nsz Git - cparser/blob - parser.c

   1 /*
   2  * This file is part of cparser.
   3  * Copyright (C) 2007-2008 Matthias Braun <matze@braunis.de>
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; either version 2
   8  * of the License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  18  * 02111-1307, USA.
  19  */
  20 #include <config.h>
  21
  22 #include <assert.h>
  23 #include <stdarg.h>
  24 #include <stdbool.h>
  25
  26 #include "parser.h"
  27 #include "diagnostic.h"
  28 #include "format_check.h"
  29 #include "lexer.h"
  30 #include "symbol_t.h"
  31 #include "token_t.h"
  32 #include "types.h"
  33 #include "type_t.h"
  34 #include "type_hash.h"
  35 #include "ast_t.h"
  36 #include "entity_t.h"
  37 #include "lang_features.h"
  38 #include "walk_statements.h"
  39 #include "warning.h"
  40 #include "adt/bitfiddle.h"
  41 #include "adt/error.h"
  42 #include "adt/array.h"
  43
  44 //#define PRINT_TOKENS
  45 #define MAX_LOOKAHEAD 2
  46
  47 typedef struct {
  48         entity_t           *old_entity;
  49         symbol_t           *symbol;
  50         entity_namespace_t  namespc;
  51 } stack_entry_t;
  52
  53 typedef struct argument_list_t argument_list_t;
  54 struct argument_list_t {
  55         long              argument;
  56         argument_list_t  *next;
  57 };
  58
  59 typedef struct gnu_attribute_t gnu_attribute_t;
  60 struct gnu_attribute_t {
  61         gnu_attribute_kind_t kind;           /**< The kind of the GNU attribute. */
  62         gnu_attribute_t     *next;
  63         bool                 invalid;        /**< Set if this attribute had argument errors, */
  64         bool                 have_arguments; /**< True, if this attribute has arguments. */
  65         union {
  66                 size_t              value;
  67                 string_t            string;
  68                 atomic_type_kind_t  akind;
  69                 long                argument;  /**< Single argument. */
  70                 argument_list_t    *arguments; /**< List of argument expressions. */
  71         } u;
  72 };
  73
  74 typedef struct declaration_specifiers_t  declaration_specifiers_t;
  75 struct declaration_specifiers_t {
  76         source_position_t  source_position;
  77         storage_class_t    storage_class;
  78         unsigned char      alignment;         /**< Alignment, 0 if not set. */
  79         bool               is_inline    : 1;
  80         bool               thread_local : 1;  /**< GCC __thread */
  81         bool               deprecated   : 1;
  82         decl_modifiers_t   modifiers;         /**< declaration modifiers */
  83         gnu_attribute_t   *gnu_attributes;    /**< list of GNU attributes */
  84         const char        *deprecated_string; /**< can be set if declaration was marked deprecated. */
  85         symbol_t          *get_property_sym;  /**< the name of the get property if set. */
  86         symbol_t          *put_property_sym;  /**< the name of the put property if set. */
  87         type_t            *type;
  88 };
  89
  90 /**
  91  * An environment for parsing initializers (and compound literals).
  92  */
  93 typedef struct parse_initializer_env_t {
  94         type_t     *type;   /**< the type of the initializer. In case of an
  95                                  array type with unspecified size this gets
  96                                  adjusted to the actual size. */
  97         entity_t   *entity; /**< the variable that is initialized if any */
  98         bool        must_be_constant;
  99 } parse_initializer_env_t;
 100
 101 /**
 102  * Capture a MS __base extension.
 103  */
 104 typedef struct based_spec_t {
 105         source_position_t  source_position;
 106         variable_t        *base_variable;
 107 } based_spec_t;
 108
 109 typedef entity_t* (*parsed_declaration_func) (entity_t *declaration, bool is_definition);
 110
 111 /** The current token. */
 112 static token_t              token;
 113 /** The lookahead ring-buffer. */
 114 static token_t              lookahead_buffer[MAX_LOOKAHEAD];
 115 /** Position of the next token in the lookahead buffer. */
 116 static int                  lookahead_bufpos;
 117 static stack_entry_t       *environment_stack = NULL;
 118 static stack_entry_t       *label_stack       = NULL;
 119 static scope_t             *file_scope        = NULL;
 120 static scope_t             *current_scope     = NULL;
 121 /** Point to the current function declaration if inside a function. */
 122 static function_t          *current_function  = NULL;
 123 static entity_t            *current_init_decl = NULL;
 124 static switch_statement_t  *current_switch    = NULL;
 125 static statement_t         *current_loop      = NULL;
 126 static statement_t         *current_parent    = NULL;
 127 static ms_try_statement_t  *current_try       = NULL;
 128 static linkage_kind_t       current_linkage   = LINKAGE_INVALID;
 129 static goto_statement_t    *goto_first        = NULL;
 130 static goto_statement_t   **goto_anchor       = NULL;
 131 static label_statement_t   *label_first       = NULL;
 132 static label_statement_t  **label_anchor      = NULL;
 133 /** current translation unit. */
 134 static translation_unit_t  *unit              = NULL;
 135 /** true if we are in a type property context (evaluation only for type. */
 136 static bool                 in_type_prop      = false;
 137 /** true in we are in a __extension__ context. */
 138 static bool                 in_gcc_extension  = false;
 139 static struct obstack       temp_obst;
 140 static entity_t            *anonymous_entity;
 141
 142
 143 #define PUSH_PARENT(stmt)                          \
 144         statement_t *const prev_parent = current_parent; \
 145         ((void)(current_parent = (stmt)))
 146 #define POP_PARENT ((void)(current_parent = prev_parent))
 147
 148 /** special symbol used for anonymous entities. */
 149 static const symbol_t *sym_anonymous = NULL;
 150
 151 /* symbols for Microsoft extended-decl-modifier */
 152 static const symbol_t *sym_align      = NULL;
 153 static const symbol_t *sym_allocate   = NULL;
 154 static const symbol_t *sym_dllimport  = NULL;
 155 static const symbol_t *sym_dllexport  = NULL;
 156 static const symbol_t *sym_naked      = NULL;
 157 static const symbol_t *sym_noinline   = NULL;
 158 static const symbol_t *sym_noreturn   = NULL;
 159 static const symbol_t *sym_nothrow    = NULL;
 160 static const symbol_t *sym_novtable   = NULL;
 161 static const symbol_t *sym_property   = NULL;
 162 static const symbol_t *sym_get        = NULL;
 163 static const symbol_t *sym_put        = NULL;
 164 static const symbol_t *sym_selectany  = NULL;
 165 static const symbol_t *sym_thread     = NULL;
 166 static const symbol_t *sym_uuid       = NULL;
 167 static const symbol_t *sym_deprecated = NULL;
 168 static const symbol_t *sym_restrict   = NULL;
 169 static const symbol_t *sym_noalias    = NULL;
 170
 171 /** The token anchor set */
 172 static unsigned char token_anchor_set[T_LAST_TOKEN];
 173
 174 /** The current source position. */
 175 #define HERE (&token.source_position)
 176
 177 /** true if we are in GCC mode. */
 178 #define GNU_MODE ((c_mode & _GNUC) || in_gcc_extension)
 179
 180 static type_t *type_valist;
 181
 182 static statement_t *parse_compound_statement(bool inside_expression_statement);
 183 static statement_t *parse_statement(void);
 184
 185 static expression_t *parse_sub_expression(precedence_t);
 186 static expression_t *parse_expression(void);
 187 static type_t       *parse_typename(void);
 188 static void          parse_externals(void);
 189 static void          parse_external(void);
 190
 191 static void parse_compound_type_entries(compound_t *compound_declaration);
 192
 193 typedef enum declarator_flags_t {
 194         DECL_FLAGS_NONE             = 0,
 195         DECL_MAY_BE_ABSTRACT        = 1U << 0,
 196         DECL_CREATE_COMPOUND_MEMBER = 1U << 1,
 197         DECL_IS_PARAMETER           = 1U << 2
 198 } declarator_flags_t;
 199
 200 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
 201                                   declarator_flags_t flags);
 202
 203 static entity_t *record_entity(entity_t *entity, bool is_definition);
 204
 205 static void semantic_comparison(binary_expression_t *expression);
 206
 207 #define STORAGE_CLASSES       \
 208         STORAGE_CLASSES_NO_EXTERN \
 209         case T_extern:
 210
 211 #define STORAGE_CLASSES_NO_EXTERN \
 212         case T_typedef:         \
 213         case T_static:          \
 214         case T_auto:            \
 215         case T_register:        \
 216         case T___thread:
 217
 218 #define TYPE_QUALIFIERS     \
 219         case T_const:           \
 220         case T_restrict:        \
 221         case T_volatile:        \
 222         case T_inline:          \
 223         case T__forceinline:    \
 224         case T___attribute__:
 225
 226 #define COMPLEX_SPECIFIERS  \
 227         case T__Complex:
 228 #define IMAGINARY_SPECIFIERS \
 229         case T__Imaginary:
 230
 231 #define TYPE_SPECIFIERS       \
 232         case T__Bool:             \
 233         case T___builtin_va_list: \
 234         case T___typeof__:        \
 235         case T__declspec:         \
 236         case T_bool:              \
 237         case T_char:              \
 238         case T_double:            \
 239         case T_enum:              \
 240         case T_float:             \
 241         case T_int:               \
 242         case T_long:              \
 243         case T_short:             \
 244         case T_signed:            \
 245         case T_struct:            \
 246         case T_union:             \
 247         case T_unsigned:          \
 248         case T_void:              \
 249         COMPLEX_SPECIFIERS        \
 250         IMAGINARY_SPECIFIERS
 251
 252 #define DECLARATION_START   \
 253         STORAGE_CLASSES         \
 254         TYPE_QUALIFIERS         \
 255         TYPE_SPECIFIERS
 256
 257 #define DECLARATION_START_NO_EXTERN \
 258         STORAGE_CLASSES_NO_EXTERN       \
 259         TYPE_QUALIFIERS                 \
 260         TYPE_SPECIFIERS
 261
 262 #define TYPENAME_START      \
 263         TYPE_QUALIFIERS         \
 264         TYPE_SPECIFIERS
 265
 266 #define EXPRESSION_START           \
 267         case '!':                        \
 268         case '&':                        \
 269         case '(':                        \
 270         case '*':                        \
 271         case '+':                        \
 272         case '-':                        \
 273         case '~':                        \
 274         case T_ANDAND:                   \
 275         case T_CHARACTER_CONSTANT:       \
 276         case T_FLOATINGPOINT:            \
 277         case T_INTEGER:                  \
 278         case T_MINUSMINUS:               \
 279         case T_PLUSPLUS:                 \
 280         case T_STRING_LITERAL:           \
 281         case T_WIDE_CHARACTER_CONSTANT:  \
 282         case T_WIDE_STRING_LITERAL:      \
 283         case T___FUNCDNAME__:            \
 284         case T___FUNCSIG__:              \
 285         case T___FUNCTION__:             \
 286         case T___PRETTY_FUNCTION__:      \
 287         case T___alignof__:              \
 288         case T___builtin_alloca:         \
 289         case T___builtin_classify_type:  \
 290         case T___builtin_constant_p:     \
 291         case T___builtin_expect:         \
 292         case T___builtin_huge_val:       \
 293         case T___builtin_inf:            \
 294         case T___builtin_inff:           \
 295         case T___builtin_infl:           \
 296         case T___builtin_isgreater:      \
 297         case T___builtin_isgreaterequal: \
 298         case T___builtin_isless:         \
 299         case T___builtin_islessequal:    \
 300         case T___builtin_islessgreater:  \
 301         case T___builtin_isunordered:    \
 302         case T___builtin_nan:            \
 303         case T___builtin_nanf:           \
 304         case T___builtin_nanl:           \
 305         case T___builtin_offsetof:       \
 306         case T___builtin_prefetch:       \
 307         case T___builtin_va_arg:         \
 308         case T___builtin_va_end:         \
 309         case T___builtin_va_start:       \
 310         case T___func__:                 \
 311         case T___noop:                   \
 312         case T__assume:                  \
 313         case T_delete:                   \
 314         case T_false:                    \
 315         case T_sizeof:                   \
 316         case T_throw:                    \
 317         case T_true:
 318
 319 /**
 320  * Allocate an AST node with given size and
 321  * initialize all fields with zero.
 322  */
 323 static void *allocate_ast_zero(size_t size)
 324 {
 325         void *res = allocate_ast(size);
 326         memset(res, 0, size);
 327         return res;
 328 }
 329
 330 static size_t get_entity_struct_size(entity_kind_t kind)
 331 {
 332         static const size_t sizes[] = {
 333                 [ENTITY_VARIABLE]        = sizeof(variable_t),
 334                 [ENTITY_PARAMETER]       = sizeof(parameter_t),
 335                 [ENTITY_COMPOUND_MEMBER] = sizeof(compound_member_t),
 336                 [ENTITY_FUNCTION]        = sizeof(function_t),
 337                 [ENTITY_TYPEDEF]         = sizeof(typedef_t),
 338                 [ENTITY_STRUCT]          = sizeof(compound_t),
 339                 [ENTITY_UNION]           = sizeof(compound_t),
 340                 [ENTITY_ENUM]            = sizeof(enum_t),
 341                 [ENTITY_ENUM_VALUE]      = sizeof(enum_value_t),
 342                 [ENTITY_LABEL]           = sizeof(label_t),
 343                 [ENTITY_LOCAL_LABEL]     = sizeof(label_t),
 344                 [ENTITY_NAMESPACE]       = sizeof(namespace_t)
 345         };
 346         assert(kind < sizeof(sizes) / sizeof(sizes[0]));
 347         assert(sizes[kind] != 0);
 348         return sizes[kind];
 349 }
 350
 351 static entity_t *allocate_entity_zero(entity_kind_t kind)
 352 {
 353         size_t    size   = get_entity_struct_size(kind);
 354         entity_t *entity = allocate_ast_zero(size);
 355         entity->kind     = kind;
 356         return entity;
 357 }
 358
 359 /**
 360  * Returns the size of a statement node.
 361  *
 362  * @param kind  the statement kind
 363  */
 364 static size_t get_statement_struct_size(statement_kind_t kind)
 365 {
 366         static const size_t sizes[] = {
 367                 [STATEMENT_INVALID]     = sizeof(invalid_statement_t),
 368                 [STATEMENT_EMPTY]       = sizeof(empty_statement_t),
 369                 [STATEMENT_COMPOUND]    = sizeof(compound_statement_t),
 370                 [STATEMENT_RETURN]      = sizeof(return_statement_t),
 371                 [STATEMENT_DECLARATION] = sizeof(declaration_statement_t),
 372                 [STATEMENT_LOCAL_LABEL] = sizeof(local_label_statement_t),
 373                 [STATEMENT_IF]          = sizeof(if_statement_t),
 374                 [STATEMENT_SWITCH]      = sizeof(switch_statement_t),
 375                 [STATEMENT_EXPRESSION]  = sizeof(expression_statement_t),
 376                 [STATEMENT_CONTINUE]    = sizeof(statement_base_t),
 377                 [STATEMENT_BREAK]       = sizeof(statement_base_t),
 378                 [STATEMENT_GOTO]        = sizeof(goto_statement_t),
 379                 [STATEMENT_LABEL]       = sizeof(label_statement_t),
 380                 [STATEMENT_CASE_LABEL]  = sizeof(case_label_statement_t),
 381                 [STATEMENT_WHILE]       = sizeof(while_statement_t),
 382                 [STATEMENT_DO_WHILE]    = sizeof(do_while_statement_t),
 383                 [STATEMENT_FOR]         = sizeof(for_statement_t),
 384                 [STATEMENT_ASM]         = sizeof(asm_statement_t),
 385                 [STATEMENT_MS_TRY]      = sizeof(ms_try_statement_t),
 386                 [STATEMENT_LEAVE]       = sizeof(leave_statement_t)
 387         };
 388         assert(kind < sizeof(sizes) / sizeof(sizes[0]));
 389         assert(sizes[kind] != 0);
 390         return sizes[kind];
 391 }
 392
 393 /**
 394  * Returns the size of an expression node.
 395  *
 396  * @param kind  the expression kind
 397  */
 398 static size_t get_expression_struct_size(expression_kind_t kind)
 399 {
 400         static const size_t sizes[] = {
 401                 [EXPR_INVALID]                 = sizeof(expression_base_t),
 402                 [EXPR_REFERENCE]               = sizeof(reference_expression_t),
 403                 [EXPR_REFERENCE_ENUM_VALUE]    = sizeof(reference_expression_t),
 404                 [EXPR_CONST]                   = sizeof(const_expression_t),
 405                 [EXPR_CHARACTER_CONSTANT]      = sizeof(const_expression_t),
 406                 [EXPR_WIDE_CHARACTER_CONSTANT] = sizeof(const_expression_t),
 407                 [EXPR_STRING_LITERAL]          = sizeof(string_literal_expression_t),
 408                 [EXPR_WIDE_STRING_LITERAL]     = sizeof(wide_string_literal_expression_t),
 409                 [EXPR_COMPOUND_LITERAL]        = sizeof(compound_literal_expression_t),
 410                 [EXPR_CALL]                    = sizeof(call_expression_t),
 411                 [EXPR_UNARY_FIRST]             = sizeof(unary_expression_t),
 412                 [EXPR_BINARY_FIRST]            = sizeof(binary_expression_t),
 413                 [EXPR_CONDITIONAL]             = sizeof(conditional_expression_t),
 414                 [EXPR_SELECT]                  = sizeof(select_expression_t),
 415                 [EXPR_ARRAY_ACCESS]            = sizeof(array_access_expression_t),
 416                 [EXPR_SIZEOF]                  = sizeof(typeprop_expression_t),
 417                 [EXPR_ALIGNOF]                 = sizeof(typeprop_expression_t),
 418                 [EXPR_CLASSIFY_TYPE]           = sizeof(classify_type_expression_t),
 419                 [EXPR_FUNCNAME]                = sizeof(funcname_expression_t),
 420                 [EXPR_BUILTIN_SYMBOL]          = sizeof(builtin_symbol_expression_t),
 421                 [EXPR_BUILTIN_CONSTANT_P]      = sizeof(builtin_constant_expression_t),
 422                 [EXPR_BUILTIN_PREFETCH]        = sizeof(builtin_prefetch_expression_t),
 423                 [EXPR_OFFSETOF]                = sizeof(offsetof_expression_t),
 424                 [EXPR_VA_START]                = sizeof(va_start_expression_t),
 425                 [EXPR_VA_ARG]                  = sizeof(va_arg_expression_t),
 426                 [EXPR_STATEMENT]               = sizeof(statement_expression_t),
 427                 [EXPR_LABEL_ADDRESS]           = sizeof(label_address_expression_t),
 428         };
 429         if (kind >= EXPR_UNARY_FIRST && kind <= EXPR_UNARY_LAST) {
 430                 return sizes[EXPR_UNARY_FIRST];
 431         }
 432         if (kind >= EXPR_BINARY_FIRST && kind <= EXPR_BINARY_LAST) {
 433                 return sizes[EXPR_BINARY_FIRST];
 434         }
 435         assert(kind < sizeof(sizes) / sizeof(sizes[0]));
 436         assert(sizes[kind] != 0);
 437         return sizes[kind];
 438 }
 439
 440 /**
 441  * Allocate a statement node of given kind and initialize all
 442  * fields with zero.
 443  */
 444 static statement_t *allocate_statement_zero(statement_kind_t kind)
 445 {
 446         size_t       size = get_statement_struct_size(kind);
 447         statement_t *res  = allocate_ast_zero(size);
 448
 449         res->base.kind            = kind;
 450         res->base.parent          = current_parent;
 451         res->base.source_position = token.source_position;
 452         return res;
 453 }
 454
 455 /**
 456  * Allocate an expression node of given kind and initialize all
 457  * fields with zero.
 458  */
 459 static expression_t *allocate_expression_zero(expression_kind_t kind)
 460 {
 461         size_t        size = get_expression_struct_size(kind);
 462         expression_t *res  = allocate_ast_zero(size);
 463
 464         res->base.kind            = kind;
 465         res->base.type            = type_error_type;
 466         res->base.source_position = token.source_position;
 467         return res;
 468 }
 469
 470 /**
 471  * Creates a new invalid expression.
 472  */
 473 static expression_t *create_invalid_expression(void)
 474 {
 475         return allocate_expression_zero(EXPR_INVALID);
 476 }
 477
 478 /**
 479  * Creates a new invalid statement.
 480  */
 481 static statement_t *create_invalid_statement(void)
 482 {
 483         return allocate_statement_zero(STATEMENT_INVALID);
 484 }
 485
 486 /**
 487  * Allocate a new empty statement.
 488  */
 489 static statement_t *create_empty_statement(void)
 490 {
 491         return allocate_statement_zero(STATEMENT_EMPTY);
 492 }
 493
 494 /**
 495  * Returns the size of a type node.
 496  *
 497  * @param kind  the type kind
 498  */
 499 static size_t get_type_struct_size(type_kind_t kind)
 500 {
 501         static const size_t sizes[] = {
 502                 [TYPE_ATOMIC]          = sizeof(atomic_type_t),
 503                 [TYPE_COMPLEX]         = sizeof(complex_type_t),
 504                 [TYPE_IMAGINARY]       = sizeof(imaginary_type_t),
 505                 [TYPE_BITFIELD]        = sizeof(bitfield_type_t),
 506                 [TYPE_COMPOUND_STRUCT] = sizeof(compound_type_t),
 507                 [TYPE_COMPOUND_UNION]  = sizeof(compound_type_t),
 508                 [TYPE_ENUM]            = sizeof(enum_type_t),
 509                 [TYPE_FUNCTION]        = sizeof(function_type_t),
 510                 [TYPE_POINTER]         = sizeof(pointer_type_t),
 511                 [TYPE_ARRAY]           = sizeof(array_type_t),
 512                 [TYPE_BUILTIN]         = sizeof(builtin_type_t),
 513                 [TYPE_TYPEDEF]         = sizeof(typedef_type_t),
 514                 [TYPE_TYPEOF]          = sizeof(typeof_type_t),
 515         };
 516         assert(sizeof(sizes) / sizeof(sizes[0]) == (int) TYPE_TYPEOF + 1);
 517         assert(kind <= TYPE_TYPEOF);
 518         assert(sizes[kind] != 0);
 519         return sizes[kind];
 520 }
 521
 522 /**
 523  * Allocate a type node of given kind and initialize all
 524  * fields with zero.
 525  *
 526  * @param kind             type kind to allocate
 527  */
 528 static type_t *allocate_type_zero(type_kind_t kind)
 529 {
 530         size_t  size = get_type_struct_size(kind);
 531         type_t *res  = obstack_alloc(type_obst, size);
 532         memset(res, 0, size);
 533         res->base.kind = kind;
 534
 535         return res;
 536 }
 537
 538 /**
 539  * Returns the size of an initializer node.
 540  *
 541  * @param kind  the initializer kind
 542  */
 543 static size_t get_initializer_size(initializer_kind_t kind)
 544 {
 545         static const size_t sizes[] = {
 546                 [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
 547                 [INITIALIZER_STRING]      = sizeof(initializer_string_t),
 548                 [INITIALIZER_WIDE_STRING] = sizeof(initializer_wide_string_t),
 549                 [INITIALIZER_LIST]        = sizeof(initializer_list_t),
 550                 [INITIALIZER_DESIGNATOR]  = sizeof(initializer_designator_t)
 551         };
 552         assert(kind < sizeof(sizes) / sizeof(*sizes));
 553         assert(sizes[kind] != 0);
 554         return sizes[kind];
 555 }
 556
 557 /**
 558  * Allocate an initializer node of given kind and initialize all
 559  * fields with zero.
 560  */
 561 static initializer_t *allocate_initializer_zero(initializer_kind_t kind)
 562 {
 563         initializer_t *result = allocate_ast_zero(get_initializer_size(kind));
 564         result->kind          = kind;
 565
 566         return result;
 567 }
 568
 569 /**
 570  * Free a type from the type obstack.
 571  */
 572 static void free_type(void *type)
 573 {
 574         obstack_free(type_obst, type);
 575 }
 576
 577 /**
 578  * Returns the index of the top element of the environment stack.
 579  */
 580 static size_t environment_top(void)
 581 {
 582         return ARR_LEN(environment_stack);
 583 }
 584
 585 /**
 586  * Returns the index of the top element of the global label stack.
 587  */
 588 static size_t label_top(void)
 589 {
 590         return ARR_LEN(label_stack);
 591 }
 592
 593 /**
 594  * Return the next token.
 595  */
 596 static inline void next_token(void)
 597 {
 598         token                              = lookahead_buffer[lookahead_bufpos];
 599         lookahead_buffer[lookahead_bufpos] = lexer_token;
 600         lexer_next_token();
 601
 602         lookahead_bufpos = (lookahead_bufpos+1) % MAX_LOOKAHEAD;
 603
 604 #ifdef PRINT_TOKENS
 605         print_token(stderr, &token);
 606         fprintf(stderr, "\n");
 607 #endif
 608 }
 609
 610 /**
 611  * Return the next token with a given lookahead.
 612  */
 613 static inline const token_t *look_ahead(int num)
 614 {
 615         assert(num > 0 && num <= MAX_LOOKAHEAD);
 616         int pos = (lookahead_bufpos+num-1) % MAX_LOOKAHEAD;
 617         return &lookahead_buffer[pos];
 618 }
 619
 620 /**
 621  * Adds a token to the token anchor set (a multi-set).
 622  */
 623 static void add_anchor_token(int token_type)
 624 {
 625         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 626         ++token_anchor_set[token_type];
 627 }
 628
 629 static int save_and_reset_anchor_state(int token_type)
 630 {
 631         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 632         int count = token_anchor_set[token_type];
 633         token_anchor_set[token_type] = 0;
 634         return count;
 635 }
 636
 637 static void restore_anchor_state(int token_type, int count)
 638 {
 639         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 640         token_anchor_set[token_type] = count;
 641 }
 642
 643 /**
 644  * Remove a token from the token anchor set (a multi-set).
 645  */
 646 static void rem_anchor_token(int token_type)
 647 {
 648         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 649         assert(token_anchor_set[token_type] != 0);
 650         --token_anchor_set[token_type];
 651 }
 652
 653 static bool at_anchor(void)
 654 {
 655         if (token.type < 0)
 656                 return false;
 657         return token_anchor_set[token.type];
 658 }
 659
 660 /**
 661  * Eat tokens until a matching token is found.
 662  */
 663 static void eat_until_matching_token(int type)
 664 {
 665         int end_token;
 666         switch (type) {
 667                 case '(': end_token = ')';  break;
 668                 case '{': end_token = '}';  break;
 669                 case '[': end_token = ']';  break;
 670                 default:  end_token = type; break;
 671         }
 672
 673         unsigned parenthesis_count = 0;
 674         unsigned brace_count       = 0;
 675         unsigned bracket_count     = 0;
 676         while (token.type        != end_token ||
 677                parenthesis_count != 0         ||
 678                brace_count       != 0         ||
 679                bracket_count     != 0) {
 680                 switch (token.type) {
 681                 case T_EOF: return;
 682                 case '(': ++parenthesis_count; break;
 683                 case '{': ++brace_count;       break;
 684                 case '[': ++bracket_count;     break;
 685
 686                 case ')':
 687                         if (parenthesis_count > 0)
 688                                 --parenthesis_count;
 689                         goto check_stop;
 690
 691                 case '}':
 692                         if (brace_count > 0)
 693                                 --brace_count;
 694                         goto check_stop;
 695
 696                 case ']':
 697                         if (bracket_count > 0)
 698                                 --bracket_count;
 699 check_stop:
 700                         if (token.type        == end_token &&
 701                             parenthesis_count == 0         &&
 702                             brace_count       == 0         &&
 703                             bracket_count     == 0)
 704                                 return;
 705                         break;
 706
 707                 default:
 708                         break;
 709                 }
 710                 next_token();
 711         }
 712 }
 713
 714 /**
 715  * Eat input tokens until an anchor is found.
 716  */
 717 static void eat_until_anchor(void)
 718 {
 719         while (token_anchor_set[token.type] == 0) {
 720                 if (token.type == '(' || token.type == '{' || token.type == '[')
 721                         eat_until_matching_token(token.type);
 722                 next_token();
 723         }
 724 }
 725
 726 static void eat_block(void)
 727 {
 728         eat_until_matching_token('{');
 729         if (token.type == '}')
 730                 next_token();
 731 }
 732
 733 #define eat(token_type)  do { assert(token.type == (token_type)); next_token(); } while (0)
 734
 735 /**
 736  * Report a parse error because an expected token was not found.
 737  */
 738 static
 739 #if defined __GNUC__ && __GNUC__ >= 4
 740 __attribute__((sentinel))
 741 #endif
 742 void parse_error_expected(const char *message, ...)
 743 {
 744         if (message != NULL) {
 745                 errorf(HERE, "%s", message);
 746         }
 747         va_list ap;
 748         va_start(ap, message);
 749         errorf(HERE, "got '%K', expected %#k", &token, &ap, ", ");
 750         va_end(ap);
 751 }
 752
 753 /**
 754  * Report an incompatible type.
 755  */
 756 static void type_error_incompatible(const char *msg,
 757                 const source_position_t *source_position, type_t *type1, type_t *type2)
 758 {
 759         errorf(source_position, "%s, incompatible types: '%T' - '%T'",
 760                msg, type1, type2);
 761 }
 762
 763 /**
 764  * Expect the the current token is the expected token.
 765  * If not, generate an error, eat the current statement,
 766  * and goto the end_error label.
 767  */
 768 #define expect(expected)                                  \
 769         do {                                                  \
 770                 if (UNLIKELY(token.type != (expected))) {         \
 771                         parse_error_expected(NULL, (expected), NULL); \
 772                         add_anchor_token(expected);                   \
 773                         eat_until_anchor();                           \
 774                         if (token.type == expected)                   \
 775                                 next_token();                             \
 776                         rem_anchor_token(expected);                   \
 777                         goto end_error;                               \
 778                 }                                                 \
 779                 next_token();                                     \
 780         } while (0)
 781
 782 static scope_t *scope_push(scope_t *new_scope)
 783 {
 784         if (current_scope != NULL) {
 785                 new_scope->depth = current_scope->depth + 1;
 786         }
 787
 788         scope_t *old_scope = current_scope;
 789         current_scope      = new_scope;
 790         return old_scope;
 791 }
 792
 793 static void scope_pop(scope_t *old_scope)
 794 {
 795         current_scope = old_scope;
 796 }
 797
 798 /**
 799  * Search an entity by its symbol in a given namespace.
 800  */
 801 static entity_t *get_entity(const symbol_t *const symbol,
 802                             namespace_tag_t namespc)
 803 {
 804         entity_t *entity = symbol->entity;
 805         for (; entity != NULL; entity = entity->base.symbol_next) {
 806                 if (entity->base.namespc == namespc)
 807                         return entity;
 808         }
 809
 810         return NULL;
 811 }
 812
 813 /**
 814  * pushs an entity on the environment stack and links the corresponding symbol
 815  * it.
 816  */
 817 static void stack_push(stack_entry_t **stack_ptr, entity_t *entity)
 818 {
 819         symbol_t           *symbol  = entity->base.symbol;
 820         entity_namespace_t  namespc = entity->base.namespc;
 821         assert(namespc != NAMESPACE_INVALID);
 822
 823         /* replace/add entity into entity list of the symbol */
 824         entity_t **anchor;
 825         entity_t  *iter;
 826         for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 827                 iter = *anchor;
 828                 if (iter == NULL)
 829                         break;
 830
 831                 /* replace an entry? */
 832                 if (iter->base.namespc == namespc) {
 833                         entity->base.symbol_next = iter->base.symbol_next;
 834                         break;
 835                 }
 836         }
 837         *anchor = entity;
 838
 839         /* remember old declaration */
 840         stack_entry_t entry;
 841         entry.symbol     = symbol;
 842         entry.old_entity = iter;
 843         entry.namespc    = namespc;
 844         ARR_APP1(stack_entry_t, *stack_ptr, entry);
 845 }
 846
 847 /**
 848  * Push an entity on the environment stack.
 849  */
 850 static void environment_push(entity_t *entity)
 851 {
 852         assert(entity->base.source_position.input_name != NULL);
 853         assert(entity->base.parent_scope != NULL);
 854         stack_push(&environment_stack, entity);
 855 }
 856
 857 /**
 858  * Push a declaration on the global label stack.
 859  *
 860  * @param declaration  the declaration
 861  */
 862 static void label_push(entity_t *label)
 863 {
 864         /* we abuse the parameters scope as parent for the labels */
 865         label->base.parent_scope = &current_function->parameters;
 866         stack_push(&label_stack, label);
 867 }
 868
 869 /**
 870  * pops symbols from the environment stack until @p new_top is the top element
 871  */
 872 static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
 873 {
 874         stack_entry_t *stack = *stack_ptr;
 875         size_t         top   = ARR_LEN(stack);
 876         size_t         i;
 877
 878         assert(new_top <= top);
 879         if (new_top == top)
 880                 return;
 881
 882         for (i = top; i > new_top; --i) {
 883                 stack_entry_t *entry = &stack[i - 1];
 884
 885                 entity_t           *old_entity = entry->old_entity;
 886                 symbol_t           *symbol     = entry->symbol;
 887                 entity_namespace_t  namespc    = entry->namespc;
 888
 889                 /* replace with old_entity/remove */
 890                 entity_t **anchor;
 891                 entity_t  *iter;
 892                 for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 893                         iter = *anchor;
 894                         assert(iter != NULL);
 895                         /* replace an entry? */
 896                         if (iter->base.namespc == namespc)
 897                                 break;
 898                 }
 899
 900                 /* restore definition from outer scopes (if there was one) */
 901                 if (old_entity != NULL) {
 902                         old_entity->base.symbol_next = iter->base.symbol_next;
 903                         *anchor                      = old_entity;
 904                 } else {
 905                         /* remove entry from list */
 906                         *anchor = iter->base.symbol_next;
 907                 }
 908         }
 909
 910         ARR_SHRINKLEN(*stack_ptr, (int) new_top);
 911 }
 912
 913 /**
 914  * Pop all entries from the environment stack until the new_top
 915  * is reached.
 916  *
 917  * @param new_top  the new stack top
 918  */
 919 static void environment_pop_to(size_t new_top)
 920 {
 921         stack_pop_to(&environment_stack, new_top);
 922 }
 923
 924 /**
 925  * Pop all entries from the global label stack until the new_top
 926  * is reached.
 927  *
 928  * @param new_top  the new stack top
 929  */
 930 static void label_pop_to(size_t new_top)
 931 {
 932         stack_pop_to(&label_stack, new_top);
 933 }
 934
 935 static int get_akind_rank(atomic_type_kind_t akind)
 936 {
 937         return (int) akind;
 938 }
 939
 940 static int get_rank(const type_t *type)
 941 {
 942         assert(!is_typeref(type));
 943         /* The C-standard allows promoting enums to int or unsigned int (see § 7.2.2
 944          * and esp. footnote 108). However we can't fold constants (yet), so we
 945          * can't decide whether unsigned int is possible, while int always works.
 946          * (unsigned int would be preferable when possible... for stuff like
 947          *  struct { enum { ... } bla : 4; } ) */
 948         if (type->kind == TYPE_ENUM)
 949                 return get_akind_rank(ATOMIC_TYPE_INT);
 950
 951         assert(type->kind == TYPE_ATOMIC);
 952         return get_akind_rank(type->atomic.akind);
 953 }
 954
 955 static type_t *promote_integer(type_t *type)
 956 {
 957         if (type->kind == TYPE_BITFIELD)
 958                 type = type->bitfield.base_type;
 959
 960         if (get_rank(type) < get_akind_rank(ATOMIC_TYPE_INT))
 961                 type = type_int;
 962
 963         return type;
 964 }
 965
 966 /**
 967  * Create a cast expression.
 968  *
 969  * @param expression  the expression to cast
 970  * @param dest_type   the destination type
 971  */
 972 static expression_t *create_cast_expression(expression_t *expression,
 973                                             type_t *dest_type)
 974 {
 975         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST_IMPLICIT);
 976
 977         cast->unary.value = expression;
 978         cast->base.type   = dest_type;
 979
 980         return cast;
 981 }
 982
 983 /**
 984  * Check if a given expression represents the 0 pointer constant.
 985  */
 986 static bool is_null_pointer_constant(const expression_t *expression)
 987 {
 988         /* skip void* cast */
 989         if (expression->kind == EXPR_UNARY_CAST
 990                         || expression->kind == EXPR_UNARY_CAST_IMPLICIT) {
 991                 expression = expression->unary.value;
 992         }
 993
 994         /* TODO: not correct yet, should be any constant integer expression
 995          * which evaluates to 0 */
 996         if (expression->kind != EXPR_CONST)
 997                 return false;
 998
 999         type_t *const type = skip_typeref(expression->base.type);
1000         if (!is_type_integer(type))
1001                 return false;
1002
1003         return expression->conste.v.int_value == 0;
1004 }
1005
1006 /**
1007  * Create an implicit cast expression.
1008  *
1009  * @param expression  the expression to cast
1010  * @param dest_type   the destination type
1011  */
1012 static expression_t *create_implicit_cast(expression_t *expression,
1013                                           type_t *dest_type)
1014 {
1015         type_t *const source_type = expression->base.type;
1016
1017         if (source_type == dest_type)
1018                 return expression;
1019
1020         return create_cast_expression(expression, dest_type);
1021 }
1022
1023 typedef enum assign_error_t {
1024         ASSIGN_SUCCESS,
1025         ASSIGN_ERROR_INCOMPATIBLE,
1026         ASSIGN_ERROR_POINTER_QUALIFIER_MISSING,
1027         ASSIGN_WARNING_POINTER_INCOMPATIBLE,
1028         ASSIGN_WARNING_POINTER_FROM_INT,
1029         ASSIGN_WARNING_INT_FROM_POINTER
1030 } assign_error_t;
1031
1032 static void report_assign_error(assign_error_t error, type_t *orig_type_left,
1033                                 const expression_t *const right,
1034                                 const char *context,
1035                                 const source_position_t *source_position)
1036 {
1037         type_t *const orig_type_right = right->base.type;
1038         type_t *const type_left       = skip_typeref(orig_type_left);
1039         type_t *const type_right      = skip_typeref(orig_type_right);
1040
1041         switch (error) {
1042         case ASSIGN_SUCCESS:
1043                 return;
1044         case ASSIGN_ERROR_INCOMPATIBLE:
1045                 errorf(source_position,
1046                        "destination type '%T' in %s is incompatible with type '%T'",
1047                        orig_type_left, context, orig_type_right);
1048                 return;
1049
1050         case ASSIGN_ERROR_POINTER_QUALIFIER_MISSING: {
1051                 if (warning.other) {
1052                         type_t *points_to_left  = skip_typeref(type_left->pointer.points_to);
1053                         type_t *points_to_right = skip_typeref(type_right->pointer.points_to);
1054
1055                         /* the left type has all qualifiers from the right type */
1056                         unsigned missing_qualifiers
1057                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
1058                         warningf(source_position,
1059                                         "destination type '%T' in %s from type '%T' lacks qualifiers '%Q' in pointer target type",
1060                                         orig_type_left, context, orig_type_right, missing_qualifiers);
1061                 }
1062                 return;
1063         }
1064
1065         case ASSIGN_WARNING_POINTER_INCOMPATIBLE:
1066                 if (warning.other) {
1067                         warningf(source_position,
1068                                         "destination type '%T' in %s is incompatible with '%E' of type '%T'",
1069                                         orig_type_left, context, right, orig_type_right);
1070                 }
1071                 return;
1072
1073         case ASSIGN_WARNING_POINTER_FROM_INT:
1074                 if (warning.other) {
1075                         warningf(source_position,
1076                                         "%s makes pointer '%T' from integer '%T' without a cast",
1077                                         context, orig_type_left, orig_type_right);
1078                 }
1079                 return;
1080
1081         case ASSIGN_WARNING_INT_FROM_POINTER:
1082                 if (warning.other) {
1083                         warningf(source_position,
1084                                         "%s makes integer '%T' from pointer '%T' without a cast",
1085                                         context, orig_type_left, orig_type_right);
1086                 }
1087                 return;
1088
1089         default:
1090                 panic("invalid error value");
1091         }
1092 }
1093
1094 /** Implements the rules from § 6.5.16.1 */
1095 static assign_error_t semantic_assign(type_t *orig_type_left,
1096                                       const expression_t *const right)
1097 {
1098         type_t *const orig_type_right = right->base.type;
1099         type_t *const type_left       = skip_typeref(orig_type_left);
1100         type_t *const type_right      = skip_typeref(orig_type_right);
1101
1102         if (is_type_pointer(type_left)) {
1103                 if (is_null_pointer_constant(right)) {
1104                         return ASSIGN_SUCCESS;
1105                 } else if (is_type_pointer(type_right)) {
1106                         type_t *points_to_left
1107                                 = skip_typeref(type_left->pointer.points_to);
1108                         type_t *points_to_right
1109                                 = skip_typeref(type_right->pointer.points_to);
1110                         assign_error_t res = ASSIGN_SUCCESS;
1111
1112                         /* the left type has all qualifiers from the right type */
1113                         unsigned missing_qualifiers
1114                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
1115                         if (missing_qualifiers != 0) {
1116                                 res = ASSIGN_ERROR_POINTER_QUALIFIER_MISSING;
1117                         }
1118
1119                         points_to_left  = get_unqualified_type(points_to_left);
1120                         points_to_right = get_unqualified_type(points_to_right);
1121
1122                         if (is_type_atomic(points_to_left, ATOMIC_TYPE_VOID))
1123                                 return res;
1124
1125                         if (is_type_atomic(points_to_right, ATOMIC_TYPE_VOID)) {
1126                                 /* ISO/IEC 14882:1998(E) §C.1.2:6 */
1127                                 return c_mode & _CXX ? ASSIGN_ERROR_INCOMPATIBLE : res;
1128                         }
1129
1130                         if (!types_compatible(points_to_left, points_to_right)) {
1131                                 return ASSIGN_WARNING_POINTER_INCOMPATIBLE;
1132                         }
1133
1134                         return res;
1135                 } else if (is_type_integer(type_right)) {
1136                         return ASSIGN_WARNING_POINTER_FROM_INT;
1137                 }
1138         } else if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
1139             (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
1140                 && is_type_pointer(type_right))) {
1141                 return ASSIGN_SUCCESS;
1142         } else if ((is_type_compound(type_left)  && is_type_compound(type_right))
1143                         || (is_type_builtin(type_left) && is_type_builtin(type_right))) {
1144                 type_t *const unqual_type_left  = get_unqualified_type(type_left);
1145                 type_t *const unqual_type_right = get_unqualified_type(type_right);
1146                 if (types_compatible(unqual_type_left, unqual_type_right)) {
1147                         return ASSIGN_SUCCESS;
1148                 }
1149         } else if (is_type_integer(type_left) && is_type_pointer(type_right)) {
1150                 return ASSIGN_WARNING_INT_FROM_POINTER;
1151         }
1152
1153         if (!is_type_valid(type_left) || !is_type_valid(type_right))
1154                 return ASSIGN_SUCCESS;
1155
1156         return ASSIGN_ERROR_INCOMPATIBLE;
1157 }
1158
1159 static expression_t *parse_constant_expression(void)
1160 {
1161         expression_t *result = parse_sub_expression(PREC_CONDITIONAL);
1162
1163         if (!is_constant_expression(result)) {
1164                 errorf(&result->base.source_position,
1165                        "expression '%E' is not constant\n", result);
1166         }
1167
1168         return result;
1169 }
1170
1171 static expression_t *parse_assignment_expression(void)
1172 {
1173         return parse_sub_expression(PREC_ASSIGNMENT);
1174 }
1175
1176 static string_t parse_string_literals(void)
1177 {
1178         assert(token.type == T_STRING_LITERAL);
1179         string_t result = token.v.string;
1180
1181         next_token();
1182
1183         while (token.type == T_STRING_LITERAL) {
1184                 result = concat_strings(&result, &token.v.string);
1185                 next_token();
1186         }
1187
1188         return result;
1189 }
1190
1191 static const char *const gnu_attribute_names[GNU_AK_LAST] = {
1192         [GNU_AK_CONST]                  = "const",
1193         [GNU_AK_VOLATILE]               = "volatile",
1194         [GNU_AK_CDECL]                  = "cdecl",
1195         [GNU_AK_STDCALL]                = "stdcall",
1196         [GNU_AK_FASTCALL]               = "fastcall",
1197         [GNU_AK_DEPRECATED]             = "deprecated",
1198         [GNU_AK_NOINLINE]               = "noinline",
1199         [GNU_AK_NORETURN]               = "noreturn",
1200         [GNU_AK_NAKED]                  = "naked",
1201         [GNU_AK_PURE]                   = "pure",
1202         [GNU_AK_ALWAYS_INLINE]          = "always_inline",
1203         [GNU_AK_MALLOC]                 = "malloc",
1204         [GNU_AK_WEAK]                   = "weak",
1205         [GNU_AK_CONSTRUCTOR]            = "constructor",
1206         [GNU_AK_DESTRUCTOR]             = "destructor",
1207         [GNU_AK_NOTHROW]                = "nothrow",
1208         [GNU_AK_TRANSPARENT_UNION]      = "transparent_union",
1209         [GNU_AK_COMMON]                 = "common",
1210         [GNU_AK_NOCOMMON]               = "nocommon",
1211         [GNU_AK_PACKED]                 = "packed",
1212         [GNU_AK_SHARED]                 = "shared",
1213         [GNU_AK_NOTSHARED]              = "notshared",
1214         [GNU_AK_USED]                   = "used",
1215         [GNU_AK_UNUSED]                 = "unused",
1216         [GNU_AK_NO_INSTRUMENT_FUNCTION] = "no_instrument_function",
1217         [GNU_AK_WARN_UNUSED_RESULT]     = "warn_unused_result",
1218         [GNU_AK_LONGCALL]               = "longcall",
1219         [GNU_AK_SHORTCALL]              = "shortcall",
1220         [GNU_AK_LONG_CALL]              = "long_call",
1221         [GNU_AK_SHORT_CALL]             = "short_call",
1222         [GNU_AK_FUNCTION_VECTOR]        = "function_vector",
1223         [GNU_AK_INTERRUPT]              = "interrupt",
1224         [GNU_AK_INTERRUPT_HANDLER]      = "interrupt_handler",
1225         [GNU_AK_NMI_HANDLER]            = "nmi_handler",
1226         [GNU_AK_NESTING]                = "nesting",
1227         [GNU_AK_NEAR]                   = "near",
1228         [GNU_AK_FAR]                    = "far",
1229         [GNU_AK_SIGNAL]                 = "signal",
1230         [GNU_AK_EIGTHBIT_DATA]          = "eightbit_data",
1231         [GNU_AK_TINY_DATA]              = "tiny_data",
1232         [GNU_AK_SAVEALL]                = "saveall",
1233         [GNU_AK_FLATTEN]                = "flatten",
1234         [GNU_AK_SSEREGPARM]             = "sseregparm",
1235         [GNU_AK_EXTERNALLY_VISIBLE]     = "externally_visible",
1236         [GNU_AK_RETURN_TWICE]           = "return_twice",
1237         [GNU_AK_MAY_ALIAS]              = "may_alias",
1238         [GNU_AK_MS_STRUCT]              = "ms_struct",
1239         [GNU_AK_GCC_STRUCT]             = "gcc_struct",
1240         [GNU_AK_DLLIMPORT]              = "dllimport",
1241         [GNU_AK_DLLEXPORT]              = "dllexport",
1242         [GNU_AK_ALIGNED]                = "aligned",
1243         [GNU_AK_ALIAS]                  = "alias",
1244         [GNU_AK_SECTION]                = "section",
1245         [GNU_AK_FORMAT]                 = "format",
1246         [GNU_AK_FORMAT_ARG]             = "format_arg",
1247         [GNU_AK_WEAKREF]                = "weakref",
1248         [GNU_AK_NONNULL]                = "nonnull",
1249         [GNU_AK_TLS_MODEL]              = "tls_model",
1250         [GNU_AK_VISIBILITY]             = "visibility",
1251         [GNU_AK_REGPARM]                = "regparm",
1252         [GNU_AK_MODE]                   = "mode",
1253         [GNU_AK_MODEL]                  = "model",
1254         [GNU_AK_TRAP_EXIT]              = "trap_exit",
1255         [GNU_AK_SP_SWITCH]              = "sp_switch",
1256         [GNU_AK_SENTINEL]               = "sentinel"
1257 };
1258
1259 /**
1260  * compare two string, ignoring double underscores on the second.
1261  */
1262 static int strcmp_underscore(const char *s1, const char *s2)
1263 {
1264         if (s2[0] == '_' && s2[1] == '_') {
1265                 size_t len2 = strlen(s2);
1266                 size_t len1 = strlen(s1);
1267                 if (len1 == len2-4 && s2[len2-2] == '_' && s2[len2-1] == '_') {
1268                         return strncmp(s1, s2+2, len2-4);
1269                 }
1270         }
1271
1272         return strcmp(s1, s2);
1273 }
1274
1275 /**
1276  * Allocate a new gnu temporal attribute.
