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 "lang_features.h"
  37 #include "walk_statements.h"
  38 #include "warning.h"
  39 #include "adt/bitfiddle.h"
  40 #include "adt/error.h"
  41 #include "adt/array.h"
  42
  43 /** if wchar_t is equal to unsigned short. */
  44 bool opt_short_wchar_t =
  45 #ifdef _WIN32
  46         true;
  47 #else
  48         false;
  49 #endif
  50
  51 //#define PRINT_TOKENS
  52 #define MAX_LOOKAHEAD 2
  53
  54 typedef struct {
  55         declaration_t *old_declaration;
  56         symbol_t      *symbol;
  57         unsigned short namespc;
  58 } stack_entry_t;
  59
  60 typedef struct argument_list_t argument_list_t;
  61 struct argument_list_t {
  62         long              argument;
  63         argument_list_t  *next;
  64 };
  65
  66 typedef struct gnu_attribute_t gnu_attribute_t;
  67 struct gnu_attribute_t {
  68         gnu_attribute_kind_t kind;           /**< The kind of the GNU attribute. */
  69         gnu_attribute_t     *next;
  70         bool                 invalid;        /**< Set if this attribute had argument errors, */
  71         bool                 have_arguments; /**< True, if this attribute has arguments. */
  72         union {
  73                 size_t              value;
  74                 string_t            string;
  75                 atomic_type_kind_t  akind;
  76                 long                argument;  /**< Single argument. */
  77                 argument_list_t    *arguments; /**< List of argument expressions. */
  78         } u;
  79 };
  80
  81 typedef struct declaration_specifiers_t  declaration_specifiers_t;
  82 struct declaration_specifiers_t {
  83         source_position_t  source_position;
  84         unsigned char      declared_storage_class;
  85         unsigned char      alignment;         /**< Alignment, 0 if not set. */
  86         unsigned int       is_inline : 1;
  87         unsigned int       deprecated : 1;
  88         decl_modifiers_t   modifiers;         /**< declaration modifiers */
  89         gnu_attribute_t   *gnu_attributes;    /**< list of GNU attributes */
  90         const char        *deprecated_string; /**< can be set if declaration was marked deprecated. */
  91         symbol_t          *get_property_sym;  /**< the name of the get property if set. */
  92         symbol_t          *put_property_sym;  /**< the name of the put property if set. */
  93         type_t            *type;
  94 };
  95
  96 /**
  97  * An environment for parsing initializers (and compound literals).
  98  */
  99 typedef struct parse_initializer_env_t {
 100         type_t        *type;        /**< the type of the initializer. In case of an
 101                                          array type with unspecified size this gets
 102                                          adjusted to the actual size. */
 103         declaration_t *declaration; /**< the declaration that is initialized if any */
 104         bool           must_be_constant;
 105 } parse_initializer_env_t;
 106
 107 typedef declaration_t* (*parsed_declaration_func) (declaration_t *declaration, bool is_definition);
 108
 109 /** The current token. */
 110 static token_t             token;
 111 /** The lookahead ring-buffer. */
 112 static token_t             lookahead_buffer[MAX_LOOKAHEAD];
 113 /** Position of the next token in the lookahead buffer. */
 114 static int                 lookahead_bufpos;
 115 static stack_entry_t      *environment_stack = NULL;
 116 static stack_entry_t      *label_stack       = NULL;
 117 static stack_entry_t      *local_label_stack = NULL;
 118 /** The global file scope. */
 119 static scope_t            *file_scope        = NULL;
 120 /** The current scope. */
 121 static scope_t            *scope             = NULL;
 122 static declaration_t      *last_declaration  = NULL;
 123 /** Point to the current function declaration if inside a function. */
 124 static declaration_t      *current_function  = NULL;
 125 static declaration_t      *current_init_decl = NULL;
 126 static switch_statement_t *current_switch    = NULL;
 127 static statement_t        *current_loop      = NULL;
 128 static statement_t        *current_parent    = NULL;
 129 static ms_try_statement_t *current_try       = NULL;
 130 static goto_statement_t   *goto_first        = NULL;
 131 static goto_statement_t   *goto_last         = NULL;
 132 static label_statement_t  *label_first       = NULL;
 133 static label_statement_t  *label_last        = NULL;
 134 /** current translation unit. */
 135 static translation_unit_t *unit              = NULL;
 136 /** true if we are in a type property context (evaluation only for type. */
 137 static bool                in_type_prop      = false;
 138 /** true in we are in a __extension__ context. */
 139 static bool                in_gcc_extension  = false;
 140 static struct obstack      temp_obst;
 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
 189 static void parse_compound_type_entries(declaration_t *compound_declaration);
 190 static declaration_t *parse_declarator(
 191                 const declaration_specifiers_t *specifiers, bool may_be_abstract);
 192 static declaration_t *record_declaration(declaration_t *declaration, bool is_definition);
 193
 194 static void semantic_comparison(binary_expression_t *expression);
 195
 196 #define STORAGE_CLASSES     \
 197         case T_typedef:         \
 198         case T_extern:          \
 199         case T_static:          \
 200         case T_auto:            \
 201         case T_register:        \
 202         case T___thread:
 203
 204 #define TYPE_QUALIFIERS     \
 205         case T_const:           \
 206         case T_restrict:        \
 207         case T_volatile:        \
 208         case T_inline:          \
 209         case T__forceinline:    \
 210         case T___attribute__:
 211
 212 #ifdef PROVIDE_COMPLEX
 213 #define COMPLEX_SPECIFIERS  \
 214         case T__Complex:
 215 #define IMAGINARY_SPECIFIERS \
 216         case T__Imaginary:
 217 #else
 218 #define COMPLEX_SPECIFIERS
 219 #define IMAGINARY_SPECIFIERS
 220 #endif
 221
 222 #define TYPE_SPECIFIERS       \
 223         case T_void:              \
 224         case T_char:              \
 225         case T_short:             \
 226         case T_int:               \
 227         case T_long:              \
 228         case T_float:             \
 229         case T_double:            \
 230         case T_signed:            \
 231         case T_unsigned:          \
 232         case T__Bool:             \
 233         case T_struct:            \
 234         case T_union:             \
 235         case T_enum:              \
 236         case T___typeof__:        \
 237         case T___builtin_va_list: \
 238         case T__declspec:         \
 239         COMPLEX_SPECIFIERS        \
 240         IMAGINARY_SPECIFIERS
 241
 242 #define DECLARATION_START   \
 243         STORAGE_CLASSES         \
 244         TYPE_QUALIFIERS         \
 245         TYPE_SPECIFIERS
 246
 247 #define TYPENAME_START      \
 248         TYPE_QUALIFIERS         \
 249         TYPE_SPECIFIERS
 250
 251 /**
 252  * Allocate an AST node with given size and
 253  * initialize all fields with zero.
 254  */
 255 static void *allocate_ast_zero(size_t size)
 256 {
 257         void *res = allocate_ast(size);
 258         memset(res, 0, size);
 259         return res;
 260 }
 261
 262 static declaration_t *allocate_declaration_zero(void)
 263 {
 264         declaration_t *declaration = allocate_ast_zero(sizeof(declaration_t));
 265         declaration->type      = type_error_type;
 266         declaration->alignment = 0;
 267         return declaration;
 268 }
 269
 270 /**
 271  * Returns the size of a statement node.
 272  *
 273  * @param kind  the statement kind
 274  */
 275 static size_t get_statement_struct_size(statement_kind_t kind)
 276 {
 277         static const size_t sizes[] = {
 278                 [STATEMENT_INVALID]     = sizeof(invalid_statement_t),
 279                 [STATEMENT_EMPTY]       = sizeof(empty_statement_t),
 280                 [STATEMENT_COMPOUND]    = sizeof(compound_statement_t),
 281                 [STATEMENT_RETURN]      = sizeof(return_statement_t),
 282                 [STATEMENT_DECLARATION] = sizeof(declaration_statement_t),
 283                 [STATEMENT_IF]          = sizeof(if_statement_t),
 284                 [STATEMENT_SWITCH]      = sizeof(switch_statement_t),
 285                 [STATEMENT_EXPRESSION]  = sizeof(expression_statement_t),
 286                 [STATEMENT_CONTINUE]    = sizeof(statement_base_t),
 287                 [STATEMENT_BREAK]       = sizeof(statement_base_t),
 288                 [STATEMENT_GOTO]        = sizeof(goto_statement_t),
 289                 [STATEMENT_LABEL]       = sizeof(label_statement_t),
 290                 [STATEMENT_CASE_LABEL]  = sizeof(case_label_statement_t),
 291                 [STATEMENT_WHILE]       = sizeof(while_statement_t),
 292                 [STATEMENT_DO_WHILE]    = sizeof(do_while_statement_t),
 293                 [STATEMENT_FOR]         = sizeof(for_statement_t),
 294                 [STATEMENT_ASM]         = sizeof(asm_statement_t),
 295                 [STATEMENT_MS_TRY]      = sizeof(ms_try_statement_t),
 296                 [STATEMENT_LEAVE]       = sizeof(leave_statement_t)
 297         };
 298         assert(kind <= sizeof(sizes) / sizeof(sizes[0]));
 299         assert(sizes[kind] != 0);
 300         return sizes[kind];
 301 }
 302
 303 /**
 304  * Returns the size of an expression node.
 305  *
 306  * @param kind  the expression kind
 307  */
 308 static size_t get_expression_struct_size(expression_kind_t kind)
 309 {
 310         static const size_t sizes[] = {
 311                 [EXPR_INVALID]                 = sizeof(expression_base_t),
 312                 [EXPR_REFERENCE]               = sizeof(reference_expression_t),
 313                 [EXPR_CONST]                   = sizeof(const_expression_t),
 314                 [EXPR_CHARACTER_CONSTANT]      = sizeof(const_expression_t),
 315                 [EXPR_WIDE_CHARACTER_CONSTANT] = sizeof(const_expression_t),
 316                 [EXPR_STRING_LITERAL]          = sizeof(string_literal_expression_t),
 317                 [EXPR_WIDE_STRING_LITERAL]     = sizeof(wide_string_literal_expression_t),
 318                 [EXPR_COMPOUND_LITERAL]        = sizeof(compound_literal_expression_t),
 319                 [EXPR_CALL]                    = sizeof(call_expression_t),
 320                 [EXPR_UNARY_FIRST]             = sizeof(unary_expression_t),
 321                 [EXPR_BINARY_FIRST]            = sizeof(binary_expression_t),
 322                 [EXPR_CONDITIONAL]             = sizeof(conditional_expression_t),
 323                 [EXPR_SELECT]                  = sizeof(select_expression_t),
 324                 [EXPR_ARRAY_ACCESS]            = sizeof(array_access_expression_t),
 325                 [EXPR_SIZEOF]                  = sizeof(typeprop_expression_t),
 326                 [EXPR_ALIGNOF]                 = sizeof(typeprop_expression_t),
 327                 [EXPR_CLASSIFY_TYPE]           = sizeof(classify_type_expression_t),
 328                 [EXPR_FUNCNAME]                = sizeof(funcname_expression_t),
 329                 [EXPR_BUILTIN_SYMBOL]          = sizeof(builtin_symbol_expression_t),
 330                 [EXPR_BUILTIN_CONSTANT_P]      = sizeof(builtin_constant_expression_t),
 331                 [EXPR_BUILTIN_PREFETCH]        = sizeof(builtin_prefetch_expression_t),
 332                 [EXPR_OFFSETOF]                = sizeof(offsetof_expression_t),
 333                 [EXPR_VA_START]                = sizeof(va_start_expression_t),
 334                 [EXPR_VA_ARG]                  = sizeof(va_arg_expression_t),
 335                 [EXPR_STATEMENT]               = sizeof(statement_expression_t),
 336                 [EXPR_LABEL_ADDRESS]           = sizeof(label_address_expression_t),
 337         };
 338         if (kind >= EXPR_UNARY_FIRST && kind <= EXPR_UNARY_LAST) {
 339                 return sizes[EXPR_UNARY_FIRST];
 340         }
 341         if (kind >= EXPR_BINARY_FIRST && kind <= EXPR_BINARY_LAST) {
 342                 return sizes[EXPR_BINARY_FIRST];
 343         }
 344         assert(kind <= sizeof(sizes) / sizeof(sizes[0]));
 345         assert(sizes[kind] != 0);
 346         return sizes[kind];
 347 }
 348
 349 /**
 350  * Allocate a statement node of given kind and initialize all
 351  * fields with zero.
 352  */
 353 static statement_t *allocate_statement_zero(statement_kind_t kind)
 354 {
 355         size_t       size = get_statement_struct_size(kind);
 356         statement_t *res  = allocate_ast_zero(size);
 357
 358         res->base.kind            = kind;
 359         res->base.parent          = current_parent;
 360         res->base.source_position = token.source_position;
 361         return res;
 362 }
 363
 364 /**
 365  * Allocate an expression node of given kind and initialize all
 366  * fields with zero.
 367  */
 368 static expression_t *allocate_expression_zero(expression_kind_t kind)
 369 {
 370         size_t        size = get_expression_struct_size(kind);
 371         expression_t *res  = allocate_ast_zero(size);
 372
 373         res->base.kind = kind;
 374         res->base.type = type_error_type;
 375         return res;
 376 }
 377
 378 /**
 379  * Creates a new invalid expression.
 380  */
 381 static expression_t *create_invalid_expression(void)
 382 {
 383         expression_t *expression         = allocate_expression_zero(EXPR_INVALID);
 384         expression->base.source_position = token.source_position;
 385         return expression;
 386 }
 387
 388 /**
 389  * Creates a new invalid statement.
 390  */
 391 static statement_t *create_invalid_statement(void)
 392 {
 393         return allocate_statement_zero(STATEMENT_INVALID);
 394 }
 395
 396 /**
 397  * Allocate a new empty statement.
 398  */
 399 static statement_t *create_empty_statement(void)
 400 {
 401         return allocate_statement_zero(STATEMENT_EMPTY);
 402 }
 403
 404 /**
 405  * Returns the size of a type node.
 406  *
 407  * @param kind  the type kind
 408  */
 409 static size_t get_type_struct_size(type_kind_t kind)
 410 {
 411         static const size_t sizes[] = {
 412                 [TYPE_ATOMIC]          = sizeof(atomic_type_t),
 413                 [TYPE_COMPLEX]         = sizeof(complex_type_t),
 414                 [TYPE_IMAGINARY]       = sizeof(imaginary_type_t),
 415                 [TYPE_BITFIELD]        = sizeof(bitfield_type_t),
 416                 [TYPE_COMPOUND_STRUCT] = sizeof(compound_type_t),
 417                 [TYPE_COMPOUND_UNION]  = sizeof(compound_type_t),
 418                 [TYPE_ENUM]            = sizeof(enum_type_t),
 419                 [TYPE_FUNCTION]        = sizeof(function_type_t),
 420                 [TYPE_POINTER]         = sizeof(pointer_type_t),
 421                 [TYPE_ARRAY]           = sizeof(array_type_t),
 422                 [TYPE_BUILTIN]         = sizeof(builtin_type_t),
 423                 [TYPE_TYPEDEF]         = sizeof(typedef_type_t),
 424                 [TYPE_TYPEOF]          = sizeof(typeof_type_t),
 425         };
 426         assert(sizeof(sizes) / sizeof(sizes[0]) == (int) TYPE_TYPEOF + 1);
 427         assert(kind <= TYPE_TYPEOF);
 428         assert(sizes[kind] != 0);
 429         return sizes[kind];
 430 }
 431
 432 /**
 433  * Allocate a type node of given kind and initialize all
 434  * fields with zero.
 435  *
 436  * @param kind             type kind to allocate
 437  */
 438 static type_t *allocate_type_zero(type_kind_t kind)
 439 {
 440         size_t  size = get_type_struct_size(kind);
 441         type_t *res  = obstack_alloc(type_obst, size);
 442         memset(res, 0, size);
 443         res->base.kind = kind;
 444
 445         return res;
 446 }
 447
 448 /**
 449  * Returns the size of an initializer node.
 450  *
 451  * @param kind  the initializer kind
 452  */
 453 static size_t get_initializer_size(initializer_kind_t kind)
 454 {
 455         static const size_t sizes[] = {
 456                 [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
 457                 [INITIALIZER_STRING]      = sizeof(initializer_string_t),
 458                 [INITIALIZER_WIDE_STRING] = sizeof(initializer_wide_string_t),
 459                 [INITIALIZER_LIST]        = sizeof(initializer_list_t),
 460                 [INITIALIZER_DESIGNATOR]  = sizeof(initializer_designator_t)
 461         };
 462         assert(kind < sizeof(sizes) / sizeof(*sizes));
 463         assert(sizes[kind] != 0);
 464         return sizes[kind];
 465 }
 466
 467 /**
 468  * Allocate an initializer node of given kind and initialize all
 469  * fields with zero.
 470  */
 471 static initializer_t *allocate_initializer_zero(initializer_kind_t kind)
 472 {
 473         initializer_t *result = allocate_ast_zero(get_initializer_size(kind));
 474         result->kind          = kind;
 475
 476         return result;
 477 }
 478
 479 /**
 480  * Free a type from the type obstack.
 481  */
 482 static void free_type(void *type)
 483 {
 484         obstack_free(type_obst, type);
 485 }
 486
 487 /**
 488  * Returns the index of the top element of the environment stack.
 489  */
 490 static size_t environment_top(void)
 491 {
 492         return ARR_LEN(environment_stack);
 493 }
 494
 495 /**
 496  * Returns the index of the top element of the global label stack.
 497  */
 498 static size_t label_top(void)
 499 {
 500         return ARR_LEN(label_stack);
 501 }
 502
 503 /**
 504  * Returns the index of the top element of the local label stack.
 505  */
 506 static size_t local_label_top(void)
 507 {
 508         return ARR_LEN(local_label_stack);
 509 }
 510
 511 /**
 512  * Return the next token.
 513  */
 514 static inline void next_token(void)
 515 {
 516         token                              = lookahead_buffer[lookahead_bufpos];
 517         lookahead_buffer[lookahead_bufpos] = lexer_token;
 518         lexer_next_token();
 519
 520         lookahead_bufpos = (lookahead_bufpos+1) % MAX_LOOKAHEAD;
 521
 522 #ifdef PRINT_TOKENS
 523         print_token(stderr, &token);
 524         fprintf(stderr, "\n");
 525 #endif
 526 }
 527
 528 /**
 529  * Return the next token with a given lookahead.
 530  */
 531 static inline const token_t *look_ahead(int num)
 532 {
 533         assert(num > 0 && num <= MAX_LOOKAHEAD);
 534         int pos = (lookahead_bufpos+num-1) % MAX_LOOKAHEAD;
 535         return &lookahead_buffer[pos];
 536 }
 537
 538 /**
 539  * Adds a token to the token anchor set (a multi-set).
 540  */
 541 static void add_anchor_token(int token_type)
 542 {
 543         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 544         ++token_anchor_set[token_type];
 545 }
 546
 547 static int save_and_reset_anchor_state(int token_type)
 548 {
 549         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 550         int count = token_anchor_set[token_type];
 551         token_anchor_set[token_type] = 0;
 552         return count;
 553 }
 554
 555 static void restore_anchor_state(int token_type, int count)
 556 {
 557         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 558         token_anchor_set[token_type] = count;
 559 }
 560
 561 /**
 562  * Remove a token from the token anchor set (a multi-set).
 563  */
 564 static void rem_anchor_token(int token_type)
 565 {
 566         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 567         assert(token_anchor_set[token_type] != 0);
 568         --token_anchor_set[token_type];
 569 }
 570
 571 static bool at_anchor(void)
 572 {
 573         if (token.type < 0)
 574                 return false;
 575         return token_anchor_set[token.type];
 576 }
 577
 578 /**
 579  * Eat tokens until a matching token is found.
 580  */
 581 static void eat_until_matching_token(int type)
 582 {
 583         int end_token;
 584         switch (type) {
 585                 case '(': end_token = ')';  break;
 586                 case '{': end_token = '}';  break;
 587                 case '[': end_token = ']';  break;
 588                 default:  end_token = type; break;
 589         }
 590
 591         unsigned parenthesis_count = 0;
 592         unsigned brace_count       = 0;
 593         unsigned bracket_count     = 0;
 594         while (token.type        != end_token ||
 595                parenthesis_count != 0         ||
 596                brace_count       != 0         ||
 597                bracket_count     != 0) {
 598                 switch (token.type) {
 599                 case T_EOF: return;
 600                 case '(': ++parenthesis_count; break;
 601                 case '{': ++brace_count;       break;
 602                 case '[': ++bracket_count;     break;
 603
 604                 case ')':
 605                         if (parenthesis_count > 0)
 606                                 --parenthesis_count;
 607                         goto check_stop;
 608
 609                 case '}':
 610                         if (brace_count > 0)
 611                                 --brace_count;
 612                         goto check_stop;
 613
 614                 case ']':
 615                         if (bracket_count > 0)
 616                                 --bracket_count;
 617 check_stop:
 618                         if (token.type        == end_token &&
 619                             parenthesis_count == 0         &&
 620                             brace_count       == 0         &&
 621                             bracket_count     == 0)
 622                                 return;
 623                         break;
 624
 625                 default:
 626                         break;
 627                 }
 628                 next_token();
 629         }
 630 }
 631
 632 /**
 633  * Eat input tokens until an anchor is found.
 634  */
 635 static void eat_until_anchor(void)
 636 {
 637         while (token_anchor_set[token.type] == 0) {
 638                 if (token.type == '(' || token.type == '{' || token.type == '[')
 639                         eat_until_matching_token(token.type);
 640                 next_token();
 641         }
 642 }
 643
 644 static void eat_block(void)
 645 {
 646         eat_until_matching_token('{');
 647         if (token.type == '}')
 648                 next_token();
 649 }
 650
 651 #define eat(token_type)  do { assert(token.type == token_type); next_token(); } while (0)
 652
 653 /**
 654  * Report a parse error because an expected token was not found.
 655  */
 656 static
 657 #if defined __GNUC__ && __GNUC__ >= 4
 658 __attribute__((sentinel))
 659 #endif
 660 void parse_error_expected(const char *message, ...)
 661 {
 662         if (message != NULL) {
 663                 errorf(HERE, "%s", message);
 664         }
 665         va_list ap;
 666         va_start(ap, message);
 667         errorf(HERE, "got %K, expected %#k", &token, &ap, ", ");
 668         va_end(ap);
 669 }
 670
 671 /**
 672  * Report a type error.
 673  */
 674 static void type_error(const char *msg, const source_position_t *source_position,
 675                        type_t *type)
 676 {
 677         errorf(source_position, "%s, but found type '%T'", msg, type);
 678 }
 679
 680 /**
 681  * Report an incompatible type.
 682  */
 683 static void type_error_incompatible(const char *msg,
 684                 const source_position_t *source_position, type_t *type1, type_t *type2)
 685 {
 686         errorf(source_position, "%s, incompatible types: '%T' - '%T'",
 687                msg, type1, type2);
 688 }
 689
 690 /**
 691  * Expect the the current token is the expected token.
 692  * If not, generate an error, eat the current statement,
 693  * and goto the end_error label.
 694  */
 695 #define expect(expected)                                  \
 696         do {                                                  \
 697                 if (UNLIKELY(token.type != (expected))) {         \
 698                         parse_error_expected(NULL, (expected), NULL); \
 699                         add_anchor_token(expected);                   \
 700                         eat_until_anchor();                           \
 701                         if (token.type == expected)                   \
 702                                 next_token();                             \
 703                         rem_anchor_token(expected);                   \
 704                         goto end_error;                               \
 705                 }                                                 \
 706                 next_token();                                     \
 707         } while (0)
 708
 709 static void scope_push(scope_t *new_scope)
 710 {
 711         if (scope != NULL) {
 712                 scope->last_declaration = last_declaration;
 713                 new_scope->depth        = scope->depth + 1;
 714         }
 715         new_scope->parent = scope;
 716         scope             = new_scope;
 717
 718         last_declaration = new_scope->last_declaration;
 719 }
 720
 721 static void scope_pop(void)
 722 {
 723         scope->last_declaration = last_declaration;
 724         scope = scope->parent;
 725         last_declaration = scope->last_declaration;
 726 }
 727
 728 /**
 729  * Search a symbol in a given namespace and returns its declaration or
 730  * NULL if this symbol was not found.
 731  */
 732 static declaration_t *get_declaration(const symbol_t *const symbol,
 733                                       const namespace_t namespc)
 734 {
 735         declaration_t *declaration = symbol->declaration;
 736         for( ; declaration != NULL; declaration = declaration->symbol_next) {
 737                 if (declaration->namespc == namespc)
 738                         return declaration;
 739         }
 740
 741         return NULL;
 742 }
 743
 744 /**
 745  * pushs an environment_entry on the environment stack and links the
 746  * corresponding symbol to the new entry
 747  */
 748 static void stack_push(stack_entry_t **stack_ptr, declaration_t *declaration)
 749 {
 750         symbol_t    *symbol  = declaration->symbol;
 751         namespace_t  namespc = (namespace_t) declaration->namespc;
 752
 753         /* replace/add declaration into declaration list of the symbol */
 754         declaration_t **anchor;
 755         declaration_t  *iter;
 756         for (anchor = &symbol->declaration;; anchor = &iter->symbol_next) {
 757                 iter = *anchor;
 758                 if (iter == NULL)
 759                         break;
 760
 761                 /* replace an entry? */
 762                 if (iter->namespc == namespc) {
 763                         declaration->symbol_next = iter->symbol_next;
 764                         break;
 765                 }
 766         }
 767         *anchor = declaration;
 768
 769         /* remember old declaration */
 770         stack_entry_t entry;
 771         entry.symbol          = symbol;
 772         entry.old_declaration = iter;
 773         entry.namespc         = (unsigned short) namespc;
 774         ARR_APP1(stack_entry_t, *stack_ptr, entry);
 775 }
 776
 777 /**
 778  * Push a declaration on the environment stack.
 779  *
 780  * @param declaration  the declaration
 781  */
 782 static void environment_push(declaration_t *declaration)
 783 {
 784         assert(declaration->source_position.input_name != NULL);
 785         assert(declaration->parent_scope != NULL);
 786         stack_push(&environment_stack, declaration);
 787 }
 788
 789 /**
 790  * Push a declaration on the global label stack.
 791  *
 792  * @param declaration  the declaration
 793  */
 794 static void label_push(declaration_t *declaration)
 795 {
 796         declaration->parent_scope = &current_function->scope;
 797         stack_push(&label_stack, declaration);
 798 }
 799
 800 /**
 801  * Push a declaration of the local label stack.
 802  *
 803  * @param declaration  the declaration
 804  */
 805 static void local_label_push(declaration_t *declaration)
 806 {
 807         assert(declaration->parent_scope != NULL);
 808         stack_push(&local_label_stack, declaration);
 809 }
 810
 811 /**
 812  * pops symbols from the environment stack until @p new_top is the top element
 813  */
 814 static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
 815 {
 816         stack_entry_t *stack = *stack_ptr;
 817         size_t         top   = ARR_LEN(stack);
 818         size_t         i;
 819
 820         assert(new_top <= top);
 821         if (new_top == top)
 822                 return;
 823
 824         for(i = top; i > new_top; --i) {
 825                 stack_entry_t *entry = &stack[i - 1];
 826
 827                 declaration_t *old_declaration = entry->old_declaration;
 828                 symbol_t      *symbol          = entry->symbol;
 829                 namespace_t    namespc         = (namespace_t)entry->namespc;
 830
 831                 /* replace/remove declaration */
 832                 declaration_t **anchor;
 833                 declaration_t  *iter;
 834                 for (anchor = &symbol->declaration;; anchor = &iter->symbol_next) {
 835                         iter = *anchor;
 836                         assert(iter != NULL);
 837                         /* replace an entry? */
 838                         if (iter->namespc == namespc)
 839                                 break;
 840                 }
 841
 842                 /* Not all declarations adhere scopes (e.g. jump labels), so this
 843                  * correction is necessary */
 844                 if (old_declaration != NULL) {
 845                         old_declaration->symbol_next = iter->symbol_next;
 846                         *anchor = old_declaration;
 847                 } else {
 848                         *anchor = iter->symbol_next;
 849                 }
 850         }
 851
 852         ARR_SHRINKLEN(*stack_ptr, (int) new_top);
 853 }
 854
 855 /**
 856  * Pop all entries from the environment stack until the new_top
 857  * is reached.
 858  *
 859  * @param new_top  the new stack top
 860  */
 861 static void environment_pop_to(size_t new_top)
 862 {
 863         stack_pop_to(&environment_stack, new_top);
 864 }
 865
 866 /**
 867  * Pop all entries from the global label stack until the new_top
 868  * is reached.
 869  *
 870  * @param new_top  the new stack top
 871  */
 872 static void label_pop_to(size_t new_top)
 873 {
 874         stack_pop_to(&label_stack, new_top);
 875 }
 876
 877 /**
 878  * Pop all entries from the local label stack until the new_top
 879  * is reached.
