(binary_expression_t const *const expression)
8877 {
8878         if (!warning.div_by_zero ||
8879             !is_type_integer(expression->base.type))
8880                 return;
8881
8882         expression_t const *const right = expression->right;
8883         /* The type of the right operand can be different for /= */
8884         if (is_type_integer(right->base.type) &&
8885             is_constant_expression(right)     &&
8886             fold_constant(right) == 0) {
8887                 warningf(&expression->base.source_position, "division by zero");
8888         }
8889 }
8890
8891 /**
8892  * Check the semantic restrictions for a div/mod expression.
8893  */
8894 static void semantic_divmod_arithmetic(binary_expression_t *expression)
8895 {
8896         semantic_binexpr_arithmetic(expression);
8897         warn_div_by_zero(expression);
8898 }
8899
8900 static void warn_addsub_in_shift(const expression_t *const expr)
8901 {
8902         if (expr->base.parenthesized)
8903                 return;
8904
8905         char op;
8906         switch (expr->kind) {
8907                 case EXPR_BINARY_ADD: op = '+'; break;
8908                 case EXPR_BINARY_SUB: op = '-'; break;
8909                 default:              return;
8910         }
8911
8912         warningf(&expr->base.source_position,
8913                         "suggest parentheses around '%c' inside shift", op);
8914 }
8915
8916 static void semantic_shift_op(binary_expression_t *expression)
8917 {
8918         expression_t *const left            = expression->left;
8919         expression_t *const right           = expression->right;
8920         type_t       *const orig_type_left  = left->base.type;
8921         type_t       *const orig_type_right = right->base.type;
8922         type_t       *      type_left       = skip_typeref(orig_type_left);
8923         type_t       *      type_right      = skip_typeref(orig_type_right);
8924
8925         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8926                 /* TODO: improve error message */
8927                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8928                         errorf(&expression->base.source_position,
8929                                "operands of shift operation must have integer types");
8930                 }
8931                 return;
8932         }
8933
8934         if (warning.parentheses) {
8935                 warn_addsub_in_shift(left);
8936                 warn_addsub_in_shift(right);
8937         }
8938
8939         type_left  = promote_integer(type_left);
8940         type_right = promote_integer(type_right);
8941
8942         expression->left      = create_implicit_cast(left, type_left);
8943         expression->right     = create_implicit_cast(right, type_right);
8944         expression->base.type = type_left;
8945 }
8946
8947 static void semantic_add(binary_expression_t *expression)
8948 {
8949         expression_t *const left            = expression->left;
8950         expression_t *const right           = expression->right;
8951         type_t       *const orig_type_left  = left->base.type;
8952         type_t       *const orig_type_right = right->base.type;
8953         type_t       *const type_left       = skip_typeref(orig_type_left);
8954         type_t       *const type_right      = skip_typeref(orig_type_right);
8955
8956         /* §6.5.6 */
8957         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8958                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8959                 expression->left  = create_implicit_cast(left, arithmetic_type);
8960                 expression->right = create_implicit_cast(right, arithmetic_type);
8961                 expression->base.type = arithmetic_type;
8962         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8963                 check_pointer_arithmetic(&expression->base.source_position,
8964                                          type_left, orig_type_left);
8965                 expression->base.type = type_left;
8966         } else if (is_type_pointer(type_right) && is_type_integer(type_left)) {
8967                 check_pointer_arithmetic(&expression->base.source_position,
8968                                          type_right, orig_type_right);
8969                 expression->base.type = type_right;
8970         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8971                 errorf(&expression->base.source_position,
8972                        "invalid operands to binary + ('%T', '%T')",
8973                        orig_type_left, orig_type_right);
8974         }
8975 }
8976
8977 static void semantic_sub(binary_expression_t *expression)
8978 {
8979         expression_t            *const left            = expression->left;
8980         expression_t            *const right           = expression->right;
8981         type_t                  *const orig_type_left  = left->base.type;
8982         type_t                  *const orig_type_right = right->base.type;
8983         type_t                  *const type_left       = skip_typeref(orig_type_left);
8984         type_t                  *const type_right      = skip_typeref(orig_type_right);
8985         source_position_t const *const pos             = &expression->base.source_position;
8986
8987         /* §5.6.5 */
8988         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8989                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8990                 expression->left        = create_implicit_cast(left, arithmetic_type);
8991                 expression->right       = create_implicit_cast(right, arithmetic_type);
8992                 expression->base.type =  arithmetic_type;
8993         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8994                 check_pointer_arithmetic(&expression->base.source_position,
8995                                          type_left, orig_type_left);
8996                 expression->base.type = type_left;
8997         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8998                 type_t *const unqual_left  = get_unqualified_type(skip_typeref(type_left->pointer.points_to));
8999                 type_t *const unqual_right = get_unqualified_type(skip_typeref(type_right->pointer.points_to));
9000                 if (!types_compatible(unqual_left, unqual_right)) {
9001                         errorf(pos,
9002                                "subtracting pointers to incompatible types '%T' and '%T'",
9003                                orig_type_left, orig_type_right);
9004                 } else if (!is_type_object(unqual_left)) {
9005                         if (!is_type_atomic(unqual_left, ATOMIC_TYPE_VOID)) {
9006                                 errorf(pos, "subtracting pointers to non-object types '%T'",
9007                                        orig_type_left);
9008                         } else if (warning.other) {
9009                                 warningf(pos, "subtracting pointers to void");
9010                         }
9011                 }
9012                 expression->base.type = type_ptrdiff_t;
9013         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
9014                 errorf(pos, "invalid operands of types '%T' and '%T' to binary '-'",
9015                        orig_type_left, orig_type_right);
9016         }
9017 }
9018
9019 static void warn_string_literal_address(expression_t const* expr)
9020 {
9021         while (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
9022                 expr = expr->unary.value;
9023                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
9024                         return;
9025                 expr = expr->unary.value;
9026         }
9027
9028         if (expr->kind == EXPR_STRING_LITERAL ||
9029             expr->kind == EXPR_WIDE_STRING_LITERAL) {
9030                 warningf(&expr->base.source_position,
9031                         "comparison with string literal results in unspecified behaviour");
9032         }
9033 }
9034
9035 static void warn_comparison_in_comparison(const expression_t *const expr)
9036 {
9037         if (expr->base.parenthesized)
9038                 return;
9039         switch (expr->base.kind) {
9040                 case EXPR_BINARY_LESS:
9041                 case EXPR_BINARY_GREATER:
9042                 case EXPR_BINARY_LESSEQUAL:
9043                 case EXPR_BINARY_GREATEREQUAL:
9044                 case EXPR_BINARY_NOTEQUAL:
9045                 case EXPR_BINARY_EQUAL:
9046                         warningf(&expr->base.source_position,
9047                                         "comparisons like 'x <= y < z' do not have their mathematical meaning");
9048                         break;
9049                 default:
9050                         break;
9051         }
9052 }
9053
9054 static bool maybe_negative(expression_t const *const expr)
9055 {
9056         return
9057                 !is_constant_expression(expr) ||
9058                 fold_constant(expr) < 0;
9059 }
9060
9061 /**
9062  * Check the semantics of comparison expressions.
9063  *
9064  * @param expression   The expression to check.
9065  */
9066 static void semantic_comparison(binary_expression_t *expression)
9067 {
9068         expression_t *left  = expression->left;
9069         expression_t *right = expression->right;
9070
9071         if (warning.address) {
9072                 warn_string_literal_address(left);
9073                 warn_string_literal_address(right);
9074
9075                 expression_t const* const func_left = get_reference_address(left);
9076                 if (func_left != NULL && is_null_pointer_constant(right)) {
9077                         warningf(&expression->base.source_position,
9078                                  "the address of '%Y' will never be NULL",
9079                                  func_left->reference.entity->base.symbol);
9080                 }
9081
9082                 expression_t const* const func_right = get_reference_address(right);
9083                 if (func_right != NULL && is_null_pointer_constant(right)) {
9084                         warningf(&expression->base.source_position,
9085                                  "the address of '%Y' will never be NULL",
9086                                  func_right->reference.entity->base.symbol);
9087                 }
9088         }
9089
9090         if (warning.parentheses) {
9091                 warn_comparison_in_comparison(left);
9092                 warn_comparison_in_comparison(right);
9093         }
9094
9095         type_t *orig_type_left  = left->base.type;
9096         type_t *orig_type_right = right->base.type;
9097         type_t *type_left       = skip_typeref(orig_type_left);
9098         type_t *type_right      = skip_typeref(orig_type_right);
9099
9100         /* TODO non-arithmetic types */
9101         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
9102                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
9103
9104                 /* test for signed vs unsigned compares */
9105                 if (warning.sign_compare && is_type_integer(arithmetic_type)) {
9106                         bool const signed_left  = is_type_signed(type_left);
9107                         bool const signed_right = is_type_signed(type_right);
9108                         if (signed_left != signed_right) {
9109                                 /* FIXME long long needs better const folding magic */
9110                                 /* TODO check whether constant value can be represented by other type */
9111                                 if ((signed_left  && maybe_negative(left)) ||
9112                                                 (signed_right && maybe_negative(right))) {
9113                                         warningf(&expression->base.source_position,
9114                                                         "comparison between signed and unsigned");
9115                                 }
9116                         }
9117                 }
9118
9119                 expression->left        = create_implicit_cast(left, arithmetic_type);
9120                 expression->right       = create_implicit_cast(right, arithmetic_type);
9121                 expression->base.type   = arithmetic_type;
9122                 if (warning.float_equal &&
9123                     (expression->base.kind == EXPR_BINARY_EQUAL ||
9124                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
9125                     is_type_float(arithmetic_type)) {
9126                         warningf(&expression->base.source_position,
9127                                  "comparing floating point with == or != is unsafe");
9128                 }
9129         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
9130                 /* TODO check compatibility */
9131         } else if (is_type_pointer(type_left)) {
9132                 expression->right = create_implicit_cast(right, type_left);
9133         } else if (is_type_pointer(type_right)) {
9134                 expression->left = create_implicit_cast(left, type_right);
9135         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
9136                 type_error_incompatible("invalid operands in comparison",
9137                                         &expression->base.source_position,
9138                                         type_left, type_right);
9139         }
9140         expression->base.type = c_mode & _CXX ? type_bool : type_int;
9141 }
9142
9143 /**
9144  * Checks if a compound type has constant fields.
9145  */
9146 static bool has_const_fields(const compound_type_t *type)
9147 {
9148         compound_t *compound = type->compound;
9149         entity_t   *entry    = compound->members.entities;
9150
9151         for (; entry != NULL; entry = entry->base.next) {
9152                 if (!is_declaration(entry))
9153                         continue;
9154
9155                 const type_t *decl_type = skip_typeref(entry->declaration.type);
9156                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
9157                         return true;
9158         }
9159
9160         return false;
9161 }
9162
9163 static bool is_valid_assignment_lhs(expression_t const* const left)
9164 {
9165         type_t *const orig_type_left = revert_automatic_type_conversion(left);
9166         type_t *const type_left      = skip_typeref(orig_type_left);
9167
9168         if (!is_lvalue(left)) {
9169                 errorf(HERE, "left hand side '%E' of assignment is not an lvalue",
9170                        left);
9171                 return false;
9172         }
9173
9174         if (left->kind == EXPR_REFERENCE
9175                         && left->reference.entity->kind == ENTITY_FUNCTION) {
9176                 errorf(HERE, "cannot assign to function '%E'", left);
9177                 return false;
9178         }
9179
9180         if (is_type_array(type_left)) {
9181                 errorf(HERE, "cannot assign to array '%E'", left);
9182                 return false;
9183         }
9184         if (type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
9185                 errorf(HERE, "assignment to readonly location '%E' (type '%T')", left,
9186                        orig_type_left);
9187                 return false;
9188         }
9189         if (is_type_incomplete(type_left)) {
9190                 errorf(HERE, "left-hand side '%E' of assignment has incomplete type '%T'",
9191                        left, orig_type_left);
9192                 return false;
9193         }
9194         if (is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
9195                 errorf(HERE, "cannot assign to '%E' because compound type '%T' has readonly fields",
9196                        left, orig_type_left);
9197                 return false;
9198         }
9199
9200         return true;
9201 }
9202
9203 static void semantic_arithmetic_assign(binary_expression_t *expression)
9204 {
9205         expression_t *left            = expression->left;
9206         expression_t *right           = expression->right;
9207         type_t       *orig_type_left  = left->base.type;
9208         type_t       *orig_type_right = right->base.type;
9209
9210         if (!is_valid_assignment_lhs(left))
9211                 return;
9212
9213         type_t *type_left  = skip_typeref(orig_type_left);
9214         type_t *type_right = skip_typeref(orig_type_right);
9215
9216         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
9217                 /* TODO: improve error message */
9218                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
9219                         errorf(&expression->base.source_position,
9220                                "operation needs arithmetic types");
9221                 }
9222                 return;
9223         }
9224
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 *arithmetic_type = semantic_arithmetic(type_left, type_right);
9230         expression->right       = create_implicit_cast(right, arithmetic_type);
9231         expression->base.type   = type_left;
9232 }
9233
9234 static void semantic_divmod_assign(binary_expression_t *expression)
9235 {
9236         semantic_arithmetic_assign(expression);
9237         warn_div_by_zero(expression);
9238 }
9239
9240 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
9241 {
9242         expression_t *const left            = expression->left;
9243         expression_t *const right           = expression->right;
9244         type_t       *const orig_type_left  = left->base.type;
9245         type_t       *const orig_type_right = right->base.type;
9246         type_t       *const type_left       = skip_typeref(orig_type_left);
9247         type_t       *const type_right      = skip_typeref(orig_type_right);
9248
9249         if (!is_valid_assignment_lhs(left))
9250                 return;
9251
9252         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
9253                 /* combined instructions are tricky. We can't create an implicit cast on
9254                  * the left side, because we need the uncasted form for the store.
