nsz Git - cparser/blob - parser.c

   1 /*
   2  * This file is part of cparser.
   3  * Copyright (C) 2007-2008 Matthias Braun <matze@braunis.de>
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; either version 2
   8  * of the License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  18  * 02111-1307, USA.
  19  */
  20 #include <config.h>
  21
  22 #include <assert.h>
  23 #include <stdarg.h>
  24 #include <stdbool.h>
  25
  26 #include "parser.h"
  27 #include "diagnostic.h"
  28 #include "format_check.h"
  29 #include "lexer.h"
  30 #include "symbol_t.h"
  31 #include "token_t.h"
  32 #include "types.h"
  33 #include "type_t.h"
  34 #include "type_hash.h"
  35 #include "ast_t.h"
  36 #include "entity_t.h"
  37 #include "lang_features.h"
  38 #include "walk_statements.h"
  39 #include "warning.h"
  40 #include "adt/bitfiddle.h"
  41 #include "adt/error.h"
  42 #include "adt/array.h"
  43
  44 //#define PRINT_TOKENS
  45 #define MAX_LOOKAHEAD 1
  46
  47 typedef struct {
  48         entity_t           *old_entity;
  49         symbol_t           *symbol;
  50         entity_namespace_t  namespc;
  51 } stack_entry_t;
  52
  53 typedef struct argument_list_t argument_list_t;
  54 struct argument_list_t {
  55         long              argument;
  56         argument_list_t  *next;
  57 };
  58
  59 typedef struct gnu_attribute_t gnu_attribute_t;
  60 struct gnu_attribute_t {
  61         gnu_attribute_kind_t kind;          /**< The kind of the GNU attribute. */
  62         gnu_attribute_t     *next;
  63         bool                 invalid;       /**< Set if this attribute had argument errors, */
  64         bool                 has_arguments; /**< True, if this attribute has arguments. */
  65         union {
  66                 size_t              value;
  67                 string_t            string;
  68                 symbol_t           *symbol;
  69                 long                argument;  /**< Single argument. */
  70                 argument_list_t    *arguments; /**< List of argument expressions. */
  71         } u;
  72 };
  73
  74 typedef struct declaration_specifiers_t  declaration_specifiers_t;
  75 struct declaration_specifiers_t {
  76         source_position_t  source_position;
  77         storage_class_t    storage_class;
  78         unsigned char      alignment;         /**< Alignment, 0 if not set. */
  79         bool               is_inline    : 1;
  80         bool               thread_local : 1;  /**< GCC __thread */
  81         bool               deprecated   : 1;
  82         decl_modifiers_t   modifiers;         /**< declaration modifiers */
  83         gnu_attribute_t   *gnu_attributes;    /**< list of GNU attributes */
  84         const char        *deprecated_string; /**< can be set if declaration was marked deprecated. */
  85         symbol_t          *get_property_sym;  /**< the name of the get property if set. */
  86         symbol_t          *put_property_sym;  /**< the name of the put property if set. */
  87         type_t            *type;
  88 };
  89
  90 /**
  91  * An environment for parsing initializers (and compound literals).
  92  */
  93 typedef struct parse_initializer_env_t {
  94         type_t     *type;   /**< the type of the initializer. In case of an
  95                                  array type with unspecified size this gets
  96                                  adjusted to the actual size. */
  97         entity_t   *entity; /**< the variable that is initialized if any */
  98         bool        must_be_constant;
  99 } parse_initializer_env_t;
 100
 101 /**
 102  * Capture a MS __base extension.
 103  */
 104 typedef struct based_spec_t {
 105         source_position_t  source_position;
 106         variable_t        *base_variable;
 107 } based_spec_t;
 108
 109 typedef entity_t* (*parsed_declaration_func) (entity_t *declaration, bool is_definition);
 110
 111 /** The current token. */
 112 static token_t              token;
 113 /** The lookahead ring-buffer. */
 114 static token_t              lookahead_buffer[MAX_LOOKAHEAD];
 115 /** Position of the next token in the lookahead buffer. */
 116 static size_t               lookahead_bufpos;
 117 static stack_entry_t       *environment_stack = NULL;
 118 static stack_entry_t       *label_stack       = NULL;
 119 static scope_t             *file_scope        = NULL;
 120 static scope_t             *current_scope     = NULL;
 121 /** Point to the current function declaration if inside a function. */
 122 static function_t          *current_function  = NULL;
 123 static entity_t            *current_init_decl = NULL;
 124 static switch_statement_t  *current_switch    = NULL;
 125 static statement_t         *current_loop      = NULL;
 126 static statement_t         *current_parent    = NULL;
 127 static ms_try_statement_t  *current_try       = NULL;
 128 static linkage_kind_t       current_linkage   = LINKAGE_INVALID;
 129 static goto_statement_t    *goto_first        = NULL;
 130 static goto_statement_t   **goto_anchor       = NULL;
 131 static label_statement_t   *label_first       = NULL;
 132 static label_statement_t  **label_anchor      = NULL;
 133 /** current translation unit. */
 134 static translation_unit_t  *unit              = NULL;
 135 /** true if we are in a type property context (evaluation only for type. */
 136 static bool                 in_type_prop      = false;
 137 /** true in we are in a __extension__ context. */
 138 static bool                 in_gcc_extension  = false;
 139 static struct obstack       temp_obst;
 140 static entity_t            *anonymous_entity;
 141 static declaration_t      **incomplete_arrays;
 142
 143
 144 #define PUSH_PARENT(stmt)                          \
 145         statement_t *const prev_parent = current_parent; \
 146         ((void)(current_parent = (stmt)))
 147 #define POP_PARENT ((void)(current_parent = prev_parent))
 148
 149 /** special symbol used for anonymous entities. */
 150 static const symbol_t *sym_anonymous = NULL;
 151
 152 /* symbols for Microsoft extended-decl-modifier */
 153 static const symbol_t *sym_align         = NULL;
 154 static const symbol_t *sym_allocate      = NULL;
 155 static const symbol_t *sym_dllimport     = NULL;
 156 static const symbol_t *sym_dllexport     = NULL;
 157 static const symbol_t *sym_naked         = NULL;
 158 static const symbol_t *sym_noinline      = NULL;
 159 static const symbol_t *sym_returns_twice = NULL;
 160 static const symbol_t *sym_noreturn      = NULL;
 161 static const symbol_t *sym_nothrow       = NULL;
 162 static const symbol_t *sym_novtable      = NULL;
 163 static const symbol_t *sym_property      = NULL;
 164 static const symbol_t *sym_get           = NULL;
 165 static const symbol_t *sym_put           = NULL;
 166 static const symbol_t *sym_selectany     = NULL;
 167 static const symbol_t *sym_thread        = NULL;
 168 static const symbol_t *sym_uuid          = NULL;
 169 static const symbol_t *sym_deprecated    = NULL;
 170 static const symbol_t *sym_restrict      = NULL;
 171 static const symbol_t *sym_noalias       = NULL;
 172
 173 /** The token anchor set */
 174 static unsigned char token_anchor_set[T_LAST_TOKEN];
 175
 176 /** The current source position. */
 177 #define HERE (&token.source_position)
 178
 179 /** true if we are in GCC mode. */
 180 #define GNU_MODE ((c_mode & _GNUC) || in_gcc_extension)
 181
 182 static type_t *type_valist;
 183
 184 static statement_t *parse_compound_statement(bool inside_expression_statement);
 185 static statement_t *parse_statement(void);
 186
 187 static expression_t *parse_sub_expression(precedence_t);
 188 static expression_t *parse_expression(void);
 189 static type_t       *parse_typename(void);
 190 static void          parse_externals(void);
 191 static void          parse_external(void);
 192
 193 static void parse_compound_type_entries(compound_t *compound_declaration);
 194
 195 typedef enum declarator_flags_t {
 196         DECL_FLAGS_NONE             = 0,
 197         DECL_MAY_BE_ABSTRACT        = 1U << 0,
 198         DECL_CREATE_COMPOUND_MEMBER = 1U << 1,
 199         DECL_IS_PARAMETER           = 1U << 2
 200 } declarator_flags_t;
 201
 202 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
 203                                   declarator_flags_t flags);
 204
 205 static entity_t *record_entity(entity_t *entity, bool is_definition);
 206
 207 static void semantic_comparison(binary_expression_t *expression);
 208
 209 #define STORAGE_CLASSES       \
 210         STORAGE_CLASSES_NO_EXTERN \
 211         case T_extern:
 212
 213 #define STORAGE_CLASSES_NO_EXTERN \
 214         case T_typedef:         \
 215         case T_static:          \
 216         case T_auto:            \
 217         case T_register:        \
 218         case T___thread:
 219
 220 #define TYPE_QUALIFIERS     \
 221         case T_const:           \
 222         case T_restrict:        \
 223         case T_volatile:        \
 224         case T_inline:          \
 225         case T__forceinline:    \
 226         case T___attribute__:
 227
 228 #define COMPLEX_SPECIFIERS  \
 229         case T__Complex:
 230 #define IMAGINARY_SPECIFIERS \
 231         case T__Imaginary:
 232
 233 #define TYPE_SPECIFIERS       \
 234         case T__Bool:             \
 235         case T___builtin_va_list: \
 236         case T___typeof__:        \
 237         case T__declspec:         \
 238         case T_bool:              \
 239         case T_char:              \
 240         case T_double:            \
 241         case T_enum:              \
 242         case T_float:             \
 243         case T_int:               \
 244         case T_long:              \
 245         case T_short:             \
 246         case T_signed:            \
 247         case T_struct:            \
 248         case T_union:             \
 249         case T_unsigned:          \
 250         case T_void:              \
 251         case T_wchar_t:           \
 252         COMPLEX_SPECIFIERS        \
 253         IMAGINARY_SPECIFIERS
 254
 255 #define DECLARATION_START   \
 256         STORAGE_CLASSES         \
 257         TYPE_QUALIFIERS         \
 258         TYPE_SPECIFIERS
 259
 260 #define DECLARATION_START_NO_EXTERN \
 261         STORAGE_CLASSES_NO_EXTERN       \
 262         TYPE_QUALIFIERS                 \
 263         TYPE_SPECIFIERS
 264
 265 #define TYPENAME_START      \
 266         TYPE_QUALIFIERS         \
 267         TYPE_SPECIFIERS
 268
 269 #define EXPRESSION_START           \
 270         case '!':                        \
 271         case '&':                        \
 272         case '(':                        \
 273         case '*':                        \
 274         case '+':                        \
 275         case '-':                        \
 276         case '~':                        \
 277         case T_ANDAND:                   \
 278         case T_CHARACTER_CONSTANT:       \
 279         case T_FLOATINGPOINT:            \
 280         case T_INTEGER:                  \
 281         case T_MINUSMINUS:               \
 282         case T_PLUSPLUS:                 \
 283         case T_STRING_LITERAL:           \
 284         case T_WIDE_CHARACTER_CONSTANT:  \
 285         case T_WIDE_STRING_LITERAL:      \
 286         case T___FUNCDNAME__:            \
 287         case T___FUNCSIG__:              \
 288         case T___FUNCTION__:             \
 289         case T___PRETTY_FUNCTION__:      \
 290         case T___alignof__:              \
 291         case T___builtin_alloca:         \
 292         case T___builtin_classify_type:  \
 293         case T___builtin_constant_p:     \
 294         case T___builtin_expect:         \
 295         case T___builtin_huge_val:       \
 296         case T___builtin_inf:            \
 297         case T___builtin_inff:           \
 298         case T___builtin_infl:           \
 299         case T___builtin_isgreater:      \
 300         case T___builtin_isgreaterequal: \
 301         case T___builtin_isless:         \
 302         case T___builtin_islessequal:    \
 303         case T___builtin_islessgreater:  \
 304         case T___builtin_isunordered:    \
 305         case T___builtin_nan:            \
 306         case T___builtin_nanf:           \
 307         case T___builtin_nanl:           \
 308         case T___builtin_offsetof:       \
 309         case T___builtin_prefetch:       \
 310         case T___builtin_va_arg:         \
 311         case T___builtin_va_end:         \
 312         case T___builtin_va_start:       \
 313         case T___func__:                 \
 314         case T___noop:                   \
 315         case T__assume:                  \
 316         case T_delete:                   \
 317         case T_false:                    \
 318         case T_sizeof:                   \
 319         case T_throw:                    \
 320         case T_true:
 321
 322 /**
 323  * Allocate an AST node with given size and
 324  * initialize all fields with zero.
 325  */
 326 static void *allocate_ast_zero(size_t size)
 327 {
 328         void *res = allocate_ast(size);
 329         memset(res, 0, size);
 330         return res;
 331 }
 332
 333 /**
 334  * Returns the size of an entity node.
 335  *
 336  * @param kind  the entity kind
 337  */
 338 static size_t get_entity_struct_size(entity_kind_t kind)
 339 {
 340         static const size_t sizes[] = {
 341                 [ENTITY_VARIABLE]        = sizeof(variable_t),
 342                 [ENTITY_PARAMETER]       = sizeof(parameter_t),
 343                 [ENTITY_COMPOUND_MEMBER] = sizeof(compound_member_t),
 344                 [ENTITY_FUNCTION]        = sizeof(function_t),
 345                 [ENTITY_TYPEDEF]         = sizeof(typedef_t),
 346                 [ENTITY_STRUCT]          = sizeof(compound_t),
 347                 [ENTITY_UNION]           = sizeof(compound_t),
 348                 [ENTITY_ENUM]            = sizeof(enum_t),
 349                 [ENTITY_ENUM_VALUE]      = sizeof(enum_value_t),
 350                 [ENTITY_LABEL]           = sizeof(label_t),
 351                 [ENTITY_LOCAL_LABEL]     = sizeof(label_t),
 352                 [ENTITY_NAMESPACE]       = sizeof(namespace_t)
 353         };
 354         assert(kind < lengthof(sizes));
 355         assert(sizes[kind] != 0);
 356         return sizes[kind];
 357 }
 358
 359 /**
 360  * Allocate an entity of given kind and initialize all
 361  * fields with zero.
 362  */
 363 static entity_t *allocate_entity_zero(entity_kind_t kind)
 364 {
 365         size_t    size   = get_entity_struct_size(kind);
 366         entity_t *entity = allocate_ast_zero(size);
 367         entity->kind     = kind;
 368         return entity;
 369 }
 370
 371 /**
 372  * Returns the size of a statement node.
 373  *
 374  * @param kind  the statement kind
 375  */
 376 static size_t get_statement_struct_size(statement_kind_t kind)
 377 {
 378         static const size_t sizes[] = {
 379                 [STATEMENT_INVALID]     = sizeof(invalid_statement_t),
 380                 [STATEMENT_EMPTY]       = sizeof(empty_statement_t),
 381                 [STATEMENT_COMPOUND]    = sizeof(compound_statement_t),
 382                 [STATEMENT_RETURN]      = sizeof(return_statement_t),
 383                 [STATEMENT_DECLARATION] = sizeof(declaration_statement_t),
 384                 [STATEMENT_IF]          = sizeof(if_statement_t),
 385                 [STATEMENT_SWITCH]      = sizeof(switch_statement_t),
 386                 [STATEMENT_EXPRESSION]  = sizeof(expression_statement_t),
 387                 [STATEMENT_CONTINUE]    = sizeof(statement_base_t),
 388                 [STATEMENT_BREAK]       = sizeof(statement_base_t),
 389                 [STATEMENT_GOTO]        = sizeof(goto_statement_t),
 390                 [STATEMENT_LABEL]       = sizeof(label_statement_t),
 391                 [STATEMENT_CASE_LABEL]  = sizeof(case_label_statement_t),
 392                 [STATEMENT_WHILE]       = sizeof(while_statement_t),
 393                 [STATEMENT_DO_WHILE]    = sizeof(do_while_statement_t),
 394                 [STATEMENT_FOR]         = sizeof(for_statement_t),
 395                 [STATEMENT_ASM]         = sizeof(asm_statement_t),
 396                 [STATEMENT_MS_TRY]      = sizeof(ms_try_statement_t),
 397                 [STATEMENT_LEAVE]       = sizeof(leave_statement_t)
 398         };
 399         assert(kind < lengthof(sizes));
 400         assert(sizes[kind] != 0);
 401         return sizes[kind];
 402 }
 403
 404 /**
 405  * Returns the size of an expression node.
 406  *
 407  * @param kind  the expression kind
 408  */
 409 static size_t get_expression_struct_size(expression_kind_t kind)
 410 {
 411         static const size_t sizes[] = {
 412                 [EXPR_INVALID]                 = sizeof(expression_base_t),
 413                 [EXPR_REFERENCE]               = sizeof(reference_expression_t),
 414                 [EXPR_REFERENCE_ENUM_VALUE]    = sizeof(reference_expression_t),
 415                 [EXPR_CONST]                   = sizeof(const_expression_t),
 416                 [EXPR_CHARACTER_CONSTANT]      = sizeof(const_expression_t),
 417                 [EXPR_WIDE_CHARACTER_CONSTANT] = sizeof(const_expression_t),
 418                 [EXPR_STRING_LITERAL]          = sizeof(string_literal_expression_t),
 419                 [EXPR_WIDE_STRING_LITERAL]     = sizeof(wide_string_literal_expression_t),
 420                 [EXPR_COMPOUND_LITERAL]        = sizeof(compound_literal_expression_t),
 421                 [EXPR_CALL]                    = sizeof(call_expression_t),
 422                 [EXPR_UNARY_FIRST]             = sizeof(unary_expression_t),
 423                 [EXPR_BINARY_FIRST]            = sizeof(binary_expression_t),
 424                 [EXPR_CONDITIONAL]             = sizeof(conditional_expression_t),
 425                 [EXPR_SELECT]                  = sizeof(select_expression_t),
 426                 [EXPR_ARRAY_ACCESS]            = sizeof(array_access_expression_t),
 427                 [EXPR_SIZEOF]                  = sizeof(typeprop_expression_t),
 428                 [EXPR_ALIGNOF]                 = sizeof(typeprop_expression_t),
 429                 [EXPR_CLASSIFY_TYPE]           = sizeof(classify_type_expression_t),
 430                 [EXPR_FUNCNAME]                = sizeof(funcname_expression_t),
 431                 [EXPR_BUILTIN_SYMBOL]          = sizeof(builtin_symbol_expression_t),
 432                 [EXPR_BUILTIN_CONSTANT_P]      = sizeof(builtin_constant_expression_t),
 433                 [EXPR_BUILTIN_PREFETCH]        = sizeof(builtin_prefetch_expression_t),
 434                 [EXPR_OFFSETOF]                = sizeof(offsetof_expression_t),
 435                 [EXPR_VA_START]                = sizeof(va_start_expression_t),
 436                 [EXPR_VA_ARG]                  = sizeof(va_arg_expression_t),
 437                 [EXPR_STATEMENT]               = sizeof(statement_expression_t),
 438                 [EXPR_LABEL_ADDRESS]           = sizeof(label_address_expression_t),
 439         };
 440         if (kind >= EXPR_UNARY_FIRST && kind <= EXPR_UNARY_LAST) {
 441                 return sizes[EXPR_UNARY_FIRST];
 442         }
 443         if (kind >= EXPR_BINARY_FIRST && kind <= EXPR_BINARY_LAST) {
 444                 return sizes[EXPR_BINARY_FIRST];
 445         }
 446         assert(kind < lengthof(sizes));
 447         assert(sizes[kind] != 0);
 448         return sizes[kind];
 449 }
 450
 451 /**
 452  * Allocate a statement node of given kind and initialize all
 453  * fields with zero. Sets its source position to the position
 454  * of the current token.
 455  */
 456 static statement_t *allocate_statement_zero(statement_kind_t kind)
 457 {
 458         size_t       size = get_statement_struct_size(kind);
 459         statement_t *res  = allocate_ast_zero(size);
 460
 461         res->base.kind            = kind;
 462         res->base.parent          = current_parent;
 463         res->base.source_position = token.source_position;
 464         return res;
 465 }
 466
 467 /**
 468  * Allocate an expression node of given kind and initialize all
 469  * fields with zero.
 470  */
 471 static expression_t *allocate_expression_zero(expression_kind_t kind)
 472 {
 473         size_t        size = get_expression_struct_size(kind);
 474         expression_t *res  = allocate_ast_zero(size);
 475
 476         res->base.kind            = kind;
 477         res->base.type            = type_error_type;
 478         res->base.source_position = token.source_position;
 479         return res;
 480 }
 481
 482 /**
 483  * Creates a new invalid expression at the source position
 484  * of the current token.
 485  */
 486 static expression_t *create_invalid_expression(void)
 487 {
 488         return allocate_expression_zero(EXPR_INVALID);
 489 }
 490
 491 /**
 492  * Creates a new invalid statement.
 493  */
 494 static statement_t *create_invalid_statement(void)
 495 {
 496         return allocate_statement_zero(STATEMENT_INVALID);
 497 }
 498
 499 /**
 500  * Allocate a new empty statement.
 501  */
 502 static statement_t *create_empty_statement(void)
 503 {
 504         return allocate_statement_zero(STATEMENT_EMPTY);
 505 }
 506
 507 /**
 508  * Returns the size of a type node.
 509  *
 510  * @param kind  the type kind
 511  */
 512 static size_t get_type_struct_size(type_kind_t kind)
 513 {
 514         static const size_t sizes[] = {
 515                 [TYPE_ATOMIC]          = sizeof(atomic_type_t),
 516                 [TYPE_COMPLEX]         = sizeof(complex_type_t),
 517                 [TYPE_IMAGINARY]       = sizeof(imaginary_type_t),
 518                 [TYPE_BITFIELD]        = sizeof(bitfield_type_t),
 519                 [TYPE_COMPOUND_STRUCT] = sizeof(compound_type_t),
 520                 [TYPE_COMPOUND_UNION]  = sizeof(compound_type_t),
 521                 [TYPE_ENUM]            = sizeof(enum_type_t),
 522                 [TYPE_FUNCTION]        = sizeof(function_type_t),
 523                 [TYPE_POINTER]         = sizeof(pointer_type_t),
 524                 [TYPE_ARRAY]           = sizeof(array_type_t),
 525                 [TYPE_BUILTIN]         = sizeof(builtin_type_t),
 526                 [TYPE_TYPEDEF]         = sizeof(typedef_type_t),
 527                 [TYPE_TYPEOF]          = sizeof(typeof_type_t),
 528         };
 529         assert(lengthof(sizes) == (int)TYPE_TYPEOF + 1);
 530         assert(kind <= TYPE_TYPEOF);
 531         assert(sizes[kind] != 0);
 532         return sizes[kind];
 533 }
 534
 535 /**
 536  * Allocate a type node of given kind and initialize all
 537  * fields with zero.
 538  *
 539  * @param kind             type kind to allocate
 540  */
 541 static type_t *allocate_type_zero(type_kind_t kind)
 542 {
 543         size_t  size = get_type_struct_size(kind);
 544         type_t *res  = obstack_alloc(type_obst, size);
 545         memset(res, 0, size);
 546         res->base.kind = kind;
 547
 548         return res;
 549 }
 550
 551 /**
 552  * Returns the size of an initializer node.
 553  *
 554  * @param kind  the initializer kind
 555  */
 556 static size_t get_initializer_size(initializer_kind_t kind)
 557 {
 558         static const size_t sizes[] = {
 559                 [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
 560                 [INITIALIZER_STRING]      = sizeof(initializer_string_t),
 561                 [INITIALIZER_WIDE_STRING] = sizeof(initializer_wide_string_t),
 562                 [INITIALIZER_LIST]        = sizeof(initializer_list_t),
 563                 [INITIALIZER_DESIGNATOR]  = sizeof(initializer_designator_t)
 564         };
 565         assert(kind < lengthof(sizes));
 566         assert(sizes[kind] != 0);
 567         return sizes[kind];
 568 }
 569
 570 /**
 571  * Allocate an initializer node of given kind and initialize all
 572  * fields with zero.
 573  */
 574 static initializer_t *allocate_initializer_zero(initializer_kind_t kind)
 575 {
 576         initializer_t *result = allocate_ast_zero(get_initializer_size(kind));
 577         result->kind          = kind;
 578
 579         return result;
 580 }
 581
 582 /**
 583  * Returns the index of the top element of the environment stack.
 584  */
 585 static size_t environment_top(void)
 586 {
 587         return ARR_LEN(environment_stack);
 588 }
 589
 590 /**
 591  * Returns the index of the top element of the global label stack.
 592  */
 593 static size_t label_top(void)
 594 {
 595         return ARR_LEN(label_stack);
 596 }
 597
 598 /**
 599  * Return the next token.
 600  */
 601 static inline void next_token(void)
 602 {
 603         token                              = lookahead_buffer[lookahead_bufpos];
 604         lookahead_buffer[lookahead_bufpos] = lexer_token;
 605         lexer_next_token();
 606
 607         lookahead_bufpos = (lookahead_bufpos + 1) % MAX_LOOKAHEAD;
 608
 609 #ifdef PRINT_TOKENS
 610         print_token(stderr, &token);
 611         fprintf(stderr, "\n");
 612 #endif
 613 }
 614
 615 /**
 616  * Return the next token with a given lookahead.
 617  */
 618 static inline const token_t *look_ahead(size_t num)
 619 {
 620         assert(0 < num && num <= MAX_LOOKAHEAD);
 621         size_t pos = (lookahead_bufpos + num - 1) % MAX_LOOKAHEAD;
 622         return &lookahead_buffer[pos];
 623 }
 624
 625 /**
 626  * Adds a token type to the token type anchor set (a multi-set).
 627  */
 628 static void add_anchor_token(int token_type)
 629 {
 630         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 631         ++token_anchor_set[token_type];
 632 }
 633
 634 /**
 635  * Set the number of tokens types of the given type
 636  * to zero and return the old count.
 637  */
 638 static int save_and_reset_anchor_state(int token_type)
 639 {
 640         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 641         int count = token_anchor_set[token_type];
 642         token_anchor_set[token_type] = 0;
 643         return count;
 644 }
 645
 646 /**
 647  * Restore the number of token types to the given count.
 648  */
 649 static void restore_anchor_state(int token_type, int count)
 650 {
 651         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 652         token_anchor_set[token_type] = count;
 653 }
 654
 655 /**
 656  * Remove a token type from the token type anchor set (a multi-set).
 657  */
 658 static void rem_anchor_token(int token_type)
 659 {
 660         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 661         assert(token_anchor_set[token_type] != 0);
 662         --token_anchor_set[token_type];
 663 }
 664
 665 /**
 666  * Return true if the token type of the current token is
 667  * in the anchor set.
 668  */
 669 static bool at_anchor(void)
 670 {
 671         if (token.type < 0)
 672                 return false;
 673         return token_anchor_set[token.type];
 674 }
 675
 676 /**
 677  * Eat tokens until a matching token type is found.
 678  */
 679 static void eat_until_matching_token(int type)
 680 {
 681         int end_token;
 682         switch (type) {
 683                 case '(': end_token = ')';  break;
 684                 case '{': end_token = '}';  break;
 685                 case '[': end_token = ']';  break;
 686                 default:  end_token = type; break;
 687         }
 688
 689         unsigned parenthesis_count = 0;
 690         unsigned brace_count       = 0;
 691         unsigned bracket_count     = 0;
 692         while (token.type        != end_token ||
 693                parenthesis_count != 0         ||
 694                brace_count       != 0         ||
 695                bracket_count     != 0) {
 696                 switch (token.type) {
 697                 case T_EOF: return;
 698                 case '(': ++parenthesis_count; break;
 699                 case '{': ++brace_count;       break;
 700                 case '[': ++bracket_count;     break;
 701
 702                 case ')':
 703                         if (parenthesis_count > 0)
 704                                 --parenthesis_count;
 705                         goto check_stop;
 706
 707                 case '}':
 708                         if (brace_count > 0)
 709                                 --brace_count;
 710                         goto check_stop;
 711
 712                 case ']':
 713                         if (bracket_count > 0)
 714                                 --bracket_count;
 715 check_stop:
 716                         if (token.type        == end_token &&
 717                             parenthesis_count == 0         &&
 718                             brace_count       == 0         &&
 719                             bracket_count     == 0)
 720                                 return;
 721                         break;
 722
 723                 default:
 724                         break;
 725                 }
 726                 next_token();
 727         }
 728 }
 729
 730 /**
 731  * Eat input tokens until an anchor is found.
 732  */
 733 static void eat_until_anchor(void)
 734 {
 735         while (token_anchor_set[token.type] == 0) {
 736                 if (token.type == '(' || token.type == '{' || token.type == '[')
 737                         eat_until_matching_token(token.type);
 738                 next_token();
 739         }
 740 }
 741
 742 /**
 743  * Eat a whole block from input tokens.
 744  */
 745 static void eat_block(void)
 746 {
 747         eat_until_matching_token('{');
 748         if (token.type == '}')
 749                 next_token();
 750 }
 751
 752 #define eat(token_type) (assert(token.type == (token_type)), next_token())
 753
 754 /**
 755  * Report a parse error because an expected token was not found.
 756  */
 757 static
 758 #if defined __GNUC__ && __GNUC__ >= 4
 759 __attribute__((sentinel))
 760 #endif
 761 void parse_error_expected(const char *message, ...)
 762 {
 763         if (message != NULL) {
 764                 errorf(HERE, "%s", message);
 765         }
 766         va_list ap;
 767         va_start(ap, message);
 768         errorf(HERE, "got %K, expected %#k", &token, &ap, ", ");
 769         va_end(ap);
 770 }
 771
 772 /**
 773  * Report an incompatible type.
 774  */
 775 static void type_error_incompatible(const char *msg,
 776                 const source_position_t *source_position, type_t *type1, type_t *type2)
 777 {
 778         errorf(source_position, "%s, incompatible types: '%T' - '%T'",
 779                msg, type1, type2);
 780 }
 781
 782 /**
 783  * Expect the current token is the expected token.
 784  * If not, generate an error, eat the current statement,
 785  * and goto the end_error label.
 786  */
 787 #define expect(expected, error_label)                     \
 788         do {                                                  \
 789                 if (UNLIKELY(token.type != (expected))) {         \
 790                         parse_error_expected(NULL, (expected), NULL); \
 791                         add_anchor_token(expected);                   \
 792                         eat_until_anchor();                           \
 793                         if (token.type == expected)                   \
 794                                 next_token();                             \
 795                         rem_anchor_token(expected);                   \
 796                         goto error_label;                             \
 797                 }                                                 \
 798                 next_token();                                     \
 799         } while (0)
 800
 801 /**
 802  * Push a given scope on the scope stack and make it the
 803  * current scope
 804  */
 805 static scope_t *scope_push(scope_t *new_scope)
 806 {
 807         if (current_scope != NULL) {
 808                 new_scope->depth = current_scope->depth + 1;
 809         }
 810
 811         scope_t *old_scope = current_scope;
 812         current_scope      = new_scope;
 813         return old_scope;
 814 }
 815
 816 /**
 817  * Pop the current scope from the scope stack.
 818  */
 819 static void scope_pop(scope_t *old_scope)
 820 {
 821         current_scope = old_scope;
 822 }
 823
 824 /**
 825  * Search an entity by its symbol in a given namespace.
 826  */
 827 static entity_t *get_entity(const symbol_t *const symbol,
 828                             namespace_tag_t namespc)
 829 {
 830         entity_t *entity = symbol->entity;
 831         for (; entity != NULL; entity = entity->base.symbol_next) {
 832                 if (entity->base.namespc == namespc)
 833                         return entity;
 834         }
 835
 836         return NULL;
 837 }
 838
 839 /**
 840  * pushs an entity on the environment stack and links the corresponding symbol
 841  * it.
 842  */
 843 static void stack_push(stack_entry_t **stack_ptr, entity_t *entity)
 844 {
 845         symbol_t           *symbol  = entity->base.symbol;
 846         entity_namespace_t  namespc = entity->base.namespc;
 847         assert(namespc != NAMESPACE_INVALID);
 848
 849         /* replace/add entity into entity list of the symbol */
 850         entity_t **anchor;
 851         entity_t  *iter;
 852         for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 853                 iter = *anchor;
 854                 if (iter == NULL)
 855                         break;
 856
 857                 /* replace an entry? */
 858                 if (iter->base.namespc == namespc) {
 859                         entity->base.symbol_next = iter->base.symbol_next;
 860                         break;
 861                 }
 862         }
 863         *anchor = entity;
 864
 865         /* remember old declaration */
 866         stack_entry_t entry;
 867         entry.symbol     = symbol;
 868         entry.old_entity = iter;
 869         entry.namespc    = namespc;
 870         ARR_APP1(stack_entry_t, *stack_ptr, entry);
 871 }
 872
 873 /**
 874  * Push an entity on the environment stack.
 875  */
 876 static void environment_push(entity_t *entity)
 877 {
 878         assert(entity->base.source_position.input_name != NULL);
 879         assert(entity->base.parent_scope != NULL);
 880         stack_push(&environment_stack, entity);
 881 }
 882
 883 /**
 884  * Push a declaration on the global label stack.
 885  *
 886  * @param declaration  the declaration
 887  */
 888 static void label_push(entity_t *label)
 889 {
 890         /* we abuse the parameters scope as parent for the labels */
 891         label->base.parent_scope = &current_function->parameters;
 892         stack_push(&label_stack, label);
 893 }
 894
 895 /**
 896  * pops symbols from the environment stack until @p new_top is the top element
 897  */
 898 static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
 899 {
 900         stack_entry_t *stack = *stack_ptr;
 901         size_t         top   = ARR_LEN(stack);
 902         size_t         i;
 903
 904         assert(new_top <= top);
 905         if (new_top == top)
 906                 return;
 907
 908         for (i = top; i > new_top; --i) {
 909                 stack_entry_t *entry = &stack[i - 1];
 910
 911                 entity_t           *old_entity = entry->old_entity;
 912                 symbol_t           *symbol     = entry->symbol;
 913                 entity_namespace_t  namespc    = entry->namespc;
 914
 915                 /* replace with old_entity/remove */
 916                 entity_t **anchor;
 917                 entity_t  *iter;
 918                 for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 919                         iter = *anchor;
 920                         assert(iter != NULL);
 921                         /* replace an entry? */
 922                         if (iter->base.namespc == namespc)
 923                                 break;
 924                 }
 925
 926                 /* restore definition from outer scopes (if there was one) */
 927                 if (old_entity != NULL) {
 928                         old_entity->base.symbol_next = iter->base.symbol_next;
 929                         *anchor                      = old_entity;
 930                 } else {
 931                         /* remove entry from list */
 932                         *anchor = iter->base.symbol_next;
 933                 }
 934         }
 935
 936         ARR_SHRINKLEN(*stack_ptr, (int) new_top);
 937 }
 938
 939 /**
 940  * Pop all entries from the environment stack until the new_top
 941  * is reached.
 942  *
 943  * @param new_top  the new stack top
 944  */
 945 static void environment_pop_to(size_t new_top)
 946 {
 947         stack_pop_to(&environment_stack, new_top);
 948 }
 949
 950 /**
 951  * Pop all entries from the global label stack until the new_top
 952  * is reached.
 953  *
 954  * @param new_top  the new stack top
 955  */
 956 static void label_pop_to(size_t new_top)
 957 {
 958         stack_pop_to(&label_stack, new_top);
 959 }
 960
 961 static int get_akind_rank(atomic_type_kind_t akind)
 962 {
 963         return (int) akind;
 964 }
 965
 966 /**
 967  * Return the type rank for an atomic type.
 968  */
 969 static int get_rank(const type_t *type)
 970 {
 971         assert(!is_typeref(type));
 972         if (type->kind == TYPE_ENUM)
 973                 return get_akind_rank(type->enumt.akind);
 974
 975         assert(type->kind == TYPE_ATOMIC);
 976         return get_akind_rank(type->atomic.akind);
 977 }
 978
 979 /**
 980  * Do integer promotion for a given type.
 981  *
 982  * @param type  the type to promote
 983  * @return the promoted type
 984  */
 985 static type_t *promote_integer(type_t *type)
 986 {
 987         if (type->kind == TYPE_BITFIELD)
 988                 type = type->bitfield.base_type;
 989
 990         if (get_rank(type) < get_akind_rank(ATOMIC_TYPE_INT))
 991                 type = type_int;
 992
 993         return type;
 994 }
 995
 996 /**
 997  * Create a cast expression.
 998  *
 999  * @param expression  the expression to cast
1000  * @param dest_type   the destination type
1001  */
1002 static expression_t *create_cast_expression(expression_t *expression,
1003                                             type_t *dest_type)
1004 {
1005         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST_IMPLICIT);
1006
1007         cast->unary.value = expression;
1008         cast->base.type   = dest_type;
1009
1010         return cast;
1011 }
1012
1013 /**
1014  * Check if a given expression represents a null pointer constant.
1015  *
1016  * @param expression  the expression to check
1017  */
1018 static bool is_null_pointer_constant(const expression_t *expression)
1019 {
1020         /* skip void* cast */
1021         if (expression->kind == EXPR_UNARY_CAST ||
1022                         expression->kind == EXPR_UNARY_CAST_IMPLICIT) {
1023                 type_t *const type = skip_typeref(expression->base.type);
1024                 if (types_compatible(type, type_void_ptr))
1025                         expression = expression->unary.value;
1026         }
1027
1028         type_t *const type = skip_typeref(expression->base.type);
1029         return
1030                 is_type_integer(type)              &&
1031                 is_constant_expression(expression) &&
1032                 fold_constant(expression) == 0;
1033 }
1034
1035 /**
1036  * Create an implicit cast expression.
1037  *
1038  * @param expression  the expression to cast
1039  * @param dest_type   the destination type
1040  */
1041 static expression_t *create_implicit_cast(expression_t *expression,
1042                                           type_t *dest_type)
1043 {
1044         type_t *const source_type = expression->base.type;
1045
1046         if (source_type == dest_type)
1047                 return expression;
1048
1049         return create_cast_expression(expression, dest_type);
1050 }
1051
1052 typedef enum assign_error_t {
1053         ASSIGN_SUCCESS,
1054         ASSIGN_ERROR_INCOMPATIBLE,
1055         ASSIGN_ERROR_POINTER_QUALIFIER_MISSING,
1056         ASSIGN_WARNING_POINTER_INCOMPATIBLE,
1057         ASSIGN_WARNING_POINTER_FROM_INT,
1058         ASSIGN_WARNING_INT_FROM_POINTER
1059 } assign_error_t;
1060
1061 static void report_assign_error(assign_error_t error, type_t *orig_type_left,
1062                                 const expression_t *const right,
1063                                 const char *context,
1064                                 const source_position_t *source_position)
1065 {
1066         type_t *const orig_type_right = right->base.type;
1067         type_t *const type_left       = skip_typeref(orig_type_left);
1068         type_t *const type_right      = skip_typeref(orig_type_right);
1069
1070         switch (error) {
1071         case ASSIGN_SUCCESS:
1072                 return;
1073         case ASSIGN_ERROR_INCOMPATIBLE:
1074                 errorf(source_position,
1075                        "destination type '%T' in %s is incompatible with type '%T'",
1076                        orig_type_left, context, orig_type_right);
1077                 return;
1078
1079         case ASSIGN_ERROR_POINTER_QUALIFIER_MISSING: {
1080                 if (warning.other) {
1081                         type_t *points_to_left  = skip_typeref(type_left->pointer.points_to);
1082                         type_t *points_to_right = skip_typeref(type_right->pointer.points_to);
1083
1084                         /* the left type has all qualifiers from the right type */
1085                         unsigned missing_qualifiers
1086                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
1087                         warningf(source_position,
1088                                         "destination type '%T' in %s from type '%T' lacks qualifiers '%Q' in pointer target type",
1089                                         orig_type_left, context, orig_type_right, missing_qualifiers);
1090                 }
1091                 return;
1092         }
1093
1094         case ASSIGN_WARNING_POINTER_INCOMPATIBLE:
1095                 if (warning.other) {
1096                         warningf(source_position,
1097                                         "destination type '%T' in %s is incompatible with '%E' of type '%T'",
1098                                         orig_type_left, context, right, orig_type_right);
1099                 }
1100                 return;
1101
1102         case ASSIGN_WARNING_POINTER_FROM_INT:
1103                 if (warning.other) {
1104                         warningf(source_position,
1105                                         "%s makes pointer '%T' from integer '%T' without a cast",
1106                                         context, orig_type_left, orig_type_right);
1107                 }
1108                 return;
1109
1110         case ASSIGN_WARNING_INT_FROM_POINTER:
1111                 if (warning.other) {
1112                         warningf(source_position,
1113                                         "%s makes integer '%T' from pointer '%T' without a cast",
1114                                         context, orig_type_left, orig_type_right);
1115                 }
1116                 return;
1117
1118         default:
1119                 panic("invalid error value");
1120         }
1121 }
1122
1123 /** Implements the rules from § 6.5.16.1 */
1124 static assign_error_t semantic_assign(type_t *orig_type_left,
1125                                       const expression_t *const right)
1126 {
1127         type_t *const orig_type_right = right->base.type;
1128         type_t *const type_left       = skip_typeref(orig_type_left);
1129         type_t *const type_right      = skip_typeref(orig_type_right);
1130
1131         if (is_type_pointer(type_left)) {
1132                 if (is_null_pointer_constant(right)) {
1133                         return ASSIGN_SUCCESS;
1134                 } else if (is_type_pointer(type_right)) {
1135                         type_t *points_to_left
1136                                 = skip_typeref(type_left->pointer.points_to);
1137                         type_t *points_to_right
1138                                 = skip_typeref(type_right->pointer.points_to);
1139                         assign_error_t res = ASSIGN_SUCCESS;
1140
1141                         /* the left type has all qualifiers from the right type */
1142                         unsigned missing_qualifiers
1143                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
1144                         if (missing_qualifiers != 0) {
1145                                 res = ASSIGN_ERROR_POINTER_QUALIFIER_MISSING;
1146                         }
1147
1148                         points_to_left  = get_unqualified_type(points_to_left);
1149                         points_to_right = get_unqualified_type(points_to_right);
1150
1151                         if (is_type_atomic(points_to_left, ATOMIC_TYPE_VOID))
1152                                 return res;
1153
1154                         if (is_type_atomic(points_to_right, ATOMIC_TYPE_VOID)) {
1155                                 /* ISO/IEC 14882:1998(E) §C.1.2:6 */
1156                                 return c_mode & _CXX ? ASSIGN_ERROR_INCOMPATIBLE : res;
1157                         }
1158
1159                         if (!types_compatible(points_to_left, points_to_right)) {
1160                                 return ASSIGN_WARNING_POINTER_INCOMPATIBLE;
1161                         }
1162
1163                         return res;
1164                 } else if (is_type_integer(type_right)) {
1165                         return ASSIGN_WARNING_POINTER_FROM_INT;
1166                 }
1167         } else if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
1168             (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
1169                 && is_type_pointer(type_right))) {
1170                 return ASSIGN_SUCCESS;
1171         } else if ((is_type_compound(type_left)  && is_type_compound(type_right))
1172                         || (is_type_builtin(type_left) && is_type_builtin(type_right))) {
1173                 type_t *const unqual_type_left  = get_unqualified_type(type_left);
1174                 type_t *const unqual_type_right = get_unqualified_type(type_right);
1175                 if (types_compatible(unqual_type_left, unqual_type_right)) {
1176                         return ASSIGN_SUCCESS;
1177                 }
1178         } else if (is_type_integer(type_left) && is_type_pointer(type_right)) {
1179                 return ASSIGN_WARNING_INT_FROM_POINTER;
1180         }
1181
1182         if (!is_type_valid(type_left) || !is_type_valid(type_right))
1183                 return ASSIGN_SUCCESS;
1184
1185         return ASSIGN_ERROR_INCOMPATIBLE;
1186 }
1187
1188 static expression_t *parse_constant_expression(void)
1189 {
1190         expression_t *result = parse_sub_expression(PREC_CONDITIONAL);
1191
1192         if (!is_constant_expression(result)) {
1193                 errorf(&result->base.source_position,
1194                        "expression '%E' is not constant", result);
1195         }
1196
1197         return result;
1198 }
1199
1200 static expression_t *parse_assignment_expression(void)
1201 {
1202         return parse_sub_expression(PREC_ASSIGNMENT);
1203 }
1204
1205 static string_t parse_string_literals(void)
1206 {
1207         assert(token.type == T_STRING_LITERAL);
1208         string_t result = token.v.string;
1209
1210         next_token();
1211
1212         while (token.type == T_STRING_LITERAL) {
1213                 result = concat_strings(&result, &token.v.string);
1214                 next_token();
1215         }
1216
1217         return result;
1218 }
1219
1220 static const char *const gnu_attribute_names[GNU_AK_LAST] = {
1221         [GNU_AK_CONST]                  = "const",
1222         [GNU_AK_VOLATILE]               = "volatile",
1223         [GNU_AK_CDECL]                  = "cdecl",
1224         [GNU_AK_STDCALL]                = "stdcall",
1225         [GNU_AK_FASTCALL]               = "fastcall",
1226         [GNU_AK_DEPRECATED]             = "deprecated",
1227         [GNU_AK_NOINLINE]               = "noinline",
1228         [GNU_AK_RETURNS_TWICE]          = "returns_twice",
1229         [GNU_AK_NORETURN]               = "noreturn",
1230         [GNU_AK_NAKED]                  = "naked",
1231         [GNU_AK_PURE]                   = "pure",
1232         [GNU_AK_ALWAYS_INLINE]          = "always_inline",
1233         [GNU_AK_MALLOC]                 = "malloc",
1234         [GNU_AK_WEAK]                   = "weak",
1235         [GNU_AK_CONSTRUCTOR]            = "constructor",
1236         [GNU_AK_DESTRUCTOR]             = "destructor",
1237         [GNU_AK_NOTHROW]                = "nothrow",
1238         [GNU_AK_TRANSPARENT_UNION]      = "transparent_union",
1239         [GNU_AK_COMMON]                 = "common",
1240         [GNU_AK_NOCOMMON]               = "nocommon",
1241         [GNU_AK_PACKED]                 = "packed",
1242         [GNU_AK_SHARED]                 = "shared",
1243         [GNU_AK_NOTSHARED]              = "notshared",
1244         [GNU_AK_USED]                   = "used",
1245         [GNU_AK_UNUSED]                 = "unused",
1246         [GNU_AK_NO_INSTRUMENT_FUNCTION] = "no_instrument_function",
1247         [GNU_AK_WARN_UNUSED_RESULT]     = "warn_unused_result",
1248         [GNU_AK_LONGCALL]               = "longcall",
1249         [GNU_AK_SHORTCALL]              = "shortcall",
1250         [GNU_AK_LONG_CALL]              = "long_call",
1251         [GNU_AK_SHORT_CALL]             = "short_call",
1252         [GNU_AK_FUNCTION_VECTOR]        = "function_vector",
1253         [GNU_AK_INTERRUPT]              = "interrupt",
1254         [GNU_AK_INTERRUPT_HANDLER]      = "interrupt_handler",
1255         [GNU_AK_NMI_HANDLER]            = "nmi_handler",
1256         [GNU_AK_NESTING]                = "nesting",
1257         [GNU_AK_NEAR]                   = "near",
1258         [GNU_AK_FAR]                    = "far",
1259         [GNU_AK_SIGNAL]                 = "signal",
1260         [GNU_AK_EIGTHBIT_DATA]          = "eightbit_data",
1261         [GNU_AK_TINY_DATA]              = "tiny_data",
1262         [GNU_AK_SAVEALL]                = "saveall",
1263         [GNU_AK_FLATTEN]                = "flatten",
1264         [GNU_AK_SSEREGPARM]             = "sseregparm",
1265         [GNU_AK_EXTERNALLY_VISIBLE]     = "externally_visible",
1266         [GNU_AK_RETURN_TWICE]           = "return_twice",
1267         [GNU_AK_MAY_ALIAS]              = "may_alias",
1268         [GNU_AK_MS_STRUCT]              = "ms_struct",
1269         [GNU_AK_GCC_STRUCT]             = "gcc_struct",
1270         [GNU_AK_DLLIMPORT]              = "dllimport",
1271         [GNU_AK_DLLEXPORT]              = "dllexport",
1272         [GNU_AK_ALIGNED]                = "aligned",
1273         [GNU_AK_ALIAS]                  = "alias",
1274         [GNU_AK_SECTION]                = "section",
1275         [GNU_AK_FORMAT]                 = "format",
1276         [GNU_AK_FORMAT_ARG]             = "format_arg",
1277         [GNU_AK_WEAKREF]                = "weakref",
1278         [GNU_AK_NONNULL]                = "nonnull",
1279         [GNU_AK_TLS_MODEL]              = "tls_model",
1280         [GNU_AK_VISIBILITY]             = "visibility",
1281         [GNU_AK_REGPARM]                = "regparm",
1282         [GNU_AK_MODE]                   = "mode",
1283         [GNU_AK_MODEL]                  = "model",
1284         [GNU_AK_TRAP_EXIT]              = "trap_exit",
1285         [GNU_AK_SP_SWITCH]              = "sp_switch",
1286         [GNU_AK_SENTINEL]               = "sentinel"
1287 };
1288
1289 /**
1290  * compare two string, ignoring double underscores on the second.
1291  */
1292 static int strcmp_underscore(const char *s1, const char *s2)
1293 {
1294         if (s2[0] == '_' && s2[1] == '_') {
1295                 size_t len2 = strlen(s2);
1296                 size_t len1 = strlen(s1);
1297                 if (len1 == len2-4 && s2[len2-2] == '_' && s2[len2-1] == '_') {
1298                         return strncmp(s1, s2+2, len2-4);
1299                 }
1300         }
1301
1302         return strcmp(s1, s2);
1303 }
1304
1305 /**
1306  * Allocate a new gnu temporal attribute of given kind.
1307  */
1308 static gnu_attribute_t *allocate_gnu_attribute(gnu_attribute_kind_t kind)
1309 {
1310         gnu_attribute_t *attribute = obstack_alloc(&temp_obst, sizeof(*attribute));
1311         attribute->kind            = kind;
1312         attribute->next            = NULL;
1313         attribute->invalid         = false;
1314         attribute->has_arguments   = false;
1315
1316         return attribute;
1317 }
1318
1319 /**
1320  * Parse one constant expression argument of the given attribute.
1321  */
1322 static void parse_gnu_attribute_const_arg(gnu_attribute_t *attribute)
1323 {
1324         expression_t *expression;
1325         add_anchor_token(')');
1326         expression = parse_constant_expression();
1327         rem_anchor_token(')');
1328         expect(')', end_error);
1329         attribute->u.argument = fold_constant(expression);
1330         return;
1331 end_error:
1332         attribute->invalid = true;
1333 }
1334
1335 /**
1336  * Parse a list of constant expressions arguments of the given attribute.
1337  */
1338 static void parse_gnu_attribute_const_arg_list(gnu_attribute_t *attribute)
1339 {
1340         argument_list_t **list = &attribute->u.arguments;
1341         argument_list_t  *entry;
1342         expression_t     *expression;
1343         add_anchor_token(')');
1344         add_anchor_token(',');
1345         while (true) {
1346                 expression = parse_constant_expression();
1347                 entry = obstack_alloc(&temp_obst, sizeof(entry));
1348                 entry->argument = fold_constant(expression);
1349                 entry->next     = NULL;
1350                 *list = entry;
1351                 list = &entry->next;
1352                 if (token.type != ',')
1353                         break;
1354                 next_token();
1355         }
1356         rem_anchor_token(',');
1357         rem_anchor_token(')');
1358         expect(')', end_error);
1359         return;
1360 end_error:
1361         attribute->invalid = true;
1362 }
1363
1364 /**
1365  * Parse one string literal argument of the given attribute.
1366  */
1367 static void parse_gnu_attribute_string_arg(gnu_attribute_t *attribute,
1368                                            string_t *string)
1369 {
1370         add_anchor_token('(');
1371         if (token.type != T_STRING_LITERAL) {
1372                 parse_error_expected("while parsing attribute directive",
1373                                      T_STRING_LITERAL, NULL);
1374                 goto end_error;
1375         }
1376         *string = parse_string_literals();
1377         rem_anchor_token('(');
1378         expect(')', end_error);
1379         return;
1380 end_error:
1381         attribute->invalid = true;
1382 }
1383
1384 /**
1385  * Parse one tls model of the given attribute.