 880  *
 881  * @param new_top  the new stack top
 882  */
 883 static void local_label_pop_to(size_t new_top)
 884 {
 885         stack_pop_to(&local_label_stack, new_top);
 886 }
 887
 888
 889 static int get_akind_rank(atomic_type_kind_t akind)
 890 {
 891         return (int) akind;
 892 }
 893
 894 static int get_rank(const type_t *type)
 895 {
 896         assert(!is_typeref(type));
 897         /* The C-standard allows promoting enums to int or unsigned int (see § 7.2.2
 898          * and esp. footnote 108). However we can't fold constants (yet), so we
 899          * can't decide whether unsigned int is possible, while int always works.
 900          * (unsigned int would be preferable when possible... for stuff like
 901          *  struct { enum { ... } bla : 4; } ) */
 902         if (type->kind == TYPE_ENUM)
 903                 return get_akind_rank(ATOMIC_TYPE_INT);
 904
 905         assert(type->kind == TYPE_ATOMIC);
 906         return get_akind_rank(type->atomic.akind);
 907 }
 908
 909 static type_t *promote_integer(type_t *type)
 910 {
 911         if (type->kind == TYPE_BITFIELD)
 912                 type = type->bitfield.base_type;
 913
 914         if (get_rank(type) < get_akind_rank(ATOMIC_TYPE_INT))
 915                 type = type_int;
 916
 917         return type;
 918 }
 919
 920 /**
 921  * Create a cast expression.
 922  *
 923  * @param expression  the expression to cast
 924  * @param dest_type   the destination type
 925  */
 926 static expression_t *create_cast_expression(expression_t *expression,
 927                                             type_t *dest_type)
 928 {
 929         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST_IMPLICIT);
 930
 931         cast->unary.value = expression;
 932         cast->base.type   = dest_type;
 933
 934         return cast;
 935 }
 936
 937 /**
 938  * Check if a given expression represents the 0 pointer constant.
 939  */
 940 static bool is_null_pointer_constant(const expression_t *expression)
 941 {
 942         /* skip void* cast */
 943         if (expression->kind == EXPR_UNARY_CAST
 944                         || expression->kind == EXPR_UNARY_CAST_IMPLICIT) {
 945                 expression = expression->unary.value;
 946         }
 947
 948         /* TODO: not correct yet, should be any constant integer expression
 949          * which evaluates to 0 */
 950         if (expression->kind != EXPR_CONST)
 951                 return false;
 952
 953         type_t *const type = skip_typeref(expression->base.type);
 954         if (!is_type_integer(type))
 955                 return false;
 956
 957         return expression->conste.v.int_value == 0;
 958 }
 959
 960 /**
 961  * Create an implicit cast expression.
 962  *
 963  * @param expression  the expression to cast
 964  * @param dest_type   the destination type
 965  */
 966 static expression_t *create_implicit_cast(expression_t *expression,
 967                                           type_t *dest_type)
 968 {
 969         type_t *const source_type = expression->base.type;
 970
 971         if (source_type == dest_type)
 972                 return expression;
 973
 974         return create_cast_expression(expression, dest_type);
 975 }
 976
 977 typedef enum assign_error_t {
 978         ASSIGN_SUCCESS,
 979         ASSIGN_ERROR_INCOMPATIBLE,
 980         ASSIGN_ERROR_POINTER_QUALIFIER_MISSING,
 981         ASSIGN_WARNING_POINTER_INCOMPATIBLE,
 982         ASSIGN_WARNING_POINTER_FROM_INT,
 983         ASSIGN_WARNING_INT_FROM_POINTER
 984 } assign_error_t;
 985
 986 static void report_assign_error(assign_error_t error, type_t *orig_type_left,
 987                                 const expression_t *const right,
 988                                 const char *context,
 989                                 const source_position_t *source_position)
 990 {
 991         type_t *const orig_type_right = right->base.type;
 992         type_t *const type_left       = skip_typeref(orig_type_left);
 993         type_t *const type_right      = skip_typeref(orig_type_right);
 994
 995         switch (error) {
 996         case ASSIGN_SUCCESS:
 997                 return;
 998         case ASSIGN_ERROR_INCOMPATIBLE:
 999                 errorf(source_position,
1000                        "destination type '%T' in %s is incompatible with type '%T'",
1001                        orig_type_left, context, orig_type_right);
1002                 return;
1003
1004         case ASSIGN_ERROR_POINTER_QUALIFIER_MISSING: {
1005                 if (warning.other) {
1006                         type_t *points_to_left  = skip_typeref(type_left->pointer.points_to);
1007                         type_t *points_to_right = skip_typeref(type_right->pointer.points_to);
1008
1009                         /* the left type has all qualifiers from the right type */
1010                         unsigned missing_qualifiers
1011                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
1012                         warningf(source_position,
1013                                         "destination type '%T' in %s from type '%T' lacks qualifiers '%Q' in pointer target type",
1014                                         orig_type_left, context, orig_type_right, missing_qualifiers);
1015                 }
1016                 return;
1017         }
1018
1019         case ASSIGN_WARNING_POINTER_INCOMPATIBLE:
1020                 if (warning.other) {
1021                         warningf(source_position,
1022                                         "destination type '%T' in %s is incompatible with '%E' of type '%T'",
1023                                         orig_type_left, context, right, orig_type_right);
1024                 }
1025                 return;
1026
1027         case ASSIGN_WARNING_POINTER_FROM_INT:
1028                 if (warning.other) {
1029                         warningf(source_position,
1030                                         "%s makes pointer '%T' from integer '%T' without a cast",
1031                                         context, orig_type_left, orig_type_right);
1032                 }
1033                 return;
1034
1035         case ASSIGN_WARNING_INT_FROM_POINTER:
1036                 if (warning.other) {
1037                         warningf(source_position,
1038                                         "%s makes integer '%T' from pointer '%T' without a cast",
1039                                         context, orig_type_left, orig_type_right);
1040                 }
1041                 return;
1042
1043         default:
1044                 panic("invalid error value");
1045         }
1046 }
1047
1048 /** Implements the rules from § 6.5.16.1 */
1049 static assign_error_t semantic_assign(type_t *orig_type_left,
1050                                       const expression_t *const right)
1051 {
1052         type_t *const orig_type_right = right->base.type;
1053         type_t *const type_left       = skip_typeref(orig_type_left);
1054         type_t *const type_right      = skip_typeref(orig_type_right);
1055
1056         if (is_type_pointer(type_left)) {
1057                 if (is_null_pointer_constant(right)) {
1058                         return ASSIGN_SUCCESS;
1059                 } else if (is_type_pointer(type_right)) {
1060                         type_t *points_to_left
1061                                 = skip_typeref(type_left->pointer.points_to);
1062                         type_t *points_to_right
1063                                 = skip_typeref(type_right->pointer.points_to);
1064                         assign_error_t res = ASSIGN_SUCCESS;
1065
1066                         /* the left type has all qualifiers from the right type */
1067                         unsigned missing_qualifiers
1068                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
1069                         if (missing_qualifiers != 0) {
1070                                 res = ASSIGN_ERROR_POINTER_QUALIFIER_MISSING;
1071                         }
1072
1073                         points_to_left  = get_unqualified_type(points_to_left);
1074                         points_to_right = get_unqualified_type(points_to_right);
1075
1076                         if (is_type_atomic(points_to_left, ATOMIC_TYPE_VOID) ||
1077                                         is_type_atomic(points_to_right, ATOMIC_TYPE_VOID)) {
1078                                 return res;
1079                         }
1080
1081                         if (!types_compatible(points_to_left, points_to_right)) {
1082                                 return ASSIGN_WARNING_POINTER_INCOMPATIBLE;
1083                         }
1084
1085                         return res;
1086                 } else if (is_type_integer(type_right)) {
1087                         return ASSIGN_WARNING_POINTER_FROM_INT;
1088                 }
1089         } else if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
1090             (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
1091                 && is_type_pointer(type_right))) {
1092                 return ASSIGN_SUCCESS;
1093         } else if ((is_type_compound(type_left)  && is_type_compound(type_right))
1094                         || (is_type_builtin(type_left) && is_type_builtin(type_right))) {
1095                 type_t *const unqual_type_left  = get_unqualified_type(type_left);
1096                 type_t *const unqual_type_right = get_unqualified_type(type_right);
1097                 if (types_compatible(unqual_type_left, unqual_type_right)) {
1098                         return ASSIGN_SUCCESS;
1099                 }
1100         } else if (is_type_integer(type_left) && is_type_pointer(type_right)) {
1101                 return ASSIGN_WARNING_INT_FROM_POINTER;
1102         }
1103
1104         if (!is_type_valid(type_left) || !is_type_valid(type_right))
1105                 return ASSIGN_SUCCESS;
1106
1107         return ASSIGN_ERROR_INCOMPATIBLE;
1108 }
1109
1110 static expression_t *parse_constant_expression(void)
1111 {
1112         expression_t *result = parse_sub_expression(PREC_CONDITIONAL);
1113
1114         if (!is_constant_expression(result)) {
1115                 errorf(&result->base.source_position,
1116                        "expression '%E' is not constant\n", result);
1117         }
1118
1119         return result;
1120 }
1121
1122 static expression_t *parse_assignment_expression(void)
1123 {
1124         return parse_sub_expression(PREC_ASSIGNMENT);
1125 }
1126
1127 static type_t *make_global_typedef(const char *name, type_t *type)
1128 {
1129         symbol_t *const symbol       = symbol_table_insert(name);
1130
1131         declaration_t *const declaration = allocate_declaration_zero();
1132         declaration->namespc                = NAMESPACE_NORMAL;
1133         declaration->storage_class          = STORAGE_CLASS_TYPEDEF;
1134         declaration->declared_storage_class = STORAGE_CLASS_TYPEDEF;
1135         declaration->type                   = type;
1136         declaration->symbol                 = symbol;
1137         declaration->source_position        = builtin_source_position;
1138         declaration->implicit               = true;
1139
1140         record_declaration(declaration, false);
1141
1142         type_t *typedef_type               = allocate_type_zero(TYPE_TYPEDEF);
1143         typedef_type->typedeft.declaration = declaration;
1144
1145         return typedef_type;
1146 }
1147
1148 static string_t parse_string_literals(void)
1149 {
1150         assert(token.type == T_STRING_LITERAL);
1151         string_t result = token.v.string;
1152
1153         next_token();
1154
1155         while (token.type == T_STRING_LITERAL) {
1156                 result = concat_strings(&result, &token.v.string);
1157                 next_token();
1158         }
1159
1160         return result;
1161 }
1162
1163 static const char *const gnu_attribute_names[GNU_AK_LAST] = {
1164         [GNU_AK_CONST]                  = "const",
1165         [GNU_AK_VOLATILE]               = "volatile",
1166         [GNU_AK_CDECL]                  = "cdecl",
1167         [GNU_AK_STDCALL]                = "stdcall",
1168         [GNU_AK_FASTCALL]               = "fastcall",
1169         [GNU_AK_DEPRECATED]             = "deprecated",
1170         [GNU_AK_NOINLINE]               = "noinline",
1171         [GNU_AK_NORETURN]               = "noreturn",
1172         [GNU_AK_NAKED]                  = "naked",
1173         [GNU_AK_PURE]                   = "pure",
1174         [GNU_AK_ALWAYS_INLINE]          = "always_inline",
1175         [GNU_AK_MALLOC]                 = "malloc",
1176         [GNU_AK_WEAK]                   = "weak",
1177         [GNU_AK_CONSTRUCTOR]            = "constructor",
1178         [GNU_AK_DESTRUCTOR]             = "destructor",
1179         [GNU_AK_NOTHROW]                = "nothrow",
1180         [GNU_AK_TRANSPARENT_UNION]      = "transparent_union",
1181         [GNU_AK_COMMON]                 = "common",
1182         [GNU_AK_NOCOMMON]               = "nocommon",
1183         [GNU_AK_PACKED]                 = "packed",
1184         [GNU_AK_SHARED]                 = "shared",
1185         [GNU_AK_NOTSHARED]              = "notshared",
1186         [GNU_AK_USED]                   = "used",
1187         [GNU_AK_UNUSED]                 = "unused",
1188         [GNU_AK_NO_INSTRUMENT_FUNCTION] = "no_instrument_function",
1189         [GNU_AK_WARN_UNUSED_RESULT]     = "warn_unused_result",
1190         [GNU_AK_LONGCALL]               = "longcall",
1191         [GNU_AK_SHORTCALL]              = "shortcall",
1192         [GNU_AK_LONG_CALL]              = "long_call",
1193         [GNU_AK_SHORT_CALL]             = "short_call",
1194         [GNU_AK_FUNCTION_VECTOR]        = "function_vector",
1195         [GNU_AK_INTERRUPT]              = "interrupt",
1196         [GNU_AK_INTERRUPT_HANDLER]      = "interrupt_handler",
1197         [GNU_AK_NMI_HANDLER]            = "nmi_handler",
1198         [GNU_AK_NESTING]                = "nesting",
1199         [GNU_AK_NEAR]                   = "near",
1200         [GNU_AK_FAR]                    = "far",
1201         [GNU_AK_SIGNAL]                 = "signal",
1202         [GNU_AK_EIGTHBIT_DATA]          = "eightbit_data",
1203         [GNU_AK_TINY_DATA]              = "tiny_data",
1204         [GNU_AK_SAVEALL]                = "saveall",
1205         [GNU_AK_FLATTEN]                = "flatten",
1206         [GNU_AK_SSEREGPARM]             = "sseregparm",
1207         [GNU_AK_EXTERNALLY_VISIBLE]     = "externally_visible",
1208         [GNU_AK_RETURN_TWICE]           = "return_twice",
1209         [GNU_AK_MAY_ALIAS]              = "may_alias",
1210         [GNU_AK_MS_STRUCT]              = "ms_struct",
1211         [GNU_AK_GCC_STRUCT]             = "gcc_struct",
1212         [GNU_AK_DLLIMPORT]              = "dllimport",
1213         [GNU_AK_DLLEXPORT]              = "dllexport",
1214         [GNU_AK_ALIGNED]                = "aligned",
1215         [GNU_AK_ALIAS]                  = "alias",
1216         [GNU_AK_SECTION]                = "section",
1217         [GNU_AK_FORMAT]                 = "format",
1218         [GNU_AK_FORMAT_ARG]             = "format_arg",
1219         [GNU_AK_WEAKREF]                = "weakref",
1220         [GNU_AK_NONNULL]                = "nonnull",
1221         [GNU_AK_TLS_MODEL]              = "tls_model",
1222         [GNU_AK_VISIBILITY]             = "visibility",
1223         [GNU_AK_REGPARM]                = "regparm",
1224         [GNU_AK_MODE]                   = "mode",
1225         [GNU_AK_MODEL]                  = "model",
1226         [GNU_AK_TRAP_EXIT]              = "trap_exit",
1227         [GNU_AK_SP_SWITCH]              = "sp_switch",
1228         [GNU_AK_SENTINEL]               = "sentinel"
1229 };
1230
1231 /**
1232  * compare two string, ignoring double underscores on the second.
1233  */
1234 static int strcmp_underscore(const char *s1, const char *s2)
1235 {
1236         if (s2[0] == '_' && s2[1] == '_') {
1237                 size_t len2 = strlen(s2);
1238                 size_t len1 = strlen(s1);
1239                 if (len1 == len2-4 && s2[len2-2] == '_' && s2[len2-1] == '_') {
1240                         return strncmp(s1, s2+2, len2-4);
1241                 }
1242         }
1243
1244         return strcmp(s1, s2);
1245 }
1246
1247 /**
1248  * Allocate a new gnu temporal attribute.
1249  */
1250 static gnu_attribute_t *allocate_gnu_attribute(gnu_attribute_kind_t kind)
1251 {
1252         gnu_attribute_t *attribute = obstack_alloc(&temp_obst, sizeof(*attribute));
1253         attribute->kind            = kind;
1254         attribute->next            = NULL;
1255         attribute->invalid         = false;
1256         attribute->have_arguments  = false;
1257
1258         return attribute;
1259 }
1260
1261 /**
1262  * parse one constant expression argument.
1263  */
1264 static void parse_gnu_attribute_const_arg(gnu_attribute_t *attribute)
1265 {
1266         expression_t *expression;
1267         add_anchor_token(')');
1268         expression = parse_constant_expression();
1269         rem_anchor_token(')');
1270         expect(')');
1271         attribute->u.argument = fold_constant(expression);
1272         return;
1273 end_error:
1274         attribute->invalid = true;
1275 }
1276
1277 /**
1278  * parse a list of constant expressions arguments.
1279  */
1280 static void parse_gnu_attribute_const_arg_list(gnu_attribute_t *attribute)
1281 {
1282         argument_list_t **list = &attribute->u.arguments;
1283         argument_list_t  *entry;
1284         expression_t     *expression;
1285         add_anchor_token(')');
1286         add_anchor_token(',');
1287         while (true) {
1288                 expression = parse_constant_expression();
1289                 entry = obstack_alloc(&temp_obst, sizeof(entry));
1290                 entry->argument = fold_constant(expression);
1291                 entry->next     = NULL;
1292                 *list = entry;
1293                 list = &entry->next;
1294                 if (token.type != ',')
1295                         break;
1296                 next_token();
1297         }
1298         rem_anchor_token(',');
1299         rem_anchor_token(')');
1300         expect(')');
1301         return;
1302 end_error:
1303         attribute->invalid = true;
1304 }
1305
1306 /**
1307  * parse one string literal argument.
1308  */
1309 static void parse_gnu_attribute_string_arg(gnu_attribute_t *attribute,
1310                                            string_t *string)
1311 {
1312         add_anchor_token('(');
1313         if (token.type != T_STRING_LITERAL) {
1314                 parse_error_expected("while parsing attribute directive",
1315                                      T_STRING_LITERAL, NULL);
1316                 goto end_error;
1317         }
1318         *string = parse_string_literals();
1319         rem_anchor_token('(');
1320         expect(')');
1321         return;
1322 end_error:
1323         attribute->invalid = true;
1324 }
1325
1326 /**
1327  * parse one tls model.
1328  */
1329 static void parse_gnu_attribute_tls_model_arg(gnu_attribute_t *attribute)
1330 {
1331         static const char *const tls_models[] = {
1332                 "global-dynamic",
1333                 "local-dynamic",
1334                 "initial-exec",
1335                 "local-exec"
1336         };
1337         string_t string = { NULL, 0 };
1338         parse_gnu_attribute_string_arg(attribute, &string);
1339         if (string.begin != NULL) {
1340                 for(size_t i = 0; i < 4; ++i) {
1341                         if (strcmp(tls_models[i], string.begin) == 0) {
1342                                 attribute->u.value = i;
1343                                 return;
1344                         }
1345                 }
1346                 errorf(HERE, "'%s' is an unrecognized tls model", string.begin);
1347         }
1348         attribute->invalid = true;
1349 }
1350
1351 /**
1352  * parse one tls model.
1353  */
1354 static void parse_gnu_attribute_visibility_arg(gnu_attribute_t *attribute)
1355 {
1356         static const char *const visibilities[] = {
1357                 "default",
1358                 "protected",
1359                 "hidden",
1360                 "internal"
1361         };
1362         string_t string = { NULL, 0 };
1363         parse_gnu_attribute_string_arg(attribute, &string);
1364         if (string.begin != NULL) {
1365                 for(size_t i = 0; i < 4; ++i) {
1366                         if (strcmp(visibilities[i], string.begin) == 0) {
1367                                 attribute->u.value = i;
1368                                 return;
1369                         }
1370                 }
1371                 errorf(HERE, "'%s' is an unrecognized visibility", string.begin);
1372         }
1373         attribute->invalid = true;
1374 }
1375
1376 /**
1377  * parse one (code) model.
1378  */
1379 static void parse_gnu_attribute_model_arg(gnu_attribute_t *attribute)
1380 {
1381         static const char *const visibilities[] = {
1382                 "small",
1383                 "medium",
1384                 "large"
1385         };
1386         string_t string = { NULL, 0 };
1387         parse_gnu_attribute_string_arg(attribute, &string);
1388         if (string.begin != NULL) {
1389                 for(int i = 0; i < 3; ++i) {
1390                         if (strcmp(visibilities[i], string.begin) == 0) {
1391                                 attribute->u.value = i;
1392                                 return;
1393                         }
1394                 }
1395                 errorf(HERE, "'%s' is an unrecognized model", string.begin);
1396         }
1397         attribute->invalid = true;
1398 }
1399
1400 static void parse_gnu_attribute_mode_arg(gnu_attribute_t *attribute)
1401 {
1402         /* TODO: find out what is allowed here... */
1403
1404         /* at least: byte, word, pointer, list of machine modes
1405          * __XXX___ is interpreted as XXX */
1406         add_anchor_token(')');
1407
1408         if (token.type != T_IDENTIFIER) {
1409                 expect(T_IDENTIFIER);
1410         }
1411
1412         /* This isn't really correct, the backend should provide a list of machine
1413          * specific modes (according to gcc philosophy that is...) */
1414         const char *symbol_str = token.v.symbol->string;
1415         if (strcmp_underscore("QI",   symbol_str) == 0 ||
1416             strcmp_underscore("byte", symbol_str) == 0) {
1417                 attribute->u.akind = ATOMIC_TYPE_CHAR;
1418         } else if (strcmp_underscore("HI", symbol_str) == 0) {
1419                 attribute->u.akind = ATOMIC_TYPE_SHORT;
1420         } else if (strcmp_underscore("SI",      symbol_str) == 0
1421                 || strcmp_underscore("word",    symbol_str) == 0
1422                 || strcmp_underscore("pointer", symbol_str) == 0) {
1423                 attribute->u.akind = ATOMIC_TYPE_INT;
1424         } else if (strcmp_underscore("DI", symbol_str) == 0) {
1425                 attribute->u.akind = ATOMIC_TYPE_LONGLONG;
1426         } else {
1427                 if (warning.other)
1428                         warningf(HERE, "ignoring unknown mode '%s'", symbol_str);
1429                 attribute->invalid = true;
1430         }
1431         next_token();
1432
1433         rem_anchor_token(')');
1434         expect(')');
1435         return;
1436 end_error:
1437         attribute->invalid = true;
1438 }
1439
1440 /**
1441  * parse one interrupt argument.
1442  */
1443 static void parse_gnu_attribute_interrupt_arg(gnu_attribute_t *attribute)
1444 {
1445         static const char *const interrupts[] = {
1446                 "IRQ",
1447                 "FIQ",
1448                 "SWI",
1449                 "ABORT",
1450                 "UNDEF"
1451         };
1452         string_t string = { NULL, 0 };
1453         parse_gnu_attribute_string_arg(attribute, &string);
1454         if (string.begin != NULL) {
1455                 for(size_t i = 0; i < 5; ++i) {
1456                         if (strcmp(interrupts[i], string.begin) == 0) {
1457                                 attribute->u.value = i;
1458                                 return;
1459                         }
1460                 }
1461                 errorf(HERE, "'%s' is not an interrupt", string.begin);
1462         }
1463         attribute->invalid = true;
1464 }
1465
1466 /**
1467  * parse ( identifier, const expression, const expression )
1468  */
1469 static void parse_gnu_attribute_format_args(gnu_attribute_t *attribute)
1470 {
1471         static const char *const format_names[] = {
1472                 "printf",
1473                 "scanf",
1474                 "strftime",
1475                 "strfmon"
1476         };
1477         int i;
1478
1479         if (token.type != T_IDENTIFIER) {
1480                 parse_error_expected("while parsing format attribute directive", T_IDENTIFIER, NULL);
1481                 goto end_error;
1482         }
1483         const char *name = token.v.symbol->string;
1484         for(i = 0; i < 4; ++i) {
1485                 if (strcmp_underscore(format_names[i], name) == 0)
1486                         break;
1487         }
1488         if (i >= 4) {
1489                 if (warning.attribute)
1490                         warningf(HERE, "'%s' is an unrecognized format function type", name);
1491         }
1492         next_token();
1493
1494         expect(',');
1495         add_anchor_token(')');
1496         add_anchor_token(',');
1497         parse_constant_expression();
1498         rem_anchor_token(',');
1499         rem_anchor_token(')');
1500
1501         expect(',');
1502         add_anchor_token(')');
1503         parse_constant_expression();
1504         rem_anchor_token(')');
1505         expect(')');
1506         return;
1507 end_error:
1508         attribute->u.value = true;
1509 }
1510
1511 static void check_no_argument(gnu_attribute_t *attribute, const char *name)
1512 {
1513         if (!attribute->have_arguments)
1514                 return;
1515
1516         /* should have no arguments */
1517         errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1518         eat_until_matching_token('(');
1519         /* we have already consumed '(', so we stop before ')', eat it */
1520         eat(')');
1521         attribute->invalid = true;
1522 }
1523
1524 /**
1525  * Parse one GNU attribute.
1526  *
1527  * Note that attribute names can be specified WITH or WITHOUT
1528  * double underscores, ie const or __const__.