1277  */
1278 static gnu_attribute_t *allocate_gnu_attribute(gnu_attribute_kind_t kind)
1279 {
1280         gnu_attribute_t *attribute = obstack_alloc(&temp_obst, sizeof(*attribute));
1281         attribute->kind            = kind;
1282         attribute->next            = NULL;
1283         attribute->invalid         = false;
1284         attribute->have_arguments  = false;
1285
1286         return attribute;
1287 }
1288
1289 /**
1290  * parse one constant expression argument.
1291  */
1292 static void parse_gnu_attribute_const_arg(gnu_attribute_t *attribute)
1293 {
1294         expression_t *expression;
1295         add_anchor_token(')');
1296         expression = parse_constant_expression();
1297         rem_anchor_token(')');
1298         expect(')');
1299         attribute->u.argument = fold_constant(expression);
1300         return;
1301 end_error:
1302         attribute->invalid = true;
1303 }
1304
1305 /**
1306  * parse a list of constant expressions arguments.
1307  */
1308 static void parse_gnu_attribute_const_arg_list(gnu_attribute_t *attribute)
1309 {
1310         argument_list_t **list = &attribute->u.arguments;
1311         argument_list_t  *entry;
1312         expression_t     *expression;
1313         add_anchor_token(')');
1314         add_anchor_token(',');
1315         while (true) {
1316                 expression = parse_constant_expression();
1317                 entry = obstack_alloc(&temp_obst, sizeof(entry));
1318                 entry->argument = fold_constant(expression);
1319                 entry->next     = NULL;
1320                 *list = entry;
1321                 list = &entry->next;
1322                 if (token.type != ',')
1323                         break;
1324                 next_token();
1325         }
1326         rem_anchor_token(',');
1327         rem_anchor_token(')');
1328         expect(')');
1329         return;
1330 end_error:
1331         attribute->invalid = true;
1332 }
1333
1334 /**
1335  * parse one string literal argument.
1336  */
1337 static void parse_gnu_attribute_string_arg(gnu_attribute_t *attribute,
1338                                            string_t *string)
1339 {
1340         add_anchor_token('(');
1341         if (token.type != T_STRING_LITERAL) {
1342                 parse_error_expected("while parsing attribute directive",
1343                                      T_STRING_LITERAL, NULL);
1344                 goto end_error;
1345         }
1346         *string = parse_string_literals();
1347         rem_anchor_token('(');
1348         expect(')');
1349         return;
1350 end_error:
1351         attribute->invalid = true;
1352 }
1353
1354 /**
1355  * parse one tls model.
1356  */
1357 static void parse_gnu_attribute_tls_model_arg(gnu_attribute_t *attribute)
1358 {
1359         static const char *const tls_models[] = {
1360                 "global-dynamic",
1361                 "local-dynamic",
1362                 "initial-exec",
1363                 "local-exec"
1364         };
1365         string_t string = { NULL, 0 };
1366         parse_gnu_attribute_string_arg(attribute, &string);
1367         if (string.begin != NULL) {
1368                 for (size_t i = 0; i < 4; ++i) {
1369                         if (strcmp(tls_models[i], string.begin) == 0) {
1370                                 attribute->u.value = i;
1371                                 return;
1372                         }
1373                 }
1374                 errorf(HERE, "'%s' is an unrecognized tls model", string.begin);
1375         }
1376         attribute->invalid = true;
1377 }
1378
1379 /**
1380  * parse one tls model.
1381  */
1382 static void parse_gnu_attribute_visibility_arg(gnu_attribute_t *attribute)
1383 {
1384         static const char *const visibilities[] = {
1385                 "default",
1386                 "protected",
1387                 "hidden",
1388                 "internal"
1389         };
1390         string_t string = { NULL, 0 };
1391         parse_gnu_attribute_string_arg(attribute, &string);
1392         if (string.begin != NULL) {
1393                 for (size_t i = 0; i < 4; ++i) {
1394                         if (strcmp(visibilities[i], string.begin) == 0) {
1395                                 attribute->u.value = i;
1396                                 return;
1397                         }
1398                 }
1399                 errorf(HERE, "'%s' is an unrecognized visibility", string.begin);
1400         }
1401         attribute->invalid = true;
1402 }
1403
1404 /**
1405  * parse one (code) model.
1406  */
1407 static void parse_gnu_attribute_model_arg(gnu_attribute_t *attribute)
1408 {
1409         static const char *const visibilities[] = {
1410                 "small",
1411                 "medium",
1412                 "large"
1413         };
1414         string_t string = { NULL, 0 };
1415         parse_gnu_attribute_string_arg(attribute, &string);
1416         if (string.begin != NULL) {
1417                 for (int i = 0; i < 3; ++i) {
1418                         if (strcmp(visibilities[i], string.begin) == 0) {
1419                                 attribute->u.value = i;
1420                                 return;
1421                         }
1422                 }
1423                 errorf(HERE, "'%s' is an unrecognized model", string.begin);
1424         }
1425         attribute->invalid = true;
1426 }
1427
1428 static void parse_gnu_attribute_mode_arg(gnu_attribute_t *attribute)
1429 {
1430         /* TODO: find out what is allowed here... */
1431
1432         /* at least: byte, word, pointer, list of machine modes
1433          * __XXX___ is interpreted as XXX */
1434         add_anchor_token(')');
1435
1436         if (token.type != T_IDENTIFIER) {
1437                 expect(T_IDENTIFIER);
1438         }
1439
1440         /* This isn't really correct, the backend should provide a list of machine
1441          * specific modes (according to gcc philosophy that is...) */
1442         const char *symbol_str = token.v.symbol->string;
1443         if (strcmp_underscore("QI",   symbol_str) == 0 ||
1444             strcmp_underscore("byte", symbol_str) == 0) {
1445                 attribute->u.akind = ATOMIC_TYPE_CHAR;
1446         } else if (strcmp_underscore("HI", symbol_str) == 0) {
1447                 attribute->u.akind = ATOMIC_TYPE_SHORT;
1448         } else if (strcmp_underscore("SI",      symbol_str) == 0
1449                 || strcmp_underscore("word",    symbol_str) == 0
1450                 || strcmp_underscore("pointer", symbol_str) == 0) {
1451                 attribute->u.akind = ATOMIC_TYPE_INT;
1452         } else if (strcmp_underscore("DI", symbol_str) == 0) {
1453                 attribute->u.akind = ATOMIC_TYPE_LONGLONG;
1454         } else {
1455                 if (warning.other)
1456                         warningf(HERE, "ignoring unknown mode '%s'", symbol_str);
1457                 attribute->invalid = true;
1458         }
1459         next_token();
1460
1461         rem_anchor_token(')');
1462         expect(')');
1463         return;
1464 end_error:
1465         attribute->invalid = true;
1466 }
1467
1468 /**
1469  * parse one interrupt argument.
1470  */
1471 static void parse_gnu_attribute_interrupt_arg(gnu_attribute_t *attribute)
1472 {
1473         static const char *const interrupts[] = {
1474                 "IRQ",
1475                 "FIQ",
1476                 "SWI",
1477                 "ABORT",
1478                 "UNDEF"
1479         };
1480         string_t string = { NULL, 0 };
1481         parse_gnu_attribute_string_arg(attribute, &string);
1482         if (string.begin != NULL) {
1483                 for (size_t i = 0; i < 5; ++i) {
1484                         if (strcmp(interrupts[i], string.begin) == 0) {
1485                                 attribute->u.value = i;
1486                                 return;
1487                         }
1488                 }
1489                 errorf(HERE, "'%s' is not an interrupt", string.begin);
1490         }
1491         attribute->invalid = true;
1492 }
1493
1494 /**
1495  * parse ( identifier, const expression, const expression )
1496  */
1497 static void parse_gnu_attribute_format_args(gnu_attribute_t *attribute)
1498 {
1499         static const char *const format_names[] = {
1500                 "printf",
1501                 "scanf",
1502                 "strftime",
1503                 "strfmon"
1504         };
1505         int i;
1506
1507         if (token.type != T_IDENTIFIER) {
1508                 parse_error_expected("while parsing format attribute directive", T_IDENTIFIER, NULL);
1509                 goto end_error;
1510         }
1511         const char *name = token.v.symbol->string;
1512         for (i = 0; i < 4; ++i) {
1513                 if (strcmp_underscore(format_names[i], name) == 0)
1514                         break;
1515         }
1516         if (i >= 4) {
1517                 if (warning.attribute)
1518                         warningf(HERE, "'%s' is an unrecognized format function type", name);
1519         }
1520         next_token();
1521
1522         expect(',');
1523         add_anchor_token(')');
1524         add_anchor_token(',');
1525         parse_constant_expression();
1526         rem_anchor_token(',');
1527         rem_anchor_token(')');
1528
1529         expect(',');
1530         add_anchor_token(')');
1531         parse_constant_expression();
1532         rem_anchor_token(')');
1533         expect(')');
1534         return;
1535 end_error:
1536         attribute->u.value = true;
1537 }
1538
1539 static void check_no_argument(gnu_attribute_t *attribute, const char *name)
1540 {
1541         if (!attribute->have_arguments)
1542                 return;
1543
1544         /* should have no arguments */
1545         errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1546         eat_until_matching_token('(');
1547         /* we have already consumed '(', so we stop before ')', eat it */
1548         eat(')');
1549         attribute->invalid = true;
1550 }
1551
1552 /**
1553  * Parse one GNU attribute.
1554  *
1555  * Note that attribute names can be specified WITH or WITHOUT
1556  * double underscores, ie const or __const__.
1557  *
1558  * The following attributes are parsed without arguments
1559  *  const
1560  *  volatile
1561  *  cdecl
1562  *  stdcall
1563  *  fastcall
1564  *  deprecated
1565  *  noinline
1566  *  noreturn
1567  *  naked
1568  *  pure
1569  *  always_inline
1570  *  malloc
1571  *  weak
1572  *  constructor
1573  *  destructor
1574  *  nothrow
1575  *  transparent_union
1576  *  common
1577  *  nocommon
1578  *  packed
1579  *  shared
1580  *  notshared
1581  *  used
1582  *  unused
1583  *  no_instrument_function
1584  *  warn_unused_result
1585  *  longcall
1586  *  shortcall
1587  *  long_call
1588  *  short_call
1589  *  function_vector
1590  *  interrupt_handler
1591  *  nmi_handler
1592  *  nesting
1593  *  near
1594  *  far
1595  *  signal
1596  *  eightbit_data
1597  *  tiny_data
1598  *  saveall
1599  *  flatten
1600  *  sseregparm
1601  *  externally_visible
1602  *  return_twice
1603  *  may_alias
1604  *  ms_struct
1605  *  gcc_struct
1606  *  dllimport
1607  *  dllexport
1608  *
1609  * The following attributes are parsed with arguments
1610  *  aligned( const expression )
1611  *  alias( string literal )
1612  *  section( string literal )
1613  *  format( identifier, const expression, const expression )
1614  *  format_arg( const expression )
1615  *  tls_model( string literal )
1616  *  visibility( string literal )
1617  *  regparm( const expression )
1618  *  model( string leteral )
1619  *  trap_exit( const expression )
1620  *  sp_switch( string literal )
1621  *
1622  * The following attributes might have arguments
1623  *  weak_ref( string literal )
1624  *  non_null( const expression // ',' )
1625  *  interrupt( string literal )
1626  *  sentinel( constant expression )
1627  */
1628 static decl_modifiers_t parse_gnu_attribute(gnu_attribute_t **attributes)
1629 {
1630         gnu_attribute_t *head      = *attributes;
1631         gnu_attribute_t *last      = *attributes;
1632         decl_modifiers_t modifiers = 0;
1633         gnu_attribute_t *attribute;
1634
1635         eat(T___attribute__);
1636         expect('(');
1637         expect('(');
1638
1639         if (token.type != ')') {
1640                 /* find the end of the list */
1641                 if (last != NULL) {
1642                         while (last->next != NULL)
1643                                 last = last->next;
1644                 }
1645
1646                 /* non-empty attribute list */
1647                 while (true) {
1648                         const char *name;
1649                         if (token.type == T_const) {
1650                                 name = "const";
1651                         } else if (token.type == T_volatile) {
1652                                 name = "volatile";
1653                         } else if (token.type == T_cdecl) {
1654                                 /* __attribute__((cdecl)), WITH ms mode */
1655                                 name = "cdecl";
1656                         } else if (token.type == T_IDENTIFIER) {
1657                                 const symbol_t *sym = token.v.symbol;
1658                                 name = sym->string;
1659                         } else {
1660                                 parse_error_expected("while parsing GNU attribute", T_IDENTIFIER, NULL);
1661                                 break;
1662                         }
1663
1664                         next_token();
1665
1666                         int i;
1667                         for (i = 0; i < GNU_AK_LAST; ++i) {
1668                                 if (strcmp_underscore(gnu_attribute_names[i], name) == 0)
1669                                         break;
1670                         }
1671                         gnu_attribute_kind_t kind = (gnu_attribute_kind_t)i;
1672
1673                         attribute = NULL;
1674                         if (kind == GNU_AK_LAST) {
1675                                 if (warning.attribute)
1676                                         warningf(HERE, "'%s' attribute directive ignored", name);
1677
1678                                 /* skip possible arguments */
1679                                 if (token.type == '(') {
1680                                         eat_until_matching_token(')');
1681                                 }
1682                         } else {
1683                                 /* check for arguments */
1684                                 attribute = allocate_gnu_attribute(kind);
1685                                 if (token.type == '(') {
1686                                         next_token();
1687                                         if (token.type == ')') {
1688                                                 /* empty args are allowed */
1689                                                 next_token();
1690                                         } else
1691                                                 attribute->have_arguments = true;
1692                                 }
1693
1694                                 switch (kind) {
1695                                 case GNU_AK_VOLATILE:
1696                                 case GNU_AK_NAKED:
1697                                 case GNU_AK_MALLOC:
1698                                 case GNU_AK_WEAK:
1699                                 case GNU_AK_COMMON:
1700                                 case GNU_AK_NOCOMMON:
1701                                 case GNU_AK_SHARED:
1702                                 case GNU_AK_NOTSHARED:
1703                                 case GNU_AK_NO_INSTRUMENT_FUNCTION:
1704                                 case GNU_AK_WARN_UNUSED_RESULT:
1705                                 case GNU_AK_LONGCALL:
1706                                 case GNU_AK_SHORTCALL:
1707                                 case GNU_AK_LONG_CALL:
1708                                 case GNU_AK_SHORT_CALL:
1709                                 case GNU_AK_FUNCTION_VECTOR:
1710                                 case GNU_AK_INTERRUPT_HANDLER:
1711                                 case GNU_AK_NMI_HANDLER:
1712                                 case GNU_AK_NESTING:
1713                                 case GNU_AK_NEAR:
1714                                 case GNU_AK_FAR:
1715                                 case GNU_AK_SIGNAL:
1716                                 case GNU_AK_EIGTHBIT_DATA:
1717                                 case GNU_AK_TINY_DATA:
1718                                 case GNU_AK_SAVEALL:
1719                                 case GNU_AK_FLATTEN:
1720                                 case GNU_AK_SSEREGPARM:
1721                                 case GNU_AK_EXTERNALLY_VISIBLE:
1722                                 case GNU_AK_RETURN_TWICE:
1723                                 case GNU_AK_MAY_ALIAS:
1724                                 case GNU_AK_MS_STRUCT:
1725                                 case GNU_AK_GCC_STRUCT:
1726                                         goto no_arg;
1727
1728                                 case GNU_AK_CDECL:             modifiers |= DM_CDECL;             goto no_arg;
1729                                 case GNU_AK_FASTCALL:          modifiers |= DM_FASTCALL;          goto no_arg;
1730                                 case GNU_AK_STDCALL:           modifiers |= DM_STDCALL;           goto no_arg;
1731                                 case GNU_AK_UNUSED:            modifiers |= DM_UNUSED;            goto no_arg;
1732                                 case GNU_AK_USED:              modifiers |= DM_USED;              goto no_arg;
1733                                 case GNU_AK_PURE:              modifiers |= DM_PURE;              goto no_arg;
1734                                 case GNU_AK_CONST:             modifiers |= DM_CONST;             goto no_arg;
1735                                 case GNU_AK_ALWAYS_INLINE:     modifiers |= DM_FORCEINLINE;       goto no_arg;
1736                                 case GNU_AK_DLLIMPORT:         modifiers |= DM_DLLIMPORT;         goto no_arg;
1737                                 case GNU_AK_DLLEXPORT:         modifiers |= DM_DLLEXPORT;         goto no_arg;
1738                                 case GNU_AK_PACKED:            modifiers |= DM_PACKED;            goto no_arg;
1739                                 case GNU_AK_NOINLINE:          modifiers |= DM_NOINLINE;          goto no_arg;
1740                                 case GNU_AK_NORETURN:          modifiers |= DM_NORETURN;          goto no_arg;
1741                                 case GNU_AK_NOTHROW:           modifiers |= DM_NOTHROW;           goto no_arg;
1742                                 case GNU_AK_TRANSPARENT_UNION: modifiers |= DM_TRANSPARENT_UNION; goto no_arg;
1743                                 case GNU_AK_CONSTRUCTOR:       modifiers |= DM_CONSTRUCTOR;       goto no_arg;
1744                                 case GNU_AK_DESTRUCTOR:        modifiers |= DM_DESTRUCTOR;        goto no_arg;
1745                                 case GNU_AK_DEPRECATED:        modifiers |= DM_DEPRECATED;        goto no_arg;
1746
1747                                 case GNU_AK_ALIGNED:
1748                                         /* __align__ may be used without an argument */
1749                                         if (attribute->have_arguments) {
1750                                                 parse_gnu_attribute_const_arg(attribute);
1751                                         }
1752                                         break;
1753
1754                                 case GNU_AK_FORMAT_ARG:
1755                                 case GNU_AK_REGPARM:
1756                                 case GNU_AK_TRAP_EXIT:
1757                                         if (!attribute->have_arguments) {
1758                                                 /* should have arguments */
1759                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1760                                                 attribute->invalid = true;
1761                                         } else
1762                                                 parse_gnu_attribute_const_arg(attribute);
1763                                         break;
1764                                 case GNU_AK_ALIAS:
1765                                 case GNU_AK_SECTION:
1766                                 case GNU_AK_SP_SWITCH:
1767                                         if (!attribute->have_arguments) {
1768                                                 /* should have arguments */
1769                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1770                                                 attribute->invalid = true;
1771                                         } else
1772                                                 parse_gnu_attribute_string_arg(attribute, &attribute->u.string);
1773                                         break;
1774                                 case GNU_AK_FORMAT:
1775                                         if (!attribute->have_arguments) {
1776                                                 /* should have arguments */
1777                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1778                                                 attribute->invalid = true;
1779                                         } else
1780                                                 parse_gnu_attribute_format_args(attribute);
1781                                         break;
1782                                 case GNU_AK_WEAKREF:
1783                                         /* may have one string argument */
1784                                         if (attribute->have_arguments)
1785                                                 parse_gnu_attribute_string_arg(attribute, &attribute->u.string);
1786                                         break;
1787                                 case GNU_AK_NONNULL:
1788                                         if (attribute->have_arguments)
1789                                                 parse_gnu_attribute_const_arg_list(attribute);
1790                                         break;
1791                                 case GNU_AK_TLS_MODEL:
1792                                         if (!attribute->have_arguments) {
1793                                                 /* should have arguments */
1794                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1795                                         } else
1796                                                 parse_gnu_attribute_tls_model_arg(attribute);
1797                                         break;
1798                                 case GNU_AK_VISIBILITY:
1799                                         if (!attribute->have_arguments) {
1800                                                 /* should have arguments */
1801                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1802                                         } else
1803                                                 parse_gnu_attribute_visibility_arg(attribute);
1804                                         break;
1805                                 case GNU_AK_MODEL:
1806                                         if (!attribute->have_arguments) {
1807                                                 /* should have arguments */
1808                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1809                                         } else {
1810                                                 parse_gnu_attribute_model_arg(attribute);
1811                                         }
1812                                         break;
1813                                 case GNU_AK_MODE:
1814                                         if (!attribute->have_arguments) {
1815                                                 /* should have arguments */
1816                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1817                                         } else {
1818                                                 parse_gnu_attribute_mode_arg(attribute);
1819                                         }
1820                                         break;
1821                                 case GNU_AK_INTERRUPT:
1822                                         /* may have one string argument */
1823                                         if (attribute->have_arguments)
1824                                                 parse_gnu_attribute_interrupt_arg(attribute);
1825                                         break;
1826                                 case GNU_AK_SENTINEL:
1827                                         /* may have one string argument */
1828                                         if (attribute->have_arguments)
1829                                                 parse_gnu_attribute_const_arg(attribute);
1830                                         break;
1831                                 case GNU_AK_LAST:
1832                                         /* already handled */
1833                                         break;
1834
1835 no_arg:
1836                                         check_no_argument(attribute, name);
1837                                 }
1838                         }
1839                         if (attribute != NULL) {
1840                                 if (last != NULL) {
1841                                         last->next = attribute;
1842                                         last       = attribute;
1843                                 } else {
1844                                         head = last = attribute;
1845                                 }
1846                         }
1847
1848                         if (token.type != ',')
1849                                 break;
1850                         next_token();
1851                 }
1852         }
1853         expect(')');
1854         expect(')');
1855 end_error:
1856         *attributes = head;
1857
1858         return modifiers;
1859 }
1860
1861 /**
1862  * Parse GNU attributes.
1863  */
1864 static decl_modifiers_t parse_attributes(gnu_attribute_t **attributes)
1865 {
1866         decl_modifiers_t modifiers = 0;
1867
1868         while (true) {
1869                 switch (token.type) {
1870                 case T___attribute__:
1871                         modifiers |= parse_gnu_attribute(attributes);
1872                         continue;
1873
1874                 case T_asm:
1875                         next_token();
1876                         expect('(');
1877                         if (token.type != T_STRING_LITERAL) {
1878                                 parse_error_expected("while parsing assembler attribute",
1879                                                      T_STRING_LITERAL, NULL);
1880                                 eat_until_matching_token('(');
1881                                 break;
1882                         } else {
1883                                 parse_string_literals();
1884                         }
1885                         expect(')');
1886                         continue;
1887
1888                 case T_cdecl:     modifiers |= DM_CDECL;    break;
1889                 case T__fastcall: modifiers |= DM_FASTCALL; break;
1890                 case T__stdcall:  modifiers |= DM_STDCALL;  break;
1891
1892                 case T___thiscall:
1893                         /* TODO record modifier */
1894                         if (warning.other)
1895                                 warningf(HERE, "Ignoring declaration modifier '%K'", &token);
1896                         break;
1897
1898 end_error:
1899                 default: return modifiers;
1900                 }
1901
1902                 next_token();
1903         }
1904 }
1905
1906 static void mark_vars_read(expression_t *expr, entity_t *lhs_ent);
1907
1908 static entity_t *determine_lhs_ent(expression_t *const expr,
1909                                    entity_t *lhs_ent)
1910 {
1911         switch (expr->kind) {
1912                 case EXPR_REFERENCE: {
1913                         entity_t *const entity = expr->reference.entity;
1914                         /* we should only find variables as lvalues... */
1915                         if (entity->base.kind != ENTITY_VARIABLE
1916                                         && entity->base.kind != ENTITY_PARAMETER)
1917                                 return NULL;
1918
1919                         return entity;
1920                 }
1921
1922                 case EXPR_ARRAY_ACCESS: {
1923                         expression_t *const ref = expr->array_access.array_ref;
1924                         entity_t     *      ent = NULL;
1925                         if (is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1926                                 ent     = determine_lhs_ent(ref, lhs_ent);
1927                                 lhs_ent = ent;
1928                         } else {
1929                                 mark_vars_read(expr->select.compound, lhs_ent);
1930                         }
1931                         mark_vars_read(expr->array_access.index, lhs_ent);
1932                         return ent;
1933                 }
1934
1935                 case EXPR_SELECT: {
1936                         if (is_type_compound(skip_typeref(expr->base.type))) {
1937                                 return determine_lhs_ent(expr->select.compound, lhs_ent);
1938                         } else {
1939                                 mark_vars_read(expr->select.compound, lhs_ent);
1940                                 return NULL;
1941                         }
1942                 }
1943
1944                 case EXPR_UNARY_DEREFERENCE: {
1945                         expression_t *const val = expr->unary.value;
1946                         if (val->kind == EXPR_UNARY_TAKE_ADDRESS) {
1947                                 /* *&x is a NOP */
1948                                 return determine_lhs_ent(val->unary.value, lhs_ent);
1949                         } else {
1950                                 mark_vars_read(val, NULL);
1951                                 return NULL;
1952                         }
1953                 }
1954
1955                 default:
1956                         mark_vars_read(expr, NULL);
1957                         return NULL;
1958         }
1959 }
1960
1961 #define ENT_ANY ((entity_t*)-1)
1962
1963 /**
1964  * Mark declarations, which are read.  This is used to detect variables, which
1965  * are never read.
1966  * Example:
1967  * x = x + 1;
1968  *   x is not marked as "read", because it is only read to calculate its own new
1969  *   value.
1970  *
1971  * x += y; y += x;
1972  *   x and y are not detected as "not read", because multiple variables are
1973  *   involved.
1974  */
1975 static void mark_vars_read(expression_t *const expr, entity_t *lhs_ent)
1976 {
1977         switch (expr->kind) {
1978                 case EXPR_REFERENCE: {
1979                         entity_t *const entity = expr->reference.entity;
1980                         if (entity->kind != ENTITY_VARIABLE
1981                                         && entity->kind != ENTITY_PARAMETER)
1982                                 return;
1983
1984                         if (lhs_ent != entity && lhs_ent != ENT_ANY) {
1985                                 if (entity->kind == ENTITY_VARIABLE) {
1986                                         entity->variable.read = true;
1987                                 } else {
1988                                         entity->parameter.read = true;
1989                                 }
1990                         }
1991                         return;
1992                 }
1993
1994                 case EXPR_CALL:
1995                         // TODO respect pure/const
1996                         mark_vars_read(expr->call.function, NULL);
1997                         for (call_argument_t *arg = expr->call.arguments; arg != NULL; arg = arg->next) {
1998                                 mark_vars_read(arg->expression, NULL);
1999                         }
2000                         return;
2001
2002                 case EXPR_CONDITIONAL:
2003                         // TODO lhs_decl should depend on whether true/false have an effect
2004                         mark_vars_read(expr->conditional.condition, NULL);
2005                         if (expr->conditional.true_expression != NULL)
2006                                 mark_vars_read(expr->conditional.true_expression, lhs_ent);
2007                         mark_vars_read(expr->conditional.false_expression, lhs_ent);
2008                         return;
2009
2010                 case EXPR_SELECT:
2011                         if (lhs_ent == ENT_ANY
2012                                         && !is_type_compound(skip_typeref(expr->base.type)))
2013                                 lhs_ent = NULL;
2014                         mark_vars_read(expr->select.compound, lhs_ent);
2015                         return;
2016
2017                 case EXPR_ARRAY_ACCESS: {
2018                         expression_t *const ref = expr->array_access.array_ref;
2019                         mark_vars_read(ref, lhs_ent);
2020                         lhs_ent = determine_lhs_ent(ref, lhs_ent);
2021                         mark_vars_read(expr->array_access.index, lhs_ent);
2022                         return;
2023                 }
2024
2025                 case EXPR_VA_ARG:
2026                         mark_vars_read(expr->va_arge.ap, lhs_ent);
2027                         return;
2028
2029                 case EXPR_UNARY_CAST:
2030                         /* Special case: Use void cast to mark a variable as "read" */
2031                         if (is_type_atomic(skip_typeref(expr->base.type), ATOMIC_TYPE_VOID))
2032                                 lhs_ent = NULL;
2033                         goto unary;
2034
2035
2036                 case EXPR_UNARY_THROW:
2037                         if (expr->unary.value == NULL)
2038                                 return;
2039                         /* FALLTHROUGH */
2040                 case EXPR_UNARY_DEREFERENCE:
2041                 case EXPR_UNARY_DELETE:
2042                 case EXPR_UNARY_DELETE_ARRAY:
2043                         if (lhs_ent == ENT_ANY)
2044                                 lhs_ent = NULL;
2045                         goto unary;
2046
2047                 case EXPR_UNARY_NEGATE:
2048                 case EXPR_UNARY_PLUS:
2049                 case EXPR_UNARY_BITWISE_NEGATE:
2050                 case EXPR_UNARY_NOT:
2051                 case EXPR_UNARY_TAKE_ADDRESS:
2052                 case EXPR_UNARY_POSTFIX_INCREMENT:
2053                 case EXPR_UNARY_POSTFIX_DECREMENT:
2054                 case EXPR_UNARY_PREFIX_INCREMENT:
2055                 case EXPR_UNARY_PREFIX_DECREMENT:
2056                 case EXPR_UNARY_CAST_IMPLICIT:
2057                 case EXPR_UNARY_ASSUME:
2058 unary:
2059                         mark_vars_read(expr->unary.value, lhs_ent);
2060                         return;
2061
2062                 case EXPR_BINARY_ADD:
2063                 case EXPR_BINARY_SUB:
2064                 case EXPR_BINARY_MUL:
2065                 case EXPR_BINARY_DIV:
2066                 case EXPR_BINARY_MOD:
2067                 case EXPR_BINARY_EQUAL:
2068                 case EXPR_BINARY_NOTEQUAL:
2069                 case EXPR_BINARY_LESS:
2070                 case EXPR_BINARY_LESSEQUAL:
2071                 case EXPR_BINARY_GREATER:
2072                 case EXPR_BINARY_GREATEREQUAL:
2073                 case EXPR_BINARY_BITWISE_AND:
2074                 case EXPR_BINARY_BITWISE_OR:
2075                 case EXPR_BINARY_BITWISE_XOR:
2076                 case EXPR_BINARY_LOGICAL_AND:
2077                 case EXPR_BINARY_LOGICAL_OR:
2078                 case EXPR_BINARY_SHIFTLEFT:
2079                 case EXPR_BINARY_SHIFTRIGHT:
2080                 case EXPR_BINARY_COMMA:
2081                 case EXPR_BINARY_ISGREATER:
2082                 case EXPR_BINARY_ISGREATEREQUAL:
2083                 case EXPR_BINARY_ISLESS:
2084                 case EXPR_BINARY_ISLESSEQUAL:
2085                 case EXPR_BINARY_ISLESSGREATER:
2086                 case EXPR_BINARY_ISUNORDERED:
2087                         mark_vars_read(expr->binary.left,  lhs_ent);
2088                         mark_vars_read(expr->binary.right, lhs_ent);
2089                         return;
2090
2091                 case EXPR_BINARY_ASSIGN:
2092                 case EXPR_BINARY_MUL_ASSIGN:
2093                 case EXPR_BINARY_DIV_ASSIGN:
2094                 case EXPR_BINARY_MOD_ASSIGN:
2095                 case EXPR_BINARY_ADD_ASSIGN:
2096                 case EXPR_BINARY_SUB_ASSIGN:
2097                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:
2098                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:
2099                 case EXPR_BINARY_BITWISE_AND_ASSIGN:
2100                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:
2101                 case EXPR_BINARY_BITWISE_OR_ASSIGN: {
2102                         if (lhs_ent == ENT_ANY)
2103                                 lhs_ent = NULL;
2104                         lhs_ent = determine_lhs_ent(expr->binary.left, lhs_ent);
2105                         mark_vars_read(expr->binary.right, lhs_ent);
2106                         return;
2107                 }
2108
2109                 case EXPR_VA_START:
2110                         determine_lhs_ent(expr->va_starte.ap, lhs_ent);
2111                         return;
2112
2113                 case EXPR_UNKNOWN:
2114                 case EXPR_INVALID:
2115                 case EXPR_CONST:
2116                 case EXPR_CHARACTER_CONSTANT:
2117                 case EXPR_WIDE_CHARACTER_CONSTANT:
2118                 case EXPR_STRING_LITERAL:
2119                 case EXPR_WIDE_STRING_LITERAL:
2120                 case EXPR_COMPOUND_LITERAL: // TODO init?
2121                 case EXPR_SIZEOF:
2122                 case EXPR_CLASSIFY_TYPE:
2123                 case EXPR_ALIGNOF:
2124                 case EXPR_FUNCNAME:
2125                 case EXPR_BUILTIN_SYMBOL:
2126                 case EXPR_BUILTIN_CONSTANT_P:
2127                 case EXPR_BUILTIN_PREFETCH:
2128                 case EXPR_OFFSETOF:
2129                 case EXPR_STATEMENT: // TODO
2130                 case EXPR_LABEL_ADDRESS:
2131                 case EXPR_BINARY_BUILTIN_EXPECT:
2132                 case EXPR_REFERENCE_ENUM_VALUE:
2133                         return;
2134         }
2135
2136         panic("unhandled expression");
2137 }
2138
2139 static designator_t *parse_designation(void)
2140 {
2141         designator_t *result = NULL;
2142         designator_t *last   = NULL;
2143
2144         while (true) {
2145                 designator_t *designator;
2146                 switch (token.type) {
2147                 case '[':
2148                         designator = allocate_ast_zero(sizeof(designator[0]));
2149                         designator->source_position = token.source_position;
2150                         next_token();
2151                         add_anchor_token(']');
2152                         designator->array_index = parse_constant_expression();
2153                         rem_anchor_token(']');
2154                         expect(']');
2155                         break;
2156                 case '.':
2157                         designator = allocate_ast_zero(sizeof(designator[0]));
2158                         designator->source_position = token.source_position;
2159                         next_token();
2160                         if (token.type != T_IDENTIFIER) {
2161                                 parse_error_expected("while parsing designator",
2162                                                      T_IDENTIFIER, NULL);
2163                                 return NULL;
2164                         }
2165                         designator->symbol = token.v.symbol;
2166                         next_token();
2167                         break;
2168                 default:
2169                         expect('=');
2170                         return result;
2171                 }
2172
2173                 assert(designator != NULL);
2174                 if (last != NULL) {
2175                         last->next = designator;
2176                 } else {
2177                         result = designator;
2178                 }
2179                 last = designator;
2180         }
2181 end_error:
2182         return NULL;
2183 }
2184
2185 static initializer_t *initializer_from_string(array_type_t *type,
2186                                               const string_t *const string)
2187 {
2188         /* TODO: check len vs. size of array type */
2189         (void) type;
2190
2191         initializer_t *initializer = allocate_initializer_zero(INITIALIZER_STRING);
2192         initializer->string.string = *string;
2193
2194         return initializer;
2195 }
2196
2197 static initializer_t *initializer_from_wide_string(array_type_t *const type,
2198                                                    wide_string_t *const string)
2199 {
2200         /* TODO: check len vs. size of array type */
2201         (void) type;
2202
2203         initializer_t *const initializer =
2204                 allocate_initializer_zero(INITIALIZER_WIDE_STRING);
2205         initializer->wide_string.string = *string;
2206
2207         return initializer;
2208 }
2209
2210 /**
2211  * Build an initializer from a given expression.
2212  */
2213 static initializer_t *initializer_from_expression(type_t *orig_type,
2214                                                   expression_t *expression)
2215 {
2216         /* TODO check that expression is a constant expression */
2217
2218         /* § 6.7.8.14/15 char array may be initialized by string literals */
2219         type_t *type           = skip_typeref(orig_type);
2220         type_t *expr_type_orig = expression->base.type;
2221         type_t *expr_type      = skip_typeref(expr_type_orig);
2222         if (is_type_array(type) && expr_type->kind == TYPE_POINTER) {
2223                 array_type_t *const array_type   = &type->array;
2224                 type_t       *const element_type = skip_typeref(array_type->element_type);
2225
2226                 if (element_type->kind == TYPE_ATOMIC) {
2227                         atomic_type_kind_t akind = element_type->atomic.akind;
2228                         switch (expression->kind) {
2229                                 case EXPR_STRING_LITERAL:
2230                                         if (akind == ATOMIC_TYPE_CHAR
2231                                                         || akind == ATOMIC_TYPE_SCHAR
2232                                                         || akind == ATOMIC_TYPE_UCHAR) {
2233                                                 return initializer_from_string(array_type,
2234                                                         &expression->string.value);
2235                                         }
2236
2237                                 case EXPR_WIDE_STRING_LITERAL: {
2238                                         type_t *bare_wchar_type = skip_typeref(type_wchar_t);
2239                                         if (get_unqualified_type(element_type) == bare_wchar_type) {
2240                                                 return initializer_from_wide_string(array_type,
2241                                                         &expression->wide_string.value);
2242                                         }
2243                                 }
2244
2245                                 default:
2246                                         break;
2247                         }
2248                 }
2249         }
2250
2251         assign_error_t error = semantic_assign(type, expression);
2252         if (error == ASSIGN_ERROR_INCOMPATIBLE)
2253                 return NULL;
2254         report_assign_error(error, type, expression, "initializer",
2255                             &expression->base.source_position);
2256
2257         initializer_t *const result = allocate_initializer_zero(INITIALIZER_VALUE);
2258 #if 0
2259         if (type->kind == TYPE_BITFIELD) {
2260                 type = type->bitfield.base_type;
2261         }
2262 #endif
2263         result->value.value = create_implicit_cast(expression, type);
2264
2265         return result;
2266 }
2267
2268 /**
2269  * Checks if a given expression can be used as an constant initializer.
2270  */
2271 static bool is_initializer_constant(const expression_t *expression)
2272 {
2273         return is_constant_expression(expression)
2274                 || is_address_constant(expression);
2275 }
2276
2277 /**
2278  * Parses an scalar initializer.
2279  *
2280  * § 6.7.8.11; eat {} without warning
2281  */
2282 static initializer_t *parse_scalar_initializer(type_t *type,
2283                                                bool must_be_constant)
2284 {
2285         /* there might be extra {} hierarchies */
2286         int braces = 0;
2287         if (token.type == '{') {
2288                 if (warning.other)
2289                         warningf(HERE, "extra curly braces around scalar initializer");
2290                 do {
2291                         ++braces;
2292                         next_token();
2293                 } while (token.type == '{');
2294         }
2295
2296         expression_t *expression = parse_assignment_expression();
2297         mark_vars_read(expression, NULL);
2298         if (must_be_constant && !is_initializer_constant(expression)) {
2299                 errorf(&expression->base.source_position,
2300                        "Initialisation expression '%E' is not constant\n",
2301                        expression);
2302         }
2303
2304         initializer_t *initializer = initializer_from_expression(type, expression);
2305
2306         if (initializer == NULL) {
2307                 errorf(&expression->base.source_position,
2308                        "expression '%E' (type '%T') doesn't match expected type '%T'",
2309                        expression, expression->base.type, type);
2310                 /* TODO */
2311                 return NULL;
2312         }
2313
2314         bool additional_warning_displayed = false;
2315         while (braces > 0) {
2316                 if (token.type == ',') {
2317                         next_token();
2318                 }
2319                 if (token.type != '}') {
2320                         if (!additional_warning_displayed && warning.other) {
2321                                 warningf(HERE, "additional elements in scalar initializer");
2322                                 additional_warning_displayed = true;
2323                         }
2324                 }
2325                 eat_block();
2326                 braces--;
2327         }
2328
2329         return initializer;
2330 }
2331
2332 /**
2333  * An entry in the type path.
2334  */
2335 typedef struct type_path_entry_t type_path_entry_t;
2336 struct type_path_entry_t {
2337         type_t *type;       /**< the upper top type. restored to path->top_tye if this entry is popped. */
2338         union {
2339                 size_t         index;          /**< For array types: the current index. */
2340                 declaration_t *compound_entry; /**< For compound types: the current declaration. */
2341         } v;
2342 };
2343
2344 /**
2345  * A type path expression a position inside compound or array types.
2346  */
2347 typedef struct type_path_t type_path_t;
2348 struct type_path_t {
2349         type_path_entry_t *path;         /**< An flexible array containing the current path. */
2350         type_t            *top_type;     /**< type of the element the path points */
2351         size_t             max_index;    /**< largest index in outermost array */
2352 };
2353
2354 /**
2355  * Prints a type path for debugging.
2356  */
2357 static __attribute__((unused)) void debug_print_type_path(
2358                 const type_path_t *path)
2359 {
2360         size_t len = ARR_LEN(path->path);
2361
2362         for (size_t i = 0; i < len; ++i) {
2363                 const type_path_entry_t *entry = & path->path[i];
2364
2365                 type_t *type = skip_typeref(entry->type);
2366                 if (is_type_compound(type)) {
2367                         /* in gcc mode structs can have no members */
2368                         if (entry->v.compound_entry == NULL) {
2369                                 assert(i == len-1);
2370                                 continue;
2371                         }
2372                         fprintf(stderr, ".%s",
2373                                 entry->v.compound_entry->base.symbol->string);
2374                 } else if (is_type_array(type)) {
2375                         fprintf(stderr, "[%u]", (unsigned) entry->v.index);
2376                 } else {
2377                         fprintf(stderr, "-INVALID-");
2378                 }
2379         }
2380         if (path->top_type != NULL) {
2381                 fprintf(stderr, "  (");
2382                 print_type(path->top_type);
2383                 fprintf(stderr, ")");
2384         }
2385 }
2386
2387 /**
2388  * Return the top type path entry, ie. in a path
2389  * (type).a.b returns the b.
2390  */
2391 static type_path_entry_t *get_type_path_top(const type_path_t *path)
2392 {
2393         size_t len = ARR_LEN(path->path);
2394         assert(len > 0);
2395         return &path->path[len-1];
2396 }
2397
2398 /**
2399  * Enlarge the type path by an (empty) element.
2400  */
2401 static type_path_entry_t *append_to_type_path(type_path_t *path)
2402 {
2403         size_t len = ARR_LEN(path->path);
2404         ARR_RESIZE(type_path_entry_t, path->path, len+1);
2405
2406         type_path_entry_t *result = & path->path[len];
2407         memset(result, 0, sizeof(result[0]));
2408         return result;
2409 }
2410
2411 /**
2412  * Descending into a sub-type. Enter the scope of the current top_type.
2413  */
2414 static void descend_into_subtype(type_path_t *path)
2415 {
2416         type_t *orig_top_type = path->top_type;
2417         type_t *top_type      = skip_typeref(orig_top_type);
2418
2419         type_path_entry_t *top = append_to_type_path(path);
2420         top->type              = top_type;
2421
2422         if (is_type_compound(top_type)) {
2423                 compound_t *compound  = top_type->compound.compound;
2424                 entity_t   *entry     = compound->members.entities;
2425
2426                 if (entry != NULL) {
2427                         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
2428                         top->v.compound_entry = &entry->declaration;
2429                         path->top_type = entry->declaration.type;
2430                 } else {
2431                         path->top_type = NULL;
2432                 }
2433         } else if (is_type_array(top_type)) {
2434                 top->v.index   = 0;
2435                 path->top_type = top_type->array.element_type;
2436         } else {
2437                 assert(!is_type_valid(top_type));
2438         }
2439 }
2440
2441 /**
2442  * Pop an entry from the given type path, ie. returning from
2443  * (type).a.b to (type).a
2444  */
2445 static void ascend_from_subtype(type_path_t *path)
2446 {
2447         type_path_entry_t *top = get_type_path_top(path);
2448
2449         path->top_type = top->type;
2450
2451         size_t len = ARR_LEN(path->path);
2452         ARR_RESIZE(type_path_entry_t, path->path, len-1);
2453 }
2454
2455 /**
2456  * Pop entries from the given type path until the given
2457  * path level is reached.
2458  */
2459 static void ascend_to(type_path_t *path, size_t top_path_level)
2460 {
2461         size_t len = ARR_LEN(path->path);
2462
2463         while (len > top_path_level) {
2464                 ascend_from_subtype(path);
2465                 len = ARR_LEN(path->path);
2466         }
2467 }
2468
2469 static bool walk_designator(type_path_t *path, const designator_t *designator,
2470                             bool used_in_offsetof)
2471 {
2472         for (; designator != NULL; designator = designator->next) {
2473                 type_path_entry_t *top       = get_type_path_top(path);
2474                 type_t            *orig_type = top->type;
2475
2476                 type_t *type = skip_typeref(orig_type);
2477
2478                 if (designator->symbol != NULL) {
2479                         symbol_t *symbol = designator->symbol;
2480                         if (!is_type_compound(type)) {
2481                                 if (is_type_valid(type)) {
2482                                         errorf(&designator->source_position,
2483                                                "'.%Y' designator used for non-compound type '%T'",
2484                                                symbol, orig_type);
2485                                 }
2486
2487                                 top->type             = type_error_type;
2488                                 top->v.compound_entry = NULL;
2489                                 orig_type             = type_error_type;
2490                         } else {
2491                                 compound_t *compound = type->compound.compound;
2492                                 entity_t   *iter     = compound->members.entities;
2493                                 for (; iter != NULL; iter = iter->base.next) {
2494                                         if (iter->base.symbol == symbol) {
2495                                                 break;
2496                                         }
2497                                 }
2498                                 if (iter == NULL) {
2499                                         errorf(&designator->source_position,
2500                                                "'%T' has no member named '%Y'", orig_type, symbol);
2501                                         goto failed;
2502                                 }
2503                                 assert(iter->kind == ENTITY_COMPOUND_MEMBER);
2504                                 if (used_in_offsetof) {
2505                                         type_t *real_type = skip_typeref(iter->declaration.type);
2506                                         if (real_type->kind == TYPE_BITFIELD) {
2507                                                 errorf(&designator->source_position,
2508                                                        "offsetof designator '%Y' may not specify bitfield",
2509                                                        symbol);
2510                                                 goto failed;
2511                                         }
2512                                 }
2513
2514                                 top->type             = orig_type;
2515                                 top->v.compound_entry = &iter->declaration;
2516                                 orig_type             = iter->declaration.type;
2517                         }
2518                 } else {
2519                         expression_t *array_index = designator->array_index;
2520                         assert(designator->array_index != NULL);
2521
2522                         if (!is_type_array(type)) {
2523                                 if (is_type_valid(type)) {
2524                                         errorf(&designator->source_position,
2525                                                "[%E] designator used for non-array type '%T'",
2526                                                array_index, orig_type);
2527                                 }
2528                                 goto failed;
2529                         }
2530
2531                         long index = fold_constant(array_index);
2532                         if (!used_in_offsetof) {
2533                                 if (index < 0) {
2534                                         errorf(&designator->source_position,
2535                                                "array index [%E] must be positive", array_index);
2536                                 } else if (type->array.size_constant) {
2537                                         long array_size = type->array.size;
2538                                         if (index >= array_size) {
2539                                                 errorf(&designator->source_position,
2540                                                        "designator [%E] (%d) exceeds array size %d",
2541                                                        array_index, index, array_size);
2542                                         }
2543                                 }
2544                         }
2545
2546                         top->type    = orig_type;
2547                         top->v.index = (size_t) index;
2548                         orig_type    = type->array.element_type;
2549                 }
2550                 path->top_type = orig_type;
2551
2552                 if (designator->next != NULL) {
2553                         descend_into_subtype(path);
2554                 }
2555         }
2556         return true;
2557
2558 failed:
2559         return false;
2560 }
2561
2562 static void advance_current_object(type_path_t *path, size_t top_path_level)
2563 {
2564         type_path_entry_t *top = get_type_path_top(path);
2565
2566         type_t *type = skip_typeref(top->type);
2567         if (is_type_union(type)) {
2568                 /* in unions only the first element is initialized */
2569                 top->v.compound_entry = NULL;
2570         } else if (is_type_struct(type)) {
2571                 declaration_t *entry = top->v.compound_entry;
2572
2573                 entity_t *next_entity = entry->base.next;
2574                 if (next_entity != NULL) {
2575                         assert(is_declaration(next_entity));
2576                         entry = &next_entity->declaration;
2577                 } else {
2578                         entry = NULL;
2579                 }
2580
2581                 top->v.compound_entry = entry;
2582                 if (entry != NULL) {
2583                         path->top_type = entry->type;
2584                         return;
2585                 }
2586         } else if (is_type_array(type)) {
2587                 assert(is_type_array(type));
2588
2589                 top->v.index++;
2590
2591                 if (!type->array.size_constant || top->v.index < type->array.size) {
2592                         return;
2593                 }
2594         } else {
2595                 assert(!is_type_valid(type));
2596                 return;
2597         }
2598
2599         /* we're past the last member of the current sub-aggregate, try if we
2600          * can ascend in the type hierarchy and continue with another subobject */
2601         size_t len = ARR_LEN(path->path);
2602
2603         if (len > top_path_level) {
2604                 ascend_from_subtype(path);
2605                 advance_current_object(path, top_path_level);
2606         } else {
2607                 path->top_type = NULL;
2608         }
2609 }
2610
2611 /**
2612  * skip until token is found.
2613  */
2614 static void skip_until(int type)
2615 {
2616         while (token.type != type) {
2617                 if (token.type == T_EOF)
2618                         return;
2619                 next_token();
2620         }
2621 }
2622
2623 /**
2624  * skip any {...} blocks until a closing bracket is reached.