1386  */
1387 static void parse_gnu_attribute_tls_model_arg(gnu_attribute_t *attribute)
1388 {
1389         static const char *const tls_models[] = {
1390                 "global-dynamic",
1391                 "local-dynamic",
1392                 "initial-exec",
1393                 "local-exec"
1394         };
1395         string_t string = { NULL, 0 };
1396         parse_gnu_attribute_string_arg(attribute, &string);
1397         if (string.begin != NULL) {
1398                 for (size_t i = 0; i < 4; ++i) {
1399                         if (strcmp(tls_models[i], string.begin) == 0) {
1400                                 attribute->u.value = i;
1401                                 return;
1402                         }
1403                 }
1404                 errorf(HERE, "'%s' is an unrecognized tls model", string.begin);
1405         }
1406         attribute->invalid = true;
1407 }
1408
1409 /**
1410  * Parse one tls model of the given attribute.
1411  */
1412 static void parse_gnu_attribute_visibility_arg(gnu_attribute_t *attribute)
1413 {
1414         static const char *const visibilities[] = {
1415                 "default",
1416                 "protected",
1417                 "hidden",
1418                 "internal"
1419         };
1420         string_t string = { NULL, 0 };
1421         parse_gnu_attribute_string_arg(attribute, &string);
1422         if (string.begin != NULL) {
1423                 for (size_t i = 0; i < 4; ++i) {
1424                         if (strcmp(visibilities[i], string.begin) == 0) {
1425                                 attribute->u.value = i;
1426                                 return;
1427                         }
1428                 }
1429                 errorf(HERE, "'%s' is an unrecognized visibility", string.begin);
1430         }
1431         attribute->invalid = true;
1432 }
1433
1434 /**
1435  * Parse one (code) model of the given attribute.
1436  */
1437 static void parse_gnu_attribute_model_arg(gnu_attribute_t *attribute)
1438 {
1439         static const char *const visibilities[] = {
1440                 "small",
1441                 "medium",
1442                 "large"
1443         };
1444         string_t string = { NULL, 0 };
1445         parse_gnu_attribute_string_arg(attribute, &string);
1446         if (string.begin != NULL) {
1447                 for (int i = 0; i < 3; ++i) {
1448                         if (strcmp(visibilities[i], string.begin) == 0) {
1449                                 attribute->u.value = i;
1450                                 return;
1451                         }
1452                 }
1453                 errorf(HERE, "'%s' is an unrecognized model", string.begin);
1454         }
1455         attribute->invalid = true;
1456 }
1457
1458 /**
1459  * Parse one mode of the given attribute.
1460  */
1461 static void parse_gnu_attribute_mode_arg(gnu_attribute_t *attribute)
1462 {
1463         add_anchor_token(')');
1464
1465         if (token.type != T_IDENTIFIER) {
1466                 expect(T_IDENTIFIER, end_error);
1467         }
1468
1469         attribute->u.symbol = token.v.symbol;
1470         next_token();
1471
1472         rem_anchor_token(')');
1473         expect(')', end_error);
1474         return;
1475 end_error:
1476         attribute->invalid = true;
1477 }
1478
1479 /**
1480  * Parse one interrupt argument of the given attribute.
1481  */
1482 static void parse_gnu_attribute_interrupt_arg(gnu_attribute_t *attribute)
1483 {
1484         static const char *const interrupts[] = {
1485                 "IRQ",
1486                 "FIQ",
1487                 "SWI",
1488                 "ABORT",
1489                 "UNDEF"
1490         };
1491         string_t string = { NULL, 0 };
1492         parse_gnu_attribute_string_arg(attribute, &string);
1493         if (string.begin != NULL) {
1494                 for (size_t i = 0; i < 5; ++i) {
1495                         if (strcmp(interrupts[i], string.begin) == 0) {
1496                                 attribute->u.value = i;
1497                                 return;
1498                         }
1499                 }
1500                 errorf(HERE, "'%s' is not an interrupt", string.begin);
1501         }
1502         attribute->invalid = true;
1503 }
1504
1505 /**
1506  * Parse ( identifier, const expression, const expression )
1507  */
1508 static void parse_gnu_attribute_format_args(gnu_attribute_t *attribute)
1509 {
1510         static const char *const format_names[] = {
1511                 "printf",
1512                 "scanf",
1513                 "strftime",
1514                 "strfmon"
1515         };
1516         int i;
1517
1518         if (token.type != T_IDENTIFIER) {
1519                 parse_error_expected("while parsing format attribute directive", T_IDENTIFIER, NULL);
1520                 goto end_error;
1521         }
1522         const char *name = token.v.symbol->string;
1523         for (i = 0; i < 4; ++i) {
1524                 if (strcmp_underscore(format_names[i], name) == 0)
1525                         break;
1526         }
1527         if (i >= 4) {
1528                 if (warning.attribute)
1529                         warningf(HERE, "'%s' is an unrecognized format function type", name);
1530         }
1531         next_token();
1532
1533         expect(',', end_error);
1534         add_anchor_token(')');
1535         add_anchor_token(',');
1536         parse_constant_expression();
1537         rem_anchor_token(',');
1538         rem_anchor_token(')');
1539
1540         expect(',', end_error);
1541         add_anchor_token(')');
1542         parse_constant_expression();
1543         rem_anchor_token(')');
1544         expect(')', end_error);
1545         return;
1546 end_error:
1547         attribute->u.value = true;
1548 }
1549
1550 /**
1551  * Check that a given GNU attribute has no arguments.
1552  */
1553 static void check_no_argument(gnu_attribute_t *attribute, const char *name)
1554 {
1555         if (!attribute->has_arguments)
1556                 return;
1557
1558         /* should have no arguments */
1559         errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1560         eat_until_matching_token('(');
1561         /* we have already consumed '(', so we stop before ')', eat it */
1562         eat(')');
1563         attribute->invalid = true;
1564 }
1565
1566 /**
1567  * Parse one GNU attribute.
1568  *
1569  * Note that attribute names can be specified WITH or WITHOUT
1570  * double underscores, ie const or __const__.
1571  *
1572  * The following attributes are parsed without arguments
1573  *  const
1574  *  volatile
1575  *  cdecl
1576  *  stdcall
1577  *  fastcall
1578  *  deprecated
1579  *  noinline
1580  *  noreturn
1581  *  naked
1582  *  pure
1583  *  always_inline
1584  *  malloc
1585  *  weak
1586  *  constructor
1587  *  destructor
1588  *  nothrow
1589  *  transparent_union
1590  *  common
1591  *  nocommon
1592  *  packed
1593  *  shared
1594  *  notshared
1595  *  used
1596  *  unused
1597  *  no_instrument_function
1598  *  warn_unused_result
1599  *  longcall
1600  *  shortcall
1601  *  long_call
1602  *  short_call
1603  *  function_vector
1604  *  interrupt_handler
1605  *  nmi_handler
1606  *  nesting
1607  *  near
1608  *  far
1609  *  signal
1610  *  eightbit_data
1611  *  tiny_data
1612  *  saveall
1613  *  flatten
1614  *  sseregparm
1615  *  externally_visible
1616  *  return_twice
1617  *  may_alias
1618  *  ms_struct
1619  *  gcc_struct
1620  *  dllimport
1621  *  dllexport
1622  *
1623  * The following attributes are parsed with arguments
1624  *  aligned( const expression )
1625  *  alias( string literal )
1626  *  section( string literal )
1627  *  format( identifier, const expression, const expression )
1628  *  format_arg( const expression )
1629  *  tls_model( string literal )
1630  *  visibility( string literal )
1631  *  regparm( const expression )
1632  *  model( string leteral )
1633  *  trap_exit( const expression )
1634  *  sp_switch( string literal )
1635  *
1636  * The following attributes might have arguments
1637  *  weak_ref( string literal )
1638  *  non_null( const expression // ',' )
1639  *  interrupt( string literal )
1640  *  sentinel( constant expression )
1641  */
1642 static decl_modifiers_t parse_gnu_attribute(gnu_attribute_t **attributes)
1643 {
1644         gnu_attribute_t *head      = *attributes;
1645         gnu_attribute_t *last      = *attributes;
1646         decl_modifiers_t modifiers = 0;
1647         gnu_attribute_t *attribute;
1648
1649         eat(T___attribute__);
1650         expect('(', end_error);
1651         expect('(', end_error);
1652
1653         if (token.type != ')') {
1654                 /* find the end of the list */
1655                 if (last != NULL) {
1656                         while (last->next != NULL)
1657                                 last = last->next;
1658                 }
1659
1660                 /* non-empty attribute list */
1661                 while (true) {
1662                         const char *name;
1663                         if (token.type == T_const) {
1664                                 name = "const";
1665                         } else if (token.type == T_volatile) {
1666                                 name = "volatile";
1667                         } else if (token.type == T_cdecl) {
1668                                 /* __attribute__((cdecl)), WITH ms mode */
1669                                 name = "cdecl";
1670                         } else if (token.type == T_IDENTIFIER) {
1671                                 const symbol_t *sym = token.v.symbol;
1672                                 name = sym->string;
1673                         } else {
1674                                 parse_error_expected("while parsing GNU attribute", T_IDENTIFIER, NULL);
1675                                 break;
1676                         }
1677
1678                         next_token();
1679
1680                         int i;
1681                         for (i = 0; i < GNU_AK_LAST; ++i) {
1682                                 if (strcmp_underscore(gnu_attribute_names[i], name) == 0)
1683                                         break;
1684                         }
1685                         gnu_attribute_kind_t kind = (gnu_attribute_kind_t)i;
1686
1687                         attribute = NULL;
1688                         if (kind == GNU_AK_LAST) {
1689                                 if (warning.attribute)
1690                                         warningf(HERE, "'%s' attribute directive ignored", name);
1691
1692                                 /* skip possible arguments */
1693                                 if (token.type == '(') {
1694                                         eat_until_matching_token(')');
1695                                 }
1696                         } else {
1697                                 /* check for arguments */
1698                                 attribute = allocate_gnu_attribute(kind);
1699                                 if (token.type == '(') {
1700                                         next_token();
1701                                         if (token.type == ')') {
1702                                                 /* empty args are allowed */
1703                                                 next_token();
1704                                         } else
1705                                                 attribute->has_arguments = true;
1706                                 }
1707
1708                                 switch (kind) {
1709                                 case GNU_AK_VOLATILE:
1710                                 case GNU_AK_NAKED:
1711                                 case GNU_AK_MALLOC:
1712                                 case GNU_AK_WEAK:
1713                                 case GNU_AK_COMMON:
1714                                 case GNU_AK_NOCOMMON:
1715                                 case GNU_AK_SHARED:
1716                                 case GNU_AK_NOTSHARED:
1717                                 case GNU_AK_NO_INSTRUMENT_FUNCTION:
1718                                 case GNU_AK_WARN_UNUSED_RESULT:
1719                                 case GNU_AK_LONGCALL:
1720                                 case GNU_AK_SHORTCALL:
1721                                 case GNU_AK_LONG_CALL:
1722                                 case GNU_AK_SHORT_CALL:
1723                                 case GNU_AK_FUNCTION_VECTOR:
1724                                 case GNU_AK_INTERRUPT_HANDLER:
1725                                 case GNU_AK_NMI_HANDLER:
1726                                 case GNU_AK_NESTING:
1727                                 case GNU_AK_NEAR:
1728                                 case GNU_AK_FAR:
1729                                 case GNU_AK_SIGNAL:
1730                                 case GNU_AK_EIGTHBIT_DATA:
1731                                 case GNU_AK_TINY_DATA:
1732                                 case GNU_AK_SAVEALL:
1733                                 case GNU_AK_FLATTEN:
1734                                 case GNU_AK_SSEREGPARM:
1735                                 case GNU_AK_EXTERNALLY_VISIBLE:
1736                                 case GNU_AK_RETURN_TWICE:
1737                                 case GNU_AK_MAY_ALIAS:
1738                                 case GNU_AK_MS_STRUCT:
1739                                 case GNU_AK_GCC_STRUCT:
1740                                         goto no_arg;
1741
1742                                 case GNU_AK_CDECL:             modifiers |= DM_CDECL;             goto no_arg;
1743                                 case GNU_AK_FASTCALL:          modifiers |= DM_FASTCALL;          goto no_arg;
1744                                 case GNU_AK_STDCALL:           modifiers |= DM_STDCALL;           goto no_arg;
1745                                 case GNU_AK_UNUSED:            modifiers |= DM_UNUSED;            goto no_arg;
1746                                 case GNU_AK_USED:              modifiers |= DM_USED;              goto no_arg;
1747                                 case GNU_AK_PURE:              modifiers |= DM_PURE;              goto no_arg;
1748                                 case GNU_AK_CONST:             modifiers |= DM_CONST;             goto no_arg;
1749                                 case GNU_AK_ALWAYS_INLINE:     modifiers |= DM_FORCEINLINE;       goto no_arg;
1750                                 case GNU_AK_DLLIMPORT:         modifiers |= DM_DLLIMPORT;         goto no_arg;
1751                                 case GNU_AK_DLLEXPORT:         modifiers |= DM_DLLEXPORT;         goto no_arg;
1752                                 case GNU_AK_PACKED:            modifiers |= DM_PACKED;            goto no_arg;
1753                                 case GNU_AK_NOINLINE:          modifiers |= DM_NOINLINE;          goto no_arg;
1754                                 case GNU_AK_RETURNS_TWICE:     modifiers |= DM_RETURNS_TWICE;     goto no_arg;
1755                                 case GNU_AK_NORETURN:          modifiers |= DM_NORETURN;          goto no_arg;
1756                                 case GNU_AK_NOTHROW:           modifiers |= DM_NOTHROW;           goto no_arg;
1757                                 case GNU_AK_TRANSPARENT_UNION: modifiers |= DM_TRANSPARENT_UNION; goto no_arg;
1758                                 case GNU_AK_CONSTRUCTOR:       modifiers |= DM_CONSTRUCTOR;       goto no_arg;
1759                                 case GNU_AK_DESTRUCTOR:        modifiers |= DM_DESTRUCTOR;        goto no_arg;
1760                                 case GNU_AK_DEPRECATED:        modifiers |= DM_DEPRECATED;        goto no_arg;
1761
1762                                 case GNU_AK_ALIGNED:
1763                                         /* __align__ may be used without an argument */
1764                                         if (attribute->has_arguments) {
1765                                                 parse_gnu_attribute_const_arg(attribute);
1766                                         }
1767                                         break;
1768
1769                                 case GNU_AK_FORMAT_ARG:
1770                                 case GNU_AK_REGPARM:
1771                                 case GNU_AK_TRAP_EXIT:
1772                                         if (!attribute->has_arguments) {
1773                                                 /* should have arguments */
1774                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1775                                                 attribute->invalid = true;
1776                                         } else
1777                                                 parse_gnu_attribute_const_arg(attribute);
1778                                         break;
1779                                 case GNU_AK_ALIAS:
1780                                 case GNU_AK_SECTION:
1781                                 case GNU_AK_SP_SWITCH:
1782                                         if (!attribute->has_arguments) {
1783                                                 /* should have arguments */
1784                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1785                                                 attribute->invalid = true;
1786                                         } else
1787                                                 parse_gnu_attribute_string_arg(attribute, &attribute->u.string);
1788                                         break;
1789                                 case GNU_AK_FORMAT:
1790                                         if (!attribute->has_arguments) {
1791                                                 /* should have arguments */
1792                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1793                                                 attribute->invalid = true;
1794                                         } else
1795                                                 parse_gnu_attribute_format_args(attribute);
1796                                         break;
1797                                 case GNU_AK_WEAKREF:
1798                                         /* may have one string argument */
1799                                         if (attribute->has_arguments)
1800                                                 parse_gnu_attribute_string_arg(attribute, &attribute->u.string);
1801                                         break;
1802                                 case GNU_AK_NONNULL:
1803                                         if (attribute->has_arguments)
1804                                                 parse_gnu_attribute_const_arg_list(attribute);
1805                                         break;
1806                                 case GNU_AK_TLS_MODEL:
1807                                         if (!attribute->has_arguments) {
1808                                                 /* should have arguments */
1809                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1810                                         } else
1811                                                 parse_gnu_attribute_tls_model_arg(attribute);
1812                                         break;
1813                                 case GNU_AK_VISIBILITY:
1814                                         if (!attribute->has_arguments) {
1815                                                 /* should have arguments */
1816                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1817                                         } else
1818                                                 parse_gnu_attribute_visibility_arg(attribute);
1819                                         break;
1820                                 case GNU_AK_MODEL:
1821                                         if (!attribute->has_arguments) {
1822                                                 /* should have arguments */
1823                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1824                                         } else {
1825                                                 parse_gnu_attribute_model_arg(attribute);
1826                                         }
1827                                         break;
1828                                 case GNU_AK_MODE:
1829                                         if (!attribute->has_arguments) {
1830                                                 /* should have arguments */
1831                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1832                                         } else {
1833                                                 parse_gnu_attribute_mode_arg(attribute);
1834                                         }
1835                                         break;
1836                                 case GNU_AK_INTERRUPT:
1837                                         /* may have one string argument */
1838                                         if (attribute->has_arguments)
1839                                                 parse_gnu_attribute_interrupt_arg(attribute);
1840                                         break;
1841                                 case GNU_AK_SENTINEL:
1842                                         /* may have one string argument */
1843                                         if (attribute->has_arguments)
1844                                                 parse_gnu_attribute_const_arg(attribute);
1845                                         break;
1846                                 case GNU_AK_LAST:
1847                                         /* already handled */
1848                                         break;
1849
1850 no_arg:
1851                                         check_no_argument(attribute, name);
1852                                 }
1853                         }
1854                         if (attribute != NULL) {
1855                                 if (last != NULL) {
1856                                         last->next = attribute;
1857                                         last       = attribute;
1858                                 } else {
1859                                         head = last = attribute;
1860                                 }
1861                         }
1862
1863                         if (token.type != ',')
1864                                 break;
1865                         next_token();
1866                 }
1867         }
1868         expect(')', end_error);
1869         expect(')', end_error);
1870 end_error:
1871         *attributes = head;
1872
1873         return modifiers;
1874 }
1875
1876 /**
1877  * Parse GNU attributes.
1878  */
1879 static decl_modifiers_t parse_attributes(gnu_attribute_t **attributes)
1880 {
1881         decl_modifiers_t modifiers = 0;
1882
1883         while (true) {
1884                 switch (token.type) {
1885                 case T___attribute__:
1886                         modifiers |= parse_gnu_attribute(attributes);
1887                         continue;
1888
1889                 case T_asm:
1890                         next_token();
1891                         expect('(', end_error);
1892                         if (token.type != T_STRING_LITERAL) {
1893                                 parse_error_expected("while parsing assembler attribute",
1894                                                      T_STRING_LITERAL, NULL);
1895                                 eat_until_matching_token('(');
1896                                 break;
1897                         } else {
1898                                 parse_string_literals();
1899                         }
1900                         expect(')', end_error);
1901                         continue;
1902
1903                 case T_cdecl:     modifiers |= DM_CDECL;    break;
1904                 case T__fastcall: modifiers |= DM_FASTCALL; break;
1905                 case T__stdcall:  modifiers |= DM_STDCALL;  break;
1906
1907                 case T___thiscall:
1908                         /* TODO record modifier */
1909                         if (warning.other)
1910                                 warningf(HERE, "Ignoring declaration modifier %K", &token);
1911                         break;
1912
1913 end_error:
1914                 default: return modifiers;
1915                 }
1916
1917                 next_token();
1918         }
1919 }
1920
1921 static void mark_vars_read(expression_t *expr, entity_t *lhs_ent);
1922
1923 static entity_t *determine_lhs_ent(expression_t *const expr,
1924                                    entity_t *lhs_ent)
1925 {
1926         switch (expr->kind) {
1927                 case EXPR_REFERENCE: {
1928                         entity_t *const entity = expr->reference.entity;
1929                         /* we should only find variables as lvalues... */
1930                         if (entity->base.kind != ENTITY_VARIABLE
1931                                         && entity->base.kind != ENTITY_PARAMETER)
1932                                 return NULL;
1933
1934                         return entity;
1935                 }
1936
1937                 case EXPR_ARRAY_ACCESS: {
1938                         expression_t *const ref = expr->array_access.array_ref;
1939                         entity_t     *      ent = NULL;
1940                         if (is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1941                                 ent     = determine_lhs_ent(ref, lhs_ent);
1942                                 lhs_ent = ent;
1943                         } else {
1944                                 mark_vars_read(expr->select.compound, lhs_ent);
1945                         }
1946                         mark_vars_read(expr->array_access.index, lhs_ent);
1947                         return ent;
1948                 }
1949
1950                 case EXPR_SELECT: {
1951                         if (is_type_compound(skip_typeref(expr->base.type))) {
1952                                 return determine_lhs_ent(expr->select.compound, lhs_ent);
1953                         } else {
1954                                 mark_vars_read(expr->select.compound, lhs_ent);
1955                                 return NULL;
1956                         }
1957                 }
1958
1959                 case EXPR_UNARY_DEREFERENCE: {
1960                         expression_t *const val = expr->unary.value;
1961                         if (val->kind == EXPR_UNARY_TAKE_ADDRESS) {
1962                                 /* *&x is a NOP */
1963                                 return determine_lhs_ent(val->unary.value, lhs_ent);
1964                         } else {
1965                                 mark_vars_read(val, NULL);
1966                                 return NULL;
1967                         }
1968                 }
1969
1970                 default:
1971                         mark_vars_read(expr, NULL);
1972                         return NULL;
1973         }
1974 }
1975
1976 #define ENT_ANY ((entity_t*)-1)
1977
1978 /**
1979  * Mark declarations, which are read.  This is used to detect variables, which
1980  * are never read.
1981  * Example:
1982  * x = x + 1;
1983  *   x is not marked as "read", because it is only read to calculate its own new
1984  *   value.
1985  *
1986  * x += y; y += x;
1987  *   x and y are not detected as "not read", because multiple variables are
1988  *   involved.
1989  */
1990 static void mark_vars_read(expression_t *const expr, entity_t *lhs_ent)
1991 {
1992         switch (expr->kind) {
1993                 case EXPR_REFERENCE: {
1994                         entity_t *const entity = expr->reference.entity;
1995                         if (entity->kind != ENTITY_VARIABLE
1996                                         && entity->kind != ENTITY_PARAMETER)
1997                                 return;
1998
1999                         if (lhs_ent != entity && lhs_ent != ENT_ANY) {
2000                                 if (entity->kind == ENTITY_VARIABLE) {
2001                                         entity->variable.read = true;
2002                                 } else {
2003                                         entity->parameter.read = true;
2004                                 }
2005                         }
2006                         return;
2007                 }
2008
2009                 case EXPR_CALL:
2010                         // TODO respect pure/const
2011                         mark_vars_read(expr->call.function, NULL);
2012                         for (call_argument_t *arg = expr->call.arguments; arg != NULL; arg = arg->next) {
2013                                 mark_vars_read(arg->expression, NULL);
2014                         }
2015                         return;
2016
2017                 case EXPR_CONDITIONAL:
2018                         // TODO lhs_decl should depend on whether true/false have an effect
2019                         mark_vars_read(expr->conditional.condition, NULL);
2020                         if (expr->conditional.true_expression != NULL)
2021                                 mark_vars_read(expr->conditional.true_expression, lhs_ent);
2022                         mark_vars_read(expr->conditional.false_expression, lhs_ent);
2023                         return;
2024
2025                 case EXPR_SELECT:
2026                         if (lhs_ent == ENT_ANY
2027                                         && !is_type_compound(skip_typeref(expr->base.type)))
2028                                 lhs_ent = NULL;
2029                         mark_vars_read(expr->select.compound, lhs_ent);
2030                         return;
2031
2032                 case EXPR_ARRAY_ACCESS: {
2033                         expression_t *const ref = expr->array_access.array_ref;
2034                         mark_vars_read(ref, lhs_ent);
2035                         lhs_ent = determine_lhs_ent(ref, lhs_ent);
2036                         mark_vars_read(expr->array_access.index, lhs_ent);
2037                         return;
2038                 }
2039
2040                 case EXPR_VA_ARG:
2041                         mark_vars_read(expr->va_arge.ap, lhs_ent);
2042                         return;
2043
2044                 case EXPR_UNARY_CAST:
2045                         /* Special case: Use void cast to mark a variable as "read" */
2046                         if (is_type_atomic(skip_typeref(expr->base.type), ATOMIC_TYPE_VOID))
2047                                 lhs_ent = NULL;
2048                         goto unary;
2049
2050
2051                 case EXPR_UNARY_THROW:
2052                         if (expr->unary.value == NULL)
2053                                 return;
2054                         /* FALLTHROUGH */
2055                 case EXPR_UNARY_DEREFERENCE:
2056                 case EXPR_UNARY_DELETE:
2057                 case EXPR_UNARY_DELETE_ARRAY:
2058                         if (lhs_ent == ENT_ANY)
2059                                 lhs_ent = NULL;
2060                         goto unary;
2061
2062                 case EXPR_UNARY_NEGATE:
2063                 case EXPR_UNARY_PLUS:
2064                 case EXPR_UNARY_BITWISE_NEGATE:
2065                 case EXPR_UNARY_NOT:
2066                 case EXPR_UNARY_TAKE_ADDRESS:
2067                 case EXPR_UNARY_POSTFIX_INCREMENT:
2068                 case EXPR_UNARY_POSTFIX_DECREMENT:
2069                 case EXPR_UNARY_PREFIX_INCREMENT:
2070                 case EXPR_UNARY_PREFIX_DECREMENT:
2071                 case EXPR_UNARY_CAST_IMPLICIT:
2072                 case EXPR_UNARY_ASSUME:
2073 unary:
2074                         mark_vars_read(expr->unary.value, lhs_ent);
2075                         return;
2076
2077                 case EXPR_BINARY_ADD:
2078                 case EXPR_BINARY_SUB:
2079                 case EXPR_BINARY_MUL:
2080                 case EXPR_BINARY_DIV:
2081                 case EXPR_BINARY_MOD:
2082                 case EXPR_BINARY_EQUAL:
2083                 case EXPR_BINARY_NOTEQUAL:
2084                 case EXPR_BINARY_LESS:
2085                 case EXPR_BINARY_LESSEQUAL:
2086                 case EXPR_BINARY_GREATER:
2087                 case EXPR_BINARY_GREATEREQUAL:
2088                 case EXPR_BINARY_BITWISE_AND:
2089                 case EXPR_BINARY_BITWISE_OR:
2090                 case EXPR_BINARY_BITWISE_XOR:
2091                 case EXPR_BINARY_LOGICAL_AND:
2092                 case EXPR_BINARY_LOGICAL_OR:
2093                 case EXPR_BINARY_SHIFTLEFT:
2094                 case EXPR_BINARY_SHIFTRIGHT:
2095                 case EXPR_BINARY_COMMA:
2096                 case EXPR_BINARY_ISGREATER:
2097                 case EXPR_BINARY_ISGREATEREQUAL:
2098                 case EXPR_BINARY_ISLESS:
2099                 case EXPR_BINARY_ISLESSEQUAL:
2100                 case EXPR_BINARY_ISLESSGREATER:
2101                 case EXPR_BINARY_ISUNORDERED:
2102                         mark_vars_read(expr->binary.left,  lhs_ent);
2103                         mark_vars_read(expr->binary.right, lhs_ent);
2104                         return;
2105
2106                 case EXPR_BINARY_ASSIGN:
2107                 case EXPR_BINARY_MUL_ASSIGN:
2108                 case EXPR_BINARY_DIV_ASSIGN:
2109                 case EXPR_BINARY_MOD_ASSIGN:
2110                 case EXPR_BINARY_ADD_ASSIGN:
2111                 case EXPR_BINARY_SUB_ASSIGN:
2112                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:
2113                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:
2114                 case EXPR_BINARY_BITWISE_AND_ASSIGN:
2115                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:
2116                 case EXPR_BINARY_BITWISE_OR_ASSIGN: {
2117                         if (lhs_ent == ENT_ANY)
2118                                 lhs_ent = NULL;
2119                         lhs_ent = determine_lhs_ent(expr->binary.left, lhs_ent);
2120                         mark_vars_read(expr->binary.right, lhs_ent);
2121                         return;
2122                 }
2123
2124                 case EXPR_VA_START:
2125                         determine_lhs_ent(expr->va_starte.ap, lhs_ent);
2126                         return;
2127
2128                 case EXPR_UNKNOWN:
2129                 case EXPR_INVALID:
2130                 case EXPR_CONST:
2131                 case EXPR_CHARACTER_CONSTANT:
2132                 case EXPR_WIDE_CHARACTER_CONSTANT:
2133                 case EXPR_STRING_LITERAL:
2134                 case EXPR_WIDE_STRING_LITERAL:
2135                 case EXPR_COMPOUND_LITERAL: // TODO init?
2136                 case EXPR_SIZEOF:
2137                 case EXPR_CLASSIFY_TYPE:
2138                 case EXPR_ALIGNOF:
2139                 case EXPR_FUNCNAME:
2140                 case EXPR_BUILTIN_SYMBOL:
2141                 case EXPR_BUILTIN_CONSTANT_P:
2142                 case EXPR_BUILTIN_PREFETCH:
2143                 case EXPR_OFFSETOF:
2144                 case EXPR_STATEMENT: // TODO
2145                 case EXPR_LABEL_ADDRESS:
2146                 case EXPR_REFERENCE_ENUM_VALUE:
2147                         return;
2148         }
2149
2150         panic("unhandled expression");
2151 }
2152
2153 static designator_t *parse_designation(void)
2154 {
2155         designator_t *result = NULL;
2156         designator_t *last   = NULL;
2157
2158         while (true) {
2159                 designator_t *designator;
2160                 switch (token.type) {
2161                 case '[':
2162                         designator = allocate_ast_zero(sizeof(designator[0]));
2163                         designator->source_position = token.source_position;
2164                         next_token();
2165                         add_anchor_token(']');
2166                         designator->array_index = parse_constant_expression();
2167                         rem_anchor_token(']');
2168                         expect(']', end_error);
2169                         break;
2170                 case '.':
2171                         designator = allocate_ast_zero(sizeof(designator[0]));
2172                         designator->source_position = token.source_position;
2173                         next_token();
2174                         if (token.type != T_IDENTIFIER) {
2175                                 parse_error_expected("while parsing designator",
2176                                                      T_IDENTIFIER, NULL);
2177                                 return NULL;
2178                         }
2179                         designator->symbol = token.v.symbol;
2180                         next_token();
2181                         break;
2182                 default:
2183                         expect('=', end_error);
2184                         return result;
2185                 }
2186
2187                 assert(designator != NULL);
2188                 if (last != NULL) {
2189                         last->next = designator;
2190                 } else {
2191                         result = designator;
2192                 }
2193                 last = designator;
2194         }
2195 end_error:
2196         return NULL;
2197 }
2198
2199 static initializer_t *initializer_from_string(array_type_t *type,
2200                                               const string_t *const string)
2201 {
2202         /* TODO: check len vs. size of array type */
2203         (void) type;
2204
2205         initializer_t *initializer = allocate_initializer_zero(INITIALIZER_STRING);
2206         initializer->string.string = *string;
2207
2208         return initializer;
2209 }
2210
2211 static initializer_t *initializer_from_wide_string(array_type_t *const type,
2212                                                    wide_string_t *const string)
2213 {
2214         /* TODO: check len vs. size of array type */
2215         (void) type;
2216
2217         initializer_t *const initializer =
2218                 allocate_initializer_zero(INITIALIZER_WIDE_STRING);
2219         initializer->wide_string.string = *string;
2220
2221         return initializer;
2222 }
2223
2224 /**
2225  * Build an initializer from a given expression.
2226  */
2227 static initializer_t *initializer_from_expression(type_t *orig_type,
2228                                                   expression_t *expression)
2229 {
2230         /* TODO check that expression is a constant expression */
2231
2232         /* § 6.7.8.14/15 char array may be initialized by string literals */
2233         type_t *type           = skip_typeref(orig_type);
2234         type_t *expr_type_orig = expression->base.type;
2235         type_t *expr_type      = skip_typeref(expr_type_orig);
2236         if (is_type_array(type) && expr_type->kind == TYPE_POINTER) {
2237                 array_type_t *const array_type   = &type->array;
2238                 type_t       *const element_type = skip_typeref(array_type->element_type);
2239
2240                 if (element_type->kind == TYPE_ATOMIC) {
2241                         atomic_type_kind_t akind = element_type->atomic.akind;
2242                         switch (expression->kind) {
2243                                 case EXPR_STRING_LITERAL:
2244                                         if (akind == ATOMIC_TYPE_CHAR
2245                                                         || akind == ATOMIC_TYPE_SCHAR
2246                                                         || akind == ATOMIC_TYPE_UCHAR) {
2247                                                 return initializer_from_string(array_type,
2248                                                         &expression->string.value);
2249                                         }
2250                                         break;
2251
2252                                 case EXPR_WIDE_STRING_LITERAL: {
2253                                         type_t *bare_wchar_type = skip_typeref(type_wchar_t);
2254                                         if (get_unqualified_type(element_type) == bare_wchar_type) {
2255                                                 return initializer_from_wide_string(array_type,
2256                                                         &expression->wide_string.value);
2257                                         }
2258                                         break;
2259                                 }
2260
2261                                 default:
2262                                         break;
2263                         }
2264                 }
2265         }
2266
2267         assign_error_t error = semantic_assign(type, expression);
2268         if (error == ASSIGN_ERROR_INCOMPATIBLE)
2269                 return NULL;
2270         report_assign_error(error, type, expression, "initializer",
2271                             &expression->base.source_position);
2272
2273         initializer_t *const result = allocate_initializer_zero(INITIALIZER_VALUE);
2274 #if 0
2275         if (type->kind == TYPE_BITFIELD) {
2276                 type = type->bitfield.base_type;
2277         }
2278 #endif
2279         result->value.value = create_implicit_cast(expression, type);
2280
2281         return result;
2282 }
2283
2284 /**
2285  * Checks if a given expression can be used as an constant initializer.
2286  */
2287 static bool is_initializer_constant(const expression_t *expression)
2288 {
2289         return is_constant_expression(expression)
2290                 || is_address_constant(expression);
2291 }
2292
2293 /**
2294  * Parses an scalar initializer.
2295  *
2296  * § 6.7.8.11; eat {} without warning
2297  */
2298 static initializer_t *parse_scalar_initializer(type_t *type,
2299                                                bool must_be_constant)
2300 {
2301         /* there might be extra {} hierarchies */
2302         int braces = 0;
2303         if (token.type == '{') {
2304                 if (warning.other)
2305                         warningf(HERE, "extra curly braces around scalar initializer");
2306                 do {
2307                         ++braces;
2308                         next_token();
2309                 } while (token.type == '{');
2310         }
2311
2312         expression_t *expression = parse_assignment_expression();
2313         mark_vars_read(expression, NULL);
2314         if (must_be_constant && !is_initializer_constant(expression)) {
2315                 errorf(&expression->base.source_position,
2316                        "Initialisation expression '%E' is not constant",
2317                        expression);
2318         }
2319
2320         initializer_t *initializer = initializer_from_expression(type, expression);
2321
2322         if (initializer == NULL) {
2323                 errorf(&expression->base.source_position,
2324                        "expression '%E' (type '%T') doesn't match expected type '%T'",
2325                        expression, expression->base.type, type);
2326                 /* TODO */
2327                 return NULL;
2328         }
2329
2330         bool additional_warning_displayed = false;
2331         while (braces > 0) {
2332                 if (token.type == ',') {
2333                         next_token();
2334                 }
2335                 if (token.type != '}') {
2336                         if (!additional_warning_displayed && warning.other) {
2337                                 warningf(HERE, "additional elements in scalar initializer");
2338                                 additional_warning_displayed = true;
2339                         }
2340                 }
2341                 eat_block();
2342                 braces--;
2343         }
2344
2345         return initializer;
2346 }
2347
2348 /**
2349  * An entry in the type path.
2350  */
2351 typedef struct type_path_entry_t type_path_entry_t;
2352 struct type_path_entry_t {
2353         type_t *type;       /**< the upper top type. restored to path->top_tye if this entry is popped. */
2354         union {
2355                 size_t         index;          /**< For array types: the current index. */
2356                 declaration_t *compound_entry; /**< For compound types: the current declaration. */
2357         } v;
2358 };
2359
2360 /**
2361  * A type path expression a position inside compound or array types.
2362  */
2363 typedef struct type_path_t type_path_t;
2364 struct type_path_t {
2365         type_path_entry_t *path;         /**< An flexible array containing the current path. */
2366         type_t            *top_type;     /**< type of the element the path points */
2367         size_t             max_index;    /**< largest index in outermost array */
2368 };
2369
2370 /**
2371  * Prints a type path for debugging.
2372  */
2373 static __attribute__((unused)) void debug_print_type_path(
2374                 const type_path_t *path)
2375 {
2376         size_t len = ARR_LEN(path->path);
2377
2378         for (size_t i = 0; i < len; ++i) {
2379                 const type_path_entry_t *entry = & path->path[i];
2380
2381                 type_t *type = skip_typeref(entry->type);
2382                 if (is_type_compound(type)) {
2383                         /* in gcc mode structs can have no members */
2384                         if (entry->v.compound_entry == NULL) {
2385                                 assert(i == len-1);
2386                                 continue;
2387                         }
2388                         fprintf(stderr, ".%s",
2389                                 entry->v.compound_entry->base.symbol->string);
2390                 } else if (is_type_array(type)) {
2391                         fprintf(stderr, "[%u]", (unsigned) entry->v.index);
2392                 } else {
2393                         fprintf(stderr, "-INVALID-");
2394                 }
2395         }
2396         if (path->top_type != NULL) {
2397                 fprintf(stderr, "  (");
2398                 print_type(path->top_type);
2399                 fprintf(stderr, ")");
2400         }
2401 }
2402
2403 /**
2404  * Return the top type path entry, ie. in a path
2405  * (type).a.b returns the b.
2406  */
2407 static type_path_entry_t *get_type_path_top(const type_path_t *path)
2408 {
2409         size_t len = ARR_LEN(path->path);
2410         assert(len > 0);
2411         return &path->path[len-1];
2412 }
2413
2414 /**
2415  * Enlarge the type path by an (empty) element.
2416  */
2417 static type_path_entry_t *append_to_type_path(type_path_t *path)
2418 {
2419         size_t len = ARR_LEN(path->path);
2420         ARR_RESIZE(type_path_entry_t, path->path, len+1);
2421
2422         type_path_entry_t *result = & path->path[len];
2423         memset(result, 0, sizeof(result[0]));
2424         return result;
2425 }
2426
2427 /**
2428  * Descending into a sub-type. Enter the scope of the current top_type.
2429  */
2430 static void descend_into_subtype(type_path_t *path)
2431 {
2432         type_t *orig_top_type = path->top_type;
2433         type_t *top_type      = skip_typeref(orig_top_type);
2434
2435         type_path_entry_t *top = append_to_type_path(path);
2436         top->type              = top_type;
2437
2438         if (is_type_compound(top_type)) {
2439                 compound_t *compound  = top_type->compound.compound;
2440                 entity_t   *entry     = compound->members.entities;
2441
2442                 if (entry != NULL) {
2443                         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
2444                         top->v.compound_entry = &entry->declaration;
2445                         path->top_type = entry->declaration.type;
2446                 } else {
2447                         path->top_type = NULL;
2448                 }
2449         } else if (is_type_array(top_type)) {
2450                 top->v.index   = 0;
2451                 path->top_type = top_type->array.element_type;
2452         } else {
2453                 assert(!is_type_valid(top_type));
2454         }
2455 }
2456
2457 /**
2458  * Pop an entry from the given type path, ie. returning from
2459  * (type).a.b to (type).a
2460  */
2461 static void ascend_from_subtype(type_path_t *path)
2462 {
2463         type_path_entry_t *top = get_type_path_top(path);
2464
2465         path->top_type = top->type;
2466
2467         size_t len = ARR_LEN(path->path);
2468         ARR_RESIZE(type_path_entry_t, path->path, len-1);
2469 }
2470
2471 /**
2472  * Pop entries from the given type path until the given
2473  * path level is reached.
2474  */
2475 static void ascend_to(type_path_t *path, size_t top_path_level)
2476 {
2477         size_t len = ARR_LEN(path->path);
2478
2479         while (len > top_path_level) {
2480                 ascend_from_subtype(path);
2481                 len = ARR_LEN(path->path);
2482         }
2483 }
2484
2485 static bool walk_designator(type_path_t *path, const designator_t *designator,
2486                             bool used_in_offsetof)
2487 {
2488         for (; designator != NULL; designator = designator->next) {
2489                 type_path_entry_t *top       = get_type_path_top(path);
2490                 type_t            *orig_type = top->type;
2491
2492                 type_t *type = skip_typeref(orig_type);
2493
2494                 if (designator->symbol != NULL) {
2495                         symbol_t *symbol = designator->symbol;
2496                         if (!is_type_compound(type)) {
2497                                 if (is_type_valid(type)) {
2498                                         errorf(&designator->source_position,
2499                                                "'.%Y' designator used for non-compound type '%T'",
2500                                                symbol, orig_type);
2501                                 }
2502
2503                                 top->type             = type_error_type;
2504                                 top->v.compound_entry = NULL;
2505                                 orig_type             = type_error_type;
2506                         } else {
2507                                 compound_t *compound = type->compound.compound;
2508                                 entity_t   *iter     = compound->members.entities;
2509                                 for (; iter != NULL; iter = iter->base.next) {
2510                                         if (iter->base.symbol == symbol) {
2511                                                 break;
2512                                         }
2513                                 }
2514                                 if (iter == NULL) {
2515                                         errorf(&designator->source_position,
2516                                                "'%T' has no member named '%Y'", orig_type, symbol);
2517                                         goto failed;
2518                                 }
2519                                 assert(iter->kind == ENTITY_COMPOUND_MEMBER);
2520                                 if (used_in_offsetof) {
2521                                         type_t *real_type = skip_typeref(iter->declaration.type);
2522                                         if (real_type->kind == TYPE_BITFIELD) {
2523                                                 errorf(&designator->source_position,
2524                                                        "offsetof designator '%Y' may not specify bitfield",
2525                                                        symbol);
2526                                                 goto failed;
2527                                         }
2528                                 }
2529
2530                                 top->type             = orig_type;
2531                                 top->v.compound_entry = &iter->declaration;
2532                                 orig_type             = iter->declaration.type;
2533                         }
2534                 } else {
2535                         expression_t *array_index = designator->array_index;
2536                         assert(designator->array_index != NULL);
2537
2538                         if (!is_type_array(type)) {
2539                                 if (is_type_valid(type)) {
2540                                         errorf(&designator->source_position,
2541                                                "[%E] designator used for non-array type '%T'",
2542                                                array_index, orig_type);
2543                                 }
2544                                 goto failed;
2545                         }
2546
2547                         long index = fold_constant(array_index);
2548                         if (!used_in_offsetof) {
2549                                 if (index < 0) {
2550                                         errorf(&designator->source_position,
2551                                                "array index [%E] must be positive", array_index);
2552                                 } else if (type->array.size_constant) {
2553                                         long array_size = type->array.size;
2554                                         if (index >= array_size) {
2555                                                 errorf(&designator->source_position,
2556                                                        "designator [%E] (%d) exceeds array size %d",
2557                                                        array_index, index, array_size);
2558                                         }
2559                                 }
2560                         }
2561
2562                         top->type    = orig_type;
2563                         top->v.index = (size_t) index;
2564                         orig_type    = type->array.element_type;
2565                 }
2566                 path->top_type = orig_type;
2567
2568                 if (designator->next != NULL) {
2569                         descend_into_subtype(path);
2570                 }
2571         }
2572         return true;
2573
2574 failed:
2575         return false;
2576 }
2577
2578 static void advance_current_object(type_path_t *path, size_t top_path_level)
2579 {
2580         type_path_entry_t *top = get_type_path_top(path);
2581
2582         type_t *type = skip_typeref(top->type);
2583         if (is_type_union(type)) {
2584                 /* in unions only the first element is initialized */
2585                 top->v.compound_entry = NULL;
2586         } else if (is_type_struct(type)) {
2587                 declaration_t *entry = top->v.compound_entry;
2588
2589                 entity_t *next_entity = entry->base.next;
2590                 if (next_entity != NULL) {
2591                         assert(is_declaration(next_entity));
2592                         entry = &next_entity->declaration;
2593                 } else {
2594                         entry = NULL;
2595                 }
2596
2597                 top->v.compound_entry = entry;
2598                 if (entry != NULL) {
2599                         path->top_type = entry->type;
2600                         return;
2601                 }
2602         } else if (is_type_array(type)) {
2603                 assert(is_type_array(type));
2604
2605                 top->v.index++;
2606
2607                 if (!type->array.size_constant || top->v.index < type->array.size) {
2608                         return;
2609                 }
2610         } else {
2611                 assert(!is_type_valid(type));
2612                 return;
2613         }
2614
2615         /* we're past the last member of the current sub-aggregate, try if we
2616          * can ascend in the type hierarchy and continue with another subobject */
2617         size_t len = ARR_LEN(path->path);
2618
2619         if (len > top_path_level) {
2620                 ascend_from_subtype(path);
2621                 advance_current_object(path, top_path_level);
2622         } else {
2623                 path->top_type = NULL;
2624         }
2625 }
2626
2627 /**
2628  * skip until token is found.
2629  */
2630 static void skip_until(int type)
2631 {
2632         while (token.type != type) {
2633                 if (token.type == T_EOF)
2634                         return;
2635                 next_token();
2636         }
2637 }
2638
2639 /**
2640  * skip any {...} blocks until a closing bracket is reached.
2641  */
2642 static void skip_initializers(void)
2643 {
2644         if (token.type == '{')
2645                 next_token();
2646
2647         while (token.type != '}') {
2648                 if (token.type == T_EOF)
2649                         return;
2650                 if (token.type == '{') {
2651                         eat_block();
2652                         continue;
2653                 }
2654                 next_token();
2655         }
2656 }
2657
2658 static initializer_t *create_empty_initializer(void)
2659 {
2660         static initializer_t empty_initializer
2661                 = { .list = { { INITIALIZER_LIST }, 0 } };
2662         return &empty_initializer;
2663 }
2664
2665 /**
2666  * Parse a part of an initialiser for a struct or union,
2667  */
2668 static initializer_t *parse_sub_initializer(type_path_t *path,
2669                 type_t *outer_type, size_t top_path_level,
2670                 parse_initializer_env_t *env)
2671 {
2672         if (token.type == '}') {
2673                 /* empty initializer */
2674                 return create_empty_initializer();
2675         }
2676
2677         type_t *orig_type = path->top_type;
2678         type_t *type      = NULL;
2679
2680         if (orig_type == NULL) {
2681                 /* We are initializing an empty compound. */
2682         } else {
2683                 type = skip_typeref(orig_type);
2684         }
2685
2686         initializer_t **initializers = NEW_ARR_F(initializer_t*, 0);
2687
2688         while (true) {
2689                 designator_t *designator = NULL;
2690                 if (token.type == '.' || token.type == '[') {
2691                         designator = parse_designation();
2692                         goto finish_designator;
2693                 } else if (token.type == T_IDENTIFIER && look_ahead(1)->type == ':') {
2694                         /* GNU-style designator ("identifier: value") */
2695                         designator = allocate_ast_zero(sizeof(designator[0]));
2696                         designator->source_position = token.source_position;
2697                         designator->symbol          = token.v.symbol;
2698                         eat(T_IDENTIFIER);
2699                         eat(':');
2700
2701 finish_designator:
2702                         /* reset path to toplevel, evaluate designator from there */
2703                         ascend_to(path, top_path_level);
2704                         if (!walk_designator(path, designator, false)) {
2705                                 /* can't continue after designation error */
2706                                 goto end_error;
2707                         }
2708
2709                         initializer_t *designator_initializer
2710                                 = allocate_initializer_zero(INITIALIZER_DESIGNATOR);
2711                         designator_initializer->designator.designator = designator;
2712                         ARR_APP1(initializer_t*, initializers, designator_initializer);
2713
2714                         orig_type = path->top_type;
2715                         type      = orig_type != NULL ? skip_typeref(orig_type) : NULL;
2716                 }
2717
2718                 initializer_t *sub;
2719
2720                 if (token.type == '{') {
2721                         if (type != NULL && is_type_scalar(type)) {
2722                                 sub = parse_scalar_initializer(type, env->must_be_constant);
2723                         } else {
2724                                 eat('{');
2725                                 if (type == NULL) {
2726                                         if (env->entity != NULL) {
2727                                                 errorf(HERE,
2728                                                      "extra brace group at end of initializer for '%Y'",
2729                                                      env->entity->base.symbol);
2730                                         } else {
2731                                                 errorf(HERE, "extra brace group at end of initializer");
2732                                         }
2733                                 } else
2734                                         descend_into_subtype(path);
2735
2736                                 add_anchor_token('}');
2737                                 sub = parse_sub_initializer(path, orig_type, top_path_level+1,
2738                                                             env);
2739                                 rem_anchor_token('}');
2740
2741                                 if (type != NULL) {
2742                                         ascend_from_subtype(path);
2743                                         expect('}', end_error);
2744                                 } else {
2745                                         expect('}', end_error);
2746                                         goto error_parse_next;
2747                                 }
2748                         }
2749                 } else {
2750                         /* must be an expression */
2751                         expression_t *expression = parse_assignment_expression();
2752                         mark_vars_read(expression, NULL);
2753
2754                         if (env->must_be_constant && !is_initializer_constant(expression)) {
2755                                 errorf(&expression->base.source_position,
2756                                        "Initialisation expression '%E' is not constant",
2757                                        expression);
2758                         }
2759
2760                         if (type == NULL) {
2761                                 /* we are already outside, ... */
2762                                 type_t *const outer_type_skip = skip_typeref(outer_type);
2763                                 if (is_type_compound(outer_type_skip) &&
2764                                     !outer_type_skip->compound.compound->complete) {
2765                                         goto error_parse_next;
2766                                 }
2767                                 goto error_excess;
2768                         }
2769
2770                         /* handle { "string" } special case */
2771                         if ((expression->kind == EXPR_STRING_LITERAL
2772                                         || expression->kind == EXPR_WIDE_STRING_LITERAL)
2773                                         && outer_type != NULL) {
2774                                 sub = initializer_from_expression(outer_type, expression);
2775                                 if (sub != NULL) {
2776                                         if (token.type == ',') {
2777                                                 next_token();
2778                                         }
2779                                         if (token.type != '}' && warning.other) {
2780                                                 warningf(HERE, "excessive elements in initializer for type '%T'",
2781                                                                  orig_type);
2782                                         }
2783                                         /* TODO: eat , ... */
2784                                         return sub;
2785                                 }
2786                         }
2787
2788                         /* descend into subtypes until expression matches type */
2789                         while (true) {
2790                                 orig_type = path->top_type;
2791                                 type      = skip_typeref(orig_type);
2792
2793                                 sub = initializer_from_expression(orig_type, expression);
2794                                 if (sub != NULL) {
2795                                         break;
2796                                 }
2797                                 if (!is_type_valid(type)) {
2798                                         goto end_error;
2799                                 }
2800                                 if (is_type_scalar(type)) {
2801                                         errorf(&expression->base.source_position,
2802                                                         "expression '%E' doesn't match expected type '%T'",
2803                                                         expression, orig_type);
2804                                         goto end_error;
2805                                 }
2806
2807                                 descend_into_subtype(path);
2808                         }
2809                 }
2810
2811                 /* update largest index of top array */
2812                 const type_path_entry_t *first      = &path->path[0];
2813                 type_t                  *first_type = first->type;
2814                 first_type                          = skip_typeref(first_type);
2815                 if (is_type_array(first_type)) {
2816                         size_t index = first->v.index;
2817                         if (index > path->max_index)
2818                                 path->max_index = index;
2819                 }
2820
2821                 if (type != NULL) {
2822                         /* append to initializers list */
2823                         ARR_APP1(initializer_t*, initializers, sub);
2824                 } else {
2825 error_excess:
2826                         if (warning.other) {
2827                                 if (env->entity != NULL) {
2828                                         warningf(HERE, "excess elements in struct initializer for '%Y'",
2829                                            env->entity->base.symbol);
2830                                 } else {
2831                                         warningf(HERE, "excess elements in struct initializer");
2832                                 }
2833                         }
2834                 }
2835
2836 error_parse_next:
2837                 if (token.type == '}') {
2838                         break;
2839                 }
2840                 expect(',', end_error);
2841                 if (token.type == '}') {
2842                         break;
2843                 }
2844
2845                 if (type != NULL) {
2846                         /* advance to the next declaration if we are not at the end */
2847                         advance_current_object(path, top_path_level);
2848                         orig_type = path->top_type;
2849                         if (orig_type != NULL)
2850                                 type = skip_typeref(orig_type);
2851                         else
2852                                 type = NULL;
2853                 }
2854         }
2855
2856         size_t len  = ARR_LEN(initializers);
2857         size_t size = sizeof(initializer_list_t) + len * sizeof(initializers[0]);
2858         initializer_t *result = allocate_ast_zero(size);
2859         result->kind          = INITIALIZER_LIST;
2860         result->list.len      = len;
2861         memcpy(&result->list.initializers, initializers,
2862                len * sizeof(initializers[0]));
2863
2864         DEL_ARR_F(initializers);
2865         ascend_to(path, top_path_level+1);
2866
2867         return result;
2868
2869 end_error:
2870         skip_initializers();
2871         DEL_ARR_F(initializers);
2872         ascend_to(path, top_path_level+1);
2873         return NULL;
2874 }
2875
2876 /**
2877  * Parses an initializer. Parsers either a compound literal
2878  * (env->declaration == NULL) or an initializer of a declaration.