1529  *
1530  * The following attributes are parsed without arguments
1531  *  const
1532  *  volatile
1533  *  cdecl
1534  *  stdcall
1535  *  fastcall
1536  *  deprecated
1537  *  noinline
1538  *  noreturn
1539  *  naked
1540  *  pure
1541  *  always_inline
1542  *  malloc
1543  *  weak
1544  *  constructor
1545  *  destructor
1546  *  nothrow
1547  *  transparent_union
1548  *  common
1549  *  nocommon
1550  *  packed
1551  *  shared
1552  *  notshared
1553  *  used
1554  *  unused
1555  *  no_instrument_function
1556  *  warn_unused_result
1557  *  longcall
1558  *  shortcall
1559  *  long_call
1560  *  short_call
1561  *  function_vector
1562  *  interrupt_handler
1563  *  nmi_handler
1564  *  nesting
1565  *  near
1566  *  far
1567  *  signal
1568  *  eightbit_data
1569  *  tiny_data
1570  *  saveall
1571  *  flatten
1572  *  sseregparm
1573  *  externally_visible
1574  *  return_twice
1575  *  may_alias
1576  *  ms_struct
1577  *  gcc_struct
1578  *  dllimport
1579  *  dllexport
1580  *
1581  * The following attributes are parsed with arguments
1582  *  aligned( const expression )
1583  *  alias( string literal )
1584  *  section( string literal )
1585  *  format( identifier, const expression, const expression )
1586  *  format_arg( const expression )
1587  *  tls_model( string literal )
1588  *  visibility( string literal )
1589  *  regparm( const expression )
1590  *  model( string leteral )
1591  *  trap_exit( const expression )
1592  *  sp_switch( string literal )
1593  *
1594  * The following attributes might have arguments
1595  *  weak_ref( string literal )
1596  *  non_null( const expression // ',' )
1597  *  interrupt( string literal )
1598  *  sentinel( constant expression )
1599  */
1600 static decl_modifiers_t parse_gnu_attribute(gnu_attribute_t **attributes)
1601 {
1602         gnu_attribute_t *head      = *attributes;
1603         gnu_attribute_t *last      = *attributes;
1604         decl_modifiers_t modifiers = 0;
1605         gnu_attribute_t *attribute;
1606
1607         eat(T___attribute__);
1608         expect('(');
1609         expect('(');
1610
1611         if (token.type != ')') {
1612                 /* find the end of the list */
1613                 if (last != NULL) {
1614                         while (last->next != NULL)
1615                                 last = last->next;
1616                 }
1617
1618                 /* non-empty attribute list */
1619                 while (true) {
1620                         const char *name;
1621                         if (token.type == T_const) {
1622                                 name = "const";
1623                         } else if (token.type == T_volatile) {
1624                                 name = "volatile";
1625                         } else if (token.type == T_cdecl) {
1626                                 /* __attribute__((cdecl)), WITH ms mode */
1627                                 name = "cdecl";
1628                         } else if (token.type == T_IDENTIFIER) {
1629                                 const symbol_t *sym = token.v.symbol;
1630                                 name = sym->string;
1631                         } else {
1632                                 parse_error_expected("while parsing GNU attribute", T_IDENTIFIER, NULL);
1633                                 break;
1634                         }
1635
1636                         next_token();
1637
1638                         int i;
1639                         for(i = 0; i < GNU_AK_LAST; ++i) {
1640                                 if (strcmp_underscore(gnu_attribute_names[i], name) == 0)
1641                                         break;
1642                         }
1643                         gnu_attribute_kind_t kind = (gnu_attribute_kind_t)i;
1644
1645                         attribute = NULL;
1646                         if (kind == GNU_AK_LAST) {
1647                                 if (warning.attribute)
1648                                         warningf(HERE, "'%s' attribute directive ignored", name);
1649
1650                                 /* skip possible arguments */
1651                                 if (token.type == '(') {
1652                                         eat_until_matching_token(')');
1653                                 }
1654                         } else {
1655                                 /* check for arguments */
1656                                 attribute = allocate_gnu_attribute(kind);
1657                                 if (token.type == '(') {
1658                                         next_token();
1659                                         if (token.type == ')') {
1660                                                 /* empty args are allowed */
1661                                                 next_token();
1662                                         } else
1663                                                 attribute->have_arguments = true;
1664                                 }
1665
1666                                 switch(kind) {
1667                                 case GNU_AK_VOLATILE:
1668                                 case GNU_AK_NAKED:
1669                                 case GNU_AK_MALLOC:
1670                                 case GNU_AK_WEAK:
1671                                 case GNU_AK_COMMON:
1672                                 case GNU_AK_NOCOMMON:
1673                                 case GNU_AK_SHARED:
1674                                 case GNU_AK_NOTSHARED:
1675                                 case GNU_AK_NO_INSTRUMENT_FUNCTION:
1676                                 case GNU_AK_WARN_UNUSED_RESULT:
1677                                 case GNU_AK_LONGCALL:
1678                                 case GNU_AK_SHORTCALL:
1679                                 case GNU_AK_LONG_CALL:
1680                                 case GNU_AK_SHORT_CALL:
1681                                 case GNU_AK_FUNCTION_VECTOR:
1682                                 case GNU_AK_INTERRUPT_HANDLER:
1683                                 case GNU_AK_NMI_HANDLER:
1684                                 case GNU_AK_NESTING:
1685                                 case GNU_AK_NEAR:
1686                                 case GNU_AK_FAR:
1687                                 case GNU_AK_SIGNAL:
1688                                 case GNU_AK_EIGTHBIT_DATA:
1689                                 case GNU_AK_TINY_DATA:
1690                                 case GNU_AK_SAVEALL:
1691                                 case GNU_AK_FLATTEN:
1692                                 case GNU_AK_SSEREGPARM:
1693                                 case GNU_AK_EXTERNALLY_VISIBLE:
1694                                 case GNU_AK_RETURN_TWICE:
1695                                 case GNU_AK_MAY_ALIAS:
1696                                 case GNU_AK_MS_STRUCT:
1697                                 case GNU_AK_GCC_STRUCT:
1698                                         goto no_arg;
1699
1700                                 case GNU_AK_CDECL:             modifiers |= DM_CDECL;             goto no_arg;
1701                                 case GNU_AK_FASTCALL:          modifiers |= DM_FASTCALL;          goto no_arg;
1702                                 case GNU_AK_STDCALL:           modifiers |= DM_STDCALL;           goto no_arg;
1703                                 case GNU_AK_UNUSED:            modifiers |= DM_UNUSED;            goto no_arg;
1704                                 case GNU_AK_USED:              modifiers |= DM_USED;              goto no_arg;
1705                                 case GNU_AK_PURE:              modifiers |= DM_PURE;              goto no_arg;
1706                                 case GNU_AK_CONST:             modifiers |= DM_CONST;             goto no_arg;
1707                                 case GNU_AK_ALWAYS_INLINE:     modifiers |= DM_FORCEINLINE;       goto no_arg;
1708                                 case GNU_AK_DLLIMPORT:         modifiers |= DM_DLLIMPORT;         goto no_arg;
1709                                 case GNU_AK_DLLEXPORT:         modifiers |= DM_DLLEXPORT;         goto no_arg;
1710                                 case GNU_AK_PACKED:            modifiers |= DM_PACKED;            goto no_arg;
1711                                 case GNU_AK_NOINLINE:          modifiers |= DM_NOINLINE;          goto no_arg;
1712                                 case GNU_AK_NORETURN:          modifiers |= DM_NORETURN;          goto no_arg;
1713                                 case GNU_AK_NOTHROW:           modifiers |= DM_NOTHROW;           goto no_arg;
1714                                 case GNU_AK_TRANSPARENT_UNION: modifiers |= DM_TRANSPARENT_UNION; goto no_arg;
1715                                 case GNU_AK_CONSTRUCTOR:       modifiers |= DM_CONSTRUCTOR;       goto no_arg;
1716                                 case GNU_AK_DESTRUCTOR:        modifiers |= DM_DESTRUCTOR;        goto no_arg;
1717                                 case GNU_AK_DEPRECATED:        modifiers |= DM_DEPRECATED;        goto no_arg;
1718
1719                                 case GNU_AK_ALIGNED:
1720                                         /* __align__ may be used without an argument */
1721                                         if (attribute->have_arguments) {
1722                                                 parse_gnu_attribute_const_arg(attribute);
1723                                         }
1724                                         break;
1725
1726                                 case GNU_AK_FORMAT_ARG:
1727                                 case GNU_AK_REGPARM:
1728                                 case GNU_AK_TRAP_EXIT:
1729                                         if (!attribute->have_arguments) {
1730                                                 /* should have arguments */
1731                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1732                                                 attribute->invalid = true;
1733                                         } else
1734                                                 parse_gnu_attribute_const_arg(attribute);
1735                                         break;
1736                                 case GNU_AK_ALIAS:
1737                                 case GNU_AK_SECTION:
1738                                 case GNU_AK_SP_SWITCH:
1739                                         if (!attribute->have_arguments) {
1740                                                 /* should have arguments */
1741                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1742                                                 attribute->invalid = true;
1743                                         } else
1744                                                 parse_gnu_attribute_string_arg(attribute, &attribute->u.string);
1745                                         break;
1746                                 case GNU_AK_FORMAT:
1747                                         if (!attribute->have_arguments) {
1748                                                 /* should have arguments */
1749                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1750                                                 attribute->invalid = true;
1751                                         } else
1752                                                 parse_gnu_attribute_format_args(attribute);
1753                                         break;
1754                                 case GNU_AK_WEAKREF:
1755                                         /* may have one string argument */
1756                                         if (attribute->have_arguments)
1757                                                 parse_gnu_attribute_string_arg(attribute, &attribute->u.string);
1758                                         break;
1759                                 case GNU_AK_NONNULL:
1760                                         if (attribute->have_arguments)
1761                                                 parse_gnu_attribute_const_arg_list(attribute);
1762                                         break;
1763                                 case GNU_AK_TLS_MODEL:
1764                                         if (!attribute->have_arguments) {
1765                                                 /* should have arguments */
1766                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1767                                         } else
1768                                                 parse_gnu_attribute_tls_model_arg(attribute);
1769                                         break;
1770                                 case GNU_AK_VISIBILITY:
1771                                         if (!attribute->have_arguments) {
1772                                                 /* should have arguments */
1773                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1774                                         } else
1775                                                 parse_gnu_attribute_visibility_arg(attribute);
1776                                         break;
1777                                 case GNU_AK_MODEL:
1778                                         if (!attribute->have_arguments) {
1779                                                 /* should have arguments */
1780                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1781                                         } else {
1782                                                 parse_gnu_attribute_model_arg(attribute);
1783                                         }
1784                                         break;
1785                                 case GNU_AK_MODE:
1786                                         if (!attribute->have_arguments) {
1787                                                 /* should have arguments */
1788                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1789                                         } else {
1790                                                 parse_gnu_attribute_mode_arg(attribute);
1791                                         }
1792                                         break;
1793                                 case GNU_AK_INTERRUPT:
1794                                         /* may have one string argument */
1795                                         if (attribute->have_arguments)
1796                                                 parse_gnu_attribute_interrupt_arg(attribute);
1797                                         break;
1798                                 case GNU_AK_SENTINEL:
1799                                         /* may have one string argument */
1800                                         if (attribute->have_arguments)
1801                                                 parse_gnu_attribute_const_arg(attribute);
1802                                         break;
1803                                 case GNU_AK_LAST:
1804                                         /* already handled */
1805                                         break;
1806
1807 no_arg:
1808                                         check_no_argument(attribute, name);
1809                                 }
1810                         }
1811                         if (attribute != NULL) {
1812                                 if (last != NULL) {
1813                                         last->next = attribute;
1814                                         last       = attribute;
1815                                 } else {
1816                                         head = last = attribute;
1817                                 }
1818                         }
1819
1820                         if (token.type != ',')
1821                                 break;
1822                         next_token();
1823                 }
1824         }
1825         expect(')');
1826         expect(')');
1827 end_error:
1828         *attributes = head;
1829
1830         return modifiers;
1831 }
1832
1833 /**
1834  * Parse GNU attributes.
1835  */
1836 static decl_modifiers_t parse_attributes(gnu_attribute_t **attributes)
1837 {
1838         decl_modifiers_t modifiers = 0;
1839
1840         while (true) {
1841                 switch(token.type) {
1842                 case T___attribute__:
1843                         modifiers |= parse_gnu_attribute(attributes);
1844                         continue;
1845
1846                 case T_asm:
1847                         next_token();
1848                         expect('(');
1849                         if (token.type != T_STRING_LITERAL) {
1850                                 parse_error_expected("while parsing assembler attribute",
1851                                                      T_STRING_LITERAL, NULL);
1852                                 eat_until_matching_token('(');
1853                                 break;
1854                         } else {
1855                                 parse_string_literals();
1856                         }
1857                         expect(')');
1858                         continue;
1859
1860                 case T_cdecl:     modifiers |= DM_CDECL;    break;
1861                 case T__fastcall: modifiers |= DM_FASTCALL; break;
1862                 case T__stdcall:  modifiers |= DM_STDCALL;  break;
1863
1864                 case T___thiscall:
1865                         /* TODO record modifier */
1866                         if (warning.other)
1867                                 warningf(HERE, "Ignoring declaration modifier %K", &token);
1868                         break;
1869
1870 end_error:
1871                 default: return modifiers;
1872                 }
1873
1874                 next_token();
1875         }
1876 }
1877
1878 static void mark_decls_read(expression_t *expr, declaration_t *lhs_decl);
1879
1880 static declaration_t *determine_lhs_decl(expression_t *const expr, declaration_t *lhs_decl)
1881 {
1882         switch (expr->kind) {
1883                 case EXPR_REFERENCE: {
1884                         declaration_t *const decl = expr->reference.declaration;
1885                         return decl;
1886                 }
1887
1888                 case EXPR_ARRAY_ACCESS: {
1889                         expression_t  *const ref  = expr->array_access.array_ref;
1890                         declaration_t *      decl = NULL;
1891                         if (is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1892                                 decl     = determine_lhs_decl(ref, lhs_decl);
1893                                 lhs_decl = decl;
1894                         } else {
1895                                 mark_decls_read(expr->select.compound, lhs_decl);
1896                         }
1897                         mark_decls_read(expr->array_access.index, lhs_decl);
1898                         return decl;
1899                 }
1900
1901                 case EXPR_SELECT: {
1902                         if (is_type_compound(skip_typeref(expr->base.type))) {
1903                                 return determine_lhs_decl(expr->select.compound, lhs_decl);
1904                         } else {
1905                                 mark_decls_read(expr->select.compound, lhs_decl);
1906                                 return NULL;
1907                         }
1908                 }
1909
1910                 case EXPR_UNARY_DEREFERENCE: {
1911                         expression_t *const val = expr->unary.value;
1912                         if (val->kind == EXPR_UNARY_TAKE_ADDRESS) {
1913                                 /* *&x is a NOP */
1914                                 return determine_lhs_decl(val->unary.value, lhs_decl);
1915                         } else {
1916                                 mark_decls_read(val, NULL);
1917                                 return NULL;
1918                         }
1919                 }
1920
1921                 default:
1922                         mark_decls_read(expr, NULL);
1923                         return NULL;
1924         }
1925 }
1926
1927 #define DECL_ANY ((declaration_t*)-1)
1928
1929 /**
1930  * Mark declarations, which are read.  This is used to deted variables, which
1931  * are never read.
1932  * Example:
1933  * x = x + 1;
1934  *   x is not marked as "read", because it is only read to calculate its own new
1935  *   value.
1936  *
1937  * x += y; y += x;
1938  *   x and y are not detected as "not read", because multiple variables are
1939  *   involved.
1940  */
1941 static void mark_decls_read(expression_t *const expr, declaration_t *lhs_decl)
1942 {
1943         switch (expr->kind) {
1944                 case EXPR_REFERENCE: {
1945                         declaration_t *const decl = expr->reference.declaration;
1946                         if (lhs_decl != decl && lhs_decl != DECL_ANY)
1947                                 decl->read = true;
1948                         return;
1949                 }
1950
1951                 case EXPR_CALL:
1952                         // TODO respect pure/const
1953                         mark_decls_read(expr->call.function, NULL);
1954                         for (call_argument_t *arg = expr->call.arguments; arg != NULL; arg = arg->next) {
1955                                 mark_decls_read(arg->expression, NULL);
1956                         }
1957                         return;
1958
1959                 case EXPR_CONDITIONAL:
1960                         // TODO lhs_decl should depend on whether true/false have an effect
1961                         mark_decls_read(expr->conditional.condition, NULL);
1962                         if (expr->conditional.true_expression != NULL)
1963                                 mark_decls_read(expr->conditional.true_expression, lhs_decl);
1964                         mark_decls_read(expr->conditional.false_expression, lhs_decl);
1965                         return;
1966
1967                 case EXPR_SELECT:
1968                         if (lhs_decl == DECL_ANY && !is_type_compound(skip_typeref(expr->base.type)))
1969                                 lhs_decl = NULL;
1970                         mark_decls_read(expr->select.compound, lhs_decl);
1971                         return;
1972
1973                 case EXPR_ARRAY_ACCESS: {
1974                         expression_t *const ref = expr->array_access.array_ref;
1975                         mark_decls_read(ref, lhs_decl);
1976                         lhs_decl = determine_lhs_decl(ref, lhs_decl);
1977                         mark_decls_read(expr->array_access.index, lhs_decl);
1978                         return;
1979                 }
1980
1981                 case EXPR_VA_ARG:
1982                         mark_decls_read(expr->va_arge.ap, lhs_decl);
1983                         return;
1984
1985                 case EXPR_UNARY_CAST:
1986                         /* Special case: Use void cast to mark a variable as "read" */
1987                         if (is_type_atomic(skip_typeref(expr->base.type), ATOMIC_TYPE_VOID))
1988                                 lhs_decl = NULL;
1989                         goto unary;
1990
1991                 case EXPR_UNARY_DEREFERENCE:
1992                         if (lhs_decl == DECL_ANY)
1993                                 lhs_decl = NULL;
1994                         goto unary;
1995
1996                 case EXPR_UNARY_NEGATE:
1997                 case EXPR_UNARY_PLUS:
1998                 case EXPR_UNARY_BITWISE_NEGATE:
1999                 case EXPR_UNARY_NOT:
2000                 case EXPR_UNARY_TAKE_ADDRESS:
2001                 case EXPR_UNARY_POSTFIX_INCREMENT:
2002                 case EXPR_UNARY_POSTFIX_DECREMENT:
2003                 case EXPR_UNARY_PREFIX_INCREMENT:
2004                 case EXPR_UNARY_PREFIX_DECREMENT:
2005                 case EXPR_UNARY_CAST_IMPLICIT:
2006                 case EXPR_UNARY_ASSUME:
2007 unary:
2008                         mark_decls_read(expr->unary.value, lhs_decl);
2009                         return;
2010
2011                 case EXPR_BINARY_ADD:
2012                 case EXPR_BINARY_SUB:
2013                 case EXPR_BINARY_MUL:
2014                 case EXPR_BINARY_DIV:
2015                 case EXPR_BINARY_MOD:
2016                 case EXPR_BINARY_EQUAL:
2017                 case EXPR_BINARY_NOTEQUAL:
2018                 case EXPR_BINARY_LESS:
2019                 case EXPR_BINARY_LESSEQUAL:
2020                 case EXPR_BINARY_GREATER:
2021                 case EXPR_BINARY_GREATEREQUAL:
2022                 case EXPR_BINARY_BITWISE_AND:
2023                 case EXPR_BINARY_BITWISE_OR:
2024                 case EXPR_BINARY_BITWISE_XOR:
2025                 case EXPR_BINARY_LOGICAL_AND:
2026                 case EXPR_BINARY_LOGICAL_OR:
2027                 case EXPR_BINARY_SHIFTLEFT:
2028                 case EXPR_BINARY_SHIFTRIGHT:
2029                 case EXPR_BINARY_COMMA:
2030                 case EXPR_BINARY_ISGREATER:
2031                 case EXPR_BINARY_ISGREATEREQUAL:
2032                 case EXPR_BINARY_ISLESS:
2033                 case EXPR_BINARY_ISLESSEQUAL:
2034                 case EXPR_BINARY_ISLESSGREATER:
2035                 case EXPR_BINARY_ISUNORDERED:
2036                         mark_decls_read(expr->binary.left,  lhs_decl);
2037                         mark_decls_read(expr->binary.right, lhs_decl);
2038                         return;
2039
2040                 case EXPR_BINARY_ASSIGN:
2041                 case EXPR_BINARY_MUL_ASSIGN:
2042                 case EXPR_BINARY_DIV_ASSIGN:
2043                 case EXPR_BINARY_MOD_ASSIGN:
2044                 case EXPR_BINARY_ADD_ASSIGN:
2045                 case EXPR_BINARY_SUB_ASSIGN:
2046                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:
2047                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:
2048                 case EXPR_BINARY_BITWISE_AND_ASSIGN:
2049                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:
2050                 case EXPR_BINARY_BITWISE_OR_ASSIGN: {
2051                         if (lhs_decl == DECL_ANY)
2052                                 lhs_decl = NULL;
2053                         lhs_decl = determine_lhs_decl(expr->binary.left, lhs_decl);
2054                         mark_decls_read(expr->binary.right, lhs_decl);
2055                         return;
2056                 }
2057
2058                 case EXPR_VA_START:
2059                         determine_lhs_decl(expr->va_starte.ap, lhs_decl);
2060                         return;
2061
2062                 case EXPR_UNKNOWN:
2063                 case EXPR_INVALID:
2064                 case EXPR_CONST:
2065                 case EXPR_CHARACTER_CONSTANT:
2066                 case EXPR_WIDE_CHARACTER_CONSTANT:
2067                 case EXPR_STRING_LITERAL:
2068                 case EXPR_WIDE_STRING_LITERAL:
2069                 case EXPR_COMPOUND_LITERAL: // TODO init?
2070                 case EXPR_SIZEOF:
2071                 case EXPR_CLASSIFY_TYPE:
2072                 case EXPR_ALIGNOF:
2073                 case EXPR_FUNCNAME:
2074                 case EXPR_BUILTIN_SYMBOL:
2075                 case EXPR_BUILTIN_CONSTANT_P:
2076                 case EXPR_BUILTIN_PREFETCH:
2077                 case EXPR_OFFSETOF:
2078                 case EXPR_STATEMENT: // TODO
2079                 case EXPR_LABEL_ADDRESS:
2080                 case EXPR_BINARY_BUILTIN_EXPECT:
2081                         return;
2082         }
2083
2084         panic("unhandled expression");
2085 }
2086
2087 static designator_t *parse_designation(void)
2088 {
2089         designator_t *result = NULL;
2090         designator_t *last   = NULL;
2091
2092         while (true) {
2093                 designator_t *designator;
2094                 switch(token.type) {
2095                 case '[':
2096                         designator = allocate_ast_zero(sizeof(designator[0]));
2097                         designator->source_position = token.source_position;
2098                         next_token();
2099                         add_anchor_token(']');
2100                         designator->array_index = parse_constant_expression();
2101                         rem_anchor_token(']');
2102                         expect(']');
2103                         break;
2104                 case '.':
2105                         designator = allocate_ast_zero(sizeof(designator[0]));
2106                         designator->source_position = token.source_position;
2107                         next_token();
2108                         if (token.type != T_IDENTIFIER) {
2109                                 parse_error_expected("while parsing designator",
2110                                                      T_IDENTIFIER, NULL);
2111                                 return NULL;
2112                         }
2113                         designator->symbol = token.v.symbol;
2114                         next_token();
2115                         break;
2116                 default:
2117                         expect('=');
2118                         return result;
2119                 }
2120
2121                 assert(designator != NULL);
2122                 if (last != NULL) {
2123                         last->next = designator;
2124                 } else {
2125                         result = designator;
2126                 }
2127                 last = designator;
2128         }
2129 end_error:
2130         return NULL;
2131 }
2132
2133 static initializer_t *initializer_from_string(array_type_t *type,
2134                                               const string_t *const string)
2135 {
2136         /* TODO: check len vs. size of array type */
2137         (void) type;
2138
2139         initializer_t *initializer = allocate_initializer_zero(INITIALIZER_STRING);
2140         initializer->string.string = *string;
2141
2142         return initializer;
2143 }
2144
2145 static initializer_t *initializer_from_wide_string(array_type_t *const type,
2146                                                    wide_string_t *const string)
2147 {
2148         /* TODO: check len vs. size of array type */
2149         (void) type;
2150
2151         initializer_t *const initializer =
2152                 allocate_initializer_zero(INITIALIZER_WIDE_STRING);
2153         initializer->wide_string.string = *string;
2154
2155         return initializer;
2156 }
2157
2158 /**
2159  * Build an initializer from a given expression.
2160  */
2161 static initializer_t *initializer_from_expression(type_t *orig_type,
2162                                                   expression_t *expression)
2163 {
2164         /* TODO check that expression is a constant expression */
2165
2166         /* § 6.7.8.14/15 char array may be initialized by string literals */
2167         type_t *type           = skip_typeref(orig_type);
2168         type_t *expr_type_orig = expression->base.type;
2169         type_t *expr_type      = skip_typeref(expr_type_orig);
2170         if (is_type_array(type) && expr_type->kind == TYPE_POINTER) {
2171                 array_type_t *const array_type   = &type->array;
2172                 type_t       *const element_type = skip_typeref(array_type->element_type);
2173
2174                 if (element_type->kind == TYPE_ATOMIC) {
2175                         atomic_type_kind_t akind = element_type->atomic.akind;
2176                         switch (expression->kind) {
2177                                 case EXPR_STRING_LITERAL:
2178                                         if (akind == ATOMIC_TYPE_CHAR
2179                                                         || akind == ATOMIC_TYPE_SCHAR
2180                                                         || akind == ATOMIC_TYPE_UCHAR) {
2181                                                 return initializer_from_string(array_type,
2182                                                         &expression->string.value);
2183                                         }
2184
2185                                 case EXPR_WIDE_STRING_LITERAL: {
2186                                         type_t *bare_wchar_type = skip_typeref(type_wchar_t);
2187                                         if (get_unqualified_type(element_type) == bare_wchar_type) {
2188                                                 return initializer_from_wide_string(array_type,
2189                                                         &expression->wide_string.value);
2190                                         }
2191                                 }
2192
2193                                 default:
2194                                         break;
2195                         }
2196                 }
2197         }
2198
2199         assign_error_t error = semantic_assign(type, expression);
2200         if (error == ASSIGN_ERROR_INCOMPATIBLE)
2201                 return NULL;
2202         report_assign_error(error, type, expression, "initializer",
2203                             &expression->base.source_position);
2204
2205         initializer_t *const result = allocate_initializer_zero(INITIALIZER_VALUE);
2206 #if 0
2207         if (type->kind == TYPE_BITFIELD) {
2208                 type = type->bitfield.base_type;
2209         }
2210 #endif
2211         result->value.value = create_implicit_cast(expression, type);
2212
2213         return result;
2214 }
2215
2216 /**
2217  * Checks if a given expression can be used as an constant initializer.
2218  */
2219 static bool is_initializer_constant(const expression_t *expression)
2220 {
2221         return is_constant_expression(expression)
2222                 || is_address_constant(expression);
2223 }
2224
2225 /**
2226  * Parses an scalar initializer.
2227  *
2228  * § 6.7.8.11; eat {} without warning
2229  */
2230 static initializer_t *parse_scalar_initializer(type_t *type,
2231                                                bool must_be_constant)
2232 {
2233         /* there might be extra {} hierarchies */
2234         int braces = 0;
2235         if (token.type == '{') {
2236                 if (warning.other)
2237                         warningf(HERE, "extra curly braces around scalar initializer");
2238                 do {
2239                         ++braces;
2240                         next_token();
2241                 } while (token.type == '{');
2242         }
2243
2244         expression_t *expression = parse_assignment_expression();
2245         mark_decls_read(expression, NULL);
2246         if (must_be_constant && !is_initializer_constant(expression)) {
2247                 errorf(&expression->base.source_position,
2248                        "Initialisation expression '%E' is not constant\n",
2249                        expression);
2250         }
2251
2252         initializer_t *initializer = initializer_from_expression(type, expression);
2253
2254         if (initializer == NULL) {
2255                 errorf(&expression->base.source_position,
2256                        "expression '%E' (type '%T') doesn't match expected type '%T'",
2257                        expression, expression->base.type, type);
2258                 /* TODO */
2259                 return NULL;
2260         }
2261
2262         bool additional_warning_displayed = false;
2263         while (braces > 0) {
2264                 if (token.type == ',') {
2265                         next_token();
2266                 }
2267                 if (token.type != '}') {
2268                         if (!additional_warning_displayed && warning.other) {
2269                                 warningf(HERE, "additional elements in scalar initializer");
2270                                 additional_warning_displayed = true;
2271                         }
2272                 }
2273                 eat_block();
2274                 braces--;
2275         }
2276
2277         return initializer;
2278 }
2279
2280 /**
2281  * An entry in the type path.
2282  */
2283 typedef struct type_path_entry_t type_path_entry_t;
2284 struct type_path_entry_t {
2285         type_t *type;       /**< the upper top type. restored to path->top_tye if this entry is popped. */
2286         union {
2287                 size_t         index;          /**< For array types: the current index. */
2288                 declaration_t *compound_entry; /**< For compound types: the current declaration. */
2289         } v;
2290 };
2291
2292 /**
2293  * A type path expression a position inside compound or array types.
2294  */
2295 typedef struct type_path_t type_path_t;
2296 struct type_path_t {
2297         type_path_entry_t *path;         /**< An flexible array containing the current path. */
2298         type_t            *top_type;     /**< type of the element the path points */
2299         size_t             max_index;    /**< largest index in outermost array */
2300 };
2301
2302 /**
2303  * Prints a type path for debugging.
2304  */
2305 static __attribute__((unused)) void debug_print_type_path(
2306                 const type_path_t *path)
2307 {
2308         size_t len = ARR_LEN(path->path);
2309
2310         for(size_t i = 0; i < len; ++i) {
2311                 const type_path_entry_t *entry = & path->path[i];
2312
2313                 type_t *type = skip_typeref(entry->type);
2314                 if (is_type_compound(type)) {
2315                         /* in gcc mode structs can have no members */
2316                         if (entry->v.compound_entry == NULL) {
2317                                 assert(i == len-1);
2318                                 continue;
2319                         }
2320                         fprintf(stderr, ".%s", entry->v.compound_entry->symbol->string);
2321                 } else if (is_type_array(type)) {
2322                         fprintf(stderr, "[%zu]", entry->v.index);
2323                 } else {
2324                         fprintf(stderr, "-INVALID-");
2325                 }
2326         }
2327         if (path->top_type != NULL) {
2328                 fprintf(stderr, "  (");
2329                 print_type(path->top_type);
2330                 fprintf(stderr, ")");
2331         }
2332 }
2333
2334 /**
2335  * Return the top type path entry, ie. in a path
2336  * (type).a.b returns the b.
2337  */
2338 static type_path_entry_t *get_type_path_top(const type_path_t *path)
2339 {
2340         size_t len = ARR_LEN(path->path);
2341         assert(len > 0);
2342         return &path->path[len-1];
2343 }
2344
2345 /**
2346  * Enlarge the type path by an (empty) element.
2347  */
2348 static type_path_entry_t *append_to_type_path(type_path_t *path)
2349 {
2350         size_t len = ARR_LEN(path->path);
2351         ARR_RESIZE(type_path_entry_t, path->path, len+1);
2352
2353         type_path_entry_t *result = & path->path[len];
2354         memset(result, 0, sizeof(result[0]));
2355         return result;
2356 }
2357
2358 /**
2359  * Descending into a sub-type. Enter the scope of the current
2360  * top_type.
2361  */
2362 static void descend_into_subtype(type_path_t *path)
2363 {
2364         type_t *orig_top_type = path->top_type;
2365         type_t *top_type      = skip_typeref(orig_top_type);
2366
2367         type_path_entry_t *top = append_to_type_path(path);
2368         top->type              = top_type;
2369
2370         if (is_type_compound(top_type)) {
2371                 declaration_t *declaration = top_type->compound.declaration;
2372                 declaration_t *entry       = declaration->scope.declarations;
2373                 top->v.compound_entry      = entry;
2374
2375                 if (entry != NULL) {
2376                         path->top_type         = entry->type;
2377                 } else {
2378                         path->top_type         = NULL;
2379                 }
2380         } else if (is_type_array(top_type)) {
2381                 top->v.index   = 0;
2382                 path->top_type = top_type->array.element_type;
2383         } else {
2384                 assert(!is_type_valid(top_type));
2385         }
2386 }
2387
2388 /**
2389  * Pop an entry from the given type path, ie. returning from
2390  * (type).a.b to (type).a
2391  */
2392 static void ascend_from_subtype(type_path_t *path)
2393 {
2394         type_path_entry_t *top = get_type_path_top(path);
2395
2396         path->top_type = top->type;
2397
2398         size_t len = ARR_LEN(path->path);
2399         ARR_RESIZE(type_path_entry_t, path->path, len-1);
2400 }
2401
2402 /**
2403  * Pop entries from the given type path until the given
2404  * path level is reached.
