nsz Git - cparser/blob - parser.c

   1 /*
   2  * This file is part of cparser.
   3  * Copyright (C) 2007-2008 Matthias Braun <matze@braunis.de>
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; either version 2
   8  * of the License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  18  * 02111-1307, USA.
  19  */
  20 #include <config.h>
  21
  22 #include <assert.h>
  23 #include <stdarg.h>
  24 #include <stdbool.h>
  25
  26 #include "parser.h"
  27 #include "diagnostic.h"
  28 #include "format_check.h"
  29 #include "lexer.h"
  30 #include "symbol_t.h"
  31 #include "token_t.h"
  32 #include "types.h"
  33 #include "type_t.h"
  34 #include "type_hash.h"
  35 #include "ast_t.h"
  36 #include "entity_t.h"
  37 #include "lang_features.h"
  38 #include "walk_statements.h"
  39 #include "warning.h"
  40 #include "adt/bitfiddle.h"
  41 #include "adt/error.h"
  42 #include "adt/array.h"
  43
  44 //#define PRINT_TOKENS
  45 #define MAX_LOOKAHEAD 2
  46
  47 typedef struct {
  48         entity_t           *old_entity;
  49         symbol_t           *symbol;
  50         entity_namespace_t  namespc;
  51 } stack_entry_t;
  52
  53 typedef struct argument_list_t argument_list_t;
  54 struct argument_list_t {
  55         long              argument;
  56         argument_list_t  *next;
  57 };
  58
  59 typedef struct gnu_attribute_t gnu_attribute_t;
  60 struct gnu_attribute_t {
  61         gnu_attribute_kind_t kind;           /**< The kind of the GNU attribute. */
  62         gnu_attribute_t     *next;
  63         bool                 invalid;        /**< Set if this attribute had argument errors, */
  64         bool                 have_arguments; /**< True, if this attribute has arguments. */
  65         union {
  66                 size_t              value;
  67                 string_t            string;
  68                 atomic_type_kind_t  akind;
  69                 long                argument;  /**< Single argument. */
  70                 argument_list_t    *arguments; /**< List of argument expressions. */
  71         } u;
  72 };
  73
  74 typedef struct declaration_specifiers_t  declaration_specifiers_t;
  75 struct declaration_specifiers_t {
  76         source_position_t  source_position;
  77         storage_class_t    storage_class;
  78         unsigned char      alignment;         /**< Alignment, 0 if not set. */
  79         bool               is_inline : 1;
  80         bool               deprecated : 1;
  81         decl_modifiers_t   modifiers;         /**< declaration modifiers */
  82         gnu_attribute_t   *gnu_attributes;    /**< list of GNU attributes */
  83         const char        *deprecated_string; /**< can be set if declaration was marked deprecated. */
  84         symbol_t          *get_property_sym;  /**< the name of the get property if set. */
  85         symbol_t          *put_property_sym;  /**< the name of the put property if set. */
  86         type_t            *type;
  87         variable_t        *based_variable;    /**< Microsoft __based variable. */
  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 typedef entity_t* (*parsed_declaration_func) (entity_t *declaration, bool is_definition);
 102
 103 /** The current token. */
 104 static token_t              token;
 105 /** The lookahead ring-buffer. */
 106 static token_t              lookahead_buffer[MAX_LOOKAHEAD];
 107 /** Position of the next token in the lookahead buffer. */
 108 static int                  lookahead_bufpos;
 109 static stack_entry_t       *environment_stack = NULL;
 110 static stack_entry_t       *label_stack       = NULL;
 111 static scope_t             *file_scope        = NULL;
 112 static scope_t             *current_scope     = NULL;
 113 /** Point to the current function declaration if inside a function. */
 114 static function_t          *current_function  = NULL;
 115 static entity_t            *current_init_decl = NULL;
 116 static switch_statement_t  *current_switch    = NULL;
 117 static statement_t         *current_loop      = NULL;
 118 static statement_t         *current_parent    = NULL;
 119 static ms_try_statement_t  *current_try       = NULL;
 120 static linkage_kind_t       current_linkage   = LINKAGE_INVALID;
 121 static goto_statement_t    *goto_first        = NULL;
 122 static goto_statement_t   **goto_anchor       = NULL;
 123 static label_statement_t   *label_first       = NULL;
 124 static label_statement_t  **label_anchor      = NULL;
 125 /** current translation unit. */
 126 static translation_unit_t  *unit              = NULL;
 127 /** true if we are in a type property context (evaluation only for type. */
 128 static bool                 in_type_prop      = false;
 129 /** true in we are in a __extension__ context. */
 130 static bool                 in_gcc_extension  = false;
 131 static struct obstack       temp_obst;
 132 static entity_t            *anonymous_entity;
 133
 134
 135 #define PUSH_PARENT(stmt)                          \
 136         statement_t *const prev_parent = current_parent; \
 137         ((void)(current_parent = (stmt)))
 138 #define POP_PARENT ((void)(current_parent = prev_parent))
 139
 140 /** special symbol used for anonymous entities. */
 141 static const symbol_t *sym_anonymous = NULL;
 142
 143 /* symbols for Microsoft extended-decl-modifier */
 144 static const symbol_t *sym_align      = NULL;
 145 static const symbol_t *sym_allocate   = NULL;
 146 static const symbol_t *sym_dllimport  = NULL;
 147 static const symbol_t *sym_dllexport  = NULL;
 148 static const symbol_t *sym_naked      = NULL;
 149 static const symbol_t *sym_noinline   = NULL;
 150 static const symbol_t *sym_noreturn   = NULL;
 151 static const symbol_t *sym_nothrow    = NULL;
 152 static const symbol_t *sym_novtable   = NULL;
 153 static const symbol_t *sym_property   = NULL;
 154 static const symbol_t *sym_get        = NULL;
 155 static const symbol_t *sym_put        = NULL;
 156 static const symbol_t *sym_selectany  = NULL;
 157 static const symbol_t *sym_thread     = NULL;
 158 static const symbol_t *sym_uuid       = NULL;
 159 static const symbol_t *sym_deprecated = NULL;
 160 static const symbol_t *sym_restrict   = NULL;
 161 static const symbol_t *sym_noalias    = NULL;
 162
 163 /** The token anchor set */
 164 static unsigned char token_anchor_set[T_LAST_TOKEN];
 165
 166 /** The current source position. */
 167 #define HERE (&token.source_position)
 168
 169 /** true if we are in GCC mode. */
 170 #define GNU_MODE ((c_mode & _GNUC) || in_gcc_extension)
 171
 172 static type_t *type_valist;
 173
 174 static statement_t *parse_compound_statement(bool inside_expression_statement);
 175 static statement_t *parse_statement(void);
 176
 177 static expression_t *parse_sub_expression(precedence_t);
 178 static expression_t *parse_expression(void);
 179 static type_t       *parse_typename(void);
 180 static void          parse_externals(void);
 181 static void          parse_external(void);
 182
 183 static void parse_compound_type_entries(compound_t *compound_declaration);
 184 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
 185                                   bool may_be_abstract,
 186                                   bool create_compound_member);
 187 static entity_t *record_entity(entity_t *entity, bool is_definition);
 188
 189 static void semantic_comparison(binary_expression_t *expression);
 190
 191 #define STORAGE_CLASSES     \
 192         case T_typedef:         \
 193         case T_extern:          \
 194         case T_static:          \
 195         case T_auto:            \
 196         case T_register:        \
 197         case T___thread:
 198
 199 #define STORAGE_CLASSES_NO_EXTERN \
 200         case T_typedef:         \
 201         case T_static:          \
 202         case T_auto:            \
 203         case T_register:        \
 204         case T___thread:
 205
 206 #define TYPE_QUALIFIERS     \
 207         case T_const:           \
 208         case T_restrict:        \
 209         case T_volatile:        \
 210         case T_inline:          \
 211         case T__forceinline:    \
 212         case T___attribute__:
 213
 214 #define COMPLEX_SPECIFIERS  \
 215         case T__Complex:
 216 #define IMAGINARY_SPECIFIERS \
 217         case T__Imaginary:
 218
 219 #define TYPE_SPECIFIERS       \
 220         case T__Bool:             \
 221         case T___builtin_va_list: \
 222         case T___typeof__:        \
 223         case T__declspec:         \
 224         case T_bool:              \
 225         case T_char:              \
 226         case T_double:            \
 227         case T_enum:              \
 228         case T_float:             \
 229         case T_int:               \
 230         case T_long:              \
 231         case T_short:             \
 232         case T_signed:            \
 233         case T_struct:            \
 234         case T_union:             \
 235         case T_unsigned:          \
 236         case T_void:              \
 237         COMPLEX_SPECIFIERS        \
 238         IMAGINARY_SPECIFIERS
 239
 240 #define DECLARATION_START   \
 241         STORAGE_CLASSES         \
 242         TYPE_QUALIFIERS         \
 243         TYPE_SPECIFIERS
 244
 245 #define DECLARATION_START_NO_EXTERN \
 246         STORAGE_CLASSES_NO_EXTERN       \
 247         TYPE_QUALIFIERS                 \
 248         TYPE_SPECIFIERS
 249
 250 #define TYPENAME_START      \
 251         TYPE_QUALIFIERS         \
 252         TYPE_SPECIFIERS
 253
 254 #define EXPRESSION_START           \
 255         case '!':                        \
 256         case '&':                        \
 257         case '(':                        \
 258         case '*':                        \
 259         case '+':                        \
 260         case '-':                        \
 261         case '~':                        \
 262         case T_ANDAND:                   \
 263         case T_CHARACTER_CONSTANT:       \
 264         case T_FLOATINGPOINT:            \
 265         case T_INTEGER:                  \
 266         case T_MINUSMINUS:               \
 267         case T_PLUSPLUS:                 \
 268         case T_STRING_LITERAL:           \
 269         case T_WIDE_CHARACTER_CONSTANT:  \
 270         case T_WIDE_STRING_LITERAL:      \
 271         case T___FUNCDNAME__:            \
 272         case T___FUNCSIG__:              \
 273         case T___FUNCTION__:             \
 274         case T___PRETTY_FUNCTION__:      \
 275         case T___alignof__:              \
 276         case T___builtin_alloca:         \
 277         case T___builtin_classify_type:  \
 278         case T___builtin_constant_p:     \
 279         case T___builtin_expect:         \
 280         case T___builtin_huge_val:       \
 281         case T___builtin_inf:            \
 282         case T___builtin_inff:           \
 283         case T___builtin_infl:           \
 284         case T___builtin_isgreater:      \
 285         case T___builtin_isgreaterequal: \
 286         case T___builtin_isless:         \
 287         case T___builtin_islessequal:    \
 288         case T___builtin_islessgreater:  \
 289         case T___builtin_isunordered:    \
 290         case T___builtin_nan:            \
 291         case T___builtin_nanf:           \
 292         case T___builtin_nanl:           \
 293         case T___builtin_offsetof:       \
 294         case T___builtin_prefetch:       \
 295         case T___builtin_va_arg:         \
 296         case T___builtin_va_end:         \
 297         case T___builtin_va_start:       \
 298         case T___func__:                 \
 299         case T___noop:                   \
 300         case T__assume:                  \
 301         case T_delete:                   \
 302         case T_false:                    \
 303         case T_sizeof:                   \
 304         case T_throw:                    \
 305         case T_true:
 306
 307 /**
 308  * Allocate an AST node with given size and
 309  * initialize all fields with zero.
 310  */
 311 static void *allocate_ast_zero(size_t size)
 312 {
 313         void *res = allocate_ast(size);
 314         memset(res, 0, size);
 315         return res;
 316 }
 317
 318 static size_t get_entity_struct_size(entity_kind_t kind)
 319 {
 320         static const size_t sizes[] = {
 321                 [ENTITY_VARIABLE]        = sizeof(variable_t),
 322                 [ENTITY_COMPOUND_MEMBER] = sizeof(variable_t),
 323                 [ENTITY_FUNCTION]        = sizeof(function_t),
 324                 [ENTITY_TYPEDEF]         = sizeof(typedef_t),
 325                 [ENTITY_STRUCT]          = sizeof(compound_t),
 326                 [ENTITY_UNION]           = sizeof(compound_t),
 327                 [ENTITY_ENUM]            = sizeof(enum_t),
 328                 [ENTITY_ENUM_VALUE]      = sizeof(enum_value_t),
 329                 [ENTITY_LABEL]           = sizeof(label_t),
 330                 [ENTITY_LOCAL_LABEL]     = sizeof(label_t),
 331                 [ENTITY_NAMESPACE]       = sizeof(namespace_t)
 332         };
 333         assert(kind < sizeof(sizes) / sizeof(sizes[0]));
 334         assert(sizes[kind] != 0);
 335         return sizes[kind];
 336 }
 337
 338 static entity_t *allocate_entity_zero(entity_kind_t kind)
 339 {
 340         size_t    size   = get_entity_struct_size(kind);
 341         entity_t *entity = allocate_ast_zero(size);
 342         entity->kind     = kind;
 343         return entity;
 344 }
 345
 346 /**
 347  * Returns the size of a statement node.
 348  *
 349  * @param kind  the statement kind
 350  */
 351 static size_t get_statement_struct_size(statement_kind_t kind)
 352 {
 353         static const size_t sizes[] = {
 354                 [STATEMENT_INVALID]     = sizeof(invalid_statement_t),
 355                 [STATEMENT_EMPTY]       = sizeof(empty_statement_t),
 356                 [STATEMENT_COMPOUND]    = sizeof(compound_statement_t),
 357                 [STATEMENT_RETURN]      = sizeof(return_statement_t),
 358                 [STATEMENT_DECLARATION] = sizeof(declaration_statement_t),
 359                 [STATEMENT_LOCAL_LABEL] = sizeof(local_label_statement_t),
 360                 [STATEMENT_IF]          = sizeof(if_statement_t),
 361                 [STATEMENT_SWITCH]      = sizeof(switch_statement_t),
 362                 [STATEMENT_EXPRESSION]  = sizeof(expression_statement_t),
 363                 [STATEMENT_CONTINUE]    = sizeof(statement_base_t),
 364                 [STATEMENT_BREAK]       = sizeof(statement_base_t),
 365                 [STATEMENT_GOTO]        = sizeof(goto_statement_t),
 366                 [STATEMENT_LABEL]       = sizeof(label_statement_t),
 367                 [STATEMENT_CASE_LABEL]  = sizeof(case_label_statement_t),
 368                 [STATEMENT_WHILE]       = sizeof(while_statement_t),
 369                 [STATEMENT_DO_WHILE]    = sizeof(do_while_statement_t),
 370                 [STATEMENT_FOR]         = sizeof(for_statement_t),
 371                 [STATEMENT_ASM]         = sizeof(asm_statement_t),
 372                 [STATEMENT_MS_TRY]      = sizeof(ms_try_statement_t),
 373                 [STATEMENT_LEAVE]       = sizeof(leave_statement_t)
 374         };
 375         assert(kind < sizeof(sizes) / sizeof(sizes[0]));
 376         assert(sizes[kind] != 0);
 377         return sizes[kind];
 378 }
 379
 380 /**
 381  * Returns the size of an expression node.
 382  *
 383  * @param kind  the expression kind
 384  */
 385 static size_t get_expression_struct_size(expression_kind_t kind)
 386 {
 387         static const size_t sizes[] = {
 388                 [EXPR_INVALID]                 = sizeof(expression_base_t),
 389                 [EXPR_REFERENCE]               = sizeof(reference_expression_t),
 390                 [EXPR_REFERENCE_ENUM_VALUE]    = sizeof(reference_expression_t),
 391                 [EXPR_CONST]                   = sizeof(const_expression_t),
 392                 [EXPR_CHARACTER_CONSTANT]      = sizeof(const_expression_t),
 393                 [EXPR_WIDE_CHARACTER_CONSTANT] = sizeof(const_expression_t),
 394                 [EXPR_STRING_LITERAL]          = sizeof(string_literal_expression_t),
 395                 [EXPR_WIDE_STRING_LITERAL]     = sizeof(wide_string_literal_expression_t),
 396                 [EXPR_COMPOUND_LITERAL]        = sizeof(compound_literal_expression_t),
 397                 [EXPR_CALL]                    = sizeof(call_expression_t),
 398                 [EXPR_UNARY_FIRST]             = sizeof(unary_expression_t),
 399                 [EXPR_BINARY_FIRST]            = sizeof(binary_expression_t),
 400                 [EXPR_CONDITIONAL]             = sizeof(conditional_expression_t),
 401                 [EXPR_SELECT]                  = sizeof(select_expression_t),
 402                 [EXPR_ARRAY_ACCESS]            = sizeof(array_access_expression_t),
 403                 [EXPR_SIZEOF]                  = sizeof(typeprop_expression_t),
 404                 [EXPR_ALIGNOF]                 = sizeof(typeprop_expression_t),
 405                 [EXPR_CLASSIFY_TYPE]           = sizeof(classify_type_expression_t),
 406                 [EXPR_FUNCNAME]                = sizeof(funcname_expression_t),
 407                 [EXPR_BUILTIN_SYMBOL]          = sizeof(builtin_symbol_expression_t),
 408                 [EXPR_BUILTIN_CONSTANT_P]      = sizeof(builtin_constant_expression_t),
 409                 [EXPR_BUILTIN_PREFETCH]        = sizeof(builtin_prefetch_expression_t),
 410                 [EXPR_OFFSETOF]                = sizeof(offsetof_expression_t),
 411                 [EXPR_VA_START]                = sizeof(va_start_expression_t),
 412                 [EXPR_VA_ARG]                  = sizeof(va_arg_expression_t),
 413                 [EXPR_STATEMENT]               = sizeof(statement_expression_t),
 414                 [EXPR_LABEL_ADDRESS]           = sizeof(label_address_expression_t),
 415         };
 416         if (kind >= EXPR_UNARY_FIRST && kind <= EXPR_UNARY_LAST) {
 417                 return sizes[EXPR_UNARY_FIRST];
 418         }
 419         if (kind >= EXPR_BINARY_FIRST && kind <= EXPR_BINARY_LAST) {
 420                 return sizes[EXPR_BINARY_FIRST];
 421         }
 422         assert(kind < sizeof(sizes) / sizeof(sizes[0]));
 423         assert(sizes[kind] != 0);
 424         return sizes[kind];
 425 }
 426
 427 /**
 428  * Allocate a statement node of given kind and initialize all
 429  * fields with zero.
 430  */
 431 static statement_t *allocate_statement_zero(statement_kind_t kind)
 432 {
 433         size_t       size = get_statement_struct_size(kind);
 434         statement_t *res  = allocate_ast_zero(size);
 435
 436         res->base.kind            = kind;
 437         res->base.parent          = current_parent;
 438         res->base.source_position = token.source_position;
 439         return res;
 440 }
 441
 442 /**
 443  * Allocate an expression node of given kind and initialize all
 444  * fields with zero.
 445  */
 446 static expression_t *allocate_expression_zero(expression_kind_t kind)
 447 {
 448         size_t        size = get_expression_struct_size(kind);
 449         expression_t *res  = allocate_ast_zero(size);
 450
 451         res->base.kind            = kind;
 452         res->base.type            = type_error_type;
 453         res->base.source_position = token.source_position;
 454         return res;
 455 }
 456
 457 /**
 458  * Creates a new invalid expression.
 459  */
 460 static expression_t *create_invalid_expression(void)
 461 {
 462         return allocate_expression_zero(EXPR_INVALID);
 463 }
 464
 465 /**
 466  * Creates a new invalid statement.
 467  */
 468 static statement_t *create_invalid_statement(void)
 469 {
 470         return allocate_statement_zero(STATEMENT_INVALID);
 471 }
 472
 473 /**
 474  * Allocate a new empty statement.
 475  */
 476 static statement_t *create_empty_statement(void)
 477 {
 478         return allocate_statement_zero(STATEMENT_EMPTY);
 479 }
 480
 481 /**
 482  * Returns the size of a type node.
 483  *
 484  * @param kind  the type kind
 485  */
 486 static size_t get_type_struct_size(type_kind_t kind)
 487 {
 488         static const size_t sizes[] = {
 489                 [TYPE_ATOMIC]          = sizeof(atomic_type_t),
 490                 [TYPE_COMPLEX]         = sizeof(complex_type_t),
 491                 [TYPE_IMAGINARY]       = sizeof(imaginary_type_t),
 492                 [TYPE_BITFIELD]        = sizeof(bitfield_type_t),
 493                 [TYPE_COMPOUND_STRUCT] = sizeof(compound_type_t),
 494                 [TYPE_COMPOUND_UNION]  = sizeof(compound_type_t),
 495                 [TYPE_ENUM]            = sizeof(enum_type_t),
 496                 [TYPE_FUNCTION]        = sizeof(function_type_t),
 497                 [TYPE_POINTER]         = sizeof(pointer_type_t),
 498                 [TYPE_ARRAY]           = sizeof(array_type_t),
 499                 [TYPE_BUILTIN]         = sizeof(builtin_type_t),
 500                 [TYPE_TYPEDEF]         = sizeof(typedef_type_t),
 501                 [TYPE_TYPEOF]          = sizeof(typeof_type_t),
 502         };
 503         assert(sizeof(sizes) / sizeof(sizes[0]) == (int) TYPE_TYPEOF + 1);
 504         assert(kind <= TYPE_TYPEOF);
 505         assert(sizes[kind] != 0);
 506         return sizes[kind];
 507 }
 508
 509 /**
 510  * Allocate a type node of given kind and initialize all
 511  * fields with zero.
 512  *
 513  * @param kind             type kind to allocate
 514  */
 515 static type_t *allocate_type_zero(type_kind_t kind)
 516 {
 517         size_t  size = get_type_struct_size(kind);
 518         type_t *res  = obstack_alloc(type_obst, size);
 519         memset(res, 0, size);
 520         res->base.kind = kind;
 521
 522         return res;
 523 }
 524
 525 /**
 526  * Returns the size of an initializer node.
 527  *
 528  * @param kind  the initializer kind
 529  */
 530 static size_t get_initializer_size(initializer_kind_t kind)
 531 {
 532         static const size_t sizes[] = {
 533                 [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
 534                 [INITIALIZER_STRING]      = sizeof(initializer_string_t),
 535                 [INITIALIZER_WIDE_STRING] = sizeof(initializer_wide_string_t),
 536                 [INITIALIZER_LIST]        = sizeof(initializer_list_t),
 537                 [INITIALIZER_DESIGNATOR]  = sizeof(initializer_designator_t)
 538         };
 539         assert(kind < sizeof(sizes) / sizeof(*sizes));
 540         assert(sizes[kind] != 0);
 541         return sizes[kind];
 542 }
 543
 544 /**
 545  * Allocate an initializer node of given kind and initialize all
 546  * fields with zero.
 547  */
 548 static initializer_t *allocate_initializer_zero(initializer_kind_t kind)
 549 {
 550         initializer_t *result = allocate_ast_zero(get_initializer_size(kind));
 551         result->kind          = kind;
 552
 553         return result;
 554 }
 555
 556 /**
 557  * Free a type from the type obstack.
 558  */
 559 static void free_type(void *type)
 560 {
 561         obstack_free(type_obst, type);
 562 }
 563
 564 /**
 565  * Returns the index of the top element of the environment stack.
 566  */
 567 static size_t environment_top(void)
 568 {
 569         return ARR_LEN(environment_stack);
 570 }
 571
 572 /**
 573  * Returns the index of the top element of the global label stack.
 574  */
 575 static size_t label_top(void)
 576 {
 577         return ARR_LEN(label_stack);
 578 }
 579
 580 /**
 581  * Return the next token.
 582  */
 583 static inline void next_token(void)
 584 {
 585         token                              = lookahead_buffer[lookahead_bufpos];
 586         lookahead_buffer[lookahead_bufpos] = lexer_token;
 587         lexer_next_token();
 588
 589         lookahead_bufpos = (lookahead_bufpos+1) % MAX_LOOKAHEAD;
 590
 591 #ifdef PRINT_TOKENS
 592         print_token(stderr, &token);
 593         fprintf(stderr, "\n");
 594 #endif
 595 }
 596
 597 /**
 598  * Return the next token with a given lookahead.
 599  */
 600 static inline const token_t *look_ahead(int num)
 601 {
 602         assert(num > 0 && num <= MAX_LOOKAHEAD);
 603         int pos = (lookahead_bufpos+num-1) % MAX_LOOKAHEAD;
 604         return &lookahead_buffer[pos];
 605 }
 606
 607 /**
 608  * Adds a token to the token anchor set (a multi-set).
 609  */
 610 static void add_anchor_token(int token_type)
 611 {
 612         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 613         ++token_anchor_set[token_type];
 614 }
 615
 616 static int save_and_reset_anchor_state(int token_type)
 617 {
 618         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 619         int count = token_anchor_set[token_type];
 620         token_anchor_set[token_type] = 0;
 621         return count;
 622 }
 623
 624 static void restore_anchor_state(int token_type, int count)
 625 {
 626         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 627         token_anchor_set[token_type] = count;
 628 }
 629
 630 /**
 631  * Remove a token from the token anchor set (a multi-set).
 632  */
 633 static void rem_anchor_token(int token_type)
 634 {
 635         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 636         assert(token_anchor_set[token_type] != 0);
 637         --token_anchor_set[token_type];
 638 }
 639
 640 static bool at_anchor(void)
 641 {
 642         if (token.type < 0)
 643                 return false;
 644         return token_anchor_set[token.type];
 645 }
 646
 647 /**
 648  * Eat tokens until a matching token is found.
 649  */
 650 static void eat_until_matching_token(int type)
 651 {
 652         int end_token;
 653         switch (type) {
 654                 case '(': end_token = ')';  break;
 655                 case '{': end_token = '}';  break;
 656                 case '[': end_token = ']';  break;
 657                 default:  end_token = type; break;
 658         }
 659
 660         unsigned parenthesis_count = 0;
 661         unsigned brace_count       = 0;
 662         unsigned bracket_count     = 0;
 663         while (token.type        != end_token ||
 664                parenthesis_count != 0         ||
 665                brace_count       != 0         ||
 666                bracket_count     != 0) {
 667                 switch (token.type) {
 668                 case T_EOF: return;
 669                 case '(': ++parenthesis_count; break;
 670                 case '{': ++brace_count;       break;
 671                 case '[': ++bracket_count;     break;
 672
 673                 case ')':
 674                         if (parenthesis_count > 0)
 675                                 --parenthesis_count;
 676                         goto check_stop;
 677
 678                 case '}':
 679                         if (brace_count > 0)
 680                                 --brace_count;
 681                         goto check_stop;
 682
 683                 case ']':
 684                         if (bracket_count > 0)
 685                                 --bracket_count;
 686 check_stop:
 687                         if (token.type        == end_token &&
 688                             parenthesis_count == 0         &&
 689                             brace_count       == 0         &&
 690                             bracket_count     == 0)
 691                                 return;
 692                         break;
 693
 694                 default:
 695                         break;
 696                 }
 697                 next_token();
 698         }
 699 }
 700
 701 /**
 702  * Eat input tokens until an anchor is found.
 703  */
 704 static void eat_until_anchor(void)
 705 {
 706         while (token_anchor_set[token.type] == 0) {
 707                 if (token.type == '(' || token.type == '{' || token.type == '[')
 708                         eat_until_matching_token(token.type);
 709                 next_token();
 710         }
 711 }
 712
 713 static void eat_block(void)
 714 {
 715         eat_until_matching_token('{');
 716         if (token.type == '}')
 717                 next_token();
 718 }
 719
 720 #define eat(token_type)  do { assert(token.type == (token_type)); next_token(); } while (0)
 721
 722 /**
 723  * Report a parse error because an expected token was not found.
 724  */
 725 static
 726 #if defined __GNUC__ && __GNUC__ >= 4
 727 __attribute__((sentinel))
 728 #endif
 729 void parse_error_expected(const char *message, ...)
 730 {
 731         if (message != NULL) {
 732                 errorf(HERE, "%s", message);
 733         }
 734         va_list ap;
 735         va_start(ap, message);
 736         errorf(HERE, "got %K, expected %#k", &token, &ap, ", ");
 737         va_end(ap);
 738 }
 739
 740 /**
 741  * Report a type error.
 742  */
 743 static void type_error(const char *msg, const source_position_t *source_position,
 744                        type_t *type)
 745 {
 746         errorf(source_position, "%s, but found type '%T'", msg, type);
 747 }
 748
 749 /**
 750  * Report an incompatible type.
 751  */
 752 static void type_error_incompatible(const char *msg,
 753                 const source_position_t *source_position, type_t *type1, type_t *type2)
 754 {
 755         errorf(source_position, "%s, incompatible types: '%T' - '%T'",
 756                msg, type1, type2);
 757 }
 758
 759 /**
 760  * Expect the the current token is the expected token.
 761  * If not, generate an error, eat the current statement,
 762  * and goto the end_error label.
 763  */
 764 #define expect(expected)                                  \
 765         do {                                                  \
 766                 if (UNLIKELY(token.type != (expected))) {         \
 767                         parse_error_expected(NULL, (expected), NULL); \
 768                         add_anchor_token(expected);                   \
 769                         eat_until_anchor();                           \
 770                         if (token.type == expected)                   \
 771                                 next_token();                             \
 772                         rem_anchor_token(expected);                   \
 773                         goto end_error;                               \
 774                 }                                                 \
 775                 next_token();                                     \
 776         } while (0)
 777
 778 static void scope_push(scope_t *new_scope)
 779 {
 780         if (current_scope != NULL) {
 781                 new_scope->depth = current_scope->depth + 1;
 782         }
 783         new_scope->parent = current_scope;
 784         current_scope     = new_scope;
 785 }
 786
 787 static void scope_pop(void)
 788 {
 789         current_scope = current_scope->parent;
 790 }
 791
 792 /**
 793  * Search an entity by its symbol in a given namespace.
 794  */
 795 static entity_t *get_entity(const symbol_t *const symbol,
 796                             namespace_tag_t namespc)
 797 {
 798         entity_t *entity = symbol->entity;
 799         for (; entity != NULL; entity = entity->base.symbol_next) {
 800                 if (entity->base.namespc == namespc)
 801                         return entity;
 802         }
 803
 804         return NULL;
 805 }
 806
 807 /**
 808  * pushs an entity on the environment stack and links the corresponding symbol
 809  * it.
 810  */
 811 static void stack_push(stack_entry_t **stack_ptr, entity_t *entity)
 812 {
 813         symbol_t           *symbol  = entity->base.symbol;
 814         entity_namespace_t  namespc = entity->base.namespc;
 815         assert(namespc != NAMESPACE_INVALID);
 816
 817         /* replace/add entity into entity list of the symbol */
 818         entity_t **anchor;
 819         entity_t  *iter;
 820         for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 821                 iter = *anchor;
 822                 if (iter == NULL)
 823                         break;
 824
 825                 /* replace an entry? */
 826                 if (iter->base.namespc == namespc) {
 827                         entity->base.symbol_next = iter->base.symbol_next;
 828                         break;
 829                 }
 830         }
 831         *anchor = entity;
 832
 833         /* remember old declaration */
 834         stack_entry_t entry;
 835         entry.symbol     = symbol;
 836         entry.old_entity = iter;
 837         entry.namespc    = namespc;
 838         ARR_APP1(stack_entry_t, *stack_ptr, entry);
 839 }
 840
 841 /**
 842  * Push an entity on the environment stack.
 843  */
 844 static void environment_push(entity_t *entity)
 845 {
 846         assert(entity->base.source_position.input_name != NULL);
 847         assert(entity->base.parent_scope != NULL);
 848         stack_push(&environment_stack, entity);
 849 }
 850
 851 /**
 852  * Push a declaration on the global label stack.
 853  *
 854  * @param declaration  the declaration
 855  */
 856 static void label_push(entity_t *label)
 857 {
 858         /* we abuse the parameters scope as parent for the labels */
 859         label->base.parent_scope = &current_function->parameters;
 860         stack_push(&label_stack, label);
 861 }
 862
 863 /**
 864  * pops symbols from the environment stack until @p new_top is the top element
 865  */
 866 static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
 867 {
 868         stack_entry_t *stack = *stack_ptr;
 869         size_t         top   = ARR_LEN(stack);
 870         size_t         i;
 871
 872         assert(new_top <= top);
 873         if (new_top == top)
 874                 return;
 875
 876         for (i = top; i > new_top; --i) {
 877                 stack_entry_t *entry = &stack[i - 1];
 878
 879                 entity_t           *old_entity = entry->old_entity;
 880                 symbol_t           *symbol     = entry->symbol;
 881                 entity_namespace_t  namespc    = entry->namespc;
 882
 883                 /* replace with old_entity/remove */
 884                 entity_t **anchor;
 885                 entity_t  *iter;
 886                 for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 887                         iter = *anchor;
 888                         assert(iter != NULL);
 889                         /* replace an entry? */
 890                         if (iter->base.namespc == namespc)
 891                                 break;
 892                 }
 893
 894                 /* restore definition from outer scopes (if there was one) */
 895                 if (old_entity != NULL) {
 896                         old_entity->base.symbol_next = iter->base.symbol_next;
 897                         *anchor                      = old_entity;
 898                 } else {
 899                         /* remove entry from list */
 900                         *anchor = iter->base.symbol_next;
 901                 }
 902         }
 903
 904         ARR_SHRINKLEN(*stack_ptr, (int) new_top);
 905 }
 906
 907 /**
 908  * Pop all entries from the environment stack until the new_top
 909  * is reached.
 910  *
 911  * @param new_top  the new stack top
 912  */
 913 static void environment_pop_to(size_t new_top)
 914 {
 915         stack_pop_to(&environment_stack, new_top);
 916 }
 917
 918 /**
 919  * Pop all entries from the global label stack until the new_top
 920  * is reached.
 921  *
 922  * @param new_top  the new stack top
 923  */
 924 static void label_pop_to(size_t new_top)
 925 {
 926         stack_pop_to(&label_stack, new_top);
 927 }
 928
 929 static int get_akind_rank(atomic_type_kind_t akind)
 930 {
 931         return (int) akind;
 932 }
 933
 934 static int get_rank(const type_t *type)
 935 {
 936         assert(!is_typeref(type));
 937         /* The C-standard allows promoting enums to int or unsigned int (see § 7.2.2
 938          * and esp. footnote 108). However we can't fold constants (yet), so we
 939          * can't decide whether unsigned int is possible, while int always works.
 940          * (unsigned int would be preferable when possible... for stuff like
 941          *  struct { enum { ... } bla : 4; } ) */
 942         if (type->kind == TYPE_ENUM)
 943                 return get_akind_rank(ATOMIC_TYPE_INT);
 944
 945         assert(type->kind == TYPE_ATOMIC);
 946         return get_akind_rank(type->atomic.akind);
 947 }
 948
 949 static type_t *promote_integer(type_t *type)
 950 {
 951         if (type->kind == TYPE_BITFIELD)
 952                 type = type->bitfield.base_type;
 953
 954         if (get_rank(type) < get_akind_rank(ATOMIC_TYPE_INT))
 955                 type = type_int;
 956
 957         return type;
 958 }
 959
 960 /**
 961  * Create a cast expression.
 962  *
 963  * @param expression  the expression to cast
 964  * @param dest_type   the destination type
 965  */
 966 static expression_t *create_cast_expression(expression_t *expression,
 967                                             type_t *dest_type)
 968 {
 969         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST_IMPLICIT);
 970
 971         cast->unary.value = expression;
 972         cast->base.type   = dest_type;
 973
 974         return cast;
 975 }
 976
 977 /**
 978  * Check if a given expression represents the 0 pointer constant.
 979  */
 980 static bool is_null_pointer_constant(const expression_t *expression)
 981 {
 982         /* skip void* cast */
 983         if (expression->kind == EXPR_UNARY_CAST
 984                         || expression->kind == EXPR_UNARY_CAST_IMPLICIT) {
 985                 expression = expression->unary.value;
 986         }
 987
 988         /* TODO: not correct yet, should be any constant integer expression
 989          * which evaluates to 0 */
 990         if (expression->kind != EXPR_CONST)
 991                 return false;
 992
 993         type_t *const type = skip_typeref(expression->base.type);
 994         if (!is_type_integer(type))
 995                 return false;
 996
 997         return expression->conste.v.int_value == 0;
 998 }
 999
1000 /**
1001  * Create an implicit cast expression.
1002  *
1003  * @param expression  the expression to cast
1004  * @param dest_type   the destination type
1005  */
1006 static expression_t *create_implicit_cast(expression_t *expression,
1007                                           type_t *dest_type)
1008 {
1009         type_t *const source_type = expression->base.type;
1010
1011         if (source_type == dest_type)
1012                 return expression;
1013
1014         return create_cast_expression(expression, dest_type);
1015 }
1016
1017 typedef enum assign_error_t {
1018         ASSIGN_SUCCESS,
1019         ASSIGN_ERROR_INCOMPATIBLE,
1020         ASSIGN_ERROR_POINTER_QUALIFIER_MISSING,
1021         ASSIGN_WARNING_POINTER_INCOMPATIBLE,
1022         ASSIGN_WARNING_POINTER_FROM_INT,
1023         ASSIGN_WARNING_INT_FROM_POINTER
1024 } assign_error_t;
1025
1026 static void report_assign_error(assign_error_t error, type_t *orig_type_left,
1027                                 const expression_t *const right,
1028                                 const char *context,
1029                                 const source_position_t *source_position)
1030 {
1031         type_t *const orig_type_right = right->base.type;
1032         type_t *const type_left       = skip_typeref(orig_type_left);
1033         type_t *const type_right      = skip_typeref(orig_type_right);
1034
1035         switch (error) {
1036         case ASSIGN_SUCCESS:
1037                 return;
1038         case ASSIGN_ERROR_INCOMPATIBLE:
1039                 errorf(source_position,
1040                        "destination type '%T' in %s is incompatible with type '%T'",
1041                        orig_type_left, context, orig_type_right);
1042                 return;
1043
1044         case ASSIGN_ERROR_POINTER_QUALIFIER_MISSING: {
1045                 if (warning.other) {
1046                         type_t *points_to_left  = skip_typeref(type_left->pointer.points_to);
1047                         type_t *points_to_right = skip_typeref(type_right->pointer.points_to);
1048
1049                         /* the left type has all qualifiers from the right type */
1050                         unsigned missing_qualifiers
1051                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
1052                         warningf(source_position,
1053                                         "destination type '%T' in %s from type '%T' lacks qualifiers '%Q' in pointer target type",
1054                                         orig_type_left, context, orig_type_right, missing_qualifiers);
1055                 }
1056                 return;
1057         }
1058
1059         case ASSIGN_WARNING_POINTER_INCOMPATIBLE:
1060                 if (warning.other) {
1061                         warningf(source_position,
1062                                         "destination type '%T' in %s is incompatible with '%E' of type '%T'",
1063                                         orig_type_left, context, right, orig_type_right);
1064                 }
1065                 return;
1066
1067         case ASSIGN_WARNING_POINTER_FROM_INT:
1068                 if (warning.other) {
1069                         warningf(source_position,
1070                                         "%s makes pointer '%T' from integer '%T' without a cast",
1071                                         context, orig_type_left, orig_type_right);
1072                 }
1073                 return;
1074
1075         case ASSIGN_WARNING_INT_FROM_POINTER:
1076                 if (warning.other) {
1077                         warningf(source_position,
1078                                         "%s makes integer '%T' from pointer '%T' without a cast",
1079                                         context, orig_type_left, orig_type_right);
1080                 }
1081                 return;
1082
1083         default:
1084                 panic("invalid error value");
1085         }
1086 }
1087
1088 /** Implements the rules from § 6.5.16.1 */
1089 static assign_error_t semantic_assign(type_t *orig_type_left,
1090                                       const expression_t *const right)
1091 {
1092         type_t *const orig_type_right = right->base.type;
1093         type_t *const type_left       = skip_typeref(orig_type_left);
1094         type_t *const type_right      = skip_typeref(orig_type_right);
1095
1096         if (is_type_pointer(type_left)) {
1097                 if (is_null_pointer_constant(right)) {
1098                         return ASSIGN_SUCCESS;
1099                 } else if (is_type_pointer(type_right)) {
1100                         type_t *points_to_left
1101                                 = skip_typeref(type_left->pointer.points_to);
1102                         type_t *points_to_right
1103                                 = skip_typeref(type_right->pointer.points_to);
1104                         assign_error_t res = ASSIGN_SUCCESS;
1105
1106                         /* the left type has all qualifiers from the right type */
1107                         unsigned missing_qualifiers
1108                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
1109                         if (missing_qualifiers != 0) {
1110                                 res = ASSIGN_ERROR_POINTER_QUALIFIER_MISSING;
1111                         }
1112
1113                         points_to_left  = get_unqualified_type(points_to_left);
1114                         points_to_right = get_unqualified_type(points_to_right);
1115
1116                         if (is_type_atomic(points_to_left, ATOMIC_TYPE_VOID))
1117                                 return res;
1118
1119                         if (is_type_atomic(points_to_right, ATOMIC_TYPE_VOID)) {
1120                                 /* ISO/IEC 14882:1998(E) §C.1.2:6 */
1121                                 return c_mode & _CXX ? ASSIGN_ERROR_INCOMPATIBLE : res;
1122                         }
1123
1124                         if (!types_compatible(points_to_left, points_to_right)) {
1125                                 return ASSIGN_WARNING_POINTER_INCOMPATIBLE;
1126                         }
1127
1128                         return res;
1129                 } else if (is_type_integer(type_right)) {
1130                         return ASSIGN_WARNING_POINTER_FROM_INT;
1131                 }
1132         } else if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
1133             (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
1134                 && is_type_pointer(type_right))) {
1135                 return ASSIGN_SUCCESS;
1136         } else if ((is_type_compound(type_left)  && is_type_compound(type_right))
1137                         || (is_type_builtin(type_left) && is_type_builtin(type_right))) {
1138                 type_t *const unqual_type_left  = get_unqualified_type(type_left);
1139                 type_t *const unqual_type_right = get_unqualified_type(type_right);
1140                 if (types_compatible(unqual_type_left, unqual_type_right)) {
1141                         return ASSIGN_SUCCESS;
1142                 }
1143         } else if (is_type_integer(type_left) && is_type_pointer(type_right)) {
1144                 return ASSIGN_WARNING_INT_FROM_POINTER;
1145         }
1146
1147         if (!is_type_valid(type_left) || !is_type_valid(type_right))
1148                 return ASSIGN_SUCCESS;
1149
1150         return ASSIGN_ERROR_INCOMPATIBLE;
1151 }
1152
1153 static expression_t *parse_constant_expression(void)
1154 {
1155         expression_t *result = parse_sub_expression(PREC_CONDITIONAL);
1156
1157         if (!is_constant_expression(result)) {
1158                 errorf(&result->base.source_position,
1159                        "expression '%E' is not constant\n", result);
1160         }
1161
1162         return result;
1163 }
1164
1165 static expression_t *parse_assignment_expression(void)
1166 {
1167         return parse_sub_expression(PREC_ASSIGNMENT);
1168 }
1169
1170 static string_t parse_string_literals(void)
1171 {
1172         assert(token.type == T_STRING_LITERAL);
1173         string_t result = token.v.string;
1174
1175         next_token();
1176
1177         while (token.type == T_STRING_LITERAL) {
1178                 result = concat_strings(&result, &token.v.string);
1179                 next_token();
1180         }
1181
1182         return result;
1183 }
1184
1185 static const char *const gnu_attribute_names[GNU_AK_LAST] = {
1186         [GNU_AK_CONST]                  = "const",
1187         [GNU_AK_VOLATILE]               = "volatile",
1188         [GNU_AK_CDECL]                  = "cdecl",
1189         [GNU_AK_STDCALL]                = "stdcall",
1190         [GNU_AK_FASTCALL]               = "fastcall",
1191         [GNU_AK_DEPRECATED]             = "deprecated",
1192         [GNU_AK_NOINLINE]               = "noinline",
1193         [GNU_AK_NORETURN]               = "noreturn",
1194         [GNU_AK_NAKED]                  = "naked",
1195         [GNU_AK_PURE]                   = "pure",
1196         [GNU_AK_ALWAYS_INLINE]          = "always_inline",
1197         [GNU_AK_MALLOC]                 = "malloc",
1198         [GNU_AK_WEAK]                   = "weak",
1199         [GNU_AK_CONSTRUCTOR]            = "constructor",
1200         [GNU_AK_DESTRUCTOR]             = "destructor",
1201         [GNU_AK_NOTHROW]                = "nothrow",
1202         [GNU_AK_TRANSPARENT_UNION]      = "transparent_union",
1203         [GNU_AK_COMMON]                 = "common",
1204         [GNU_AK_NOCOMMON]               = "nocommon",
1205         [GNU_AK_PACKED]                 = "packed",
1206         [GNU_AK_SHARED]                 = "shared",
1207         [GNU_AK_NOTSHARED]              = "notshared",
1208         [GNU_AK_USED]                   = "used",
1209         [GNU_AK_UNUSED]                 = "unused",
1210         [GNU_AK_NO_INSTRUMENT_FUNCTION] = "no_instrument_function",
1211         [GNU_AK_WARN_UNUSED_RESULT]     = "warn_unused_result",
1212         [GNU_AK_LONGCALL]               = "longcall",
1213         [GNU_AK_SHORTCALL]              = "shortcall",
1214         [GNU_AK_LONG_CALL]              = "long_call",
1215         [GNU_AK_SHORT_CALL]             = "short_call",
1216         [GNU_AK_FUNCTION_VECTOR]        = "function_vector",
1217         [GNU_AK_INTERRUPT]              = "interrupt",
1218         [GNU_AK_INTERRUPT_HANDLER]      = "interrupt_handler",
1219         [GNU_AK_NMI_HANDLER]            = "nmi_handler",
1220         [GNU_AK_NESTING]                = "nesting",
1221         [GNU_AK_NEAR]                   = "near",
1222         [GNU_AK_FAR]                    = "far",
1223         [GNU_AK_SIGNAL]                 = "signal",
1224         [GNU_AK_EIGTHBIT_DATA]          = "eightbit_data",
1225         [GNU_AK_TINY_DATA]              = "tiny_data",
1226         [GNU_AK_SAVEALL]                = "saveall",
1227         [GNU_AK_FLATTEN]                = "flatten",
1228         [GNU_AK_SSEREGPARM]             = "sseregparm",
1229         [GNU_AK_EXTERNALLY_VISIBLE]     = "externally_visible",
1230         [GNU_AK_RETURN_TWICE]           = "return_twice",
1231         [GNU_AK_MAY_ALIAS]              = "may_alias",
1232         [GNU_AK_MS_STRUCT]              = "ms_struct",
1233         [GNU_AK_GCC_STRUCT]             = "gcc_struct",
1234         [GNU_AK_DLLIMPORT]              = "dllimport",
1235         [GNU_AK_DLLEXPORT]              = "dllexport",
1236         [GNU_AK_ALIGNED]                = "aligned",
1237         [GNU_AK_ALIAS]                  = "alias",
1238         [GNU_AK_SECTION]                = "section",
1239         [GNU_AK_FORMAT]                 = "format",
1240         [GNU_AK_FORMAT_ARG]             = "format_arg",
1241         [GNU_AK_WEAKREF]                = "weakref",
1242         [GNU_AK_NONNULL]                = "nonnull",
1243         [GNU_AK_TLS_MODEL]              = "tls_model",
1244         [GNU_AK_VISIBILITY]             = "visibility",
1245         [GNU_AK_REGPARM]                = "regparm",
1246         [GNU_AK_MODE]                   = "mode",
1247         [GNU_AK_MODEL]                  = "model",
1248         [GNU_AK_TRAP_EXIT]              = "trap_exit",
1249         [GNU_AK_SP_SWITCH]              = "sp_switch",
1250         [GNU_AK_SENTINEL]               = "sentinel"
1251 };
1252
1253 /**
1254  * compare two string, ignoring double underscores on the second.