2625  */
2626 static void skip_initializers(void)
2627 {
2628         if (token.type == '{')
2629                 next_token();
2630
2631         while (token.type != '}') {
2632                 if (token.type == T_EOF)
2633                         return;
2634                 if (token.type == '{') {
2635                         eat_block();
2636                         continue;
2637                 }
2638                 next_token();
2639         }
2640 }
2641
2642 static initializer_t *create_empty_initializer(void)
2643 {
2644         static initializer_t empty_initializer
2645                 = { .list = { { INITIALIZER_LIST }, 0 } };
2646         return &empty_initializer;
2647 }
2648
2649 /**
2650  * Parse a part of an initialiser for a struct or union,
2651  */
2652 static initializer_t *parse_sub_initializer(type_path_t *path,
2653                 type_t *outer_type, size_t top_path_level,
2654                 parse_initializer_env_t *env)
2655 {
2656         if (token.type == '}') {
2657                 /* empty initializer */
2658                 return create_empty_initializer();
2659         }
2660
2661         type_t *orig_type = path->top_type;
2662         type_t *type      = NULL;
2663
2664         if (orig_type == NULL) {
2665                 /* We are initializing an empty compound. */
2666         } else {
2667                 type = skip_typeref(orig_type);
2668         }
2669
2670         initializer_t **initializers = NEW_ARR_F(initializer_t*, 0);
2671
2672         while (true) {
2673                 designator_t *designator = NULL;
2674                 if (token.type == '.' || token.type == '[') {
2675                         designator = parse_designation();
2676                         goto finish_designator;
2677                 } else if (token.type == T_IDENTIFIER && look_ahead(1)->type == ':') {
2678                         /* GNU-style designator ("identifier: value") */
2679                         designator = allocate_ast_zero(sizeof(designator[0]));
2680                         designator->source_position = token.source_position;
2681                         designator->symbol          = token.v.symbol;
2682                         eat(T_IDENTIFIER);
2683                         eat(':');
2684
2685 finish_designator:
2686                         /* reset path to toplevel, evaluate designator from there */
2687                         ascend_to(path, top_path_level);
2688                         if (!walk_designator(path, designator, false)) {
2689                                 /* can't continue after designation error */
2690                                 goto end_error;
2691                         }
2692
2693                         initializer_t *designator_initializer
2694                                 = allocate_initializer_zero(INITIALIZER_DESIGNATOR);
2695                         designator_initializer->designator.designator = designator;
2696                         ARR_APP1(initializer_t*, initializers, designator_initializer);
2697
2698                         orig_type = path->top_type;
2699                         type      = orig_type != NULL ? skip_typeref(orig_type) : NULL;
2700                 }
2701
2702                 initializer_t *sub;
2703
2704                 if (token.type == '{') {
2705                         if (type != NULL && is_type_scalar(type)) {
2706                                 sub = parse_scalar_initializer(type, env->must_be_constant);
2707                         } else {
2708                                 eat('{');
2709                                 if (type == NULL) {
2710                                         if (env->entity != NULL) {
2711                                                 errorf(HERE,
2712                                                      "extra brace group at end of initializer for '%Y'",
2713                                                      env->entity->base.symbol);
2714                                         } else {
2715                                                 errorf(HERE, "extra brace group at end of initializer");
2716                                         }
2717                                 } else
2718                                         descend_into_subtype(path);
2719
2720                                 add_anchor_token('}');
2721                                 sub = parse_sub_initializer(path, orig_type, top_path_level+1,
2722                                                             env);
2723                                 rem_anchor_token('}');
2724
2725                                 if (type != NULL) {
2726                                         ascend_from_subtype(path);
2727                                         expect('}');
2728                                 } else {
2729                                         expect('}');
2730                                         goto error_parse_next;
2731                                 }
2732                         }
2733                 } else {
2734                         /* must be an expression */
2735                         expression_t *expression = parse_assignment_expression();
2736
2737                         if (env->must_be_constant && !is_initializer_constant(expression)) {
2738                                 errorf(&expression->base.source_position,
2739                                        "Initialisation expression '%E' is not constant\n",
2740                                        expression);
2741                         }
2742
2743                         if (type == NULL) {
2744                                 /* we are already outside, ... */
2745                                 type_t *const outer_type_skip = skip_typeref(outer_type);
2746                                 if (is_type_compound(outer_type_skip) &&
2747                                     !outer_type_skip->compound.compound->complete) {
2748                                         goto error_parse_next;
2749                                 }
2750                                 goto error_excess;
2751                         }
2752
2753                         /* handle { "string" } special case */
2754                         if ((expression->kind == EXPR_STRING_LITERAL
2755                                         || expression->kind == EXPR_WIDE_STRING_LITERAL)
2756                                         && outer_type != NULL) {
2757                                 sub = initializer_from_expression(outer_type, expression);
2758                                 if (sub != NULL) {
2759                                         if (token.type == ',') {
2760                                                 next_token();
2761                                         }
2762                                         if (token.type != '}' && warning.other) {
2763                                                 warningf(HERE, "excessive elements in initializer for type '%T'",
2764                                                                  orig_type);
2765                                         }
2766                                         /* TODO: eat , ... */
2767                                         return sub;
2768                                 }
2769                         }
2770
2771                         /* descend into subtypes until expression matches type */
2772                         while (true) {
2773                                 orig_type = path->top_type;
2774                                 type      = skip_typeref(orig_type);
2775
2776                                 sub = initializer_from_expression(orig_type, expression);
2777                                 if (sub != NULL) {
2778                                         break;
2779                                 }
2780                                 if (!is_type_valid(type)) {
2781                                         goto end_error;
2782                                 }
2783                                 if (is_type_scalar(type)) {
2784                                         errorf(&expression->base.source_position,
2785                                                         "expression '%E' doesn't match expected type '%T'",
2786                                                         expression, orig_type);
2787                                         goto end_error;
2788                                 }
2789
2790                                 descend_into_subtype(path);
2791                         }
2792                 }
2793
2794                 /* update largest index of top array */
2795                 const type_path_entry_t *first      = &path->path[0];
2796                 type_t                  *first_type = first->type;
2797                 first_type                          = skip_typeref(first_type);
2798                 if (is_type_array(first_type)) {
2799                         size_t index = first->v.index;
2800                         if (index > path->max_index)
2801                                 path->max_index = index;
2802                 }
2803
2804                 if (type != NULL) {
2805                         /* append to initializers list */
2806                         ARR_APP1(initializer_t*, initializers, sub);
2807                 } else {
2808 error_excess:
2809                         if (warning.other) {
2810                                 if (env->entity != NULL) {
2811                                         warningf(HERE, "excess elements in struct initializer for '%Y'",
2812                                            env->entity->base.symbol);
2813                                 } else {
2814                                         warningf(HERE, "excess elements in struct initializer");
2815                                 }
2816                         }
2817                 }
2818
2819 error_parse_next:
2820                 if (token.type == '}') {
2821                         break;
2822                 }
2823                 expect(',');
2824                 if (token.type == '}') {
2825                         break;
2826                 }
2827
2828                 if (type != NULL) {
2829                         /* advance to the next declaration if we are not at the end */
2830                         advance_current_object(path, top_path_level);
2831                         orig_type = path->top_type;
2832                         if (orig_type != NULL)
2833                                 type = skip_typeref(orig_type);
2834                         else
2835                                 type = NULL;
2836                 }
2837         }
2838
2839         size_t len  = ARR_LEN(initializers);
2840         size_t size = sizeof(initializer_list_t) + len * sizeof(initializers[0]);
2841         initializer_t *result = allocate_ast_zero(size);
2842         result->kind          = INITIALIZER_LIST;
2843         result->list.len      = len;
2844         memcpy(&result->list.initializers, initializers,
2845                len * sizeof(initializers[0]));
2846
2847         DEL_ARR_F(initializers);
2848         ascend_to(path, top_path_level+1);
2849
2850         return result;
2851
2852 end_error:
2853         skip_initializers();
2854         DEL_ARR_F(initializers);
2855         ascend_to(path, top_path_level+1);
2856         return NULL;
2857 }
2858
2859 /**
2860  * Parses an initializer. Parsers either a compound literal
2861  * (env->declaration == NULL) or an initializer of a declaration.
2862  */
2863 static initializer_t *parse_initializer(parse_initializer_env_t *env)
2864 {
2865         type_t        *type   = skip_typeref(env->type);
2866         initializer_t *result = NULL;
2867         size_t         max_index;
2868
2869         if (is_type_scalar(type)) {
2870                 result = parse_scalar_initializer(type, env->must_be_constant);
2871         } else if (token.type == '{') {
2872                 eat('{');
2873
2874                 type_path_t path;
2875                 memset(&path, 0, sizeof(path));
2876                 path.top_type = env->type;
2877                 path.path     = NEW_ARR_F(type_path_entry_t, 0);
2878
2879                 descend_into_subtype(&path);
2880
2881                 add_anchor_token('}');
2882                 result = parse_sub_initializer(&path, env->type, 1, env);
2883                 rem_anchor_token('}');
2884
2885                 max_index = path.max_index;
2886                 DEL_ARR_F(path.path);
2887
2888                 expect('}');
2889         } else {
2890                 /* parse_scalar_initializer() also works in this case: we simply
2891                  * have an expression without {} around it */
2892                 result = parse_scalar_initializer(type, env->must_be_constant);
2893         }
2894
2895         /* § 6.7.8 (22) array initializers for arrays with unknown size determine
2896          * the array type size */
2897         if (is_type_array(type) && type->array.size_expression == NULL
2898                         && result != NULL) {
2899                 size_t size;
2900                 switch (result->kind) {
2901                 case INITIALIZER_LIST:
2902                         size = max_index + 1;
2903                         break;
2904
2905                 case INITIALIZER_STRING:
2906                         size = result->string.string.size;
2907                         break;
2908
2909                 case INITIALIZER_WIDE_STRING:
2910                         size = result->wide_string.string.size;
2911                         break;
2912
2913                 case INITIALIZER_DESIGNATOR:
2914                 case INITIALIZER_VALUE:
2915                         /* can happen for parse errors */
2916                         size = 0;
2917                         break;
2918
2919                 default:
2920                         internal_errorf(HERE, "invalid initializer type");
2921                 }
2922
2923                 expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
2924                 cnst->base.type          = type_size_t;
2925                 cnst->conste.v.int_value = size;
2926
2927                 type_t *new_type = duplicate_type(type);
2928
2929                 new_type->array.size_expression   = cnst;
2930                 new_type->array.size_constant     = true;
2931                 new_type->array.has_implicit_size = true;
2932                 new_type->array.size              = size;
2933                 env->type = new_type;
2934         }
2935
2936         return result;
2937 end_error:
2938         return NULL;
2939 }
2940
2941 static void append_entity(scope_t *scope, entity_t *entity)
2942 {
2943         if (scope->last_entity != NULL) {
2944                 scope->last_entity->base.next = entity;
2945         } else {
2946                 scope->entities = entity;
2947         }
2948         scope->last_entity = entity;
2949 }
2950
2951
2952 static compound_t *parse_compound_type_specifier(bool is_struct)
2953 {
2954         gnu_attribute_t  *attributes = NULL;
2955         decl_modifiers_t  modifiers  = 0;
2956         if (is_struct) {
2957                 eat(T_struct);
2958         } else {
2959                 eat(T_union);
2960         }
2961
2962         symbol_t   *symbol   = NULL;
2963         compound_t *compound = NULL;
2964
2965         if (token.type == T___attribute__) {
2966                 modifiers |= parse_attributes(&attributes);
2967         }
2968
2969         if (token.type == T_IDENTIFIER) {
2970                 symbol = token.v.symbol;
2971                 next_token();
2972
2973                 namespace_tag_t const namespc =
2974                         is_struct ? NAMESPACE_STRUCT : NAMESPACE_UNION;
2975                 entity_t *entity = get_entity(symbol, namespc);
2976                 if (entity != NULL) {
2977                         assert(entity->kind == (is_struct ? ENTITY_STRUCT : ENTITY_UNION));
2978                         compound = &entity->compound;
2979                         if (compound->base.parent_scope != current_scope &&
2980                             (token.type == '{' || token.type == ';')) {
2981                                 /* we're in an inner scope and have a definition. Override
2982                                    existing definition in outer scope */
2983                                 compound = NULL;
2984                         } else if (compound->complete && token.type == '{') {
2985                                 assert(symbol != NULL);
2986                                 errorf(HERE, "multiple definitions of '%s %Y' (previous definition %P)",
2987                                        is_struct ? "struct" : "union", symbol,
2988                                        &compound->base.source_position);
2989                                 /* clear members in the hope to avoid further errors */
2990                                 compound->members.entities = NULL;
2991                         }
2992                 }
2993         } else if (token.type != '{') {
2994                 if (is_struct) {
2995                         parse_error_expected("while parsing struct type specifier",
2996                                              T_IDENTIFIER, '{', NULL);
2997                 } else {
2998                         parse_error_expected("while parsing union type specifier",
2999                                              T_IDENTIFIER, '{', NULL);
3000                 }
3001
3002                 return NULL;
3003         }
3004
3005         if (compound == NULL) {
3006                 entity_kind_t  kind   = is_struct ? ENTITY_STRUCT : ENTITY_UNION;
3007                 entity_t      *entity = allocate_entity_zero(kind);
3008                 compound              = &entity->compound;
3009
3010                 compound->base.namespc =
3011                         (is_struct ? NAMESPACE_STRUCT : NAMESPACE_UNION);
3012                 compound->base.source_position = token.source_position;
3013                 compound->base.symbol          = symbol;
3014                 compound->base.parent_scope    = current_scope;
3015                 if (symbol != NULL) {
3016                         environment_push(entity);
3017                 }
3018                 append_entity(current_scope, entity);
3019         }
3020
3021         if (token.type == '{') {
3022                 parse_compound_type_entries(compound);
3023                 modifiers |= parse_attributes(&attributes);
3024
3025                 if (symbol == NULL) {
3026                         assert(anonymous_entity == NULL);
3027                         anonymous_entity = (entity_t*)compound;
3028                 }
3029         }
3030
3031         compound->modifiers |= modifiers;
3032         return compound;
3033 }
3034
3035 static void parse_enum_entries(type_t *const enum_type)
3036 {
3037         eat('{');
3038
3039         if (token.type == '}') {
3040                 errorf(HERE, "empty enum not allowed");
3041                 next_token();
3042                 return;
3043         }
3044
3045         add_anchor_token('}');
3046         do {
3047                 if (token.type != T_IDENTIFIER) {
3048                         parse_error_expected("while parsing enum entry", T_IDENTIFIER, NULL);
3049                         eat_block();
3050                         rem_anchor_token('}');
3051                         return;
3052                 }
3053
3054                 entity_t *entity             = allocate_entity_zero(ENTITY_ENUM_VALUE);
3055                 entity->enum_value.enum_type = enum_type;
3056                 entity->base.symbol          = token.v.symbol;
3057                 entity->base.source_position = token.source_position;
3058                 next_token();
3059
3060                 if (token.type == '=') {
3061                         next_token();
3062                         expression_t *value = parse_constant_expression();
3063
3064                         value = create_implicit_cast(value, enum_type);
3065                         entity->enum_value.value = value;
3066
3067                         /* TODO semantic */
3068                 }
3069
3070                 record_entity(entity, false);
3071
3072                 if (token.type != ',')
3073                         break;
3074                 next_token();
3075         } while (token.type != '}');
3076         rem_anchor_token('}');
3077
3078         expect('}');
3079
3080 end_error:
3081         ;
3082 }
3083
3084 static type_t *parse_enum_specifier(void)
3085 {
3086         gnu_attribute_t *attributes = NULL;
3087         entity_t        *entity;
3088         symbol_t        *symbol;
3089
3090         eat(T_enum);
3091         if (token.type == T_IDENTIFIER) {
3092                 symbol = token.v.symbol;
3093                 next_token();
3094
3095                 entity = get_entity(symbol, NAMESPACE_ENUM);
3096                 assert(entity == NULL || entity->kind == ENTITY_ENUM);
3097         } else if (token.type != '{') {
3098                 parse_error_expected("while parsing enum type specifier",
3099                                      T_IDENTIFIER, '{', NULL);
3100                 return NULL;
3101         } else {
3102                 entity  = NULL;
3103                 symbol  = NULL;
3104         }
3105
3106         if (entity == NULL) {
3107                 entity                       = allocate_entity_zero(ENTITY_ENUM);
3108                 entity->base.namespc         = NAMESPACE_ENUM;
3109                 entity->base.source_position = token.source_position;
3110                 entity->base.symbol          = symbol;
3111                 entity->base.parent_scope    = current_scope;
3112         }
3113
3114         type_t *const type = allocate_type_zero(TYPE_ENUM);
3115         type->enumt.enume  = &entity->enume;
3116
3117         if (token.type == '{') {
3118                 if (entity->enume.complete) {
3119                         errorf(HERE, "multiple definitions of enum %Y (previous definition %P)",
3120                                symbol, &entity->base.source_position);
3121                 }
3122                 if (symbol != NULL) {
3123                         environment_push(entity);
3124                 }
3125                 append_entity(current_scope, entity);
3126                 entity->enume.complete = true;
3127
3128                 parse_enum_entries(type);
3129                 parse_attributes(&attributes);
3130
3131                 if (symbol == NULL) {
3132                         assert(anonymous_entity == NULL);
3133                         anonymous_entity = entity;
3134                 }
3135         } else if (!entity->enume.complete && !(c_mode & _GNUC)) {
3136                 errorf(HERE, "enum %Y used before definition (incomplete enumes are a GNU extension)",
3137                        symbol);
3138         }
3139
3140         return type;
3141 }
3142
3143 /**
3144  * if a symbol is a typedef to another type, return true
3145  */
3146 static bool is_typedef_symbol(symbol_t *symbol)
3147 {
3148         const entity_t *const entity = get_entity(symbol, NAMESPACE_NORMAL);
3149         return entity != NULL && entity->kind == ENTITY_TYPEDEF;
3150 }
3151
3152 static type_t *parse_typeof(void)
3153 {
3154         eat(T___typeof__);
3155
3156         type_t *type;
3157
3158         expect('(');
3159         add_anchor_token(')');
3160
3161         expression_t *expression  = NULL;
3162
3163         bool old_type_prop     = in_type_prop;
3164         bool old_gcc_extension = in_gcc_extension;
3165         in_type_prop           = true;
3166
3167         while (token.type == T___extension__) {
3168                 /* This can be a prefix to a typename or an expression. */
3169                 next_token();
3170                 in_gcc_extension = true;
3171         }
3172         switch (token.type) {
3173         case T_IDENTIFIER:
3174                 if (is_typedef_symbol(token.v.symbol)) {
3175                         type = parse_typename();
3176                 } else {
3177                         expression = parse_expression();
3178                         type       = expression->base.type;
3179                 }
3180                 break;
3181
3182         TYPENAME_START
3183                 type = parse_typename();
3184                 break;
3185
3186         default:
3187                 expression = parse_expression();
3188                 type       = expression->base.type;
3189                 break;
3190         }
3191         in_type_prop     = old_type_prop;
3192         in_gcc_extension = old_gcc_extension;
3193
3194         rem_anchor_token(')');
3195         expect(')');
3196
3197         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF);
3198         typeof_type->typeoft.expression  = expression;
3199         typeof_type->typeoft.typeof_type = type;
3200
3201         return typeof_type;
3202 end_error:
3203         return NULL;
3204 }
3205
3206 typedef enum specifiers_t {
3207         SPECIFIER_SIGNED    = 1 << 0,
3208         SPECIFIER_UNSIGNED  = 1 << 1,
3209         SPECIFIER_LONG      = 1 << 2,
3210         SPECIFIER_INT       = 1 << 3,
3211         SPECIFIER_DOUBLE    = 1 << 4,
3212         SPECIFIER_CHAR      = 1 << 5,
3213         SPECIFIER_SHORT     = 1 << 6,
3214         SPECIFIER_LONG_LONG = 1 << 7,
3215         SPECIFIER_FLOAT     = 1 << 8,
3216         SPECIFIER_BOOL      = 1 << 9,
3217         SPECIFIER_VOID      = 1 << 10,
3218         SPECIFIER_INT8      = 1 << 11,
3219         SPECIFIER_INT16     = 1 << 12,
3220         SPECIFIER_INT32     = 1 << 13,
3221         SPECIFIER_INT64     = 1 << 14,
3222         SPECIFIER_INT128    = 1 << 15,
3223         SPECIFIER_COMPLEX   = 1 << 16,
3224         SPECIFIER_IMAGINARY = 1 << 17,
3225 } specifiers_t;
3226
3227 static type_t *create_builtin_type(symbol_t *const symbol,
3228                                    type_t *const real_type)
3229 {
3230         type_t *type            = allocate_type_zero(TYPE_BUILTIN);
3231         type->builtin.symbol    = symbol;
3232         type->builtin.real_type = real_type;
3233
3234         type_t *result = typehash_insert(type);
3235         if (type != result) {
3236                 free_type(type);
3237         }
3238
3239         return result;
3240 }
3241
3242 static type_t *get_typedef_type(symbol_t *symbol)
3243 {
3244         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
3245         if (entity == NULL || entity->kind != ENTITY_TYPEDEF)
3246                 return NULL;
3247
3248         type_t *type            = allocate_type_zero(TYPE_TYPEDEF);
3249         type->typedeft.typedefe = &entity->typedefe;
3250
3251         return type;
3252 }
3253
3254 /**
3255  * check for the allowed MS alignment values.
3256  */
3257 static bool check_alignment_value(long long intvalue)
3258 {
3259         if (intvalue < 1 || intvalue > 8192) {
3260                 errorf(HERE, "illegal alignment value");
3261                 return false;
3262         }
3263         unsigned v = (unsigned)intvalue;
3264         for (unsigned i = 1; i <= 8192; i += i) {
3265                 if (i == v)
3266                         return true;
3267         }
3268         errorf(HERE, "alignment must be power of two");
3269         return false;
3270 }
3271
3272 #define DET_MOD(name, tag) do { \
3273         if (*modifiers & tag && warning.other) warningf(HERE, #name " used more than once"); \
3274         *modifiers |= tag; \
3275 } while (0)
3276
3277 static void parse_microsoft_extended_decl_modifier(declaration_specifiers_t *specifiers)
3278 {
3279         decl_modifiers_t *modifiers = &specifiers->modifiers;
3280
3281         while (true) {
3282                 if (token.type == T_restrict) {
3283                         next_token();
3284                         DET_MOD(restrict, DM_RESTRICT);
3285                         goto end_loop;
3286                 } else if (token.type != T_IDENTIFIER)
3287                         break;
3288                 symbol_t *symbol = token.v.symbol;
3289                 if (symbol == sym_align) {
3290                         next_token();
3291                         expect('(');
3292                         if (token.type != T_INTEGER)
3293                                 goto end_error;
3294                         if (check_alignment_value(token.v.intvalue)) {
3295                                 if (specifiers->alignment != 0 && warning.other)
3296                                         warningf(HERE, "align used more than once");
3297                                 specifiers->alignment = (unsigned char)token.v.intvalue;
3298                         }
3299                         next_token();
3300                         expect(')');
3301                 } else if (symbol == sym_allocate) {
3302                         next_token();
3303                         expect('(');
3304                         if (token.type != T_IDENTIFIER)
3305                                 goto end_error;
3306                         (void)token.v.symbol;
3307                         expect(')');
3308                 } else if (symbol == sym_dllimport) {
3309                         next_token();
3310                         DET_MOD(dllimport, DM_DLLIMPORT);
3311                 } else if (symbol == sym_dllexport) {
3312                         next_token();
3313                         DET_MOD(dllexport, DM_DLLEXPORT);
3314                 } else if (symbol == sym_thread) {
3315                         next_token();
3316                         DET_MOD(thread, DM_THREAD);
3317                 } else if (symbol == sym_naked) {
3318                         next_token();
3319                         DET_MOD(naked, DM_NAKED);
3320                 } else if (symbol == sym_noinline) {
3321                         next_token();
3322                         DET_MOD(noinline, DM_NOINLINE);
3323                 } else if (symbol == sym_noreturn) {
3324                         next_token();
3325                         DET_MOD(noreturn, DM_NORETURN);
3326                 } else if (symbol == sym_nothrow) {
3327                         next_token();
3328                         DET_MOD(nothrow, DM_NOTHROW);
3329                 } else if (symbol == sym_novtable) {
3330                         next_token();
3331                         DET_MOD(novtable, DM_NOVTABLE);
3332                 } else if (symbol == sym_property) {
3333                         next_token();
3334                         expect('(');
3335                         for (;;) {
3336                                 bool is_get = false;
3337                                 if (token.type != T_IDENTIFIER)
3338                                         goto end_error;
3339                                 if (token.v.symbol == sym_get) {
3340                                         is_get = true;
3341                                 } else if (token.v.symbol == sym_put) {
3342                                 } else {
3343                                         errorf(HERE, "Bad property name '%Y'", token.v.symbol);
3344                                         goto end_error;
3345                                 }
3346                                 next_token();
3347                                 expect('=');
3348                                 if (token.type != T_IDENTIFIER)
3349                                         goto end_error;
3350                                 if (is_get) {
3351                                         if (specifiers->get_property_sym != NULL) {
3352                                                 errorf(HERE, "get property name already specified");
3353                                         } else {
3354                                                 specifiers->get_property_sym = token.v.symbol;
3355                                         }
3356                                 } else {
3357                                         if (specifiers->put_property_sym != NULL) {
3358                                                 errorf(HERE, "put property name already specified");
3359                                         } else {
3360                                                 specifiers->put_property_sym = token.v.symbol;
3361                                         }
3362                                 }
3363                                 next_token();
3364                                 if (token.type == ',') {
3365                                         next_token();
3366                                         continue;
3367                                 }
3368                                 break;
3369                         }
3370                         expect(')');
3371                 } else if (symbol == sym_selectany) {
3372                         next_token();
3373                         DET_MOD(selectany, DM_SELECTANY);
3374                 } else if (symbol == sym_uuid) {
3375                         next_token();
3376                         expect('(');
3377                         if (token.type != T_STRING_LITERAL)
3378                                 goto end_error;
3379                         next_token();
3380                         expect(')');
3381                 } else if (symbol == sym_deprecated) {
3382                         next_token();
3383                         if (specifiers->deprecated != 0 && warning.other)
3384                                 warningf(HERE, "deprecated used more than once");
3385                         specifiers->deprecated = true;
3386                         if (token.type == '(') {
3387                                 next_token();
3388                                 if (token.type == T_STRING_LITERAL) {
3389                                         specifiers->deprecated_string = token.v.string.begin;
3390                                         next_token();
3391                                 } else {
3392                                         errorf(HERE, "string literal expected");
3393                                 }
3394                                 expect(')');
3395                         }
3396                 } else if (symbol == sym_noalias) {
3397                         next_token();
3398                         DET_MOD(noalias, DM_NOALIAS);
3399                 } else {
3400                         if (warning.other)
3401                                 warningf(HERE, "Unknown modifier %Y ignored", token.v.symbol);
3402                         next_token();
3403                         if (token.type == '(')
3404                                 skip_until(')');
3405                 }
3406 end_loop:
3407                 if (token.type == ',')
3408                         next_token();
3409         }
3410 end_error:
3411         return;
3412 }
3413
3414 static entity_t *create_error_entity(symbol_t *symbol, entity_kind_tag_t kind)
3415 {
3416         entity_t *entity             = allocate_entity_zero(kind);
3417         entity->base.source_position = *HERE;
3418         entity->base.symbol          = symbol;
3419         if (is_declaration(entity)) {
3420                 entity->declaration.type     = type_error_type;
3421                 entity->declaration.implicit = true;
3422         } else if (kind == ENTITY_TYPEDEF) {
3423                 entity->typedefe.type = type_error_type;
3424         }
3425         record_entity(entity, false);
3426         return entity;
3427 }
3428
3429 static void parse_microsoft_based(based_spec_t *based_spec)
3430 {
3431         if (token.type != T_IDENTIFIER) {
3432                 parse_error_expected("while parsing __based", T_IDENTIFIER, NULL);
3433                 return;
3434         }
3435         symbol_t *symbol = token.v.symbol;
3436         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
3437
3438         if (entity == NULL || entity->base.kind != ENTITY_VARIABLE) {
3439                 errorf(HERE, "'%Y' is not a variable name.", symbol);
3440                 entity = create_error_entity(symbol, ENTITY_VARIABLE);
3441         } else {
3442                 variable_t *variable = &entity->variable;
3443
3444                 if (based_spec->base_variable != NULL) {
3445                         errorf(HERE, "__based type qualifier specified more than once");
3446                 }
3447                 based_spec->source_position = token.source_position;
3448                 based_spec->base_variable   = variable;
3449
3450                 type_t *const type = variable->base.type;
3451
3452                 if (is_type_valid(type)) {
3453                         if (! is_type_pointer(skip_typeref(type))) {
3454                                 errorf(HERE, "variable in __based modifier must have pointer type instead of '%T'", type);
3455                         }
3456                         if (variable->base.base.parent_scope != file_scope) {
3457                                 errorf(HERE, "a nonstatic local variable may not be used in a __based specification");
3458                         }
3459                 }
3460         }
3461         next_token();
3462 }
3463
3464 /**
3465  * Finish the construction of a struct type by calculating
3466  * its size, offsets, alignment.
3467  */
3468 static void finish_struct_type(compound_type_t *type)
3469 {
3470         assert(type->compound != NULL);
3471
3472         compound_t *compound = type->compound;
3473         if (!compound->complete)
3474                 return;
3475
3476         il_size_t      size           = 0;
3477         il_size_t      offset;
3478         il_alignment_t alignment      = 1;
3479         bool           need_pad       = false;
3480
3481         entity_t *entry = compound->members.entities;
3482         for (; entry != NULL; entry = entry->base.next) {
3483                 if (entry->kind != ENTITY_COMPOUND_MEMBER)
3484                         continue;
3485
3486                 type_t *m_type = skip_typeref(entry->declaration.type);
3487                 if (! is_type_valid(m_type)) {
3488                         /* simply ignore errors here */
3489                         continue;
3490                 }
3491                 il_alignment_t m_alignment = m_type->base.alignment;
3492                 if (m_alignment > alignment)
3493                         alignment = m_alignment;
3494
3495                 offset = (size + m_alignment - 1) & -m_alignment;
3496
3497                 if (offset > size)
3498                         need_pad = true;
3499                 entry->compound_member.offset = offset;
3500                 size = offset + m_type->base.size;
3501         }
3502         if (type->base.alignment != 0) {
3503                 alignment = type->base.alignment;
3504         }
3505
3506         offset = (size + alignment - 1) & -alignment;
3507         if (offset > size)
3508                 need_pad = true;
3509
3510         if (warning.padded && need_pad) {
3511                 warningf(&compound->base.source_position,
3512                         "'%#T' needs padding", type, compound->base.symbol);
3513         }
3514         if (warning.packed && !need_pad) {
3515                 warningf(&compound->base.source_position,
3516                         "superfluous packed attribute on '%#T'",
3517                         type, compound->base.symbol);
3518         }
3519
3520         type->base.size      = offset;
3521         type->base.alignment = alignment;
3522 }
3523
3524 /**
3525  * Finish the construction of an union type by calculating
3526  * its size and alignment.
3527  */
3528 static void finish_union_type(compound_type_t *type)
3529 {
3530         assert(type->compound != NULL);
3531
3532         compound_t *compound = type->compound;
3533         if (! compound->complete)
3534                 return;
3535
3536         il_size_t      size      = 0;
3537         il_alignment_t alignment = 1;
3538
3539         entity_t *entry = compound->members.entities;
3540         for (; entry != NULL; entry = entry->base.next) {
3541                 if (entry->kind != ENTITY_COMPOUND_MEMBER)
3542                         continue;
3543
3544                 type_t *m_type = skip_typeref(entry->declaration.type);
3545                 if (! is_type_valid(m_type))
3546                         continue;
3547
3548                 entry->compound_member.offset = 0;
3549                 if (m_type->base.size > size)
3550                         size = m_type->base.size;
3551                 if (m_type->base.alignment > alignment)
3552                         alignment = m_type->base.alignment;
3553         }
3554         if (type->base.alignment != 0) {
3555                 alignment = type->base.alignment;
3556         }
3557         size = (size + alignment - 1) & -alignment;
3558         type->base.size      = size;
3559         type->base.alignment = alignment;
3560 }
3561
3562 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
3563 {
3564         type_t            *type              = NULL;
3565         type_qualifiers_t  qualifiers        = TYPE_QUALIFIER_NONE;
3566         type_modifiers_t   modifiers         = TYPE_MODIFIER_NONE;
3567         unsigned           type_specifiers   = 0;
3568         bool               newtype           = false;
3569         bool               saw_error         = false;
3570         bool               old_gcc_extension = in_gcc_extension;
3571
3572         specifiers->source_position = token.source_position;
3573
3574         while (true) {
3575                 specifiers->modifiers
3576                         |= parse_attributes(&specifiers->gnu_attributes);
3577                 if (specifiers->modifiers & DM_TRANSPARENT_UNION)
3578                         modifiers |= TYPE_MODIFIER_TRANSPARENT_UNION;
3579
3580                 switch (token.type) {
3581                 /* storage class */
3582 #define MATCH_STORAGE_CLASS(token, class)                                  \
3583                 case token:                                                        \
3584                         if (specifiers->storage_class != STORAGE_CLASS_NONE) {         \
3585                                 errorf(HERE, "multiple storage classes in declaration specifiers"); \
3586                         }                                                              \
3587                         specifiers->storage_class = class;                             \
3588                         if (specifiers->thread_local)                                  \
3589                                 goto check_thread_storage_class;                           \
3590                         next_token();                                                  \
3591                         break;
3592
3593                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
3594                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
3595                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
3596                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
3597                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
3598
3599                 case T__declspec:
3600                         next_token();
3601                         expect('(');
3602                         add_anchor_token(')');
3603                         parse_microsoft_extended_decl_modifier(specifiers);
3604                         rem_anchor_token(')');
3605                         expect(')');
3606                         break;
3607
3608                 case T___thread:
3609                         if (specifiers->thread_local) {
3610                                 errorf(HERE, "duplicate '__thread'");
3611                         } else {
3612                                 specifiers->thread_local = true;
3613 check_thread_storage_class:
3614                                 switch (specifiers->storage_class) {
3615                                         case STORAGE_CLASS_EXTERN:
3616                                         case STORAGE_CLASS_NONE:
3617                                         case STORAGE_CLASS_STATIC:
3618                                                 break;
3619
3620                                                 char const* wrong;
3621                                         case STORAGE_CLASS_AUTO:     wrong = "auto";     goto wrong_thread_stoarge_class;
3622                                         case STORAGE_CLASS_REGISTER: wrong = "register"; goto wrong_thread_stoarge_class;
3623                                         case STORAGE_CLASS_TYPEDEF:  wrong = "typedef";  goto wrong_thread_stoarge_class;
3624 wrong_thread_stoarge_class:
3625                                                 errorf(HERE, "'__thread' used with '%s'", wrong);
3626                                                 break;
3627                                 }
3628                         }
3629                         next_token();
3630                         break;
3631
3632                 /* type qualifiers */
3633 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
3634                 case token:                                                     \
3635                         qualifiers |= qualifier;                                    \
3636                         next_token();                                               \
3637                         break
3638
3639                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3640                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3641                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3642                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3643                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3644                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3645                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3646                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3647
3648                 case T___extension__:
3649                         next_token();
3650                         in_gcc_extension = true;
3651                         break;
3652
3653                 /* type specifiers */
3654 #define MATCH_SPECIFIER(token, specifier, name)                         \
3655                 case token:                                                     \
3656                         if (type_specifiers & specifier) {                           \
3657                                 errorf(HERE, "multiple " name " type specifiers given"); \
3658                         } else {                                                    \
3659                                 type_specifiers |= specifier;                           \
3660                         }                                                           \
3661                         next_token();                                               \
3662                         break
3663
3664                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool");
3665                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex");
3666                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary");
3667                 MATCH_SPECIFIER(T__int128,    SPECIFIER_INT128,    "_int128");
3668                 MATCH_SPECIFIER(T__int16,     SPECIFIER_INT16,     "_int16");
3669                 MATCH_SPECIFIER(T__int32,     SPECIFIER_INT32,     "_int32");
3670                 MATCH_SPECIFIER(T__int64,     SPECIFIER_INT64,     "_int64");
3671                 MATCH_SPECIFIER(T__int8,      SPECIFIER_INT8,      "_int8");
3672                 MATCH_SPECIFIER(T_bool,       SPECIFIER_BOOL,      "bool");
3673                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char");
3674                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double");
3675                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float");
3676                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int");
3677                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short");
3678                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed");
3679                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned");
3680                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void");
3681
3682                 case T__forceinline:
3683                         /* only in microsoft mode */
3684                         specifiers->modifiers |= DM_FORCEINLINE;
3685                         /* FALLTHROUGH */
3686
3687                 case T_inline:
3688                         next_token();
3689                         specifiers->is_inline = true;
3690                         break;
3691
3692                 case T_long:
3693                         if (type_specifiers & SPECIFIER_LONG_LONG) {
3694                                 errorf(HERE, "multiple type specifiers given");
3695                         } else if (type_specifiers & SPECIFIER_LONG) {
3696                                 type_specifiers |= SPECIFIER_LONG_LONG;
3697                         } else {
3698                                 type_specifiers |= SPECIFIER_LONG;
3699                         }
3700                         next_token();
3701                         break;
3702
3703                 case T_struct: {
3704                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
3705
3706                         type->compound.compound = parse_compound_type_specifier(true);
3707                         finish_struct_type(&type->compound);
3708                         break;
3709                 }
3710                 case T_union: {
3711                         type = allocate_type_zero(TYPE_COMPOUND_UNION);
3712                         type->compound.compound = parse_compound_type_specifier(false);
3713                         if (type->compound.compound->modifiers & DM_TRANSPARENT_UNION)
3714                                 modifiers |= TYPE_MODIFIER_TRANSPARENT_UNION;
3715                         finish_union_type(&type->compound);
3716                         break;
3717                 }
3718                 case T_enum:
3719                         type = parse_enum_specifier();
3720                         break;
3721                 case T___typeof__:
3722                         type = parse_typeof();
3723                         break;
3724                 case T___builtin_va_list:
3725                         type = duplicate_type(type_valist);
3726                         next_token();
3727                         break;
3728
3729                 case T_IDENTIFIER: {
3730                         /* only parse identifier if we haven't found a type yet */
3731                         if (type != NULL || type_specifiers != 0) {
3732                                 /* Be somewhat resilient to typos like 'unsigned lng* f()' in a
3733                                  * declaration, so it doesn't generate errors about expecting '(' or
3734                                  * '{' later on. */
3735                                 switch (look_ahead(1)->type) {
3736                                         STORAGE_CLASSES
3737                                         TYPE_SPECIFIERS
3738                                         case T_const:
3739                                         case T_restrict:
3740                                         case T_volatile:
3741                                         case T_inline:
3742                                         case T__forceinline: /* ^ DECLARATION_START except for __attribute__ */
3743                                         case T_IDENTIFIER:
3744                                         case '&':
3745                                         case '*':
3746                                                 errorf(HERE, "discarding stray '%K' in declaration specifier", &token);
3747                                                 next_token();
3748                                                 continue;
3749
3750                                         default:
3751                                                 goto finish_specifiers;
3752                                 }
3753                         }
3754
3755                         type_t *const typedef_type = get_typedef_type(token.v.symbol);
3756                         if (typedef_type == NULL) {
3757                                 /* Be somewhat resilient to typos like 'vodi f()' at the beginning of a
3758                                  * declaration, so it doesn't generate 'implicit int' followed by more
3759                                  * errors later on. */
3760                                 token_type_t const la1_type = (token_type_t)look_ahead(1)->type;
3761                                 switch (la1_type) {
3762                                         DECLARATION_START
3763                                         case T_IDENTIFIER:
3764                                         case '&':
3765                                         case '*': {
3766                                                 errorf(HERE, "'%K' does not name a type", &token);
3767
3768                                                 entity_t *entity =
3769                                                         create_error_entity(token.v.symbol, ENTITY_TYPEDEF);
3770
3771                                                 type = allocate_type_zero(TYPE_TYPEDEF);
3772                                                 type->typedeft.typedefe = &entity->typedefe;
3773
3774                                                 next_token();
3775                                                 saw_error = true;
3776                                                 if (la1_type == '&' || la1_type == '*')
3777                                                         goto finish_specifiers;
3778                                                 continue;
3779                                         }
3780
3781                                         default:
3782                                                 goto finish_specifiers;
3783                                 }
3784                         }
3785
3786                         next_token();
3787                         type = typedef_type;
3788                         break;
3789                 }
3790
3791                 /* function specifier */
3792                 default:
3793                         goto finish_specifiers;
3794                 }
3795         }
3796
3797 finish_specifiers:
3798         in_gcc_extension = old_gcc_extension;
3799
3800         if (type == NULL || (saw_error && type_specifiers != 0)) {
3801                 atomic_type_kind_t atomic_type;
3802
3803                 /* match valid basic types */
3804                 switch (type_specifiers) {
3805                 case SPECIFIER_VOID:
3806                         atomic_type = ATOMIC_TYPE_VOID;
3807                         break;
3808                 case SPECIFIER_CHAR:
3809                         atomic_type = ATOMIC_TYPE_CHAR;
3810                         break;
3811                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
3812                         atomic_type = ATOMIC_TYPE_SCHAR;
3813                         break;
3814                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
3815                         atomic_type = ATOMIC_TYPE_UCHAR;
3816                         break;
3817                 case SPECIFIER_SHORT:
3818                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
3819                 case SPECIFIER_SHORT | SPECIFIER_INT:
3820                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
3821                         atomic_type = ATOMIC_TYPE_SHORT;
3822                         break;
3823                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
3824                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
3825                         atomic_type = ATOMIC_TYPE_USHORT;
3826                         break;
3827                 case SPECIFIER_INT:
3828                 case SPECIFIER_SIGNED:
3829                 case SPECIFIER_SIGNED | SPECIFIER_INT:
3830                         atomic_type = ATOMIC_TYPE_INT;
3831                         break;
3832                 case SPECIFIER_UNSIGNED:
3833                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
3834                         atomic_type = ATOMIC_TYPE_UINT;
3835                         break;
3836                 case SPECIFIER_LONG:
3837                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
3838                 case SPECIFIER_LONG | SPECIFIER_INT:
3839                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
3840                         atomic_type = ATOMIC_TYPE_LONG;
3841                         break;
3842                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
3843                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
3844                         atomic_type = ATOMIC_TYPE_ULONG;
3845                         break;
3846
3847                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3848                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3849                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
3850                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3851                         | SPECIFIER_INT:
3852                         atomic_type = ATOMIC_TYPE_LONGLONG;
3853                         goto warn_about_long_long;
3854
3855                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3856                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3857                         | SPECIFIER_INT:
3858                         atomic_type = ATOMIC_TYPE_ULONGLONG;
3859 warn_about_long_long:
3860                         if (warning.long_long) {
3861                                 warningf(&specifiers->source_position,
3862                                          "ISO C90 does not support 'long long'");
3863                         }
3864                         break;
3865
3866                 case SPECIFIER_UNSIGNED | SPECIFIER_INT8:
3867                         atomic_type = unsigned_int8_type_kind;
3868                         break;
3869
3870                 case SPECIFIER_UNSIGNED | SPECIFIER_INT16:
3871                         atomic_type = unsigned_int16_type_kind;
3872                         break;
3873
3874                 case SPECIFIER_UNSIGNED | SPECIFIER_INT32:
3875                         atomic_type = unsigned_int32_type_kind;
3876                         break;
3877
3878                 case SPECIFIER_UNSIGNED | SPECIFIER_INT64:
3879                         atomic_type = unsigned_int64_type_kind;
3880                         break;
3881
3882                 case SPECIFIER_UNSIGNED | SPECIFIER_INT128:
3883                         atomic_type = unsigned_int128_type_kind;
3884                         break;
3885
3886                 case SPECIFIER_INT8:
3887                 case SPECIFIER_SIGNED | SPECIFIER_INT8:
3888                         atomic_type = int8_type_kind;
3889                         break;
3890
3891                 case SPECIFIER_INT16:
3892                 case SPECIFIER_SIGNED | SPECIFIER_INT16:
3893                         atomic_type = int16_type_kind;
3894                         break;
3895
3896                 case SPECIFIER_INT32:
3897                 case SPECIFIER_SIGNED | SPECIFIER_INT32:
3898                         atomic_type = int32_type_kind;
3899                         break;
3900
3901                 case SPECIFIER_INT64:
3902                 case SPECIFIER_SIGNED | SPECIFIER_INT64:
3903                         atomic_type = int64_type_kind;
3904                         break;
3905
3906                 case SPECIFIER_INT128:
3907                 case SPECIFIER_SIGNED | SPECIFIER_INT128:
3908                         atomic_type = int128_type_kind;
3909                         break;
3910
3911                 case SPECIFIER_FLOAT:
3912                         atomic_type = ATOMIC_TYPE_FLOAT;
3913                         break;
3914                 case SPECIFIER_DOUBLE:
3915                         atomic_type = ATOMIC_TYPE_DOUBLE;
3916                         break;
3917                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
3918                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
3919                         break;
3920                 case SPECIFIER_BOOL:
3921                         atomic_type = ATOMIC_TYPE_BOOL;
3922                         break;
3923                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
3924                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
3925                         atomic_type = ATOMIC_TYPE_FLOAT;
3926                         break;
3927                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3928                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3929                         atomic_type = ATOMIC_TYPE_DOUBLE;
3930                         break;
3931                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3932                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3933                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
3934                         break;
3935                 default:
3936                         /* invalid specifier combination, give an error message */
3937                         if (type_specifiers == 0) {
3938                                 if (saw_error)
3939                                         goto end_error;
3940
3941                                 /* ISO/IEC 14882:1998(E) §C.1.5:4 */
3942                                 if (!(c_mode & _CXX) && !strict_mode) {
3943                                         if (warning.implicit_int) {
3944                                                 warningf(HERE, "no type specifiers in declaration, using 'int'");
3945                                         }
3946                                         atomic_type = ATOMIC_TYPE_INT;
3947                                         break;
3948                                 } else {
3949                                         errorf(HERE, "no type specifiers given in declaration");
3950                                 }
3951                         } else if ((type_specifiers & SPECIFIER_SIGNED) &&
3952                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
3953                                 errorf(HERE, "signed and unsigned specifiers given");
3954                         } else if (type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
3955                                 errorf(HERE, "only integer types can be signed or unsigned");
3956                         } else {
3957                                 errorf(HERE, "multiple datatypes in declaration");
3958                         }
3959                         goto end_error;
3960                 }
3961
3962                 if (type_specifiers & SPECIFIER_COMPLEX) {
3963                         type                = allocate_type_zero(TYPE_COMPLEX);
3964                         type->complex.akind = atomic_type;
3965                 } else if (type_specifiers & SPECIFIER_IMAGINARY) {
3966                         type                  = allocate_type_zero(TYPE_IMAGINARY);
3967                         type->imaginary.akind = atomic_type;
3968                 } else {
3969                         type               = allocate_type_zero(TYPE_ATOMIC);
3970                         type->atomic.akind = atomic_type;
3971                 }
3972                 newtype = true;
3973         } else if (type_specifiers != 0) {
3974                 errorf(HERE, "multiple datatypes in declaration");
3975         }
3976
3977         /* FIXME: check type qualifiers here */
3978
3979         type->base.qualifiers = qualifiers;
3980         type->base.modifiers  = modifiers;
3981
3982         type_t *result = typehash_insert(type);
3983         if (newtype && result != type) {
3984                 free_type(type);
3985         }
3986
3987         specifiers->type = result;
3988         return;
3989
3990 end_error:
3991         specifiers->type = type_error_type;
3992         return;
3993 }
3994
3995 static type_qualifiers_t parse_type_qualifiers(void)
3996 {
3997         type_qualifiers_t qualifiers = TYPE_QUALIFIER_NONE;
3998
3999         while (true) {
4000                 switch (token.type) {
4001                 /* type qualifiers */
4002                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
4003                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
4004                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
4005                 /* microsoft extended type modifiers */
4006                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
4007                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
4008                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
4009                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
4010                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
4011
4012                 default:
4013                         return qualifiers;
4014                 }
4015         }
4016 }
4017
4018 /**
4019  * Parses an K&R identifier list
4020  */
4021 static void parse_identifier_list(scope_t *scope)
4022 {
4023         do {
4024                 entity_t *entity = allocate_entity_zero(ENTITY_PARAMETER);
4025                 entity->base.source_position = token.source_position;
4026                 entity->base.namespc         = NAMESPACE_NORMAL;
4027                 entity->base.symbol          = token.v.symbol;
4028                 /* a K&R parameter has no type, yet */
4029                 next_token();
4030
4031                 append_entity(scope, entity);