2405  */
2406 static void ascend_to(type_path_t *path, size_t top_path_level)
2407 {
2408         size_t len = ARR_LEN(path->path);
2409
2410         while (len > top_path_level) {
2411                 ascend_from_subtype(path);
2412                 len = ARR_LEN(path->path);
2413         }
2414 }
2415
2416 static bool walk_designator(type_path_t *path, const designator_t *designator,
2417                             bool used_in_offsetof)
2418 {
2419         for( ; designator != NULL; designator = designator->next) {
2420                 type_path_entry_t *top       = get_type_path_top(path);
2421                 type_t            *orig_type = top->type;
2422
2423                 type_t *type = skip_typeref(orig_type);
2424
2425                 if (designator->symbol != NULL) {
2426                         symbol_t *symbol = designator->symbol;
2427                         if (!is_type_compound(type)) {
2428                                 if (is_type_valid(type)) {
2429                                         errorf(&designator->source_position,
2430                                                "'.%Y' designator used for non-compound type '%T'",
2431                                                symbol, orig_type);
2432                                 }
2433
2434                                 top->type             = type_error_type;
2435                                 top->v.compound_entry = NULL;
2436                                 orig_type             = type_error_type;
2437                         } else {
2438                                 declaration_t *declaration = type->compound.declaration;
2439                                 declaration_t *iter        = declaration->scope.declarations;
2440                                 for( ; iter != NULL; iter = iter->next) {
2441                                         if (iter->symbol == symbol) {
2442                                                 break;
2443                                         }
2444                                 }
2445                                 if (iter == NULL) {
2446                                         errorf(&designator->source_position,
2447                                                "'%T' has no member named '%Y'", orig_type, symbol);
2448                                         goto failed;
2449                                 }
2450                                 if (used_in_offsetof) {
2451                                         type_t *real_type = skip_typeref(iter->type);
2452                                         if (real_type->kind == TYPE_BITFIELD) {
2453                                                 errorf(&designator->source_position,
2454                                                        "offsetof designator '%Y' may not specify bitfield",
2455                                                        symbol);
2456                                                 goto failed;
2457                                         }
2458                                 }
2459
2460                                 top->type             = orig_type;
2461                                 top->v.compound_entry = iter;
2462                                 orig_type             = iter->type;
2463                         }
2464                 } else {
2465                         expression_t *array_index = designator->array_index;
2466                         assert(designator->array_index != NULL);
2467
2468                         if (!is_type_array(type)) {
2469                                 if (is_type_valid(type)) {
2470                                         errorf(&designator->source_position,
2471                                                "[%E] designator used for non-array type '%T'",
2472                                                array_index, orig_type);
2473                                 }
2474                                 goto failed;
2475                         }
2476
2477                         long index = fold_constant(array_index);
2478                         if (!used_in_offsetof) {
2479                                 if (index < 0) {
2480                                         errorf(&designator->source_position,
2481                                                "array index [%E] must be positive", array_index);
2482                                 } else if (type->array.size_constant) {
2483                                         long array_size = type->array.size;
2484                                         if (index >= array_size) {
2485                                                 errorf(&designator->source_position,
2486                                                        "designator [%E] (%d) exceeds array size %d",
2487                                                        array_index, index, array_size);
2488                                         }
2489                                 }
2490                         }
2491
2492                         top->type    = orig_type;
2493                         top->v.index = (size_t) index;
2494                         orig_type    = type->array.element_type;
2495                 }
2496                 path->top_type = orig_type;
2497
2498                 if (designator->next != NULL) {
2499                         descend_into_subtype(path);
2500                 }
2501         }
2502         return true;
2503
2504 failed:
2505         return false;
2506 }
2507
2508 static void advance_current_object(type_path_t *path, size_t top_path_level)
2509 {
2510         type_path_entry_t *top = get_type_path_top(path);
2511
2512         type_t *type = skip_typeref(top->type);
2513         if (is_type_union(type)) {
2514                 /* in unions only the first element is initialized */
2515                 top->v.compound_entry = NULL;
2516         } else if (is_type_struct(type)) {
2517                 declaration_t *entry = top->v.compound_entry;
2518
2519                 entry                 = entry->next;
2520                 top->v.compound_entry = entry;
2521                 if (entry != NULL) {
2522                         path->top_type = entry->type;
2523                         return;
2524                 }
2525         } else if (is_type_array(type)) {
2526                 assert(is_type_array(type));
2527
2528                 top->v.index++;
2529
2530                 if (!type->array.size_constant || top->v.index < type->array.size) {
2531                         return;
2532                 }
2533         } else {
2534                 assert(!is_type_valid(type));
2535                 return;
2536         }
2537
2538         /* we're past the last member of the current sub-aggregate, try if we
2539          * can ascend in the type hierarchy and continue with another subobject */
2540         size_t len = ARR_LEN(path->path);
2541
2542         if (len > top_path_level) {
2543                 ascend_from_subtype(path);
2544                 advance_current_object(path, top_path_level);
2545         } else {
2546                 path->top_type = NULL;
2547         }
2548 }
2549
2550 /**
2551  * skip until token is found.
2552  */
2553 static void skip_until(int type)
2554 {
2555         while (token.type != type) {
2556                 if (token.type == T_EOF)
2557                         return;
2558                 next_token();
2559         }
2560 }
2561
2562 /**
2563  * skip any {...} blocks until a closing bracket is reached.
2564  */
2565 static void skip_initializers(void)
2566 {
2567         if (token.type == '{')
2568                 next_token();
2569
2570         while (token.type != '}') {
2571                 if (token.type == T_EOF)
2572                         return;
2573                 if (token.type == '{') {
2574                         eat_block();
2575                         continue;
2576                 }
2577                 next_token();
2578         }
2579 }
2580
2581 static initializer_t *create_empty_initializer(void)
2582 {
2583         static initializer_t empty_initializer
2584                 = { .list = { { INITIALIZER_LIST }, 0 } };
2585         return &empty_initializer;
2586 }
2587
2588 /**
2589  * Parse a part of an initialiser for a struct or union,
2590  */
2591 static initializer_t *parse_sub_initializer(type_path_t *path,
2592                 type_t *outer_type, size_t top_path_level,
2593                 parse_initializer_env_t *env)
2594 {
2595         if (token.type == '}') {
2596                 /* empty initializer */
2597                 return create_empty_initializer();
2598         }
2599
2600         type_t *orig_type = path->top_type;
2601         type_t *type      = NULL;
2602
2603         if (orig_type == NULL) {
2604                 /* We are initializing an empty compound. */
2605         } else {
2606                 type = skip_typeref(orig_type);
2607         }
2608
2609         initializer_t **initializers = NEW_ARR_F(initializer_t*, 0);
2610
2611         while (true) {
2612                 designator_t *designator = NULL;
2613                 if (token.type == '.' || token.type == '[') {
2614                         designator = parse_designation();
2615                         goto finish_designator;
2616                 } else if (token.type == T_IDENTIFIER && look_ahead(1)->type == ':') {
2617                         /* GNU-style designator ("identifier: value") */
2618                         designator = allocate_ast_zero(sizeof(designator[0]));
2619                         designator->source_position = token.source_position;
2620                         designator->symbol          = token.v.symbol;
2621                         eat(T_IDENTIFIER);
2622                         eat(':');
2623
2624 finish_designator:
2625                         /* reset path to toplevel, evaluate designator from there */
2626                         ascend_to(path, top_path_level);
2627                         if (!walk_designator(path, designator, false)) {
2628                                 /* can't continue after designation error */
2629                                 goto end_error;
2630                         }
2631
2632                         initializer_t *designator_initializer
2633                                 = allocate_initializer_zero(INITIALIZER_DESIGNATOR);
2634                         designator_initializer->designator.designator = designator;
2635                         ARR_APP1(initializer_t*, initializers, designator_initializer);
2636
2637                         orig_type = path->top_type;
2638                         type      = orig_type != NULL ? skip_typeref(orig_type) : NULL;
2639                 }
2640
2641                 initializer_t *sub;
2642
2643                 if (token.type == '{') {
2644                         if (type != NULL && is_type_scalar(type)) {
2645                                 sub = parse_scalar_initializer(type, env->must_be_constant);
2646                         } else {
2647                                 eat('{');
2648                                 if (type == NULL) {
2649                                         if (env->declaration != NULL) {
2650                                                 errorf(HERE, "extra brace group at end of initializer for '%Y'",
2651                                                        env->declaration->symbol);
2652                                         } else {
2653                                                 errorf(HERE, "extra brace group at end of initializer");
2654                                         }
2655                                 } else
2656                                         descend_into_subtype(path);
2657
2658                                 add_anchor_token('}');
2659                                 sub = parse_sub_initializer(path, orig_type, top_path_level+1,
2660                                                             env);
2661                                 rem_anchor_token('}');
2662
2663                                 if (type != NULL) {
2664                                         ascend_from_subtype(path);
2665                                         expect('}');
2666                                 } else {
2667                                         expect('}');
2668                                         goto error_parse_next;
2669                                 }
2670                         }
2671                 } else {
2672                         /* must be an expression */
2673                         expression_t *expression = parse_assignment_expression();
2674
2675                         if (env->must_be_constant && !is_initializer_constant(expression)) {
2676                                 errorf(&expression->base.source_position,
2677                                        "Initialisation expression '%E' is not constant\n",
2678                                        expression);
2679                         }
2680
2681                         if (type == NULL) {
2682                                 /* we are already outside, ... */
2683                                 type_t *const outer_type_skip = skip_typeref(outer_type);
2684                                 if (is_type_compound(outer_type_skip) &&
2685                                     !outer_type_skip->compound.declaration->init.complete) {
2686                                         goto error_parse_next;
2687                                 }
2688                                 goto error_excess;
2689                         }
2690
2691                         /* handle { "string" } special case */
2692                         if ((expression->kind == EXPR_STRING_LITERAL
2693                                         || expression->kind == EXPR_WIDE_STRING_LITERAL)
2694                                         && outer_type != NULL) {
2695                                 sub = initializer_from_expression(outer_type, expression);
2696                                 if (sub != NULL) {
2697                                         if (token.type == ',') {
2698                                                 next_token();
2699                                         }
2700                                         if (token.type != '}' && warning.other) {
2701                                                 warningf(HERE, "excessive elements in initializer for type '%T'",
2702                                                                  orig_type);
2703                                         }
2704                                         /* TODO: eat , ... */
2705                                         return sub;
2706                                 }
2707                         }
2708
2709                         /* descend into subtypes until expression matches type */
2710                         while (true) {
2711                                 orig_type = path->top_type;
2712                                 type      = skip_typeref(orig_type);
2713
2714                                 sub = initializer_from_expression(orig_type, expression);
2715                                 if (sub != NULL) {
2716                                         break;
2717                                 }
2718                                 if (!is_type_valid(type)) {
2719                                         goto end_error;
2720                                 }
2721                                 if (is_type_scalar(type)) {
2722                                         errorf(&expression->base.source_position,
2723                                                         "expression '%E' doesn't match expected type '%T'",
2724                                                         expression, orig_type);
2725                                         goto end_error;
2726                                 }
2727
2728                                 descend_into_subtype(path);
2729                         }
2730                 }
2731
2732                 /* update largest index of top array */
2733                 const type_path_entry_t *first      = &path->path[0];
2734                 type_t                  *first_type = first->type;
2735                 first_type                          = skip_typeref(first_type);
2736                 if (is_type_array(first_type)) {
2737                         size_t index = first->v.index;
2738                         if (index > path->max_index)
2739                                 path->max_index = index;
2740                 }
2741
2742                 if (type != NULL) {
2743                         /* append to initializers list */
2744                         ARR_APP1(initializer_t*, initializers, sub);
2745                 } else {
2746 error_excess:
2747                         if (warning.other) {
2748                                 if (env->declaration != NULL) {
2749                                         warningf(HERE, "excess elements in struct initializer for '%Y'",
2750                                            env->declaration->symbol);
2751                                 } else {
2752                                         warningf(HERE, "excess elements in struct initializer");
2753                                 }
2754                         }
2755                 }
2756
2757 error_parse_next:
2758                 if (token.type == '}') {
2759                         break;
2760                 }
2761                 expect(',');
2762                 if (token.type == '}') {
2763                         break;
2764                 }
2765
2766                 if (type != NULL) {
2767                         /* advance to the next declaration if we are not at the end */
2768                         advance_current_object(path, top_path_level);
2769                         orig_type = path->top_type;
2770                         if (orig_type != NULL)
2771                                 type = skip_typeref(orig_type);
2772                         else
2773                                 type = NULL;
2774                 }
2775         }
2776
2777         size_t len  = ARR_LEN(initializers);
2778         size_t size = sizeof(initializer_list_t) + len * sizeof(initializers[0]);
2779         initializer_t *result = allocate_ast_zero(size);
2780         result->kind          = INITIALIZER_LIST;
2781         result->list.len      = len;
2782         memcpy(&result->list.initializers, initializers,
2783                len * sizeof(initializers[0]));
2784
2785         DEL_ARR_F(initializers);
2786         ascend_to(path, top_path_level+1);
2787
2788         return result;
2789
2790 end_error:
2791         skip_initializers();
2792         DEL_ARR_F(initializers);
2793         ascend_to(path, top_path_level+1);
2794         return NULL;
2795 }
2796
2797 /**
2798  * Parses an initializer. Parsers either a compound literal
2799  * (env->declaration == NULL) or an initializer of a declaration.
2800  */
2801 static initializer_t *parse_initializer(parse_initializer_env_t *env)
2802 {
2803         type_t        *type   = skip_typeref(env->type);
2804         initializer_t *result = NULL;
2805         size_t         max_index;
2806
2807         if (is_type_scalar(type)) {
2808                 result = parse_scalar_initializer(type, env->must_be_constant);
2809         } else if (token.type == '{') {
2810                 eat('{');
2811
2812                 type_path_t path;
2813                 memset(&path, 0, sizeof(path));
2814                 path.top_type = env->type;
2815                 path.path     = NEW_ARR_F(type_path_entry_t, 0);
2816
2817                 descend_into_subtype(&path);
2818
2819                 add_anchor_token('}');
2820                 result = parse_sub_initializer(&path, env->type, 1, env);
2821                 rem_anchor_token('}');
2822
2823                 max_index = path.max_index;
2824                 DEL_ARR_F(path.path);
2825
2826                 expect('}');
2827         } else {
2828                 /* parse_scalar_initializer() also works in this case: we simply
2829                  * have an expression without {} around it */
2830                 result = parse_scalar_initializer(type, env->must_be_constant);
2831         }
2832
2833         /* § 6.7.5 (22)  array initializers for arrays with unknown size determine
2834          * the array type size */
2835         if (is_type_array(type) && type->array.size_expression == NULL
2836                         && result != NULL) {
2837                 size_t size;
2838                 switch (result->kind) {
2839                 case INITIALIZER_LIST:
2840                         size = max_index + 1;
2841                         break;
2842
2843                 case INITIALIZER_STRING:
2844                         size = result->string.string.size;
2845                         break;
2846
2847                 case INITIALIZER_WIDE_STRING:
2848                         size = result->wide_string.string.size;
2849                         break;
2850
2851                 case INITIALIZER_DESIGNATOR:
2852                 case INITIALIZER_VALUE:
2853                         /* can happen for parse errors */
2854                         size = 0;
2855                         break;
2856
2857                 default:
2858                         internal_errorf(HERE, "invalid initializer type");
2859                 }
2860
2861                 expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
2862                 cnst->base.type          = type_size_t;
2863                 cnst->conste.v.int_value = size;
2864
2865                 type_t *new_type = duplicate_type(type);
2866
2867                 new_type->array.size_expression = cnst;
2868                 new_type->array.size_constant   = true;
2869                 new_type->array.size            = size;
2870                 env->type = new_type;
2871         }
2872
2873         return result;
2874 end_error:
2875         return NULL;
2876 }
2877
2878 static declaration_t *append_declaration(declaration_t *declaration);
2879
2880 static declaration_t *parse_compound_type_specifier(bool is_struct)
2881 {
2882         gnu_attribute_t  *attributes = NULL;
2883         decl_modifiers_t  modifiers  = 0;
2884         if (is_struct) {
2885                 eat(T_struct);
2886         } else {
2887                 eat(T_union);
2888         }
2889
2890         symbol_t      *symbol      = NULL;
2891         declaration_t *declaration = NULL;
2892
2893         if (token.type == T___attribute__) {
2894                 modifiers |= parse_attributes(&attributes);
2895         }
2896
2897         if (token.type == T_IDENTIFIER) {
2898                 symbol = token.v.symbol;
2899                 next_token();
2900
2901                 namespace_t const namespc =
2902                         is_struct ? NAMESPACE_STRUCT : NAMESPACE_UNION;
2903                 declaration = get_declaration(symbol, namespc);
2904                 if (declaration != NULL) {
2905                         if (declaration->parent_scope != scope &&
2906                             (token.type == '{' || token.type == ';')) {
2907                                 declaration = NULL;
2908                         } else if (declaration->init.complete &&
2909                                    token.type == '{') {
2910                                 assert(symbol != NULL);
2911                                 errorf(HERE, "multiple definitions of '%s %Y' (previous definition at %P)",
2912                                        is_struct ? "struct" : "union", symbol,
2913                                        &declaration->source_position);
2914                                 declaration->scope.declarations = NULL;
2915                         }
2916                 }
2917         } else if (token.type != '{') {
2918                 if (is_struct) {
2919                         parse_error_expected("while parsing struct type specifier",
2920                                              T_IDENTIFIER, '{', NULL);
2921                 } else {
2922                         parse_error_expected("while parsing union type specifier",
2923                                              T_IDENTIFIER, '{', NULL);
2924                 }
2925
2926                 return NULL;
2927         }
2928
2929         if (declaration == NULL) {
2930                 declaration = allocate_declaration_zero();
2931                 declaration->namespc         =
2932                         (is_struct ? NAMESPACE_STRUCT : NAMESPACE_UNION);
2933                 declaration->source_position = token.source_position;
2934                 declaration->symbol          = symbol;
2935                 declaration->parent_scope    = scope;
2936                 if (symbol != NULL) {
2937                         environment_push(declaration);
2938                 }
2939                 append_declaration(declaration);
2940         }
2941
2942         if (token.type == '{') {
2943                 declaration->init.complete = true;
2944
2945                 parse_compound_type_entries(declaration);
2946                 modifiers |= parse_attributes(&attributes);
2947         }
2948
2949         declaration->modifiers |= modifiers;
2950         return declaration;
2951 }
2952
2953 static void parse_enum_entries(type_t *const enum_type)
2954 {
2955         eat('{');
2956
2957         if (token.type == '}') {
2958                 next_token();
2959                 errorf(HERE, "empty enum not allowed");
2960                 return;
2961         }
2962
2963         add_anchor_token('}');
2964         do {
2965                 if (token.type != T_IDENTIFIER) {
2966                         parse_error_expected("while parsing enum entry", T_IDENTIFIER, NULL);
2967                         eat_block();
2968                         rem_anchor_token('}');
2969                         return;
2970                 }
2971
2972                 declaration_t *const entry = allocate_declaration_zero();
2973                 entry->storage_class   = STORAGE_CLASS_ENUM_ENTRY;
2974                 entry->type            = enum_type;
2975                 entry->symbol          = token.v.symbol;
2976                 entry->source_position = token.source_position;
2977                 next_token();
2978
2979                 if (token.type == '=') {
2980                         next_token();
2981                         expression_t *value = parse_constant_expression();
2982
2983                         value = create_implicit_cast(value, enum_type);
2984                         entry->init.enum_value = value;
2985
2986                         /* TODO semantic */
2987                 }
2988
2989                 record_declaration(entry, false);
2990
2991                 if (token.type != ',')
2992                         break;
2993                 next_token();
2994         } while (token.type != '}');
2995         rem_anchor_token('}');
2996
2997         expect('}');
2998
2999 end_error:
3000         ;
3001 }
3002
3003 static type_t *parse_enum_specifier(void)
3004 {
3005         gnu_attribute_t *attributes = NULL;
3006         declaration_t   *declaration;
3007         symbol_t        *symbol;
3008
3009         eat(T_enum);
3010         if (token.type == T_IDENTIFIER) {
3011                 symbol = token.v.symbol;
3012                 next_token();
3013
3014                 declaration = get_declaration(symbol, NAMESPACE_ENUM);
3015         } else if (token.type != '{') {
3016                 parse_error_expected("while parsing enum type specifier",
3017                                      T_IDENTIFIER, '{', NULL);
3018                 return NULL;
3019         } else {
3020                 declaration = NULL;
3021                 symbol      = NULL;
3022         }
3023
3024         if (declaration == NULL) {
3025                 declaration = allocate_declaration_zero();
3026                 declaration->namespc         = NAMESPACE_ENUM;
3027                 declaration->source_position = token.source_position;
3028                 declaration->symbol          = symbol;
3029                 declaration->parent_scope  = scope;
3030         }
3031
3032         type_t *const type      = allocate_type_zero(TYPE_ENUM);
3033         type->enumt.declaration = declaration;
3034
3035         if (token.type == '{') {
3036                 if (declaration->init.complete) {
3037                         errorf(HERE, "multiple definitions of enum %Y", symbol);
3038                 }
3039                 if (symbol != NULL) {
3040                         environment_push(declaration);
3041                 }
3042                 append_declaration(declaration);
3043                 declaration->init.complete = true;
3044
3045                 parse_enum_entries(type);
3046                 parse_attributes(&attributes);
3047         }
3048
3049         return type;
3050 }
3051
3052 /**
3053  * if a symbol is a typedef to another type, return true
3054  */
3055 static bool is_typedef_symbol(symbol_t *symbol)
3056 {
3057         const declaration_t *const declaration =
3058                 get_declaration(symbol, NAMESPACE_NORMAL);
3059         return
3060                 declaration != NULL &&
3061                 declaration->storage_class == STORAGE_CLASS_TYPEDEF;
3062 }
3063
3064 static type_t *parse_typeof(void)
3065 {
3066         eat(T___typeof__);
3067
3068         type_t *type;
3069
3070         expect('(');
3071         add_anchor_token(')');
3072
3073         expression_t *expression  = NULL;
3074
3075         bool old_type_prop     = in_type_prop;
3076         bool old_gcc_extension = in_gcc_extension;
3077         in_type_prop           = true;
3078
3079         while (token.type == T___extension__) {
3080                 /* This can be a prefix to a typename or an expression. */
3081                 next_token();
3082                 in_gcc_extension = true;
3083         }
3084         switch (token.type) {
3085         case T_IDENTIFIER:
3086                 if (is_typedef_symbol(token.v.symbol)) {
3087                         type = parse_typename();
3088                 } else {
3089                         expression = parse_expression();
3090                         type       = expression->base.type;
3091                 }
3092                 break;
3093
3094         TYPENAME_START
3095                 type = parse_typename();
3096                 break;
3097
3098         default:
3099                 expression = parse_expression();
3100                 type       = expression->base.type;
3101                 break;
3102         }
3103         in_type_prop     = old_type_prop;
3104         in_gcc_extension = old_gcc_extension;
3105
3106         rem_anchor_token(')');
3107         expect(')');
3108
3109         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF);
3110         typeof_type->typeoft.expression  = expression;
3111         typeof_type->typeoft.typeof_type = type;
3112
3113         return typeof_type;
3114 end_error:
3115         return NULL;
3116 }
3117
3118 typedef enum specifiers_t {
3119         SPECIFIER_SIGNED    = 1 << 0,
3120         SPECIFIER_UNSIGNED  = 1 << 1,
3121         SPECIFIER_LONG      = 1 << 2,
3122         SPECIFIER_INT       = 1 << 3,
3123         SPECIFIER_DOUBLE    = 1 << 4,
3124         SPECIFIER_CHAR      = 1 << 5,
3125         SPECIFIER_SHORT     = 1 << 6,
3126         SPECIFIER_LONG_LONG = 1 << 7,
3127         SPECIFIER_FLOAT     = 1 << 8,
3128         SPECIFIER_BOOL      = 1 << 9,
3129         SPECIFIER_VOID      = 1 << 10,
3130         SPECIFIER_INT8      = 1 << 11,
3131         SPECIFIER_INT16     = 1 << 12,
3132         SPECIFIER_INT32     = 1 << 13,
3133         SPECIFIER_INT64     = 1 << 14,
3134         SPECIFIER_INT128    = 1 << 15,
3135         SPECIFIER_COMPLEX   = 1 << 16,
3136         SPECIFIER_IMAGINARY = 1 << 17,
3137 } specifiers_t;
3138
3139 static type_t *create_builtin_type(symbol_t *const symbol,
3140                                    type_t *const real_type)
3141 {
3142         type_t *type            = allocate_type_zero(TYPE_BUILTIN);
3143         type->builtin.symbol    = symbol;
3144         type->builtin.real_type = real_type;
3145
3146         type_t *result = typehash_insert(type);
3147         if (type != result) {
3148                 free_type(type);
3149         }
3150
3151         return result;
3152 }
3153
3154 static type_t *get_typedef_type(symbol_t *symbol)
3155 {
3156         declaration_t *declaration = get_declaration(symbol, NAMESPACE_NORMAL);
3157         if (declaration == NULL ||
3158            declaration->storage_class != STORAGE_CLASS_TYPEDEF)
3159                 return NULL;
3160
3161         type_t *type               = allocate_type_zero(TYPE_TYPEDEF);
3162         type->typedeft.declaration = declaration;
3163
3164         return type;
3165 }
3166
3167 /**
3168  * check for the allowed MS alignment values.
3169  */
3170 static bool check_alignment_value(long long intvalue)
3171 {
3172         if (intvalue < 1 || intvalue > 8192) {
3173                 errorf(HERE, "illegal alignment value");
3174                 return false;
3175         }
3176         unsigned v = (unsigned)intvalue;
3177         for (unsigned i = 1; i <= 8192; i += i) {
3178                 if (i == v)
3179                         return true;
3180         }
3181         errorf(HERE, "alignment must be power of two");
3182         return false;
3183 }
3184
3185 #define DET_MOD(name, tag) do { \
3186         if (*modifiers & tag && warning.other) warningf(HERE, #name " used more than once"); \
3187         *modifiers |= tag; \
3188 } while (0)
3189
3190 static void parse_microsoft_extended_decl_modifier(declaration_specifiers_t *specifiers)
3191 {
3192         decl_modifiers_t *modifiers = &specifiers->modifiers;
3193
3194         while (true) {
3195                 if (token.type == T_restrict) {
3196                         next_token();
3197                         DET_MOD(restrict, DM_RESTRICT);
3198                         goto end_loop;
3199                 } else if (token.type != T_IDENTIFIER)
3200                         break;
3201                 symbol_t *symbol = token.v.symbol;
3202                 if (symbol == sym_align) {
3203                         next_token();
3204                         expect('(');
3205                         if (token.type != T_INTEGER)
3206                                 goto end_error;
3207                         if (check_alignment_value(token.v.intvalue)) {
3208                                 if (specifiers->alignment != 0 && warning.other)
3209                                         warningf(HERE, "align used more than once");
3210                                 specifiers->alignment = (unsigned char)token.v.intvalue;
3211                         }
3212                         next_token();
3213                         expect(')');
3214                 } else if (symbol == sym_allocate) {
3215                         next_token();
3216                         expect('(');
3217                         if (token.type != T_IDENTIFIER)
3218                                 goto end_error;
3219                         (void)token.v.symbol;
3220                         expect(')');
3221                 } else if (symbol == sym_dllimport) {
3222                         next_token();
3223                         DET_MOD(dllimport, DM_DLLIMPORT);
3224                 } else if (symbol == sym_dllexport) {
3225                         next_token();
3226                         DET_MOD(dllexport, DM_DLLEXPORT);
3227                 } else if (symbol == sym_thread) {
3228                         next_token();
3229                         DET_MOD(thread, DM_THREAD);
3230                 } else if (symbol == sym_naked) {
3231                         next_token();
3232                         DET_MOD(naked, DM_NAKED);
3233                 } else if (symbol == sym_noinline) {
3234                         next_token();
3235                         DET_MOD(noinline, DM_NOINLINE);
3236                 } else if (symbol == sym_noreturn) {
3237                         next_token();
3238                         DET_MOD(noreturn, DM_NORETURN);
3239                 } else if (symbol == sym_nothrow) {
3240                         next_token();
3241                         DET_MOD(nothrow, DM_NOTHROW);
3242                 } else if (symbol == sym_novtable) {
3243                         next_token();
3244                         DET_MOD(novtable, DM_NOVTABLE);
3245                 } else if (symbol == sym_property) {
3246                         next_token();
3247                         expect('(');
3248                         for (;;) {
3249                                 bool is_get = false;
3250                                 if (token.type != T_IDENTIFIER)
3251                                         goto end_error;
3252                                 if (token.v.symbol == sym_get) {
3253                                         is_get = true;
3254                                 } else if (token.v.symbol == sym_put) {
3255                                 } else {
3256                                         errorf(HERE, "Bad property name '%Y'", token.v.symbol);
3257                                         goto end_error;
3258                                 }
3259                                 next_token();
3260                                 expect('=');
3261                                 if (token.type != T_IDENTIFIER)
3262                                         goto end_error;
3263                                 if (is_get) {
3264                                         if (specifiers->get_property_sym != NULL) {
3265                                                 errorf(HERE, "get property name already specified");
3266                                         } else {
3267                                                 specifiers->get_property_sym = token.v.symbol;
3268                                         }
3269                                 } else {
3270                                         if (specifiers->put_property_sym != NULL) {
3271                                                 errorf(HERE, "put property name already specified");
3272                                         } else {
3273                                                 specifiers->put_property_sym = token.v.symbol;
3274                                         }
3275                                 }
3276                                 next_token();
3277                                 if (token.type == ',') {
3278                                         next_token();
3279                                         continue;
3280                                 }
3281                                 break;
3282                         }
3283                         expect(')');
3284                 } else if (symbol == sym_selectany) {
3285                         next_token();
3286                         DET_MOD(selectany, DM_SELECTANY);
3287                 } else if (symbol == sym_uuid) {
3288                         next_token();
3289                         expect('(');
3290                         if (token.type != T_STRING_LITERAL)
3291                                 goto end_error;
3292                         next_token();
3293                         expect(')');
3294                 } else if (symbol == sym_deprecated) {
3295                         next_token();
3296                         if (specifiers->deprecated != 0 && warning.other)
3297                                 warningf(HERE, "deprecated used more than once");
3298                         specifiers->deprecated = 1;
3299                         if (token.type == '(') {
3300                                 next_token();
3301                                 if (token.type == T_STRING_LITERAL) {
3302                                         specifiers->deprecated_string = token.v.string.begin;
3303                                         next_token();
3304                                 } else {
3305                                         errorf(HERE, "string literal expected");
3306                                 }
3307                                 expect(')');
3308                         }
3309                 } else if (symbol == sym_noalias) {
3310                         next_token();
3311                         DET_MOD(noalias, DM_NOALIAS);
3312                 } else {
3313                         if (warning.other)
3314                                 warningf(HERE, "Unknown modifier %Y ignored", token.v.symbol);
3315                         next_token();
3316                         if (token.type == '(')
3317                                 skip_until(')');
3318                 }
3319 end_loop:
3320                 if (token.type == ',')
3321                         next_token();
3322         }
3323 end_error:
3324         return;
3325 }
3326
3327 static declaration_t *create_error_declaration(symbol_t *symbol, storage_class_tag_t storage_class)
3328 {
3329         declaration_t *const decl    = allocate_declaration_zero();
3330         decl->source_position        = *HERE;
3331         decl->declared_storage_class = storage_class;
3332         decl->storage_class          =
3333                 storage_class != STORAGE_CLASS_NONE || scope == file_scope ?