1255  */
1256 static int strcmp_underscore(const char *s1, const char *s2)
1257 {
1258         if (s2[0] == '_' && s2[1] == '_') {
1259                 size_t len2 = strlen(s2);
1260                 size_t len1 = strlen(s1);
1261                 if (len1 == len2-4 && s2[len2-2] == '_' && s2[len2-1] == '_') {
1262                         return strncmp(s1, s2+2, len2-4);
1263                 }
1264         }
1265
1266         return strcmp(s1, s2);
1267 }
1268
1269 /**
1270  * Allocate a new gnu temporal attribute.
1271  */
1272 static gnu_attribute_t *allocate_gnu_attribute(gnu_attribute_kind_t kind)
1273 {
1274         gnu_attribute_t *attribute = obstack_alloc(&temp_obst, sizeof(*attribute));
1275         attribute->kind            = kind;
1276         attribute->next            = NULL;
1277         attribute->invalid         = false;
1278         attribute->have_arguments  = false;
1279
1280         return attribute;
1281 }
1282
1283 /**
1284  * parse one constant expression argument.
1285  */
1286 static void parse_gnu_attribute_const_arg(gnu_attribute_t *attribute)
1287 {
1288         expression_t *expression;
1289         add_anchor_token(')');
1290         expression = parse_constant_expression();
1291         rem_anchor_token(')');
1292         expect(')');
1293         attribute->u.argument = fold_constant(expression);
1294         return;
1295 end_error:
1296         attribute->invalid = true;
1297 }
1298
1299 /**
1300  * parse a list of constant expressions arguments.
1301  */
1302 static void parse_gnu_attribute_const_arg_list(gnu_attribute_t *attribute)
1303 {
1304         argument_list_t **list = &attribute->u.arguments;
1305         argument_list_t  *entry;
1306         expression_t     *expression;
1307         add_anchor_token(')');
1308         add_anchor_token(',');
1309         while (true) {
1310                 expression = parse_constant_expression();
1311                 entry = obstack_alloc(&temp_obst, sizeof(entry));
1312                 entry->argument = fold_constant(expression);
1313                 entry->next     = NULL;
1314                 *list = entry;
1315                 list = &entry->next;
1316                 if (token.type != ',')
1317                         break;
1318                 next_token();
1319         }
1320         rem_anchor_token(',');
1321         rem_anchor_token(')');
1322         expect(')');
1323         return;
1324 end_error:
1325         attribute->invalid = true;
1326 }
1327
1328 /**
1329  * parse one string literal argument.
1330  */
1331 static void parse_gnu_attribute_string_arg(gnu_attribute_t *attribute,
1332                                            string_t *string)
1333 {
1334         add_anchor_token('(');
1335         if (token.type != T_STRING_LITERAL) {
1336                 parse_error_expected("while parsing attribute directive",
1337                                      T_STRING_LITERAL, NULL);
1338                 goto end_error;
1339         }
1340         *string = parse_string_literals();
1341         rem_anchor_token('(');
1342         expect(')');
1343         return;
1344 end_error:
1345         attribute->invalid = true;
1346 }
1347
1348 /**
1349  * parse one tls model.
1350  */
1351 static void parse_gnu_attribute_tls_model_arg(gnu_attribute_t *attribute)
1352 {
1353         static const char *const tls_models[] = {
1354                 "global-dynamic",
1355                 "local-dynamic",
1356                 "initial-exec",
1357                 "local-exec"
1358         };
1359         string_t string = { NULL, 0 };
1360         parse_gnu_attribute_string_arg(attribute, &string);
1361         if (string.begin != NULL) {
1362                 for (size_t i = 0; i < 4; ++i) {
1363                         if (strcmp(tls_models[i], string.begin) == 0) {
1364                                 attribute->u.value = i;
1365                                 return;
1366                         }
1367                 }
1368                 errorf(HERE, "'%s' is an unrecognized tls model", string.begin);
1369         }
1370         attribute->invalid = true;
1371 }
1372
1373 /**
1374  * parse one tls model.
1375  */
1376 static void parse_gnu_attribute_visibility_arg(gnu_attribute_t *attribute)
1377 {
1378         static const char *const visibilities[] = {
1379                 "default",
1380                 "protected",
1381                 "hidden",
1382                 "internal"
1383         };
1384         string_t string = { NULL, 0 };
1385         parse_gnu_attribute_string_arg(attribute, &string);
1386         if (string.begin != NULL) {
1387                 for (size_t i = 0; i < 4; ++i) {
1388                         if (strcmp(visibilities[i], string.begin) == 0) {
1389                                 attribute->u.value = i;
1390                                 return;
1391                         }
1392                 }
1393                 errorf(HERE, "'%s' is an unrecognized visibility", string.begin);
1394         }
1395         attribute->invalid = true;
1396 }
1397
1398 /**
1399  * parse one (code) model.
1400  */
1401 static void parse_gnu_attribute_model_arg(gnu_attribute_t *attribute)
1402 {
1403         static const char *const visibilities[] = {
1404                 "small",
1405                 "medium",
1406                 "large"
1407         };
1408         string_t string = { NULL, 0 };
1409         parse_gnu_attribute_string_arg(attribute, &string);
1410         if (string.begin != NULL) {
1411                 for (int i = 0; i < 3; ++i) {
1412                         if (strcmp(visibilities[i], string.begin) == 0) {
1413                                 attribute->u.value = i;
1414                                 return;
1415                         }
1416                 }
1417                 errorf(HERE, "'%s' is an unrecognized model", string.begin);
1418         }
1419         attribute->invalid = true;
1420 }
1421
1422 static void parse_gnu_attribute_mode_arg(gnu_attribute_t *attribute)
1423 {
1424         /* TODO: find out what is allowed here... */
1425
1426         /* at least: byte, word, pointer, list of machine modes
1427          * __XXX___ is interpreted as XXX */
1428         add_anchor_token(')');
1429
1430         if (token.type != T_IDENTIFIER) {
1431                 expect(T_IDENTIFIER);
1432         }
1433
1434         /* This isn't really correct, the backend should provide a list of machine
1435          * specific modes (according to gcc philosophy that is...) */
1436         const char *symbol_str = token.v.symbol->string;
1437         if (strcmp_underscore("QI",   symbol_str) == 0 ||
1438             strcmp_underscore("byte", symbol_str) == 0) {
1439                 attribute->u.akind = ATOMIC_TYPE_CHAR;
1440         } else if (strcmp_underscore("HI", symbol_str) == 0) {
1441                 attribute->u.akind = ATOMIC_TYPE_SHORT;
1442         } else if (strcmp_underscore("SI",      symbol_str) == 0
1443                 || strcmp_underscore("word",    symbol_str) == 0
1444                 || strcmp_underscore("pointer", symbol_str) == 0) {
1445                 attribute->u.akind = ATOMIC_TYPE_INT;
1446         } else if (strcmp_underscore("DI", symbol_str) == 0) {
1447                 attribute->u.akind = ATOMIC_TYPE_LONGLONG;
1448         } else {
1449                 if (warning.other)
1450                         warningf(HERE, "ignoring unknown mode '%s'", symbol_str);
1451                 attribute->invalid = true;
1452         }
1453         next_token();
1454
1455         rem_anchor_token(')');
1456         expect(')');
1457         return;
1458 end_error:
1459         attribute->invalid = true;
1460 }
1461
1462 /**
1463  * parse one interrupt argument.
1464  */
1465 static void parse_gnu_attribute_interrupt_arg(gnu_attribute_t *attribute)
1466 {
1467         static const char *const interrupts[] = {
1468                 "IRQ",
1469                 "FIQ",
1470                 "SWI",
1471                 "ABORT",
1472                 "UNDEF"
1473         };
1474         string_t string = { NULL, 0 };
1475         parse_gnu_attribute_string_arg(attribute, &string);
1476         if (string.begin != NULL) {
1477                 for (size_t i = 0; i < 5; ++i) {
1478                         if (strcmp(interrupts[i], string.begin) == 0) {
1479                                 attribute->u.value = i;
1480                                 return;
1481                         }
1482                 }
1483                 errorf(HERE, "'%s' is not an interrupt", string.begin);
1484         }
1485         attribute->invalid = true;
1486 }
1487
1488 /**
1489  * parse ( identifier, const expression, const expression )
1490  */
1491 static void parse_gnu_attribute_format_args(gnu_attribute_t *attribute)
1492 {
1493         static const char *const format_names[] = {
1494                 "printf",
1495                 "scanf",
1496                 "strftime",
1497                 "strfmon"
1498         };
1499         int i;
1500
1501         if (token.type != T_IDENTIFIER) {
1502                 parse_error_expected("while parsing format attribute directive", T_IDENTIFIER, NULL);
1503                 goto end_error;
1504         }
1505         const char *name = token.v.symbol->string;
1506         for (i = 0; i < 4; ++i) {
1507                 if (strcmp_underscore(format_names[i], name) == 0)
1508                         break;
1509         }
1510         if (i >= 4) {
1511                 if (warning.attribute)
1512                         warningf(HERE, "'%s' is an unrecognized format function type", name);
1513         }
1514         next_token();
1515
1516         expect(',');
1517         add_anchor_token(')');
1518         add_anchor_token(',');
1519         parse_constant_expression();
1520         rem_anchor_token(',');
1521         rem_anchor_token(')');
1522
1523         expect(',');
1524         add_anchor_token(')');
1525         parse_constant_expression();
1526         rem_anchor_token(')');
1527         expect(')');
1528         return;
1529 end_error:
1530         attribute->u.value = true;
1531 }
1532
1533 static void check_no_argument(gnu_attribute_t *attribute, const char *name)
1534 {
1535         if (!attribute->have_arguments)
1536                 return;
1537
1538         /* should have no arguments */
1539         errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1540         eat_until_matching_token('(');
1541         /* we have already consumed '(', so we stop before ')', eat it */
1542         eat(')');
1543         attribute->invalid = true;
1544 }
1545
1546 /**
1547  * Parse one GNU attribute.
1548  *
1549  * Note that attribute names can be specified WITH or WITHOUT
1550  * double underscores, ie const or __const__.
1551  *
1552  * The following attributes are parsed without arguments
1553  *  const
1554  *  volatile
1555  *  cdecl
1556  *  stdcall
1557  *  fastcall
1558  *  deprecated
1559  *  noinline
1560  *  noreturn
1561  *  naked
1562  *  pure
1563  *  always_inline
1564  *  malloc
1565  *  weak
1566  *  constructor
1567  *  destructor
1568  *  nothrow
1569  *  transparent_union
1570  *  common
1571  *  nocommon
1572  *  packed
1573  *  shared
1574  *  notshared
1575  *  used
1576  *  unused
1577  *  no_instrument_function
1578  *  warn_unused_result
1579  *  longcall
1580  *  shortcall
1581  *  long_call
1582  *  short_call
1583  *  function_vector
1584  *  interrupt_handler
1585  *  nmi_handler
1586  *  nesting
1587  *  near
1588  *  far
1589  *  signal
1590  *  eightbit_data
1591  *  tiny_data
1592  *  saveall
1593  *  flatten
1594  *  sseregparm
1595  *  externally_visible
1596  *  return_twice
1597  *  may_alias
1598  *  ms_struct
1599  *  gcc_struct
1600  *  dllimport
1601  *  dllexport
1602  *
1603  * The following attributes are parsed with arguments
1604  *  aligned( const expression )
1605  *  alias( string literal )
1606  *  section( string literal )
1607  *  format( identifier, const expression, const expression )
1608  *  format_arg( const expression )
1609  *  tls_model( string literal )
1610  *  visibility( string literal )
1611  *  regparm( const expression )
1612  *  model( string leteral )
1613  *  trap_exit( const expression )
1614  *  sp_switch( string literal )
1615  *
1616  * The following attributes might have arguments
1617  *  weak_ref( string literal )
1618  *  non_null( const expression // ',' )
1619  *  interrupt( string literal )
1620  *  sentinel( constant expression )
1621  */
1622 static decl_modifiers_t parse_gnu_attribute(gnu_attribute_t **attributes)
1623 {
1624         gnu_attribute_t *head      = *attributes;
1625         gnu_attribute_t *last      = *attributes;
1626         decl_modifiers_t modifiers = 0;
1627         gnu_attribute_t *attribute;
1628
1629         eat(T___attribute__);
1630         expect('(');
1631         expect('(');
1632
1633         if (token.type != ')') {
1634                 /* find the end of the list */
1635                 if (last != NULL) {
1636                         while (last->next != NULL)
1637                                 last = last->next;
1638                 }
1639
1640                 /* non-empty attribute list */
1641                 while (true) {
1642                         const char *name;
1643                         if (token.type == T_const) {
1644                                 name = "const";
1645                         } else if (token.type == T_volatile) {
1646                                 name = "volatile";
1647                         } else if (token.type == T_cdecl) {
1648                                 /* __attribute__((cdecl)), WITH ms mode */
1649                                 name = "cdecl";
1650                         } else if (token.type == T_IDENTIFIER) {
1651                                 const symbol_t *sym = token.v.symbol;
1652                                 name = sym->string;
1653                         } else {
1654                                 parse_error_expected("while parsing GNU attribute", T_IDENTIFIER, NULL);
1655                                 break;
1656                         }
1657
1658                         next_token();
1659
1660                         int i;
1661                         for (i = 0; i < GNU_AK_LAST; ++i) {
1662                                 if (strcmp_underscore(gnu_attribute_names[i], name) == 0)
1663                                         break;
1664                         }
1665                         gnu_attribute_kind_t kind = (gnu_attribute_kind_t)i;
1666
1667                         attribute = NULL;
1668                         if (kind == GNU_AK_LAST) {
1669                                 if (warning.attribute)
1670                                         warningf(HERE, "'%s' attribute directive ignored", name);
1671
1672                                 /* skip possible arguments */
1673                                 if (token.type == '(') {
1674                                         eat_until_matching_token(')');
1675                                 }
1676                         } else {
1677                                 /* check for arguments */
1678                                 attribute = allocate_gnu_attribute(kind);
1679                                 if (token.type == '(') {
1680                                         next_token();
1681                                         if (token.type == ')') {
1682                                                 /* empty args are allowed */
1683                                                 next_token();
1684                                         } else
1685                                                 attribute->have_arguments = true;
1686                                 }
1687
1688                                 switch (kind) {
1689                                 case GNU_AK_VOLATILE:
1690                                 case GNU_AK_NAKED:
1691                                 case GNU_AK_MALLOC:
1692                                 case GNU_AK_WEAK:
1693                                 case GNU_AK_COMMON:
1694                                 case GNU_AK_NOCOMMON:
1695                                 case GNU_AK_SHARED:
1696                                 case GNU_AK_NOTSHARED:
1697                                 case GNU_AK_NO_INSTRUMENT_FUNCTION:
1698                                 case GNU_AK_WARN_UNUSED_RESULT:
1699                                 case GNU_AK_LONGCALL:
1700                                 case GNU_AK_SHORTCALL:
1701                                 case GNU_AK_LONG_CALL:
1702                                 case GNU_AK_SHORT_CALL:
1703                                 case GNU_AK_FUNCTION_VECTOR:
1704                                 case GNU_AK_INTERRUPT_HANDLER:
1705                                 case GNU_AK_NMI_HANDLER:
1706                                 case GNU_AK_NESTING:
1707                                 case GNU_AK_NEAR:
1708                                 case GNU_AK_FAR:
1709                                 case GNU_AK_SIGNAL:
1710                                 case GNU_AK_EIGTHBIT_DATA:
1711                                 case GNU_AK_TINY_DATA:
1712                                 case GNU_AK_SAVEALL:
1713                                 case GNU_AK_FLATTEN:
1714                                 case GNU_AK_SSEREGPARM:
1715                                 case GNU_AK_EXTERNALLY_VISIBLE:
1716                                 case GNU_AK_RETURN_TWICE:
1717                                 case GNU_AK_MAY_ALIAS:
1718                                 case GNU_AK_MS_STRUCT:
1719                                 case GNU_AK_GCC_STRUCT:
1720                                         goto no_arg;
1721
1722                                 case GNU_AK_CDECL:             modifiers |= DM_CDECL;             goto no_arg;
1723                                 case GNU_AK_FASTCALL:          modifiers |= DM_FASTCALL;          goto no_arg;
1724                                 case GNU_AK_STDCALL:           modifiers |= DM_STDCALL;           goto no_arg;
1725                                 case GNU_AK_UNUSED:            modifiers |= DM_UNUSED;            goto no_arg;
1726                                 case GNU_AK_USED:              modifiers |= DM_USED;              goto no_arg;
1727                                 case GNU_AK_PURE:              modifiers |= DM_PURE;              goto no_arg;
1728                                 case GNU_AK_CONST:             modifiers |= DM_CONST;             goto no_arg;
1729                                 case GNU_AK_ALWAYS_INLINE:     modifiers |= DM_FORCEINLINE;       goto no_arg;
1730                                 case GNU_AK_DLLIMPORT:         modifiers |= DM_DLLIMPORT;         goto no_arg;
1731                                 case GNU_AK_DLLEXPORT:         modifiers |= DM_DLLEXPORT;         goto no_arg;
1732                                 case GNU_AK_PACKED:            modifiers |= DM_PACKED;            goto no_arg;
1733                                 case GNU_AK_NOINLINE:          modifiers |= DM_NOINLINE;          goto no_arg;
1734                                 case GNU_AK_NORETURN:          modifiers |= DM_NORETURN;          goto no_arg;
1735                                 case GNU_AK_NOTHROW:           modifiers |= DM_NOTHROW;           goto no_arg;
1736                                 case GNU_AK_TRANSPARENT_UNION: modifiers |= DM_TRANSPARENT_UNION; goto no_arg;
1737                                 case GNU_AK_CONSTRUCTOR:       modifiers |= DM_CONSTRUCTOR;       goto no_arg;
1738                                 case GNU_AK_DESTRUCTOR:        modifiers |= DM_DESTRUCTOR;        goto no_arg;
1739                                 case GNU_AK_DEPRECATED:        modifiers |= DM_DEPRECATED;        goto no_arg;
1740
1741                                 case GNU_AK_ALIGNED:
1742                                         /* __align__ may be used without an argument */
1743                                         if (attribute->have_arguments) {
1744                                                 parse_gnu_attribute_const_arg(attribute);
1745                                         }
1746                                         break;
1747
1748                                 case GNU_AK_FORMAT_ARG:
1749                                 case GNU_AK_REGPARM:
1750                                 case GNU_AK_TRAP_EXIT:
1751                                         if (!attribute->have_arguments) {
1752                                                 /* should have arguments */
1753                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1754                                                 attribute->invalid = true;
1755                                         } else
1756                                                 parse_gnu_attribute_const_arg(attribute);
1757                                         break;
1758                                 case GNU_AK_ALIAS:
1759                                 case GNU_AK_SECTION:
1760                                 case GNU_AK_SP_SWITCH:
1761                                         if (!attribute->have_arguments) {
1762                                                 /* should have arguments */
1763                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1764                                                 attribute->invalid = true;
1765                                         } else
1766                                                 parse_gnu_attribute_string_arg(attribute, &attribute->u.string);
1767                                         break;
1768                                 case GNU_AK_FORMAT:
1769                                         if (!attribute->have_arguments) {
1770                                                 /* should have arguments */
1771                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1772                                                 attribute->invalid = true;
1773                                         } else
1774                                                 parse_gnu_attribute_format_args(attribute);
1775                                         break;
1776                                 case GNU_AK_WEAKREF:
1777                                         /* may have one string argument */
1778                                         if (attribute->have_arguments)
1779                                                 parse_gnu_attribute_string_arg(attribute, &attribute->u.string);
1780                                         break;
1781                                 case GNU_AK_NONNULL:
1782                                         if (attribute->have_arguments)
1783                                                 parse_gnu_attribute_const_arg_list(attribute);
1784                                         break;
1785                                 case GNU_AK_TLS_MODEL:
1786                                         if (!attribute->have_arguments) {
1787                                                 /* should have arguments */
1788                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1789                                         } else
1790                                                 parse_gnu_attribute_tls_model_arg(attribute);
1791                                         break;
1792                                 case GNU_AK_VISIBILITY:
1793                                         if (!attribute->have_arguments) {
1794                                                 /* should have arguments */
1795                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1796                                         } else
1797                                                 parse_gnu_attribute_visibility_arg(attribute);
1798                                         break;
1799                                 case GNU_AK_MODEL:
1800                                         if (!attribute->have_arguments) {
1801                                                 /* should have arguments */
1802                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1803                                         } else {
1804                                                 parse_gnu_attribute_model_arg(attribute);
1805                                         }
1806                                         break;
1807                                 case GNU_AK_MODE:
1808                                         if (!attribute->have_arguments) {
1809                                                 /* should have arguments */
1810                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1811                                         } else {
1812                                                 parse_gnu_attribute_mode_arg(attribute);
1813                                         }
1814                                         break;
1815                                 case GNU_AK_INTERRUPT:
1816                                         /* may have one string argument */
1817                                         if (attribute->have_arguments)
1818                                                 parse_gnu_attribute_interrupt_arg(attribute);
1819                                         break;
1820                                 case GNU_AK_SENTINEL:
1821                                         /* may have one string argument */
1822                                         if (attribute->have_arguments)
1823                                                 parse_gnu_attribute_const_arg(attribute);
1824                                         break;
1825                                 case GNU_AK_LAST:
1826                                         /* already handled */
1827                                         break;
1828
1829 no_arg:
1830                                         check_no_argument(attribute, name);
1831                                 }
1832                         }
1833                         if (attribute != NULL) {
1834                                 if (last != NULL) {
1835                                         last->next = attribute;
1836                                         last       = attribute;
1837                                 } else {
1838                                         head = last = attribute;
1839                                 }
1840                         }
1841
1842                         if (token.type != ',')
1843                                 break;
1844                         next_token();
1845                 }
1846         }
1847         expect(')');
1848         expect(')');
1849 end_error:
1850         *attributes = head;
1851
1852         return modifiers;
1853 }
1854
1855 /**
1856  * Parse GNU attributes.
1857  */
1858 static decl_modifiers_t parse_attributes(gnu_attribute_t **attributes)
1859 {
1860         decl_modifiers_t modifiers = 0;
1861
1862         while (true) {
1863                 switch (token.type) {
1864                 case T___attribute__:
1865                         modifiers |= parse_gnu_attribute(attributes);
1866                         continue;
1867
1868                 case T_asm:
1869                         next_token();
1870                         expect('(');
1871                         if (token.type != T_STRING_LITERAL) {
1872                                 parse_error_expected("while parsing assembler attribute",
1873                                                      T_STRING_LITERAL, NULL);
1874                                 eat_until_matching_token('(');
1875                                 break;
1876                         } else {
1877                                 parse_string_literals();
1878                         }
1879                         expect(')');
1880                         continue;
1881
1882                 case T_cdecl:     modifiers |= DM_CDECL;    break;
1883                 case T__fastcall: modifiers |= DM_FASTCALL; break;
1884                 case T__stdcall:  modifiers |= DM_STDCALL;  break;
1885
1886                 case T___thiscall:
1887                         /* TODO record modifier */
1888                         if (warning.other)
1889                                 warningf(HERE, "Ignoring declaration modifier %K", &token);
1890                         break;
1891
1892 end_error:
1893                 default: return modifiers;
1894                 }
1895
1896                 next_token();
1897         }
1898 }
1899
1900 static void mark_vars_read(expression_t *expr, variable_t *lhs_var);
1901
1902 static variable_t *determine_lhs_var(expression_t *const expr,
1903                                      variable_t *lhs_var)
1904 {
1905         switch (expr->kind) {
1906                 case EXPR_REFERENCE: {
1907                         entity_t *const entity = expr->reference.entity;
1908                         /* we should only find variables as lavlues... */
1909                         if (entity->base.kind != ENTITY_VARIABLE)
1910                                 return NULL;
1911
1912                         return &entity->variable;
1913                 }
1914
1915                 case EXPR_ARRAY_ACCESS: {
1916                         expression_t  *const ref = expr->array_access.array_ref;
1917                         variable_t    *      var = NULL;
1918                         if (is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1919                                 var     = determine_lhs_var(ref, lhs_var);
1920                                 lhs_var = var;
1921                         } else {
1922                                 mark_vars_read(expr->select.compound, lhs_var);
1923                         }
1924                         mark_vars_read(expr->array_access.index, lhs_var);
1925                         return var;
1926                 }
1927
1928                 case EXPR_SELECT: {
1929                         if (is_type_compound(skip_typeref(expr->base.type))) {
1930                                 return determine_lhs_var(expr->select.compound, lhs_var);
1931                         } else {
1932                                 mark_vars_read(expr->select.compound, lhs_var);
1933                                 return NULL;
1934                         }
1935                 }
1936
1937                 case EXPR_UNARY_DEREFERENCE: {
1938                         expression_t *const val = expr->unary.value;
1939                         if (val->kind == EXPR_UNARY_TAKE_ADDRESS) {
1940                                 /* *&x is a NOP */
1941                                 return determine_lhs_var(val->unary.value, lhs_var);
1942                         } else {
1943                                 mark_vars_read(val, NULL);
1944                                 return NULL;
1945                         }
1946                 }
1947
1948                 default:
1949                         mark_vars_read(expr, NULL);
1950                         return NULL;
1951         }
1952 }
1953
1954 #define VAR_ANY ((variable_t*)-1)
1955
1956 /**
1957  * Mark declarations, which are read.  This is used to deted variables, which
1958  * are never read.
1959  * Example:
1960  * x = x + 1;
1961  *   x is not marked as "read", because it is only read to calculate its own new
1962  *   value.
1963  *
1964  * x += y; y += x;
1965  *   x and y are not detected as "not read", because multiple variables are
1966  *   involved.
1967  */
1968 static void mark_vars_read(expression_t *const expr, variable_t *lhs_var)
1969 {
1970         switch (expr->kind) {
1971                 case EXPR_REFERENCE: {
1972                         entity_t *const entity = expr->reference.entity;
1973                         if (entity->kind != ENTITY_VARIABLE)
1974                                 return;
1975
1976                         variable_t *variable = &entity->variable;
1977                         if (lhs_var != variable && lhs_var != VAR_ANY) {
1978                                 variable->read = true;
1979                         }
1980                         return;
1981                 }
1982
1983                 case EXPR_CALL:
1984                         // TODO respect pure/const
1985                         mark_vars_read(expr->call.function, NULL);
1986                         for (call_argument_t *arg = expr->call.arguments; arg != NULL; arg = arg->next) {
1987                                 mark_vars_read(arg->expression, NULL);
1988                         }
1989                         return;
1990
1991                 case EXPR_CONDITIONAL:
1992                         // TODO lhs_decl should depend on whether true/false have an effect
1993                         mark_vars_read(expr->conditional.condition, NULL);
1994                         if (expr->conditional.true_expression != NULL)
1995                                 mark_vars_read(expr->conditional.true_expression, lhs_var);
1996                         mark_vars_read(expr->conditional.false_expression, lhs_var);
1997                         return;
1998
1999                 case EXPR_SELECT:
2000                         if (lhs_var == VAR_ANY && !is_type_compound(skip_typeref(expr->base.type)))
2001                                 lhs_var = NULL;
2002                         mark_vars_read(expr->select.compound, lhs_var);
2003                         return;
2004
2005                 case EXPR_ARRAY_ACCESS: {
2006                         expression_t *const ref = expr->array_access.array_ref;
2007                         mark_vars_read(ref, lhs_var);
2008                         lhs_var = determine_lhs_var(ref, lhs_var);
2009                         mark_vars_read(expr->array_access.index, lhs_var);
2010                         return;
2011                 }
2012
2013                 case EXPR_VA_ARG:
2014                         mark_vars_read(expr->va_arge.ap, lhs_var);
2015                         return;
2016
2017                 case EXPR_UNARY_CAST:
2018                         /* Special case: Use void cast to mark a variable as "read" */
2019                         if (is_type_atomic(skip_typeref(expr->base.type), ATOMIC_TYPE_VOID))
2020                                 lhs_var = NULL;
2021                         goto unary;
2022
2023
2024                 case EXPR_UNARY_THROW:
2025                         if (expr->unary.value == NULL)
2026                                 return;
2027                         /* FALLTHROUGH */
2028                 case EXPR_UNARY_DEREFERENCE:
2029                 case EXPR_UNARY_DELETE:
2030                 case EXPR_UNARY_DELETE_ARRAY:
2031                         if (lhs_var == VAR_ANY)
2032                                 lhs_var = NULL;
2033                         goto unary;
2034
2035                 case EXPR_UNARY_NEGATE:
2036                 case EXPR_UNARY_PLUS:
2037                 case EXPR_UNARY_BITWISE_NEGATE:
2038                 case EXPR_UNARY_NOT:
2039                 case EXPR_UNARY_TAKE_ADDRESS:
2040                 case EXPR_UNARY_POSTFIX_INCREMENT:
2041                 case EXPR_UNARY_POSTFIX_DECREMENT:
2042                 case EXPR_UNARY_PREFIX_INCREMENT:
2043                 case EXPR_UNARY_PREFIX_DECREMENT:
2044                 case EXPR_UNARY_CAST_IMPLICIT:
2045                 case EXPR_UNARY_ASSUME:
2046 unary:
2047                         mark_vars_read(expr->unary.value, lhs_var);
2048                         return;
2049
2050                 case EXPR_BINARY_ADD:
2051                 case EXPR_BINARY_SUB:
2052                 case EXPR_BINARY_MUL:
2053                 case EXPR_BINARY_DIV:
2054                 case EXPR_BINARY_MOD:
2055                 case EXPR_BINARY_EQUAL:
2056                 case EXPR_BINARY_NOTEQUAL:
2057                 case EXPR_BINARY_LESS:
2058                 case EXPR_BINARY_LESSEQUAL:
2059                 case EXPR_BINARY_GREATER:
2060                 case EXPR_BINARY_GREATEREQUAL:
2061                 case EXPR_BINARY_BITWISE_AND:
2062                 case EXPR_BINARY_BITWISE_OR:
2063                 case EXPR_BINARY_BITWISE_XOR:
2064                 case EXPR_BINARY_LOGICAL_AND:
2065                 case EXPR_BINARY_LOGICAL_OR:
2066                 case EXPR_BINARY_SHIFTLEFT:
2067                 case EXPR_BINARY_SHIFTRIGHT:
2068                 case EXPR_BINARY_COMMA:
2069                 case EXPR_BINARY_ISGREATER:
2070                 case EXPR_BINARY_ISGREATEREQUAL:
2071                 case EXPR_BINARY_ISLESS:
2072                 case EXPR_BINARY_ISLESSEQUAL:
2073                 case EXPR_BINARY_ISLESSGREATER:
2074                 case EXPR_BINARY_ISUNORDERED:
2075                         mark_vars_read(expr->binary.left,  lhs_var);
2076                         mark_vars_read(expr->binary.right, lhs_var);
2077                         return;
2078
2079                 case EXPR_BINARY_ASSIGN:
2080                 case EXPR_BINARY_MUL_ASSIGN:
2081                 case EXPR_BINARY_DIV_ASSIGN:
2082                 case EXPR_BINARY_MOD_ASSIGN:
2083                 case EXPR_BINARY_ADD_ASSIGN:
2084                 case EXPR_BINARY_SUB_ASSIGN:
2085                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:
2086                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:
2087                 case EXPR_BINARY_BITWISE_AND_ASSIGN:
2088                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:
2089                 case EXPR_BINARY_BITWISE_OR_ASSIGN: {
2090                         if (lhs_var == VAR_ANY)
2091                                 lhs_var = NULL;
2092                         lhs_var = determine_lhs_var(expr->binary.left, lhs_var);
2093                         mark_vars_read(expr->binary.right, lhs_var);
2094                         return;
2095                 }
2096
2097                 case EXPR_VA_START:
2098                         determine_lhs_var(expr->va_starte.ap, lhs_var);
2099                         return;
2100
2101                 case EXPR_UNKNOWN:
2102                 case EXPR_INVALID:
2103                 case EXPR_CONST:
2104                 case EXPR_CHARACTER_CONSTANT:
2105                 case EXPR_WIDE_CHARACTER_CONSTANT:
2106                 case EXPR_STRING_LITERAL:
2107                 case EXPR_WIDE_STRING_LITERAL:
2108                 case EXPR_COMPOUND_LITERAL: // TODO init?
2109                 case EXPR_SIZEOF:
2110                 case EXPR_CLASSIFY_TYPE:
2111                 case EXPR_ALIGNOF:
2112                 case EXPR_FUNCNAME:
2113                 case EXPR_BUILTIN_SYMBOL:
2114                 case EXPR_BUILTIN_CONSTANT_P:
2115                 case EXPR_BUILTIN_PREFETCH:
2116                 case EXPR_OFFSETOF:
2117                 case EXPR_STATEMENT: // TODO
2118                 case EXPR_LABEL_ADDRESS:
2119                 case EXPR_BINARY_BUILTIN_EXPECT:
2120                 case EXPR_REFERENCE_ENUM_VALUE:
2121                         return;
2122         }
2123
2124         panic("unhandled expression");
2125 }
2126
2127 static designator_t *parse_designation(void)
2128 {
2129         designator_t *result = NULL;
2130         designator_t *last   = NULL;
2131
2132         while (true) {
2133                 designator_t *designator;
2134                 switch (token.type) {
2135                 case '[':
2136                         designator = allocate_ast_zero(sizeof(designator[0]));
2137                         designator->source_position = token.source_position;
2138                         next_token();
2139                         add_anchor_token(']');
2140                         designator->array_index = parse_constant_expression();
2141                         rem_anchor_token(']');
2142                         expect(']');
2143                         break;
2144                 case '.':
2145                         designator = allocate_ast_zero(sizeof(designator[0]));
2146                         designator->source_position = token.source_position;
2147                         next_token();
2148                         if (token.type != T_IDENTIFIER) {
2149                                 parse_error_expected("while parsing designator",
2150                                                      T_IDENTIFIER, NULL);
2151                                 return NULL;
2152                         }
2153                         designator->symbol = token.v.symbol;
2154                         next_token();
2155                         break;
2156                 default:
2157                         expect('=');
2158                         return result;
2159                 }
2160
2161                 assert(designator != NULL);
2162                 if (last != NULL) {
2163                         last->next = designator;
2164                 } else {
2165                         result = designator;
2166                 }
2167                 last = designator;
2168         }
2169 end_error:
2170         return NULL;
2171 }
2172
2173 static initializer_t *initializer_from_string(array_type_t *type,
2174                                               const string_t *const string)
2175 {
2176         /* TODO: check len vs. size of array type */
2177         (void) type;
2178
2179         initializer_t *initializer = allocate_initializer_zero(INITIALIZER_STRING);
2180         initializer->string.string = *string;
2181
2182         return initializer;
2183 }
2184
2185 static initializer_t *initializer_from_wide_string(array_type_t *const type,
2186                                                    wide_string_t *const string)
2187 {
2188         /* TODO: check len vs. size of array type */
2189         (void) type;
2190
2191         initializer_t *const initializer =
2192                 allocate_initializer_zero(INITIALIZER_WIDE_STRING);
2193         initializer->wide_string.string = *string;
2194
2195         return initializer;
2196 }
2197
2198 /**
2199  * Build an initializer from a given expression.
2200  */
2201 static initializer_t *initializer_from_expression(type_t *orig_type,
2202                                                   expression_t *expression)
2203 {
2204         /* TODO check that expression is a constant expression */
2205
2206         /* § 6.7.8.14/15 char array may be initialized by string literals */
2207         type_t *type           = skip_typeref(orig_type);
2208         type_t *expr_type_orig = expression->base.type;
2209         type_t *expr_type      = skip_typeref(expr_type_orig);
2210         if (is_type_array(type) && expr_type->kind == TYPE_POINTER) {
2211                 array_type_t *const array_type   = &type->array;
2212                 type_t       *const element_type = skip_typeref(array_type->element_type);
2213
2214                 if (element_type->kind == TYPE_ATOMIC) {
2215                         atomic_type_kind_t akind = element_type->atomic.akind;
2216                         switch (expression->kind) {
2217                                 case EXPR_STRING_LITERAL:
2218                                         if (akind == ATOMIC_TYPE_CHAR
2219                                                         || akind == ATOMIC_TYPE_SCHAR
2220                                                         || akind == ATOMIC_TYPE_UCHAR) {
2221                                                 return initializer_from_string(array_type,
2222                                                         &expression->string.value);
2223                                         }
2224
2225                                 case EXPR_WIDE_STRING_LITERAL: {
2226                                         type_t *bare_wchar_type = skip_typeref(type_wchar_t);
2227                                         if (get_unqualified_type(element_type) == bare_wchar_type) {
2228                                                 return initializer_from_wide_string(array_type,
2229                                                         &expression->wide_string.value);
2230                                         }
2231                                 }
2232
2233                                 default:
2234                                         break;
2235                         }
2236                 }
2237         }
2238
2239         assign_error_t error = semantic_assign(type, expression);
2240         if (error == ASSIGN_ERROR_INCOMPATIBLE)
2241                 return NULL;
2242         report_assign_error(error, type, expression, "initializer",
2243                             &expression->base.source_position);
2244
2245         initializer_t *const result = allocate_initializer_zero(INITIALIZER_VALUE);
2246 #if 0
2247         if (type->kind == TYPE_BITFIELD) {
2248                 type = type->bitfield.base_type;
2249         }
2250 #endif
2251         result->value.value = create_implicit_cast(expression, type);
2252
2253         return result;
2254 }
2255
2256 /**
2257  * Checks if a given expression can be used as an constant initializer.
2258  */
2259 static bool is_initializer_constant(const expression_t *expression)
2260 {
2261         return is_constant_expression(expression)
2262                 || is_address_constant(expression);
2263 }
2264
2265 /**
2266  * Parses an scalar initializer.
2267  *
2268  * § 6.7.8.11; eat {} without warning
2269  */
2270 static initializer_t *parse_scalar_initializer(type_t *type,
2271                                                bool must_be_constant)
2272 {
2273         /* there might be extra {} hierarchies */
2274         int braces = 0;
2275         if (token.type == '{') {
2276                 if (warning.other)
2277                         warningf(HERE, "extra curly braces around scalar initializer");
2278                 do {
2279                         ++braces;
2280                         next_token();
2281                 } while (token.type == '{');
2282         }
2283
2284         expression_t *expression = parse_assignment_expression();
2285         mark_vars_read(expression, NULL);
2286         if (must_be_constant && !is_initializer_constant(expression)) {
2287                 errorf(&expression->base.source_position,
2288                        "Initialisation expression '%E' is not constant\n",
2289                        expression);
2290         }
2291
2292         initializer_t *initializer = initializer_from_expression(type, expression);
2293
2294         if (initializer == NULL) {
2295                 errorf(&expression->base.source_position,
2296                        "expression '%E' (type '%T') doesn't match expected type '%T'",
2297                        expression, expression->base.type, type);
2298                 /* TODO */
2299                 return NULL;
2300         }
2301
2302         bool additional_warning_displayed = false;
2303         while (braces > 0) {
2304                 if (token.type == ',') {
2305                         next_token();
2306                 }
2307                 if (token.type != '}') {
2308                         if (!additional_warning_displayed && warning.other) {
2309                                 warningf(HERE, "additional elements in scalar initializer");
2310                                 additional_warning_displayed = true;
2311                         }
2312                 }
2313                 eat_block();
2314                 braces--;
2315         }
2316
2317         return initializer;
2318 }
2319
2320 /**
2321  * An entry in the type path.
2322  */
2323 typedef struct type_path_entry_t type_path_entry_t;
2324 struct type_path_entry_t {
2325         type_t *type;       /**< the upper top type. restored to path->top_tye if this entry is popped. */
2326         union {
2327                 size_t         index;          /**< For array types: the current index. */
2328                 declaration_t *compound_entry; /**< For compound types: the current declaration. */
2329         } v;
2330 };
2331
2332 /**
2333  * A type path expression a position inside compound or array types.
2334  */
2335 typedef struct type_path_t type_path_t;
2336 struct type_path_t {
2337         type_path_entry_t *path;         /**< An flexible array containing the current path. */
2338         type_t            *top_type;     /**< type of the element the path points */
2339         size_t             max_index;    /**< largest index in outermost array */
2340 };
2341
2342 /**
2343  * Prints a type path for debugging.
2344  */
2345 static __attribute__((unused)) void debug_print_type_path(
2346                 const type_path_t *path)
2347 {
2348         size_t len = ARR_LEN(path->path);
2349
2350         for (size_t i = 0; i < len; ++i) {
2351                 const type_path_entry_t *entry = & path->path[i];
2352
2353                 type_t *type = skip_typeref(entry->type);
2354                 if (is_type_compound(type)) {
2355                         /* in gcc mode structs can have no members */
2356                         if (entry->v.compound_entry == NULL) {
2357                                 assert(i == len-1);
2358                                 continue;
2359                         }
2360                         fprintf(stderr, ".%s",
2361                                 entry->v.compound_entry->base.symbol->string);
2362                 } else if (is_type_array(type)) {
2363                         fprintf(stderr, "[%u]", (unsigned) entry->v.index);
2364                 } else {
2365                         fprintf(stderr, "-INVALID-");
2366                 }
2367         }
2368         if (path->top_type != NULL) {
2369                 fprintf(stderr, "  (");
2370                 print_type(path->top_type);
2371                 fprintf(stderr, ")");
2372         }
2373 }
2374
2375 /**
2376  * Return the top type path entry, ie. in a path
2377  * (type).a.b returns the b.
2378  */
2379 static type_path_entry_t *get_type_path_top(const type_path_t *path)
2380 {
2381         size_t len = ARR_LEN(path->path);
2382         assert(len > 0);
2383         return &path->path[len-1];
2384 }
2385
2386 /**
2387  * Enlarge the type path by an (empty) element.
2388  */
2389 static type_path_entry_t *append_to_type_path(type_path_t *path)
2390 {
2391         size_t len = ARR_LEN(path->path);
2392         ARR_RESIZE(type_path_entry_t, path->path, len+1);
2393
2394         type_path_entry_t *result = & path->path[len];
2395         memset(result, 0, sizeof(result[0]));
2396         return result;
2397 }
2398
2399 /**
2400  * Descending into a sub-type. Enter the scope of the current top_type.
2401  */
2402 static void descend_into_subtype(type_path_t *path)
2403 {
2404         type_t *orig_top_type = path->top_type;
2405         type_t *top_type      = skip_typeref(orig_top_type);
2406
2407         type_path_entry_t *top = append_to_type_path(path);
2408         top->type              = top_type;
2409
2410         if (is_type_compound(top_type)) {
2411                 compound_t *compound  = top_type->compound.compound;
2412                 entity_t   *entry     = compound->members.entities;
2413
2414                 if (entry != NULL) {
2415                         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
2416                         top->v.compound_entry = &entry->declaration;
2417                         path->top_type = entry->declaration.type;
2418                 } else {
2419                         path->top_type = NULL;
2420                 }
2421         } else if (is_type_array(top_type)) {
2422                 top->v.index   = 0;
2423                 path->top_type = top_type->array.element_type;
2424         } else {
2425                 assert(!is_type_valid(top_type));
2426         }
2427 }
2428
2429 /**
2430  * Pop an entry from the given type path, ie. returning from
2431  * (type).a.b to (type).a
2432  */
2433 static void ascend_from_subtype(type_path_t *path)
2434 {
2435         type_path_entry_t *top = get_type_path_top(path);
2436
2437         path->top_type = top->type;
2438
2439         size_t len = ARR_LEN(path->path);
2440         ARR_RESIZE(type_path_entry_t, path->path, len-1);
2441 }
2442
2443 /**
2444  * Pop entries from the given type path until the given
2445  * path level is reached.
2446  */
2447 static void ascend_to(type_path_t *path, size_t top_path_level)
2448 {
2449         size_t len = ARR_LEN(path->path);
2450
2451         while (len > top_path_level) {
2452                 ascend_from_subtype(path);
2453                 len = ARR_LEN(path->path);
2454         }
2455 }
2456
2457 static bool walk_designator(type_path_t *path, const designator_t *designator,
2458                             bool used_in_offsetof)
2459 {
2460         for (; designator != NULL; designator = designator->next) {
2461                 type_path_entry_t *top       = get_type_path_top(path);
2462                 type_t            *orig_type = top->type;
2463
2464                 type_t *type = skip_typeref(orig_type);
2465
2466                 if (designator->symbol != NULL) {
2467                         symbol_t *symbol = designator->symbol;
2468                         if (!is_type_compound(type)) {
2469                                 if (is_type_valid(type)) {
2470                                         errorf(&designator->source_position,
2471                                                "'.%Y' designator used for non-compound type '%T'",
2472                                                symbol, orig_type);
2473                                 }
2474
2475                                 top->type             = type_error_type;
2476                                 top->v.compound_entry = NULL;
2477                                 orig_type             = type_error_type;
2478                         } else {
2479                                 compound_t *compound = type->compound.compound;
2480                                 entity_t   *iter     = compound->members.entities;
2481                                 for (; iter != NULL; iter = iter->base.next) {
2482                                         if (iter->base.symbol == symbol) {
2483                                                 break;
2484                                         }
2485                                 }
2486                                 if (iter == NULL) {
2487                                         errorf(&designator->source_position,
2488                                                "'%T' has no member named '%Y'", orig_type, symbol);
2489                                         goto failed;
2490                                 }
2491                                 assert(iter->kind == ENTITY_COMPOUND_MEMBER);
2492                                 if (used_in_offsetof) {
2493                                         type_t *real_type = skip_typeref(iter->declaration.type);
2494                                         if (real_type->kind == TYPE_BITFIELD) {
2495                                                 errorf(&designator->source_position,
2496                                                        "offsetof designator '%Y' may not specify bitfield",
2497                                                        symbol);
2498                                                 goto failed;
2499                                         }
2500                                 }
2501
2502                                 top->type             = orig_type;
2503                                 top->v.compound_entry = &iter->declaration;
2504                                 orig_type             = iter->declaration.type;
2505                         }
2506                 } else {
2507                         expression_t *array_index = designator->array_index;
2508                         assert(designator->array_index != NULL);
2509
2510                         if (!is_type_array(type)) {
2511                                 if (is_type_valid(type)) {
2512                                         errorf(&designator->source_position,
2513                                                "[%E] designator used for non-array type '%T'",
2514                                                array_index, orig_type);
2515                                 }
2516                                 goto failed;
2517                         }
2518
2519                         long index = fold_constant(array_index);
2520                         if (!used_in_offsetof) {
2521                                 if (index < 0) {
2522                                         errorf(&designator->source_position,
2523                                                "array index [%E] must be positive", array_index);
2524                                 } else if (type->array.size_constant) {
2525                                         long array_size = type->array.size;
2526                                         if (index >= array_size) {
2527                                                 errorf(&designator->source_position,
2528                                                        "designator [%E] (%d) exceeds array size %d",
2529                                                        array_index, index, array_size);
2530                                         }
2531                                 }
2532                         }
2533
2534                         top->type    = orig_type;
2535                         top->v.index = (size_t) index;
2536                         orig_type    = type->array.element_type;
2537                 }
2538                 path->top_type = orig_type;
2539
2540                 if (designator->next != NULL) {
2541                         descend_into_subtype(path);
2542                 }
2543         }
2544         return true;
2545
2546 failed:
2547         return false;
2548 }
2549
2550 static void advance_current_object(type_path_t *path, size_t top_path_level)
2551 {
2552         type_path_entry_t *top = get_type_path_top(path);
2553
2554         type_t *type = skip_typeref(top->type);
2555         if (is_type_union(type)) {
2556                 /* in unions only the first element is initialized */
2557                 top->v.compound_entry = NULL;
2558         } else if (is_type_struct(type)) {
2559                 declaration_t *entry = top->v.compound_entry;
2560
2561                 entity_t *next_entity = entry->base.next;
2562                 if (next_entity != NULL) {
2563                         assert(is_declaration(next_entity));
2564                         entry = &next_entity->declaration;
2565                 } else {
2566                         entry = NULL;
2567                 }
2568
2569                 top->v.compound_entry = entry;
2570                 if (entry != NULL) {
2571                         path->top_type = entry->type;
2572                         return;
2573                 }
2574         } else if (is_type_array(type)) {
2575                 assert(is_type_array(type));
2576
2577                 top->v.index++;
2578
2579                 if (!type->array.size_constant || top->v.index < type->array.size) {
2580                         return;
2581                 }
2582         } else {
2583                 assert(!is_type_valid(type));
2584                 return;
2585         }
2586
2587         /* we're past the last member of the current sub-aggregate, try if we
2588          * can ascend in the type hierarchy and continue with another subobject */
2589         size_t len = ARR_LEN(path->path);
2590
2591         if (len > top_path_level) {
2592                 ascend_from_subtype(path);
2593                 advance_current_object(path, top_path_level);
2594         } else {
2595                 path->top_type = NULL;
2596         }
2597 }
2598
2599 /**
2600  * skip until token is found.