4032
4033                 if (token.type != ',') {
4034                         break;
4035                 }
4036                 next_token();
4037         } while (token.type == T_IDENTIFIER);
4038 }
4039
4040 static entity_t *parse_parameter(void)
4041 {
4042         declaration_specifiers_t specifiers;
4043         memset(&specifiers, 0, sizeof(specifiers));
4044
4045         parse_declaration_specifiers(&specifiers);
4046
4047         entity_t *entity = parse_declarator(&specifiers,
4048                         DECL_MAY_BE_ABSTRACT | DECL_IS_PARAMETER);
4049         anonymous_entity = NULL;
4050         return entity;
4051 }
4052
4053 static void semantic_parameter_incomplete(const entity_t *entity)
4054 {
4055         assert(entity->kind == ENTITY_PARAMETER);
4056
4057         /* §6.7.5.3:4  After adjustment, the parameters in a parameter type
4058          *             list in a function declarator that is part of a
4059          *             definition of that function shall not have
4060          *             incomplete type. */
4061         type_t *type = skip_typeref(entity->declaration.type);
4062         if (is_type_incomplete(type)) {
4063                 errorf(&entity->base.source_position,
4064                        "parameter '%Y' has incomplete type %T", entity->base.symbol,
4065                        entity->declaration.type);
4066         }
4067 }
4068
4069 /**
4070  * Parses function type parameters (and optionally creates variable_t entities
4071  * for them in a scope)
4072  */
4073 static void parse_parameters(function_type_t *type, scope_t *scope)
4074 {
4075         eat('(');
4076         add_anchor_token(')');
4077         int saved_comma_state = save_and_reset_anchor_state(',');
4078
4079         if (token.type == T_IDENTIFIER &&
4080             !is_typedef_symbol(token.v.symbol)) {
4081                 token_type_t la1_type = (token_type_t)look_ahead(1)->type;
4082                 if (la1_type == ',' || la1_type == ')') {
4083                         type->kr_style_parameters = true;
4084                         parse_identifier_list(scope);
4085                         goto parameters_finished;
4086                 }
4087         }
4088
4089         if (token.type == ')') {
4090                 /* ISO/IEC 14882:1998(E) §C.1.6:1 */
4091                 if (!(c_mode & _CXX))
4092                         type->unspecified_parameters = true;
4093                 goto parameters_finished;
4094         }
4095
4096         function_parameter_t *parameter;
4097         function_parameter_t *last_parameter = NULL;
4098
4099         while (true) {
4100                 switch (token.type) {
4101                 case T_DOTDOTDOT:
4102                         next_token();
4103                         type->variadic = true;
4104                         goto parameters_finished;
4105
4106                 case T_IDENTIFIER:
4107                 case T___extension__:
4108                 DECLARATION_START
4109                 {
4110                         entity_t *entity = parse_parameter();
4111                         if (entity->kind == ENTITY_TYPEDEF) {
4112                                 errorf(&entity->base.source_position,
4113                                        "typedef not allowed as function parameter");
4114                                 break;
4115                         }
4116                         assert(is_declaration(entity));
4117
4118                         /* func(void) is not a parameter */
4119                         if (last_parameter == NULL
4120                                         && token.type == ')'
4121                                         && entity->base.symbol == NULL
4122                                         && skip_typeref(entity->declaration.type) == type_void) {
4123                                 goto parameters_finished;
4124                         }
4125                         semantic_parameter_incomplete(entity);
4126
4127                         parameter = obstack_alloc(type_obst, sizeof(parameter[0]));
4128                         memset(parameter, 0, sizeof(parameter[0]));
4129                         parameter->type = entity->declaration.type;
4130
4131                         if (scope != NULL) {
4132                                 append_entity(scope, entity);
4133                         }
4134
4135                         if (last_parameter != NULL) {
4136                                 last_parameter->next = parameter;
4137                         } else {
4138                                 type->parameters = parameter;
4139                         }
4140                         last_parameter   = parameter;
4141                         break;
4142                 }
4143
4144                 default:
4145                         goto parameters_finished;
4146                 }
4147                 if (token.type != ',') {
4148                         goto parameters_finished;
4149                 }
4150                 next_token();
4151         }
4152
4153
4154 parameters_finished:
4155         rem_anchor_token(')');
4156         expect(')');
4157
4158 end_error:
4159         restore_anchor_state(',', saved_comma_state);
4160 }
4161
4162 typedef enum construct_type_kind_t {
4163         CONSTRUCT_INVALID,
4164         CONSTRUCT_POINTER,
4165         CONSTRUCT_REFERENCE,
4166         CONSTRUCT_FUNCTION,
4167         CONSTRUCT_ARRAY
4168 } construct_type_kind_t;
4169
4170 typedef struct construct_type_t construct_type_t;
4171 struct construct_type_t {
4172         construct_type_kind_t  kind;
4173         construct_type_t      *next;
4174 };
4175
4176 typedef struct parsed_pointer_t parsed_pointer_t;
4177 struct parsed_pointer_t {
4178         construct_type_t  construct_type;
4179         type_qualifiers_t type_qualifiers;
4180         variable_t        *base_variable;  /**< MS __based extension. */
4181 };
4182
4183 typedef struct parsed_reference_t parsed_reference_t;
4184 struct parsed_reference_t {
4185         construct_type_t construct_type;
4186 };
4187
4188 typedef struct construct_function_type_t construct_function_type_t;
4189 struct construct_function_type_t {
4190         construct_type_t  construct_type;
4191         type_t           *function_type;
4192 };
4193
4194 typedef struct parsed_array_t parsed_array_t;
4195 struct parsed_array_t {
4196         construct_type_t  construct_type;
4197         type_qualifiers_t type_qualifiers;
4198         bool              is_static;
4199         bool              is_variable;
4200         expression_t     *size;
4201 };
4202
4203 typedef struct construct_base_type_t construct_base_type_t;
4204 struct construct_base_type_t {
4205         construct_type_t  construct_type;
4206         type_t           *type;
4207 };
4208
4209 static construct_type_t *parse_pointer_declarator(variable_t *base_variable)
4210 {
4211         eat('*');
4212
4213         parsed_pointer_t *pointer = obstack_alloc(&temp_obst, sizeof(pointer[0]));
4214         memset(pointer, 0, sizeof(pointer[0]));
4215         pointer->construct_type.kind = CONSTRUCT_POINTER;
4216         pointer->type_qualifiers     = parse_type_qualifiers();
4217         pointer->base_variable       = base_variable;
4218
4219         return &pointer->construct_type;
4220 }
4221
4222 static construct_type_t *parse_reference_declarator(void)
4223 {
4224         eat('&');
4225
4226         parsed_reference_t *reference = obstack_alloc(&temp_obst, sizeof(reference[0]));
4227         memset(reference, 0, sizeof(reference[0]));
4228         reference->construct_type.kind = CONSTRUCT_REFERENCE;
4229
4230         return (construct_type_t*)reference;
4231 }
4232
4233 static construct_type_t *parse_array_declarator(void)
4234 {
4235         eat('[');
4236         add_anchor_token(']');
4237
4238         parsed_array_t *array = obstack_alloc(&temp_obst, sizeof(array[0]));
4239         memset(array, 0, sizeof(array[0]));
4240         array->construct_type.kind = CONSTRUCT_ARRAY;
4241
4242         if (token.type == T_static) {
4243                 array->is_static = true;
4244                 next_token();
4245         }
4246
4247         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
4248         if (type_qualifiers != 0) {
4249                 if (token.type == T_static) {
4250                         array->is_static = true;
4251                         next_token();
4252                 }
4253         }
4254         array->type_qualifiers = type_qualifiers;
4255
4256         if (token.type == '*' && look_ahead(1)->type == ']') {
4257                 array->is_variable = true;
4258                 next_token();
4259         } else if (token.type != ']') {
4260                 array->size = parse_assignment_expression();
4261         }
4262
4263         rem_anchor_token(']');
4264         expect(']');
4265
4266 end_error:
4267         return &array->construct_type;
4268 }
4269
4270 static construct_type_t *parse_function_declarator(scope_t *scope,
4271                                                    decl_modifiers_t modifiers)
4272 {
4273         type_t          *type  = allocate_type_zero(TYPE_FUNCTION);
4274         function_type_t *ftype = &type->function;
4275
4276         ftype->linkage = current_linkage;
4277
4278         switch (modifiers & (DM_CDECL | DM_STDCALL | DM_FASTCALL | DM_THISCALL)) {
4279                 case DM_NONE:     break;
4280                 case DM_CDECL:    ftype->calling_convention = CC_CDECL;    break;
4281                 case DM_STDCALL:  ftype->calling_convention = CC_STDCALL;  break;
4282                 case DM_FASTCALL: ftype->calling_convention = CC_FASTCALL; break;
4283                 case DM_THISCALL: ftype->calling_convention = CC_THISCALL; break;
4284
4285                 default:
4286                         errorf(HERE, "multiple calling conventions in declaration");
4287                         break;
4288         }
4289
4290         parse_parameters(ftype, scope);
4291
4292         construct_function_type_t *construct_function_type =
4293                 obstack_alloc(&temp_obst, sizeof(construct_function_type[0]));
4294         memset(construct_function_type, 0, sizeof(construct_function_type[0]));
4295         construct_function_type->construct_type.kind = CONSTRUCT_FUNCTION;
4296         construct_function_type->function_type       = type;
4297
4298         return &construct_function_type->construct_type;
4299 }
4300
4301 typedef struct parse_declarator_env_t {
4302         decl_modifiers_t   modifiers;
4303         symbol_t          *symbol;
4304         source_position_t  source_position;
4305         scope_t            parameters;
4306 } parse_declarator_env_t;
4307
4308 static construct_type_t *parse_inner_declarator(parse_declarator_env_t *env,
4309                 bool may_be_abstract)
4310 {
4311         /* construct a single linked list of construct_type_t's which describe
4312          * how to construct the final declarator type */
4313         construct_type_t *first      = NULL;
4314         construct_type_t *last       = NULL;
4315         gnu_attribute_t  *attributes = NULL;
4316
4317         decl_modifiers_t modifiers = parse_attributes(&attributes);
4318
4319         /* MS __based extension */
4320         based_spec_t base_spec;
4321         base_spec.base_variable = NULL;
4322
4323         for (;;) {
4324                 construct_type_t *type;
4325                 switch (token.type) {
4326                         case '&':
4327                                 if (!(c_mode & _CXX))
4328                                         errorf(HERE, "references are only available for C++");
4329                                 if (base_spec.base_variable != NULL && warning.other) {
4330                                         warningf(&base_spec.source_position,
4331                                                  "__based does not precede a pointer operator, ignored");
4332                                 }
4333                                 type = parse_reference_declarator();
4334                                 /* consumed */
4335                                 base_spec.base_variable = NULL;
4336                                 break;
4337
4338                         case '*':
4339                                 type = parse_pointer_declarator(base_spec.base_variable);
4340                                 /* consumed */
4341                                 base_spec.base_variable = NULL;
4342                                 break;
4343
4344                         case T__based:
4345                                 next_token();
4346                                 expect('(');
4347                                 add_anchor_token(')');
4348                                 parse_microsoft_based(&base_spec);
4349                                 rem_anchor_token(')');
4350                                 expect(')');
4351                                 continue;
4352
4353                         default:
4354                                 goto ptr_operator_end;
4355                 }
4356
4357                 if (last == NULL) {
4358                         first = type;
4359                         last  = type;
4360                 } else {
4361                         last->next = type;
4362                         last       = type;
4363                 }
4364
4365                 /* TODO: find out if this is correct */
4366                 modifiers |= parse_attributes(&attributes);
4367         }
4368 ptr_operator_end:
4369         if (base_spec.base_variable != NULL && warning.other) {
4370                 warningf(&base_spec.source_position,
4371                          "__based does not precede a pointer operator, ignored");
4372         }
4373
4374         if (env != NULL) {
4375                 modifiers      |= env->modifiers;
4376                 env->modifiers  = modifiers;
4377         }
4378
4379         construct_type_t *inner_types = NULL;
4380
4381         switch (token.type) {
4382         case T_IDENTIFIER:
4383                 if (env == NULL) {
4384                         errorf(HERE, "no identifier expected in typename");
4385                 } else {
4386                         env->symbol          = token.v.symbol;
4387                         env->source_position = token.source_position;
4388                 }
4389                 next_token();
4390                 break;
4391         case '(':
4392                 next_token();
4393                 add_anchor_token(')');
4394                 inner_types = parse_inner_declarator(env, may_be_abstract);
4395                 if (inner_types != NULL) {
4396                         /* All later declarators only modify the return type */
4397                         env = NULL;
4398                 }
4399                 rem_anchor_token(')');
4400                 expect(')');
4401                 break;
4402         default:
4403                 if (may_be_abstract)
4404                         break;
4405                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', NULL);
4406                 eat_until_anchor();
4407                 return NULL;
4408         }
4409
4410         construct_type_t *p = last;
4411
4412         while (true) {
4413                 construct_type_t *type;
4414                 switch (token.type) {
4415                 case '(': {
4416                         scope_t *scope = NULL;
4417                         if (env != NULL)
4418                                 scope = &env->parameters;
4419
4420                         type = parse_function_declarator(scope, modifiers);
4421                         break;
4422                 }
4423                 case '[':
4424                         type = parse_array_declarator();
4425                         break;
4426                 default:
4427                         goto declarator_finished;
4428                 }
4429
4430                 /* insert in the middle of the list (behind p) */
4431                 if (p != NULL) {
4432                         type->next = p->next;
4433                         p->next    = type;
4434                 } else {
4435                         type->next = first;
4436                         first      = type;
4437                 }
4438                 if (last == p) {
4439                         last = type;
4440                 }
4441         }
4442
4443 declarator_finished:
4444         /* append inner_types at the end of the list, we don't to set last anymore
4445          * as it's not needed anymore */
4446         if (last == NULL) {
4447                 assert(first == NULL);
4448                 first = inner_types;
4449         } else {
4450                 last->next = inner_types;
4451         }
4452
4453         return first;
4454 end_error:
4455         return NULL;
4456 }
4457
4458 static void parse_declaration_attributes(entity_t *entity)
4459 {
4460         gnu_attribute_t  *attributes = NULL;
4461         decl_modifiers_t  modifiers  = parse_attributes(&attributes);
4462
4463         if (entity == NULL)
4464                 return;
4465
4466         type_t *type;
4467         if (entity->kind == ENTITY_TYPEDEF) {
4468                 modifiers |= entity->typedefe.modifiers;
4469                 type       = entity->typedefe.type;
4470         } else {
4471                 assert(is_declaration(entity));
4472                 modifiers |= entity->declaration.modifiers;
4473                 type       = entity->declaration.type;
4474         }
4475         if (type == NULL)
4476                 return;
4477
4478         /* handle these strange/stupid mode attributes */
4479         gnu_attribute_t *attribute = attributes;
4480         for ( ; attribute != NULL; attribute = attribute->next) {
4481                 if (attribute->kind != GNU_AK_MODE || attribute->invalid)
4482                         continue;
4483
4484                 atomic_type_kind_t  akind = attribute->u.akind;
4485                 if (!is_type_signed(type)) {
4486                         switch (akind) {
4487                         case ATOMIC_TYPE_CHAR: akind = ATOMIC_TYPE_UCHAR; break;
4488                         case ATOMIC_TYPE_SHORT: akind = ATOMIC_TYPE_USHORT; break;
4489                         case ATOMIC_TYPE_INT: akind = ATOMIC_TYPE_UINT; break;
4490                         case ATOMIC_TYPE_LONGLONG: akind = ATOMIC_TYPE_ULONGLONG; break;
4491                         default:
4492                                 panic("invalid akind in mode attribute");
4493                         }
4494                 } else {
4495                         switch (akind) {
4496                         case ATOMIC_TYPE_CHAR: akind = ATOMIC_TYPE_SCHAR; break;
4497                         case ATOMIC_TYPE_SHORT: akind = ATOMIC_TYPE_SHORT; break;
4498                         case ATOMIC_TYPE_INT: akind = ATOMIC_TYPE_INT; break;
4499                         case ATOMIC_TYPE_LONGLONG: akind = ATOMIC_TYPE_LONGLONG; break;
4500                         default:
4501                                 panic("invalid akind in mode attribute");
4502                         }
4503                 }
4504
4505                 type = make_atomic_type(akind, type->base.qualifiers);
4506         }
4507
4508         type_modifiers_t type_modifiers = type->base.modifiers;
4509         if (modifiers & DM_TRANSPARENT_UNION)
4510                 modifiers |= TYPE_MODIFIER_TRANSPARENT_UNION;
4511
4512         if (type->base.modifiers != type_modifiers) {
4513                 type_t *copy = duplicate_type(type);
4514                 copy->base.modifiers = type_modifiers;
4515
4516                 type = typehash_insert(copy);
4517                 if (type != copy) {
4518                         obstack_free(type_obst, copy);
4519                 }
4520         }
4521
4522         if (entity->kind == ENTITY_TYPEDEF) {
4523                 entity->typedefe.type      = type;
4524                 entity->typedefe.modifiers = modifiers;
4525         } else {
4526                 entity->declaration.type      = type;
4527                 entity->declaration.modifiers = modifiers;
4528         }
4529 }
4530
4531 static type_t *construct_declarator_type(construct_type_t *construct_list, type_t *type)
4532 {
4533         construct_type_t *iter = construct_list;
4534         for (; iter != NULL; iter = iter->next) {
4535                 switch (iter->kind) {
4536                 case CONSTRUCT_INVALID:
4537                         internal_errorf(HERE, "invalid type construction found");
4538                 case CONSTRUCT_FUNCTION: {
4539                         construct_function_type_t *construct_function_type
4540                                 = (construct_function_type_t*) iter;
4541
4542                         type_t *function_type = construct_function_type->function_type;
4543
4544                         function_type->function.return_type = type;
4545
4546                         type_t *skipped_return_type = skip_typeref(type);
4547                         /* §6.7.5.3(1) */
4548                         if (is_type_function(skipped_return_type)) {
4549                                 errorf(HERE, "function returning function is not allowed");
4550                         } else if (is_type_array(skipped_return_type)) {
4551                                 errorf(HERE, "function returning array is not allowed");
4552                         } else {
4553                                 if (skipped_return_type->base.qualifiers != 0 && warning.other) {
4554                                         warningf(HERE,
4555                                                 "type qualifiers in return type of function type are meaningless");
4556                                 }
4557                         }
4558
4559                         type = function_type;
4560                         break;
4561                 }
4562
4563                 case CONSTRUCT_POINTER: {
4564                         if (is_type_reference(skip_typeref(type)))
4565                                 errorf(HERE, "cannot declare a pointer to reference");
4566
4567                         parsed_pointer_t *parsed_pointer = (parsed_pointer_t*) iter;
4568                         type = make_based_pointer_type(type, parsed_pointer->type_qualifiers, parsed_pointer->base_variable);
4569                         continue;
4570                 }
4571
4572                 case CONSTRUCT_REFERENCE:
4573                         if (is_type_reference(skip_typeref(type)))
4574                                 errorf(HERE, "cannot declare a reference to reference");
4575
4576                         type = make_reference_type(type);
4577                         continue;
4578
4579                 case CONSTRUCT_ARRAY: {
4580                         if (is_type_reference(skip_typeref(type)))
4581                                 errorf(HERE, "cannot declare an array of references");
4582
4583                         parsed_array_t *parsed_array  = (parsed_array_t*) iter;
4584                         type_t         *array_type    = allocate_type_zero(TYPE_ARRAY);
4585
4586                         expression_t *size_expression = parsed_array->size;
4587                         if (size_expression != NULL) {
4588                                 size_expression
4589                                         = create_implicit_cast(size_expression, type_size_t);
4590                         }
4591
4592                         array_type->base.qualifiers       = parsed_array->type_qualifiers;
4593                         array_type->array.element_type    = type;
4594                         array_type->array.is_static       = parsed_array->is_static;
4595                         array_type->array.is_variable     = parsed_array->is_variable;
4596                         array_type->array.size_expression = size_expression;
4597
4598                         if (size_expression != NULL) {
4599                                 if (is_constant_expression(size_expression)) {
4600                                         array_type->array.size_constant = true;
4601                                         array_type->array.size
4602                                                 = fold_constant(size_expression);
4603                                 } else {
4604                                         array_type->array.is_vla = true;
4605                                 }
4606                         }
4607
4608                         type_t *skipped_type = skip_typeref(type);
4609                         /* §6.7.5.2(1) */
4610                         if (is_type_incomplete(skipped_type)) {
4611                                 errorf(HERE, "array of incomplete type '%T' is not allowed", type);
4612                         } else if (is_type_function(skipped_type)) {
4613                                 errorf(HERE, "array of functions is not allowed");
4614                         }
4615                         type = array_type;
4616                         break;
4617                 }
4618                 }
4619
4620                 type_t *hashed_type = typehash_insert(type);
4621                 if (hashed_type != type) {
4622                         /* the function type was constructed earlier freeing it here will
4623                          * destroy other types... */
4624                         if (iter->kind != CONSTRUCT_FUNCTION) {
4625                                 free_type(type);
4626                         }
4627                         type = hashed_type;
4628                 }
4629         }
4630
4631         return type;
4632 }
4633
4634 static type_t *automatic_type_conversion(type_t *orig_type);
4635
4636 static type_t *semantic_parameter(const source_position_t *pos,
4637                                   type_t *type,
4638                                   const declaration_specifiers_t *specifiers,
4639                                   symbol_t *symbol)
4640 {
4641         /* §6.7.5.3:7  A declaration of a parameter as ``array of type''
4642          *             shall be adjusted to ``qualified pointer to type'',
4643          *             [...]
4644          * §6.7.5.3:8  A declaration of a parameter as ``function returning
4645          *             type'' shall be adjusted to ``pointer to function
4646          *             returning type'', as in 6.3.2.1. */
4647         type = automatic_type_conversion(type);
4648
4649         if (specifiers->is_inline && is_type_valid(type)) {
4650                 errorf(pos, "parameter '%Y' declared 'inline'", symbol);
4651         }
4652
4653         /* §6.9.1:6  The declarations in the declaration list shall contain
4654          *           no storage-class specifier other than register and no
4655          *           initializations. */
4656         if (specifiers->thread_local || (
4657                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
4658                         specifiers->storage_class != STORAGE_CLASS_REGISTER)
4659            ) {
4660                 errorf(pos, "invalid storage class for parameter '%Y'", symbol);
4661         }
4662
4663         /* delay test for incomplete type, because we might have (void)
4664          * which is legal but incomplete... */
4665
4666         return type;
4667 }
4668
4669 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
4670                                   declarator_flags_t flags)
4671 {
4672         parse_declarator_env_t env;
4673         memset(&env, 0, sizeof(env));
4674         env.modifiers = specifiers->modifiers;
4675
4676         construct_type_t *construct_type =
4677                 parse_inner_declarator(&env, (flags & DECL_MAY_BE_ABSTRACT) != 0);
4678         type_t           *orig_type      =
4679                 construct_declarator_type(construct_type, specifiers->type);
4680         type_t           *type           = skip_typeref(orig_type);
4681
4682         if (construct_type != NULL) {
4683                 obstack_free(&temp_obst, construct_type);
4684         }
4685
4686         entity_t *entity;
4687         if (specifiers->storage_class == STORAGE_CLASS_TYPEDEF) {
4688                 entity                       = allocate_entity_zero(ENTITY_TYPEDEF);
4689                 entity->base.symbol          = env.symbol;
4690                 entity->base.source_position = env.source_position;
4691                 entity->typedefe.type        = orig_type;
4692
4693                 if (anonymous_entity != NULL) {
4694                         if (is_type_compound(type)) {
4695                                 assert(anonymous_entity->compound.alias == NULL);
4696                                 assert(anonymous_entity->kind == ENTITY_STRUCT ||
4697                                        anonymous_entity->kind == ENTITY_UNION);
4698                                 anonymous_entity->compound.alias = entity;
4699                                 anonymous_entity = NULL;
4700                         } else if (is_type_enum(type)) {
4701                                 assert(anonymous_entity->enume.alias == NULL);
4702                                 assert(anonymous_entity->kind == ENTITY_ENUM);
4703                                 anonymous_entity->enume.alias = entity;
4704                                 anonymous_entity = NULL;
4705                         }
4706                 }
4707         } else {
4708                 /* create a declaration type entity */
4709                 if (flags & DECL_CREATE_COMPOUND_MEMBER) {
4710                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER);
4711
4712                         if (specifiers->is_inline && is_type_valid(type)) {
4713                                 errorf(&env.source_position,
4714                                                 "compound member '%Y' declared 'inline'", env.symbol);
4715                         }
4716
4717                         if (specifiers->thread_local ||
4718                                 specifiers->storage_class != STORAGE_CLASS_NONE) {
4719                                 errorf(&env.source_position,
4720                                            "compound member '%Y' must have no storage class",
4721                                            env.symbol);
4722                         }
4723                 } else if (flags & DECL_IS_PARAMETER) {
4724                         orig_type = semantic_parameter(&env.source_position, type,
4725                                                        specifiers, env.symbol);
4726
4727                         entity = allocate_entity_zero(ENTITY_PARAMETER);
4728                 } else if (is_type_function(type)) {
4729                         entity = allocate_entity_zero(ENTITY_FUNCTION);
4730
4731                         entity->function.is_inline  = specifiers->is_inline;
4732                         entity->function.parameters = env.parameters;
4733
4734                         if (specifiers->thread_local || (
4735                                         specifiers->storage_class != STORAGE_CLASS_EXTERN &&
4736                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
4737                                         specifiers->storage_class != STORAGE_CLASS_STATIC)
4738                            ) {
4739                                 errorf(&env.source_position,
4740                                            "invalid storage class for function '%Y'", env.symbol);
4741                         }
4742                 } else {
4743                         entity = allocate_entity_zero(ENTITY_VARIABLE);
4744
4745                         entity->variable.get_property_sym = specifiers->get_property_sym;
4746                         entity->variable.put_property_sym = specifiers->put_property_sym;
4747                         if (specifiers->alignment != 0) {
4748                                 /* TODO: add checks here */
4749                                 entity->variable.alignment = specifiers->alignment;
4750                         }
4751
4752                         if (specifiers->is_inline && is_type_valid(type)) {
4753                                 errorf(&env.source_position,
4754                                            "variable '%Y' declared 'inline'", env.symbol);
4755                         }
4756
4757                         entity->variable.thread_local = specifiers->thread_local;
4758
4759                         bool invalid_storage_class = false;
4760                         if (current_scope == file_scope) {
4761                                 if (specifiers->storage_class != STORAGE_CLASS_EXTERN &&
4762                                                 specifiers->storage_class != STORAGE_CLASS_NONE   &&
4763                                                 specifiers->storage_class != STORAGE_CLASS_STATIC) {
4764                                         invalid_storage_class = true;
4765                                 }
4766                         } else {
4767                                 if (specifiers->thread_local &&
4768                                                 specifiers->storage_class == STORAGE_CLASS_NONE) {
4769                                         invalid_storage_class = true;
4770                                 }
4771                         }
4772                         if (invalid_storage_class) {
4773                                 errorf(&env.source_position,
4774                                                 "invalid storage class for variable '%Y'", env.symbol);
4775                         }
4776                 }
4777
4778                 entity->base.source_position          = env.source_position;
4779                 entity->base.symbol                   = env.symbol;
4780                 entity->base.namespc                  = NAMESPACE_NORMAL;
4781                 entity->declaration.type              = orig_type;
4782                 entity->declaration.modifiers         = env.modifiers;
4783                 entity->declaration.deprecated_string = specifiers->deprecated_string;
4784
4785                 storage_class_t storage_class = specifiers->storage_class;
4786                 entity->declaration.declared_storage_class = storage_class;
4787
4788                 if (storage_class == STORAGE_CLASS_NONE && current_scope != file_scope)
4789                         storage_class = STORAGE_CLASS_AUTO;
4790                 entity->declaration.storage_class = storage_class;
4791         }
4792
4793         parse_declaration_attributes(entity);
4794
4795         return entity;
4796 }
4797
4798 static type_t *parse_abstract_declarator(type_t *base_type)
4799 {
4800         construct_type_t *construct_type = parse_inner_declarator(NULL, 1);
4801
4802         type_t *result = construct_declarator_type(construct_type, base_type);
4803         if (construct_type != NULL) {
4804                 obstack_free(&temp_obst, construct_type);
4805         }
4806
4807         return result;
4808 }
4809
4810 /**
4811  * Check if the declaration of main is suspicious.  main should be a
4812  * function with external linkage, returning int, taking either zero
4813  * arguments, two, or three arguments of appropriate types, ie.
4814  *
4815  * int main([ int argc, char **argv [, char **env ] ]).
4816  *
4817  * @param decl    the declaration to check
4818  * @param type    the function type of the declaration
4819  */
4820 static void check_type_of_main(const entity_t *entity)
4821 {
4822         const source_position_t *pos = &entity->base.source_position;
4823         if (entity->kind != ENTITY_FUNCTION) {
4824                 warningf(pos, "'main' is not a function");
4825                 return;
4826         }
4827
4828         if (entity->declaration.storage_class == STORAGE_CLASS_STATIC) {
4829                 warningf(pos, "'main' is normally a non-static function");
4830         }
4831
4832         type_t *type = skip_typeref(entity->declaration.type);
4833         assert(is_type_function(type));
4834
4835         function_type_t *func_type = &type->function;
4836         if (!types_compatible(skip_typeref(func_type->return_type), type_int)) {
4837                 warningf(pos, "return type of 'main' should be 'int', but is '%T'",
4838                          func_type->return_type);
4839         }
4840         const function_parameter_t *parm = func_type->parameters;
4841         if (parm != NULL) {
4842                 type_t *const first_type = parm->type;
4843                 if (!types_compatible(skip_typeref(first_type), type_int)) {
4844                         warningf(pos,
4845                                  "first argument of 'main' should be 'int', but is '%T'",
4846                                  first_type);
4847                 }
4848                 parm = parm->next;
4849                 if (parm != NULL) {
4850                         type_t *const second_type = parm->type;
4851                         if (!types_compatible(skip_typeref(second_type), type_char_ptr_ptr)) {
4852                                 warningf(pos, "second argument of 'main' should be 'char**', but is '%T'", second_type);
4853                         }
4854                         parm = parm->next;
4855                         if (parm != NULL) {
4856                                 type_t *const third_type = parm->type;
4857                                 if (!types_compatible(skip_typeref(third_type), type_char_ptr_ptr)) {
4858                                         warningf(pos, "third argument of 'main' should be 'char**', but is '%T'", third_type);
4859                                 }
4860                                 parm = parm->next;
4861                                 if (parm != NULL)
4862                                         goto warn_arg_count;
4863                         }
4864                 } else {
4865 warn_arg_count:
4866                         warningf(pos, "'main' takes only zero, two or three arguments");
4867                 }
4868         }
4869 }
4870
4871 /**
4872  * Check if a symbol is the equal to "main".
4873  */
4874 static bool is_sym_main(const symbol_t *const sym)
4875 {
4876         return strcmp(sym->string, "main") == 0;
4877 }
4878
4879 static void error_redefined_as_different_kind(const source_position_t *pos,
4880                 const entity_t *old, entity_kind_t new_kind)
4881 {
4882         errorf(pos, "redeclaration of %s '%Y' as %s (declared %P)",
4883                get_entity_kind_name(old->kind), old->base.symbol,
4884                get_entity_kind_name(new_kind), &old->base.source_position);
4885 }
4886
4887 /**
4888  * record entities for the NAMESPACE_NORMAL, and produce error messages/warnings
4889  * for various problems that occur for multiple definitions
4890  */
4891 static entity_t *record_entity(entity_t *entity, const bool is_definition)
4892 {
4893         const symbol_t *const    symbol  = entity->base.symbol;
4894         const namespace_tag_t    namespc = (namespace_tag_t)entity->base.namespc;
4895         const source_position_t *pos     = &entity->base.source_position;
4896
4897         assert(symbol != NULL);
4898         entity_t *previous_entity = get_entity(symbol, namespc);
4899         /* pushing the same entity twice will break the stack structure */
4900         assert(previous_entity != entity);
4901
4902         if (entity->kind == ENTITY_FUNCTION) {
4903                 type_t *const orig_type = entity->declaration.type;
4904                 type_t *const type      = skip_typeref(orig_type);
4905
4906                 assert(is_type_function(type));
4907                 if (type->function.unspecified_parameters &&
4908                                 warning.strict_prototypes &&
4909                                 previous_entity == NULL) {
4910                         warningf(pos, "function declaration '%#T' is not a prototype",
4911                                          orig_type, symbol);
4912                 }
4913
4914                 if (warning.main && current_scope == file_scope
4915                                 && is_sym_main(symbol)) {
4916                         check_type_of_main(entity);
4917                 }
4918         }
4919
4920         if (is_declaration(entity)) {
4921                 if (warning.nested_externs
4922                                 && entity->declaration.storage_class == STORAGE_CLASS_EXTERN
4923                                 && current_scope != file_scope) {
4924                         warningf(pos, "nested extern declaration of '%#T'",
4925                                  entity->declaration.type, symbol);
4926                 }
4927         }
4928
4929         if (previous_entity != NULL
4930             && previous_entity->base.parent_scope == &current_function->parameters
4931                 && current_scope->depth == previous_entity->base.parent_scope->depth+1){
4932
4933                 assert(previous_entity->kind == ENTITY_PARAMETER);
4934                 errorf(pos,
4935                        "declaration '%#T' redeclares the parameter '%#T' (declared %P)",
4936                        entity->declaration.type, symbol,
4937                            previous_entity->declaration.type, symbol,
4938                            &previous_entity->base.source_position);
4939                 goto finish;
4940         }
4941
4942         if (previous_entity != NULL
4943                         && previous_entity->base.parent_scope == current_scope) {
4944
4945                 if (previous_entity->kind != entity->kind) {
4946                         error_redefined_as_different_kind(pos, previous_entity,
4947                                                           entity->kind);
4948                         goto finish;
4949                 }
4950                 if (previous_entity->kind == ENTITY_ENUM_VALUE) {
4951                         errorf(pos,
4952                                    "redeclaration of enum entry '%Y' (declared %P)",
4953                                    symbol, &previous_entity->base.source_position);
4954                         goto finish;
4955                 }
4956                 if (previous_entity->kind == ENTITY_TYPEDEF) {
4957                         /* TODO: C++ allows this for exactly the same type */
4958                         errorf(pos,
4959                                "redefinition of typedef '%Y' (declared %P)",
4960                                symbol, &previous_entity->base.source_position);
4961                         goto finish;
4962                 }
4963
4964                 /* at this point we should have only VARIABLES or FUNCTIONS */
4965                 assert(is_declaration(previous_entity) && is_declaration(entity));
4966
4967                 /* can happen for K&R style declarations */
4968                 if (previous_entity->kind == ENTITY_PARAMETER
4969                                 && previous_entity->declaration.type == NULL
4970                                 && entity->kind == ENTITY_PARAMETER) {
4971                         previous_entity->declaration.type = entity->declaration.type;
4972                         previous_entity->declaration.storage_class
4973                                 = entity->declaration.storage_class;
4974                         previous_entity->declaration.declared_storage_class
4975                                 = entity->declaration.declared_storage_class;
4976                         previous_entity->declaration.modifiers
4977                                 = entity->declaration.modifiers;
4978                         previous_entity->declaration.deprecated_string
4979                                 = entity->declaration.deprecated_string;
4980                 }
4981                 assert(entity->declaration.type != NULL);
4982
4983                 declaration_t *const previous_declaration
4984                         = &previous_entity->declaration;
4985                 declaration_t *const declaration = &entity->declaration;
4986                 type_t *const orig_type = entity->declaration.type;
4987                 type_t *const type      = skip_typeref(orig_type);
4988
4989                 type_t *prev_type       = skip_typeref(previous_declaration->type);
4990
4991                 if (!types_compatible(type, prev_type)) {
4992                         errorf(pos,
4993                                    "declaration '%#T' is incompatible with '%#T' (declared %P)",
4994                                    orig_type, symbol, previous_declaration->type, symbol,
4995                                    &previous_entity->base.source_position);
4996                 } else {
4997                         unsigned old_storage_class = previous_declaration->storage_class;
4998                         if (warning.redundant_decls     && is_definition
4999                                 && previous_declaration->storage_class == STORAGE_CLASS_STATIC
5000                                 && !(previous_declaration->modifiers & DM_USED)
5001                                 && !previous_declaration->used) {
5002                                 warningf(&previous_entity->base.source_position,
5003                                          "unnecessary static forward declaration for '%#T'",
5004                                          previous_declaration->type, symbol);
5005                         }
5006
5007                         unsigned new_storage_class = declaration->storage_class;
5008                         if (is_type_incomplete(prev_type)) {
5009                                 previous_declaration->type = type;
5010                                 prev_type                  = type;
5011                         }
5012
5013                         /* pretend no storage class means extern for function
5014                          * declarations (except if the previous declaration is neither
5015                          * none nor extern) */
5016                         if (entity->kind == ENTITY_FUNCTION) {
5017                                 if (prev_type->function.unspecified_parameters) {
5018                                         previous_declaration->type = type;
5019                                         prev_type                  = type;
5020                                 }
5021
5022                                 switch (old_storage_class) {
5023                                 case STORAGE_CLASS_NONE:
5024                                         old_storage_class = STORAGE_CLASS_EXTERN;
5025                                         /* FALLTHROUGH */
5026
5027                                 case STORAGE_CLASS_EXTERN:
5028                                         if (is_definition) {
5029                                                 if (warning.missing_prototypes &&
5030                                                     prev_type->function.unspecified_parameters &&
5031                                                     !is_sym_main(symbol)) {
5032                                                         warningf(pos, "no previous prototype for '%#T'",
5033                                                                          orig_type, symbol);
5034                                                 }
5035                                         } else if (new_storage_class == STORAGE_CLASS_NONE) {
5036                                                 new_storage_class = STORAGE_CLASS_EXTERN;
5037                                         }
5038                                         break;
5039
5040                                 default:
5041                                         break;
5042                                 }
5043                         }
5044
5045                         if (old_storage_class == STORAGE_CLASS_EXTERN &&
5046                                         new_storage_class == STORAGE_CLASS_EXTERN) {
5047 warn_redundant_declaration:
5048                                 if (!is_definition           &&
5049                                     warning.redundant_decls  &&
5050                                     is_type_valid(prev_type) &&
5051                                     strcmp(previous_entity->base.source_position.input_name,
5052                                            "<builtin>") != 0) {
5053                                         warningf(pos,
5054                                                  "redundant declaration for '%Y' (declared %P)",
5055                                                  symbol, &previous_entity->base.source_position);
5056                                 }
5057                         } else if (current_function == NULL) {
5058                                 if (old_storage_class != STORAGE_CLASS_STATIC &&
5059                                     new_storage_class == STORAGE_CLASS_STATIC) {
5060                                         errorf(pos,
5061                                                "static declaration of '%Y' follows non-static declaration (declared %P)",
5062                                                symbol, &previous_entity->base.source_position);
5063                                 } else if (old_storage_class == STORAGE_CLASS_EXTERN) {
5064                                         previous_declaration->storage_class          = STORAGE_CLASS_NONE;
5065                                         previous_declaration->declared_storage_class = STORAGE_CLASS_NONE;
5066                                 } else {
5067                                         /* ISO/IEC 14882:1998(E) §C.1.2:1 */
5068                                         if (c_mode & _CXX)
5069                                                 goto error_redeclaration;
5070                                         goto warn_redundant_declaration;
5071                                 }
5072                         } else if (is_type_valid(prev_type)) {
5073                                 if (old_storage_class == new_storage_class) {
5074 error_redeclaration:
5075                                         errorf(pos, "redeclaration of '%Y' (declared %P)",
5076                                                symbol, &previous_entity->base.source_position);
5077                                 } else {
5078                                         errorf(pos,
5079                                                "redeclaration of '%Y' with different linkage (declared %P)",
5080                                                symbol, &previous_entity->base.source_position);
5081                                 }
5082                         }
5083                 }
5084
5085                 previous_declaration->modifiers |= declaration->modifiers;
5086                 if (entity->kind == ENTITY_FUNCTION) {
5087                         previous_entity->function.is_inline |= entity->function.is_inline;
5088                 }
5089                 return previous_entity;
5090         }
5091
5092         if (entity->kind == ENTITY_FUNCTION) {
5093                 if (is_definition &&
5094                                 entity->declaration.storage_class != STORAGE_CLASS_STATIC) {
5095                         if (warning.missing_prototypes && !is_sym_main(symbol)) {
5096                                 warningf(pos, "no previous prototype for '%#T'",
5097                                          entity->declaration.type, symbol);
5098                         } else if (warning.missing_declarations && !is_sym_main(symbol)) {
5099                                 warningf(pos, "no previous declaration for '%#T'",
5100                                          entity->declaration.type, symbol);
5101                         }
5102                 }
5103         } else if (warning.missing_declarations
5104                         && entity->kind == ENTITY_VARIABLE
5105                         && current_scope == file_scope) {
5106                 declaration_t *declaration = &entity->declaration;
5107                 if (declaration->storage_class == STORAGE_CLASS_NONE) {
5108                         warningf(pos, "no previous declaration for '%#T'",
5109                                  declaration->type, symbol);
5110                 }
5111         }
5112
5113 finish:
5114         assert(entity->base.parent_scope == NULL);
5115         assert(current_scope != NULL);
5116
5117         entity->base.parent_scope = current_scope;
5118         entity->base.namespc      = NAMESPACE_NORMAL;
5119         environment_push(entity);
5120         append_entity(current_scope, entity);
5121
5122         return entity;
5123 }
5124
5125 static void parser_error_multiple_definition(entity_t *entity,
5126                 const source_position_t *source_position)
5127 {
5128         errorf(source_position, "multiple definition of symbol '%Y' (declared %P)",
5129                entity->base.symbol, &entity->base.source_position);
5130 }
5131
5132 static bool is_declaration_specifier(const token_t *token,
5133                                      bool only_specifiers_qualifiers)
5134 {
5135         switch (token->type) {
5136                 TYPE_SPECIFIERS
5137                 TYPE_QUALIFIERS
5138                         return true;
5139                 case T_IDENTIFIER:
5140                         return is_typedef_symbol(token->v.symbol);
5141
5142                 case T___extension__:
5143                 STORAGE_CLASSES
5144                         return !only_specifiers_qualifiers;
5145
5146                 default:
5147                         return false;
5148         }
5149 }
5150
5151 static void parse_init_declarator_rest(entity_t *entity)
5152 {
5153         assert(is_declaration(entity));
5154         declaration_t *const declaration = &entity->declaration;
5155
5156         eat('=');
5157
5158         type_t *orig_type = declaration->type;
5159         type_t *type      = skip_typeref(orig_type);
5160
5161         if (entity->kind == ENTITY_VARIABLE
5162                         && entity->variable.initializer != NULL) {
5163                 parser_error_multiple_definition(entity, HERE);
5164         }
5165
5166         bool must_be_constant = false;
5167         if (declaration->storage_class == STORAGE_CLASS_STATIC ||
5168             entity->base.parent_scope  == file_scope) {
5169                 must_be_constant = true;
5170         }
5171
5172         if (is_type_function(type)) {
5173                 errorf(&entity->base.source_position,
5174                        "function '%#T' is initialized like a variable",
5175                        orig_type, entity->base.symbol);
5176                 orig_type = type_error_type;
5177         }
5178
5179         parse_initializer_env_t env;
5180         env.type             = orig_type;
5181         env.must_be_constant = must_be_constant;
5182         env.entity           = entity;
5183         current_init_decl    = entity;
5184
5185         initializer_t *initializer = parse_initializer(&env);
5186         current_init_decl = NULL;
5187
5188         if (entity->kind == ENTITY_VARIABLE) {
5189                 /* § 6.7.5 (22)  array initializers for arrays with unknown size
5190                  * determine the array type size */
5191                 declaration->type            = env.type;
5192                 entity->variable.initializer = initializer;
5193         }
5194 }
5195
5196 /* parse rest of a declaration without any declarator */
5197 static void parse_anonymous_declaration_rest(
5198                 const declaration_specifiers_t *specifiers)
5199 {
5200         eat(';');
5201         anonymous_entity = NULL;
5202
5203         if (warning.other) {
5204                 if (specifiers->storage_class != STORAGE_CLASS_NONE ||
5205                                 specifiers->thread_local) {
5206                         warningf(&specifiers->source_position,
5207                                  "useless storage class in empty declaration");
5208                 }
5209
5210                 type_t *type = specifiers->type;
5211                 switch (type->kind) {
5212                         case TYPE_COMPOUND_STRUCT:
5213                         case TYPE_COMPOUND_UNION: {
5214                                 if (type->compound.compound->base.symbol == NULL) {
5215                                         warningf(&specifiers->source_position,
5216                                                  "unnamed struct/union that defines no instances");
5217                                 }
5218                                 break;
5219                         }
5220
5221                         case TYPE_ENUM:
5222                                 break;
5223
5224                         default:
5225                                 warningf(&specifiers->source_position, "empty declaration");
5226                                 break;
5227                 }
5228         }
5229 }
5230
5231 static void check_variable_type_complete(entity_t *ent)
5232 {
5233         if (ent->kind != ENTITY_VARIABLE)
5234                 return;
5235
5236         /* §6.7:7  If an identifier for an object is declared with no linkage, the
5237          *         type for the object shall be complete [...] */
5238         declaration_t *decl = &ent->declaration;
5239         if (decl->storage_class != STORAGE_CLASS_NONE)
5240                 return;
5241
5242         type_t *type = decl->type;
5243         if (!is_type_incomplete(skip_typeref(type)))
5244                 return;
5245
5246         errorf(&ent->base.source_position, "variable '%#T' has incomplete type",
5247                         type, ent->base.symbol);
5248 }
5249
5250
5251 static void parse_declaration_rest(entity_t *ndeclaration,
5252                 const declaration_specifiers_t *specifiers,
5253                 parsed_declaration_func         finished_declaration,
5254                 declarator_flags_t              flags)
5255 {
5256         add_anchor_token(';');
5257         add_anchor_token(',');
5258         while (true) {
5259                 entity_t *entity = finished_declaration(ndeclaration, token.type == '=');
5260
5261                 if (token.type == '=') {
5262                         parse_init_declarator_rest(entity);
5263                 } else if (entity->kind == ENTITY_VARIABLE) {
5264                         /* ISO/IEC 14882:1998(E) §8.5.3:3  The initializer can be omitted
5265                          * [...] where the extern specifier is explicitly used. */
5266                         declaration_t *decl = &entity->declaration;
5267                         if (decl->storage_class != STORAGE_CLASS_EXTERN) {
5268                                 type_t *type = decl->type;
5269                                 if (is_type_reference(skip_typeref(type))) {
5270                                         errorf(&entity->base.source_position,
5271                                                         "reference '%#T' must be initialized",
5272                                                         type, entity->base.symbol);
5273                                 }
5274                         }
5275                 }
5276
5277                 check_variable_type_complete(entity);
5278
5279                 if (token.type != ',')
5280                         break;
5281                 eat(',');
5282
5283                 add_anchor_token('=');
5284                 ndeclaration = parse_declarator(specifiers, flags);
5285                 rem_anchor_token('=');
5286         }
5287         expect(';');
5288
5289 end_error:
5290         anonymous_entity = NULL;
5291         rem_anchor_token(';');
5292         rem_anchor_token(',');
5293 }
5294
5295 static entity_t *finished_kr_declaration(entity_t *entity, bool is_definition)
5296 {
5297         symbol_t *symbol = entity->base.symbol;
5298         if (symbol == NULL) {
5299                 errorf(HERE, "anonymous declaration not valid as function parameter");
5300                 return entity;
5301         }
5302
5303         assert(entity->base.namespc == NAMESPACE_NORMAL);
5304         entity_t *previous_entity = get_entity(symbol, NAMESPACE_NORMAL);
5305         if (previous_entity == NULL
5306                         || previous_entity->base.parent_scope != current_scope) {
5307                 errorf(HERE, "expected declaration of a function parameter, found '%Y'",
5308                        symbol);
5309                 return entity;
5310         }
5311
5312         if (is_definition) {
5313                 errorf(HERE, "parameter %Y is initialised", entity->base.symbol);
5314         }
5315
5316         return record_entity(entity, false);
5317 }
5318
5319 static void parse_declaration(parsed_declaration_func finished_declaration,
5320                               declarator_flags_t      flags)
5321 {
5322         declaration_specifiers_t specifiers;
5323         memset(&specifiers, 0, sizeof(specifiers));
5324
5325         add_anchor_token(';');
5326         parse_declaration_specifiers(&specifiers);
5327         rem_anchor_token(';');
5328
5329         if (token.type == ';') {
5330                 parse_anonymous_declaration_rest(&specifiers);
5331         } else {
5332                 entity_t *entity = parse_declarator(&specifiers, flags);
5333                 parse_declaration_rest(entity, &specifiers, finished_declaration, flags);
5334         }
5335 }
5336
5337 static type_t *get_default_promoted_type(type_t *orig_type)
5338 {
5339         type_t *result = orig_type;
5340
5341         type_t *type = skip_typeref(orig_type);
5342         if (is_type_integer(type)) {
5343                 result = promote_integer(type);
5344         } else if (type == type_float) {
5345                 result = type_double;
5346         }
5347
5348         return result;
5349 }
5350
5351 static void parse_kr_declaration_list(entity_t *entity)
5352 {
5353         if (entity->kind != ENTITY_FUNCTION)
5354                 return;
5355
5356         type_t *type = skip_typeref(entity->declaration.type);
5357         assert(is_type_function(type));
5358         if (!type->function.kr_style_parameters)
5359                 return;
5360
5361
5362         add_anchor_token('{');
5363
5364         /* push function parameters */
5365         size_t const  top       = environment_top();
5366         scope_t      *old_scope = scope_push(&entity->function.parameters);
5367
5368         entity_t *parameter = entity->function.parameters.entities;
5369         for ( ; parameter != NULL; parameter = parameter->base.next) {
5370                 assert(parameter->base.parent_scope == NULL);
5371                 parameter->base.parent_scope = current_scope;
5372                 environment_push(parameter);
5373         }
5374
5375         /* parse declaration list */
5376         while (is_declaration_specifier(&token, false)) {
5377                 parse_declaration(finished_kr_declaration, DECL_IS_PARAMETER);
5378         }
5379
5380         /* pop function parameters */
5381         assert(current_scope == &entity->function.parameters);
5382         scope_pop(old_scope);
5383         environment_pop_to(top);
5384
5385         /* update function type */
5386         type_t *new_type = duplicate_type(type);
5387
5388         function_parameter_t *parameters     = NULL;
5389         function_parameter_t *last_parameter = NULL;
5390
5391         parameter = entity->function.parameters.entities;
5392         for (; parameter != NULL; parameter = parameter->base.next) {
5393                 type_t *parameter_type = parameter->declaration.type;
5394                 if (parameter_type == NULL) {
5395                         if (strict_mode) {
5396                                 errorf(HERE, "no type specified for function parameter '%Y'",
5397                                        parameter->base.symbol);
5398                         } else {
5399                                 if (warning.implicit_int) {
5400                                         warningf(HERE, "no type specified for function parameter '%Y', using 'int'",
5401                                                  parameter->base.symbol);
5402                                 }
5403                                 parameter_type              = type_int;
5404                                 parameter->declaration.type = parameter_type;
5405                         }
5406                 }
5407
5408                 semantic_parameter_incomplete(parameter);
5409                 parameter_type = parameter->declaration.type;
5410
5411                 /*
5412                  * we need the default promoted types for the function type
5413                  */
5414                 parameter_type = get_default_promoted_type(parameter_type);
5415
5416                 function_parameter_t *function_parameter
5417                         = obstack_alloc(type_obst, sizeof(function_parameter[0]));
5418                 memset(function_parameter, 0, sizeof(function_parameter[0]));
5419
5420                 function_parameter->type = parameter_type;
5421                 if (last_parameter != NULL) {
5422                         last_parameter->next = function_parameter;
5423                 } else {
5424                         parameters = function_parameter;
5425                 }
5426                 last_parameter = function_parameter;
5427         }
5428
5429         /* § 6.9.1.7: A K&R style parameter list does NOT act as a function
5430          * prototype */
5431         new_type->function.parameters             = parameters;
5432         new_type->function.unspecified_parameters = true;
5433
5434         type = typehash_insert(new_type);
5435         if (type != new_type) {
5436                 obstack_free(type_obst, new_type);
5437         }
5438
5439         entity->declaration.type = type;
5440
5441         rem_anchor_token('{');
5442 }
5443
5444 static bool first_err = true;
5445
5446 /**
5447  * When called with first_err set, prints the name of the current function,
5448  * else does noting.