9255                  * The ast2firm pass has to know that left_type must be right_type
9256                  * for the arithmetic operation and create a cast by itself */
9257                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
9258                 expression->right     = create_implicit_cast(right, arithmetic_type);
9259                 expression->base.type = type_left;
9260         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
9261                 check_pointer_arithmetic(&expression->base.source_position,
9262                                          type_left, orig_type_left);
9263                 expression->base.type = type_left;
9264         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
9265                 errorf(&expression->base.source_position,
9266                        "incompatible types '%T' and '%T' in assignment",
9267                        orig_type_left, orig_type_right);
9268         }
9269 }
9270
9271 static void warn_logical_and_within_or(const expression_t *const expr)
9272 {
9273         if (expr->base.kind != EXPR_BINARY_LOGICAL_AND)
9274                 return;
9275         if (expr->base.parenthesized)
9276                 return;
9277         warningf(&expr->base.source_position,
9278                         "suggest parentheses around && within ||");
9279 }
9280
9281 /**
9282  * Check the semantic restrictions of a logical expression.
9283  */
9284 static void semantic_logical_op(binary_expression_t *expression)
9285 {
9286         /* §6.5.13:2  Each of the operands shall have scalar type.
9287          * §6.5.14:2  Each of the operands shall have scalar type. */
9288         semantic_condition(expression->left,   "left operand of logical operator");
9289         semantic_condition(expression->right, "right operand of logical operator");
9290         if (expression->base.kind == EXPR_BINARY_LOGICAL_OR &&
9291                         warning.parentheses) {
9292                 warn_logical_and_within_or(expression->left);
9293                 warn_logical_and_within_or(expression->right);
9294         }
9295         expression->base.type = c_mode & _CXX ? type_bool : type_int;
9296 }
9297
9298 /**
9299  * Check the semantic restrictions of a binary assign expression.
9300  */
9301 static void semantic_binexpr_assign(binary_expression_t *expression)
9302 {
9303         expression_t *left           = expression->left;
9304         type_t       *orig_type_left = left->base.type;
9305
9306         if (!is_valid_assignment_lhs(left))
9307                 return;
9308
9309         assign_error_t error = semantic_assign(orig_type_left, expression->right);
9310         report_assign_error(error, orig_type_left, expression->right,
9311                         "assignment", &left->base.source_position);
9312         expression->right = create_implicit_cast(expression->right, orig_type_left);
9313         expression->base.type = orig_type_left;
9314 }
9315
9316 /**
9317  * Determine if the outermost operation (or parts thereof) of the given
9318  * expression has no effect in order to generate a warning about this fact.
9319  * Therefore in some cases this only examines some of the operands of the
9320  * expression (see comments in the function and examples below).
9321  * Examples:
9322  *   f() + 23;    // warning, because + has no effect
9323  *   x || f();    // no warning, because x controls execution of f()
9324  *   x ? y : f(); // warning, because y has no effect
9325  *   (void)x;     // no warning to be able to suppress the warning
9326  * This function can NOT be used for an "expression has definitely no effect"-
9327  * analysis. */
9328 static bool expression_has_effect(const expression_t *const expr)
9329 {
9330         switch (expr->kind) {
9331                 case EXPR_UNKNOWN:                    break;
9332                 case EXPR_INVALID:                    return true; /* do NOT warn */
9333                 case EXPR_REFERENCE:                  return false;
9334                 case EXPR_REFERENCE_ENUM_VALUE:       return false;
9335                 /* suppress the warning for microsoft __noop operations */
9336                 case EXPR_CONST:                      return expr->conste.is_ms_noop;
9337                 case EXPR_CHARACTER_CONSTANT:         return false;
9338                 case EXPR_WIDE_CHARACTER_CONSTANT:    return false;
9339                 case EXPR_STRING_LITERAL:             return false;
9340                 case EXPR_WIDE_STRING_LITERAL:        return false;
9341                 case EXPR_LABEL_ADDRESS:              return false;
9342
9343                 case EXPR_CALL: {
9344                         const call_expression_t *const call = &expr->call;
9345                         if (call->function->kind != EXPR_REFERENCE)
9346                                 return true;
9347
9348                         switch (call->function->reference.entity->function.btk) {
9349                                 /* FIXME: which builtins have no effect? */
9350                                 default:                      return true;
9351                         }
9352                 }
9353
9354                 /* Generate the warning if either the left or right hand side of a
9355                  * conditional expression has no effect */
9356                 case EXPR_CONDITIONAL: {
9357                         conditional_expression_t const *const cond = &expr->conditional;
9358                         expression_t             const *const t    = cond->true_expression;
9359                         return
9360                                 (t == NULL || expression_has_effect(t)) &&
9361                                 expression_has_effect(cond->false_expression);
9362                 }
9363
9364                 case EXPR_SELECT:                     return false;
9365                 case EXPR_ARRAY_ACCESS:               return false;
9366                 case EXPR_SIZEOF:                     return false;
9367                 case EXPR_CLASSIFY_TYPE:              return false;
9368                 case EXPR_ALIGNOF:                    return false;
9369
9370                 case EXPR_FUNCNAME:                   return false;
9371                 case EXPR_BUILTIN_CONSTANT_P:         return false;
9372                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P: return false;
9373                 case EXPR_OFFSETOF:                   return false;
9374                 case EXPR_VA_START:                   return true;
9375                 case EXPR_VA_ARG:                     return true;
9376                 case EXPR_STATEMENT:                  return true; // TODO
9377                 case EXPR_COMPOUND_LITERAL:           return false;
9378
9379                 case EXPR_UNARY_NEGATE:               return false;
9380                 case EXPR_UNARY_PLUS:                 return false;
9381                 case EXPR_UNARY_BITWISE_NEGATE:       return false;
9382                 case EXPR_UNARY_NOT:                  return false;
9383                 case EXPR_UNARY_DEREFERENCE:          return false;
9384                 case EXPR_UNARY_TAKE_ADDRESS:         return false;
9385                 case EXPR_UNARY_POSTFIX_INCREMENT:    return true;
9386                 case EXPR_UNARY_POSTFIX_DECREMENT:    return true;
9387                 case EXPR_UNARY_PREFIX_INCREMENT:     return true;
9388                 case EXPR_UNARY_PREFIX_DECREMENT:     return true;
9389
9390                 /* Treat void casts as if they have an effect in order to being able to
9391                  * suppress the warning */
9392                 case EXPR_UNARY_CAST: {
9393                         type_t *const type = skip_typeref(expr->base.type);
9394                         return is_type_atomic(type, ATOMIC_TYPE_VOID);
9395                 }
9396
9397                 case EXPR_UNARY_CAST_IMPLICIT:        return true;
9398                 case EXPR_UNARY_ASSUME:               return true;
9399                 case EXPR_UNARY_DELETE:               return true;
9400                 case EXPR_UNARY_DELETE_ARRAY:         return true;
9401                 case EXPR_UNARY_THROW:                return true;
9402
9403                 case EXPR_BINARY_ADD:                 return false;
9404                 case EXPR_BINARY_SUB:                 return false;
9405                 case EXPR_BINARY_MUL:                 return false;
9406                 case EXPR_BINARY_DIV:                 return false;
9407                 case EXPR_BINARY_MOD:                 return false;
9408                 case EXPR_BINARY_EQUAL:               return false;
9409                 case EXPR_BINARY_NOTEQUAL:            return false;
9410                 case EXPR_BINARY_LESS:                return false;
9411                 case EXPR_BINARY_LESSEQUAL:           return false;
9412                 case EXPR_BINARY_GREATER:             return false;
9413                 case EXPR_BINARY_GREATEREQUAL:        return false;
9414                 case EXPR_BINARY_BITWISE_AND:         return false;
9415                 case EXPR_BINARY_BITWISE_OR:          return false;
9416                 case EXPR_BINARY_BITWISE_XOR:         return false;
9417                 case EXPR_BINARY_SHIFTLEFT:           return false;
9418                 case EXPR_BINARY_SHIFTRIGHT:          return false;
9419                 case EXPR_BINARY_ASSIGN:              return true;
9420                 case EXPR_BINARY_MUL_ASSIGN:          return true;
9421                 case EXPR_BINARY_DIV_ASSIGN:          return true;
9422                 case EXPR_BINARY_MOD_ASSIGN:          return true;
9423                 case EXPR_BINARY_ADD_ASSIGN:          return true;
9424                 case EXPR_BINARY_SUB_ASSIGN:          return true;
9425                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:    return true;
9426                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:   return true;
9427                 case EXPR_BINARY_BITWISE_AND_ASSIGN:  return true;
9428                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:  return true;
9429                 case EXPR_BINARY_BITWISE_OR_ASSIGN:   return true;
9430
9431                 /* Only examine the right hand side of && and ||, because the left hand
9432                  * side already has the effect of controlling the execution of the right
9433                  * hand side */
9434                 case EXPR_BINARY_LOGICAL_AND:
9435                 case EXPR_BINARY_LOGICAL_OR:
9436                 /* Only examine the right hand side of a comma expression, because the left
9437                  * hand side has a separate warning */
9438                 case EXPR_BINARY_COMMA:
9439                         return expression_has_effect(expr->binary.right);
9440
9441                 case EXPR_BINARY_ISGREATER:           return false;
9442                 case EXPR_BINARY_ISGREATEREQUAL:      return false;
9443                 case EXPR_BINARY_ISLESS:              return false;
9444                 case EXPR_BINARY_ISLESSEQUAL:         return false;
9445                 case EXPR_BINARY_ISLESSGREATER:       return false;
9446                 case EXPR_BINARY_ISUNORDERED:         return false;
9447         }
9448
9449         internal_errorf(HERE, "unexpected expression");
9450 }
9451
9452 static void semantic_comma(binary_expression_t *expression)
9453 {
9454         if (warning.unused_value) {
9455                 const expression_t *const left = expression->left;
9456                 if (!expression_has_effect(left)) {
9457                         warningf(&left->base.source_position,
9458                                  "left-hand operand of comma expression has no effect");
9459                 }
9460         }
9461         expression->base.type = expression->right->base.type;
9462 }
9463
9464 /**
9465  * @param prec_r precedence of the right operand
9466  */
9467 #define CREATE_BINEXPR_PARSER(token_type, binexpression_type, prec_r, sfunc) \
9468 static expression_t *parse_##binexpression_type(expression_t *left)          \
9469 {                                                                            \
9470         expression_t *binexpr = allocate_expression_zero(binexpression_type);    \
9471         binexpr->binary.left  = left;                                            \
9472         eat(token_type);                                                         \
9473                                                                              \
9474         expression_t *right = parse_sub_expression(prec_r);                      \
9475                                                                              \
9476         binexpr->binary.right = right;                                           \
9477         sfunc(&binexpr->binary);                                                 \
9478                                                                              \
9479         return binexpr;                                                          \
9480 }
9481
9482 CREATE_BINEXPR_PARSER('*',                    EXPR_BINARY_MUL,                PREC_CAST,           semantic_binexpr_arithmetic)
9483 CREATE_BINEXPR_PARSER('/',                    EXPR_BINARY_DIV,                PREC_CAST,           semantic_divmod_arithmetic)
9484 CREATE_BINEXPR_PARSER('%',                    EXPR_BINARY_MOD,                PREC_CAST,           semantic_divmod_arithmetic)
9485 CREATE_BINEXPR_PARSER('+',                    EXPR_BINARY_ADD,                PREC_MULTIPLICATIVE, semantic_add)
9486 CREATE_BINEXPR_PARSER('-',                    EXPR_BINARY_SUB,                PREC_MULTIPLICATIVE, semantic_sub)
9487 CREATE_BINEXPR_PARSER(T_LESSLESS,             EXPR_BINARY_SHIFTLEFT,          PREC_ADDITIVE,       semantic_shift_op)
9488 CREATE_BINEXPR_PARSER(T_GREATERGREATER,       EXPR_BINARY_SHIFTRIGHT,         PREC_ADDITIVE,       semantic_shift_op)
9489 CREATE_BINEXPR_PARSER('<',                    EXPR_BINARY_LESS,               PREC_SHIFT,          semantic_comparison)
9490 CREATE_BINEXPR_PARSER('>',                    EXPR_BINARY_GREATER,            PREC_SHIFT,          semantic_comparison)
9491 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,          PREC_SHIFT,          semantic_comparison)
9492 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,       PREC_SHIFT,          semantic_comparison)
9493 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,           PREC_RELATIONAL,     semantic_comparison)
9494 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,              PREC_RELATIONAL,     semantic_comparison)
9495 CREATE_BINEXPR_PARSER('&',                    EXPR_BINARY_BITWISE_AND,        PREC_EQUALITY,       semantic_binexpr_arithmetic)
9496 CREATE_BINEXPR_PARSER('^',                    EXPR_BINARY_BITWISE_XOR,        PREC_AND,            semantic_binexpr_arithmetic)
9497 CREATE_BINEXPR_PARSER('|',                    EXPR_BINARY_BITWISE_OR,         PREC_XOR,            semantic_binexpr_arithmetic)
9498 CREATE_BINEXPR_PARSER(T_ANDAND,               EXPR_BINARY_LOGICAL_AND,        PREC_OR,             semantic_logical_op)
9499 CREATE_BINEXPR_PARSER(T_PIPEPIPE,             EXPR_BINARY_LOGICAL_OR,         PREC_LOGICAL_AND,    semantic_logical_op)
9500 CREATE_BINEXPR_PARSER('=',                    EXPR_BINARY_ASSIGN,             PREC_ASSIGNMENT,     semantic_binexpr_assign)
9501 CREATE_BINEXPR_PARSER(T_PLUSEQUAL,            EXPR_BINARY_ADD_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
9502 CREATE_BINEXPR_PARSER(T_MINUSEQUAL,           EXPR_BINARY_SUB_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
9503 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL,        EXPR_BINARY_MUL_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9504 CREATE_BINEXPR_PARSER(T_SLASHEQUAL,           EXPR_BINARY_DIV_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
9505 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL,         EXPR_BINARY_MOD_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
9506 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL,        EXPR_BINARY_SHIFTLEFT_ASSIGN,   PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9507 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL,  EXPR_BINARY_SHIFTRIGHT_ASSIGN,  PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9508 CREATE_BINEXPR_PARSER(T_ANDEQUAL,             EXPR_BINARY_BITWISE_AND_ASSIGN, PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9509 CREATE_BINEXPR_PARSER(T_PIPEEQUAL,            EXPR_BINARY_BITWISE_OR_ASSIGN,  PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9510 CREATE_BINEXPR_PARSER(T_CARETEQUAL,           EXPR_BINARY_BITWISE_XOR_ASSIGN, PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9511 CREATE_BINEXPR_PARSER(',',                    EXPR_BINARY_COMMA,              PREC_ASSIGNMENT,     semantic_comma)
9512
9513
9514 static expression_t *parse_sub_expression(precedence_t precedence)
9515 {
9516         if (token.type < 0) {
9517                 return expected_expression_error();
9518         }
9519
9520         expression_parser_function_t *parser
9521                 = &expression_parsers[token.type];
9522         source_position_t             source_position = token.source_position;
9523         expression_t                 *left;
9524
9525         if (parser->parser != NULL) {
9526                 left = parser->parser();
9527         } else {
9528                 left = parse_primary_expression();
9529         }
9530         assert(left != NULL);
9531         left->base.source_position = source_position;
9532
9533         while (true) {
9534                 if (token.type < 0) {
9535                         return expected_expression_error();
9536                 }
9537
9538                 parser = &expression_parsers[token.type];
9539                 if (parser->infix_parser == NULL)
9540                         break;
9541                 if (parser->infix_precedence < precedence)
9542                         break;
9543
9544                 left = parser->infix_parser(left);
9545
9546                 assert(left != NULL);
9547                 assert(left->kind != EXPR_UNKNOWN);
9548                 left->base.source_position = source_position;
9549         }
9550
9551         return left;
9552 }
9553
9554 /**
9555  * Parse an expression.