2879  */
2880 static initializer_t *parse_initializer(parse_initializer_env_t *env)
2881 {
2882         type_t        *type      = skip_typeref(env->type);
2883         size_t         max_index = 0xdeadbeaf;   // TODO: Resolve this uninitialized variable problem
2884         initializer_t *result;
2885
2886         if (is_type_scalar(type)) {
2887                 result = parse_scalar_initializer(type, env->must_be_constant);
2888         } else if (token.type == '{') {
2889                 eat('{');
2890
2891                 type_path_t path;
2892                 memset(&path, 0, sizeof(path));
2893                 path.top_type = env->type;
2894                 path.path     = NEW_ARR_F(type_path_entry_t, 0);
2895
2896                 descend_into_subtype(&path);
2897
2898                 add_anchor_token('}');
2899                 result = parse_sub_initializer(&path, env->type, 1, env);
2900                 rem_anchor_token('}');
2901
2902                 max_index = path.max_index;
2903                 DEL_ARR_F(path.path);
2904
2905                 expect('}', end_error);
2906         } else {
2907                 /* parse_scalar_initializer() also works in this case: we simply
2908                  * have an expression without {} around it */
2909                 result = parse_scalar_initializer(type, env->must_be_constant);
2910         }
2911
2912         /* § 6.7.8:22 array initializers for arrays with unknown size determine
2913          * the array type size */
2914         if (is_type_array(type) && type->array.size_expression == NULL
2915                         && result != NULL) {
2916                 size_t size;
2917                 switch (result->kind) {
2918                 case INITIALIZER_LIST:
2919                         assert(max_index != 0xdeadbeaf);
2920                         size = max_index + 1;
2921                         break;
2922
2923                 case INITIALIZER_STRING:
2924                         size = result->string.string.size;
2925                         break;
2926
2927                 case INITIALIZER_WIDE_STRING:
2928                         size = result->wide_string.string.size;
2929                         break;
2930
2931                 case INITIALIZER_DESIGNATOR:
2932                 case INITIALIZER_VALUE:
2933                         /* can happen for parse errors */
2934                         size = 0;
2935                         break;
2936
2937                 default:
2938                         internal_errorf(HERE, "invalid initializer type");
2939                 }
2940
2941                 expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
2942                 cnst->base.type          = type_size_t;
2943                 cnst->conste.v.int_value = size;
2944
2945                 type_t *new_type = duplicate_type(type);
2946
2947                 new_type->array.size_expression   = cnst;
2948                 new_type->array.size_constant     = true;
2949                 new_type->array.has_implicit_size = true;
2950                 new_type->array.size              = size;
2951                 env->type = new_type;
2952         }
2953
2954         return result;
2955 end_error:
2956         return NULL;
2957 }
2958
2959 static void append_entity(scope_t *scope, entity_t *entity)
2960 {
2961         if (scope->last_entity != NULL) {
2962                 scope->last_entity->base.next = entity;
2963         } else {
2964                 scope->entities = entity;
2965         }
2966         scope->last_entity = entity;
2967 }
2968
2969
2970 static compound_t *parse_compound_type_specifier(bool is_struct)
2971 {
2972         gnu_attribute_t  *attributes = NULL;
2973         decl_modifiers_t  modifiers  = 0;
2974         if (is_struct) {
2975                 eat(T_struct);
2976         } else {
2977                 eat(T_union);
2978         }
2979
2980         symbol_t   *symbol   = NULL;
2981         compound_t *compound = NULL;
2982
2983         if (token.type == T___attribute__) {
2984                 modifiers |= parse_attributes(&attributes);
2985         }
2986
2987         if (token.type == T_IDENTIFIER) {
2988                 symbol = token.v.symbol;
2989                 next_token();
2990
2991                 namespace_tag_t const namespc =
2992                         is_struct ? NAMESPACE_STRUCT : NAMESPACE_UNION;
2993                 entity_t *entity = get_entity(symbol, namespc);
2994                 if (entity != NULL) {
2995                         assert(entity->kind == (is_struct ? ENTITY_STRUCT : ENTITY_UNION));
2996                         compound = &entity->compound;
2997                         if (compound->base.parent_scope != current_scope &&
2998                             (token.type == '{' || token.type == ';')) {
2999                                 /* we're in an inner scope and have a definition. Shadow
3000                                  * existing definition in outer scope */
3001                                 compound = NULL;
3002                         } else if (compound->complete && token.type == '{') {
3003                                 assert(symbol != NULL);
3004                                 errorf(HERE, "multiple definitions of '%s %Y' (previous definition %P)",
3005                                        is_struct ? "struct" : "union", symbol,
3006                                        &compound->base.source_position);
3007                                 /* clear members in the hope to avoid further errors */
3008                                 compound->members.entities = NULL;
3009                         }
3010                 }
3011         } else if (token.type != '{') {
3012                 if (is_struct) {
3013                         parse_error_expected("while parsing struct type specifier",
3014                                              T_IDENTIFIER, '{', NULL);
3015                 } else {
3016                         parse_error_expected("while parsing union type specifier",
3017                                              T_IDENTIFIER, '{', NULL);
3018                 }
3019
3020                 return NULL;
3021         }
3022
3023         if (compound == NULL) {
3024                 entity_kind_t  kind   = is_struct ? ENTITY_STRUCT : ENTITY_UNION;
3025                 entity_t      *entity = allocate_entity_zero(kind);
3026                 compound              = &entity->compound;
3027
3028                 compound->base.namespc =
3029                         (is_struct ? NAMESPACE_STRUCT : NAMESPACE_UNION);
3030                 compound->base.source_position = token.source_position;
3031                 compound->base.symbol          = symbol;
3032                 compound->base.parent_scope    = current_scope;
3033                 if (symbol != NULL) {
3034                         environment_push(entity);
3035                 }
3036                 append_entity(current_scope, entity);
3037         }
3038
3039         if (token.type == '{') {
3040                 parse_compound_type_entries(compound);
3041                 modifiers |= parse_attributes(&attributes);
3042
3043                 if (symbol == NULL) {
3044                         assert(anonymous_entity == NULL);
3045                         anonymous_entity = (entity_t*)compound;
3046                 }
3047         }
3048
3049         compound->modifiers |= modifiers;
3050         return compound;
3051 }
3052
3053 static void parse_enum_entries(type_t *const enum_type)
3054 {
3055         eat('{');
3056
3057         if (token.type == '}') {
3058                 errorf(HERE, "empty enum not allowed");
3059                 next_token();
3060                 return;
3061         }
3062
3063         add_anchor_token('}');
3064         do {
3065                 if (token.type != T_IDENTIFIER) {
3066                         parse_error_expected("while parsing enum entry", T_IDENTIFIER, NULL);
3067                         eat_block();
3068                         rem_anchor_token('}');
3069                         return;
3070                 }
3071
3072                 entity_t *entity             = allocate_entity_zero(ENTITY_ENUM_VALUE);
3073                 entity->enum_value.enum_type = enum_type;
3074                 entity->base.symbol          = token.v.symbol;
3075                 entity->base.source_position = token.source_position;
3076                 next_token();
3077
3078                 if (token.type == '=') {
3079                         next_token();
3080                         expression_t *value = parse_constant_expression();
3081
3082                         value = create_implicit_cast(value, enum_type);
3083                         entity->enum_value.value = value;
3084
3085                         /* TODO semantic */
3086                 }
3087
3088                 record_entity(entity, false);
3089
3090                 if (token.type != ',')
3091                         break;
3092                 next_token();
3093         } while (token.type != '}');
3094         rem_anchor_token('}');
3095
3096         expect('}', end_error);
3097
3098 end_error:
3099         ;
3100 }
3101
3102 static type_t *parse_enum_specifier(void)
3103 {
3104         gnu_attribute_t *attributes = NULL;
3105         entity_t        *entity;
3106         symbol_t        *symbol;
3107
3108         eat(T_enum);
3109         if (token.type == T_IDENTIFIER) {
3110                 symbol = token.v.symbol;
3111                 next_token();
3112
3113                 entity = get_entity(symbol, NAMESPACE_ENUM);
3114                 if (entity != NULL) {
3115                         assert(entity->kind == ENTITY_ENUM);
3116                         if (entity->base.parent_scope != current_scope &&
3117                                         (token.type == '{' || token.type == ';')) {
3118                                 /* we're in an inner scope and have a definition. Shadow
3119                                  * existing definition in outer scope */
3120                                 entity = NULL;
3121                         } else if (entity->enume.complete && token.type == '{') {
3122                                 errorf(HERE, "multiple definitions of 'enum %Y' (previous definition %P)",
3123                                                 symbol, &entity->base.source_position);
3124                         }
3125                 }
3126         } else if (token.type != '{') {
3127                 parse_error_expected("while parsing enum type specifier",
3128                                      T_IDENTIFIER, '{', NULL);
3129                 return NULL;
3130         } else {
3131                 entity  = NULL;
3132                 symbol  = NULL;
3133         }
3134
3135         if (entity == NULL) {
3136                 entity                       = allocate_entity_zero(ENTITY_ENUM);
3137                 entity->base.namespc         = NAMESPACE_ENUM;
3138                 entity->base.source_position = token.source_position;
3139                 entity->base.symbol          = symbol;
3140                 entity->base.parent_scope    = current_scope;
3141         }
3142
3143         type_t *const type = allocate_type_zero(TYPE_ENUM);
3144         type->enumt.enume  = &entity->enume;
3145         type->enumt.akind  = ATOMIC_TYPE_INT;
3146
3147         if (token.type == '{') {
3148                 if (symbol != NULL) {
3149                         environment_push(entity);
3150                 }
3151                 append_entity(current_scope, entity);
3152                 entity->enume.complete = true;
3153
3154                 parse_enum_entries(type);
3155                 parse_attributes(&attributes);
3156
3157                 if (symbol == NULL) {
3158                         assert(anonymous_entity == NULL);
3159                         anonymous_entity = entity;
3160                 }
3161         } else if (!entity->enume.complete && !(c_mode & _GNUC)) {
3162                 errorf(HERE, "'enum %Y' used before definition (incomplete enums are a GNU extension)",
3163                        symbol);
3164         }
3165
3166         return type;
3167 }
3168
3169 /**
3170  * if a symbol is a typedef to another type, return true
3171  */
3172 static bool is_typedef_symbol(symbol_t *symbol)
3173 {
3174         const entity_t *const entity = get_entity(symbol, NAMESPACE_NORMAL);
3175         return entity != NULL && entity->kind == ENTITY_TYPEDEF;
3176 }
3177
3178 static type_t *parse_typeof(void)
3179 {
3180         eat(T___typeof__);
3181
3182         type_t *type;
3183
3184         expect('(', end_error);
3185         add_anchor_token(')');
3186
3187         expression_t *expression  = NULL;
3188
3189         bool old_type_prop     = in_type_prop;
3190         bool old_gcc_extension = in_gcc_extension;
3191         in_type_prop           = true;
3192
3193         while (token.type == T___extension__) {
3194                 /* This can be a prefix to a typename or an expression. */
3195                 next_token();
3196                 in_gcc_extension = true;
3197         }
3198         switch (token.type) {
3199         case T_IDENTIFIER:
3200                 if (is_typedef_symbol(token.v.symbol)) {
3201                         type = parse_typename();
3202                 } else {
3203                         expression = parse_expression();
3204                         type       = expression->base.type;
3205                 }
3206                 break;
3207
3208         TYPENAME_START
3209                 type = parse_typename();
3210                 break;
3211
3212         default:
3213                 expression = parse_expression();
3214                 type       = expression->base.type;
3215                 break;
3216         }
3217         in_type_prop     = old_type_prop;
3218         in_gcc_extension = old_gcc_extension;
3219
3220         rem_anchor_token(')');
3221         expect(')', end_error);
3222
3223         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF);
3224         typeof_type->typeoft.expression  = expression;
3225         typeof_type->typeoft.typeof_type = type;
3226
3227         return typeof_type;
3228 end_error:
3229         return NULL;
3230 }
3231
3232 typedef enum specifiers_t {
3233         SPECIFIER_SIGNED    = 1 << 0,
3234         SPECIFIER_UNSIGNED  = 1 << 1,
3235         SPECIFIER_LONG      = 1 << 2,
3236         SPECIFIER_INT       = 1 << 3,
3237         SPECIFIER_DOUBLE    = 1 << 4,
3238         SPECIFIER_CHAR      = 1 << 5,
3239         SPECIFIER_WCHAR_T   = 1 << 6,
3240         SPECIFIER_SHORT     = 1 << 7,
3241         SPECIFIER_LONG_LONG = 1 << 8,
3242         SPECIFIER_FLOAT     = 1 << 9,
3243         SPECIFIER_BOOL      = 1 << 10,
3244         SPECIFIER_VOID      = 1 << 11,
3245         SPECIFIER_INT8      = 1 << 12,
3246         SPECIFIER_INT16     = 1 << 13,
3247         SPECIFIER_INT32     = 1 << 14,
3248         SPECIFIER_INT64     = 1 << 15,
3249         SPECIFIER_INT128    = 1 << 16,
3250         SPECIFIER_COMPLEX   = 1 << 17,
3251         SPECIFIER_IMAGINARY = 1 << 18,
3252 } specifiers_t;
3253
3254 static type_t *create_builtin_type(symbol_t *const symbol,
3255                                    type_t *const real_type)
3256 {
3257         type_t *type            = allocate_type_zero(TYPE_BUILTIN);
3258         type->builtin.symbol    = symbol;
3259         type->builtin.real_type = real_type;
3260         return identify_new_type(type);
3261 }
3262
3263 static type_t *get_typedef_type(symbol_t *symbol)
3264 {
3265         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
3266         if (entity == NULL || entity->kind != ENTITY_TYPEDEF)
3267                 return NULL;
3268
3269         type_t *type            = allocate_type_zero(TYPE_TYPEDEF);
3270         type->typedeft.typedefe = &entity->typedefe;
3271
3272         return type;
3273 }
3274
3275 /**
3276  * check for the allowed MS alignment values.
3277  */
3278 static bool check_alignment_value(long long intvalue)
3279 {
3280         if (intvalue < 1 || intvalue > 8192) {
3281                 errorf(HERE, "illegal alignment value");
3282                 return false;
3283         }
3284         unsigned v = (unsigned)intvalue;
3285         for (unsigned i = 1; i <= 8192; i += i) {
3286                 if (i == v)
3287                         return true;
3288         }
3289         errorf(HERE, "alignment must be power of two");
3290         return false;
3291 }
3292
3293 #define DET_MOD(name, tag) do { \
3294         if (*modifiers & tag && warning.other) warningf(HERE, #name " used more than once"); \
3295         *modifiers |= tag; \
3296 } while (0)
3297
3298 static void parse_microsoft_extended_decl_modifier(declaration_specifiers_t *specifiers)
3299 {
3300         decl_modifiers_t *modifiers = &specifiers->modifiers;
3301
3302         while (true) {
3303                 if (token.type == T_restrict) {
3304                         next_token();
3305                         DET_MOD(restrict, DM_RESTRICT);
3306                         goto end_loop;
3307                 } else if (token.type != T_IDENTIFIER)
3308                         break;
3309                 symbol_t *symbol = token.v.symbol;
3310                 if (symbol == sym_align) {
3311                         next_token();
3312                         expect('(', end_error);
3313                         if (token.type != T_INTEGER)
3314                                 goto end_error;
3315                         if (check_alignment_value(token.v.intvalue)) {
3316                                 if (specifiers->alignment != 0 && warning.other)
3317                                         warningf(HERE, "align used more than once");
3318                                 specifiers->alignment = (unsigned char)token.v.intvalue;
3319                         }
3320                         next_token();
3321                         expect(')', end_error);
3322                 } else if (symbol == sym_allocate) {
3323                         next_token();
3324                         expect('(', end_error);
3325                         if (token.type != T_IDENTIFIER)
3326                                 goto end_error;
3327                         (void)token.v.symbol;
3328                         expect(')', end_error);
3329                 } else if (symbol == sym_dllimport) {
3330                         next_token();
3331                         DET_MOD(dllimport, DM_DLLIMPORT);
3332                 } else if (symbol == sym_dllexport) {
3333                         next_token();
3334                         DET_MOD(dllexport, DM_DLLEXPORT);
3335                 } else if (symbol == sym_thread) {
3336                         next_token();
3337                         DET_MOD(thread, DM_THREAD);
3338                 } else if (symbol == sym_naked) {
3339                         next_token();
3340                         DET_MOD(naked, DM_NAKED);
3341                 } else if (symbol == sym_noinline) {
3342                         next_token();
3343                         DET_MOD(noinline, DM_NOINLINE);
3344                 } else if (symbol == sym_returns_twice) {
3345                         next_token();
3346                         DET_MOD(returns_twice, DM_RETURNS_TWICE);
3347                 } else if (symbol == sym_noreturn) {
3348                         next_token();
3349                         DET_MOD(noreturn, DM_NORETURN);
3350                 } else if (symbol == sym_nothrow) {
3351                         next_token();
3352                         DET_MOD(nothrow, DM_NOTHROW);
3353                 } else if (symbol == sym_novtable) {
3354                         next_token();
3355                         DET_MOD(novtable, DM_NOVTABLE);
3356                 } else if (symbol == sym_property) {
3357                         next_token();
3358                         expect('(', end_error);
3359                         for (;;) {
3360                                 bool is_get = false;
3361                                 if (token.type != T_IDENTIFIER)
3362                                         goto end_error;
3363                                 if (token.v.symbol == sym_get) {
3364                                         is_get = true;
3365                                 } else if (token.v.symbol == sym_put) {
3366                                 } else {
3367                                         errorf(HERE, "Bad property name '%Y'", token.v.symbol);
3368                                         goto end_error;
3369                                 }
3370                                 next_token();
3371                                 expect('=', end_error);
3372                                 if (token.type != T_IDENTIFIER)
3373                                         goto end_error;
3374                                 if (is_get) {
3375                                         if (specifiers->get_property_sym != NULL) {
3376                                                 errorf(HERE, "get property name already specified");
3377                                         } else {
3378                                                 specifiers->get_property_sym = token.v.symbol;
3379                                         }
3380                                 } else {
3381                                         if (specifiers->put_property_sym != NULL) {
3382                                                 errorf(HERE, "put property name already specified");
3383                                         } else {
3384                                                 specifiers->put_property_sym = token.v.symbol;
3385                                         }
3386                                 }
3387                                 next_token();
3388                                 if (token.type == ',') {
3389                                         next_token();
3390                                         continue;
3391                                 }
3392                                 break;
3393                         }
3394                         expect(')', end_error);
3395                 } else if (symbol == sym_selectany) {
3396                         next_token();
3397                         DET_MOD(selectany, DM_SELECTANY);
3398                 } else if (symbol == sym_uuid) {
3399                         next_token();
3400                         expect('(', end_error);
3401                         if (token.type != T_STRING_LITERAL)
3402                                 goto end_error;
3403                         next_token();
3404                         expect(')', end_error);
3405                 } else if (symbol == sym_deprecated) {
3406                         next_token();
3407                         if (specifiers->deprecated != 0 && warning.other)
3408                                 warningf(HERE, "deprecated used more than once");
3409                         specifiers->deprecated = true;
3410                         if (token.type == '(') {
3411                                 next_token();
3412                                 if (token.type == T_STRING_LITERAL) {
3413                                         specifiers->deprecated_string = token.v.string.begin;
3414                                         next_token();
3415                                 } else {
3416                                         errorf(HERE, "string literal expected");
3417                                 }
3418                                 expect(')', end_error);
3419                         }
3420                 } else if (symbol == sym_noalias) {
3421                         next_token();
3422                         DET_MOD(noalias, DM_NOALIAS);
3423                 } else {
3424                         if (warning.other)
3425                                 warningf(HERE, "Unknown modifier '%Y' ignored", token.v.symbol);
3426                         next_token();
3427                         if (token.type == '(')
3428                                 skip_until(')');
3429                 }
3430 end_loop:
3431                 if (token.type == ',')
3432                         next_token();
3433         }
3434 end_error:
3435         return;
3436 }
3437
3438 static entity_t *create_error_entity(symbol_t *symbol, entity_kind_tag_t kind)
3439 {
3440         entity_t *entity             = allocate_entity_zero(kind);
3441         entity->base.source_position = *HERE;
3442         entity->base.symbol          = symbol;
3443         if (is_declaration(entity)) {
3444                 entity->declaration.type     = type_error_type;
3445                 entity->declaration.implicit = true;
3446         } else if (kind == ENTITY_TYPEDEF) {
3447                 entity->typedefe.type    = type_error_type;
3448                 entity->typedefe.builtin = true;
3449         }
3450         if (kind != ENTITY_COMPOUND_MEMBER)
3451                 record_entity(entity, false);
3452         return entity;
3453 }
3454
3455 static void parse_microsoft_based(based_spec_t *based_spec)
3456 {
3457         if (token.type != T_IDENTIFIER) {
3458                 parse_error_expected("while parsing __based", T_IDENTIFIER, NULL);
3459                 return;
3460         }
3461         symbol_t *symbol = token.v.symbol;
3462         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
3463
3464         if (entity == NULL || entity->base.kind != ENTITY_VARIABLE) {
3465                 errorf(HERE, "'%Y' is not a variable name.", symbol);
3466                 entity = create_error_entity(symbol, ENTITY_VARIABLE);
3467         } else {
3468                 variable_t *variable = &entity->variable;
3469
3470                 if (based_spec->base_variable != NULL) {
3471                         errorf(HERE, "__based type qualifier specified more than once");
3472                 }
3473                 based_spec->source_position = token.source_position;
3474                 based_spec->base_variable   = variable;
3475
3476                 type_t *const type = variable->base.type;
3477
3478                 if (is_type_valid(type)) {
3479                         if (! is_type_pointer(skip_typeref(type))) {
3480                                 errorf(HERE, "variable in __based modifier must have pointer type instead of '%T'", type);
3481                         }
3482                         if (variable->base.base.parent_scope != file_scope) {
3483                                 errorf(HERE, "a nonstatic local variable may not be used in a __based specification");
3484                         }
3485                 }
3486         }
3487         next_token();
3488 }
3489
3490 /**
3491  * Finish the construction of a struct type by calculating
3492  * its size, offsets, alignment.
3493  */
3494 static void finish_struct_type(compound_type_t *type)
3495 {
3496         assert(type->compound != NULL);
3497
3498         compound_t *compound = type->compound;
3499         if (!compound->complete)
3500                 return;
3501
3502         il_size_t      size           = 0;
3503         il_size_t      offset;
3504         il_alignment_t alignment      = 1;
3505         bool           need_pad       = false;
3506
3507         entity_t *entry = compound->members.entities;
3508         for (; entry != NULL; entry = entry->base.next) {
3509                 if (entry->kind != ENTITY_COMPOUND_MEMBER)
3510                         continue;
3511
3512                 type_t *m_type = skip_typeref(entry->declaration.type);
3513                 if (! is_type_valid(m_type)) {
3514                         /* simply ignore errors here */
3515                         continue;
3516                 }
3517                 il_alignment_t m_alignment = m_type->base.alignment;
3518                 if (m_alignment > alignment)
3519                         alignment = m_alignment;
3520
3521                 offset = (size + m_alignment - 1) & -m_alignment;
3522
3523                 if (offset > size)
3524                         need_pad = true;
3525                 entry->compound_member.offset = offset;
3526                 size = offset + m_type->base.size;
3527         }
3528         if (type->base.alignment != 0) {
3529                 alignment = type->base.alignment;
3530         }
3531
3532         offset = (size + alignment - 1) & -alignment;
3533         if (offset > size)
3534                 need_pad = true;
3535
3536         if (need_pad) {
3537                 if (warning.padded) {
3538                         warningf(&compound->base.source_position, "'%T' needs padding", type);
3539                 }
3540         } else {
3541                 if (compound->modifiers & DM_PACKED && warning.packed) {
3542                         warningf(&compound->base.source_position,
3543                                         "superfluous packed attribute on '%T'", type);
3544                 }
3545         }
3546
3547         type->base.size      = offset;
3548         type->base.alignment = alignment;
3549 }
3550
3551 /**
3552  * Finish the construction of an union type by calculating
3553  * its size and alignment.
3554  */
3555 static void finish_union_type(compound_type_t *type)
3556 {
3557         assert(type->compound != NULL);
3558
3559         compound_t *compound = type->compound;
3560         if (! compound->complete)
3561                 return;
3562
3563         il_size_t      size      = 0;
3564         il_alignment_t alignment = 1;
3565
3566         entity_t *entry = compound->members.entities;
3567         for (; entry != NULL; entry = entry->base.next) {
3568                 if (entry->kind != ENTITY_COMPOUND_MEMBER)
3569                         continue;
3570
3571                 type_t *m_type = skip_typeref(entry->declaration.type);
3572                 if (! is_type_valid(m_type))
3573                         continue;
3574
3575                 entry->compound_member.offset = 0;
3576                 if (m_type->base.size > size)
3577                         size = m_type->base.size;
3578                 if (m_type->base.alignment > alignment)
3579                         alignment = m_type->base.alignment;
3580         }
3581         if (type->base.alignment != 0) {
3582                 alignment = type->base.alignment;
3583         }
3584         size = (size + alignment - 1) & -alignment;
3585         type->base.size      = size;
3586         type->base.alignment = alignment;
3587 }
3588
3589 static type_t *handle_attribute_mode(const gnu_attribute_t *attribute,
3590                                      type_t *orig_type)
3591 {
3592         type_t *type = skip_typeref(orig_type);
3593
3594         /* at least: byte, word, pointer, list of machine modes
3595          * __XXX___ is interpreted as XXX */
3596
3597         /* This isn't really correct, the backend should provide a list of machine
3598          * specific modes (according to gcc philosophy that is...) */
3599         const char         *symbol_str = attribute->u.symbol->string;
3600         bool                sign       = is_type_signed(type);
3601         atomic_type_kind_t  akind;
3602         if (strcmp_underscore("QI",   symbol_str) == 0 ||
3603             strcmp_underscore("byte", symbol_str) == 0) {
3604                 akind = sign ? ATOMIC_TYPE_CHAR : ATOMIC_TYPE_UCHAR;
3605         } else if (strcmp_underscore("HI", symbol_str) == 0) {
3606                 akind = sign ? ATOMIC_TYPE_SHORT : ATOMIC_TYPE_USHORT;
3607         } else if (strcmp_underscore("SI",      symbol_str) == 0
3608                 || strcmp_underscore("word",    symbol_str) == 0
3609                 || strcmp_underscore("pointer", symbol_str) == 0) {
3610                 akind = sign ? ATOMIC_TYPE_INT : ATOMIC_TYPE_UINT;
3611         } else if (strcmp_underscore("DI", symbol_str) == 0) {
3612                 akind = sign ? ATOMIC_TYPE_LONGLONG : ATOMIC_TYPE_ULONGLONG;
3613         } else {
3614                 if (warning.other)
3615                         warningf(HERE, "ignoring unknown mode '%s'", symbol_str);
3616                 return orig_type;
3617         }
3618
3619         if (type->kind == TYPE_ATOMIC) {
3620                 type_t *copy       = duplicate_type(type);
3621                 copy->atomic.akind = akind;
3622                 return identify_new_type(copy);
3623         } else if (type->kind == TYPE_ENUM) {
3624                 type_t *copy      = duplicate_type(type);
3625                 copy->enumt.akind = akind;
3626                 return identify_new_type(copy);
3627         } else if (is_type_pointer(type)) {
3628                 warningf(HERE, "__attribute__((mode)) on pointers not implemented yet (ignored)");
3629                 return type;
3630         }
3631
3632         errorf(HERE, "__attribute__((mode)) only allowed on integer, enum or pointer type");
3633         return orig_type;
3634 }
3635
3636 static type_t *handle_type_attributes(const gnu_attribute_t *attributes,
3637                                       type_t *type)
3638 {
3639         const gnu_attribute_t *attribute = attributes;
3640         for ( ; attribute != NULL; attribute = attribute->next) {
3641                 if (attribute->invalid)
3642                         continue;
3643
3644                 if (attribute->kind == GNU_AK_MODE) {
3645                         type = handle_attribute_mode(attribute, type);
3646                 } else if (attribute->kind == GNU_AK_ALIGNED) {
3647                         int alignment = 32; /* TODO: fill in maximum useful alignment for
3648                                                target machine */
3649                         if (attribute->has_arguments)
3650                                 alignment = attribute->u.argument;
3651
3652                         type_t *copy         = duplicate_type(type);
3653                         copy->base.alignment = attribute->u.argument;
3654                         type                 = identify_new_type(copy);
3655                 }
3656         }
3657
3658         return type;
3659 }
3660
3661 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
3662 {
3663         type_t            *type              = NULL;
3664         type_qualifiers_t  qualifiers        = TYPE_QUALIFIER_NONE;
3665         type_modifiers_t   modifiers         = TYPE_MODIFIER_NONE;
3666         unsigned           type_specifiers   = 0;
3667         bool               newtype           = false;
3668         bool               saw_error         = false;
3669         bool               old_gcc_extension = in_gcc_extension;
3670
3671         specifiers->source_position = token.source_position;
3672
3673         while (true) {
3674                 specifiers->modifiers
3675                         |= parse_attributes(&specifiers->gnu_attributes);
3676
3677                 switch (token.type) {
3678                 /* storage class */
3679 #define MATCH_STORAGE_CLASS(token, class)                                  \
3680                 case token:                                                        \
3681                         if (specifiers->storage_class != STORAGE_CLASS_NONE) {         \
3682                                 errorf(HERE, "multiple storage classes in declaration specifiers"); \
3683                         }                                                              \
3684                         specifiers->storage_class = class;                             \
3685                         if (specifiers->thread_local)                                  \
3686                                 goto check_thread_storage_class;                           \
3687                         next_token();                                                  \
3688                         break;
3689
3690                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
3691                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
3692                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
3693                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
3694                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
3695
3696                 case T__declspec:
3697                         next_token();
3698                         expect('(', end_error);
3699                         add_anchor_token(')');
3700                         parse_microsoft_extended_decl_modifier(specifiers);
3701                         rem_anchor_token(')');
3702                         expect(')', end_error);
3703                         break;
3704
3705                 case T___thread:
3706                         if (specifiers->thread_local) {
3707                                 errorf(HERE, "duplicate '__thread'");
3708                         } else {
3709                                 specifiers->thread_local = true;
3710 check_thread_storage_class:
3711                                 switch (specifiers->storage_class) {
3712                                         case STORAGE_CLASS_EXTERN:
3713                                         case STORAGE_CLASS_NONE:
3714                                         case STORAGE_CLASS_STATIC:
3715                                                 break;
3716
3717                                                 char const* wrong;
3718                                         case STORAGE_CLASS_AUTO:     wrong = "auto";     goto wrong_thread_stoarge_class;
3719                                         case STORAGE_CLASS_REGISTER: wrong = "register"; goto wrong_thread_stoarge_class;
3720                                         case STORAGE_CLASS_TYPEDEF:  wrong = "typedef";  goto wrong_thread_stoarge_class;
3721 wrong_thread_stoarge_class:
3722                                                 errorf(HERE, "'__thread' used with '%s'", wrong);
3723                                                 break;
3724                                 }
3725                         }
3726                         next_token();
3727                         break;
3728
3729                 /* type qualifiers */
3730 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
3731                 case token:                                                     \
3732                         qualifiers |= qualifier;                                    \
3733                         next_token();                                               \
3734                         break
3735
3736                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3737                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3738                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3739                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3740                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3741                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3742                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3743                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3744
3745                 case T___extension__:
3746                         next_token();
3747                         in_gcc_extension = true;
3748                         break;
3749
3750                 /* type specifiers */
3751 #define MATCH_SPECIFIER(token, specifier, name)                         \
3752                 case token:                                                     \
3753                         if (type_specifiers & specifier) {                           \
3754                                 errorf(HERE, "multiple " name " type specifiers given"); \
3755                         } else {                                                    \
3756                                 type_specifiers |= specifier;                           \
3757                         }                                                           \
3758                         next_token();                                               \
3759                         break
3760
3761                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool");
3762                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex");
3763                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary");
3764                 MATCH_SPECIFIER(T__int128,    SPECIFIER_INT128,    "_int128");
3765                 MATCH_SPECIFIER(T__int16,     SPECIFIER_INT16,     "_int16");
3766                 MATCH_SPECIFIER(T__int32,     SPECIFIER_INT32,     "_int32");
3767                 MATCH_SPECIFIER(T__int64,     SPECIFIER_INT64,     "_int64");
3768                 MATCH_SPECIFIER(T__int8,      SPECIFIER_INT8,      "_int8");
3769                 MATCH_SPECIFIER(T_bool,       SPECIFIER_BOOL,      "bool");
3770                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char");
3771                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double");
3772                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float");
3773                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int");
3774                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short");
3775                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed");
3776                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned");
3777                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void");
3778                 MATCH_SPECIFIER(T_wchar_t,    SPECIFIER_WCHAR_T,   "wchar_t");
3779
3780                 case T__forceinline:
3781                         /* only in microsoft mode */
3782                         specifiers->modifiers |= DM_FORCEINLINE;
3783                         /* FALLTHROUGH */
3784
3785                 case T_inline:
3786                         next_token();
3787                         specifiers->is_inline = true;
3788                         break;
3789
3790                 case T_long:
3791                         if (type_specifiers & SPECIFIER_LONG_LONG) {
3792                                 errorf(HERE, "multiple type specifiers given");
3793                         } else if (type_specifiers & SPECIFIER_LONG) {
3794                                 type_specifiers |= SPECIFIER_LONG_LONG;
3795                         } else {
3796                                 type_specifiers |= SPECIFIER_LONG;
3797                         }
3798                         next_token();
3799                         break;
3800
3801                 case T_struct: {
3802                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
3803
3804                         type->compound.compound = parse_compound_type_specifier(true);
3805                         finish_struct_type(&type->compound);
3806                         break;
3807                 }
3808                 case T_union: {
3809                         type = allocate_type_zero(TYPE_COMPOUND_UNION);
3810                         type->compound.compound = parse_compound_type_specifier(false);
3811                         if (type->compound.compound->modifiers & DM_TRANSPARENT_UNION)
3812                                 modifiers |= TYPE_MODIFIER_TRANSPARENT_UNION;
3813                         finish_union_type(&type->compound);
3814                         break;
3815                 }
3816                 case T_enum:
3817                         type = parse_enum_specifier();
3818                         break;
3819                 case T___typeof__:
3820                         type = parse_typeof();
3821                         break;
3822                 case T___builtin_va_list:
3823                         type = duplicate_type(type_valist);
3824                         next_token();
3825                         break;
3826
3827                 case T_IDENTIFIER: {
3828                         /* only parse identifier if we haven't found a type yet */
3829                         if (type != NULL || type_specifiers != 0) {
3830                                 /* Be somewhat resilient to typos like 'unsigned lng* f()' in a
3831                                  * declaration, so it doesn't generate errors about expecting '(' or
3832                                  * '{' later on. */
3833                                 switch (look_ahead(1)->type) {
3834                                         STORAGE_CLASSES
3835                                         TYPE_SPECIFIERS
3836                                         case T_const:
3837                                         case T_restrict:
3838                                         case T_volatile:
3839                                         case T_inline:
3840                                         case T__forceinline: /* ^ DECLARATION_START except for __attribute__ */
3841                                         case T_IDENTIFIER:
3842                                         case '&':
3843                                         case '*':
3844                                                 errorf(HERE, "discarding stray %K in declaration specifier", &token);
3845                                                 next_token();
3846                                                 continue;
3847
3848                                         default:
3849                                                 goto finish_specifiers;
3850                                 }
3851                         }
3852
3853                         type_t *const typedef_type = get_typedef_type(token.v.symbol);
3854                         if (typedef_type == NULL) {
3855                                 /* Be somewhat resilient to typos like 'vodi f()' at the beginning of a
3856                                  * declaration, so it doesn't generate 'implicit int' followed by more
3857                                  * errors later on. */
3858                                 token_type_t const la1_type = (token_type_t)look_ahead(1)->type;
3859                                 switch (la1_type) {
3860                                         DECLARATION_START
3861                                         case T_IDENTIFIER:
3862                                         case '&':
3863                                         case '*': {
3864                                                 errorf(HERE, "%K does not name a type", &token);
3865
3866                                                 entity_t *entity =
3867                                                         create_error_entity(token.v.symbol, ENTITY_TYPEDEF);
3868
3869                                                 type = allocate_type_zero(TYPE_TYPEDEF);
3870                                                 type->typedeft.typedefe = &entity->typedefe;
3871
3872                                                 next_token();
3873                                                 saw_error = true;
3874                                                 if (la1_type == '&' || la1_type == '*')
3875                                                         goto finish_specifiers;
3876                                                 continue;
3877                                         }
3878
3879                                         default:
3880                                                 goto finish_specifiers;
3881                                 }
3882                         }
3883
3884                         next_token();
3885                         type = typedef_type;
3886                         break;
3887                 }
3888
3889                 /* function specifier */
3890                 default:
3891                         goto finish_specifiers;
3892                 }
3893         }
3894
3895 finish_specifiers:
3896         specifiers->modifiers
3897                 |= parse_attributes(&specifiers->gnu_attributes);
3898
3899         in_gcc_extension = old_gcc_extension;
3900
3901         if (type == NULL || (saw_error && type_specifiers != 0)) {
3902                 atomic_type_kind_t atomic_type;
3903
3904                 /* match valid basic types */
3905                 switch (type_specifiers) {
3906                 case SPECIFIER_VOID:
3907                         atomic_type = ATOMIC_TYPE_VOID;
3908                         break;
3909                 case SPECIFIER_WCHAR_T:
3910                         atomic_type = ATOMIC_TYPE_WCHAR_T;
3911                         break;
3912                 case SPECIFIER_CHAR:
3913                         atomic_type = ATOMIC_TYPE_CHAR;
3914                         break;
3915                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
3916                         atomic_type = ATOMIC_TYPE_SCHAR;
3917                         break;
3918                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
3919                         atomic_type = ATOMIC_TYPE_UCHAR;
3920                         break;
3921                 case SPECIFIER_SHORT:
3922                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
3923                 case SPECIFIER_SHORT | SPECIFIER_INT:
3924                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
3925                         atomic_type = ATOMIC_TYPE_SHORT;
3926                         break;
3927                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
3928                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
3929                         atomic_type = ATOMIC_TYPE_USHORT;
3930                         break;
3931                 case SPECIFIER_INT:
3932                 case SPECIFIER_SIGNED:
3933                 case SPECIFIER_SIGNED | SPECIFIER_INT:
3934                         atomic_type = ATOMIC_TYPE_INT;
3935                         break;
3936                 case SPECIFIER_UNSIGNED:
3937                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
3938                         atomic_type = ATOMIC_TYPE_UINT;
3939                         break;
3940                 case SPECIFIER_LONG:
3941                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
3942                 case SPECIFIER_LONG | SPECIFIER_INT:
3943                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
3944                         atomic_type = ATOMIC_TYPE_LONG;
3945                         break;
3946                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
3947                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
3948                         atomic_type = ATOMIC_TYPE_ULONG;
3949                         break;
3950
3951                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3952                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3953                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
3954                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3955                         | SPECIFIER_INT:
3956                         atomic_type = ATOMIC_TYPE_LONGLONG;
3957                         goto warn_about_long_long;
3958
3959                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3960                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3961                         | SPECIFIER_INT:
3962                         atomic_type = ATOMIC_TYPE_ULONGLONG;
3963 warn_about_long_long:
3964                         if (warning.long_long) {
3965                                 warningf(&specifiers->source_position,
3966                                          "ISO C90 does not support 'long long'");
3967                         }
3968                         break;
3969
3970                 case SPECIFIER_UNSIGNED | SPECIFIER_INT8:
3971                         atomic_type = unsigned_int8_type_kind;
3972                         break;
3973
3974                 case SPECIFIER_UNSIGNED | SPECIFIER_INT16:
3975                         atomic_type = unsigned_int16_type_kind;
3976                         break;
3977
3978                 case SPECIFIER_UNSIGNED | SPECIFIER_INT32:
3979                         atomic_type = unsigned_int32_type_kind;
3980                         break;
3981
3982                 case SPECIFIER_UNSIGNED | SPECIFIER_INT64:
3983                         atomic_type = unsigned_int64_type_kind;
3984                         break;
3985
3986                 case SPECIFIER_UNSIGNED | SPECIFIER_INT128:
3987                         atomic_type = unsigned_int128_type_kind;
3988                         break;
3989
3990                 case SPECIFIER_INT8:
3991                 case SPECIFIER_SIGNED | SPECIFIER_INT8:
3992                         atomic_type = int8_type_kind;
3993                         break;
3994
3995                 case SPECIFIER_INT16:
3996                 case SPECIFIER_SIGNED | SPECIFIER_INT16:
3997                         atomic_type = int16_type_kind;
3998                         break;
3999
4000                 case SPECIFIER_INT32:
4001                 case SPECIFIER_SIGNED | SPECIFIER_INT32:
4002                         atomic_type = int32_type_kind;
4003                         break;
4004
4005                 case SPECIFIER_INT64:
4006                 case SPECIFIER_SIGNED | SPECIFIER_INT64:
4007                         atomic_type = int64_type_kind;
4008                         break;
4009
4010                 case SPECIFIER_INT128:
4011                 case SPECIFIER_SIGNED | SPECIFIER_INT128:
4012                         atomic_type = int128_type_kind;
4013                         break;
4014
4015                 case SPECIFIER_FLOAT:
4016                         atomic_type = ATOMIC_TYPE_FLOAT;
4017                         break;
4018                 case SPECIFIER_DOUBLE:
4019                         atomic_type = ATOMIC_TYPE_DOUBLE;
4020                         break;
4021                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
4022                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
4023                         break;
4024                 case SPECIFIER_BOOL:
4025                         atomic_type = ATOMIC_TYPE_BOOL;
4026                         break;
4027                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
4028                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
4029                         atomic_type = ATOMIC_TYPE_FLOAT;
4030                         break;
4031                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
4032                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
4033                         atomic_type = ATOMIC_TYPE_DOUBLE;
4034                         break;
4035                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
4036                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
4037                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
4038                         break;
4039                 default:
4040                         /* invalid specifier combination, give an error message */
4041                         if (type_specifiers == 0) {
4042                                 if (saw_error)
4043                                         goto end_error;
4044
4045                                 /* ISO/IEC 14882:1998(E) §C.1.5:4 */
4046                                 if (!(c_mode & _CXX) && !strict_mode) {
4047                                         if (warning.implicit_int) {
4048                                                 warningf(HERE, "no type specifiers in declaration, using 'int'");
4049                                         }
4050                                         atomic_type = ATOMIC_TYPE_INT;
4051                                         break;
4052                                 } else {
4053                                         errorf(HERE, "no type specifiers given in declaration");
4054                                 }
4055                         } else if ((type_specifiers & SPECIFIER_SIGNED) &&
4056                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
4057                                 errorf(HERE, "signed and unsigned specifiers given");
4058                         } else if (type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
4059                                 errorf(HERE, "only integer types can be signed or unsigned");
4060                         } else {
4061                                 errorf(HERE, "multiple datatypes in declaration");
4062                         }
4063                         goto end_error;
4064                 }
4065
4066                 if (type_specifiers & SPECIFIER_COMPLEX) {
4067                         type                = allocate_type_zero(TYPE_COMPLEX);
4068                         type->complex.akind = atomic_type;
4069                 } else if (type_specifiers & SPECIFIER_IMAGINARY) {
4070                         type                  = allocate_type_zero(TYPE_IMAGINARY);
4071                         type->imaginary.akind = atomic_type;
4072                 } else {
4073                         type                 = allocate_type_zero(TYPE_ATOMIC);
4074                         type->atomic.akind   = atomic_type;
4075                 }
4076                 type->base.alignment = get_atomic_type_alignment(atomic_type);
4077                 unsigned const size  = get_atomic_type_size(atomic_type);
4078                 type->base.size      =
4079                         type_specifiers & SPECIFIER_COMPLEX ? size * 2 : size;
4080                 newtype = true;
4081         } else if (type_specifiers != 0) {
4082                 errorf(HERE, "multiple datatypes in declaration");
4083         }
4084
4085         /* FIXME: check type qualifiers here */
4086
4087         if (specifiers->modifiers & DM_TRANSPARENT_UNION)
4088                 modifiers |= TYPE_MODIFIER_TRANSPARENT_UNION;
4089         type->base.qualifiers = qualifiers;
4090         type->base.modifiers  = modifiers;
4091
4092         if (newtype) {
4093                 type = identify_new_type(type);
4094         } else {
4095                 type = typehash_insert(type);
4096         }
4097
4098         type = handle_type_attributes(specifiers->gnu_attributes, type);
4099         specifiers->type = type;
4100         return;
4101
4102 end_error:
4103         specifiers->type = type_error_type;
4104         return;
4105 }
4106
4107 static type_qualifiers_t parse_type_qualifiers(void)
4108 {
4109         type_qualifiers_t qualifiers = TYPE_QUALIFIER_NONE;
4110
4111         while (true) {
4112                 switch (token.type) {
4113                 /* type qualifiers */
4114                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
4115                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
4116                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
4117                 /* microsoft extended type modifiers */
4118                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
4119                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
4120                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
4121                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
4122                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
4123
4124                 default:
4125                         return qualifiers;
4126                 }
4127         }
4128 }
4129
4130 /**
4131  * Parses an K&R identifier list
4132  */
4133 static void parse_identifier_list(scope_t *scope)
4134 {
4135         do {
4136                 entity_t *entity = allocate_entity_zero(ENTITY_PARAMETER);
4137                 entity->base.source_position = token.source_position;
4138                 entity->base.namespc         = NAMESPACE_NORMAL;
4139                 entity->base.symbol          = token.v.symbol;
4140                 /* a K&R parameter has no type, yet */
4141                 next_token();
4142
4143                 if (scope != NULL)
4144                         append_entity(scope, entity);
4145
4146                 if (token.type != ',') {
4147                         break;
4148                 }
4149                 next_token();
4150         } while (token.type == T_IDENTIFIER);
4151 }
4152
4153 static entity_t *parse_parameter(void)
4154 {
4155         declaration_specifiers_t specifiers;
4156         memset(&specifiers, 0, sizeof(specifiers));
4157
4158         parse_declaration_specifiers(&specifiers);
4159
4160         entity_t *entity = parse_declarator(&specifiers,
4161                         DECL_MAY_BE_ABSTRACT | DECL_IS_PARAMETER);
4162         anonymous_entity = NULL;
4163         return entity;
4164 }
4165
4166 static void semantic_parameter_incomplete(const entity_t *entity)
4167 {
4168         assert(entity->kind == ENTITY_PARAMETER);
4169
4170         /* §6.7.5.3:4  After adjustment, the parameters in a parameter type
4171          *             list in a function declarator that is part of a
4172          *             definition of that function shall not have
4173          *             incomplete type. */
4174         type_t *type = skip_typeref(entity->declaration.type);
4175         if (is_type_incomplete(type)) {
4176                 errorf(&entity->base.source_position,
4177                        "parameter '%Y' has incomplete type '%T'", entity->base.symbol,
4178                        entity->declaration.type);
4179         }
4180 }
4181
4182 /**
4183  * Parses function type parameters (and optionally creates variable_t entities
4184  * for them in a scope)
4185  */
4186 static void parse_parameters(function_type_t *type, scope_t *scope)
4187 {
4188         eat('(');
4189         add_anchor_token(')');
4190         int saved_comma_state = save_and_reset_anchor_state(',');
4191
4192         if (token.type == T_IDENTIFIER &&
4193             !is_typedef_symbol(token.v.symbol)) {
4194                 token_type_t la1_type = (token_type_t)look_ahead(1)->type;
4195                 if (la1_type == ',' || la1_type == ')') {
4196                         type->kr_style_parameters    = true;
4197                         type->unspecified_parameters = true;
4198                         parse_identifier_list(scope);
4199                         goto parameters_finished;
4200                 }
4201         }
4202
4203         if (token.type == ')') {
4204                 /* ISO/IEC 14882:1998(E) §C.1.6:1 */
4205                 if (!(c_mode & _CXX))
4206                         type->unspecified_parameters = true;
4207                 goto parameters_finished;
4208         }
4209
4210         function_parameter_t *parameter;
4211         function_parameter_t *last_parameter = NULL;
4212
4213         while (true) {
4214                 switch (token.type) {
4215                 case T_DOTDOTDOT:
4216                         next_token();
4217                         type->variadic = true;
4218                         goto parameters_finished;
4219
4220                 case T_IDENTIFIER:
4221                 case T___extension__:
4222                 DECLARATION_START
4223                 {
4224                         entity_t *entity = parse_parameter();
4225                         if (entity->kind == ENTITY_TYPEDEF) {
4226                                 errorf(&entity->base.source_position,
4227                                        "typedef not allowed as function parameter");
4228                                 break;
4229                         }
4230                         assert(is_declaration(entity));
4231
4232                         /* func(void) is not a parameter */
4233                         if (last_parameter == NULL
4234                                         && token.type == ')'
4235                                         && entity->base.symbol == NULL
4236                                         && skip_typeref(entity->declaration.type) == type_void) {
4237                                 goto parameters_finished;
4238                         }
4239                         semantic_parameter_incomplete(entity);
4240
4241                         parameter = obstack_alloc(type_obst, sizeof(parameter[0]));
4242                         memset(parameter, 0, sizeof(parameter[0]));
4243                         parameter->type = entity->declaration.type;
4244
4245                         if (scope != NULL) {
4246                                 append_entity(scope, entity);
4247                         }
4248
4249                         if (last_parameter != NULL) {
4250                                 last_parameter->next = parameter;
4251                         } else {
4252                                 type->parameters = parameter;
4253                         }
4254                         last_parameter   = parameter;
4255                         break;
4256                 }
4257
4258                 default:
4259                         goto parameters_finished;
4260                 }
4261                 if (token.type != ',') {
4262                         goto parameters_finished;
4263                 }
4264                 next_token();
4265         }
4266
4267
4268 parameters_finished:
4269         rem_anchor_token(')');
4270         expect(')', end_error);
4271
4272 end_error:
4273         restore_anchor_state(',', saved_comma_state);
4274 }
4275
4276 typedef enum construct_type_kind_t {
4277         CONSTRUCT_INVALID,
4278         CONSTRUCT_POINTER,
4279         CONSTRUCT_REFERENCE,
4280         CONSTRUCT_FUNCTION,
4281         CONSTRUCT_ARRAY
4282 } construct_type_kind_t;
4283
4284 typedef struct construct_type_t construct_type_t;
4285 struct construct_type_t {
4286         construct_type_kind_t  kind;
4287         construct_type_t      *next;
4288 };
4289
4290 typedef struct parsed_pointer_t parsed_pointer_t;
4291 struct parsed_pointer_t {
4292         construct_type_t  construct_type;
4293         type_qualifiers_t type_qualifiers;
4294         variable_t        *base_variable;  /**< MS __based extension. */