5449  */
5450 static void print_in_function(void)
5451 {
5452         if (first_err) {
5453                 first_err = false;
5454                 diagnosticf("%s: In function '%Y':\n",
5455                             current_function->base.base.source_position.input_name,
5456                             current_function->base.base.symbol);
5457         }
5458 }
5459
5460 /**
5461  * Check if all labels are defined in the current function.
5462  * Check if all labels are used in the current function.
5463  */
5464 static void check_labels(void)
5465 {
5466         for (const goto_statement_t *goto_statement = goto_first;
5467             goto_statement != NULL;
5468             goto_statement = goto_statement->next) {
5469                 /* skip computed gotos */
5470                 if (goto_statement->expression != NULL)
5471                         continue;
5472
5473                 label_t *label = goto_statement->label;
5474
5475                 label->used = true;
5476                 if (label->base.source_position.input_name == NULL) {
5477                         print_in_function();
5478                         errorf(&goto_statement->base.source_position,
5479                                "label '%Y' used but not defined", label->base.symbol);
5480                  }
5481         }
5482
5483         if (warning.unused_label) {
5484                 for (const label_statement_t *label_statement = label_first;
5485                          label_statement != NULL;
5486                          label_statement = label_statement->next) {
5487                         label_t *label = label_statement->label;
5488
5489                         if (! label->used) {
5490                                 print_in_function();
5491                                 warningf(&label_statement->base.source_position,
5492                                          "label '%Y' defined but not used", label->base.symbol);
5493                         }
5494                 }
5495         }
5496 }
5497
5498 static void warn_unused_entity(entity_t *entity, entity_t *end)
5499 {
5500         for (; entity != NULL; entity = entity->base.next) {
5501                 if (!is_declaration(entity))
5502                         continue;
5503
5504                 declaration_t *declaration = &entity->declaration;
5505                 if (declaration->implicit)
5506                         continue;
5507
5508                 if (!declaration->used) {
5509                         print_in_function();
5510                         const char *what = get_entity_kind_name(entity->kind);
5511                         warningf(&entity->base.source_position, "%s '%Y' is unused",
5512                                  what, entity->base.symbol);
5513                 } else if (entity->kind == ENTITY_VARIABLE && !entity->variable.read) {
5514                         print_in_function();
5515                         const char *what = get_entity_kind_name(entity->kind);
5516                         warningf(&entity->base.source_position, "%s '%Y' is never read",
5517                                  what, entity->base.symbol);
5518                 }
5519
5520                 if (entity == end)
5521                         break;
5522         }
5523 }
5524
5525 static void check_unused_variables(statement_t *const stmt, void *const env)
5526 {
5527         (void)env;
5528
5529         switch (stmt->kind) {
5530                 case STATEMENT_DECLARATION: {
5531                         declaration_statement_t const *const decls = &stmt->declaration;
5532                         warn_unused_entity(decls->declarations_begin,
5533                                            decls->declarations_end);
5534                         return;
5535                 }
5536
5537                 case STATEMENT_FOR:
5538                         warn_unused_entity(stmt->fors.scope.entities, NULL);
5539                         return;
5540
5541                 default:
5542                         return;
5543         }
5544 }
5545
5546 /**
5547  * Check declarations of current_function for unused entities.
5548  */
5549 static void check_declarations(void)
5550 {
5551         if (warning.unused_parameter) {
5552                 const scope_t *scope = &current_function->parameters;
5553
5554                 /* do not issue unused warnings for main */
5555                 if (!is_sym_main(current_function->base.base.symbol)) {
5556                         warn_unused_entity(scope->entities, NULL);
5557                 }
5558         }
5559         if (warning.unused_variable) {
5560                 walk_statements(current_function->statement, check_unused_variables,
5561                                 NULL);
5562         }
5563 }
5564
5565 static int determine_truth(expression_t const* const cond)
5566 {
5567         return
5568                 !is_constant_expression(cond) ? 0 :
5569                 fold_constant(cond) != 0      ? 1 :
5570                 -1;
5571 }
5572
5573 static void check_reachable(statement_t *);
5574
5575 static bool expression_returns(expression_t const *const expr)
5576 {
5577         switch (expr->kind) {
5578                 case EXPR_CALL: {
5579                         expression_t const *const func = expr->call.function;
5580                         if (func->kind == EXPR_REFERENCE) {
5581                                 entity_t *entity = func->reference.entity;
5582                                 if (entity->kind == ENTITY_FUNCTION
5583                                                 && entity->declaration.modifiers & DM_NORETURN)
5584                                         return false;
5585                         }
5586
5587                         if (!expression_returns(func))
5588                                 return false;
5589
5590                         for (call_argument_t const* arg = expr->call.arguments; arg != NULL; arg = arg->next) {
5591                                 if (!expression_returns(arg->expression))
5592                                         return false;
5593                         }
5594
5595                         return true;
5596                 }
5597
5598                 case EXPR_REFERENCE:
5599                 case EXPR_REFERENCE_ENUM_VALUE:
5600                 case EXPR_CONST:
5601                 case EXPR_CHARACTER_CONSTANT:
5602                 case EXPR_WIDE_CHARACTER_CONSTANT:
5603                 case EXPR_STRING_LITERAL:
5604                 case EXPR_WIDE_STRING_LITERAL:
5605                 case EXPR_COMPOUND_LITERAL: // TODO descend into initialisers
5606                 case EXPR_LABEL_ADDRESS:
5607                 case EXPR_CLASSIFY_TYPE:
5608                 case EXPR_SIZEOF: // TODO handle obscure VLA case
5609                 case EXPR_ALIGNOF:
5610                 case EXPR_FUNCNAME:
5611                 case EXPR_BUILTIN_SYMBOL:
5612                 case EXPR_BUILTIN_CONSTANT_P:
5613                 case EXPR_BUILTIN_PREFETCH:
5614                 case EXPR_OFFSETOF:
5615                 case EXPR_INVALID:
5616                         return true;
5617
5618                 case EXPR_STATEMENT:
5619                         check_reachable(expr->statement.statement);
5620                         // TODO check if statement can be left
5621                         return true;
5622
5623                 case EXPR_CONDITIONAL:
5624                         // TODO handle constant expression
5625                         return
5626                                 expression_returns(expr->conditional.condition) && (
5627                                         expression_returns(expr->conditional.true_expression) ||
5628                                         expression_returns(expr->conditional.false_expression)
5629                                 );
5630
5631                 case EXPR_SELECT:
5632                         return expression_returns(expr->select.compound);
5633
5634                 case EXPR_ARRAY_ACCESS:
5635                         return
5636                                 expression_returns(expr->array_access.array_ref) &&
5637                                 expression_returns(expr->array_access.index);
5638
5639                 case EXPR_VA_START:
5640                         return expression_returns(expr->va_starte.ap);
5641
5642                 case EXPR_VA_ARG:
5643                         return expression_returns(expr->va_arge.ap);
5644
5645                 EXPR_UNARY_CASES_MANDATORY
5646                         return expression_returns(expr->unary.value);
5647
5648                 case EXPR_UNARY_THROW:
5649                         return false;
5650
5651                 EXPR_BINARY_CASES
5652                         // TODO handle constant lhs of && and ||
5653                         return
5654                                 expression_returns(expr->binary.left) &&
5655                                 expression_returns(expr->binary.right);
5656
5657                 case EXPR_UNKNOWN:
5658                         break;
5659         }
5660
5661         panic("unhandled expression");
5662 }
5663
5664 static bool initializer_returns(initializer_t const *const init)
5665 {
5666         switch (init->kind) {
5667                 case INITIALIZER_VALUE:
5668                         return expression_returns(init->value.value);
5669
5670                 case INITIALIZER_LIST: {
5671                         initializer_t * const*       i       = init->list.initializers;
5672                         initializer_t * const* const end     = i + init->list.len;
5673                         bool                         returns = true;
5674                         for (; i != end; ++i) {
5675                                 if (!initializer_returns(*i))
5676                                         returns = false;
5677                         }
5678                         return returns;
5679                 }
5680
5681                 case INITIALIZER_STRING:
5682                 case INITIALIZER_WIDE_STRING:
5683                 case INITIALIZER_DESIGNATOR: // designators have no payload
5684                         return true;
5685         }
5686         panic("unhandled initializer");
5687 }
5688
5689 static bool noreturn_candidate;
5690
5691 static void check_reachable(statement_t *const stmt)
5692 {
5693         if (stmt->base.reachable)
5694                 return;
5695         if (stmt->kind != STATEMENT_DO_WHILE)
5696                 stmt->base.reachable = true;
5697
5698         statement_t *last = stmt;
5699         statement_t *next;
5700         switch (stmt->kind) {
5701                 case STATEMENT_INVALID:
5702                 case STATEMENT_EMPTY:
5703                 case STATEMENT_LOCAL_LABEL:
5704                 case STATEMENT_ASM:
5705                         next = stmt->base.next;
5706                         break;
5707
5708                 case STATEMENT_DECLARATION: {
5709                         declaration_statement_t const *const decl = &stmt->declaration;
5710                         entity_t                const *      ent  = decl->declarations_begin;
5711                         entity_t                const *const last = decl->declarations_end;
5712                         for (;; ent = ent->base.next) {
5713                                 if (ent->kind                 == ENTITY_VARIABLE &&
5714                                                 ent->variable.initializer != NULL            &&
5715                                                 !initializer_returns(ent->variable.initializer)) {
5716                                         return;
5717                                 }
5718                                 if (ent == last)
5719                                         break;
5720                         }
5721                         next = stmt->base.next;
5722                         break;
5723                 }
5724
5725                 case STATEMENT_COMPOUND:
5726                         next = stmt->compound.statements;
5727                         break;
5728
5729                 case STATEMENT_RETURN: {
5730                         expression_t const *const val = stmt->returns.value;
5731                         if (val == NULL || expression_returns(val))
5732                                 noreturn_candidate = false;
5733                         return;
5734                 }
5735
5736                 case STATEMENT_IF: {
5737                         if_statement_t const *const ifs  = &stmt->ifs;
5738                         expression_t   const *const cond = ifs->condition;
5739
5740                         if (!expression_returns(cond))
5741                                 return;
5742
5743                         int const val = determine_truth(cond);
5744
5745                         if (val >= 0)
5746                                 check_reachable(ifs->true_statement);
5747
5748                         if (val > 0)
5749                                 return;
5750
5751                         if (ifs->false_statement != NULL) {
5752                                 check_reachable(ifs->false_statement);
5753                                 return;
5754                         }
5755
5756                         next = stmt->base.next;
5757                         break;
5758                 }
5759
5760                 case STATEMENT_SWITCH: {
5761                         switch_statement_t const *const switchs = &stmt->switchs;
5762                         expression_t       const *const expr    = switchs->expression;
5763
5764                         if (!expression_returns(expr))
5765                                 return;
5766
5767                         if (is_constant_expression(expr)) {
5768                                 long                    const val      = fold_constant(expr);
5769                                 case_label_statement_t *      defaults = NULL;
5770                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
5771                                         if (i->expression == NULL) {
5772                                                 defaults = i;
5773                                                 continue;
5774                                         }
5775
5776                                         if (i->first_case <= val && val <= i->last_case) {
5777                                                 check_reachable((statement_t*)i);
5778                                                 return;
5779                                         }
5780                                 }
5781
5782                                 if (defaults != NULL) {
5783                                         check_reachable((statement_t*)defaults);
5784                                         return;
5785                                 }
5786                         } else {
5787                                 bool has_default = false;
5788                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
5789                                         if (i->expression == NULL)
5790                                                 has_default = true;
5791
5792                                         check_reachable((statement_t*)i);
5793                                 }
5794
5795                                 if (has_default)
5796                                         return;
5797                         }
5798
5799                         next = stmt->base.next;
5800                         break;
5801                 }
5802
5803                 case STATEMENT_EXPRESSION: {
5804                         /* Check for noreturn function call */
5805                         expression_t const *const expr = stmt->expression.expression;
5806                         if (!expression_returns(expr))
5807                                 return;
5808
5809                         next = stmt->base.next;
5810                         break;
5811                 }
5812
5813                 case STATEMENT_CONTINUE: {
5814                         statement_t *parent = stmt;
5815                         for (;;) {
5816                                 parent = parent->base.parent;
5817                                 if (parent == NULL) /* continue not within loop */
5818                                         return;
5819
5820                                 next = parent;
5821                                 switch (parent->kind) {
5822                                         case STATEMENT_WHILE:    goto continue_while;
5823                                         case STATEMENT_DO_WHILE: goto continue_do_while;
5824                                         case STATEMENT_FOR:      goto continue_for;
5825
5826                                         default: break;
5827                                 }
5828                         }
5829                 }
5830
5831                 case STATEMENT_BREAK: {
5832                         statement_t *parent = stmt;
5833                         for (;;) {
5834                                 parent = parent->base.parent;
5835                                 if (parent == NULL) /* break not within loop/switch */
5836                                         return;
5837
5838                                 switch (parent->kind) {
5839                                         case STATEMENT_SWITCH:
5840                                         case STATEMENT_WHILE:
5841                                         case STATEMENT_DO_WHILE:
5842                                         case STATEMENT_FOR:
5843                                                 last = parent;
5844                                                 next = parent->base.next;
5845                                                 goto found_break_parent;
5846
5847                                         default: break;
5848                                 }
5849                         }
5850 found_break_parent:
5851                         break;
5852                 }
5853
5854                 case STATEMENT_GOTO:
5855                         if (stmt->gotos.expression) {
5856                                 if (!expression_returns(stmt->gotos.expression))
5857                                         return;
5858
5859                                 statement_t *parent = stmt->base.parent;
5860                                 if (parent == NULL) /* top level goto */
5861                                         return;
5862                                 next = parent;
5863                         } else {
5864                                 next = stmt->gotos.label->statement;
5865                                 if (next == NULL) /* missing label */
5866                                         return;
5867                         }
5868                         break;
5869
5870                 case STATEMENT_LABEL:
5871                         next = stmt->label.statement;
5872                         break;
5873
5874                 case STATEMENT_CASE_LABEL:
5875                         next = stmt->case_label.statement;
5876                         break;
5877
5878                 case STATEMENT_WHILE: {
5879                         while_statement_t const *const whiles = &stmt->whiles;
5880                         expression_t      const *const cond   = whiles->condition;
5881
5882                         if (!expression_returns(cond))
5883                                 return;
5884
5885                         int const val = determine_truth(cond);
5886
5887                         if (val >= 0)
5888                                 check_reachable(whiles->body);
5889
5890                         if (val > 0)
5891                                 return;
5892
5893                         next = stmt->base.next;
5894                         break;
5895                 }
5896
5897                 case STATEMENT_DO_WHILE:
5898                         next = stmt->do_while.body;
5899                         break;
5900
5901                 case STATEMENT_FOR: {
5902                         for_statement_t *const fors = &stmt->fors;
5903
5904                         if (fors->condition_reachable)
5905                                 return;
5906                         fors->condition_reachable = true;
5907
5908                         expression_t const *const cond = fors->condition;
5909
5910                         int val;
5911                         if (cond == NULL) {
5912                                 val = 1;
5913                         } else if (expression_returns(cond)) {
5914                                 val = determine_truth(cond);
5915                         } else {
5916                                 return;
5917                         }
5918
5919                         if (val >= 0)
5920                                 check_reachable(fors->body);
5921
5922                         if (val > 0)
5923                                 return;
5924
5925                         next = stmt->base.next;
5926                         break;
5927                 }
5928
5929                 case STATEMENT_MS_TRY: {
5930                         ms_try_statement_t const *const ms_try = &stmt->ms_try;
5931                         check_reachable(ms_try->try_statement);
5932                         next = ms_try->final_statement;
5933                         break;
5934                 }
5935
5936                 case STATEMENT_LEAVE: {
5937                         statement_t *parent = stmt;
5938                         for (;;) {
5939                                 parent = parent->base.parent;
5940                                 if (parent == NULL) /* __leave not within __try */
5941                                         return;
5942
5943                                 if (parent->kind == STATEMENT_MS_TRY) {
5944                                         last = parent;
5945                                         next = parent->ms_try.final_statement;
5946                                         break;
5947                                 }
5948                         }
5949                         break;
5950                 }
5951         }
5952
5953         while (next == NULL) {
5954                 next = last->base.parent;
5955                 if (next == NULL) {
5956                         noreturn_candidate = false;
5957
5958                         type_t *const type = current_function->base.type;
5959                         assert(is_type_function(type));
5960                         type_t *const ret  = skip_typeref(type->function.return_type);
5961                         if (warning.return_type                    &&
5962                             !is_type_atomic(ret, ATOMIC_TYPE_VOID) &&
5963                             is_type_valid(ret)                     &&
5964                             !is_sym_main(current_function->base.base.symbol)) {
5965                                 warningf(&stmt->base.source_position,
5966                                          "control reaches end of non-void function");
5967                         }
5968                         return;
5969                 }
5970
5971                 switch (next->kind) {
5972                         case STATEMENT_INVALID:
5973                         case STATEMENT_EMPTY:
5974                         case STATEMENT_DECLARATION:
5975                         case STATEMENT_LOCAL_LABEL:
5976                         case STATEMENT_EXPRESSION:
5977                         case STATEMENT_ASM:
5978                         case STATEMENT_RETURN:
5979                         case STATEMENT_CONTINUE:
5980                         case STATEMENT_BREAK:
5981                         case STATEMENT_GOTO:
5982                         case STATEMENT_LEAVE:
5983                                 panic("invalid control flow in function");
5984
5985                         case STATEMENT_COMPOUND:
5986                         case STATEMENT_IF:
5987                         case STATEMENT_SWITCH:
5988                         case STATEMENT_LABEL:
5989                         case STATEMENT_CASE_LABEL:
5990                                 last = next;
5991                                 next = next->base.next;
5992                                 break;
5993
5994                         case STATEMENT_WHILE: {
5995 continue_while:
5996                                 if (next->base.reachable)
5997                                         return;
5998                                 next->base.reachable = true;
5999
6000                                 while_statement_t const *const whiles = &next->whiles;
6001                                 expression_t      const *const cond   = whiles->condition;
6002
6003                                 if (!expression_returns(cond))
6004                                         return;
6005
6006                                 int const val = determine_truth(cond);
6007
6008                                 if (val >= 0)
6009                                         check_reachable(whiles->body);
6010
6011                                 if (val > 0)
6012                                         return;
6013
6014                                 last = next;
6015                                 next = next->base.next;
6016                                 break;
6017                         }
6018
6019                         case STATEMENT_DO_WHILE: {
6020 continue_do_while:
6021                                 if (next->base.reachable)
6022                                         return;
6023                                 next->base.reachable = true;
6024
6025                                 do_while_statement_t const *const dw   = &next->do_while;
6026                                 expression_t         const *const cond = dw->condition;
6027
6028                                 if (!expression_returns(cond))
6029                                         return;
6030
6031                                 int const val = determine_truth(cond);
6032
6033                                 if (val >= 0)
6034                                         check_reachable(dw->body);
6035
6036                                 if (val > 0)
6037                                         return;
6038
6039                                 last = next;
6040                                 next = next->base.next;
6041                                 break;
6042                         }
6043
6044                         case STATEMENT_FOR: {
6045 continue_for:;
6046                                 for_statement_t *const fors = &next->fors;
6047
6048                                 fors->step_reachable = true;
6049
6050                                 if (fors->condition_reachable)
6051                                         return;
6052                                 fors->condition_reachable = true;
6053
6054                                 expression_t const *const cond = fors->condition;
6055
6056                                 int val;
6057                                 if (cond == NULL) {
6058                                         val = 1;
6059                                 } else if (expression_returns(cond)) {
6060                                         val = determine_truth(cond);
6061                                 } else {
6062                                         return;
6063                                 }
6064
6065                                 if (val >= 0)
6066                                         check_reachable(fors->body);
6067
6068                                 if (val > 0)
6069                                         return;
6070
6071                                 last = next;
6072                                 next = next->base.next;
6073                                 break;
6074                         }
6075
6076                         case STATEMENT_MS_TRY:
6077                                 last = next;
6078                                 next = next->ms_try.final_statement;
6079                                 break;
6080                 }
6081         }
6082
6083         check_reachable(next);
6084 }
6085
6086 static void check_unreachable(statement_t* const stmt, void *const env)
6087 {
6088         (void)env;
6089
6090         switch (stmt->kind) {
6091                 case STATEMENT_DO_WHILE:
6092                         if (!stmt->base.reachable) {
6093                                 expression_t const *const cond = stmt->do_while.condition;
6094                                 if (determine_truth(cond) >= 0) {
6095                                         warningf(&cond->base.source_position,
6096                                                  "condition of do-while-loop is unreachable");
6097                                 }
6098                         }
6099                         return;
6100
6101                 case STATEMENT_FOR: {
6102                         for_statement_t const* const fors = &stmt->fors;
6103
6104                         // if init and step are unreachable, cond is unreachable, too
6105                         if (!stmt->base.reachable && !fors->step_reachable) {
6106                                 warningf(&stmt->base.source_position, "statement is unreachable");
6107                         } else {
6108                                 if (!stmt->base.reachable && fors->initialisation != NULL) {
6109                                         warningf(&fors->initialisation->base.source_position,
6110                                                  "initialisation of for-statement is unreachable");
6111                                 }
6112
6113                                 if (!fors->condition_reachable && fors->condition != NULL) {
6114                                         warningf(&fors->condition->base.source_position,
6115                                                  "condition of for-statement is unreachable");
6116                                 }
6117
6118                                 if (!fors->step_reachable && fors->step != NULL) {
6119                                         warningf(&fors->step->base.source_position,
6120                                                  "step of for-statement is unreachable");
6121                                 }
6122                         }
6123                         return;
6124                 }
6125
6126                 case STATEMENT_COMPOUND:
6127                         if (stmt->compound.statements != NULL)
6128                                 return;
6129                         goto warn_unreachable;
6130
6131                 case STATEMENT_DECLARATION: {
6132                         /* Only warn if there is at least one declarator with an initializer.
6133                          * This typically occurs in switch statements. */
6134                         declaration_statement_t const *const decl = &stmt->declaration;
6135                         entity_t                const *      ent  = decl->declarations_begin;
6136                         entity_t                const *const last = decl->declarations_end;
6137                         for (;; ent = ent->base.next) {
6138                                 if (ent->kind                 == ENTITY_VARIABLE &&
6139                                                 ent->variable.initializer != NULL) {
6140                                         goto warn_unreachable;
6141                                 }
6142                                 if (ent == last)
6143                                         return;
6144                         }
6145                 }
6146
6147                 default:
6148 warn_unreachable:
6149                         if (!stmt->base.reachable)
6150                                 warningf(&stmt->base.source_position, "statement is unreachable");
6151                         return;
6152         }
6153 }
6154
6155 static void parse_external_declaration(void)
6156 {
6157         /* function-definitions and declarations both start with declaration
6158          * specifiers */
6159         declaration_specifiers_t specifiers;
6160         memset(&specifiers, 0, sizeof(specifiers));
6161
6162         add_anchor_token(';');
6163         parse_declaration_specifiers(&specifiers);
6164         rem_anchor_token(';');
6165
6166         /* must be a declaration */
6167         if (token.type == ';') {
6168                 parse_anonymous_declaration_rest(&specifiers);
6169                 return;
6170         }
6171
6172         add_anchor_token(',');
6173         add_anchor_token('=');
6174         add_anchor_token(';');
6175         add_anchor_token('{');
6176
6177         /* declarator is common to both function-definitions and declarations */
6178         entity_t *ndeclaration = parse_declarator(&specifiers, DECL_FLAGS_NONE);
6179
6180         rem_anchor_token('{');
6181         rem_anchor_token(';');
6182         rem_anchor_token('=');
6183         rem_anchor_token(',');
6184
6185         /* must be a declaration */
6186         switch (token.type) {
6187                 case ',':
6188                 case ';':
6189                 case '=':
6190                         parse_declaration_rest(ndeclaration, &specifiers, record_entity,
6191                                         DECL_FLAGS_NONE);
6192                         return;
6193         }
6194
6195         /* must be a function definition */
6196         parse_kr_declaration_list(ndeclaration);
6197
6198         if (token.type != '{') {
6199                 parse_error_expected("while parsing function definition", '{', NULL);
6200                 eat_until_matching_token(';');
6201                 return;
6202         }
6203
6204         assert(is_declaration(ndeclaration));
6205         type_t *type = skip_typeref(ndeclaration->declaration.type);
6206
6207         if (!is_type_function(type)) {
6208                 if (is_type_valid(type)) {
6209                         errorf(HERE, "declarator '%#T' has a body but is not a function type",
6210                                type, ndeclaration->base.symbol);
6211                 }
6212                 eat_block();
6213                 return;
6214         }
6215
6216         if (warning.aggregate_return &&
6217             is_type_compound(skip_typeref(type->function.return_type))) {
6218                 warningf(HERE, "function '%Y' returns an aggregate",
6219                          ndeclaration->base.symbol);
6220         }
6221         if (warning.traditional && !type->function.unspecified_parameters) {
6222                 warningf(HERE, "traditional C rejects ISO C style function definition of function '%Y'",
6223                         ndeclaration->base.symbol);
6224         }
6225         if (warning.old_style_definition && type->function.unspecified_parameters) {
6226                 warningf(HERE, "old-style function definition '%Y'",
6227                         ndeclaration->base.symbol);
6228         }
6229
6230         /* § 6.7.5.3 (14) a function definition with () means no
6231          * parameters (and not unspecified parameters) */
6232         if (type->function.unspecified_parameters
6233                         && type->function.parameters == NULL
6234                         && !type->function.kr_style_parameters) {
6235                 type_t *duplicate = duplicate_type(type);
6236                 duplicate->function.unspecified_parameters = false;
6237
6238                 type = typehash_insert(duplicate);
6239                 if (type != duplicate) {
6240                         obstack_free(type_obst, duplicate);
6241                 }
6242                 ndeclaration->declaration.type = type;
6243         }
6244
6245         entity_t *const entity = record_entity(ndeclaration, true);
6246         assert(entity->kind == ENTITY_FUNCTION);
6247         assert(ndeclaration->kind == ENTITY_FUNCTION);
6248
6249         function_t *function = &entity->function;
6250         if (ndeclaration != entity) {
6251                 function->parameters = ndeclaration->function.parameters;
6252         }
6253         assert(is_declaration(entity));
6254         type = skip_typeref(entity->declaration.type);
6255
6256         /* push function parameters and switch scope */
6257         size_t const  top       = environment_top();
6258         scope_t      *old_scope = scope_push(&function->parameters);
6259
6260         entity_t *parameter = function->parameters.entities;
6261         for (; parameter != NULL; parameter = parameter->base.next) {
6262                 if (parameter->base.parent_scope == &ndeclaration->function.parameters) {
6263                         parameter->base.parent_scope = current_scope;
6264                 }
6265                 assert(parameter->base.parent_scope == NULL
6266                                 || parameter->base.parent_scope == current_scope);
6267                 parameter->base.parent_scope = current_scope;
6268                 if (parameter->base.symbol == NULL) {
6269                         errorf(&parameter->base.source_position, "parameter name omitted");
6270                         continue;
6271                 }
6272                 environment_push(parameter);
6273         }
6274
6275         if (function->statement != NULL) {
6276                 parser_error_multiple_definition(entity, HERE);
6277                 eat_block();
6278         } else {
6279                 /* parse function body */
6280                 int         label_stack_top      = label_top();
6281                 function_t *old_current_function = current_function;
6282                 current_function                 = function;
6283                 current_parent                   = NULL;
6284
6285                 goto_first   = NULL;
6286                 goto_anchor  = &goto_first;
6287                 label_first  = NULL;
6288                 label_anchor = &label_first;
6289
6290                 statement_t *const body = parse_compound_statement(false);
6291                 function->statement = body;
6292                 first_err = true;
6293                 check_labels();
6294                 check_declarations();
6295                 if (warning.return_type      ||
6296                     warning.unreachable_code ||
6297                     (warning.missing_noreturn
6298                      && !(function->base.modifiers & DM_NORETURN))) {
6299                         noreturn_candidate = true;
6300                         check_reachable(body);
6301                         if (warning.unreachable_code)
6302                                 walk_statements(body, check_unreachable, NULL);
6303                         if (warning.missing_noreturn &&
6304                             noreturn_candidate       &&
6305                             !(function->base.modifiers & DM_NORETURN)) {
6306                                 warningf(&body->base.source_position,
6307                                          "function '%#T' is candidate for attribute 'noreturn'",
6308                                          type, entity->base.symbol);
6309                         }
6310                 }
6311
6312                 assert(current_parent   == NULL);
6313                 assert(current_function == function);
6314                 current_function = old_current_function;
6315                 label_pop_to(label_stack_top);
6316         }
6317
6318         assert(current_scope == &function->parameters);
6319         scope_pop(old_scope);
6320         environment_pop_to(top);
6321 }
6322
6323 static type_t *make_bitfield_type(type_t *base_type, expression_t *size,
6324                                   source_position_t *source_position,
6325                                   const symbol_t *symbol)
6326 {
6327         type_t *type = allocate_type_zero(TYPE_BITFIELD);
6328
6329         type->bitfield.base_type       = base_type;
6330         type->bitfield.size_expression = size;
6331
6332         il_size_t bit_size;
6333         type_t *skipped_type = skip_typeref(base_type);
6334         if (!is_type_integer(skipped_type)) {
6335                 errorf(HERE, "bitfield base type '%T' is not an integer type",
6336                         base_type);
6337                 bit_size = 0;
6338         } else {
6339                 bit_size = skipped_type->base.size * 8;
6340         }
6341
6342         if (is_constant_expression(size)) {
6343                 long v = fold_constant(size);
6344
6345                 if (v < 0) {
6346                         errorf(source_position, "negative width in bit-field '%Y'", symbol);
6347                 } else if (v == 0) {
6348                         errorf(source_position, "zero width for bit-field '%Y'", symbol);
6349                 } else if (bit_size > 0 && (il_size_t)v > bit_size) {
6350                         errorf(source_position, "width of '%Y' exceeds its type", symbol);
6351                 } else {
6352                         type->bitfield.bit_size = v;
6353                 }
6354         }
6355
6356         return type;
6357 }
6358
6359 static entity_t *find_compound_entry(compound_t *compound, symbol_t *symbol)
6360 {
6361         entity_t *iter = compound->members.entities;
6362         for (; iter != NULL; iter = iter->base.next) {
6363                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
6364                         continue;
6365
6366                 if (iter->base.symbol == symbol) {
6367                         return iter;
6368                 } else if (iter->base.symbol == NULL) {
6369                         type_t *type = skip_typeref(iter->declaration.type);
6370                         if (is_type_compound(type)) {
6371                                 entity_t *result
6372                                         = find_compound_entry(type->compound.compound, symbol);
6373                                 if (result != NULL)
6374                                         return result;
6375                         }
6376                         continue;
6377                 }
6378         }
6379
6380         return NULL;
6381 }
6382
6383 static void parse_compound_declarators(compound_t *compound,
6384                 const declaration_specifiers_t *specifiers)
6385 {
6386         while (true) {
6387                 entity_t *entity;
6388
6389                 if (token.type == ':') {
6390                         source_position_t source_position = *HERE;
6391                         next_token();
6392
6393                         type_t *base_type = specifiers->type;
6394                         expression_t *size = parse_constant_expression();
6395
6396                         type_t *type = make_bitfield_type(base_type, size,
6397                                         &source_position, sym_anonymous);
6398
6399                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER);
6400                         entity->base.namespc                       = NAMESPACE_NORMAL;
6401                         entity->base.source_position               = source_position;
6402                         entity->declaration.declared_storage_class = STORAGE_CLASS_NONE;
6403                         entity->declaration.storage_class          = STORAGE_CLASS_NONE;
6404                         entity->declaration.modifiers              = specifiers->modifiers;
6405                         entity->declaration.type                   = type;
6406                 } else {
6407                         entity = parse_declarator(specifiers,
6408                                         DECL_MAY_BE_ABSTRACT | DECL_CREATE_COMPOUND_MEMBER);
6409                         assert(entity->kind == ENTITY_COMPOUND_MEMBER);
6410
6411                         if (token.type == ':') {
6412                                 source_position_t source_position = *HERE;
6413                                 next_token();
6414                                 expression_t *size = parse_constant_expression();
6415
6416                                 type_t *type = entity->declaration.type;
6417                                 type_t *bitfield_type = make_bitfield_type(type, size,
6418                                                 &source_position, entity->base.symbol);
6419                                 entity->declaration.type = bitfield_type;
6420                         }
6421                 }
6422
6423                 /* make sure we don't define a symbol multiple times */
6424                 symbol_t *symbol = entity->base.symbol;
6425                 if (symbol != NULL) {
6426                         entity_t *prev = find_compound_entry(compound, symbol);
6427
6428                         if (prev != NULL) {
6429                                 errorf(&entity->base.source_position,
6430                                        "multiple declarations of symbol '%Y' (declared %P)",
6431                                        symbol, &prev->base.source_position);
6432                         }
6433                 }
6434
6435                 append_entity(&compound->members, entity);
6436
6437                 type_t *orig_type = entity->declaration.type;
6438                 type_t *type      = skip_typeref(orig_type);
6439                 if (is_type_function(type)) {
6440                         errorf(&entity->base.source_position,
6441                                         "compound member '%Y' must not have function type '%T'",
6442                                         entity->base.symbol, orig_type);
6443                 } else if (is_type_incomplete(type)) {
6444                         /* §6.7.2.1:16 flexible array member */
6445                         if (is_type_array(type) &&
6446                                         token.type == ';'   &&
6447                                         look_ahead(1)->type == '}') {
6448                                 compound->has_flexible_member = true;
6449                         } else {
6450                                 errorf(&entity->base.source_position,
6451                                                 "compound member '%Y' has incomplete type '%T'",
6452                                                 entity->base.symbol, orig_type);
6453                         }
6454                 }
6455
6456                 if (token.type != ',')
6457                         break;
6458                 next_token();
6459         }
6460         expect(';');
6461
6462 end_error:
6463         anonymous_entity = NULL;
6464 }
6465
6466 static void parse_compound_type_entries(compound_t *compound)
6467 {
6468         eat('{');
6469         add_anchor_token('}');
6470
6471         while (token.type != '}') {
6472                 if (token.type == T_EOF) {
6473                         errorf(HERE, "EOF while parsing struct");
6474                         break;
6475                 }
6476                 declaration_specifiers_t specifiers;
6477                 memset(&specifiers, 0, sizeof(specifiers));
6478                 parse_declaration_specifiers(&specifiers);
6479
6480                 parse_compound_declarators(compound, &specifiers);
6481         }
6482         rem_anchor_token('}');
6483         next_token();
6484
6485         /* §6.7.2.1:7 */
6486         compound->complete = true;
6487 }
6488
6489 static type_t *parse_typename(void)
6490 {
6491         declaration_specifiers_t specifiers;
6492         memset(&specifiers, 0, sizeof(specifiers));
6493         parse_declaration_specifiers(&specifiers);
6494         if (specifiers.storage_class != STORAGE_CLASS_NONE ||
6495                         specifiers.thread_local) {
6496                 /* TODO: improve error message, user does probably not know what a
6497                  * storage class is...
6498                  */
6499                 errorf(HERE, "typename may not have a storage class");
6500         }
6501
6502         type_t *result = parse_abstract_declarator(specifiers.type);
6503
6504         return result;
6505 }
6506
6507
6508
6509
6510 typedef expression_t* (*parse_expression_function)(void);
6511 typedef expression_t* (*parse_expression_infix_function)(expression_t *left);
6512
6513 typedef struct expression_parser_function_t expression_parser_function_t;
6514 struct expression_parser_function_t {
6515         parse_expression_function        parser;
6516         unsigned                         infix_precedence;
6517         parse_expression_infix_function  infix_parser;
6518 };
6519
6520 expression_parser_function_t expression_parsers[T_LAST_TOKEN];
6521
6522 /**
6523  * Prints an error message if an expression was expected but not read
6524  */
6525 static expression_t *expected_expression_error(void)
6526 {
6527         /* skip the error message if the error token was read */
6528         if (token.type != T_ERROR) {
6529                 errorf(HERE, "expected expression, got token '%K'", &token);
6530         }
6531         next_token();
6532
6533         return create_invalid_expression();
6534 }
6535
6536 /**
6537  * Parse a string constant.
6538  */
6539 static expression_t *parse_string_const(void)
6540 {
6541         wide_string_t wres;
6542         if (token.type == T_STRING_LITERAL) {
6543                 string_t res = token.v.string;
6544                 next_token();
6545                 while (token.type == T_STRING_LITERAL) {
6546                         res = concat_strings(&res, &token.v.string);
6547                         next_token();
6548                 }
6549                 if (token.type != T_WIDE_STRING_LITERAL) {
6550                         expression_t *const cnst = allocate_expression_zero(EXPR_STRING_LITERAL);
6551                         /* note: that we use type_char_ptr here, which is already the
6552                          * automatic converted type. revert_automatic_type_conversion
6553                          * will construct the array type */
6554                         cnst->base.type    = warning.write_strings ? type_const_char_ptr : type_char_ptr;
6555                         cnst->string.value = res;
6556                         return cnst;
6557                 }
6558
6559                 wres = concat_string_wide_string(&res, &token.v.wide_string);
6560         } else {
6561                 wres = token.v.wide_string;
6562         }
6563         next_token();
6564
6565         for (;;) {
6566                 switch (token.type) {
6567                         case T_WIDE_STRING_LITERAL:
6568                                 wres = concat_wide_strings(&wres, &token.v.wide_string);
6569                                 break;
6570
6571                         case T_STRING_LITERAL:
6572                                 wres = concat_wide_string_string(&wres, &token.v.string);
6573                                 break;
6574
6575                         default: {
6576                                 expression_t *const cnst = allocate_expression_zero(EXPR_WIDE_STRING_LITERAL);
6577                                 cnst->base.type         = warning.write_strings ? type_const_wchar_t_ptr : type_wchar_t_ptr;
6578                                 cnst->wide_string.value = wres;
6579                                 return cnst;
6580                         }
6581                 }
6582                 next_token();
6583         }
6584 }
6585
6586 /**
6587  * Parse a boolean constant.
6588  */
6589 static expression_t *parse_bool_const(bool value)
6590 {
6591         expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
6592         cnst->base.type          = type_bool;
6593         cnst->conste.v.int_value = value;
6594
6595         next_token();
6596
6597         return cnst;
6598 }
6599
6600 /**
6601  * Parse an integer constant.
6602  */
6603 static expression_t *parse_int_const(void)
6604 {
6605         expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
6606         cnst->base.type          = token.datatype;
6607         cnst->conste.v.int_value = token.v.intvalue;
6608
6609         next_token();
6610
6611         return cnst;
6612 }
6613
6614 /**
6615  * Parse a character constant.
6616  */
6617 static expression_t *parse_character_constant(void)
6618 {
6619         expression_t *cnst = allocate_expression_zero(EXPR_CHARACTER_CONSTANT);
6620         cnst->base.type          = token.datatype;
6621         cnst->conste.v.character = token.v.string;
6622
6623         if (cnst->conste.v.character.size != 1) {
6624                 if (!GNU_MODE) {
6625                         errorf(HERE, "more than 1 character in character constant");
6626                 } else if (warning.multichar) {
6627                         warningf(HERE, "multi-character character constant");
6628                 }
6629         }
6630         next_token();
6631
6632         return cnst;
6633 }
6634
6635 /**
6636  * Parse a wide character constant.
6637  */
6638 static expression_t *parse_wide_character_constant(void)
6639 {
6640         expression_t *cnst = allocate_expression_zero(EXPR_WIDE_CHARACTER_CONSTANT);
6641         cnst->base.type               = token.datatype;
6642         cnst->conste.v.wide_character = token.v.wide_string;
6643
6644         if (cnst->conste.v.wide_character.size != 1) {
6645                 if (!GNU_MODE) {
6646                         errorf(HERE, "more than 1 character in character constant");
6647                 } else if (warning.multichar) {
6648                         warningf(HERE, "multi-character character constant");
6649                 }
6650         }
6651         next_token();
6652
6653         return cnst;
6654 }
6655
6656 /**
6657  * Parse a float constant.
6658  */
6659 static expression_t *parse_float_const(void)
6660 {
6661         expression_t *cnst         = allocate_expression_zero(EXPR_CONST);
6662         cnst->base.type            = token.datatype;
6663         cnst->conste.v.float_value = token.v.floatvalue;
6664
6665         next_token();
6666
6667         return cnst;
6668 }
6669
6670 static entity_t *create_implicit_function(symbol_t *symbol,
6671                 const source_position_t *source_position)
6672 {
6673         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
6674         ntype->function.return_type            = type_int;
6675         ntype->function.unspecified_parameters = true;
6676
6677         type_t *type = typehash_insert(ntype);
6678         if (type != ntype) {
6679                 free_type(ntype);
6680         }
6681
6682         entity_t *entity = allocate_entity_zero(ENTITY_FUNCTION);
6683         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
6684         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
6685         entity->declaration.type                   = type;
6686         entity->declaration.implicit               = true;
6687         entity->base.symbol                        = symbol;
6688         entity->base.source_position               = *source_position;
6689
6690         bool strict_prototypes_old = warning.strict_prototypes;
6691         warning.strict_prototypes  = false;
6692         record_entity(entity, false);
6693         warning.strict_prototypes = strict_prototypes_old;
6694
6695         return entity;
6696 }
6697
6698 /**
6699  * Creates a return_type (func)(argument_type) function type if not
6700  * already exists.
6701  */
6702 static type_t *make_function_2_type(type_t *return_type, type_t *argument_type1,
6703                                     type_t *argument_type2)
6704 {
6705         function_parameter_t *parameter2
6706                 = obstack_alloc(type_obst, sizeof(parameter2[0]));
6707         memset(parameter2, 0, sizeof(parameter2[0]));
6708         parameter2->type = argument_type2;
6709
6710         function_parameter_t *parameter1
6711                 = obstack_alloc(type_obst, sizeof(parameter1[0]));
6712         memset(parameter1, 0, sizeof(parameter1[0]));
6713         parameter1->type = argument_type1;
6714         parameter1->next = parameter2;
6715
6716         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6717         type->function.return_type = return_type;
6718         type->function.parameters  = parameter1;
6719
6720         type_t *result = typehash_insert(type);
6721         if (result != type) {
6722                 free_type(type);
6723         }
6724
6725         return result;
6726 }
6727
6728 /**
6729  * Creates a return_type (func)(argument_type) function type if not
6730  * already exists.
6731  *
6732  * @param return_type    the return type
6733  * @param argument_type  the argument type
6734  */
6735 static type_t *make_function_1_type(type_t *return_type, type_t *argument_type)
6736 {
6737         function_parameter_t *parameter
6738                 = obstack_alloc(type_obst, sizeof(parameter[0]));
6739         memset(parameter, 0, sizeof(parameter[0]));
6740         parameter->type = argument_type;
6741
6742         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6743         type->function.return_type = return_type;
6744         type->function.parameters  = parameter;
6745
6746         type_t *result = typehash_insert(type);
6747         if (result != type) {
6748                 free_type(type);
6749         }
6750
6751         return result;
6752 }
6753
6754 static type_t *make_function_0_type(type_t *return_type)
6755 {
6756         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6757         type->function.return_type = return_type;
6758         type->function.parameters  = NULL;
6759
6760         type_t *result = typehash_insert(type);
6761         if (result != type) {
6762                 free_type(type);
6763         }
6764
6765         return result;
6766 }
6767
6768 /**
6769  * Creates a function type for some function like builtins.
6770  *
6771  * @param symbol   the symbol describing the builtin
6772  */
6773 static type_t *get_builtin_symbol_type(symbol_t *symbol)
6774 {
6775         switch (symbol->ID) {
6776         case T___builtin_alloca:
6777                 return make_function_1_type(type_void_ptr, type_size_t);
6778         case T___builtin_huge_val:
6779                 return make_function_0_type(type_double);
6780         case T___builtin_inf:
6781                 return make_function_0_type(type_double);
6782         case T___builtin_inff:
6783                 return make_function_0_type(type_float);
6784         case T___builtin_infl:
6785                 return make_function_0_type(type_long_double);
6786         case T___builtin_nan:
6787                 return make_function_1_type(type_double, type_char_ptr);
6788         case T___builtin_nanf:
6789                 return make_function_1_type(type_float, type_char_ptr);
6790         case T___builtin_nanl:
6791                 return make_function_1_type(type_long_double, type_char_ptr);
6792         case T___builtin_va_end:
6793                 return make_function_1_type(type_void, type_valist);
6794         case T___builtin_expect:
6795                 return make_function_2_type(type_long, type_long, type_long);
6796         default:
6797                 internal_errorf(HERE, "not implemented builtin symbol found");
6798         }
6799 }
6800
6801 /**
6802  * Performs automatic type cast as described in § 6.3.2.1.