3334                         storage_class : STORAGE_CLASS_AUTO;
3335         decl->symbol                 = symbol;
3336         decl->implicit               = true;
3337         record_declaration(decl, false);
3338         return decl;
3339 }
3340
3341 /**
3342  * Finish the construction of a struct type by calculating
3343  * its size, offsets, alignment.
3344  */
3345 static void finish_struct_type(compound_type_t *type) {
3346         if (type->declaration == NULL)
3347                 return;
3348         declaration_t *struct_decl = type->declaration;
3349         if (! struct_decl->init.complete)
3350                 return;
3351
3352         il_size_t      size           = 0;
3353         il_size_t      offset;
3354         il_alignment_t alignment      = 1;
3355         bool           need_pad       = false;
3356
3357         declaration_t *entry = struct_decl->scope.declarations;
3358         for (; entry != NULL; entry = entry->next) {
3359                 if (entry->namespc != NAMESPACE_NORMAL)
3360                         continue;
3361
3362                 type_t *m_type = skip_typeref(entry->type);
3363                 if (! is_type_valid(m_type)) {
3364                         /* simply ignore errors here */
3365                         continue;
3366                 }
3367                 il_alignment_t m_alignment = m_type->base.alignment;
3368                 if (m_alignment > alignment)
3369                         alignment = m_alignment;
3370
3371                 offset = (size + m_alignment - 1) & -m_alignment;
3372
3373                 if (offset > size)
3374                         need_pad = true;
3375                 entry->offset = offset;
3376                 size = offset + m_type->base.size;
3377         }
3378         if (type->base.alignment != 0) {
3379                 alignment = type->base.alignment;
3380         }
3381
3382         offset = (size + alignment - 1) & -alignment;
3383         if (offset > size)
3384                 need_pad = true;
3385
3386         if (warning.padded && need_pad) {
3387                 warningf(&struct_decl->source_position,
3388                         "'%#T' needs padding", type, struct_decl->symbol);
3389         }
3390         if (warning.packed && !need_pad) {
3391                 warningf(&struct_decl->source_position,
3392                         "superfluous packed attribute on '%#T'",
3393                         type, struct_decl->symbol);
3394         }
3395
3396         type->base.size      = offset;
3397         type->base.alignment = alignment;
3398 }
3399
3400 /**
3401  * Finish the construction of an union type by calculating
3402  * its size and alignment.
3403  */
3404 static void finish_union_type(compound_type_t *type) {
3405         if (type->declaration == NULL)
3406                 return;
3407         declaration_t *union_decl = type->declaration;
3408         if (! union_decl->init.complete)
3409                 return;
3410
3411         il_size_t      size      = 0;
3412         il_alignment_t alignment = 1;
3413
3414         declaration_t *entry = union_decl->scope.declarations;
3415         for (; entry != NULL; entry = entry->next) {
3416                 if (entry->namespc != NAMESPACE_NORMAL)
3417                         continue;
3418
3419                 type_t *m_type = skip_typeref(entry->type);
3420                 if (! is_type_valid(m_type))
3421                         continue;
3422
3423                 entry->offset = 0;
3424                 if (m_type->base.size > size)
3425                         size = m_type->base.size;
3426                 if (m_type->base.alignment > alignment)
3427                         alignment = m_type->base.alignment;
3428         }
3429         if (type->base.alignment != 0) {
3430                 alignment = type->base.alignment;
3431         }
3432         size = (size + alignment - 1) & -alignment;
3433         type->base.size      = size;
3434         type->base.alignment = alignment;
3435 }
3436
3437 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
3438 {
3439         type_t            *type              = NULL;
3440         type_qualifiers_t  qualifiers        = TYPE_QUALIFIER_NONE;
3441         type_modifiers_t   modifiers         = TYPE_MODIFIER_NONE;
3442         unsigned           type_specifiers   = 0;
3443         bool               newtype           = false;
3444         bool               saw_error         = false;
3445         bool               old_gcc_extension = in_gcc_extension;
3446
3447         specifiers->source_position = token.source_position;
3448
3449         while (true) {
3450                 specifiers->modifiers
3451                         |= parse_attributes(&specifiers->gnu_attributes);
3452                 if (specifiers->modifiers & DM_TRANSPARENT_UNION)
3453                         modifiers |= TYPE_MODIFIER_TRANSPARENT_UNION;
3454
3455                 switch (token.type) {
3456
3457                 /* storage class */
3458 #define MATCH_STORAGE_CLASS(token, class)                                  \
3459                 case token:                                                        \
3460                         if (specifiers->declared_storage_class != STORAGE_CLASS_NONE) { \
3461                                 errorf(HERE, "multiple storage classes in declaration specifiers"); \
3462                         }                                                              \
3463                         specifiers->declared_storage_class = class;                    \
3464                         next_token();                                                  \
3465                         break;
3466
3467                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
3468                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
3469                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
3470                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
3471                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
3472
3473                 case T__declspec:
3474                         next_token();
3475                         expect('(');
3476                         add_anchor_token(')');
3477                         parse_microsoft_extended_decl_modifier(specifiers);
3478                         rem_anchor_token(')');
3479                         expect(')');
3480                         break;
3481
3482                 case T___thread:
3483                         switch (specifiers->declared_storage_class) {
3484                         case STORAGE_CLASS_NONE:
3485                                 specifiers->declared_storage_class = STORAGE_CLASS_THREAD;
3486                                 break;
3487
3488                         case STORAGE_CLASS_EXTERN:
3489                                 specifiers->declared_storage_class = STORAGE_CLASS_THREAD_EXTERN;
3490                                 break;
3491
3492                         case STORAGE_CLASS_STATIC:
3493                                 specifiers->declared_storage_class = STORAGE_CLASS_THREAD_STATIC;
3494                                 break;
3495
3496                         default:
3497                                 errorf(HERE, "multiple storage classes in declaration specifiers");
3498                                 break;
3499                         }
3500                         next_token();
3501                         break;
3502
3503                 /* type qualifiers */
3504 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
3505                 case token:                                                     \
3506                         qualifiers |= qualifier;                                    \
3507                         next_token();                                               \
3508                         break
3509
3510                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3511                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3512                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3513                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3514                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3515                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3516                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3517                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3518
3519                 case T___extension__:
3520                         next_token();
3521                         in_gcc_extension = true;
3522                         break;
3523
3524                 /* type specifiers */
3525 #define MATCH_SPECIFIER(token, specifier, name)                         \
3526                 case token:                                                     \
3527                         next_token();                                               \
3528                         if (type_specifiers & specifier) {                           \
3529                                 errorf(HERE, "multiple " name " type specifiers given"); \
3530                         } else {                                                    \
3531                                 type_specifiers |= specifier;                           \
3532                         }                                                           \
3533                         break
3534
3535                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void");
3536                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char");
3537                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short");
3538                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int");
3539                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float");
3540                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double");
3541                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed");
3542                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned");
3543                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool");
3544                 MATCH_SPECIFIER(T__int8,      SPECIFIER_INT8,      "_int8");
3545                 MATCH_SPECIFIER(T__int16,     SPECIFIER_INT16,     "_int16");
3546                 MATCH_SPECIFIER(T__int32,     SPECIFIER_INT32,     "_int32");
3547                 MATCH_SPECIFIER(T__int64,     SPECIFIER_INT64,     "_int64");
3548                 MATCH_SPECIFIER(T__int128,    SPECIFIER_INT128,    "_int128");
3549                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex");
3550                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary");
3551
3552                 case T__forceinline:
3553                         /* only in microsoft mode */
3554                         specifiers->modifiers |= DM_FORCEINLINE;
3555                         /* FALLTHROUGH */
3556
3557                 case T_inline:
3558                         next_token();
3559                         specifiers->is_inline = true;
3560                         break;
3561
3562                 case T_long:
3563                         next_token();
3564                         if (type_specifiers & SPECIFIER_LONG_LONG) {
3565                                 errorf(HERE, "multiple type specifiers given");
3566                         } else if (type_specifiers & SPECIFIER_LONG) {
3567                                 type_specifiers |= SPECIFIER_LONG_LONG;
3568                         } else {
3569                                 type_specifiers |= SPECIFIER_LONG;
3570                         }
3571                         break;
3572
3573                 case T_struct: {
3574                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
3575
3576                         type->compound.declaration = parse_compound_type_specifier(true);
3577                         finish_struct_type(&type->compound);
3578                         break;
3579                 }
3580                 case T_union: {
3581                         type = allocate_type_zero(TYPE_COMPOUND_UNION);
3582                         type->compound.declaration = parse_compound_type_specifier(false);
3583                         if (type->compound.declaration->modifiers & DM_TRANSPARENT_UNION)
3584                                 modifiers |= TYPE_MODIFIER_TRANSPARENT_UNION;
3585                         finish_union_type(&type->compound);
3586                         break;
3587                 }
3588                 case T_enum:
3589                         type = parse_enum_specifier();
3590                         break;
3591                 case T___typeof__:
3592                         type = parse_typeof();
3593                         break;
3594                 case T___builtin_va_list:
3595                         type = duplicate_type(type_valist);
3596                         next_token();
3597                         break;
3598
3599                 case T_IDENTIFIER: {
3600                         /* only parse identifier if we haven't found a type yet */
3601                         if (type != NULL || type_specifiers != 0) {
3602                                 /* Be somewhat resilient to typos like 'unsigned lng* f()' in a
3603                                  * declaration, so it doesn't generate errors about expecting '(' or
3604                                  * '{' later on. */
3605                                 switch (look_ahead(1)->type) {
3606                                         STORAGE_CLASSES
3607                                         TYPE_SPECIFIERS
3608                                         case T_const:
3609                                         case T_restrict:
3610                                         case T_volatile:
3611                                         case T_inline:
3612                                         case T__forceinline: /* ^ DECLARATION_START except for __attribute__ */
3613                                         case T_IDENTIFIER:
3614                                         case '*':
3615                                                 errorf(HERE, "discarding stray %K in declaration specifier", &token);
3616                                                 next_token();
3617                                                 continue;
3618
3619                                         default:
3620                                                 goto finish_specifiers;
3621                                 }
3622                         }
3623
3624                         type_t *const typedef_type = get_typedef_type(token.v.symbol);
3625                         if (typedef_type == NULL) {
3626                                 /* Be somewhat resilient to typos like 'vodi f()' at the beginning of a
3627                                  * declaration, so it doesn't generate 'implicit int' followed by more
3628                                  * errors later on. */
3629                                 token_type_t const la1_type = (token_type_t)look_ahead(1)->type;
3630                                 switch (la1_type) {
3631                                         DECLARATION_START
3632                                         case T_IDENTIFIER:
3633                                         case '*': {
3634                                                 errorf(HERE, "%K does not name a type", &token);
3635
3636                                                 declaration_t *const decl =
3637                                                         create_error_declaration(token.v.symbol, STORAGE_CLASS_TYPEDEF);
3638
3639                                                 type = allocate_type_zero(TYPE_TYPEDEF);
3640                                                 type->typedeft.declaration = decl;
3641
3642                                                 next_token();
3643                                                 saw_error = true;
3644                                                 if (la1_type == '*')
3645                                                         goto finish_specifiers;
3646                                                 continue;
3647                                         }
3648
3649                                         default:
3650                                                 goto finish_specifiers;
3651                                 }
3652                         }
3653
3654                         next_token();
3655                         type = typedef_type;
3656                         break;
3657                 }
3658
3659                 /* function specifier */
3660                 default:
3661                         goto finish_specifiers;
3662                 }
3663         }
3664
3665 finish_specifiers:
3666         in_gcc_extension = old_gcc_extension;
3667
3668         if (type == NULL || (saw_error && type_specifiers != 0)) {
3669                 atomic_type_kind_t atomic_type;
3670
3671                 /* match valid basic types */
3672                 switch(type_specifiers) {
3673                 case SPECIFIER_VOID:
3674                         atomic_type = ATOMIC_TYPE_VOID;
3675                         break;
3676                 case SPECIFIER_CHAR:
3677                         atomic_type = ATOMIC_TYPE_CHAR;
3678                         break;
3679                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
3680                         atomic_type = ATOMIC_TYPE_SCHAR;
3681                         break;
3682                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
3683                         atomic_type = ATOMIC_TYPE_UCHAR;
3684                         break;
3685                 case SPECIFIER_SHORT:
3686                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
3687                 case SPECIFIER_SHORT | SPECIFIER_INT:
3688                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
3689                         atomic_type = ATOMIC_TYPE_SHORT;
3690                         break;
3691                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
3692                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
3693                         atomic_type = ATOMIC_TYPE_USHORT;
3694                         break;
3695                 case SPECIFIER_INT:
3696                 case SPECIFIER_SIGNED:
3697                 case SPECIFIER_SIGNED | SPECIFIER_INT:
3698                         atomic_type = ATOMIC_TYPE_INT;
3699                         break;
3700                 case SPECIFIER_UNSIGNED:
3701                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
3702                         atomic_type = ATOMIC_TYPE_UINT;
3703                         break;
3704                 case SPECIFIER_LONG:
3705                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
3706                 case SPECIFIER_LONG | SPECIFIER_INT:
3707                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
3708                         atomic_type = ATOMIC_TYPE_LONG;
3709                         break;
3710                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
3711                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
3712                         atomic_type = ATOMIC_TYPE_ULONG;
3713                         break;
3714
3715                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3716                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3717                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
3718                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3719                         | SPECIFIER_INT:
3720                         atomic_type = ATOMIC_TYPE_LONGLONG;
3721                         goto warn_about_long_long;
3722
3723                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3724                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3725                         | SPECIFIER_INT:
3726                         atomic_type = ATOMIC_TYPE_ULONGLONG;
3727 warn_about_long_long:
3728                         if (warning.long_long) {
3729                                 warningf(&specifiers->source_position,
3730                                          "ISO C90 does not support 'long long'");
3731                         }
3732                         break;
3733
3734                 case SPECIFIER_UNSIGNED | SPECIFIER_INT8:
3735                         atomic_type = unsigned_int8_type_kind;
3736                         break;
3737
3738                 case SPECIFIER_UNSIGNED | SPECIFIER_INT16:
3739                         atomic_type = unsigned_int16_type_kind;
3740                         break;
3741
3742                 case SPECIFIER_UNSIGNED | SPECIFIER_INT32:
3743                         atomic_type = unsigned_int32_type_kind;
3744                         break;
3745
3746                 case SPECIFIER_UNSIGNED | SPECIFIER_INT64:
3747                         atomic_type = unsigned_int64_type_kind;
3748                         break;
3749
3750                 case SPECIFIER_UNSIGNED | SPECIFIER_INT128:
3751                         atomic_type = unsigned_int128_type_kind;
3752                         break;
3753
3754                 case SPECIFIER_INT8:
3755                 case SPECIFIER_SIGNED | SPECIFIER_INT8:
3756                         atomic_type = int8_type_kind;
3757                         break;
3758
3759                 case SPECIFIER_INT16:
3760                 case SPECIFIER_SIGNED | SPECIFIER_INT16:
3761                         atomic_type = int16_type_kind;
3762                         break;
3763
3764                 case SPECIFIER_INT32:
3765                 case SPECIFIER_SIGNED | SPECIFIER_INT32:
3766                         atomic_type = int32_type_kind;
3767                         break;
3768
3769                 case SPECIFIER_INT64:
3770                 case SPECIFIER_SIGNED | SPECIFIER_INT64:
3771                         atomic_type = int64_type_kind;
3772                         break;
3773
3774                 case SPECIFIER_INT128:
3775                 case SPECIFIER_SIGNED | SPECIFIER_INT128:
3776                         atomic_type = int128_type_kind;
3777                         break;
3778
3779                 case SPECIFIER_FLOAT:
3780                         atomic_type = ATOMIC_TYPE_FLOAT;
3781                         break;
3782                 case SPECIFIER_DOUBLE:
3783                         atomic_type = ATOMIC_TYPE_DOUBLE;
3784                         break;
3785                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
3786                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
3787                         break;
3788                 case SPECIFIER_BOOL:
3789                         atomic_type = ATOMIC_TYPE_BOOL;
3790                         break;
3791                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
3792                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
3793                         atomic_type = ATOMIC_TYPE_FLOAT;
3794                         break;
3795                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3796                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3797                         atomic_type = ATOMIC_TYPE_DOUBLE;
3798                         break;
3799                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3800                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3801                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
3802                         break;
3803                 default:
3804                         /* invalid specifier combination, give an error message */
3805                         if (type_specifiers == 0) {
3806                                 if (saw_error)
3807                                         goto end_error;
3808
3809                                 if (!strict_mode) {
3810                                         if (warning.implicit_int) {
3811                                                 warningf(HERE, "no type specifiers in declaration, using 'int'");
3812                                         }
3813                                         atomic_type = ATOMIC_TYPE_INT;
3814                                         break;
3815                                 } else {
3816                                         errorf(HERE, "no type specifiers given in declaration");
3817                                 }
3818                         } else if ((type_specifiers & SPECIFIER_SIGNED) &&
3819                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
3820                                 errorf(HERE, "signed and unsigned specifiers given");
3821                         } else if (type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
3822                                 errorf(HERE, "only integer types can be signed or unsigned");
3823                         } else {
3824                                 errorf(HERE, "multiple datatypes in declaration");
3825                         }
3826                         goto end_error;
3827                 }
3828
3829                 if (type_specifiers & SPECIFIER_COMPLEX) {
3830                         type                = allocate_type_zero(TYPE_COMPLEX);
3831                         type->complex.akind = atomic_type;
3832                 } else if (type_specifiers & SPECIFIER_IMAGINARY) {
3833                         type                  = allocate_type_zero(TYPE_IMAGINARY);
3834                         type->imaginary.akind = atomic_type;
3835                 } else {
3836                         type               = allocate_type_zero(TYPE_ATOMIC);
3837                         type->atomic.akind = atomic_type;
3838                 }
3839                 newtype = true;
3840         } else if (type_specifiers != 0) {
3841                 errorf(HERE, "multiple datatypes in declaration");
3842         }
3843
3844         /* FIXME: check type qualifiers here */
3845
3846         type->base.qualifiers = qualifiers;
3847         type->base.modifiers  = modifiers;
3848
3849         type_t *result = typehash_insert(type);
3850         if (newtype && result != type) {
3851                 free_type(type);
3852         }
3853
3854         specifiers->type = result;
3855         return;
3856
3857 end_error:
3858         specifiers->type = type_error_type;
3859         return;
3860 }
3861
3862 static type_qualifiers_t parse_type_qualifiers(void)
3863 {
3864         type_qualifiers_t qualifiers = TYPE_QUALIFIER_NONE;
3865
3866         while (true) {
3867                 switch(token.type) {
3868                 /* type qualifiers */
3869                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3870                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3871                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3872                 /* microsoft extended type modifiers */
3873                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3874                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3875                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3876                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3877                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3878
3879                 default:
3880                         return qualifiers;
3881                 }
3882         }
3883 }
3884
3885 /**
3886  * Parses an K&R identifier list and return a list of declarations.
3887  *
3888  * @param last  points to the last declaration in the list
3889  * @return the list of declarations
3890  */
3891 static declaration_t *parse_identifier_list(declaration_t **last)
3892 {
3893         declaration_t *declarations     = NULL;
3894         declaration_t *last_declaration = NULL;
3895         do {
3896                 declaration_t *const declaration = allocate_declaration_zero();
3897                 declaration->type            = NULL; /* a K&R parameter list has no types, yet */
3898                 declaration->source_position = token.source_position;
3899                 declaration->symbol          = token.v.symbol;
3900                 next_token();
3901
3902                 if (last_declaration != NULL) {
3903                         last_declaration->next = declaration;
3904                 } else {
3905                         declarations = declaration;
3906                 }
3907                 last_declaration = declaration;
3908
3909                 if (token.type != ',') {
3910                         break;
3911                 }
3912                 next_token();
3913         } while (token.type == T_IDENTIFIER);
3914
3915         *last = last_declaration;
3916         return declarations;
3917 }
3918
3919 static type_t *automatic_type_conversion(type_t *orig_type);
3920
3921 static void semantic_parameter(declaration_t *declaration)
3922 {
3923         /* TODO: improve error messages */
3924         source_position_t const* const pos = &declaration->source_position;
3925
3926         switch (declaration->declared_storage_class) {
3927                 case STORAGE_CLASS_TYPEDEF:
3928                         errorf(pos, "typedef not allowed in parameter list");
3929                         break;
3930
3931                 /* Allowed storage classes */
3932                 case STORAGE_CLASS_NONE:
3933                 case STORAGE_CLASS_REGISTER:
3934                         break;
3935
3936                 default:
3937                         errorf(pos, "parameter may only have none or register storage class");
3938                         break;
3939         }
3940
3941         type_t *const orig_type = declaration->type;
3942         /* §6.7.5.3(7): Array as last part of a parameter type is just syntactic
3943          * sugar.  Turn it into a pointer.
3944          * §6.7.5.3(8): A declaration of a parameter as ``function returning type''
3945          * shall be adjusted to ``pointer to function returning type'', as in 6.3.2.1.
3946          */
3947         type_t *const type = automatic_type_conversion(orig_type);
3948         declaration->type = type;
3949
3950         if (is_type_incomplete(skip_typeref(type))) {
3951                 errorf(pos, "parameter '%#T' is of incomplete type",
3952                        orig_type, declaration->symbol);
3953         }
3954 }
3955
3956 static declaration_t *parse_parameter(void)
3957 {
3958         declaration_specifiers_t specifiers;
3959         memset(&specifiers, 0, sizeof(specifiers));
3960
3961         parse_declaration_specifiers(&specifiers);
3962
3963         declaration_t *declaration = parse_declarator(&specifiers, /*may_be_abstract=*/true);
3964
3965         return declaration;
3966 }
3967
3968 /**
3969  * Parses a function type parameter list and return a list of declarations.