2601  */
2602 static void skip_until(int type)
2603 {
2604         while (token.type != type) {
2605                 if (token.type == T_EOF)
2606                         return;
2607                 next_token();
2608         }
2609 }
2610
2611 /**
2612  * skip any {...} blocks until a closing bracket is reached.
2613  */
2614 static void skip_initializers(void)
2615 {
2616         if (token.type == '{')
2617                 next_token();
2618
2619         while (token.type != '}') {
2620                 if (token.type == T_EOF)
2621                         return;
2622                 if (token.type == '{') {
2623                         eat_block();
2624                         continue;
2625                 }
2626                 next_token();
2627         }
2628 }
2629
2630 static initializer_t *create_empty_initializer(void)
2631 {
2632         static initializer_t empty_initializer
2633                 = { .list = { { INITIALIZER_LIST }, 0 } };
2634         return &empty_initializer;
2635 }
2636
2637 /**
2638  * Parse a part of an initialiser for a struct or union,
2639  */
2640 static initializer_t *parse_sub_initializer(type_path_t *path,
2641                 type_t *outer_type, size_t top_path_level,
2642                 parse_initializer_env_t *env)
2643 {
2644         if (token.type == '}') {
2645                 /* empty initializer */
2646                 return create_empty_initializer();
2647         }
2648
2649         type_t *orig_type = path->top_type;
2650         type_t *type      = NULL;
2651
2652         if (orig_type == NULL) {
2653                 /* We are initializing an empty compound. */
2654         } else {
2655                 type = skip_typeref(orig_type);
2656         }
2657
2658         initializer_t **initializers = NEW_ARR_F(initializer_t*, 0);
2659
2660         while (true) {
2661                 designator_t *designator = NULL;
2662                 if (token.type == '.' || token.type == '[') {
2663                         designator = parse_designation();
2664                         goto finish_designator;
2665                 } else if (token.type == T_IDENTIFIER && look_ahead(1)->type == ':') {
2666                         /* GNU-style designator ("identifier: value") */
2667                         designator = allocate_ast_zero(sizeof(designator[0]));
2668                         designator->source_position = token.source_position;
2669                         designator->symbol          = token.v.symbol;
2670                         eat(T_IDENTIFIER);
2671                         eat(':');
2672
2673 finish_designator:
2674                         /* reset path to toplevel, evaluate designator from there */
2675                         ascend_to(path, top_path_level);
2676                         if (!walk_designator(path, designator, false)) {
2677                                 /* can't continue after designation error */
2678                                 goto end_error;
2679                         }
2680
2681                         initializer_t *designator_initializer
2682                                 = allocate_initializer_zero(INITIALIZER_DESIGNATOR);
2683                         designator_initializer->designator.designator = designator;
2684                         ARR_APP1(initializer_t*, initializers, designator_initializer);
2685
2686                         orig_type = path->top_type;
2687                         type      = orig_type != NULL ? skip_typeref(orig_type) : NULL;
2688                 }
2689
2690                 initializer_t *sub;
2691
2692                 if (token.type == '{') {
2693                         if (type != NULL && is_type_scalar(type)) {
2694                                 sub = parse_scalar_initializer(type, env->must_be_constant);
2695                         } else {
2696                                 eat('{');
2697                                 if (type == NULL) {
2698                                         if (env->entity != NULL) {
2699                                                 errorf(HERE,
2700                                                      "extra brace group at end of initializer for '%Y'",
2701                                                      env->entity->base.symbol);
2702                                         } else {
2703                                                 errorf(HERE, "extra brace group at end of initializer");
2704                                         }
2705                                 } else
2706                                         descend_into_subtype(path);
2707
2708                                 add_anchor_token('}');
2709                                 sub = parse_sub_initializer(path, orig_type, top_path_level+1,
2710                                                             env);
2711                                 rem_anchor_token('}');
2712
2713                                 if (type != NULL) {
2714                                         ascend_from_subtype(path);
2715                                         expect('}');
2716                                 } else {
2717                                         expect('}');
2718                                         goto error_parse_next;
2719                                 }
2720                         }
2721                 } else {
2722                         /* must be an expression */
2723                         expression_t *expression = parse_assignment_expression();
2724
2725                         if (env->must_be_constant && !is_initializer_constant(expression)) {
2726                                 errorf(&expression->base.source_position,
2727                                        "Initialisation expression '%E' is not constant\n",
2728                                        expression);
2729                         }
2730
2731                         if (type == NULL) {
2732                                 /* we are already outside, ... */
2733                                 type_t *const outer_type_skip = skip_typeref(outer_type);
2734                                 if (is_type_compound(outer_type_skip) &&
2735                                     !outer_type_skip->compound.compound->complete) {
2736                                         goto error_parse_next;
2737                                 }
2738                                 goto error_excess;
2739                         }
2740
2741                         /* handle { "string" } special case */
2742                         if ((expression->kind == EXPR_STRING_LITERAL
2743                                         || expression->kind == EXPR_WIDE_STRING_LITERAL)
2744                                         && outer_type != NULL) {
2745                                 sub = initializer_from_expression(outer_type, expression);
2746                                 if (sub != NULL) {
2747                                         if (token.type == ',') {
2748                                                 next_token();
2749                                         }
2750                                         if (token.type != '}' && warning.other) {
2751                                                 warningf(HERE, "excessive elements in initializer for type '%T'",
2752                                                                  orig_type);
2753                                         }
2754                                         /* TODO: eat , ... */
2755                                         return sub;
2756                                 }
2757                         }
2758
2759                         /* descend into subtypes until expression matches type */
2760                         while (true) {
2761                                 orig_type = path->top_type;
2762                                 type      = skip_typeref(orig_type);
2763
2764                                 sub = initializer_from_expression(orig_type, expression);
2765                                 if (sub != NULL) {
2766                                         break;
2767                                 }
2768                                 if (!is_type_valid(type)) {
2769                                         goto end_error;
2770                                 }
2771                                 if (is_type_scalar(type)) {
2772                                         errorf(&expression->base.source_position,
2773                                                         "expression '%E' doesn't match expected type '%T'",
2774                                                         expression, orig_type);
2775                                         goto end_error;
2776                                 }
2777
2778                                 descend_into_subtype(path);
2779                         }
2780                 }
2781
2782                 /* update largest index of top array */
2783                 const type_path_entry_t *first      = &path->path[0];
2784                 type_t                  *first_type = first->type;
2785                 first_type                          = skip_typeref(first_type);
2786                 if (is_type_array(first_type)) {
2787                         size_t index = first->v.index;
2788                         if (index > path->max_index)
2789                                 path->max_index = index;
2790                 }
2791
2792                 if (type != NULL) {
2793                         /* append to initializers list */
2794                         ARR_APP1(initializer_t*, initializers, sub);
2795                 } else {
2796 error_excess:
2797                         if (warning.other) {
2798                                 if (env->entity != NULL) {
2799                                         warningf(HERE, "excess elements in struct initializer for '%Y'",
2800                                            env->entity->base.symbol);
2801                                 } else {
2802                                         warningf(HERE, "excess elements in struct initializer");
2803                                 }
2804                         }
2805                 }
2806
2807 error_parse_next:
2808                 if (token.type == '}') {
2809                         break;
2810                 }
2811                 expect(',');
2812                 if (token.type == '}') {
2813                         break;
2814                 }
2815
2816                 if (type != NULL) {
2817                         /* advance to the next declaration if we are not at the end */
2818                         advance_current_object(path, top_path_level);
2819                         orig_type = path->top_type;
2820                         if (orig_type != NULL)
2821                                 type = skip_typeref(orig_type);
2822                         else
2823                                 type = NULL;
2824                 }
2825         }
2826
2827         size_t len  = ARR_LEN(initializers);
2828         size_t size = sizeof(initializer_list_t) + len * sizeof(initializers[0]);
2829         initializer_t *result = allocate_ast_zero(size);
2830         result->kind          = INITIALIZER_LIST;
2831         result->list.len      = len;
2832         memcpy(&result->list.initializers, initializers,
2833                len * sizeof(initializers[0]));
2834
2835         DEL_ARR_F(initializers);
2836         ascend_to(path, top_path_level+1);
2837
2838         return result;
2839
2840 end_error:
2841         skip_initializers();
2842         DEL_ARR_F(initializers);
2843         ascend_to(path, top_path_level+1);
2844         return NULL;
2845 }
2846
2847 /**
2848  * Parses an initializer. Parsers either a compound literal
2849  * (env->declaration == NULL) or an initializer of a declaration.
2850  */
2851 static initializer_t *parse_initializer(parse_initializer_env_t *env)
2852 {
2853         type_t        *type   = skip_typeref(env->type);
2854         initializer_t *result = NULL;
2855         size_t         max_index;
2856
2857         if (is_type_scalar(type)) {
2858                 result = parse_scalar_initializer(type, env->must_be_constant);
2859         } else if (token.type == '{') {
2860                 eat('{');
2861
2862                 type_path_t path;
2863                 memset(&path, 0, sizeof(path));
2864                 path.top_type = env->type;
2865                 path.path     = NEW_ARR_F(type_path_entry_t, 0);
2866
2867                 descend_into_subtype(&path);
2868
2869                 add_anchor_token('}');
2870                 result = parse_sub_initializer(&path, env->type, 1, env);
2871                 rem_anchor_token('}');
2872
2873                 max_index = path.max_index;
2874                 DEL_ARR_F(path.path);
2875
2876                 expect('}');
2877         } else {
2878                 /* parse_scalar_initializer() also works in this case: we simply
2879                  * have an expression without {} around it */
2880                 result = parse_scalar_initializer(type, env->must_be_constant);
2881         }
2882
2883         /* § 6.7.8 (22) array initializers for arrays with unknown size determine
2884          * the array type size */
2885         if (is_type_array(type) && type->array.size_expression == NULL
2886                         && result != NULL) {
2887                 size_t size;
2888                 switch (result->kind) {
2889                 case INITIALIZER_LIST:
2890                         size = max_index + 1;
2891                         break;
2892
2893                 case INITIALIZER_STRING:
2894                         size = result->string.string.size;
2895                         break;
2896
2897                 case INITIALIZER_WIDE_STRING:
2898                         size = result->wide_string.string.size;
2899                         break;
2900
2901                 case INITIALIZER_DESIGNATOR:
2902                 case INITIALIZER_VALUE:
2903                         /* can happen for parse errors */
2904                         size = 0;
2905                         break;
2906
2907                 default:
2908                         internal_errorf(HERE, "invalid initializer type");
2909                 }
2910
2911                 expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
2912                 cnst->base.type          = type_size_t;
2913                 cnst->conste.v.int_value = size;
2914
2915                 type_t *new_type = duplicate_type(type);
2916
2917                 new_type->array.size_expression   = cnst;
2918                 new_type->array.size_constant     = true;
2919                 new_type->array.has_implicit_size = true;
2920                 new_type->array.size              = size;
2921                 env->type = new_type;
2922         }
2923
2924         return result;
2925 end_error:
2926         return NULL;
2927 }
2928
2929 static void append_entity(scope_t *scope, entity_t *entity)
2930 {
2931         if (scope->last_entity != NULL) {
2932                 scope->last_entity->base.next = entity;
2933         } else {
2934                 scope->entities = entity;
2935         }
2936         scope->last_entity = entity;
2937 }
2938
2939
2940 static compound_t *parse_compound_type_specifier(bool is_struct)
2941 {
2942         gnu_attribute_t  *attributes = NULL;
2943         decl_modifiers_t  modifiers  = 0;
2944         if (is_struct) {
2945                 eat(T_struct);
2946         } else {
2947                 eat(T_union);
2948         }
2949
2950         symbol_t   *symbol   = NULL;
2951         compound_t *compound = NULL;
2952
2953         if (token.type == T___attribute__) {
2954                 modifiers |= parse_attributes(&attributes);
2955         }
2956
2957         if (token.type == T_IDENTIFIER) {
2958                 symbol = token.v.symbol;
2959                 next_token();
2960
2961                 namespace_tag_t const namespc =
2962                         is_struct ? NAMESPACE_STRUCT : NAMESPACE_UNION;
2963                 entity_t *entity = get_entity(symbol, namespc);
2964                 if (entity != NULL) {
2965                         assert(entity->kind == (is_struct ? ENTITY_STRUCT : ENTITY_UNION));
2966                         compound = &entity->compound;
2967                         if (compound->base.parent_scope != current_scope &&
2968                             (token.type == '{' || token.type == ';')) {
2969                                 /* we're in an inner scope and have a definition. Override
2970                                    existing definition in outer scope */
2971                                 compound = NULL;
2972                         } else if (compound->complete && token.type == '{') {
2973                                 assert(symbol != NULL);
2974                                 errorf(HERE, "multiple definitions of '%s %Y' (previous definition %P)",
2975                                        is_struct ? "struct" : "union", symbol,
2976                                        &compound->base.source_position);
2977                                 /* clear members in the hope to avoid further errors */
2978                                 compound->members.entities = NULL;
2979                         }
2980                 }
2981         } else if (token.type != '{') {
2982                 if (is_struct) {
2983                         parse_error_expected("while parsing struct type specifier",
2984                                              T_IDENTIFIER, '{', NULL);
2985                 } else {
2986                         parse_error_expected("while parsing union type specifier",
2987                                              T_IDENTIFIER, '{', NULL);
2988                 }
2989
2990                 return NULL;
2991         }
2992
2993         if (compound == NULL) {
2994                 entity_kind_t  kind   = is_struct ? ENTITY_STRUCT : ENTITY_UNION;
2995                 entity_t      *entity = allocate_entity_zero(kind);
2996                 compound              = &entity->compound;
2997
2998                 compound->base.namespc =
2999                         (is_struct ? NAMESPACE_STRUCT : NAMESPACE_UNION);
3000                 compound->base.source_position = token.source_position;
3001                 compound->base.symbol          = symbol;
3002                 compound->base.parent_scope    = current_scope;
3003                 if (symbol != NULL) {
3004                         environment_push(entity);
3005                 }
3006                 append_entity(current_scope, entity);
3007         }
3008
3009         if (token.type == '{') {
3010                 parse_compound_type_entries(compound);
3011                 modifiers |= parse_attributes(&attributes);
3012
3013                 if (symbol == NULL) {
3014                         assert(anonymous_entity == NULL);
3015                         anonymous_entity = (entity_t*)compound;
3016                 }
3017         }
3018
3019         compound->modifiers |= modifiers;
3020         return compound;
3021 }
3022
3023 static void parse_enum_entries(type_t *const enum_type)
3024 {
3025         eat('{');
3026
3027         if (token.type == '}') {
3028                 errorf(HERE, "empty enum not allowed");
3029                 next_token();
3030                 return;
3031         }
3032
3033         add_anchor_token('}');
3034         do {
3035                 if (token.type != T_IDENTIFIER) {
3036                         parse_error_expected("while parsing enum entry", T_IDENTIFIER, NULL);
3037                         eat_block();
3038                         rem_anchor_token('}');
3039                         return;
3040                 }
3041
3042                 entity_t *entity             = allocate_entity_zero(ENTITY_ENUM_VALUE);
3043                 entity->enum_value.enum_type = enum_type;
3044                 entity->base.symbol          = token.v.symbol;
3045                 entity->base.source_position = token.source_position;
3046                 next_token();
3047
3048                 if (token.type == '=') {
3049                         next_token();
3050                         expression_t *value = parse_constant_expression();
3051
3052                         value = create_implicit_cast(value, enum_type);
3053                         entity->enum_value.value = value;
3054
3055                         /* TODO semantic */
3056                 }
3057
3058                 record_entity(entity, false);
3059
3060                 if (token.type != ',')
3061                         break;
3062                 next_token();
3063         } while (token.type != '}');
3064         rem_anchor_token('}');
3065
3066         expect('}');
3067
3068 end_error:
3069         ;
3070 }
3071
3072 static type_t *parse_enum_specifier(void)
3073 {
3074         gnu_attribute_t *attributes = NULL;
3075         entity_t        *entity;
3076         symbol_t        *symbol;
3077
3078         eat(T_enum);
3079         if (token.type == T_IDENTIFIER) {
3080                 symbol = token.v.symbol;
3081                 next_token();
3082
3083                 entity = get_entity(symbol, NAMESPACE_ENUM);
3084                 assert(entity == NULL || entity->kind == ENTITY_ENUM);
3085         } else if (token.type != '{') {
3086                 parse_error_expected("while parsing enum type specifier",
3087                                      T_IDENTIFIER, '{', NULL);
3088                 return NULL;
3089         } else {
3090                 entity  = NULL;
3091                 symbol  = NULL;
3092         }
3093
3094         if (entity == NULL) {
3095                 entity                       = allocate_entity_zero(ENTITY_ENUM);
3096                 entity->base.namespc         = NAMESPACE_ENUM;
3097                 entity->base.source_position = token.source_position;
3098                 entity->base.symbol          = symbol;
3099                 entity->base.parent_scope    = current_scope;
3100         }
3101
3102         type_t *const type = allocate_type_zero(TYPE_ENUM);
3103         type->enumt.enume  = &entity->enume;
3104
3105         if (token.type == '{') {
3106                 if (entity->enume.complete) {
3107                         errorf(HERE, "multiple definitions of enum %Y (previous definition %P)",
3108                                symbol, &entity->base.source_position);
3109                 }
3110                 if (symbol != NULL) {
3111                         environment_push(entity);
3112                 }
3113                 append_entity(current_scope, entity);
3114                 entity->enume.complete = true;
3115
3116                 parse_enum_entries(type);
3117                 parse_attributes(&attributes);
3118
3119                 if (symbol == NULL) {
3120                         assert(anonymous_entity == NULL);
3121                         anonymous_entity = entity;
3122                 }
3123         } else if (!entity->enume.complete && !(c_mode & _GNUC)) {
3124                 errorf(HERE, "enum %Y used before definition (incomplete enumes are a GNU extension)",
3125                        symbol);
3126         }
3127
3128         return type;
3129 }
3130
3131 /**
3132  * if a symbol is a typedef to another type, return true
3133  */
3134 static bool is_typedef_symbol(symbol_t *symbol)
3135 {
3136         const entity_t *const entity = get_entity(symbol, NAMESPACE_NORMAL);
3137         return entity != NULL && entity->kind == ENTITY_TYPEDEF;
3138 }
3139
3140 static type_t *parse_typeof(void)
3141 {
3142         eat(T___typeof__);
3143
3144         type_t *type;
3145
3146         expect('(');
3147         add_anchor_token(')');
3148
3149         expression_t *expression  = NULL;
3150
3151         bool old_type_prop     = in_type_prop;
3152         bool old_gcc_extension = in_gcc_extension;
3153         in_type_prop           = true;
3154
3155         while (token.type == T___extension__) {
3156                 /* This can be a prefix to a typename or an expression. */
3157                 next_token();
3158                 in_gcc_extension = true;
3159         }
3160         switch (token.type) {
3161         case T_IDENTIFIER:
3162                 if (is_typedef_symbol(token.v.symbol)) {
3163                         type = parse_typename();
3164                 } else {
3165                         expression = parse_expression();
3166                         type       = expression->base.type;
3167                 }
3168                 break;
3169
3170         TYPENAME_START
3171                 type = parse_typename();
3172                 break;
3173
3174         default:
3175                 expression = parse_expression();
3176                 type       = expression->base.type;
3177                 break;
3178         }
3179         in_type_prop     = old_type_prop;
3180         in_gcc_extension = old_gcc_extension;
3181
3182         rem_anchor_token(')');
3183         expect(')');
3184
3185         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF);
3186         typeof_type->typeoft.expression  = expression;
3187         typeof_type->typeoft.typeof_type = type;
3188
3189         return typeof_type;
3190 end_error:
3191         return NULL;
3192 }
3193
3194 typedef enum specifiers_t {
3195         SPECIFIER_SIGNED    = 1 << 0,
3196         SPECIFIER_UNSIGNED  = 1 << 1,
3197         SPECIFIER_LONG      = 1 << 2,
3198         SPECIFIER_INT       = 1 << 3,
3199         SPECIFIER_DOUBLE    = 1 << 4,
3200         SPECIFIER_CHAR      = 1 << 5,
3201         SPECIFIER_SHORT     = 1 << 6,
3202         SPECIFIER_LONG_LONG = 1 << 7,
3203         SPECIFIER_FLOAT     = 1 << 8,
3204         SPECIFIER_BOOL      = 1 << 9,
3205         SPECIFIER_VOID      = 1 << 10,
3206         SPECIFIER_INT8      = 1 << 11,
3207         SPECIFIER_INT16     = 1 << 12,
3208         SPECIFIER_INT32     = 1 << 13,
3209         SPECIFIER_INT64     = 1 << 14,
3210         SPECIFIER_INT128    = 1 << 15,
3211         SPECIFIER_COMPLEX   = 1 << 16,
3212         SPECIFIER_IMAGINARY = 1 << 17,
3213 } specifiers_t;
3214
3215 static type_t *create_builtin_type(symbol_t *const symbol,
3216                                    type_t *const real_type)
3217 {
3218         type_t *type            = allocate_type_zero(TYPE_BUILTIN);
3219         type->builtin.symbol    = symbol;
3220         type->builtin.real_type = real_type;
3221
3222         type_t *result = typehash_insert(type);
3223         if (type != result) {
3224                 free_type(type);
3225         }
3226
3227         return result;
3228 }
3229
3230 static type_t *get_typedef_type(symbol_t *symbol)
3231 {
3232         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
3233         if (entity == NULL || entity->kind != ENTITY_TYPEDEF)
3234                 return NULL;
3235
3236         type_t *type            = allocate_type_zero(TYPE_TYPEDEF);
3237         type->typedeft.typedefe = &entity->typedefe;
3238
3239         return type;
3240 }
3241
3242 /**
3243  * check for the allowed MS alignment values.
3244  */
3245 static bool check_alignment_value(long long intvalue)
3246 {
3247         if (intvalue < 1 || intvalue > 8192) {
3248                 errorf(HERE, "illegal alignment value");
3249                 return false;
3250         }
3251         unsigned v = (unsigned)intvalue;
3252         for (unsigned i = 1; i <= 8192; i += i) {
3253                 if (i == v)
3254                         return true;
3255         }
3256         errorf(HERE, "alignment must be power of two");
3257         return false;
3258 }
3259
3260 #define DET_MOD(name, tag) do { \
3261         if (*modifiers & tag && warning.other) warningf(HERE, #name " used more than once"); \
3262         *modifiers |= tag; \
3263 } while (0)
3264
3265 static void parse_microsoft_extended_decl_modifier(declaration_specifiers_t *specifiers)
3266 {
3267         decl_modifiers_t *modifiers = &specifiers->modifiers;
3268
3269         while (true) {
3270                 if (token.type == T_restrict) {
3271                         next_token();
3272                         DET_MOD(restrict, DM_RESTRICT);
3273                         goto end_loop;
3274                 } else if (token.type != T_IDENTIFIER)
3275                         break;
3276                 symbol_t *symbol = token.v.symbol;
3277                 if (symbol == sym_align) {
3278                         next_token();
3279                         expect('(');
3280                         if (token.type != T_INTEGER)
3281                                 goto end_error;
3282                         if (check_alignment_value(token.v.intvalue)) {
3283                                 if (specifiers->alignment != 0 && warning.other)
3284                                         warningf(HERE, "align used more than once");
3285                                 specifiers->alignment = (unsigned char)token.v.intvalue;
3286                         }
3287                         next_token();
3288                         expect(')');
3289                 } else if (symbol == sym_allocate) {
3290                         next_token();
3291                         expect('(');
3292                         if (token.type != T_IDENTIFIER)
3293                                 goto end_error;
3294                         (void)token.v.symbol;
3295                         expect(')');
3296                 } else if (symbol == sym_dllimport) {
3297                         next_token();
3298                         DET_MOD(dllimport, DM_DLLIMPORT);
3299                 } else if (symbol == sym_dllexport) {
3300                         next_token();
3301                         DET_MOD(dllexport, DM_DLLEXPORT);
3302                 } else if (symbol == sym_thread) {
3303                         next_token();
3304                         DET_MOD(thread, DM_THREAD);
3305                 } else if (symbol == sym_naked) {
3306                         next_token();
3307                         DET_MOD(naked, DM_NAKED);
3308                 } else if (symbol == sym_noinline) {
3309                         next_token();
3310                         DET_MOD(noinline, DM_NOINLINE);
3311                 } else if (symbol == sym_noreturn) {
3312                         next_token();
3313                         DET_MOD(noreturn, DM_NORETURN);
3314                 } else if (symbol == sym_nothrow) {
3315                         next_token();
3316                         DET_MOD(nothrow, DM_NOTHROW);
3317                 } else if (symbol == sym_novtable) {
3318                         next_token();
3319                         DET_MOD(novtable, DM_NOVTABLE);
3320                 } else if (symbol == sym_property) {
3321                         next_token();
3322                         expect('(');
3323                         for (;;) {
3324                                 bool is_get = false;
3325                                 if (token.type != T_IDENTIFIER)
3326                                         goto end_error;
3327                                 if (token.v.symbol == sym_get) {
3328                                         is_get = true;
3329                                 } else if (token.v.symbol == sym_put) {
3330                                 } else {
3331                                         errorf(HERE, "Bad property name '%Y'", token.v.symbol);
3332                                         goto end_error;
3333                                 }
3334                                 next_token();
3335                                 expect('=');
3336                                 if (token.type != T_IDENTIFIER)
3337                                         goto end_error;
3338                                 if (is_get) {
3339                                         if (specifiers->get_property_sym != NULL) {
3340                                                 errorf(HERE, "get property name already specified");
3341                                         } else {
3342                                                 specifiers->get_property_sym = token.v.symbol;
3343                                         }
3344                                 } else {
3345                                         if (specifiers->put_property_sym != NULL) {
3346                                                 errorf(HERE, "put property name already specified");
3347                                         } else {
3348                                                 specifiers->put_property_sym = token.v.symbol;
3349                                         }
3350                                 }
3351                                 next_token();
3352                                 if (token.type == ',') {
3353                                         next_token();
3354                                         continue;
3355                                 }
3356                                 break;
3357                         }
3358                         expect(')');
3359                 } else if (symbol == sym_selectany) {
3360                         next_token();
3361                         DET_MOD(selectany, DM_SELECTANY);
3362                 } else if (symbol == sym_uuid) {
3363                         next_token();
3364                         expect('(');
3365                         if (token.type != T_STRING_LITERAL)
3366                                 goto end_error;
3367                         next_token();
3368                         expect(')');
3369                 } else if (symbol == sym_deprecated) {
3370                         next_token();
3371                         if (specifiers->deprecated != 0 && warning.other)
3372                                 warningf(HERE, "deprecated used more than once");
3373                         specifiers->deprecated = true;
3374                         if (token.type == '(') {
3375                                 next_token();
3376                                 if (token.type == T_STRING_LITERAL) {
3377                                         specifiers->deprecated_string = token.v.string.begin;
3378                                         next_token();
3379                                 } else {
3380                                         errorf(HERE, "string literal expected");
3381                                 }
3382                                 expect(')');
3383                         }
3384                 } else if (symbol == sym_noalias) {
3385                         next_token();
3386                         DET_MOD(noalias, DM_NOALIAS);
3387                 } else {
3388                         if (warning.other)
3389                                 warningf(HERE, "Unknown modifier %Y ignored", token.v.symbol);
3390                         next_token();
3391                         if (token.type == '(')
3392                                 skip_until(')');
3393                 }
3394 end_loop:
3395                 if (token.type == ',')
3396                         next_token();
3397         }
3398 end_error:
3399         return;
3400 }
3401
3402 static entity_t *create_error_entity(symbol_t *symbol, entity_kind_tag_t kind)
3403 {
3404         entity_t *entity             = allocate_entity_zero(kind);
3405         entity->base.source_position = *HERE;
3406         entity->base.symbol          = symbol;
3407         if (is_declaration(entity)) {
3408                 entity->declaration.type     = type_error_type;
3409                 entity->declaration.implicit = true;
3410         } else if (kind == ENTITY_TYPEDEF) {
3411                 entity->typedefe.type = type_error_type;
3412         }
3413         record_entity(entity, false);
3414         return entity;
3415 }
3416
3417 static void parse_microsoft_based(declaration_specifiers_t *specifiers)
3418 {
3419         if (token.type != T_IDENTIFIER) {
3420                 parse_error_expected("while parsing __based", T_IDENTIFIER, NULL);
3421                 return;
3422         }
3423         symbol_t *symbol = token.v.symbol;
3424         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
3425
3426         if (entity == NULL || entity->base.kind != ENTITY_VARIABLE) {
3427                 errorf(HERE, "'%Y' is not a variable name.", symbol);
3428                 entity = create_error_entity(symbol, ENTITY_VARIABLE);
3429         } else {
3430                 variable_t *variable = &entity->variable;
3431
3432                 if (specifiers->based_variable != NULL) {
3433                         errorf(HERE, "__based type qualifier specified more than once");
3434                 }
3435                 specifiers->based_variable = variable;
3436
3437                 type_t *const type = variable->base.type;
3438
3439                 if (is_type_valid(type)) {
3440                         if (! is_type_pointer(skip_typeref(type))) {
3441                                 errorf(HERE, "variable in __based modifier must have pointer type instead of %T", type);
3442                         }
3443                         if (variable->base.base.parent_scope != file_scope) {
3444                                 errorf(HERE, "a nonstatic local variable may not be used in a __based specification");
3445                         }
3446                 }
3447         }
3448         next_token();
3449 }
3450
3451 /**
3452  * Finish the construction of a struct type by calculating
3453  * its size, offsets, alignment.
3454  */
3455 static void finish_struct_type(compound_type_t *type)
3456 {
3457         assert(type->compound != NULL);
3458
3459         compound_t *compound = type->compound;
3460         if (!compound->complete)
3461                 return;
3462
3463         il_size_t      size           = 0;
3464         il_size_t      offset;
3465         il_alignment_t alignment      = 1;
3466         bool           need_pad       = false;
3467
3468         entity_t *entry = compound->members.entities;
3469         for (; entry != NULL; entry = entry->base.next) {
3470                 if (entry->kind != ENTITY_COMPOUND_MEMBER)
3471                         continue;
3472
3473                 type_t *m_type = skip_typeref(entry->declaration.type);
3474                 if (! is_type_valid(m_type)) {
3475                         /* simply ignore errors here */
3476                         continue;
3477                 }
3478                 il_alignment_t m_alignment = m_type->base.alignment;
3479                 if (m_alignment > alignment)
3480                         alignment = m_alignment;
3481
3482                 offset = (size + m_alignment - 1) & -m_alignment;
3483
3484                 if (offset > size)
3485                         need_pad = true;
3486                 entry->compound_member.offset = offset;
3487                 size = offset + m_type->base.size;
3488         }
3489         if (type->base.alignment != 0) {
3490                 alignment = type->base.alignment;
3491         }
3492
3493         offset = (size + alignment - 1) & -alignment;
3494         if (offset > size)
3495                 need_pad = true;
3496
3497         if (warning.padded && need_pad) {
3498                 warningf(&compound->base.source_position,
3499                         "'%#T' needs padding", type, compound->base.symbol);
3500         }
3501         if (warning.packed && !need_pad) {
3502                 warningf(&compound->base.source_position,
3503                         "superfluous packed attribute on '%#T'",
3504                         type, compound->base.symbol);
3505         }
3506
3507         type->base.size      = offset;
3508         type->base.alignment = alignment;
3509 }
3510
3511 /**
3512  * Finish the construction of an union type by calculating
3513  * its size and alignment.
3514  */
3515 static void finish_union_type(compound_type_t *type)
3516 {
3517         assert(type->compound != NULL);
3518
3519         compound_t *compound = type->compound;
3520         if (! compound->complete)
3521                 return;
3522
3523         il_size_t      size      = 0;
3524         il_alignment_t alignment = 1;
3525
3526         entity_t *entry = compound->members.entities;
3527         for (; entry != NULL; entry = entry->base.next) {
3528                 if (entry->kind != ENTITY_COMPOUND_MEMBER)
3529                         continue;
3530
3531                 type_t *m_type = skip_typeref(entry->declaration.type);
3532                 if (! is_type_valid(m_type))
3533                         continue;
3534
3535                 entry->compound_member.offset = 0;
3536                 if (m_type->base.size > size)
3537                         size = m_type->base.size;
3538                 if (m_type->base.alignment > alignment)
3539                         alignment = m_type->base.alignment;
3540         }
3541         if (type->base.alignment != 0) {
3542                 alignment = type->base.alignment;
3543         }
3544         size = (size + alignment - 1) & -alignment;
3545         type->base.size      = size;
3546         type->base.alignment = alignment;
3547 }
3548
3549 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
3550 {
3551         type_t            *type              = NULL;
3552         type_qualifiers_t  qualifiers        = TYPE_QUALIFIER_NONE;
3553         type_modifiers_t   modifiers         = TYPE_MODIFIER_NONE;
3554         unsigned           type_specifiers   = 0;
3555         bool               newtype           = false;
3556         bool               saw_error         = false;
3557         bool               old_gcc_extension = in_gcc_extension;
3558
3559         specifiers->source_position = token.source_position;
3560
3561         while (true) {
3562                 specifiers->modifiers
3563                         |= parse_attributes(&specifiers->gnu_attributes);
3564                 if (specifiers->modifiers & DM_TRANSPARENT_UNION)
3565                         modifiers |= TYPE_MODIFIER_TRANSPARENT_UNION;
3566
3567                 switch (token.type) {
3568
3569                 /* storage class */
3570 #define MATCH_STORAGE_CLASS(token, class)                                  \
3571                 case token:                                                        \
3572                         if (specifiers->storage_class != STORAGE_CLASS_NONE) {         \
3573                                 errorf(HERE, "multiple storage classes in declaration specifiers"); \
3574                         }                                                              \
3575                         specifiers->storage_class = class;                             \
3576                         next_token();                                                  \
3577                         break;
3578
3579                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
3580                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
3581                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
3582                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
3583                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
3584
3585                 case T__declspec:
3586                         next_token();
3587                         expect('(');
3588                         add_anchor_token(')');
3589                         parse_microsoft_extended_decl_modifier(specifiers);
3590                         rem_anchor_token(')');
3591                         expect(')');
3592                         break;
3593
3594                 case T__based:
3595                         next_token();
3596                         expect('(');
3597                         add_anchor_token(')');
3598                         parse_microsoft_based(specifiers);
3599                         rem_anchor_token(')');
3600                         expect(')');
3601                         break;
3602
3603                 case T___thread:
3604                         switch (specifiers->storage_class) {
3605                         case STORAGE_CLASS_NONE:
3606                                 specifiers->storage_class = STORAGE_CLASS_THREAD;
3607                                 break;
3608
3609                         case STORAGE_CLASS_EXTERN:
3610                                 specifiers->storage_class = STORAGE_CLASS_THREAD_EXTERN;
3611                                 break;
3612
3613                         case STORAGE_CLASS_STATIC:
3614                                 specifiers->storage_class = STORAGE_CLASS_THREAD_STATIC;
3615                                 break;
3616
3617                         default:
3618                                 errorf(HERE, "multiple storage classes in declaration specifiers");
3619                                 break;
3620                         }
3621                         next_token();
3622                         break;
3623
3624                 /* type qualifiers */
3625 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
3626                 case token:                                                     \
3627                         qualifiers |= qualifier;                                    \
3628                         next_token();                                               \
3629                         break
3630
3631                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3632                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3633                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3634                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3635                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3636                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3637                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3638                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3639
3640                 case T___extension__:
3641                         next_token();
3642                         in_gcc_extension = true;
3643                         break;
3644
3645                 /* type specifiers */
3646 #define MATCH_SPECIFIER(token, specifier, name)                         \
3647                 case token:                                                     \
3648                         if (type_specifiers & specifier) {                           \
3649                                 errorf(HERE, "multiple " name " type specifiers given"); \
3650                         } else {                                                    \
3651                                 type_specifiers |= specifier;                           \
3652                         }                                                           \
3653                         next_token();                                               \
3654                         break
3655
3656                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool");
3657                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex");
3658                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary");
3659                 MATCH_SPECIFIER(T__int128,    SPECIFIER_INT128,    "_int128");
3660                 MATCH_SPECIFIER(T__int16,     SPECIFIER_INT16,     "_int16");
3661                 MATCH_SPECIFIER(T__int32,     SPECIFIER_INT32,     "_int32");
3662                 MATCH_SPECIFIER(T__int64,     SPECIFIER_INT64,     "_int64");
3663                 MATCH_SPECIFIER(T__int8,      SPECIFIER_INT8,      "_int8");
3664                 MATCH_SPECIFIER(T_bool,       SPECIFIER_BOOL,      "bool");
3665                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char");
3666                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double");
3667                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float");
3668                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int");
3669                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short");
3670                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed");
3671                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned");
3672                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void");
3673
3674                 case T__forceinline:
3675                         /* only in microsoft mode */
3676                         specifiers->modifiers |= DM_FORCEINLINE;
3677                         /* FALLTHROUGH */
3678
3679                 case T_inline:
3680                         next_token();
3681                         specifiers->is_inline = true;
3682                         break;
3683
3684                 case T_long:
3685                         if (type_specifiers & SPECIFIER_LONG_LONG) {
3686                                 errorf(HERE, "multiple type specifiers given");
3687                         } else if (type_specifiers & SPECIFIER_LONG) {
3688                                 type_specifiers |= SPECIFIER_LONG_LONG;
3689                         } else {
3690                                 type_specifiers |= SPECIFIER_LONG;
3691                         }
3692                         next_token();
3693                         break;
3694
3695                 case T_struct: {
3696                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
3697
3698                         type->compound.compound = parse_compound_type_specifier(true);
3699                         finish_struct_type(&type->compound);
3700                         break;
3701                 }
3702                 case T_union: {
3703                         type = allocate_type_zero(TYPE_COMPOUND_UNION);
3704                         type->compound.compound = parse_compound_type_specifier(false);
3705                         if (type->compound.compound->modifiers & DM_TRANSPARENT_UNION)
3706                                 modifiers |= TYPE_MODIFIER_TRANSPARENT_UNION;
3707                         finish_union_type(&type->compound);
3708                         break;
3709                 }
3710                 case T_enum:
3711                         type = parse_enum_specifier();
3712                         break;
3713                 case T___typeof__:
3714                         type = parse_typeof();
3715                         break;
3716                 case T___builtin_va_list:
3717                         type = duplicate_type(type_valist);
3718                         next_token();
3719                         break;
3720
3721                 case T_IDENTIFIER: {
3722                         /* only parse identifier if we haven't found a type yet */
3723                         if (type != NULL || type_specifiers != 0) {
3724                                 /* Be somewhat resilient to typos like 'unsigned lng* f()' in a
3725                                  * declaration, so it doesn't generate errors about expecting '(' or
3726                                  * '{' later on. */
3727                                 switch (look_ahead(1)->type) {
3728                                         STORAGE_CLASSES
3729                                         TYPE_SPECIFIERS
3730                                         case T_const:
3731                                         case T_restrict:
3732                                         case T_volatile:
3733                                         case T_inline:
3734                                         case T__forceinline: /* ^ DECLARATION_START except for __attribute__ */
3735                                         case T_IDENTIFIER:
3736                                         case '&':
3737                                         case '*':
3738                                                 errorf(HERE, "discarding stray %K in declaration specifier", &token);
3739                                                 next_token();
3740                                                 continue;
3741
3742                                         default:
3743                                                 goto finish_specifiers;
3744                                 }
3745                         }
3746
3747                         type_t *const typedef_type = get_typedef_type(token.v.symbol);
3748                         if (typedef_type == NULL) {
3749                                 /* Be somewhat resilient to typos like 'vodi f()' at the beginning of a
3750                                  * declaration, so it doesn't generate 'implicit int' followed by more
3751                                  * errors later on. */
3752                                 token_type_t const la1_type = (token_type_t)look_ahead(1)->type;
3753                                 switch (la1_type) {
3754                                         DECLARATION_START
3755                                         case T_IDENTIFIER:
3756                                         case '&':
3757                                         case '*': {
3758                                                 errorf(HERE, "%K does not name a type", &token);
3759
3760                                                 entity_t *entity =
3761                                                         create_error_entity(token.v.symbol, ENTITY_TYPEDEF);
3762
3763                                                 type = allocate_type_zero(TYPE_TYPEDEF);
3764                                                 type->typedeft.typedefe = &entity->typedefe;
3765
3766                                                 next_token();
3767                                                 saw_error = true;
3768                                                 if (la1_type == '&' || la1_type == '*')
3769                                                         goto finish_specifiers;
3770                                                 continue;
3771                                         }
3772
3773                                         default:
3774                                                 goto finish_specifiers;
3775                                 }
3776                         }
3777
3778                         next_token();
3779                         type = typedef_type;
3780                         break;
3781                 }
3782
3783                 /* function specifier */
3784                 default:
3785                         goto finish_specifiers;
3786                 }
3787         }
3788
3789 finish_specifiers:
3790         in_gcc_extension = old_gcc_extension;
3791
3792         if (type == NULL || (saw_error && type_specifiers != 0)) {
3793                 atomic_type_kind_t atomic_type;
3794
3795                 /* match valid basic types */
3796                 switch (type_specifiers) {
3797                 case SPECIFIER_VOID:
3798                         atomic_type = ATOMIC_TYPE_VOID;
3799                         break;
3800                 case SPECIFIER_CHAR:
3801                         atomic_type = ATOMIC_TYPE_CHAR;
3802                         break;
3803                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
3804                         atomic_type = ATOMIC_TYPE_SCHAR;
3805                         break;
3806                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
3807                         atomic_type = ATOMIC_TYPE_UCHAR;
3808                         break;
3809                 case SPECIFIER_SHORT:
3810                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
3811                 case SPECIFIER_SHORT | SPECIFIER_INT:
3812                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
3813                         atomic_type = ATOMIC_TYPE_SHORT;
3814                         break;
3815                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
3816                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
3817                         atomic_type = ATOMIC_TYPE_USHORT;
3818                         break;
3819                 case SPECIFIER_INT:
3820                 case SPECIFIER_SIGNED:
3821                 case SPECIFIER_SIGNED | SPECIFIER_INT:
3822                         atomic_type = ATOMIC_TYPE_INT;
3823                         break;
3824                 case SPECIFIER_UNSIGNED:
3825                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
3826                         atomic_type = ATOMIC_TYPE_UINT;
3827                         break;
3828                 case SPECIFIER_LONG:
3829                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
3830                 case SPECIFIER_LONG | SPECIFIER_INT:
3831                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
3832                         atomic_type = ATOMIC_TYPE_LONG;
3833                         break;
3834                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
3835                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
3836                         atomic_type = ATOMIC_TYPE_ULONG;
3837                         break;
3838
3839                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3840                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3841                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
3842                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3843                         | SPECIFIER_INT:
3844                         atomic_type = ATOMIC_TYPE_LONGLONG;
3845                         goto warn_about_long_long;
3846
3847                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3848                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3849                         | SPECIFIER_INT:
3850                         atomic_type = ATOMIC_TYPE_ULONGLONG;
3851 warn_about_long_long:
3852                         if (warning.long_long) {
3853                                 warningf(&specifiers->source_position,
3854                                          "ISO C90 does not support 'long long'");
3855                         }
3856                         break;
3857
3858                 case SPECIFIER_UNSIGNED | SPECIFIER_INT8:
3859                         atomic_type = unsigned_int8_type_kind;
3860                         break;
3861
3862                 case SPECIFIER_UNSIGNED | SPECIFIER_INT16:
3863                         atomic_type = unsigned_int16_type_kind;
3864                         break;
3865
3866                 case SPECIFIER_UNSIGNED | SPECIFIER_INT32:
3867                         atomic_type = unsigned_int32_type_kind;
3868                         break;
3869
3870                 case SPECIFIER_UNSIGNED | SPECIFIER_INT64:
3871                         atomic_type = unsigned_int64_type_kind;
3872                         break;
3873
3874                 case SPECIFIER_UNSIGNED | SPECIFIER_INT128:
3875                         atomic_type = unsigned_int128_type_kind;
3876                         break;
3877
3878                 case SPECIFIER_INT8:
3879                 case SPECIFIER_SIGNED | SPECIFIER_INT8:
3880                         atomic_type = int8_type_kind;
3881                         break;
3882
3883                 case SPECIFIER_INT16:
3884                 case SPECIFIER_SIGNED | SPECIFIER_INT16:
3885                         atomic_type = int16_type_kind;
3886                         break;
3887
3888                 case SPECIFIER_INT32:
3889                 case SPECIFIER_SIGNED | SPECIFIER_INT32:
3890                         atomic_type = int32_type_kind;
3891                         break;
3892
3893                 case SPECIFIER_INT64:
3894                 case SPECIFIER_SIGNED | SPECIFIER_INT64:
3895                         atomic_type = int64_type_kind;
3896                         break;
3897
3898                 case SPECIFIER_INT128:
3899                 case SPECIFIER_SIGNED | SPECIFIER_INT128:
3900                         atomic_type = int128_type_kind;
3901                         break;
3902
3903                 case SPECIFIER_FLOAT:
3904                         atomic_type = ATOMIC_TYPE_FLOAT;
3905                         break;
3906                 case SPECIFIER_DOUBLE:
3907                         atomic_type = ATOMIC_TYPE_DOUBLE;
3908                         break;
3909                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
3910                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
3911                         break;
3912                 case SPECIFIER_BOOL:
3913                         atomic_type = ATOMIC_TYPE_BOOL;
3914                         break;
3915                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
3916                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
3917                         atomic_type = ATOMIC_TYPE_FLOAT;
3918                         break;
3919                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3920                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3921                         atomic_type = ATOMIC_TYPE_DOUBLE;
3922                         break;
3923                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3924                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3925                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
3926                         break;
3927                 default:
3928                         /* invalid specifier combination, give an error message */
3929                         if (type_specifiers == 0) {
3930                                 if (saw_error)
3931                                         goto end_error;
3932
3933                                 /* ISO/IEC 14882:1998(E) §C.1.5:4 */
3934                                 if (!(c_mode & _CXX) && !strict_mode) {
3935                                         if (warning.implicit_int) {
3936                                                 warningf(HERE, "no type specifiers in declaration, using 'int'");
3937                                         }
3938                                         atomic_type = ATOMIC_TYPE_INT;
3939                                         break;
3940                                 } else {
3941                                         errorf(HERE, "no type specifiers given in declaration");
3942                                 }
3943                         } else if ((type_specifiers & SPECIFIER_SIGNED) &&
3944                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
3945                                 errorf(HERE, "signed and unsigned specifiers given");
3946                         } else if (type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
3947                                 errorf(HERE, "only integer types can be signed or unsigned");
3948                         } else {
3949                                 errorf(HERE, "multiple datatypes in declaration");
3950                         }
3951                         goto end_error;
3952                 }
3953
3954                 if (type_specifiers & SPECIFIER_COMPLEX) {
3955                         type                = allocate_type_zero(TYPE_COMPLEX);
3956                         type->complex.akind = atomic_type;
3957                 } else if (type_specifiers & SPECIFIER_IMAGINARY) {
3958                         type                  = allocate_type_zero(TYPE_IMAGINARY);
3959                         type->imaginary.akind = atomic_type;
3960                 } else {
3961                         type               = allocate_type_zero(TYPE_ATOMIC);
3962                         type->atomic.akind = atomic_type;
3963                 }
3964                 newtype = true;
3965         } else if (type_specifiers != 0) {
3966                 errorf(HERE, "multiple datatypes in declaration");
3967         }
3968
3969         /* FIXME: check type qualifiers here */
3970
3971         type->base.qualifiers = qualifiers;
3972         type->base.modifiers  = modifiers;
3973
3974         type_t *result = typehash_insert(type);
3975         if (newtype && result != type) {
3976                 free_type(type);
3977         }
3978
3979         specifiers->type = result;
3980         return;
3981
3982 end_error:
3983         specifiers->type = type_error_type;
3984         return;
3985 }
3986
3987 static type_qualifiers_t parse_type_qualifiers(void)
3988 {
3989         type_qualifiers_t qualifiers = TYPE_QUALIFIER_NONE;
3990
3991         while (true) {
3992                 switch (token.type) {
3993                 /* type qualifiers */
3994                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3995                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3996                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3997                 /* microsoft extended type modifiers */
3998                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3999                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
4000                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
4001                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
4002                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
4003
4004                 default:
4005                         return qualifiers;
4006                 }
4007         }
4008 }
4009
4010 /**
4011  * Parses an K&R identifier list
4012  */
4013 static void parse_identifier_list(scope_t *scope)
4014 {
4015         do {
4016                 entity_t *entity = allocate_entity_zero(ENTITY_VARIABLE);
4017                 entity->base.source_position = token.source_position;
4018                 entity->base.namespc         = NAMESPACE_NORMAL;
4019                 entity->base.symbol          = token.v.symbol;
4020                 /* a K&R parameter has no type, yet */
4021                 next_token();
4022
4023                 append_entity(scope, entity);
4024
4025                 if (token.type != ',') {
4026                         break;
4027                 }
4028                 next_token();
4029         } while (token.type == T_IDENTIFIER);
4030 }
4031
4032 static type_t *automatic_type_conversion(type_t *orig_type);
4033
4034 static void semantic_parameter(declaration_t *declaration)
4035 {
4036         /* TODO: improve error messages */
4037         source_position_t const* const pos = &declaration->base.source_position;
4038
4039         /* §6.9.1:6 */
4040         switch (declaration->declared_storage_class) {
4041                 /* Allowed storage classes */
4042                 case STORAGE_CLASS_NONE:
4043                 case STORAGE_CLASS_REGISTER:
4044                         break;
4045
4046                 default:
4047                         errorf(pos, "parameter may only have none or register storage class");
4048                         break;
4049         }
4050
4051         type_t *const orig_type = declaration->type;
4052         /* §6.7.5.3(7): Array as last part of a parameter type is just syntactic
4053          * sugar.  Turn it into a pointer.