6803  *
6804  * @param orig_type  the original type
6805  */
6806 static type_t *automatic_type_conversion(type_t *orig_type)
6807 {
6808         type_t *type = skip_typeref(orig_type);
6809         if (is_type_array(type)) {
6810                 array_type_t *array_type   = &type->array;
6811                 type_t       *element_type = array_type->element_type;
6812                 unsigned      qualifiers   = array_type->base.qualifiers;
6813
6814                 return make_pointer_type(element_type, qualifiers);
6815         }
6816
6817         if (is_type_function(type)) {
6818                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
6819         }
6820
6821         return orig_type;
6822 }
6823
6824 /**
6825  * reverts the automatic casts of array to pointer types and function
6826  * to function-pointer types as defined § 6.3.2.1
6827  */
6828 type_t *revert_automatic_type_conversion(const expression_t *expression)
6829 {
6830         switch (expression->kind) {
6831                 case EXPR_REFERENCE: {
6832                         entity_t *entity = expression->reference.entity;
6833                         if (is_declaration(entity)) {
6834                                 return entity->declaration.type;
6835                         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6836                                 return entity->enum_value.enum_type;
6837                         } else {
6838                                 panic("no declaration or enum in reference");
6839                         }
6840                 }
6841
6842                 case EXPR_SELECT: {
6843                         entity_t *entity = expression->select.compound_entry;
6844                         assert(is_declaration(entity));
6845                         type_t   *type   = entity->declaration.type;
6846                         return get_qualified_type(type,
6847                                                   expression->base.type->base.qualifiers);
6848                 }
6849
6850                 case EXPR_UNARY_DEREFERENCE: {
6851                         const expression_t *const value = expression->unary.value;
6852                         type_t             *const type  = skip_typeref(value->base.type);
6853                         assert(is_type_pointer(type));
6854                         return type->pointer.points_to;
6855                 }
6856
6857                 case EXPR_BUILTIN_SYMBOL:
6858                         return get_builtin_symbol_type(expression->builtin_symbol.symbol);
6859
6860                 case EXPR_ARRAY_ACCESS: {
6861                         const expression_t *array_ref = expression->array_access.array_ref;
6862                         type_t             *type_left = skip_typeref(array_ref->base.type);
6863                         if (!is_type_valid(type_left))
6864                                 return type_left;
6865                         assert(is_type_pointer(type_left));
6866                         return type_left->pointer.points_to;
6867                 }
6868
6869                 case EXPR_STRING_LITERAL: {
6870                         size_t size = expression->string.value.size;
6871                         return make_array_type(type_char, size, TYPE_QUALIFIER_NONE);
6872                 }
6873
6874                 case EXPR_WIDE_STRING_LITERAL: {
6875                         size_t size = expression->wide_string.value.size;
6876                         return make_array_type(type_wchar_t, size, TYPE_QUALIFIER_NONE);
6877                 }
6878
6879                 case EXPR_COMPOUND_LITERAL:
6880                         return expression->compound_literal.type;
6881
6882                 default: break;
6883         }
6884
6885         return expression->base.type;
6886 }
6887
6888 static expression_t *parse_reference(void)
6889 {
6890         symbol_t *const symbol = token.v.symbol;
6891
6892         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
6893
6894         if (entity == NULL) {
6895                 if (!strict_mode && look_ahead(1)->type == '(') {
6896                         /* an implicitly declared function */
6897                         if (warning.implicit_function_declaration) {
6898                                 warningf(HERE, "implicit declaration of function '%Y'",
6899                                         symbol);
6900                         }
6901
6902                         entity = create_implicit_function(symbol, HERE);
6903                 } else {
6904                         errorf(HERE, "unknown symbol '%Y' found.", symbol);
6905                         entity = create_error_entity(symbol, ENTITY_VARIABLE);
6906                 }
6907         }
6908
6909         type_t *orig_type;
6910
6911         if (is_declaration(entity)) {
6912                 orig_type = entity->declaration.type;
6913         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6914                 orig_type = entity->enum_value.enum_type;
6915         } else if (entity->kind == ENTITY_TYPEDEF) {
6916                 errorf(HERE, "encountered typedef name '%Y' while parsing expression",
6917                         symbol);
6918                 next_token();
6919                 return create_invalid_expression();
6920         } else {
6921                 panic("expected declaration or enum value in reference");
6922         }
6923
6924         /* we always do the auto-type conversions; the & and sizeof parser contains
6925          * code to revert this! */
6926         type_t *type = automatic_type_conversion(orig_type);
6927
6928         expression_kind_t kind = EXPR_REFERENCE;
6929         if (entity->kind == ENTITY_ENUM_VALUE)
6930                 kind = EXPR_REFERENCE_ENUM_VALUE;
6931
6932         expression_t *expression     = allocate_expression_zero(kind);
6933         expression->reference.entity = entity;
6934         expression->base.type        = type;
6935
6936         /* this declaration is used */
6937         if (is_declaration(entity)) {
6938                 entity->declaration.used = true;
6939         }
6940
6941         if (entity->base.parent_scope != file_scope
6942                 && entity->base.parent_scope->depth < current_function->parameters.depth
6943                 && is_type_valid(orig_type) && !is_type_function(orig_type)) {
6944                 if (entity->kind == ENTITY_VARIABLE) {
6945                         /* access of a variable from an outer function */
6946                         entity->variable.address_taken = true;
6947                 } else if (entity->kind == ENTITY_PARAMETER) {
6948                         entity->parameter.address_taken = true;
6949                 }
6950                 current_function->need_closure = true;
6951         }
6952
6953         /* check for deprecated functions */
6954         if (warning.deprecated_declarations
6955                 && is_declaration(entity)
6956                 && entity->declaration.modifiers & DM_DEPRECATED) {
6957                 declaration_t *declaration = &entity->declaration;
6958
6959                 char const *const prefix = entity->kind == ENTITY_FUNCTION ?
6960                         "function" : "variable";
6961
6962                 if (declaration->deprecated_string != NULL) {
6963                         warningf(HERE, "%s '%Y' is deprecated (declared %P): \"%s\"",
6964                                  prefix, entity->base.symbol, &entity->base.source_position,
6965                                  declaration->deprecated_string);
6966                 } else {
6967                         warningf(HERE, "%s '%Y' is deprecated (declared %P)", prefix,
6968                                  entity->base.symbol, &entity->base.source_position);
6969                 }
6970         }
6971
6972         if (warning.init_self && entity == current_init_decl && !in_type_prop
6973             && entity->kind == ENTITY_VARIABLE) {
6974                 current_init_decl = NULL;
6975                 warningf(HERE, "variable '%#T' is initialized by itself",
6976                          entity->declaration.type, entity->base.symbol);
6977         }
6978
6979         next_token();
6980         return expression;
6981 }
6982
6983 static bool semantic_cast(expression_t *cast)
6984 {
6985         expression_t            *expression      = cast->unary.value;
6986         type_t                  *orig_dest_type  = cast->base.type;
6987         type_t                  *orig_type_right = expression->base.type;
6988         type_t            const *dst_type        = skip_typeref(orig_dest_type);
6989         type_t            const *src_type        = skip_typeref(orig_type_right);
6990         source_position_t const *pos             = &cast->base.source_position;
6991
6992         /* §6.5.4 A (void) cast is explicitly permitted, more for documentation than for utility. */
6993         if (dst_type == type_void)
6994                 return true;
6995
6996         /* only integer and pointer can be casted to pointer */
6997         if (is_type_pointer(dst_type)  &&
6998             !is_type_pointer(src_type) &&
6999             !is_type_integer(src_type) &&
7000             is_type_valid(src_type)) {
7001                 errorf(pos, "cannot convert type '%T' to a pointer type", orig_type_right);
7002                 return false;
7003         }
7004
7005         if (!is_type_scalar(dst_type) && is_type_valid(dst_type)) {
7006                 errorf(pos, "conversion to non-scalar type '%T' requested", orig_dest_type);
7007                 return false;
7008         }
7009
7010         if (!is_type_scalar(src_type) && is_type_valid(src_type)) {
7011                 errorf(pos, "conversion from non-scalar type '%T' requested", orig_type_right);
7012                 return false;
7013         }
7014
7015         if (warning.cast_qual &&
7016             is_type_pointer(src_type) &&
7017             is_type_pointer(dst_type)) {
7018                 type_t *src = skip_typeref(src_type->pointer.points_to);
7019                 type_t *dst = skip_typeref(dst_type->pointer.points_to);
7020                 unsigned missing_qualifiers =
7021                         src->base.qualifiers & ~dst->base.qualifiers;
7022                 if (missing_qualifiers != 0) {
7023                         warningf(pos,
7024                                  "cast discards qualifiers '%Q' in pointer target type of '%T'",
7025                                  missing_qualifiers, orig_type_right);
7026                 }
7027         }
7028         return true;
7029 }
7030
7031 static expression_t *parse_compound_literal(type_t *type)
7032 {
7033         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
7034
7035         parse_initializer_env_t env;
7036         env.type             = type;
7037         env.entity           = NULL;
7038         env.must_be_constant = false;
7039         initializer_t *initializer = parse_initializer(&env);
7040         type = env.type;
7041
7042         expression->compound_literal.initializer = initializer;
7043         expression->compound_literal.type        = type;
7044         expression->base.type                    = automatic_type_conversion(type);
7045
7046         return expression;
7047 }
7048
7049 /**
7050  * Parse a cast expression.
7051  */
7052 static expression_t *parse_cast(void)
7053 {
7054         add_anchor_token(')');
7055
7056         source_position_t source_position = token.source_position;
7057
7058         type_t *type = parse_typename();
7059
7060         rem_anchor_token(')');
7061         expect(')');
7062
7063         if (token.type == '{') {
7064                 return parse_compound_literal(type);
7065         }
7066
7067         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
7068         cast->base.source_position = source_position;
7069
7070         expression_t *value = parse_sub_expression(PREC_CAST);
7071         cast->base.type   = type;
7072         cast->unary.value = value;
7073
7074         if (! semantic_cast(cast)) {
7075                 /* TODO: record the error in the AST. else it is impossible to detect it */
7076         }
7077
7078         return cast;
7079 end_error:
7080         return create_invalid_expression();
7081 }
7082
7083 /**
7084  * Parse a statement expression.
7085  */
7086 static expression_t *parse_statement_expression(void)
7087 {
7088         add_anchor_token(')');
7089
7090         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
7091
7092         statement_t *statement          = parse_compound_statement(true);
7093         expression->statement.statement = statement;
7094
7095         /* find last statement and use its type */
7096         type_t *type = type_void;
7097         const statement_t *stmt = statement->compound.statements;
7098         if (stmt != NULL) {
7099                 while (stmt->base.next != NULL)
7100                         stmt = stmt->base.next;
7101
7102                 if (stmt->kind == STATEMENT_EXPRESSION) {
7103                         type = stmt->expression.expression->base.type;
7104                 }
7105         } else if (warning.other) {
7106                 warningf(&expression->base.source_position, "empty statement expression ({})");
7107         }
7108         expression->base.type = type;
7109
7110         rem_anchor_token(')');
7111         expect(')');
7112
7113 end_error:
7114         return expression;
7115 }
7116
7117 /**
7118  * Parse a parenthesized expression.
7119  */
7120 static expression_t *parse_parenthesized_expression(void)
7121 {
7122         eat('(');
7123
7124         switch (token.type) {
7125         case '{':
7126                 /* gcc extension: a statement expression */
7127                 return parse_statement_expression();
7128
7129         TYPE_QUALIFIERS
7130         TYPE_SPECIFIERS
7131                 return parse_cast();
7132         case T_IDENTIFIER:
7133                 if (is_typedef_symbol(token.v.symbol)) {
7134                         return parse_cast();
7135                 }
7136         }
7137
7138         add_anchor_token(')');
7139         expression_t *result = parse_expression();
7140         rem_anchor_token(')');
7141         expect(')');
7142
7143 end_error:
7144         return result;
7145 }
7146
7147 static expression_t *parse_function_keyword(void)
7148 {
7149         /* TODO */
7150
7151         if (current_function == NULL) {
7152                 errorf(HERE, "'__func__' used outside of a function");
7153         }
7154
7155         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
7156         expression->base.type     = type_char_ptr;
7157         expression->funcname.kind = FUNCNAME_FUNCTION;
7158
7159         next_token();
7160
7161         return expression;
7162 }
7163
7164 static expression_t *parse_pretty_function_keyword(void)
7165 {
7166         if (current_function == NULL) {
7167                 errorf(HERE, "'__PRETTY_FUNCTION__' used outside of a function");
7168         }
7169
7170         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
7171         expression->base.type     = type_char_ptr;
7172         expression->funcname.kind = FUNCNAME_PRETTY_FUNCTION;
7173
7174         eat(T___PRETTY_FUNCTION__);
7175
7176         return expression;
7177 }
7178
7179 static expression_t *parse_funcsig_keyword(void)
7180 {
7181         if (current_function == NULL) {
7182                 errorf(HERE, "'__FUNCSIG__' used outside of a function");
7183         }
7184
7185         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
7186         expression->base.type     = type_char_ptr;
7187         expression->funcname.kind = FUNCNAME_FUNCSIG;
7188
7189         eat(T___FUNCSIG__);
7190
7191         return expression;
7192 }
7193
7194 static expression_t *parse_funcdname_keyword(void)
7195 {
7196         if (current_function == NULL) {
7197                 errorf(HERE, "'__FUNCDNAME__' used outside of a function");
7198         }
7199
7200         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
7201         expression->base.type     = type_char_ptr;
7202         expression->funcname.kind = FUNCNAME_FUNCDNAME;
7203
7204         eat(T___FUNCDNAME__);
7205
7206         return expression;
7207 }
7208
7209 static designator_t *parse_designator(void)
7210 {
7211         designator_t *result    = allocate_ast_zero(sizeof(result[0]));
7212         result->source_position = *HERE;
7213
7214         if (token.type != T_IDENTIFIER) {
7215                 parse_error_expected("while parsing member designator",
7216                                      T_IDENTIFIER, NULL);
7217                 return NULL;
7218         }
7219         result->symbol = token.v.symbol;
7220         next_token();
7221
7222         designator_t *last_designator = result;
7223         while (true) {
7224                 if (token.type == '.') {
7225                         next_token();
7226                         if (token.type != T_IDENTIFIER) {
7227                                 parse_error_expected("while parsing member designator",
7228                                                      T_IDENTIFIER, NULL);
7229                                 return NULL;
7230                         }
7231                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
7232                         designator->source_position = *HERE;
7233                         designator->symbol          = token.v.symbol;
7234                         next_token();
7235
7236                         last_designator->next = designator;
7237                         last_designator       = designator;
7238                         continue;
7239                 }
7240                 if (token.type == '[') {
7241                         next_token();
7242                         add_anchor_token(']');
7243                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
7244                         designator->source_position = *HERE;
7245                         designator->array_index     = parse_expression();
7246                         rem_anchor_token(']');
7247                         expect(']');
7248                         if (designator->array_index == NULL) {
7249                                 return NULL;
7250                         }
7251
7252                         last_designator->next = designator;
7253                         last_designator       = designator;
7254                         continue;
7255                 }
7256                 break;
7257         }
7258
7259         return result;
7260 end_error:
7261         return NULL;
7262 }
7263
7264 /**
7265  * Parse the __builtin_offsetof() expression.
7266  */
7267 static expression_t *parse_offsetof(void)
7268 {
7269         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
7270         expression->base.type    = type_size_t;
7271
7272         eat(T___builtin_offsetof);
7273
7274         expect('(');
7275         add_anchor_token(',');
7276         type_t *type = parse_typename();
7277         rem_anchor_token(',');
7278         expect(',');
7279         add_anchor_token(')');
7280         designator_t *designator = parse_designator();
7281         rem_anchor_token(')');
7282         expect(')');
7283
7284         expression->offsetofe.type       = type;
7285         expression->offsetofe.designator = designator;
7286
7287         type_path_t path;
7288         memset(&path, 0, sizeof(path));
7289         path.top_type = type;
7290         path.path     = NEW_ARR_F(type_path_entry_t, 0);
7291
7292         descend_into_subtype(&path);
7293
7294         if (!walk_designator(&path, designator, true)) {
7295                 return create_invalid_expression();
7296         }
7297
7298         DEL_ARR_F(path.path);
7299
7300         return expression;
7301 end_error:
7302         return create_invalid_expression();
7303 }
7304
7305 /**
7306  * Parses a _builtin_va_start() expression.
7307  */
7308 static expression_t *parse_va_start(void)
7309 {
7310         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
7311
7312         eat(T___builtin_va_start);
7313
7314         expect('(');
7315         add_anchor_token(',');
7316         expression->va_starte.ap = parse_assignment_expression();
7317         rem_anchor_token(',');
7318         expect(',');
7319         expression_t *const expr = parse_assignment_expression();
7320         if (expr->kind == EXPR_REFERENCE) {
7321                 entity_t *const entity = expr->reference.entity;
7322                 if (entity->base.parent_scope != &current_function->parameters
7323                                 || entity->base.next != NULL
7324                                 || entity->kind != ENTITY_PARAMETER) {
7325                         errorf(&expr->base.source_position,
7326                                "second argument of 'va_start' must be last parameter of the current function");
7327                 } else {
7328                         expression->va_starte.parameter = &entity->variable;
7329                 }
7330                 expect(')');
7331                 return expression;
7332         }
7333         expect(')');
7334 end_error:
7335         return create_invalid_expression();
7336 }
7337
7338 /**
7339  * Parses a _builtin_va_arg() expression.
7340  */
7341 static expression_t *parse_va_arg(void)
7342 {
7343         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
7344
7345         eat(T___builtin_va_arg);
7346
7347         expect('(');
7348         expression->va_arge.ap = parse_assignment_expression();
7349         expect(',');
7350         expression->base.type = parse_typename();
7351         expect(')');
7352
7353         return expression;
7354 end_error:
7355         return create_invalid_expression();
7356 }
7357
7358 static expression_t *parse_builtin_symbol(void)
7359 {
7360         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_SYMBOL);
7361
7362         symbol_t *symbol = token.v.symbol;
7363
7364         expression->builtin_symbol.symbol = symbol;
7365         next_token();
7366
7367         type_t *type = get_builtin_symbol_type(symbol);
7368         type = automatic_type_conversion(type);
7369
7370         expression->base.type = type;
7371         return expression;
7372 }
7373
7374 /**
7375  * Parses a __builtin_constant() expression.
7376  */
7377 static expression_t *parse_builtin_constant(void)
7378 {
7379         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
7380
7381         eat(T___builtin_constant_p);
7382
7383         expect('(');
7384         add_anchor_token(')');
7385         expression->builtin_constant.value = parse_assignment_expression();
7386         rem_anchor_token(')');
7387         expect(')');
7388         expression->base.type = type_int;
7389
7390         return expression;
7391 end_error:
7392         return create_invalid_expression();
7393 }
7394
7395 /**
7396  * Parses a __builtin_prefetch() expression.
7397  */
7398 static expression_t *parse_builtin_prefetch(void)
7399 {
7400         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_PREFETCH);
7401
7402         eat(T___builtin_prefetch);
7403
7404         expect('(');
7405         add_anchor_token(')');
7406         expression->builtin_prefetch.adr = parse_assignment_expression();
7407         if (token.type == ',') {
7408                 next_token();
7409                 expression->builtin_prefetch.rw = parse_assignment_expression();
7410         }
7411         if (token.type == ',') {
7412                 next_token();
7413                 expression->builtin_prefetch.locality = parse_assignment_expression();
7414         }
7415         rem_anchor_token(')');
7416         expect(')');
7417         expression->base.type = type_void;
7418
7419         return expression;
7420 end_error:
7421         return create_invalid_expression();
7422 }
7423
7424 /**
7425  * Parses a __builtin_is_*() compare expression.
7426  */
7427 static expression_t *parse_compare_builtin(void)
7428 {
7429         expression_t *expression;
7430
7431         switch (token.type) {
7432         case T___builtin_isgreater:
7433                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATER);
7434                 break;
7435         case T___builtin_isgreaterequal:
7436                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATEREQUAL);
7437                 break;
7438         case T___builtin_isless:
7439                 expression = allocate_expression_zero(EXPR_BINARY_ISLESS);
7440                 break;
7441         case T___builtin_islessequal:
7442                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSEQUAL);
7443                 break;
7444         case T___builtin_islessgreater:
7445                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSGREATER);
7446                 break;
7447         case T___builtin_isunordered:
7448                 expression = allocate_expression_zero(EXPR_BINARY_ISUNORDERED);
7449                 break;
7450         default:
7451                 internal_errorf(HERE, "invalid compare builtin found");
7452         }
7453         expression->base.source_position = *HERE;
7454         next_token();
7455
7456         expect('(');
7457         expression->binary.left = parse_assignment_expression();
7458         expect(',');
7459         expression->binary.right = parse_assignment_expression();
7460         expect(')');
7461
7462         type_t *const orig_type_left  = expression->binary.left->base.type;
7463         type_t *const orig_type_right = expression->binary.right->base.type;
7464
7465         type_t *const type_left  = skip_typeref(orig_type_left);
7466         type_t *const type_right = skip_typeref(orig_type_right);
7467         if (!is_type_float(type_left) && !is_type_float(type_right)) {
7468                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7469                         type_error_incompatible("invalid operands in comparison",
7470                                 &expression->base.source_position, orig_type_left, orig_type_right);
7471                 }
7472         } else {
7473                 semantic_comparison(&expression->binary);
7474         }
7475
7476         return expression;
7477 end_error:
7478         return create_invalid_expression();
7479 }
7480
7481 #if 0
7482 /**
7483  * Parses a __builtin_expect() expression.
7484  */
7485 static expression_t *parse_builtin_expect(void)
7486 {
7487         expression_t *expression
7488                 = allocate_expression_zero(EXPR_BINARY_BUILTIN_EXPECT);
7489
7490         eat(T___builtin_expect);
7491
7492         expect('(');
7493         expression->binary.left = parse_assignment_expression();
7494         expect(',');
7495         expression->binary.right = parse_constant_expression();
7496         expect(')');
7497
7498         expression->base.type = expression->binary.left->base.type;
7499
7500         return expression;
7501 end_error:
7502         return create_invalid_expression();
7503 }
7504 #endif
7505
7506 /**
7507  * Parses a MS assume() expression.
7508  */
7509 static expression_t *parse_assume(void)
7510 {
7511         expression_t *expression = allocate_expression_zero(EXPR_UNARY_ASSUME);
7512
7513         eat(T__assume);
7514
7515         expect('(');
7516         add_anchor_token(')');
7517         expression->unary.value = parse_assignment_expression();
7518         rem_anchor_token(')');
7519         expect(')');
7520
7521         expression->base.type = type_void;
7522         return expression;
7523 end_error:
7524         return create_invalid_expression();
7525 }
7526
7527 /**
7528  * Return the declaration for a given label symbol or create a new one.
7529  *
7530  * @param symbol  the symbol of the label
7531  */
7532 static label_t *get_label(symbol_t *symbol)
7533 {
7534         entity_t *label;
7535         assert(current_function != NULL);
7536
7537         label = get_entity(symbol, NAMESPACE_LABEL);
7538         /* if we found a local label, we already created the declaration */
7539         if (label != NULL && label->kind == ENTITY_LOCAL_LABEL) {
7540                 if (label->base.parent_scope != current_scope) {
7541                         assert(label->base.parent_scope->depth < current_scope->depth);
7542                         current_function->goto_to_outer = true;
7543                 }
7544                 return &label->label;
7545         }
7546
7547         label = get_entity(symbol, NAMESPACE_LABEL);
7548         /* if we found a label in the same function, then we already created the
7549          * declaration */
7550         if (label != NULL
7551                         && label->base.parent_scope == &current_function->parameters) {
7552                 return &label->label;
7553         }
7554
7555         /* otherwise we need to create a new one */
7556         label               = allocate_entity_zero(ENTITY_LABEL);
7557         label->base.namespc = NAMESPACE_LABEL;
7558         label->base.symbol  = symbol;
7559
7560         label_push(label);
7561
7562         return &label->label;
7563 }
7564
7565 /**
7566  * Parses a GNU && label address expression.
7567  */
7568 static expression_t *parse_label_address(void)
7569 {
7570         source_position_t source_position = token.source_position;
7571         eat(T_ANDAND);
7572         if (token.type != T_IDENTIFIER) {
7573                 parse_error_expected("while parsing label address", T_IDENTIFIER, NULL);
7574                 goto end_error;
7575         }
7576         symbol_t *symbol = token.v.symbol;
7577         next_token();
7578
7579         label_t *label       = get_label(symbol);
7580         label->used          = true;
7581         label->address_taken = true;
7582
7583         expression_t *expression = allocate_expression_zero(EXPR_LABEL_ADDRESS);
7584         expression->base.source_position = source_position;
7585
7586         /* label address is threaten as a void pointer */
7587         expression->base.type           = type_void_ptr;
7588         expression->label_address.label = label;
7589         return expression;
7590 end_error:
7591         return create_invalid_expression();
7592 }
7593
7594 /**
7595  * Parse a microsoft __noop expression.
7596  */
7597 static expression_t *parse_noop_expression(void)
7598 {
7599         /* the result is a (int)0 */
7600         expression_t *cnst         = allocate_expression_zero(EXPR_CONST);
7601         cnst->base.type            = type_int;
7602         cnst->conste.v.int_value   = 0;
7603         cnst->conste.is_ms_noop    = true;
7604
7605         eat(T___noop);
7606
7607         if (token.type == '(') {
7608                 /* parse arguments */
7609                 eat('(');
7610                 add_anchor_token(')');
7611                 add_anchor_token(',');
7612
7613                 if (token.type != ')') {
7614                         while (true) {
7615                                 (void)parse_assignment_expression();
7616                                 if (token.type != ',')
7617                                         break;
7618                                 next_token();
7619                         }
7620                 }
7621         }
7622         rem_anchor_token(',');
7623         rem_anchor_token(')');
7624         expect(')');
7625
7626 end_error:
7627         return cnst;
7628 }
7629
7630 /**
7631  * Parses a primary expression.
7632  */
7633 static expression_t *parse_primary_expression(void)
7634 {
7635         switch (token.type) {
7636                 case T_false:                    return parse_bool_const(false);
7637                 case T_true:                     return parse_bool_const(true);
7638                 case T_INTEGER:                  return parse_int_const();
7639                 case T_CHARACTER_CONSTANT:       return parse_character_constant();
7640                 case T_WIDE_CHARACTER_CONSTANT:  return parse_wide_character_constant();
7641                 case T_FLOATINGPOINT:            return parse_float_const();
7642                 case T_STRING_LITERAL:
7643                 case T_WIDE_STRING_LITERAL:      return parse_string_const();
7644                 case T_IDENTIFIER:               return parse_reference();
7645                 case T___FUNCTION__:
7646                 case T___func__:                 return parse_function_keyword();
7647                 case T___PRETTY_FUNCTION__:      return parse_pretty_function_keyword();
7648                 case T___FUNCSIG__:              return parse_funcsig_keyword();
7649                 case T___FUNCDNAME__:            return parse_funcdname_keyword();
7650                 case T___builtin_offsetof:       return parse_offsetof();
7651                 case T___builtin_va_start:       return parse_va_start();
7652                 case T___builtin_va_arg:         return parse_va_arg();
7653                 case T___builtin_expect:
7654                 case T___builtin_alloca:
7655                 case T___builtin_inf:
7656                 case T___builtin_inff:
7657                 case T___builtin_infl:
7658                 case T___builtin_nan:
7659                 case T___builtin_nanf:
7660                 case T___builtin_nanl:
7661                 case T___builtin_huge_val:
7662                 case T___builtin_va_end:         return parse_builtin_symbol();
7663                 case T___builtin_isgreater:
7664                 case T___builtin_isgreaterequal:
7665                 case T___builtin_isless:
7666                 case T___builtin_islessequal:
7667                 case T___builtin_islessgreater:
7668                 case T___builtin_isunordered:    return parse_compare_builtin();
7669                 case T___builtin_constant_p:     return parse_builtin_constant();
7670                 case T___builtin_prefetch:       return parse_builtin_prefetch();
7671                 case T__assume:                  return parse_assume();
7672                 case T_ANDAND:
7673                         if (GNU_MODE)
7674                                 return parse_label_address();
7675                         break;
7676
7677                 case '(':                        return parse_parenthesized_expression();
7678                 case T___noop:                   return parse_noop_expression();
7679         }
7680
7681         errorf(HERE, "unexpected token '%K', expected an expression", &token);
7682         return create_invalid_expression();
7683 }
7684
7685 /**
7686  * Check if the expression has the character type and issue a warning then.
7687  */
7688 static void check_for_char_index_type(const expression_t *expression)
7689 {
7690         type_t       *const type      = expression->base.type;
7691         const type_t *const base_type = skip_typeref(type);
7692
7693         if (is_type_atomic(base_type, ATOMIC_TYPE_CHAR) &&
7694                         warning.char_subscripts) {
7695                 warningf(&expression->base.source_position,
7696                          "array subscript has type '%T'", type);
7697         }
7698 }
7699
7700 static expression_t *parse_array_expression(expression_t *left)
7701 {
7702         expression_t *expression = allocate_expression_zero(EXPR_ARRAY_ACCESS);
7703
7704         eat('[');
7705         add_anchor_token(']');
7706
7707         expression_t *inside = parse_expression();
7708
7709         type_t *const orig_type_left   = left->base.type;
7710         type_t *const orig_type_inside = inside->base.type;
7711
7712         type_t *const type_left   = skip_typeref(orig_type_left);
7713         type_t *const type_inside = skip_typeref(orig_type_inside);
7714
7715         type_t                    *return_type;
7716         array_access_expression_t *array_access = &expression->array_access;
7717         if (is_type_pointer(type_left)) {
7718                 return_type             = type_left->pointer.points_to;
7719                 array_access->array_ref = left;
7720                 array_access->index     = inside;
7721                 check_for_char_index_type(inside);
7722         } else if (is_type_pointer(type_inside)) {
7723                 return_type             = type_inside->pointer.points_to;
7724                 array_access->array_ref = inside;
7725                 array_access->index     = left;
7726                 array_access->flipped   = true;
7727                 check_for_char_index_type(left);
7728         } else {
7729                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
7730                         errorf(HERE,
7731                                 "array access on object with non-pointer types '%T', '%T'",
7732                                 orig_type_left, orig_type_inside);
7733                 }
7734                 return_type             = type_error_type;
7735                 array_access->array_ref = left;
7736                 array_access->index     = inside;
7737         }
7738
7739         expression->base.type = automatic_type_conversion(return_type);
7740
7741         rem_anchor_token(']');
7742         expect(']');
7743 end_error:
7744         return expression;
7745 }
7746
7747 static expression_t *parse_typeprop(expression_kind_t const kind)
7748 {
7749         expression_t  *tp_expression = allocate_expression_zero(kind);
7750         tp_expression->base.type     = type_size_t;
7751
7752         eat(kind == EXPR_SIZEOF ? T_sizeof : T___alignof__);
7753
7754         /* we only refer to a type property, mark this case */
7755         bool old     = in_type_prop;
7756         in_type_prop = true;
7757
7758         type_t       *orig_type;
7759         expression_t *expression;
7760         if (token.type == '(' && is_declaration_specifier(look_ahead(1), true)) {
7761                 next_token();
7762                 add_anchor_token(')');
7763                 orig_type = parse_typename();
7764                 rem_anchor_token(')');
7765                 expect(')');
7766
7767                 if (token.type == '{') {
7768                         /* It was not sizeof(type) after all.  It is sizeof of an expression
7769                          * starting with a compound literal */
7770                         expression = parse_compound_literal(orig_type);
7771                         goto typeprop_expression;
7772                 }
7773         } else {
7774                 expression = parse_sub_expression(PREC_UNARY);
7775
7776 typeprop_expression:
7777                 tp_expression->typeprop.tp_expression = expression;
7778
7779                 orig_type = revert_automatic_type_conversion(expression);
7780                 expression->base.type = orig_type;
7781         }
7782
7783         tp_expression->typeprop.type   = orig_type;
7784         type_t const* const type       = skip_typeref(orig_type);
7785         char   const* const wrong_type =
7786                 is_type_incomplete(type)    ? "incomplete"          :
7787                 type->kind == TYPE_FUNCTION ? "function designator" :
7788                 type->kind == TYPE_BITFIELD ? "bitfield"            :
7789                 NULL;
7790         if (wrong_type != NULL) {
7791                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
7792                 errorf(&tp_expression->base.source_position,
7793                                 "operand of %s expression must not be of %s type '%T'",
7794                                 what, wrong_type, orig_type);
7795         }
7796
7797 end_error:
7798         in_type_prop = old;
7799         return tp_expression;
7800 }
7801
7802 static expression_t *parse_sizeof(void)
7803 {
7804         return parse_typeprop(EXPR_SIZEOF);
7805 }
7806
7807 static expression_t *parse_alignof(void)
7808 {
7809         return parse_typeprop(EXPR_ALIGNOF);
7810 }
7811
7812 static expression_t *parse_select_expression(expression_t *compound)
7813 {
7814         expression_t *select    = allocate_expression_zero(EXPR_SELECT);
7815         select->select.compound = compound;
7816
7817         assert(token.type == '.' || token.type == T_MINUSGREATER);
7818         bool is_pointer = (token.type == T_MINUSGREATER);
7819         next_token();
7820
7821         if (token.type != T_IDENTIFIER) {
7822                 parse_error_expected("while parsing select", T_IDENTIFIER, NULL);
7823                 return select;
7824         }
7825         symbol_t *symbol = token.v.symbol;
7826         next_token();
7827
7828         type_t *const orig_type = compound->base.type;
7829         type_t *const type      = skip_typeref(orig_type);
7830
7831         type_t *type_left;
7832         bool    saw_error = false;
7833         if (is_type_pointer(type)) {
7834                 if (!is_pointer) {
7835                         errorf(HERE,
7836                                "request for member '%Y' in something not a struct or union, but '%T'",
7837                                symbol, orig_type);
7838                         saw_error = true;
7839                 }
7840                 type_left = skip_typeref(type->pointer.points_to);
7841         } else {
7842                 if (is_pointer && is_type_valid(type)) {
7843                         errorf(HERE, "left hand side of '->' is not a pointer, but '%T'", orig_type);
7844                         saw_error = true;
7845                 }
7846                 type_left = type;
7847         }
7848
7849         entity_t *entry;
7850         if (type_left->kind == TYPE_COMPOUND_STRUCT ||
7851             type_left->kind == TYPE_COMPOUND_UNION) {
7852                 compound_t *compound = type_left->compound.compound;
7853
7854                 if (!compound->complete) {
7855                         errorf(HERE, "request for member '%Y' of incomplete type '%T'",
7856                                symbol, type_left);
7857                         goto create_error_entry;
7858                 }
7859
7860                 entry = find_compound_entry(compound, symbol);
7861                 if (entry == NULL) {
7862                         errorf(HERE, "'%T' has no member named '%Y'", orig_type, symbol);
7863                         goto create_error_entry;
7864                 }
7865         } else {
7866                 if (is_type_valid(type_left) && !saw_error) {
7867                         errorf(HERE,
7868                                "request for member '%Y' in something not a struct or union, but '%T'",
7869                                symbol, type_left);
7870                 }
7871 create_error_entry:
7872                 return create_invalid_expression();
7873         }
7874
7875         assert(is_declaration(entry));
7876         select->select.compound_entry = entry;
7877
7878         type_t *entry_type = entry->declaration.type;
7879         type_t *res_type
7880                 = get_qualified_type(entry_type, type_left->base.qualifiers);
7881
7882         /* we always do the auto-type conversions; the & and sizeof parser contains
7883          * code to revert this! */
7884         select->base.type = automatic_type_conversion(res_type);
7885
7886         type_t *skipped = skip_typeref(res_type);
7887         if (skipped->kind == TYPE_BITFIELD) {
7888                 select->base.type = skipped->bitfield.base_type;
7889         }
7890
7891         return select;
7892 }
7893
7894 static void check_call_argument(const function_parameter_t *parameter,
7895                                 call_argument_t *argument, unsigned pos)
7896 {
7897         type_t         *expected_type      = parameter->type;
7898         type_t         *expected_type_skip = skip_typeref(expected_type);
7899         assign_error_t  error              = ASSIGN_ERROR_INCOMPATIBLE;
7900         expression_t   *arg_expr           = argument->expression;
7901         type_t         *arg_type           = skip_typeref(arg_expr->base.type);
7902
7903         /* handle transparent union gnu extension */
7904         if (is_type_union(expected_type_skip)
7905                         && (expected_type_skip->base.modifiers
7906                                 & TYPE_MODIFIER_TRANSPARENT_UNION)) {
7907                 compound_t *union_decl  = expected_type_skip->compound.compound;
7908                 type_t     *best_type   = NULL;
7909                 entity_t   *entry       = union_decl->members.entities;
7910                 for ( ; entry != NULL; entry = entry->base.next) {
7911                         assert(is_declaration(entry));
7912                         type_t *decl_type = entry->declaration.type;
7913                         error = semantic_assign(decl_type, arg_expr);
7914                         if (error == ASSIGN_ERROR_INCOMPATIBLE
7915                                 || error == ASSIGN_ERROR_POINTER_QUALIFIER_MISSING)
7916                                 continue;
7917
7918                         if (error == ASSIGN_SUCCESS) {
7919                                 best_type = decl_type;
7920                         } else if (best_type == NULL) {
7921                                 best_type = decl_type;
7922                         }
7923                 }
7924
7925                 if (best_type != NULL) {
7926                         expected_type = best_type;
7927                 }
7928         }
7929
7930         error                = semantic_assign(expected_type, arg_expr);
7931         argument->expression = create_implicit_cast(argument->expression,
7932                                                     expected_type);
7933
7934         if (error != ASSIGN_SUCCESS) {
7935                 /* report exact scope in error messages (like "in argument 3") */
7936                 char buf[64];
7937                 snprintf(buf, sizeof(buf), "call argument %u", pos);
7938                 report_assign_error(error, expected_type, arg_expr,     buf,
7939                                                         &arg_expr->base.source_position);
7940         } else if (warning.traditional || warning.conversion) {
7941                 type_t *const promoted_type = get_default_promoted_type(arg_type);
7942                 if (!types_compatible(expected_type_skip, promoted_type) &&
7943                     !types_compatible(expected_type_skip, type_void_ptr) &&
7944                     !types_compatible(type_void_ptr,      promoted_type)) {
7945                         /* Deliberately show the skipped types in this warning */
7946                         warningf(&arg_expr->base.source_position,
7947                                 "passing call argument %u as '%T' rather than '%T' due to prototype",
7948                                 pos, expected_type_skip, promoted_type);
7949                 }
7950         }
7951 }
7952
7953 /**
7954  * Parse a call expression, ie. expression '( ... )'.
7955  *
7956  * @param expression  the function address
7957  */
7958 static expression_t *parse_call_expression(expression_t *expression)
7959 {
7960         expression_t      *result = allocate_expression_zero(EXPR_CALL);
7961         call_expression_t *call   = &result->call;
7962         call->function            = expression;
7963
7964         type_t *const orig_type = expression->base.type;
7965         type_t *const type      = skip_typeref(orig_type);
7966
7967         function_type_t *function_type = NULL;
7968         if (is_type_pointer(type)) {
7969                 type_t *const to_type = skip_typeref(type->pointer.points_to);
7970
7971                 if (is_type_function(to_type)) {
7972                         function_type   = &to_type->function;
7973                         call->base.type = function_type->return_type;
7974                 }
7975         }
7976
7977         if (function_type == NULL && is_type_valid(type)) {
7978                 errorf(HERE, "called object '%E' (type '%T') is not a pointer to a function", expression, orig_type);
7979         }
7980
7981         /* parse arguments */
7982         eat('(');
7983         add_anchor_token(')');
7984         add_anchor_token(',');
7985
7986         if (token.type != ')') {
7987                 call_argument_t *last_argument = NULL;
7988
7989                 while (true) {
7990                         call_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
7991
7992                         argument->expression = parse_assignment_expression();
7993                         if (last_argument == NULL) {
7994                                 call->arguments = argument;
7995                         } else {
7996                                 last_argument->next = argument;
7997                         }
7998                         last_argument = argument;
7999
8000                         if (token.type != ',')
8001                                 break;
8002                         next_token();
8003                 }
8004         }
8005         rem_anchor_token(',');
8006         rem_anchor_token(')');
8007         expect(')');
8008
8009         if (function_type == NULL)
8010                 return result;
8011
8012         function_parameter_t *parameter = function_type->parameters;
8013         call_argument_t      *argument  = call->arguments;
8014         if (!function_type->unspecified_parameters) {
8015                 for (unsigned pos = 0; parameter != NULL && argument != NULL;
8016                                 parameter = parameter->next, argument = argument->next) {
8017                         check_call_argument(parameter, argument, ++pos);
8018                 }
8019
8020                 if (parameter != NULL) {
8021                         errorf(HERE, "too few arguments to function '%E'", expression);
8022                 } else if (argument != NULL && !function_type->variadic) {
8023                         errorf(HERE, "too many arguments to function '%E'", expression);
8024                 }
8025         }
8026
8027         /* do default promotion */
8028         for (; argument != NULL; argument = argument->next) {
8029                 type_t *type = argument->expression->base.type;
8030
8031                 type = get_default_promoted_type(type);
8032
8033                 argument->expression
8034                         = create_implicit_cast(argument->expression, type);
8035         }
8036
8037         check_format(&result->call);
8038
8039         if (warning.aggregate_return &&
8040             is_type_compound(skip_typeref(function_type->return_type))) {
8041                 warningf(&result->base.source_position,
8042                          "function call has aggregate value");
8043         }
8044
8045 end_error:
8046         return result;
8047 }
8048
8049 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
8050
8051 static bool same_compound_type(const type_t *type1, const type_t *type2)
8052 {
8053         return
8054                 is_type_compound(type1) &&
8055                 type1->kind == type2->kind &&
8056                 type1->compound.compound == type2->compound.compound;
8057 }
8058
8059 static expression_t const *get_reference_address(expression_t const *expr)
8060 {
8061         bool regular_take_address = true;
8062         for (;;) {
8063                 if (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
8064                         expr = expr->unary.value;
8065                 } else {
8066                         regular_take_address = false;
8067                 }
8068
8069                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
8070                         break;
8071
8072                 expr = expr->unary.value;
8073         }
8074
8075         if (expr->kind != EXPR_REFERENCE)
8076                 return NULL;
8077
8078         /* special case for functions which are automatically converted to a
8079          * pointer to function without an extra TAKE_ADDRESS operation */
8080         if (!regular_take_address &&
8081                         expr->reference.entity->kind != ENTITY_FUNCTION) {
8082                 return NULL;
8083         }
8084
8085         return expr;
8086 }
8087
8088 static void warn_reference_address_as_bool(expression_t const* expr)
8089 {
8090         if (!warning.address)
8091                 return;
8092
8093         expr = get_reference_address(expr);
8094         if (expr != NULL) {
8095                 warningf(&expr->base.source_position,
8096                          "the address of '%Y' will always evaluate as 'true'",
8097                          expr->reference.entity->base.symbol);
8098         }
8099 }
8100
8101 static void semantic_condition(expression_t const *const expr,
8102                                char const *const context)
8103 {
8104         type_t *const type = skip_typeref(expr->base.type);
8105         if (is_type_scalar(type)) {
8106                 warn_reference_address_as_bool(expr);
8107         } else if (is_type_valid(type)) {
8108                 errorf(&expr->base.source_position,
8109                                 "%s must have scalar type", context);
8110         }
8111 }
8112
8113 /**
8114  * Parse a conditional expression, ie. 'expression ? ... : ...'.
8115  *
8116  * @param expression  the conditional expression
8117  */
8118 static expression_t *parse_conditional_expression(expression_t *expression)
8119 {
8120         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
8121
8122         conditional_expression_t *conditional = &result->conditional;
8123         conditional->condition                = expression;
8124
8125         eat('?');
8126         add_anchor_token(':');
8127
8128         /* §6.5.15:2  The first operand shall have scalar type. */
8129         semantic_condition(expression, "condition of conditional operator");
8130
8131         expression_t *true_expression = expression;
8132         bool          gnu_cond = false;
8133         if (GNU_MODE && token.type == ':') {
8134                 gnu_cond = true;
8135         } else {
8136                 true_expression = parse_expression();
8137         }
8138         rem_anchor_token(':');
8139         expect(':');
8140         expression_t *false_expression =
8141                 parse_sub_expression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
8142
8143         type_t *const orig_true_type  = true_expression->base.type;
8144         type_t *const orig_false_type = false_expression->base.type;
8145         type_t *const true_type       = skip_typeref(orig_true_type);
8146         type_t *const false_type      = skip_typeref(orig_false_type);
8147
8148         /* 6.5.15.3 */
8149         type_t *result_type;
8150         if (is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
8151                         is_type_atomic(false_type, ATOMIC_TYPE_VOID)) {
8152                 /* ISO/IEC 14882:1998(E) §5.16:2 */
8153                 if (true_expression->kind == EXPR_UNARY_THROW) {
8154                         result_type = false_type;
8155                 } else if (false_expression->kind == EXPR_UNARY_THROW) {
8156                         result_type = true_type;
8157                 } else {
8158                         if (warning.other && (
8159                                                 !is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
8160                                                 !is_type_atomic(false_type, ATOMIC_TYPE_VOID)
8161                                         )) {
8162                                 warningf(&conditional->base.source_position,
8163                                                 "ISO C forbids conditional expression with only one void side");
8164                         }
8165                         result_type = type_void;
8166                 }
8167         } else if (is_type_arithmetic(true_type)
8168                    && is_type_arithmetic(false_type)) {
8169                 result_type = semantic_arithmetic(true_type, false_type);
8170
8171                 true_expression  = create_implicit_cast(true_expression, result_type);
8172                 false_expression = create_implicit_cast(false_expression, result_type);
8173
8174                 conditional->true_expression  = true_expression;
8175                 conditional->false_expression = false_expression;
8176                 conditional->base.type        = result_type;
8177         } else if (same_compound_type(true_type, false_type)) {
8178                 /* just take 1 of the 2 types */
8179                 result_type = true_type;
8180         } else if (is_type_pointer(true_type) || is_type_pointer(false_type)) {
8181                 type_t *pointer_type;
8182                 type_t *other_type;
8183                 expression_t *other_expression;
8184                 if (is_type_pointer(true_type) &&
8185                                 (!is_type_pointer(false_type) || is_null_pointer_constant(false_expression))) {
8186                         pointer_type     = true_type;
8187                         other_type       = false_type;
8188                         other_expression = false_expression;
8189                 } else {
8190                         pointer_type     = false_type;
8191                         other_type       = true_type;
8192                         other_expression = true_expression;
8193                 }
8194
8195                 if (is_null_pointer_constant(other_expression)) {
8196                         result_type = pointer_type;
8197                 } else if (is_type_pointer(other_type)) {
8198                         type_t *to1 = skip_typeref(pointer_type->pointer.points_to);
8199                         type_t *to2 = skip_typeref(other_type->pointer.points_to);
8200
8201                         type_t *to;
8202                         if (is_type_atomic(to1, ATOMIC_TYPE_VOID) ||
8203                             is_type_atomic(to2, ATOMIC_TYPE_VOID)) {
8204                                 to = type_void;
8205                         } else if (types_compatible(get_unqualified_type(to1),
8206                                                     get_unqualified_type(to2))) {
8207                                 to = to1;
8208                         } else {
8209                                 if (warning.other) {
8210                                         warningf(&conditional->base.source_position,
8211                                                         "pointer types '%T' and '%T' in conditional expression are incompatible",
8212                                                         true_type, false_type);
8213                                 }
8214                                 to = type_void;
8215                         }
8216
8217                         type_t *const type =
8218                                 get_qualified_type(to, to1->base.qualifiers | to2->base.qualifiers);
8219                         result_type = make_pointer_type(type, TYPE_QUALIFIER_NONE);
8220                 } else if (is_type_integer(other_type)) {
8221                         if (warning.other) {
8222                                 warningf(&conditional->base.source_position,
8223                                                 "pointer/integer type mismatch in conditional expression ('%T' and '%T')", true_type, false_type);
8224                         }
8225                         result_type = pointer_type;
8226                 } else {
8227                         if (is_type_valid(other_type)) {
8228                                 type_error_incompatible("while parsing conditional",
8229                                                 &expression->base.source_position, true_type, false_type);
8230                         }
8231                         result_type = type_error_type;
8232                 }
8233         } else {
8234                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
8235                         type_error_incompatible("while parsing conditional",
8236                                                 &conditional->base.source_position, true_type,
8237                                                 false_type);
8238                 }
8239                 result_type = type_error_type;
8240         }
8241
8242         conditional->true_expression
8243                 = gnu_cond ? NULL : create_implicit_cast(true_expression, result_type);
8244         conditional->false_expression
8245                 = create_implicit_cast(false_expression, result_type);
8246         conditional->base.type = result_type;
8247         return result;
8248 end_error:
8249         return create_invalid_expression();
8250 }
8251
8252 /**
8253  * Parse an extension expression.
8254  */
8255 static expression_t *parse_extension(void)
8256 {
8257         eat(T___extension__);
8258
8259         bool old_gcc_extension   = in_gcc_extension;
8260         in_gcc_extension         = true;
8261         expression_t *expression = parse_sub_expression(PREC_UNARY);
8262         in_gcc_extension         = old_gcc_extension;
8263         return expression;
8264 }
8265
8266 /**
8267  * Parse a __builtin_classify_type() expression.