4295 };
4296
4297 typedef struct parsed_reference_t parsed_reference_t;
4298 struct parsed_reference_t {
4299         construct_type_t construct_type;
4300 };
4301
4302 typedef struct construct_function_type_t construct_function_type_t;
4303 struct construct_function_type_t {
4304         construct_type_t  construct_type;
4305         type_t           *function_type;
4306 };
4307
4308 typedef struct parsed_array_t parsed_array_t;
4309 struct parsed_array_t {
4310         construct_type_t  construct_type;
4311         type_qualifiers_t type_qualifiers;
4312         bool              is_static;
4313         bool              is_variable;
4314         expression_t     *size;
4315 };
4316
4317 typedef struct construct_base_type_t construct_base_type_t;
4318 struct construct_base_type_t {
4319         construct_type_t  construct_type;
4320         type_t           *type;
4321 };
4322
4323 static construct_type_t *parse_pointer_declarator(variable_t *base_variable)
4324 {
4325         eat('*');
4326
4327         parsed_pointer_t *pointer = obstack_alloc(&temp_obst, sizeof(pointer[0]));
4328         memset(pointer, 0, sizeof(pointer[0]));
4329         pointer->construct_type.kind = CONSTRUCT_POINTER;
4330         pointer->type_qualifiers     = parse_type_qualifiers();
4331         pointer->base_variable       = base_variable;
4332
4333         return &pointer->construct_type;
4334 }
4335
4336 static construct_type_t *parse_reference_declarator(void)
4337 {
4338         eat('&');
4339
4340         parsed_reference_t *reference = obstack_alloc(&temp_obst, sizeof(reference[0]));
4341         memset(reference, 0, sizeof(reference[0]));
4342         reference->construct_type.kind = CONSTRUCT_REFERENCE;
4343
4344         return (construct_type_t*)reference;
4345 }
4346
4347 static construct_type_t *parse_array_declarator(void)
4348 {
4349         eat('[');
4350         add_anchor_token(']');
4351
4352         parsed_array_t *array = obstack_alloc(&temp_obst, sizeof(array[0]));
4353         memset(array, 0, sizeof(array[0]));
4354         array->construct_type.kind = CONSTRUCT_ARRAY;
4355
4356         if (token.type == T_static) {
4357                 array->is_static = true;
4358                 next_token();
4359         }
4360
4361         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
4362         if (type_qualifiers != 0) {
4363                 if (token.type == T_static) {
4364                         array->is_static = true;
4365                         next_token();
4366                 }
4367         }
4368         array->type_qualifiers = type_qualifiers;
4369
4370         if (token.type == '*' && look_ahead(1)->type == ']') {
4371                 array->is_variable = true;
4372                 next_token();
4373         } else if (token.type != ']') {
4374                 expression_t *const size = parse_assignment_expression();
4375                 array->size = size;
4376                 mark_vars_read(size, NULL);
4377         }
4378
4379         rem_anchor_token(']');
4380         expect(']', end_error);
4381
4382 end_error:
4383         return &array->construct_type;
4384 }
4385
4386 static construct_type_t *parse_function_declarator(scope_t *scope,
4387                                                    decl_modifiers_t modifiers)
4388 {
4389         type_t          *type  = allocate_type_zero(TYPE_FUNCTION);
4390         function_type_t *ftype = &type->function;
4391
4392         ftype->linkage = current_linkage;
4393
4394         switch (modifiers & (DM_CDECL | DM_STDCALL | DM_FASTCALL | DM_THISCALL)) {
4395                 case DM_NONE:     break;
4396                 case DM_CDECL:    ftype->calling_convention = CC_CDECL;    break;
4397                 case DM_STDCALL:  ftype->calling_convention = CC_STDCALL;  break;
4398                 case DM_FASTCALL: ftype->calling_convention = CC_FASTCALL; break;
4399                 case DM_THISCALL: ftype->calling_convention = CC_THISCALL; break;
4400
4401                 default:
4402                         errorf(HERE, "multiple calling conventions in declaration");
4403                         break;
4404         }
4405
4406         parse_parameters(ftype, scope);
4407
4408         construct_function_type_t *construct_function_type =
4409                 obstack_alloc(&temp_obst, sizeof(construct_function_type[0]));
4410         memset(construct_function_type, 0, sizeof(construct_function_type[0]));
4411         construct_function_type->construct_type.kind = CONSTRUCT_FUNCTION;
4412         construct_function_type->function_type       = type;
4413
4414         return &construct_function_type->construct_type;
4415 }
4416
4417 typedef struct parse_declarator_env_t {
4418         decl_modifiers_t   modifiers;
4419         symbol_t          *symbol;
4420         source_position_t  source_position;
4421         scope_t            parameters;
4422 } parse_declarator_env_t;
4423
4424 static construct_type_t *parse_inner_declarator(parse_declarator_env_t *env,
4425                 bool may_be_abstract)
4426 {
4427         /* construct a single linked list of construct_type_t's which describe
4428          * how to construct the final declarator type */
4429         construct_type_t *first      = NULL;
4430         construct_type_t *last       = NULL;
4431         gnu_attribute_t  *attributes = NULL;
4432
4433         decl_modifiers_t modifiers = parse_attributes(&attributes);
4434
4435         /* MS __based extension */
4436         based_spec_t base_spec;
4437         base_spec.base_variable = NULL;
4438
4439         for (;;) {
4440                 construct_type_t *type;
4441                 switch (token.type) {
4442                         case '&':
4443                                 if (!(c_mode & _CXX))
4444                                         errorf(HERE, "references are only available for C++");
4445                                 if (base_spec.base_variable != NULL && warning.other) {
4446                                         warningf(&base_spec.source_position,
4447                                                  "__based does not precede a pointer operator, ignored");
4448                                 }
4449                                 type = parse_reference_declarator();
4450                                 /* consumed */
4451                                 base_spec.base_variable = NULL;
4452                                 break;
4453
4454                         case '*':
4455                                 type = parse_pointer_declarator(base_spec.base_variable);
4456                                 /* consumed */
4457                                 base_spec.base_variable = NULL;
4458                                 break;
4459
4460                         case T__based:
4461                                 next_token();
4462                                 expect('(', end_error);
4463                                 add_anchor_token(')');
4464                                 parse_microsoft_based(&base_spec);
4465                                 rem_anchor_token(')');
4466                                 expect(')', end_error);
4467                                 continue;
4468
4469                         default:
4470                                 goto ptr_operator_end;
4471                 }
4472
4473                 if (last == NULL) {
4474                         first = type;
4475                         last  = type;
4476                 } else {
4477                         last->next = type;
4478                         last       = type;
4479                 }
4480
4481                 /* TODO: find out if this is correct */
4482                 modifiers |= parse_attributes(&attributes);
4483         }
4484 ptr_operator_end:
4485         if (base_spec.base_variable != NULL && warning.other) {
4486                 warningf(&base_spec.source_position,
4487                          "__based does not precede a pointer operator, ignored");
4488         }
4489
4490         if (env != NULL) {
4491                 modifiers      |= env->modifiers;
4492                 env->modifiers  = modifiers;
4493         }
4494
4495         construct_type_t *inner_types = NULL;
4496
4497         switch (token.type) {
4498         case T_IDENTIFIER:
4499                 if (env == NULL) {
4500                         errorf(HERE, "no identifier expected in typename");
4501                 } else {
4502                         env->symbol          = token.v.symbol;
4503                         env->source_position = token.source_position;
4504                 }
4505                 next_token();
4506                 break;
4507         case '(':
4508                 /* §6.7.6:2 footnote 126:  Empty parentheses in a type name are
4509                  * interpreted as ``function with no parameter specification'', rather
4510                  * than redundant parentheses around the omitted identifier. */
4511                 if (look_ahead(1)->type != ')') {
4512                         next_token();
4513                         add_anchor_token(')');
4514                         inner_types = parse_inner_declarator(env, may_be_abstract);
4515                         if (inner_types != NULL) {
4516                                 /* All later declarators only modify the return type */
4517                                 env = NULL;
4518                         }
4519                         rem_anchor_token(')');
4520                         expect(')', end_error);
4521                 }
4522                 break;
4523         default:
4524                 if (may_be_abstract)
4525                         break;
4526                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', NULL);
4527                 eat_until_anchor();
4528                 return NULL;
4529         }
4530
4531         construct_type_t *p = last;
4532
4533         while (true) {
4534                 construct_type_t *type;
4535                 switch (token.type) {
4536                 case '(': {
4537                         scope_t *scope = NULL;
4538                         if (env != NULL)
4539                                 scope = &env->parameters;
4540
4541                         type = parse_function_declarator(scope, modifiers);
4542                         break;
4543                 }
4544                 case '[':
4545                         type = parse_array_declarator();
4546                         break;
4547                 default:
4548                         goto declarator_finished;
4549                 }
4550
4551                 /* insert in the middle of the list (behind p) */
4552                 if (p != NULL) {
4553                         type->next = p->next;
4554                         p->next    = type;
4555                 } else {
4556                         type->next = first;
4557                         first      = type;
4558                 }
4559                 if (last == p) {
4560                         last = type;
4561                 }
4562         }
4563
4564 declarator_finished:
4565         /* append inner_types at the end of the list, we don't to set last anymore
4566          * as it's not needed anymore */
4567         if (last == NULL) {
4568                 assert(first == NULL);
4569                 first = inner_types;
4570         } else {
4571                 last->next = inner_types;
4572         }
4573
4574         return first;
4575 end_error:
4576         return NULL;
4577 }
4578
4579 static void parse_declaration_attributes(entity_t *entity)
4580 {
4581         gnu_attribute_t  *attributes = NULL;
4582         decl_modifiers_t  modifiers  = parse_attributes(&attributes);
4583
4584         if (entity == NULL)
4585                 return;
4586
4587         type_t *type;
4588         if (entity->kind == ENTITY_TYPEDEF) {
4589                 modifiers |= entity->typedefe.modifiers;
4590                 type       = entity->typedefe.type;
4591         } else {
4592                 assert(is_declaration(entity));
4593                 modifiers |= entity->declaration.modifiers;
4594                 type       = entity->declaration.type;
4595         }
4596         if (type == NULL)
4597                 return;
4598
4599         gnu_attribute_t *attribute = attributes;
4600         for ( ; attribute != NULL; attribute = attribute->next) {
4601                 if (attribute->invalid)
4602                         continue;
4603
4604                 if (attribute->kind == GNU_AK_MODE) {
4605                         type = handle_attribute_mode(attribute, type);
4606                 } else if (attribute->kind == GNU_AK_ALIGNED) {
4607                         int alignment = 32; /* TODO: fill in maximum usefull alignment for target machine */
4608                         if (attribute->has_arguments)
4609                                 alignment = attribute->u.argument;
4610
4611                         if (entity->kind == ENTITY_TYPEDEF) {
4612                                 type_t *copy         = duplicate_type(type);
4613                                 copy->base.alignment = attribute->u.argument;
4614                                 type                 = identify_new_type(copy);
4615                         } else if(entity->kind == ENTITY_VARIABLE) {
4616                                 entity->variable.alignment = alignment;
4617                         } else if(entity->kind == ENTITY_COMPOUND_MEMBER) {
4618                                 entity->compound_member.alignment = alignment;
4619                         }
4620                 }
4621         }
4622
4623         type_modifiers_t type_modifiers = type->base.modifiers;
4624         if (modifiers & DM_TRANSPARENT_UNION)
4625                 type_modifiers |= TYPE_MODIFIER_TRANSPARENT_UNION;
4626
4627         if (type->base.modifiers != type_modifiers) {
4628                 type_t *copy         = duplicate_type(type);
4629                 copy->base.modifiers = type_modifiers;
4630                 type                 = identify_new_type(copy);
4631         }
4632
4633         if (entity->kind == ENTITY_TYPEDEF) {
4634                 entity->typedefe.type      = type;
4635                 entity->typedefe.modifiers = modifiers;
4636         } else {
4637                 entity->declaration.type      = type;
4638                 entity->declaration.modifiers = modifiers;
4639         }
4640 }
4641
4642 static type_t *construct_declarator_type(construct_type_t *construct_list, type_t *type)
4643 {
4644         construct_type_t *iter = construct_list;
4645         for (; iter != NULL; iter = iter->next) {
4646                 switch (iter->kind) {
4647                 case CONSTRUCT_INVALID:
4648                         internal_errorf(HERE, "invalid type construction found");
4649                 case CONSTRUCT_FUNCTION: {
4650                         construct_function_type_t *construct_function_type
4651                                 = (construct_function_type_t*) iter;
4652
4653                         type_t *function_type = construct_function_type->function_type;
4654
4655                         function_type->function.return_type = type;
4656
4657                         type_t *skipped_return_type = skip_typeref(type);
4658                         /* §6.7.5.3:1 */
4659                         if (is_type_function(skipped_return_type)) {
4660                                 errorf(HERE, "function returning function is not allowed");
4661                         } else if (is_type_array(skipped_return_type)) {
4662                                 errorf(HERE, "function returning array is not allowed");
4663                         } else {
4664                                 if (skipped_return_type->base.qualifiers != 0 && warning.other) {
4665                                         warningf(HERE,
4666                                                 "type qualifiers in return type of function type are meaningless");
4667                                 }
4668                         }
4669
4670                         type = function_type;
4671                         break;
4672                 }
4673
4674                 case CONSTRUCT_POINTER: {
4675                         if (is_type_reference(skip_typeref(type)))
4676                                 errorf(HERE, "cannot declare a pointer to reference");
4677
4678                         parsed_pointer_t *parsed_pointer = (parsed_pointer_t*) iter;
4679                         type = make_based_pointer_type(type, parsed_pointer->type_qualifiers, parsed_pointer->base_variable);
4680                         continue;
4681                 }
4682
4683                 case CONSTRUCT_REFERENCE:
4684                         if (is_type_reference(skip_typeref(type)))
4685                                 errorf(HERE, "cannot declare a reference to reference");
4686
4687                         type = make_reference_type(type);
4688                         continue;
4689
4690                 case CONSTRUCT_ARRAY: {
4691                         if (is_type_reference(skip_typeref(type)))
4692                                 errorf(HERE, "cannot declare an array of references");
4693
4694                         parsed_array_t *parsed_array  = (parsed_array_t*) iter;
4695                         type_t         *array_type    = allocate_type_zero(TYPE_ARRAY);
4696
4697                         expression_t *size_expression = parsed_array->size;
4698                         if (size_expression != NULL) {
4699                                 size_expression
4700                                         = create_implicit_cast(size_expression, type_size_t);
4701                         }
4702
4703                         array_type->base.qualifiers       = parsed_array->type_qualifiers;
4704                         array_type->array.element_type    = type;
4705                         array_type->array.is_static       = parsed_array->is_static;
4706                         array_type->array.is_variable     = parsed_array->is_variable;
4707                         array_type->array.size_expression = size_expression;
4708
4709                         if (size_expression != NULL) {
4710                                 if (is_constant_expression(size_expression)) {
4711                                         array_type->array.size_constant = true;
4712                                         array_type->array.size
4713                                                 = fold_constant(size_expression);
4714                                 } else {
4715                                         array_type->array.is_vla = true;
4716                                 }
4717                         }
4718
4719                         type_t *skipped_type = skip_typeref(type);
4720                         /* §6.7.5.2:1 */
4721                         if (is_type_incomplete(skipped_type)) {
4722                                 errorf(HERE, "array of incomplete type '%T' is not allowed", type);
4723                         } else if (is_type_function(skipped_type)) {
4724                                 errorf(HERE, "array of functions is not allowed");
4725                         }
4726                         type = array_type;
4727                         break;
4728                 }
4729                 }
4730
4731                 /* The function type was constructed earlier.  Freeing it here will
4732                  * destroy other types. */
4733                 if (iter->kind == CONSTRUCT_FUNCTION) {
4734                         type = typehash_insert(type);
4735                 } else {
4736                         type = identify_new_type(type);
4737                 }
4738         }
4739
4740         return type;
4741 }
4742
4743 static type_t *automatic_type_conversion(type_t *orig_type);
4744
4745 static type_t *semantic_parameter(const source_position_t *pos,
4746                                   type_t *type,
4747                                   const declaration_specifiers_t *specifiers,
4748                                   symbol_t *symbol)
4749 {
4750         /* §6.7.5.3:7  A declaration of a parameter as ``array of type''
4751          *             shall be adjusted to ``qualified pointer to type'',
4752          *             [...]
4753          * §6.7.5.3:8  A declaration of a parameter as ``function returning
4754          *             type'' shall be adjusted to ``pointer to function
4755          *             returning type'', as in 6.3.2.1. */
4756         type = automatic_type_conversion(type);
4757
4758         if (specifiers->is_inline && is_type_valid(type)) {
4759                 errorf(pos, "parameter '%Y' declared 'inline'", symbol);
4760         }
4761
4762         /* §6.9.1:6  The declarations in the declaration list shall contain
4763          *           no storage-class specifier other than register and no
4764          *           initializations. */
4765         if (specifiers->thread_local || (
4766                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
4767                         specifiers->storage_class != STORAGE_CLASS_REGISTER)
4768            ) {
4769                 errorf(pos, "invalid storage class for parameter '%Y'", symbol);
4770         }
4771
4772         /* delay test for incomplete type, because we might have (void)
4773          * which is legal but incomplete... */
4774
4775         return type;
4776 }
4777
4778 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
4779                                   declarator_flags_t flags)
4780 {
4781         parse_declarator_env_t env;
4782         memset(&env, 0, sizeof(env));
4783         env.modifiers = specifiers->modifiers;
4784
4785         construct_type_t *construct_type =
4786                 parse_inner_declarator(&env, (flags & DECL_MAY_BE_ABSTRACT) != 0);
4787         type_t           *orig_type      =
4788                 construct_declarator_type(construct_type, specifiers->type);
4789         type_t           *type           = skip_typeref(orig_type);
4790
4791         if (construct_type != NULL) {
4792                 obstack_free(&temp_obst, construct_type);
4793         }
4794
4795         entity_t *entity;
4796         if (specifiers->storage_class == STORAGE_CLASS_TYPEDEF) {
4797                 entity                       = allocate_entity_zero(ENTITY_TYPEDEF);
4798                 entity->base.symbol          = env.symbol;
4799                 entity->base.source_position = env.source_position;
4800                 entity->typedefe.type        = orig_type;
4801
4802                 if (anonymous_entity != NULL) {
4803                         if (is_type_compound(type)) {
4804                                 assert(anonymous_entity->compound.alias == NULL);
4805                                 assert(anonymous_entity->kind == ENTITY_STRUCT ||
4806                                        anonymous_entity->kind == ENTITY_UNION);
4807                                 anonymous_entity->compound.alias = entity;
4808                                 anonymous_entity = NULL;
4809                         } else if (is_type_enum(type)) {
4810                                 assert(anonymous_entity->enume.alias == NULL);
4811                                 assert(anonymous_entity->kind == ENTITY_ENUM);
4812                                 anonymous_entity->enume.alias = entity;
4813                                 anonymous_entity = NULL;
4814                         }
4815                 }
4816         } else {
4817                 /* create a declaration type entity */
4818                 if (flags & DECL_CREATE_COMPOUND_MEMBER) {
4819                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER);
4820
4821                         if (env.symbol != NULL) {
4822                                 if (specifiers->is_inline && is_type_valid(type)) {
4823                                         errorf(&env.source_position,
4824                                                         "compound member '%Y' declared 'inline'", env.symbol);
4825                                 }
4826
4827                                 if (specifiers->thread_local ||
4828                                                 specifiers->storage_class != STORAGE_CLASS_NONE) {
4829                                         errorf(&env.source_position,
4830                                                         "compound member '%Y' must have no storage class",
4831                                                         env.symbol);
4832                                 }
4833                         }
4834                 } else if (flags & DECL_IS_PARAMETER) {
4835                         orig_type = semantic_parameter(&env.source_position, orig_type,
4836                                                        specifiers, env.symbol);
4837
4838                         entity = allocate_entity_zero(ENTITY_PARAMETER);
4839                 } else if (is_type_function(type)) {
4840                         entity = allocate_entity_zero(ENTITY_FUNCTION);
4841
4842                         entity->function.is_inline  = specifiers->is_inline;
4843                         entity->function.parameters = env.parameters;
4844
4845                         if (env.symbol != NULL) {
4846                                 if (specifiers->thread_local || (
4847                                                         specifiers->storage_class != STORAGE_CLASS_EXTERN &&
4848                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
4849                                                         specifiers->storage_class != STORAGE_CLASS_STATIC
4850                                                 )) {
4851                                         errorf(&env.source_position,
4852                                                         "invalid storage class for function '%Y'", env.symbol);
4853                                 }
4854                         }
4855                 } else {
4856                         entity = allocate_entity_zero(ENTITY_VARIABLE);
4857
4858                         entity->variable.get_property_sym = specifiers->get_property_sym;
4859                         entity->variable.put_property_sym = specifiers->put_property_sym;
4860
4861                         entity->variable.thread_local = specifiers->thread_local;
4862
4863                         if (env.symbol != NULL) {
4864                                 if (specifiers->is_inline && is_type_valid(type)) {
4865                                         errorf(&env.source_position,
4866                                                         "variable '%Y' declared 'inline'", env.symbol);
4867                                 }
4868
4869                                 bool invalid_storage_class = false;
4870                                 if (current_scope == file_scope) {
4871                                         if (specifiers->storage_class != STORAGE_CLASS_EXTERN &&
4872                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
4873                                                         specifiers->storage_class != STORAGE_CLASS_STATIC) {
4874                                                 invalid_storage_class = true;
4875                                         }
4876                                 } else {
4877                                         if (specifiers->thread_local &&
4878                                                         specifiers->storage_class == STORAGE_CLASS_NONE) {
4879                                                 invalid_storage_class = true;
4880                                         }
4881                                 }
4882                                 if (invalid_storage_class) {
4883                                         errorf(&env.source_position,
4884                                                         "invalid storage class for variable '%Y'", env.symbol);
4885                                 }
4886                         }
4887                 }
4888
4889                 if (env.symbol != NULL) {
4890                         entity->base.symbol          = env.symbol;
4891                         entity->base.source_position = env.source_position;
4892                 } else {
4893                         entity->base.source_position = specifiers->source_position;
4894                 }
4895                 entity->base.namespc                  = NAMESPACE_NORMAL;
4896                 entity->declaration.type              = orig_type;
4897                 entity->declaration.modifiers         = env.modifiers;
4898                 entity->declaration.deprecated_string = specifiers->deprecated_string;
4899
4900                 storage_class_t storage_class = specifiers->storage_class;
4901                 entity->declaration.declared_storage_class = storage_class;
4902
4903                 if (storage_class == STORAGE_CLASS_NONE && current_scope != file_scope)
4904                         storage_class = STORAGE_CLASS_AUTO;
4905                 entity->declaration.storage_class = storage_class;
4906         }
4907
4908         parse_declaration_attributes(entity);
4909
4910         return entity;
4911 }
4912
4913 static type_t *parse_abstract_declarator(type_t *base_type)
4914 {
4915         construct_type_t *construct_type = parse_inner_declarator(NULL, 1);
4916
4917         type_t *result = construct_declarator_type(construct_type, base_type);
4918         if (construct_type != NULL) {
4919                 obstack_free(&temp_obst, construct_type);
4920         }
4921
4922         return result;
4923 }
4924
4925 /**
4926  * Check if the declaration of main is suspicious.  main should be a
4927  * function with external linkage, returning int, taking either zero
4928  * arguments, two, or three arguments of appropriate types, ie.
4929  *
4930  * int main([ int argc, char **argv [, char **env ] ]).
4931  *
4932  * @param decl    the declaration to check
4933  * @param type    the function type of the declaration
4934  */
4935 static void check_type_of_main(const entity_t *entity)
4936 {
4937         const source_position_t *pos = &entity->base.source_position;
4938         if (entity->kind != ENTITY_FUNCTION) {
4939                 warningf(pos, "'main' is not a function");
4940                 return;
4941         }
4942
4943         if (entity->declaration.storage_class == STORAGE_CLASS_STATIC) {
4944                 warningf(pos, "'main' is normally a non-static function");
4945         }
4946
4947         type_t *type = skip_typeref(entity->declaration.type);
4948         assert(is_type_function(type));
4949
4950         function_type_t *func_type = &type->function;
4951         if (!types_compatible(skip_typeref(func_type->return_type), type_int)) {
4952                 warningf(pos, "return type of 'main' should be 'int', but is '%T'",
4953                          func_type->return_type);
4954         }
4955         const function_parameter_t *parm = func_type->parameters;
4956         if (parm != NULL) {
4957                 type_t *const first_type = parm->type;
4958                 if (!types_compatible(skip_typeref(first_type), type_int)) {
4959                         warningf(pos,
4960                                  "first argument of 'main' should be 'int', but is '%T'",
4961                                  first_type);
4962                 }
4963                 parm = parm->next;
4964                 if (parm != NULL) {
4965                         type_t *const second_type = parm->type;
4966                         if (!types_compatible(skip_typeref(second_type), type_char_ptr_ptr)) {
4967                                 warningf(pos, "second argument of 'main' should be 'char**', but is '%T'", second_type);
4968                         }
4969                         parm = parm->next;
4970                         if (parm != NULL) {
4971                                 type_t *const third_type = parm->type;
4972                                 if (!types_compatible(skip_typeref(third_type), type_char_ptr_ptr)) {
4973                                         warningf(pos, "third argument of 'main' should be 'char**', but is '%T'", third_type);
4974                                 }
4975                                 parm = parm->next;
4976                                 if (parm != NULL)
4977                                         goto warn_arg_count;
4978                         }
4979                 } else {
4980 warn_arg_count:
4981                         warningf(pos, "'main' takes only zero, two or three arguments");
4982                 }
4983         }
4984 }
4985
4986 /**
4987  * Check if a symbol is the equal to "main".
4988  */
4989 static bool is_sym_main(const symbol_t *const sym)
4990 {
4991         return strcmp(sym->string, "main") == 0;
4992 }
4993
4994 static void error_redefined_as_different_kind(const source_position_t *pos,
4995                 const entity_t *old, entity_kind_t new_kind)
4996 {
4997         errorf(pos, "redeclaration of %s '%Y' as %s (declared %P)",
4998                get_entity_kind_name(old->kind), old->base.symbol,
4999                get_entity_kind_name(new_kind), &old->base.source_position);
5000 }
5001
5002 static bool is_error_entity(entity_t *const ent)
5003 {
5004         if (is_declaration(ent)) {
5005                 return is_type_valid(skip_typeref(ent->declaration.type));
5006         } else if (ent->kind == ENTITY_TYPEDEF) {
5007                 return is_type_valid(skip_typeref(ent->typedefe.type));
5008         }
5009         return false;
5010 }
5011
5012 /**
5013  * record entities for the NAMESPACE_NORMAL, and produce error messages/warnings
5014  * for various problems that occur for multiple definitions
5015  */
5016 static entity_t *record_entity(entity_t *entity, const bool is_definition)
5017 {
5018         const symbol_t *const    symbol  = entity->base.symbol;
5019         const namespace_tag_t    namespc = (namespace_tag_t)entity->base.namespc;
5020         const source_position_t *pos     = &entity->base.source_position;
5021
5022         /* can happen in error cases */
5023         if (symbol == NULL)
5024                 return entity;
5025
5026         entity_t *previous_entity = get_entity(symbol, namespc);
5027         /* pushing the same entity twice will break the stack structure */
5028         assert(previous_entity != entity);
5029
5030         if (entity->kind == ENTITY_FUNCTION) {
5031                 type_t *const orig_type = entity->declaration.type;
5032                 type_t *const type      = skip_typeref(orig_type);
5033
5034                 assert(is_type_function(type));
5035                 if (type->function.unspecified_parameters &&
5036                                 warning.strict_prototypes &&
5037                                 previous_entity == NULL) {
5038                         warningf(pos, "function declaration '%#T' is not a prototype",
5039                                          orig_type, symbol);
5040                 }
5041
5042                 if (warning.main && current_scope == file_scope
5043                                 && is_sym_main(symbol)) {
5044                         check_type_of_main(entity);
5045                 }
5046         }
5047
5048         if (is_declaration(entity) &&
5049                         warning.nested_externs &&
5050                         entity->declaration.storage_class == STORAGE_CLASS_EXTERN &&
5051                         current_scope != file_scope) {
5052                 warningf(pos, "nested extern declaration of '%#T'",
5053                          entity->declaration.type, symbol);
5054         }
5055
5056         if (previous_entity != NULL &&
5057                         previous_entity->base.parent_scope == &current_function->parameters &&
5058                         previous_entity->base.parent_scope->depth + 1 == current_scope->depth) {
5059                 assert(previous_entity->kind == ENTITY_PARAMETER);
5060                 errorf(pos,
5061                        "declaration '%#T' redeclares the parameter '%#T' (declared %P)",
5062                                          entity->declaration.type, symbol,
5063                                          previous_entity->declaration.type, symbol,
5064                                          &previous_entity->base.source_position);
5065                 goto finish;
5066         }
5067
5068         if (previous_entity != NULL &&
5069                         previous_entity->base.parent_scope == current_scope) {
5070                 if (previous_entity->kind != entity->kind) {
5071                         if (!is_error_entity(previous_entity) && !is_error_entity(entity)) {
5072                                 error_redefined_as_different_kind(pos, previous_entity,
5073                                                 entity->kind);
5074                         }
5075                         goto finish;
5076                 }
5077                 if (previous_entity->kind == ENTITY_ENUM_VALUE) {
5078                         errorf(pos, "redeclaration of enum entry '%Y' (declared %P)",
5079                                    symbol, &previous_entity->base.source_position);
5080                         goto finish;
5081                 }
5082                 if (previous_entity->kind == ENTITY_TYPEDEF) {
5083                         /* TODO: C++ allows this for exactly the same type */
5084                         errorf(pos, "redefinition of typedef '%Y' (declared %P)",
5085                                symbol, &previous_entity->base.source_position);
5086                         goto finish;
5087                 }
5088
5089                 /* at this point we should have only VARIABLES or FUNCTIONS */
5090                 assert(is_declaration(previous_entity) && is_declaration(entity));
5091
5092                 declaration_t *const prev_decl = &previous_entity->declaration;
5093                 declaration_t *const decl      = &entity->declaration;
5094
5095                 /* can happen for K&R style declarations */
5096                 if (prev_decl->type       == NULL             &&
5097                                 previous_entity->kind == ENTITY_PARAMETER &&
5098                                 entity->kind          == ENTITY_PARAMETER) {
5099                         prev_decl->type                   = decl->type;
5100                         prev_decl->storage_class          = decl->storage_class;
5101                         prev_decl->declared_storage_class = decl->declared_storage_class;
5102                         prev_decl->modifiers              = decl->modifiers;
5103                         prev_decl->deprecated_string      = decl->deprecated_string;
5104                         return previous_entity;
5105                 }
5106
5107                 type_t *const orig_type = decl->type;
5108                 assert(orig_type != NULL);
5109                 type_t *const type      = skip_typeref(orig_type);
5110                 type_t *const prev_type = skip_typeref(prev_decl->type);
5111
5112                 if (!types_compatible(type, prev_type)) {
5113                         errorf(pos,
5114                                    "declaration '%#T' is incompatible with '%#T' (declared %P)",
5115                                    orig_type, symbol, prev_decl->type, symbol,
5116                                    &previous_entity->base.source_position);
5117                 } else {
5118                         unsigned old_storage_class = prev_decl->storage_class;
5119                         if (warning.redundant_decls               &&
5120                                         is_definition                     &&
5121                                         !prev_decl->used                  &&
5122                                         !(prev_decl->modifiers & DM_USED) &&
5123                                         prev_decl->storage_class == STORAGE_CLASS_STATIC) {
5124                                 warningf(&previous_entity->base.source_position,
5125                                          "unnecessary static forward declaration for '%#T'",
5126                                          prev_decl->type, symbol);
5127                         }
5128
5129                         storage_class_t new_storage_class = decl->storage_class;
5130
5131                         /* pretend no storage class means extern for function
5132                          * declarations (except if the previous declaration is neither
5133                          * none nor extern) */
5134                         if (entity->kind == ENTITY_FUNCTION) {
5135                                 /* the previous declaration could have unspecified parameters or
5136                                  * be a typedef, so use the new type */
5137                                 if (prev_type->function.unspecified_parameters || is_definition)
5138                                         prev_decl->type = type;
5139
5140                                 switch (old_storage_class) {
5141                                 case STORAGE_CLASS_NONE:
5142                                         old_storage_class = STORAGE_CLASS_EXTERN;
5143                                         /* FALLTHROUGH */
5144
5145                                 case STORAGE_CLASS_EXTERN:
5146                                         if (is_definition) {
5147                                                 if (warning.missing_prototypes &&
5148                                                     prev_type->function.unspecified_parameters &&
5149                                                     !is_sym_main(symbol)) {
5150                                                         warningf(pos, "no previous prototype for '%#T'",
5151                                                                          orig_type, symbol);
5152                                                 }
5153                                         } else if (new_storage_class == STORAGE_CLASS_NONE) {
5154                                                 new_storage_class = STORAGE_CLASS_EXTERN;
5155                                         }
5156                                         break;
5157
5158                                 default:
5159                                         break;
5160                                 }
5161                         } else if (is_type_incomplete(prev_type)) {
5162                                 prev_decl->type = type;
5163                         }
5164
5165                         if (old_storage_class == STORAGE_CLASS_EXTERN &&
5166                                         new_storage_class == STORAGE_CLASS_EXTERN) {
5167 warn_redundant_declaration:
5168                                 if (!is_definition           &&
5169                                     warning.redundant_decls  &&
5170                                     is_type_valid(prev_type) &&
5171                                     strcmp(previous_entity->base.source_position.input_name,
5172                                            "<builtin>") != 0) {
5173                                         warningf(pos,
5174                                                  "redundant declaration for '%Y' (declared %P)",
5175                                                  symbol, &previous_entity->base.source_position);
5176                                 }
5177                         } else if (current_function == NULL) {
5178                                 if (old_storage_class != STORAGE_CLASS_STATIC &&
5179                                     new_storage_class == STORAGE_CLASS_STATIC) {
5180                                         errorf(pos,
5181                                                "static declaration of '%Y' follows non-static declaration (declared %P)",
5182                                                symbol, &previous_entity->base.source_position);
5183                                 } else if (old_storage_class == STORAGE_CLASS_EXTERN) {
5184                                         prev_decl->storage_class          = STORAGE_CLASS_NONE;
5185                                         prev_decl->declared_storage_class = STORAGE_CLASS_NONE;
5186                                 } else {
5187                                         /* ISO/IEC 14882:1998(E) §C.1.2:1 */
5188                                         if (c_mode & _CXX)
5189                                                 goto error_redeclaration;
5190                                         goto warn_redundant_declaration;
5191                                 }
5192                         } else if (is_type_valid(prev_type)) {
5193                                 if (old_storage_class == new_storage_class) {
5194 error_redeclaration:
5195                                         errorf(pos, "redeclaration of '%Y' (declared %P)",
5196                                                symbol, &previous_entity->base.source_position);
5197                                 } else {
5198                                         errorf(pos,
5199                                                "redeclaration of '%Y' with different linkage (declared %P)",
5200                                                symbol, &previous_entity->base.source_position);
5201                                 }
5202                         }
5203                 }
5204
5205                 prev_decl->modifiers |= decl->modifiers;
5206                 if (entity->kind == ENTITY_FUNCTION) {
5207                         previous_entity->function.is_inline |= entity->function.is_inline;
5208                 }
5209                 return previous_entity;
5210         }
5211
5212         if (entity->kind == ENTITY_FUNCTION) {
5213                 if (is_definition &&
5214                                 entity->declaration.storage_class != STORAGE_CLASS_STATIC) {
5215                         if (warning.missing_prototypes && !is_sym_main(symbol)) {
5216                                 warningf(pos, "no previous prototype for '%#T'",
5217                                          entity->declaration.type, symbol);
5218                         } else if (warning.missing_declarations && !is_sym_main(symbol)) {
5219                                 warningf(pos, "no previous declaration for '%#T'",
5220                                          entity->declaration.type, symbol);
5221                         }
5222                 }
5223         } else if (warning.missing_declarations &&
5224                         entity->kind == ENTITY_VARIABLE &&
5225                         current_scope == file_scope) {
5226                 declaration_t *declaration = &entity->declaration;
5227                 if (declaration->storage_class == STORAGE_CLASS_NONE) {
5228                         warningf(pos, "no previous declaration for '%#T'",
5229                                  declaration->type, symbol);
5230                 }
5231         }
5232
5233 finish:
5234         assert(entity->base.parent_scope == NULL);
5235         assert(current_scope != NULL);
5236
5237         entity->base.parent_scope = current_scope;
5238         entity->base.namespc      = NAMESPACE_NORMAL;
5239         environment_push(entity);
5240         append_entity(current_scope, entity);
5241
5242         return entity;
5243 }
5244
5245 static void parser_error_multiple_definition(entity_t *entity,
5246                 const source_position_t *source_position)
5247 {
5248         errorf(source_position, "multiple definition of '%Y' (declared %P)",
5249                entity->base.symbol, &entity->base.source_position);
5250 }
5251
5252 static bool is_declaration_specifier(const token_t *token,
5253                                      bool only_specifiers_qualifiers)
5254 {
5255         switch (token->type) {
5256                 TYPE_SPECIFIERS
5257                 TYPE_QUALIFIERS
5258                         return true;
5259                 case T_IDENTIFIER:
5260                         return is_typedef_symbol(token->v.symbol);
5261
5262                 case T___extension__:
5263                 STORAGE_CLASSES
5264                         return !only_specifiers_qualifiers;
5265
5266                 default:
5267                         return false;
5268         }
5269 }
5270
5271 static void parse_init_declarator_rest(entity_t *entity)
5272 {
5273         assert(is_declaration(entity));
5274         declaration_t *const declaration = &entity->declaration;
5275
5276         eat('=');
5277
5278         type_t *orig_type = declaration->type;
5279         type_t *type      = skip_typeref(orig_type);
5280
5281         if (entity->kind == ENTITY_VARIABLE
5282                         && entity->variable.initializer != NULL) {
5283                 parser_error_multiple_definition(entity, HERE);
5284         }
5285
5286         bool must_be_constant = false;
5287         if (declaration->storage_class == STORAGE_CLASS_STATIC ||
5288             entity->base.parent_scope  == file_scope) {
5289                 must_be_constant = true;
5290         }
5291
5292         if (is_type_function(type)) {
5293                 errorf(&entity->base.source_position,
5294                        "function '%#T' is initialized like a variable",
5295                        orig_type, entity->base.symbol);
5296                 orig_type = type_error_type;
5297         }
5298
5299         parse_initializer_env_t env;
5300         env.type             = orig_type;
5301         env.must_be_constant = must_be_constant;
5302         env.entity           = entity;
5303         current_init_decl    = entity;
5304
5305         initializer_t *initializer = parse_initializer(&env);
5306         current_init_decl = NULL;
5307
5308         if (entity->kind == ENTITY_VARIABLE) {
5309                 /* § 6.7.5:22  array initializers for arrays with unknown size
5310                  * determine the array type size */
5311                 declaration->type            = env.type;
5312                 entity->variable.initializer = initializer;
5313         }
5314 }
5315
5316 /* parse rest of a declaration without any declarator */
5317 static void parse_anonymous_declaration_rest(
5318                 const declaration_specifiers_t *specifiers)
5319 {
5320         eat(';');
5321         anonymous_entity = NULL;
5322
5323         if (warning.other) {
5324                 if (specifiers->storage_class != STORAGE_CLASS_NONE ||
5325                                 specifiers->thread_local) {
5326                         warningf(&specifiers->source_position,
5327                                  "useless storage class in empty declaration");
5328                 }
5329
5330                 type_t *type = specifiers->type;
5331                 switch (type->kind) {
5332                         case TYPE_COMPOUND_STRUCT:
5333                         case TYPE_COMPOUND_UNION: {
5334                                 if (type->compound.compound->base.symbol == NULL) {
5335                                         warningf(&specifiers->source_position,
5336                                                  "unnamed struct/union that defines no instances");
5337                                 }
5338                                 break;
5339                         }
5340
5341                         case TYPE_ENUM:
5342                                 break;
5343
5344                         default:
5345                                 warningf(&specifiers->source_position, "empty declaration");
5346                                 break;
5347                 }
5348         }
5349 }
5350
5351 static void check_variable_type_complete(entity_t *ent)
5352 {
5353         if (ent->kind != ENTITY_VARIABLE)
5354                 return;
5355
5356         /* §6.7:7  If an identifier for an object is declared with no linkage, the
5357          *         type for the object shall be complete [...] */
5358         declaration_t *decl = &ent->declaration;
5359         if (decl->storage_class != STORAGE_CLASS_NONE)
5360                 return;
5361
5362         type_t *const orig_type = decl->type;
5363         type_t *const type      = skip_typeref(orig_type);
5364         if (!is_type_incomplete(type))
5365                 return;
5366
5367         /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
5368          * are given length one. */
5369         if (is_type_array(type) && ent->base.parent_scope == file_scope) {
5370                 ARR_APP1(declaration_t*, incomplete_arrays, decl);
5371                 return;
5372         }
5373
5374         errorf(&ent->base.source_position, "variable '%#T' has incomplete type",
5375                         orig_type, ent->base.symbol);
5376 }
5377
5378
5379 static void parse_declaration_rest(entity_t *ndeclaration,
5380                 const declaration_specifiers_t *specifiers,
5381                 parsed_declaration_func         finished_declaration,
5382                 declarator_flags_t              flags)
5383 {
5384         add_anchor_token(';');
5385         add_anchor_token(',');
5386         while (true) {
5387                 entity_t *entity = finished_declaration(ndeclaration, token.type == '=');
5388
5389                 if (token.type == '=') {
5390                         parse_init_declarator_rest(entity);
5391                 } else if (entity->kind == ENTITY_VARIABLE) {
5392                         /* ISO/IEC 14882:1998(E) §8.5.3:3  The initializer can be omitted
5393                          * [...] where the extern specifier is explicitly used. */
5394                         declaration_t *decl = &entity->declaration;
5395                         if (decl->storage_class != STORAGE_CLASS_EXTERN) {
5396                                 type_t *type = decl->type;
5397                                 if (is_type_reference(skip_typeref(type))) {
5398                                         errorf(&entity->base.source_position,
5399                                                         "reference '%#T' must be initialized",
5400                                                         type, entity->base.symbol);
5401                                 }
5402                         }
5403                 }
5404
5405                 check_variable_type_complete(entity);
5406
5407                 if (token.type != ',')
5408                         break;
5409                 eat(',');
5410
5411                 add_anchor_token('=');
5412                 ndeclaration = parse_declarator(specifiers, flags);
5413                 rem_anchor_token('=');
5414         }
5415         expect(';', end_error);
5416
5417 end_error:
5418         anonymous_entity = NULL;
5419         rem_anchor_token(';');
5420         rem_anchor_token(',');
5421 }
5422
5423 static entity_t *finished_kr_declaration(entity_t *entity, bool is_definition)
5424 {
5425         symbol_t *symbol = entity->base.symbol;
5426         if (symbol == NULL) {
5427                 errorf(HERE, "anonymous declaration not valid as function parameter");
5428                 return entity;
5429         }
5430
5431         assert(entity->base.namespc == NAMESPACE_NORMAL);
5432         entity_t *previous_entity = get_entity(symbol, NAMESPACE_NORMAL);
5433         if (previous_entity == NULL
5434                         || previous_entity->base.parent_scope != current_scope) {
5435                 errorf(HERE, "expected declaration of a function parameter, found '%Y'",
5436                        symbol);
5437                 return entity;
5438         }
5439
5440         if (is_definition) {
5441                 errorf(HERE, "parameter '%Y' is initialised", entity->base.symbol);
5442         }
5443
5444         return record_entity(entity, false);
5445 }
5446
5447 static void parse_declaration(parsed_declaration_func finished_declaration,
5448                               declarator_flags_t      flags)
5449 {
5450         declaration_specifiers_t specifiers;
5451         memset(&specifiers, 0, sizeof(specifiers));
5452
5453         add_anchor_token(';');
5454         parse_declaration_specifiers(&specifiers);
5455         rem_anchor_token(';');
5456
5457         if (token.type == ';') {
5458                 parse_anonymous_declaration_rest(&specifiers);
5459         } else {
5460                 entity_t *entity = parse_declarator(&specifiers, flags);
5461                 parse_declaration_rest(entity, &specifiers, finished_declaration, flags);
5462         }
5463 }
5464
5465 static type_t *get_default_promoted_type(type_t *orig_type)
5466 {
5467         type_t *result = orig_type;
5468
5469         type_t *type = skip_typeref(orig_type);
5470         if (is_type_integer(type)) {
5471                 result = promote_integer(type);
5472         } else if (type == type_float) {
5473                 result = type_double;
5474         }
5475
5476         return result;
5477 }
5478
5479 static void parse_kr_declaration_list(entity_t *entity)
5480 {
5481         if (entity->kind != ENTITY_FUNCTION)
5482                 return;
5483
5484         type_t *type = skip_typeref(entity->declaration.type);
5485         assert(is_type_function(type));
5486         if (!type->function.kr_style_parameters)
5487                 return;
5488
5489
5490         add_anchor_token('{');
5491
5492         /* push function parameters */
5493         size_t const  top       = environment_top();
5494         scope_t      *old_scope = scope_push(&entity->function.parameters);
5495
5496         entity_t *parameter = entity->function.parameters.entities;
5497         for ( ; parameter != NULL; parameter = parameter->base.next) {
5498                 assert(parameter->base.parent_scope == NULL);
5499                 parameter->base.parent_scope = current_scope;
5500                 environment_push(parameter);
5501         }
5502
5503         /* parse declaration list */
5504         for (;;) {
5505                 switch (token.type) {
5506                         DECLARATION_START
5507                         case T___extension__:
5508                         /* This covers symbols, which are no type, too, and results in
5509                          * better error messages.  The typical cases are misspelled type
5510                          * names and missing includes. */
5511                         case T_IDENTIFIER:
5512                                 parse_declaration(finished_kr_declaration, DECL_IS_PARAMETER);
5513                                 break;
5514                         default:
5515                                 goto decl_list_end;
5516                 }
5517         }
5518 decl_list_end:
5519
5520         /* pop function parameters */
5521         assert(current_scope == &entity->function.parameters);
5522         scope_pop(old_scope);
5523         environment_pop_to(top);
5524
5525         /* update function type */
5526         type_t *new_type = duplicate_type(type);
5527
5528         function_parameter_t *parameters     = NULL;
5529         function_parameter_t *last_parameter = NULL;
5530
5531         parameter = entity->function.parameters.entities;
5532         for (; parameter != NULL; parameter = parameter->base.next) {
5533                 type_t *parameter_type = parameter->declaration.type;
5534                 if (parameter_type == NULL) {
5535                         if (strict_mode) {
5536                                 errorf(HERE, "no type specified for function parameter '%Y'",
5537                                        parameter->base.symbol);
5538                         } else {
5539                                 if (warning.implicit_int) {
5540                                         warningf(HERE, "no type specified for function parameter '%Y', using 'int'",
5541                                                  parameter->base.symbol);
5542                                 }
5543                                 parameter_type              = type_int;
5544                                 parameter->declaration.type = parameter_type;
5545                         }
5546                 }
5547
5548                 semantic_parameter_incomplete(parameter);
5549                 parameter_type = parameter->declaration.type;
5550
5551                 /*
5552                  * we need the default promoted types for the function type
5553                  */
5554                 parameter_type = get_default_promoted_type(parameter_type);
5555
5556                 function_parameter_t *function_parameter
5557                         = obstack_alloc(type_obst, sizeof(function_parameter[0]));
5558                 memset(function_parameter, 0, sizeof(function_parameter[0]));
5559
5560                 function_parameter->type = parameter_type;
5561                 if (last_parameter != NULL) {
5562                         last_parameter->next = function_parameter;
5563                 } else {
5564                         parameters = function_parameter;
5565                 }
5566                 last_parameter = function_parameter;
5567         }
5568
5569         /* § 6.9.1.7: A K&R style parameter list does NOT act as a function
5570          * prototype */
5571         new_type->function.parameters             = parameters;
5572         new_type->function.unspecified_parameters = true;
5573
5574         new_type = identify_new_type(new_type);
5575
5576         entity->declaration.type = new_type;
5577
5578         rem_anchor_token('{');
5579 }
5580
5581 static bool first_err = true;
5582
5583 /**
5584  * When called with first_err set, prints the name of the current function,
5585  * else does noting.
5586  */
5587 static void print_in_function(void)
5588 {
5589         if (first_err) {
5590                 first_err = false;
5591                 diagnosticf("%s: In function '%Y':\n",
5592                             current_function->base.base.source_position.input_name,
5593                             current_function->base.base.symbol);
5594         }
5595 }
5596
5597 /**
5598  * Check if all labels are defined in the current function.
5599  * Check if all labels are used in the current function.
5600  */
5601 static void check_labels(void)
5602 {
5603         for (const goto_statement_t *goto_statement = goto_first;
5604             goto_statement != NULL;
5605             goto_statement = goto_statement->next) {
5606                 /* skip computed gotos */
5607                 if (goto_statement->expression != NULL)
5608                         continue;
5609
5610                 label_t *label = goto_statement->label;
5611
5612                 label->used = true;
5613                 if (label->base.source_position.input_name == NULL) {
5614                         print_in_function();
5615                         errorf(&goto_statement->base.source_position,
5616                                "label '%Y' used but not defined", label->base.symbol);
5617                  }
5618         }
5619
5620         if (warning.unused_label) {
5621                 for (const label_statement_t *label_statement = label_first;
5622                          label_statement != NULL;
5623                          label_statement = label_statement->next) {
5624                         label_t *label = label_statement->label;
5625
5626                         if (! label->used) {
5627                                 print_in_function();
5628                                 warningf(&label_statement->base.source_position,
5629                                          "label '%Y' defined but not used", label->base.symbol);
5630                         }
5631                 }
5632         }
5633 }
5634
5635 static void warn_unused_entity(entity_t *entity, entity_t *last)
5636 {
5637         entity_t const *const end = last != NULL ? last->base.next : NULL;
5638         for (; entity != end; entity = entity->base.next) {
5639                 if (!is_declaration(entity))
5640                         continue;
5641
5642                 declaration_t *declaration = &entity->declaration;
5643                 if (declaration->implicit)
5644                         continue;
5645
5646                 if (!declaration->used) {
5647                         print_in_function();
5648                         const char *what = get_entity_kind_name(entity->kind);
5649                         warningf(&entity->base.source_position, "%s '%Y' is unused",
5650                                  what, entity->base.symbol);
5651                 } else if (entity->kind == ENTITY_VARIABLE && !entity->variable.read) {
5652                         print_in_function();
5653                         const char *what = get_entity_kind_name(entity->kind);
5654                         warningf(&entity->base.source_position, "%s '%Y' is never read",
5655                                  what, entity->base.symbol);
5656                 }
5657         }
5658 }
5659
5660 static void check_unused_variables(statement_t *const stmt, void *const env)
5661 {
5662         (void)env;
5663
5664         switch (stmt->kind) {
5665                 case STATEMENT_DECLARATION: {
5666                         declaration_statement_t const *const decls = &stmt->declaration;
5667                         warn_unused_entity(decls->declarations_begin,
5668                                            decls->declarations_end);
5669                         return;
5670                 }
5671
5672                 case STATEMENT_FOR:
5673                         warn_unused_entity(stmt->fors.scope.entities, NULL);
5674                         return;
5675
5676                 default:
5677                         return;
5678         }
5679 }
5680
5681 /**
5682  * Check declarations of current_function for unused entities.