4054          * §6.7.5.3(8): A declaration of a parameter as ``function returning type''
4055          * shall be adjusted to ``pointer to function returning type'', as in 6.3.2.1.
4056          */
4057         type_t *const type = automatic_type_conversion(orig_type);
4058         declaration->type = type;
4059
4060         if (is_type_incomplete(skip_typeref(type))) {
4061                 errorf(pos, "parameter '%#T' is of incomplete type",
4062                        orig_type, declaration->base.symbol);
4063         }
4064 }
4065
4066 static entity_t *parse_parameter(void)
4067 {
4068         declaration_specifiers_t specifiers;
4069         memset(&specifiers, 0, sizeof(specifiers));
4070
4071         parse_declaration_specifiers(&specifiers);
4072
4073         entity_t *entity = parse_declarator(&specifiers, true, false);
4074         anonymous_entity = NULL;
4075         return entity;
4076 }
4077
4078 /**
4079  * Parses function type parameters (and optionally creates variable_t entities
4080  * for them in a scope)
4081  */
4082 static void parse_parameters(function_type_t *type, scope_t *scope)
4083 {
4084         eat('(');
4085         add_anchor_token(')');
4086         int saved_comma_state = save_and_reset_anchor_state(',');
4087
4088         if (token.type == T_IDENTIFIER &&
4089             !is_typedef_symbol(token.v.symbol)) {
4090                 token_type_t la1_type = (token_type_t)look_ahead(1)->type;
4091                 if (la1_type == ',' || la1_type == ')') {
4092                         type->kr_style_parameters = true;
4093                         parse_identifier_list(scope);
4094                         goto parameters_finished;
4095                 }
4096         }
4097
4098         if (token.type == ')') {
4099                 /* ISO/IEC 14882:1998(E) §C.1.6:1 */
4100                 if (!(c_mode & _CXX))
4101                         type->unspecified_parameters = true;
4102                 goto parameters_finished;
4103         }
4104
4105         function_parameter_t *parameter;
4106         function_parameter_t *last_parameter = NULL;
4107
4108         while (true) {
4109                 switch (token.type) {
4110                 case T_DOTDOTDOT:
4111                         next_token();
4112                         type->variadic = true;
4113                         goto parameters_finished;
4114
4115                 case T_IDENTIFIER:
4116                 case T___extension__:
4117                 DECLARATION_START
4118                 {
4119                         entity_t *entity = parse_parameter();
4120                         if (entity->kind == ENTITY_TYPEDEF) {
4121                                 errorf(&entity->base.source_position,
4122                                        "typedef not allowed as function parameter");
4123                                 break;
4124                         }
4125                         assert(is_declaration(entity));
4126
4127                         /* func(void) is not a parameter */
4128                         if (last_parameter == NULL
4129                                         && token.type == ')'
4130                                         && entity->base.symbol == NULL
4131                                         && skip_typeref(entity->declaration.type) == type_void) {
4132                                 goto parameters_finished;
4133                         }
4134                         semantic_parameter(&entity->declaration);
4135
4136                         parameter = obstack_alloc(type_obst, sizeof(parameter[0]));
4137                         memset(parameter, 0, sizeof(parameter[0]));
4138                         parameter->type = entity->declaration.type;
4139
4140                         if (scope != NULL) {
4141                                 append_entity(scope, entity);
4142                         }
4143
4144                         if (last_parameter != NULL) {
4145                                 last_parameter->next = parameter;
4146                         } else {
4147                                 type->parameters = parameter;
4148                         }
4149                         last_parameter   = parameter;
4150                         break;
4151                 }
4152
4153                 default:
4154                         goto parameters_finished;
4155                 }
4156                 if (token.type != ',') {
4157                         goto parameters_finished;
4158                 }
4159                 next_token();
4160         }
4161
4162
4163 parameters_finished:
4164         rem_anchor_token(')');
4165         expect(')');
4166
4167 end_error:
4168         restore_anchor_state(',', saved_comma_state);
4169 }
4170
4171 typedef enum construct_type_kind_t {
4172         CONSTRUCT_INVALID,
4173         CONSTRUCT_POINTER,
4174         CONSTRUCT_REFERENCE,
4175         CONSTRUCT_FUNCTION,
4176         CONSTRUCT_ARRAY
4177 } construct_type_kind_t;
4178
4179 typedef struct construct_type_t construct_type_t;
4180 struct construct_type_t {
4181         construct_type_kind_t  kind;
4182         construct_type_t      *next;
4183 };
4184
4185 typedef struct parsed_pointer_t parsed_pointer_t;
4186 struct parsed_pointer_t {
4187         construct_type_t  construct_type;
4188         type_qualifiers_t type_qualifiers;
4189 };
4190
4191 typedef struct parsed_reference_t parsed_reference_t;
4192 struct parsed_reference_t {
4193         construct_type_t construct_type;
4194 };
4195
4196 typedef struct construct_function_type_t construct_function_type_t;
4197 struct construct_function_type_t {
4198         construct_type_t  construct_type;
4199         type_t           *function_type;
4200 };
4201
4202 typedef struct parsed_array_t parsed_array_t;
4203 struct parsed_array_t {
4204         construct_type_t  construct_type;
4205         type_qualifiers_t type_qualifiers;
4206         bool              is_static;
4207         bool              is_variable;
4208         expression_t     *size;
4209 };
4210
4211 typedef struct construct_base_type_t construct_base_type_t;
4212 struct construct_base_type_t {
4213         construct_type_t  construct_type;
4214         type_t           *type;
4215 };
4216
4217 static construct_type_t *parse_pointer_declarator(void)
4218 {
4219         eat('*');
4220
4221         parsed_pointer_t *pointer = obstack_alloc(&temp_obst, sizeof(pointer[0]));
4222         memset(pointer, 0, sizeof(pointer[0]));
4223         pointer->construct_type.kind = CONSTRUCT_POINTER;
4224         pointer->type_qualifiers     = parse_type_qualifiers();
4225
4226         return (construct_type_t*) pointer;
4227 }
4228
4229 static construct_type_t *parse_reference_declarator(void)
4230 {
4231         eat('&');
4232
4233         parsed_reference_t *reference = obstack_alloc(&temp_obst, sizeof(reference[0]));
4234         memset(reference, 0, sizeof(reference[0]));
4235         reference->construct_type.kind = CONSTRUCT_REFERENCE;
4236
4237         return (construct_type_t*)reference;
4238 }
4239
4240 static construct_type_t *parse_array_declarator(void)
4241 {
4242         eat('[');
4243         add_anchor_token(']');
4244
4245         parsed_array_t *array = obstack_alloc(&temp_obst, sizeof(array[0]));
4246         memset(array, 0, sizeof(array[0]));
4247         array->construct_type.kind = CONSTRUCT_ARRAY;
4248
4249         if (token.type == T_static) {
4250                 array->is_static = true;
4251                 next_token();
4252         }
4253
4254         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
4255         if (type_qualifiers != 0) {
4256                 if (token.type == T_static) {
4257                         array->is_static = true;
4258                         next_token();
4259                 }
4260         }
4261         array->type_qualifiers = type_qualifiers;
4262
4263         if (token.type == '*' && look_ahead(1)->type == ']') {
4264                 array->is_variable = true;
4265                 next_token();
4266         } else if (token.type != ']') {
4267                 array->size = parse_assignment_expression();
4268         }
4269
4270         rem_anchor_token(']');
4271         expect(']');
4272
4273 end_error:
4274         return (construct_type_t*) array;
4275 }
4276
4277 static construct_type_t *parse_function_declarator(scope_t *scope,
4278                                                    decl_modifiers_t modifiers)
4279 {
4280         type_t          *type  = allocate_type_zero(TYPE_FUNCTION);
4281         function_type_t *ftype = &type->function;
4282
4283         ftype->linkage = current_linkage;
4284
4285         switch (modifiers & (DM_CDECL | DM_STDCALL | DM_FASTCALL | DM_THISCALL)) {
4286                 case DM_NONE:     break;
4287                 case DM_CDECL:    ftype->calling_convention = CC_CDECL;    break;
4288                 case DM_STDCALL:  ftype->calling_convention = CC_STDCALL;  break;
4289                 case DM_FASTCALL: ftype->calling_convention = CC_FASTCALL; break;
4290                 case DM_THISCALL: ftype->calling_convention = CC_THISCALL; break;
4291
4292                 default:
4293                         errorf(HERE, "multiple calling conventions in declaration");
4294                         break;
4295         }
4296
4297         parse_parameters(ftype, scope);
4298
4299         construct_function_type_t *construct_function_type =
4300                 obstack_alloc(&temp_obst, sizeof(construct_function_type[0]));
4301         memset(construct_function_type, 0, sizeof(construct_function_type[0]));
4302         construct_function_type->construct_type.kind = CONSTRUCT_FUNCTION;
4303         construct_function_type->function_type       = type;
4304
4305         return &construct_function_type->construct_type;
4306 }
4307
4308 typedef struct parse_declarator_env_t {
4309         decl_modifiers_t   modifiers;
4310         symbol_t          *symbol;
4311         source_position_t  source_position;
4312         scope_t            parameters;
4313 } parse_declarator_env_t;
4314
4315 static construct_type_t *parse_inner_declarator(parse_declarator_env_t *env,
4316                 bool may_be_abstract)
4317 {
4318         /* construct a single linked list of construct_type_t's which describe
4319          * how to construct the final declarator type */
4320         construct_type_t *first      = NULL;
4321         construct_type_t *last       = NULL;
4322         gnu_attribute_t  *attributes = NULL;
4323
4324         decl_modifiers_t modifiers = parse_attributes(&attributes);
4325
4326         for (;;) {
4327                 construct_type_t *type;
4328                 switch (token.type) {
4329                         case '&':
4330                                 if (!(c_mode & _CXX))
4331                                         errorf(HERE, "references are only available for C++");
4332                                 type = parse_reference_declarator();
4333                                 break;
4334
4335                         case '*':
4336                                 type = parse_pointer_declarator();
4337                                 break;
4338
4339                         default:
4340                                 goto ptr_operator_end;
4341                 }
4342
4343                 if (last == NULL) {
4344                         first = type;
4345                         last  = type;
4346                 } else {
4347                         last->next = type;
4348                         last       = type;
4349                 }
4350
4351                 /* TODO: find out if this is correct */
4352                 modifiers |= parse_attributes(&attributes);
4353         }
4354 ptr_operator_end:
4355
4356         if (env != NULL) {
4357                 modifiers      |= env->modifiers;
4358                 env->modifiers  = modifiers;
4359         }
4360
4361         construct_type_t *inner_types = NULL;
4362
4363         switch (token.type) {
4364         case T_IDENTIFIER:
4365                 if (env == NULL) {
4366                         errorf(HERE, "no identifier expected in typename");
4367                 } else {
4368                         env->symbol          = token.v.symbol;
4369                         env->source_position = token.source_position;
4370                 }
4371                 next_token();
4372                 break;
4373         case '(':
4374                 next_token();
4375                 add_anchor_token(')');
4376                 inner_types = parse_inner_declarator(env, may_be_abstract);
4377                 if (inner_types != NULL) {
4378                         /* All later declarators only modify the return type */
4379                         env = NULL;
4380                 }
4381                 rem_anchor_token(')');
4382                 expect(')');
4383                 break;
4384         default:
4385                 if (may_be_abstract)
4386                         break;
4387                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', NULL);
4388                 eat_until_anchor();
4389                 return NULL;
4390         }
4391
4392         construct_type_t *p = last;
4393
4394         while (true) {
4395                 construct_type_t *type;
4396                 switch (token.type) {
4397                 case '(': {
4398                         scope_t *scope = NULL;
4399                         if (env != NULL)
4400                                 scope = &env->parameters;
4401
4402                         type = parse_function_declarator(scope, modifiers);
4403                         break;
4404                 }
4405                 case '[':
4406                         type = parse_array_declarator();
4407                         break;
4408                 default:
4409                         goto declarator_finished;
4410                 }
4411
4412                 /* insert in the middle of the list (behind p) */
4413                 if (p != NULL) {
4414                         type->next = p->next;
4415                         p->next    = type;
4416                 } else {
4417                         type->next = first;
4418                         first      = type;
4419                 }
4420                 if (last == p) {
4421                         last = type;
4422                 }
4423         }
4424
4425 declarator_finished:
4426         /* append inner_types at the end of the list, we don't to set last anymore
4427          * as it's not needed anymore */
4428         if (last == NULL) {
4429                 assert(first == NULL);
4430                 first = inner_types;
4431         } else {
4432                 last->next = inner_types;
4433         }
4434
4435         return first;
4436 end_error:
4437         return NULL;
4438 }
4439
4440 static void parse_declaration_attributes(entity_t *entity)
4441 {
4442         gnu_attribute_t  *attributes = NULL;
4443         decl_modifiers_t  modifiers  = parse_attributes(&attributes);
4444
4445         if (entity == NULL)
4446                 return;
4447
4448         type_t *type;
4449         if (entity->kind == ENTITY_TYPEDEF) {
4450                 modifiers |= entity->typedefe.modifiers;
4451                 type       = entity->typedefe.type;
4452         } else {
4453                 assert(is_declaration(entity));
4454                 modifiers |= entity->declaration.modifiers;
4455                 type       = entity->declaration.type;
4456         }
4457         if (type == NULL)
4458                 return;
4459
4460         /* handle these strange/stupid mode attributes */
4461         gnu_attribute_t *attribute = attributes;
4462         for ( ; attribute != NULL; attribute = attribute->next) {
4463                 if (attribute->kind != GNU_AK_MODE || attribute->invalid)
4464                         continue;
4465
4466                 atomic_type_kind_t  akind = attribute->u.akind;
4467                 if (!is_type_signed(type)) {
4468                         switch (akind) {
4469                         case ATOMIC_TYPE_CHAR: akind = ATOMIC_TYPE_UCHAR; break;
4470                         case ATOMIC_TYPE_SHORT: akind = ATOMIC_TYPE_USHORT; break;
4471                         case ATOMIC_TYPE_INT: akind = ATOMIC_TYPE_UINT; break;
4472                         case ATOMIC_TYPE_LONGLONG: akind = ATOMIC_TYPE_ULONGLONG; break;
4473                         default:
4474                                 panic("invalid akind in mode attribute");
4475                         }
4476                 } else {
4477                         switch (akind) {
4478                         case ATOMIC_TYPE_CHAR: akind = ATOMIC_TYPE_SCHAR; break;
4479                         case ATOMIC_TYPE_SHORT: akind = ATOMIC_TYPE_SHORT; break;
4480                         case ATOMIC_TYPE_INT: akind = ATOMIC_TYPE_INT; break;
4481                         case ATOMIC_TYPE_LONGLONG: akind = ATOMIC_TYPE_LONGLONG; break;
4482                         default:
4483                                 panic("invalid akind in mode attribute");
4484                         }
4485                 }
4486
4487                 type = make_atomic_type(akind, type->base.qualifiers);
4488         }
4489
4490         type_modifiers_t type_modifiers = type->base.modifiers;
4491         if (modifiers & DM_TRANSPARENT_UNION)
4492                 modifiers |= TYPE_MODIFIER_TRANSPARENT_UNION;
4493
4494         if (type->base.modifiers != type_modifiers) {
4495                 type_t *copy = duplicate_type(type);
4496                 copy->base.modifiers = type_modifiers;
4497
4498                 type = typehash_insert(copy);
4499                 if (type != copy) {
4500                         obstack_free(type_obst, copy);
4501                 }
4502         }
4503
4504         if (entity->kind == ENTITY_TYPEDEF) {
4505                 entity->typedefe.type      = type;
4506                 entity->typedefe.modifiers = modifiers;
4507         } else {
4508                 entity->declaration.type      = type;
4509                 entity->declaration.modifiers = modifiers;
4510         }
4511 }
4512
4513 static type_t *construct_declarator_type(construct_type_t *construct_list,
4514                                          type_t *type, variable_t *variable)
4515 {
4516         construct_type_t *iter = construct_list;
4517         for (; iter != NULL; iter = iter->next) {
4518                 switch (iter->kind) {
4519                 case CONSTRUCT_INVALID:
4520                         internal_errorf(HERE, "invalid type construction found");
4521                 case CONSTRUCT_FUNCTION: {
4522                         construct_function_type_t *construct_function_type
4523                                 = (construct_function_type_t*) iter;
4524
4525                         type_t *function_type = construct_function_type->function_type;
4526
4527                         function_type->function.return_type = type;
4528
4529                         type_t *skipped_return_type = skip_typeref(type);
4530                         /* §6.7.5.3(1) */
4531                         if (is_type_function(skipped_return_type)) {
4532                                 errorf(HERE, "function returning function is not allowed");
4533                         } else if (is_type_array(skipped_return_type)) {
4534                                 errorf(HERE, "function returning array is not allowed");
4535                         } else {
4536                                 if (skipped_return_type->base.qualifiers != 0 && warning.other) {
4537                                         warningf(HERE,
4538                                                 "type qualifiers in return type of function type are meaningless");
4539                                 }
4540                         }
4541
4542                         type = function_type;
4543                         break;
4544                 }
4545
4546                 case CONSTRUCT_POINTER: {
4547                         if (is_type_reference(skip_typeref(type)))
4548                                 errorf(HERE, "cannot declare a pointer to reference");
4549
4550                         parsed_pointer_t *parsed_pointer = (parsed_pointer_t*) iter;
4551                         type = make_based_pointer_type(type, parsed_pointer->type_qualifiers, variable);
4552                         continue;
4553                 }
4554
4555                 case CONSTRUCT_REFERENCE:
4556                         if (is_type_reference(skip_typeref(type)))
4557                                 errorf(HERE, "cannot declare a reference to reference");
4558
4559                         type = make_reference_type(type);
4560                         continue;
4561
4562                 case CONSTRUCT_ARRAY: {
4563                         if (is_type_reference(skip_typeref(type)))
4564                                 errorf(HERE, "cannot declare an array of references");
4565
4566                         parsed_array_t *parsed_array  = (parsed_array_t*) iter;
4567                         type_t         *array_type    = allocate_type_zero(TYPE_ARRAY);
4568
4569                         expression_t *size_expression = parsed_array->size;
4570                         if (size_expression != NULL) {
4571                                 size_expression
4572                                         = create_implicit_cast(size_expression, type_size_t);
4573                         }
4574
4575                         array_type->base.qualifiers       = parsed_array->type_qualifiers;
4576                         array_type->array.element_type    = type;
4577                         array_type->array.is_static       = parsed_array->is_static;
4578                         array_type->array.is_variable     = parsed_array->is_variable;
4579                         array_type->array.size_expression = size_expression;
4580
4581                         if (size_expression != NULL) {
4582                                 if (is_constant_expression(size_expression)) {
4583                                         array_type->array.size_constant = true;
4584                                         array_type->array.size
4585                                                 = fold_constant(size_expression);
4586                                 } else {
4587                                         array_type->array.is_vla = true;
4588                                 }
4589                         }
4590
4591                         type_t *skipped_type = skip_typeref(type);
4592                         /* §6.7.5.2(1) */
4593                         if (is_type_incomplete(skipped_type)) {
4594                                 errorf(HERE, "array of incomplete type '%T' is not allowed", type);
4595                         } else if (is_type_function(skipped_type)) {
4596                                 errorf(HERE, "array of functions is not allowed");
4597                         }
4598                         type = array_type;
4599                         break;
4600                 }
4601                 }
4602
4603                 type_t *hashed_type = typehash_insert(type);
4604                 if (hashed_type != type) {
4605                         /* the function type was constructed earlier freeing it here will
4606                          * destroy other types... */
4607                         if (iter->kind != CONSTRUCT_FUNCTION) {
4608                                 free_type(type);
4609                         }
4610                         type = hashed_type;
4611                 }
4612         }
4613
4614         return type;
4615 }
4616
4617 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
4618                                   bool may_be_abstract,
4619                                   bool create_compound_member)
4620 {
4621         parse_declarator_env_t env;
4622         memset(&env, 0, sizeof(env));
4623         env.modifiers = specifiers->modifiers;
4624
4625         construct_type_t *construct_type
4626                 = parse_inner_declarator(&env, may_be_abstract);
4627         type_t *type = construct_declarator_type(construct_type, specifiers->type, specifiers->based_variable);
4628
4629         if (construct_type != NULL) {
4630                 obstack_free(&temp_obst, construct_type);
4631         }
4632
4633         entity_t *entity;
4634         if (specifiers->storage_class == STORAGE_CLASS_TYPEDEF) {
4635                 entity                       = allocate_entity_zero(ENTITY_TYPEDEF);
4636                 entity->base.symbol          = env.symbol;
4637                 entity->base.source_position = env.source_position;
4638                 entity->typedefe.type        = type;
4639
4640                 if (anonymous_entity != NULL) {
4641                         if (is_type_compound(type)) {
4642                                 assert(anonymous_entity->compound.alias == NULL);
4643                                 assert(anonymous_entity->kind == ENTITY_STRUCT ||
4644                                        anonymous_entity->kind == ENTITY_UNION);
4645                                 anonymous_entity->compound.alias = entity;
4646                                 anonymous_entity = NULL;
4647                         } else if (is_type_enum(type)) {
4648                                 assert(anonymous_entity->enume.alias == NULL);
4649                                 assert(anonymous_entity->kind == ENTITY_ENUM);
4650                                 anonymous_entity->enume.alias = entity;
4651                                 anonymous_entity = NULL;
4652                         }
4653                 }
4654         } else {
4655                 if (create_compound_member) {
4656                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER);
4657                 } else if (is_type_function(skip_typeref(type))) {
4658                         entity = allocate_entity_zero(ENTITY_FUNCTION);
4659
4660                         entity->function.is_inline  = specifiers->is_inline;
4661                         entity->function.parameters = env.parameters;
4662                 } else {
4663                         entity = allocate_entity_zero(ENTITY_VARIABLE);
4664
4665                         entity->variable.get_property_sym = specifiers->get_property_sym;
4666                         entity->variable.put_property_sym = specifiers->put_property_sym;
4667                         if (specifiers->alignment != 0) {
4668                                 /* TODO: add checks here */
4669                                 entity->variable.alignment = specifiers->alignment;
4670                         }
4671
4672                         if (warning.other && specifiers->is_inline && is_type_valid(type)) {
4673                                 warningf(&env.source_position,
4674                                                  "variable '%Y' declared 'inline'\n", env.symbol);
4675                         }
4676                 }
4677
4678                 entity->base.source_position          = env.source_position;
4679                 entity->base.symbol                   = env.symbol;
4680                 entity->base.namespc                  = NAMESPACE_NORMAL;
4681                 entity->declaration.type              = type;
4682                 entity->declaration.modifiers         = env.modifiers;
4683                 entity->declaration.deprecated_string = specifiers->deprecated_string;
4684
4685                 storage_class_t storage_class = specifiers->storage_class;
4686                 entity->declaration.declared_storage_class = storage_class;
4687
4688                 if (storage_class == STORAGE_CLASS_NONE
4689                                 && current_scope != file_scope) {
4690                         storage_class = STORAGE_CLASS_AUTO;
4691                 }
4692                 entity->declaration.storage_class = storage_class;
4693         }
4694
4695         parse_declaration_attributes(entity);
4696
4697         return entity;
4698 }
4699
4700 static type_t *parse_abstract_declarator(type_t *base_type)
4701 {
4702         construct_type_t *construct_type = parse_inner_declarator(NULL, 1);
4703
4704         type_t *result = construct_declarator_type(construct_type, base_type, NULL);
4705         if (construct_type != NULL) {
4706                 obstack_free(&temp_obst, construct_type);
4707         }
4708
4709         return result;
4710 }
4711
4712 /**
4713  * Check if the declaration of main is suspicious.  main should be a
4714  * function with external linkage, returning int, taking either zero
4715  * arguments, two, or three arguments of appropriate types, ie.
4716  *
4717  * int main([ int argc, char **argv [, char **env ] ]).
4718  *
4719  * @param decl    the declaration to check
4720  * @param type    the function type of the declaration
4721  */
4722 static void check_type_of_main(const entity_t *entity)
4723 {
4724         const source_position_t *pos = &entity->base.source_position;
4725         if (entity->kind != ENTITY_FUNCTION) {
4726                 warningf(pos, "'main' is not a function");
4727                 return;
4728         }
4729
4730         if (entity->declaration.storage_class == STORAGE_CLASS_STATIC) {
4731                 warningf(pos, "'main' is normally a non-static function");
4732         }
4733
4734         type_t *type = skip_typeref(entity->declaration.type);
4735         assert(is_type_function(type));
4736
4737         function_type_t *func_type = &type->function;
4738         if (!types_compatible(skip_typeref(func_type->return_type), type_int)) {
4739                 warningf(pos, "return type of 'main' should be 'int', but is '%T'",
4740                          func_type->return_type);
4741         }
4742         const function_parameter_t *parm = func_type->parameters;
4743         if (parm != NULL) {
4744                 type_t *const first_type = parm->type;
4745                 if (!types_compatible(skip_typeref(first_type), type_int)) {
4746                         warningf(pos,
4747                                  "first argument of 'main' should be 'int', but is '%T'",
4748                                  first_type);
4749                 }
4750                 parm = parm->next;
4751                 if (parm != NULL) {
4752                         type_t *const second_type = parm->type;
4753                         if (!types_compatible(skip_typeref(second_type), type_char_ptr_ptr)) {
4754                                 warningf(pos, "second argument of 'main' should be 'char**', but is '%T'", second_type);
4755                         }
4756                         parm = parm->next;
4757                         if (parm != NULL) {
4758                                 type_t *const third_type = parm->type;
4759                                 if (!types_compatible(skip_typeref(third_type), type_char_ptr_ptr)) {
4760                                         warningf(pos, "third argument of 'main' should be 'char**', but is '%T'", third_type);
4761                                 }
4762                                 parm = parm->next;
4763                                 if (parm != NULL)
4764                                         goto warn_arg_count;
4765                         }
4766                 } else {
4767 warn_arg_count:
4768                         warningf(pos, "'main' takes only zero, two or three arguments");
4769                 }
4770         }
4771 }
4772
4773 /**
4774  * Check if a symbol is the equal to "main".
4775  */
4776 static bool is_sym_main(const symbol_t *const sym)
4777 {
4778         return strcmp(sym->string, "main") == 0;
4779 }
4780
4781 static const char *get_entity_kind_name(entity_kind_t kind)
4782 {
4783         switch ((entity_kind_tag_t) kind) {
4784         case ENTITY_FUNCTION:        return "function";
4785         case ENTITY_VARIABLE:        return "variable";
4786         case ENTITY_COMPOUND_MEMBER: return "compound type member";
4787         case ENTITY_STRUCT:          return "struct";
4788         case ENTITY_UNION:           return "union";
4789         case ENTITY_ENUM:            return "enum";
4790         case ENTITY_ENUM_VALUE:      return "enum value";
4791         case ENTITY_LABEL:           return "label";
4792         case ENTITY_LOCAL_LABEL:     return "local label";
4793         case ENTITY_TYPEDEF:         return "typedef";
4794         case ENTITY_NAMESPACE:       return "namespace";
4795         case ENTITY_INVALID:         break;
4796         }
4797
4798         panic("Invalid entity kind encountered in get_entity_kind_name");
4799 }
4800
4801 static void error_redefined_as_different_kind(const source_position_t *pos,
4802                 const entity_t *old, entity_kind_t new_kind)
4803 {
4804         errorf(pos, "redeclaration of %s '%Y' as %s (declared %P)",
4805                get_entity_kind_name(old->kind), old->base.symbol,
4806                get_entity_kind_name(new_kind), &old->base.source_position);
4807 }
4808
4809 /**
4810  * record entities for the NAMESPACE_NORMAL, and produce error messages/warnings
4811  * for various problems that occur for multiple definitions
4812  */
4813 static entity_t *record_entity(entity_t *entity, const bool is_definition)
4814 {
4815         const symbol_t *const    symbol  = entity->base.symbol;
4816         const namespace_tag_t    namespc = (namespace_tag_t)entity->base.namespc;
4817         const source_position_t *pos     = &entity->base.source_position;
4818
4819         assert(symbol != NULL);
4820         entity_t *previous_entity = get_entity(symbol, namespc);
4821         /* pushing the same entity twice will break the stack structure */
4822         assert(previous_entity != entity);
4823
4824         if (entity->kind == ENTITY_FUNCTION) {
4825                 type_t *const orig_type = entity->declaration.type;
4826                 type_t *const type      = skip_typeref(orig_type);
4827
4828                 assert(is_type_function(type));
4829                 if (type->function.unspecified_parameters &&
4830                                 warning.strict_prototypes &&
4831                                 previous_entity == NULL) {
4832                         warningf(pos, "function declaration '%#T' is not a prototype",
4833                                          orig_type, symbol);
4834                 }
4835
4836                 if (warning.main && current_scope == file_scope
4837                                 && is_sym_main(symbol)) {
4838                         check_type_of_main(entity);
4839                 }
4840         }
4841
4842         if (is_declaration(entity)) {
4843                 if (warning.nested_externs
4844                                 && entity->declaration.storage_class == STORAGE_CLASS_EXTERN
4845                                 && current_scope != file_scope) {
4846                         warningf(pos, "nested extern declaration of '%#T'",
4847                                  entity->declaration.type, symbol);
4848                 }
4849         }
4850
4851         if (previous_entity != NULL
4852             && previous_entity->base.parent_scope == &current_function->parameters
4853                 && current_scope->depth == previous_entity->base.parent_scope->depth+1){
4854
4855                 assert(previous_entity->kind == ENTITY_VARIABLE);
4856                 errorf(pos,
4857                        "declaration '%#T' redeclares the parameter '%#T' (declared %P)",
4858                        entity->declaration.type, symbol,
4859                            previous_entity->declaration.type, symbol,
4860                            &previous_entity->base.source_position);
4861                 goto finish;
4862         }
4863
4864         if (previous_entity != NULL
4865                         && previous_entity->base.parent_scope == current_scope) {
4866
4867                 if (previous_entity->kind != entity->kind) {
4868                         error_redefined_as_different_kind(pos, previous_entity,
4869                                                           entity->kind);
4870                         goto finish;
4871                 }
4872                 if (previous_entity->kind == ENTITY_ENUM_VALUE) {
4873                         errorf(pos,
4874                                    "redeclaration of enum entry '%Y' (declared %P)",
4875                                    symbol, &previous_entity->base.source_position);
4876                         goto finish;
4877                 }
4878                 if (previous_entity->kind == ENTITY_TYPEDEF) {
4879                         /* TODO: C++ allows this for exactly the same type */
4880                         errorf(pos,
4881                                "redefinition of typedef '%Y' (declared %P)",
4882                                symbol, &previous_entity->base.source_position);
4883                         goto finish;
4884                 }
4885
4886                 /* at this point we should have only VARIABLES or FUNCTIONS */
4887                 assert(is_declaration(previous_entity) && is_declaration(entity));
4888
4889                 /* can happen for K&R style declarations */
4890                 if (previous_entity->kind == ENTITY_VARIABLE
4891                                 && previous_entity->declaration.type == NULL
4892                                 && entity->kind == ENTITY_VARIABLE) {
4893                         previous_entity->declaration.type = entity->declaration.type;
4894                         previous_entity->declaration.storage_class
4895                                 = entity->declaration.storage_class;
4896                         previous_entity->declaration.declared_storage_class
4897                                 = entity->declaration.declared_storage_class;
4898                         previous_entity->declaration.modifiers
4899                                 = entity->declaration.modifiers;
4900                         previous_entity->declaration.deprecated_string
4901                                 = entity->declaration.deprecated_string;
4902                 }
4903                 assert(entity->declaration.type != NULL);
4904
4905                 declaration_t *const previous_declaration
4906                         = &previous_entity->declaration;
4907                 declaration_t *const declaration = &entity->declaration;
4908                 type_t *const orig_type = entity->declaration.type;
4909                 type_t *const type      = skip_typeref(orig_type);
4910
4911                 type_t *prev_type       = skip_typeref(previous_declaration->type);
4912
4913                 if (!types_compatible(type, prev_type)) {
4914                         errorf(pos,
4915                                    "declaration '%#T' is incompatible with '%#T' (declared %P)",
4916                                    orig_type, symbol, previous_declaration->type, symbol,
4917                                    &previous_entity->base.source_position);
4918                 } else {
4919                         unsigned old_storage_class = previous_declaration->storage_class;
4920                         if (warning.redundant_decls     && is_definition
4921                                 && previous_declaration->storage_class == STORAGE_CLASS_STATIC
4922                                 && !(previous_declaration->modifiers & DM_USED)
4923                                 && !previous_declaration->used) {
4924                                 warningf(&previous_entity->base.source_position,
4925                                          "unnecessary static forward declaration for '%#T'",
4926                                          previous_declaration->type, symbol);
4927                         }
4928
4929                         unsigned new_storage_class = declaration->storage_class;
4930                         if (is_type_incomplete(prev_type)) {
4931                                 previous_declaration->type = type;
4932                                 prev_type                  = type;
4933                         }
4934
4935                         /* pretend no storage class means extern for function
4936                          * declarations (except if the previous declaration is neither
4937                          * none nor extern) */
4938                         if (entity->kind == ENTITY_FUNCTION) {
4939                                 if (prev_type->function.unspecified_parameters) {
4940                                         previous_declaration->type = type;
4941                                         prev_type                  = type;
4942                                 }
4943
4944                                 switch (old_storage_class) {
4945                                 case STORAGE_CLASS_NONE:
4946                                         old_storage_class = STORAGE_CLASS_EXTERN;
4947                                         /* FALLTHROUGH */
4948
4949                                 case STORAGE_CLASS_EXTERN:
4950                                         if (is_definition) {
4951                                                 if (warning.missing_prototypes &&
4952                                                     prev_type->function.unspecified_parameters &&
4953                                                     !is_sym_main(symbol)) {
4954                                                         warningf(pos, "no previous prototype for '%#T'",
4955                                                                          orig_type, symbol);
4956                                                 }
4957                                         } else if (new_storage_class == STORAGE_CLASS_NONE) {
4958                                                 new_storage_class = STORAGE_CLASS_EXTERN;
4959                                         }
4960                                         break;
4961
4962                                 default:
4963                                         break;
4964                                 }
4965                         }
4966
4967                         if (old_storage_class == STORAGE_CLASS_EXTERN &&
4968                                         new_storage_class == STORAGE_CLASS_EXTERN) {
4969 warn_redundant_declaration:
4970                                 if (!is_definition           &&
4971                                     warning.redundant_decls  &&
4972                                     is_type_valid(prev_type) &&
4973                                     strcmp(previous_entity->base.source_position.input_name, "<builtin>") != 0) {
4974                                         warningf(pos,
4975                                                  "redundant declaration for '%Y' (declared %P)",
4976                                                  symbol, &previous_entity->base.source_position);
4977                                 }
4978                         } else if (current_function == NULL) {
4979                                 if (old_storage_class != STORAGE_CLASS_STATIC &&
4980                                     new_storage_class == STORAGE_CLASS_STATIC) {
4981                                         errorf(pos,
4982                                                "static declaration of '%Y' follows non-static declaration (declared %P)",
4983                                                symbol, &previous_entity->base.source_position);
4984                                 } else if (old_storage_class == STORAGE_CLASS_EXTERN) {
4985                                         previous_declaration->storage_class          = STORAGE_CLASS_NONE;
4986                                         previous_declaration->declared_storage_class = STORAGE_CLASS_NONE;
4987                                 } else {
4988                                         /* ISO/IEC 14882:1998(E) §C.1.2:1 */
4989                                         if (c_mode & _CXX)
4990                                                 goto error_redeclaration;
4991                                         goto warn_redundant_declaration;
4992                                 }
4993                         } else if (is_type_valid(prev_type)) {
4994                                 if (old_storage_class == new_storage_class) {
4995 error_redeclaration:
4996                                         errorf(pos, "redeclaration of '%Y' (declared %P)",
4997                                                symbol, &previous_entity->base.source_position);
4998                                 } else {
4999                                         errorf(pos,
5000                                                "redeclaration of '%Y' with different linkage (declared %P)",
5001                                                symbol, &previous_entity->base.source_position);
5002                                 }
5003                         }
5004                 }
5005
5006                 previous_declaration->modifiers |= declaration->modifiers;
5007                 if (entity->kind == ENTITY_FUNCTION) {
5008                         previous_entity->function.is_inline |= entity->function.is_inline;
5009                 }
5010                 return previous_entity;
5011         }
5012
5013         if (entity->kind == ENTITY_FUNCTION) {
5014                 if (is_definition &&
5015                                 entity->declaration.storage_class != STORAGE_CLASS_STATIC) {
5016                         if (warning.missing_prototypes && !is_sym_main(symbol)) {
5017                                 warningf(pos, "no previous prototype for '%#T'",
5018                                          entity->declaration.type, symbol);
5019                         } else if (warning.missing_declarations && !is_sym_main(symbol)) {
5020                                 warningf(pos, "no previous declaration for '%#T'",
5021                                          entity->declaration.type, symbol);
5022                         }
5023                 }
5024         } else if (warning.missing_declarations
5025                         && entity->kind == ENTITY_VARIABLE
5026                         && current_scope == file_scope) {
5027                 declaration_t *declaration = &entity->declaration;
5028                 if (declaration->storage_class == STORAGE_CLASS_NONE ||
5029                                 declaration->storage_class == STORAGE_CLASS_THREAD) {
5030                         warningf(pos, "no previous declaration for '%#T'",
5031                                  declaration->type, symbol);
5032                 }
5033         }
5034
5035 finish:
5036         assert(entity->base.parent_scope == NULL);
5037         assert(current_scope != NULL);
5038
5039         entity->base.parent_scope = current_scope;
5040         entity->base.namespc      = NAMESPACE_NORMAL;
5041         environment_push(entity);
5042         append_entity(current_scope, entity);
5043
5044         return entity;
5045 }
5046
5047 static void parser_error_multiple_definition(entity_t *entity,
5048                 const source_position_t *source_position)
5049 {
5050         errorf(source_position, "multiple definition of symbol '%Y' (declared %P)",
5051                entity->base.symbol, &entity->base.source_position);
5052 }
5053
5054 static bool is_declaration_specifier(const token_t *token,
5055                                      bool only_specifiers_qualifiers)
5056 {
5057         switch (token->type) {
5058                 TYPE_SPECIFIERS
5059                 TYPE_QUALIFIERS
5060                         return true;
5061                 case T_IDENTIFIER:
5062                         return is_typedef_symbol(token->v.symbol);
5063
5064                 case T___extension__:
5065                 STORAGE_CLASSES
5066                         return !only_specifiers_qualifiers;
5067
5068                 default:
5069                         return false;
5070         }
5071 }
5072
5073 static void parse_init_declarator_rest(entity_t *entity)
5074 {
5075         assert(is_declaration(entity));
5076         declaration_t *const declaration = &entity->declaration;
5077
5078         eat('=');
5079
5080         type_t *orig_type = declaration->type;
5081         type_t *type      = skip_typeref(orig_type);
5082
5083         if (entity->kind == ENTITY_VARIABLE
5084                         && entity->variable.initializer != NULL) {
5085                 parser_error_multiple_definition(entity, HERE);
5086         }
5087
5088         bool must_be_constant = false;
5089         if (declaration->storage_class == STORAGE_CLASS_STATIC        ||
5090             declaration->storage_class == STORAGE_CLASS_THREAD_STATIC ||
5091             entity->base.parent_scope  == file_scope) {
5092                 must_be_constant = true;
5093         }
5094
5095         if (is_type_function(type)) {
5096                 errorf(&entity->base.source_position,
5097                        "function '%#T' is initialized like a variable",
5098                        orig_type, entity->base.symbol);
5099                 orig_type = type_error_type;
5100         }
5101
5102         parse_initializer_env_t env;
5103         env.type             = orig_type;
5104         env.must_be_constant = must_be_constant;
5105         env.entity           = entity;
5106         current_init_decl    = entity;
5107
5108         initializer_t *initializer = parse_initializer(&env);
5109         current_init_decl = NULL;
5110
5111         if (entity->kind == ENTITY_VARIABLE) {
5112                 /* § 6.7.5 (22)  array initializers for arrays with unknown size
5113                  * determine the array type size */
5114                 declaration->type            = env.type;
5115                 entity->variable.initializer = initializer;
5116         }
5117 }
5118
5119 /* parse rest of a declaration without any declarator */
5120 static void parse_anonymous_declaration_rest(
5121                 const declaration_specifiers_t *specifiers)
5122 {
5123         eat(';');
5124
5125         if (warning.other) {
5126                 if (specifiers->storage_class != STORAGE_CLASS_NONE) {
5127                         warningf(&specifiers->source_position,
5128                                  "useless storage class in empty declaration");
5129                 }
5130
5131                 type_t *type = specifiers->type;
5132                 switch (type->kind) {
5133                         case TYPE_COMPOUND_STRUCT:
5134                         case TYPE_COMPOUND_UNION: {
5135                                 if (type->compound.compound->base.symbol == NULL) {
5136                                         warningf(&specifiers->source_position,
5137                                                  "unnamed struct/union that defines no instances");
5138                                 }
5139                                 break;
5140                         }
5141
5142                         case TYPE_ENUM:
5143                                 break;
5144
5145                         default:
5146                                 warningf(&specifiers->source_position, "empty declaration");
5147                                 break;
5148                 }
5149         }
5150 }
5151
5152 static void check_variable_type_complete(entity_t *ent)
5153 {
5154         if (ent->kind != ENTITY_VARIABLE)
5155                 return;
5156
5157         declaration_t *decl = &ent->declaration;
5158         if (decl->storage_class == STORAGE_CLASS_EXTERN)
5159                 return;
5160
5161         type_t *type = decl->type;
5162         if (!is_type_incomplete(skip_typeref(type)))
5163                 return;
5164
5165         errorf(&ent->base.source_position,
5166                         "variable '%#T' is of incomplete type", type, ent->base.symbol);
5167 }
5168
5169
5170 static void parse_declaration_rest(entity_t *ndeclaration,
5171                 const declaration_specifiers_t *specifiers,
5172                 parsed_declaration_func finished_declaration)
5173 {
5174         add_anchor_token(';');
5175         add_anchor_token(',');
5176         while (true) {
5177                 entity_t *entity = finished_declaration(ndeclaration, token.type == '=');
5178
5179                 if (token.type == '=') {
5180                         parse_init_declarator_rest(entity);
5181                 }
5182
5183                 check_variable_type_complete(entity);
5184
5185                 if (token.type != ',')
5186                         break;
5187                 eat(',');
5188
5189                 add_anchor_token('=');
5190                 ndeclaration = parse_declarator(specifiers, /*may_be_abstract=*/false, false);
5191                 rem_anchor_token('=');
5192         }
5193         expect(';');
5194
5195 end_error:
5196         anonymous_entity = NULL;
5197         rem_anchor_token(';');
5198         rem_anchor_token(',');
5199 }
5200
5201 static entity_t *finished_kr_declaration(entity_t *entity, bool is_definition)
5202 {
5203         symbol_t *symbol = entity->base.symbol;
5204         if (symbol == NULL) {
5205                 errorf(HERE, "anonymous declaration not valid as function parameter");
5206                 return entity;
5207         }
5208
5209         assert(entity->base.namespc == NAMESPACE_NORMAL);
5210         entity_t *previous_entity = get_entity(symbol, NAMESPACE_NORMAL);
5211         if (previous_entity == NULL
5212                         || previous_entity->base.parent_scope != current_scope) {
5213                 errorf(HERE, "expected declaration of a function parameter, found '%Y'",
5214                        symbol);
5215                 return entity;
5216         }
5217
5218         if (is_definition) {
5219                 errorf(HERE, "parameter %Y is initialised", entity->base.symbol);
5220         }
5221
5222         return record_entity(entity, false);
5223 }
5224
5225 static void parse_declaration(parsed_declaration_func finished_declaration)
5226 {
5227         declaration_specifiers_t specifiers;
5228         memset(&specifiers, 0, sizeof(specifiers));
5229
5230         add_anchor_token(';');
5231         parse_declaration_specifiers(&specifiers);
5232         rem_anchor_token(';');
5233
5234         if (token.type == ';') {
5235                 parse_anonymous_declaration_rest(&specifiers);
5236         } else {
5237                 entity_t *entity = parse_declarator(&specifiers, /*may_be_abstract=*/false, false);
5238                 parse_declaration_rest(entity, &specifiers, finished_declaration);
5239         }
5240 }
5241
5242 static type_t *get_default_promoted_type(type_t *orig_type)
5243 {
5244         type_t *result = orig_type;
5245
5246         type_t *type = skip_typeref(orig_type);
5247         if (is_type_integer(type)) {
5248                 result = promote_integer(type);
5249         } else if (type == type_float) {
5250                 result = type_double;
5251         }
5252
5253         return result;
5254 }
5255
5256 static void parse_kr_declaration_list(entity_t *entity)
5257 {
5258         if (entity->kind != ENTITY_FUNCTION)
5259                 return;
5260
5261         type_t *type = skip_typeref(entity->declaration.type);
5262         assert(is_type_function(type));
5263         if (!type->function.kr_style_parameters)
5264                 return;
5265
5266
5267         add_anchor_token('{');
5268
5269         /* push function parameters */
5270         size_t const top = environment_top();
5271         scope_push(&entity->function.parameters);
5272
5273         entity_t *parameter = entity->function.parameters.entities;
5274         for ( ; parameter != NULL; parameter = parameter->base.next) {
5275                 assert(parameter->base.parent_scope == NULL);
5276                 parameter->base.parent_scope = current_scope;
5277                 environment_push(parameter);
5278         }
5279
5280         /* parse declaration list */
5281         while (is_declaration_specifier(&token, false)) {
5282                 parse_declaration(finished_kr_declaration);
5283         }
5284
5285         /* pop function parameters */
5286         assert(current_scope == &entity->function.parameters);
5287         scope_pop();
5288         environment_pop_to(top);
5289
5290         /* update function type */
5291         type_t *new_type = duplicate_type(type);
5292
5293         function_parameter_t *parameters     = NULL;
5294         function_parameter_t *last_parameter = NULL;
5295
5296         entity_t *parameter_declaration = entity->function.parameters.entities;
5297         for (; parameter_declaration != NULL;
5298                         parameter_declaration = parameter_declaration->base.next) {
5299                 type_t *parameter_type = parameter_declaration->declaration.type;
5300                 if (parameter_type == NULL) {
5301                         if (strict_mode) {
5302                                 errorf(HERE, "no type specified for function parameter '%Y'",
5303                                        parameter_declaration->base.symbol);
5304                         } else {
5305                                 if (warning.implicit_int) {
5306                                         warningf(HERE, "no type specified for function parameter '%Y', using 'int'",
5307                                                  parameter_declaration->base.symbol);
5308                                 }
5309                                 parameter_type                          = type_int;
5310                                 parameter_declaration->declaration.type = parameter_type;
5311                         }
5312                 }
5313
5314                 semantic_parameter(&parameter_declaration->declaration);
5315                 parameter_type = parameter_declaration->declaration.type;
5316
5317                 /*
5318                  * we need the default promoted types for the function type
5319                  */
5320                 parameter_type = get_default_promoted_type(parameter_type);
5321
5322                 function_parameter_t *function_parameter
5323                         = obstack_alloc(type_obst, sizeof(function_parameter[0]));
5324                 memset(function_parameter, 0, sizeof(function_parameter[0]));
5325
5326                 function_parameter->type = parameter_type;
5327                 if (last_parameter != NULL) {
5328                         last_parameter->next = function_parameter;
5329                 } else {
5330                         parameters = function_parameter;
5331                 }
5332                 last_parameter = function_parameter;
5333         }
5334
5335         /* § 6.9.1.7: A K&R style parameter list does NOT act as a function
5336          * prototype */
5337         new_type->function.parameters             = parameters;
5338         new_type->function.unspecified_parameters = true;
5339
5340         type = typehash_insert(new_type);
5341         if (type != new_type) {
5342                 obstack_free(type_obst, new_type);
5343         }
5344
5345         entity->declaration.type = type;
5346
5347         rem_anchor_token('{');
5348 }
5349
5350 static bool first_err = true;
5351
5352 /**
5353  * When called with first_err set, prints the name of the current function,
5354  * else does noting.