9556  */
9557 static expression_t *parse_expression(void)
9558 {
9559         return parse_sub_expression(PREC_EXPRESSION);
9560 }
9561
9562 /**
9563  * Register a parser for a prefix-like operator.
9564  *
9565  * @param parser      the parser function
9566  * @param token_type  the token type of the prefix token
9567  */
9568 static void register_expression_parser(parse_expression_function parser,
9569                                        int token_type)
9570 {
9571         expression_parser_function_t *entry = &expression_parsers[token_type];
9572
9573         if (entry->parser != NULL) {
9574                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
9575                 panic("trying to register multiple expression parsers for a token");
9576         }
9577         entry->parser = parser;
9578 }
9579
9580 /**
9581  * Register a parser for an infix operator with given precedence.
9582  *
9583  * @param parser      the parser function
9584  * @param token_type  the token type of the infix operator
9585  * @param precedence  the precedence of the operator
9586  */
9587 static void register_infix_parser(parse_expression_infix_function parser,
9588                 int token_type, precedence_t precedence)
9589 {
9590         expression_parser_function_t *entry = &expression_parsers[token_type];
9591
9592         if (entry->infix_parser != NULL) {
9593                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
9594                 panic("trying to register multiple infix expression parsers for a "
9595                       "token");
9596         }
9597         entry->infix_parser     = parser;
9598         entry->infix_precedence = precedence;
9599 }
9600
9601 /**
9602  * Initialize the expression parsers.
9603  */
9604 static void init_expression_parsers(void)
9605 {
9606         memset(&expression_parsers, 0, sizeof(expression_parsers));
9607
9608         register_infix_parser(parse_array_expression,               '[',                    PREC_POSTFIX);
9609         register_infix_parser(parse_call_expression,                '(',                    PREC_POSTFIX);
9610         register_infix_parser(parse_select_expression,              '.',                    PREC_POSTFIX);
9611         register_infix_parser(parse_select_expression,              T_MINUSGREATER,         PREC_POSTFIX);
9612         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,   T_PLUSPLUS,             PREC_POSTFIX);
9613         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,   T_MINUSMINUS,           PREC_POSTFIX);
9614         register_infix_parser(parse_EXPR_BINARY_MUL,                '*',                    PREC_MULTIPLICATIVE);
9615         register_infix_parser(parse_EXPR_BINARY_DIV,                '/',                    PREC_MULTIPLICATIVE);
9616         register_infix_parser(parse_EXPR_BINARY_MOD,                '%',                    PREC_MULTIPLICATIVE);
9617         register_infix_parser(parse_EXPR_BINARY_ADD,                '+',                    PREC_ADDITIVE);
9618         register_infix_parser(parse_EXPR_BINARY_SUB,                '-',                    PREC_ADDITIVE);
9619         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,          T_LESSLESS,             PREC_SHIFT);
9620         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,         T_GREATERGREATER,       PREC_SHIFT);
9621         register_infix_parser(parse_EXPR_BINARY_LESS,               '<',                    PREC_RELATIONAL);
9622         register_infix_parser(parse_EXPR_BINARY_GREATER,            '>',                    PREC_RELATIONAL);
9623         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,          T_LESSEQUAL,            PREC_RELATIONAL);
9624         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL,       T_GREATEREQUAL,         PREC_RELATIONAL);
9625         register_infix_parser(parse_EXPR_BINARY_EQUAL,              T_EQUALEQUAL,           PREC_EQUALITY);
9626         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,           T_EXCLAMATIONMARKEQUAL, PREC_EQUALITY);
9627         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,        '&',                    PREC_AND);
9628         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,        '^',                    PREC_XOR);
9629         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,         '|',                    PREC_OR);
9630         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,        T_ANDAND,               PREC_LOGICAL_AND);
9631         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,         T_PIPEPIPE,             PREC_LOGICAL_OR);
9632         register_infix_parser(parse_conditional_expression,         '?',                    PREC_CONDITIONAL);
9633         register_infix_parser(parse_EXPR_BINARY_ASSIGN,             '=',                    PREC_ASSIGNMENT);
9634         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,         T_PLUSEQUAL,            PREC_ASSIGNMENT);
9635         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,         T_MINUSEQUAL,           PREC_ASSIGNMENT);
9636         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,         T_ASTERISKEQUAL,        PREC_ASSIGNMENT);
9637         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,         T_SLASHEQUAL,           PREC_ASSIGNMENT);
9638         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,         T_PERCENTEQUAL,         PREC_ASSIGNMENT);
9639         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,   T_LESSLESSEQUAL,        PREC_ASSIGNMENT);
9640         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,  T_GREATERGREATEREQUAL,  PREC_ASSIGNMENT);
9641         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN, T_ANDEQUAL,             PREC_ASSIGNMENT);
9642         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,  T_PIPEEQUAL,            PREC_ASSIGNMENT);
9643         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN, T_CARETEQUAL,           PREC_ASSIGNMENT);
9644         register_infix_parser(parse_EXPR_BINARY_COMMA,              ',',                    PREC_EXPRESSION);
9645
9646         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-');
9647         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+');
9648         register_expression_parser(parse_EXPR_UNARY_NOT,              '!');
9649         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~');
9650         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*');
9651         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&');
9652         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT, T_PLUSPLUS);
9653         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT, T_MINUSMINUS);
9654         register_expression_parser(parse_sizeof,                      T_sizeof);
9655         register_expression_parser(parse_alignof,                     T___alignof__);
9656         register_expression_parser(parse_extension,                   T___extension__);
9657         register_expression_parser(parse_builtin_classify_type,       T___builtin_classify_type);
9658         register_expression_parser(parse_delete,                      T_delete);
9659         register_expression_parser(parse_throw,                       T_throw);
9660 }
9661
9662 /**
9663  * Parse a asm statement arguments specification.
9664  */
9665 static asm_argument_t *parse_asm_arguments(bool is_out)
9666 {
9667         asm_argument_t  *result = NULL;
9668         asm_argument_t **anchor = &result;
9669
9670         while (token.type == T_STRING_LITERAL || token.type == '[') {
9671                 asm_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
9672                 memset(argument, 0, sizeof(argument[0]));
9673
9674                 if (token.type == '[') {
9675                         eat('[');
9676                         if (token.type != T_IDENTIFIER) {
9677                                 parse_error_expected("while parsing asm argument",
9678                                                      T_IDENTIFIER, NULL);
9679                                 return NULL;
9680                         }
9681                         argument->symbol = token.v.symbol;
9682
9683                         expect(']', end_error);
9684                 }
9685
9686                 argument->constraints = parse_string_literals();
9687                 expect('(', end_error);
9688                 add_anchor_token(')');
9689                 expression_t *expression = parse_expression();
9690                 rem_anchor_token(')');
9691                 if (is_out) {
9692                         /* Ugly GCC stuff: Allow lvalue casts.  Skip casts, when they do not
9693                          * change size or type representation (e.g. int -> long is ok, but
9694                          * int -> float is not) */
9695                         if (expression->kind == EXPR_UNARY_CAST) {
9696                                 type_t      *const type = expression->base.type;
9697                                 type_kind_t  const kind = type->kind;
9698                                 if (kind == TYPE_ATOMIC || kind == TYPE_POINTER) {
9699                                         unsigned flags;
9700                                         unsigned size;
9701                                         if (kind == TYPE_ATOMIC) {
9702                                                 atomic_type_kind_t const akind = type->atomic.akind;
9703                                                 flags = get_atomic_type_flags(akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
9704                                                 size  = get_atomic_type_size(akind);
9705                                         } else {
9706                                                 flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
9707                                                 size  = get_atomic_type_size(get_intptr_kind());
9708                                         }
9709
9710                                         do {
9711                                                 expression_t *const value      = expression->unary.value;
9712                                                 type_t       *const value_type = value->base.type;
9713                                                 type_kind_t   const value_kind = value_type->kind;
9714
9715                                                 unsigned value_flags;
9716                                                 unsigned value_size;
9717                                                 if (value_kind == TYPE_ATOMIC) {
9718                                                         atomic_type_kind_t const value_akind = value_type->atomic.akind;
9719                                                         value_flags = get_atomic_type_flags(value_akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
9720                                                         value_size  = get_atomic_type_size(value_akind);
9721                                                 } else if (value_kind == TYPE_POINTER) {
9722                                                         value_flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
9723                                                         value_size  = get_atomic_type_size(get_intptr_kind());
9724                                                 } else {
9725                                                         break;
9726                                                 }
9727
9728                                                 if (value_flags != flags || value_size != size)
9729                                                         break;
9730
9731                                                 expression = value;
9732                                         } while (expression->kind == EXPR_UNARY_CAST);
9733                                 }
9734                         }
9735
9736                         if (!is_lvalue(expression)) {
9737                                 errorf(&expression->base.source_position,
9738                                        "asm output argument is not an lvalue");
9739                         }
9740
9741                         if (argument->constraints.begin[0] == '+')
9742                                 mark_vars_read(expression, NULL);
9743                 } else {
9744                         mark_vars_read(expression, NULL);
9745                 }
9746                 argument->expression = expression;
9747                 expect(')', end_error);
9748
9749                 set_address_taken(expression, true);
9750
9751                 *anchor = argument;
9752                 anchor  = &argument->next;
9753
9754                 if (token.type != ',')
9755                         break;
9756                 eat(',');
9757         }
9758
9759         return result;
9760 end_error:
9761         return NULL;
9762 }
9763
9764 /**
9765  * Parse a asm statement clobber specification.