3970  *
3971  * @param last  point to the last element of the list
3972  * @return the parameter list
3973  */
3974 static declaration_t *parse_parameters(function_type_t *type, declaration_t **last)
3975 {
3976         declaration_t *declarations = NULL;
3977
3978         eat('(');
3979         add_anchor_token(')');
3980         int saved_comma_state = save_and_reset_anchor_state(',');
3981
3982         if (token.type == T_IDENTIFIER &&
3983             !is_typedef_symbol(token.v.symbol)) {
3984                 token_type_t la1_type = (token_type_t)look_ahead(1)->type;
3985                 if (la1_type == ',' || la1_type == ')') {
3986                         type->kr_style_parameters = true;
3987                         declarations = parse_identifier_list(last);
3988                         goto parameters_finished;
3989                 }
3990         }
3991
3992         if (token.type == ')') {
3993                 type->unspecified_parameters = 1;
3994                 goto parameters_finished;
3995         }
3996
3997         declaration_t        *declaration;
3998         declaration_t        *last_declaration = NULL;
3999         function_parameter_t *parameter;
4000         function_parameter_t *last_parameter = NULL;
4001
4002         while (true) {
4003                 switch(token.type) {
4004                 case T_DOTDOTDOT:
4005                         next_token();
4006                         type->variadic = 1;
4007                         goto parameters_finished;
4008
4009                 case T_IDENTIFIER:
4010                 case T___extension__:
4011                 DECLARATION_START
4012                         declaration = parse_parameter();
4013
4014                         /* func(void) is not a parameter */
4015                         if (last_parameter == NULL
4016                                         && token.type == ')'
4017                                         && declaration->symbol == NULL
4018                                         && skip_typeref(declaration->type) == type_void) {
4019                                 goto parameters_finished;
4020                         }
4021                         semantic_parameter(declaration);
4022
4023                         parameter       = obstack_alloc(type_obst, sizeof(parameter[0]));
4024                         memset(parameter, 0, sizeof(parameter[0]));
4025                         parameter->type = declaration->type;
4026
4027                         if (last_parameter != NULL) {
4028                                 last_declaration->next = declaration;
4029                                 last_parameter->next   = parameter;
4030                         } else {
4031                                 type->parameters = parameter;
4032                                 declarations     = declaration;
4033                         }
4034                         last_parameter   = parameter;
4035                         last_declaration = declaration;
4036                         break;
4037
4038                 default:
4039                         goto parameters_finished;
4040                 }
4041                 if (token.type != ',') {
4042                         goto parameters_finished;
4043                 }
4044                 next_token();
4045         }
4046
4047
4048 parameters_finished:
4049         rem_anchor_token(')');
4050         expect(')');
4051
4052         restore_anchor_state(',', saved_comma_state);
4053         *last = last_declaration;
4054         return declarations;
4055
4056 end_error:
4057         restore_anchor_state(',', saved_comma_state);
4058         *last = NULL;
4059         return NULL;
4060 }
4061
4062 typedef enum construct_type_kind_t {
4063         CONSTRUCT_INVALID,
4064         CONSTRUCT_POINTER,
4065         CONSTRUCT_FUNCTION,
4066         CONSTRUCT_ARRAY
4067 } construct_type_kind_t;
4068
4069 typedef struct construct_type_t construct_type_t;
4070 struct construct_type_t {
4071         construct_type_kind_t  kind;
4072         construct_type_t      *next;
4073 };
4074
4075 typedef struct parsed_pointer_t parsed_pointer_t;
4076 struct parsed_pointer_t {
4077         construct_type_t  construct_type;
4078         type_qualifiers_t type_qualifiers;
4079 };
4080
4081 typedef struct construct_function_type_t construct_function_type_t;
4082 struct construct_function_type_t {
4083         construct_type_t  construct_type;
4084         type_t           *function_type;
4085 };
4086
4087 typedef struct parsed_array_t parsed_array_t;
4088 struct parsed_array_t {
4089         construct_type_t  construct_type;
4090         type_qualifiers_t type_qualifiers;
4091         bool              is_static;
4092         bool              is_variable;
4093         expression_t     *size;
4094 };
4095
4096 typedef struct construct_base_type_t construct_base_type_t;
4097 struct construct_base_type_t {
4098         construct_type_t  construct_type;
4099         type_t           *type;
4100 };
4101
4102 static construct_type_t *parse_pointer_declarator(void)
4103 {
4104         eat('*');
4105
4106         parsed_pointer_t *pointer = obstack_alloc(&temp_obst, sizeof(pointer[0]));
4107         memset(pointer, 0, sizeof(pointer[0]));
4108         pointer->construct_type.kind = CONSTRUCT_POINTER;
4109         pointer->type_qualifiers     = parse_type_qualifiers();
4110
4111         return (construct_type_t*) pointer;
4112 }
4113
4114 static construct_type_t *parse_array_declarator(void)
4115 {
4116         eat('[');
4117         add_anchor_token(']');
4118
4119         parsed_array_t *array = obstack_alloc(&temp_obst, sizeof(array[0]));
4120         memset(array, 0, sizeof(array[0]));
4121         array->construct_type.kind = CONSTRUCT_ARRAY;
4122
4123         if (token.type == T_static) {
4124                 array->is_static = true;
4125                 next_token();
4126         }
4127
4128         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
4129         if (type_qualifiers != 0) {
4130                 if (token.type == T_static) {
4131                         array->is_static = true;
4132                         next_token();
4133                 }
4134         }
4135         array->type_qualifiers = type_qualifiers;
4136
4137         if (token.type == '*' && look_ahead(1)->type == ']') {
4138                 array->is_variable = true;
4139                 next_token();
4140         } else if (token.type != ']') {
4141                 array->size = parse_assignment_expression();
4142         }
4143
4144         rem_anchor_token(']');
4145         expect(']');
4146
4147 end_error:
4148         return (construct_type_t*) array;
4149 }
4150
4151 static construct_type_t *parse_function_declarator(declaration_t *declaration)
4152 {
4153         type_t *type;
4154         if (declaration != NULL) {
4155                 type = allocate_type_zero(TYPE_FUNCTION);
4156
4157                 unsigned mask = declaration->modifiers & (DM_CDECL|DM_STDCALL|DM_FASTCALL|DM_THISCALL);
4158
4159                 if (mask & (mask-1)) {
4160                         const char *first = NULL, *second = NULL;
4161
4162                         /* more than one calling convention set */
4163                         if (declaration->modifiers & DM_CDECL) {
4164                                 if (first == NULL)       first = "cdecl";
4165                                 else if (second == NULL) second = "cdecl";
4166                         }
4167                         if (declaration->modifiers & DM_STDCALL) {
4168                                 if (first == NULL)       first = "stdcall";
4169                                 else if (second == NULL) second = "stdcall";
4170                         }
4171                         if (declaration->modifiers & DM_FASTCALL) {
4172                                 if (first == NULL)       first = "fastcall";
4173                                 else if (second == NULL) second = "fastcall";
4174                         }
4175                         if (declaration->modifiers & DM_THISCALL) {
4176                                 if (first == NULL)       first = "thiscall";
4177                                 else if (second == NULL) second = "thiscall";
4178                         }
4179                         errorf(&declaration->source_position, "%s and %s attributes are not compatible", first, second);
4180                 }
4181
4182                 if (declaration->modifiers & DM_CDECL)
4183                         type->function.calling_convention = CC_CDECL;
4184                 else if (declaration->modifiers & DM_STDCALL)
4185                         type->function.calling_convention = CC_STDCALL;
4186                 else if (declaration->modifiers & DM_FASTCALL)
4187                         type->function.calling_convention = CC_FASTCALL;
4188                 else if (declaration->modifiers & DM_THISCALL)
4189                         type->function.calling_convention = CC_THISCALL;
4190         } else {
4191                 type = allocate_type_zero(TYPE_FUNCTION);
4192         }
4193
4194         declaration_t *last;
4195         declaration_t *parameters = parse_parameters(&type->function, &last);
4196         if (declaration != NULL) {
4197                 declaration->scope.declarations     = parameters;
4198                 declaration->scope.last_declaration = last;
4199         }
4200
4201         construct_function_type_t *construct_function_type =
4202                 obstack_alloc(&temp_obst, sizeof(construct_function_type[0]));
4203         memset(construct_function_type, 0, sizeof(construct_function_type[0]));
4204         construct_function_type->construct_type.kind = CONSTRUCT_FUNCTION;
4205         construct_function_type->function_type       = type;
4206
4207         return &construct_function_type->construct_type;
4208 }
4209
4210 static void fix_declaration_type(declaration_t *declaration)
4211 {
4212         decl_modifiers_t declaration_modifiers = declaration->modifiers;
4213         type_modifiers_t type_modifiers        = declaration->type->base.modifiers;
4214
4215         if (declaration_modifiers & DM_TRANSPARENT_UNION)
4216                 type_modifiers |= TYPE_MODIFIER_TRANSPARENT_UNION;
4217
4218         if (declaration->type->base.modifiers == type_modifiers)
4219                 return;
4220
4221         type_t *copy = duplicate_type(declaration->type);
4222         copy->base.modifiers = type_modifiers;
4223
4224         type_t *result = typehash_insert(copy);
4225         if (result != copy) {
4226                 obstack_free(type_obst, copy);
4227         }
4228
4229         declaration->type = result;
4230 }
4231
4232 static construct_type_t *parse_inner_declarator(declaration_t *declaration,
4233                 bool may_be_abstract)
4234 {
4235         /* construct a single linked list of construct_type_t's which describe
4236          * how to construct the final declarator type */
4237         construct_type_t *first = NULL;
4238         construct_type_t *last  = NULL;
4239         gnu_attribute_t  *attributes = NULL;
4240
4241         decl_modifiers_t modifiers = parse_attributes(&attributes);
4242
4243         /* pointers */
4244         while (token.type == '*') {
4245                 construct_type_t *type = parse_pointer_declarator();
4246
4247                 if (last == NULL) {
4248                         first = type;
4249                         last  = type;
4250                 } else {
4251                         last->next = type;
4252                         last       = type;
4253                 }
4254
4255                 /* TODO: find out if this is correct */
4256                 modifiers |= parse_attributes(&attributes);
4257         }
4258
4259         if (declaration != NULL)
4260                 declaration->modifiers |= modifiers;
4261
4262         construct_type_t *inner_types = NULL;
4263
4264         switch(token.type) {
4265         case T_IDENTIFIER:
4266                 if (declaration == NULL) {
4267                         errorf(HERE, "no identifier expected in typename");
4268                 } else {
4269                         declaration->symbol          = token.v.symbol;
4270                         declaration->source_position = token.source_position;
4271                 }
4272                 next_token();
4273                 break;
4274         case '(':
4275                 next_token();
4276                 add_anchor_token(')');
4277                 inner_types = parse_inner_declarator(declaration, may_be_abstract);
4278                 if (inner_types != NULL) {
4279                         /* All later declarators only modify the return type, not declaration */
4280                         declaration = NULL;
4281                 }
4282                 rem_anchor_token(')');
4283                 expect(')');
4284                 break;
4285         default:
4286                 if (may_be_abstract)
4287                         break;
4288                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', NULL);
4289                 eat_until_anchor();
4290                 return NULL;
4291         }
4292
4293         construct_type_t *p = last;
4294
4295         while(true) {
4296                 construct_type_t *type;
4297                 switch(token.type) {
4298                 case '(':
4299                         type = parse_function_declarator(declaration);
4300                         break;
4301                 case '[':
4302                         type = parse_array_declarator();
4303                         break;
4304                 default:
4305                         goto declarator_finished;
4306                 }
4307
4308                 /* insert in the middle of the list (behind p) */
4309                 if (p != NULL) {
4310                         type->next = p->next;
4311                         p->next    = type;
4312                 } else {
4313                         type->next = first;
4314                         first      = type;
4315                 }
4316                 if (last == p) {
4317                         last = type;
4318                 }
4319         }
4320
4321 declarator_finished:
4322         /* append inner_types at the end of the list, we don't to set last anymore
4323          * as it's not needed anymore */
4324         if (last == NULL) {
4325                 assert(first == NULL);
4326                 first = inner_types;
4327         } else {
4328                 last->next = inner_types;
4329         }
4330
4331         return first;
4332 end_error:
4333         return NULL;
4334 }
4335
4336 static void parse_declaration_attributes(declaration_t *declaration)
4337 {
4338         gnu_attribute_t  *attributes = NULL;
4339         decl_modifiers_t  modifiers  = parse_attributes(&attributes);
4340
4341         if (declaration == NULL)
4342                 return;
4343
4344         declaration->modifiers |= modifiers;
4345         /* check if we have these stupid mode attributes... */
4346         type_t *old_type = declaration->type;
4347         if (old_type == NULL)
4348                 return;
4349
4350         gnu_attribute_t *attribute = attributes;
4351         for ( ; attribute != NULL; attribute = attribute->next) {
4352                 if (attribute->kind != GNU_AK_MODE || attribute->invalid)
4353                         continue;
4354
4355                 atomic_type_kind_t  akind = attribute->u.akind;
4356                 if (!is_type_signed(old_type)) {
4357                         switch(akind) {
4358                         case ATOMIC_TYPE_CHAR: akind = ATOMIC_TYPE_UCHAR; break;
4359                         case ATOMIC_TYPE_SHORT: akind = ATOMIC_TYPE_USHORT; break;
4360                         case ATOMIC_TYPE_INT: akind = ATOMIC_TYPE_UINT; break;
4361                         case ATOMIC_TYPE_LONGLONG: akind = ATOMIC_TYPE_ULONGLONG; break;
4362                         default:
4363                                 panic("invalid akind in mode attribute");
4364                         }
4365                 }
4366                 declaration->type
4367                         = make_atomic_type(akind, old_type->base.qualifiers);
4368         }
4369 }
4370
4371 static type_t *construct_declarator_type(construct_type_t *construct_list,
4372                                          type_t *type)
4373 {
4374         construct_type_t *iter = construct_list;
4375         for( ; iter != NULL; iter = iter->next) {
4376                 switch(iter->kind) {
4377                 case CONSTRUCT_INVALID:
4378                         internal_errorf(HERE, "invalid type construction found");
4379                 case CONSTRUCT_FUNCTION: {
4380                         construct_function_type_t *construct_function_type
4381                                 = (construct_function_type_t*) iter;
4382
4383                         type_t *function_type = construct_function_type->function_type;
4384
4385                         function_type->function.return_type = type;
4386
4387                         type_t *skipped_return_type = skip_typeref(type);
4388                         /* §6.7.5.3(1) */
4389                         if (is_type_function(skipped_return_type)) {
4390                                 errorf(HERE, "function returning function is not allowed");
4391                         } else if (is_type_array(skipped_return_type)) {
4392                                 errorf(HERE, "function returning array is not allowed");
4393                         } else {
4394                                 if (skipped_return_type->base.qualifiers != 0 && warning.other) {
4395                                         warningf(HERE,
4396                                                 "type qualifiers in return type of function type are meaningless");
4397                                 }
4398                         }
4399
4400                         type = function_type;
4401                         break;
4402                 }
4403
4404                 case CONSTRUCT_POINTER: {
4405                         parsed_pointer_t *parsed_pointer = (parsed_pointer_t*) iter;
4406                         type = make_pointer_type(type, parsed_pointer->type_qualifiers);
4407                         continue;
4408                 }
4409
4410                 case CONSTRUCT_ARRAY: {
4411                         parsed_array_t *parsed_array  = (parsed_array_t*) iter;
4412                         type_t         *array_type    = allocate_type_zero(TYPE_ARRAY);
4413
4414                         expression_t *size_expression = parsed_array->size;
4415                         if (size_expression != NULL) {
4416                                 size_expression
4417                                         = create_implicit_cast(size_expression, type_size_t);
4418                         }
4419
4420                         array_type->base.qualifiers       = parsed_array->type_qualifiers;
4421                         array_type->array.element_type    = type;
4422                         array_type->array.is_static       = parsed_array->is_static;
4423                         array_type->array.is_variable     = parsed_array->is_variable;
4424                         array_type->array.size_expression = size_expression;
4425
4426                         if (size_expression != NULL) {
4427                                 if (is_constant_expression(size_expression)) {
4428                                         array_type->array.size_constant = true;
4429                                         array_type->array.size
4430                                                 = fold_constant(size_expression);
4431                                 } else {
4432                                         array_type->array.is_vla = true;
4433                                 }
4434                         }
4435
4436                         type_t *skipped_type = skip_typeref(type);
4437                         /* §6.7.5.2(1) */
4438                         if (is_type_incomplete(skipped_type)) {
4439                                 errorf(HERE, "array of incomplete type '%T' is not allowed", type);
4440                         } else if (is_type_function(skipped_type)) {
4441                                 errorf(HERE, "array of functions is not allowed");
4442                         }
4443                         type = array_type;
4444                         break;
4445                 }
4446                 }
4447
4448                 type_t *hashed_type = typehash_insert(type);
4449                 if (hashed_type != type) {
4450                         /* the function type was constructed earlier freeing it here will
4451                          * destroy other types... */
4452                         if (iter->kind != CONSTRUCT_FUNCTION) {
4453                                 free_type(type);
4454                         }
4455                         type = hashed_type;
4456                 }
4457         }
4458
4459         return type;
4460 }
4461
4462 static declaration_t *parse_declarator(
4463                 const declaration_specifiers_t *specifiers, bool may_be_abstract)
4464 {
4465         declaration_t *const declaration    = allocate_declaration_zero();
4466         declaration->source_position        = specifiers->source_position;
4467         declaration->declared_storage_class = specifiers->declared_storage_class;
4468         declaration->modifiers              = specifiers->modifiers;
4469         declaration->deprecated_string      = specifiers->deprecated_string;
4470         declaration->get_property_sym       = specifiers->get_property_sym;
4471         declaration->put_property_sym       = specifiers->put_property_sym;
4472         declaration->is_inline              = specifiers->is_inline;
4473
4474         declaration->storage_class          = specifiers->declared_storage_class;
4475         if (declaration->storage_class == STORAGE_CLASS_NONE &&
4476             scope != file_scope) {
4477                 declaration->storage_class = STORAGE_CLASS_AUTO;
4478         }
4479
4480         if (specifiers->alignment != 0) {
4481                 /* TODO: add checks here */
4482                 declaration->alignment = specifiers->alignment;
4483         }
4484
4485         construct_type_t *construct_type
4486                 = parse_inner_declarator(declaration, may_be_abstract);
4487         type_t *const type = specifiers->type;
4488         declaration->type = construct_declarator_type(construct_type, type);
4489
4490         parse_declaration_attributes(declaration);
4491
4492         fix_declaration_type(declaration);
4493
4494         if (construct_type != NULL) {
4495                 obstack_free(&temp_obst, construct_type);
4496         }
4497
4498         return declaration;
4499 }
4500
4501 static type_t *parse_abstract_declarator(type_t *base_type)
4502 {
4503         construct_type_t *construct_type = parse_inner_declarator(NULL, 1);
4504
4505         type_t *result = construct_declarator_type(construct_type, base_type);
4506         if (construct_type != NULL) {
4507                 obstack_free(&temp_obst, construct_type);
4508         }
4509
4510         return result;
4511 }
4512
4513 static declaration_t *append_declaration(declaration_t* const declaration)
4514 {
4515         if (last_declaration != NULL) {
4516                 last_declaration->next = declaration;
4517         } else {
4518                 scope->declarations = declaration;
4519         }
4520         last_declaration = declaration;
4521         return declaration;
4522 }
4523
4524 /**
4525  * Check if the declaration of main is suspicious.  main should be a
4526  * function with external linkage, returning int, taking either zero
4527  * arguments, two, or three arguments of appropriate types, ie.
4528  *
4529  * int main([ int argc, char **argv [, char **env ] ]).
4530  *
4531  * @param decl    the declaration to check
4532  * @param type    the function type of the declaration
4533  */
4534 static void check_type_of_main(const declaration_t *const decl, const function_type_t *const func_type)
4535 {
4536         if (decl->storage_class == STORAGE_CLASS_STATIC) {
4537                 warningf(&decl->source_position,
4538                          "'main' is normally a non-static function");
4539         }
4540         if (!types_compatible(skip_typeref(func_type->return_type), type_int)) {
4541                 warningf(&decl->source_position,
4542                          "return type of 'main' should be 'int', but is '%T'",
4543                          func_type->return_type);
4544         }
4545         const function_parameter_t *parm = func_type->parameters;
4546         if (parm != NULL) {
4547                 type_t *const first_type = parm->type;
4548                 if (!types_compatible(skip_typeref(first_type), type_int)) {
4549                         warningf(&decl->source_position,
4550                                  "first argument of 'main' should be 'int', but is '%T'", first_type);
4551                 }
4552                 parm = parm->next;
4553                 if (parm != NULL) {
4554                         type_t *const second_type = parm->type;
4555                         if (!types_compatible(skip_typeref(second_type), type_char_ptr_ptr)) {
4556                                 warningf(&decl->source_position,
4557                                          "second argument of 'main' should be 'char**', but is '%T'", second_type);
4558                         }
4559                         parm = parm->next;
4560                         if (parm != NULL) {
4561                                 type_t *const third_type = parm->type;
4562                                 if (!types_compatible(skip_typeref(third_type), type_char_ptr_ptr)) {
4563                                         warningf(&decl->source_position,
4564                                                  "third argument of 'main' should be 'char**', but is '%T'", third_type);
4565                                 }
4566                                 parm = parm->next;
4567                                 if (parm != NULL)
4568                                         goto warn_arg_count;
4569                         }
4570                 } else {
4571 warn_arg_count:
4572                         warningf(&decl->source_position, "'main' takes only zero, two or three arguments");
4573                 }
4574         }
4575 }
4576
4577 /**
4578  * Check if a symbol is the equal to "main".
4579  */
4580 static bool is_sym_main(const symbol_t *const sym)
4581 {
4582         return strcmp(sym->string, "main") == 0;
4583 }
4584
4585 static declaration_t *record_declaration(
4586         declaration_t *const declaration,
4587         const bool is_definition)
4588 {
4589         const symbol_t *const symbol  = declaration->symbol;
4590         const namespace_t     namespc = (namespace_t)declaration->namespc;
4591
4592         assert(symbol != NULL);
4593         declaration_t *previous_declaration = get_declaration(symbol, namespc);
4594
4595         type_t *const orig_type = declaration->type;
4596         type_t *const type      = skip_typeref(orig_type);
4597         if (is_type_function(type) &&
4598                         type->function.unspecified_parameters &&
4599                         warning.strict_prototypes &&
4600                         previous_declaration == NULL) {
4601                 warningf(&declaration->source_position,
4602                          "function declaration '%#T' is not a prototype",
4603                          orig_type, symbol);
4604         }
4605
4606         if (warning.main && is_type_function(type) && is_sym_main(symbol)) {
4607                 check_type_of_main(declaration, &type->function);
4608         }
4609
4610         if (warning.nested_externs                             &&
4611             declaration->storage_class == STORAGE_CLASS_EXTERN &&
4612             scope                      != file_scope) {
4613                 warningf(&declaration->source_position,
4614                          "nested extern declaration of '%#T'", declaration->type, symbol);
4615         }
4616
4617         assert(declaration != previous_declaration);
4618         if (previous_declaration != NULL &&
4619             previous_declaration->parent_scope == &current_function->scope &&
4620             scope->depth == previous_declaration->parent_scope->depth + 1) {
4621                 errorf(&declaration->source_position,
4622                         "declaration '%#T' redeclares the parameter '%#T' (declared %P)",
4623                         orig_type, symbol, previous_declaration->type, symbol,
4624                         &previous_declaration->source_position);
4625                 goto finish;
4626         }
4627         if (previous_declaration != NULL &&
4628             previous_declaration->parent_scope == scope) {
4629                 /* can happen for K&R style declarations */
4630                 if (previous_declaration->type == NULL) {
4631                         previous_declaration->type = declaration->type;
4632                 }
4633
4634                 const type_t *prev_type = skip_typeref(previous_declaration->type);
4635                 if (!types_compatible(type, prev_type)) {
4636                         errorf(&declaration->source_position,
4637                                    "declaration '%#T' is incompatible with '%#T' (declared %P)",
4638                                    orig_type, symbol, previous_declaration->type, symbol,
4639                                    &previous_declaration->source_position);
4640                 } else {
4641                         unsigned old_storage_class = previous_declaration->storage_class;
4642                         if (old_storage_class == STORAGE_CLASS_ENUM_ENTRY) {
4643                                 errorf(&declaration->source_position,
4644                                            "redeclaration of enum entry '%Y' (declared %P)",
4645                                            symbol, &previous_declaration->source_position);
4646                                 return previous_declaration;
4647                         }
4648
4649                         if (warning.redundant_decls                                     &&
4650                             is_definition                                               &&
4651                             previous_declaration->storage_class == STORAGE_CLASS_STATIC &&
4652                             !(previous_declaration->modifiers & DM_USED)                &&
4653                             !previous_declaration->used) {
4654                                 warningf(&previous_declaration->source_position,
4655                                          "unnecessary static forward declaration for '%#T'",
4656                                          previous_declaration->type, symbol);
4657                         }
4658
4659                         unsigned new_storage_class = declaration->storage_class;
4660
4661                         if (is_type_incomplete(prev_type)) {
4662                                 previous_declaration->type = type;
4663                                 prev_type                  = type;
4664                         }
4665
4666                         /* pretend no storage class means extern for function
4667                          * declarations (except if the previous declaration is neither
4668                          * none nor extern) */
4669                         if (is_type_function(type)) {
4670                                 if (prev_type->function.unspecified_parameters) {
4671                                         previous_declaration->type = type;
4672                                         prev_type                  = type;
4673                                 }
4674
4675                                 switch (old_storage_class) {
4676                                 case STORAGE_CLASS_NONE:
4677                                         old_storage_class = STORAGE_CLASS_EXTERN;
4678                                         /* FALLTHROUGH */
4679
4680                                 case STORAGE_CLASS_EXTERN:
4681                                         if (is_definition) {
4682                                                 if (warning.missing_prototypes &&
4683                                                     prev_type->function.unspecified_parameters &&
4684                                                     !is_sym_main(symbol)) {
4685                                                         warningf(&declaration->source_position,
4686                                                                          "no previous prototype for '%#T'",
4687                                                                          orig_type, symbol);
4688                                                 }
4689                                         } else if (new_storage_class == STORAGE_CLASS_NONE) {
4690                                                 new_storage_class = STORAGE_CLASS_EXTERN;
4691                                         }
4692                                         break;
4693
4694                                 default:
4695                                         break;
4696                                 }
4697                         }
4698
4699                         if (old_storage_class == STORAGE_CLASS_EXTERN &&
4700                                         new_storage_class == STORAGE_CLASS_EXTERN) {
4701 warn_redundant_declaration:
4702                                 if (!is_definition           &&
4703                                     warning.redundant_decls  &&
4704                                     is_type_valid(prev_type) &&
4705                                     strcmp(previous_declaration->source_position.input_name, "<builtin>") != 0) {
4706                                         warningf(&declaration->source_position,
4707                                                  "redundant declaration for '%Y' (declared %P)",
4708                                                  symbol, &previous_declaration->source_position);
4709                                 }
4710                         } else if (current_function == NULL) {
4711                                 if (old_storage_class != STORAGE_CLASS_STATIC &&
4712                                     new_storage_class == STORAGE_CLASS_STATIC) {
4713                                         errorf(&declaration->source_position,
4714                                                "static declaration of '%Y' follows non-static declaration (declared %P)",
4715                                                symbol, &previous_declaration->source_position);
4716                                 } else if (old_storage_class == STORAGE_CLASS_EXTERN) {
4717                                         previous_declaration->storage_class          = STORAGE_CLASS_NONE;
4718                                         previous_declaration->declared_storage_class = STORAGE_CLASS_NONE;
4719                                 } else {
4720                                         goto warn_redundant_declaration;
4721                                 }
4722                         } else if (is_type_valid(prev_type)) {
4723                                 if (old_storage_class == new_storage_class) {
4724                                         errorf(&declaration->source_position,
4725                                                "redeclaration of '%Y' (declared %P)",
4726                                                symbol, &previous_declaration->source_position);
4727                                 } else {
4728                                         errorf(&declaration->source_position,
4729                                                "redeclaration of '%Y' with different linkage (declared %P)",
4730                                                symbol, &previous_declaration->source_position);
4731                                 }
4732                         }
4733                 }
4734
4735                 previous_declaration->modifiers |= declaration->modifiers;
4736                 previous_declaration->is_inline |= declaration->is_inline;
4737                 return previous_declaration;
4738         } else if (is_type_function(type)) {
4739                 if (is_definition &&
4740                     declaration->storage_class != STORAGE_CLASS_STATIC) {
4741                         if (warning.missing_prototypes && !is_sym_main(symbol)) {
4742                                 warningf(&declaration->source_position,
4743                                          "no previous prototype for '%#T'", orig_type, symbol);
4744                         } else if (warning.missing_declarations && !is_sym_main(symbol)) {
4745                                 warningf(&declaration->source_position,
4746                                          "no previous declaration for '%#T'", orig_type,
4747                                          symbol);
4748                         }
4749                 }
4750         } else {
4751                 if (warning.missing_declarations &&
4752                     scope == file_scope && (
4753                       declaration->storage_class == STORAGE_CLASS_NONE ||
4754                       declaration->storage_class == STORAGE_CLASS_THREAD
4755                     )) {
4756                         warningf(&declaration->source_position,
4757                                  "no previous declaration for '%#T'", orig_type, symbol);
4758                 }
4759         }
4760 finish:
4761         assert(declaration->parent_scope == NULL);
4762         assert(scope != NULL);
4763
4764         declaration->parent_scope = scope;
4765
4766         environment_push(declaration);
4767         return append_declaration(declaration);
4768 }
4769
4770 static void parser_error_multiple_definition(declaration_t *declaration,
4771                 const source_position_t *source_position)
4772 {
4773         errorf(source_position, "multiple definition of symbol '%Y' (declared %P)",
4774                declaration->symbol, &declaration->source_position);
4775 }
4776
4777 static bool is_declaration_specifier(const token_t *token,
4778                                      bool only_specifiers_qualifiers)
4779 {
4780         switch (token->type) {
4781                 TYPE_SPECIFIERS
4782                 TYPE_QUALIFIERS
4783                         return true;
4784                 case T_IDENTIFIER:
4785                         return is_typedef_symbol(token->v.symbol);
4786
4787                 case T___extension__:
4788                 STORAGE_CLASSES
4789                         return !only_specifiers_qualifiers;
4790
4791                 default:
4792                         return false;
4793         }
4794 }
4795
4796 static void parse_init_declarator_rest(declaration_t *declaration)
4797 {
4798         eat('=');
4799
4800         type_t *orig_type = declaration->type;
4801         type_t *type      = skip_typeref(orig_type);
4802
4803         if (declaration->init.initializer != NULL) {
4804                 parser_error_multiple_definition(declaration, HERE);
4805         }
4806
4807         bool must_be_constant = false;
4808         if (declaration->storage_class == STORAGE_CLASS_STATIC        ||
4809             declaration->storage_class == STORAGE_CLASS_THREAD_STATIC ||
4810             declaration->parent_scope  == file_scope) {
4811                 must_be_constant = true;
4812         }
4813
4814         if (is_type_function(type)) {
4815                 errorf(&declaration->source_position,
4816                        "function '%#T' is initialized like a variable",
4817                        orig_type, declaration->symbol);
4818                 orig_type = type_error_type;
4819         }
4820
4821         parse_initializer_env_t env;
4822         env.type             = orig_type;
4823         env.must_be_constant = must_be_constant;
4824         env.declaration      = current_init_decl = declaration;
4825
4826         initializer_t *initializer = parse_initializer(&env);
4827         current_init_decl = NULL;
4828
4829         if (!is_type_function(type)) {
4830                 /* § 6.7.5 (22)  array initializers for arrays with unknown size determine
4831                  * the array type size */
4832                 declaration->type             = env.type;
4833                 declaration->init.initializer = initializer;
4834         }
4835 }
4836
4837 /* parse rest of a declaration without any declarator */
4838 static void parse_anonymous_declaration_rest(
4839                 const declaration_specifiers_t *specifiers)
4840 {
4841         eat(';');
4842
4843         if (warning.other) {
4844                 if (specifiers->declared_storage_class != STORAGE_CLASS_NONE) {
4845                         warningf(&specifiers->source_position,
4846                                  "useless storage class in empty declaration");
4847                 }
4848
4849                 type_t *type = specifiers->type;
4850                 switch (type->kind) {
4851                         case TYPE_COMPOUND_STRUCT:
4852                         case TYPE_COMPOUND_UNION: {
4853                                 if (type->compound.declaration->symbol == NULL) {
4854                                         warningf(&specifiers->source_position,
4855                                                  "unnamed struct/union that defines no instances");
4856                                 }
4857                                 break;
4858                         }
4859
4860                         case TYPE_ENUM:
4861                                 break;
4862
4863                         default:
4864                                 warningf(&specifiers->source_position, "empty declaration");
4865                                 break;
4866                 }
4867         }
4868
4869 #ifdef RECORD_EMPTY_DECLARATIONS
4870         declaration_t *const declaration    = allocate_declaration_zero();
4871         declaration->type                   = specifiers->type;
4872         declaration->declared_storage_class = specifiers->declared_storage_class;
4873         declaration->source_position        = specifiers->source_position;
4874         declaration->modifiers              = specifiers->modifiers;
4875         declaration->storage_class          = STORAGE_CLASS_NONE;
4876
4877         append_declaration(declaration);
4878 #endif
4879 }
4880
4881 static void parse_declaration_rest(declaration_t *ndeclaration,
4882                 const declaration_specifiers_t *specifiers,
4883                 parsed_declaration_func finished_declaration)
4884 {
4885         add_anchor_token(';');
4886         add_anchor_token(',');
4887         while(true) {
4888                 declaration_t *declaration =
4889                         finished_declaration(ndeclaration, token.type == '=');
4890
4891                 type_t *orig_type = declaration->type;
4892                 type_t *type      = skip_typeref(orig_type);
4893
4894                 if (warning.other               &&
4895                                 type->kind != TYPE_FUNCTION &&
4896                     declaration->is_inline      &&
4897                     is_type_valid(type)) {
4898                         warningf(&declaration->source_position,
4899                                  "variable '%Y' declared 'inline'\n", declaration->symbol);
4900                 }
4901
4902                 if (token.type == '=') {
4903                         parse_init_declarator_rest(declaration);
4904                 }
4905
4906                 if (token.type != ',')
4907                         break;
4908                 eat(',');
4909
4910                 add_anchor_token('=');
4911                 ndeclaration = parse_declarator(specifiers, /*may_be_abstract=*/false);
4912                 rem_anchor_token('=');
4913         }
4914         expect(';');
4915
4916 end_error:
4917         rem_anchor_token(';');
4918         rem_anchor_token(',');
4919 }
4920
4921 static declaration_t *finished_kr_declaration(declaration_t *declaration, bool is_definition)
4922 {
4923         symbol_t *symbol  = declaration->symbol;
4924         if (symbol == NULL) {
4925                 errorf(HERE, "anonymous declaration not valid as function parameter");
4926                 return declaration;
4927         }
4928         namespace_t namespc = (namespace_t) declaration->namespc;
4929         if (namespc != NAMESPACE_NORMAL) {
4930                 return record_declaration(declaration, false);
4931         }
4932
4933         declaration_t *previous_declaration = get_declaration(symbol, namespc);
4934         if (previous_declaration == NULL ||
4935                         previous_declaration->parent_scope != scope) {
4936                 errorf(HERE, "expected declaration of a function parameter, found '%Y'",
4937                        symbol);
4938                 return declaration;
4939         }
4940
4941         if (is_definition) {
4942                 errorf(HERE, "parameter %Y is initialised", declaration->symbol);
4943         }
4944
4945         if (previous_declaration->type == NULL) {
4946                 previous_declaration->type          = declaration->type;
4947                 previous_declaration->declared_storage_class = declaration->declared_storage_class;
4948                 previous_declaration->storage_class = declaration->storage_class;
4949                 previous_declaration->parent_scope  = scope;
4950                 return previous_declaration;
4951         } else {
4952                 return record_declaration(declaration, false);
4953         }
4954 }
4955
4956 static void parse_declaration(parsed_declaration_func finished_declaration)
4957 {
4958         declaration_specifiers_t specifiers;
4959         memset(&specifiers, 0, sizeof(specifiers));
4960
4961         add_anchor_token(';');
4962         parse_declaration_specifiers(&specifiers);
4963         rem_anchor_token(';');
4964
4965         if (token.type == ';') {
4966                 parse_anonymous_declaration_rest(&specifiers);
4967         } else {
4968                 declaration_t *declaration = parse_declarator(&specifiers, /*may_be_abstract=*/false);
4969                 parse_declaration_rest(declaration, &specifiers, finished_declaration);
4970         }
4971 }
4972
4973 static type_t *get_default_promoted_type(type_t *orig_type)
4974 {
4975         type_t *result = orig_type;
4976
4977         type_t *type = skip_typeref(orig_type);
4978         if (is_type_integer(type)) {
4979                 result = promote_integer(type);
4980         } else if (type == type_float) {
4981                 result = type_double;
4982         }
4983
4984         return result;
4985 }
4986
4987 static void parse_kr_declaration_list(declaration_t *declaration)
4988 {
4989         type_t *type = skip_typeref(declaration->type);
4990         if (!is_type_function(type))
4991                 return;
4992
4993         if (!type->function.kr_style_parameters)
4994                 return;
4995
4996         add_anchor_token('{');
4997
4998         /* push function parameters */
4999         size_t const top = environment_top();
5000         scope_push(&declaration->scope);
5001
5002         declaration_t *parameter = declaration->scope.declarations;
5003         for ( ; parameter != NULL; parameter = parameter->next) {
5004                 assert(parameter->parent_scope == NULL);
5005                 parameter->parent_scope = scope;
5006                 environment_push(parameter);
5007         }
5008
5009         /* parse declaration list */
5010         while (is_declaration_specifier(&token, false)) {
5011                 parse_declaration(finished_kr_declaration);
5012         }
5013
5014         /* pop function parameters */
5015         assert(scope == &declaration->scope);
5016         scope_pop();
5017         environment_pop_to(top);
5018
5019         /* update function type */
5020         type_t *new_type = duplicate_type(type);
5021
5022         function_parameter_t *parameters     = NULL;
5023         function_parameter_t *last_parameter = NULL;
5024
5025         declaration_t *parameter_declaration = declaration->scope.declarations;
5026         for( ; parameter_declaration != NULL;
5027                         parameter_declaration = parameter_declaration->next) {
5028                 type_t *parameter_type = parameter_declaration->type;
5029                 if (parameter_type == NULL) {
5030                         if (strict_mode) {
5031                                 errorf(HERE, "no type specified for function parameter '%Y'",
5032                                        parameter_declaration->symbol);
5033                         } else {
5034                                 if (warning.implicit_int) {
5035                                         warningf(HERE, "no type specified for function parameter '%Y', using 'int'",
5036                                                 parameter_declaration->symbol);
5037                                 }
5038                                 parameter_type              = type_int;
5039                                 parameter_declaration->type = parameter_type;
5040                         }
5041                 }
5042
5043                 semantic_parameter(parameter_declaration);
5044                 parameter_type = parameter_declaration->type;
5045
5046                 /*
5047                  * we need the default promoted types for the function type
5048                  */
5049                 parameter_type = get_default_promoted_type(parameter_type);
5050
5051                 function_parameter_t *function_parameter
5052                         = obstack_alloc(type_obst, sizeof(function_parameter[0]));
5053                 memset(function_parameter, 0, sizeof(function_parameter[0]));
5054
5055                 function_parameter->type = parameter_type;
5056                 if (last_parameter != NULL) {
5057                         last_parameter->next = function_parameter;
5058                 } else {
5059                         parameters = function_parameter;
5060                 }
5061                 last_parameter = function_parameter;
5062         }
5063
5064         /* § 6.9.1.7: A K&R style parameter list does NOT act as a function
5065          * prototype */
5066         new_type->function.parameters             = parameters;
5067         new_type->function.unspecified_parameters = true;
5068
5069         type = typehash_insert(new_type);
5070         if (type != new_type) {
5071                 obstack_free(type_obst, new_type);
5072         }
5073
5074         declaration->type = type;
5075
5076         rem_anchor_token('{');
5077 }
5078
5079 static bool first_err = true;
5080
5081 /**
5082  * When called with first_err set, prints the name of the current function,
5083  * else does noting.