5355  */
5356 static void print_in_function(void)
5357 {
5358         if (first_err) {
5359                 first_err = false;
5360                 diagnosticf("%s: In function '%Y':\n",
5361                             current_function->base.base.source_position.input_name,
5362                             current_function->base.base.symbol);
5363         }
5364 }
5365
5366 /**
5367  * Check if all labels are defined in the current function.
5368  * Check if all labels are used in the current function.
5369  */
5370 static void check_labels(void)
5371 {
5372         for (const goto_statement_t *goto_statement = goto_first;
5373             goto_statement != NULL;
5374             goto_statement = goto_statement->next) {
5375                 /* skip computed gotos */
5376                 if (goto_statement->expression != NULL)
5377                         continue;
5378
5379                 label_t *label = goto_statement->label;
5380
5381                 label->used = true;
5382                 if (label->base.source_position.input_name == NULL) {
5383                         print_in_function();
5384                         errorf(&goto_statement->base.source_position,
5385                                "label '%Y' used but not defined", label->base.symbol);
5386                  }
5387         }
5388
5389         if (warning.unused_label) {
5390                 for (const label_statement_t *label_statement = label_first;
5391                          label_statement != NULL;
5392                          label_statement = label_statement->next) {
5393                         label_t *label = label_statement->label;
5394
5395                         if (! label->used) {
5396                                 print_in_function();
5397                                 warningf(&label_statement->base.source_position,
5398                                          "label '%Y' defined but not used", label->base.symbol);
5399                         }
5400                 }
5401         }
5402 }
5403
5404 static void warn_unused_decl(entity_t *entity, entity_t *end,
5405                              char const *const what)
5406 {
5407         for (; entity != NULL; entity = entity->base.next) {
5408                 if (!is_declaration(entity))
5409                         continue;
5410
5411                 declaration_t *declaration = &entity->declaration;
5412                 if (declaration->implicit)
5413                         continue;
5414
5415                 if (!declaration->used) {
5416                         print_in_function();
5417                         warningf(&entity->base.source_position, "%s '%Y' is unused",
5418                                  what, entity->base.symbol);
5419                 } else if (entity->kind == ENTITY_VARIABLE && !entity->variable.read) {
5420                         print_in_function();
5421                         warningf(&entity->base.source_position, "%s '%Y' is never read",
5422                                  what, entity->base.symbol);
5423                 }
5424
5425                 if (entity == end)
5426                         break;
5427         }
5428 }
5429
5430 static void check_unused_variables(statement_t *const stmt, void *const env)
5431 {
5432         (void)env;
5433
5434         switch (stmt->kind) {
5435                 case STATEMENT_DECLARATION: {
5436                         declaration_statement_t const *const decls = &stmt->declaration;
5437                         warn_unused_decl(decls->declarations_begin, decls->declarations_end,
5438                                          "variable");
5439                         return;
5440                 }
5441
5442                 case STATEMENT_FOR:
5443                         warn_unused_decl(stmt->fors.scope.entities, NULL, "variable");
5444                         return;
5445
5446                 default:
5447                         return;
5448         }
5449 }
5450
5451 /**
5452  * Check declarations of current_function for unused entities.
5453  */
5454 static void check_declarations(void)
5455 {
5456         if (warning.unused_parameter) {
5457                 const scope_t *scope = &current_function->parameters;
5458
5459                 /* do not issue unused warnings for main */
5460                 if (!is_sym_main(current_function->base.base.symbol)) {
5461                         warn_unused_decl(scope->entities, NULL, "parameter");
5462                 }
5463         }
5464         if (warning.unused_variable) {
5465                 walk_statements(current_function->statement, check_unused_variables,
5466                                 NULL);
5467         }
5468 }
5469
5470 static int determine_truth(expression_t const* const cond)
5471 {
5472         return
5473                 !is_constant_expression(cond) ? 0 :
5474                 fold_constant(cond) != 0      ? 1 :
5475                 -1;
5476 }
5477
5478 static bool expression_returns(expression_t const *const expr)
5479 {
5480         switch (expr->kind) {
5481                 case EXPR_CALL: {
5482                         expression_t const *const func = expr->call.function;
5483                         if (func->kind == EXPR_REFERENCE) {
5484                                 entity_t *entity = func->reference.entity;
5485                                 if (entity->kind == ENTITY_FUNCTION
5486                                                 && entity->declaration.modifiers & DM_NORETURN)
5487                                         return false;
5488                         }
5489
5490                         if (!expression_returns(func))
5491                                 return false;
5492
5493                         for (call_argument_t const* arg = expr->call.arguments; arg != NULL; arg = arg->next) {
5494                                 if (!expression_returns(arg->expression))
5495                                         return false;
5496                         }
5497
5498                         return true;
5499                 }
5500
5501                 case EXPR_REFERENCE:
5502                 case EXPR_REFERENCE_ENUM_VALUE:
5503                 case EXPR_CONST:
5504                 case EXPR_CHARACTER_CONSTANT:
5505                 case EXPR_WIDE_CHARACTER_CONSTANT:
5506                 case EXPR_STRING_LITERAL:
5507                 case EXPR_WIDE_STRING_LITERAL:
5508                 case EXPR_COMPOUND_LITERAL: // TODO descend into initialisers
5509                 case EXPR_LABEL_ADDRESS:
5510                 case EXPR_CLASSIFY_TYPE:
5511                 case EXPR_SIZEOF: // TODO handle obscure VLA case
5512                 case EXPR_ALIGNOF:
5513                 case EXPR_FUNCNAME:
5514                 case EXPR_BUILTIN_SYMBOL:
5515                 case EXPR_BUILTIN_CONSTANT_P:
5516                 case EXPR_BUILTIN_PREFETCH:
5517                 case EXPR_OFFSETOF:
5518                 case EXPR_INVALID:
5519                 case EXPR_STATEMENT: // TODO implement
5520                         return true;
5521
5522                 case EXPR_CONDITIONAL:
5523                         // TODO handle constant expression
5524                         return
5525                                 expression_returns(expr->conditional.condition) && (
5526                                         expression_returns(expr->conditional.true_expression) ||
5527                                         expression_returns(expr->conditional.false_expression)
5528                                 );
5529
5530                 case EXPR_SELECT:
5531                         return expression_returns(expr->select.compound);
5532
5533                 case EXPR_ARRAY_ACCESS:
5534                         return
5535                                 expression_returns(expr->array_access.array_ref) &&
5536                                 expression_returns(expr->array_access.index);
5537
5538                 case EXPR_VA_START:
5539                         return expression_returns(expr->va_starte.ap);
5540
5541                 case EXPR_VA_ARG:
5542                         return expression_returns(expr->va_arge.ap);
5543
5544                 EXPR_UNARY_CASES_MANDATORY
5545                         return expression_returns(expr->unary.value);
5546
5547                 case EXPR_UNARY_THROW:
5548                         return false;
5549
5550                 EXPR_BINARY_CASES
5551                         // TODO handle constant lhs of && and ||
5552                         return
5553                                 expression_returns(expr->binary.left) &&
5554                                 expression_returns(expr->binary.right);
5555
5556                 case EXPR_UNKNOWN:
5557                         break;
5558         }
5559
5560         panic("unhandled expression");
5561 }
5562
5563 static bool noreturn_candidate;
5564
5565 static void check_reachable(statement_t *const stmt)
5566 {
5567         if (stmt->base.reachable)
5568                 return;
5569         if (stmt->kind != STATEMENT_DO_WHILE)
5570                 stmt->base.reachable = true;
5571
5572         statement_t *last = stmt;
5573         statement_t *next;
5574         switch (stmt->kind) {
5575                 case STATEMENT_INVALID:
5576                 case STATEMENT_EMPTY:
5577                 case STATEMENT_DECLARATION:
5578                 case STATEMENT_LOCAL_LABEL:
5579                 case STATEMENT_ASM:
5580                         next = stmt->base.next;
5581                         break;
5582
5583                 case STATEMENT_COMPOUND:
5584                         next = stmt->compound.statements;
5585                         break;
5586
5587                 case STATEMENT_RETURN:
5588                         noreturn_candidate = false;
5589                         return;
5590
5591                 case STATEMENT_IF: {
5592                         if_statement_t const* const ifs = &stmt->ifs;
5593                         int            const        val = determine_truth(ifs->condition);
5594
5595                         if (val >= 0)
5596                                 check_reachable(ifs->true_statement);
5597
5598                         if (val > 0)
5599                                 return;
5600
5601                         if (ifs->false_statement != NULL) {
5602                                 check_reachable(ifs->false_statement);
5603                                 return;
5604                         }
5605
5606                         next = stmt->base.next;
5607                         break;
5608                 }
5609
5610                 case STATEMENT_SWITCH: {
5611                         switch_statement_t const *const switchs = &stmt->switchs;
5612                         expression_t       const *const expr    = switchs->expression;
5613
5614                         if (is_constant_expression(expr)) {
5615                                 long                    const val      = fold_constant(expr);
5616                                 case_label_statement_t *      defaults = NULL;
5617                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
5618                                         if (i->expression == NULL) {
5619                                                 defaults = i;
5620                                                 continue;
5621                                         }
5622
5623                                         if (i->first_case <= val && val <= i->last_case) {
5624                                                 check_reachable((statement_t*)i);
5625                                                 return;
5626                                         }
5627                                 }
5628
5629                                 if (defaults != NULL) {
5630                                         check_reachable((statement_t*)defaults);
5631                                         return;
5632                                 }
5633                         } else {
5634                                 bool has_default = false;
5635                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
5636                                         if (i->expression == NULL)
5637                                                 has_default = true;
5638
5639                                         check_reachable((statement_t*)i);
5640                                 }
5641
5642                                 if (has_default)
5643                                         return;
5644                         }
5645
5646                         next = stmt->base.next;
5647                         break;
5648                 }
5649
5650                 case STATEMENT_EXPRESSION: {
5651                         /* Check for noreturn function call */
5652                         expression_t const *const expr = stmt->expression.expression;
5653                         if (!expression_returns(expr))
5654                                 return;
5655
5656                         next = stmt->base.next;
5657                         break;
5658                 }
5659
5660                 case STATEMENT_CONTINUE: {
5661                         statement_t *parent = stmt;
5662                         for (;;) {
5663                                 parent = parent->base.parent;
5664                                 if (parent == NULL) /* continue not within loop */
5665                                         return;
5666
5667                                 next = parent;
5668                                 switch (parent->kind) {
5669                                         case STATEMENT_WHILE:    goto continue_while;
5670                                         case STATEMENT_DO_WHILE: goto continue_do_while;
5671                                         case STATEMENT_FOR:      goto continue_for;
5672
5673                                         default: break;
5674                                 }
5675                         }
5676                 }
5677
5678                 case STATEMENT_BREAK: {
5679                         statement_t *parent = stmt;
5680                         for (;;) {
5681                                 parent = parent->base.parent;
5682                                 if (parent == NULL) /* break not within loop/switch */
5683                                         return;
5684
5685                                 switch (parent->kind) {
5686                                         case STATEMENT_SWITCH:
5687                                         case STATEMENT_WHILE:
5688                                         case STATEMENT_DO_WHILE:
5689                                         case STATEMENT_FOR:
5690                                                 last = parent;
5691                                                 next = parent->base.next;
5692                                                 goto found_break_parent;
5693
5694                                         default: break;
5695                                 }
5696                         }
5697 found_break_parent:
5698                         break;
5699                 }
5700
5701                 case STATEMENT_GOTO:
5702                         if (stmt->gotos.expression) {
5703                                 statement_t *parent = stmt->base.parent;
5704                                 if (parent == NULL) /* top level goto */
5705                                         return;
5706                                 next = parent;
5707                         } else {
5708                                 next = stmt->gotos.label->statement;
5709                                 if (next == NULL) /* missing label */
5710                                         return;
5711                         }
5712                         break;
5713
5714                 case STATEMENT_LABEL:
5715                         next = stmt->label.statement;
5716                         break;
5717
5718                 case STATEMENT_CASE_LABEL:
5719                         next = stmt->case_label.statement;
5720                         break;
5721
5722                 case STATEMENT_WHILE: {
5723                         while_statement_t const *const whiles = &stmt->whiles;
5724                         int                      const val    = determine_truth(whiles->condition);
5725
5726                         if (val >= 0)
5727                                 check_reachable(whiles->body);
5728
5729                         if (val > 0)
5730                                 return;
5731
5732                         next = stmt->base.next;
5733                         break;
5734                 }
5735
5736                 case STATEMENT_DO_WHILE:
5737                         next = stmt->do_while.body;
5738                         break;
5739
5740                 case STATEMENT_FOR: {
5741                         for_statement_t *const fors = &stmt->fors;
5742
5743                         if (fors->condition_reachable)
5744                                 return;
5745                         fors->condition_reachable = true;
5746
5747                         expression_t const *const cond = fors->condition;
5748                         int          const        val  =
5749                                 cond == NULL ? 1 : determine_truth(cond);
5750
5751                         if (val >= 0)
5752                                 check_reachable(fors->body);
5753
5754                         if (val > 0)
5755                                 return;
5756
5757                         next = stmt->base.next;
5758                         break;
5759                 }
5760
5761                 case STATEMENT_MS_TRY: {
5762                         ms_try_statement_t const *const ms_try = &stmt->ms_try;
5763                         check_reachable(ms_try->try_statement);
5764                         next = ms_try->final_statement;
5765                         break;
5766                 }
5767
5768                 case STATEMENT_LEAVE: {
5769                         statement_t *parent = stmt;
5770                         for (;;) {
5771                                 parent = parent->base.parent;
5772                                 if (parent == NULL) /* __leave not within __try */
5773                                         return;
5774
5775                                 if (parent->kind == STATEMENT_MS_TRY) {
5776                                         last = parent;
5777                                         next = parent->ms_try.final_statement;
5778                                         break;
5779                                 }
5780                         }
5781                         break;
5782                 }
5783         }
5784
5785         while (next == NULL) {
5786                 next = last->base.parent;
5787                 if (next == NULL) {
5788                         noreturn_candidate = false;
5789
5790                         type_t *const type = current_function->base.type;
5791                         assert(is_type_function(type));
5792                         type_t *const ret  = skip_typeref(type->function.return_type);
5793                         if (warning.return_type                    &&
5794                             !is_type_atomic(ret, ATOMIC_TYPE_VOID) &&
5795                             is_type_valid(ret)                     &&
5796                             !is_sym_main(current_function->base.base.symbol)) {
5797                                 warningf(&stmt->base.source_position,
5798                                          "control reaches end of non-void function");
5799                         }
5800                         return;
5801                 }
5802
5803                 switch (next->kind) {
5804                         case STATEMENT_INVALID:
5805                         case STATEMENT_EMPTY:
5806                         case STATEMENT_DECLARATION:
5807                         case STATEMENT_LOCAL_LABEL:
5808                         case STATEMENT_EXPRESSION:
5809                         case STATEMENT_ASM:
5810                         case STATEMENT_RETURN:
5811                         case STATEMENT_CONTINUE:
5812                         case STATEMENT_BREAK:
5813                         case STATEMENT_GOTO:
5814                         case STATEMENT_LEAVE:
5815                                 panic("invalid control flow in function");
5816
5817                         case STATEMENT_COMPOUND:
5818                         case STATEMENT_IF:
5819                         case STATEMENT_SWITCH:
5820                         case STATEMENT_LABEL:
5821                         case STATEMENT_CASE_LABEL:
5822                                 last = next;
5823                                 next = next->base.next;
5824                                 break;
5825
5826                         case STATEMENT_WHILE: {
5827 continue_while:
5828                                 if (next->base.reachable)
5829                                         return;
5830                                 next->base.reachable = true;
5831
5832                                 while_statement_t const *const whiles = &next->whiles;
5833                                 int                      const val    = determine_truth(whiles->condition);
5834
5835                                 if (val >= 0)
5836                                         check_reachable(whiles->body);
5837
5838                                 if (val > 0)
5839                                         return;
5840
5841                                 last = next;
5842                                 next = next->base.next;
5843                                 break;
5844                         }
5845
5846                         case STATEMENT_DO_WHILE: {
5847 continue_do_while:
5848                                 if (next->base.reachable)
5849                                         return;
5850                                 next->base.reachable = true;
5851
5852                                 do_while_statement_t const *const dw  = &next->do_while;
5853                                 int                  const        val = determine_truth(dw->condition);
5854
5855                                 if (val >= 0)
5856                                         check_reachable(dw->body);
5857
5858                                 if (val > 0)
5859                                         return;
5860
5861                                 last = next;
5862                                 next = next->base.next;
5863                                 break;
5864                         }
5865
5866                         case STATEMENT_FOR: {
5867 continue_for:;
5868                                 for_statement_t *const fors = &next->fors;
5869
5870                                 fors->step_reachable = true;
5871
5872                                 if (fors->condition_reachable)
5873                                         return;
5874                                 fors->condition_reachable = true;
5875
5876                                 expression_t const *const cond = fors->condition;
5877                                 int          const        val  =
5878                                         cond == NULL ? 1 : determine_truth(cond);
5879
5880                                 if (val >= 0)
5881                                         check_reachable(fors->body);
5882
5883                                 if (val > 0)
5884                                         return;
5885
5886                                 last = next;
5887                                 next = next->base.next;
5888                                 break;
5889                         }
5890
5891                         case STATEMENT_MS_TRY:
5892                                 last = next;
5893                                 next = next->ms_try.final_statement;
5894                                 break;
5895                 }
5896         }
5897
5898         check_reachable(next);
5899 }
5900
5901 static void check_unreachable(statement_t* const stmt, void *const env)
5902 {
5903         (void)env;
5904
5905         switch (stmt->kind) {
5906                 case STATEMENT_DO_WHILE:
5907                         if (!stmt->base.reachable) {
5908                                 expression_t const *const cond = stmt->do_while.condition;
5909                                 if (determine_truth(cond) >= 0) {
5910                                         warningf(&cond->base.source_position,
5911                                                  "condition of do-while-loop is unreachable");
5912                                 }
5913                         }
5914                         return;
5915
5916                 case STATEMENT_FOR: {
5917                         for_statement_t const* const fors = &stmt->fors;
5918
5919                         // if init and step are unreachable, cond is unreachable, too
5920                         if (!stmt->base.reachable && !fors->step_reachable) {
5921                                 warningf(&stmt->base.source_position, "statement is unreachable");
5922                         } else {
5923                                 if (!stmt->base.reachable && fors->initialisation != NULL) {
5924                                         warningf(&fors->initialisation->base.source_position,
5925                                                  "initialisation of for-statement is unreachable");
5926                                 }
5927
5928                                 if (!fors->condition_reachable && fors->condition != NULL) {
5929                                         warningf(&fors->condition->base.source_position,
5930                                                  "condition of for-statement is unreachable");
5931                                 }
5932
5933                                 if (!fors->step_reachable && fors->step != NULL) {
5934                                         warningf(&fors->step->base.source_position,
5935                                                  "step of for-statement is unreachable");
5936                                 }
5937                         }
5938                         return;
5939                 }
5940
5941                 case STATEMENT_COMPOUND:
5942                         if (stmt->compound.statements != NULL)
5943                                 return;
5944                         /* FALLTHROUGH*/
5945
5946                 default:
5947                         if (!stmt->base.reachable)
5948                                 warningf(&stmt->base.source_position, "statement is unreachable");
5949                         return;
5950         }
5951 }
5952
5953 static void parse_external_declaration(void)
5954 {
5955         /* function-definitions and declarations both start with declaration
5956          * specifiers */
5957         declaration_specifiers_t specifiers;
5958         memset(&specifiers, 0, sizeof(specifiers));
5959
5960         add_anchor_token(';');
5961         parse_declaration_specifiers(&specifiers);
5962         rem_anchor_token(';');
5963
5964         /* must be a declaration */
5965         if (token.type == ';') {
5966                 parse_anonymous_declaration_rest(&specifiers);
5967                 return;
5968         }
5969
5970         add_anchor_token(',');
5971         add_anchor_token('=');
5972         add_anchor_token(';');
5973         add_anchor_token('{');
5974
5975         /* declarator is common to both function-definitions and declarations */
5976         entity_t *ndeclaration = parse_declarator(&specifiers, /*may_be_abstract=*/false, false);
5977
5978         rem_anchor_token('{');
5979         rem_anchor_token(';');
5980         rem_anchor_token('=');
5981         rem_anchor_token(',');
5982
5983         /* must be a declaration */
5984         switch (token.type) {
5985                 case ',':
5986                 case ';':
5987                 case '=':
5988                         parse_declaration_rest(ndeclaration, &specifiers, record_entity);
5989                         return;
5990         }
5991
5992         /* must be a function definition */
5993         parse_kr_declaration_list(ndeclaration);
5994
5995         if (token.type != '{') {
5996                 parse_error_expected("while parsing function definition", '{', NULL);
5997                 eat_until_matching_token(';');
5998                 return;
5999         }
6000
6001         assert(is_declaration(ndeclaration));
6002         type_t *type = skip_typeref(ndeclaration->declaration.type);
6003
6004         if (!is_type_function(type)) {
6005                 if (is_type_valid(type)) {
6006                         errorf(HERE, "declarator '%#T' has a body but is not a function type",
6007                                type, ndeclaration->base.symbol);
6008                 }
6009                 eat_block();
6010                 return;
6011         }
6012
6013         if (warning.aggregate_return &&
6014             is_type_compound(skip_typeref(type->function.return_type))) {
6015                 warningf(HERE, "function '%Y' returns an aggregate",
6016                          ndeclaration->base.symbol);
6017         }
6018         if (warning.traditional && !type->function.unspecified_parameters) {
6019                 warningf(HERE, "traditional C rejects ISO C style function definition of function '%Y'",
6020                         ndeclaration->base.symbol);
6021         }
6022         if (warning.old_style_definition && type->function.unspecified_parameters) {
6023                 warningf(HERE, "old-style function definition '%Y'",
6024                         ndeclaration->base.symbol);
6025         }
6026
6027         /* § 6.7.5.3 (14) a function definition with () means no
6028          * parameters (and not unspecified parameters) */
6029         if (type->function.unspecified_parameters
6030                         && type->function.parameters == NULL
6031                         && !type->function.kr_style_parameters) {
6032                 type_t *duplicate = duplicate_type(type);
6033                 duplicate->function.unspecified_parameters = false;
6034
6035                 type = typehash_insert(duplicate);
6036                 if (type != duplicate) {
6037                         obstack_free(type_obst, duplicate);
6038                 }
6039                 ndeclaration->declaration.type = type;
6040         }
6041
6042         entity_t *const entity = record_entity(ndeclaration, true);
6043         assert(entity->kind == ENTITY_FUNCTION);
6044         assert(ndeclaration->kind == ENTITY_FUNCTION);
6045
6046         function_t *function = &entity->function;
6047         if (ndeclaration != entity) {
6048                 function->parameters = ndeclaration->function.parameters;
6049         }
6050         assert(is_declaration(entity));
6051         type = skip_typeref(entity->declaration.type);
6052
6053         /* push function parameters and switch scope */
6054         size_t const top = environment_top();
6055         scope_push(&function->parameters);
6056
6057         entity_t *parameter = function->parameters.entities;
6058         for (; parameter != NULL; parameter = parameter->base.next) {
6059                 if (parameter->base.parent_scope == &ndeclaration->function.parameters) {
6060                         parameter->base.parent_scope = current_scope;
6061                 }
6062                 assert(parameter->base.parent_scope == NULL
6063                                 || parameter->base.parent_scope == current_scope);
6064                 parameter->base.parent_scope = current_scope;
6065                 if (parameter->base.symbol == NULL) {
6066                         errorf(&parameter->base.source_position, "parameter name omitted");
6067                         continue;
6068                 }
6069                 environment_push(parameter);
6070         }
6071
6072         if (function->statement != NULL) {
6073                 parser_error_multiple_definition(entity, HERE);
6074                 eat_block();
6075         } else {
6076                 /* parse function body */
6077                 int         label_stack_top      = label_top();
6078                 function_t *old_current_function = current_function;
6079                 current_function                 = function;
6080                 current_parent                   = NULL;
6081
6082                 goto_first   = NULL;
6083                 goto_anchor  = &goto_first;
6084                 label_first  = NULL;
6085                 label_anchor = &label_first;
6086
6087                 statement_t *const body = parse_compound_statement(false);
6088                 function->statement = body;
6089                 first_err = true;
6090                 check_labels();
6091                 check_declarations();
6092                 if (warning.return_type      ||
6093                     warning.unreachable_code ||
6094                     (warning.missing_noreturn
6095                      && !(function->base.modifiers & DM_NORETURN))) {
6096                         noreturn_candidate = true;
6097                         check_reachable(body);
6098                         if (warning.unreachable_code)
6099                                 walk_statements(body, check_unreachable, NULL);
6100                         if (warning.missing_noreturn &&
6101                             noreturn_candidate       &&
6102                             !(function->base.modifiers & DM_NORETURN)) {
6103                                 warningf(&body->base.source_position,
6104                                          "function '%#T' is candidate for attribute 'noreturn'",
6105                                          type, entity->base.symbol);
6106                         }
6107                 }
6108
6109                 assert(current_parent   == NULL);
6110                 assert(current_function == function);
6111                 current_function = old_current_function;
6112                 label_pop_to(label_stack_top);
6113         }
6114
6115         assert(current_scope == &function->parameters);
6116         scope_pop();
6117         environment_pop_to(top);
6118 }
6119
6120 static type_t *make_bitfield_type(type_t *base_type, expression_t *size,
6121                                   source_position_t *source_position,
6122                                   const symbol_t *symbol)
6123 {
6124         type_t *type = allocate_type_zero(TYPE_BITFIELD);
6125
6126         type->bitfield.base_type       = base_type;
6127         type->bitfield.size_expression = size;
6128
6129         il_size_t bit_size;
6130         type_t *skipped_type = skip_typeref(base_type);
6131         if (!is_type_integer(skipped_type)) {
6132                 errorf(HERE, "bitfield base type '%T' is not an integer type",
6133                         base_type);
6134                 bit_size = 0;
6135         } else {
6136                 bit_size = skipped_type->base.size * 8;
6137         }
6138
6139         if (is_constant_expression(size)) {
6140                 long v = fold_constant(size);
6141
6142                 if (v < 0) {
6143                         errorf(source_position, "negative width in bit-field '%Y'", symbol);
6144                 } else if (v == 0) {
6145                         errorf(source_position, "zero width for bit-field '%Y'", symbol);
6146                 } else if (bit_size > 0 && (il_size_t)v > bit_size) {
6147                         errorf(source_position, "width of '%Y' exceeds its type", symbol);
6148                 } else {
6149                         type->bitfield.bit_size = v;
6150                 }
6151         }
6152
6153         return type;
6154 }
6155
6156 static entity_t *find_compound_entry(compound_t *compound, symbol_t *symbol)
6157 {
6158         entity_t *iter = compound->members.entities;
6159         for (; iter != NULL; iter = iter->base.next) {
6160                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
6161                         continue;
6162
6163                 if (iter->base.symbol == symbol) {
6164                         return iter;
6165                 } else if (iter->base.symbol == NULL) {
6166                         type_t *type = skip_typeref(iter->declaration.type);
6167                         if (is_type_compound(type)) {
6168                                 entity_t *result
6169                                         = find_compound_entry(type->compound.compound, symbol);
6170                                 if (result != NULL)
6171                                         return result;
6172                         }
6173                         continue;
6174                 }
6175         }
6176
6177         return NULL;
6178 }
6179
6180 static void parse_compound_declarators(compound_t *compound,
6181                 const declaration_specifiers_t *specifiers)
6182 {
6183         while (true) {
6184                 entity_t *entity;
6185
6186                 if (token.type == ':') {
6187                         source_position_t source_position = *HERE;
6188                         next_token();
6189
6190                         type_t *base_type = specifiers->type;
6191                         expression_t *size = parse_constant_expression();
6192
6193                         type_t *type = make_bitfield_type(base_type, size,
6194                                         &source_position, sym_anonymous);
6195
6196                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER);
6197                         entity->base.namespc                       = NAMESPACE_NORMAL;
6198                         entity->base.source_position               = source_position;
6199                         entity->declaration.declared_storage_class = STORAGE_CLASS_NONE;
6200                         entity->declaration.storage_class          = STORAGE_CLASS_NONE;
6201                         entity->declaration.modifiers              = specifiers->modifiers;
6202                         entity->declaration.type                   = type;
6203                 } else {
6204                         entity = parse_declarator(specifiers,/*may_be_abstract=*/true, true);
6205                         assert(entity->kind == ENTITY_COMPOUND_MEMBER);
6206
6207                         if (token.type == ':') {
6208                                 source_position_t source_position = *HERE;
6209                                 next_token();
6210                                 expression_t *size = parse_constant_expression();
6211
6212                                 type_t *type = entity->declaration.type;
6213                                 type_t *bitfield_type = make_bitfield_type(type, size,
6214                                                 &source_position, entity->base.symbol);
6215                                 entity->declaration.type = bitfield_type;
6216                         }
6217                 }
6218
6219                 /* make sure we don't define a symbol multiple times */
6220                 symbol_t *symbol = entity->base.symbol;
6221                 if (symbol != NULL) {
6222                         entity_t *prev = find_compound_entry(compound, symbol);
6223
6224                         if (prev != NULL) {
6225                                 errorf(&entity->base.source_position,
6226                                        "multiple declarations of symbol '%Y' (declared %P)",
6227                                        symbol, &prev->base.source_position);
6228                         }
6229                 }
6230
6231                 append_entity(&compound->members, entity);
6232
6233                 type_t *orig_type = entity->declaration.type;
6234                 type_t *type      = skip_typeref(orig_type);
6235                 if (is_type_function(type)) {
6236                         errorf(&entity->base.source_position,
6237                                         "compound member '%Y' must not have function type '%T'",
6238                                         entity->base.symbol, orig_type);
6239                 } else if (is_type_incomplete(type)) {
6240                         /* §6.7.2.1:16 flexible array member */
6241                         if (is_type_array(type) &&
6242                                         token.type == ';'   &&
6243                                         look_ahead(1)->type == '}') {
6244                                 compound->has_flexible_member = true;
6245                         } else {
6246                                 errorf(&entity->base.source_position,
6247                                                 "compound member '%Y' has incomplete type '%T'",
6248                                                 entity->base.symbol, orig_type);
6249                         }
6250                 }
6251
6252                 if (token.type != ',')
6253                         break;
6254                 next_token();
6255         }
6256         expect(';');
6257
6258 end_error:
6259         anonymous_entity = NULL;
6260 }
6261
6262 static void parse_compound_type_entries(compound_t *compound)
6263 {
6264         eat('{');
6265         add_anchor_token('}');
6266
6267         while (token.type != '}') {
6268                 if (token.type == T_EOF) {
6269                         errorf(HERE, "EOF while parsing struct");
6270                         break;
6271                 }
6272                 declaration_specifiers_t specifiers;
6273                 memset(&specifiers, 0, sizeof(specifiers));
6274                 parse_declaration_specifiers(&specifiers);
6275
6276                 parse_compound_declarators(compound, &specifiers);
6277         }
6278         rem_anchor_token('}');
6279         next_token();
6280
6281         /* §6.7.2.1:7 */
6282         compound->complete = true;
6283 }
6284
6285 static type_t *parse_typename(void)
6286 {
6287         declaration_specifiers_t specifiers;
6288         memset(&specifiers, 0, sizeof(specifiers));
6289         parse_declaration_specifiers(&specifiers);
6290         if (specifiers.storage_class != STORAGE_CLASS_NONE) {
6291                 /* TODO: improve error message, user does probably not know what a
6292                  * storage class is...
6293                  */
6294                 errorf(HERE, "typename may not have a storage class");
6295         }
6296
6297         type_t *result = parse_abstract_declarator(specifiers.type);
6298
6299         return result;
6300 }
6301
6302
6303
6304
6305 typedef expression_t* (*parse_expression_function)(void);
6306 typedef expression_t* (*parse_expression_infix_function)(expression_t *left);
6307
6308 typedef struct expression_parser_function_t expression_parser_function_t;
6309 struct expression_parser_function_t {
6310         parse_expression_function        parser;
6311         unsigned                         infix_precedence;
6312         parse_expression_infix_function  infix_parser;
6313 };
6314
6315 expression_parser_function_t expression_parsers[T_LAST_TOKEN];
6316
6317 /**
6318  * Prints an error message if an expression was expected but not read
6319  */
6320 static expression_t *expected_expression_error(void)
6321 {
6322         /* skip the error message if the error token was read */
6323         if (token.type != T_ERROR) {
6324                 errorf(HERE, "expected expression, got token '%K'", &token);
6325         }
6326         next_token();
6327
6328         return create_invalid_expression();
6329 }
6330
6331 /**
6332  * Parse a string constant.
6333  */
6334 static expression_t *parse_string_const(void)
6335 {
6336         wide_string_t wres;
6337         if (token.type == T_STRING_LITERAL) {
6338                 string_t res = token.v.string;
6339                 next_token();
6340                 while (token.type == T_STRING_LITERAL) {
6341                         res = concat_strings(&res, &token.v.string);
6342                         next_token();
6343                 }
6344                 if (token.type != T_WIDE_STRING_LITERAL) {
6345                         expression_t *const cnst = allocate_expression_zero(EXPR_STRING_LITERAL);
6346                         /* note: that we use type_char_ptr here, which is already the
6347                          * automatic converted type. revert_automatic_type_conversion
6348                          * will construct the array type */
6349                         cnst->base.type    = warning.write_strings ? type_const_char_ptr : type_char_ptr;
6350                         cnst->string.value = res;
6351                         return cnst;
6352                 }
6353
6354                 wres = concat_string_wide_string(&res, &token.v.wide_string);
6355         } else {
6356                 wres = token.v.wide_string;
6357         }
6358         next_token();
6359
6360         for (;;) {
6361                 switch (token.type) {
6362                         case T_WIDE_STRING_LITERAL:
6363                                 wres = concat_wide_strings(&wres, &token.v.wide_string);
6364                                 break;
6365
6366                         case T_STRING_LITERAL:
6367                                 wres = concat_wide_string_string(&wres, &token.v.string);
6368                                 break;
6369
6370                         default: {
6371                                 expression_t *const cnst = allocate_expression_zero(EXPR_WIDE_STRING_LITERAL);
6372                                 cnst->base.type         = warning.write_strings ? type_const_wchar_t_ptr : type_wchar_t_ptr;
6373                                 cnst->wide_string.value = wres;
6374                                 return cnst;
6375                         }
6376                 }
6377                 next_token();
6378         }
6379 }
6380
6381 /**
6382  * Parse a boolean constant.
6383  */
6384 static expression_t *parse_bool_const(bool value)
6385 {
6386         expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
6387         cnst->base.type          = type_bool;
6388         cnst->conste.v.int_value = value;
6389
6390         next_token();
6391
6392         return cnst;
6393 }
6394
6395 /**
6396  * Parse an integer constant.
6397  */
6398 static expression_t *parse_int_const(void)
6399 {
6400         expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
6401         cnst->base.type          = token.datatype;
6402         cnst->conste.v.int_value = token.v.intvalue;
6403
6404         next_token();
6405
6406         return cnst;
6407 }
6408
6409 /**
6410  * Parse a character constant.
6411  */
6412 static expression_t *parse_character_constant(void)
6413 {
6414         expression_t *cnst = allocate_expression_zero(EXPR_CHARACTER_CONSTANT);
6415         cnst->base.type          = token.datatype;
6416         cnst->conste.v.character = token.v.string;
6417
6418         if (cnst->conste.v.character.size != 1) {
6419                 if (!GNU_MODE) {
6420                         errorf(HERE, "more than 1 character in character constant");
6421                 } else if (warning.multichar) {
6422                         warningf(HERE, "multi-character character constant");
6423                 }
6424         }
6425         next_token();
6426
6427         return cnst;
6428 }
6429
6430 /**
6431  * Parse a wide character constant.
6432  */
6433 static expression_t *parse_wide_character_constant(void)
6434 {
6435         expression_t *cnst = allocate_expression_zero(EXPR_WIDE_CHARACTER_CONSTANT);
6436         cnst->base.type               = token.datatype;
6437         cnst->conste.v.wide_character = token.v.wide_string;
6438
6439         if (cnst->conste.v.wide_character.size != 1) {
6440                 if (!GNU_MODE) {
6441                         errorf(HERE, "more than 1 character in character constant");
6442                 } else if (warning.multichar) {
6443                         warningf(HERE, "multi-character character constant");
6444                 }
6445         }
6446         next_token();
6447
6448         return cnst;
6449 }
6450
6451 /**
6452  * Parse a float constant.
6453  */
6454 static expression_t *parse_float_const(void)
6455 {
6456         expression_t *cnst         = allocate_expression_zero(EXPR_CONST);
6457         cnst->base.type            = token.datatype;
6458         cnst->conste.v.float_value = token.v.floatvalue;
6459
6460         next_token();
6461
6462         return cnst;
6463 }
6464
6465 static entity_t *create_implicit_function(symbol_t *symbol,
6466                 const source_position_t *source_position)
6467 {
6468         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
6469         ntype->function.return_type            = type_int;
6470         ntype->function.unspecified_parameters = true;
6471
6472         type_t *type = typehash_insert(ntype);
6473         if (type != ntype) {
6474                 free_type(ntype);
6475         }
6476
6477         entity_t *entity = allocate_entity_zero(ENTITY_FUNCTION);
6478         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
6479         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
6480         entity->declaration.type                   = type;
6481         entity->declaration.implicit               = true;
6482         entity->base.symbol                        = symbol;
6483         entity->base.source_position               = *source_position;
6484
6485         bool strict_prototypes_old = warning.strict_prototypes;
6486         warning.strict_prototypes  = false;
6487         record_entity(entity, false);
6488         warning.strict_prototypes = strict_prototypes_old;
6489
6490         return entity;
6491 }
6492
6493 /**
6494  * Creates a return_type (func)(argument_type) function type if not
6495  * already exists.
6496  */
6497 static type_t *make_function_2_type(type_t *return_type, type_t *argument_type1,
6498                                     type_t *argument_type2)
6499 {
6500         function_parameter_t *parameter2
6501                 = obstack_alloc(type_obst, sizeof(parameter2[0]));
6502         memset(parameter2, 0, sizeof(parameter2[0]));
6503         parameter2->type = argument_type2;
6504
6505         function_parameter_t *parameter1
6506                 = obstack_alloc(type_obst, sizeof(parameter1[0]));
6507         memset(parameter1, 0, sizeof(parameter1[0]));
6508         parameter1->type = argument_type1;
6509         parameter1->next = parameter2;
6510
6511         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6512         type->function.return_type = return_type;
6513         type->function.parameters  = parameter1;
6514
6515         type_t *result = typehash_insert(type);
6516         if (result != type) {
6517                 free_type(type);
6518         }
6519
6520         return result;
6521 }
6522
6523 /**
6524  * Creates a return_type (func)(argument_type) function type if not
6525  * already exists.
6526  *
6527  * @param return_type    the return type
6528  * @param argument_type  the argument type
6529  */
6530 static type_t *make_function_1_type(type_t *return_type, type_t *argument_type)
6531 {
6532         function_parameter_t *parameter
6533                 = obstack_alloc(type_obst, sizeof(parameter[0]));
6534         memset(parameter, 0, sizeof(parameter[0]));
6535         parameter->type = argument_type;
6536
6537         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6538         type->function.return_type = return_type;
6539         type->function.parameters  = parameter;
6540
6541         type_t *result = typehash_insert(type);
6542         if (result != type) {
6543                 free_type(type);
6544         }
6545
6546         return result;
6547 }
6548
6549 static type_t *make_function_0_type(type_t *return_type)
6550 {
6551         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6552         type->function.return_type = return_type;
6553         type->function.parameters  = NULL;
6554
6555         type_t *result = typehash_insert(type);
6556         if (result != type) {
6557                 free_type(type);
6558         }
6559
6560         return result;
6561 }
6562
6563 /**
6564  * Creates a function type for some function like builtins.
6565  *
6566  * @param symbol   the symbol describing the builtin
6567  */
6568 static type_t *get_builtin_symbol_type(symbol_t *symbol)
6569 {
6570         switch (symbol->ID) {
6571         case T___builtin_alloca:
6572                 return make_function_1_type(type_void_ptr, type_size_t);
6573         case T___builtin_huge_val:
6574                 return make_function_0_type(type_double);
6575         case T___builtin_inf:
6576                 return make_function_0_type(type_double);
6577         case T___builtin_inff:
6578                 return make_function_0_type(type_float);
6579         case T___builtin_infl:
6580                 return make_function_0_type(type_long_double);
6581         case T___builtin_nan:
6582                 return make_function_1_type(type_double, type_char_ptr);
6583         case T___builtin_nanf:
6584                 return make_function_1_type(type_float, type_char_ptr);
6585         case T___builtin_nanl:
6586                 return make_function_1_type(type_long_double, type_char_ptr);
6587         case T___builtin_va_end:
6588                 return make_function_1_type(type_void, type_valist);
6589         case T___builtin_expect:
6590                 return make_function_2_type(type_long, type_long, type_long);
6591         default:
6592                 internal_errorf(HERE, "not implemented builtin symbol found");
6593         }
6594 }
6595
6596 /**
6597  * Performs automatic type cast as described in § 6.3.2.1.
6598  *
6599  * @param orig_type  the original type
6600  */
6601 static type_t *automatic_type_conversion(type_t *orig_type)
6602 {
6603         type_t *type = skip_typeref(orig_type);
6604         if (is_type_array(type)) {
6605                 array_type_t *array_type   = &type->array;
6606                 type_t       *element_type = array_type->element_type;
6607                 unsigned      qualifiers   = array_type->base.qualifiers;
6608
6609                 return make_pointer_type(element_type, qualifiers);
6610         }
6611
6612         if (is_type_function(type)) {
6613                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
6614         }
6615
6616         return orig_type;
6617 }
6618
6619 /**
6620  * reverts the automatic casts of array to pointer types and function
6621  * to function-pointer types as defined § 6.3.2.1
6622  */
6623 type_t *revert_automatic_type_conversion(const expression_t *expression)
6624 {
6625         switch (expression->kind) {
6626                 case EXPR_REFERENCE: {
6627                         entity_t *entity = expression->reference.entity;
6628                         if (is_declaration(entity)) {
6629                                 return entity->declaration.type;
6630                         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6631                                 return entity->enum_value.enum_type;
6632                         } else {
6633                                 panic("no declaration or enum in reference");
6634                         }
6635                 }
6636
6637                 case EXPR_SELECT: {
6638                         entity_t *entity = expression->select.compound_entry;
6639                         assert(is_declaration(entity));
6640                         type_t   *type   = entity->declaration.type;
6641                         return get_qualified_type(type,
6642                                                   expression->base.type->base.qualifiers);
6643                 }
6644
6645                 case EXPR_UNARY_DEREFERENCE: {
6646                         const expression_t *const value = expression->unary.value;
6647                         type_t             *const type  = skip_typeref(value->base.type);
6648                         assert(is_type_pointer(type));
6649                         return type->pointer.points_to;
6650                 }
6651
6652                 case EXPR_BUILTIN_SYMBOL:
6653                         return get_builtin_symbol_type(expression->builtin_symbol.symbol);
6654
6655                 case EXPR_ARRAY_ACCESS: {
6656                         const expression_t *array_ref = expression->array_access.array_ref;
6657                         type_t             *type_left = skip_typeref(array_ref->base.type);
6658                         if (!is_type_valid(type_left))
6659                                 return type_left;
6660                         assert(is_type_pointer(type_left));
6661                         return type_left->pointer.points_to;
6662                 }
6663
6664                 case EXPR_STRING_LITERAL: {
6665                         size_t size = expression->string.value.size;
6666                         return make_array_type(type_char, size, TYPE_QUALIFIER_NONE);
6667                 }
6668
6669                 case EXPR_WIDE_STRING_LITERAL: {
6670                         size_t size = expression->wide_string.value.size;
6671                         return make_array_type(type_wchar_t, size, TYPE_QUALIFIER_NONE);
6672                 }
6673
6674                 case EXPR_COMPOUND_LITERAL:
6675                         return expression->compound_literal.type;
6676
6677                 default: break;
6678         }
6679
6680         return expression->base.type;
6681 }
6682
6683 static expression_t *parse_reference(void)
6684 {
6685         symbol_t *const symbol = token.v.symbol;
6686
6687         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
6688
6689         if (entity == NULL) {
6690                 if (!strict_mode && look_ahead(1)->type == '(') {
6691                         /* an implicitly declared function */
6692                         if (warning.implicit_function_declaration) {
6693                                 warningf(HERE, "implicit declaration of function '%Y'",
6694                                         symbol);
6695                         }
6696
6697                         entity = create_implicit_function(symbol, HERE);
6698                 } else {
6699                         errorf(HERE, "unknown symbol '%Y' found.", symbol);
6700                         entity = create_error_entity(symbol, ENTITY_VARIABLE);
6701                 }
6702         }
6703
6704         type_t *orig_type;
6705
6706         if (is_declaration(entity)) {
6707                 orig_type = entity->declaration.type;
6708         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6709                 orig_type = entity->enum_value.enum_type;
6710         } else if (entity->kind == ENTITY_TYPEDEF) {
6711                 errorf(HERE, "encountered typedef name '%Y' while parsing expression",
6712                         symbol);
6713                 next_token();
6714                 return create_invalid_expression();
6715         } else {
6716                 panic("expected declaration or enum value in reference");
6717         }
6718
6719         /* we always do the auto-type conversions; the & and sizeof parser contains
6720          * code to revert this! */
6721         type_t *type = automatic_type_conversion(orig_type);
6722
6723         expression_kind_t kind = EXPR_REFERENCE;
6724         if (entity->kind == ENTITY_ENUM_VALUE)
6725                 kind = EXPR_REFERENCE_ENUM_VALUE;
6726
6727         expression_t *expression     = allocate_expression_zero(kind);
6728         expression->reference.entity = entity;
6729         expression->base.type        = type;
6730
6731         /* this declaration is used */
6732         if (is_declaration(entity)) {
6733                 entity->declaration.used = true;
6734         }
6735
6736         if (entity->base.parent_scope != file_scope
6737                 && entity->base.parent_scope->depth < current_function->parameters.depth
6738                 && is_type_valid(orig_type) && !is_type_function(orig_type)) {
6739                 if (entity->kind == ENTITY_VARIABLE) {
6740                         /* access of a variable from an outer function */
6741                         entity->variable.address_taken = true;
6742                 }
6743                 current_function->need_closure = true;
6744         }
6745
6746         /* check for deprecated functions */
6747         if (warning.deprecated_declarations
6748                 && is_declaration(entity)
6749                 && entity->declaration.modifiers & DM_DEPRECATED) {
6750                 declaration_t *declaration = &entity->declaration;
6751
6752                 char const *const prefix = entity->kind == ENTITY_FUNCTION ?