5683  */
5684 static void check_declarations(void)
5685 {
5686         if (warning.unused_parameter) {
5687                 const scope_t *scope = &current_function->parameters;
5688
5689                 /* do not issue unused warnings for main */
5690                 if (!is_sym_main(current_function->base.base.symbol)) {
5691                         warn_unused_entity(scope->entities, NULL);
5692                 }
5693         }
5694         if (warning.unused_variable) {
5695                 walk_statements(current_function->statement, check_unused_variables,
5696                                 NULL);
5697         }
5698 }
5699
5700 static int determine_truth(expression_t const* const cond)
5701 {
5702         return
5703                 !is_constant_expression(cond) ? 0 :
5704                 fold_constant(cond) != 0      ? 1 :
5705                 -1;
5706 }
5707
5708 static void check_reachable(statement_t *);
5709 static bool reaches_end;
5710
5711 static bool expression_returns(expression_t const *const expr)
5712 {
5713         switch (expr->kind) {
5714                 case EXPR_CALL: {
5715                         expression_t const *const func = expr->call.function;
5716                         if (func->kind == EXPR_REFERENCE) {
5717                                 entity_t *entity = func->reference.entity;
5718                                 if (entity->kind == ENTITY_FUNCTION
5719                                                 && entity->declaration.modifiers & DM_NORETURN)
5720                                         return false;
5721                         }
5722
5723                         if (!expression_returns(func))
5724                                 return false;
5725
5726                         for (call_argument_t const* arg = expr->call.arguments; arg != NULL; arg = arg->next) {
5727                                 if (!expression_returns(arg->expression))
5728                                         return false;
5729                         }
5730
5731                         return true;
5732                 }
5733
5734                 case EXPR_REFERENCE:
5735                 case EXPR_REFERENCE_ENUM_VALUE:
5736                 case EXPR_CONST:
5737                 case EXPR_CHARACTER_CONSTANT:
5738                 case EXPR_WIDE_CHARACTER_CONSTANT:
5739                 case EXPR_STRING_LITERAL:
5740                 case EXPR_WIDE_STRING_LITERAL:
5741                 case EXPR_COMPOUND_LITERAL: // TODO descend into initialisers
5742                 case EXPR_LABEL_ADDRESS:
5743                 case EXPR_CLASSIFY_TYPE:
5744                 case EXPR_SIZEOF: // TODO handle obscure VLA case
5745                 case EXPR_ALIGNOF:
5746                 case EXPR_FUNCNAME:
5747                 case EXPR_BUILTIN_SYMBOL:
5748                 case EXPR_BUILTIN_CONSTANT_P:
5749                 case EXPR_BUILTIN_PREFETCH:
5750                 case EXPR_OFFSETOF:
5751                 case EXPR_INVALID:
5752                         return true;
5753
5754                 case EXPR_STATEMENT: {
5755                         bool old_reaches_end = reaches_end;
5756                         reaches_end = false;
5757                         check_reachable(expr->statement.statement);
5758                         bool returns = reaches_end;
5759                         reaches_end = old_reaches_end;
5760                         return returns;
5761                 }
5762
5763                 case EXPR_CONDITIONAL:
5764                         // TODO handle constant expression
5765
5766                         if (!expression_returns(expr->conditional.condition))
5767                                 return false;
5768
5769                         if (expr->conditional.true_expression != NULL
5770                                         && expression_returns(expr->conditional.true_expression))
5771                                 return true;
5772
5773                         return expression_returns(expr->conditional.false_expression);
5774
5775                 case EXPR_SELECT:
5776                         return expression_returns(expr->select.compound);
5777
5778                 case EXPR_ARRAY_ACCESS:
5779                         return
5780                                 expression_returns(expr->array_access.array_ref) &&
5781                                 expression_returns(expr->array_access.index);
5782
5783                 case EXPR_VA_START:
5784                         return expression_returns(expr->va_starte.ap);
5785
5786                 case EXPR_VA_ARG:
5787                         return expression_returns(expr->va_arge.ap);
5788
5789                 EXPR_UNARY_CASES_MANDATORY
5790                         return expression_returns(expr->unary.value);
5791
5792                 case EXPR_UNARY_THROW:
5793                         return false;
5794
5795                 EXPR_BINARY_CASES
5796                         // TODO handle constant lhs of && and ||
5797                         return
5798                                 expression_returns(expr->binary.left) &&
5799                                 expression_returns(expr->binary.right);
5800
5801                 case EXPR_UNKNOWN:
5802                         break;
5803         }
5804
5805         panic("unhandled expression");
5806 }
5807
5808 static bool initializer_returns(initializer_t const *const init)
5809 {
5810         switch (init->kind) {
5811                 case INITIALIZER_VALUE:
5812                         return expression_returns(init->value.value);
5813
5814                 case INITIALIZER_LIST: {
5815                         initializer_t * const*       i       = init->list.initializers;
5816                         initializer_t * const* const end     = i + init->list.len;
5817                         bool                         returns = true;
5818                         for (; i != end; ++i) {
5819                                 if (!initializer_returns(*i))
5820                                         returns = false;
5821                         }
5822                         return returns;
5823                 }
5824
5825                 case INITIALIZER_STRING:
5826                 case INITIALIZER_WIDE_STRING:
5827                 case INITIALIZER_DESIGNATOR: // designators have no payload
5828                         return true;
5829         }
5830         panic("unhandled initializer");
5831 }
5832
5833 static bool noreturn_candidate;
5834
5835 static void check_reachable(statement_t *const stmt)
5836 {
5837         if (stmt->base.reachable)
5838                 return;
5839         if (stmt->kind != STATEMENT_DO_WHILE)
5840                 stmt->base.reachable = true;
5841
5842         statement_t *last = stmt;
5843         statement_t *next;
5844         switch (stmt->kind) {
5845                 case STATEMENT_INVALID:
5846                 case STATEMENT_EMPTY:
5847                 case STATEMENT_ASM:
5848                         next = stmt->base.next;
5849                         break;
5850
5851                 case STATEMENT_DECLARATION: {
5852                         declaration_statement_t const *const decl = &stmt->declaration;
5853                         entity_t                const *      ent  = decl->declarations_begin;
5854                         entity_t                const *const last = decl->declarations_end;
5855                         if (ent != NULL) {
5856                                 for (;; ent = ent->base.next) {
5857                                         if (ent->kind                 == ENTITY_VARIABLE &&
5858                                                         ent->variable.initializer != NULL            &&
5859                                                         !initializer_returns(ent->variable.initializer)) {
5860                                                 return;
5861                                         }
5862                                         if (ent == last)
5863                                                 break;
5864                                 }
5865                         }
5866                         next = stmt->base.next;
5867                         break;
5868                 }
5869
5870                 case STATEMENT_COMPOUND:
5871                         next = stmt->compound.statements;
5872                         if (next == NULL)
5873                                 next = stmt->base.next;
5874                         break;
5875
5876                 case STATEMENT_RETURN: {
5877                         expression_t const *const val = stmt->returns.value;
5878                         if (val == NULL || expression_returns(val))
5879                                 noreturn_candidate = false;
5880                         return;
5881                 }
5882
5883                 case STATEMENT_IF: {
5884                         if_statement_t const *const ifs  = &stmt->ifs;
5885                         expression_t   const *const cond = ifs->condition;
5886
5887                         if (!expression_returns(cond))
5888                                 return;
5889
5890                         int const val = determine_truth(cond);
5891
5892                         if (val >= 0)
5893                                 check_reachable(ifs->true_statement);
5894
5895                         if (val > 0)
5896                                 return;
5897
5898                         if (ifs->false_statement != NULL) {
5899                                 check_reachable(ifs->false_statement);
5900                                 return;
5901                         }
5902
5903                         next = stmt->base.next;
5904                         break;
5905                 }
5906
5907                 case STATEMENT_SWITCH: {
5908                         switch_statement_t const *const switchs = &stmt->switchs;
5909                         expression_t       const *const expr    = switchs->expression;
5910
5911                         if (!expression_returns(expr))
5912                                 return;
5913
5914                         if (is_constant_expression(expr)) {
5915                                 long                    const val      = fold_constant(expr);
5916                                 case_label_statement_t *      defaults = NULL;
5917                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
5918                                         if (i->expression == NULL) {
5919                                                 defaults = i;
5920                                                 continue;
5921                                         }
5922
5923                                         if (i->first_case <= val && val <= i->last_case) {
5924                                                 check_reachable((statement_t*)i);
5925                                                 return;
5926                                         }
5927                                 }
5928
5929                                 if (defaults != NULL) {
5930                                         check_reachable((statement_t*)defaults);
5931                                         return;
5932                                 }
5933                         } else {
5934                                 bool has_default = false;
5935                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
5936                                         if (i->expression == NULL)
5937                                                 has_default = true;
5938
5939                                         check_reachable((statement_t*)i);
5940                                 }
5941
5942                                 if (has_default)
5943                                         return;
5944                         }
5945
5946                         next = stmt->base.next;
5947                         break;
5948                 }
5949
5950                 case STATEMENT_EXPRESSION: {
5951                         /* Check for noreturn function call */
5952                         expression_t const *const expr = stmt->expression.expression;
5953                         if (!expression_returns(expr))
5954                                 return;
5955
5956                         next = stmt->base.next;
5957                         break;
5958                 }
5959
5960                 case STATEMENT_CONTINUE: {
5961                         statement_t *parent = stmt;
5962                         for (;;) {
5963                                 parent = parent->base.parent;
5964                                 if (parent == NULL) /* continue not within loop */
5965                                         return;
5966
5967                                 next = parent;
5968                                 switch (parent->kind) {
5969                                         case STATEMENT_WHILE:    goto continue_while;
5970                                         case STATEMENT_DO_WHILE: goto continue_do_while;
5971                                         case STATEMENT_FOR:      goto continue_for;
5972
5973                                         default: break;
5974                                 }
5975                         }
5976                 }
5977
5978                 case STATEMENT_BREAK: {
5979                         statement_t *parent = stmt;
5980                         for (;;) {
5981                                 parent = parent->base.parent;
5982                                 if (parent == NULL) /* break not within loop/switch */
5983                                         return;
5984
5985                                 switch (parent->kind) {
5986                                         case STATEMENT_SWITCH:
5987                                         case STATEMENT_WHILE:
5988                                         case STATEMENT_DO_WHILE:
5989                                         case STATEMENT_FOR:
5990                                                 last = parent;
5991                                                 next = parent->base.next;
5992                                                 goto found_break_parent;
5993
5994                                         default: break;
5995                                 }
5996                         }
5997 found_break_parent:
5998                         break;
5999                 }
6000
6001                 case STATEMENT_GOTO:
6002                         if (stmt->gotos.expression) {
6003                                 if (!expression_returns(stmt->gotos.expression))
6004                                         return;
6005
6006                                 statement_t *parent = stmt->base.parent;
6007                                 if (parent == NULL) /* top level goto */
6008                                         return;
6009                                 next = parent;
6010                         } else {
6011                                 next = stmt->gotos.label->statement;
6012                                 if (next == NULL) /* missing label */
6013                                         return;
6014                         }
6015                         break;
6016
6017                 case STATEMENT_LABEL:
6018                         next = stmt->label.statement;
6019                         break;
6020
6021                 case STATEMENT_CASE_LABEL:
6022                         next = stmt->case_label.statement;
6023                         break;
6024
6025                 case STATEMENT_WHILE: {
6026                         while_statement_t const *const whiles = &stmt->whiles;
6027                         expression_t      const *const cond   = whiles->condition;
6028
6029                         if (!expression_returns(cond))
6030                                 return;
6031
6032                         int const val = determine_truth(cond);
6033
6034                         if (val >= 0)
6035                                 check_reachable(whiles->body);
6036
6037                         if (val > 0)
6038                                 return;
6039
6040                         next = stmt->base.next;
6041                         break;
6042                 }
6043
6044                 case STATEMENT_DO_WHILE:
6045                         next = stmt->do_while.body;
6046                         break;
6047
6048                 case STATEMENT_FOR: {
6049                         for_statement_t *const fors = &stmt->fors;
6050
6051                         if (fors->condition_reachable)
6052                                 return;
6053                         fors->condition_reachable = true;
6054
6055                         expression_t const *const cond = fors->condition;
6056
6057                         int val;
6058                         if (cond == NULL) {
6059                                 val = 1;
6060                         } else if (expression_returns(cond)) {
6061                                 val = determine_truth(cond);
6062                         } else {
6063                                 return;
6064                         }
6065
6066                         if (val >= 0)
6067                                 check_reachable(fors->body);
6068
6069                         if (val > 0)
6070                                 return;
6071
6072                         next = stmt->base.next;
6073                         break;
6074                 }
6075
6076                 case STATEMENT_MS_TRY: {
6077                         ms_try_statement_t const *const ms_try = &stmt->ms_try;
6078                         check_reachable(ms_try->try_statement);
6079                         next = ms_try->final_statement;
6080                         break;
6081                 }
6082
6083                 case STATEMENT_LEAVE: {
6084                         statement_t *parent = stmt;
6085                         for (;;) {
6086                                 parent = parent->base.parent;
6087                                 if (parent == NULL) /* __leave not within __try */
6088                                         return;
6089
6090                                 if (parent->kind == STATEMENT_MS_TRY) {
6091                                         last = parent;
6092                                         next = parent->ms_try.final_statement;
6093                                         break;
6094                                 }
6095                         }
6096                         break;
6097                 }
6098
6099                 default:
6100                         panic("invalid statement kind");
6101         }
6102
6103         while (next == NULL) {
6104                 next = last->base.parent;
6105                 if (next == NULL) {
6106                         noreturn_candidate = false;
6107
6108                         type_t *const type = skip_typeref(current_function->base.type);
6109                         assert(is_type_function(type));
6110                         type_t *const ret  = skip_typeref(type->function.return_type);
6111                         if (warning.return_type                    &&
6112                             !is_type_atomic(ret, ATOMIC_TYPE_VOID) &&
6113                             is_type_valid(ret)                     &&
6114                             !is_sym_main(current_function->base.base.symbol)) {
6115                                 warningf(&stmt->base.source_position,
6116                                          "control reaches end of non-void function");
6117                         }
6118                         return;
6119                 }
6120
6121                 switch (next->kind) {
6122                         case STATEMENT_INVALID:
6123                         case STATEMENT_EMPTY:
6124                         case STATEMENT_DECLARATION:
6125                         case STATEMENT_EXPRESSION:
6126                         case STATEMENT_ASM:
6127                         case STATEMENT_RETURN:
6128                         case STATEMENT_CONTINUE:
6129                         case STATEMENT_BREAK:
6130                         case STATEMENT_GOTO:
6131                         case STATEMENT_LEAVE:
6132                                 panic("invalid control flow in function");
6133
6134                         case STATEMENT_COMPOUND:
6135                                 if (next->compound.stmt_expr) {
6136                                         reaches_end = true;
6137                                         return;
6138                                 }
6139                                 /* FALLTHROUGH */
6140                         case STATEMENT_IF:
6141                         case STATEMENT_SWITCH:
6142                         case STATEMENT_LABEL:
6143                         case STATEMENT_CASE_LABEL:
6144                                 last = next;
6145                                 next = next->base.next;
6146                                 break;
6147
6148                         case STATEMENT_WHILE: {
6149 continue_while:
6150                                 if (next->base.reachable)
6151                                         return;
6152                                 next->base.reachable = true;
6153
6154                                 while_statement_t const *const whiles = &next->whiles;
6155                                 expression_t      const *const cond   = whiles->condition;
6156
6157                                 if (!expression_returns(cond))
6158                                         return;
6159
6160                                 int const val = determine_truth(cond);
6161
6162                                 if (val >= 0)
6163                                         check_reachable(whiles->body);
6164
6165                                 if (val > 0)
6166                                         return;
6167
6168                                 last = next;
6169                                 next = next->base.next;
6170                                 break;
6171                         }
6172
6173                         case STATEMENT_DO_WHILE: {
6174 continue_do_while:
6175                                 if (next->base.reachable)
6176                                         return;
6177                                 next->base.reachable = true;
6178
6179                                 do_while_statement_t const *const dw   = &next->do_while;
6180                                 expression_t         const *const cond = dw->condition;
6181
6182                                 if (!expression_returns(cond))
6183                                         return;
6184
6185                                 int const val = determine_truth(cond);
6186
6187                                 if (val >= 0)
6188                                         check_reachable(dw->body);
6189
6190                                 if (val > 0)
6191                                         return;
6192
6193                                 last = next;
6194                                 next = next->base.next;
6195                                 break;
6196                         }
6197
6198                         case STATEMENT_FOR: {
6199 continue_for:;
6200                                 for_statement_t *const fors = &next->fors;
6201
6202                                 fors->step_reachable = true;
6203
6204                                 if (fors->condition_reachable)
6205                                         return;
6206                                 fors->condition_reachable = true;
6207
6208                                 expression_t const *const cond = fors->condition;
6209
6210                                 int val;
6211                                 if (cond == NULL) {
6212                                         val = 1;
6213                                 } else if (expression_returns(cond)) {
6214                                         val = determine_truth(cond);
6215                                 } else {
6216                                         return;
6217                                 }
6218
6219                                 if (val >= 0)
6220                                         check_reachable(fors->body);
6221
6222                                 if (val > 0)
6223                                         return;
6224
6225                                 last = next;
6226                                 next = next->base.next;
6227                                 break;
6228                         }
6229
6230                         case STATEMENT_MS_TRY:
6231                                 last = next;
6232                                 next = next->ms_try.final_statement;
6233                                 break;
6234                 }
6235         }
6236
6237         check_reachable(next);
6238 }
6239
6240 static void check_unreachable(statement_t* const stmt, void *const env)
6241 {
6242         (void)env;
6243
6244         switch (stmt->kind) {
6245                 case STATEMENT_DO_WHILE:
6246                         if (!stmt->base.reachable) {
6247                                 expression_t const *const cond = stmt->do_while.condition;
6248                                 if (determine_truth(cond) >= 0) {
6249                                         warningf(&cond->base.source_position,
6250                                                  "condition of do-while-loop is unreachable");
6251                                 }
6252                         }
6253                         return;
6254
6255                 case STATEMENT_FOR: {
6256                         for_statement_t const* const fors = &stmt->fors;
6257
6258                         // if init and step are unreachable, cond is unreachable, too
6259                         if (!stmt->base.reachable && !fors->step_reachable) {
6260                                 warningf(&stmt->base.source_position, "statement is unreachable");
6261                         } else {
6262                                 if (!stmt->base.reachable && fors->initialisation != NULL) {
6263                                         warningf(&fors->initialisation->base.source_position,
6264                                                  "initialisation of for-statement is unreachable");
6265                                 }
6266
6267                                 if (!fors->condition_reachable && fors->condition != NULL) {
6268                                         warningf(&fors->condition->base.source_position,
6269                                                  "condition of for-statement is unreachable");
6270                                 }
6271
6272                                 if (!fors->step_reachable && fors->step != NULL) {
6273                                         warningf(&fors->step->base.source_position,
6274                                                  "step of for-statement is unreachable");
6275                                 }
6276                         }
6277                         return;
6278                 }
6279
6280                 case STATEMENT_COMPOUND:
6281                         if (stmt->compound.statements != NULL)
6282                                 return;
6283                         goto warn_unreachable;
6284
6285                 case STATEMENT_DECLARATION: {
6286                         /* Only warn if there is at least one declarator with an initializer.
6287                          * This typically occurs in switch statements. */
6288                         declaration_statement_t const *const decl = &stmt->declaration;
6289                         entity_t                const *      ent  = decl->declarations_begin;
6290                         entity_t                const *const last = decl->declarations_end;
6291                         if (ent != NULL) {
6292                                 for (;; ent = ent->base.next) {
6293                                         if (ent->kind                 == ENTITY_VARIABLE &&
6294                                                         ent->variable.initializer != NULL) {
6295                                                 goto warn_unreachable;
6296                                         }
6297                                         if (ent == last)
6298                                                 return;
6299                                 }
6300                         }
6301                 }
6302
6303                 default:
6304 warn_unreachable:
6305                         if (!stmt->base.reachable)
6306                                 warningf(&stmt->base.source_position, "statement is unreachable");
6307                         return;
6308         }
6309 }
6310
6311 static void parse_external_declaration(void)
6312 {
6313         /* function-definitions and declarations both start with declaration
6314          * specifiers */
6315         declaration_specifiers_t specifiers;
6316         memset(&specifiers, 0, sizeof(specifiers));
6317
6318         add_anchor_token(';');
6319         parse_declaration_specifiers(&specifiers);
6320         rem_anchor_token(';');
6321
6322         /* must be a declaration */
6323         if (token.type == ';') {
6324                 parse_anonymous_declaration_rest(&specifiers);
6325                 return;
6326         }
6327
6328         add_anchor_token(',');
6329         add_anchor_token('=');
6330         add_anchor_token(';');
6331         add_anchor_token('{');
6332
6333         /* declarator is common to both function-definitions and declarations */
6334         entity_t *ndeclaration = parse_declarator(&specifiers, DECL_FLAGS_NONE);
6335
6336         rem_anchor_token('{');
6337         rem_anchor_token(';');
6338         rem_anchor_token('=');
6339         rem_anchor_token(',');
6340
6341         /* must be a declaration */
6342         switch (token.type) {
6343                 case ',':
6344                 case ';':
6345                 case '=':
6346                         parse_declaration_rest(ndeclaration, &specifiers, record_entity,
6347                                         DECL_FLAGS_NONE);
6348                         return;
6349         }
6350
6351         /* must be a function definition */
6352         parse_kr_declaration_list(ndeclaration);
6353
6354         if (token.type != '{') {
6355                 parse_error_expected("while parsing function definition", '{', NULL);
6356                 eat_until_matching_token(';');
6357                 return;
6358         }
6359
6360         assert(is_declaration(ndeclaration));
6361         type_t *const orig_type = ndeclaration->declaration.type;
6362         type_t *      type      = skip_typeref(orig_type);
6363
6364         if (!is_type_function(type)) {
6365                 if (is_type_valid(type)) {
6366                         errorf(HERE, "declarator '%#T' has a body but is not a function type",
6367                                type, ndeclaration->base.symbol);
6368                 }
6369                 eat_block();
6370                 return;
6371         } else if (is_typeref(orig_type)) {
6372                 /* §6.9.1:2 */
6373                 errorf(&ndeclaration->base.source_position,
6374                                 "type of function definition '%#T' is a typedef",
6375                                 orig_type, ndeclaration->base.symbol);
6376         }
6377
6378         if (warning.aggregate_return &&
6379             is_type_compound(skip_typeref(type->function.return_type))) {
6380                 warningf(HERE, "function '%Y' returns an aggregate",
6381                          ndeclaration->base.symbol);
6382         }
6383         if (warning.traditional && !type->function.unspecified_parameters) {
6384                 warningf(HERE, "traditional C rejects ISO C style function definition of function '%Y'",
6385                         ndeclaration->base.symbol);
6386         }
6387         if (warning.old_style_definition && type->function.unspecified_parameters) {
6388                 warningf(HERE, "old-style function definition '%Y'",
6389                         ndeclaration->base.symbol);
6390         }
6391
6392         /* § 6.7.5.3:14 a function definition with () means no
6393          * parameters (and not unspecified parameters) */
6394         if (type->function.unspecified_parameters &&
6395                         type->function.parameters == NULL     &&
6396                         !type->function.kr_style_parameters) {
6397                 type_t *copy                          = duplicate_type(type);
6398                 copy->function.unspecified_parameters = false;
6399                 type                                  = identify_new_type(copy);
6400
6401                 ndeclaration->declaration.type = type;
6402         }
6403
6404         entity_t *const entity = record_entity(ndeclaration, true);
6405         assert(entity->kind == ENTITY_FUNCTION);
6406         assert(ndeclaration->kind == ENTITY_FUNCTION);
6407
6408         function_t *function = &entity->function;
6409         if (ndeclaration != entity) {
6410                 function->parameters = ndeclaration->function.parameters;
6411         }
6412         assert(is_declaration(entity));
6413         type = skip_typeref(entity->declaration.type);
6414
6415         /* push function parameters and switch scope */
6416         size_t const  top       = environment_top();
6417         scope_t      *old_scope = scope_push(&function->parameters);
6418
6419         entity_t *parameter = function->parameters.entities;
6420         for (; parameter != NULL; parameter = parameter->base.next) {
6421                 if (parameter->base.parent_scope == &ndeclaration->function.parameters) {
6422                         parameter->base.parent_scope = current_scope;
6423                 }
6424                 assert(parameter->base.parent_scope == NULL
6425                                 || parameter->base.parent_scope == current_scope);
6426                 parameter->base.parent_scope = current_scope;
6427                 if (parameter->base.symbol == NULL) {
6428                         errorf(&parameter->base.source_position, "parameter name omitted");
6429                         continue;
6430                 }
6431                 environment_push(parameter);
6432         }
6433
6434         if (function->statement != NULL) {
6435                 parser_error_multiple_definition(entity, HERE);
6436                 eat_block();
6437         } else {
6438                 /* parse function body */
6439                 int         label_stack_top      = label_top();
6440                 function_t *old_current_function = current_function;
6441                 current_function                 = function;
6442                 current_parent                   = NULL;
6443
6444                 goto_first   = NULL;
6445                 goto_anchor  = &goto_first;
6446                 label_first  = NULL;
6447                 label_anchor = &label_first;
6448
6449                 statement_t *const body = parse_compound_statement(false);
6450                 function->statement = body;
6451                 first_err = true;
6452                 check_labels();
6453                 check_declarations();
6454                 if (warning.return_type      ||
6455                     warning.unreachable_code ||
6456                     (warning.missing_noreturn
6457                      && !(function->base.modifiers & DM_NORETURN))) {
6458                         noreturn_candidate = true;
6459                         check_reachable(body);
6460                         if (warning.unreachable_code)
6461                                 walk_statements(body, check_unreachable, NULL);
6462                         if (warning.missing_noreturn &&
6463                             noreturn_candidate       &&
6464                             !(function->base.modifiers & DM_NORETURN)) {
6465                                 warningf(&body->base.source_position,
6466                                          "function '%#T' is candidate for attribute 'noreturn'",
6467                                          type, entity->base.symbol);
6468                         }
6469                 }
6470
6471                 assert(current_parent   == NULL);
6472                 assert(current_function == function);
6473                 current_function = old_current_function;
6474                 label_pop_to(label_stack_top);
6475         }
6476
6477         assert(current_scope == &function->parameters);
6478         scope_pop(old_scope);
6479         environment_pop_to(top);
6480 }
6481
6482 static type_t *make_bitfield_type(type_t *base_type, expression_t *size,
6483                                   source_position_t *source_position,
6484                                   const symbol_t *symbol)
6485 {
6486         type_t *type = allocate_type_zero(TYPE_BITFIELD);
6487
6488         type->bitfield.base_type       = base_type;
6489         type->bitfield.size_expression = size;
6490
6491         il_size_t bit_size;
6492         type_t *skipped_type = skip_typeref(base_type);
6493         if (!is_type_integer(skipped_type)) {
6494                 errorf(HERE, "bitfield base type '%T' is not an integer type",
6495                         base_type);
6496                 bit_size = 0;
6497         } else {
6498                 bit_size = skipped_type->base.size * 8;
6499         }
6500
6501         if (is_constant_expression(size)) {
6502                 long v = fold_constant(size);
6503
6504                 if (v < 0) {
6505                         errorf(source_position, "negative width in bit-field '%Y'", symbol);
6506                 } else if (v == 0) {
6507                         errorf(source_position, "zero width for bit-field '%Y'", symbol);
6508                 } else if (bit_size > 0 && (il_size_t)v > bit_size) {
6509                         errorf(source_position, "width of '%Y' exceeds its type", symbol);
6510                 } else {
6511                         type->bitfield.bit_size = v;
6512                 }
6513         }
6514
6515         return type;
6516 }
6517
6518 static entity_t *find_compound_entry(compound_t *compound, symbol_t *symbol)
6519 {
6520         entity_t *iter = compound->members.entities;
6521         for (; iter != NULL; iter = iter->base.next) {
6522                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
6523                         continue;
6524
6525                 if (iter->base.symbol == symbol) {
6526                         return iter;
6527                 } else if (iter->base.symbol == NULL) {
6528                         type_t *type = skip_typeref(iter->declaration.type);
6529                         if (is_type_compound(type)) {
6530                                 entity_t *result
6531                                         = find_compound_entry(type->compound.compound, symbol);
6532                                 if (result != NULL)
6533                                         return result;
6534                         }
6535                         continue;
6536                 }
6537         }
6538
6539         return NULL;
6540 }
6541
6542 static void parse_compound_declarators(compound_t *compound,
6543                 const declaration_specifiers_t *specifiers)
6544 {
6545         while (true) {
6546                 entity_t *entity;
6547
6548                 if (token.type == ':') {
6549                         source_position_t source_position = *HERE;
6550                         next_token();
6551
6552                         type_t *base_type = specifiers->type;
6553                         expression_t *size = parse_constant_expression();
6554
6555                         type_t *type = make_bitfield_type(base_type, size,
6556                                         &source_position, sym_anonymous);
6557
6558                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER);
6559                         entity->base.namespc                       = NAMESPACE_NORMAL;
6560                         entity->base.source_position               = source_position;
6561                         entity->declaration.declared_storage_class = STORAGE_CLASS_NONE;
6562                         entity->declaration.storage_class          = STORAGE_CLASS_NONE;
6563                         entity->declaration.modifiers              = specifiers->modifiers;
6564                         entity->declaration.type                   = type;
6565                         append_entity(&compound->members, entity);
6566                 } else {
6567                         entity = parse_declarator(specifiers,
6568                                         DECL_MAY_BE_ABSTRACT | DECL_CREATE_COMPOUND_MEMBER);
6569                         if (entity->kind == ENTITY_TYPEDEF) {
6570                                 errorf(&entity->base.source_position,
6571                                                 "typedef not allowed as compound member");
6572                         } else {
6573                                 assert(entity->kind == ENTITY_COMPOUND_MEMBER);
6574
6575                                 /* make sure we don't define a symbol multiple times */
6576                                 symbol_t *symbol = entity->base.symbol;
6577                                 if (symbol != NULL) {
6578                                         entity_t *prev = find_compound_entry(compound, symbol);
6579                                         if (prev != NULL) {
6580                                                 errorf(&entity->base.source_position,
6581                                                                 "multiple declarations of symbol '%Y' (declared %P)",
6582                                                                 symbol, &prev->base.source_position);
6583                                         }
6584                                 }
6585
6586                                 if (token.type == ':') {
6587                                         source_position_t source_position = *HERE;
6588                                         next_token();
6589                                         expression_t *size = parse_constant_expression();
6590
6591                                         type_t *type          = entity->declaration.type;
6592                                         type_t *bitfield_type = make_bitfield_type(type, size,
6593                                                         &source_position, entity->base.symbol);
6594                                         entity->declaration.type = bitfield_type;
6595                                 } else {
6596                                         type_t *orig_type = entity->declaration.type;
6597                                         type_t *type      = skip_typeref(orig_type);
6598                                         if (is_type_function(type)) {
6599                                                 errorf(&entity->base.source_position,
6600                                                                 "compound member '%Y' must not have function type '%T'",
6601                                                                 entity->base.symbol, orig_type);
6602                                         } else if (is_type_incomplete(type)) {
6603                                                 /* §6.7.2.1:16 flexible array member */
6604                                                 if (is_type_array(type) &&
6605                                                                 token.type == ';'   &&
6606                                                                 look_ahead(1)->type == '}') {
6607                                                         compound->has_flexible_member = true;
6608                                                 } else {
6609                                                         errorf(&entity->base.source_position,
6610                                                                         "compound member '%Y' has incomplete type '%T'",
6611                                                                         entity->base.symbol, orig_type);
6612                                                 }
6613                                         }
6614                                 }
6615
6616                                 append_entity(&compound->members, entity);
6617                         }
6618                 }
6619
6620                 if (token.type != ',')
6621                         break;
6622                 next_token();
6623         }
6624         expect(';', end_error);
6625
6626 end_error:
6627         anonymous_entity = NULL;
6628 }
6629
6630 static void parse_compound_type_entries(compound_t *compound)
6631 {
6632         eat('{');
6633         add_anchor_token('}');
6634
6635         while (token.type != '}') {
6636                 if (token.type == T_EOF) {
6637                         errorf(HERE, "EOF while parsing struct");
6638                         break;
6639                 }
6640                 declaration_specifiers_t specifiers;
6641                 memset(&specifiers, 0, sizeof(specifiers));
6642                 parse_declaration_specifiers(&specifiers);
6643
6644                 parse_compound_declarators(compound, &specifiers);
6645         }
6646         rem_anchor_token('}');
6647         next_token();
6648
6649         /* §6.7.2.1:7 */
6650         compound->complete = true;
6651 }
6652
6653 static type_t *parse_typename(void)
6654 {
6655         declaration_specifiers_t specifiers;
6656         memset(&specifiers, 0, sizeof(specifiers));
6657         parse_declaration_specifiers(&specifiers);
6658         if (specifiers.storage_class != STORAGE_CLASS_NONE ||
6659                         specifiers.thread_local) {
6660                 /* TODO: improve error message, user does probably not know what a
6661                  * storage class is...
6662                  */
6663                 errorf(HERE, "typename may not have a storage class");
6664         }
6665
6666         type_t *result = parse_abstract_declarator(specifiers.type);
6667
6668         return result;
6669 }
6670
6671
6672
6673
6674 typedef expression_t* (*parse_expression_function)(void);
6675 typedef expression_t* (*parse_expression_infix_function)(expression_t *left);
6676
6677 typedef struct expression_parser_function_t expression_parser_function_t;
6678 struct expression_parser_function_t {
6679         parse_expression_function        parser;
6680         precedence_t                     infix_precedence;
6681         parse_expression_infix_function  infix_parser;
6682 };
6683
6684 expression_parser_function_t expression_parsers[T_LAST_TOKEN];
6685
6686 /**
6687  * Prints an error message if an expression was expected but not read
6688  */
6689 static expression_t *expected_expression_error(void)
6690 {
6691         /* skip the error message if the error token was read */
6692         if (token.type != T_ERROR) {
6693                 errorf(HERE, "expected expression, got token %K", &token);
6694         }
6695         next_token();
6696
6697         return create_invalid_expression();
6698 }
6699
6700 /**
6701  * Parse a string constant.
6702  */
6703 static expression_t *parse_string_const(void)
6704 {
6705         wide_string_t wres;
6706         if (token.type == T_STRING_LITERAL) {
6707                 string_t res = token.v.string;
6708                 next_token();
6709                 while (token.type == T_STRING_LITERAL) {
6710                         res = concat_strings(&res, &token.v.string);
6711                         next_token();
6712                 }
6713                 if (token.type != T_WIDE_STRING_LITERAL) {
6714                         expression_t *const cnst = allocate_expression_zero(EXPR_STRING_LITERAL);
6715                         /* note: that we use type_char_ptr here, which is already the
6716                          * automatic converted type. revert_automatic_type_conversion
6717                          * will construct the array type */
6718                         cnst->base.type    = warning.write_strings ? type_const_char_ptr : type_char_ptr;
6719                         cnst->string.value = res;
6720                         return cnst;
6721                 }
6722
6723                 wres = concat_string_wide_string(&res, &token.v.wide_string);
6724         } else {
6725                 wres = token.v.wide_string;
6726         }
6727         next_token();
6728
6729         for (;;) {
6730                 switch (token.type) {
6731                         case T_WIDE_STRING_LITERAL:
6732                                 wres = concat_wide_strings(&wres, &token.v.wide_string);
6733                                 break;
6734
6735                         case T_STRING_LITERAL:
6736                                 wres = concat_wide_string_string(&wres, &token.v.string);
6737                                 break;
6738
6739                         default: {
6740                                 expression_t *const cnst = allocate_expression_zero(EXPR_WIDE_STRING_LITERAL);
6741                                 cnst->base.type         = warning.write_strings ? type_const_wchar_t_ptr : type_wchar_t_ptr;
6742                                 cnst->wide_string.value = wres;
6743                                 return cnst;
6744                         }
6745                 }
6746                 next_token();
6747         }
6748 }
6749
6750 /**
6751  * Parse a boolean constant.
6752  */
6753 static expression_t *parse_bool_const(bool value)
6754 {
6755         expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
6756         cnst->base.type          = type_bool;
6757         cnst->conste.v.int_value = value;
6758
6759         next_token();
6760
6761         return cnst;
6762 }
6763
6764 /**
6765  * Parse an integer constant.
6766  */
6767 static expression_t *parse_int_const(void)
6768 {
6769         expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
6770         cnst->base.type          = token.datatype;
6771         cnst->conste.v.int_value = token.v.intvalue;
6772
6773         next_token();
6774
6775         return cnst;
6776 }
6777
6778 /**
6779  * Parse a character constant.
6780  */
6781 static expression_t *parse_character_constant(void)
6782 {
6783         expression_t *cnst = allocate_expression_zero(EXPR_CHARACTER_CONSTANT);
6784         cnst->base.type          = token.datatype;
6785         cnst->conste.v.character = token.v.string;
6786
6787         if (cnst->conste.v.character.size != 1) {
6788                 if (!GNU_MODE) {
6789                         errorf(HERE, "more than 1 character in character constant");
6790                 } else if (warning.multichar) {
6791                         warningf(HERE, "multi-character character constant");
6792                 }
6793         }
6794         next_token();
6795
6796         return cnst;
6797 }
6798
6799 /**
6800  * Parse a wide character constant.
6801  */
6802 static expression_t *parse_wide_character_constant(void)
6803 {
6804         expression_t *cnst = allocate_expression_zero(EXPR_WIDE_CHARACTER_CONSTANT);
6805         cnst->base.type               = token.datatype;
6806         cnst->conste.v.wide_character = token.v.wide_string;
6807
6808         if (cnst->conste.v.wide_character.size != 1) {
6809                 if (!GNU_MODE) {
6810                         errorf(HERE, "more than 1 character in character constant");
6811                 } else if (warning.multichar) {
6812                         warningf(HERE, "multi-character character constant");
6813                 }
6814         }
6815         next_token();
6816
6817         return cnst;
6818 }
6819
6820 /**
6821  * Parse a float constant.
6822  */
6823 static expression_t *parse_float_const(void)
6824 {
6825         expression_t *cnst         = allocate_expression_zero(EXPR_CONST);
6826         cnst->base.type            = token.datatype;
6827         cnst->conste.v.float_value = token.v.floatvalue;
6828
6829         next_token();
6830
6831         return cnst;
6832 }
6833
6834 static entity_t *create_implicit_function(symbol_t *symbol,
6835                 const source_position_t *source_position)
6836 {
6837         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
6838         ntype->function.return_type            = type_int;
6839         ntype->function.unspecified_parameters = true;
6840         ntype->function.linkage                = LINKAGE_C;
6841         type_t *type                           = identify_new_type(ntype);
6842
6843         entity_t *entity = allocate_entity_zero(ENTITY_FUNCTION);
6844         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
6845         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
6846         entity->declaration.type                   = type;
6847         entity->declaration.implicit               = true;
6848         entity->base.symbol                        = symbol;
6849         entity->base.source_position               = *source_position;
6850
6851         bool strict_prototypes_old = warning.strict_prototypes;
6852         warning.strict_prototypes  = false;
6853         record_entity(entity, false);
6854         warning.strict_prototypes = strict_prototypes_old;
6855
6856         return entity;
6857 }
6858
6859 /**
6860  * Creates a return_type (func)(argument_type) function type if not
6861  * already exists.
6862  */
6863 static type_t *make_function_2_type(type_t *return_type, type_t *argument_type1,
6864                                     type_t *argument_type2)
6865 {
6866         function_parameter_t *parameter2
6867                 = obstack_alloc(type_obst, sizeof(parameter2[0]));
6868         memset(parameter2, 0, sizeof(parameter2[0]));
6869         parameter2->type = argument_type2;
6870
6871         function_parameter_t *parameter1
6872                 = obstack_alloc(type_obst, sizeof(parameter1[0]));
6873         memset(parameter1, 0, sizeof(parameter1[0]));
6874         parameter1->type = argument_type1;
6875         parameter1->next = parameter2;
6876
6877         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6878         type->function.return_type = return_type;
6879         type->function.parameters  = parameter1;
6880
6881         return identify_new_type(type);
6882 }
6883
6884 /**
6885  * Creates a return_type (func)(argument_type) function type if not
6886  * already exists.
6887  *
6888  * @param return_type    the return type
6889  * @param argument_type  the argument type
6890  */
6891 static type_t *make_function_1_type(type_t *return_type, type_t *argument_type)
6892 {
6893         function_parameter_t *parameter
6894                 = obstack_alloc(type_obst, sizeof(parameter[0]));
6895         memset(parameter, 0, sizeof(parameter[0]));
6896         parameter->type = argument_type;
6897
6898         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6899         type->function.return_type = return_type;
6900         type->function.parameters  = parameter;
6901
6902         return identify_new_type(type);
6903 }
6904
6905 static type_t *make_function_0_type(type_t *return_type)
6906 {
6907         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6908         type->function.return_type = return_type;
6909         type->function.parameters  = NULL;
6910
6911         return identify_new_type(type);
6912 }
6913
6914 /**
6915  * Creates a function type for some function like builtins.
6916  *
6917  * @param symbol   the symbol describing the builtin
6918  */
6919 static type_t *get_builtin_symbol_type(symbol_t *symbol)
6920 {
6921         switch (symbol->ID) {
6922         case T___builtin_alloca:
6923                 return make_function_1_type(type_void_ptr, type_size_t);
6924         case T___builtin_huge_val:
6925                 return make_function_0_type(type_double);
6926         case T___builtin_inf:
6927                 return make_function_0_type(type_double);
6928         case T___builtin_inff:
6929                 return make_function_0_type(type_float);
6930         case T___builtin_infl:
6931                 return make_function_0_type(type_long_double);
6932         case T___builtin_nan:
6933                 return make_function_1_type(type_double, type_char_ptr);
6934         case T___builtin_nanf:
6935                 return make_function_1_type(type_float, type_char_ptr);
6936         case T___builtin_nanl:
6937                 return make_function_1_type(type_long_double, type_char_ptr);
6938         case T___builtin_va_end:
6939                 return make_function_1_type(type_void, type_valist);
6940         case T___builtin_expect:
6941                 return make_function_2_type(type_long, type_long, type_long);
6942         case T___builtin_return_address:
6943         case T___builtin_frame_address:
6944                 return make_function_1_type(type_void_ptr, type_unsigned_int);
6945         default:
6946                 internal_errorf(HERE, "not implemented builtin identifier found");
6947         }
6948 }
6949
6950 /**
6951  * Performs automatic type cast as described in § 6.3.2.1.
6952  *
6953  * @param orig_type  the original type
6954  */
6955 static type_t *automatic_type_conversion(type_t *orig_type)
6956 {
6957         type_t *type = skip_typeref(orig_type);
6958         if (is_type_array(type)) {
6959                 array_type_t *array_type   = &type->array;
6960                 type_t       *element_type = array_type->element_type;
6961                 unsigned      qualifiers   = array_type->base.qualifiers;
6962
6963                 return make_pointer_type(element_type, qualifiers);
6964         }
6965
6966         if (is_type_function(type)) {
6967                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
6968         }
6969
6970         return orig_type;
6971 }
6972
6973 /**
6974  * reverts the automatic casts of array to pointer types and function
6975  * to function-pointer types as defined § 6.3.2.1
6976  */
6977 type_t *revert_automatic_type_conversion(const expression_t *expression)
6978 {
6979         switch (expression->kind) {
6980                 case EXPR_REFERENCE: {
6981                         entity_t *entity = expression->reference.entity;
6982                         if (is_declaration(entity)) {
6983                                 return entity->declaration.type;
6984                         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6985                                 return entity->enum_value.enum_type;
6986                         } else {
6987                                 panic("no declaration or enum in reference");
6988                         }
6989                 }
6990
6991                 case EXPR_SELECT: {
6992                         entity_t *entity = expression->select.compound_entry;
6993                         assert(is_declaration(entity));
6994                         type_t   *type   = entity->declaration.type;
6995                         return get_qualified_type(type,
6996                                         expression->base.type->base.qualifiers);
6997                 }
6998
6999                 case EXPR_UNARY_DEREFERENCE: {
7000                         const expression_t *const value = expression->unary.value;
7001                         type_t             *const type  = skip_typeref(value->base.type);
7002                         if (!is_type_pointer(type))
7003                                 return type_error_type;
7004                         return type->pointer.points_to;
7005                 }
7006
7007                 case EXPR_BUILTIN_SYMBOL:
7008                         return get_builtin_symbol_type(expression->builtin_symbol.symbol);
7009
7010                 case EXPR_ARRAY_ACCESS: {
7011                         const expression_t *array_ref = expression->array_access.array_ref;
7012                         type_t             *type_left = skip_typeref(array_ref->base.type);
7013                         if (!is_type_pointer(type_left))
7014                                 return type_error_type;
7015                         return type_left->pointer.points_to;
7016                 }
7017
7018                 case EXPR_STRING_LITERAL: {
7019                         size_t size = expression->string.value.size;
7020                         return make_array_type(type_char, size, TYPE_QUALIFIER_NONE);
7021                 }
7022
7023                 case EXPR_WIDE_STRING_LITERAL: {
7024                         size_t size = expression->wide_string.value.size;
7025                         return make_array_type(type_wchar_t, size, TYPE_QUALIFIER_NONE);
7026                 }
7027
7028                 case EXPR_COMPOUND_LITERAL:
7029                         return expression->compound_literal.type;
7030
7031                 default:
7032                         return expression->base.type;
7033         }
7034 }
7035
7036 static expression_t *parse_reference(void)
7037 {
7038         symbol_t *const symbol = token.v.symbol;
7039
7040         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
7041
7042         if (entity == NULL) {
7043                 if (!strict_mode && look_ahead(1)->type == '(') {
7044                         /* an implicitly declared function */
7045                         if (warning.error_implicit_function_declaration) {
7046                                 errorf(HERE, "implicit declaration of function '%Y'", symbol);
7047                         } else if (warning.implicit_function_declaration) {
7048                                 warningf(HERE, "implicit declaration of function '%Y'", symbol);
7049                         }
7050
7051                         entity = create_implicit_function(symbol, HERE);
7052                 } else {
7053                         errorf(HERE, "unknown identifier '%Y' found.", symbol);
7054                         entity = create_error_entity(symbol, ENTITY_VARIABLE);
7055                 }
7056         }
7057
7058         type_t *orig_type;
7059
7060         if (is_declaration(entity)) {
7061                 orig_type = entity->declaration.type;
7062         } else if (entity->kind == ENTITY_ENUM_VALUE) {
7063                 orig_type = entity->enum_value.enum_type;
7064         } else if (entity->kind == ENTITY_TYPEDEF) {
7065                 errorf(HERE, "encountered typedef name '%Y' while parsing expression",
7066                         symbol);
7067                 next_token();
7068                 return create_invalid_expression();
7069         } else {
7070                 panic("expected declaration or enum value in reference");
7071         }
7072
7073         /* we always do the auto-type conversions; the & and sizeof parser contains
7074          * code to revert this! */
7075         type_t *type = automatic_type_conversion(orig_type);
7076
7077         expression_kind_t kind = EXPR_REFERENCE;
7078         if (entity->kind == ENTITY_ENUM_VALUE)
7079                 kind = EXPR_REFERENCE_ENUM_VALUE;
7080
7081         expression_t *expression     = allocate_expression_zero(kind);
7082         expression->reference.entity = entity;
7083         expression->base.type        = type;
7084
7085         /* this declaration is used */
7086         if (is_declaration(entity)) {
7087                 entity->declaration.used = true;
7088         }
7089
7090         if (entity->base.parent_scope != file_scope
7091                 && entity->base.parent_scope->depth < current_function->parameters.depth
7092                 && is_type_valid(orig_type) && !is_type_function(orig_type)) {
7093                 if (entity->kind == ENTITY_VARIABLE) {
7094                         /* access of a variable from an outer function */
7095                         entity->variable.address_taken = true;
7096                 } else if (entity->kind == ENTITY_PARAMETER) {
7097                         entity->parameter.address_taken = true;
7098                 }
7099                 current_function->need_closure = true;
7100         }
7101
7102         /* check for deprecated functions */
7103         if (warning.deprecated_declarations
7104                 && is_declaration(entity)
7105                 && entity->declaration.modifiers & DM_DEPRECATED) {
7106                 declaration_t *declaration = &entity->declaration;
7107
7108                 char const *const prefix = entity->kind == ENTITY_FUNCTION ?
7109                         "function" : "variable";
7110
7111                 if (declaration->deprecated_string != NULL) {
7112                         warningf(HERE, "%s '%Y' is deprecated (declared %P): \"%s\"",
7113                                  prefix, entity->base.symbol, &entity->base.source_position,
7114                                  declaration->deprecated_string);
7115                 } else {
7116                         warningf(HERE, "%s '%Y' is deprecated (declared %P)", prefix,
7117                                  entity->base.symbol, &entity->base.source_position);
7118                 }
7119         }
7120
7121         if (warning.init_self && entity == current_init_decl && !in_type_prop
7122             && entity->kind == ENTITY_VARIABLE) {
7123                 current_init_decl = NULL;
7124                 warningf(HERE, "variable '%#T' is initialized by itself",
7125                          entity->declaration.type, entity->base.symbol);
7126         }
7127
7128         next_token();
7129         return expression;
7130 }
7131
7132 static bool semantic_cast(expression_t *cast)
7133 {
7134         expression_t            *expression      = cast->unary.value;
7135         type_t                  *orig_dest_type  = cast->base.type;
7136         type_t                  *orig_type_right = expression->base.type;
7137         type_t            const *dst_type        = skip_typeref(orig_dest_type);
7138         type_t            const *src_type        = skip_typeref(orig_type_right);
7139         source_position_t const *pos             = &cast->base.source_position;
7140
7141         /* §6.5.4 A (void) cast is explicitly permitted, more for documentation than for utility. */
7142         if (dst_type == type_void)
7143                 return true;
7144
7145         /* only integer and pointer can be casted to pointer */
7146         if (is_type_pointer(dst_type)  &&
7147             !is_type_pointer(src_type) &&
7148             !is_type_integer(src_type) &&
7149             is_type_valid(src_type)) {
7150                 errorf(pos, "cannot convert type '%T' to a pointer type", orig_type_right);
7151                 return false;
7152         }
7153
7154         if (!is_type_scalar(dst_type) && is_type_valid(dst_type)) {
7155                 errorf(pos, "conversion to non-scalar type '%T' requested", orig_dest_type);
7156                 return false;
7157         }
7158
7159         if (!is_type_scalar(src_type) && is_type_valid(src_type)) {
7160                 errorf(pos, "conversion from non-scalar type '%T' requested", orig_type_right);
7161                 return false;
7162         }
7163
7164         if (warning.cast_qual &&
7165             is_type_pointer(src_type) &&
7166             is_type_pointer(dst_type)) {
7167                 type_t *src = skip_typeref(src_type->pointer.points_to);
7168                 type_t *dst = skip_typeref(dst_type->pointer.points_to);
7169                 unsigned missing_qualifiers =
7170                         src->base.qualifiers & ~dst->base.qualifiers;
7171                 if (missing_qualifiers != 0) {
7172                         warningf(pos,
7173                                  "cast discards qualifiers '%Q' in pointer target type of '%T'",
7174                                  missing_qualifiers, orig_type_right);
7175                 }
7176         }
7177         return true;
7178 }
7179
7180 static expression_t *parse_compound_literal(type_t *type)
7181 {
7182         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
7183
7184         parse_initializer_env_t env;
7185         env.type             = type;
7186         env.entity           = NULL;
7187         env.must_be_constant = false;
7188         initializer_t *initializer = parse_initializer(&env);
7189         type = env.type;
7190
7191         expression->compound_literal.initializer = initializer;
7192         expression->compound_literal.type        = type;
7193         expression->base.type                    = automatic_type_conversion(type);
7194
7195         return expression;
7196 }
7197
7198 /**
7199  * Parse a cast expression.