5084  */
5085 static void print_in_function(void)
5086 {
5087         if (first_err) {
5088                 first_err = false;
5089                 diagnosticf("%s: In function '%Y':\n",
5090                         current_function->source_position.input_name,
5091                         current_function->symbol);
5092         }
5093 }
5094
5095 /**
5096  * Check if all labels are defined in the current function.
5097  * Check if all labels are used in the current function.
5098  */
5099 static void check_labels(void)
5100 {
5101         for (const goto_statement_t *goto_statement = goto_first;
5102             goto_statement != NULL;
5103             goto_statement = goto_statement->next) {
5104                 /* skip computed gotos */
5105                 if (goto_statement->expression != NULL)
5106                         continue;
5107
5108                 declaration_t *label = goto_statement->label;
5109
5110                 label->used = true;
5111                 if (label->source_position.input_name == NULL) {
5112                         print_in_function();
5113                         errorf(&goto_statement->base.source_position,
5114                                "label '%Y' used but not defined", label->symbol);
5115                  }
5116         }
5117         goto_first = goto_last = NULL;
5118
5119         if (warning.unused_label) {
5120                 for (const label_statement_t *label_statement = label_first;
5121                          label_statement != NULL;
5122                          label_statement = label_statement->next) {
5123                         const declaration_t *label = label_statement->label;
5124
5125                         if (! label->used) {
5126                                 print_in_function();
5127                                 warningf(&label_statement->base.source_position,
5128                                         "label '%Y' defined but not used", label->symbol);
5129                         }
5130                 }
5131         }
5132         label_first = label_last = NULL;
5133 }
5134
5135 static void warn_unused_decl(declaration_t *decl, declaration_t *end, char const *const what)
5136 {
5137         for (; decl != NULL; decl = decl->next) {
5138                 if (decl->implicit)
5139                         continue;
5140
5141                 if (!decl->used) {
5142                         print_in_function();
5143                         warningf(&decl->source_position, "%s '%Y' is unused", what, decl->symbol);
5144                 } else if (!decl->read) {
5145                         print_in_function();
5146                         warningf(&decl->source_position, "%s '%Y' is never read", what, decl->symbol);
5147                 }
5148
5149                 if (decl == end)
5150                         break;
5151         }
5152 }
5153
5154 static void check_unused_variables(statement_t *const stmt, void *const env)
5155 {
5156         (void)env;
5157
5158         switch (stmt->kind) {
5159                 case STATEMENT_DECLARATION: {
5160                         declaration_statement_t const *const decls = &stmt->declaration;
5161                         warn_unused_decl(decls->declarations_begin, decls->declarations_end, "variable");
5162                         return;
5163                 }
5164
5165                 case STATEMENT_FOR:
5166                         warn_unused_decl(stmt->fors.scope.declarations, NULL, "variable");
5167                         return;
5168
5169                 default:
5170                         return;
5171         }
5172 }
5173
5174 /**
5175  * Check declarations of current_function for unused entities.
5176  */
5177 static void check_declarations(void)
5178 {
5179         if (warning.unused_parameter) {
5180                 const scope_t *scope = &current_function->scope;
5181
5182                 /* do not issue unused warnings for main */
5183                 if (!is_sym_main(current_function->symbol)) {
5184                         warn_unused_decl(scope->declarations, NULL, "parameter");
5185                 }
5186         }
5187         if (warning.unused_variable) {
5188                 walk_statements(current_function->init.statement, check_unused_variables, NULL);
5189         }
5190 }
5191
5192 static int determine_truth(expression_t const* const cond)
5193 {
5194         return
5195                 !is_constant_expression(cond) ? 0 :
5196                 fold_constant(cond) != 0      ? 1 :
5197                 -1;
5198 }
5199
5200 static bool noreturn_candidate;
5201
5202 static void check_reachable(statement_t *const stmt)
5203 {
5204         if (stmt->base.reachable)
5205                 return;
5206         if (stmt->kind != STATEMENT_DO_WHILE)
5207                 stmt->base.reachable = true;
5208
5209         statement_t *last = stmt;
5210         statement_t *next;
5211         switch (stmt->kind) {
5212                 case STATEMENT_INVALID:
5213                 case STATEMENT_EMPTY:
5214                 case STATEMENT_DECLARATION:
5215                 case STATEMENT_ASM:
5216                         next = stmt->base.next;
5217                         break;
5218
5219                 case STATEMENT_COMPOUND:
5220                         next = stmt->compound.statements;
5221                         break;
5222
5223                 case STATEMENT_RETURN:
5224                         noreturn_candidate = false;
5225                         return;
5226
5227                 case STATEMENT_IF: {
5228                         if_statement_t const* const ifs = &stmt->ifs;
5229                         int            const        val = determine_truth(ifs->condition);
5230
5231                         if (val >= 0)
5232                                 check_reachable(ifs->true_statement);
5233
5234                         if (val > 0)
5235                                 return;
5236
5237                         if (ifs->false_statement != NULL) {
5238                                 check_reachable(ifs->false_statement);
5239                                 return;
5240                         }
5241
5242                         next = stmt->base.next;
5243                         break;
5244                 }
5245
5246                 case STATEMENT_SWITCH: {
5247                         switch_statement_t const *const switchs = &stmt->switchs;
5248                         expression_t       const *const expr    = switchs->expression;
5249
5250                         if (is_constant_expression(expr)) {
5251                                 long                    const val      = fold_constant(expr);
5252                                 case_label_statement_t *      defaults = NULL;
5253                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
5254                                         if (i->expression == NULL) {
5255                                                 defaults = i;
5256                                                 continue;
5257                                         }
5258
5259                                         if (i->first_case <= val && val <= i->last_case) {
5260                                                 check_reachable((statement_t*)i);
5261                                                 return;
5262                                         }
5263                                 }
5264
5265                                 if (defaults != NULL) {
5266                                         check_reachable((statement_t*)defaults);
5267                                         return;
5268                                 }
5269                         } else {
5270                                 bool has_default = false;
5271                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
5272                                         if (i->expression == NULL)
5273                                                 has_default = true;
5274
5275                                         check_reachable((statement_t*)i);
5276                                 }
5277
5278                                 if (has_default)
5279                                         return;
5280                         }
5281
5282                         next = stmt->base.next;
5283                         break;
5284                 }
5285
5286                 case STATEMENT_EXPRESSION: {
5287                         /* Check for noreturn function call */
5288                         expression_t const *const expr = stmt->expression.expression;
5289                         if (expr->kind == EXPR_CALL) {
5290                                 expression_t const *const func = expr->call.function;
5291                                 if (func->kind == EXPR_REFERENCE) {
5292                                         declaration_t const *const decl = func->reference.declaration;
5293                                         if (decl != NULL && decl->modifiers & DM_NORETURN) {
5294                                                 return;
5295                                         }
5296                                 }
5297                         }
5298
5299                         next = stmt->base.next;
5300                         break;
5301                 }
5302
5303                 case STATEMENT_CONTINUE: {
5304                         statement_t *parent = stmt;
5305                         for (;;) {
5306                                 parent = parent->base.parent;
5307                                 if (parent == NULL) /* continue not within loop */
5308                                         return;
5309
5310                                 next = parent;
5311                                 switch (parent->kind) {
5312                                         case STATEMENT_WHILE:    goto continue_while;
5313                                         case STATEMENT_DO_WHILE: goto continue_do_while;
5314                                         case STATEMENT_FOR:      goto continue_for;
5315
5316                                         default: break;
5317                                 }
5318                         }
5319                 }
5320
5321                 case STATEMENT_BREAK: {
5322                         statement_t *parent = stmt;
5323                         for (;;) {
5324                                 parent = parent->base.parent;
5325                                 if (parent == NULL) /* break not within loop/switch */
5326                                         return;
5327
5328                                 switch (parent->kind) {
5329                                         case STATEMENT_SWITCH:
5330                                         case STATEMENT_WHILE:
5331                                         case STATEMENT_DO_WHILE:
5332                                         case STATEMENT_FOR:
5333                                                 last = parent;
5334                                                 next = parent->base.next;
5335                                                 goto found_break_parent;
5336
5337                                         default: break;
5338                                 }
5339                         }
5340 found_break_parent:
5341                         break;
5342                 }
5343
5344                 case STATEMENT_GOTO:
5345                         if (stmt->gotos.expression) {
5346                                 statement_t *parent = stmt->base.parent;
5347                                 if (parent == NULL) /* top level goto */
5348                                         return;
5349                                 next = parent;
5350                         } else {
5351                                 next = stmt->gotos.label->init.statement;
5352                                 if (next == NULL) /* missing label */
5353                                         return;
5354                         }
5355                         break;
5356
5357                 case STATEMENT_LABEL:
5358                         next = stmt->label.statement;
5359                         break;
5360
5361                 case STATEMENT_CASE_LABEL:
5362                         next = stmt->case_label.statement;
5363                         break;
5364
5365                 case STATEMENT_WHILE: {
5366                         while_statement_t const *const whiles = &stmt->whiles;
5367                         int                      const val    = determine_truth(whiles->condition);
5368
5369                         if (val >= 0)
5370                                 check_reachable(whiles->body);
5371
5372                         if (val > 0)
5373                                 return;
5374
5375                         next = stmt->base.next;
5376                         break;
5377                 }
5378
5379                 case STATEMENT_DO_WHILE:
5380                         next = stmt->do_while.body;
5381                         break;
5382
5383                 case STATEMENT_FOR: {
5384                         for_statement_t *const fors = &stmt->fors;
5385
5386                         if (fors->condition_reachable)
5387                                 return;
5388                         fors->condition_reachable = true;
5389
5390                         expression_t const *const cond = fors->condition;
5391                         int          const        val  =
5392                                 cond == NULL ? 1 : determine_truth(cond);
5393
5394                         if (val >= 0)
5395                                 check_reachable(fors->body);
5396
5397                         if (val > 0)
5398                                 return;
5399
5400                         next = stmt->base.next;
5401                         break;
5402                 }
5403
5404                 case STATEMENT_MS_TRY: {
5405                         ms_try_statement_t const *const ms_try = &stmt->ms_try;
5406                         check_reachable(ms_try->try_statement);
5407                         next = ms_try->final_statement;
5408                         break;
5409                 }
5410
5411                 case STATEMENT_LEAVE: {
5412                         statement_t *parent = stmt;
5413                         for (;;) {
5414                                 parent = parent->base.parent;
5415                                 if (parent == NULL) /* __leave not within __try */
5416                                         return;
5417
5418                                 if (parent->kind == STATEMENT_MS_TRY) {
5419                                         last = parent;
5420                                         next = parent->ms_try.final_statement;
5421                                         break;
5422                                 }
5423                         }
5424                         break;
5425                 }
5426         }
5427
5428         while (next == NULL) {
5429                 next = last->base.parent;
5430                 if (next == NULL) {
5431                         noreturn_candidate = false;
5432
5433                         type_t *const type = current_function->type;
5434                         assert(is_type_function(type));
5435                         type_t *const ret  = skip_typeref(type->function.return_type);
5436                         if (warning.return_type                    &&
5437                             !is_type_atomic(ret, ATOMIC_TYPE_VOID) &&
5438                             is_type_valid(ret)                     &&
5439                             !is_sym_main(current_function->symbol)) {
5440                                 warningf(&stmt->base.source_position,
5441                                          "control reaches end of non-void function");
5442                         }
5443                         return;
5444                 }
5445
5446                 switch (next->kind) {
5447                         case STATEMENT_INVALID:
5448                         case STATEMENT_EMPTY:
5449                         case STATEMENT_DECLARATION:
5450                         case STATEMENT_EXPRESSION:
5451                         case STATEMENT_ASM:
5452                         case STATEMENT_RETURN:
5453                         case STATEMENT_CONTINUE:
5454                         case STATEMENT_BREAK:
5455                         case STATEMENT_GOTO:
5456                         case STATEMENT_LEAVE:
5457                                 panic("invalid control flow in function");
5458
5459                         case STATEMENT_COMPOUND:
5460                         case STATEMENT_IF:
5461                         case STATEMENT_SWITCH:
5462                         case STATEMENT_LABEL:
5463                         case STATEMENT_CASE_LABEL:
5464                                 last = next;
5465                                 next = next->base.next;
5466                                 break;
5467
5468                         case STATEMENT_WHILE: {
5469 continue_while:
5470                                 if (next->base.reachable)
5471                                         return;
5472                                 next->base.reachable = true;
5473
5474                                 while_statement_t const *const whiles = &next->whiles;
5475                                 int                      const val    = determine_truth(whiles->condition);
5476
5477                                 if (val >= 0)
5478                                         check_reachable(whiles->body);
5479
5480                                 if (val > 0)
5481                                         return;
5482
5483                                 last = next;
5484                                 next = next->base.next;
5485                                 break;
5486                         }
5487
5488                         case STATEMENT_DO_WHILE: {
5489 continue_do_while:
5490                                 if (next->base.reachable)
5491                                         return;
5492                                 next->base.reachable = true;
5493
5494                                 do_while_statement_t const *const dw  = &next->do_while;
5495                                 int                  const        val = determine_truth(dw->condition);
5496
5497                                 if (val >= 0)
5498                                         check_reachable(dw->body);
5499
5500                                 if (val > 0)
5501                                         return;
5502
5503                                 last = next;
5504                                 next = next->base.next;
5505                                 break;
5506                         }
5507
5508                         case STATEMENT_FOR: {
5509 continue_for:;
5510                                 for_statement_t *const fors = &next->fors;
5511
5512                                 fors->step_reachable = true;
5513
5514                                 if (fors->condition_reachable)
5515                                         return;
5516                                 fors->condition_reachable = true;
5517
5518                                 expression_t const *const cond = fors->condition;
5519                                 int          const        val  =
5520                                         cond == NULL ? 1 : determine_truth(cond);
5521
5522                                 if (val >= 0)
5523                                         check_reachable(fors->body);
5524
5525                                 if (val > 0)
5526                                         return;
5527
5528                                 last = next;
5529                                 next = next->base.next;
5530                                 break;
5531                         }
5532
5533                         case STATEMENT_MS_TRY:
5534                                 last = next;
5535                                 next = next->ms_try.final_statement;
5536                                 break;
5537                 }
5538         }
5539
5540         check_reachable(next);
5541 }
5542
5543 static void check_unreachable(statement_t* const stmt, void *const env)
5544 {
5545         (void)env;
5546
5547         switch (stmt->kind) {
5548                 case STATEMENT_DO_WHILE:
5549                         if (!stmt->base.reachable) {
5550                                 expression_t const *const cond = stmt->do_while.condition;
5551                                 if (determine_truth(cond) >= 0) {
5552                                         warningf(&cond->base.source_position,
5553                                                  "condition of do-while-loop is unreachable");
5554                                 }
5555                         }
5556                         return;
5557
5558                 case STATEMENT_FOR: {
5559                         for_statement_t const* const fors = &stmt->fors;
5560
5561                         // if init and step are unreachable, cond is unreachable, too
5562                         if (!stmt->base.reachable && !fors->step_reachable) {
5563                                 warningf(&stmt->base.source_position, "statement is unreachable");
5564                         } else {
5565                                 if (!stmt->base.reachable && fors->initialisation != NULL) {
5566                                         warningf(&fors->initialisation->base.source_position,
5567                                                  "initialisation of for-statement is unreachable");
5568                                 }
5569
5570                                 if (!fors->condition_reachable && fors->condition != NULL) {
5571                                         warningf(&fors->condition->base.source_position,
5572                                                  "condition of for-statement is unreachable");
5573                                 }
5574
5575                                 if (!fors->step_reachable && fors->step != NULL) {
5576                                         warningf(&fors->step->base.source_position,
5577                                                  "step of for-statement is unreachable");
5578                                 }
5579                         }
5580                         return;
5581                 }
5582
5583                 case STATEMENT_COMPOUND:
5584                         if (stmt->compound.statements != NULL)
5585                                 return;
5586                         /* FALLTHROUGH*/
5587
5588                 default:
5589                         if (!stmt->base.reachable)
5590                                 warningf(&stmt->base.source_position, "statement is unreachable");
5591                         return;
5592         }
5593 }
5594
5595 static void parse_external_declaration(void)
5596 {
5597         /* function-definitions and declarations both start with declaration
5598          * specifiers */
5599         declaration_specifiers_t specifiers;
5600         memset(&specifiers, 0, sizeof(specifiers));
5601
5602         add_anchor_token(';');
5603         parse_declaration_specifiers(&specifiers);
5604         rem_anchor_token(';');
5605
5606         /* must be a declaration */
5607         if (token.type == ';') {
5608                 parse_anonymous_declaration_rest(&specifiers);
5609                 return;
5610         }
5611
5612         add_anchor_token(',');
5613         add_anchor_token('=');
5614         add_anchor_token(';');
5615         add_anchor_token('{');
5616
5617         /* declarator is common to both function-definitions and declarations */
5618         declaration_t *ndeclaration = parse_declarator(&specifiers, /*may_be_abstract=*/false);
5619
5620         rem_anchor_token('{');
5621         rem_anchor_token(';');
5622         rem_anchor_token('=');
5623         rem_anchor_token(',');
5624
5625         /* must be a declaration */
5626         switch (token.type) {
5627                 case ',':
5628                 case ';':
5629                 case '=':
5630                         parse_declaration_rest(ndeclaration, &specifiers, record_declaration);
5631                         return;
5632         }
5633
5634         /* must be a function definition */
5635         parse_kr_declaration_list(ndeclaration);
5636
5637         if (token.type != '{') {
5638                 parse_error_expected("while parsing function definition", '{', NULL);
5639                 eat_until_matching_token(';');
5640                 return;
5641         }
5642
5643         type_t *type = ndeclaration->type;
5644
5645         /* note that we don't skip typerefs: the standard doesn't allow them here
5646          * (so we can't use is_type_function here) */
5647         if (type->kind != TYPE_FUNCTION) {
5648                 if (is_type_valid(type)) {
5649                         errorf(HERE, "declarator '%#T' has a body but is not a function type",
5650                                type, ndeclaration->symbol);
5651                 }
5652                 eat_block();
5653                 return;
5654         }
5655
5656         if (warning.aggregate_return &&
5657             is_type_compound(skip_typeref(type->function.return_type))) {
5658                 warningf(HERE, "function '%Y' returns an aggregate",
5659                          ndeclaration->symbol);
5660         }
5661         if (warning.traditional && !type->function.unspecified_parameters) {
5662                 warningf(HERE, "traditional C rejects ISO C style function definition of function '%Y'",
5663                         ndeclaration->symbol);
5664         }
5665         if (warning.old_style_definition && type->function.unspecified_parameters) {
5666                 warningf(HERE, "old-style function definition '%Y'",
5667                         ndeclaration->symbol);
5668         }
5669
5670         /* § 6.7.5.3 (14) a function definition with () means no
5671          * parameters (and not unspecified parameters) */
5672         if (type->function.unspecified_parameters
5673                         && type->function.parameters == NULL
5674                         && !type->function.kr_style_parameters) {
5675                 type_t *duplicate = duplicate_type(type);
5676                 duplicate->function.unspecified_parameters = false;
5677
5678                 type = typehash_insert(duplicate);
5679                 if (type != duplicate) {
5680                         obstack_free(type_obst, duplicate);
5681                 }
5682                 ndeclaration->type = type;
5683         }
5684
5685         declaration_t *const declaration = record_declaration(ndeclaration, true);
5686         if (ndeclaration != declaration) {
5687                 declaration->scope = ndeclaration->scope;
5688         }
5689         type = skip_typeref(declaration->type);
5690
5691         /* push function parameters and switch scope */
5692         size_t const top = environment_top();
5693         scope_push(&declaration->scope);
5694
5695         declaration_t *parameter = declaration->scope.declarations;
5696         for( ; parameter != NULL; parameter = parameter->next) {
5697                 if (parameter->parent_scope == &ndeclaration->scope) {
5698                         parameter->parent_scope = scope;
5699                 }
5700                 assert(parameter->parent_scope == NULL
5701                                 || parameter->parent_scope == scope);
5702                 parameter->parent_scope = scope;
5703                 if (parameter->symbol == NULL) {
5704                         errorf(&parameter->source_position, "parameter name omitted");
5705                         continue;
5706                 }
5707                 environment_push(parameter);
5708         }
5709
5710         if (declaration->init.statement != NULL) {
5711                 parser_error_multiple_definition(declaration, HERE);
5712                 eat_block();
5713         } else {
5714                 /* parse function body */
5715                 int            label_stack_top      = label_top();
5716                 declaration_t *old_current_function = current_function;
5717                 current_function                    = declaration;
5718                 current_parent                      = NULL;
5719
5720                 statement_t *const body = parse_compound_statement(false);
5721                 declaration->init.statement = body;
5722                 first_err = true;
5723                 check_labels();
5724                 check_declarations();
5725                 if (warning.return_type      ||
5726                     warning.unreachable_code ||
5727                     (warning.missing_noreturn && !(declaration->modifiers & DM_NORETURN))) {
5728                         noreturn_candidate = true;
5729                         check_reachable(body);
5730                         if (warning.unreachable_code)
5731                                 walk_statements(body, check_unreachable, NULL);
5732                         if (warning.missing_noreturn &&
5733                             noreturn_candidate       &&
5734                             !(declaration->modifiers & DM_NORETURN)) {
5735                                 warningf(&body->base.source_position,
5736                                          "function '%#T' is candidate for attribute 'noreturn'",
5737                                          type, declaration->symbol);
5738                         }
5739                 }
5740
5741                 assert(current_parent   == NULL);
5742                 assert(current_function == declaration);
5743                 current_function = old_current_function;
5744                 label_pop_to(label_stack_top);
5745         }
5746
5747         assert(scope == &declaration->scope);
5748         scope_pop();
5749         environment_pop_to(top);
5750 }
5751
5752 static type_t *make_bitfield_type(type_t *base_type, expression_t *size,
5753                                   source_position_t *source_position,
5754                                   const symbol_t *symbol)
5755 {
5756         type_t *type = allocate_type_zero(TYPE_BITFIELD);
5757
5758         type->bitfield.base_type       = base_type;
5759         type->bitfield.size_expression = size;
5760
5761         il_size_t bit_size;
5762         type_t *skipped_type = skip_typeref(base_type);
5763         if (!is_type_integer(skipped_type)) {
5764                 errorf(HERE, "bitfield base type '%T' is not an integer type",
5765                         base_type);
5766                 bit_size = 0;
5767         } else {
5768                 bit_size = skipped_type->base.size * 8;
5769         }
5770
5771         if (is_constant_expression(size)) {
5772                 long v = fold_constant(size);
5773
5774                 if (v < 0) {
5775                         errorf(source_position, "negative width in bit-field '%Y'",
5776                                 symbol);
5777                 } else if (v == 0) {
5778                         errorf(source_position, "zero width for bit-field '%Y'",
5779                                 symbol);
5780                 } else if (bit_size > 0 && (il_size_t)v > bit_size) {
5781                         errorf(source_position, "width of '%Y' exceeds its type",
5782                                 symbol);
5783                 } else {
5784                         type->bitfield.bit_size = v;
5785                 }
5786         }
5787
5788         return type;
5789 }
5790
5791 static declaration_t *find_compound_entry(declaration_t *compound_declaration,
5792                                           symbol_t *symbol)
5793 {
5794         declaration_t *iter = compound_declaration->scope.declarations;
5795         for( ; iter != NULL; iter = iter->next) {
5796                 if (iter->namespc != NAMESPACE_NORMAL)
5797                         continue;
5798
5799                 if (iter->symbol == NULL) {
5800                         type_t *type = skip_typeref(iter->type);
5801                         if (is_type_compound(type)) {
5802                                 declaration_t *result
5803                                         = find_compound_entry(type->compound.declaration, symbol);
5804                                 if (result != NULL)
5805                                         return result;
5806                         }
5807                         continue;
5808                 }
5809
5810                 if (iter->symbol == symbol) {
5811                         return iter;
5812                 }
5813         }
5814
5815         return NULL;
5816 }
5817
5818 static void parse_compound_declarators(declaration_t *struct_declaration,
5819                 const declaration_specifiers_t *specifiers)
5820 {
5821         declaration_t *last_declaration = struct_declaration->scope.declarations;
5822         if (last_declaration != NULL) {
5823                 while (last_declaration->next != NULL) {
5824                         last_declaration = last_declaration->next;
5825                 }
5826         }
5827
5828         while (true) {
5829                 declaration_t *declaration;
5830
5831                 if (token.type == ':') {
5832                         source_position_t source_position = *HERE;
5833                         next_token();
5834
5835                         type_t *base_type = specifiers->type;
5836                         expression_t *size = parse_constant_expression();
5837
5838                         type_t *type = make_bitfield_type(base_type, size,
5839                                         &source_position, sym_anonymous);
5840
5841                         declaration                         = allocate_declaration_zero();
5842                         declaration->namespc                = NAMESPACE_NORMAL;
5843                         declaration->declared_storage_class = STORAGE_CLASS_NONE;
5844                         declaration->storage_class          = STORAGE_CLASS_NONE;
5845                         declaration->source_position        = source_position;
5846                         declaration->modifiers              = specifiers->modifiers;
5847                         declaration->type                   = type;
5848                 } else {
5849                         declaration = parse_declarator(specifiers,/*may_be_abstract=*/true);
5850
5851                         type_t *orig_type = declaration->type;
5852                         type_t *type      = skip_typeref(orig_type);
5853
5854                         if (token.type == ':') {
5855                                 source_position_t source_position = *HERE;
5856                                 next_token();
5857                                 expression_t *size = parse_constant_expression();
5858
5859                                 type_t *bitfield_type = make_bitfield_type(orig_type, size,
5860                                                 &source_position, declaration->symbol);
5861                                 declaration->type = bitfield_type;
5862                         } else {
5863                                 /* TODO we ignore arrays for now... what is missing is a check
5864                                  * that they're at the end of the struct */
5865                                 if (is_type_incomplete(type) && !is_type_array(type)) {
5866                                         errorf(HERE,
5867                                                "compound member '%Y' has incomplete type '%T'",
5868                                                declaration->symbol, orig_type);
5869                                 } else if (is_type_function(type)) {
5870                                         errorf(HERE, "compound member '%Y' must not have function type '%T'",
5871                                                declaration->symbol, orig_type);
5872                                 }
5873                         }
5874                 }
5875
5876                 /* make sure we don't define a symbol multiple times */
5877                 symbol_t *symbol = declaration->symbol;
5878                 if (symbol != NULL) {
5879                         declaration_t *prev_decl
5880                                 = find_compound_entry(struct_declaration, symbol);
5881
5882                         if (prev_decl != NULL) {
5883                                 assert(prev_decl->symbol == symbol);
5884                                 errorf(&declaration->source_position,
5885                                        "multiple declarations of symbol '%Y' (declared %P)",
5886                                        symbol, &prev_decl->source_position);
5887                         }
5888                 }
5889
5890                 /* append declaration */
5891                 if (last_declaration != NULL) {
5892                         last_declaration->next = declaration;
5893                 } else {
5894                         struct_declaration->scope.declarations = declaration;
5895                 }
5896                 last_declaration = declaration;
5897
5898                 if (token.type != ',')
5899                         break;
5900                 next_token();
5901         }
5902         expect(';');
5903
5904 end_error:
5905         ;
5906 }
5907
5908 static void parse_compound_type_entries(declaration_t *compound_declaration)
5909 {
5910         eat('{');
5911         add_anchor_token('}');
5912
5913         while (token.type != '}') {
5914                 if (token.type == T_EOF) {
5915                         errorf(HERE, "EOF while parsing struct");
5916                         break;
5917                 }
5918                 declaration_specifiers_t specifiers;
5919                 memset(&specifiers, 0, sizeof(specifiers));
5920                 parse_declaration_specifiers(&specifiers);
5921
5922                 parse_compound_declarators(compound_declaration, &specifiers);
5923         }
5924         rem_anchor_token('}');
5925         next_token();
5926 }
5927
5928 static type_t *parse_typename(void)
5929 {
5930         declaration_specifiers_t specifiers;
5931         memset(&specifiers, 0, sizeof(specifiers));
5932         parse_declaration_specifiers(&specifiers);
5933         if (specifiers.declared_storage_class != STORAGE_CLASS_NONE) {
5934                 /* TODO: improve error message, user does probably not know what a
5935                  * storage class is...