6753                         "function" : "variable";
6754
6755                 if (declaration->deprecated_string != NULL) {
6756                         warningf(HERE, "%s '%Y' is deprecated (declared %P): \"%s\"",
6757                                  prefix, entity->base.symbol, &entity->base.source_position,
6758                                  declaration->deprecated_string);
6759                 } else {
6760                         warningf(HERE, "%s '%Y' is deprecated (declared %P)", prefix,
6761                                  entity->base.symbol, &entity->base.source_position);
6762                 }
6763         }
6764
6765         if (warning.init_self && entity == current_init_decl && !in_type_prop
6766             && entity->kind == ENTITY_VARIABLE) {
6767                 current_init_decl = NULL;
6768                 warningf(HERE, "variable '%#T' is initialized by itself",
6769                          entity->declaration.type, entity->base.symbol);
6770         }
6771
6772         next_token();
6773         return expression;
6774 }
6775
6776 static bool semantic_cast(expression_t *cast)
6777 {
6778         expression_t            *expression      = cast->unary.value;
6779         type_t                  *orig_dest_type  = cast->base.type;
6780         type_t                  *orig_type_right = expression->base.type;
6781         type_t            const *dst_type        = skip_typeref(orig_dest_type);
6782         type_t            const *src_type        = skip_typeref(orig_type_right);
6783         source_position_t const *pos             = &cast->base.source_position;
6784
6785         /* §6.5.4 A (void) cast is explicitly permitted, more for documentation than for utility. */
6786         if (dst_type == type_void)
6787                 return true;
6788
6789         /* only integer and pointer can be casted to pointer */
6790         if (is_type_pointer(dst_type)  &&
6791             !is_type_pointer(src_type) &&
6792             !is_type_integer(src_type) &&
6793             is_type_valid(src_type)) {
6794                 errorf(pos, "cannot convert type '%T' to a pointer type", orig_type_right);
6795                 return false;
6796         }
6797
6798         if (!is_type_scalar(dst_type) && is_type_valid(dst_type)) {
6799                 errorf(pos, "conversion to non-scalar type '%T' requested", orig_dest_type);
6800                 return false;
6801         }
6802
6803         if (!is_type_scalar(src_type) && is_type_valid(src_type)) {
6804                 errorf(pos, "conversion from non-scalar type '%T' requested", orig_type_right);
6805                 return false;
6806         }
6807
6808         if (warning.cast_qual &&
6809             is_type_pointer(src_type) &&
6810             is_type_pointer(dst_type)) {
6811                 type_t *src = skip_typeref(src_type->pointer.points_to);
6812                 type_t *dst = skip_typeref(dst_type->pointer.points_to);
6813                 unsigned missing_qualifiers =
6814                         src->base.qualifiers & ~dst->base.qualifiers;
6815                 if (missing_qualifiers != 0) {
6816                         warningf(pos,
6817                                  "cast discards qualifiers '%Q' in pointer target type of '%T'",
6818                                  missing_qualifiers, orig_type_right);
6819                 }
6820         }
6821         return true;
6822 }
6823
6824 static expression_t *parse_compound_literal(type_t *type)
6825 {
6826         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
6827
6828         parse_initializer_env_t env;
6829         env.type             = type;
6830         env.entity           = NULL;
6831         env.must_be_constant = false;
6832         initializer_t *initializer = parse_initializer(&env);
6833         type = env.type;
6834
6835         expression->compound_literal.initializer = initializer;
6836         expression->compound_literal.type        = type;
6837         expression->base.type                    = automatic_type_conversion(type);
6838
6839         return expression;
6840 }
6841
6842 /**
6843  * Parse a cast expression.
6844  */
6845 static expression_t *parse_cast(void)
6846 {
6847         add_anchor_token(')');
6848
6849         source_position_t source_position = token.source_position;
6850
6851         type_t *type = parse_typename();
6852
6853         rem_anchor_token(')');
6854         expect(')');
6855
6856         if (token.type == '{') {
6857                 return parse_compound_literal(type);
6858         }
6859
6860         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
6861         cast->base.source_position = source_position;
6862
6863         expression_t *value = parse_sub_expression(PREC_CAST);
6864         cast->base.type   = type;
6865         cast->unary.value = value;
6866
6867         if (! semantic_cast(cast)) {
6868                 /* TODO: record the error in the AST. else it is impossible to detect it */
6869         }
6870
6871         return cast;
6872 end_error:
6873         return create_invalid_expression();
6874 }
6875
6876 /**
6877  * Parse a statement expression.
6878  */
6879 static expression_t *parse_statement_expression(void)
6880 {
6881         add_anchor_token(')');
6882
6883         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
6884
6885         statement_t *statement          = parse_compound_statement(true);
6886         expression->statement.statement = statement;
6887
6888         /* find last statement and use its type */
6889         type_t *type = type_void;
6890         const statement_t *stmt = statement->compound.statements;
6891         if (stmt != NULL) {
6892                 while (stmt->base.next != NULL)
6893                         stmt = stmt->base.next;
6894
6895                 if (stmt->kind == STATEMENT_EXPRESSION) {
6896                         type = stmt->expression.expression->base.type;
6897                 }
6898         } else if (warning.other) {
6899                 warningf(&expression->base.source_position, "empty statement expression ({})");
6900         }
6901         expression->base.type = type;
6902
6903         rem_anchor_token(')');
6904         expect(')');
6905
6906 end_error:
6907         return expression;
6908 }
6909
6910 /**
6911  * Parse a parenthesized expression.
6912  */
6913 static expression_t *parse_parenthesized_expression(void)
6914 {
6915         eat('(');
6916
6917         switch (token.type) {
6918         case '{':
6919                 /* gcc extension: a statement expression */
6920                 return parse_statement_expression();
6921
6922         TYPE_QUALIFIERS
6923         TYPE_SPECIFIERS
6924                 return parse_cast();
6925         case T_IDENTIFIER:
6926                 if (is_typedef_symbol(token.v.symbol)) {
6927                         return parse_cast();
6928                 }
6929         }
6930
6931         add_anchor_token(')');
6932         expression_t *result = parse_expression();
6933         rem_anchor_token(')');
6934         expect(')');
6935
6936 end_error:
6937         return result;
6938 }
6939
6940 static expression_t *parse_function_keyword(void)
6941 {
6942         /* TODO */
6943
6944         if (current_function == NULL) {
6945                 errorf(HERE, "'__func__' used outside of a function");
6946         }
6947
6948         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6949         expression->base.type     = type_char_ptr;
6950         expression->funcname.kind = FUNCNAME_FUNCTION;
6951
6952         next_token();
6953
6954         return expression;
6955 }
6956
6957 static expression_t *parse_pretty_function_keyword(void)
6958 {
6959         if (current_function == NULL) {
6960                 errorf(HERE, "'__PRETTY_FUNCTION__' used outside of a function");
6961         }
6962
6963         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6964         expression->base.type     = type_char_ptr;
6965         expression->funcname.kind = FUNCNAME_PRETTY_FUNCTION;
6966
6967         eat(T___PRETTY_FUNCTION__);
6968
6969         return expression;
6970 }
6971
6972 static expression_t *parse_funcsig_keyword(void)
6973 {
6974         if (current_function == NULL) {
6975                 errorf(HERE, "'__FUNCSIG__' used outside of a function");
6976         }
6977
6978         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6979         expression->base.type     = type_char_ptr;
6980         expression->funcname.kind = FUNCNAME_FUNCSIG;
6981
6982         eat(T___FUNCSIG__);
6983
6984         return expression;
6985 }
6986
6987 static expression_t *parse_funcdname_keyword(void)
6988 {
6989         if (current_function == NULL) {
6990                 errorf(HERE, "'__FUNCDNAME__' used outside of a function");
6991         }
6992
6993         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6994         expression->base.type     = type_char_ptr;
6995         expression->funcname.kind = FUNCNAME_FUNCDNAME;
6996
6997         eat(T___FUNCDNAME__);
6998
6999         return expression;
7000 }
7001
7002 static designator_t *parse_designator(void)
7003 {
7004         designator_t *result    = allocate_ast_zero(sizeof(result[0]));
7005         result->source_position = *HERE;
7006
7007         if (token.type != T_IDENTIFIER) {
7008                 parse_error_expected("while parsing member designator",
7009                                      T_IDENTIFIER, NULL);
7010                 return NULL;
7011         }
7012         result->symbol = token.v.symbol;
7013         next_token();
7014
7015         designator_t *last_designator = result;
7016         while (true) {
7017                 if (token.type == '.') {
7018                         next_token();
7019                         if (token.type != T_IDENTIFIER) {
7020                                 parse_error_expected("while parsing member designator",
7021                                                      T_IDENTIFIER, NULL);
7022                                 return NULL;
7023                         }
7024                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
7025                         designator->source_position = *HERE;
7026                         designator->symbol          = token.v.symbol;
7027                         next_token();
7028
7029                         last_designator->next = designator;
7030                         last_designator       = designator;
7031                         continue;
7032                 }
7033                 if (token.type == '[') {
7034                         next_token();
7035                         add_anchor_token(']');
7036                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
7037                         designator->source_position = *HERE;
7038                         designator->array_index     = parse_expression();
7039                         rem_anchor_token(']');
7040                         expect(']');
7041                         if (designator->array_index == NULL) {
7042                                 return NULL;
7043                         }
7044
7045                         last_designator->next = designator;
7046                         last_designator       = designator;
7047                         continue;
7048                 }
7049                 break;
7050         }
7051
7052         return result;
7053 end_error:
7054         return NULL;
7055 }
7056
7057 /**
7058  * Parse the __builtin_offsetof() expression.
7059  */
7060 static expression_t *parse_offsetof(void)
7061 {
7062         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
7063         expression->base.type    = type_size_t;
7064
7065         eat(T___builtin_offsetof);
7066
7067         expect('(');
7068         add_anchor_token(',');
7069         type_t *type = parse_typename();
7070         rem_anchor_token(',');
7071         expect(',');
7072         add_anchor_token(')');
7073         designator_t *designator = parse_designator();
7074         rem_anchor_token(')');
7075         expect(')');
7076
7077         expression->offsetofe.type       = type;
7078         expression->offsetofe.designator = designator;
7079
7080         type_path_t path;
7081         memset(&path, 0, sizeof(path));
7082         path.top_type = type;
7083         path.path     = NEW_ARR_F(type_path_entry_t, 0);
7084
7085         descend_into_subtype(&path);
7086
7087         if (!walk_designator(&path, designator, true)) {
7088                 return create_invalid_expression();
7089         }
7090
7091         DEL_ARR_F(path.path);
7092
7093         return expression;
7094 end_error:
7095         return create_invalid_expression();
7096 }
7097
7098 /**
7099  * Parses a _builtin_va_start() expression.
7100  */
7101 static expression_t *parse_va_start(void)
7102 {
7103         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
7104
7105         eat(T___builtin_va_start);
7106
7107         expect('(');
7108         add_anchor_token(',');
7109         expression->va_starte.ap = parse_assignment_expression();
7110         rem_anchor_token(',');
7111         expect(',');
7112         expression_t *const expr = parse_assignment_expression();
7113         if (expr->kind == EXPR_REFERENCE) {
7114                 entity_t *const entity = expr->reference.entity;
7115                 if (entity->base.parent_scope != &current_function->parameters
7116                                 || entity->base.next != NULL
7117                                 || entity->kind != ENTITY_VARIABLE) {
7118                         errorf(&expr->base.source_position,
7119                                "second argument of 'va_start' must be last parameter of the current function");
7120                 } else {
7121                         expression->va_starte.parameter = &entity->variable;
7122                 }
7123                 expect(')');
7124                 return expression;
7125         }
7126         expect(')');
7127 end_error:
7128         return create_invalid_expression();
7129 }
7130
7131 /**
7132  * Parses a _builtin_va_arg() expression.
7133  */
7134 static expression_t *parse_va_arg(void)
7135 {
7136         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
7137
7138         eat(T___builtin_va_arg);
7139
7140         expect('(');
7141         expression->va_arge.ap = parse_assignment_expression();
7142         expect(',');
7143         expression->base.type = parse_typename();
7144         expect(')');
7145
7146         return expression;
7147 end_error:
7148         return create_invalid_expression();
7149 }
7150
7151 static expression_t *parse_builtin_symbol(void)
7152 {
7153         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_SYMBOL);
7154
7155         symbol_t *symbol = token.v.symbol;
7156
7157         expression->builtin_symbol.symbol = symbol;
7158         next_token();
7159
7160         type_t *type = get_builtin_symbol_type(symbol);
7161         type = automatic_type_conversion(type);
7162
7163         expression->base.type = type;
7164         return expression;
7165 }
7166
7167 /**
7168  * Parses a __builtin_constant() expression.
7169  */
7170 static expression_t *parse_builtin_constant(void)
7171 {
7172         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
7173
7174         eat(T___builtin_constant_p);
7175
7176         expect('(');
7177         add_anchor_token(')');
7178         expression->builtin_constant.value = parse_assignment_expression();
7179         rem_anchor_token(')');
7180         expect(')');
7181         expression->base.type = type_int;
7182
7183         return expression;
7184 end_error:
7185         return create_invalid_expression();
7186 }
7187
7188 /**
7189  * Parses a __builtin_prefetch() expression.
7190  */
7191 static expression_t *parse_builtin_prefetch(void)
7192 {
7193         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_PREFETCH);
7194
7195         eat(T___builtin_prefetch);
7196
7197         expect('(');
7198         add_anchor_token(')');
7199         expression->builtin_prefetch.adr = parse_assignment_expression();
7200         if (token.type == ',') {
7201                 next_token();
7202                 expression->builtin_prefetch.rw = parse_assignment_expression();
7203         }
7204         if (token.type == ',') {
7205                 next_token();
7206                 expression->builtin_prefetch.locality = parse_assignment_expression();
7207         }
7208         rem_anchor_token(')');
7209         expect(')');
7210         expression->base.type = type_void;
7211
7212         return expression;
7213 end_error:
7214         return create_invalid_expression();
7215 }
7216
7217 /**
7218  * Parses a __builtin_is_*() compare expression.
7219  */
7220 static expression_t *parse_compare_builtin(void)
7221 {
7222         expression_t *expression;
7223
7224         switch (token.type) {
7225         case T___builtin_isgreater:
7226                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATER);
7227                 break;
7228         case T___builtin_isgreaterequal:
7229                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATEREQUAL);
7230                 break;
7231         case T___builtin_isless:
7232                 expression = allocate_expression_zero(EXPR_BINARY_ISLESS);
7233                 break;
7234         case T___builtin_islessequal:
7235                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSEQUAL);
7236                 break;
7237         case T___builtin_islessgreater:
7238                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSGREATER);
7239                 break;
7240         case T___builtin_isunordered:
7241                 expression = allocate_expression_zero(EXPR_BINARY_ISUNORDERED);
7242                 break;
7243         default:
7244                 internal_errorf(HERE, "invalid compare builtin found");
7245         }
7246         expression->base.source_position = *HERE;
7247         next_token();
7248
7249         expect('(');
7250         expression->binary.left = parse_assignment_expression();
7251         expect(',');
7252         expression->binary.right = parse_assignment_expression();
7253         expect(')');
7254
7255         type_t *const orig_type_left  = expression->binary.left->base.type;
7256         type_t *const orig_type_right = expression->binary.right->base.type;
7257
7258         type_t *const type_left  = skip_typeref(orig_type_left);
7259         type_t *const type_right = skip_typeref(orig_type_right);
7260         if (!is_type_float(type_left) && !is_type_float(type_right)) {
7261                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7262                         type_error_incompatible("invalid operands in comparison",
7263                                 &expression->base.source_position, orig_type_left, orig_type_right);
7264                 }
7265         } else {
7266                 semantic_comparison(&expression->binary);
7267         }
7268
7269         return expression;
7270 end_error:
7271         return create_invalid_expression();
7272 }
7273
7274 #if 0
7275 /**
7276  * Parses a __builtin_expect() expression.
7277  */
7278 static expression_t *parse_builtin_expect(void)
7279 {
7280         expression_t *expression
7281                 = allocate_expression_zero(EXPR_BINARY_BUILTIN_EXPECT);
7282
7283         eat(T___builtin_expect);
7284
7285         expect('(');
7286         expression->binary.left = parse_assignment_expression();
7287         expect(',');
7288         expression->binary.right = parse_constant_expression();
7289         expect(')');
7290
7291         expression->base.type = expression->binary.left->base.type;
7292
7293         return expression;
7294 end_error:
7295         return create_invalid_expression();
7296 }
7297 #endif
7298
7299 /**
7300  * Parses a MS assume() expression.
7301  */
7302 static expression_t *parse_assume(void)
7303 {
7304         expression_t *expression = allocate_expression_zero(EXPR_UNARY_ASSUME);
7305
7306         eat(T__assume);
7307
7308         expect('(');
7309         add_anchor_token(')');
7310         expression->unary.value = parse_assignment_expression();
7311         rem_anchor_token(')');
7312         expect(')');
7313
7314         expression->base.type = type_void;
7315         return expression;
7316 end_error:
7317         return create_invalid_expression();
7318 }
7319
7320 /**
7321  * Return the declaration for a given label symbol or create a new one.
7322  *
7323  * @param symbol  the symbol of the label
7324  */
7325 static label_t *get_label(symbol_t *symbol)
7326 {
7327         entity_t *label;
7328         assert(current_function != NULL);
7329
7330         label = get_entity(symbol, NAMESPACE_LABEL);
7331         /* if we found a local label, we already created the declaration */
7332         if (label != NULL && label->kind == ENTITY_LOCAL_LABEL) {
7333                 if (label->base.parent_scope != current_scope) {
7334                         assert(label->base.parent_scope->depth < current_scope->depth);
7335                         current_function->goto_to_outer = true;
7336                 }
7337                 return &label->label;
7338         }
7339
7340         label = get_entity(symbol, NAMESPACE_LABEL);
7341         /* if we found a label in the same function, then we already created the
7342          * declaration */
7343         if (label != NULL
7344                         && label->base.parent_scope == &current_function->parameters) {
7345                 return &label->label;
7346         }
7347
7348         /* otherwise we need to create a new one */
7349         label               = allocate_entity_zero(ENTITY_LABEL);
7350         label->base.namespc = NAMESPACE_LABEL;
7351         label->base.symbol  = symbol;
7352
7353         label_push(label);
7354
7355         return &label->label;
7356 }
7357
7358 /**
7359  * Parses a GNU && label address expression.
7360  */
7361 static expression_t *parse_label_address(void)
7362 {
7363         source_position_t source_position = token.source_position;
7364         eat(T_ANDAND);
7365         if (token.type != T_IDENTIFIER) {
7366                 parse_error_expected("while parsing label address", T_IDENTIFIER, NULL);
7367                 goto end_error;
7368         }
7369         symbol_t *symbol = token.v.symbol;
7370         next_token();
7371
7372         label_t *label       = get_label(symbol);
7373         label->used          = true;
7374         label->address_taken = true;
7375
7376         expression_t *expression = allocate_expression_zero(EXPR_LABEL_ADDRESS);
7377         expression->base.source_position = source_position;
7378
7379         /* label address is threaten as a void pointer */
7380         expression->base.type           = type_void_ptr;
7381         expression->label_address.label = label;
7382         return expression;
7383 end_error:
7384         return create_invalid_expression();
7385 }
7386
7387 /**
7388  * Parse a microsoft __noop expression.
7389  */
7390 static expression_t *parse_noop_expression(void)
7391 {
7392         /* the result is a (int)0 */
7393         expression_t *cnst         = allocate_expression_zero(EXPR_CONST);
7394         cnst->base.type            = type_int;
7395         cnst->conste.v.int_value   = 0;
7396         cnst->conste.is_ms_noop    = true;
7397
7398         eat(T___noop);
7399
7400         if (token.type == '(') {
7401                 /* parse arguments */
7402                 eat('(');
7403                 add_anchor_token(')');
7404                 add_anchor_token(',');
7405
7406                 if (token.type != ')') {
7407                         while (true) {
7408                                 (void)parse_assignment_expression();
7409                                 if (token.type != ',')
7410                                         break;
7411                                 next_token();
7412                         }
7413                 }
7414         }
7415         rem_anchor_token(',');
7416         rem_anchor_token(')');
7417         expect(')');
7418
7419 end_error:
7420         return cnst;
7421 }
7422
7423 /**
7424  * Parses a primary expression.
7425  */
7426 static expression_t *parse_primary_expression(void)
7427 {
7428         switch (token.type) {
7429                 case T_false:                    return parse_bool_const(false);
7430                 case T_true:                     return parse_bool_const(true);
7431                 case T_INTEGER:                  return parse_int_const();
7432                 case T_CHARACTER_CONSTANT:       return parse_character_constant();
7433                 case T_WIDE_CHARACTER_CONSTANT:  return parse_wide_character_constant();
7434                 case T_FLOATINGPOINT:            return parse_float_const();
7435                 case T_STRING_LITERAL:
7436                 case T_WIDE_STRING_LITERAL:      return parse_string_const();
7437                 case T_IDENTIFIER:               return parse_reference();
7438                 case T___FUNCTION__:
7439                 case T___func__:                 return parse_function_keyword();
7440                 case T___PRETTY_FUNCTION__:      return parse_pretty_function_keyword();
7441                 case T___FUNCSIG__:              return parse_funcsig_keyword();
7442                 case T___FUNCDNAME__:            return parse_funcdname_keyword();
7443                 case T___builtin_offsetof:       return parse_offsetof();
7444                 case T___builtin_va_start:       return parse_va_start();
7445                 case T___builtin_va_arg:         return parse_va_arg();
7446                 case T___builtin_expect:
7447                 case T___builtin_alloca:
7448                 case T___builtin_inf:
7449                 case T___builtin_inff:
7450                 case T___builtin_infl:
7451                 case T___builtin_nan:
7452                 case T___builtin_nanf:
7453                 case T___builtin_nanl:
7454                 case T___builtin_huge_val:
7455                 case T___builtin_va_end:         return parse_builtin_symbol();
7456                 case T___builtin_isgreater:
7457                 case T___builtin_isgreaterequal:
7458                 case T___builtin_isless:
7459                 case T___builtin_islessequal:
7460                 case T___builtin_islessgreater:
7461                 case T___builtin_isunordered:    return parse_compare_builtin();
7462                 case T___builtin_constant_p:     return parse_builtin_constant();
7463                 case T___builtin_prefetch:       return parse_builtin_prefetch();
7464                 case T__assume:                  return parse_assume();
7465                 case T_ANDAND:
7466                         if (GNU_MODE)
7467                                 return parse_label_address();
7468                         break;
7469
7470                 case '(':                        return parse_parenthesized_expression();
7471                 case T___noop:                   return parse_noop_expression();
7472         }
7473
7474         errorf(HERE, "unexpected token %K, expected an expression", &token);
7475         return create_invalid_expression();
7476 }
7477
7478 /**
7479  * Check if the expression has the character type and issue a warning then.
7480  */
7481 static void check_for_char_index_type(const expression_t *expression)
7482 {
7483         type_t       *const type      = expression->base.type;
7484         const type_t *const base_type = skip_typeref(type);
7485
7486         if (is_type_atomic(base_type, ATOMIC_TYPE_CHAR) &&
7487                         warning.char_subscripts) {
7488                 warningf(&expression->base.source_position,
7489                          "array subscript has type '%T'", type);
7490         }
7491 }
7492
7493 static expression_t *parse_array_expression(expression_t *left)
7494 {
7495         expression_t *expression = allocate_expression_zero(EXPR_ARRAY_ACCESS);
7496
7497         eat('[');
7498         add_anchor_token(']');
7499
7500         expression_t *inside = parse_expression();
7501
7502         type_t *const orig_type_left   = left->base.type;
7503         type_t *const orig_type_inside = inside->base.type;
7504
7505         type_t *const type_left   = skip_typeref(orig_type_left);
7506         type_t *const type_inside = skip_typeref(orig_type_inside);
7507
7508         type_t                    *return_type;
7509         array_access_expression_t *array_access = &expression->array_access;
7510         if (is_type_pointer(type_left)) {
7511                 return_type             = type_left->pointer.points_to;
7512                 array_access->array_ref = left;
7513                 array_access->index     = inside;
7514                 check_for_char_index_type(inside);
7515         } else if (is_type_pointer(type_inside)) {
7516                 return_type             = type_inside->pointer.points_to;
7517                 array_access->array_ref = inside;
7518                 array_access->index     = left;
7519                 array_access->flipped   = true;
7520                 check_for_char_index_type(left);
7521         } else {
7522                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
7523                         errorf(HERE,
7524                                 "array access on object with non-pointer types '%T', '%T'",
7525                                 orig_type_left, orig_type_inside);
7526                 }
7527                 return_type             = type_error_type;
7528                 array_access->array_ref = left;
7529                 array_access->index     = inside;
7530         }
7531
7532         expression->base.type = automatic_type_conversion(return_type);
7533
7534         rem_anchor_token(']');
7535         expect(']');
7536 end_error:
7537         return expression;
7538 }
7539
7540 static expression_t *parse_typeprop(expression_kind_t const kind)
7541 {
7542         expression_t  *tp_expression = allocate_expression_zero(kind);
7543         tp_expression->base.type     = type_size_t;
7544
7545         eat(kind == EXPR_SIZEOF ? T_sizeof : T___alignof__);
7546
7547         /* we only refer to a type property, mark this case */
7548         bool old     = in_type_prop;
7549         in_type_prop = true;
7550
7551         type_t       *orig_type;
7552         expression_t *expression;
7553         if (token.type == '(' && is_declaration_specifier(look_ahead(1), true)) {
7554                 next_token();
7555                 add_anchor_token(')');
7556                 orig_type = parse_typename();
7557                 rem_anchor_token(')');
7558                 expect(')');
7559
7560                 if (token.type == '{') {
7561                         /* It was not sizeof(type) after all.  It is sizeof of an expression
7562                          * starting with a compound literal */
7563                         expression = parse_compound_literal(orig_type);
7564                         goto typeprop_expression;
7565                 }
7566         } else {
7567                 expression = parse_sub_expression(PREC_UNARY);
7568
7569 typeprop_expression:
7570                 tp_expression->typeprop.tp_expression = expression;
7571
7572                 orig_type = revert_automatic_type_conversion(expression);
7573                 expression->base.type = orig_type;
7574         }
7575
7576         tp_expression->typeprop.type   = orig_type;
7577         type_t const* const type       = skip_typeref(orig_type);
7578         char   const* const wrong_type =
7579                 is_type_incomplete(type)    ? "incomplete"          :
7580                 type->kind == TYPE_FUNCTION ? "function designator" :
7581                 type->kind == TYPE_BITFIELD ? "bitfield"            :
7582                 NULL;
7583         if (wrong_type != NULL) {
7584                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
7585                 errorf(&tp_expression->base.source_position,
7586                                 "operand of %s expression must not be of %s type '%T'",
7587                                 what, wrong_type, orig_type);
7588         }
7589
7590 end_error:
7591         in_type_prop = old;
7592         return tp_expression;
7593 }
7594
7595 static expression_t *parse_sizeof(void)
7596 {
7597         return parse_typeprop(EXPR_SIZEOF);
7598 }
7599
7600 static expression_t *parse_alignof(void)
7601 {
7602         return parse_typeprop(EXPR_ALIGNOF);
7603 }
7604
7605 static expression_t *parse_select_expression(expression_t *compound)
7606 {
7607         expression_t *select    = allocate_expression_zero(EXPR_SELECT);
7608         select->select.compound = compound;
7609
7610         assert(token.type == '.' || token.type == T_MINUSGREATER);
7611         bool is_pointer = (token.type == T_MINUSGREATER);
7612         next_token();
7613
7614         if (token.type != T_IDENTIFIER) {
7615                 parse_error_expected("while parsing select", T_IDENTIFIER, NULL);
7616                 return select;
7617         }
7618         symbol_t *symbol = token.v.symbol;
7619         next_token();
7620
7621         type_t *const orig_type = compound->base.type;
7622         type_t *const type      = skip_typeref(orig_type);
7623
7624         type_t *type_left;
7625         bool    saw_error = false;
7626         if (is_type_pointer(type)) {
7627                 if (!is_pointer) {
7628                         errorf(HERE,
7629                                "request for member '%Y' in something not a struct or union, but '%T'",
7630                                symbol, orig_type);
7631                         saw_error = true;
7632                 }
7633                 type_left = skip_typeref(type->pointer.points_to);
7634         } else {
7635                 if (is_pointer && is_type_valid(type)) {
7636                         errorf(HERE, "left hand side of '->' is not a pointer, but '%T'", orig_type);
7637                         saw_error = true;
7638                 }
7639                 type_left = type;
7640         }
7641
7642         entity_t *entry;
7643         if (type_left->kind == TYPE_COMPOUND_STRUCT ||
7644             type_left->kind == TYPE_COMPOUND_UNION) {
7645                 compound_t *compound = type_left->compound.compound;
7646
7647                 if (!compound->complete) {
7648                         errorf(HERE, "request for member '%Y' of incomplete type '%T'",
7649                                symbol, type_left);
7650                         goto create_error_entry;
7651                 }
7652
7653                 entry = find_compound_entry(compound, symbol);
7654                 if (entry == NULL) {
7655                         errorf(HERE, "'%T' has no member named '%Y'", orig_type, symbol);
7656                         goto create_error_entry;
7657                 }
7658         } else {
7659                 if (is_type_valid(type_left) && !saw_error) {
7660                         errorf(HERE,
7661                                "request for member '%Y' in something not a struct or union, but '%T'",
7662                                symbol, type_left);
7663                 }
7664 create_error_entry:
7665                 return create_invalid_expression();
7666         }
7667
7668         assert(is_declaration(entry));
7669         select->select.compound_entry = entry;
7670
7671         type_t *entry_type = entry->declaration.type;
7672         type_t *res_type
7673                 = get_qualified_type(entry_type, type_left->base.qualifiers);
7674
7675         /* we always do the auto-type conversions; the & and sizeof parser contains
7676          * code to revert this! */
7677         select->base.type = automatic_type_conversion(res_type);
7678
7679         type_t *skipped = skip_typeref(res_type);
7680         if (skipped->kind == TYPE_BITFIELD) {
7681                 select->base.type = skipped->bitfield.base_type;
7682         }
7683
7684         return select;
7685 }
7686
7687 static void check_call_argument(const function_parameter_t *parameter,
7688                                 call_argument_t *argument, unsigned pos)
7689 {
7690         type_t         *expected_type      = parameter->type;
7691         type_t         *expected_type_skip = skip_typeref(expected_type);
7692         assign_error_t  error              = ASSIGN_ERROR_INCOMPATIBLE;
7693         expression_t   *arg_expr           = argument->expression;
7694         type_t         *arg_type           = skip_typeref(arg_expr->base.type);
7695
7696         /* handle transparent union gnu extension */
7697         if (is_type_union(expected_type_skip)
7698                         && (expected_type_skip->base.modifiers
7699                                 & TYPE_MODIFIER_TRANSPARENT_UNION)) {
7700                 compound_t *union_decl  = expected_type_skip->compound.compound;
7701                 type_t     *best_type   = NULL;
7702                 entity_t   *entry       = union_decl->members.entities;
7703                 for ( ; entry != NULL; entry = entry->base.next) {
7704                         assert(is_declaration(entry));
7705                         type_t *decl_type = entry->declaration.type;
7706                         error = semantic_assign(decl_type, arg_expr);
7707                         if (error == ASSIGN_ERROR_INCOMPATIBLE
7708                                 || error == ASSIGN_ERROR_POINTER_QUALIFIER_MISSING)
7709                                 continue;
7710
7711                         if (error == ASSIGN_SUCCESS) {
7712                                 best_type = decl_type;
7713                         } else if (best_type == NULL) {
7714                                 best_type = decl_type;
7715                         }
7716                 }
7717
7718                 if (best_type != NULL) {
7719                         expected_type = best_type;
7720                 }
7721         }
7722
7723         error                = semantic_assign(expected_type, arg_expr);
7724         argument->expression = create_implicit_cast(argument->expression,
7725                                                     expected_type);
7726
7727         if (error != ASSIGN_SUCCESS) {
7728                 /* report exact scope in error messages (like "in argument 3") */
7729                 char buf[64];
7730                 snprintf(buf, sizeof(buf), "call argument %u", pos);
7731                 report_assign_error(error, expected_type, arg_expr,     buf,
7732                                                         &arg_expr->base.source_position);
7733         } else if (warning.traditional || warning.conversion) {
7734                 type_t *const promoted_type = get_default_promoted_type(arg_type);
7735                 if (!types_compatible(expected_type_skip, promoted_type) &&
7736                     !types_compatible(expected_type_skip, type_void_ptr) &&
7737                     !types_compatible(type_void_ptr,      promoted_type)) {
7738                         /* Deliberately show the skipped types in this warning */
7739                         warningf(&arg_expr->base.source_position,
7740                                 "passing call argument %u as '%T' rather than '%T' due to prototype",
7741                                 pos, expected_type_skip, promoted_type);
7742                 }
7743         }
7744 }
7745
7746 /**
7747  * Parse a call expression, ie. expression '( ... )'.
7748  *
7749  * @param expression  the function address
7750  */
7751 static expression_t *parse_call_expression(expression_t *expression)
7752 {
7753         expression_t      *result = allocate_expression_zero(EXPR_CALL);
7754         call_expression_t *call   = &result->call;
7755         call->function            = expression;
7756
7757         type_t *const orig_type = expression->base.type;
7758         type_t *const type      = skip_typeref(orig_type);
7759
7760         function_type_t *function_type = NULL;
7761         if (is_type_pointer(type)) {
7762                 type_t *const to_type = skip_typeref(type->pointer.points_to);
7763
7764                 if (is_type_function(to_type)) {
7765                         function_type   = &to_type->function;
7766                         call->base.type = function_type->return_type;
7767                 }
7768         }
7769
7770         if (function_type == NULL && is_type_valid(type)) {
7771                 errorf(HERE, "called object '%E' (type '%T') is not a pointer to a function", expression, orig_type);
7772         }
7773
7774         /* parse arguments */
7775         eat('(');
7776         add_anchor_token(')');
7777         add_anchor_token(',');
7778
7779         if (token.type != ')') {
7780                 call_argument_t *last_argument = NULL;
7781
7782                 while (true) {
7783                         call_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
7784
7785                         argument->expression = parse_assignment_expression();
7786                         if (last_argument == NULL) {
7787                                 call->arguments = argument;
7788                         } else {
7789                                 last_argument->next = argument;
7790                         }
7791                         last_argument = argument;
7792
7793                         if (token.type != ',')
7794                                 break;
7795                         next_token();
7796                 }
7797         }
7798         rem_anchor_token(',');
7799         rem_anchor_token(')');
7800         expect(')');
7801
7802         if (function_type == NULL)
7803                 return result;
7804
7805         function_parameter_t *parameter = function_type->parameters;
7806         call_argument_t      *argument  = call->arguments;
7807         if (!function_type->unspecified_parameters) {
7808                 for (unsigned pos = 0; parameter != NULL && argument != NULL;
7809                                 parameter = parameter->next, argument = argument->next) {
7810                         check_call_argument(parameter, argument, ++pos);
7811                 }
7812
7813                 if (parameter != NULL) {
7814                         errorf(HERE, "too few arguments to function '%E'", expression);
7815                 } else if (argument != NULL && !function_type->variadic) {
7816                         errorf(HERE, "too many arguments to function '%E'", expression);
7817                 }
7818         }
7819
7820         /* do default promotion */
7821         for (; argument != NULL; argument = argument->next) {
7822                 type_t *type = argument->expression->base.type;
7823
7824                 type = get_default_promoted_type(type);
7825
7826                 argument->expression
7827                         = create_implicit_cast(argument->expression, type);
7828         }
7829
7830         check_format(&result->call);
7831
7832         if (warning.aggregate_return &&
7833             is_type_compound(skip_typeref(function_type->return_type))) {
7834                 warningf(&result->base.source_position,
7835                          "function call has aggregate value");
7836         }
7837
7838 end_error:
7839         return result;
7840 }
7841
7842 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
7843
7844 static bool same_compound_type(const type_t *type1, const type_t *type2)
7845 {
7846         return
7847                 is_type_compound(type1) &&
7848                 type1->kind == type2->kind &&
7849                 type1->compound.compound == type2->compound.compound;
7850 }
7851
7852 static expression_t const *get_reference_address(expression_t const *expr)
7853 {
7854         bool regular_take_address = true;
7855         for (;;) {
7856                 if (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
7857                         expr = expr->unary.value;
7858                 } else {
7859                         regular_take_address = false;
7860                 }
7861
7862                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
7863                         break;
7864
7865                 expr = expr->unary.value;
7866         }
7867
7868         if (expr->kind != EXPR_REFERENCE)
7869                 return NULL;
7870
7871         /* special case for functions which are automatically converted to a
7872          * pointer to function without an extra TAKE_ADDRESS operation */
7873         if (!regular_take_address &&
7874                         expr->reference.entity->kind != ENTITY_FUNCTION) {
7875                 return NULL;
7876         }
7877
7878         return expr;
7879 }
7880
7881 static void warn_reference_address_as_bool(expression_t const* expr)
7882 {
7883         if (!warning.address)
7884                 return;
7885
7886         expr = get_reference_address(expr);
7887         if (expr != NULL) {
7888                 warningf(&expr->base.source_position,
7889                          "the address of '%Y' will always evaluate as 'true'",
7890                          expr->reference.entity->base.symbol);
7891         }
7892 }
7893
7894 /**
7895  * Parse a conditional expression, ie. 'expression ? ... : ...'.
7896  *
7897  * @param expression  the conditional expression
7898  */
7899 static expression_t *parse_conditional_expression(expression_t *expression)
7900 {
7901         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
7902
7903         conditional_expression_t *conditional = &result->conditional;
7904         conditional->condition                = expression;
7905
7906         warn_reference_address_as_bool(expression);
7907
7908         eat('?');
7909         add_anchor_token(':');
7910
7911         /* 6.5.15.2 */
7912         type_t *const condition_type_orig = expression->base.type;
7913         type_t *const condition_type      = skip_typeref(condition_type_orig);
7914         if (!is_type_scalar(condition_type) && is_type_valid(condition_type)) {
7915                 type_error("expected a scalar type in conditional condition",
7916                            &expression->base.source_position, condition_type_orig);
7917         }
7918
7919         expression_t *true_expression = expression;
7920         bool          gnu_cond = false;
7921         if (GNU_MODE && token.type == ':') {
7922                 gnu_cond = true;
7923         } else {
7924                 true_expression = parse_expression();
7925         }
7926         rem_anchor_token(':');
7927         expect(':');
7928         expression_t *false_expression =
7929                 parse_sub_expression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
7930
7931         type_t *const orig_true_type  = true_expression->base.type;
7932         type_t *const orig_false_type = false_expression->base.type;
7933         type_t *const true_type       = skip_typeref(orig_true_type);
7934         type_t *const false_type      = skip_typeref(orig_false_type);
7935
7936         /* 6.5.15.3 */
7937         type_t *result_type;
7938         if (is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
7939                         is_type_atomic(false_type, ATOMIC_TYPE_VOID)) {
7940                 /* ISO/IEC 14882:1998(E) §5.16:2 */
7941                 if (true_expression->kind == EXPR_UNARY_THROW) {
7942                         result_type = false_type;
7943                 } else if (false_expression->kind == EXPR_UNARY_THROW) {
7944                         result_type = true_type;
7945                 } else {
7946                         if (warning.other && (
7947                                                 !is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
7948                                                 !is_type_atomic(false_type, ATOMIC_TYPE_VOID)
7949                                         )) {
7950                                 warningf(&conditional->base.source_position,
7951                                                 "ISO C forbids conditional expression with only one void side");
7952                         }
7953                         result_type = type_void;
7954                 }
7955         } else if (is_type_arithmetic(true_type)
7956                    && is_type_arithmetic(false_type)) {
7957                 result_type = semantic_arithmetic(true_type, false_type);
7958
7959                 true_expression  = create_implicit_cast(true_expression, result_type);
7960                 false_expression = create_implicit_cast(false_expression, result_type);
7961
7962                 conditional->true_expression  = true_expression;
7963                 conditional->false_expression = false_expression;
7964                 conditional->base.type        = result_type;
7965         } else if (same_compound_type(true_type, false_type)) {
7966                 /* just take 1 of the 2 types */
7967                 result_type = true_type;
7968         } else if (is_type_pointer(true_type) || is_type_pointer(false_type)) {
7969                 type_t *pointer_type;
7970                 type_t *other_type;
7971                 expression_t *other_expression;
7972                 if (is_type_pointer(true_type) &&
7973                                 (!is_type_pointer(false_type) || is_null_pointer_constant(false_expression))) {
7974                         pointer_type     = true_type;
7975                         other_type       = false_type;
7976                         other_expression = false_expression;
7977                 } else {
7978                         pointer_type     = false_type;
7979                         other_type       = true_type;
7980                         other_expression = true_expression;
7981                 }
7982
7983                 if (is_null_pointer_constant(other_expression)) {
7984                         result_type = pointer_type;
7985                 } else if (is_type_pointer(other_type)) {
7986                         type_t *to1 = skip_typeref(pointer_type->pointer.points_to);
7987                         type_t *to2 = skip_typeref(other_type->pointer.points_to);
7988
7989                         type_t *to;
7990                         if (is_type_atomic(to1, ATOMIC_TYPE_VOID) ||
7991                             is_type_atomic(to2, ATOMIC_TYPE_VOID)) {
7992                                 to = type_void;
7993                         } else if (types_compatible(get_unqualified_type(to1),
7994                                                     get_unqualified_type(to2))) {
7995                                 to = to1;
7996                         } else {
7997                                 if (warning.other) {
7998                                         warningf(&conditional->base.source_position,
7999                                                         "pointer types '%T' and '%T' in conditional expression are incompatible",
8000                                                         true_type, false_type);
8001                                 }
8002                                 to = type_void;
8003                         }
8004
8005                         type_t *const type =
8006                                 get_qualified_type(to, to1->base.qualifiers | to2->base.qualifiers);
8007                         result_type = make_pointer_type(type, TYPE_QUALIFIER_NONE);
8008                 } else if (is_type_integer(other_type)) {
8009                         if (warning.other) {
8010                                 warningf(&conditional->base.source_position,
8011                                                 "pointer/integer type mismatch in conditional expression ('%T' and '%T')", true_type, false_type);
8012                         }
8013                         result_type = pointer_type;
8014                 } else {
8015                         if (is_type_valid(other_type)) {
8016                                 type_error_incompatible("while parsing conditional",
8017                                                 &expression->base.source_position, true_type, false_type);
8018                         }
8019                         result_type = type_error_type;
8020                 }
8021         } else {
8022                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
8023                         type_error_incompatible("while parsing conditional",
8024                                                 &conditional->base.source_position, true_type,
8025                                                 false_type);
8026                 }
8027                 result_type = type_error_type;
8028         }
8029
8030         conditional->true_expression
8031                 = gnu_cond ? NULL : create_implicit_cast(true_expression, result_type);
8032         conditional->false_expression
8033                 = create_implicit_cast(false_expression, result_type);
8034         conditional->base.type = result_type;
8035         return result;
8036 end_error:
8037         return create_invalid_expression();
8038 }
8039
8040 /**
8041  * Parse an extension expression.
8042  */
8043 static expression_t *parse_extension(void)
8044 {
8045         eat(T___extension__);
8046
8047         bool old_gcc_extension   = in_gcc_extension;
8048         in_gcc_extension         = true;
8049         expression_t *expression = parse_sub_expression(PREC_UNARY);
8050         in_gcc_extension         = old_gcc_extension;
8051         return expression;
8052 }
8053
8054 /**
8055  * Parse a __builtin_classify_type() expression.