9766  */
9767 static asm_clobber_t *parse_asm_clobbers(void)
9768 {
9769         asm_clobber_t *result = NULL;
9770         asm_clobber_t *last   = NULL;
9771
9772         while (token.type == T_STRING_LITERAL) {
9773                 asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
9774                 clobber->clobber       = parse_string_literals();
9775
9776                 if (last != NULL) {
9777                         last->next = clobber;
9778                 } else {
9779                         result = clobber;
9780                 }
9781                 last = clobber;
9782
9783                 if (token.type != ',')
9784                         break;
9785                 eat(',');
9786         }
9787
9788         return result;
9789 }
9790
9791 /**
9792  * Parse an asm statement.
9793  */
9794 static statement_t *parse_asm_statement(void)
9795 {
9796         statement_t     *statement     = allocate_statement_zero(STATEMENT_ASM);
9797         asm_statement_t *asm_statement = &statement->asms;
9798
9799         eat(T_asm);
9800
9801         if (token.type == T_volatile) {
9802                 next_token();
9803                 asm_statement->is_volatile = true;
9804         }
9805
9806         expect('(', end_error);
9807         add_anchor_token(')');
9808         add_anchor_token(':');
9809         asm_statement->asm_text = parse_string_literals();
9810
9811         if (token.type != ':') {
9812                 rem_anchor_token(':');
9813                 goto end_of_asm;
9814         }
9815         eat(':');
9816
9817         asm_statement->outputs = parse_asm_arguments(true);
9818         if (token.type != ':') {
9819                 rem_anchor_token(':');
9820                 goto end_of_asm;
9821         }
9822         eat(':');
9823
9824         asm_statement->inputs = parse_asm_arguments(false);
9825         if (token.type != ':') {
9826                 rem_anchor_token(':');
9827                 goto end_of_asm;
9828         }
9829         rem_anchor_token(':');
9830         eat(':');
9831
9832         asm_statement->clobbers = parse_asm_clobbers();
9833
9834 end_of_asm:
9835         rem_anchor_token(')');
9836         expect(')', end_error);
9837         expect(';', end_error);
9838
9839         if (asm_statement->outputs == NULL) {
9840                 /* GCC: An 'asm' instruction without any output operands will be treated
9841                  * identically to a volatile 'asm' instruction. */
9842                 asm_statement->is_volatile = true;
9843         }
9844
9845         return statement;
9846 end_error:
9847         return create_invalid_statement();
9848 }
9849
9850 /**
9851  * Parse a case statement.
9852  */
9853 static statement_t *parse_case_statement(void)
9854 {
9855         statement_t       *const statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9856         source_position_t *const pos       = &statement->base.source_position;
9857
9858         eat(T_case);
9859
9860         expression_t *const expression   = parse_expression();
9861         statement->case_label.expression = expression;
9862         if (!is_constant_expression(expression)) {
9863                 /* This check does not prevent the error message in all cases of an
9864                  * prior error while parsing the expression.  At least it catches the
9865                  * common case of a mistyped enum entry. */
9866                 if (is_type_valid(skip_typeref(expression->base.type))) {
9867                         errorf(pos, "case label does not reduce to an integer constant");
9868                 }
9869                 statement->case_label.is_bad = true;
9870         } else {
9871                 long const val = fold_constant(expression);
9872                 statement->case_label.first_case = val;
9873                 statement->case_label.last_case  = val;
9874         }
9875
9876         if (GNU_MODE) {
9877                 if (token.type == T_DOTDOTDOT) {
9878                         next_token();
9879                         expression_t *const end_range   = parse_expression();
9880                         statement->case_label.end_range = end_range;
9881                         if (!is_constant_expression(end_range)) {
9882                                 /* This check does not prevent the error message in all cases of an
9883                                  * prior error while parsing the expression.  At least it catches the
9884                                  * common case of a mistyped enum entry. */
9885                                 if (is_type_valid(skip_typeref(end_range->base.type))) {
9886                                         errorf(pos, "case range does not reduce to an integer constant");
9887                                 }
9888                                 statement->case_label.is_bad = true;
9889                         } else {
9890                                 long const val = fold_constant(end_range);
9891                                 statement->case_label.last_case = val;
9892
9893                                 if (warning.other && val < statement->case_label.first_case) {
9894                                         statement->case_label.is_empty_range = true;
9895                                         warningf(pos, "empty range specified");
9896                                 }
9897                         }
9898                 }
9899         }
9900
9901         PUSH_PARENT(statement);
9902
9903         expect(':', end_error);
9904 end_error:
9905
9906         if (current_switch != NULL) {
9907                 if (! statement->case_label.is_bad) {
9908                         /* Check for duplicate case values */
9909                         case_label_statement_t *c = &statement->case_label;
9910                         for (case_label_statement_t *l = current_switch->first_case; l != NULL; l = l->next) {
9911                                 if (l->is_bad || l->is_empty_range || l->expression == NULL)
9912                                         continue;
9913
9914                                 if (c->last_case < l->first_case || c->first_case > l->last_case)
9915                                         continue;
9916
9917                                 errorf(pos, "duplicate case value (previously used %P)",
9918                                        &l->base.source_position);
9919                                 break;
9920                         }
9921                 }
9922                 /* link all cases into the switch statement */
9923                 if (current_switch->last_case == NULL) {
9924                         current_switch->first_case      = &statement->case_label;
9925                 } else {
9926                         current_switch->last_case->next = &statement->case_label;
9927                 }
9928                 current_switch->last_case = &statement->case_label;
9929         } else {
9930                 errorf(pos, "case label not within a switch statement");
9931         }
9932
9933         statement_t *const inner_stmt = parse_statement();
9934         statement->case_label.statement = inner_stmt;
9935         if (inner_stmt->kind == STATEMENT_DECLARATION) {
9936                 errorf(&inner_stmt->base.source_position, "declaration after case label");
9937         }
9938
9939         POP_PARENT;
9940         return statement;
9941 }
9942
9943 /**
9944  * Parse a default statement.
9945  */
9946 static statement_t *parse_default_statement(void)
9947 {
9948         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9949
9950         eat(T_default);
9951
9952         PUSH_PARENT(statement);
9953
9954         expect(':', end_error);
9955         if (current_switch != NULL) {
9956                 const case_label_statement_t *def_label = current_switch->default_label;
9957                 if (def_label != NULL) {
9958                         errorf(HERE, "multiple default labels in one switch (previous declared %P)",
9959                                &def_label->base.source_position);
9960                 } else {
9961                         current_switch->default_label = &statement->case_label;
9962
9963                         /* link all cases into the switch statement */
9964                         if (current_switch->last_case == NULL) {
9965                                 current_switch->first_case      = &statement->case_label;
9966                         } else {
9967                                 current_switch->last_case->next = &statement->case_label;
9968                         }
9969                         current_switch->last_case = &statement->case_label;
9970                 }
9971         } else {
9972                 errorf(&statement->base.source_position,
9973                         "'default' label not within a switch statement");
9974         }
9975
9976         statement_t *const inner_stmt = parse_statement();
9977         statement->case_label.statement = inner_stmt;
9978         if (inner_stmt->kind == STATEMENT_DECLARATION) {
9979                 errorf(&inner_stmt->base.source_position, "declaration after default label");
9980         }
9981
9982         POP_PARENT;
9983         return statement;
9984 end_error:
9985         POP_PARENT;
9986         return create_invalid_statement();
9987 }
9988
9989 /**
9990  * Parse a label statement.
9991  */
9992 static statement_t *parse_label_statement(void)
9993 {
9994         assert(token.type == T_IDENTIFIER);
9995         symbol_t *symbol = token.v.symbol;
9996         label_t  *label  = get_label(symbol);
9997
9998         statement_t *const statement = allocate_statement_zero(STATEMENT_LABEL);
9999         statement->label.label       = label;
10000
10001         next_token();
10002
10003         PUSH_PARENT(statement);
10004
10005         /* if statement is already set then the label is defined twice,
10006          * otherwise it was just mentioned in a goto/local label declaration so far
10007          */
10008         if (label->statement != NULL) {
10009                 errorf(HERE, "duplicate label '%Y' (declared %P)",
10010                        symbol, &label->base.source_position);
10011         } else {
10012                 label->base.source_position = token.source_position;
10013                 label->statement            = statement;
10014         }
10015
10016         eat(':');
10017
10018         if (token.type == '}') {
10019                 /* TODO only warn? */
10020                 if (warning.other && false) {
10021                         warningf(HERE, "label at end of compound statement");
10022                         statement->label.statement = create_empty_statement();
10023                 } else {
10024                         errorf(HERE, "label at end of compound statement");
10025                         statement->label.statement = create_invalid_statement();
10026                 }
10027         } else if (token.type == ';') {
10028                 /* Eat an empty statement here, to avoid the warning about an empty
10029                  * statement after a label.  label:; is commonly used to have a label
10030                  * before a closing brace. */
10031                 statement->label.statement = create_empty_statement();
10032                 next_token();
10033         } else {
10034                 statement_t *const inner_stmt = parse_statement();
10035                 statement->label.statement = inner_stmt;
10036                 if (inner_stmt->kind == STATEMENT_DECLARATION) {
10037                         errorf(&inner_stmt->base.source_position, "declaration after label");
10038                 }
10039         }
10040
10041         /* remember the labels in a list for later checking */
10042         *label_anchor = &statement->label;
10043         label_anchor  = &statement->label.next;
10044
10045         POP_PARENT;
10046         return statement;
10047 }
10048
10049 /**
10050  * Parse an if statement.
10051  */
10052 static statement_t *parse_if(void)
10053 {
10054         statement_t *statement = allocate_statement_zero(STATEMENT_IF);
10055
10056         eat(T_if);
10057
10058         PUSH_PARENT(statement);
10059
10060         add_anchor_token('{');
10061
10062         expect('(', end_error);
10063         add_anchor_token(')');
10064         expression_t *const expr = parse_expression();
10065         statement->ifs.condition = expr;
10066         /* §6.8.4.1:1  The controlling expression of an if statement shall have
10067          *             scalar type. */
10068         semantic_condition(expr, "condition of 'if'-statment");
10069         mark_vars_read(expr, NULL);
10070         rem_anchor_token(')');
10071         expect(')', end_error);
10072
10073 end_error:
10074         rem_anchor_token('{');
10075
10076         add_anchor_token(T_else);
10077         statement_t *const true_stmt = parse_statement();
10078         statement->ifs.true_statement = true_stmt;
10079         rem_anchor_token(T_else);
10080
10081         if (token.type == T_else) {
10082                 next_token();
10083                 statement->ifs.false_statement = parse_statement();
10084         } else if (warning.parentheses &&
10085                         true_stmt->kind == STATEMENT_IF &&
10086                         true_stmt->ifs.false_statement != NULL) {
10087                 warningf(&true_stmt->base.source_position,
10088                                 "suggest explicit braces to avoid ambiguous 'else'");
10089         }
10090
10091         POP_PARENT;
10092         return statement;
10093 }
10094
10095 /**
10096  * Check that all enums are handled in a switch.
10097  *
10098  * @param statement  the switch statement to check
10099  */
10100 static void check_enum_cases(const switch_statement_t *statement)
10101 {
10102         const type_t *type = skip_typeref(statement->expression->base.type);
10103         if (! is_type_enum(type))
10104                 return;
10105         const enum_type_t *enumt = &type->enumt;
10106
10107         /* if we have a default, no warnings */
10108         if (statement->default_label != NULL)
10109                 return;
10110
10111         /* FIXME: calculation of value should be done while parsing */
10112         /* TODO: quadratic algorithm here. Change to an n log n one */
10113         long            last_value = -1;
10114         const entity_t *entry      = enumt->enume->base.next;
10115         for (; entry != NULL && entry->kind == ENTITY_ENUM_VALUE;
10116              entry = entry->base.next) {
10117                 const expression_t *expression = entry->enum_value.value;
10118                 long                value      = expression != NULL ? fold_constant(expression) : last_value + 1;
10119                 bool                found      = false;
10120                 for (const case_label_statement_t *l = statement->first_case; l != NULL; l = l->next) {
10121                         if (l->expression == NULL)
10122                                 continue;
10123                         if (l->first_case <= value && value <= l->last_case) {
10124                                 found = true;
10125                                 break;
10126                         }
10127                 }
10128                 if (! found) {
10129                         warningf(&statement->base.source_position,
10130                                  "enumeration value '%Y' not handled in switch",
10131                                  entry->base.symbol);
10132                 }
10133                 last_value = value;
10134         }
10135 }
10136
10137 /**
10138  * Parse a switch statement.