8268  */
8269 static expression_t *parse_builtin_classify_type(void)
8270 {
8271         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
8272         result->base.type    = type_int;
8273
8274         eat(T___builtin_classify_type);
8275
8276         expect('(');
8277         add_anchor_token(')');
8278         expression_t *expression = parse_expression();
8279         rem_anchor_token(')');
8280         expect(')');
8281         result->classify_type.type_expression = expression;
8282
8283         return result;
8284 end_error:
8285         return create_invalid_expression();
8286 }
8287
8288 /**
8289  * Parse a delete expression
8290  * ISO/IEC 14882:1998(E) §5.3.5
8291  */
8292 static expression_t *parse_delete(void)
8293 {
8294         expression_t *const result = allocate_expression_zero(EXPR_UNARY_DELETE);
8295         result->base.type          = type_void;
8296
8297         eat(T_delete);
8298
8299         if (token.type == '[') {
8300                 next_token();
8301                 result->kind = EXPR_UNARY_DELETE_ARRAY;
8302                 expect(']');
8303 end_error:;
8304         }
8305
8306         expression_t *const value = parse_sub_expression(PREC_CAST);
8307         result->unary.value = value;
8308
8309         type_t *const type = skip_typeref(value->base.type);
8310         if (!is_type_pointer(type)) {
8311                 errorf(&value->base.source_position,
8312                                 "operand of delete must have pointer type");
8313         } else if (warning.other &&
8314                         is_type_atomic(skip_typeref(type->pointer.points_to), ATOMIC_TYPE_VOID)) {
8315                 warningf(&value->base.source_position,
8316                                 "deleting 'void*' is undefined");
8317         }
8318
8319         return result;
8320 }
8321
8322 /**
8323  * Parse a throw expression
8324  * ISO/IEC 14882:1998(E) §15:1
8325  */
8326 static expression_t *parse_throw(void)
8327 {
8328         expression_t *const result = allocate_expression_zero(EXPR_UNARY_THROW);
8329         result->base.type          = type_void;
8330
8331         eat(T_throw);
8332
8333         expression_t *value = NULL;
8334         switch (token.type) {
8335                 EXPRESSION_START {
8336                         value = parse_assignment_expression();
8337                         /* ISO/IEC 14882:1998(E) §15.1:3 */
8338                         type_t *const orig_type = value->base.type;
8339                         type_t *const type      = skip_typeref(orig_type);
8340                         if (is_type_incomplete(type)) {
8341                                 errorf(&value->base.source_position,
8342                                                 "cannot throw object of incomplete type '%T'", orig_type);
8343                         } else if (is_type_pointer(type)) {
8344                                 type_t *const points_to = skip_typeref(type->pointer.points_to);
8345                                 if (is_type_incomplete(points_to) &&
8346                                                 !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
8347                                         errorf(&value->base.source_position,
8348                                                         "cannot throw pointer to incomplete type '%T'", orig_type);
8349                                 }
8350                         }
8351                 }
8352
8353                 default:
8354                         break;
8355         }
8356         result->unary.value = value;
8357
8358         return result;
8359 }
8360
8361 static bool check_pointer_arithmetic(const source_position_t *source_position,
8362                                      type_t *pointer_type,
8363                                      type_t *orig_pointer_type)
8364 {
8365         type_t *points_to = pointer_type->pointer.points_to;
8366         points_to = skip_typeref(points_to);
8367
8368         if (is_type_incomplete(points_to)) {
8369                 if (!GNU_MODE || !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
8370                         errorf(source_position,
8371                                "arithmetic with pointer to incomplete type '%T' not allowed",
8372                                orig_pointer_type);
8373                         return false;
8374                 } else if (warning.pointer_arith) {
8375                         warningf(source_position,
8376                                  "pointer of type '%T' used in arithmetic",
8377                                  orig_pointer_type);
8378                 }
8379         } else if (is_type_function(points_to)) {
8380                 if (!GNU_MODE) {
8381                         errorf(source_position,
8382                                "arithmetic with pointer to function type '%T' not allowed",
8383                                orig_pointer_type);
8384                         return false;
8385                 } else if (warning.pointer_arith) {
8386                         warningf(source_position,
8387                                  "pointer to a function '%T' used in arithmetic",
8388                                  orig_pointer_type);
8389                 }
8390         }
8391         return true;
8392 }
8393
8394 static bool is_lvalue(const expression_t *expression)
8395 {
8396         /* TODO: doesn't seem to be consistent with §6.3.2.1 (1) */
8397         switch (expression->kind) {
8398         case EXPR_REFERENCE:
8399         case EXPR_ARRAY_ACCESS:
8400         case EXPR_SELECT:
8401         case EXPR_UNARY_DEREFERENCE:
8402                 return true;
8403
8404         default: {
8405           type_t *type = skip_typeref(expression->base.type);
8406           return
8407                 /* ISO/IEC 14882:1998(E) §3.10:3 */
8408                 is_type_reference(type) ||
8409                 /* Claim it is an lvalue, if the type is invalid.  There was a parse
8410                  * error before, which maybe prevented properly recognizing it as
8411                  * lvalue. */
8412                 !is_type_valid(type);
8413         }
8414         }
8415 }
8416
8417 static void semantic_incdec(unary_expression_t *expression)
8418 {
8419         type_t *const orig_type = expression->value->base.type;
8420         type_t *const type      = skip_typeref(orig_type);
8421         if (is_type_pointer(type)) {
8422                 if (!check_pointer_arithmetic(&expression->base.source_position,
8423                                               type, orig_type)) {
8424                         return;
8425                 }
8426         } else if (!is_type_real(type) && is_type_valid(type)) {
8427                 /* TODO: improve error message */
8428                 errorf(&expression->base.source_position,
8429                        "operation needs an arithmetic or pointer type");
8430                 return;
8431         }
8432         if (!is_lvalue(expression->value)) {
8433                 /* TODO: improve error message */
8434                 errorf(&expression->base.source_position, "lvalue required as operand");
8435         }
8436         expression->base.type = orig_type;
8437 }
8438
8439 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
8440 {
8441         type_t *const orig_type = expression->value->base.type;
8442         type_t *const type      = skip_typeref(orig_type);
8443         if (!is_type_arithmetic(type)) {
8444                 if (is_type_valid(type)) {
8445                         /* TODO: improve error message */
8446                         errorf(&expression->base.source_position,
8447                                 "operation needs an arithmetic type");
8448                 }
8449                 return;
8450         }
8451
8452         expression->base.type = orig_type;
8453 }
8454
8455 static void semantic_unexpr_plus(unary_expression_t *expression)
8456 {
8457         semantic_unexpr_arithmetic(expression);
8458         if (warning.traditional)
8459                 warningf(&expression->base.source_position,
8460                         "traditional C rejects the unary plus operator");
8461 }
8462
8463 static void semantic_not(unary_expression_t *expression)
8464 {
8465         /* §6.5.3.3:1  The operand [...] of the ! operator, scalar type. */
8466         semantic_condition(expression->value, "operand of !");
8467         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8468 }
8469
8470 static void semantic_unexpr_integer(unary_expression_t *expression)
8471 {
8472         type_t *const orig_type = expression->value->base.type;
8473         type_t *const type      = skip_typeref(orig_type);
8474         if (!is_type_integer(type)) {
8475                 if (is_type_valid(type)) {
8476                         errorf(&expression->base.source_position,
8477                                "operand of ~ must be of integer type");
8478                 }
8479                 return;
8480         }
8481
8482         expression->base.type = orig_type;
8483 }
8484
8485 static void semantic_dereference(unary_expression_t *expression)
8486 {
8487         type_t *const orig_type = expression->value->base.type;
8488         type_t *const type      = skip_typeref(orig_type);
8489         if (!is_type_pointer(type)) {
8490                 if (is_type_valid(type)) {
8491                         errorf(&expression->base.source_position,
8492                                "Unary '*' needs pointer or array type, but type '%T' given", orig_type);
8493                 }
8494                 return;
8495         }
8496
8497         type_t *result_type   = type->pointer.points_to;
8498         result_type           = automatic_type_conversion(result_type);
8499         expression->base.type = result_type;
8500 }
8501
8502 /**
8503  * Record that an address is taken (expression represents an lvalue).
8504  *
8505  * @param expression       the expression
8506  * @param may_be_register  if true, the expression might be an register
8507  */
8508 static void set_address_taken(expression_t *expression, bool may_be_register)
8509 {
8510         if (expression->kind != EXPR_REFERENCE)
8511                 return;
8512
8513         entity_t *const entity = expression->reference.entity;
8514
8515         if (entity->kind != ENTITY_VARIABLE && entity->kind != ENTITY_PARAMETER)
8516                 return;
8517
8518         if (entity->declaration.storage_class == STORAGE_CLASS_REGISTER
8519                         && !may_be_register) {
8520                 errorf(&expression->base.source_position,
8521                                 "address of register %s '%Y' requested",
8522                                 get_entity_kind_name(entity->kind),     entity->base.symbol);
8523         }
8524
8525         if (entity->kind == ENTITY_VARIABLE) {
8526                 entity->variable.address_taken = true;
8527         } else {
8528                 assert(entity->kind == ENTITY_PARAMETER);
8529                 entity->parameter.address_taken = true;
8530         }
8531 }
8532
8533 /**
8534  * Check the semantic of the address taken expression.
8535  */
8536 static void semantic_take_addr(unary_expression_t *expression)
8537 {
8538         expression_t *value = expression->value;
8539         value->base.type    = revert_automatic_type_conversion(value);
8540
8541         type_t *orig_type = value->base.type;
8542         type_t *type      = skip_typeref(orig_type);
8543         if (!is_type_valid(type))
8544                 return;
8545
8546         /* §6.5.3.2 */
8547         if (!is_lvalue(value)) {
8548                 errorf(&expression->base.source_position, "'&' requires an lvalue");
8549         }
8550         if (type->kind == TYPE_BITFIELD) {
8551                 errorf(&expression->base.source_position,
8552                        "'&' not allowed on object with bitfield type '%T'",
8553                        type);
8554         }
8555
8556         set_address_taken(value, false);
8557
8558         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
8559 }
8560
8561 #define CREATE_UNARY_EXPRESSION_PARSER(token_type, unexpression_type, sfunc) \
8562 static expression_t *parse_##unexpression_type(void)                         \
8563 {                                                                            \
8564         expression_t *unary_expression                                           \
8565                 = allocate_expression_zero(unexpression_type);                       \
8566         eat(token_type);                                                         \
8567         unary_expression->unary.value = parse_sub_expression(PREC_UNARY);        \
8568                                                                                  \
8569         sfunc(&unary_expression->unary);                                         \
8570                                                                                  \
8571         return unary_expression;                                                 \
8572 }
8573
8574 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
8575                                semantic_unexpr_arithmetic)
8576 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
8577                                semantic_unexpr_plus)
8578 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
8579                                semantic_not)
8580 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
8581                                semantic_dereference)
8582 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
8583                                semantic_take_addr)
8584 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
8585                                semantic_unexpr_integer)
8586 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
8587                                semantic_incdec)
8588 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
8589                                semantic_incdec)
8590
8591 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_type, unexpression_type, \
8592                                                sfunc)                         \
8593 static expression_t *parse_##unexpression_type(expression_t *left)            \
8594 {                                                                             \
8595         expression_t *unary_expression                                            \
8596                 = allocate_expression_zero(unexpression_type);                        \
8597         eat(token_type);                                                          \
8598         unary_expression->unary.value = left;                                     \
8599                                                                                   \
8600         sfunc(&unary_expression->unary);                                          \
8601                                                                               \
8602         return unary_expression;                                                  \
8603 }
8604
8605 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
8606                                        EXPR_UNARY_POSTFIX_INCREMENT,
8607                                        semantic_incdec)
8608 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
8609                                        EXPR_UNARY_POSTFIX_DECREMENT,
8610                                        semantic_incdec)
8611
8612 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
8613 {
8614         /* TODO: handle complex + imaginary types */
8615
8616         type_left  = get_unqualified_type(type_left);
8617         type_right = get_unqualified_type(type_right);
8618
8619         /* § 6.3.1.8 Usual arithmetic conversions */
8620         if (type_left == type_long_double || type_right == type_long_double) {
8621                 return type_long_double;
8622         } else if (type_left == type_double || type_right == type_double) {
8623                 return type_double;
8624         } else if (type_left == type_float || type_right == type_float) {
8625                 return type_float;
8626         }
8627
8628         type_left  = promote_integer(type_left);
8629         type_right = promote_integer(type_right);
8630
8631         if (type_left == type_right)
8632                 return type_left;
8633
8634         bool const signed_left  = is_type_signed(type_left);
8635         bool const signed_right = is_type_signed(type_right);
8636         int const  rank_left    = get_rank(type_left);
8637         int const  rank_right   = get_rank(type_right);
8638
8639         if (signed_left == signed_right)
8640                 return rank_left >= rank_right ? type_left : type_right;
8641
8642         int     s_rank;
8643         int     u_rank;
8644         type_t *s_type;
8645         type_t *u_type;
8646         if (signed_left) {
8647                 s_rank = rank_left;
8648                 s_type = type_left;
8649                 u_rank = rank_right;
8650                 u_type = type_right;
8651         } else {
8652                 s_rank = rank_right;
8653                 s_type = type_right;
8654                 u_rank = rank_left;
8655                 u_type = type_left;
8656         }
8657
8658         if (u_rank >= s_rank)
8659                 return u_type;
8660
8661         /* casting rank to atomic_type_kind is a bit hacky, but makes things
8662          * easier here... */
8663         if (get_atomic_type_size((atomic_type_kind_t) s_rank)
8664                         > get_atomic_type_size((atomic_type_kind_t) u_rank))
8665                 return s_type;
8666
8667         switch (s_rank) {
8668                 case ATOMIC_TYPE_INT:      return type_unsigned_int;
8669                 case ATOMIC_TYPE_LONG:     return type_unsigned_long;
8670                 case ATOMIC_TYPE_LONGLONG: return type_unsigned_long_long;
8671
8672                 default: panic("invalid atomic type");
8673         }
8674 }
8675
8676 /**
8677  * Check the semantic restrictions for a binary expression.
8678  */
8679 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
8680 {
8681         expression_t *const left            = expression->left;
8682         expression_t *const right           = expression->right;
8683         type_t       *const orig_type_left  = left->base.type;
8684         type_t       *const orig_type_right = right->base.type;
8685         type_t       *const type_left       = skip_typeref(orig_type_left);
8686         type_t       *const type_right      = skip_typeref(orig_type_right);
8687
8688         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8689                 /* TODO: improve error message */
8690                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8691                         errorf(&expression->base.source_position,
8692                                "operation needs arithmetic types");
8693                 }
8694                 return;
8695         }
8696
8697         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8698         expression->left      = create_implicit_cast(left, arithmetic_type);
8699         expression->right     = create_implicit_cast(right, arithmetic_type);
8700         expression->base.type = arithmetic_type;
8701 }
8702
8703 static void warn_div_by_zero(binary_expression_t const *const expression)
8704 {
8705         if (!warning.div_by_zero ||
8706             !is_type_integer(expression->base.type))
8707                 return;
8708
8709         expression_t const *const right = expression->right;
8710         /* The type of the right operand can be different for /= */
8711         if (is_type_integer(right->base.type) &&
8712             is_constant_expression(right)     &&
8713             fold_constant(right) == 0) {
8714                 warningf(&expression->base.source_position, "division by zero");
8715         }
8716 }
8717
8718 /**
8719  * Check the semantic restrictions for a div/mod expression.
8720  */
8721 static void semantic_divmod_arithmetic(binary_expression_t *expression) {
8722         semantic_binexpr_arithmetic(expression);
8723         warn_div_by_zero(expression);
8724 }
8725
8726 static void semantic_shift_op(binary_expression_t *expression)
8727 {
8728         expression_t *const left            = expression->left;
8729         expression_t *const right           = expression->right;
8730         type_t       *const orig_type_left  = left->base.type;
8731         type_t       *const orig_type_right = right->base.type;
8732         type_t       *      type_left       = skip_typeref(orig_type_left);
8733         type_t       *      type_right      = skip_typeref(orig_type_right);
8734
8735         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8736                 /* TODO: improve error message */
8737                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8738                         errorf(&expression->base.source_position,
8739                                "operands of shift operation must have integer types");
8740                 }
8741                 return;
8742         }
8743
8744         type_left  = promote_integer(type_left);
8745         type_right = promote_integer(type_right);
8746
8747         expression->left      = create_implicit_cast(left, type_left);
8748         expression->right     = create_implicit_cast(right, type_right);
8749         expression->base.type = type_left;
8750 }
8751
8752 static void semantic_add(binary_expression_t *expression)
8753 {
8754         expression_t *const left            = expression->left;
8755         expression_t *const right           = expression->right;
8756         type_t       *const orig_type_left  = left->base.type;
8757         type_t       *const orig_type_right = right->base.type;
8758         type_t       *const type_left       = skip_typeref(orig_type_left);
8759         type_t       *const type_right      = skip_typeref(orig_type_right);
8760
8761         /* § 6.5.6 */
8762         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8763                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8764                 expression->left  = create_implicit_cast(left, arithmetic_type);
8765                 expression->right = create_implicit_cast(right, arithmetic_type);
8766                 expression->base.type = arithmetic_type;
8767                 return;
8768         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8769                 check_pointer_arithmetic(&expression->base.source_position,
8770                                          type_left, orig_type_left);
8771                 expression->base.type = type_left;
8772         } else if (is_type_pointer(type_right) && is_type_integer(type_left)) {
8773                 check_pointer_arithmetic(&expression->base.source_position,
8774                                          type_right, orig_type_right);
8775                 expression->base.type = type_right;
8776         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8777                 errorf(&expression->base.source_position,
8778                        "invalid operands to binary + ('%T', '%T')",
8779                        orig_type_left, orig_type_right);
8780         }
8781 }
8782
8783 static void semantic_sub(binary_expression_t *expression)
8784 {
8785         expression_t            *const left            = expression->left;
8786         expression_t            *const right           = expression->right;
8787         type_t                  *const orig_type_left  = left->base.type;
8788         type_t                  *const orig_type_right = right->base.type;
8789         type_t                  *const type_left       = skip_typeref(orig_type_left);
8790         type_t                  *const type_right      = skip_typeref(orig_type_right);
8791         source_position_t const *const pos             = &expression->base.source_position;
8792
8793         /* § 5.6.5 */
8794         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8795                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8796                 expression->left        = create_implicit_cast(left, arithmetic_type);
8797                 expression->right       = create_implicit_cast(right, arithmetic_type);
8798                 expression->base.type =  arithmetic_type;
8799                 return;
8800         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8801                 check_pointer_arithmetic(&expression->base.source_position,
8802                                          type_left, orig_type_left);
8803                 expression->base.type = type_left;
8804         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8805                 type_t *const unqual_left  = get_unqualified_type(skip_typeref(type_left->pointer.points_to));
8806                 type_t *const unqual_right = get_unqualified_type(skip_typeref(type_right->pointer.points_to));
8807                 if (!types_compatible(unqual_left, unqual_right)) {
8808                         errorf(pos,
8809                                "subtracting pointers to incompatible types '%T' and '%T'",
8810                                orig_type_left, orig_type_right);
8811                 } else if (!is_type_object(unqual_left)) {
8812                         if (!is_type_atomic(unqual_left, ATOMIC_TYPE_VOID)) {
8813                                 errorf(pos, "subtracting pointers to non-object types '%T'",
8814                                        orig_type_left);
8815                         } else if (warning.other) {
8816                                 warningf(pos, "subtracting pointers to void");
8817                         }
8818                 }
8819                 expression->base.type = type_ptrdiff_t;
8820         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8821                 errorf(pos, "invalid operands of types '%T' and '%T' to binary '-'",
8822                        orig_type_left, orig_type_right);
8823         }
8824 }
8825
8826 static void warn_string_literal_address(expression_t const* expr)
8827 {
8828         while (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
8829                 expr = expr->unary.value;
8830                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
8831                         return;
8832                 expr = expr->unary.value;
8833         }
8834
8835         if (expr->kind == EXPR_STRING_LITERAL ||
8836             expr->kind == EXPR_WIDE_STRING_LITERAL) {
8837                 warningf(&expr->base.source_position,
8838                         "comparison with string literal results in unspecified behaviour");
8839         }
8840 }
8841
8842 /**
8843  * Check the semantics of comparison expressions.
8844  *
8845  * @param expression   The expression to check.
8846  */
8847 static void semantic_comparison(binary_expression_t *expression)
8848 {
8849         expression_t *left  = expression->left;
8850         expression_t *right = expression->right;
8851
8852         if (warning.address) {
8853                 warn_string_literal_address(left);
8854                 warn_string_literal_address(right);
8855
8856                 expression_t const* const func_left = get_reference_address(left);
8857                 if (func_left != NULL && is_null_pointer_constant(right)) {
8858                         warningf(&expression->base.source_position,
8859                                  "the address of '%Y' will never be NULL",
8860                                  func_left->reference.entity->base.symbol);
8861                 }
8862
8863                 expression_t const* const func_right = get_reference_address(right);
8864                 if (func_right != NULL && is_null_pointer_constant(right)) {
8865                         warningf(&expression->base.source_position,
8866                                  "the address of '%Y' will never be NULL",
8867                                  func_right->reference.entity->base.symbol);
8868                 }
8869         }
8870
8871         type_t *orig_type_left  = left->base.type;
8872         type_t *orig_type_right = right->base.type;
8873         type_t *type_left       = skip_typeref(orig_type_left);
8874         type_t *type_right      = skip_typeref(orig_type_right);
8875
8876         /* TODO non-arithmetic types */
8877         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8878                 /* test for signed vs unsigned compares */
8879                 if (warning.sign_compare &&
8880                     (expression->base.kind != EXPR_BINARY_EQUAL &&
8881                      expression->base.kind != EXPR_BINARY_NOTEQUAL) &&
8882                     (is_type_signed(type_left) != is_type_signed(type_right))) {
8883
8884                         /* check if 1 of the operands is a constant, in this case we just
8885                          * check wether we can safely represent the resulting constant in
8886                          * the type of the other operand. */
8887                         expression_t *const_expr = NULL;
8888                         expression_t *other_expr = NULL;
8889
8890                         if (is_constant_expression(left)) {
8891                                 const_expr = left;
8892                                 other_expr = right;
8893                         } else if (is_constant_expression(right)) {
8894                                 const_expr = right;
8895                                 other_expr = left;
8896                         }
8897
8898                         if (const_expr != NULL) {
8899                                 type_t *other_type = skip_typeref(other_expr->base.type);
8900                                 long    val        = fold_constant(const_expr);
8901                                 /* TODO: check if val can be represented by other_type */
8902                                 (void) other_type;
8903                                 (void) val;
8904                         }
8905                         warningf(&expression->base.source_position,
8906                                  "comparison between signed and unsigned");
8907                 }
8908                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8909                 expression->left        = create_implicit_cast(left, arithmetic_type);
8910                 expression->right       = create_implicit_cast(right, arithmetic_type);
8911                 expression->base.type   = arithmetic_type;
8912                 if (warning.float_equal &&
8913                     (expression->base.kind == EXPR_BINARY_EQUAL ||
8914                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
8915                     is_type_float(arithmetic_type)) {
8916                         warningf(&expression->base.source_position,
8917                                  "comparing floating point with == or != is unsafe");
8918                 }
8919         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8920                 /* TODO check compatibility */
8921         } else if (is_type_pointer(type_left)) {
8922                 expression->right = create_implicit_cast(right, type_left);
8923         } else if (is_type_pointer(type_right)) {
8924                 expression->left = create_implicit_cast(left, type_right);
8925         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8926                 type_error_incompatible("invalid operands in comparison",
8927                                         &expression->base.source_position,
8928                                         type_left, type_right);
8929         }
8930         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8931 }
8932
8933 /**
8934  * Checks if a compound type has constant fields.
8935  */
8936 static bool has_const_fields(const compound_type_t *type)
8937 {
8938         compound_t *compound = type->compound;
8939         entity_t   *entry    = compound->members.entities;
8940
8941         for (; entry != NULL; entry = entry->base.next) {
8942                 if (!is_declaration(entry))
8943                         continue;
8944
8945                 const type_t *decl_type = skip_typeref(entry->declaration.type);
8946                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
8947                         return true;
8948         }
8949
8950         return false;
8951 }
8952
8953 static bool is_valid_assignment_lhs(expression_t const* const left)
8954 {
8955         type_t *const orig_type_left = revert_automatic_type_conversion(left);
8956         type_t *const type_left      = skip_typeref(orig_type_left);
8957
8958         if (!is_lvalue(left)) {
8959                 errorf(HERE, "left hand side '%E' of assignment is not an lvalue",
8960                        left);
8961                 return false;
8962         }
8963
8964         if (left->kind == EXPR_REFERENCE
8965                         && left->reference.entity->kind == ENTITY_FUNCTION) {
8966                 errorf(HERE, "cannot assign to function '%E'", left);
8967                 return false;
8968         }
8969
8970         if (is_type_array(type_left)) {
8971                 errorf(HERE, "cannot assign to array '%E'", left);
8972                 return false;
8973         }
8974         if (type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
8975                 errorf(HERE, "assignment to readonly location '%E' (type '%T')", left,
8976                        orig_type_left);
8977                 return false;
8978         }
8979         if (is_type_incomplete(type_left)) {
8980                 errorf(HERE, "left-hand side '%E' of assignment has incomplete type '%T'",
8981                        left, orig_type_left);
8982                 return false;
8983         }
8984         if (is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
8985                 errorf(HERE, "cannot assign to '%E' because compound type '%T' has readonly fields",
8986                        left, orig_type_left);
8987                 return false;
8988         }
8989
8990         return true;
8991 }
8992
8993 static void semantic_arithmetic_assign(binary_expression_t *expression)
8994 {
8995         expression_t *left            = expression->left;
8996         expression_t *right           = expression->right;
8997         type_t       *orig_type_left  = left->base.type;
8998         type_t       *orig_type_right = right->base.type;
8999
9000         if (!is_valid_assignment_lhs(left))
9001                 return;
9002
9003         type_t *type_left  = skip_typeref(orig_type_left);
9004         type_t *type_right = skip_typeref(orig_type_right);
9005
9006         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
9007                 /* TODO: improve error message */
9008                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
9009                         errorf(&expression->base.source_position,
9010                                "operation needs arithmetic types");
9011                 }
9012                 return;
9013         }
9014
9015         /* combined instructions are tricky. We can't create an implicit cast on
9016          * the left side, because we need the uncasted form for the store.
9017          * The ast2firm pass has to know that left_type must be right_type
9018          * for the arithmetic operation and create a cast by itself */
9019         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
9020         expression->right       = create_implicit_cast(right, arithmetic_type);
9021         expression->base.type   = type_left;
9022 }
9023
9024 static void semantic_divmod_assign(binary_expression_t *expression)
9025 {
9026         semantic_arithmetic_assign(expression);
9027         warn_div_by_zero(expression);
9028 }
9029
9030 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
9031 {
9032         expression_t *const left            = expression->left;
9033         expression_t *const right           = expression->right;
9034         type_t       *const orig_type_left  = left->base.type;
9035         type_t       *const orig_type_right = right->base.type;
9036         type_t       *const type_left       = skip_typeref(orig_type_left);
9037         type_t       *const type_right      = skip_typeref(orig_type_right);
9038
9039         if (!is_valid_assignment_lhs(left))
9040                 return;
9041
9042         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
9043                 /* combined instructions are tricky. We can't create an implicit cast on
9044                  * the left side, because we need the uncasted form for the store.
9045                  * The ast2firm pass has to know that left_type must be right_type
9046                  * for the arithmetic operation and create a cast by itself */
9047                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
9048                 expression->right     = create_implicit_cast(right, arithmetic_type);
9049                 expression->base.type = type_left;
9050         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
9051                 check_pointer_arithmetic(&expression->base.source_position,
9052                                          type_left, orig_type_left);
9053                 expression->base.type = type_left;
9054         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
9055                 errorf(&expression->base.source_position,
9056                        "incompatible types '%T' and '%T' in assignment",
9057                        orig_type_left, orig_type_right);
9058         }
9059 }
9060
9061 /**
9062  * Check the semantic restrictions of a logical expression.
9063  */
9064 static void semantic_logical_op(binary_expression_t *expression)
9065 {
9066         /* §6.5.13:2  Each of the operands shall have scalar type.
9067          * §6.5.14:2  Each of the operands shall have scalar type. */
9068         semantic_condition(expression->left,   "left operand of logical operator");
9069         semantic_condition(expression->right, "right operand of logical operator");
9070         expression->base.type = c_mode & _CXX ? type_bool : type_int;
9071 }
9072
9073 /**
9074  * Check the semantic restrictions of a binary assign expression.
9075  */
9076 static void semantic_binexpr_assign(binary_expression_t *expression)
9077 {
9078         expression_t *left           = expression->left;
9079         type_t       *orig_type_left = left->base.type;
9080
9081         if (!is_valid_assignment_lhs(left))
9082                 return;
9083
9084         assign_error_t error = semantic_assign(orig_type_left, expression->right);
9085         report_assign_error(error, orig_type_left, expression->right,
9086                         "assignment", &left->base.source_position);
9087         expression->right = create_implicit_cast(expression->right, orig_type_left);
9088         expression->base.type = orig_type_left;
9089 }
9090
9091 /**
9092  * Determine if the outermost operation (or parts thereof) of the given
9093  * expression has no effect in order to generate a warning about this fact.
9094  * Therefore in some cases this only examines some of the operands of the
9095  * expression (see comments in the function and examples below).
9096  * Examples:
9097  *   f() + 23;    // warning, because + has no effect
9098  *   x || f();    // no warning, because x controls execution of f()
9099  *   x ? y : f(); // warning, because y has no effect
9100  *   (void)x;     // no warning to be able to suppress the warning
9101  * This function can NOT be used for an "expression has definitely no effect"-
9102  * analysis. */
9103 static bool expression_has_effect(const expression_t *const expr)
9104 {
9105         switch (expr->kind) {
9106                 case EXPR_UNKNOWN:                   break;
9107                 case EXPR_INVALID:                   return true; /* do NOT warn */
9108                 case EXPR_REFERENCE:                 return false;
9109                 case EXPR_REFERENCE_ENUM_VALUE:      return false;
9110                 /* suppress the warning for microsoft __noop operations */
9111                 case EXPR_CONST:                     return expr->conste.is_ms_noop;
9112                 case EXPR_CHARACTER_CONSTANT:        return false;
9113                 case EXPR_WIDE_CHARACTER_CONSTANT:   return false;
9114                 case EXPR_STRING_LITERAL:            return false;
9115                 case EXPR_WIDE_STRING_LITERAL:       return false;
9116                 case EXPR_LABEL_ADDRESS:             return false;
9117
9118                 case EXPR_CALL: {
9119                         const call_expression_t *const call = &expr->call;
9120                         if (call->function->kind != EXPR_BUILTIN_SYMBOL)
9121                                 return true;
9122
9123                         switch (call->function->builtin_symbol.symbol->ID) {
9124                                 case T___builtin_va_end: return true;
9125                                 default:                 return false;
9126                         }
9127                 }
9128
9129                 /* Generate the warning if either the left or right hand side of a
9130                  * conditional expression has no effect */
9131                 case EXPR_CONDITIONAL: {
9132                         const conditional_expression_t *const cond = &expr->conditional;
9133                         return
9134                                 expression_has_effect(cond->true_expression) &&
9135                                 expression_has_effect(cond->false_expression);
9136                 }
9137
9138                 case EXPR_SELECT:                    return false;
9139                 case EXPR_ARRAY_ACCESS:              return false;
9140                 case EXPR_SIZEOF:                    return false;
9141                 case EXPR_CLASSIFY_TYPE:             return false;
9142                 case EXPR_ALIGNOF:                   return false;
9143
9144                 case EXPR_FUNCNAME:                  return false;
9145                 case EXPR_BUILTIN_SYMBOL:            break; /* handled in EXPR_CALL */
9146                 case EXPR_BUILTIN_CONSTANT_P:        return false;
9147                 case EXPR_BUILTIN_PREFETCH:          return true;
9148                 case EXPR_OFFSETOF:                  return false;
9149                 case EXPR_VA_START:                  return true;
9150                 case EXPR_VA_ARG:                    return true;
9151                 case EXPR_STATEMENT:                 return true; // TODO
9152                 case EXPR_COMPOUND_LITERAL:          return false;
9153
9154                 case EXPR_UNARY_NEGATE:              return false;
9155                 case EXPR_UNARY_PLUS:                return false;
9156                 case EXPR_UNARY_BITWISE_NEGATE:      return false;
9157                 case EXPR_UNARY_NOT:                 return false;
9158                 case EXPR_UNARY_DEREFERENCE:         return false;
9159                 case EXPR_UNARY_TAKE_ADDRESS:        return false;
9160                 case EXPR_UNARY_POSTFIX_INCREMENT:   return true;
9161                 case EXPR_UNARY_POSTFIX_DECREMENT:   return true;
9162                 case EXPR_UNARY_PREFIX_INCREMENT:    return true;
9163                 case EXPR_UNARY_PREFIX_DECREMENT:    return true;
9164
9165                 /* Treat void casts as if they have an effect in order to being able to
9166                  * suppress the warning */
9167                 case EXPR_UNARY_CAST: {
9168                         type_t *const type = skip_typeref(expr->base.type);
9169                         return is_type_atomic(type, ATOMIC_TYPE_VOID);
9170                 }
9171
9172                 case EXPR_UNARY_CAST_IMPLICIT:       return true;
9173                 case EXPR_UNARY_ASSUME:              return true;
9174                 case EXPR_UNARY_DELETE:              return true;
9175                 case EXPR_UNARY_DELETE_ARRAY:        return true;
9176                 case EXPR_UNARY_THROW:               return true;
9177
9178                 case EXPR_BINARY_ADD:                return false;
9179                 case EXPR_BINARY_SUB:                return false;
9180                 case EXPR_BINARY_MUL:                return false;
9181                 case EXPR_BINARY_DIV:                return false;
9182                 case EXPR_BINARY_MOD:                return false;
9183                 case EXPR_BINARY_EQUAL:              return false;
9184                 case EXPR_BINARY_NOTEQUAL:           return false;
9185                 case EXPR_BINARY_LESS:               return false;
9186                 case EXPR_BINARY_LESSEQUAL:          return false;
9187                 case EXPR_BINARY_GREATER:            return false;
9188                 case EXPR_BINARY_GREATEREQUAL:       return false;
9189                 case EXPR_BINARY_BITWISE_AND:        return false;
9190                 case EXPR_BINARY_BITWISE_OR:         return false;
9191                 case EXPR_BINARY_BITWISE_XOR:        return false;
9192                 case EXPR_BINARY_SHIFTLEFT:          return false;
9193                 case EXPR_BINARY_SHIFTRIGHT:         return false;
9194                 case EXPR_BINARY_ASSIGN:             return true;
9195                 case EXPR_BINARY_MUL_ASSIGN:         return true;
9196                 case EXPR_BINARY_DIV_ASSIGN:         return true;
9197                 case EXPR_BINARY_MOD_ASSIGN:         return true;
9198                 case EXPR_BINARY_ADD_ASSIGN:         return true;
9199                 case EXPR_BINARY_SUB_ASSIGN:         return true;
9200                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:   return true;
9201                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:  return true;
9202                 case EXPR_BINARY_BITWISE_AND_ASSIGN: return true;
9203                 case EXPR_BINARY_BITWISE_XOR_ASSIGN: return true;
9204                 case EXPR_BINARY_BITWISE_OR_ASSIGN:  return true;
9205
9206                 /* Only examine the right hand side of && and ||, because the left hand
9207                  * side already has the effect of controlling the execution of the right
9208                  * hand side */
9209                 case EXPR_BINARY_LOGICAL_AND:
9210                 case EXPR_BINARY_LOGICAL_OR:
9211                 /* Only examine the right hand side of a comma expression, because the left
9212                  * hand side has a separate warning */
9213                 case EXPR_BINARY_COMMA:
9214                         return expression_has_effect(expr->binary.right);
9215
9216                 case EXPR_BINARY_BUILTIN_EXPECT:     return true;
9217                 case EXPR_BINARY_ISGREATER:          return false;
9218                 case EXPR_BINARY_ISGREATEREQUAL:     return false;
9219                 case EXPR_BINARY_ISLESS:             return false;
9220                 case EXPR_BINARY_ISLESSEQUAL:        return false;
9221                 case EXPR_BINARY_ISLESSGREATER:      return false;
9222                 case EXPR_BINARY_ISUNORDERED:        return false;
9223         }
9224
9225         internal_errorf(HERE, "unexpected expression");
9226 }
9227
9228 static void semantic_comma(binary_expression_t *expression)
9229 {
9230         if (warning.unused_value) {
9231                 const expression_t *const left = expression->left;
9232                 if (!expression_has_effect(left)) {
9233                         warningf(&left->base.source_position,
9234                                  "left-hand operand of comma expression has no effect");
9235                 }
9236         }
9237         expression->base.type = expression->right->base.type;
9238 }
9239
9240 /**
9241  * @param prec_r precedence of the right operand
9242  */
9243 #define CREATE_BINEXPR_PARSER(token_type, binexpression_type, prec_r, sfunc) \
9244 static expression_t *parse_##binexpression_type(expression_t *left)          \
9245 {                                                                            \
9246         expression_t *binexpr = allocate_expression_zero(binexpression_type);    \
9247         binexpr->binary.left  = left;                                            \
9248         eat(token_type);                                                         \
9249                                                                              \
9250         expression_t *right = parse_sub_expression(prec_r);                      \
9251                                                                              \
9252         binexpr->binary.right = right;                                           \
9253         sfunc(&binexpr->binary);                                                 \
9254                                                                              \
9255         return binexpr;                                                          \
9256 }
9257
9258 CREATE_BINEXPR_PARSER('*',                    EXPR_BINARY_MUL,                PREC_CAST,           semantic_binexpr_arithmetic)
9259 CREATE_BINEXPR_PARSER('/',                    EXPR_BINARY_DIV,                PREC_CAST,           semantic_divmod_arithmetic)
9260 CREATE_BINEXPR_PARSER('%',                    EXPR_BINARY_MOD,                PREC_CAST,           semantic_divmod_arithmetic)
9261 CREATE_BINEXPR_PARSER('+',                    EXPR_BINARY_ADD,                PREC_MULTIPLICATIVE, semantic_add)
9262 CREATE_BINEXPR_PARSER('-',                    EXPR_BINARY_SUB,                PREC_MULTIPLICATIVE, semantic_sub)
9263 CREATE_BINEXPR_PARSER(T_LESSLESS,             EXPR_BINARY_SHIFTLEFT,          PREC_ADDITIVE,       semantic_shift_op)
9264 CREATE_BINEXPR_PARSER(T_GREATERGREATER,       EXPR_BINARY_SHIFTRIGHT,         PREC_ADDITIVE,       semantic_shift_op)
9265 CREATE_BINEXPR_PARSER('<',                    EXPR_BINARY_LESS,               PREC_SHIFT,          semantic_comparison)
9266 CREATE_BINEXPR_PARSER('>',                    EXPR_BINARY_GREATER,            PREC_SHIFT,          semantic_comparison)
9267 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,          PREC_SHIFT,          semantic_comparison)
9268 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,       PREC_SHIFT,          semantic_comparison)
9269 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,           PREC_RELATIONAL,     semantic_comparison)
9270 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,              PREC_RELATIONAL,     semantic_comparison)
9271 CREATE_BINEXPR_PARSER('&',                    EXPR_BINARY_BITWISE_AND,        PREC_EQUALITY,       semantic_binexpr_arithmetic)
9272 CREATE_BINEXPR_PARSER('^',                    EXPR_BINARY_BITWISE_XOR,        PREC_AND,            semantic_binexpr_arithmetic)
9273 CREATE_BINEXPR_PARSER('|',                    EXPR_BINARY_BITWISE_OR,         PREC_XOR,            semantic_binexpr_arithmetic)
9274 CREATE_BINEXPR_PARSER(T_ANDAND,               EXPR_BINARY_LOGICAL_AND,        PREC_OR,             semantic_logical_op)
9275 CREATE_BINEXPR_PARSER(T_PIPEPIPE,             EXPR_BINARY_LOGICAL_OR,         PREC_LOGICAL_AND,    semantic_logical_op)
9276 CREATE_BINEXPR_PARSER('=',                    EXPR_BINARY_ASSIGN,             PREC_ASSIGNMENT,     semantic_binexpr_assign)
9277 CREATE_BINEXPR_PARSER(T_PLUSEQUAL,            EXPR_BINARY_ADD_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
9278 CREATE_BINEXPR_PARSER(T_MINUSEQUAL,           EXPR_BINARY_SUB_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
9279 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL,        EXPR_BINARY_MUL_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9280 CREATE_BINEXPR_PARSER(T_SLASHEQUAL,           EXPR_BINARY_DIV_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
9281 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL,         EXPR_BINARY_MOD_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
9282 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL,        EXPR_BINARY_SHIFTLEFT_ASSIGN,   PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9283 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL,  EXPR_BINARY_SHIFTRIGHT_ASSIGN,  PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9284 CREATE_BINEXPR_PARSER(T_ANDEQUAL,             EXPR_BINARY_BITWISE_AND_ASSIGN, PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9285 CREATE_BINEXPR_PARSER(T_PIPEEQUAL,            EXPR_BINARY_BITWISE_OR_ASSIGN,  PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9286 CREATE_BINEXPR_PARSER(T_CARETEQUAL,           EXPR_BINARY_BITWISE_XOR_ASSIGN, PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9287 CREATE_BINEXPR_PARSER(',',                    EXPR_BINARY_COMMA,              PREC_ASSIGNMENT,     semantic_comma)
9288
9289
9290 static expression_t *parse_sub_expression(precedence_t precedence)
9291 {
9292         if (token.type < 0) {
9293                 return expected_expression_error();
9294         }
9295
9296         expression_parser_function_t *parser
9297                 = &expression_parsers[token.type];
9298         source_position_t             source_position = token.source_position;
9299         expression_t                 *left;
9300
9301         if (parser->parser != NULL) {
9302                 left = parser->parser();
9303         } else {
9304                 left = parse_primary_expression();
9305         }
9306         assert(left != NULL);
9307         left->base.source_position = source_position;
9308
9309         while (true) {
9310                 if (token.type < 0) {
9311                         return expected_expression_error();
9312                 }
9313
9314                 parser = &expression_parsers[token.type];
9315                 if (parser->infix_parser == NULL)
9316                         break;
9317                 if (parser->infix_precedence < precedence)
9318                         break;
9319
9320                 left = parser->infix_parser(left);
9321
9322                 assert(left != NULL);
9323                 assert(left->kind != EXPR_UNKNOWN);
9324                 left->base.source_position = source_position;
9325         }
9326
9327         return left;
9328 }
9329
9330 /**
9331  * Parse an expression.
9332  */
9333 static expression_t *parse_expression(void)
9334 {
9335         return parse_sub_expression(PREC_EXPRESSION);
9336 }
9337
9338 /**
9339  * Register a parser for a prefix-like operator.
9340  *
9341  * @param parser      the parser function
9342  * @param token_type  the token type of the prefix token
9343  */
9344 static void register_expression_parser(parse_expression_function parser,
9345                                        int token_type)
9346 {
9347         expression_parser_function_t *entry = &expression_parsers[token_type];
9348
9349         if (entry->parser != NULL) {
9350                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
9351                 panic("trying to register multiple expression parsers for a token");
9352         }
9353         entry->parser = parser;
9354 }
9355
9356 /**
9357  * Register a parser for an infix operator with given precedence.
9358  *
9359  * @param parser      the parser function
9360  * @param token_type  the token type of the infix operator
9361  * @param precedence  the precedence of the operator
9362  */
9363 static void register_infix_parser(parse_expression_infix_function parser,
9364                 int token_type, unsigned precedence)
9365 {
9366         expression_parser_function_t *entry = &expression_parsers[token_type];
9367
9368         if (entry->infix_parser != NULL) {
9369                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
9370                 panic("trying to register multiple infix expression parsers for a "
9371                       "token");
9372         }
9373         entry->infix_parser     = parser;
9374         entry->infix_precedence = precedence;
9375 }
9376
9377 /**
9378  * Initialize the expression parsers.
9379  */
9380 static void init_expression_parsers(void)
9381 {
9382         memset(&expression_parsers, 0, sizeof(expression_parsers));
9383
9384         register_infix_parser(parse_array_expression,               '[',                    PREC_POSTFIX);
9385         register_infix_parser(parse_call_expression,                '(',                    PREC_POSTFIX);
9386         register_infix_parser(parse_select_expression,              '.',                    PREC_POSTFIX);
9387         register_infix_parser(parse_select_expression,              T_MINUSGREATER,         PREC_POSTFIX);
9388         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,   T_PLUSPLUS,             PREC_POSTFIX);
9389         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,   T_MINUSMINUS,           PREC_POSTFIX);
9390         register_infix_parser(parse_EXPR_BINARY_MUL,                '*',                    PREC_MULTIPLICATIVE);
9391         register_infix_parser(parse_EXPR_BINARY_DIV,                '/',                    PREC_MULTIPLICATIVE);
9392         register_infix_parser(parse_EXPR_BINARY_MOD,                '%',                    PREC_MULTIPLICATIVE);
9393         register_infix_parser(parse_EXPR_BINARY_ADD,                '+',                    PREC_ADDITIVE);
9394         register_infix_parser(parse_EXPR_BINARY_SUB,                '-',                    PREC_ADDITIVE);
9395         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,          T_LESSLESS,             PREC_SHIFT);
9396         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,         T_GREATERGREATER,       PREC_SHIFT);
9397         register_infix_parser(parse_EXPR_BINARY_LESS,               '<',                    PREC_RELATIONAL);
9398         register_infix_parser(parse_EXPR_BINARY_GREATER,            '>',                    PREC_RELATIONAL);
9399         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,          T_LESSEQUAL,            PREC_RELATIONAL);
9400         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL,       T_GREATEREQUAL,         PREC_RELATIONAL);
9401         register_infix_parser(parse_EXPR_BINARY_EQUAL,              T_EQUALEQUAL,           PREC_EQUALITY);
9402         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,           T_EXCLAMATIONMARKEQUAL, PREC_EQUALITY);
9403         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,        '&',                    PREC_AND);
9404         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,        '^',                    PREC_XOR);
9405         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,         '|',                    PREC_OR);
9406         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,        T_ANDAND,               PREC_LOGICAL_AND);
9407         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,         T_PIPEPIPE,             PREC_LOGICAL_OR);
9408         register_infix_parser(parse_conditional_expression,         '?',                    PREC_CONDITIONAL);
9409         register_infix_parser(parse_EXPR_BINARY_ASSIGN,             '=',                    PREC_ASSIGNMENT);
9410         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,         T_PLUSEQUAL,            PREC_ASSIGNMENT);
9411         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,         T_MINUSEQUAL,           PREC_ASSIGNMENT);
9412         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,         T_ASTERISKEQUAL,        PREC_ASSIGNMENT);
9413         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,         T_SLASHEQUAL,           PREC_ASSIGNMENT);
9414         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,         T_PERCENTEQUAL,         PREC_ASSIGNMENT);
9415         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,   T_LESSLESSEQUAL,        PREC_ASSIGNMENT);
9416         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,  T_GREATERGREATEREQUAL,  PREC_ASSIGNMENT);
9417         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN, T_ANDEQUAL,             PREC_ASSIGNMENT);
9418         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,  T_PIPEEQUAL,            PREC_ASSIGNMENT);
9419         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN, T_CARETEQUAL,           PREC_ASSIGNMENT);
9420         register_infix_parser(parse_EXPR_BINARY_COMMA,              ',',                    PREC_EXPRESSION);
9421
9422         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-');
9423         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+');
9424         register_expression_parser(parse_EXPR_UNARY_NOT,              '!');
9425         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~');
9426         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*');
9427         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&');
9428         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT, T_PLUSPLUS);
9429         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT, T_MINUSMINUS);
9430         register_expression_parser(parse_sizeof,                      T_sizeof);
9431         register_expression_parser(parse_alignof,                     T___alignof__);
9432         register_expression_parser(parse_extension,                   T___extension__);
9433         register_expression_parser(parse_builtin_classify_type,       T___builtin_classify_type);
9434         register_expression_parser(parse_delete,                      T_delete);
9435         register_expression_parser(parse_throw,                       T_throw);
9436 }
9437
9438 /**
9439  * Parse a asm statement arguments specification.
9440  */
9441 static asm_argument_t *parse_asm_arguments(bool is_out)
9442 {
9443         asm_argument_t  *result = NULL;
9444         asm_argument_t **anchor = &result;
9445
9446         while (token.type == T_STRING_LITERAL || token.type == '[') {
9447                 asm_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
9448                 memset(argument, 0, sizeof(argument[0]));
9449
9450                 if (token.type == '[') {
9451                         eat('[');
9452                         if (token.type != T_IDENTIFIER) {
9453                                 parse_error_expected("while parsing asm argument",
9454                                                      T_IDENTIFIER, NULL);
9455                                 return NULL;
9456                         }
9457                         argument->symbol = token.v.symbol;
9458
9459                         expect(']');
9460                 }
9461
9462                 argument->constraints = parse_string_literals();
9463                 expect('(');
9464                 add_anchor_token(')');
9465                 expression_t *expression = parse_expression();
9466                 rem_anchor_token(')');
9467                 if (is_out) {
9468                         /* Ugly GCC stuff: Allow lvalue casts.  Skip casts, when they do not
9469                          * change size or type representation (e.g. int -> long is ok, but
9470                          * int -> float is not) */
9471                         if (expression->kind == EXPR_UNARY_CAST) {
9472                                 type_t      *const type = expression->base.type;
9473                                 type_kind_t  const kind = type->kind;
9474                                 if (kind == TYPE_ATOMIC || kind == TYPE_POINTER) {
9475                                         unsigned flags;
9476                                         unsigned size;
9477                                         if (kind == TYPE_ATOMIC) {
9478                                                 atomic_type_kind_t const akind = type->atomic.akind;
9479                                                 flags = get_atomic_type_flags(akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
9480                                                 size  = get_atomic_type_size(akind);
9481                                         } else {
9482                                                 flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
9483                                                 size  = get_atomic_type_size(get_intptr_kind());
9484                                         }
9485
9486                                         do {
9487                                                 expression_t *const value      = expression->unary.value;
9488                                                 type_t       *const value_type = value->base.type;
9489                                                 type_kind_t   const value_kind = value_type->kind;
9490
9491                                                 unsigned value_flags;
9492                                                 unsigned value_size;
9493                                                 if (value_kind == TYPE_ATOMIC) {
9494                                                         atomic_type_kind_t const value_akind = value_type->atomic.akind;
9495                                                         value_flags = get_atomic_type_flags(value_akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
9496                                                         value_size  = get_atomic_type_size(value_akind);
9497                                                 } else if (value_kind == TYPE_POINTER) {
9498                                                         value_flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
9499                                                         value_size  = get_atomic_type_size(get_intptr_kind());
9500                                                 } else {
9501                                                         break;
9502                                                 }
9503
9504                                                 if (value_flags != flags || value_size != size)
9505                                                         break;
9506
9507                                                 expression = value;
9508                                         } while (expression->kind == EXPR_UNARY_CAST);
9509                                 }
9510                         }
9511
9512                         if (!is_lvalue(expression)) {
9513                                 errorf(&expression->base.source_position,
9514                                        "asm output argument is not an lvalue");
9515                         }
9516
9517                         if (argument->constraints.begin[0] == '+')
9518                                 mark_vars_read(expression, NULL);
9519                 } else {
9520                         mark_vars_read(expression, NULL);
9521                 }
9522                 argument->expression = expression;
9523                 expect(')');
9524
9525                 set_address_taken(expression, true);
9526
9527                 *anchor = argument;
9528                 anchor  = &argument->next;
9529
9530                 if (token.type != ',')
9531                         break;
9532                 eat(',');
9533         }
9534
9535         return result;
9536 end_error:
9537         return NULL;
9538 }
9539
9540 /**
9541  * Parse a asm statement clobber specification.
