nsz Git - cparser/blob - parser.c

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