10139  */
10140 static statement_t *parse_switch(void)
10141 {
10142         statement_t *statement = allocate_statement_zero(STATEMENT_SWITCH);
10143
10144         eat(T_switch);
10145
10146         PUSH_PARENT(statement);
10147
10148         expect('(', end_error);
10149         add_anchor_token(')');
10150         expression_t *const expr = parse_expression();
10151         mark_vars_read(expr, NULL);
10152         type_t       *      type = skip_typeref(expr->base.type);
10153         if (is_type_integer(type)) {
10154                 type = promote_integer(type);
10155                 if (warning.traditional) {
10156                         if (get_rank(type) >= get_akind_rank(ATOMIC_TYPE_LONG)) {
10157                                 warningf(&expr->base.source_position,
10158                                         "'%T' switch expression not converted to '%T' in ISO C",
10159                                         type, type_int);
10160                         }
10161                 }
10162         } else if (is_type_valid(type)) {
10163                 errorf(&expr->base.source_position,
10164                        "switch quantity is not an integer, but '%T'", type);
10165                 type = type_error_type;
10166         }
10167         statement->switchs.expression = create_implicit_cast(expr, type);
10168         expect(')', end_error);
10169         rem_anchor_token(')');
10170
10171         switch_statement_t *rem = current_switch;
10172         current_switch          = &statement->switchs;
10173         statement->switchs.body = parse_statement();
10174         current_switch          = rem;
10175
10176         if (warning.switch_default &&
10177             statement->switchs.default_label == NULL) {
10178                 warningf(&statement->base.source_position, "switch has no default case");
10179         }
10180         if (warning.switch_enum)
10181                 check_enum_cases(&statement->switchs);
10182
10183         POP_PARENT;
10184         return statement;
10185 end_error:
10186         POP_PARENT;
10187         return create_invalid_statement();
10188 }
10189
10190 static statement_t *parse_loop_body(statement_t *const loop)
10191 {
10192         statement_t *const rem = current_loop;
10193         current_loop = loop;
10194
10195         statement_t *const body = parse_statement();
10196
10197         current_loop = rem;
10198         return body;
10199 }
10200
10201 /**
10202  * Parse a while statement.
10203  */
10204 static statement_t *parse_while(void)
10205 {
10206         statement_t *statement = allocate_statement_zero(STATEMENT_WHILE);
10207
10208         eat(T_while);
10209
10210         PUSH_PARENT(statement);
10211
10212         expect('(', end_error);
10213         add_anchor_token(')');
10214         expression_t *const cond = parse_expression();
10215         statement->whiles.condition = cond;
10216         /* §6.8.5:2    The controlling expression of an iteration statement shall
10217          *             have scalar type. */
10218         semantic_condition(cond, "condition of 'while'-statement");
10219         mark_vars_read(cond, NULL);
10220         rem_anchor_token(')');
10221         expect(')', end_error);
10222
10223         statement->whiles.body = parse_loop_body(statement);
10224
10225         POP_PARENT;
10226         return statement;
10227 end_error:
10228         POP_PARENT;
10229         return create_invalid_statement();
10230 }
10231
10232 /**
10233  * Parse a do statement.
10234  */
10235 static statement_t *parse_do(void)
10236 {
10237         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
10238
10239         eat(T_do);
10240
10241         PUSH_PARENT(statement);
10242
10243         add_anchor_token(T_while);
10244         statement->do_while.body = parse_loop_body(statement);
10245         rem_anchor_token(T_while);
10246
10247         expect(T_while, end_error);
10248         expect('(', end_error);
10249         add_anchor_token(')');
10250         expression_t *const cond = parse_expression();
10251         statement->do_while.condition = cond;
10252         /* §6.8.5:2    The controlling expression of an iteration statement shall
10253          *             have scalar type. */
10254         semantic_condition(cond, "condition of 'do-while'-statement");
10255         mark_vars_read(cond, NULL);
10256         rem_anchor_token(')');
10257         expect(')', end_error);
10258         expect(';', end_error);
10259
10260         POP_PARENT;
10261         return statement;
10262 end_error:
10263         POP_PARENT;
10264         return create_invalid_statement();
10265 }
10266
10267 /**
10268  * Parse a for statement.
10269  */
10270 static statement_t *parse_for(void)
10271 {
10272         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
10273
10274         eat(T_for);
10275
10276         expect('(', end_error1);
10277         add_anchor_token(')');
10278
10279         PUSH_PARENT(statement);
10280
10281         size_t const  top       = environment_top();
10282         scope_t      *old_scope = scope_push(&statement->fors.scope);
10283
10284         if (token.type == ';') {
10285                 next_token();
10286         } else if (is_declaration_specifier(&token, false)) {
10287                 parse_declaration(record_entity, DECL_FLAGS_NONE);
10288         } else {
10289                 add_anchor_token(';');
10290                 expression_t *const init = parse_expression();
10291                 statement->fors.initialisation = init;
10292                 mark_vars_read(init, ENT_ANY);
10293                 if (warning.unused_value && !expression_has_effect(init)) {
10294                         warningf(&init->base.source_position,
10295                                         "initialisation of 'for'-statement has no effect");
10296                 }
10297                 rem_anchor_token(';');
10298                 expect(';', end_error2);
10299         }
10300
10301         if (token.type != ';') {
10302                 add_anchor_token(';');
10303                 expression_t *const cond = parse_expression();
10304                 statement->fors.condition = cond;
10305                 /* §6.8.5:2    The controlling expression of an iteration statement
10306                  *             shall have scalar type. */
10307                 semantic_condition(cond, "condition of 'for'-statement");
10308                 mark_vars_read(cond, NULL);
10309                 rem_anchor_token(';');
10310         }
10311         expect(';', end_error2);
10312         if (token.type != ')') {
10313                 expression_t *const step = parse_expression();
10314                 statement->fors.step = step;
10315                 mark_vars_read(step, ENT_ANY);
10316                 if (warning.unused_value && !expression_has_effect(step)) {
10317                         warningf(&step->base.source_position,
10318                                  "step of 'for'-statement has no effect");
10319                 }
10320         }
10321         expect(')', end_error2);
10322         rem_anchor_token(')');
10323         statement->fors.body = parse_loop_body(statement);
10324
10325         assert(current_scope == &statement->fors.scope);
10326         scope_pop(old_scope);
10327         environment_pop_to(top);
10328
10329         POP_PARENT;
10330         return statement;
10331
10332 end_error2:
10333         POP_PARENT;
10334         rem_anchor_token(')');
10335         assert(current_scope == &statement->fors.scope);
10336         scope_pop(old_scope);
10337         environment_pop_to(top);
10338         /* fallthrough */
10339
10340 end_error1:
10341         return create_invalid_statement();
10342 }
10343
10344 /**
10345  * Parse a goto statement.
10346  */
10347 static statement_t *parse_goto(void)
10348 {
10349         statement_t *statement = allocate_statement_zero(STATEMENT_GOTO);
10350         eat(T_goto);
10351
10352         if (GNU_MODE && token.type == '*') {
10353                 next_token();
10354                 expression_t *expression = parse_expression();
10355                 mark_vars_read(expression, NULL);
10356
10357                 /* Argh: although documentation says the expression must be of type void*,
10358                  * gcc accepts anything that can be casted into void* without error */
10359                 type_t *type = expression->base.type;
10360
10361                 if (type != type_error_type) {
10362                         if (!is_type_pointer(type) && !is_type_integer(type)) {
10363                                 errorf(&expression->base.source_position,
10364                                         "cannot convert to a pointer type");
10365                         } else if (warning.other && type != type_void_ptr) {
10366                                 warningf(&expression->base.source_position,
10367                                         "type of computed goto expression should be 'void*' not '%T'", type);
10368                         }
10369                         expression = create_implicit_cast(expression, type_void_ptr);
10370                 }
10371
10372                 statement->gotos.expression = expression;
10373         } else {
10374                 if (token.type != T_IDENTIFIER) {
10375                         if (GNU_MODE)
10376                                 parse_error_expected("while parsing goto", T_IDENTIFIER, '*', NULL);
10377                         else
10378                                 parse_error_expected("while parsing goto", T_IDENTIFIER, NULL);
10379                         eat_until_anchor();
10380                         goto end_error;
10381                 }
10382                 symbol_t *symbol = token.v.symbol;
10383                 next_token();
10384
10385                 statement->gotos.label = get_label(symbol);
10386         }
10387
10388         /* remember the goto's in a list for later checking */
10389         *goto_anchor = &statement->gotos;
10390         goto_anchor  = &statement->gotos.next;
10391
10392         expect(';', end_error);
10393
10394         return statement;
10395 end_error:
10396         return create_invalid_statement();
10397 }
10398
10399 /**
10400  * Parse a continue statement.
10401  */
10402 static statement_t *parse_continue(void)
10403 {
10404         if (current_loop == NULL) {
10405                 errorf(HERE, "continue statement not within loop");
10406         }
10407
10408         statement_t *statement = allocate_statement_zero(STATEMENT_CONTINUE);
10409
10410         eat(T_continue);
10411         expect(';', end_error);
10412
10413 end_error:
10414         return statement;
10415 }
10416
10417 /**
10418  * Parse a break statement.
10419  */
10420 static statement_t *parse_break(void)
10421 {
10422         if (current_switch == NULL && current_loop == NULL) {
10423                 errorf(HERE, "break statement not within loop or switch");
10424         }
10425
10426         statement_t *statement = allocate_statement_zero(STATEMENT_BREAK);
10427
10428         eat(T_break);
10429         expect(';', end_error);
10430
10431 end_error:
10432         return statement;
10433 }
10434
10435 /**
10436  * Parse a __leave statement.
10437  */
10438 static statement_t *parse_leave_statement(void)
10439 {
10440         if (current_try == NULL) {
10441                 errorf(HERE, "__leave statement not within __try");
10442         }
10443
10444         statement_t *statement = allocate_statement_zero(STATEMENT_LEAVE);
10445
10446         eat(T___leave);
10447         expect(';', end_error);
10448
10449 end_error:
10450         return statement;
10451 }
10452
10453 /**
10454  * Check if a given entity represents a local variable.
10455  */
10456 static bool is_local_variable(const entity_t *entity)
10457 {
10458         if (entity->kind != ENTITY_VARIABLE)
10459                 return false;
10460
10461         switch ((storage_class_tag_t) entity->declaration.storage_class) {
10462         case STORAGE_CLASS_AUTO:
10463         case STORAGE_CLASS_REGISTER: {
10464                 const type_t *type = skip_typeref(entity->declaration.type);
10465                 if (is_type_function(type)) {
10466                         return false;
10467                 } else {
10468                         return true;
10469                 }
10470         }
10471         default:
10472                 return false;
10473         }
10474 }
10475
10476 /**
10477  * Check if a given expression represents a local variable.
10478  */
10479 static bool expression_is_local_variable(const expression_t *expression)
10480 {
10481         if (expression->base.kind != EXPR_REFERENCE) {
10482                 return false;
10483         }
10484         const entity_t *entity = expression->reference.entity;
10485         return is_local_variable(entity);
10486 }
10487
10488 /**
10489  * Check if a given expression represents a local variable and
10490  * return its declaration then, else return NULL.
10491  */
10492 entity_t *expression_is_variable(const expression_t *expression)
10493 {
10494         if (expression->base.kind != EXPR_REFERENCE) {
10495                 return NULL;
10496         }
10497         entity_t *entity = expression->reference.entity;
10498         if (entity->kind != ENTITY_VARIABLE)
10499                 return NULL;
10500
10501         return entity;
10502 }
10503
10504 /**
10505  * Parse a return statement.
10506  */
10507 static statement_t *parse_return(void)
10508 {
10509         eat(T_return);
10510
10511         statement_t *statement = allocate_statement_zero(STATEMENT_RETURN);
10512
10513         expression_t *return_value = NULL;
10514         if (token.type != ';') {
10515                 return_value = parse_expression();
10516                 mark_vars_read(return_value, NULL);
10517         }
10518
10519         const type_t *const func_type = skip_typeref(current_function->base.type);
10520         assert(is_type_function(func_type));
10521         type_t *const return_type = skip_typeref(func_type->function.return_type);
10522
10523         source_position_t const *const pos = &statement->base.source_position;
10524         if (return_value != NULL) {
10525                 type_t *return_value_type = skip_typeref(return_value->base.type);
10526
10527                 if (is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
10528                         if (is_type_atomic(return_value_type, ATOMIC_TYPE_VOID)) {
10529                                 /* ISO/IEC 14882:1998(E) §6.6.3:2 */
10530                                 /* Only warn in C mode, because GCC does the same */
10531                                 if (c_mode & _CXX || strict_mode) {
10532                                         errorf(pos,
10533                                                         "'return' with a value, in function returning 'void'");
10534                                 } else if (warning.other) {
10535                                         warningf(pos,
10536                                                         "'return' with a value, in function returning 'void'");
10537                                 }
10538                         } else if (!(c_mode & _CXX)) { /* ISO/IEC 14882:1998(E) §6.6.3:3 */
10539                                 /* Only warn in C mode, because GCC does the same */
10540                                 if (strict_mode) {
10541                                         errorf(pos,
10542                                                         "'return' with expression in function return 'void'");
10543                                 } else if (warning.other) {
10544                                         warningf(pos,
10545                                                         "'return' with expression in function return 'void'");
10546                                 }
10547                         }
10548                 } else {
10549                         assign_error_t error = semantic_assign(return_type, return_value);
10550                         report_assign_error(error, return_type, return_value, "'return'",
10551                                         pos);
10552                 }
10553                 return_value = create_implicit_cast(return_value, return_type);
10554                 /* check for returning address of a local var */
10555                 if (warning.other && return_value != NULL
10556                                 && return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
10557                         const expression_t *expression = return_value->unary.value;
10558                         if (expression_is_local_variable(expression)) {
10559                                 warningf(pos, "function returns address of local variable");
10560                         }
10561                 }
10562         } else if (warning.other && !is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
10563                 /* ISO/IEC 14882:1998(E) §6.6.3:3 */
10564                 if (c_mode & _CXX || strict_mode) {
10565                         errorf(pos,
10566                                         "'return' without value, in function returning non-void");
10567                 } else {
10568                         warningf(pos,
10569                                         "'return' without value, in function returning non-void");
10570                 }
10571         }
10572         statement->returns.value = return_value;
10573
10574         expect(';', end_error);
10575
10576 end_error:
10577         return statement;
10578 }
10579
10580 /**
10581  * Parse a declaration statement.
