nsz Git - cparser/blob - parser.c

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