8056  */
8057 static expression_t *parse_builtin_classify_type(void)
8058 {
8059         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
8060         result->base.type    = type_int;
8061
8062         eat(T___builtin_classify_type);
8063
8064         expect('(');
8065         add_anchor_token(')');
8066         expression_t *expression = parse_expression();
8067         rem_anchor_token(')');
8068         expect(')');
8069         result->classify_type.type_expression = expression;
8070
8071         return result;
8072 end_error:
8073         return create_invalid_expression();
8074 }
8075
8076 /**
8077  * Parse a delete expression
8078  * ISO/IEC 14882:1998(E) §5.3.5
8079  */
8080 static expression_t *parse_delete(void)
8081 {
8082         expression_t *const result = allocate_expression_zero(EXPR_UNARY_DELETE);
8083         result->base.type          = type_void;
8084
8085         eat(T_delete);
8086
8087         if (token.type == '[') {
8088                 next_token();
8089                 result->kind = EXPR_UNARY_DELETE_ARRAY;
8090                 expect(']');
8091 end_error:;
8092         }
8093
8094         expression_t *const value = parse_sub_expression(PREC_CAST);
8095         result->unary.value = value;
8096
8097         type_t *const type = skip_typeref(value->base.type);
8098         if (!is_type_pointer(type)) {
8099                 errorf(&value->base.source_position,
8100                                 "operand of delete must have pointer type");
8101         } else if (warning.other &&
8102                         is_type_atomic(skip_typeref(type->pointer.points_to), ATOMIC_TYPE_VOID)) {
8103                 warningf(&value->base.source_position,
8104                                 "deleting 'void*' is undefined");
8105         }
8106
8107         return result;
8108 }
8109
8110 /**
8111  * Parse a throw expression
8112  * ISO/IEC 14882:1998(E) §15:1
8113  */
8114 static expression_t *parse_throw(void)
8115 {
8116         expression_t *const result = allocate_expression_zero(EXPR_UNARY_THROW);
8117         result->base.type          = type_void;
8118
8119         eat(T_throw);
8120
8121         expression_t *value = NULL;
8122         switch (token.type) {
8123                 EXPRESSION_START {
8124                         value = parse_assignment_expression();
8125                         /* ISO/IEC 14882:1998(E) §15.1:3 */
8126                         type_t *const orig_type = value->base.type;
8127                         type_t *const type      = skip_typeref(orig_type);
8128                         if (is_type_incomplete(type)) {
8129                                 errorf(&value->base.source_position,
8130                                                 "cannot throw object of incomplete type '%T'", orig_type);
8131                         } else if (is_type_pointer(type)) {
8132                                 type_t *const points_to = skip_typeref(type->pointer.points_to);
8133                                 if (is_type_incomplete(points_to) &&
8134                                                 !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
8135                                         errorf(&value->base.source_position,
8136                                                         "cannot throw pointer to incomplete type '%T'", orig_type);
8137                                 }
8138                         }
8139                 }
8140
8141                 default:
8142                         break;
8143         }
8144         result->unary.value = value;
8145
8146         return result;
8147 }
8148
8149 static bool check_pointer_arithmetic(const source_position_t *source_position,
8150                                      type_t *pointer_type,
8151                                      type_t *orig_pointer_type)
8152 {
8153         type_t *points_to = pointer_type->pointer.points_to;
8154         points_to = skip_typeref(points_to);
8155
8156         if (is_type_incomplete(points_to)) {
8157                 if (!GNU_MODE || !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
8158                         errorf(source_position,
8159                                "arithmetic with pointer to incomplete type '%T' not allowed",
8160                                orig_pointer_type);
8161                         return false;
8162                 } else if (warning.pointer_arith) {
8163                         warningf(source_position,
8164                                  "pointer of type '%T' used in arithmetic",
8165                                  orig_pointer_type);
8166                 }
8167         } else if (is_type_function(points_to)) {
8168                 if (!GNU_MODE) {
8169                         errorf(source_position,
8170                                "arithmetic with pointer to function type '%T' not allowed",
8171                                orig_pointer_type);
8172                         return false;
8173                 } else if (warning.pointer_arith) {
8174                         warningf(source_position,
8175                                  "pointer to a function '%T' used in arithmetic",
8176                                  orig_pointer_type);
8177                 }
8178         }
8179         return true;
8180 }
8181
8182 static bool is_lvalue(const expression_t *expression)
8183 {
8184         /* TODO: doesn't seem to be consistent with §6.3.2.1 (1) */
8185         switch (expression->kind) {
8186         case EXPR_REFERENCE:
8187         case EXPR_ARRAY_ACCESS:
8188         case EXPR_SELECT:
8189         case EXPR_UNARY_DEREFERENCE:
8190                 return true;
8191
8192         default:
8193                 /* Claim it is an lvalue, if the type is invalid.  There was a parse
8194                  * error before, which maybe prevented properly recognizing it as
8195                  * lvalue. */
8196                 return !is_type_valid(skip_typeref(expression->base.type));
8197         }
8198 }
8199
8200 static void semantic_incdec(unary_expression_t *expression)
8201 {
8202         type_t *const orig_type = expression->value->base.type;
8203         type_t *const type      = skip_typeref(orig_type);
8204         if (is_type_pointer(type)) {
8205                 if (!check_pointer_arithmetic(&expression->base.source_position,
8206                                               type, orig_type)) {
8207                         return;
8208                 }
8209         } else if (!is_type_real(type) && is_type_valid(type)) {
8210                 /* TODO: improve error message */
8211                 errorf(&expression->base.source_position,
8212                        "operation needs an arithmetic or pointer type");
8213                 return;
8214         }
8215         if (!is_lvalue(expression->value)) {
8216                 /* TODO: improve error message */
8217                 errorf(&expression->base.source_position, "lvalue required as operand");
8218         }
8219         expression->base.type = orig_type;
8220 }
8221
8222 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
8223 {
8224         type_t *const orig_type = expression->value->base.type;
8225         type_t *const type      = skip_typeref(orig_type);
8226         if (!is_type_arithmetic(type)) {
8227                 if (is_type_valid(type)) {
8228                         /* TODO: improve error message */
8229                         errorf(&expression->base.source_position,
8230                                 "operation needs an arithmetic type");
8231                 }
8232                 return;
8233         }
8234
8235         expression->base.type = orig_type;
8236 }
8237
8238 static void semantic_unexpr_plus(unary_expression_t *expression)
8239 {
8240         semantic_unexpr_arithmetic(expression);
8241         if (warning.traditional)
8242                 warningf(&expression->base.source_position,
8243                         "traditional C rejects the unary plus operator");
8244 }
8245
8246 static void semantic_not(unary_expression_t *expression)
8247 {
8248         type_t *const orig_type = expression->value->base.type;
8249         type_t *const type      = skip_typeref(orig_type);
8250         if (!is_type_scalar(type) && is_type_valid(type)) {
8251                 errorf(&expression->base.source_position,
8252                        "operand of ! must be of scalar type");
8253         }
8254
8255         warn_reference_address_as_bool(expression->value);
8256
8257         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8258 }
8259
8260 static void semantic_unexpr_integer(unary_expression_t *expression)
8261 {
8262         type_t *const orig_type = expression->value->base.type;
8263         type_t *const type      = skip_typeref(orig_type);
8264         if (!is_type_integer(type)) {
8265                 if (is_type_valid(type)) {
8266                         errorf(&expression->base.source_position,
8267                                "operand of ~ must be of integer type");
8268                 }
8269                 return;
8270         }
8271
8272         expression->base.type = orig_type;
8273 }
8274
8275 static void semantic_dereference(unary_expression_t *expression)
8276 {
8277         type_t *const orig_type = expression->value->base.type;
8278         type_t *const type      = skip_typeref(orig_type);
8279         if (!is_type_pointer(type)) {
8280                 if (is_type_valid(type)) {
8281                         errorf(&expression->base.source_position,
8282                                "Unary '*' needs pointer or array type, but type '%T' given", orig_type);
8283                 }
8284                 return;
8285         }
8286
8287         type_t *result_type   = type->pointer.points_to;
8288         result_type           = automatic_type_conversion(result_type);
8289         expression->base.type = result_type;
8290 }
8291
8292 /**
8293  * Record that an address is taken (expression represents an lvalue).
8294  *
8295  * @param expression       the expression
8296  * @param may_be_register  if true, the expression might be an register
8297  */
8298 static void set_address_taken(expression_t *expression, bool may_be_register)
8299 {
8300         if (expression->kind != EXPR_REFERENCE)
8301                 return;
8302
8303         entity_t *const entity = expression->reference.entity;
8304
8305         if (entity->kind != ENTITY_VARIABLE)
8306                 return;
8307
8308         if (entity->declaration.storage_class == STORAGE_CLASS_REGISTER
8309                         && !may_be_register) {
8310                 errorf(&expression->base.source_position,
8311                                 "address of register variable '%Y' requested",
8312                                 entity->base.symbol);
8313         }
8314
8315         entity->variable.address_taken = true;
8316 }
8317
8318 /**
8319  * Check the semantic of the address taken expression.
8320  */
8321 static void semantic_take_addr(unary_expression_t *expression)
8322 {
8323         expression_t *value = expression->value;
8324         value->base.type    = revert_automatic_type_conversion(value);
8325
8326         type_t *orig_type = value->base.type;
8327         type_t *type      = skip_typeref(orig_type);
8328         if (!is_type_valid(type))
8329                 return;
8330
8331         /* §6.5.3.2 */
8332         if (!is_lvalue(value)) {
8333                 errorf(&expression->base.source_position, "'&' requires an lvalue");
8334         }
8335         if (type->kind == TYPE_BITFIELD) {
8336                 errorf(&expression->base.source_position,
8337                        "'&' not allowed on object with bitfield type '%T'",
8338                        type);
8339         }
8340
8341         set_address_taken(value, false);
8342
8343         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
8344 }
8345
8346 #define CREATE_UNARY_EXPRESSION_PARSER(token_type, unexpression_type, sfunc) \
8347 static expression_t *parse_##unexpression_type(void)                         \
8348 {                                                                            \
8349         expression_t *unary_expression                                           \
8350                 = allocate_expression_zero(unexpression_type);                       \
8351         eat(token_type);                                                         \
8352         unary_expression->unary.value = parse_sub_expression(PREC_UNARY);        \
8353                                                                                  \
8354         sfunc(&unary_expression->unary);                                         \
8355                                                                                  \
8356         return unary_expression;                                                 \
8357 }
8358
8359 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
8360                                semantic_unexpr_arithmetic)
8361 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
8362                                semantic_unexpr_plus)
8363 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
8364                                semantic_not)
8365 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
8366                                semantic_dereference)
8367 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
8368                                semantic_take_addr)
8369 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
8370                                semantic_unexpr_integer)
8371 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
8372                                semantic_incdec)
8373 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
8374                                semantic_incdec)
8375
8376 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_type, unexpression_type, \
8377                                                sfunc)                         \
8378 static expression_t *parse_##unexpression_type(expression_t *left)            \
8379 {                                                                             \
8380         expression_t *unary_expression                                            \
8381                 = allocate_expression_zero(unexpression_type);                        \
8382         eat(token_type);                                                          \
8383         unary_expression->unary.value = left;                                     \
8384                                                                                   \
8385         sfunc(&unary_expression->unary);                                          \
8386                                                                               \
8387         return unary_expression;                                                  \
8388 }
8389
8390 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
8391                                        EXPR_UNARY_POSTFIX_INCREMENT,
8392                                        semantic_incdec)
8393 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
8394                                        EXPR_UNARY_POSTFIX_DECREMENT,
8395                                        semantic_incdec)
8396
8397 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
8398 {
8399         /* TODO: handle complex + imaginary types */
8400
8401         type_left  = get_unqualified_type(type_left);
8402         type_right = get_unqualified_type(type_right);
8403
8404         /* § 6.3.1.8 Usual arithmetic conversions */
8405         if (type_left == type_long_double || type_right == type_long_double) {
8406                 return type_long_double;
8407         } else if (type_left == type_double || type_right == type_double) {
8408                 return type_double;
8409         } else if (type_left == type_float || type_right == type_float) {
8410                 return type_float;
8411         }
8412
8413         type_left  = promote_integer(type_left);
8414         type_right = promote_integer(type_right);
8415
8416         if (type_left == type_right)
8417                 return type_left;
8418
8419         bool const signed_left  = is_type_signed(type_left);
8420         bool const signed_right = is_type_signed(type_right);
8421         int const  rank_left    = get_rank(type_left);
8422         int const  rank_right   = get_rank(type_right);
8423
8424         if (signed_left == signed_right)
8425                 return rank_left >= rank_right ? type_left : type_right;
8426
8427         int     s_rank;
8428         int     u_rank;
8429         type_t *s_type;
8430         type_t *u_type;
8431         if (signed_left) {
8432                 s_rank = rank_left;
8433                 s_type = type_left;
8434                 u_rank = rank_right;
8435                 u_type = type_right;
8436         } else {
8437                 s_rank = rank_right;
8438                 s_type = type_right;
8439                 u_rank = rank_left;
8440                 u_type = type_left;
8441         }
8442
8443         if (u_rank >= s_rank)
8444                 return u_type;
8445
8446         /* casting rank to atomic_type_kind is a bit hacky, but makes things
8447          * easier here... */
8448         if (get_atomic_type_size((atomic_type_kind_t) s_rank)
8449                         > get_atomic_type_size((atomic_type_kind_t) u_rank))
8450                 return s_type;
8451
8452         switch (s_rank) {
8453                 case ATOMIC_TYPE_INT:      return type_unsigned_int;
8454                 case ATOMIC_TYPE_LONG:     return type_unsigned_long;
8455                 case ATOMIC_TYPE_LONGLONG: return type_unsigned_long_long;
8456
8457                 default: panic("invalid atomic type");
8458         }
8459 }
8460
8461 /**
8462  * Check the semantic restrictions for a binary expression.
8463  */
8464 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
8465 {
8466         expression_t *const left            = expression->left;
8467         expression_t *const right           = expression->right;
8468         type_t       *const orig_type_left  = left->base.type;
8469         type_t       *const orig_type_right = right->base.type;
8470         type_t       *const type_left       = skip_typeref(orig_type_left);
8471         type_t       *const type_right      = skip_typeref(orig_type_right);
8472
8473         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8474                 /* TODO: improve error message */
8475                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8476                         errorf(&expression->base.source_position,
8477                                "operation needs arithmetic types");
8478                 }
8479                 return;
8480         }
8481
8482         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8483         expression->left      = create_implicit_cast(left, arithmetic_type);
8484         expression->right     = create_implicit_cast(right, arithmetic_type);
8485         expression->base.type = arithmetic_type;
8486 }
8487
8488 static void warn_div_by_zero(binary_expression_t const *const expression)
8489 {
8490         if (!warning.div_by_zero ||
8491             !is_type_integer(expression->base.type))
8492                 return;
8493
8494         expression_t const *const right = expression->right;
8495         /* The type of the right operand can be different for /= */
8496         if (is_type_integer(right->base.type) &&
8497             is_constant_expression(right)     &&
8498             fold_constant(right) == 0) {
8499                 warningf(&expression->base.source_position, "division by zero");
8500         }
8501 }
8502
8503 /**
8504  * Check the semantic restrictions for a div/mod expression.
8505  */
8506 static void semantic_divmod_arithmetic(binary_expression_t *expression) {
8507         semantic_binexpr_arithmetic(expression);
8508         warn_div_by_zero(expression);
8509 }
8510
8511 static void semantic_shift_op(binary_expression_t *expression)
8512 {
8513         expression_t *const left            = expression->left;
8514         expression_t *const right           = expression->right;
8515         type_t       *const orig_type_left  = left->base.type;
8516         type_t       *const orig_type_right = right->base.type;
8517         type_t       *      type_left       = skip_typeref(orig_type_left);
8518         type_t       *      type_right      = skip_typeref(orig_type_right);
8519
8520         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8521                 /* TODO: improve error message */
8522                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8523                         errorf(&expression->base.source_position,
8524                                "operands of shift operation must have integer types");
8525                 }
8526                 return;
8527         }
8528
8529         type_left  = promote_integer(type_left);
8530         type_right = promote_integer(type_right);
8531
8532         expression->left      = create_implicit_cast(left, type_left);
8533         expression->right     = create_implicit_cast(right, type_right);
8534         expression->base.type = type_left;
8535 }
8536
8537 static void semantic_add(binary_expression_t *expression)
8538 {
8539         expression_t *const left            = expression->left;
8540         expression_t *const right           = expression->right;
8541         type_t       *const orig_type_left  = left->base.type;
8542         type_t       *const orig_type_right = right->base.type;
8543         type_t       *const type_left       = skip_typeref(orig_type_left);
8544         type_t       *const type_right      = skip_typeref(orig_type_right);
8545
8546         /* § 6.5.6 */
8547         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8548                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8549                 expression->left  = create_implicit_cast(left, arithmetic_type);
8550                 expression->right = create_implicit_cast(right, arithmetic_type);
8551                 expression->base.type = arithmetic_type;
8552                 return;
8553         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8554                 check_pointer_arithmetic(&expression->base.source_position,
8555                                          type_left, orig_type_left);
8556                 expression->base.type = type_left;
8557         } else if (is_type_pointer(type_right) && is_type_integer(type_left)) {
8558                 check_pointer_arithmetic(&expression->base.source_position,
8559                                          type_right, orig_type_right);
8560                 expression->base.type = type_right;
8561         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8562                 errorf(&expression->base.source_position,
8563                        "invalid operands to binary + ('%T', '%T')",
8564                        orig_type_left, orig_type_right);
8565         }
8566 }
8567
8568 static void semantic_sub(binary_expression_t *expression)
8569 {
8570         expression_t            *const left            = expression->left;
8571         expression_t            *const right           = expression->right;
8572         type_t                  *const orig_type_left  = left->base.type;
8573         type_t                  *const orig_type_right = right->base.type;
8574         type_t                  *const type_left       = skip_typeref(orig_type_left);
8575         type_t                  *const type_right      = skip_typeref(orig_type_right);
8576         source_position_t const *const pos             = &expression->base.source_position;
8577
8578         /* § 5.6.5 */
8579         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8580                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8581                 expression->left        = create_implicit_cast(left, arithmetic_type);
8582                 expression->right       = create_implicit_cast(right, arithmetic_type);
8583                 expression->base.type =  arithmetic_type;
8584                 return;
8585         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8586                 check_pointer_arithmetic(&expression->base.source_position,
8587                                          type_left, orig_type_left);
8588                 expression->base.type = type_left;
8589         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8590                 type_t *const unqual_left  = get_unqualified_type(skip_typeref(type_left->pointer.points_to));
8591                 type_t *const unqual_right = get_unqualified_type(skip_typeref(type_right->pointer.points_to));
8592                 if (!types_compatible(unqual_left, unqual_right)) {
8593                         errorf(pos,
8594                                "subtracting pointers to incompatible types '%T' and '%T'",
8595                                orig_type_left, orig_type_right);
8596                 } else if (!is_type_object(unqual_left)) {
8597                         if (!is_type_atomic(unqual_left, ATOMIC_TYPE_VOID)) {
8598                                 errorf(pos, "subtracting pointers to non-object types '%T'",
8599                                        orig_type_left);
8600                         } else if (warning.other) {
8601                                 warningf(pos, "subtracting pointers to void");
8602                         }
8603                 }
8604                 expression->base.type = type_ptrdiff_t;
8605         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8606                 errorf(pos, "invalid operands of types '%T' and '%T' to binary '-'",
8607                        orig_type_left, orig_type_right);
8608         }
8609 }
8610
8611 static void warn_string_literal_address(expression_t const* expr)
8612 {
8613         while (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
8614                 expr = expr->unary.value;
8615                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
8616                         return;
8617                 expr = expr->unary.value;
8618         }
8619
8620         if (expr->kind == EXPR_STRING_LITERAL ||
8621             expr->kind == EXPR_WIDE_STRING_LITERAL) {
8622                 warningf(&expr->base.source_position,
8623                         "comparison with string literal results in unspecified behaviour");
8624         }
8625 }
8626
8627 /**
8628  * Check the semantics of comparison expressions.
8629  *
8630  * @param expression   The expression to check.
8631  */
8632 static void semantic_comparison(binary_expression_t *expression)
8633 {
8634         expression_t *left  = expression->left;
8635         expression_t *right = expression->right;
8636
8637         if (warning.address) {
8638                 warn_string_literal_address(left);
8639                 warn_string_literal_address(right);
8640
8641                 expression_t const* const func_left = get_reference_address(left);
8642                 if (func_left != NULL && is_null_pointer_constant(right)) {
8643                         warningf(&expression->base.source_position,
8644                                  "the address of '%Y' will never be NULL",
8645                                  func_left->reference.entity->base.symbol);
8646                 }
8647
8648                 expression_t const* const func_right = get_reference_address(right);
8649                 if (func_right != NULL && is_null_pointer_constant(right)) {
8650                         warningf(&expression->base.source_position,
8651                                  "the address of '%Y' will never be NULL",
8652                                  func_right->reference.entity->base.symbol);
8653                 }
8654         }
8655
8656         type_t *orig_type_left  = left->base.type;
8657         type_t *orig_type_right = right->base.type;
8658         type_t *type_left       = skip_typeref(orig_type_left);
8659         type_t *type_right      = skip_typeref(orig_type_right);
8660
8661         /* TODO non-arithmetic types */
8662         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8663                 /* test for signed vs unsigned compares */
8664                 if (warning.sign_compare &&
8665                     (expression->base.kind != EXPR_BINARY_EQUAL &&
8666                      expression->base.kind != EXPR_BINARY_NOTEQUAL) &&
8667                     (is_type_signed(type_left) != is_type_signed(type_right))) {
8668
8669                         /* check if 1 of the operands is a constant, in this case we just
8670                          * check wether we can safely represent the resulting constant in
8671                          * the type of the other operand. */
8672                         expression_t *const_expr = NULL;
8673                         expression_t *other_expr = NULL;
8674
8675                         if (is_constant_expression(left)) {
8676                                 const_expr = left;
8677                                 other_expr = right;
8678                         } else if (is_constant_expression(right)) {
8679                                 const_expr = right;
8680                                 other_expr = left;
8681                         }
8682
8683                         if (const_expr != NULL) {
8684                                 type_t *other_type = skip_typeref(other_expr->base.type);
8685                                 long    val        = fold_constant(const_expr);
8686                                 /* TODO: check if val can be represented by other_type */
8687                                 (void) other_type;
8688                                 (void) val;
8689                         }
8690                         warningf(&expression->base.source_position,
8691                                  "comparison between signed and unsigned");
8692                 }
8693                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8694                 expression->left        = create_implicit_cast(left, arithmetic_type);
8695                 expression->right       = create_implicit_cast(right, arithmetic_type);
8696                 expression->base.type   = arithmetic_type;
8697                 if (warning.float_equal &&
8698                     (expression->base.kind == EXPR_BINARY_EQUAL ||
8699                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
8700                     is_type_float(arithmetic_type)) {
8701                         warningf(&expression->base.source_position,
8702                                  "comparing floating point with == or != is unsafe");
8703                 }
8704         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8705                 /* TODO check compatibility */
8706         } else if (is_type_pointer(type_left)) {
8707                 expression->right = create_implicit_cast(right, type_left);
8708         } else if (is_type_pointer(type_right)) {
8709                 expression->left = create_implicit_cast(left, type_right);
8710         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8711                 type_error_incompatible("invalid operands in comparison",
8712                                         &expression->base.source_position,
8713                                         type_left, type_right);
8714         }
8715         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8716 }
8717
8718 /**
8719  * Checks if a compound type has constant fields.
8720  */
8721 static bool has_const_fields(const compound_type_t *type)
8722 {
8723         compound_t *compound = type->compound;
8724         entity_t   *entry    = compound->members.entities;
8725
8726         for (; entry != NULL; entry = entry->base.next) {
8727                 if (!is_declaration(entry))
8728                         continue;
8729
8730                 const type_t *decl_type = skip_typeref(entry->declaration.type);
8731                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
8732                         return true;
8733         }
8734
8735         return false;
8736 }
8737
8738 static bool is_valid_assignment_lhs(expression_t const* const left)
8739 {
8740         type_t *const orig_type_left = revert_automatic_type_conversion(left);
8741         type_t *const type_left      = skip_typeref(orig_type_left);
8742
8743         if (!is_lvalue(left)) {
8744                 errorf(HERE, "left hand side '%E' of assignment is not an lvalue",
8745                        left);
8746                 return false;
8747         }
8748
8749         if (is_type_array(type_left)) {
8750                 errorf(HERE, "cannot assign to arrays ('%E')", left);
8751                 return false;
8752         }
8753         if (type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
8754                 errorf(HERE, "assignment to readonly location '%E' (type '%T')", left,
8755                        orig_type_left);
8756                 return false;
8757         }
8758         if (is_type_incomplete(type_left)) {
8759                 errorf(HERE, "left-hand side '%E' of assignment has incomplete type '%T'",
8760                        left, orig_type_left);
8761                 return false;
8762         }
8763         if (is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
8764                 errorf(HERE, "cannot assign to '%E' because compound type '%T' has readonly fields",
8765                        left, orig_type_left);
8766                 return false;
8767         }
8768
8769         return true;
8770 }
8771
8772 static void semantic_arithmetic_assign(binary_expression_t *expression)
8773 {
8774         expression_t *left            = expression->left;
8775         expression_t *right           = expression->right;
8776         type_t       *orig_type_left  = left->base.type;
8777         type_t       *orig_type_right = right->base.type;
8778
8779         if (!is_valid_assignment_lhs(left))
8780                 return;
8781
8782         type_t *type_left  = skip_typeref(orig_type_left);
8783         type_t *type_right = skip_typeref(orig_type_right);
8784
8785         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8786                 /* TODO: improve error message */
8787                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8788                         errorf(&expression->base.source_position,
8789                                "operation needs arithmetic types");
8790                 }
8791                 return;
8792         }
8793
8794         /* combined instructions are tricky. We can't create an implicit cast on
8795          * the left side, because we need the uncasted form for the store.
8796          * The ast2firm pass has to know that left_type must be right_type
8797          * for the arithmetic operation and create a cast by itself */
8798         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8799         expression->right       = create_implicit_cast(right, arithmetic_type);
8800         expression->base.type   = type_left;
8801 }
8802
8803 static void semantic_divmod_assign(binary_expression_t *expression)
8804 {
8805         semantic_arithmetic_assign(expression);
8806         warn_div_by_zero(expression);
8807 }
8808
8809 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
8810 {
8811         expression_t *const left            = expression->left;
8812         expression_t *const right           = expression->right;
8813         type_t       *const orig_type_left  = left->base.type;
8814         type_t       *const orig_type_right = right->base.type;
8815         type_t       *const type_left       = skip_typeref(orig_type_left);
8816         type_t       *const type_right      = skip_typeref(orig_type_right);
8817
8818         if (!is_valid_assignment_lhs(left))
8819                 return;
8820
8821         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8822                 /* combined instructions are tricky. We can't create an implicit cast on
8823                  * the left side, because we need the uncasted form for the store.
8824                  * The ast2firm pass has to know that left_type must be right_type
8825                  * for the arithmetic operation and create a cast by itself */
8826                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
8827                 expression->right     = create_implicit_cast(right, arithmetic_type);
8828                 expression->base.type = type_left;
8829         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8830                 check_pointer_arithmetic(&expression->base.source_position,
8831                                          type_left, orig_type_left);
8832                 expression->base.type = type_left;
8833         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8834                 errorf(&expression->base.source_position,
8835                        "incompatible types '%T' and '%T' in assignment",
8836                        orig_type_left, orig_type_right);
8837         }
8838 }
8839
8840 /**
8841  * Check the semantic restrictions of a logical expression.
8842  */
8843 static void semantic_logical_op(binary_expression_t *expression)
8844 {
8845         expression_t *const left            = expression->left;
8846         expression_t *const right           = expression->right;
8847         type_t       *const orig_type_left  = left->base.type;
8848         type_t       *const orig_type_right = right->base.type;
8849         type_t       *const type_left       = skip_typeref(orig_type_left);
8850         type_t       *const type_right      = skip_typeref(orig_type_right);
8851
8852         warn_reference_address_as_bool(left);
8853         warn_reference_address_as_bool(right);
8854
8855         if (!is_type_scalar(type_left) || !is_type_scalar(type_right)) {
8856                 /* TODO: improve error message */
8857                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8858                         errorf(&expression->base.source_position,
8859                                "operation needs scalar types");
8860                 }
8861                 return;
8862         }
8863
8864         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8865 }
8866
8867 /**
8868  * Check the semantic restrictions of a binary assign expression.
8869  */
8870 static void semantic_binexpr_assign(binary_expression_t *expression)
8871 {
8872         expression_t *left           = expression->left;
8873         type_t       *orig_type_left = left->base.type;
8874
8875         if (!is_valid_assignment_lhs(left))
8876                 return;
8877
8878         assign_error_t error = semantic_assign(orig_type_left, expression->right);
8879         report_assign_error(error, orig_type_left, expression->right,
8880                         "assignment", &left->base.source_position);
8881         expression->right = create_implicit_cast(expression->right, orig_type_left);
8882         expression->base.type = orig_type_left;
8883 }
8884
8885 /**
8886  * Determine if the outermost operation (or parts thereof) of the given
8887  * expression has no effect in order to generate a warning about this fact.
8888  * Therefore in some cases this only examines some of the operands of the
8889  * expression (see comments in the function and examples below).
8890  * Examples:
8891  *   f() + 23;    // warning, because + has no effect
8892  *   x || f();    // no warning, because x controls execution of f()
8893  *   x ? y : f(); // warning, because y has no effect
8894  *   (void)x;     // no warning to be able to suppress the warning
8895  * This function can NOT be used for an "expression has definitely no effect"-
8896  * analysis. */
8897 static bool expression_has_effect(const expression_t *const expr)
8898 {
8899         switch (expr->kind) {
8900                 case EXPR_UNKNOWN:                   break;
8901                 case EXPR_INVALID:                   return true; /* do NOT warn */
8902                 case EXPR_REFERENCE:                 return false;
8903                 case EXPR_REFERENCE_ENUM_VALUE:      return false;
8904                 /* suppress the warning for microsoft __noop operations */
8905                 case EXPR_CONST:                     return expr->conste.is_ms_noop;
8906                 case EXPR_CHARACTER_CONSTANT:        return false;
8907                 case EXPR_WIDE_CHARACTER_CONSTANT:   return false;
8908                 case EXPR_STRING_LITERAL:            return false;
8909                 case EXPR_WIDE_STRING_LITERAL:       return false;
8910                 case EXPR_LABEL_ADDRESS:             return false;
8911
8912                 case EXPR_CALL: {
8913                         const call_expression_t *const call = &expr->call;
8914                         if (call->function->kind != EXPR_BUILTIN_SYMBOL)
8915                                 return true;
8916
8917                         switch (call->function->builtin_symbol.symbol->ID) {
8918                                 case T___builtin_va_end: return true;
8919                                 default:                 return false;
8920                         }
8921                 }
8922
8923                 /* Generate the warning if either the left or right hand side of a
8924                  * conditional expression has no effect */
8925                 case EXPR_CONDITIONAL: {
8926                         const conditional_expression_t *const cond = &expr->conditional;
8927                         return
8928                                 expression_has_effect(cond->true_expression) &&
8929                                 expression_has_effect(cond->false_expression);
8930                 }
8931
8932                 case EXPR_SELECT:                    return false;
8933                 case EXPR_ARRAY_ACCESS:              return false;
8934                 case EXPR_SIZEOF:                    return false;
8935                 case EXPR_CLASSIFY_TYPE:             return false;
8936                 case EXPR_ALIGNOF:                   return false;
8937
8938                 case EXPR_FUNCNAME:                  return false;
8939                 case EXPR_BUILTIN_SYMBOL:            break; /* handled in EXPR_CALL */
8940                 case EXPR_BUILTIN_CONSTANT_P:        return false;
8941                 case EXPR_BUILTIN_PREFETCH:          return true;
8942                 case EXPR_OFFSETOF:                  return false;
8943                 case EXPR_VA_START:                  return true;
8944                 case EXPR_VA_ARG:                    return true;
8945                 case EXPR_STATEMENT:                 return true; // TODO
8946                 case EXPR_COMPOUND_LITERAL:          return false;
8947
8948                 case EXPR_UNARY_NEGATE:              return false;
8949                 case EXPR_UNARY_PLUS:                return false;
8950                 case EXPR_UNARY_BITWISE_NEGATE:      return false;
8951                 case EXPR_UNARY_NOT:                 return false;
8952                 case EXPR_UNARY_DEREFERENCE:         return false;
8953                 case EXPR_UNARY_TAKE_ADDRESS:        return false;
8954                 case EXPR_UNARY_POSTFIX_INCREMENT:   return true;
8955                 case EXPR_UNARY_POSTFIX_DECREMENT:   return true;
8956                 case EXPR_UNARY_PREFIX_INCREMENT:    return true;
8957                 case EXPR_UNARY_PREFIX_DECREMENT:    return true;
8958
8959                 /* Treat void casts as if they have an effect in order to being able to
8960                  * suppress the warning */
8961                 case EXPR_UNARY_CAST: {
8962                         type_t *const type = skip_typeref(expr->base.type);
8963                         return is_type_atomic(type, ATOMIC_TYPE_VOID);
8964                 }
8965
8966                 case EXPR_UNARY_CAST_IMPLICIT:       return true;
8967                 case EXPR_UNARY_ASSUME:              return true;
8968                 case EXPR_UNARY_DELETE:              return true;
8969                 case EXPR_UNARY_DELETE_ARRAY:        return true;
8970                 case EXPR_UNARY_THROW:               return true;
8971
8972                 case EXPR_BINARY_ADD:                return false;
8973                 case EXPR_BINARY_SUB:                return false;
8974                 case EXPR_BINARY_MUL:                return false;
8975                 case EXPR_BINARY_DIV:                return false;
8976                 case EXPR_BINARY_MOD:                return false;
8977                 case EXPR_BINARY_EQUAL:              return false;
8978                 case EXPR_BINARY_NOTEQUAL:           return false;
8979                 case EXPR_BINARY_LESS:               return false;
8980                 case EXPR_BINARY_LESSEQUAL:          return false;
8981                 case EXPR_BINARY_GREATER:            return false;
8982                 case EXPR_BINARY_GREATEREQUAL:       return false;
8983                 case EXPR_BINARY_BITWISE_AND:        return false;
8984                 case EXPR_BINARY_BITWISE_OR:         return false;
8985                 case EXPR_BINARY_BITWISE_XOR:        return false;
8986                 case EXPR_BINARY_SHIFTLEFT:          return false;
8987                 case EXPR_BINARY_SHIFTRIGHT:         return false;
8988                 case EXPR_BINARY_ASSIGN:             return true;
8989                 case EXPR_BINARY_MUL_ASSIGN:         return true;
8990                 case EXPR_BINARY_DIV_ASSIGN:         return true;
8991                 case EXPR_BINARY_MOD_ASSIGN:         return true;
8992                 case EXPR_BINARY_ADD_ASSIGN:         return true;
8993                 case EXPR_BINARY_SUB_ASSIGN:         return true;
8994                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:   return true;
8995                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:  return true;
8996                 case EXPR_BINARY_BITWISE_AND_ASSIGN: return true;
8997                 case EXPR_BINARY_BITWISE_XOR_ASSIGN: return true;
8998                 case EXPR_BINARY_BITWISE_OR_ASSIGN:  return true;
8999
9000                 /* Only examine the right hand side of && and ||, because the left hand
9001                  * side already has the effect of controlling the execution of the right
9002                  * hand side */
9003                 case EXPR_BINARY_LOGICAL_AND:
9004                 case EXPR_BINARY_LOGICAL_OR:
9005                 /* Only examine the right hand side of a comma expression, because the left
9006                  * hand side has a separate warning */
9007                 case EXPR_BINARY_COMMA:
9008                         return expression_has_effect(expr->binary.right);
9009
9010                 case EXPR_BINARY_BUILTIN_EXPECT:     return true;
9011                 case EXPR_BINARY_ISGREATER:          return false;
9012                 case EXPR_BINARY_ISGREATEREQUAL:     return false;
9013                 case EXPR_BINARY_ISLESS:             return false;
9014                 case EXPR_BINARY_ISLESSEQUAL:        return false;
9015                 case EXPR_BINARY_ISLESSGREATER:      return false;
9016                 case EXPR_BINARY_ISUNORDERED:        return false;
9017         }
9018
9019         internal_errorf(HERE, "unexpected expression");
9020 }
9021
9022 static void semantic_comma(binary_expression_t *expression)
9023 {
9024         if (warning.unused_value) {
9025                 const expression_t *const left = expression->left;
9026                 if (!expression_has_effect(left)) {
9027                         warningf(&left->base.source_position,
9028                                  "left-hand operand of comma expression has no effect");
9029                 }
9030         }
9031         expression->base.type = expression->right->base.type;
9032 }
9033
9034 /**
9035  * @param prec_r precedence of the right operand
9036  */
9037 #define CREATE_BINEXPR_PARSER(token_type, binexpression_type, prec_r, sfunc) \
9038 static expression_t *parse_##binexpression_type(expression_t *left)          \
9039 {                                                                            \
9040         expression_t *binexpr = allocate_expression_zero(binexpression_type);    \
9041         binexpr->binary.left  = left;                                            \
9042         eat(token_type);                                                         \
9043                                                                              \
9044         expression_t *right = parse_sub_expression(prec_r);                      \
9045                                                                              \
9046         binexpr->binary.right = right;                                           \
9047         sfunc(&binexpr->binary);                                                 \
9048                                                                              \
9049         return binexpr;                                                          \
9050 }
9051
9052 CREATE_BINEXPR_PARSER('*',                    EXPR_BINARY_MUL,                PREC_CAST,           semantic_binexpr_arithmetic)
9053 CREATE_BINEXPR_PARSER('/',                    EXPR_BINARY_DIV,                PREC_CAST,           semantic_divmod_arithmetic)
9054 CREATE_BINEXPR_PARSER('%',                    EXPR_BINARY_MOD,                PREC_CAST,           semantic_divmod_arithmetic)
9055 CREATE_BINEXPR_PARSER('+',                    EXPR_BINARY_ADD,                PREC_MULTIPLICATIVE, semantic_add)
9056 CREATE_BINEXPR_PARSER('-',                    EXPR_BINARY_SUB,                PREC_MULTIPLICATIVE, semantic_sub)
9057 CREATE_BINEXPR_PARSER(T_LESSLESS,             EXPR_BINARY_SHIFTLEFT,          PREC_ADDITIVE,       semantic_shift_op)
9058 CREATE_BINEXPR_PARSER(T_GREATERGREATER,       EXPR_BINARY_SHIFTRIGHT,         PREC_ADDITIVE,       semantic_shift_op)
9059 CREATE_BINEXPR_PARSER('<',                    EXPR_BINARY_LESS,               PREC_SHIFT,          semantic_comparison)
9060 CREATE_BINEXPR_PARSER('>',                    EXPR_BINARY_GREATER,            PREC_SHIFT,          semantic_comparison)
9061 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,          PREC_SHIFT,          semantic_comparison)
9062 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,       PREC_SHIFT,          semantic_comparison)
9063 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,           PREC_RELATIONAL,     semantic_comparison)
9064 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,              PREC_RELATIONAL,     semantic_comparison)
9065 CREATE_BINEXPR_PARSER('&',                    EXPR_BINARY_BITWISE_AND,        PREC_EQUALITY,       semantic_binexpr_arithmetic)
9066 CREATE_BINEXPR_PARSER('^',                    EXPR_BINARY_BITWISE_XOR,        PREC_AND,            semantic_binexpr_arithmetic)
9067 CREATE_BINEXPR_PARSER('|',                    EXPR_BINARY_BITWISE_OR,         PREC_XOR,            semantic_binexpr_arithmetic)
9068 CREATE_BINEXPR_PARSER(T_ANDAND,               EXPR_BINARY_LOGICAL_AND,        PREC_OR,             semantic_logical_op)
9069 CREATE_BINEXPR_PARSER(T_PIPEPIPE,             EXPR_BINARY_LOGICAL_OR,         PREC_LOGICAL_AND,    semantic_logical_op)
9070 CREATE_BINEXPR_PARSER('=',                    EXPR_BINARY_ASSIGN,             PREC_ASSIGNMENT,     semantic_binexpr_assign)
9071 CREATE_BINEXPR_PARSER(T_PLUSEQUAL,            EXPR_BINARY_ADD_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
9072 CREATE_BINEXPR_PARSER(T_MINUSEQUAL,           EXPR_BINARY_SUB_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
9073 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL,        EXPR_BINARY_MUL_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9074 CREATE_BINEXPR_PARSER(T_SLASHEQUAL,           EXPR_BINARY_DIV_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
9075 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL,         EXPR_BINARY_MOD_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
9076 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL,        EXPR_BINARY_SHIFTLEFT_ASSIGN,   PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9077 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL,  EXPR_BINARY_SHIFTRIGHT_ASSIGN,  PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9078 CREATE_BINEXPR_PARSER(T_ANDEQUAL,             EXPR_BINARY_BITWISE_AND_ASSIGN, PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9079 CREATE_BINEXPR_PARSER(T_PIPEEQUAL,            EXPR_BINARY_BITWISE_OR_ASSIGN,  PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9080 CREATE_BINEXPR_PARSER(T_CARETEQUAL,           EXPR_BINARY_BITWISE_XOR_ASSIGN, PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9081 CREATE_BINEXPR_PARSER(',',                    EXPR_BINARY_COMMA,              PREC_ASSIGNMENT,     semantic_comma)
9082
9083
9084 static expression_t *parse_sub_expression(precedence_t precedence)
9085 {
9086         if (token.type < 0) {
9087                 return expected_expression_error();
9088         }
9089
9090         expression_parser_function_t *parser
9091                 = &expression_parsers[token.type];
9092         source_position_t             source_position = token.source_position;
9093         expression_t                 *left;
9094
9095         if (parser->parser != NULL) {
9096                 left = parser->parser();
9097         } else {
9098                 left = parse_primary_expression();
9099         }
9100         assert(left != NULL);
9101         left->base.source_position = source_position;
9102
9103         while (true) {
9104                 if (token.type < 0) {
9105                         return expected_expression_error();
9106                 }
9107
9108                 parser = &expression_parsers[token.type];
9109                 if (parser->infix_parser == NULL)
9110                         break;
9111                 if (parser->infix_precedence < precedence)
9112                         break;
9113
9114                 left = parser->infix_parser(left);
9115
9116                 assert(left != NULL);
9117                 assert(left->kind != EXPR_UNKNOWN);
9118                 left->base.source_position = source_position;
9119         }
9120
9121         return left;
9122 }
9123
9124 /**
9125  * Parse an expression.
9126  */
9127 static expression_t *parse_expression(void)
9128 {
9129         return parse_sub_expression(PREC_EXPRESSION);
9130 }
9131
9132 /**
9133  * Register a parser for a prefix-like operator.
9134  *
9135  * @param parser      the parser function
9136  * @param token_type  the token type of the prefix token
9137  */
9138 static void register_expression_parser(parse_expression_function parser,
9139                                        int token_type)
9140 {
9141         expression_parser_function_t *entry = &expression_parsers[token_type];
9142
9143         if (entry->parser != NULL) {
9144                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
9145                 panic("trying to register multiple expression parsers for a token");
9146         }
9147         entry->parser = parser;
9148 }
9149
9150 /**
9151  * Register a parser for an infix operator with given precedence.
9152  *
9153  * @param parser      the parser function
9154  * @param token_type  the token type of the infix operator
9155  * @param precedence  the precedence of the operator
9156  */
9157 static void register_infix_parser(parse_expression_infix_function parser,
9158                 int token_type, unsigned precedence)
9159 {
9160         expression_parser_function_t *entry = &expression_parsers[token_type];
9161
9162         if (entry->infix_parser != NULL) {
9163                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
9164                 panic("trying to register multiple infix expression parsers for a "
9165                       "token");
9166         }
9167         entry->infix_parser     = parser;
9168         entry->infix_precedence = precedence;
9169 }
9170
9171 /**
9172  * Initialize the expression parsers.
9173  */
9174 static void init_expression_parsers(void)
9175 {
9176         memset(&expression_parsers, 0, sizeof(expression_parsers));
9177
9178         register_infix_parser(parse_array_expression,               '[',                    PREC_POSTFIX);
9179         register_infix_parser(parse_call_expression,                '(',                    PREC_POSTFIX);
9180         register_infix_parser(parse_select_expression,              '.',                    PREC_POSTFIX);
9181         register_infix_parser(parse_select_expression,              T_MINUSGREATER,         PREC_POSTFIX);
9182         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,   T_PLUSPLUS,             PREC_POSTFIX);
9183         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,   T_MINUSMINUS,           PREC_POSTFIX);
9184         register_infix_parser(parse_EXPR_BINARY_MUL,                '*',                    PREC_MULTIPLICATIVE);
9185         register_infix_parser(parse_EXPR_BINARY_DIV,                '/',                    PREC_MULTIPLICATIVE);
9186         register_infix_parser(parse_EXPR_BINARY_MOD,                '%',                    PREC_MULTIPLICATIVE);
9187         register_infix_parser(parse_EXPR_BINARY_ADD,                '+',                    PREC_ADDITIVE);
9188         register_infix_parser(parse_EXPR_BINARY_SUB,                '-',                    PREC_ADDITIVE);
9189         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,          T_LESSLESS,             PREC_SHIFT);
9190         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,         T_GREATERGREATER,       PREC_SHIFT);
9191         register_infix_parser(parse_EXPR_BINARY_LESS,               '<',                    PREC_RELATIONAL);
9192         register_infix_parser(parse_EXPR_BINARY_GREATER,            '>',                    PREC_RELATIONAL);
9193         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,          T_LESSEQUAL,            PREC_RELATIONAL);
9194         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL,       T_GREATEREQUAL,         PREC_RELATIONAL);
9195         register_infix_parser(parse_EXPR_BINARY_EQUAL,              T_EQUALEQUAL,           PREC_EQUALITY);
9196         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,           T_EXCLAMATIONMARKEQUAL, PREC_EQUALITY);
9197         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,        '&',                    PREC_AND);
9198         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,        '^',                    PREC_XOR);
9199         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,         '|',                    PREC_OR);
9200         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,        T_ANDAND,               PREC_LOGICAL_AND);
9201         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,         T_PIPEPIPE,             PREC_LOGICAL_OR);
9202         register_infix_parser(parse_conditional_expression,         '?',                    PREC_CONDITIONAL);
9203         register_infix_parser(parse_EXPR_BINARY_ASSIGN,             '=',                    PREC_ASSIGNMENT);
9204         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,         T_PLUSEQUAL,            PREC_ASSIGNMENT);
9205         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,         T_MINUSEQUAL,           PREC_ASSIGNMENT);
9206         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,         T_ASTERISKEQUAL,        PREC_ASSIGNMENT);
9207         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,         T_SLASHEQUAL,           PREC_ASSIGNMENT);
9208         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,         T_PERCENTEQUAL,         PREC_ASSIGNMENT);
9209         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,   T_LESSLESSEQUAL,        PREC_ASSIGNMENT);
9210         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,  T_GREATERGREATEREQUAL,  PREC_ASSIGNMENT);
9211         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN, T_ANDEQUAL,             PREC_ASSIGNMENT);
9212         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,  T_PIPEEQUAL,            PREC_ASSIGNMENT);
9213         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN, T_CARETEQUAL,           PREC_ASSIGNMENT);
9214         register_infix_parser(parse_EXPR_BINARY_COMMA,              ',',                    PREC_EXPRESSION);
9215
9216         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-');
9217         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+');
9218         register_expression_parser(parse_EXPR_UNARY_NOT,              '!');
9219         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~');
9220         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*');
9221         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&');
9222         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT, T_PLUSPLUS);
9223         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT, T_MINUSMINUS);
9224         register_expression_parser(parse_sizeof,                      T_sizeof);
9225         register_expression_parser(parse_alignof,                     T___alignof__);
9226         register_expression_parser(parse_extension,                   T___extension__);
9227         register_expression_parser(parse_builtin_classify_type,       T___builtin_classify_type);
9228         register_expression_parser(parse_delete,                      T_delete);
9229         register_expression_parser(parse_throw,                       T_throw);
9230 }
9231
9232 /**
9233  * Parse a asm statement arguments specification.
9234  */
9235 static asm_argument_t *parse_asm_arguments(bool is_out)
9236 {
9237         asm_argument_t  *result = NULL;
9238         asm_argument_t **anchor = &result;
9239
9240         while (token.type == T_STRING_LITERAL || token.type == '[') {
9241                 asm_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
9242                 memset(argument, 0, sizeof(argument[0]));
9243
9244                 if (token.type == '[') {
9245                         eat('[');
9246                         if (token.type != T_IDENTIFIER) {
9247                                 parse_error_expected("while parsing asm argument",
9248                                                      T_IDENTIFIER, NULL);
9249                                 return NULL;
9250                         }
9251                         argument->symbol = token.v.symbol;
9252
9253                         expect(']');
9254                 }
9255
9256                 argument->constraints = parse_string_literals();
9257                 expect('(');
9258                 add_anchor_token(')');
9259                 expression_t *expression = parse_expression();
9260                 rem_anchor_token(')');
9261                 if (is_out) {
9262                         /* Ugly GCC stuff: Allow lvalue casts.  Skip casts, when they do not
9263                          * change size or type representation (e.g. int -> long is ok, but
9264                          * int -> float is not) */
9265                         if (expression->kind == EXPR_UNARY_CAST) {
9266                                 type_t      *const type = expression->base.type;
9267                                 type_kind_t  const kind = type->kind;
9268                                 if (kind == TYPE_ATOMIC || kind == TYPE_POINTER) {
9269                                         unsigned flags;
9270                                         unsigned size;
9271                                         if (kind == TYPE_ATOMIC) {
9272                                                 atomic_type_kind_t const akind = type->atomic.akind;
9273                                                 flags = get_atomic_type_flags(akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
9274                                                 size  = get_atomic_type_size(akind);
9275                                         } else {
9276                                                 flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
9277                                                 size  = get_atomic_type_size(get_intptr_kind());
9278                                         }
9279
9280                                         do {
9281                                                 expression_t *const value      = expression->unary.value;
9282                                                 type_t       *const value_type = value->base.type;
9283                                                 type_kind_t   const value_kind = value_type->kind;
9284
9285                                                 unsigned value_flags;
9286                                                 unsigned value_size;
9287                                                 if (value_kind == TYPE_ATOMIC) {
9288                                                         atomic_type_kind_t const value_akind = value_type->atomic.akind;
9289                                                         value_flags = get_atomic_type_flags(value_akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
9290                                                         value_size  = get_atomic_type_size(value_akind);
9291                                                 } else if (value_kind == TYPE_POINTER) {
9292                                                         value_flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
9293                                                         value_size  = get_atomic_type_size(get_intptr_kind());
9294                                                 } else {
9295                                                         break;
9296                                                 }
9297
9298                                                 if (value_flags != flags || value_size != size)
9299                                                         break;
9300
9301                                                 expression = value;
9302                                         } while (expression->kind == EXPR_UNARY_CAST);
9303                                 }
9304                         }
9305
9306                         if (!is_lvalue(expression)) {
9307                                 errorf(&expression->base.source_position,
9308                                        "asm output argument is not an lvalue");
9309                         }
9310
9311                         if (argument->constraints.begin[0] == '+')
9312                                 mark_vars_read(expression, NULL);
9313                 } else {
9314                         mark_vars_read(expression, NULL);
9315                 }
9316                 argument->expression = expression;
9317                 expect(')');
9318
9319                 set_address_taken(expression, true);
9320
9321                 *anchor = argument;
9322                 anchor  = &argument->next;
9323
9324                 if (token.type != ',')
9325                         break;
9326                 eat(',');
9327         }
9328
9329         return result;
9330 end_error:
9331         return NULL;
9332 }
9333
9334 /**
9335  * Parse a asm statement clobber specification.