7200  */
7201 static expression_t *parse_cast(void)
7202 {
7203         add_anchor_token(')');
7204
7205         source_position_t source_position = token.source_position;
7206
7207         type_t *type = parse_typename();
7208
7209         rem_anchor_token(')');
7210         expect(')', end_error);
7211
7212         if (token.type == '{') {
7213                 return parse_compound_literal(type);
7214         }
7215
7216         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
7217         cast->base.source_position = source_position;
7218
7219         expression_t *value = parse_sub_expression(PREC_CAST);
7220         cast->base.type   = type;
7221         cast->unary.value = value;
7222
7223         if (! semantic_cast(cast)) {
7224                 /* TODO: record the error in the AST. else it is impossible to detect it */
7225         }
7226
7227         return cast;
7228 end_error:
7229         return create_invalid_expression();
7230 }
7231
7232 /**
7233  * Parse a statement expression.
7234  */
7235 static expression_t *parse_statement_expression(void)
7236 {
7237         add_anchor_token(')');
7238
7239         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
7240
7241         statement_t *statement          = parse_compound_statement(true);
7242         statement->compound.stmt_expr   = true;
7243         expression->statement.statement = statement;
7244
7245         /* find last statement and use its type */
7246         type_t *type = type_void;
7247         const statement_t *stmt = statement->compound.statements;
7248         if (stmt != NULL) {
7249                 while (stmt->base.next != NULL)
7250                         stmt = stmt->base.next;
7251
7252                 if (stmt->kind == STATEMENT_EXPRESSION) {
7253                         type = stmt->expression.expression->base.type;
7254                 }
7255         } else if (warning.other) {
7256                 warningf(&expression->base.source_position, "empty statement expression ({})");
7257         }
7258         expression->base.type = type;
7259
7260         rem_anchor_token(')');
7261         expect(')', end_error);
7262
7263 end_error:
7264         return expression;
7265 }
7266
7267 /**
7268  * Parse a parenthesized expression.
7269  */
7270 static expression_t *parse_parenthesized_expression(void)
7271 {
7272         eat('(');
7273
7274         switch (token.type) {
7275         case '{':
7276                 /* gcc extension: a statement expression */
7277                 return parse_statement_expression();
7278
7279         TYPE_QUALIFIERS
7280         TYPE_SPECIFIERS
7281                 return parse_cast();
7282         case T_IDENTIFIER:
7283                 if (is_typedef_symbol(token.v.symbol)) {
7284                         return parse_cast();
7285                 }
7286         }
7287
7288         add_anchor_token(')');
7289         expression_t *result = parse_expression();
7290         result->base.parenthesized = true;
7291         rem_anchor_token(')');
7292         expect(')', end_error);
7293
7294 end_error:
7295         return result;
7296 }
7297
7298 static expression_t *parse_function_keyword(void)
7299 {
7300         /* TODO */
7301
7302         if (current_function == NULL) {
7303                 errorf(HERE, "'__func__' used outside of a function");
7304         }
7305
7306         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
7307         expression->base.type     = type_char_ptr;
7308         expression->funcname.kind = FUNCNAME_FUNCTION;
7309
7310         next_token();
7311
7312         return expression;
7313 }
7314
7315 static expression_t *parse_pretty_function_keyword(void)
7316 {
7317         if (current_function == NULL) {
7318                 errorf(HERE, "'__PRETTY_FUNCTION__' used outside of a function");
7319         }
7320
7321         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
7322         expression->base.type     = type_char_ptr;
7323         expression->funcname.kind = FUNCNAME_PRETTY_FUNCTION;
7324
7325         eat(T___PRETTY_FUNCTION__);
7326
7327         return expression;
7328 }
7329
7330 static expression_t *parse_funcsig_keyword(void)
7331 {
7332         if (current_function == NULL) {
7333                 errorf(HERE, "'__FUNCSIG__' used outside of a function");
7334         }
7335
7336         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
7337         expression->base.type     = type_char_ptr;
7338         expression->funcname.kind = FUNCNAME_FUNCSIG;
7339
7340         eat(T___FUNCSIG__);
7341
7342         return expression;
7343 }
7344
7345 static expression_t *parse_funcdname_keyword(void)
7346 {
7347         if (current_function == NULL) {
7348                 errorf(HERE, "'__FUNCDNAME__' used outside of a function");
7349         }
7350
7351         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
7352         expression->base.type     = type_char_ptr;
7353         expression->funcname.kind = FUNCNAME_FUNCDNAME;
7354
7355         eat(T___FUNCDNAME__);
7356
7357         return expression;
7358 }
7359
7360 static designator_t *parse_designator(void)
7361 {
7362         designator_t *result    = allocate_ast_zero(sizeof(result[0]));
7363         result->source_position = *HERE;
7364
7365         if (token.type != T_IDENTIFIER) {
7366                 parse_error_expected("while parsing member designator",
7367                                      T_IDENTIFIER, NULL);
7368                 return NULL;
7369         }
7370         result->symbol = token.v.symbol;
7371         next_token();
7372
7373         designator_t *last_designator = result;
7374         while (true) {
7375                 if (token.type == '.') {
7376                         next_token();
7377                         if (token.type != T_IDENTIFIER) {
7378                                 parse_error_expected("while parsing member designator",
7379                                                      T_IDENTIFIER, NULL);
7380                                 return NULL;
7381                         }
7382                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
7383                         designator->source_position = *HERE;
7384                         designator->symbol          = token.v.symbol;
7385                         next_token();
7386
7387                         last_designator->next = designator;
7388                         last_designator       = designator;
7389                         continue;
7390                 }
7391                 if (token.type == '[') {
7392                         next_token();
7393                         add_anchor_token(']');
7394                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
7395                         designator->source_position = *HERE;
7396                         designator->array_index     = parse_expression();
7397                         rem_anchor_token(']');
7398                         expect(']', end_error);
7399                         if (designator->array_index == NULL) {
7400                                 return NULL;
7401                         }
7402
7403                         last_designator->next = designator;
7404                         last_designator       = designator;
7405                         continue;
7406                 }
7407                 break;
7408         }
7409
7410         return result;
7411 end_error:
7412         return NULL;
7413 }
7414
7415 /**
7416  * Parse the __builtin_offsetof() expression.
7417  */
7418 static expression_t *parse_offsetof(void)
7419 {
7420         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
7421         expression->base.type    = type_size_t;
7422
7423         eat(T___builtin_offsetof);
7424
7425         expect('(', end_error);
7426         add_anchor_token(',');
7427         type_t *type = parse_typename();
7428         rem_anchor_token(',');
7429         expect(',', end_error);
7430         add_anchor_token(')');
7431         designator_t *designator = parse_designator();
7432         rem_anchor_token(')');
7433         expect(')', end_error);
7434
7435         expression->offsetofe.type       = type;
7436         expression->offsetofe.designator = designator;
7437
7438         type_path_t path;
7439         memset(&path, 0, sizeof(path));
7440         path.top_type = type;
7441         path.path     = NEW_ARR_F(type_path_entry_t, 0);
7442
7443         descend_into_subtype(&path);
7444
7445         if (!walk_designator(&path, designator, true)) {
7446                 return create_invalid_expression();
7447         }
7448
7449         DEL_ARR_F(path.path);
7450
7451         return expression;
7452 end_error:
7453         return create_invalid_expression();
7454 }
7455
7456 /**
7457  * Parses a _builtin_va_start() expression.
7458  */
7459 static expression_t *parse_va_start(void)
7460 {
7461         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
7462
7463         eat(T___builtin_va_start);
7464
7465         expect('(', end_error);
7466         add_anchor_token(',');
7467         expression->va_starte.ap = parse_assignment_expression();
7468         rem_anchor_token(',');
7469         expect(',', end_error);
7470         expression_t *const expr = parse_assignment_expression();
7471         if (expr->kind == EXPR_REFERENCE) {
7472                 entity_t *const entity = expr->reference.entity;
7473                 if (entity->base.parent_scope != &current_function->parameters
7474                                 || entity->base.next != NULL
7475                                 || entity->kind != ENTITY_PARAMETER) {
7476                         errorf(&expr->base.source_position,
7477                                "second argument of 'va_start' must be last parameter of the current function");
7478                 } else {
7479                         expression->va_starte.parameter = &entity->variable;
7480                 }
7481                 expect(')', end_error);
7482                 return expression;
7483         }
7484         expect(')', end_error);
7485 end_error:
7486         return create_invalid_expression();
7487 }
7488
7489 /**
7490  * Parses a _builtin_va_arg() expression.
7491  */
7492 static expression_t *parse_va_arg(void)
7493 {
7494         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
7495
7496         eat(T___builtin_va_arg);
7497
7498         expect('(', end_error);
7499         expression->va_arge.ap = parse_assignment_expression();
7500         expect(',', end_error);
7501         expression->base.type = parse_typename();
7502         expect(')', end_error);
7503
7504         return expression;
7505 end_error:
7506         return create_invalid_expression();
7507 }
7508
7509 static expression_t *parse_builtin_symbol(void)
7510 {
7511         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_SYMBOL);
7512
7513         symbol_t *symbol = token.v.symbol;
7514
7515         expression->builtin_symbol.symbol = symbol;
7516         next_token();
7517
7518         type_t *type = get_builtin_symbol_type(symbol);
7519         type = automatic_type_conversion(type);
7520
7521         expression->base.type = type;
7522         return expression;
7523 }
7524
7525 /**
7526  * Parses a __builtin_constant() expression.
7527  */
7528 static expression_t *parse_builtin_constant(void)
7529 {
7530         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
7531
7532         eat(T___builtin_constant_p);
7533
7534         expect('(', end_error);
7535         add_anchor_token(')');
7536         expression->builtin_constant.value = parse_assignment_expression();
7537         rem_anchor_token(')');
7538         expect(')', end_error);
7539         expression->base.type = type_int;
7540
7541         return expression;
7542 end_error:
7543         return create_invalid_expression();
7544 }
7545
7546 /**
7547  * Parses a __builtin_prefetch() expression.
7548  */
7549 static expression_t *parse_builtin_prefetch(void)
7550 {
7551         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_PREFETCH);
7552
7553         eat(T___builtin_prefetch);
7554
7555         expect('(', end_error);
7556         add_anchor_token(')');
7557         expression->builtin_prefetch.adr = parse_assignment_expression();
7558         if (token.type == ',') {
7559                 next_token();
7560                 expression->builtin_prefetch.rw = parse_assignment_expression();
7561         }
7562         if (token.type == ',') {
7563                 next_token();
7564                 expression->builtin_prefetch.locality = parse_assignment_expression();
7565         }
7566         rem_anchor_token(')');
7567         expect(')', end_error);
7568         expression->base.type = type_void;
7569
7570         return expression;
7571 end_error:
7572         return create_invalid_expression();
7573 }
7574
7575 /**
7576  * Parses a __builtin_is_*() compare expression.
7577  */
7578 static expression_t *parse_compare_builtin(void)
7579 {
7580         expression_t *expression;
7581
7582         switch (token.type) {
7583         case T___builtin_isgreater:
7584                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATER);
7585                 break;
7586         case T___builtin_isgreaterequal:
7587                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATEREQUAL);
7588                 break;
7589         case T___builtin_isless:
7590                 expression = allocate_expression_zero(EXPR_BINARY_ISLESS);
7591                 break;
7592         case T___builtin_islessequal:
7593                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSEQUAL);
7594                 break;
7595         case T___builtin_islessgreater:
7596                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSGREATER);
7597                 break;
7598         case T___builtin_isunordered:
7599                 expression = allocate_expression_zero(EXPR_BINARY_ISUNORDERED);
7600                 break;
7601         default:
7602                 internal_errorf(HERE, "invalid compare builtin found");
7603         }
7604         expression->base.source_position = *HERE;
7605         next_token();
7606
7607         expect('(', end_error);
7608         expression->binary.left = parse_assignment_expression();
7609         expect(',', end_error);
7610         expression->binary.right = parse_assignment_expression();
7611         expect(')', end_error);
7612
7613         type_t *const orig_type_left  = expression->binary.left->base.type;
7614         type_t *const orig_type_right = expression->binary.right->base.type;
7615
7616         type_t *const type_left  = skip_typeref(orig_type_left);
7617         type_t *const type_right = skip_typeref(orig_type_right);
7618         if (!is_type_float(type_left) && !is_type_float(type_right)) {
7619                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7620                         type_error_incompatible("invalid operands in comparison",
7621                                 &expression->base.source_position, orig_type_left, orig_type_right);
7622                 }
7623         } else {
7624                 semantic_comparison(&expression->binary);
7625         }
7626
7627         return expression;
7628 end_error:
7629         return create_invalid_expression();
7630 }
7631
7632 #if 0
7633 /**
7634  * Parses a __builtin_expect(, end_error) expression.
7635  */
7636 static expression_t *parse_builtin_expect(void, end_error)
7637 {
7638         expression_t *expression
7639                 = allocate_expression_zero(EXPR_BINARY_BUILTIN_EXPECT);
7640
7641         eat(T___builtin_expect);
7642
7643         expect('(', end_error);
7644         expression->binary.left = parse_assignment_expression();
7645         expect(',', end_error);
7646         expression->binary.right = parse_constant_expression();
7647         expect(')', end_error);
7648
7649         expression->base.type = expression->binary.left->base.type;
7650
7651         return expression;
7652 end_error:
7653         return create_invalid_expression();
7654 }
7655 #endif
7656
7657 /**
7658  * Parses a MS assume() expression.
7659  */
7660 static expression_t *parse_assume(void)
7661 {
7662         expression_t *expression = allocate_expression_zero(EXPR_UNARY_ASSUME);
7663
7664         eat(T__assume);
7665
7666         expect('(', end_error);
7667         add_anchor_token(')');
7668         expression->unary.value = parse_assignment_expression();
7669         rem_anchor_token(')');
7670         expect(')', end_error);
7671
7672         expression->base.type = type_void;
7673         return expression;
7674 end_error:
7675         return create_invalid_expression();
7676 }
7677
7678 /**
7679  * Return the declaration for a given label symbol or create a new one.
7680  *
7681  * @param symbol  the symbol of the label
7682  */
7683 static label_t *get_label(symbol_t *symbol)
7684 {
7685         entity_t *label;
7686         assert(current_function != NULL);
7687
7688         label = get_entity(symbol, NAMESPACE_LABEL);
7689         /* if we found a local label, we already created the declaration */
7690         if (label != NULL && label->kind == ENTITY_LOCAL_LABEL) {
7691                 if (label->base.parent_scope != current_scope) {
7692                         assert(label->base.parent_scope->depth < current_scope->depth);
7693                         current_function->goto_to_outer = true;
7694                 }
7695                 return &label->label;
7696         }
7697
7698         label = get_entity(symbol, NAMESPACE_LABEL);
7699         /* if we found a label in the same function, then we already created the
7700          * declaration */
7701         if (label != NULL
7702                         && label->base.parent_scope == &current_function->parameters) {
7703                 return &label->label;
7704         }
7705
7706         /* otherwise we need to create a new one */
7707         label               = allocate_entity_zero(ENTITY_LABEL);
7708         label->base.namespc = NAMESPACE_LABEL;
7709         label->base.symbol  = symbol;
7710
7711         label_push(label);
7712
7713         return &label->label;
7714 }
7715
7716 /**
7717  * Parses a GNU && label address expression.
7718  */
7719 static expression_t *parse_label_address(void)
7720 {
7721         source_position_t source_position = token.source_position;
7722         eat(T_ANDAND);
7723         if (token.type != T_IDENTIFIER) {
7724                 parse_error_expected("while parsing label address", T_IDENTIFIER, NULL);
7725                 goto end_error;
7726         }
7727         symbol_t *symbol = token.v.symbol;
7728         next_token();
7729
7730         label_t *label       = get_label(symbol);
7731         label->used          = true;
7732         label->address_taken = true;
7733
7734         expression_t *expression = allocate_expression_zero(EXPR_LABEL_ADDRESS);
7735         expression->base.source_position = source_position;
7736
7737         /* label address is threaten as a void pointer */
7738         expression->base.type           = type_void_ptr;
7739         expression->label_address.label = label;
7740         return expression;
7741 end_error:
7742         return create_invalid_expression();
7743 }
7744
7745 /**
7746  * Parse a microsoft __noop expression.
7747  */
7748 static expression_t *parse_noop_expression(void)
7749 {
7750         /* the result is a (int)0 */
7751         expression_t *cnst         = allocate_expression_zero(EXPR_CONST);
7752         cnst->base.type            = type_int;
7753         cnst->conste.v.int_value   = 0;
7754         cnst->conste.is_ms_noop    = true;
7755
7756         eat(T___noop);
7757
7758         if (token.type == '(') {
7759                 /* parse arguments */
7760                 eat('(');
7761                 add_anchor_token(')');
7762                 add_anchor_token(',');
7763
7764                 if (token.type != ')') {
7765                         while (true) {
7766                                 (void)parse_assignment_expression();
7767                                 if (token.type != ',')
7768                                         break;
7769                                 next_token();
7770                         }
7771                 }
7772         }
7773         rem_anchor_token(',');
7774         rem_anchor_token(')');
7775         expect(')', end_error);
7776
7777 end_error:
7778         return cnst;
7779 }
7780
7781 /**
7782  * Parses a primary expression.
7783  */
7784 static expression_t *parse_primary_expression(void)
7785 {
7786         switch (token.type) {
7787                 case T_false:                    return parse_bool_const(false);
7788                 case T_true:                     return parse_bool_const(true);
7789                 case T_INTEGER:                  return parse_int_const();
7790                 case T_CHARACTER_CONSTANT:       return parse_character_constant();
7791                 case T_WIDE_CHARACTER_CONSTANT:  return parse_wide_character_constant();
7792                 case T_FLOATINGPOINT:            return parse_float_const();
7793                 case T_STRING_LITERAL:
7794                 case T_WIDE_STRING_LITERAL:      return parse_string_const();
7795                 case T_IDENTIFIER:               return parse_reference();
7796                 case T___FUNCTION__:
7797                 case T___func__:                 return parse_function_keyword();
7798                 case T___PRETTY_FUNCTION__:      return parse_pretty_function_keyword();
7799                 case T___FUNCSIG__:              return parse_funcsig_keyword();
7800                 case T___FUNCDNAME__:            return parse_funcdname_keyword();
7801                 case T___builtin_offsetof:       return parse_offsetof();
7802                 case T___builtin_va_start:       return parse_va_start();
7803                 case T___builtin_va_arg:         return parse_va_arg();
7804                 case T___builtin_expect:
7805                 case T___builtin_alloca:
7806                 case T___builtin_inf:
7807                 case T___builtin_inff:
7808                 case T___builtin_infl:
7809                 case T___builtin_nan:
7810                 case T___builtin_nanf:
7811                 case T___builtin_nanl:
7812                 case T___builtin_huge_val:
7813                 case T___builtin_va_end:
7814                 case T___builtin_return_address:
7815                 case T___builtin_frame_address:  return parse_builtin_symbol();
7816                 case T___builtin_isgreater:
7817                 case T___builtin_isgreaterequal:
7818                 case T___builtin_isless:
7819                 case T___builtin_islessequal:
7820                 case T___builtin_islessgreater:
7821                 case T___builtin_isunordered:    return parse_compare_builtin();
7822                 case T___builtin_constant_p:     return parse_builtin_constant();
7823                 case T___builtin_prefetch:       return parse_builtin_prefetch();
7824                 case T__assume:                  return parse_assume();
7825                 case T_ANDAND:
7826                         if (GNU_MODE)
7827                                 return parse_label_address();
7828                         break;
7829
7830                 case '(':                        return parse_parenthesized_expression();
7831                 case T___noop:                   return parse_noop_expression();
7832         }
7833
7834         errorf(HERE, "unexpected token %K, expected an expression", &token);
7835         return create_invalid_expression();
7836 }
7837
7838 /**
7839  * Check if the expression has the character type and issue a warning then.
7840  */
7841 static void check_for_char_index_type(const expression_t *expression)
7842 {
7843         type_t       *const type      = expression->base.type;
7844         const type_t *const base_type = skip_typeref(type);
7845
7846         if (is_type_atomic(base_type, ATOMIC_TYPE_CHAR) &&
7847                         warning.char_subscripts) {
7848                 warningf(&expression->base.source_position,
7849                          "array subscript has type '%T'", type);
7850         }
7851 }
7852
7853 static expression_t *parse_array_expression(expression_t *left)
7854 {
7855         expression_t *expression = allocate_expression_zero(EXPR_ARRAY_ACCESS);
7856
7857         eat('[');
7858         add_anchor_token(']');
7859
7860         expression_t *inside = parse_expression();
7861
7862         type_t *const orig_type_left   = left->base.type;
7863         type_t *const orig_type_inside = inside->base.type;
7864
7865         type_t *const type_left   = skip_typeref(orig_type_left);
7866         type_t *const type_inside = skip_typeref(orig_type_inside);
7867
7868         type_t                    *return_type;
7869         array_access_expression_t *array_access = &expression->array_access;
7870         if (is_type_pointer(type_left)) {
7871                 return_type             = type_left->pointer.points_to;
7872                 array_access->array_ref = left;
7873                 array_access->index     = inside;
7874                 check_for_char_index_type(inside);
7875         } else if (is_type_pointer(type_inside)) {
7876                 return_type             = type_inside->pointer.points_to;
7877                 array_access->array_ref = inside;
7878                 array_access->index     = left;
7879                 array_access->flipped   = true;
7880                 check_for_char_index_type(left);
7881         } else {
7882                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
7883                         errorf(HERE,
7884                                 "array access on object with non-pointer types '%T', '%T'",
7885                                 orig_type_left, orig_type_inside);
7886                 }
7887                 return_type             = type_error_type;
7888                 array_access->array_ref = left;
7889                 array_access->index     = inside;
7890         }
7891
7892         expression->base.type = automatic_type_conversion(return_type);
7893
7894         rem_anchor_token(']');
7895         expect(']', end_error);
7896 end_error:
7897         return expression;
7898 }
7899
7900 static expression_t *parse_typeprop(expression_kind_t const kind)
7901 {
7902         expression_t  *tp_expression = allocate_expression_zero(kind);
7903         tp_expression->base.type     = type_size_t;
7904
7905         eat(kind == EXPR_SIZEOF ? T_sizeof : T___alignof__);
7906
7907         /* we only refer to a type property, mark this case */
7908         bool old     = in_type_prop;
7909         in_type_prop = true;
7910
7911         type_t       *orig_type;
7912         expression_t *expression;
7913         if (token.type == '(' && is_declaration_specifier(look_ahead(1), true)) {
7914                 next_token();
7915                 add_anchor_token(')');
7916                 orig_type = parse_typename();
7917                 rem_anchor_token(')');
7918                 expect(')', end_error);
7919
7920                 if (token.type == '{') {
7921                         /* It was not sizeof(type) after all.  It is sizeof of an expression
7922                          * starting with a compound literal */
7923                         expression = parse_compound_literal(orig_type);
7924                         goto typeprop_expression;
7925                 }
7926         } else {
7927                 expression = parse_sub_expression(PREC_UNARY);
7928
7929 typeprop_expression:
7930                 tp_expression->typeprop.tp_expression = expression;
7931
7932                 orig_type = revert_automatic_type_conversion(expression);
7933                 expression->base.type = orig_type;
7934         }
7935
7936         tp_expression->typeprop.type   = orig_type;
7937         type_t const* const type       = skip_typeref(orig_type);
7938         char   const* const wrong_type =
7939                 GNU_MODE && is_type_atomic(type, ATOMIC_TYPE_VOID) ? NULL                  :
7940                 is_type_incomplete(type)                           ? "incomplete"          :
7941                 type->kind == TYPE_FUNCTION                        ? "function designator" :
7942                 type->kind == TYPE_BITFIELD                        ? "bitfield"            :
7943                 NULL;
7944         if (wrong_type != NULL) {
7945                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
7946                 errorf(&tp_expression->base.source_position,
7947                                 "operand of %s expression must not be of %s type '%T'",
7948                                 what, wrong_type, orig_type);
7949         }
7950
7951 end_error:
7952         in_type_prop = old;
7953         return tp_expression;
7954 }
7955
7956 static expression_t *parse_sizeof(void)
7957 {
7958         return parse_typeprop(EXPR_SIZEOF);
7959 }
7960
7961 static expression_t *parse_alignof(void)
7962 {
7963         return parse_typeprop(EXPR_ALIGNOF);
7964 }
7965
7966 static expression_t *parse_select_expression(expression_t *compound)
7967 {
7968         expression_t *select    = allocate_expression_zero(EXPR_SELECT);
7969         select->select.compound = compound;
7970
7971         assert(token.type == '.' || token.type == T_MINUSGREATER);
7972         bool is_pointer = (token.type == T_MINUSGREATER);
7973         next_token();
7974
7975         if (token.type != T_IDENTIFIER) {
7976                 parse_error_expected("while parsing select", T_IDENTIFIER, NULL);
7977                 return select;
7978         }
7979         symbol_t *symbol = token.v.symbol;
7980         next_token();
7981
7982         type_t *const orig_type = compound->base.type;
7983         type_t *const type      = skip_typeref(orig_type);
7984
7985         type_t *type_left;
7986         bool    saw_error = false;
7987         if (is_type_pointer(type)) {
7988                 if (!is_pointer) {
7989                         errorf(HERE,
7990                                "request for member '%Y' in something not a struct or union, but '%T'",
7991                                symbol, orig_type);
7992                         saw_error = true;
7993                 }
7994                 type_left = skip_typeref(type->pointer.points_to);
7995         } else {
7996                 if (is_pointer && is_type_valid(type)) {
7997                         errorf(HERE, "left hand side of '->' is not a pointer, but '%T'", orig_type);
7998                         saw_error = true;
7999                 }
8000                 type_left = type;
8001         }
8002
8003         entity_t *entry;
8004         if (type_left->kind == TYPE_COMPOUND_STRUCT ||
8005             type_left->kind == TYPE_COMPOUND_UNION) {
8006                 compound_t *compound = type_left->compound.compound;
8007
8008                 if (!compound->complete) {
8009                         errorf(HERE, "request for member '%Y' of incomplete type '%T'",
8010                                symbol, type_left);
8011                         goto create_error_entry;
8012                 }
8013
8014                 entry = find_compound_entry(compound, symbol);
8015                 if (entry == NULL) {
8016                         errorf(HERE, "'%T' has no member named '%Y'", orig_type, symbol);
8017                         goto create_error_entry;
8018                 }
8019         } else {
8020                 if (is_type_valid(type_left) && !saw_error) {
8021                         errorf(HERE,
8022                                "request for member '%Y' in something not a struct or union, but '%T'",
8023                                symbol, type_left);
8024                 }
8025 create_error_entry:
8026                 entry = create_error_entity(symbol, ENTITY_COMPOUND_MEMBER);
8027         }
8028
8029         assert(is_declaration(entry));
8030         select->select.compound_entry = entry;
8031
8032         type_t *entry_type = entry->declaration.type;
8033         type_t *res_type
8034                 = get_qualified_type(entry_type, type_left->base.qualifiers);
8035
8036         /* we always do the auto-type conversions; the & and sizeof parser contains
8037          * code to revert this! */
8038         select->base.type = automatic_type_conversion(res_type);
8039
8040         type_t *skipped = skip_typeref(res_type);
8041         if (skipped->kind == TYPE_BITFIELD) {
8042                 select->base.type = skipped->bitfield.base_type;
8043         }
8044
8045         return select;
8046 }
8047
8048 static void check_call_argument(const function_parameter_t *parameter,
8049                                 call_argument_t *argument, unsigned pos)
8050 {
8051         type_t         *expected_type      = parameter->type;
8052         type_t         *expected_type_skip = skip_typeref(expected_type);
8053         assign_error_t  error              = ASSIGN_ERROR_INCOMPATIBLE;
8054         expression_t   *arg_expr           = argument->expression;
8055         type_t         *arg_type           = skip_typeref(arg_expr->base.type);
8056
8057         /* handle transparent union gnu extension */
8058         if (is_type_union(expected_type_skip)
8059                         && (expected_type_skip->base.modifiers
8060                                 & TYPE_MODIFIER_TRANSPARENT_UNION)) {
8061                 compound_t *union_decl  = expected_type_skip->compound.compound;
8062                 type_t     *best_type   = NULL;
8063                 entity_t   *entry       = union_decl->members.entities;
8064                 for ( ; entry != NULL; entry = entry->base.next) {
8065                         assert(is_declaration(entry));
8066                         type_t *decl_type = entry->declaration.type;
8067                         error = semantic_assign(decl_type, arg_expr);
8068                         if (error == ASSIGN_ERROR_INCOMPATIBLE
8069                                 || error == ASSIGN_ERROR_POINTER_QUALIFIER_MISSING)
8070                                 continue;
8071
8072                         if (error == ASSIGN_SUCCESS) {
8073                                 best_type = decl_type;
8074                         } else if (best_type == NULL) {
8075                                 best_type = decl_type;
8076                         }
8077                 }
8078
8079                 if (best_type != NULL) {
8080                         expected_type = best_type;
8081                 }
8082         }
8083
8084         error                = semantic_assign(expected_type, arg_expr);
8085         argument->expression = create_implicit_cast(argument->expression,
8086                                                     expected_type);
8087
8088         if (error != ASSIGN_SUCCESS) {
8089                 /* report exact scope in error messages (like "in argument 3") */
8090                 char buf[64];
8091                 snprintf(buf, sizeof(buf), "call argument %u", pos);
8092                 report_assign_error(error, expected_type, arg_expr,     buf,
8093                                                         &arg_expr->base.source_position);
8094         } else if (warning.traditional || warning.conversion) {
8095                 type_t *const promoted_type = get_default_promoted_type(arg_type);
8096                 if (!types_compatible(expected_type_skip, promoted_type) &&
8097                     !types_compatible(expected_type_skip, type_void_ptr) &&
8098                     !types_compatible(type_void_ptr,      promoted_type)) {
8099                         /* Deliberately show the skipped types in this warning */
8100                         warningf(&arg_expr->base.source_position,
8101                                 "passing call argument %u as '%T' rather than '%T' due to prototype",
8102                                 pos, expected_type_skip, promoted_type);
8103                 }
8104         }
8105 }
8106
8107 /**
8108  * Handle the semantic restrictions of builtin calls
8109  */
8110 static void handle_builtin_argument_restrictions(call_expression_t *call) {
8111         switch (call->function->builtin_symbol.symbol->ID) {
8112                 case T___builtin_return_address:
8113                 case T___builtin_frame_address: {
8114                         /* argument must be constant */
8115                         call_argument_t *argument = call->arguments;
8116
8117                         if (! is_constant_expression(argument->expression)) {
8118                                 errorf(&call->base.source_position,
8119                                        "argument of '%Y' must be a constant expression",
8120                                        call->function->builtin_symbol.symbol);
8121                         }
8122                         break;
8123                 }
8124                 default:
8125                         break;
8126         }
8127 }
8128
8129 /**
8130  * Parse a call expression, ie. expression '( ... )'.
8131  *
8132  * @param expression  the function address
8133  */
8134 static expression_t *parse_call_expression(expression_t *expression)
8135 {
8136         expression_t      *result = allocate_expression_zero(EXPR_CALL);
8137         call_expression_t *call   = &result->call;
8138         call->function            = expression;
8139
8140         type_t *const orig_type = expression->base.type;
8141         type_t *const type      = skip_typeref(orig_type);
8142
8143         function_type_t *function_type = NULL;
8144         if (is_type_pointer(type)) {
8145                 type_t *const to_type = skip_typeref(type->pointer.points_to);
8146
8147                 if (is_type_function(to_type)) {
8148                         function_type   = &to_type->function;
8149                         call->base.type = function_type->return_type;
8150                 }
8151         }
8152
8153         if (function_type == NULL && is_type_valid(type)) {
8154                 errorf(HERE, "called object '%E' (type '%T') is not a pointer to a function", expression, orig_type);
8155         }
8156
8157         /* parse arguments */
8158         eat('(');
8159         add_anchor_token(')');
8160         add_anchor_token(',');
8161
8162         if (token.type != ')') {
8163                 call_argument_t *last_argument = NULL;
8164
8165                 while (true) {
8166                         call_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
8167
8168                         argument->expression = parse_assignment_expression();
8169                         if (last_argument == NULL) {
8170                                 call->arguments = argument;
8171                         } else {
8172                                 last_argument->next = argument;
8173                         }
8174                         last_argument = argument;
8175
8176                         if (token.type != ',')
8177                                 break;
8178                         next_token();
8179                 }
8180         }
8181         rem_anchor_token(',');
8182         rem_anchor_token(')');
8183         expect(')', end_error);
8184
8185         if (function_type == NULL)
8186                 return result;
8187
8188         function_parameter_t *parameter = function_type->parameters;
8189         call_argument_t      *argument  = call->arguments;
8190         if (!function_type->unspecified_parameters) {
8191                 for (unsigned pos = 0; parameter != NULL && argument != NULL;
8192                                 parameter = parameter->next, argument = argument->next) {
8193                         check_call_argument(parameter, argument, ++pos);
8194                 }
8195
8196                 if (parameter != NULL) {
8197                         errorf(HERE, "too few arguments to function '%E'", expression);
8198                 } else if (argument != NULL && !function_type->variadic) {
8199                         errorf(HERE, "too many arguments to function '%E'", expression);
8200                 }
8201         }
8202
8203         /* do default promotion */
8204         for (; argument != NULL; argument = argument->next) {
8205                 type_t *type = argument->expression->base.type;
8206
8207                 type = get_default_promoted_type(type);
8208
8209                 argument->expression
8210                         = create_implicit_cast(argument->expression, type);
8211         }
8212
8213         check_format(&result->call);
8214
8215         if (warning.aggregate_return &&
8216             is_type_compound(skip_typeref(function_type->return_type))) {
8217                 warningf(&result->base.source_position,
8218                          "function call has aggregate value");
8219         }
8220
8221         if (call->function->kind == EXPR_BUILTIN_SYMBOL) {
8222                 handle_builtin_argument_restrictions(&result->call);
8223         }
8224
8225 end_error:
8226         return result;
8227 }
8228
8229 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
8230
8231 static bool same_compound_type(const type_t *type1, const type_t *type2)
8232 {
8233         return
8234                 is_type_compound(type1) &&
8235                 type1->kind == type2->kind &&
8236                 type1->compound.compound == type2->compound.compound;
8237 }
8238
8239 static expression_t const *get_reference_address(expression_t const *expr)
8240 {
8241         bool regular_take_address = true;
8242         for (;;) {
8243                 if (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
8244                         expr = expr->unary.value;
8245                 } else {
8246                         regular_take_address = false;
8247                 }
8248
8249                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
8250                         break;
8251
8252                 expr = expr->unary.value;
8253         }
8254
8255         if (expr->kind != EXPR_REFERENCE)
8256                 return NULL;
8257
8258         /* special case for functions which are automatically converted to a
8259          * pointer to function without an extra TAKE_ADDRESS operation */
8260         if (!regular_take_address &&
8261                         expr->reference.entity->kind != ENTITY_FUNCTION) {
8262                 return NULL;
8263         }
8264
8265         return expr;
8266 }
8267
8268 static void warn_reference_address_as_bool(expression_t const* expr)
8269 {
8270         if (!warning.address)
8271                 return;
8272
8273         expr = get_reference_address(expr);
8274         if (expr != NULL) {
8275                 warningf(&expr->base.source_position,
8276                          "the address of '%Y' will always evaluate as 'true'",
8277                          expr->reference.entity->base.symbol);
8278         }
8279 }
8280
8281 static void warn_assignment_in_condition(const expression_t *const expr)
8282 {
8283         if (!warning.parentheses)
8284                 return;
8285         if (expr->base.kind != EXPR_BINARY_ASSIGN)
8286                 return;
8287         if (expr->base.parenthesized)
8288                 return;
8289         warningf(&expr->base.source_position,
8290                         "suggest parentheses around assignment used as truth value");
8291 }
8292
8293 static void semantic_condition(expression_t const *const expr,
8294                                char const *const context)
8295 {
8296         type_t *const type = skip_typeref(expr->base.type);
8297         if (is_type_scalar(type)) {
8298                 warn_reference_address_as_bool(expr);
8299                 warn_assignment_in_condition(expr);
8300         } else if (is_type_valid(type)) {
8301                 errorf(&expr->base.source_position,
8302                                 "%s must have scalar type", context);
8303         }
8304 }
8305
8306 /**
8307  * Parse a conditional expression, ie. 'expression ? ... : ...'.
8308  *
8309  * @param expression  the conditional expression
8310  */
8311 static expression_t *parse_conditional_expression(expression_t *expression)
8312 {
8313         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
8314
8315         conditional_expression_t *conditional = &result->conditional;
8316         conditional->condition                = expression;
8317
8318         eat('?');
8319         add_anchor_token(':');
8320
8321         /* §6.5.15:2  The first operand shall have scalar type. */
8322         semantic_condition(expression, "condition of conditional operator");
8323
8324         expression_t *true_expression = expression;
8325         bool          gnu_cond = false;
8326         if (GNU_MODE && token.type == ':') {
8327                 gnu_cond = true;
8328         } else {
8329                 true_expression = parse_expression();
8330         }
8331         rem_anchor_token(':');
8332         expect(':', end_error);
8333 end_error:;
8334         expression_t *false_expression =
8335                 parse_sub_expression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
8336
8337         type_t *const orig_true_type  = true_expression->base.type;
8338         type_t *const orig_false_type = false_expression->base.type;
8339         type_t *const true_type       = skip_typeref(orig_true_type);
8340         type_t *const false_type      = skip_typeref(orig_false_type);
8341
8342         /* 6.5.15.3 */
8343         type_t *result_type;
8344         if (is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
8345                         is_type_atomic(false_type, ATOMIC_TYPE_VOID)) {
8346                 /* ISO/IEC 14882:1998(E) §5.16:2 */
8347                 if (true_expression->kind == EXPR_UNARY_THROW) {
8348                         result_type = false_type;
8349                 } else if (false_expression->kind == EXPR_UNARY_THROW) {
8350                         result_type = true_type;
8351                 } else {
8352                         if (warning.other && (
8353                                                 !is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
8354                                                 !is_type_atomic(false_type, ATOMIC_TYPE_VOID)
8355                                         )) {
8356                                 warningf(&conditional->base.source_position,
8357                                                 "ISO C forbids conditional expression with only one void side");
8358                         }
8359                         result_type = type_void;
8360                 }
8361         } else if (is_type_arithmetic(true_type)
8362                    && is_type_arithmetic(false_type)) {
8363                 result_type = semantic_arithmetic(true_type, false_type);
8364
8365                 true_expression  = create_implicit_cast(true_expression, result_type);
8366                 false_expression = create_implicit_cast(false_expression, result_type);
8367
8368                 conditional->true_expression  = true_expression;
8369                 conditional->false_expression = false_expression;
8370                 conditional->base.type        = result_type;
8371         } else if (same_compound_type(true_type, false_type)) {
8372                 /* just take 1 of the 2 types */
8373                 result_type = true_type;
8374         } else if (is_type_pointer(true_type) || is_type_pointer(false_type)) {
8375                 type_t *pointer_type;
8376                 type_t *other_type;
8377                 expression_t *other_expression;
8378                 if (is_type_pointer(true_type) &&
8379                                 (!is_type_pointer(false_type) || is_null_pointer_constant(false_expression))) {
8380                         pointer_type     = true_type;
8381                         other_type       = false_type;
8382                         other_expression = false_expression;
8383                 } else {
8384                         pointer_type     = false_type;
8385                         other_type       = true_type;
8386                         other_expression = true_expression;
8387                 }
8388
8389                 if (is_null_pointer_constant(other_expression)) {
8390                         result_type = pointer_type;
8391                 } else if (is_type_pointer(other_type)) {
8392                         type_t *to1 = skip_typeref(pointer_type->pointer.points_to);
8393                         type_t *to2 = skip_typeref(other_type->pointer.points_to);
8394
8395                         type_t *to;
8396                         if (is_type_atomic(to1, ATOMIC_TYPE_VOID) ||
8397                             is_type_atomic(to2, ATOMIC_TYPE_VOID)) {
8398                                 to = type_void;
8399                         } else if (types_compatible(get_unqualified_type(to1),
8400                                                     get_unqualified_type(to2))) {
8401                                 to = to1;
8402                         } else {
8403                                 if (warning.other) {
8404                                         warningf(&conditional->base.source_position,
8405                                                         "pointer types '%T' and '%T' in conditional expression are incompatible",
8406                                                         true_type, false_type);
8407                                 }
8408                                 to = type_void;
8409                         }
8410
8411                         type_t *const type =
8412                                 get_qualified_type(to, to1->base.qualifiers | to2->base.qualifiers);
8413                         result_type = make_pointer_type(type, TYPE_QUALIFIER_NONE);
8414                 } else if (is_type_integer(other_type)) {
8415                         if (warning.other) {
8416                                 warningf(&conditional->base.source_position,
8417                                                 "pointer/integer type mismatch in conditional expression ('%T' and '%T')", true_type, false_type);
8418                         }
8419                         result_type = pointer_type;
8420                 } else {
8421                         if (is_type_valid(other_type)) {
8422                                 type_error_incompatible("while parsing conditional",
8423                                                 &expression->base.source_position, true_type, false_type);
8424                         }
8425                         result_type = type_error_type;
8426                 }
8427         } else {
8428                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
8429                         type_error_incompatible("while parsing conditional",
8430                                                 &conditional->base.source_position, true_type,
8431                                                 false_type);
8432                 }
8433                 result_type = type_error_type;
8434         }
8435
8436         conditional->true_expression
8437                 = gnu_cond ? NULL : create_implicit_cast(true_expression, result_type);
8438         conditional->false_expression
8439                 = create_implicit_cast(false_expression, result_type);
8440         conditional->base.type = result_type;
8441         return result;
8442 }
8443
8444 /**
8445  * Parse an extension expression.
8446  */
8447 static expression_t *parse_extension(void)
8448 {
8449         eat(T___extension__);
8450
8451         bool old_gcc_extension   = in_gcc_extension;
8452         in_gcc_extension         = true;
8453         expression_t *expression = parse_sub_expression(PREC_UNARY);
8454         in_gcc_extension         = old_gcc_extension;
8455         return expression;
8456 }
8457
8458 /**
8459  * Parse a __builtin_classify_type() expression.
8460  */
8461 static expression_t *parse_builtin_classify_type(void)
8462 {
8463         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
8464         result->base.type    = type_int;
8465
8466         eat(T___builtin_classify_type);
8467
8468         expect('(', end_error);
8469         add_anchor_token(')');
8470         expression_t *expression = parse_expression();
8471         rem_anchor_token(')');
8472         expect(')', end_error);
8473         result->classify_type.type_expression = expression;
8474
8475         return result;
8476 end_error:
8477         return create_invalid_expression();
8478 }
8479
8480 /**
8481  * Parse a delete expression
8482  * ISO/IEC 14882:1998(E) §5.3.5
8483  */
8484 static expression_t *parse_delete(void)
8485 {
8486         expression_t *const result = allocate_expression_zero(EXPR_UNARY_DELETE);
8487         result->base.type          = type_void;
8488
8489         eat(T_delete);
8490
8491         if (token.type == '[') {
8492                 next_token();
8493                 result->kind = EXPR_UNARY_DELETE_ARRAY;
8494                 expect(']', end_error);
8495 end_error:;
8496         }
8497
8498         expression_t *const value = parse_sub_expression(PREC_CAST);
8499         result->unary.value = value;
8500
8501         type_t *const type = skip_typeref(value->base.type);
8502         if (!is_type_pointer(type)) {
8503                 if (is_type_valid(type)) {
8504                         errorf(&value->base.source_position,
8505                                         "operand of delete must have pointer type");
8506                 }
8507         } else if (warning.other &&
8508                         is_type_atomic(skip_typeref(type->pointer.points_to), ATOMIC_TYPE_VOID)) {
8509                 warningf(&value->base.source_position,
8510                                 "deleting 'void*' is undefined");
8511         }
8512
8513         return result;
8514 }
8515
8516 /**
8517  * Parse a throw expression
8518  * ISO/IEC 14882:1998(E) §15:1
8519  */
8520 static expression_t *parse_throw(void)
8521 {
8522         expression_t *const result = allocate_expression_zero(EXPR_UNARY_THROW);
8523         result->base.type          = type_void;
8524
8525         eat(T_throw);
8526
8527         expression_t *value = NULL;
8528         switch (token.type) {
8529                 EXPRESSION_START {
8530                         value = parse_assignment_expression();
8531                         /* ISO/IEC 14882:1998(E) §15.1:3 */
8532                         type_t *const orig_type = value->base.type;
8533                         type_t *const type      = skip_typeref(orig_type);
8534                         if (is_type_incomplete(type)) {
8535                                 errorf(&value->base.source_position,
8536                                                 "cannot throw object of incomplete type '%T'", orig_type);
8537                         } else if (is_type_pointer(type)) {
8538                                 type_t *const points_to = skip_typeref(type->pointer.points_to);
8539                                 if (is_type_incomplete(points_to) &&
8540                                                 !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
8541                                         errorf(&value->base.source_position,
8542                                                         "cannot throw pointer to incomplete type '%T'", orig_type);
8543                                 }
8544                         }
8545                 }
8546
8547                 default:
8548                         break;
8549         }
8550         result->unary.value = value;
8551
8552         return result;
8553 }
8554
8555 static bool check_pointer_arithmetic(const source_position_t *source_position,
8556                                      type_t *pointer_type,
8557                                      type_t *orig_pointer_type)
8558 {
8559         type_t *points_to = pointer_type->pointer.points_to;
8560         points_to = skip_typeref(points_to);
8561
8562         if (is_type_incomplete(points_to)) {
8563                 if (!GNU_MODE || !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
8564                         errorf(source_position,
8565                                "arithmetic with pointer to incomplete type '%T' not allowed",
8566                                orig_pointer_type);
8567                         return false;
8568                 } else if (warning.pointer_arith) {
8569                         warningf(source_position,
8570                                  "pointer of type '%T' used in arithmetic",
8571                                  orig_pointer_type);
8572                 }
8573         } else if (is_type_function(points_to)) {
8574                 if (!GNU_MODE) {
8575                         errorf(source_position,
8576                                "arithmetic with pointer to function type '%T' not allowed",
8577                                orig_pointer_type);
8578                         return false;
8579                 } else if (warning.pointer_arith) {
8580                         warningf(source_position,
8581                                  "pointer to a function '%T' used in arithmetic",
8582                                  orig_pointer_type);
8583                 }
8584         }
8585         return true;
8586 }
8587
8588 static bool is_lvalue(const expression_t *expression)
8589 {
8590         /* TODO: doesn't seem to be consistent with §6.3.2.1:1 */
8591         switch (expression->kind) {
8592         case EXPR_ARRAY_ACCESS:
8593         case EXPR_COMPOUND_LITERAL:
8594         case EXPR_REFERENCE:
8595         case EXPR_SELECT:
8596         case EXPR_UNARY_DEREFERENCE:
8597                 return true;
8598
8599         default: {
8600           type_t *type = skip_typeref(expression->base.type);
8601           return
8602                 /* ISO/IEC 14882:1998(E) §3.10:3 */
8603                 is_type_reference(type) ||
8604                 /* Claim it is an lvalue, if the type is invalid.  There was a parse
8605                  * error before, which maybe prevented properly recognizing it as
8606                  * lvalue. */
8607                 !is_type_valid(type);
8608         }
8609         }
8610 }
8611
8612 static void semantic_incdec(unary_expression_t *expression)
8613 {
8614         type_t *const orig_type = expression->value->base.type;
8615         type_t *const type      = skip_typeref(orig_type);
8616         if (is_type_pointer(type)) {
8617                 if (!check_pointer_arithmetic(&expression->base.source_position,
8618                                               type, orig_type)) {
8619                         return;
8620                 }
8621         } else if (!is_type_real(type) && is_type_valid(type)) {
8622                 /* TODO: improve error message */
8623                 errorf(&expression->base.source_position,
8624                        "operation needs an arithmetic or pointer type");
8625                 return;
8626         }
8627         if (!is_lvalue(expression->value)) {
8628                 /* TODO: improve error message */
8629                 errorf(&expression->base.source_position, "lvalue required as operand");
8630         }
8631         expression->base.type = orig_type;
8632 }
8633
8634 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
8635 {
8636         type_t *const orig_type = expression->value->base.type;
8637         type_t *const type      = skip_typeref(orig_type);
8638         if (!is_type_arithmetic(type)) {
8639                 if (is_type_valid(type)) {
8640                         /* TODO: improve error message */
8641                         errorf(&expression->base.source_position,
8642                                 "operation needs an arithmetic type");
8643                 }
8644                 return;
8645         }
8646
8647         expression->base.type = orig_type;
8648 }
8649
8650 static void semantic_unexpr_plus(unary_expression_t *expression)
8651 {
8652         semantic_unexpr_arithmetic(expression);
8653         if (warning.traditional)
8654                 warningf(&expression->base.source_position,
8655                         "traditional C rejects the unary plus operator");
8656 }
8657
8658 static void semantic_not(unary_expression_t *expression)
8659 {
8660         /* §6.5.3.3:1  The operand [...] of the ! operator, scalar type. */
8661         semantic_condition(expression->value, "operand of !");
8662         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8663 }
8664
8665 static void semantic_unexpr_integer(unary_expression_t *expression)
8666 {
8667         type_t *const orig_type = expression->value->base.type;
8668         type_t *const type      = skip_typeref(orig_type);
8669         if (!is_type_integer(type)) {
8670                 if (is_type_valid(type)) {
8671                         errorf(&expression->base.source_position,
8672                                "operand of ~ must be of integer type");
8673                 }
8674                 return;
8675         }
8676
8677         expression->base.type = orig_type;
8678 }
8679
8680 static void semantic_dereference(unary_expression_t *expression)
8681 {
8682         type_t *const orig_type = expression->value->base.type;
8683         type_t *const type      = skip_typeref(orig_type);
8684         if (!is_type_pointer(type)) {
8685                 if (is_type_valid(type)) {
8686                         errorf(&expression->base.source_position,
8687                                "Unary '*' needs pointer or array type, but type '%T' given", orig_type);
8688                 }
8689                 return;
8690         }
8691
8692         type_t *result_type   = type->pointer.points_to;
8693         result_type           = automatic_type_conversion(result_type);
8694         expression->base.type = result_type;
8695 }
8696
8697 /**
8698  * Record that an address is taken (expression represents an lvalue).