10582  */
10583 static statement_t *parse_declaration_statement(void)
10584 {
10585         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
10586
10587         entity_t *before = current_scope->last_entity;
10588         if (GNU_MODE) {
10589                 parse_external_declaration();
10590         } else {
10591                 parse_declaration(record_entity, DECL_FLAGS_NONE);
10592         }
10593
10594         declaration_statement_t *const decl  = &statement->declaration;
10595         entity_t                *const begin =
10596                 before != NULL ? before->base.next : current_scope->entities;
10597         decl->declarations_begin = begin;
10598         decl->declarations_end   = begin != NULL ? current_scope->last_entity : NULL;
10599
10600         return statement;
10601 }
10602
10603 /**
10604  * Parse an expression statement, ie. expr ';'.
10605  */
10606 static statement_t *parse_expression_statement(void)
10607 {
10608         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10609
10610         expression_t *const expr         = parse_expression();
10611         statement->expression.expression = expr;
10612         mark_vars_read(expr, ENT_ANY);
10613
10614         expect(';', end_error);
10615
10616 end_error:
10617         return statement;
10618 }
10619
10620 /**
10621  * Parse a microsoft __try { } __finally { } or
10622  * __try{ } __except() { }
10623  */
10624 static statement_t *parse_ms_try_statment(void)
10625 {
10626         statement_t *statement = allocate_statement_zero(STATEMENT_MS_TRY);
10627         eat(T___try);
10628
10629         PUSH_PARENT(statement);
10630
10631         ms_try_statement_t *rem = current_try;
10632         current_try = &statement->ms_try;
10633         statement->ms_try.try_statement = parse_compound_statement(false);
10634         current_try = rem;
10635
10636         POP_PARENT;
10637
10638         if (token.type == T___except) {
10639                 eat(T___except);
10640                 expect('(', end_error);
10641                 add_anchor_token(')');
10642                 expression_t *const expr = parse_expression();
10643                 mark_vars_read(expr, NULL);
10644                 type_t       *      type = skip_typeref(expr->base.type);
10645                 if (is_type_integer(type)) {
10646                         type = promote_integer(type);
10647                 } else if (is_type_valid(type)) {
10648                         errorf(&expr->base.source_position,
10649                                "__expect expression is not an integer, but '%T'", type);
10650                         type = type_error_type;
10651                 }
10652                 statement->ms_try.except_expression = create_implicit_cast(expr, type);
10653                 rem_anchor_token(')');
10654                 expect(')', end_error);
10655                 statement->ms_try.final_statement = parse_compound_statement(false);
10656         } else if (token.type == T__finally) {
10657                 eat(T___finally);
10658                 statement->ms_try.final_statement = parse_compound_statement(false);
10659         } else {
10660                 parse_error_expected("while parsing __try statement", T___except, T___finally, NULL);
10661                 return create_invalid_statement();
10662         }
10663         return statement;
10664 end_error:
10665         return create_invalid_statement();
10666 }
10667
10668 static statement_t *parse_empty_statement(void)
10669 {
10670         if (warning.empty_statement) {
10671                 warningf(HERE, "statement is empty");
10672         }
10673         statement_t *const statement = create_empty_statement();
10674         eat(';');
10675         return statement;
10676 }
10677
10678 static statement_t *parse_local_label_declaration(void)
10679 {
10680         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
10681
10682         eat(T___label__);
10683
10684         entity_t *begin = NULL, *end = NULL;
10685
10686         while (true) {
10687                 if (token.type != T_IDENTIFIER) {
10688                         parse_error_expected("while parsing local label declaration",
10689                                 T_IDENTIFIER, NULL);
10690                         goto end_error;
10691                 }
10692                 symbol_t *symbol = token.v.symbol;
10693                 entity_t *entity = get_entity(symbol, NAMESPACE_LABEL);
10694                 if (entity != NULL && entity->base.parent_scope == current_scope) {
10695                         errorf(HERE, "multiple definitions of '__label__ %Y' (previous definition %P)",
10696                                symbol, &entity->base.source_position);
10697                 } else {
10698                         entity = allocate_entity_zero(ENTITY_LOCAL_LABEL);
10699
10700                         entity->base.parent_scope    = current_scope;
10701                         entity->base.namespc         = NAMESPACE_LABEL;
10702                         entity->base.source_position = token.source_position;
10703                         entity->base.symbol          = symbol;
10704
10705                         if (end != NULL)
10706                                 end->base.next = entity;
10707                         end = entity;
10708                         if (begin == NULL)
10709                                 begin = entity;
10710
10711                         environment_push(entity);
10712                 }
10713                 next_token();
10714
10715                 if (token.type != ',')
10716                         break;
10717                 next_token();
10718         }
10719         eat(';');
10720 end_error:
10721         statement->declaration.declarations_begin = begin;
10722         statement->declaration.declarations_end   = end;
10723         return statement;
10724 }
10725
10726 static void parse_namespace_definition(void)
10727 {
10728         eat(T_namespace);
10729
10730         entity_t *entity = NULL;
10731         symbol_t *symbol = NULL;
10732
10733         if (token.type == T_IDENTIFIER) {
10734                 symbol = token.v.symbol;
10735                 next_token();
10736
10737                 entity = get_entity(symbol, NAMESPACE_NORMAL);
10738                 if (entity       != NULL             &&
10739                                 entity->kind != ENTITY_NAMESPACE &&
10740                                 entity->base.parent_scope == current_scope) {
10741                         if (!is_error_entity(entity)) {
10742                                 error_redefined_as_different_kind(&token.source_position,
10743                                                 entity, ENTITY_NAMESPACE);
10744                         }
10745                         entity = NULL;
10746                 }
10747         }
10748
10749         if (entity == NULL) {
10750                 entity                       = allocate_entity_zero(ENTITY_NAMESPACE);
10751                 entity->base.symbol          = symbol;
10752                 entity->base.source_position = token.source_position;
10753                 entity->base.namespc         = NAMESPACE_NORMAL;
10754                 entity->base.parent_scope    = current_scope;
10755         }
10756
10757         if (token.type == '=') {
10758                 /* TODO: parse namespace alias */
10759                 panic("namespace alias definition not supported yet");
10760         }
10761
10762         environment_push(entity);
10763         append_entity(current_scope, entity);
10764
10765         size_t const  top       = environment_top();
10766         scope_t      *old_scope = scope_push(&entity->namespacee.members);
10767
10768         expect('{', end_error);
10769         parse_externals();
10770         expect('}', end_error);
10771
10772 end_error:
10773         assert(current_scope == &entity->namespacee.members);
10774         scope_pop(old_scope);
10775         environment_pop_to(top);
10776 }
10777
10778 /**
10779  * Parse a statement.
10780  * There's also parse_statement() which additionally checks for
10781  * "statement has no effect" warnings
10782  */
10783 static statement_t *intern_parse_statement(void)
10784 {
10785         statement_t *statement = NULL;
10786
10787         /* declaration or statement */
10788         add_anchor_token(';');
10789         switch (token.type) {
10790         case T_IDENTIFIER: {
10791                 token_type_t la1_type = (token_type_t)look_ahead(1)->type;
10792                 if (la1_type == ':') {
10793                         statement = parse_label_statement();
10794                 } else if (is_typedef_symbol(token.v.symbol)) {
10795                         statement = parse_declaration_statement();
10796                 } else {
10797                         /* it's an identifier, the grammar says this must be an
10798                          * expression statement. However it is common that users mistype
10799                          * declaration types, so we guess a bit here to improve robustness
10800                          * for incorrect programs */
10801                         switch (la1_type) {
10802                         case '&':
10803                         case '*':
10804                                 if (get_entity(token.v.symbol, NAMESPACE_NORMAL) != NULL)
10805                                         goto expression_statment;
10806                                 /* FALLTHROUGH */
10807
10808                         DECLARATION_START
10809                         case T_IDENTIFIER:
10810                                 statement = parse_declaration_statement();
10811                                 break;
10812
10813                         default:
10814 expression_statment:
10815                                 statement = parse_expression_statement();
10816                                 break;
10817                         }
10818                 }
10819                 break;
10820         }
10821
10822         case T___extension__:
10823                 /* This can be a prefix to a declaration or an expression statement.
10824                  * We simply eat it now and parse the rest with tail recursion. */
10825                 do {
10826                         next_token();
10827                 } while (token.type == T___extension__);
10828                 bool old_gcc_extension = in_gcc_extension;
10829                 in_gcc_extension       = true;
10830                 statement = intern_parse_statement();
10831                 in_gcc_extension = old_gcc_extension;
10832                 break;
10833
10834         DECLARATION_START
10835                 statement = parse_declaration_statement();
10836                 break;
10837
10838         case T___label__:
10839                 statement = parse_local_label_declaration();
10840                 break;
10841
10842         case ';':         statement = parse_empty_statement();         break;
10843         case '{':         statement = parse_compound_statement(false); break;
10844         case T___leave:   statement = parse_leave_statement();         break;
10845         case T___try:     statement = parse_ms_try_statment();         break;
10846         case T_asm:       statement = parse_asm_statement();           break;
10847         case T_break:     statement = parse_break();                   break;
10848         case T_case:      statement = parse_case_statement();          break;
10849         case T_continue:  statement = parse_continue();                break;
10850         case T_default:   statement = parse_default_statement();       break;
10851         case T_do:        statement = parse_do();                      break;
10852         case T_for:       statement = parse_for();                     break;
10853         case T_goto:      statement = parse_goto();                    break;
10854         case T_if:        statement = parse_if();                      break;
10855         case T_return:    statement = parse_return();                  break;
10856         case T_switch:    statement = parse_switch();                  break;
10857         case T_while:     statement = parse_while();                   break;
10858
10859         EXPRESSION_START
10860                 statement = parse_expression_statement();
10861                 break;
10862
10863         default:
10864                 errorf(HERE, "unexpected token %K while parsing statement", &token);
10865                 statement = create_invalid_statement();
10866                 if (!at_anchor())
10867                         next_token();
10868                 break;
10869         }
10870         rem_anchor_token(';');
10871
10872         assert(statement != NULL
10873                         && statement->base.source_position.input_name != NULL);
10874
10875         return statement;
10876 }
10877
10878 /**
10879  * parse a statement and emits "statement has no effect" warning if needed
10880  * (This is really a wrapper around intern_parse_statement with check for 1
10881  *  single warning. It is needed, because for statement expressions we have
10882  *  to avoid the warning on the last statement)
10883  */
10884 static statement_t *parse_statement(void)
10885 {
10886         statement_t *statement = intern_parse_statement();
10887
10888         if (statement->kind == STATEMENT_EXPRESSION && warning.unused_value) {
10889                 expression_t *expression = statement->expression.expression;
10890                 if (!expression_has_effect(expression)) {
10891                         warningf(&expression->base.source_position,
10892                                         "statement has no effect");
10893                 }
10894         }
10895
10896         return statement;
10897 }
10898
10899 /**
10900  * Parse a compound statement.