9336  */
9337 static asm_clobber_t *parse_asm_clobbers(void)
9338 {
9339         asm_clobber_t *result = NULL;
9340         asm_clobber_t *last   = NULL;
9341
9342         while (token.type == T_STRING_LITERAL) {
9343                 asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
9344                 clobber->clobber       = parse_string_literals();
9345
9346                 if (last != NULL) {
9347                         last->next = clobber;
9348                 } else {
9349                         result = clobber;
9350                 }
9351                 last = clobber;
9352
9353                 if (token.type != ',')
9354                         break;
9355                 eat(',');
9356         }
9357
9358         return result;
9359 }
9360
9361 /**
9362  * Parse an asm statement.
9363  */
9364 static statement_t *parse_asm_statement(void)
9365 {
9366         statement_t     *statement     = allocate_statement_zero(STATEMENT_ASM);
9367         asm_statement_t *asm_statement = &statement->asms;
9368
9369         eat(T_asm);
9370
9371         if (token.type == T_volatile) {
9372                 next_token();
9373                 asm_statement->is_volatile = true;
9374         }
9375
9376         expect('(');
9377         add_anchor_token(')');
9378         add_anchor_token(':');
9379         asm_statement->asm_text = parse_string_literals();
9380
9381         if (token.type != ':') {
9382                 rem_anchor_token(':');
9383                 goto end_of_asm;
9384         }
9385         eat(':');
9386
9387         asm_statement->outputs = parse_asm_arguments(true);
9388         if (token.type != ':') {
9389                 rem_anchor_token(':');
9390                 goto end_of_asm;
9391         }
9392         eat(':');
9393
9394         asm_statement->inputs = parse_asm_arguments(false);
9395         if (token.type != ':') {
9396                 rem_anchor_token(':');
9397                 goto end_of_asm;
9398         }
9399         rem_anchor_token(':');
9400         eat(':');
9401
9402         asm_statement->clobbers = parse_asm_clobbers();
9403
9404 end_of_asm:
9405         rem_anchor_token(')');
9406         expect(')');
9407         expect(';');
9408
9409         if (asm_statement->outputs == NULL) {
9410                 /* GCC: An 'asm' instruction without any output operands will be treated
9411                  * identically to a volatile 'asm' instruction. */
9412                 asm_statement->is_volatile = true;
9413         }
9414
9415         return statement;
9416 end_error:
9417         return create_invalid_statement();
9418 }
9419
9420 /**
9421  * Parse a case statement.
9422  */
9423 static statement_t *parse_case_statement(void)
9424 {
9425         statement_t       *const statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9426         source_position_t *const pos       = &statement->base.source_position;
9427
9428         eat(T_case);
9429
9430         expression_t *const expression   = parse_expression();
9431         statement->case_label.expression = expression;
9432         if (!is_constant_expression(expression)) {
9433                 /* This check does not prevent the error message in all cases of an
9434                  * prior error while parsing the expression.  At least it catches the
9435                  * common case of a mistyped enum entry. */
9436                 if (is_type_valid(skip_typeref(expression->base.type))) {
9437                         errorf(pos, "case label does not reduce to an integer constant");
9438                 }
9439                 statement->case_label.is_bad = true;
9440         } else {
9441                 long const val = fold_constant(expression);
9442                 statement->case_label.first_case = val;
9443                 statement->case_label.last_case  = val;
9444         }
9445
9446         if (GNU_MODE) {
9447                 if (token.type == T_DOTDOTDOT) {
9448                         next_token();
9449                         expression_t *const end_range   = parse_expression();
9450                         statement->case_label.end_range = end_range;
9451                         if (!is_constant_expression(end_range)) {
9452                                 /* This check does not prevent the error message in all cases of an
9453                                  * prior error while parsing the expression.  At least it catches the
9454                                  * common case of a mistyped enum entry. */
9455                                 if (is_type_valid(skip_typeref(end_range->base.type))) {
9456                                         errorf(pos, "case range does not reduce to an integer constant");
9457                                 }
9458                                 statement->case_label.is_bad = true;
9459                         } else {
9460                                 long const val = fold_constant(end_range);
9461                                 statement->case_label.last_case = val;
9462
9463                                 if (warning.other && val < statement->case_label.first_case) {
9464                                         statement->case_label.is_empty_range = true;
9465                                         warningf(pos, "empty range specified");
9466                                 }
9467                         }
9468                 }
9469         }
9470
9471         PUSH_PARENT(statement);
9472
9473         expect(':');
9474
9475         if (current_switch != NULL) {
9476                 if (! statement->case_label.is_bad) {
9477                         /* Check for duplicate case values */
9478                         case_label_statement_t *c = &statement->case_label;
9479                         for (case_label_statement_t *l = current_switch->first_case; l != NULL; l = l->next) {
9480                                 if (l->is_bad || l->is_empty_range || l->expression == NULL)
9481                                         continue;
9482
9483                                 if (c->last_case < l->first_case || c->first_case > l->last_case)
9484                                         continue;
9485
9486                                 errorf(pos, "duplicate case value (previously used %P)",
9487                                        &l->base.source_position);
9488                                 break;
9489                         }
9490                 }
9491                 /* link all cases into the switch statement */
9492                 if (current_switch->last_case == NULL) {
9493                         current_switch->first_case      = &statement->case_label;
9494                 } else {
9495                         current_switch->last_case->next = &statement->case_label;
9496                 }
9497                 current_switch->last_case = &statement->case_label;
9498         } else {
9499                 errorf(pos, "case label not within a switch statement");
9500         }
9501
9502         statement_t *const inner_stmt = parse_statement();
9503         statement->case_label.statement = inner_stmt;
9504         if (inner_stmt->kind == STATEMENT_DECLARATION) {
9505                 errorf(&inner_stmt->base.source_position, "declaration after case label");
9506         }
9507
9508         POP_PARENT;
9509         return statement;
9510 end_error:
9511         POP_PARENT;
9512         return create_invalid_statement();
9513 }
9514
9515 /**
9516  * Parse a default statement.
9517  */
9518 static statement_t *parse_default_statement(void)
9519 {
9520         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9521
9522         eat(T_default);
9523
9524         PUSH_PARENT(statement);
9525
9526         expect(':');
9527         if (current_switch != NULL) {
9528                 const case_label_statement_t *def_label = current_switch->default_label;
9529                 if (def_label != NULL) {
9530                         errorf(HERE, "multiple default labels in one switch (previous declared %P)",
9531                                &def_label->base.source_position);
9532                 } else {
9533                         current_switch->default_label = &statement->case_label;
9534
9535                         /* link all cases into the switch statement */
9536                         if (current_switch->last_case == NULL) {
9537                                 current_switch->first_case      = &statement->case_label;
9538                         } else {
9539                                 current_switch->last_case->next = &statement->case_label;
9540                         }
9541                         current_switch->last_case = &statement->case_label;
9542                 }
9543         } else {
9544                 errorf(&statement->base.source_position,
9545                         "'default' label not within a switch statement");
9546         }
9547
9548         statement_t *const inner_stmt = parse_statement();
9549         statement->case_label.statement = inner_stmt;
9550         if (inner_stmt->kind == STATEMENT_DECLARATION) {
9551                 errorf(&inner_stmt->base.source_position, "declaration after default label");
9552         }
9553
9554         POP_PARENT;
9555         return statement;
9556 end_error:
9557         POP_PARENT;
9558         return create_invalid_statement();
9559 }
9560
9561 /**
9562  * Parse a label statement.
9563  */
9564 static statement_t *parse_label_statement(void)
9565 {
9566         assert(token.type == T_IDENTIFIER);
9567         symbol_t *symbol = token.v.symbol;
9568         label_t  *label  = get_label(symbol);
9569
9570         statement_t *const statement = allocate_statement_zero(STATEMENT_LABEL);
9571         statement->label.label       = label;
9572
9573         next_token();
9574
9575         PUSH_PARENT(statement);
9576
9577         /* if statement is already set then the label is defined twice,
9578          * otherwise it was just mentioned in a goto/local label declaration so far
9579          */
9580         if (label->statement != NULL) {
9581                 errorf(HERE, "duplicate label '%Y' (declared %P)",
9582                        symbol, &label->base.source_position);
9583         } else {
9584                 label->base.source_position = token.source_position;
9585                 label->statement            = statement;
9586         }
9587
9588         eat(':');
9589
9590         if (token.type == '}') {
9591                 /* TODO only warn? */
9592                 if (warning.other && false) {
9593                         warningf(HERE, "label at end of compound statement");
9594                         statement->label.statement = create_empty_statement();
9595                 } else {
9596                         errorf(HERE, "label at end of compound statement");
9597                         statement->label.statement = create_invalid_statement();
9598                 }
9599         } else if (token.type == ';') {
9600                 /* Eat an empty statement here, to avoid the warning about an empty
9601                  * statement after a label.  label:; is commonly used to have a label
9602                  * before a closing brace. */
9603                 statement->label.statement = create_empty_statement();
9604                 next_token();
9605         } else {
9606                 statement_t *const inner_stmt = parse_statement();
9607                 statement->label.statement = inner_stmt;
9608                 if (inner_stmt->kind == STATEMENT_DECLARATION) {
9609                         errorf(&inner_stmt->base.source_position, "declaration after label");
9610                 }
9611         }
9612
9613         /* remember the labels in a list for later checking */
9614         *label_anchor = &statement->label;
9615         label_anchor  = &statement->label.next;
9616
9617         POP_PARENT;
9618         return statement;
9619 }
9620
9621 /**
9622  * Parse an if statement.
9623  */
9624 static statement_t *parse_if(void)
9625 {
9626         statement_t *statement = allocate_statement_zero(STATEMENT_IF);
9627
9628         eat(T_if);
9629
9630         PUSH_PARENT(statement);
9631
9632         add_anchor_token('{');
9633
9634         expect('(');
9635         add_anchor_token(')');
9636         expression_t *const expr = parse_expression();
9637         statement->ifs.condition = expr;
9638         warn_reference_address_as_bool(expr);
9639         mark_vars_read(expr, NULL);
9640         rem_anchor_token(')');
9641         expect(')');
9642
9643 end_error:
9644         rem_anchor_token('{');
9645
9646         add_anchor_token(T_else);
9647         statement->ifs.true_statement = parse_statement();
9648         rem_anchor_token(T_else);
9649
9650         if (token.type == T_else) {
9651                 next_token();
9652                 statement->ifs.false_statement = parse_statement();
9653         }
9654
9655         POP_PARENT;
9656         return statement;
9657 }
9658
9659 /**
9660  * Check that all enums are handled in a switch.
9661  *
9662  * @param statement  the switch statement to check
9663  */
9664 static void check_enum_cases(const switch_statement_t *statement) {
9665         const type_t *type = skip_typeref(statement->expression->base.type);
9666         if (! is_type_enum(type))
9667                 return;
9668         const enum_type_t *enumt = &type->enumt;
9669
9670         /* if we have a default, no warnings */
9671         if (statement->default_label != NULL)
9672                 return;
9673
9674         /* FIXME: calculation of value should be done while parsing */
9675         /* TODO: quadratic algorithm here. Change to an n log n one */
9676         long            last_value = -1;
9677         const entity_t *entry      = enumt->enume->base.next;
9678         for (; entry != NULL && entry->kind == ENTITY_ENUM_VALUE;
9679              entry = entry->base.next) {
9680                 const expression_t *expression = entry->enum_value.value;
9681                 long                value      = expression != NULL ? fold_constant(expression) : last_value + 1;
9682                 bool                found      = false;
9683                 for (const case_label_statement_t *l = statement->first_case; l != NULL; l = l->next) {
9684                         if (l->expression == NULL)
9685                                 continue;
9686                         if (l->first_case <= value && value <= l->last_case) {
9687                                 found = true;
9688                                 break;
9689                         }
9690                 }
9691                 if (! found) {
9692                         warningf(&statement->base.source_position,
9693                                  "enumeration value '%Y' not handled in switch",
9694                                  entry->base.symbol);
9695                 }
9696                 last_value = value;
9697         }
9698 }
9699
9700 /**
9701  * Parse a switch statement.
9702  */
9703 static statement_t *parse_switch(void)
9704 {
9705         statement_t *statement = allocate_statement_zero(STATEMENT_SWITCH);
9706
9707         eat(T_switch);
9708
9709         PUSH_PARENT(statement);
9710
9711         expect('(');
9712         add_anchor_token(')');
9713         expression_t *const expr = parse_expression();
9714         mark_vars_read(expr, NULL);
9715         type_t       *      type = skip_typeref(expr->base.type);
9716         if (is_type_integer(type)) {
9717                 type = promote_integer(type);
9718                 if (warning.traditional) {
9719                         if (get_rank(type) >= get_akind_rank(ATOMIC_TYPE_LONG)) {
9720                                 warningf(&expr->base.source_position,
9721                                         "'%T' switch expression not converted to '%T' in ISO C",
9722                                         type, type_int);
9723                         }
9724                 }
9725         } else if (is_type_valid(type)) {
9726                 errorf(&expr->base.source_position,
9727                        "switch quantity is not an integer, but '%T'", type);
9728                 type = type_error_type;
9729         }
9730         statement->switchs.expression = create_implicit_cast(expr, type);
9731         expect(')');
9732         rem_anchor_token(')');
9733
9734         switch_statement_t *rem = current_switch;
9735         current_switch          = &statement->switchs;
9736         statement->switchs.body = parse_statement();
9737         current_switch          = rem;
9738
9739         if (warning.switch_default &&
9740             statement->switchs.default_label == NULL) {
9741                 warningf(&statement->base.source_position, "switch has no default case");
9742         }
9743         if (warning.switch_enum)
9744                 check_enum_cases(&statement->switchs);
9745
9746         POP_PARENT;
9747         return statement;
9748 end_error:
9749         POP_PARENT;
9750         return create_invalid_statement();
9751 }
9752
9753 static statement_t *parse_loop_body(statement_t *const loop)
9754 {
9755         statement_t *const rem = current_loop;
9756         current_loop = loop;
9757
9758         statement_t *const body = parse_statement();
9759
9760         current_loop = rem;
9761         return body;
9762 }
9763
9764 /**
9765  * Parse a while statement.
9766  */
9767 static statement_t *parse_while(void)
9768 {
9769         statement_t *statement = allocate_statement_zero(STATEMENT_WHILE);
9770
9771         eat(T_while);
9772
9773         PUSH_PARENT(statement);
9774
9775         expect('(');
9776         add_anchor_token(')');
9777         expression_t *const cond = parse_expression();
9778         statement->whiles.condition = cond;
9779         warn_reference_address_as_bool(cond);
9780         mark_vars_read(cond, NULL);
9781         rem_anchor_token(')');
9782         expect(')');
9783
9784         statement->whiles.body = parse_loop_body(statement);
9785
9786         POP_PARENT;
9787         return statement;
9788 end_error:
9789         POP_PARENT;
9790         return create_invalid_statement();
9791 }
9792
9793 /**
9794  * Parse a do statement.
9795  */
9796 static statement_t *parse_do(void)
9797 {
9798         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
9799
9800         eat(T_do);
9801
9802         PUSH_PARENT(statement);
9803
9804         add_anchor_token(T_while);
9805         statement->do_while.body = parse_loop_body(statement);
9806         rem_anchor_token(T_while);
9807
9808         expect(T_while);
9809         expect('(');
9810         add_anchor_token(')');
9811         expression_t *const cond = parse_expression();
9812         statement->do_while.condition = cond;
9813         warn_reference_address_as_bool(cond);
9814         mark_vars_read(cond, NULL);
9815         rem_anchor_token(')');
9816         expect(')');
9817         expect(';');
9818
9819         POP_PARENT;
9820         return statement;
9821 end_error:
9822         POP_PARENT;
9823         return create_invalid_statement();
9824 }
9825
9826 /**
9827  * Parse a for statement.
9828  */
9829 static statement_t *parse_for(void)
9830 {
9831         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
9832
9833         eat(T_for);
9834
9835         PUSH_PARENT(statement);
9836
9837         size_t const top = environment_top();
9838         scope_push(&statement->fors.scope);
9839
9840         expect('(');
9841         add_anchor_token(')');
9842
9843         if (token.type != ';') {
9844                 if (is_declaration_specifier(&token, false)) {
9845                         parse_declaration(record_entity);
9846                 } else {
9847                         add_anchor_token(';');
9848                         expression_t *const init = parse_expression();
9849                         statement->fors.initialisation = init;
9850                         mark_vars_read(init, VAR_ANY);
9851                         if (warning.unused_value && !expression_has_effect(init)) {
9852                                 warningf(&init->base.source_position,
9853                                          "initialisation of 'for'-statement has no effect");
9854                         }
9855                         rem_anchor_token(';');
9856                         expect(';');
9857                 }
9858         } else {
9859                 expect(';');
9860         }
9861
9862         if (token.type != ';') {
9863                 add_anchor_token(';');
9864                 expression_t *const cond = parse_expression();
9865                 statement->fors.condition = cond;
9866                 warn_reference_address_as_bool(cond);
9867                 mark_vars_read(cond, NULL);
9868                 rem_anchor_token(';');
9869         }
9870         expect(';');
9871         if (token.type != ')') {
9872                 expression_t *const step = parse_expression();
9873                 statement->fors.step = step;
9874                 mark_vars_read(step, VAR_ANY);
9875                 if (warning.unused_value && !expression_has_effect(step)) {
9876                         warningf(&step->base.source_position,
9877                                  "step of 'for'-statement has no effect");
9878                 }
9879         }
9880         expect(')');
9881         rem_anchor_token(')');
9882         statement->fors.body = parse_loop_body(statement);
9883
9884         assert(current_scope == &statement->fors.scope);
9885         scope_pop();
9886         environment_pop_to(top);
9887
9888         POP_PARENT;
9889         return statement;
9890
9891 end_error:
9892         POP_PARENT;
9893         rem_anchor_token(')');
9894         assert(current_scope == &statement->fors.scope);
9895         scope_pop();
9896         environment_pop_to(top);
9897
9898         return create_invalid_statement();
9899 }
9900
9901 /**
9902  * Parse a goto statement.
9903  */
9904 static statement_t *parse_goto(void)
9905 {
9906         statement_t *statement = allocate_statement_zero(STATEMENT_GOTO);
9907         eat(T_goto);
9908
9909         if (GNU_MODE && token.type == '*') {
9910                 next_token();
9911                 expression_t *expression = parse_expression();
9912                 mark_vars_read(expression, NULL);
9913
9914                 /* Argh: although documentation says the expression must be of type void*,
9915                  * gcc accepts anything that can be casted into void* without error */
9916                 type_t *type = expression->base.type;
9917
9918                 if (type != type_error_type) {
9919                         if (!is_type_pointer(type) && !is_type_integer(type)) {
9920                                 errorf(&expression->base.source_position,
9921                                         "cannot convert to a pointer type");
9922                         } else if (warning.other && type != type_void_ptr) {
9923                                 warningf(&expression->base.source_position,
9924                                         "type of computed goto expression should be 'void*' not '%T'", type);
9925                         }
9926                         expression = create_implicit_cast(expression, type_void_ptr);
9927                 }
9928
9929                 statement->gotos.expression = expression;
9930         } else {
9931                 if (token.type != T_IDENTIFIER) {
9932                         if (GNU_MODE)
9933                                 parse_error_expected("while parsing goto", T_IDENTIFIER, '*', NULL);
9934                         else
9935                                 parse_error_expected("while parsing goto", T_IDENTIFIER, NULL);
9936                         eat_until_anchor();
9937                         goto end_error;
9938                 }
9939                 symbol_t *symbol = token.v.symbol;
9940                 next_token();
9941
9942                 statement->gotos.label = get_label(symbol);
9943         }
9944
9945         /* remember the goto's in a list for later checking */
9946         *goto_anchor = &statement->gotos;
9947         goto_anchor  = &statement->gotos.next;
9948
9949         expect(';');
9950
9951         return statement;
9952 end_error:
9953         return create_invalid_statement();
9954 }
9955
9956 /**
9957  * Parse a continue statement.
9958  */
9959 static statement_t *parse_continue(void)
9960 {
9961         if (current_loop == NULL) {
9962                 errorf(HERE, "continue statement not within loop");
9963         }
9964
9965         statement_t *statement = allocate_statement_zero(STATEMENT_CONTINUE);
9966
9967         eat(T_continue);
9968         expect(';');
9969
9970 end_error:
9971         return statement;
9972 }
9973
9974 /**
9975  * Parse a break statement.
9976  */
9977 static statement_t *parse_break(void)
9978 {
9979         if (current_switch == NULL && current_loop == NULL) {
9980                 errorf(HERE, "break statement not within loop or switch");
9981         }
9982
9983         statement_t *statement = allocate_statement_zero(STATEMENT_BREAK);
9984
9985         eat(T_break);
9986         expect(';');
9987
9988 end_error:
9989         return statement;
9990 }
9991
9992 /**
9993  * Parse a __leave statement.
9994  */
9995 static statement_t *parse_leave_statement(void)
9996 {
9997         if (current_try == NULL) {
9998                 errorf(HERE, "__leave statement not within __try");
9999         }
10000
10001         statement_t *statement = allocate_statement_zero(STATEMENT_LEAVE);
10002
10003         eat(T___leave);
10004         expect(';');
10005
10006 end_error:
10007         return statement;
10008 }
10009
10010 /**
10011  * Check if a given entity represents a local variable.
10012  */
10013 static bool is_local_variable(const entity_t *entity)
10014 {
10015         if (entity->kind != ENTITY_VARIABLE)
10016                 return false;
10017
10018         switch ((storage_class_tag_t) entity->declaration.storage_class) {
10019         case STORAGE_CLASS_AUTO:
10020         case STORAGE_CLASS_REGISTER: {
10021                 const type_t *type = skip_typeref(entity->declaration.type);
10022                 if (is_type_function(type)) {
10023                         return false;
10024                 } else {
10025                         return true;
10026                 }
10027         }
10028         default:
10029                 return false;
10030         }
10031 }
10032
10033 /**
10034  * Check if a given expression represents a local variable.
10035  */
10036 static bool expression_is_local_variable(const expression_t *expression)
10037 {
10038         if (expression->base.kind != EXPR_REFERENCE) {
10039                 return false;
10040         }
10041         const entity_t *entity = expression->reference.entity;
10042         return is_local_variable(entity);
10043 }
10044
10045 /**
10046  * Check if a given expression represents a local variable and
10047  * return its declaration then, else return NULL.
10048  */
10049 entity_t *expression_is_variable(const expression_t *expression)
10050 {
10051         if (expression->base.kind != EXPR_REFERENCE) {
10052                 return NULL;
10053         }
10054         entity_t *entity = expression->reference.entity;
10055         if (entity->kind != ENTITY_VARIABLE)
10056                 return NULL;
10057
10058         return entity;
10059 }
10060
10061 /**
10062  * Parse a return statement.
10063  */
10064 static statement_t *parse_return(void)
10065 {
10066         eat(T_return);
10067
10068         statement_t *statement = allocate_statement_zero(STATEMENT_RETURN);
10069
10070         expression_t *return_value = NULL;
10071         if (token.type != ';') {
10072                 return_value = parse_expression();
10073                 mark_vars_read(return_value, NULL);
10074         }
10075
10076         const type_t *const func_type = skip_typeref(current_function->base.type);
10077         assert(is_type_function(func_type));
10078         type_t *const return_type = skip_typeref(func_type->function.return_type);
10079
10080         if (return_value != NULL) {
10081                 type_t *return_value_type = skip_typeref(return_value->base.type);
10082
10083                 if (is_type_atomic(return_type,        ATOMIC_TYPE_VOID) &&
10084                                 !is_type_atomic(return_value_type, ATOMIC_TYPE_VOID)) {
10085                         if (warning.other) {
10086                                 warningf(&statement->base.source_position,
10087                                                 "'return' with a value, in function returning void");
10088                         }
10089                         return_value = NULL;
10090                 } else {
10091                         assign_error_t error = semantic_assign(return_type, return_value);
10092                         report_assign_error(error, return_type, return_value, "'return'",
10093                                             &statement->base.source_position);
10094                         return_value = create_implicit_cast(return_value, return_type);
10095                 }
10096                 /* check for returning address of a local var */
10097                 if (warning.other && return_value != NULL
10098                                 && return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
10099                         const expression_t *expression = return_value->unary.value;
10100                         if (expression_is_local_variable(expression)) {
10101                                 warningf(&statement->base.source_position,
10102                                          "function returns address of local variable");
10103                         }
10104                 }
10105         } else if (warning.other && !is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
10106                 warningf(&statement->base.source_position,
10107                                 "'return' without value, in function returning non-void");
10108         }
10109         statement->returns.value = return_value;
10110
10111         expect(';');
10112
10113 end_error:
10114         return statement;
10115 }
10116
10117 /**
10118  * Parse a declaration statement.
10119  */
10120 static statement_t *parse_declaration_statement(void)
10121 {
10122         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
10123
10124         entity_t *before = current_scope->last_entity;
10125         if (GNU_MODE)
10126                 parse_external_declaration();
10127         else
10128                 parse_declaration(record_entity);
10129
10130         if (before == NULL) {
10131                 statement->declaration.declarations_begin = current_scope->entities;
10132         } else {
10133                 statement->declaration.declarations_begin = before->base.next;
10134         }
10135         statement->declaration.declarations_end = current_scope->last_entity;
10136
10137         return statement;
10138 }
10139
10140 /**
10141  * Parse an expression statement, ie. expr ';'.
10142  */
10143 static statement_t *parse_expression_statement(void)
10144 {
10145         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10146
10147         expression_t *const expr         = parse_expression();
10148         statement->expression.expression = expr;
10149         mark_vars_read(expr, VAR_ANY);
10150
10151         expect(';');
10152
10153 end_error:
10154         return statement;
10155 }
10156
10157 /**
10158  * Parse a microsoft __try { } __finally { } or
10159  * __try{ } __except() { }
10160  */
10161 static statement_t *parse_ms_try_statment(void)
10162 {
10163         statement_t *statement = allocate_statement_zero(STATEMENT_MS_TRY);
10164         eat(T___try);
10165
10166         PUSH_PARENT(statement);
10167
10168         ms_try_statement_t *rem = current_try;
10169         current_try = &statement->ms_try;
10170         statement->ms_try.try_statement = parse_compound_statement(false);
10171         current_try = rem;
10172
10173         POP_PARENT;
10174
10175         if (token.type == T___except) {
10176                 eat(T___except);
10177                 expect('(');
10178                 add_anchor_token(')');
10179                 expression_t *const expr = parse_expression();
10180                 mark_vars_read(expr, NULL);
10181                 type_t       *      type = skip_typeref(expr->base.type);
10182                 if (is_type_integer(type)) {
10183                         type = promote_integer(type);
10184                 } else if (is_type_valid(type)) {
10185                         errorf(&expr->base.source_position,
10186                                "__expect expression is not an integer, but '%T'", type);
10187                         type = type_error_type;
10188                 }
10189                 statement->ms_try.except_expression = create_implicit_cast(expr, type);
10190                 rem_anchor_token(')');
10191                 expect(')');
10192                 statement->ms_try.final_statement = parse_compound_statement(false);
10193         } else if (token.type == T__finally) {
10194                 eat(T___finally);
10195                 statement->ms_try.final_statement = parse_compound_statement(false);
10196         } else {
10197                 parse_error_expected("while parsing __try statement", T___except, T___finally, NULL);
10198                 return create_invalid_statement();
10199         }
10200         return statement;
10201 end_error:
10202         return create_invalid_statement();
10203 }
10204
10205 static statement_t *parse_empty_statement(void)
10206 {
10207         if (warning.empty_statement) {
10208                 warningf(HERE, "statement is empty");
10209         }
10210         statement_t *const statement = create_empty_statement();
10211         eat(';');
10212         return statement;
10213 }
10214
10215 static statement_t *parse_local_label_declaration(void)
10216 {
10217         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
10218
10219         eat(T___label__);
10220
10221         entity_t *begin = NULL, *end = NULL;
10222
10223         while (true) {
10224                 if (token.type != T_IDENTIFIER) {
10225                         parse_error_expected("while parsing local label declaration",
10226                                 T_IDENTIFIER, NULL);
10227                         goto end_error;
10228                 }
10229                 symbol_t *symbol = token.v.symbol;
10230                 entity_t *entity = get_entity(symbol, NAMESPACE_LABEL);
10231                 if (entity != NULL && entity->base.parent_scope == current_scope) {
10232                         errorf(HERE, "multiple definitions of '__label__ %Y' (previous definition %P)",
10233                                symbol, &entity->base.source_position);
10234                 } else {
10235                         entity = allocate_entity_zero(ENTITY_LOCAL_LABEL);
10236
10237                         entity->base.parent_scope    = current_scope;
10238                         entity->base.namespc         = NAMESPACE_LABEL;
10239                         entity->base.source_position = token.source_position;
10240                         entity->base.symbol          = symbol;
10241
10242                         if (end != NULL)
10243                                 end->base.next = entity;
10244                         end = entity;
10245                         if (begin == NULL)
10246                                 begin = entity;
10247
10248                         environment_push(entity);
10249                 }
10250                 next_token();
10251
10252                 if (token.type != ',')
10253                         break;
10254                 next_token();
10255         }
10256         eat(';');
10257 end_error:
10258         statement->declaration.declarations_begin = begin;
10259         statement->declaration.declarations_end   = end;
10260         return statement;
10261 }
10262
10263 static void parse_namespace_definition(void)
10264 {
10265         eat(T_namespace);
10266
10267         entity_t *entity = NULL;
10268         symbol_t *symbol = NULL;
10269
10270         if (token.type == T_IDENTIFIER) {
10271                 symbol = token.v.symbol;
10272                 next_token();
10273
10274                 entity = get_entity(symbol, NAMESPACE_NORMAL);
10275                 if (entity != NULL && entity->kind != ENTITY_NAMESPACE
10276                                 && entity->base.parent_scope == current_scope) {
10277                         error_redefined_as_different_kind(&token.source_position,
10278                                                           entity, ENTITY_NAMESPACE);
10279                         entity = NULL;
10280                 }
10281         }
10282
10283         if (entity == NULL) {
10284                 entity                       = allocate_entity_zero(ENTITY_NAMESPACE);
10285                 entity->base.symbol          = symbol;
10286                 entity->base.source_position = token.source_position;
10287                 entity->base.namespc         = NAMESPACE_NORMAL;
10288                 entity->base.parent_scope    = current_scope;
10289         }
10290
10291         if (token.type == '=') {
10292                 /* TODO: parse namespace alias */
10293                 panic("namespace alias definition not supported yet");
10294         }
10295
10296         environment_push(entity);
10297         append_entity(current_scope, entity);
10298
10299         size_t const top = environment_top();
10300         scope_push(&entity->namespacee.members);
10301
10302         expect('{');
10303         parse_externals();
10304         expect('}');
10305
10306 end_error:
10307         assert(current_scope == &entity->namespacee.members);
10308         scope_pop();
10309         environment_pop_to(top);
10310 }
10311
10312 /**
10313  * Parse a statement.
10314  * There's also parse_statement() which additionally checks for
10315  * "statement has no effect" warnings
10316  */
10317 static statement_t *intern_parse_statement(void)
10318 {
10319         statement_t *statement = NULL;
10320
10321         /* declaration or statement */
10322         add_anchor_token(';');
10323         switch (token.type) {
10324         case T_IDENTIFIER: {
10325                 token_type_t la1_type = (token_type_t)look_ahead(1)->type;
10326                 if (la1_type == ':') {
10327                         statement = parse_label_statement();
10328                 } else if (is_typedef_symbol(token.v.symbol)) {
10329                         statement = parse_declaration_statement();
10330                 } else {
10331                         /* it's an identifier, the grammar says this must be an
10332                          * expression statement. However it is common that users mistype
10333                          * declaration types, so we guess a bit here to improve robustness
10334                          * for incorrect programs */
10335                         switch (la1_type) {
10336                         case '&':
10337                         case '*':
10338                                 if (get_entity(token.v.symbol, NAMESPACE_NORMAL) != NULL)
10339                                         goto expression_statment;
10340                                 /* FALLTHROUGH */
10341
10342                         DECLARATION_START
10343                         case T_IDENTIFIER:
10344                                 statement = parse_declaration_statement();
10345                                 break;
10346
10347                         default:
10348 expression_statment:
10349                                 statement = parse_expression_statement();
10350                                 break;
10351                         }
10352                 }
10353                 break;
10354         }
10355
10356         case T___extension__:
10357                 /* This can be a prefix to a declaration or an expression statement.
10358                  * We simply eat it now and parse the rest with tail recursion. */
10359                 do {
10360                         next_token();
10361                 } while (token.type == T___extension__);
10362                 bool old_gcc_extension = in_gcc_extension;
10363                 in_gcc_extension       = true;
10364                 statement = parse_statement();
10365                 in_gcc_extension = old_gcc_extension;
10366                 break;
10367
10368         DECLARATION_START
10369                 statement = parse_declaration_statement();
10370                 break;
10371
10372         case T___label__:
10373                 statement = parse_local_label_declaration();
10374                 break;
10375
10376         case ';':         statement = parse_empty_statement();         break;
10377         case '{':         statement = parse_compound_statement(false); break;
10378         case T___leave:   statement = parse_leave_statement();         break;
10379         case T___try:     statement = parse_ms_try_statment();         break;
10380         case T_asm:       statement = parse_asm_statement();           break;
10381         case T_break:     statement = parse_break();                   break;
10382         case T_case:      statement = parse_case_statement();          break;
10383         case T_continue:  statement = parse_continue();                break;
10384         case T_default:   statement = parse_default_statement();       break;
10385         case T_do:        statement = parse_do();                      break;
10386         case T_for:       statement = parse_for();                     break;
10387         case T_goto:      statement = parse_goto();                    break;
10388         case T_if:        statement = parse_if();                      break;
10389         case T_return:    statement = parse_return();                  break;
10390         case T_switch:    statement = parse_switch();                  break;
10391         case T_while:     statement = parse_while();                   break;
10392
10393         EXPRESSION_START
10394                 statement = parse_expression_statement();
10395                 break;
10396
10397         default:
10398                 errorf(HERE, "unexpected token %K while parsing statement", &token);
10399                 statement = create_invalid_statement();
10400                 if (!at_anchor())
10401                         next_token();
10402                 break;
10403         }
10404         rem_anchor_token(';');
10405
10406         assert(statement != NULL
10407                         && statement->base.source_position.input_name != NULL);
10408
10409         return statement;
10410 }
10411
10412 /**
10413  * parse a statement and emits "statement has no effect" warning if needed
10414  * (This is really a wrapper around intern_parse_statement with check for 1
10415  *  single warning. It is needed, because for statement expressions we have
10416  *  to avoid the warning on the last statement)
10417  */
10418 static statement_t *parse_statement(void)
10419 {
10420         statement_t *statement = intern_parse_statement();
10421
10422         if (statement->kind == STATEMENT_EXPRESSION && warning.unused_value) {
10423                 expression_t *expression = statement->expression.expression;
10424                 if (!expression_has_effect(expression)) {
10425                         warningf(&expression->base.source_position,
10426                                         "statement has no effect");
10427                 }
10428         }
10429
10430         return statement;
10431 }
10432
10433 /**
10434  * Parse a compound statement.
10435  */
10436 static statement_t *parse_compound_statement(bool inside_expression_statement)
10437 {
10438         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
10439
10440         PUSH_PARENT(statement);
10441
10442         eat('{');
10443         add_anchor_token('}');
10444
10445         size_t const top = environment_top();
10446         scope_push(&statement->compound.scope);
10447
10448         statement_t **anchor            = &statement->compound.statements;
10449         bool          only_decls_so_far = true;
10450         while (token.type != '}') {
10451                 if (token.type == T_EOF) {
10452                         errorf(&statement->base.source_position,
10453                                "EOF while parsing compound statement");
10454                         break;
10455                 }
10456                 statement_t *sub_statement = intern_parse_statement();
10457                 if (is_invalid_statement(sub_statement)) {
10458                         /* an error occurred. if we are at an anchor, return */
10459                         if (at_anchor())
10460                                 goto end_error;
10461                         continue;
10462                 }
10463
10464                 if (warning.declaration_after_statement) {
10465                         if (sub_statement->kind != STATEMENT_DECLARATION) {
10466                                 only_decls_so_far = false;
10467                         } else if (!only_decls_so_far) {
10468                                 warningf(&sub_statement->base.source_position,
10469                                          "ISO C90 forbids mixed declarations and code");
10470                         }
10471                 }
10472
10473                 *anchor = sub_statement;
10474
10475                 while (sub_statement->base.next != NULL)
10476                         sub_statement = sub_statement->base.next;
10477
10478                 anchor = &sub_statement->base.next;
10479         }
10480         next_token();
10481
10482         /* look over all statements again to produce no effect warnings */
10483         if (warning.unused_value) {
10484                 statement_t *sub_statement = statement->compound.statements;
10485                 for (; sub_statement != NULL; sub_statement = sub_statement->base.next) {
10486                         if (sub_statement->kind != STATEMENT_EXPRESSION)
10487                                 continue;
10488                         /* don't emit a warning for the last expression in an expression
10489                          * statement as it has always an effect */
10490                         if (inside_expression_statement && sub_statement->base.next == NULL)
10491                                 continue;
10492
10493                         expression_t *expression = sub_statement->expression.expression;
10494                         if (!expression_has_effect(expression)) {
10495                                 warningf(&expression->base.source_position,
10496                                          "statement has no effect");
10497                         }
10498                 }
10499         }
10500
10501 end_error:
10502         rem_anchor_token('}');
10503         assert(current_scope == &statement->compound.scope);
10504         scope_pop();
10505         environment_pop_to(top);
10506
10507         POP_PARENT;
10508         return statement;
10509 }
10510
10511 /**
10512  * Check for unused global static functions and variables
10513  */
10514 static void check_unused_globals(void)
10515 {
10516         if (!warning.unused_function && !warning.unused_variable)
10517                 return;
10518
10519         for (const entity_t *entity = file_scope->entities; entity != NULL;
10520              entity = entity->base.next) {
10521                 if (!is_declaration(entity))
10522                         continue;
10523
10524                 const declaration_t *declaration = &entity->declaration;
10525                 if (declaration->used                  ||
10526                     declaration->modifiers & DM_UNUSED ||
10527                     declaration->modifiers & DM_USED   ||
10528                     declaration->storage_class != STORAGE_CLASS_STATIC)
10529                         continue;
10530
10531                 type_t *const type = declaration->type;
10532                 const char *s;
10533                 if (entity->kind == ENTITY_FUNCTION) {
10534                         /* inhibit warning for static inline functions */
10535                         if (entity->function.is_inline)
10536                                 continue;
10537
10538                         s = entity->function.statement != NULL ? "defined" : "declared";
10539                 } else {
10540                         s = "defined";
10541                 }
10542
10543                 warningf(&declaration->base.source_position, "'%#T' %s but not used",
10544                         type, declaration->base.symbol, s);
10545         }
10546 }
10547
10548 static void parse_global_asm(void)
10549 {
10550         statement_t *statement = allocate_statement_zero(STATEMENT_ASM);
10551
10552         eat(T_asm);
10553         expect('(');
10554
10555         statement->asms.asm_text = parse_string_literals();
10556         statement->base.next     = unit->global_asm;
10557         unit->global_asm         = statement;
10558
10559         expect(')');
10560         expect(';');
10561
10562 end_error:;
10563 }
10564
10565 static void parse_linkage_specification(void)
10566 {
10567         eat(T_extern);
10568         assert(token.type == T_STRING_LITERAL);
10569
10570         const char *linkage = parse_string_literals().begin;
10571
10572         linkage_kind_t old_linkage = current_linkage;
10573         linkage_kind_t new_linkage;
10574         if (strcmp(linkage, "C") == 0) {
10575                 new_linkage = LINKAGE_C;
10576         } else if (strcmp(linkage, "C++") == 0) {
10577                 new_linkage = LINKAGE_CXX;
10578         } else {
10579                 errorf(HERE, "linkage string \"%s\" not recognized", linkage);
10580                 new_linkage = LINKAGE_INVALID;
10581         }
10582         current_linkage = new_linkage;
10583
10584         if (token.type == '{') {
10585                 next_token();
10586                 parse_externals();
10587                 expect('}');
10588         } else {
10589                 parse_external();
10590         }
10591
10592 end_error:
10593         assert(current_linkage == new_linkage);
10594         current_linkage = old_linkage;
10595 }
10596
10597 static void parse_external(void)
10598 {
10599         switch (token.type) {
10600                 DECLARATION_START_NO_EXTERN
10601                 case T_IDENTIFIER:
10602                 case T___extension__:
10603                 case '(': /* for function declarations with implicit return type and
10604                                    * parenthesized declarator, i.e. (f)(void); */
10605                         parse_external_declaration();
10606                         return;
10607
10608                 case T_extern:
10609                         if (look_ahead(1)->type == T_STRING_LITERAL) {
10610                                 parse_linkage_specification();
10611                         } else {
10612                                 parse_external_declaration();
10613                         }
10614                         return;
10615
10616                 case T_asm:
10617                         parse_global_asm();
10618                         return;
10619
10620                 case T_namespace:
10621                         parse_namespace_definition();
10622                         return;
10623
10624                 case ';':
10625                         if (!strict_mode) {
10626                                 if (warning.other)
10627                                         warningf(HERE, "stray ';' outside of function");
10628                                 next_token();
10629                                 return;
10630                         }
10631                         /* FALLTHROUGH */
10632
10633                 default:
10634                         errorf(HERE, "stray %K outside of function", &token);
10635                         if (token.type == '(' || token.type == '{' || token.type == '[')
10636                                 eat_until_matching_token(token.type);
10637                         next_token();
10638                         return;
10639         }
10640 }
10641
10642 static void parse_externals(void)
10643 {
10644         add_anchor_token('}');
10645         add_anchor_token(T_EOF);
10646
10647 #ifndef NDEBUG
10648         unsigned char token_anchor_copy[T_LAST_TOKEN];
10649         memcpy(token_anchor_copy, token_anchor_set, sizeof(token_anchor_copy));
10650 #endif
10651
10652         while (token.type != T_EOF && token.type != '}') {
10653 #ifndef NDEBUG
10654                 bool anchor_leak = false;
10655                 for (int i = 0; i != T_LAST_TOKEN; ++i) {
10656                         unsigned char count = token_anchor_set[i] - token_anchor_copy[i];
10657                         if (count != 0) {
10658                                 errorf(HERE, "Leaked anchor token %k %d times", i, count);
10659                                 anchor_leak = true;
10660                         }
10661                 }
10662                 if (in_gcc_extension) {
10663                         errorf(HERE, "Leaked __extension__");
10664                         anchor_leak = true;
10665                 }
10666
10667                 if (anchor_leak)
10668                         abort();
10669 #endif
10670
10671                 parse_external();
10672         }
10673
10674         rem_anchor_token(T_EOF);
10675         rem_anchor_token('}');
10676 }
10677
10678 /**
10679  * Parse a translation unit.
10680  */
10681 static void parse_translation_unit(void)
10682 {
10683         add_anchor_token(T_EOF);
10684
10685         while (true) {
10686                 parse_externals();
10687
10688                 if (token.type == T_EOF)
10689                         break;
10690
10691                 errorf(HERE, "stray %K outside of function", &token);
10692                 if (token.type == '(' || token.type == '{' || token.type == '[')
10693                         eat_until_matching_token(token.type);
10694                 next_token();
10695         }
10696 }
10697
10698 /**
10699  * Parse the input.
10700  *
10701  * @return  the translation unit or NULL if errors occurred.
10702  */
10703 void start_parsing(void)
10704 {
10705         environment_stack = NEW_ARR_F(stack_entry_t, 0);
10706         label_stack       = NEW_ARR_F(stack_entry_t, 0);
10707         diagnostic_count  = 0;
10708         error_count       = 0;
10709         warning_count     = 0;
10710
10711         type_set_output(stderr);
10712         ast_set_output(stderr);
10713
10714         assert(unit == NULL);
10715         unit = allocate_ast_zero(sizeof(unit[0]));
10716
10717         assert(file_scope == NULL);
10718         file_scope = &unit->scope;
10719
10720         assert(current_scope == NULL);
10721         scope_push(&unit->scope);
10722 }
10723
10724 translation_unit_t *finish_parsing(void)
10725 {
10726         /* do NOT use scope_pop() here, this will crash, will it by hand */
10727         assert(current_scope == &unit->scope);
10728         current_scope = NULL;
10729
10730         assert(file_scope == &unit->scope);
10731         check_unused_globals();
10732         file_scope = NULL;
10733
10734         DEL_ARR_F(environment_stack);
10735         DEL_ARR_F(label_stack);
10736
10737         translation_unit_t *result = unit;
10738         unit = NULL;
10739         return result;
10740 }
10741
10742 void parse(void)
10743 {
10744         lookahead_bufpos = 0;
10745         for (int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
10746                 next_token();
10747         }
10748         current_linkage = c_mode & _CXX ? LINKAGE_CXX : LINKAGE_C;
10749         parse_translation_unit();
10750 }
10751
10752 /**
10753  * Initialize the parser.
10754  */
10755 void init_parser(void)
10756 {
10757         sym_anonymous = symbol_table_insert("<anonymous>");
10758
10759         if (c_mode & _MS) {
10760                 /* add predefined symbols for extended-decl-modifier */
10761                 sym_align      = symbol_table_insert("align");
10762                 sym_allocate   = symbol_table_insert("allocate");
10763                 sym_dllimport  = symbol_table_insert("dllimport");
10764                 sym_dllexport  = symbol_table_insert("dllexport");
10765                 sym_naked      = symbol_table_insert("naked");
10766                 sym_noinline   = symbol_table_insert("noinline");
10767                 sym_noreturn   = symbol_table_insert("noreturn");
10768                 sym_nothrow    = symbol_table_insert("nothrow");
10769                 sym_novtable   = symbol_table_insert("novtable");
10770                 sym_property   = symbol_table_insert("property");
10771                 sym_get        = symbol_table_insert("get");
10772                 sym_put        = symbol_table_insert("put");
10773                 sym_selectany  = symbol_table_insert("selectany");
10774                 sym_thread     = symbol_table_insert("thread");
10775                 sym_uuid       = symbol_table_insert("uuid");
10776                 sym_deprecated = symbol_table_insert("deprecated");
10777                 sym_restrict   = symbol_table_insert("restrict");
10778                 sym_noalias    = symbol_table_insert("noalias");
10779         }
10780         memset(token_anchor_set, 0, sizeof(token_anchor_set));
10781
10782         init_expression_parsers();
10783         obstack_init(&temp_obst);
10784
10785         symbol_t *const va_list_sym = symbol_table_insert("__builtin_va_list");
10786         type_valist = create_builtin_type(va_list_sym, type_void_ptr);
10787 }
10788
10789 /**
10790  * Terminate the parser.
10791  */
10792 void exit_parser(void)
10793 {
10794         obstack_free(&temp_obst, NULL);
10795 }