8699  *
8700  * @param expression       the expression
8701  * @param may_be_register  if true, the expression might be an register
8702  */
8703 static void set_address_taken(expression_t *expression, bool may_be_register)
8704 {
8705         if (expression->kind != EXPR_REFERENCE)
8706                 return;
8707
8708         entity_t *const entity = expression->reference.entity;
8709
8710         if (entity->kind != ENTITY_VARIABLE && entity->kind != ENTITY_PARAMETER)
8711                 return;
8712
8713         if (entity->declaration.storage_class == STORAGE_CLASS_REGISTER
8714                         && !may_be_register) {
8715                 errorf(&expression->base.source_position,
8716                                 "address of register %s '%Y' requested",
8717                                 get_entity_kind_name(entity->kind),     entity->base.symbol);
8718         }
8719
8720         if (entity->kind == ENTITY_VARIABLE) {
8721                 entity->variable.address_taken = true;
8722         } else {
8723                 assert(entity->kind == ENTITY_PARAMETER);
8724                 entity->parameter.address_taken = true;
8725         }
8726 }
8727
8728 /**
8729  * Check the semantic of the address taken expression.
8730  */
8731 static void semantic_take_addr(unary_expression_t *expression)
8732 {
8733         expression_t *value = expression->value;
8734         value->base.type    = revert_automatic_type_conversion(value);
8735
8736         type_t *orig_type = value->base.type;
8737         type_t *type      = skip_typeref(orig_type);
8738         if (!is_type_valid(type))
8739                 return;
8740
8741         /* §6.5.3.2 */
8742         if (!is_lvalue(value)) {
8743                 errorf(&expression->base.source_position, "'&' requires an lvalue");
8744         }
8745         if (type->kind == TYPE_BITFIELD) {
8746                 errorf(&expression->base.source_position,
8747                        "'&' not allowed on object with bitfield type '%T'",
8748                        type);
8749         }
8750
8751         set_address_taken(value, false);
8752
8753         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
8754 }
8755
8756 #define CREATE_UNARY_EXPRESSION_PARSER(token_type, unexpression_type, sfunc) \
8757 static expression_t *parse_##unexpression_type(void)                         \
8758 {                                                                            \
8759         expression_t *unary_expression                                           \
8760                 = allocate_expression_zero(unexpression_type);                       \
8761         eat(token_type);                                                         \
8762         unary_expression->unary.value = parse_sub_expression(PREC_UNARY);        \
8763                                                                                  \
8764         sfunc(&unary_expression->unary);                                         \
8765                                                                                  \
8766         return unary_expression;                                                 \
8767 }
8768
8769 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
8770                                semantic_unexpr_arithmetic)
8771 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
8772                                semantic_unexpr_plus)
8773 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
8774                                semantic_not)
8775 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
8776                                semantic_dereference)
8777 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
8778                                semantic_take_addr)
8779 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
8780                                semantic_unexpr_integer)
8781 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
8782                                semantic_incdec)
8783 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
8784                                semantic_incdec)
8785
8786 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_type, unexpression_type, \
8787                                                sfunc)                         \
8788 static expression_t *parse_##unexpression_type(expression_t *left)            \
8789 {                                                                             \
8790         expression_t *unary_expression                                            \
8791                 = allocate_expression_zero(unexpression_type);                        \
8792         eat(token_type);                                                          \
8793         unary_expression->unary.value = left;                                     \
8794                                                                                   \
8795         sfunc(&unary_expression->unary);                                          \
8796                                                                               \
8797         return unary_expression;                                                  \
8798 }
8799
8800 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
8801                                        EXPR_UNARY_POSTFIX_INCREMENT,
8802                                        semantic_incdec)
8803 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
8804                                        EXPR_UNARY_POSTFIX_DECREMENT,
8805                                        semantic_incdec)
8806
8807 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
8808 {
8809         /* TODO: handle complex + imaginary types */
8810
8811         type_left  = get_unqualified_type(type_left);
8812         type_right = get_unqualified_type(type_right);
8813
8814         /* § 6.3.1.8 Usual arithmetic conversions */
8815         if (type_left == type_long_double || type_right == type_long_double) {
8816                 return type_long_double;
8817         } else if (type_left == type_double || type_right == type_double) {
8818                 return type_double;
8819         } else if (type_left == type_float || type_right == type_float) {
8820                 return type_float;
8821         }
8822
8823         type_left  = promote_integer(type_left);
8824         type_right = promote_integer(type_right);
8825
8826         if (type_left == type_right)
8827                 return type_left;
8828
8829         bool const signed_left  = is_type_signed(type_left);
8830         bool const signed_right = is_type_signed(type_right);
8831         int const  rank_left    = get_rank(type_left);
8832         int const  rank_right   = get_rank(type_right);
8833
8834         if (signed_left == signed_right)
8835                 return rank_left >= rank_right ? type_left : type_right;
8836
8837         int     s_rank;
8838         int     u_rank;
8839         type_t *s_type;
8840         type_t *u_type;
8841         if (signed_left) {
8842                 s_rank = rank_left;
8843                 s_type = type_left;
8844                 u_rank = rank_right;
8845                 u_type = type_right;
8846         } else {
8847                 s_rank = rank_right;
8848                 s_type = type_right;
8849                 u_rank = rank_left;
8850                 u_type = type_left;
8851         }
8852
8853         if (u_rank >= s_rank)
8854                 return u_type;
8855
8856         /* casting rank to atomic_type_kind is a bit hacky, but makes things
8857          * easier here... */
8858         if (get_atomic_type_size((atomic_type_kind_t) s_rank)
8859                         > get_atomic_type_size((atomic_type_kind_t) u_rank))
8860                 return s_type;
8861
8862         switch (s_rank) {
8863                 case ATOMIC_TYPE_INT:      return type_unsigned_int;
8864                 case ATOMIC_TYPE_LONG:     return type_unsigned_long;
8865                 case ATOMIC_TYPE_LONGLONG: return type_unsigned_long_long;
8866
8867                 default: panic("invalid atomic type");
8868         }
8869 }
8870
8871 /**
8872  * Check the semantic restrictions for a binary expression.
8873  */
8874 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
8875 {
8876         expression_t *const left            = expression->left;
8877         expression_t *const right           = expression->right;
8878         type_t       *const orig_type_left  = left->base.type;
8879         type_t       *const orig_type_right = right->base.type;
8880         type_t       *const type_left       = skip_typeref(orig_type_left);
8881         type_t       *const type_right      = skip_typeref(orig_type_right);
8882
8883         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8884                 /* TODO: improve error message */
8885                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8886                         errorf(&expression->base.source_position,
8887                                "operation needs arithmetic types");
8888                 }
8889                 return;
8890         }
8891
8892         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8893         expression->left      = create_implicit_cast(left, arithmetic_type);
8894         expression->right     = create_implicit_cast(right, arithmetic_type);
8895         expression->base.type = arithmetic_type;
8896 }
8897
8898 static void warn_div_by_zero(binary_expression_t const *const expression)
8899 {
8900         if (!warning.div_by_zero ||
8901             !is_type_integer(expression->base.type))
8902                 return;
8903
8904         expression_t const *const right = expression->right;
8905         /* The type of the right operand can be different for /= */
8906         if (is_type_integer(right->base.type) &&
8907             is_constant_expression(right)     &&
8908             fold_constant(right) == 0) {
8909                 warningf(&expression->base.source_position, "division by zero");
8910         }
8911 }
8912
8913 /**
8914  * Check the semantic restrictions for a div/mod expression.
8915  */
8916 static void semantic_divmod_arithmetic(binary_expression_t *expression)
8917 {
8918         semantic_binexpr_arithmetic(expression);
8919         warn_div_by_zero(expression);
8920 }
8921
8922 static void warn_addsub_in_shift(const expression_t *const expr)
8923 {
8924         if (expr->base.parenthesized)
8925                 return;
8926
8927         char op;
8928         switch (expr->kind) {
8929                 case EXPR_BINARY_ADD: op = '+'; break;
8930                 case EXPR_BINARY_SUB: op = '-'; break;
8931                 default:              return;
8932         }
8933
8934         warningf(&expr->base.source_position,
8935                         "suggest parentheses around '%c' inside shift", op);
8936 }
8937
8938 static void semantic_shift_op(binary_expression_t *expression)
8939 {
8940         expression_t *const left            = expression->left;
8941         expression_t *const right           = expression->right;
8942         type_t       *const orig_type_left  = left->base.type;
8943         type_t       *const orig_type_right = right->base.type;
8944         type_t       *      type_left       = skip_typeref(orig_type_left);
8945         type_t       *      type_right      = skip_typeref(orig_type_right);
8946
8947         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8948                 /* TODO: improve error message */
8949                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8950                         errorf(&expression->base.source_position,
8951                                "operands of shift operation must have integer types");
8952                 }
8953                 return;
8954         }
8955
8956         if (warning.parentheses) {
8957                 warn_addsub_in_shift(left);
8958                 warn_addsub_in_shift(right);
8959         }
8960
8961         type_left  = promote_integer(type_left);
8962         type_right = promote_integer(type_right);
8963
8964         expression->left      = create_implicit_cast(left, type_left);
8965         expression->right     = create_implicit_cast(right, type_right);
8966         expression->base.type = type_left;
8967 }
8968
8969 static void semantic_add(binary_expression_t *expression)
8970 {
8971         expression_t *const left            = expression->left;
8972         expression_t *const right           = expression->right;
8973         type_t       *const orig_type_left  = left->base.type;
8974         type_t       *const orig_type_right = right->base.type;
8975         type_t       *const type_left       = skip_typeref(orig_type_left);
8976         type_t       *const type_right      = skip_typeref(orig_type_right);
8977
8978         /* § 6.5.6 */
8979         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8980                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8981                 expression->left  = create_implicit_cast(left, arithmetic_type);
8982                 expression->right = create_implicit_cast(right, arithmetic_type);
8983                 expression->base.type = arithmetic_type;
8984         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8985                 check_pointer_arithmetic(&expression->base.source_position,
8986                                          type_left, orig_type_left);
8987                 expression->base.type = type_left;
8988         } else if (is_type_pointer(type_right) && is_type_integer(type_left)) {
8989                 check_pointer_arithmetic(&expression->base.source_position,
8990                                          type_right, orig_type_right);
8991                 expression->base.type = type_right;
8992         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8993                 errorf(&expression->base.source_position,
8994                        "invalid operands to binary + ('%T', '%T')",
8995                        orig_type_left, orig_type_right);
8996         }
8997 }
8998
8999 static void semantic_sub(binary_expression_t *expression)
9000 {
9001         expression_t            *const left            = expression->left;
9002         expression_t            *const right           = expression->right;
9003         type_t                  *const orig_type_left  = left->base.type;
9004         type_t                  *const orig_type_right = right->base.type;
9005         type_t                  *const type_left       = skip_typeref(orig_type_left);
9006         type_t                  *const type_right      = skip_typeref(orig_type_right);
9007         source_position_t const *const pos             = &expression->base.source_position;
9008
9009         /* § 5.6.5 */
9010         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
9011                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
9012                 expression->left        = create_implicit_cast(left, arithmetic_type);
9013                 expression->right       = create_implicit_cast(right, arithmetic_type);
9014                 expression->base.type =  arithmetic_type;
9015         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
9016                 check_pointer_arithmetic(&expression->base.source_position,
9017                                          type_left, orig_type_left);
9018                 expression->base.type = type_left;
9019         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
9020                 type_t *const unqual_left  = get_unqualified_type(skip_typeref(type_left->pointer.points_to));
9021                 type_t *const unqual_right = get_unqualified_type(skip_typeref(type_right->pointer.points_to));
9022                 if (!types_compatible(unqual_left, unqual_right)) {
9023                         errorf(pos,
9024                                "subtracting pointers to incompatible types '%T' and '%T'",
9025                                orig_type_left, orig_type_right);
9026                 } else if (!is_type_object(unqual_left)) {
9027                         if (!is_type_atomic(unqual_left, ATOMIC_TYPE_VOID)) {
9028                                 errorf(pos, "subtracting pointers to non-object types '%T'",
9029                                        orig_type_left);
9030                         } else if (warning.other) {
9031                                 warningf(pos, "subtracting pointers to void");
9032                         }
9033                 }
9034                 expression->base.type = type_ptrdiff_t;
9035         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
9036                 errorf(pos, "invalid operands of types '%T' and '%T' to binary '-'",
9037                        orig_type_left, orig_type_right);
9038         }
9039 }
9040
9041 static void warn_string_literal_address(expression_t const* expr)
9042 {
9043         while (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
9044                 expr = expr->unary.value;
9045                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
9046                         return;
9047                 expr = expr->unary.value;
9048         }
9049
9050         if (expr->kind == EXPR_STRING_LITERAL ||
9051             expr->kind == EXPR_WIDE_STRING_LITERAL) {
9052                 warningf(&expr->base.source_position,
9053                         "comparison with string literal results in unspecified behaviour");
9054         }
9055 }
9056
9057 static void warn_comparison_in_comparison(const expression_t *const expr)
9058 {
9059         if (expr->base.parenthesized)
9060                 return;
9061         switch (expr->base.kind) {
9062                 case EXPR_BINARY_LESS:
9063                 case EXPR_BINARY_GREATER:
9064                 case EXPR_BINARY_LESSEQUAL:
9065                 case EXPR_BINARY_GREATEREQUAL:
9066                 case EXPR_BINARY_NOTEQUAL:
9067                 case EXPR_BINARY_EQUAL:
9068                         warningf(&expr->base.source_position,
9069                                         "comparisons like 'x <= y < z' do not have their mathematical meaning");
9070                         break;
9071                 default:
9072                         break;
9073         }
9074 }
9075
9076 static bool maybe_negative(expression_t const *const expr)
9077 {
9078         return
9079                 !is_constant_expression(expr) ||
9080                 fold_constant(expr) < 0;
9081 }
9082
9083 /**
9084  * Check the semantics of comparison expressions.
9085  *
9086  * @param expression   The expression to check.
9087  */
9088 static void semantic_comparison(binary_expression_t *expression)
9089 {
9090         expression_t *left  = expression->left;
9091         expression_t *right = expression->right;
9092
9093         if (warning.address) {
9094                 warn_string_literal_address(left);
9095                 warn_string_literal_address(right);
9096
9097                 expression_t const* const func_left = get_reference_address(left);
9098                 if (func_left != NULL && is_null_pointer_constant(right)) {
9099                         warningf(&expression->base.source_position,
9100                                  "the address of '%Y' will never be NULL",
9101                                  func_left->reference.entity->base.symbol);
9102                 }
9103
9104                 expression_t const* const func_right = get_reference_address(right);
9105                 if (func_right != NULL && is_null_pointer_constant(right)) {
9106                         warningf(&expression->base.source_position,
9107                                  "the address of '%Y' will never be NULL",
9108                                  func_right->reference.entity->base.symbol);
9109                 }
9110         }
9111
9112         if (warning.parentheses) {
9113                 warn_comparison_in_comparison(left);
9114                 warn_comparison_in_comparison(right);
9115         }
9116
9117         type_t *orig_type_left  = left->base.type;
9118         type_t *orig_type_right = right->base.type;
9119         type_t *type_left       = skip_typeref(orig_type_left);
9120         type_t *type_right      = skip_typeref(orig_type_right);
9121
9122         /* TODO non-arithmetic types */
9123         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
9124                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
9125
9126                 /* test for signed vs unsigned compares */
9127                 if (warning.sign_compare && is_type_integer(arithmetic_type)) {
9128                         bool const signed_left  = is_type_signed(type_left);
9129                         bool const signed_right = is_type_signed(type_right);
9130                         if (signed_left != signed_right) {
9131                                 /* FIXME long long needs better const folding magic */
9132                                 /* TODO check whether constant value can be represented by other type */
9133                                 if ((signed_left  && maybe_negative(left)) ||
9134                                                 (signed_right && maybe_negative(right))) {
9135                                         warningf(&expression->base.source_position,
9136                                                         "comparison between signed and unsigned");
9137                                 }
9138                         }
9139                 }
9140
9141                 expression->left        = create_implicit_cast(left, arithmetic_type);
9142                 expression->right       = create_implicit_cast(right, arithmetic_type);
9143                 expression->base.type   = arithmetic_type;
9144                 if (warning.float_equal &&
9145                     (expression->base.kind == EXPR_BINARY_EQUAL ||
9146                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
9147                     is_type_float(arithmetic_type)) {
9148                         warningf(&expression->base.source_position,
9149                                  "comparing floating point with == or != is unsafe");
9150                 }
9151         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
9152                 /* TODO check compatibility */
9153         } else if (is_type_pointer(type_left)) {
9154                 expression->right = create_implicit_cast(right, type_left);
9155         } else if (is_type_pointer(type_right)) {
9156                 expression->left = create_implicit_cast(left, type_right);
9157         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
9158                 type_error_incompatible("invalid operands in comparison",
9159                                         &expression->base.source_position,
9160                                         type_left, type_right);
9161         }
9162         expression->base.type = c_mode & _CXX ? type_bool : type_int;
9163 }
9164
9165 /**
9166  * Checks if a compound type has constant fields.
9167  */
9168 static bool has_const_fields(const compound_type_t *type)
9169 {
9170         compound_t *compound = type->compound;
9171         entity_t   *entry    = compound->members.entities;
9172
9173         for (; entry != NULL; entry = entry->base.next) {
9174                 if (!is_declaration(entry))
9175                         continue;
9176
9177                 const type_t *decl_type = skip_typeref(entry->declaration.type);
9178                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
9179                         return true;
9180         }
9181
9182         return false;
9183 }
9184
9185 static bool is_valid_assignment_lhs(expression_t const* const left)
9186 {
9187         type_t *const orig_type_left = revert_automatic_type_conversion(left);
9188         type_t *const type_left      = skip_typeref(orig_type_left);
9189
9190         if (!is_lvalue(left)) {
9191                 errorf(HERE, "left hand side '%E' of assignment is not an lvalue",
9192                        left);
9193                 return false;
9194         }
9195
9196         if (left->kind == EXPR_REFERENCE
9197                         && left->reference.entity->kind == ENTITY_FUNCTION) {
9198                 errorf(HERE, "cannot assign to function '%E'", left);
9199                 return false;
9200         }
9201
9202         if (is_type_array(type_left)) {
9203                 errorf(HERE, "cannot assign to array '%E'", left);
9204                 return false;
9205         }
9206         if (type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
9207                 errorf(HERE, "assignment to readonly location '%E' (type '%T')", left,
9208                        orig_type_left);
9209                 return false;
9210         }
9211         if (is_type_incomplete(type_left)) {
9212                 errorf(HERE, "left-hand side '%E' of assignment has incomplete type '%T'",
9213                        left, orig_type_left);
9214                 return false;
9215         }
9216         if (is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
9217                 errorf(HERE, "cannot assign to '%E' because compound type '%T' has readonly fields",
9218                        left, orig_type_left);
9219                 return false;
9220         }
9221
9222         return true;
9223 }
9224
9225 static void semantic_arithmetic_assign(binary_expression_t *expression)
9226 {
9227         expression_t *left            = expression->left;
9228         expression_t *right           = expression->right;
9229         type_t       *orig_type_left  = left->base.type;
9230         type_t       *orig_type_right = right->base.type;
9231
9232         if (!is_valid_assignment_lhs(left))
9233                 return;
9234
9235         type_t *type_left  = skip_typeref(orig_type_left);
9236         type_t *type_right = skip_typeref(orig_type_right);
9237
9238         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
9239                 /* TODO: improve error message */
9240                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
9241                         errorf(&expression->base.source_position,
9242                                "operation needs arithmetic types");
9243                 }
9244                 return;
9245         }
9246
9247         /* combined instructions are tricky. We can't create an implicit cast on
9248          * the left side, because we need the uncasted form for the store.
9249          * The ast2firm pass has to know that left_type must be right_type
9250          * for the arithmetic operation and create a cast by itself */
9251         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
9252         expression->right       = create_implicit_cast(right, arithmetic_type);
9253         expression->base.type   = type_left;
9254 }
9255
9256 static void semantic_divmod_assign(binary_expression_t *expression)
9257 {
9258         semantic_arithmetic_assign(expression);
9259         warn_div_by_zero(expression);
9260 }
9261
9262 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
9263 {
9264         expression_t *const left            = expression->left;
9265         expression_t *const right           = expression->right;
9266         type_t       *const orig_type_left  = left->base.type;
9267         type_t       *const orig_type_right = right->base.type;
9268         type_t       *const type_left       = skip_typeref(orig_type_left);
9269         type_t       *const type_right      = skip_typeref(orig_type_right);
9270
9271         if (!is_valid_assignment_lhs(left))
9272                 return;
9273
9274         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
9275                 /* combined instructions are tricky. We can't create an implicit cast on
9276                  * the left side, because we need the uncasted form for the store.
9277                  * The ast2firm pass has to know that left_type must be right_type
9278                  * for the arithmetic operation and create a cast by itself */
9279                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
9280                 expression->right     = create_implicit_cast(right, arithmetic_type);
9281                 expression->base.type = type_left;
9282         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
9283                 check_pointer_arithmetic(&expression->base.source_position,
9284                                          type_left, orig_type_left);
9285                 expression->base.type = type_left;
9286         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
9287                 errorf(&expression->base.source_position,
9288                        "incompatible types '%T' and '%T' in assignment",
9289                        orig_type_left, orig_type_right);
9290         }
9291 }
9292
9293 static void warn_logical_and_within_or(const expression_t *const expr)
9294 {
9295         if (expr->base.kind != EXPR_BINARY_LOGICAL_AND)
9296                 return;
9297         if (expr->base.parenthesized)
9298                 return;
9299         warningf(&expr->base.source_position,
9300                         "suggest parentheses around && within ||");
9301 }
9302
9303 /**
9304  * Check the semantic restrictions of a logical expression.
9305  */
9306 static void semantic_logical_op(binary_expression_t *expression)
9307 {
9308         /* §6.5.13:2  Each of the operands shall have scalar type.
9309          * §6.5.14:2  Each of the operands shall have scalar type. */
9310         semantic_condition(expression->left,   "left operand of logical operator");
9311         semantic_condition(expression->right, "right operand of logical operator");
9312         if (expression->base.kind == EXPR_BINARY_LOGICAL_OR &&
9313                         warning.parentheses) {
9314                 warn_logical_and_within_or(expression->left);
9315                 warn_logical_and_within_or(expression->right);
9316         }
9317         expression->base.type = c_mode & _CXX ? type_bool : type_int;
9318 }
9319
9320 /**
9321  * Check the semantic restrictions of a binary assign expression.
9322  */
9323 static void semantic_binexpr_assign(binary_expression_t *expression)
9324 {
9325         expression_t *left           = expression->left;
9326         type_t       *orig_type_left = left->base.type;
9327
9328         if (!is_valid_assignment_lhs(left))
9329                 return;
9330
9331         assign_error_t error = semantic_assign(orig_type_left, expression->right);
9332         report_assign_error(error, orig_type_left, expression->right,
9333                         "assignment", &left->base.source_position);
9334         expression->right = create_implicit_cast(expression->right, orig_type_left);
9335         expression->base.type = orig_type_left;
9336 }
9337
9338 /**
9339  * Determine if the outermost operation (or parts thereof) of the given
9340  * expression has no effect in order to generate a warning about this fact.
9341  * Therefore in some cases this only examines some of the operands of the
9342  * expression (see comments in the function and examples below).
9343  * Examples:
9344  *   f() + 23;    // warning, because + has no effect
9345  *   x || f();    // no warning, because x controls execution of f()
9346  *   x ? y : f(); // warning, because y has no effect
9347  *   (void)x;     // no warning to be able to suppress the warning
9348  * This function can NOT be used for an "expression has definitely no effect"-
9349  * analysis. */
9350 static bool expression_has_effect(const expression_t *const expr)
9351 {
9352         switch (expr->kind) {
9353                 case EXPR_UNKNOWN:                   break;
9354                 case EXPR_INVALID:                   return true; /* do NOT warn */
9355                 case EXPR_REFERENCE:                 return false;
9356                 case EXPR_REFERENCE_ENUM_VALUE:      return false;
9357                 /* suppress the warning for microsoft __noop operations */
9358                 case EXPR_CONST:                     return expr->conste.is_ms_noop;
9359                 case EXPR_CHARACTER_CONSTANT:        return false;
9360                 case EXPR_WIDE_CHARACTER_CONSTANT:   return false;
9361                 case EXPR_STRING_LITERAL:            return false;
9362                 case EXPR_WIDE_STRING_LITERAL:       return false;
9363                 case EXPR_LABEL_ADDRESS:             return false;
9364
9365                 case EXPR_CALL: {
9366                         const call_expression_t *const call = &expr->call;
9367                         if (call->function->kind != EXPR_BUILTIN_SYMBOL)
9368                                 return true;
9369
9370                         switch (call->function->builtin_symbol.symbol->ID) {
9371                                 case T___builtin_va_end: return true;
9372                                 default:                 return false;
9373                         }
9374                 }
9375
9376                 /* Generate the warning if either the left or right hand side of a
9377                  * conditional expression has no effect */
9378                 case EXPR_CONDITIONAL: {
9379                         conditional_expression_t const *const cond = &expr->conditional;
9380                         expression_t             const *const t    = cond->true_expression;
9381                         return
9382                                 (t == NULL || expression_has_effect(t)) &&
9383                                 expression_has_effect(cond->false_expression);
9384                 }
9385
9386                 case EXPR_SELECT:                    return false;
9387                 case EXPR_ARRAY_ACCESS:              return false;
9388                 case EXPR_SIZEOF:                    return false;
9389                 case EXPR_CLASSIFY_TYPE:             return false;
9390                 case EXPR_ALIGNOF:                   return false;
9391
9392                 case EXPR_FUNCNAME:                  return false;
9393                 case EXPR_BUILTIN_SYMBOL:            break; /* handled in EXPR_CALL */
9394                 case EXPR_BUILTIN_CONSTANT_P:        return false;
9395                 case EXPR_BUILTIN_PREFETCH:          return true;
9396                 case EXPR_OFFSETOF:                  return false;
9397                 case EXPR_VA_START:                  return true;
9398                 case EXPR_VA_ARG:                    return true;
9399                 case EXPR_STATEMENT:                 return true; // TODO
9400                 case EXPR_COMPOUND_LITERAL:          return false;
9401
9402                 case EXPR_UNARY_NEGATE:              return false;
9403                 case EXPR_UNARY_PLUS:                return false;
9404                 case EXPR_UNARY_BITWISE_NEGATE:      return false;
9405                 case EXPR_UNARY_NOT:                 return false;
9406                 case EXPR_UNARY_DEREFERENCE:         return false;
9407                 case EXPR_UNARY_TAKE_ADDRESS:        return false;
9408                 case EXPR_UNARY_POSTFIX_INCREMENT:   return true;
9409                 case EXPR_UNARY_POSTFIX_DECREMENT:   return true;
9410                 case EXPR_UNARY_PREFIX_INCREMENT:    return true;
9411                 case EXPR_UNARY_PREFIX_DECREMENT:    return true;
9412
9413                 /* Treat void casts as if they have an effect in order to being able to
9414                  * suppress the warning */
9415                 case EXPR_UNARY_CAST: {
9416                         type_t *const type = skip_typeref(expr->base.type);
9417                         return is_type_atomic(type, ATOMIC_TYPE_VOID);
9418                 }
9419
9420                 case EXPR_UNARY_CAST_IMPLICIT:       return true;
9421                 case EXPR_UNARY_ASSUME:              return true;
9422                 case EXPR_UNARY_DELETE:              return true;
9423                 case EXPR_UNARY_DELETE_ARRAY:        return true;
9424                 case EXPR_UNARY_THROW:               return true;
9425
9426                 case EXPR_BINARY_ADD:                return false;
9427                 case EXPR_BINARY_SUB:                return false;
9428                 case EXPR_BINARY_MUL:                return false;
9429                 case EXPR_BINARY_DIV:                return false;
9430                 case EXPR_BINARY_MOD:                return false;
9431                 case EXPR_BINARY_EQUAL:              return false;
9432                 case EXPR_BINARY_NOTEQUAL:           return false;
9433                 case EXPR_BINARY_LESS:               return false;
9434                 case EXPR_BINARY_LESSEQUAL:          return false;
9435                 case EXPR_BINARY_GREATER:            return false;
9436                 case EXPR_BINARY_GREATEREQUAL:       return false;
9437                 case EXPR_BINARY_BITWISE_AND:        return false;
9438                 case EXPR_BINARY_BITWISE_OR:         return false;
9439                 case EXPR_BINARY_BITWISE_XOR:        return false;
9440                 case EXPR_BINARY_SHIFTLEFT:          return false;
9441                 case EXPR_BINARY_SHIFTRIGHT:         return false;
9442                 case EXPR_BINARY_ASSIGN:             return true;
9443                 case EXPR_BINARY_MUL_ASSIGN:         return true;
9444                 case EXPR_BINARY_DIV_ASSIGN:         return true;
9445                 case EXPR_BINARY_MOD_ASSIGN:         return true;
9446                 case EXPR_BINARY_ADD_ASSIGN:         return true;
9447                 case EXPR_BINARY_SUB_ASSIGN:         return true;
9448                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:   return true;
9449                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:  return true;
9450                 case EXPR_BINARY_BITWISE_AND_ASSIGN: return true;
9451                 case EXPR_BINARY_BITWISE_XOR_ASSIGN: return true;
9452                 case EXPR_BINARY_BITWISE_OR_ASSIGN:  return true;
9453
9454                 /* Only examine the right hand side of && and ||, because the left hand
9455                  * side already has the effect of controlling the execution of the right
9456                  * hand side */
9457                 case EXPR_BINARY_LOGICAL_AND:
9458                 case EXPR_BINARY_LOGICAL_OR:
9459                 /* Only examine the right hand side of a comma expression, because the left
9460                  * hand side has a separate warning */
9461                 case EXPR_BINARY_COMMA:
9462                         return expression_has_effect(expr->binary.right);
9463
9464                 case EXPR_BINARY_ISGREATER:          return false;
9465                 case EXPR_BINARY_ISGREATEREQUAL:     return false;
9466                 case EXPR_BINARY_ISLESS:             return false;
9467                 case EXPR_BINARY_ISLESSEQUAL:        return false;
9468                 case EXPR_BINARY_ISLESSGREATER:      return false;
9469                 case EXPR_BINARY_ISUNORDERED:        return false;
9470         }
9471
9472         internal_errorf(HERE, "unexpected expression");
9473 }
9474
9475 static void semantic_comma(binary_expression_t *expression)
9476 {
9477         if (warning.unused_value) {
9478                 const expression_t *const left = expression->left;
9479                 if (!expression_has_effect(left)) {
9480                         warningf(&left->base.source_position,
9481                                  "left-hand operand of comma expression has no effect");
9482                 }
9483         }
9484         expression->base.type = expression->right->base.type;
9485 }
9486
9487 /**
9488  * @param prec_r precedence of the right operand
9489  */
9490 #define CREATE_BINEXPR_PARSER(token_type, binexpression_type, prec_r, sfunc) \
9491 static expression_t *parse_##binexpression_type(expression_t *left)          \
9492 {                                                                            \
9493         expression_t *binexpr = allocate_expression_zero(binexpression_type);    \
9494         binexpr->binary.left  = left;                                            \
9495         eat(token_type);                                                         \
9496                                                                              \
9497         expression_t *right = parse_sub_expression(prec_r);                      \
9498                                                                              \
9499         binexpr->binary.right = right;                                           \
9500         sfunc(&binexpr->binary);                                                 \
9501                                                                              \
9502         return binexpr;                                                          \
9503 }
9504
9505 CREATE_BINEXPR_PARSER('*',                    EXPR_BINARY_MUL,                PREC_CAST,           semantic_binexpr_arithmetic)
9506 CREATE_BINEXPR_PARSER('/',                    EXPR_BINARY_DIV,                PREC_CAST,           semantic_divmod_arithmetic)
9507 CREATE_BINEXPR_PARSER('%',                    EXPR_BINARY_MOD,                PREC_CAST,           semantic_divmod_arithmetic)
9508 CREATE_BINEXPR_PARSER('+',                    EXPR_BINARY_ADD,                PREC_MULTIPLICATIVE, semantic_add)
9509 CREATE_BINEXPR_PARSER('-',                    EXPR_BINARY_SUB,                PREC_MULTIPLICATIVE, semantic_sub)
9510 CREATE_BINEXPR_PARSER(T_LESSLESS,             EXPR_BINARY_SHIFTLEFT,          PREC_ADDITIVE,       semantic_shift_op)
9511 CREATE_BINEXPR_PARSER(T_GREATERGREATER,       EXPR_BINARY_SHIFTRIGHT,         PREC_ADDITIVE,       semantic_shift_op)
9512 CREATE_BINEXPR_PARSER('<',                    EXPR_BINARY_LESS,               PREC_SHIFT,          semantic_comparison)
9513 CREATE_BINEXPR_PARSER('>',                    EXPR_BINARY_GREATER,            PREC_SHIFT,          semantic_comparison)
9514 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,          PREC_SHIFT,          semantic_comparison)
9515 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,       PREC_SHIFT,          semantic_comparison)
9516 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,           PREC_RELATIONAL,     semantic_comparison)
9517 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,              PREC_RELATIONAL,     semantic_comparison)
9518 CREATE_BINEXPR_PARSER('&',                    EXPR_BINARY_BITWISE_AND,        PREC_EQUALITY,       semantic_binexpr_arithmetic)
9519 CREATE_BINEXPR_PARSER('^',                    EXPR_BINARY_BITWISE_XOR,        PREC_AND,            semantic_binexpr_arithmetic)
9520 CREATE_BINEXPR_PARSER('|',                    EXPR_BINARY_BITWISE_OR,         PREC_XOR,            semantic_binexpr_arithmetic)
9521 CREATE_BINEXPR_PARSER(T_ANDAND,               EXPR_BINARY_LOGICAL_AND,        PREC_OR,             semantic_logical_op)
9522 CREATE_BINEXPR_PARSER(T_PIPEPIPE,             EXPR_BINARY_LOGICAL_OR,         PREC_LOGICAL_AND,    semantic_logical_op)
9523 CREATE_BINEXPR_PARSER('=',                    EXPR_BINARY_ASSIGN,             PREC_ASSIGNMENT,     semantic_binexpr_assign)
9524 CREATE_BINEXPR_PARSER(T_PLUSEQUAL,            EXPR_BINARY_ADD_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
9525 CREATE_BINEXPR_PARSER(T_MINUSEQUAL,           EXPR_BINARY_SUB_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
9526 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL,        EXPR_BINARY_MUL_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9527 CREATE_BINEXPR_PARSER(T_SLASHEQUAL,           EXPR_BINARY_DIV_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
9528 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL,         EXPR_BINARY_MOD_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
9529 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL,        EXPR_BINARY_SHIFTLEFT_ASSIGN,   PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9530 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL,  EXPR_BINARY_SHIFTRIGHT_ASSIGN,  PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9531 CREATE_BINEXPR_PARSER(T_ANDEQUAL,             EXPR_BINARY_BITWISE_AND_ASSIGN, PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9532 CREATE_BINEXPR_PARSER(T_PIPEEQUAL,            EXPR_BINARY_BITWISE_OR_ASSIGN,  PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9533 CREATE_BINEXPR_PARSER(T_CARETEQUAL,           EXPR_BINARY_BITWISE_XOR_ASSIGN, PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9534 CREATE_BINEXPR_PARSER(',',                    EXPR_BINARY_COMMA,              PREC_ASSIGNMENT,     semantic_comma)
9535
9536
9537 static expression_t *parse_sub_expression(precedence_t precedence)
9538 {
9539         if (token.type < 0) {
9540                 return expected_expression_error();
9541         }
9542
9543         expression_parser_function_t *parser
9544                 = &expression_parsers[token.type];
9545         source_position_t             source_position = token.source_position;
9546         expression_t                 *left;
9547
9548         if (parser->parser != NULL) {
9549                 left = parser->parser();
9550         } else {
9551                 left = parse_primary_expression();
9552         }
9553         assert(left != NULL);
9554         left->base.source_position = source_position;
9555
9556         while (true) {
9557                 if (token.type < 0) {
9558                         return expected_expression_error();
9559                 }
9560
9561                 parser = &expression_parsers[token.type];
9562                 if (parser->infix_parser == NULL)
9563                         break;
9564                 if (parser->infix_precedence < precedence)
9565                         break;
9566
9567                 left = parser->infix_parser(left);
9568
9569                 assert(left != NULL);
9570                 assert(left->kind != EXPR_UNKNOWN);
9571                 left->base.source_position = source_position;
9572         }
9573
9574         return left;
9575 }
9576
9577 /**
9578  * Parse an expression.
9579  */
9580 static expression_t *parse_expression(void)
9581 {
9582         return parse_sub_expression(PREC_EXPRESSION);
9583 }
9584
9585 /**
9586  * Register a parser for a prefix-like operator.
9587  *
9588  * @param parser      the parser function
9589  * @param token_type  the token type of the prefix token
9590  */
9591 static void register_expression_parser(parse_expression_function parser,
9592                                        int token_type)
9593 {
9594         expression_parser_function_t *entry = &expression_parsers[token_type];
9595
9596         if (entry->parser != NULL) {
9597                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
9598                 panic("trying to register multiple expression parsers for a token");
9599         }
9600         entry->parser = parser;
9601 }
9602
9603 /**
9604  * Register a parser for an infix operator with given precedence.
9605  *
9606  * @param parser      the parser function
9607  * @param token_type  the token type of the infix operator
9608  * @param precedence  the precedence of the operator
9609  */
9610 static void register_infix_parser(parse_expression_infix_function parser,
9611                 int token_type, precedence_t precedence)
9612 {
9613         expression_parser_function_t *entry = &expression_parsers[token_type];
9614
9615         if (entry->infix_parser != NULL) {
9616                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
9617                 panic("trying to register multiple infix expression parsers for a "
9618                       "token");
9619         }
9620         entry->infix_parser     = parser;
9621         entry->infix_precedence = precedence;
9622 }
9623
9624 /**
9625  * Initialize the expression parsers.
9626  */
9627 static void init_expression_parsers(void)
9628 {
9629         memset(&expression_parsers, 0, sizeof(expression_parsers));
9630
9631         register_infix_parser(parse_array_expression,               '[',                    PREC_POSTFIX);
9632         register_infix_parser(parse_call_expression,                '(',                    PREC_POSTFIX);
9633         register_infix_parser(parse_select_expression,              '.',                    PREC_POSTFIX);
9634         register_infix_parser(parse_select_expression,              T_MINUSGREATER,         PREC_POSTFIX);
9635         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,   T_PLUSPLUS,             PREC_POSTFIX);
9636         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,   T_MINUSMINUS,           PREC_POSTFIX);
9637         register_infix_parser(parse_EXPR_BINARY_MUL,                '*',                    PREC_MULTIPLICATIVE);
9638         register_infix_parser(parse_EXPR_BINARY_DIV,                '/',                    PREC_MULTIPLICATIVE);
9639         register_infix_parser(parse_EXPR_BINARY_MOD,                '%',                    PREC_MULTIPLICATIVE);
9640         register_infix_parser(parse_EXPR_BINARY_ADD,                '+',                    PREC_ADDITIVE);
9641         register_infix_parser(parse_EXPR_BINARY_SUB,                '-',                    PREC_ADDITIVE);
9642         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,          T_LESSLESS,             PREC_SHIFT);
9643         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,         T_GREATERGREATER,       PREC_SHIFT);
9644         register_infix_parser(parse_EXPR_BINARY_LESS,               '<',                    PREC_RELATIONAL);
9645         register_infix_parser(parse_EXPR_BINARY_GREATER,            '>',                    PREC_RELATIONAL);
9646         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,          T_LESSEQUAL,            PREC_RELATIONAL);
9647         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL,       T_GREATEREQUAL,         PREC_RELATIONAL);
9648         register_infix_parser(parse_EXPR_BINARY_EQUAL,              T_EQUALEQUAL,           PREC_EQUALITY);
9649         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,           T_EXCLAMATIONMARKEQUAL, PREC_EQUALITY);
9650         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,        '&',                    PREC_AND);
9651         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,        '^',                    PREC_XOR);
9652         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,         '|',                    PREC_OR);
9653         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,        T_ANDAND,               PREC_LOGICAL_AND);
9654         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,         T_PIPEPIPE,             PREC_LOGICAL_OR);
9655         register_infix_parser(parse_conditional_expression,         '?',                    PREC_CONDITIONAL);
9656         register_infix_parser(parse_EXPR_BINARY_ASSIGN,             '=',                    PREC_ASSIGNMENT);
9657         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,         T_PLUSEQUAL,            PREC_ASSIGNMENT);
9658         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,         T_MINUSEQUAL,           PREC_ASSIGNMENT);
9659         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,         T_ASTERISKEQUAL,        PREC_ASSIGNMENT);
9660         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,         T_SLASHEQUAL,           PREC_ASSIGNMENT);
9661         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,         T_PERCENTEQUAL,         PREC_ASSIGNMENT);
9662         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,   T_LESSLESSEQUAL,        PREC_ASSIGNMENT);
9663         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,  T_GREATERGREATEREQUAL,  PREC_ASSIGNMENT);
9664         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN, T_ANDEQUAL,             PREC_ASSIGNMENT);
9665         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,  T_PIPEEQUAL,            PREC_ASSIGNMENT);
9666         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN, T_CARETEQUAL,           PREC_ASSIGNMENT);
9667         register_infix_parser(parse_EXPR_BINARY_COMMA,              ',',                    PREC_EXPRESSION);
9668
9669         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-');
9670         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+');
9671         register_expression_parser(parse_EXPR_UNARY_NOT,              '!');
9672         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~');
9673         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*');
9674         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&');
9675         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT, T_PLUSPLUS);
9676         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT, T_MINUSMINUS);
9677         register_expression_parser(parse_sizeof,                      T_sizeof);
9678         register_expression_parser(parse_alignof,                     T___alignof__);
9679         register_expression_parser(parse_extension,                   T___extension__);
9680         register_expression_parser(parse_builtin_classify_type,       T___builtin_classify_type);
9681         register_expression_parser(parse_delete,                      T_delete);
9682         register_expression_parser(parse_throw,                       T_throw);
9683 }
9684
9685 /**
9686  * Parse a asm statement arguments specification.
9687  */
9688 static asm_argument_t *parse_asm_arguments(bool is_out)
9689 {
9690         asm_argument_t  *result = NULL;
9691         asm_argument_t **anchor = &result;
9692
9693         while (token.type == T_STRING_LITERAL || token.type == '[') {
9694                 asm_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
9695                 memset(argument, 0, sizeof(argument[0]));
9696
9697                 if (token.type == '[') {
9698                         eat('[');
9699                         if (token.type != T_IDENTIFIER) {
9700                                 parse_error_expected("while parsing asm argument",
9701                                                      T_IDENTIFIER, NULL);
9702                                 return NULL;
9703                         }
9704                         argument->symbol = token.v.symbol;
9705
9706                         expect(']', end_error);
9707                 }
9708
9709                 argument->constraints = parse_string_literals();
9710                 expect('(', end_error);
9711                 add_anchor_token(')');
9712                 expression_t *expression = parse_expression();
9713                 rem_anchor_token(')');
9714                 if (is_out) {
9715                         /* Ugly GCC stuff: Allow lvalue casts.  Skip casts, when they do not
9716                          * change size or type representation (e.g. int -> long is ok, but
9717                          * int -> float is not) */
9718                         if (expression->kind == EXPR_UNARY_CAST) {
9719                                 type_t      *const type = expression->base.type;
9720                                 type_kind_t  const kind = type->kind;
9721                                 if (kind == TYPE_ATOMIC || kind == TYPE_POINTER) {
9722                                         unsigned flags;
9723                                         unsigned size;
9724                                         if (kind == TYPE_ATOMIC) {
9725                                                 atomic_type_kind_t const akind = type->atomic.akind;
9726                                                 flags = get_atomic_type_flags(akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
9727                                                 size  = get_atomic_type_size(akind);
9728                                         } else {
9729                                                 flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
9730                                                 size  = get_atomic_type_size(get_intptr_kind());
9731                                         }
9732
9733                                         do {
9734                                                 expression_t *const value      = expression->unary.value;
9735                                                 type_t       *const value_type = value->base.type;
9736                                                 type_kind_t   const value_kind = value_type->kind;
9737
9738                                                 unsigned value_flags;
9739                                                 unsigned value_size;
9740                                                 if (value_kind == TYPE_ATOMIC) {
9741                                                         atomic_type_kind_t const value_akind = value_type->atomic.akind;
9742                                                         value_flags = get_atomic_type_flags(value_akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
9743                                                         value_size  = get_atomic_type_size(value_akind);
9744                                                 } else if (value_kind == TYPE_POINTER) {
9745                                                         value_flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
9746                                                         value_size  = get_atomic_type_size(get_intptr_kind());
9747                                                 } else {
9748                                                         break;
9749                                                 }
9750
9751                                                 if (value_flags != flags || value_size != size)
9752                                                         break;
9753
9754                                                 expression = value;
9755                                         } while (expression->kind == EXPR_UNARY_CAST);
9756                                 }
9757                         }
9758
9759                         if (!is_lvalue(expression)) {
9760                                 errorf(&expression->base.source_position,
9761                                        "asm output argument is not an lvalue");
9762                         }
9763
9764                         if (argument->constraints.begin[0] == '+')
9765                                 mark_vars_read(expression, NULL);
9766                 } else {
9767                         mark_vars_read(expression, NULL);
9768                 }
9769                 argument->expression = expression;
9770                 expect(')', end_error);
9771
9772                 set_address_taken(expression, true);
9773
9774                 *anchor = argument;
9775                 anchor  = &argument->next;
9776
9777                 if (token.type != ',')
9778                         break;
9779                 eat(',');
9780         }
9781
9782         return result;
9783 end_error:
9784         return NULL;
9785 }
9786
9787 /**
9788  * Parse a asm statement clobber specification.
9789  */
9790 static asm_clobber_t *parse_asm_clobbers(void)
9791 {
9792         asm_clobber_t *result = NULL;
9793         asm_clobber_t *last   = NULL;
9794
9795         while (token.type == T_STRING_LITERAL) {
9796                 asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
9797                 clobber->clobber       = parse_string_literals();
9798
9799                 if (last != NULL) {
9800                         last->next = clobber;
9801                 } else {
9802                         result = clobber;
9803                 }
9804                 last = clobber;
9805
9806                 if (token.type != ',')
9807                         break;
9808                 eat(',');
9809         }
9810
9811         return result;
9812 }
9813
9814 /**
9815  * Parse an asm statement.
9816  */
9817 static statement_t *parse_asm_statement(void)
9818 {
9819         statement_t     *statement     = allocate_statement_zero(STATEMENT_ASM);
9820         asm_statement_t *asm_statement = &statement->asms;
9821
9822         eat(T_asm);
9823
9824         if (token.type == T_volatile) {
9825                 next_token();
9826                 asm_statement->is_volatile = true;
9827         }
9828
9829         expect('(', end_error);
9830         add_anchor_token(')');
9831         add_anchor_token(':');
9832         asm_statement->asm_text = parse_string_literals();
9833
9834         if (token.type != ':') {
9835                 rem_anchor_token(':');
9836                 goto end_of_asm;
9837         }
9838         eat(':');
9839
9840         asm_statement->outputs = parse_asm_arguments(true);
9841         if (token.type != ':') {
9842                 rem_anchor_token(':');
9843                 goto end_of_asm;
9844         }
9845         eat(':');
9846
9847         asm_statement->inputs = parse_asm_arguments(false);
9848         if (token.type != ':') {
9849                 rem_anchor_token(':');
9850                 goto end_of_asm;
9851         }
9852         rem_anchor_token(':');
9853         eat(':');
9854
9855         asm_statement->clobbers = parse_asm_clobbers();
9856
9857 end_of_asm:
9858         rem_anchor_token(')');
9859         expect(')', end_error);
9860         expect(';', end_error);
9861
9862         if (asm_statement->outputs == NULL) {
9863                 /* GCC: An 'asm' instruction without any output operands will be treated
9864                  * identically to a volatile 'asm' instruction. */
9865                 asm_statement->is_volatile = true;
9866         }
9867
9868         return statement;
9869 end_error:
9870         return create_invalid_statement();
9871 }
9872
9873 /**
9874  * Parse a case statement.
9875  */
9876 static statement_t *parse_case_statement(void)
9877 {
9878         statement_t       *const statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9879         source_position_t *const pos       = &statement->base.source_position;
9880
9881         eat(T_case);
9882
9883         expression_t *const expression   = parse_expression();
9884         statement->case_label.expression = expression;
9885         if (!is_constant_expression(expression)) {
9886                 /* This check does not prevent the error message in all cases of an
9887                  * prior error while parsing the expression.  At least it catches the
9888                  * common case of a mistyped enum entry. */
9889                 if (is_type_valid(skip_typeref(expression->base.type))) {
9890                         errorf(pos, "case label does not reduce to an integer constant");
9891                 }
9892                 statement->case_label.is_bad = true;
9893         } else {
9894                 long const val = fold_constant(expression);
9895                 statement->case_label.first_case = val;
9896                 statement->case_label.last_case  = val;
9897         }
9898
9899         if (GNU_MODE) {
9900                 if (token.type == T_DOTDOTDOT) {
9901                         next_token();
9902                         expression_t *const end_range   = parse_expression();
9903                         statement->case_label.end_range = end_range;
9904                         if (!is_constant_expression(end_range)) {
9905                                 /* This check does not prevent the error message in all cases of an
9906                                  * prior error while parsing the expression.  At least it catches the
9907                                  * common case of a mistyped enum entry. */
9908                                 if (is_type_valid(skip_typeref(end_range->base.type))) {
9909                                         errorf(pos, "case range does not reduce to an integer constant");
9910                                 }
9911                                 statement->case_label.is_bad = true;
9912                         } else {
9913                                 long const val = fold_constant(end_range);
9914                                 statement->case_label.last_case = val;
9915
9916                                 if (warning.other && val < statement->case_label.first_case) {
9917                                         statement->case_label.is_empty_range = true;
9918                                         warningf(pos, "empty range specified");
9919                                 }
9920                         }
9921                 }
9922         }
9923
9924         PUSH_PARENT(statement);
9925
9926         expect(':', end_error);
9927 end_error:
9928
9929         if (current_switch != NULL) {
9930                 if (! statement->case_label.is_bad) {
9931                         /* Check for duplicate case values */
9932                         case_label_statement_t *c = &statement->case_label;
9933                         for (case_label_statement_t *l = current_switch->first_case; l != NULL; l = l->next) {
9934                                 if (l->is_bad || l->is_empty_range || l->expression == NULL)
9935                                         continue;
9936
9937                                 if (c->last_case < l->first_case || c->first_case > l->last_case)
9938                                         continue;
9939
9940                                 errorf(pos, "duplicate case value (previously used %P)",
9941                                        &l->base.source_position);
9942                                 break;
9943                         }
9944                 }
9945                 /* link all cases into the switch statement */
9946                 if (current_switch->last_case == NULL) {
9947                         current_switch->first_case      = &statement->case_label;
9948                 } else {
9949                         current_switch->last_case->next = &statement->case_label;
9950                 }
9951                 current_switch->last_case = &statement->case_label;
9952         } else {
9953                 errorf(pos, "case label not within a switch statement");
9954         }
9955
9956         statement_t *const inner_stmt = parse_statement();
9957         statement->case_label.statement = inner_stmt;
9958         if (inner_stmt->kind == STATEMENT_DECLARATION) {
9959                 errorf(&inner_stmt->base.source_position, "declaration after case label");
9960         }
9961
9962         POP_PARENT;
9963         return statement;
9964 }
9965
9966 /**
9967  * Parse a default statement.