10901  */
10902 static statement_t *parse_compound_statement(bool inside_expression_statement)
10903 {
10904         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
10905
10906         PUSH_PARENT(statement);
10907
10908         eat('{');
10909         add_anchor_token('}');
10910         /* tokens, which can start a statement */
10911         /* TODO MS, __builtin_FOO */
10912         add_anchor_token('!');
10913         add_anchor_token('&');
10914         add_anchor_token('(');
10915         add_anchor_token('*');
10916         add_anchor_token('+');
10917         add_anchor_token('-');
10918         add_anchor_token('{');
10919         add_anchor_token('~');
10920         add_anchor_token(T_CHARACTER_CONSTANT);
10921         add_anchor_token(T_COLONCOLON);
10922         add_anchor_token(T_FLOATINGPOINT);
10923         add_anchor_token(T_IDENTIFIER);
10924         add_anchor_token(T_INTEGER);
10925         add_anchor_token(T_MINUSMINUS);
10926         add_anchor_token(T_PLUSPLUS);
10927         add_anchor_token(T_STRING_LITERAL);
10928         add_anchor_token(T_WIDE_CHARACTER_CONSTANT);
10929         add_anchor_token(T_WIDE_STRING_LITERAL);
10930         add_anchor_token(T__Bool);
10931         add_anchor_token(T__Complex);
10932         add_anchor_token(T__Imaginary);
10933         add_anchor_token(T___FUNCTION__);
10934         add_anchor_token(T___PRETTY_FUNCTION__);
10935         add_anchor_token(T___alignof__);
10936         add_anchor_token(T___attribute__);
10937         add_anchor_token(T___builtin_va_start);
10938         add_anchor_token(T___extension__);
10939         add_anchor_token(T___func__);
10940         add_anchor_token(T___imag__);
10941         add_anchor_token(T___label__);
10942         add_anchor_token(T___real__);
10943         add_anchor_token(T___thread);
10944         add_anchor_token(T_asm);
10945         add_anchor_token(T_auto);
10946         add_anchor_token(T_bool);
10947         add_anchor_token(T_break);
10948         add_anchor_token(T_case);
10949         add_anchor_token(T_char);
10950         add_anchor_token(T_class);
10951         add_anchor_token(T_const);
10952         add_anchor_token(T_const_cast);
10953         add_anchor_token(T_continue);
10954         add_anchor_token(T_default);
10955         add_anchor_token(T_delete);
10956         add_anchor_token(T_double);
10957         add_anchor_token(T_do);
10958         add_anchor_token(T_dynamic_cast);
10959         add_anchor_token(T_enum);
10960         add_anchor_token(T_extern);
10961         add_anchor_token(T_false);
10962         add_anchor_token(T_float);
10963         add_anchor_token(T_for);
10964         add_anchor_token(T_goto);
10965         add_anchor_token(T_if);
10966         add_anchor_token(T_inline);
10967         add_anchor_token(T_int);
10968         add_anchor_token(T_long);
10969         add_anchor_token(T_new);
10970         add_anchor_token(T_operator);
10971         add_anchor_token(T_register);
10972         add_anchor_token(T_reinterpret_cast);
10973         add_anchor_token(T_restrict);
10974         add_anchor_token(T_return);
10975         add_anchor_token(T_short);
10976         add_anchor_token(T_signed);
10977         add_anchor_token(T_sizeof);
10978         add_anchor_token(T_static);
10979         add_anchor_token(T_static_cast);
10980         add_anchor_token(T_struct);
10981         add_anchor_token(T_switch);
10982         add_anchor_token(T_template);
10983         add_anchor_token(T_this);
10984         add_anchor_token(T_throw);
10985         add_anchor_token(T_true);
10986         add_anchor_token(T_try);
10987         add_anchor_token(T_typedef);
10988         add_anchor_token(T_typeid);
10989         add_anchor_token(T_typename);
10990         add_anchor_token(T_typeof);
10991         add_anchor_token(T_union);
10992         add_anchor_token(T_unsigned);
10993         add_anchor_token(T_using);
10994         add_anchor_token(T_void);
10995         add_anchor_token(T_volatile);
10996         add_anchor_token(T_wchar_t);
10997         add_anchor_token(T_while);
10998
10999         size_t const  top       = environment_top();
11000         scope_t      *old_scope = scope_push(&statement->compound.scope);
11001
11002         statement_t **anchor            = &statement->compound.statements;
11003         bool          only_decls_so_far = true;
11004         while (token.type != '}') {
11005                 if (token.type == T_EOF) {
11006                         errorf(&statement->base.source_position,
11007                                "EOF while parsing compound statement");
11008                         break;
11009                 }
11010                 statement_t *sub_statement = intern_parse_statement();
11011                 if (is_invalid_statement(sub_statement)) {
11012                         /* an error occurred. if we are at an anchor, return */
11013                         if (at_anchor())
11014                                 goto end_error;
11015                         continue;
11016                 }
11017
11018                 if (warning.declaration_after_statement) {
11019                         if (sub_statement->kind != STATEMENT_DECLARATION) {
11020                                 only_decls_so_far = false;
11021                         } else if (!only_decls_so_far) {
11022                                 warningf(&sub_statement->base.source_position,
11023                                          "ISO C90 forbids mixed declarations and code");
11024                         }
11025                 }
11026
11027                 *anchor = sub_statement;
11028
11029                 while (sub_statement->base.next != NULL)
11030                         sub_statement = sub_statement->base.next;
11031
11032                 anchor = &sub_statement->base.next;
11033         }
11034         next_token();
11035
11036         /* look over all statements again to produce no effect warnings */
11037         if (warning.unused_value) {
11038                 statement_t *sub_statement = statement->compound.statements;
11039                 for (; sub_statement != NULL; sub_statement = sub_statement->base.next) {
11040                         if (sub_statement->kind != STATEMENT_EXPRESSION)
11041                                 continue;
11042                         /* don't emit a warning for the last expression in an expression
11043                          * statement as it has always an effect */
11044                         if (inside_expression_statement && sub_statement->base.next == NULL)
11045                                 continue;
11046
11047                         expression_t *expression = sub_statement->expression.expression;
11048                         if (!expression_has_effect(expression)) {
11049                                 warningf(&expression->base.source_position,
11050                                          "statement has no effect");
11051                         }
11052                 }
11053         }
11054
11055 end_error:
11056         rem_anchor_token(T_while);
11057         rem_anchor_token(T_wchar_t);
11058         rem_anchor_token(T_volatile);
11059         rem_anchor_token(T_void);
11060         rem_anchor_token(T_using);
11061         rem_anchor_token(T_unsigned);
11062         rem_anchor_token(T_union);
11063         rem_anchor_token(T_typeof);
11064         rem_anchor_token(T_typename);
11065         rem_anchor_token(T_typeid);
11066         rem_anchor_token(T_typedef);
11067         rem_anchor_token(T_try);
11068         rem_anchor_token(T_true);
11069         rem_anchor_token(T_throw);
11070         rem_anchor_token(T_this);
11071         rem_anchor_token(T_template);
11072         rem_anchor_token(T_switch);
11073         rem_anchor_token(T_struct);
11074         rem_anchor_token(T_static_cast);
11075         rem_anchor_token(T_static);
11076         rem_anchor_token(T_sizeof);
11077         rem_anchor_token(T_signed);
11078         rem_anchor_token(T_short);
11079         rem_anchor_token(T_return);
11080         rem_anchor_token(T_restrict);
11081         rem_anchor_token(T_reinterpret_cast);
11082         rem_anchor_token(T_register);
11083         rem_anchor_token(T_operator);
11084         rem_anchor_token(T_new);
11085         rem_anchor_token(T_long);
11086         rem_anchor_token(T_int);
11087         rem_anchor_token(T_inline);
11088         rem_anchor_token(T_if);
11089         rem_anchor_token(T_goto);
11090         rem_anchor_token(T_for);
11091         rem_anchor_token(T_float);
11092         rem_anchor_token(T_false);
11093         rem_anchor_token(T_extern);
11094         rem_anchor_token(T_enum);
11095         rem_anchor_token(T_dynamic_cast);
11096         rem_anchor_token(T_do);
11097         rem_anchor_token(T_double);
11098         rem_anchor_token(T_delete);
11099         rem_anchor_token(T_default);
11100         rem_anchor_token(T_continue);
11101         rem_anchor_token(T_const_cast);
11102         rem_anchor_token(T_const);
11103         rem_anchor_token(T_class);
11104         rem_anchor_token(T_char);
11105         rem_anchor_token(T_case);
11106         rem_anchor_token(T_break);
11107         rem_anchor_token(T_bool);
11108         rem_anchor_token(T_auto);
11109         rem_anchor_token(T_asm);
11110         rem_anchor_token(T___thread);
11111         rem_anchor_token(T___real__);
11112         rem_anchor_token(T___label__);
11113         rem_anchor_token(T___imag__);
11114         rem_anchor_token(T___func__);
11115         rem_anchor_token(T___extension__);
11116         rem_anchor_token(T___builtin_va_start);
11117         rem_anchor_token(T___attribute__);
11118         rem_anchor_token(T___alignof__);
11119         rem_anchor_token(T___PRETTY_FUNCTION__);
11120         rem_anchor_token(T___FUNCTION__);
11121         rem_anchor_token(T__Imaginary);
11122         rem_anchor_token(T__Complex);
11123         rem_anchor_token(T__Bool);
11124         rem_anchor_token(T_WIDE_STRING_LITERAL);
11125         rem_anchor_token(T_WIDE_CHARACTER_CONSTANT);
11126         rem_anchor_token(T_STRING_LITERAL);
11127         rem_anchor_token(T_PLUSPLUS);
11128         rem_anchor_token(T_MINUSMINUS);
11129         rem_anchor_token(T_INTEGER);
11130         rem_anchor_token(T_IDENTIFIER);
11131         rem_anchor_token(T_FLOATINGPOINT);
11132         rem_anchor_token(T_COLONCOLON);
11133         rem_anchor_token(T_CHARACTER_CONSTANT);
11134         rem_anchor_token('~');
11135         rem_anchor_token('{');
11136         rem_anchor_token('-');
11137         rem_anchor_token('+');
11138         rem_anchor_token('*');
11139         rem_anchor_token('(');
11140         rem_anchor_token('&');
11141         rem_anchor_token('!');
11142         rem_anchor_token('}');
11143         assert(current_scope == &statement->compound.scope);
11144         scope_pop(old_scope);
11145         environment_pop_to(top);
11146
11147         POP_PARENT;
11148         return statement;
11149 }
11150
11151 /**
11152  * Check for unused global static functions and variables
11153  */
11154 static void check_unused_globals(void)
11155 {
11156         if (!warning.unused_function && !warning.unused_variable)
11157                 return;
11158
11159         for (const entity_t *entity = file_scope->entities; entity != NULL;
11160              entity = entity->base.next) {
11161                 if (!is_declaration(entity))
11162                         continue;
11163
11164                 const declaration_t *declaration = &entity->declaration;
11165                 if (declaration->used                  ||
11166                     declaration->modifiers & DM_UNUSED ||
11167                     declaration->modifiers & DM_USED   ||
11168                     declaration->storage_class != STORAGE_CLASS_STATIC)
11169                         continue;
11170
11171                 type_t *const type = declaration->type;
11172                 const char *s;
11173                 if (entity->kind == ENTITY_FUNCTION) {
11174                         /* inhibit warning for static inline functions */
11175                         if (entity->function.is_inline)
11176                                 continue;
11177
11178                         s = entity->function.statement != NULL ? "defined" : "declared";
11179                 } else {
11180                         s = "defined";
11181                 }
11182
11183                 warningf(&declaration->base.source_position, "'%#T' %s but not used",
11184                         type, declaration->base.symbol, s);
11185         }
11186 }
11187
11188 static void parse_global_asm(void)
11189 {
11190         statement_t *statement = allocate_statement_zero(STATEMENT_ASM);
11191
11192         eat(T_asm);
11193         expect('(', end_error);
11194
11195         statement->asms.asm_text = parse_string_literals();
11196         statement->base.next     = unit->global_asm;
11197         unit->global_asm         = statement;
11198
11199         expect(')', end_error);
11200         expect(';', end_error);
11201
11202 end_error:;
11203 }
11204
11205 static void parse_linkage_specification(void)
11206 {
11207         eat(T_extern);
11208         assert(token.type == T_STRING_LITERAL);
11209
11210         const char *linkage = parse_string_literals().begin;
11211
11212         linkage_kind_t old_linkage = current_linkage;
11213         linkage_kind_t new_linkage;
11214         if (strcmp(linkage, "C") == 0) {
11215                 new_linkage = LINKAGE_C;
11216         } else if (strcmp(linkage, "C++") == 0) {
11217                 new_linkage = LINKAGE_CXX;
11218         } else {
11219                 errorf(HERE, "linkage string \"%s\" not recognized", linkage);
11220                 new_linkage = LINKAGE_INVALID;
11221         }
11222         current_linkage = new_linkage;
11223
11224         if (token.type == '{') {
11225                 next_token();
11226                 parse_externals();
11227                 expect('}', end_error);
11228         } else {
11229                 parse_external();
11230         }
11231
11232 end_error:
11233         assert(current_linkage == new_linkage);
11234         current_linkage = old_linkage;
11235 }
11236
11237 static void parse_external(void)
11238 {
11239         switch (token.type) {
11240                 DECLARATION_START_NO_EXTERN
11241                 case T_IDENTIFIER:
11242                 case T___extension__:
11243                 /* tokens below are for implicit int */
11244                 case '&': /* & x; -> int& x; (and error later, because C++ has no
11245                              implicit int) */
11246                 case '*': /* * x; -> int* x; */
11247                 case '(': /* (x); -> int (x); */
11248                         parse_external_declaration();
11249                         return;
11250
11251                 case T_extern:
11252                         if (look_ahead(1)->type == T_STRING_LITERAL) {
11253                                 parse_linkage_specification();
11254                         } else {
11255                                 parse_external_declaration();
11256                         }
11257                         return;
11258
11259                 case T_asm:
11260                         parse_global_asm();
11261                         return;
11262
11263                 case T_namespace:
11264                         parse_namespace_definition();
11265                         return;
11266
11267                 case ';':
11268                         if (!strict_mode) {
11269                                 if (warning.other)
11270                                         warningf(HERE, "stray ';' outside of function");
11271                                 next_token();
11272                                 return;
11273                         }
11274                         /* FALLTHROUGH */
11275
11276                 default:
11277                         errorf(HERE, "stray %K outside of function", &token);
11278                         if (token.type == '(' || token.type == '{' || token.type == '[')
11279                                 eat_until_matching_token(token.type);
11280                         next_token();
11281                         return;
11282         }
11283 }
11284
11285 static void parse_externals(void)
11286 {
11287         add_anchor_token('}');
11288         add_anchor_token(T_EOF);
11289
11290 #ifndef NDEBUG
11291         unsigned char token_anchor_copy[T_LAST_TOKEN];
11292         memcpy(token_anchor_copy, token_anchor_set, sizeof(token_anchor_copy));
11293 #endif
11294
11295         while (token.type != T_EOF && token.type != '}') {
11296 #ifndef NDEBUG
11297                 bool anchor_leak = false;
11298                 for (int i = 0; i != T_LAST_TOKEN; ++i) {
11299                         unsigned char count = token_anchor_set[i] - token_anchor_copy[i];
11300                         if (count != 0) {
11301                                 errorf(HERE, "Leaked anchor token %k %d times", i, count);
11302                                 anchor_leak = true;
11303                         }
11304                 }
11305                 if (in_gcc_extension) {
11306                         errorf(HERE, "Leaked __extension__");
11307                         anchor_leak = true;
11308                 }
11309
11310                 if (anchor_leak)
11311                         abort();
11312 #endif
11313
11314                 parse_external();
11315         }
11316
11317         rem_anchor_token(T_EOF);
11318         rem_anchor_token('}');
11319 }
11320
11321 /**
11322  * Parse a translation unit.