9542  */
9543 static asm_clobber_t *parse_asm_clobbers(void)
9544 {
9545         asm_clobber_t *result = NULL;
9546         asm_clobber_t *last   = NULL;
9547
9548         while (token.type == T_STRING_LITERAL) {
9549                 asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
9550                 clobber->clobber       = parse_string_literals();
9551
9552                 if (last != NULL) {
9553                         last->next = clobber;
9554                 } else {
9555                         result = clobber;
9556                 }
9557                 last = clobber;
9558
9559                 if (token.type != ',')
9560                         break;
9561                 eat(',');
9562         }
9563
9564         return result;
9565 }
9566
9567 /**
9568  * Parse an asm statement.
9569  */
9570 static statement_t *parse_asm_statement(void)
9571 {
9572         statement_t     *statement     = allocate_statement_zero(STATEMENT_ASM);
9573         asm_statement_t *asm_statement = &statement->asms;
9574
9575         eat(T_asm);
9576
9577         if (token.type == T_volatile) {
9578                 next_token();
9579                 asm_statement->is_volatile = true;
9580         }
9581
9582         expect('(');
9583         add_anchor_token(')');
9584         add_anchor_token(':');
9585         asm_statement->asm_text = parse_string_literals();
9586
9587         if (token.type != ':') {
9588                 rem_anchor_token(':');
9589                 goto end_of_asm;
9590         }
9591         eat(':');
9592
9593         asm_statement->outputs = parse_asm_arguments(true);
9594         if (token.type != ':') {
9595                 rem_anchor_token(':');
9596                 goto end_of_asm;
9597         }
9598         eat(':');
9599
9600         asm_statement->inputs = parse_asm_arguments(false);
9601         if (token.type != ':') {
9602                 rem_anchor_token(':');
9603                 goto end_of_asm;
9604         }
9605         rem_anchor_token(':');
9606         eat(':');
9607
9608         asm_statement->clobbers = parse_asm_clobbers();
9609
9610 end_of_asm:
9611         rem_anchor_token(')');
9612         expect(')');
9613         expect(';');
9614
9615         if (asm_statement->outputs == NULL) {
9616                 /* GCC: An 'asm' instruction without any output operands will be treated
9617                  * identically to a volatile 'asm' instruction. */
9618                 asm_statement->is_volatile = true;
9619         }
9620
9621         return statement;
9622 end_error:
9623         return create_invalid_statement();
9624 }
9625
9626 /**
9627  * Parse a case statement.
9628  */
9629 static statement_t *parse_case_statement(void)
9630 {
9631         statement_t       *const statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9632         source_position_t *const pos       = &statement->base.source_position;
9633
9634         eat(T_case);
9635
9636         expression_t *const expression   = parse_expression();
9637         statement->case_label.expression = expression;
9638         if (!is_constant_expression(expression)) {
9639                 /* This check does not prevent the error message in all cases of an
9640                  * prior error while parsing the expression.  At least it catches the
9641                  * common case of a mistyped enum entry. */
9642                 if (is_type_valid(skip_typeref(expression->base.type))) {
9643                         errorf(pos, "case label does not reduce to an integer constant");
9644                 }
9645                 statement->case_label.is_bad = true;
9646         } else {
9647                 long const val = fold_constant(expression);
9648                 statement->case_label.first_case = val;
9649                 statement->case_label.last_case  = val;
9650         }
9651
9652         if (GNU_MODE) {
9653                 if (token.type == T_DOTDOTDOT) {
9654                         next_token();
9655                         expression_t *const end_range   = parse_expression();
9656                         statement->case_label.end_range = end_range;
9657                         if (!is_constant_expression(end_range)) {
9658                                 /* This check does not prevent the error message in all cases of an
9659                                  * prior error while parsing the expression.  At least it catches the
9660                                  * common case of a mistyped enum entry. */
9661                                 if (is_type_valid(skip_typeref(end_range->base.type))) {
9662                                         errorf(pos, "case range does not reduce to an integer constant");
9663                                 }
9664                                 statement->case_label.is_bad = true;
9665                         } else {
9666                                 long const val = fold_constant(end_range);
9667                                 statement->case_label.last_case = val;
9668
9669                                 if (warning.other && val < statement->case_label.first_case) {
9670                                         statement->case_label.is_empty_range = true;
9671                                         warningf(pos, "empty range specified");
9672                                 }
9673                         }
9674                 }
9675         }
9676
9677         PUSH_PARENT(statement);
9678
9679         expect(':');
9680 end_error:
9681
9682         if (current_switch != NULL) {
9683                 if (! statement->case_label.is_bad) {
9684                         /* Check for duplicate case values */
9685                         case_label_statement_t *c = &statement->case_label;
9686                         for (case_label_statement_t *l = current_switch->first_case; l != NULL; l = l->next) {
9687                                 if (l->is_bad || l->is_empty_range || l->expression == NULL)
9688                                         continue;
9689
9690                                 if (c->last_case < l->first_case || c->first_case > l->last_case)
9691                                         continue;
9692
9693                                 errorf(pos, "duplicate case value (previously used %P)",
9694                                        &l->base.source_position);
9695                                 break;
9696                         }
9697                 }
9698                 /* link all cases into the switch statement */
9699                 if (current_switch->last_case == NULL) {
9700                         current_switch->first_case      = &statement->case_label;
9701                 } else {
9702                         current_switch->last_case->next = &statement->case_label;
9703                 }
9704                 current_switch->last_case = &statement->case_label;
9705         } else {
9706                 errorf(pos, "case label not within a switch statement");
9707         }
9708
9709         statement_t *const inner_stmt = parse_statement();
9710         statement->case_label.statement = inner_stmt;
9711         if (inner_stmt->kind == STATEMENT_DECLARATION) {
9712                 errorf(&inner_stmt->base.source_position, "declaration after case label");
9713         }
9714
9715         POP_PARENT;
9716         return statement;
9717 }
9718
9719 /**
9720  * Parse a default statement.
9721  */
9722 static statement_t *parse_default_statement(void)
9723 {
9724         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9725
9726         eat(T_default);
9727
9728         PUSH_PARENT(statement);
9729
9730         expect(':');
9731         if (current_switch != NULL) {
9732                 const case_label_statement_t *def_label = current_switch->default_label;
9733                 if (def_label != NULL) {
9734                         errorf(HERE, "multiple default labels in one switch (previous declared %P)",
9735                                &def_label->base.source_position);
9736                 } else {
9737                         current_switch->default_label = &statement->case_label;
9738
9739                         /* link all cases into the switch statement */
9740                         if (current_switch->last_case == NULL) {
9741                                 current_switch->first_case      = &statement->case_label;
9742                         } else {
9743                                 current_switch->last_case->next = &statement->case_label;
9744                         }
9745                         current_switch->last_case = &statement->case_label;
9746                 }
9747         } else {
9748                 errorf(&statement->base.source_position,
9749                         "'default' label not within a switch statement");
9750         }
9751
9752         statement_t *const inner_stmt = parse_statement();
9753         statement->case_label.statement = inner_stmt;
9754         if (inner_stmt->kind == STATEMENT_DECLARATION) {
9755                 errorf(&inner_stmt->base.source_position, "declaration after default label");
9756         }
9757
9758         POP_PARENT;
9759         return statement;
9760 end_error:
9761         POP_PARENT;
9762         return create_invalid_statement();
9763 }
9764
9765 /**
9766  * Parse a label statement.
9767  */
9768 static statement_t *parse_label_statement(void)
9769 {
9770         assert(token.type == T_IDENTIFIER);
9771         symbol_t *symbol = token.v.symbol;
9772         label_t  *label  = get_label(symbol);
9773
9774         statement_t *const statement = allocate_statement_zero(STATEMENT_LABEL);
9775         statement->label.label       = label;
9776
9777         next_token();
9778
9779         PUSH_PARENT(statement);
9780
9781         /* if statement is already set then the label is defined twice,
9782          * otherwise it was just mentioned in a goto/local label declaration so far
9783          */
9784         if (label->statement != NULL) {
9785                 errorf(HERE, "duplicate label '%Y' (declared %P)",
9786                        symbol, &label->base.source_position);
9787         } else {
9788                 label->base.source_position = token.source_position;
9789                 label->statement            = statement;
9790         }
9791
9792         eat(':');
9793
9794         if (token.type == '}') {
9795                 /* TODO only warn? */
9796                 if (warning.other && false) {
9797                         warningf(HERE, "label at end of compound statement");
9798                         statement->label.statement = create_empty_statement();
9799                 } else {
9800                         errorf(HERE, "label at end of compound statement");
9801                         statement->label.statement = create_invalid_statement();
9802                 }
9803         } else if (token.type == ';') {
9804                 /* Eat an empty statement here, to avoid the warning about an empty
9805                  * statement after a label.  label:; is commonly used to have a label
9806                  * before a closing brace. */
9807                 statement->label.statement = create_empty_statement();
9808                 next_token();
9809         } else {
9810                 statement_t *const inner_stmt = parse_statement();
9811                 statement->label.statement = inner_stmt;
9812                 if (inner_stmt->kind == STATEMENT_DECLARATION) {
9813                         errorf(&inner_stmt->base.source_position, "declaration after label");
9814                 }
9815         }
9816
9817         /* remember the labels in a list for later checking */
9818         *label_anchor = &statement->label;
9819         label_anchor  = &statement->label.next;
9820
9821         POP_PARENT;
9822         return statement;
9823 }
9824
9825 /**
9826  * Parse an if statement.
9827  */
9828 static statement_t *parse_if(void)
9829 {
9830         statement_t *statement = allocate_statement_zero(STATEMENT_IF);
9831
9832         eat(T_if);
9833
9834         PUSH_PARENT(statement);
9835
9836         add_anchor_token('{');
9837
9838         expect('(');
9839         add_anchor_token(')');
9840         expression_t *const expr = parse_expression();
9841         statement->ifs.condition = expr;
9842         /* §6.8.4.1:1  The controlling expression of an if statement shall have
9843          *             scalar type. */
9844         semantic_condition(expr, "condition of 'if'-statment");
9845         mark_vars_read(expr, NULL);
9846         rem_anchor_token(')');
9847         expect(')');
9848
9849 end_error:
9850         rem_anchor_token('{');
9851
9852         add_anchor_token(T_else);
9853         statement->ifs.true_statement = parse_statement();
9854         rem_anchor_token(T_else);
9855
9856         if (token.type == T_else) {
9857                 next_token();
9858                 statement->ifs.false_statement = parse_statement();
9859         }
9860
9861         POP_PARENT;
9862         return statement;
9863 }
9864
9865 /**
9866  * Check that all enums are handled in a switch.
9867  *
9868  * @param statement  the switch statement to check
9869  */
9870 static void check_enum_cases(const switch_statement_t *statement) {
9871         const type_t *type = skip_typeref(statement->expression->base.type);
9872         if (! is_type_enum(type))
9873                 return;
9874         const enum_type_t *enumt = &type->enumt;
9875
9876         /* if we have a default, no warnings */
9877         if (statement->default_label != NULL)
9878                 return;
9879
9880         /* FIXME: calculation of value should be done while parsing */
9881         /* TODO: quadratic algorithm here. Change to an n log n one */
9882         long            last_value = -1;
9883         const entity_t *entry      = enumt->enume->base.next;
9884         for (; entry != NULL && entry->kind == ENTITY_ENUM_VALUE;
9885              entry = entry->base.next) {
9886                 const expression_t *expression = entry->enum_value.value;
9887                 long                value      = expression != NULL ? fold_constant(expression) : last_value + 1;
9888                 bool                found      = false;
9889                 for (const case_label_statement_t *l = statement->first_case; l != NULL; l = l->next) {
9890                         if (l->expression == NULL)
9891                                 continue;
9892                         if (l->first_case <= value && value <= l->last_case) {
9893                                 found = true;
9894                                 break;
9895                         }
9896                 }
9897                 if (! found) {
9898                         warningf(&statement->base.source_position,
9899                                  "enumeration value '%Y' not handled in switch",
9900                                  entry->base.symbol);
9901                 }
9902                 last_value = value;
9903         }
9904 }
9905
9906 /**
9907  * Parse a switch statement.
9908  */
9909 static statement_t *parse_switch(void)
9910 {
9911         statement_t *statement = allocate_statement_zero(STATEMENT_SWITCH);
9912
9913         eat(T_switch);
9914
9915         PUSH_PARENT(statement);
9916
9917         expect('(');
9918         add_anchor_token(')');
9919         expression_t *const expr = parse_expression();
9920         mark_vars_read(expr, NULL);
9921         type_t       *      type = skip_typeref(expr->base.type);
9922         if (is_type_integer(type)) {
9923                 type = promote_integer(type);
9924                 if (warning.traditional) {
9925                         if (get_rank(type) >= get_akind_rank(ATOMIC_TYPE_LONG)) {
9926                                 warningf(&expr->base.source_position,
9927                                         "'%T' switch expression not converted to '%T' in ISO C",
9928                                         type, type_int);
9929                         }
9930                 }
9931         } else if (is_type_valid(type)) {
9932                 errorf(&expr->base.source_position,
9933                        "switch quantity is not an integer, but '%T'", type);
9934                 type = type_error_type;
9935         }
9936         statement->switchs.expression = create_implicit_cast(expr, type);
9937         expect(')');
9938         rem_anchor_token(')');
9939
9940         switch_statement_t *rem = current_switch;
9941         current_switch          = &statement->switchs;
9942         statement->switchs.body = parse_statement();
9943         current_switch          = rem;
9944
9945         if (warning.switch_default &&
9946             statement->switchs.default_label == NULL) {
9947                 warningf(&statement->base.source_position, "switch has no default case");
9948         }
9949         if (warning.switch_enum)
9950                 check_enum_cases(&statement->switchs);
9951
9952         POP_PARENT;
9953         return statement;
9954 end_error:
9955         POP_PARENT;
9956         return create_invalid_statement();
9957 }
9958
9959 static statement_t *parse_loop_body(statement_t *const loop)
9960 {
9961         statement_t *const rem = current_loop;
9962         current_loop = loop;
9963
9964         statement_t *const body = parse_statement();
9965
9966         current_loop = rem;
9967         return body;
9968 }
9969
9970 /**
9971  * Parse a while statement.
9972  */
9973 static statement_t *parse_while(void)
9974 {
9975         statement_t *statement = allocate_statement_zero(STATEMENT_WHILE);
9976
9977         eat(T_while);
9978
9979         PUSH_PARENT(statement);
9980
9981         expect('(');
9982         add_anchor_token(')');
9983         expression_t *const cond = parse_expression();
9984         statement->whiles.condition = cond;
9985         /* §6.8.5:2    The controlling expression of an iteration statement shall
9986          *             have scalar type. */
9987         semantic_condition(cond, "condition of 'while'-statement");
9988         mark_vars_read(cond, NULL);
9989         rem_anchor_token(')');
9990         expect(')');
9991
9992         statement->whiles.body = parse_loop_body(statement);
9993
9994         POP_PARENT;
9995         return statement;
9996 end_error:
9997         POP_PARENT;
9998         return create_invalid_statement();
9999 }
10000
10001 /**
10002  * Parse a do statement.
10003  */
10004 static statement_t *parse_do(void)
10005 {
10006         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
10007
10008         eat(T_do);
10009
10010         PUSH_PARENT(statement);
10011
10012         add_anchor_token(T_while);
10013         statement->do_while.body = parse_loop_body(statement);
10014         rem_anchor_token(T_while);
10015
10016         expect(T_while);
10017         expect('(');
10018         add_anchor_token(')');
10019         expression_t *const cond = parse_expression();
10020         statement->do_while.condition = cond;
10021         /* §6.8.5:2    The controlling expression of an iteration statement shall
10022          *             have scalar type. */
10023         semantic_condition(cond, "condition of 'do-while'-statement");
10024         mark_vars_read(cond, NULL);
10025         rem_anchor_token(')');
10026         expect(')');
10027         expect(';');
10028
10029         POP_PARENT;
10030         return statement;
10031 end_error:
10032         POP_PARENT;
10033         return create_invalid_statement();
10034 }
10035
10036 /**
10037  * Parse a for statement.
10038  */
10039 static statement_t *parse_for(void)
10040 {
10041         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
10042
10043         eat(T_for);
10044
10045         PUSH_PARENT(statement);
10046
10047         size_t const  top       = environment_top();
10048         scope_t      *old_scope = scope_push(&statement->fors.scope);
10049
10050         expect('(');
10051         add_anchor_token(')');
10052
10053         if (token.type == ';') {
10054                 next_token();
10055         } else if (is_declaration_specifier(&token, false)) {
10056                 parse_declaration(record_entity, DECL_FLAGS_NONE);
10057         } else {
10058                 add_anchor_token(';');
10059                 expression_t *const init = parse_expression();
10060                 statement->fors.initialisation = init;
10061                 mark_vars_read(init, ENT_ANY);
10062                 if (warning.unused_value && !expression_has_effect(init)) {
10063                         warningf(&init->base.source_position,
10064                                         "initialisation of 'for'-statement has no effect");
10065                 }
10066                 rem_anchor_token(';');
10067                 expect(';');
10068         }
10069
10070         if (token.type != ';') {
10071                 add_anchor_token(';');
10072                 expression_t *const cond = parse_expression();
10073                 statement->fors.condition = cond;
10074                 /* §6.8.5:2    The controlling expression of an iteration statement
10075                  *             shall have scalar type. */
10076                 semantic_condition(cond, "condition of 'for'-statement");
10077                 mark_vars_read(cond, NULL);
10078                 rem_anchor_token(';');
10079         }
10080         expect(';');
10081         if (token.type != ')') {
10082                 expression_t *const step = parse_expression();
10083                 statement->fors.step = step;
10084                 mark_vars_read(step, ENT_ANY);
10085                 if (warning.unused_value && !expression_has_effect(step)) {
10086                         warningf(&step->base.source_position,
10087                                  "step of 'for'-statement has no effect");
10088                 }
10089         }
10090         expect(')');
10091         rem_anchor_token(')');
10092         statement->fors.body = parse_loop_body(statement);
10093
10094         assert(current_scope == &statement->fors.scope);
10095         scope_pop(old_scope);
10096         environment_pop_to(top);
10097
10098         POP_PARENT;
10099         return statement;
10100
10101 end_error:
10102         POP_PARENT;
10103         rem_anchor_token(')');
10104         assert(current_scope == &statement->fors.scope);
10105         scope_pop(old_scope);
10106         environment_pop_to(top);
10107
10108         return create_invalid_statement();
10109 }
10110
10111 /**
10112  * Parse a goto statement.
10113  */
10114 static statement_t *parse_goto(void)
10115 {
10116         statement_t *statement = allocate_statement_zero(STATEMENT_GOTO);
10117         eat(T_goto);
10118
10119         if (GNU_MODE && token.type == '*') {
10120                 next_token();
10121                 expression_t *expression = parse_expression();
10122                 mark_vars_read(expression, NULL);
10123
10124                 /* Argh: although documentation says the expression must be of type void*,
10125                  * gcc accepts anything that can be casted into void* without error */
10126                 type_t *type = expression->base.type;
10127
10128                 if (type != type_error_type) {
10129                         if (!is_type_pointer(type) && !is_type_integer(type)) {
10130                                 errorf(&expression->base.source_position,
10131                                         "cannot convert to a pointer type");
10132                         } else if (warning.other && type != type_void_ptr) {
10133                                 warningf(&expression->base.source_position,
10134                                         "type of computed goto expression should be 'void*' not '%T'", type);
10135                         }
10136                         expression = create_implicit_cast(expression, type_void_ptr);
10137                 }
10138
10139                 statement->gotos.expression = expression;
10140         } else {
10141                 if (token.type != T_IDENTIFIER) {
10142                         if (GNU_MODE)
10143                                 parse_error_expected("while parsing goto", T_IDENTIFIER, '*', NULL);
10144                         else
10145                                 parse_error_expected("while parsing goto", T_IDENTIFIER, NULL);
10146                         eat_until_anchor();
10147                         goto end_error;
10148                 }
10149                 symbol_t *symbol = token.v.symbol;
10150                 next_token();
10151
10152                 statement->gotos.label = get_label(symbol);
10153         }
10154
10155         /* remember the goto's in a list for later checking */
10156         *goto_anchor = &statement->gotos;
10157         goto_anchor  = &statement->gotos.next;
10158
10159         expect(';');
10160
10161         return statement;
10162 end_error:
10163         return create_invalid_statement();
10164 }
10165
10166 /**
10167  * Parse a continue statement.
10168  */
10169 static statement_t *parse_continue(void)
10170 {
10171         if (current_loop == NULL) {
10172                 errorf(HERE, "continue statement not within loop");
10173         }
10174
10175         statement_t *statement = allocate_statement_zero(STATEMENT_CONTINUE);
10176
10177         eat(T_continue);
10178         expect(';');
10179
10180 end_error:
10181         return statement;
10182 }
10183
10184 /**
10185  * Parse a break statement.
10186  */
10187 static statement_t *parse_break(void)
10188 {
10189         if (current_switch == NULL && current_loop == NULL) {
10190                 errorf(HERE, "break statement not within loop or switch");
10191         }
10192
10193         statement_t *statement = allocate_statement_zero(STATEMENT_BREAK);
10194
10195         eat(T_break);
10196         expect(';');
10197
10198 end_error:
10199         return statement;
10200 }
10201
10202 /**
10203  * Parse a __leave statement.
10204  */
10205 static statement_t *parse_leave_statement(void)
10206 {
10207         if (current_try == NULL) {
10208                 errorf(HERE, "__leave statement not within __try");
10209         }
10210
10211         statement_t *statement = allocate_statement_zero(STATEMENT_LEAVE);
10212
10213         eat(T___leave);
10214         expect(';');
10215
10216 end_error:
10217         return statement;
10218 }
10219
10220 /**
10221  * Check if a given entity represents a local variable.
10222  */
10223 static bool is_local_variable(const entity_t *entity)
10224 {
10225         if (entity->kind != ENTITY_VARIABLE)
10226                 return false;
10227
10228         switch ((storage_class_tag_t) entity->declaration.storage_class) {
10229         case STORAGE_CLASS_AUTO:
10230         case STORAGE_CLASS_REGISTER: {
10231                 const type_t *type = skip_typeref(entity->declaration.type);
10232                 if (is_type_function(type)) {
10233                         return false;
10234                 } else {
10235                         return true;
10236                 }
10237         }
10238         default:
10239                 return false;
10240         }
10241 }
10242
10243 /**
10244  * Check if a given expression represents a local variable.
10245  */
10246 static bool expression_is_local_variable(const expression_t *expression)
10247 {
10248         if (expression->base.kind != EXPR_REFERENCE) {
10249                 return false;
10250         }
10251         const entity_t *entity = expression->reference.entity;
10252         return is_local_variable(entity);
10253 }
10254
10255 /**
10256  * Check if a given expression represents a local variable and
10257  * return its declaration then, else return NULL.
10258  */
10259 entity_t *expression_is_variable(const expression_t *expression)
10260 {
10261         if (expression->base.kind != EXPR_REFERENCE) {
10262                 return NULL;
10263         }
10264         entity_t *entity = expression->reference.entity;
10265         if (entity->kind != ENTITY_VARIABLE)
10266                 return NULL;
10267
10268         return entity;
10269 }
10270
10271 /**
10272  * Parse a return statement.
10273  */
10274 static statement_t *parse_return(void)
10275 {
10276         eat(T_return);
10277
10278         statement_t *statement = allocate_statement_zero(STATEMENT_RETURN);
10279
10280         expression_t *return_value = NULL;
10281         if (token.type != ';') {
10282                 return_value = parse_expression();
10283                 mark_vars_read(return_value, NULL);
10284         }
10285
10286         const type_t *const func_type = skip_typeref(current_function->base.type);
10287         assert(is_type_function(func_type));
10288         type_t *const return_type = skip_typeref(func_type->function.return_type);
10289
10290         if (return_value != NULL) {
10291                 type_t *return_value_type = skip_typeref(return_value->base.type);
10292
10293                 if (is_type_atomic(return_type,        ATOMIC_TYPE_VOID) &&
10294                                 !is_type_atomic(return_value_type, ATOMIC_TYPE_VOID)) {
10295                         if (warning.other) {
10296                                 warningf(&statement->base.source_position,
10297                                                 "'return' with a value, in function returning void");
10298                         }
10299                         return_value = NULL;
10300                 } else {
10301                         assign_error_t error = semantic_assign(return_type, return_value);
10302                         report_assign_error(error, return_type, return_value, "'return'",
10303                                             &statement->base.source_position);
10304                         return_value = create_implicit_cast(return_value, return_type);
10305                 }
10306                 /* check for returning address of a local var */
10307                 if (warning.other && return_value != NULL
10308                                 && return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
10309                         const expression_t *expression = return_value->unary.value;
10310                         if (expression_is_local_variable(expression)) {
10311                                 warningf(&statement->base.source_position,
10312                                          "function returns address of local variable");
10313                         }
10314                 }
10315         } else if (warning.other && !is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
10316                 warningf(&statement->base.source_position,
10317                                 "'return' without value, in function returning non-void");
10318         }
10319         statement->returns.value = return_value;
10320
10321         expect(';');
10322
10323 end_error:
10324         return statement;
10325 }
10326
10327 /**
10328  * Parse a declaration statement.
10329  */
10330 static statement_t *parse_declaration_statement(void)
10331 {
10332         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
10333
10334         entity_t *before = current_scope->last_entity;
10335         if (GNU_MODE) {
10336                 parse_external_declaration();
10337         } else {
10338                 parse_declaration(record_entity, DECL_FLAGS_NONE);
10339         }
10340
10341         if (before == NULL) {
10342                 statement->declaration.declarations_begin = current_scope->entities;
10343         } else {
10344                 statement->declaration.declarations_begin = before->base.next;
10345         }
10346         statement->declaration.declarations_end = current_scope->last_entity;
10347
10348         return statement;
10349 }
10350
10351 /**
10352  * Parse an expression statement, ie. expr ';'.
10353  */
10354 static statement_t *parse_expression_statement(void)
10355 {
10356         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10357
10358         expression_t *const expr         = parse_expression();
10359         statement->expression.expression = expr;
10360         mark_vars_read(expr, ENT_ANY);
10361
10362         expect(';');
10363
10364 end_error:
10365         return statement;
10366 }
10367
10368 /**
10369  * Parse a microsoft __try { } __finally { } or
10370  * __try{ } __except() { }
10371  */
10372 static statement_t *parse_ms_try_statment(void)
10373 {
10374         statement_t *statement = allocate_statement_zero(STATEMENT_MS_TRY);
10375         eat(T___try);
10376
10377         PUSH_PARENT(statement);
10378
10379         ms_try_statement_t *rem = current_try;
10380         current_try = &statement->ms_try;
10381         statement->ms_try.try_statement = parse_compound_statement(false);
10382         current_try = rem;
10383
10384         POP_PARENT;
10385
10386         if (token.type == T___except) {
10387                 eat(T___except);
10388                 expect('(');
10389                 add_anchor_token(')');
10390                 expression_t *const expr = parse_expression();
10391                 mark_vars_read(expr, NULL);
10392                 type_t       *      type = skip_typeref(expr->base.type);
10393                 if (is_type_integer(type)) {
10394                         type = promote_integer(type);
10395                 } else if (is_type_valid(type)) {
10396                         errorf(&expr->base.source_position,
10397                                "__expect expression is not an integer, but '%T'", type);
10398                         type = type_error_type;
10399                 }
10400                 statement->ms_try.except_expression = create_implicit_cast(expr, type);
10401                 rem_anchor_token(')');
10402                 expect(')');
10403                 statement->ms_try.final_statement = parse_compound_statement(false);
10404         } else if (token.type == T__finally) {
10405                 eat(T___finally);
10406                 statement->ms_try.final_statement = parse_compound_statement(false);
10407         } else {
10408                 parse_error_expected("while parsing __try statement", T___except, T___finally, NULL);
10409                 return create_invalid_statement();
10410         }
10411         return statement;
10412 end_error:
10413         return create_invalid_statement();
10414 }
10415
10416 static statement_t *parse_empty_statement(void)
10417 {
10418         if (warning.empty_statement) {
10419                 warningf(HERE, "statement is empty");
10420         }
10421         statement_t *const statement = create_empty_statement();
10422         eat(';');
10423         return statement;
10424 }
10425
10426 static statement_t *parse_local_label_declaration(void)
10427 {
10428         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
10429
10430         eat(T___label__);
10431
10432         entity_t *begin = NULL, *end = NULL;
10433
10434         while (true) {
10435                 if (token.type != T_IDENTIFIER) {
10436                         parse_error_expected("while parsing local label declaration",
10437                                 T_IDENTIFIER, NULL);
10438                         goto end_error;
10439                 }
10440                 symbol_t *symbol = token.v.symbol;
10441                 entity_t *entity = get_entity(symbol, NAMESPACE_LABEL);
10442                 if (entity != NULL && entity->base.parent_scope == current_scope) {
10443                         errorf(HERE, "multiple definitions of '__label__ %Y' (previous definition %P)",
10444                                symbol, &entity->base.source_position);
10445                 } else {
10446                         entity = allocate_entity_zero(ENTITY_LOCAL_LABEL);
10447
10448                         entity->base.parent_scope    = current_scope;
10449                         entity->base.namespc         = NAMESPACE_LABEL;
10450                         entity->base.source_position = token.source_position;
10451                         entity->base.symbol          = symbol;
10452
10453                         if (end != NULL)
10454                                 end->base.next = entity;
10455                         end = entity;
10456                         if (begin == NULL)
10457                                 begin = entity;
10458
10459                         environment_push(entity);
10460                 }
10461                 next_token();
10462
10463                 if (token.type != ',')
10464                         break;
10465                 next_token();
10466         }
10467         eat(';');
10468 end_error:
10469         statement->declaration.declarations_begin = begin;
10470         statement->declaration.declarations_end   = end;
10471         return statement;
10472 }
10473
10474 static void parse_namespace_definition(void)
10475 {
10476         eat(T_namespace);
10477
10478         entity_t *entity = NULL;
10479         symbol_t *symbol = NULL;
10480
10481         if (token.type == T_IDENTIFIER) {
10482                 symbol = token.v.symbol;
10483                 next_token();
10484
10485                 entity = get_entity(symbol, NAMESPACE_NORMAL);
10486                 if (entity != NULL && entity->kind != ENTITY_NAMESPACE
10487                                 && entity->base.parent_scope == current_scope) {
10488                         error_redefined_as_different_kind(&token.source_position,
10489                                                           entity, ENTITY_NAMESPACE);
10490                         entity = NULL;
10491                 }
10492         }
10493
10494         if (entity == NULL) {
10495                 entity                       = allocate_entity_zero(ENTITY_NAMESPACE);
10496                 entity->base.symbol          = symbol;
10497                 entity->base.source_position = token.source_position;
10498                 entity->base.namespc         = NAMESPACE_NORMAL;
10499                 entity->base.parent_scope    = current_scope;
10500         }
10501
10502         if (token.type == '=') {
10503                 /* TODO: parse namespace alias */
10504                 panic("namespace alias definition not supported yet");
10505         }
10506
10507         environment_push(entity);
10508         append_entity(current_scope, entity);
10509
10510         size_t const  top       = environment_top();
10511         scope_t      *old_scope = scope_push(&entity->namespacee.members);
10512
10513         expect('{');
10514         parse_externals();
10515         expect('}');
10516
10517 end_error:
10518         assert(current_scope == &entity->namespacee.members);
10519         scope_pop(old_scope);
10520         environment_pop_to(top);
10521 }
10522
10523 /**
10524  * Parse a statement.
10525  * There's also parse_statement() which additionally checks for
10526  * "statement has no effect" warnings
10527  */
10528 static statement_t *intern_parse_statement(void)
10529 {
10530         statement_t *statement = NULL;
10531
10532         /* declaration or statement */
10533         add_anchor_token(';');
10534         switch (token.type) {
10535         case T_IDENTIFIER: {
10536                 token_type_t la1_type = (token_type_t)look_ahead(1)->type;
10537                 if (la1_type == ':') {
10538                         statement = parse_label_statement();
10539                 } else if (is_typedef_symbol(token.v.symbol)) {
10540                         statement = parse_declaration_statement();
10541                 } else {
10542                         /* it's an identifier, the grammar says this must be an
10543                          * expression statement. However it is common that users mistype
10544                          * declaration types, so we guess a bit here to improve robustness
10545                          * for incorrect programs */
10546                         switch (la1_type) {
10547                         case '&':
10548                         case '*':
10549                                 if (get_entity(token.v.symbol, NAMESPACE_NORMAL) != NULL)
10550                                         goto expression_statment;
10551                                 /* FALLTHROUGH */
10552
10553                         DECLARATION_START
10554                         case T_IDENTIFIER:
10555                                 statement = parse_declaration_statement();
10556                                 break;
10557
10558                         default:
10559 expression_statment:
10560                                 statement = parse_expression_statement();
10561                                 break;
10562                         }
10563                 }
10564                 break;
10565         }
10566
10567         case T___extension__:
10568                 /* This can be a prefix to a declaration or an expression statement.
10569                  * We simply eat it now and parse the rest with tail recursion. */
10570                 do {
10571                         next_token();
10572                 } while (token.type == T___extension__);
10573                 bool old_gcc_extension = in_gcc_extension;
10574                 in_gcc_extension       = true;
10575                 statement = intern_parse_statement();
10576                 in_gcc_extension = old_gcc_extension;
10577                 break;
10578
10579         DECLARATION_START
10580                 statement = parse_declaration_statement();
10581                 break;
10582
10583         case T___label__:
10584                 statement = parse_local_label_declaration();
10585                 break;
10586
10587         case ';':         statement = parse_empty_statement();         break;
10588         case '{':         statement = parse_compound_statement(false); break;
10589         case T___leave:   statement = parse_leave_statement();         break;
10590         case T___try:     statement = parse_ms_try_statment();         break;
10591         case T_asm:       statement = parse_asm_statement();           break;
10592         case T_break:     statement = parse_break();                   break;
10593         case T_case:      statement = parse_case_statement();          break;
10594         case T_continue:  statement = parse_continue();                break;
10595         case T_default:   statement = parse_default_statement();       break;
10596         case T_do:        statement = parse_do();                      break;
10597         case T_for:       statement = parse_for();                     break;
10598         case T_goto:      statement = parse_goto();                    break;
10599         case T_if:        statement = parse_if();                      break;
10600         case T_return:    statement = parse_return();                  break;
10601         case T_switch:    statement = parse_switch();                  break;
10602         case T_while:     statement = parse_while();                   break;
10603
10604         EXPRESSION_START
10605                 statement = parse_expression_statement();
10606                 break;
10607
10608         default:
10609                 errorf(HERE, "unexpected token '%K' while parsing statement", &token);
10610                 statement = create_invalid_statement();
10611                 if (!at_anchor())
10612                         next_token();
10613                 break;
10614         }
10615         rem_anchor_token(';');
10616
10617         assert(statement != NULL
10618                         && statement->base.source_position.input_name != NULL);
10619
10620         return statement;
10621 }
10622
10623 /**
10624  * parse a statement and emits "statement has no effect" warning if needed
10625  * (This is really a wrapper around intern_parse_statement with check for 1
10626  *  single warning. It is needed, because for statement expressions we have
10627  *  to avoid the warning on the last statement)
10628  */
10629 static statement_t *parse_statement(void)
10630 {
10631         statement_t *statement = intern_parse_statement();
10632
10633         if (statement->kind == STATEMENT_EXPRESSION && warning.unused_value) {
10634                 expression_t *expression = statement->expression.expression;
10635                 if (!expression_has_effect(expression)) {
10636                         warningf(&expression->base.source_position,
10637                                         "statement has no effect");
10638                 }
10639         }
10640
10641         return statement;
10642 }
10643
10644 /**
10645  * Parse a compound statement.
10646  */
10647 static statement_t *parse_compound_statement(bool inside_expression_statement)
10648 {
10649         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
10650
10651         PUSH_PARENT(statement);
10652
10653         eat('{');
10654         add_anchor_token('}');
10655
10656         size_t const  top       = environment_top();
10657         scope_t      *old_scope = scope_push(&statement->compound.scope);
10658
10659         statement_t **anchor            = &statement->compound.statements;
10660         bool          only_decls_so_far = true;
10661         while (token.type != '}') {
10662                 if (token.type == T_EOF) {
10663                         errorf(&statement->base.source_position,
10664                                "EOF while parsing compound statement");
10665                         break;
10666                 }
10667                 statement_t *sub_statement = intern_parse_statement();
10668                 if (is_invalid_statement(sub_statement)) {
10669                         /* an error occurred. if we are at an anchor, return */
10670                         if (at_anchor())
10671                                 goto end_error;
10672                         continue;
10673                 }
10674
10675                 if (warning.declaration_after_statement) {
10676                         if (sub_statement->kind != STATEMENT_DECLARATION) {
10677                                 only_decls_so_far = false;
10678                         } else if (!only_decls_so_far) {
10679                                 warningf(&sub_statement->base.source_position,
10680                                          "ISO C90 forbids mixed declarations and code");
10681                         }
10682                 }
10683
10684                 *anchor = sub_statement;
10685
10686                 while (sub_statement->base.next != NULL)
10687                         sub_statement = sub_statement->base.next;
10688
10689                 anchor = &sub_statement->base.next;
10690         }
10691         next_token();
10692
10693         /* look over all statements again to produce no effect warnings */
10694         if (warning.unused_value) {
10695                 statement_t *sub_statement = statement->compound.statements;
10696                 for (; sub_statement != NULL; sub_statement = sub_statement->base.next) {
10697                         if (sub_statement->kind != STATEMENT_EXPRESSION)
10698                                 continue;
10699                         /* don't emit a warning for the last expression in an expression
10700                          * statement as it has always an effect */
10701                         if (inside_expression_statement && sub_statement->base.next == NULL)
10702                                 continue;
10703
10704                         expression_t *expression = sub_statement->expression.expression;
10705                         if (!expression_has_effect(expression)) {
10706                                 warningf(&expression->base.source_position,
10707                                          "statement has no effect");
10708                         }
10709                 }
10710         }
10711
10712 end_error:
10713         rem_anchor_token('}');
10714         assert(current_scope == &statement->compound.scope);
10715         scope_pop(old_scope);
10716         environment_pop_to(top);
10717
10718         POP_PARENT;
10719         return statement;
10720 }
10721
10722 /**
10723  * Check for unused global static functions and variables
10724  */
10725 static void check_unused_globals(void)
10726 {
10727         if (!warning.unused_function && !warning.unused_variable)
10728                 return;
10729
10730         for (const entity_t *entity = file_scope->entities; entity != NULL;
10731              entity = entity->base.next) {
10732                 if (!is_declaration(entity))
10733                         continue;
10734
10735                 const declaration_t *declaration = &entity->declaration;
10736                 if (declaration->used                  ||
10737                     declaration->modifiers & DM_UNUSED ||
10738                     declaration->modifiers & DM_USED   ||
10739                     declaration->storage_class != STORAGE_CLASS_STATIC)
10740                         continue;
10741
10742                 type_t *const type = declaration->type;
10743                 const char *s;
10744                 if (entity->kind == ENTITY_FUNCTION) {
10745                         /* inhibit warning for static inline functions */
10746                         if (entity->function.is_inline)
10747                                 continue;
10748
10749                         s = entity->function.statement != NULL ? "defined" : "declared";
10750                 } else {
10751                         s = "defined";
10752                 }
10753
10754                 warningf(&declaration->base.source_position, "'%#T' %s but not used",
10755                         type, declaration->base.symbol, s);
10756         }
10757 }
10758
10759 static void parse_global_asm(void)
10760 {
10761         statement_t *statement = allocate_statement_zero(STATEMENT_ASM);
10762
10763         eat(T_asm);
10764         expect('(');
10765
10766         statement->asms.asm_text = parse_string_literals();
10767         statement->base.next     = unit->global_asm;
10768         unit->global_asm         = statement;
10769
10770         expect(')');
10771         expect(';');
10772
10773 end_error:;
10774 }
10775
10776 static void parse_linkage_specification(void)
10777 {
10778         eat(T_extern);
10779         assert(token.type == T_STRING_LITERAL);
10780
10781         const char *linkage = parse_string_literals().begin;
10782
10783         linkage_kind_t old_linkage = current_linkage;
10784         linkage_kind_t new_linkage;
10785         if (strcmp(linkage, "C") == 0) {
10786                 new_linkage = LINKAGE_C;
10787         } else if (strcmp(linkage, "C++") == 0) {
10788                 new_linkage = LINKAGE_CXX;
10789         } else {
10790                 errorf(HERE, "linkage string \"%s\" not recognized", linkage);
10791                 new_linkage = LINKAGE_INVALID;
10792         }
10793         current_linkage = new_linkage;
10794
10795         if (token.type == '{') {
10796                 next_token();
10797                 parse_externals();
10798                 expect('}');
10799         } else {
10800                 parse_external();
10801         }
10802
10803 end_error:
10804         assert(current_linkage == new_linkage);
10805         current_linkage = old_linkage;
10806 }
10807
10808 static void parse_external(void)
10809 {
10810         switch (token.type) {
10811                 DECLARATION_START_NO_EXTERN
10812                 case T_IDENTIFIER:
10813                 case T___extension__:
10814                 /* tokens below are for implicit int */
10815                 case '&': /* & x; -> int& x; (and error later, because C++ has no
10816                              implicit int) */
10817                 case '*': /* * x; -> int* x; */
10818                 case '(': /* (x); -> int (x); */
10819                         parse_external_declaration();
10820                         return;
10821
10822                 case T_extern:
10823                         if (look_ahead(1)->type == T_STRING_LITERAL) {
10824                                 parse_linkage_specification();
10825                         } else {
10826                                 parse_external_declaration();
10827                         }
10828                         return;
10829
10830                 case T_asm:
10831                         parse_global_asm();
10832                         return;
10833
10834                 case T_namespace:
10835                         parse_namespace_definition();
10836                         return;
10837
10838                 case ';':
10839                         if (!strict_mode) {
10840                                 if (warning.other)
10841                                         warningf(HERE, "stray ';' outside of function");
10842                                 next_token();
10843                                 return;
10844                         }
10845                         /* FALLTHROUGH */
10846
10847                 default:
10848                         errorf(HERE, "stray '%K' outside of function", &token);
10849                         if (token.type == '(' || token.type == '{' || token.type == '[')
10850                                 eat_until_matching_token(token.type);
10851                         next_token();
10852                         return;
10853         }
10854 }
10855
10856 static void parse_externals(void)
10857 {
10858         add_anchor_token('}');
10859         add_anchor_token(T_EOF);
10860
10861 #ifndef NDEBUG
10862         unsigned char token_anchor_copy[T_LAST_TOKEN];
10863         memcpy(token_anchor_copy, token_anchor_set, sizeof(token_anchor_copy));
10864 #endif
10865
10866         while (token.type != T_EOF && token.type != '}') {
10867 #ifndef NDEBUG
10868                 bool anchor_leak = false;
10869                 for (int i = 0; i != T_LAST_TOKEN; ++i) {
10870                         unsigned char count = token_anchor_set[i] - token_anchor_copy[i];
10871                         if (count != 0) {
10872                                 errorf(HERE, "Leaked anchor token %k %d times", i, count);
10873                                 anchor_leak = true;
10874                         }
10875                 }
10876                 if (in_gcc_extension) {
10877                         errorf(HERE, "Leaked __extension__");
10878                         anchor_leak = true;
10879                 }
10880
10881                 if (anchor_leak)
10882                         abort();
10883 #endif
10884
10885                 parse_external();
10886         }
10887
10888         rem_anchor_token(T_EOF);
10889         rem_anchor_token('}');
10890 }
10891
10892 /**
10893  * Parse a translation unit.
10894  */
10895 static void parse_translation_unit(void)
10896 {
10897         add_anchor_token(T_EOF);
10898
10899         while (true) {
10900                 parse_externals();
10901
10902                 if (token.type == T_EOF)
10903                         break;
10904
10905                 errorf(HERE, "stray '%K' outside of function", &token);
10906                 if (token.type == '(' || token.type == '{' || token.type == '[')
10907                         eat_until_matching_token(token.type);
10908                 next_token();
10909         }
10910 }
10911
10912 /**
10913  * Parse the input.
10914  *
10915  * @return  the translation unit or NULL if errors occurred.
10916  */
10917 void start_parsing(void)
10918 {
10919         environment_stack = NEW_ARR_F(stack_entry_t, 0);
10920         label_stack       = NEW_ARR_F(stack_entry_t, 0);
10921         diagnostic_count  = 0;
10922         error_count       = 0;
10923         warning_count     = 0;
10924
10925         type_set_output(stderr);
10926         ast_set_output(stderr);
10927
10928         assert(unit == NULL);
10929         unit = allocate_ast_zero(sizeof(unit[0]));
10930
10931         assert(file_scope == NULL);
10932         file_scope = &unit->scope;
10933
10934         assert(current_scope == NULL);
10935         scope_push(&unit->scope);
10936 }
10937
10938 translation_unit_t *finish_parsing(void)
10939 {
10940         assert(current_scope == &unit->scope);
10941         scope_pop(NULL);
10942
10943         assert(file_scope == &unit->scope);
10944         check_unused_globals();
10945         file_scope = NULL;
10946
10947         DEL_ARR_F(environment_stack);
10948         DEL_ARR_F(label_stack);
10949
10950         translation_unit_t *result = unit;
10951         unit = NULL;
10952         return result;
10953 }
10954
10955 void parse(void)
10956 {
10957         lookahead_bufpos = 0;
10958         for (int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
10959                 next_token();
10960         }
10961         current_linkage = c_mode & _CXX ? LINKAGE_CXX : LINKAGE_C;
10962         parse_translation_unit();
10963 }
10964
10965 /**
10966  * Initialize the parser.
10967  */
10968 void init_parser(void)
10969 {
10970         sym_anonymous = symbol_table_insert("<anonymous>");
10971
10972         if (c_mode & _MS) {
10973                 /* add predefined symbols for extended-decl-modifier */
10974                 sym_align      = symbol_table_insert("align");
10975                 sym_allocate   = symbol_table_insert("allocate");
10976                 sym_dllimport  = symbol_table_insert("dllimport");
10977                 sym_dllexport  = symbol_table_insert("dllexport");
10978                 sym_naked      = symbol_table_insert("naked");
10979                 sym_noinline   = symbol_table_insert("noinline");
10980                 sym_noreturn   = symbol_table_insert("noreturn");
10981                 sym_nothrow    = symbol_table_insert("nothrow");
10982                 sym_novtable   = symbol_table_insert("novtable");
10983                 sym_property   = symbol_table_insert("property");
10984                 sym_get        = symbol_table_insert("get");
10985                 sym_put        = symbol_table_insert("put");
10986                 sym_selectany  = symbol_table_insert("selectany");
10987                 sym_thread     = symbol_table_insert("thread");
10988                 sym_uuid       = symbol_table_insert("uuid");
10989                 sym_deprecated = symbol_table_insert("deprecated");
10990                 sym_restrict   = symbol_table_insert("restrict");
10991                 sym_noalias    = symbol_table_insert("noalias");
10992         }
10993         memset(token_anchor_set, 0, sizeof(token_anchor_set));
10994
10995         init_expression_parsers();
10996         obstack_init(&temp_obst);
10997
10998         symbol_t *const va_list_sym = symbol_table_insert("__builtin_va_list");
10999         type_valist = create_builtin_type(va_list_sym, type_void_ptr);
11000 }
11001
11002 /**
11003  * Terminate the parser.
11004  */
11005 void exit_parser(void)
11006 {
11007         obstack_free(&temp_obst, NULL);
11008 }