9968  */
9969 static statement_t *parse_default_statement(void)
9970 {
9971         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9972
9973         eat(T_default);
9974
9975         PUSH_PARENT(statement);
9976
9977         expect(':', end_error);
9978         if (current_switch != NULL) {
9979                 const case_label_statement_t *def_label = current_switch->default_label;
9980                 if (def_label != NULL) {
9981                         errorf(HERE, "multiple default labels in one switch (previous declared %P)",
9982                                &def_label->base.source_position);
9983                 } else {
9984                         current_switch->default_label = &statement->case_label;
9985
9986                         /* link all cases into the switch statement */
9987                         if (current_switch->last_case == NULL) {
9988                                 current_switch->first_case      = &statement->case_label;
9989                         } else {
9990                                 current_switch->last_case->next = &statement->case_label;
9991                         }
9992                         current_switch->last_case = &statement->case_label;
9993                 }
9994         } else {
9995                 errorf(&statement->base.source_position,
9996                         "'default' label not within a switch statement");
9997         }
9998
9999         statement_t *const inner_stmt = parse_statement();
10000         statement->case_label.statement = inner_stmt;
10001         if (inner_stmt->kind == STATEMENT_DECLARATION) {
10002                 errorf(&inner_stmt->base.source_position, "declaration after default label");
10003         }
10004
10005         POP_PARENT;
10006         return statement;
10007 end_error:
10008         POP_PARENT;
10009         return create_invalid_statement();
10010 }
10011
10012 /**
10013  * Parse a label statement.
10014  */
10015 static statement_t *parse_label_statement(void)
10016 {
10017         assert(token.type == T_IDENTIFIER);
10018         symbol_t *symbol = token.v.symbol;
10019         label_t  *label  = get_label(symbol);
10020
10021         statement_t *const statement = allocate_statement_zero(STATEMENT_LABEL);
10022         statement->label.label       = label;
10023
10024         next_token();
10025
10026         PUSH_PARENT(statement);
10027
10028         /* if statement is already set then the label is defined twice,
10029          * otherwise it was just mentioned in a goto/local label declaration so far
10030          */
10031         if (label->statement != NULL) {
10032                 errorf(HERE, "duplicate label '%Y' (declared %P)",
10033                        symbol, &label->base.source_position);
10034         } else {
10035                 label->base.source_position = token.source_position;
10036                 label->statement            = statement;
10037         }
10038
10039         eat(':');
10040
10041         if (token.type == '}') {
10042                 /* TODO only warn? */
10043                 if (warning.other && false) {
10044                         warningf(HERE, "label at end of compound statement");
10045                         statement->label.statement = create_empty_statement();
10046                 } else {
10047                         errorf(HERE, "label at end of compound statement");
10048                         statement->label.statement = create_invalid_statement();
10049                 }
10050         } else if (token.type == ';') {
10051                 /* Eat an empty statement here, to avoid the warning about an empty
10052                  * statement after a label.  label:; is commonly used to have a label
10053                  * before a closing brace. */
10054                 statement->label.statement = create_empty_statement();
10055                 next_token();
10056         } else {
10057                 statement_t *const inner_stmt = parse_statement();
10058                 statement->label.statement = inner_stmt;
10059                 if (inner_stmt->kind == STATEMENT_DECLARATION) {
10060                         errorf(&inner_stmt->base.source_position, "declaration after label");
10061                 }
10062         }
10063
10064         /* remember the labels in a list for later checking */
10065         *label_anchor = &statement->label;
10066         label_anchor  = &statement->label.next;
10067
10068         POP_PARENT;
10069         return statement;
10070 }
10071
10072 /**
10073  * Parse an if statement.
10074  */
10075 static statement_t *parse_if(void)
10076 {
10077         statement_t *statement = allocate_statement_zero(STATEMENT_IF);
10078
10079         eat(T_if);
10080
10081         PUSH_PARENT(statement);
10082
10083         add_anchor_token('{');
10084
10085         expect('(', end_error);
10086         add_anchor_token(')');
10087         expression_t *const expr = parse_expression();
10088         statement->ifs.condition = expr;
10089         /* §6.8.4.1:1  The controlling expression of an if statement shall have
10090          *             scalar type. */
10091         semantic_condition(expr, "condition of 'if'-statment");
10092         mark_vars_read(expr, NULL);
10093         rem_anchor_token(')');
10094         expect(')', end_error);
10095
10096 end_error:
10097         rem_anchor_token('{');
10098
10099         add_anchor_token(T_else);
10100         statement_t *const true_stmt = parse_statement();
10101         statement->ifs.true_statement = true_stmt;
10102         rem_anchor_token(T_else);
10103
10104         if (token.type == T_else) {
10105                 next_token();
10106                 statement->ifs.false_statement = parse_statement();
10107         } else if (warning.parentheses &&
10108                         true_stmt->kind == STATEMENT_IF &&
10109                         true_stmt->ifs.false_statement != NULL) {
10110                 warningf(&true_stmt->base.source_position,
10111                                 "suggest explicit braces to avoid ambiguous 'else'");
10112         }
10113
10114         POP_PARENT;
10115         return statement;
10116 }
10117
10118 /**
10119  * Check that all enums are handled in a switch.
10120  *
10121  * @param statement  the switch statement to check
10122  */
10123 static void check_enum_cases(const switch_statement_t *statement)
10124 {
10125         const type_t *type = skip_typeref(statement->expression->base.type);
10126         if (! is_type_enum(type))
10127                 return;
10128         const enum_type_t *enumt = &type->enumt;
10129
10130         /* if we have a default, no warnings */
10131         if (statement->default_label != NULL)
10132                 return;
10133
10134         /* FIXME: calculation of value should be done while parsing */
10135         /* TODO: quadratic algorithm here. Change to an n log n one */
10136         long            last_value = -1;
10137         const entity_t *entry      = enumt->enume->base.next;
10138         for (; entry != NULL && entry->kind == ENTITY_ENUM_VALUE;
10139              entry = entry->base.next) {
10140                 const expression_t *expression = entry->enum_value.value;
10141                 long                value      = expression != NULL ? fold_constant(expression) : last_value + 1;
10142                 bool                found      = false;
10143                 for (const case_label_statement_t *l = statement->first_case; l != NULL; l = l->next) {
10144                         if (l->expression == NULL)
10145                                 continue;
10146                         if (l->first_case <= value && value <= l->last_case) {
10147                                 found = true;
10148                                 break;
10149                         }
10150                 }
10151                 if (! found) {
10152                         warningf(&statement->base.source_position,
10153                                  "enumeration value '%Y' not handled in switch",
10154                                  entry->base.symbol);
10155                 }
10156                 last_value = value;
10157         }
10158 }
10159
10160 /**
10161  * Parse a switch statement.
10162  */
10163 static statement_t *parse_switch(void)
10164 {
10165         statement_t *statement = allocate_statement_zero(STATEMENT_SWITCH);
10166
10167         eat(T_switch);
10168
10169         PUSH_PARENT(statement);
10170
10171         expect('(', end_error);
10172         add_anchor_token(')');
10173         expression_t *const expr = parse_expression();
10174         mark_vars_read(expr, NULL);
10175         type_t       *      type = skip_typeref(expr->base.type);
10176         if (is_type_integer(type)) {
10177                 type = promote_integer(type);
10178                 if (warning.traditional) {
10179                         if (get_rank(type) >= get_akind_rank(ATOMIC_TYPE_LONG)) {
10180                                 warningf(&expr->base.source_position,
10181                                         "'%T' switch expression not converted to '%T' in ISO C",
10182                                         type, type_int);
10183                         }
10184                 }
10185         } else if (is_type_valid(type)) {
10186                 errorf(&expr->base.source_position,
10187                        "switch quantity is not an integer, but '%T'", type);
10188                 type = type_error_type;
10189         }
10190         statement->switchs.expression = create_implicit_cast(expr, type);
10191         expect(')', end_error);
10192         rem_anchor_token(')');
10193
10194         switch_statement_t *rem = current_switch;
10195         current_switch          = &statement->switchs;
10196         statement->switchs.body = parse_statement();
10197         current_switch          = rem;
10198
10199         if (warning.switch_default &&
10200             statement->switchs.default_label == NULL) {
10201                 warningf(&statement->base.source_position, "switch has no default case");
10202         }
10203         if (warning.switch_enum)
10204                 check_enum_cases(&statement->switchs);
10205
10206         POP_PARENT;
10207         return statement;
10208 end_error:
10209         POP_PARENT;
10210         return create_invalid_statement();
10211 }
10212
10213 static statement_t *parse_loop_body(statement_t *const loop)
10214 {
10215         statement_t *const rem = current_loop;
10216         current_loop = loop;
10217
10218         statement_t *const body = parse_statement();
10219
10220         current_loop = rem;
10221         return body;
10222 }
10223
10224 /**
10225  * Parse a while statement.
10226  */
10227 static statement_t *parse_while(void)
10228 {
10229         statement_t *statement = allocate_statement_zero(STATEMENT_WHILE);
10230
10231         eat(T_while);
10232
10233         PUSH_PARENT(statement);
10234
10235         expect('(', end_error);
10236         add_anchor_token(')');
10237         expression_t *const cond = parse_expression();
10238         statement->whiles.condition = cond;
10239         /* §6.8.5:2    The controlling expression of an iteration statement shall
10240          *             have scalar type. */
10241         semantic_condition(cond, "condition of 'while'-statement");
10242         mark_vars_read(cond, NULL);
10243         rem_anchor_token(')');
10244         expect(')', end_error);
10245
10246         statement->whiles.body = parse_loop_body(statement);
10247
10248         POP_PARENT;
10249         return statement;
10250 end_error:
10251         POP_PARENT;
10252         return create_invalid_statement();
10253 }
10254
10255 /**
10256  * Parse a do statement.
10257  */
10258 static statement_t *parse_do(void)
10259 {
10260         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
10261
10262         eat(T_do);
10263
10264         PUSH_PARENT(statement);
10265
10266         add_anchor_token(T_while);
10267         statement->do_while.body = parse_loop_body(statement);
10268         rem_anchor_token(T_while);
10269
10270         expect(T_while, end_error);
10271         expect('(', end_error);
10272         add_anchor_token(')');
10273         expression_t *const cond = parse_expression();
10274         statement->do_while.condition = cond;
10275         /* §6.8.5:2    The controlling expression of an iteration statement shall
10276          *             have scalar type. */
10277         semantic_condition(cond, "condition of 'do-while'-statement");
10278         mark_vars_read(cond, NULL);
10279         rem_anchor_token(')');
10280         expect(')', end_error);
10281         expect(';', end_error);
10282
10283         POP_PARENT;
10284         return statement;
10285 end_error:
10286         POP_PARENT;
10287         return create_invalid_statement();
10288 }
10289
10290 /**
10291  * Parse a for statement.
10292  */
10293 static statement_t *parse_for(void)
10294 {
10295         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
10296
10297         eat(T_for);
10298
10299         expect('(', end_error1);
10300         add_anchor_token(')');
10301
10302         PUSH_PARENT(statement);
10303
10304         size_t const  top       = environment_top();
10305         scope_t      *old_scope = scope_push(&statement->fors.scope);
10306
10307         if (token.type == ';') {
10308                 next_token();
10309         } else if (is_declaration_specifier(&token, false)) {
10310                 parse_declaration(record_entity, DECL_FLAGS_NONE);
10311         } else {
10312                 add_anchor_token(';');
10313                 expression_t *const init = parse_expression();
10314                 statement->fors.initialisation = init;
10315                 mark_vars_read(init, ENT_ANY);
10316                 if (warning.unused_value && !expression_has_effect(init)) {
10317                         warningf(&init->base.source_position,
10318                                         "initialisation of 'for'-statement has no effect");
10319                 }
10320                 rem_anchor_token(';');
10321                 expect(';', end_error2);
10322         }
10323
10324         if (token.type != ';') {
10325                 add_anchor_token(';');
10326                 expression_t *const cond = parse_expression();
10327                 statement->fors.condition = cond;
10328                 /* §6.8.5:2    The controlling expression of an iteration statement
10329                  *             shall have scalar type. */
10330                 semantic_condition(cond, "condition of 'for'-statement");
10331                 mark_vars_read(cond, NULL);
10332                 rem_anchor_token(';');
10333         }
10334         expect(';', end_error2);
10335         if (token.type != ')') {
10336                 expression_t *const step = parse_expression();
10337                 statement->fors.step = step;
10338                 mark_vars_read(step, ENT_ANY);
10339                 if (warning.unused_value && !expression_has_effect(step)) {
10340                         warningf(&step->base.source_position,
10341                                  "step of 'for'-statement has no effect");
10342                 }
10343         }
10344         expect(')', end_error2);
10345         rem_anchor_token(')');
10346         statement->fors.body = parse_loop_body(statement);
10347
10348         assert(current_scope == &statement->fors.scope);
10349         scope_pop(old_scope);
10350         environment_pop_to(top);
10351
10352         POP_PARENT;
10353         return statement;
10354
10355 end_error2:
10356         POP_PARENT;
10357         rem_anchor_token(')');
10358         assert(current_scope == &statement->fors.scope);
10359         scope_pop(old_scope);
10360         environment_pop_to(top);
10361         /* fallthrough */
10362
10363 end_error1:
10364         return create_invalid_statement();
10365 }
10366
10367 /**
10368  * Parse a goto statement.
10369  */
10370 static statement_t *parse_goto(void)
10371 {
10372         statement_t *statement = allocate_statement_zero(STATEMENT_GOTO);
10373         eat(T_goto);
10374
10375         if (GNU_MODE && token.type == '*') {
10376                 next_token();
10377                 expression_t *expression = parse_expression();
10378                 mark_vars_read(expression, NULL);
10379
10380                 /* Argh: although documentation says the expression must be of type void*,
10381                  * gcc accepts anything that can be casted into void* without error */
10382                 type_t *type = expression->base.type;
10383
10384                 if (type != type_error_type) {
10385                         if (!is_type_pointer(type) && !is_type_integer(type)) {
10386                                 errorf(&expression->base.source_position,
10387                                         "cannot convert to a pointer type");
10388                         } else if (warning.other && type != type_void_ptr) {
10389                                 warningf(&expression->base.source_position,
10390                                         "type of computed goto expression should be 'void*' not '%T'", type);
10391                         }
10392                         expression = create_implicit_cast(expression, type_void_ptr);
10393                 }
10394
10395                 statement->gotos.expression = expression;
10396         } else {
10397                 if (token.type != T_IDENTIFIER) {
10398                         if (GNU_MODE)
10399                                 parse_error_expected("while parsing goto", T_IDENTIFIER, '*', NULL);
10400                         else
10401                                 parse_error_expected("while parsing goto", T_IDENTIFIER, NULL);
10402                         eat_until_anchor();
10403                         goto end_error;
10404                 }
10405                 symbol_t *symbol = token.v.symbol;
10406                 next_token();
10407
10408                 statement->gotos.label = get_label(symbol);
10409         }
10410
10411         /* remember the goto's in a list for later checking */
10412         *goto_anchor = &statement->gotos;
10413         goto_anchor  = &statement->gotos.next;
10414
10415         expect(';', end_error);
10416
10417         return statement;
10418 end_error:
10419         return create_invalid_statement();
10420 }
10421
10422 /**
10423  * Parse a continue statement.
10424  */
10425 static statement_t *parse_continue(void)
10426 {
10427         if (current_loop == NULL) {
10428                 errorf(HERE, "continue statement not within loop");
10429         }
10430
10431         statement_t *statement = allocate_statement_zero(STATEMENT_CONTINUE);
10432
10433         eat(T_continue);
10434         expect(';', end_error);
10435
10436 end_error:
10437         return statement;
10438 }
10439
10440 /**
10441  * Parse a break statement.
10442  */
10443 static statement_t *parse_break(void)
10444 {
10445         if (current_switch == NULL && current_loop == NULL) {
10446                 errorf(HERE, "break statement not within loop or switch");
10447         }
10448
10449         statement_t *statement = allocate_statement_zero(STATEMENT_BREAK);
10450
10451         eat(T_break);
10452         expect(';', end_error);
10453
10454 end_error:
10455         return statement;
10456 }
10457
10458 /**
10459  * Parse a __leave statement.
10460  */
10461 static statement_t *parse_leave_statement(void)
10462 {
10463         if (current_try == NULL) {
10464                 errorf(HERE, "__leave statement not within __try");
10465         }
10466
10467         statement_t *statement = allocate_statement_zero(STATEMENT_LEAVE);
10468
10469         eat(T___leave);
10470         expect(';', end_error);
10471
10472 end_error:
10473         return statement;
10474 }
10475
10476 /**
10477  * Check if a given entity represents a local variable.
10478  */
10479 static bool is_local_variable(const entity_t *entity)
10480 {
10481         if (entity->kind != ENTITY_VARIABLE)
10482                 return false;
10483
10484         switch ((storage_class_tag_t) entity->declaration.storage_class) {
10485         case STORAGE_CLASS_AUTO:
10486         case STORAGE_CLASS_REGISTER: {
10487                 const type_t *type = skip_typeref(entity->declaration.type);
10488                 if (is_type_function(type)) {
10489                         return false;
10490                 } else {
10491                         return true;
10492                 }
10493         }
10494         default:
10495                 return false;
10496         }
10497 }
10498
10499 /**
10500  * Check if a given expression represents a local variable.
10501  */
10502 static bool expression_is_local_variable(const expression_t *expression)
10503 {
10504         if (expression->base.kind != EXPR_REFERENCE) {
10505                 return false;
10506         }
10507         const entity_t *entity = expression->reference.entity;
10508         return is_local_variable(entity);
10509 }
10510
10511 /**
10512  * Check if a given expression represents a local variable and
10513  * return its declaration then, else return NULL.
10514  */
10515 entity_t *expression_is_variable(const expression_t *expression)
10516 {
10517         if (expression->base.kind != EXPR_REFERENCE) {
10518                 return NULL;
10519         }
10520         entity_t *entity = expression->reference.entity;
10521         if (entity->kind != ENTITY_VARIABLE)
10522                 return NULL;
10523
10524         return entity;
10525 }
10526
10527 /**
10528  * Parse a return statement.
10529  */
10530 static statement_t *parse_return(void)
10531 {
10532         eat(T_return);
10533
10534         statement_t *statement = allocate_statement_zero(STATEMENT_RETURN);
10535
10536         expression_t *return_value = NULL;
10537         if (token.type != ';') {
10538                 return_value = parse_expression();
10539                 mark_vars_read(return_value, NULL);
10540         }
10541
10542         const type_t *const func_type = skip_typeref(current_function->base.type);
10543         assert(is_type_function(func_type));
10544         type_t *const return_type = skip_typeref(func_type->function.return_type);
10545
10546         source_position_t const *const pos = &statement->base.source_position;
10547         if (return_value != NULL) {
10548                 type_t *return_value_type = skip_typeref(return_value->base.type);
10549
10550                 if (is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
10551                         if (is_type_atomic(return_value_type, ATOMIC_TYPE_VOID)) {
10552                                 /* ISO/IEC 14882:1998(E) §6.6.3:2 */
10553                                 /* Only warn in C mode, because GCC does the same */
10554                                 if (c_mode & _CXX || strict_mode) {
10555                                         errorf(pos,
10556                                                         "'return' with a value, in function returning 'void'");
10557                                 } else if (warning.other) {
10558                                         warningf(pos,
10559                                                         "'return' with a value, in function returning 'void'");
10560                                 }
10561                         } else if (!(c_mode & _CXX)) { /* ISO/IEC 14882:1998(E) §6.6.3:3 */
10562                                 /* Only warn in C mode, because GCC does the same */
10563                                 if (strict_mode) {
10564                                         errorf(pos,
10565                                                         "'return' with expression in function return 'void'");
10566                                 } else if (warning.other) {
10567                                         warningf(pos,
10568                                                         "'return' with expression in function return 'void'");
10569                                 }
10570                         }
10571                 } else {
10572                         assign_error_t error = semantic_assign(return_type, return_value);
10573                         report_assign_error(error, return_type, return_value, "'return'",
10574                                         pos);
10575                 }
10576                 return_value = create_implicit_cast(return_value, return_type);
10577                 /* check for returning address of a local var */
10578                 if (warning.other && return_value != NULL
10579                                 && return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
10580                         const expression_t *expression = return_value->unary.value;
10581                         if (expression_is_local_variable(expression)) {
10582                                 warningf(pos, "function returns address of local variable");
10583                         }
10584                 }
10585         } else if (warning.other && !is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
10586                 /* ISO/IEC 14882:1998(E) §6.6.3:3 */
10587                 if (c_mode & _CXX || strict_mode) {
10588                         errorf(pos,
10589                                         "'return' without value, in function returning non-void");
10590                 } else {
10591                         warningf(pos,
10592                                         "'return' without value, in function returning non-void");
10593                 }
10594         }
10595         statement->returns.value = return_value;
10596
10597         expect(';', end_error);
10598
10599 end_error:
10600         return statement;
10601 }
10602
10603 /**
10604  * Parse a declaration statement.
10605  */
10606 static statement_t *parse_declaration_statement(void)
10607 {
10608         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
10609
10610         entity_t *before = current_scope->last_entity;
10611         if (GNU_MODE) {
10612                 parse_external_declaration();
10613         } else {
10614                 parse_declaration(record_entity, DECL_FLAGS_NONE);
10615         }
10616
10617         declaration_statement_t *const decl  = &statement->declaration;
10618         entity_t                *const begin =
10619                 before != NULL ? before->base.next : current_scope->entities;
10620         decl->declarations_begin = begin;
10621         decl->declarations_end   = begin != NULL ? current_scope->last_entity : NULL;
10622
10623         return statement;
10624 }
10625
10626 /**
10627  * Parse an expression statement, ie. expr ';'.
10628  */
10629 static statement_t *parse_expression_statement(void)
10630 {
10631         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10632
10633         expression_t *const expr         = parse_expression();
10634         statement->expression.expression = expr;
10635         mark_vars_read(expr, ENT_ANY);
10636
10637         expect(';', end_error);
10638
10639 end_error:
10640         return statement;
10641 }
10642
10643 /**
10644  * Parse a microsoft __try { } __finally { } or
10645  * __try{ } __except() { }
10646  */
10647 static statement_t *parse_ms_try_statment(void)
10648 {
10649         statement_t *statement = allocate_statement_zero(STATEMENT_MS_TRY);
10650         eat(T___try);
10651
10652         PUSH_PARENT(statement);
10653
10654         ms_try_statement_t *rem = current_try;
10655         current_try = &statement->ms_try;
10656         statement->ms_try.try_statement = parse_compound_statement(false);
10657         current_try = rem;
10658
10659         POP_PARENT;
10660
10661         if (token.type == T___except) {
10662                 eat(T___except);
10663                 expect('(', end_error);
10664                 add_anchor_token(')');
10665                 expression_t *const expr = parse_expression();
10666                 mark_vars_read(expr, NULL);
10667                 type_t       *      type = skip_typeref(expr->base.type);
10668                 if (is_type_integer(type)) {
10669                         type = promote_integer(type);
10670                 } else if (is_type_valid(type)) {
10671                         errorf(&expr->base.source_position,
10672                                "__expect expression is not an integer, but '%T'", type);
10673                         type = type_error_type;
10674                 }
10675                 statement->ms_try.except_expression = create_implicit_cast(expr, type);
10676                 rem_anchor_token(')');
10677                 expect(')', end_error);
10678                 statement->ms_try.final_statement = parse_compound_statement(false);
10679         } else if (token.type == T__finally) {
10680                 eat(T___finally);
10681                 statement->ms_try.final_statement = parse_compound_statement(false);
10682         } else {
10683                 parse_error_expected("while parsing __try statement", T___except, T___finally, NULL);
10684                 return create_invalid_statement();
10685         }
10686         return statement;
10687 end_error:
10688         return create_invalid_statement();
10689 }
10690
10691 static statement_t *parse_empty_statement(void)
10692 {
10693         if (warning.empty_statement) {
10694                 warningf(HERE, "statement is empty");
10695         }
10696         statement_t *const statement = create_empty_statement();
10697         eat(';');
10698         return statement;
10699 }
10700
10701 static statement_t *parse_local_label_declaration(void)
10702 {
10703         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
10704
10705         eat(T___label__);
10706
10707         entity_t *begin = NULL, *end = NULL;
10708
10709         while (true) {
10710                 if (token.type != T_IDENTIFIER) {
10711                         parse_error_expected("while parsing local label declaration",
10712                                 T_IDENTIFIER, NULL);
10713                         goto end_error;
10714                 }
10715                 symbol_t *symbol = token.v.symbol;
10716                 entity_t *entity = get_entity(symbol, NAMESPACE_LABEL);
10717                 if (entity != NULL && entity->base.parent_scope == current_scope) {
10718                         errorf(HERE, "multiple definitions of '__label__ %Y' (previous definition %P)",
10719                                symbol, &entity->base.source_position);
10720                 } else {
10721                         entity = allocate_entity_zero(ENTITY_LOCAL_LABEL);
10722
10723                         entity->base.parent_scope    = current_scope;
10724                         entity->base.namespc         = NAMESPACE_LABEL;
10725                         entity->base.source_position = token.source_position;
10726                         entity->base.symbol          = symbol;
10727
10728                         if (end != NULL)
10729                                 end->base.next = entity;
10730                         end = entity;
10731                         if (begin == NULL)
10732                                 begin = entity;
10733
10734                         environment_push(entity);
10735                 }
10736                 next_token();
10737
10738                 if (token.type != ',')
10739                         break;
10740                 next_token();
10741         }
10742         eat(';');
10743 end_error:
10744         statement->declaration.declarations_begin = begin;
10745         statement->declaration.declarations_end   = end;
10746         return statement;
10747 }
10748
10749 static void parse_namespace_definition(void)
10750 {
10751         eat(T_namespace);
10752
10753         entity_t *entity = NULL;
10754         symbol_t *symbol = NULL;
10755
10756         if (token.type == T_IDENTIFIER) {
10757                 symbol = token.v.symbol;
10758                 next_token();
10759
10760                 entity = get_entity(symbol, NAMESPACE_NORMAL);
10761                 if (entity       != NULL             &&
10762                                 entity->kind != ENTITY_NAMESPACE &&
10763                                 entity->base.parent_scope == current_scope) {
10764                         if (!is_error_entity(entity)) {
10765                                 error_redefined_as_different_kind(&token.source_position,
10766                                                 entity, ENTITY_NAMESPACE);
10767                         }
10768                         entity = NULL;
10769                 }
10770         }
10771
10772         if (entity == NULL) {
10773                 entity                       = allocate_entity_zero(ENTITY_NAMESPACE);
10774                 entity->base.symbol          = symbol;
10775                 entity->base.source_position = token.source_position;
10776                 entity->base.namespc         = NAMESPACE_NORMAL;
10777                 entity->base.parent_scope    = current_scope;
10778         }
10779
10780         if (token.type == '=') {
10781                 /* TODO: parse namespace alias */
10782                 panic("namespace alias definition not supported yet");
10783         }
10784
10785         environment_push(entity);
10786         append_entity(current_scope, entity);
10787
10788         size_t const  top       = environment_top();
10789         scope_t      *old_scope = scope_push(&entity->namespacee.members);
10790
10791         expect('{', end_error);
10792         parse_externals();
10793         expect('}', end_error);
10794
10795 end_error:
10796         assert(current_scope == &entity->namespacee.members);
10797         scope_pop(old_scope);
10798         environment_pop_to(top);
10799 }
10800
10801 /**
10802  * Parse a statement.
10803  * There's also parse_statement() which additionally checks for
10804  * "statement has no effect" warnings
10805  */
10806 static statement_t *intern_parse_statement(void)
10807 {
10808         statement_t *statement = NULL;
10809
10810         /* declaration or statement */
10811         add_anchor_token(';');
10812         switch (token.type) {
10813         case T_IDENTIFIER: {
10814                 token_type_t la1_type = (token_type_t)look_ahead(1)->type;
10815                 if (la1_type == ':') {
10816                         statement = parse_label_statement();
10817                 } else if (is_typedef_symbol(token.v.symbol)) {
10818                         statement = parse_declaration_statement();
10819                 } else {
10820                         /* it's an identifier, the grammar says this must be an
10821                          * expression statement. However it is common that users mistype
10822                          * declaration types, so we guess a bit here to improve robustness
10823                          * for incorrect programs */
10824                         switch (la1_type) {
10825                         case '&':
10826                         case '*':
10827                                 if (get_entity(token.v.symbol, NAMESPACE_NORMAL) != NULL)
10828                                         goto expression_statment;
10829                                 /* FALLTHROUGH */
10830
10831                         DECLARATION_START
10832                         case T_IDENTIFIER:
10833                                 statement = parse_declaration_statement();
10834                                 break;
10835
10836                         default:
10837 expression_statment:
10838                                 statement = parse_expression_statement();
10839                                 break;
10840                         }
10841                 }
10842                 break;
10843         }
10844
10845         case T___extension__:
10846                 /* This can be a prefix to a declaration or an expression statement.
10847                  * We simply eat it now and parse the rest with tail recursion. */
10848                 do {
10849                         next_token();
10850                 } while (token.type == T___extension__);
10851                 bool old_gcc_extension = in_gcc_extension;
10852                 in_gcc_extension       = true;
10853                 statement = intern_parse_statement();
10854                 in_gcc_extension = old_gcc_extension;
10855                 break;
10856
10857         DECLARATION_START
10858                 statement = parse_declaration_statement();
10859                 break;
10860
10861         case T___label__:
10862                 statement = parse_local_label_declaration();
10863                 break;
10864
10865         case ';':         statement = parse_empty_statement();         break;
10866         case '{':         statement = parse_compound_statement(false); break;
10867         case T___leave:   statement = parse_leave_statement();         break;
10868         case T___try:     statement = parse_ms_try_statment();         break;
10869         case T_asm:       statement = parse_asm_statement();           break;
10870         case T_break:     statement = parse_break();                   break;
10871         case T_case:      statement = parse_case_statement();          break;
10872         case T_continue:  statement = parse_continue();                break;
10873         case T_default:   statement = parse_default_statement();       break;
10874         case T_do:        statement = parse_do();                      break;
10875         case T_for:       statement = parse_for();                     break;
10876         case T_goto:      statement = parse_goto();                    break;
10877         case T_if:        statement = parse_if();                      break;
10878         case T_return:    statement = parse_return();                  break;
10879         case T_switch:    statement = parse_switch();                  break;
10880         case T_while:     statement = parse_while();                   break;
10881
10882         EXPRESSION_START
10883                 statement = parse_expression_statement();
10884                 break;
10885
10886         default:
10887                 errorf(HERE, "unexpected token %K while parsing statement", &token);
10888                 statement = create_invalid_statement();
10889                 if (!at_anchor())
10890                         next_token();
10891                 break;
10892         }
10893         rem_anchor_token(';');
10894
10895         assert(statement != NULL
10896                         && statement->base.source_position.input_name != NULL);
10897
10898         return statement;
10899 }
10900
10901 /**
10902  * parse a statement and emits "statement has no effect" warning if needed
10903  * (This is really a wrapper around intern_parse_statement with check for 1
10904  *  single warning. It is needed, because for statement expressions we have
10905  *  to avoid the warning on the last statement)
10906  */
10907 static statement_t *parse_statement(void)
10908 {
10909         statement_t *statement = intern_parse_statement();
10910
10911         if (statement->kind == STATEMENT_EXPRESSION && warning.unused_value) {
10912                 expression_t *expression = statement->expression.expression;
10913                 if (!expression_has_effect(expression)) {
10914                         warningf(&expression->base.source_position,
10915                                         "statement has no effect");
10916                 }
10917         }
10918
10919         return statement;
10920 }
10921
10922 /**
10923  * Parse a compound statement.
10924  */
10925 static statement_t *parse_compound_statement(bool inside_expression_statement)
10926 {
10927         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
10928
10929         PUSH_PARENT(statement);
10930
10931         eat('{');
10932         add_anchor_token('}');
10933         /* tokens, which can start a statement */
10934         /* TODO MS, __builtin_FOO */
10935         add_anchor_token('!');
10936         add_anchor_token('&');
10937         add_anchor_token('(');
10938         add_anchor_token('*');
10939         add_anchor_token('+');
10940         add_anchor_token('-');
10941         add_anchor_token('{');
10942         add_anchor_token('~');
10943         add_anchor_token(T_CHARACTER_CONSTANT);
10944         add_anchor_token(T_COLONCOLON);
10945         add_anchor_token(T_FLOATINGPOINT);
10946         add_anchor_token(T_IDENTIFIER);
10947         add_anchor_token(T_INTEGER);
10948         add_anchor_token(T_MINUSMINUS);
10949         add_anchor_token(T_PLUSPLUS);
10950         add_anchor_token(T_STRING_LITERAL);
10951         add_anchor_token(T_WIDE_CHARACTER_CONSTANT);
10952         add_anchor_token(T_WIDE_STRING_LITERAL);
10953         add_anchor_token(T__Bool);
10954         add_anchor_token(T__Complex);
10955         add_anchor_token(T__Imaginary);
10956         add_anchor_token(T___FUNCTION__);
10957         add_anchor_token(T___PRETTY_FUNCTION__);
10958         add_anchor_token(T___alignof__);
10959         add_anchor_token(T___attribute__);
10960         add_anchor_token(T___builtin_va_start);
10961         add_anchor_token(T___extension__);
10962         add_anchor_token(T___func__);
10963         add_anchor_token(T___imag__);
10964         add_anchor_token(T___label__);
10965         add_anchor_token(T___real__);
10966         add_anchor_token(T___thread);
10967         add_anchor_token(T_asm);
10968         add_anchor_token(T_auto);
10969         add_anchor_token(T_bool);
10970         add_anchor_token(T_break);
10971         add_anchor_token(T_case);
10972         add_anchor_token(T_char);
10973         add_anchor_token(T_class);
10974         add_anchor_token(T_const);
10975         add_anchor_token(T_const_cast);
10976         add_anchor_token(T_continue);
10977         add_anchor_token(T_default);
10978         add_anchor_token(T_delete);
10979         add_anchor_token(T_double);
10980         add_anchor_token(T_do);
10981         add_anchor_token(T_dynamic_cast);
10982         add_anchor_token(T_enum);
10983         add_anchor_token(T_extern);
10984         add_anchor_token(T_false);
10985         add_anchor_token(T_float);
10986         add_anchor_token(T_for);
10987         add_anchor_token(T_goto);
10988         add_anchor_token(T_if);
10989         add_anchor_token(T_inline);
10990         add_anchor_token(T_int);
10991         add_anchor_token(T_long);
10992         add_anchor_token(T_new);
10993         add_anchor_token(T_operator);
10994         add_anchor_token(T_register);
10995         add_anchor_token(T_reinterpret_cast);
10996         add_anchor_token(T_restrict);
10997         add_anchor_token(T_return);
10998         add_anchor_token(T_short);
10999         add_anchor_token(T_signed);
11000         add_anchor_token(T_sizeof);
11001         add_anchor_token(T_static);
11002         add_anchor_token(T_static_cast);
11003         add_anchor_token(T_struct);
11004         add_anchor_token(T_switch);
11005         add_anchor_token(T_template);
11006         add_anchor_token(T_this);
11007         add_anchor_token(T_throw);
11008         add_anchor_token(T_true);
11009         add_anchor_token(T_try);
11010         add_anchor_token(T_typedef);
11011         add_anchor_token(T_typeid);
11012         add_anchor_token(T_typename);
11013         add_anchor_token(T_typeof);
11014         add_anchor_token(T_union);
11015         add_anchor_token(T_unsigned);
11016         add_anchor_token(T_using);
11017         add_anchor_token(T_void);
11018         add_anchor_token(T_volatile);
11019         add_anchor_token(T_wchar_t);
11020         add_anchor_token(T_while);
11021
11022         size_t const  top       = environment_top();
11023         scope_t      *old_scope = scope_push(&statement->compound.scope);
11024
11025         statement_t **anchor            = &statement->compound.statements;
11026         bool          only_decls_so_far = true;
11027         while (token.type != '}') {
11028                 if (token.type == T_EOF) {
11029                         errorf(&statement->base.source_position,
11030                                "EOF while parsing compound statement");
11031                         break;
11032                 }
11033                 statement_t *sub_statement = intern_parse_statement();
11034                 if (is_invalid_statement(sub_statement)) {
11035                         /* an error occurred. if we are at an anchor, return */
11036                         if (at_anchor())
11037                                 goto end_error;
11038                         continue;
11039                 }
11040
11041                 if (warning.declaration_after_statement) {
11042                         if (sub_statement->kind != STATEMENT_DECLARATION) {
11043                                 only_decls_so_far = false;
11044                         } else if (!only_decls_so_far) {
11045                                 warningf(&sub_statement->base.source_position,
11046                                          "ISO C90 forbids mixed declarations and code");
11047                         }
11048                 }
11049
11050                 *anchor = sub_statement;
11051
11052                 while (sub_statement->base.next != NULL)
11053                         sub_statement = sub_statement->base.next;
11054
11055                 anchor = &sub_statement->base.next;
11056         }
11057         next_token();
11058
11059         /* look over all statements again to produce no effect warnings */
11060         if (warning.unused_value) {
11061                 statement_t *sub_statement = statement->compound.statements;
11062                 for (; sub_statement != NULL; sub_statement = sub_statement->base.next) {
11063                         if (sub_statement->kind != STATEMENT_EXPRESSION)
11064                                 continue;
11065                         /* don't emit a warning for the last expression in an expression
11066                          * statement as it has always an effect */
11067                         if (inside_expression_statement && sub_statement->base.next == NULL)
11068                                 continue;
11069
11070                         expression_t *expression = sub_statement->expression.expression;
11071                         if (!expression_has_effect(expression)) {
11072                                 warningf(&expression->base.source_position,
11073                                          "statement has no effect");
11074                         }
11075                 }
11076         }
11077
11078 end_error:
11079         rem_anchor_token(T_while);
11080         rem_anchor_token(T_wchar_t);
11081         rem_anchor_token(T_volatile);
11082         rem_anchor_token(T_void);
11083         rem_anchor_token(T_using);
11084         rem_anchor_token(T_unsigned);
11085         rem_anchor_token(T_union);
11086         rem_anchor_token(T_typeof);
11087         rem_anchor_token(T_typename);
11088         rem_anchor_token(T_typeid);
11089         rem_anchor_token(T_typedef);
11090         rem_anchor_token(T_try);
11091         rem_anchor_token(T_true);
11092         rem_anchor_token(T_throw);
11093         rem_anchor_token(T_this);
11094         rem_anchor_token(T_template);
11095         rem_anchor_token(T_switch);
11096         rem_anchor_token(T_struct);
11097         rem_anchor_token(T_static_cast);
11098         rem_anchor_token(T_static);
11099         rem_anchor_token(T_sizeof);
11100         rem_anchor_token(T_signed);
11101         rem_anchor_token(T_short);
11102         rem_anchor_token(T_return);
11103         rem_anchor_token(T_restrict);
11104         rem_anchor_token(T_reinterpret_cast);
11105         rem_anchor_token(T_register);
11106         rem_anchor_token(T_operator);
11107         rem_anchor_token(T_new);
11108         rem_anchor_token(T_long);
11109         rem_anchor_token(T_int);
11110         rem_anchor_token(T_inline);
11111         rem_anchor_token(T_if);
11112         rem_anchor_token(T_goto);
11113         rem_anchor_token(T_for);
11114         rem_anchor_token(T_float);
11115         rem_anchor_token(T_false);
11116         rem_anchor_token(T_extern);
11117         rem_anchor_token(T_enum);
11118         rem_anchor_token(T_dynamic_cast);
11119         rem_anchor_token(T_do);
11120         rem_anchor_token(T_double);
11121         rem_anchor_token(T_delete);
11122         rem_anchor_token(T_default);
11123         rem_anchor_token(T_continue);
11124         rem_anchor_token(T_const_cast);
11125         rem_anchor_token(T_const);
11126         rem_anchor_token(T_class);
11127         rem_anchor_token(T_char);
11128         rem_anchor_token(T_case);
11129         rem_anchor_token(T_break);
11130         rem_anchor_token(T_bool);
11131         rem_anchor_token(T_auto);
11132         rem_anchor_token(T_asm);
11133         rem_anchor_token(T___thread);
11134         rem_anchor_token(T___real__);
11135         rem_anchor_token(T___label__);
11136         rem_anchor_token(T___imag__);
11137         rem_anchor_token(T___func__);
11138         rem_anchor_token(T___extension__);
11139         rem_anchor_token(T___builtin_va_start);
11140         rem_anchor_token(T___attribute__);
11141         rem_anchor_token(T___alignof__);
11142         rem_anchor_token(T___PRETTY_FUNCTION__);
11143         rem_anchor_token(T___FUNCTION__);
11144         rem_anchor_token(T__Imaginary);
11145         rem_anchor_token(T__Complex);
11146         rem_anchor_token(T__Bool);
11147         rem_anchor_token(T_WIDE_STRING_LITERAL);
11148         rem_anchor_token(T_WIDE_CHARACTER_CONSTANT);
11149         rem_anchor_token(T_STRING_LITERAL);
11150         rem_anchor_token(T_PLUSPLUS);
11151         rem_anchor_token(T_MINUSMINUS);
11152         rem_anchor_token(T_INTEGER);
11153         rem_anchor_token(T_IDENTIFIER);
11154         rem_anchor_token(T_FLOATINGPOINT);
11155         rem_anchor_token(T_COLONCOLON);
11156         rem_anchor_token(T_CHARACTER_CONSTANT);
11157         rem_anchor_token('~');
11158         rem_anchor_token('{');
11159         rem_anchor_token('-');
11160         rem_anchor_token('+');
11161         rem_anchor_token('*');
11162         rem_anchor_token('(');
11163         rem_anchor_token('&');
11164         rem_anchor_token('!');
11165         rem_anchor_token('}');
11166         assert(current_scope == &statement->compound.scope);
11167         scope_pop(old_scope);
11168         environment_pop_to(top);
11169
11170         POP_PARENT;
11171         return statement;
11172 }
11173
11174 /**
11175  * Check for unused global static functions and variables
11176  */
11177 static void check_unused_globals(void)
11178 {
11179         if (!warning.unused_function && !warning.unused_variable)
11180                 return;
11181
11182         for (const entity_t *entity = file_scope->entities; entity != NULL;
11183              entity = entity->base.next) {
11184                 if (!is_declaration(entity))
11185                         continue;
11186
11187                 const declaration_t *declaration = &entity->declaration;
11188                 if (declaration->used                  ||
11189                     declaration->modifiers & DM_UNUSED ||
11190                     declaration->modifiers & DM_USED   ||
11191                     declaration->storage_class != STORAGE_CLASS_STATIC)
11192                         continue;
11193
11194                 type_t *const type = declaration->type;
11195                 const char *s;
11196                 if (entity->kind == ENTITY_FUNCTION) {
11197                         /* inhibit warning for static inline functions */
11198                         if (entity->function.is_inline)
11199                                 continue;
11200
11201                         s = entity->function.statement != NULL ? "defined" : "declared";
11202                 } else {
11203                         s = "defined";
11204                 }
11205
11206                 warningf(&declaration->base.source_position, "'%#T' %s but not used",
11207                         type, declaration->base.symbol, s);
11208         }
11209 }
11210
11211 static void parse_global_asm(void)
11212 {
11213         statement_t *statement = allocate_statement_zero(STATEMENT_ASM);
11214
11215         eat(T_asm);
11216         expect('(', end_error);
11217
11218         statement->asms.asm_text = parse_string_literals();
11219         statement->base.next     = unit->global_asm;
11220         unit->global_asm         = statement;
11221
11222         expect(')', end_error);
11223         expect(';', end_error);
11224
11225 end_error:;
11226 }
11227
11228 static void parse_linkage_specification(void)
11229 {
11230         eat(T_extern);
11231         assert(token.type == T_STRING_LITERAL);
11232
11233         const char *linkage = parse_string_literals().begin;
11234
11235         linkage_kind_t old_linkage = current_linkage;
11236         linkage_kind_t new_linkage;
11237         if (strcmp(linkage, "C") == 0) {
11238                 new_linkage = LINKAGE_C;
11239         } else if (strcmp(linkage, "C++") == 0) {
11240                 new_linkage = LINKAGE_CXX;
11241         } else {
11242                 errorf(HERE, "linkage string \"%s\" not recognized", linkage);
11243                 new_linkage = LINKAGE_INVALID;
11244         }
11245         current_linkage = new_linkage;
11246
11247         if (token.type == '{') {
11248                 next_token();
11249                 parse_externals();
11250                 expect('}', end_error);
11251         } else {
11252                 parse_external();
11253         }
11254
11255 end_error:
11256         assert(current_linkage == new_linkage);
11257         current_linkage = old_linkage;
11258 }
11259
11260 static void parse_external(void)
11261 {
11262         switch (token.type) {
11263                 DECLARATION_START_NO_EXTERN
11264                 case T_IDENTIFIER:
11265                 case T___extension__:
11266                 /* tokens below are for implicit int */
11267                 case '&': /* & x; -> int& x; (and error later, because C++ has no
11268                              implicit int) */
11269                 case '*': /* * x; -> int* x; */
11270                 case '(': /* (x); -> int (x); */
11271                         parse_external_declaration();
11272                         return;
11273
11274                 case T_extern:
11275                         if (look_ahead(1)->type == T_STRING_LITERAL) {
11276                                 parse_linkage_specification();
11277                         } else {
11278                                 parse_external_declaration();
11279                         }
11280                         return;
11281
11282                 case T_asm:
11283                         parse_global_asm();
11284                         return;
11285
11286                 case T_namespace:
11287                         parse_namespace_definition();
11288                         return;
11289
11290                 case ';':
11291                         if (!strict_mode) {
11292                                 if (warning.other)
11293                                         warningf(HERE, "stray ';' outside of function");
11294                                 next_token();
11295                                 return;
11296                         }
11297                         /* FALLTHROUGH */
11298
11299                 default:
11300                         errorf(HERE, "stray %K outside of function", &token);
11301                         if (token.type == '(' || token.type == '{' || token.type == '[')
11302                                 eat_until_matching_token(token.type);
11303                         next_token();
11304                         return;
11305         }
11306 }
11307
11308 static void parse_externals(void)
11309 {
11310         add_anchor_token('}');
11311         add_anchor_token(T_EOF);
11312
11313 #ifndef NDEBUG
11314         unsigned char token_anchor_copy[T_LAST_TOKEN];
11315         memcpy(token_anchor_copy, token_anchor_set, sizeof(token_anchor_copy));
11316 #endif
11317
11318         while (token.type != T_EOF && token.type != '}') {
11319 #ifndef NDEBUG
11320                 bool anchor_leak = false;
11321                 for (int i = 0; i != T_LAST_TOKEN; ++i) {
11322                         unsigned char count = token_anchor_set[i] - token_anchor_copy[i];
11323                         if (count != 0) {
11324                                 errorf(HERE, "Leaked anchor token %k %d times", i, count);
11325                                 anchor_leak = true;
11326                         }
11327                 }
11328                 if (in_gcc_extension) {
11329                         errorf(HERE, "Leaked __extension__");
11330                         anchor_leak = true;
11331                 }
11332
11333                 if (anchor_leak)
11334                         abort();
11335 #endif
11336
11337                 parse_external();
11338         }
11339
11340         rem_anchor_token(T_EOF);
11341         rem_anchor_token('}');
11342 }
11343
11344 /**
11345  * Parse a translation unit.
11346  */
11347 static void parse_translation_unit(void)
11348 {
11349         add_anchor_token(T_EOF);
11350
11351         while (true) {
11352                 parse_externals();
11353
11354                 if (token.type == T_EOF)
11355                         break;
11356
11357                 errorf(HERE, "stray %K outside of function", &token);
11358                 if (token.type == '(' || token.type == '{' || token.type == '[')
11359                         eat_until_matching_token(token.type);
11360                 next_token();
11361         }
11362 }
11363
11364 /**
11365  * Parse the input.
11366  *
11367  * @return  the translation unit or NULL if errors occurred.
11368  */
11369 void start_parsing(void)
11370 {
11371         environment_stack = NEW_ARR_F(stack_entry_t, 0);
11372         label_stack       = NEW_ARR_F(stack_entry_t, 0);
11373         diagnostic_count  = 0;
11374         error_count       = 0;
11375         warning_count     = 0;
11376
11377         type_set_output(stderr);
11378         ast_set_output(stderr);
11379
11380         assert(unit == NULL);
11381         unit = allocate_ast_zero(sizeof(unit[0]));
11382
11383         assert(file_scope == NULL);
11384         file_scope = &unit->scope;
11385
11386         assert(current_scope == NULL);
11387         scope_push(&unit->scope);
11388 }
11389
11390 translation_unit_t *finish_parsing(void)
11391 {
11392         assert(current_scope == &unit->scope);
11393         scope_pop(NULL);
11394
11395         assert(file_scope == &unit->scope);
11396         check_unused_globals();
11397         file_scope = NULL;
11398
11399         DEL_ARR_F(environment_stack);
11400         DEL_ARR_F(label_stack);
11401
11402         translation_unit_t *result = unit;
11403         unit = NULL;
11404         return result;
11405 }
11406
11407 /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
11408  * are given length one. */
11409 static void complete_incomplete_arrays(void)
11410 {
11411         size_t n = ARR_LEN(incomplete_arrays);
11412         for (size_t i = 0; i != n; ++i) {
11413                 declaration_t *const decl      = incomplete_arrays[i];
11414                 type_t        *const orig_type = decl->type;
11415                 type_t        *const type      = skip_typeref(orig_type);
11416
11417                 if (!is_type_incomplete(type))
11418                         continue;
11419
11420                 if (warning.other) {
11421                         warningf(&decl->base.source_position,
11422                                         "array '%#T' assumed to have one element",
11423                                         orig_type, decl->base.symbol);
11424                 }
11425
11426                 type_t *const new_type = duplicate_type(type);
11427                 new_type->array.size_constant     = true;
11428                 new_type->array.has_implicit_size = true;
11429                 new_type->array.size              = 1;
11430
11431                 type_t *const result = identify_new_type(new_type);
11432
11433                 decl->type = result;
11434         }
11435 }
11436
11437 void parse(void)
11438 {
11439         lookahead_bufpos = 0;
11440         for (int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
11441                 next_token();
11442         }
11443         current_linkage   = c_mode & _CXX ? LINKAGE_CXX : LINKAGE_C;
11444         incomplete_arrays = NEW_ARR_F(declaration_t*, 0);
11445         parse_translation_unit();
11446         complete_incomplete_arrays();
11447         DEL_ARR_F(incomplete_arrays);
11448         incomplete_arrays = NULL;
11449 }
11450
11451 /**
11452  * Initialize the parser.
11453  */
11454 void init_parser(void)
11455 {
11456         sym_anonymous = symbol_table_insert("<anonymous>");
11457
11458         if (c_mode & _MS) {
11459                 /* add predefined symbols for extended-decl-modifier */
11460                 sym_align         = symbol_table_insert("align");
11461                 sym_allocate      = symbol_table_insert("allocate");
11462                 sym_dllimport     = symbol_table_insert("dllimport");
11463                 sym_dllexport     = symbol_table_insert("dllexport");
11464                 sym_naked         = symbol_table_insert("naked");
11465                 sym_noinline      = symbol_table_insert("noinline");
11466                 sym_returns_twice = symbol_table_insert("returns_twice");
11467                 sym_noreturn      = symbol_table_insert("noreturn");
11468                 sym_nothrow       = symbol_table_insert("nothrow");
11469                 sym_novtable      = symbol_table_insert("novtable");
11470                 sym_property      = symbol_table_insert("property");
11471                 sym_get           = symbol_table_insert("get");
11472                 sym_put           = symbol_table_insert("put");
11473                 sym_selectany     = symbol_table_insert("selectany");
11474                 sym_thread        = symbol_table_insert("thread");
11475                 sym_uuid          = symbol_table_insert("uuid");
11476                 sym_deprecated    = symbol_table_insert("deprecated");
11477                 sym_restrict      = symbol_table_insert("restrict");
11478                 sym_noalias       = symbol_table_insert("noalias");
11479         }
11480         memset(token_anchor_set, 0, sizeof(token_anchor_set));
11481
11482         init_expression_parsers();
11483         obstack_init(&temp_obst);
11484
11485         symbol_t *const va_list_sym = symbol_table_insert("__builtin_va_list");
11486         type_valist = create_builtin_type(va_list_sym, type_void_ptr);
11487 }
11488
11489 /**
11490  * Terminate the parser.
11491  */
11492 void exit_parser(void)
11493 {
11494         obstack_free(&temp_obst, NULL);
11495 }