11323  */
11324 static void parse_translation_unit(void)
11325 {
11326         add_anchor_token(T_EOF);
11327
11328         while (true) {
11329                 parse_externals();
11330
11331                 if (token.type == T_EOF)
11332                         break;
11333
11334                 errorf(HERE, "stray %K outside of function", &token);
11335                 if (token.type == '(' || token.type == '{' || token.type == '[')
11336                         eat_until_matching_token(token.type);
11337                 next_token();
11338         }
11339 }
11340
11341 /**
11342  * Parse the input.
11343  *
11344  * @return  the translation unit or NULL if errors occurred.
11345  */
11346 void start_parsing(void)
11347 {
11348         environment_stack = NEW_ARR_F(stack_entry_t, 0);
11349         label_stack       = NEW_ARR_F(stack_entry_t, 0);
11350         diagnostic_count  = 0;
11351         error_count       = 0;
11352         warning_count     = 0;
11353
11354         type_set_output(stderr);
11355         ast_set_output(stderr);
11356
11357         assert(unit == NULL);
11358         unit = allocate_ast_zero(sizeof(unit[0]));
11359
11360         assert(file_scope == NULL);
11361         file_scope = &unit->scope;
11362
11363         assert(current_scope == NULL);
11364         scope_push(&unit->scope);
11365
11366         create_gnu_builtins();
11367         if (c_mode & _MS)
11368                 create_microsoft_intrinsics();
11369 }
11370
11371 translation_unit_t *finish_parsing(void)
11372 {
11373         assert(current_scope == &unit->scope);
11374         scope_pop(NULL);
11375
11376         assert(file_scope == &unit->scope);
11377         check_unused_globals();
11378         file_scope = NULL;
11379
11380         DEL_ARR_F(environment_stack);
11381         DEL_ARR_F(label_stack);
11382
11383         translation_unit_t *result = unit;
11384         unit = NULL;
11385         return result;
11386 }
11387
11388 /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
11389  * are given length one. */
11390 static void complete_incomplete_arrays(void)
11391 {
11392         size_t n = ARR_LEN(incomplete_arrays);
11393         for (size_t i = 0; i != n; ++i) {
11394                 declaration_t *const decl      = incomplete_arrays[i];
11395                 type_t        *const orig_type = decl->type;
11396                 type_t        *const type      = skip_typeref(orig_type);
11397
11398                 if (!is_type_incomplete(type))
11399                         continue;
11400
11401                 if (warning.other) {
11402                         warningf(&decl->base.source_position,
11403                                         "array '%#T' assumed to have one element",
11404                                         orig_type, decl->base.symbol);
11405                 }
11406
11407                 type_t *const new_type = duplicate_type(type);
11408                 new_type->array.size_constant     = true;
11409                 new_type->array.has_implicit_size = true;
11410                 new_type->array.size              = 1;
11411
11412                 type_t *const result = identify_new_type(new_type);
11413
11414                 decl->type = result;
11415         }
11416 }
11417
11418 void parse(void)
11419 {
11420         lookahead_bufpos = 0;
11421         for (int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
11422                 next_token();
11423         }
11424         current_linkage   = c_mode & _CXX ? LINKAGE_CXX : LINKAGE_C;
11425         incomplete_arrays = NEW_ARR_F(declaration_t*, 0);
11426         parse_translation_unit();
11427         complete_incomplete_arrays();
11428         DEL_ARR_F(incomplete_arrays);
11429         incomplete_arrays = NULL;
11430 }
11431
11432 /**
11433  * create a builtin function.
11434  */
11435 static entity_t *create_builtin_function(builtin_kind_t kind, const char *name, type_t *function_type)
11436 {
11437         symbol_t *symbol = symbol_table_insert(name);
11438         entity_t *entity = allocate_entity_zero(ENTITY_FUNCTION);
11439         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
11440         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
11441         entity->declaration.type                   = function_type;
11442         entity->declaration.implicit               = true;
11443         entity->base.symbol                        = symbol;
11444         entity->base.source_position               = builtin_source_position;
11445
11446         entity->function.btk                       = kind;
11447
11448         record_entity(entity, /*is_definition=*/false);
11449         return entity;
11450 }
11451
11452
11453 /**
11454  * Create predefined gnu builtins.
11455  */
11456 static void create_gnu_builtins(void)
11457 {
11458 #define GNU_BUILTIN(a, b) create_builtin_function(bk_gnu_builtin_##a, "__builtin_" #a, b)
11459
11460         GNU_BUILTIN(alloca,         make_function_1_type(type_void_ptr, type_size_t));
11461         GNU_BUILTIN(huge_val,       make_function_0_type(type_double));
11462         GNU_BUILTIN(inf,            make_function_0_type(type_double));
11463         GNU_BUILTIN(inff,           make_function_0_type(type_float));
11464         GNU_BUILTIN(infl,           make_function_0_type(type_long_double));
11465         GNU_BUILTIN(nan,            make_function_1_type(type_double, type_char_ptr));
11466         GNU_BUILTIN(nanf,           make_function_1_type(type_float, type_char_ptr));
11467         GNU_BUILTIN(nanl,           make_function_1_type(type_long_double, type_char_ptr));
11468         GNU_BUILTIN(va_end,         make_function_1_type(type_void, type_valist));
11469         GNU_BUILTIN(expect,         make_function_2_type(type_long, type_long, type_long));
11470         GNU_BUILTIN(return_address, make_function_1_type(type_void_ptr, type_unsigned_int));
11471         GNU_BUILTIN(frame_address,  make_function_1_type(type_void_ptr, type_unsigned_int));
11472         GNU_BUILTIN(ffs,            make_function_1_type(type_int, type_unsigned_int));
11473         GNU_BUILTIN(clz,            make_function_1_type(type_int, type_unsigned_int));
11474         GNU_BUILTIN(ctz,            make_function_1_type(type_int, type_unsigned_int));
11475         GNU_BUILTIN(popcount,       make_function_1_type(type_int, type_unsigned_int));
11476         GNU_BUILTIN(parity,         make_function_1_type(type_int, type_unsigned_int));
11477         GNU_BUILTIN(prefetch,       make_function_1_type_variadic(type_float, type_void_ptr));
11478         GNU_BUILTIN(trap,           make_function_0_type_noreturn(type_void));
11479
11480 #undef GNU_BUILTIN
11481 }
11482
11483 /**
11484  * Create predefined MS intrinsics.
11485  */
11486 static void create_microsoft_intrinsics(void)
11487 {
11488 #define MS_BUILTIN(a, b) create_builtin_function(bk_ms##a, #a, b)
11489
11490         /* intrinsics for all architectures */
11491         MS_BUILTIN(_rotl,                  make_function_2_type(type_unsigned_int,   type_unsigned_int, type_int));
11492         MS_BUILTIN(_rotr,                  make_function_2_type(type_unsigned_int,   type_unsigned_int, type_int));
11493         MS_BUILTIN(_rotl64,                make_function_2_type(type_unsigned_int64, type_unsigned_int64, type_int));
11494         MS_BUILTIN(_rotr64,                make_function_2_type(type_unsigned_int64, type_unsigned_int64, type_int));
11495         MS_BUILTIN(_byteswap_ushort,       make_function_1_type(type_unsigned_short, type_unsigned_short));
11496         MS_BUILTIN(_byteswap_ulong,        make_function_1_type(type_unsigned_long,  type_unsigned_long));
11497         MS_BUILTIN(_byteswap_uint64,       make_function_1_type(type_unsigned_int64, type_unsigned_int64));
11498
11499         MS_BUILTIN(__debugbreak,    make_function_0_type(type_void));
11500         MS_BUILTIN(_ReturnAddress,  make_function_0_type(type_void_ptr));
11501         MS_BUILTIN(__popcount,      make_function_1_type(type_unsigned_int, type_unsigned_int));
11502
11503         /* x86/x64 only */
11504         MS_BUILTIN(_enable,                make_function_0_type(type_void));
11505         MS_BUILTIN(_disable,               make_function_0_type(type_void));
11506         MS_BUILTIN(__inbyte,               make_function_1_type(type_unsigned_char, type_unsigned_short));
11507         MS_BUILTIN(__inword,               make_function_1_type(type_unsigned_short, type_unsigned_short));
11508         MS_BUILTIN(__indword,              make_function_1_type(type_unsigned_long, type_unsigned_short));
11509         MS_BUILTIN(__outbyte,              make_function_2_type(type_void, type_unsigned_short, type_unsigned_char));
11510         MS_BUILTIN(__outword,              make_function_2_type(type_void, type_unsigned_short, type_unsigned_short));
11511         MS_BUILTIN(__outdword,             make_function_2_type(type_void, type_unsigned_short, type_unsigned_long));
11512         MS_BUILTIN(__ud2,                  make_function_0_type_noreturn(type_void));
11513         MS_BUILTIN(_BitScanForward,        make_function_2_type(type_unsigned_char, type_unsigned_long_ptr, type_unsigned_long));
11514         MS_BUILTIN(_BitScanReverse,        make_function_2_type(type_unsigned_char, type_unsigned_long_ptr, type_unsigned_long));
11515         MS_BUILTIN(_InterlockedExchange,   make_function_2_type(type_long, type_long_ptr, type_long));
11516         MS_BUILTIN(_InterlockedExchange64, make_function_2_type(type_int64, type_int64_ptr, type_int64));
11517
11518         if (machine_size <= 32) {
11519                 MS_BUILTIN(__readeflags,           make_function_0_type(type_unsigned_int));
11520                 MS_BUILTIN(__writeeflags,          make_function_1_type(type_void, type_unsigned_int));
11521         } else {
11522                 MS_BUILTIN(__readeflags,           make_function_0_type(type_unsigned_int64));
11523                 MS_BUILTIN(__writeeflags,          make_function_1_type(type_void, type_unsigned_int64));
11524         }
11525
11526 #undef MS_BUILTIN
11527 }
11528
11529 /**
11530  * Initialize the parser.
11531  */
11532 void init_parser(void)
11533 {
11534         sym_anonymous = symbol_table_insert("<anonymous>");
11535
11536         if (c_mode & _MS) {
11537                 /* add predefined symbols for extended-decl-modifier */
11538                 sym_align         = symbol_table_insert("align");
11539                 sym_allocate      = symbol_table_insert("allocate");
11540                 sym_dllimport     = symbol_table_insert("dllimport");
11541                 sym_dllexport     = symbol_table_insert("dllexport");
11542                 sym_naked         = symbol_table_insert("naked");
11543                 sym_noinline      = symbol_table_insert("noinline");
11544                 sym_returns_twice = symbol_table_insert("returns_twice");
11545                 sym_noreturn      = symbol_table_insert("noreturn");
11546                 sym_nothrow       = symbol_table_insert("nothrow");
11547                 sym_novtable      = symbol_table_insert("novtable");
11548                 sym_property      = symbol_table_insert("property");
11549                 sym_get           = symbol_table_insert("get");
11550                 sym_put           = symbol_table_insert("put");
11551                 sym_selectany     = symbol_table_insert("selectany");
11552                 sym_thread        = symbol_table_insert("thread");
11553                 sym_uuid          = symbol_table_insert("uuid");
11554                 sym_deprecated    = symbol_table_insert("deprecated");
11555                 sym_restrict      = symbol_table_insert("restrict");
11556                 sym_noalias       = symbol_table_insert("noalias");
11557         }
11558         memset(token_anchor_set, 0, sizeof(token_anchor_set));
11559
11560         init_expression_parsers();
11561         obstack_init(&temp_obst);
11562
11563         symbol_t *const va_list_sym = symbol_table_insert("__builtin_va_list");
11564         type_valist = create_builtin_type(va_list_sym, type_void_ptr);
11565 }
11566
11567 /**
11568  * Terminate the parser.
11569  */
11570 void exit_parser(void)
11571 {
11572         obstack_free(&temp_obst, NULL);
11573 }