5936                  */
5937                 errorf(HERE, "typename may not have a storage class");
5938         }
5939
5940         type_t *result = parse_abstract_declarator(specifiers.type);
5941
5942         return result;
5943 }
5944
5945
5946
5947
5948 typedef expression_t* (*parse_expression_function)(void);
5949 typedef expression_t* (*parse_expression_infix_function)(expression_t *left);
5950
5951 typedef struct expression_parser_function_t expression_parser_function_t;
5952 struct expression_parser_function_t {
5953         parse_expression_function        parser;
5954         unsigned                         infix_precedence;
5955         parse_expression_infix_function  infix_parser;
5956 };
5957
5958 expression_parser_function_t expression_parsers[T_LAST_TOKEN];
5959
5960 /**
5961  * Prints an error message if an expression was expected but not read
5962  */
5963 static expression_t *expected_expression_error(void)
5964 {
5965         /* skip the error message if the error token was read */
5966         if (token.type != T_ERROR) {
5967                 errorf(HERE, "expected expression, got token '%K'", &token);
5968         }
5969         next_token();
5970
5971         return create_invalid_expression();
5972 }
5973
5974 /**
5975  * Parse a string constant.
5976  */
5977 static expression_t *parse_string_const(void)
5978 {
5979         wide_string_t wres;
5980         if (token.type == T_STRING_LITERAL) {
5981                 string_t res = token.v.string;
5982                 next_token();
5983                 while (token.type == T_STRING_LITERAL) {
5984                         res = concat_strings(&res, &token.v.string);
5985                         next_token();
5986                 }
5987                 if (token.type != T_WIDE_STRING_LITERAL) {
5988                         expression_t *const cnst = allocate_expression_zero(EXPR_STRING_LITERAL);
5989                         /* note: that we use type_char_ptr here, which is already the
5990                          * automatic converted type. revert_automatic_type_conversion
5991                          * will construct the array type */
5992                         cnst->base.type    = warning.write_strings ? type_const_char_ptr : type_char_ptr;
5993                         cnst->string.value = res;
5994                         return cnst;
5995                 }
5996
5997                 wres = concat_string_wide_string(&res, &token.v.wide_string);
5998         } else {
5999                 wres = token.v.wide_string;
6000         }
6001         next_token();
6002
6003         for (;;) {
6004                 switch (token.type) {
6005                         case T_WIDE_STRING_LITERAL:
6006                                 wres = concat_wide_strings(&wres, &token.v.wide_string);
6007                                 break;
6008
6009                         case T_STRING_LITERAL:
6010                                 wres = concat_wide_string_string(&wres, &token.v.string);
6011                                 break;
6012
6013                         default: {
6014                                 expression_t *const cnst = allocate_expression_zero(EXPR_WIDE_STRING_LITERAL);
6015                                 cnst->base.type         = warning.write_strings ? type_const_wchar_t_ptr : type_wchar_t_ptr;
6016                                 cnst->wide_string.value = wres;
6017                                 return cnst;
6018                         }
6019                 }
6020                 next_token();
6021         }
6022 }
6023
6024 /**
6025  * Parse an integer constant.
6026  */
6027 static expression_t *parse_int_const(void)
6028 {
6029         expression_t *cnst         = allocate_expression_zero(EXPR_CONST);
6030         cnst->base.source_position = *HERE;
6031         cnst->base.type            = token.datatype;
6032         cnst->conste.v.int_value   = token.v.intvalue;
6033
6034         next_token();
6035
6036         return cnst;
6037 }
6038
6039 /**
6040  * Parse a character constant.
6041  */
6042 static expression_t *parse_character_constant(void)
6043 {
6044         expression_t *cnst = allocate_expression_zero(EXPR_CHARACTER_CONSTANT);
6045
6046         cnst->base.source_position = *HERE;
6047         cnst->base.type            = token.datatype;
6048         cnst->conste.v.character   = token.v.string;
6049
6050         if (cnst->conste.v.character.size != 1) {
6051                 if (warning.multichar && GNU_MODE) {
6052                         warningf(HERE, "multi-character character constant");
6053                 } else {
6054                         errorf(HERE, "more than 1 characters in character constant");
6055                 }
6056         }
6057         next_token();
6058
6059         return cnst;
6060 }
6061
6062 /**
6063  * Parse a wide character constant.
6064  */
6065 static expression_t *parse_wide_character_constant(void)
6066 {
6067         expression_t *cnst = allocate_expression_zero(EXPR_WIDE_CHARACTER_CONSTANT);
6068
6069         cnst->base.source_position    = *HERE;
6070         cnst->base.type               = token.datatype;
6071         cnst->conste.v.wide_character = token.v.wide_string;
6072
6073         if (cnst->conste.v.wide_character.size != 1) {
6074                 if (warning.multichar && GNU_MODE) {
6075                         warningf(HERE, "multi-character character constant");
6076                 } else {
6077                         errorf(HERE, "more than 1 characters in character constant");
6078                 }
6079         }
6080         next_token();
6081
6082         return cnst;
6083 }
6084
6085 /**
6086  * Parse a float constant.
6087  */
6088 static expression_t *parse_float_const(void)
6089 {
6090         expression_t *cnst         = allocate_expression_zero(EXPR_CONST);
6091         cnst->base.type            = token.datatype;
6092         cnst->conste.v.float_value = token.v.floatvalue;
6093
6094         next_token();
6095
6096         return cnst;
6097 }
6098
6099 static declaration_t *create_implicit_function(symbol_t *symbol,
6100                 const source_position_t *source_position)
6101 {
6102         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
6103         ntype->function.return_type            = type_int;
6104         ntype->function.unspecified_parameters = true;
6105
6106         type_t *type = typehash_insert(ntype);
6107         if (type != ntype) {
6108                 free_type(ntype);
6109         }
6110
6111         declaration_t *const declaration    = allocate_declaration_zero();
6112         declaration->storage_class          = STORAGE_CLASS_EXTERN;
6113         declaration->declared_storage_class = STORAGE_CLASS_EXTERN;
6114         declaration->type                   = type;
6115         declaration->symbol                 = symbol;
6116         declaration->source_position        = *source_position;
6117         declaration->implicit               = true;
6118
6119         bool strict_prototypes_old = warning.strict_prototypes;
6120         warning.strict_prototypes  = false;
6121         record_declaration(declaration, false);
6122         warning.strict_prototypes = strict_prototypes_old;
6123
6124         return declaration;
6125 }
6126
6127 /**
6128  * Creates a return_type (func)(argument_type) function type if not
6129  * already exists.
6130  */
6131 static type_t *make_function_2_type(type_t *return_type, type_t *argument_type1,
6132                                     type_t *argument_type2)
6133 {
6134         function_parameter_t *parameter2
6135                 = obstack_alloc(type_obst, sizeof(parameter2[0]));
6136         memset(parameter2, 0, sizeof(parameter2[0]));
6137         parameter2->type = argument_type2;
6138
6139         function_parameter_t *parameter1
6140                 = obstack_alloc(type_obst, sizeof(parameter1[0]));
6141         memset(parameter1, 0, sizeof(parameter1[0]));
6142         parameter1->type = argument_type1;
6143         parameter1->next = parameter2;
6144
6145         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6146         type->function.return_type = return_type;
6147         type->function.parameters  = parameter1;
6148
6149         type_t *result = typehash_insert(type);
6150         if (result != type) {
6151                 free_type(type);
6152         }
6153
6154         return result;
6155 }
6156
6157 /**
6158  * Creates a return_type (func)(argument_type) function type if not
6159  * already exists.
6160  *
6161  * @param return_type    the return type
6162  * @param argument_type  the argument type
6163  */
6164 static type_t *make_function_1_type(type_t *return_type, type_t *argument_type)
6165 {
6166         function_parameter_t *parameter
6167                 = obstack_alloc(type_obst, sizeof(parameter[0]));
6168         memset(parameter, 0, sizeof(parameter[0]));
6169         parameter->type = argument_type;
6170
6171         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6172         type->function.return_type = return_type;
6173         type->function.parameters  = parameter;
6174
6175         type_t *result = typehash_insert(type);
6176         if (result != type) {
6177                 free_type(type);
6178         }
6179
6180         return result;
6181 }
6182
6183 static type_t *make_function_0_type(type_t *return_type)
6184 {
6185         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6186         type->function.return_type = return_type;
6187         type->function.parameters  = NULL;
6188
6189         type_t *result = typehash_insert(type);
6190         if (result != type) {
6191                 free_type(type);
6192         }
6193
6194         return result;
6195 }
6196
6197 /**
6198  * Creates a function type for some function like builtins.
6199  *
6200  * @param symbol   the symbol describing the builtin
6201  */
6202 static type_t *get_builtin_symbol_type(symbol_t *symbol)
6203 {
6204         switch(symbol->ID) {
6205         case T___builtin_alloca:
6206                 return make_function_1_type(type_void_ptr, type_size_t);
6207         case T___builtin_huge_val:
6208                 return make_function_0_type(type_double);
6209         case T___builtin_inf:
6210                 return make_function_0_type(type_double);
6211         case T___builtin_inff:
6212                 return make_function_0_type(type_float);
6213         case T___builtin_infl:
6214                 return make_function_0_type(type_long_double);
6215         case T___builtin_nan:
6216                 return make_function_1_type(type_double, type_char_ptr);
6217         case T___builtin_nanf:
6218                 return make_function_1_type(type_float, type_char_ptr);
6219         case T___builtin_nanl:
6220                 return make_function_1_type(type_long_double, type_char_ptr);
6221         case T___builtin_va_end:
6222                 return make_function_1_type(type_void, type_valist);
6223         case T___builtin_expect:
6224                 return make_function_2_type(type_long, type_long, type_long);
6225         default:
6226                 internal_errorf(HERE, "not implemented builtin symbol found");
6227         }
6228 }
6229
6230 /**
6231  * Performs automatic type cast as described in § 6.3.2.1.
6232  *
6233  * @param orig_type  the original type
6234  */
6235 static type_t *automatic_type_conversion(type_t *orig_type)
6236 {
6237         type_t *type = skip_typeref(orig_type);
6238         if (is_type_array(type)) {
6239                 array_type_t *array_type   = &type->array;
6240                 type_t       *element_type = array_type->element_type;
6241                 unsigned      qualifiers   = array_type->base.qualifiers;
6242
6243                 return make_pointer_type(element_type, qualifiers);
6244         }
6245
6246         if (is_type_function(type)) {
6247                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
6248         }
6249
6250         return orig_type;
6251 }
6252
6253 /**
6254  * reverts the automatic casts of array to pointer types and function
6255  * to function-pointer types as defined § 6.3.2.1
6256  */
6257 type_t *revert_automatic_type_conversion(const expression_t *expression)
6258 {
6259         switch (expression->kind) {
6260                 case EXPR_REFERENCE: return expression->reference.declaration->type;
6261
6262                 case EXPR_SELECT:
6263                         return get_qualified_type(expression->select.compound_entry->type,
6264                                                   expression->base.type->base.qualifiers);
6265
6266                 case EXPR_UNARY_DEREFERENCE: {
6267                         const expression_t *const value = expression->unary.value;
6268                         type_t             *const type  = skip_typeref(value->base.type);
6269                         assert(is_type_pointer(type));
6270                         return type->pointer.points_to;
6271                 }
6272
6273                 case EXPR_BUILTIN_SYMBOL:
6274                         return get_builtin_symbol_type(expression->builtin_symbol.symbol);
6275
6276                 case EXPR_ARRAY_ACCESS: {
6277                         const expression_t *array_ref = expression->array_access.array_ref;
6278                         type_t             *type_left = skip_typeref(array_ref->base.type);
6279                         if (!is_type_valid(type_left))
6280                                 return type_left;
6281                         assert(is_type_pointer(type_left));
6282                         return type_left->pointer.points_to;
6283                 }
6284
6285                 case EXPR_STRING_LITERAL: {
6286                         size_t size = expression->string.value.size;
6287                         return make_array_type(type_char, size, TYPE_QUALIFIER_NONE);
6288                 }
6289
6290                 case EXPR_WIDE_STRING_LITERAL: {
6291                         size_t size = expression->wide_string.value.size;
6292                         return make_array_type(type_wchar_t, size, TYPE_QUALIFIER_NONE);
6293                 }
6294
6295                 case EXPR_COMPOUND_LITERAL:
6296                         return expression->compound_literal.type;
6297
6298                 default: break;
6299         }
6300
6301         return expression->base.type;
6302 }
6303
6304 static expression_t *parse_reference(void)
6305 {
6306         expression_t *expression = allocate_expression_zero(EXPR_REFERENCE);
6307
6308         reference_expression_t *ref = &expression->reference;
6309         symbol_t *const symbol = token.v.symbol;
6310
6311         declaration_t *declaration = get_declaration(symbol, NAMESPACE_NORMAL);
6312
6313         if (declaration == NULL) {
6314                 if (!strict_mode && look_ahead(1)->type == '(') {
6315                         /* an implicitly declared function */
6316                         if (warning.implicit_function_declaration) {
6317                                 warningf(HERE, "implicit declaration of function '%Y'",
6318                                         symbol);
6319                         }
6320
6321                         declaration = create_implicit_function(symbol, HERE);
6322                 } else {
6323                         errorf(HERE, "unknown symbol '%Y' found.", symbol);
6324                         declaration = create_error_declaration(symbol, STORAGE_CLASS_NONE);
6325                 }
6326         }
6327
6328         type_t *orig_type = declaration->type;
6329
6330         /* we always do the auto-type conversions; the & and sizeof parser contains
6331          * code to revert this! */
6332         type_t *type = automatic_type_conversion(orig_type);
6333
6334         ref->declaration = declaration;
6335         ref->base.type   = type;
6336
6337         /* this declaration is used */
6338         declaration->used = true;
6339
6340         if (declaration->parent_scope != file_scope                          &&
6341             declaration->parent_scope->depth < current_function->scope.depth &&
6342             is_type_valid(orig_type) && !is_type_function(orig_type)) {
6343                 /* access of a variable from an outer function */
6344                 declaration->address_taken     = true;
6345                 current_function->need_closure = true;
6346         }
6347
6348         /* check for deprecated functions */
6349         if (warning.deprecated_declarations &&
6350             declaration->modifiers & DM_DEPRECATED) {
6351                 char const *const prefix = is_type_function(declaration->type) ?
6352                         "function" : "variable";
6353
6354                 if (declaration->deprecated_string != NULL) {
6355                         warningf(HERE, "%s '%Y' is deprecated (declared %P): \"%s\"",
6356                                 prefix, declaration->symbol, &declaration->source_position,
6357                                 declaration->deprecated_string);
6358                 } else {
6359                         warningf(HERE, "%s '%Y' is deprecated (declared %P)", prefix,
6360                                 declaration->symbol, &declaration->source_position);
6361                 }
6362         }
6363         if (warning.init_self && declaration == current_init_decl && !in_type_prop) {
6364                 current_init_decl = NULL;
6365                 warningf(HERE, "variable '%#T' is initialized by itself",
6366                         declaration->type, declaration->symbol);
6367         }
6368
6369         next_token();
6370         return expression;
6371 }
6372
6373 static bool semantic_cast(expression_t *cast)
6374 {
6375         expression_t            *expression      = cast->unary.value;
6376         type_t                  *orig_dest_type  = cast->base.type;
6377         type_t                  *orig_type_right = expression->base.type;
6378         type_t            const *dst_type        = skip_typeref(orig_dest_type);
6379         type_t            const *src_type        = skip_typeref(orig_type_right);
6380         source_position_t const *pos             = &cast->base.source_position;
6381
6382         /* §6.5.4 A (void) cast is explicitly permitted, more for documentation than for utility. */
6383         if (dst_type == type_void)
6384                 return true;
6385
6386         /* only integer and pointer can be casted to pointer */
6387         if (is_type_pointer(dst_type)  &&
6388             !is_type_pointer(src_type) &&
6389             !is_type_integer(src_type) &&
6390             is_type_valid(src_type)) {
6391                 errorf(pos, "cannot convert type '%T' to a pointer type", orig_type_right);
6392                 return false;
6393         }
6394
6395         if (!is_type_scalar(dst_type) && is_type_valid(dst_type)) {
6396                 errorf(pos, "conversion to non-scalar type '%T' requested", orig_dest_type);
6397                 return false;
6398         }
6399
6400         if (!is_type_scalar(src_type) && is_type_valid(src_type)) {
6401                 errorf(pos, "conversion from non-scalar type '%T' requested", orig_type_right);
6402                 return false;
6403         }
6404
6405         if (warning.cast_qual &&
6406             is_type_pointer(src_type) &&
6407             is_type_pointer(dst_type)) {
6408                 type_t *src = skip_typeref(src_type->pointer.points_to);
6409                 type_t *dst = skip_typeref(dst_type->pointer.points_to);
6410                 unsigned missing_qualifiers =
6411                         src->base.qualifiers & ~dst->base.qualifiers;
6412                 if (missing_qualifiers != 0) {
6413                         warningf(pos,
6414                                  "cast discards qualifiers '%Q' in pointer target type of '%T'",
6415                                  missing_qualifiers, orig_type_right);
6416                 }
6417         }
6418         return true;
6419 }
6420
6421 static expression_t *parse_compound_literal(type_t *type)
6422 {
6423         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
6424
6425         parse_initializer_env_t env;
6426         env.type             = type;
6427         env.declaration      = NULL;
6428         env.must_be_constant = false;
6429         initializer_t *initializer = parse_initializer(&env);
6430         type = env.type;
6431
6432         expression->compound_literal.initializer = initializer;
6433         expression->compound_literal.type        = type;
6434         expression->base.type                    = automatic_type_conversion(type);
6435
6436         return expression;
6437 }
6438
6439 /**
6440  * Parse a cast expression.
6441  */
6442 static expression_t *parse_cast(void)
6443 {
6444         add_anchor_token(')');
6445
6446         source_position_t source_position = token.source_position;
6447
6448         type_t *type  = parse_typename();
6449
6450         rem_anchor_token(')');
6451         expect(')');
6452
6453         if (token.type == '{') {
6454                 return parse_compound_literal(type);
6455         }
6456
6457         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
6458         cast->base.source_position = source_position;
6459
6460         expression_t *value = parse_sub_expression(PREC_CAST);
6461         cast->base.type   = type;
6462         cast->unary.value = value;
6463
6464         if (! semantic_cast(cast)) {
6465                 /* TODO: record the error in the AST. else it is impossible to detect it */
6466         }
6467
6468         return cast;
6469 end_error:
6470         return create_invalid_expression();
6471 }
6472
6473 /**
6474  * Parse a statement expression.
6475  */
6476 static expression_t *parse_statement_expression(void)
6477 {
6478         add_anchor_token(')');
6479
6480         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
6481
6482         statement_t *statement           = parse_compound_statement(true);
6483         expression->statement.statement  = statement;
6484         expression->base.source_position = statement->base.source_position;
6485
6486         /* find last statement and use its type */
6487         type_t *type = type_void;
6488         const statement_t *stmt = statement->compound.statements;
6489         if (stmt != NULL) {
6490                 while (stmt->base.next != NULL)
6491                         stmt = stmt->base.next;
6492
6493                 if (stmt->kind == STATEMENT_EXPRESSION) {
6494                         type = stmt->expression.expression->base.type;
6495                 }
6496         } else if (warning.other) {
6497                 warningf(&expression->base.source_position, "empty statement expression ({})");
6498         }
6499         expression->base.type = type;
6500
6501         rem_anchor_token(')');
6502         expect(')');
6503
6504 end_error:
6505         return expression;
6506 }
6507
6508 /**
6509  * Parse a parenthesized expression.
6510  */
6511 static expression_t *parse_parenthesized_expression(void)
6512 {
6513         eat('(');
6514
6515         switch(token.type) {
6516         case '{':
6517                 /* gcc extension: a statement expression */
6518                 return parse_statement_expression();
6519
6520         TYPE_QUALIFIERS
6521         TYPE_SPECIFIERS
6522                 return parse_cast();
6523         case T_IDENTIFIER:
6524                 if (is_typedef_symbol(token.v.symbol)) {
6525                         return parse_cast();
6526                 }
6527         }
6528
6529         add_anchor_token(')');
6530         expression_t *result = parse_expression();
6531         rem_anchor_token(')');
6532         expect(')');
6533
6534 end_error:
6535         return result;
6536 }
6537
6538 static expression_t *parse_function_keyword(void)
6539 {
6540         next_token();
6541         /* TODO */
6542
6543         if (current_function == NULL) {
6544                 errorf(HERE, "'__func__' used outside of a function");
6545         }
6546
6547         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6548         expression->base.type     = type_char_ptr;
6549         expression->funcname.kind = FUNCNAME_FUNCTION;
6550
6551         return expression;
6552 }
6553
6554 static expression_t *parse_pretty_function_keyword(void)
6555 {
6556         eat(T___PRETTY_FUNCTION__);
6557
6558         if (current_function == NULL) {
6559                 errorf(HERE, "'__PRETTY_FUNCTION__' used outside of a function");
6560         }
6561
6562         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6563         expression->base.type     = type_char_ptr;
6564         expression->funcname.kind = FUNCNAME_PRETTY_FUNCTION;
6565
6566         return expression;
6567 }
6568
6569 static expression_t *parse_funcsig_keyword(void)
6570 {
6571         eat(T___FUNCSIG__);
6572
6573         if (current_function == NULL) {
6574                 errorf(HERE, "'__FUNCSIG__' used outside of a function");
6575         }
6576
6577         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6578         expression->base.type     = type_char_ptr;
6579         expression->funcname.kind = FUNCNAME_FUNCSIG;
6580
6581         return expression;
6582 }
6583
6584 static expression_t *parse_funcdname_keyword(void)
6585 {
6586         eat(T___FUNCDNAME__);
6587
6588         if (current_function == NULL) {
6589                 errorf(HERE, "'__FUNCDNAME__' used outside of a function");
6590         }
6591
6592         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6593         expression->base.type     = type_char_ptr;
6594         expression->funcname.kind = FUNCNAME_FUNCDNAME;
6595
6596         return expression;
6597 }
6598
6599 static designator_t *parse_designator(void)
6600 {
6601         designator_t *result    = allocate_ast_zero(sizeof(result[0]));
6602         result->source_position = *HERE;
6603
6604         if (token.type != T_IDENTIFIER) {
6605                 parse_error_expected("while parsing member designator",
6606                                      T_IDENTIFIER, NULL);
6607                 return NULL;
6608         }
6609         result->symbol = token.v.symbol;
6610         next_token();
6611
6612         designator_t *last_designator = result;
6613         while(true) {
6614                 if (token.type == '.') {
6615                         next_token();
6616                         if (token.type != T_IDENTIFIER) {
6617                                 parse_error_expected("while parsing member designator",
6618                                                      T_IDENTIFIER, NULL);
6619                                 return NULL;
6620                         }
6621                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
6622                         designator->source_position = *HERE;
6623                         designator->symbol          = token.v.symbol;
6624                         next_token();
6625
6626                         last_designator->next = designator;
6627                         last_designator       = designator;
6628                         continue;
6629                 }
6630                 if (token.type == '[') {
6631                         next_token();
6632                         add_anchor_token(']');
6633                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
6634                         designator->source_position = *HERE;
6635                         designator->array_index     = parse_expression();
6636                         rem_anchor_token(']');
6637                         expect(']');
6638                         if (designator->array_index == NULL) {
6639                                 return NULL;
6640                         }
6641
6642                         last_designator->next = designator;
6643                         last_designator       = designator;
6644                         continue;
6645                 }
6646                 break;
6647         }
6648
6649         return result;
6650 end_error:
6651         return NULL;
6652 }
6653
6654 /**
6655  * Parse the __builtin_offsetof() expression.
6656  */
6657 static expression_t *parse_offsetof(void)
6658 {
6659         eat(T___builtin_offsetof);
6660
6661         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
6662         expression->base.type    = type_size_t;
6663
6664         expect('(');
6665         add_anchor_token(',');
6666         type_t *type = parse_typename();
6667         rem_anchor_token(',');
6668         expect(',');
6669         add_anchor_token(')');
6670         designator_t *designator = parse_designator();
6671         rem_anchor_token(')');
6672         expect(')');
6673
6674         expression->offsetofe.type       = type;
6675         expression->offsetofe.designator = designator;
6676
6677         type_path_t path;
6678         memset(&path, 0, sizeof(path));
6679         path.top_type = type;
6680         path.path     = NEW_ARR_F(type_path_entry_t, 0);
6681
6682         descend_into_subtype(&path);
6683
6684         if (!walk_designator(&path, designator, true)) {
6685                 return create_invalid_expression();
6686         }
6687
6688         DEL_ARR_F(path.path);
6689
6690         return expression;
6691 end_error:
6692         return create_invalid_expression();
6693 }
6694
6695 /**
6696  * Parses a _builtin_va_start() expression.
6697  */
6698 static expression_t *parse_va_start(void)
6699 {
6700         eat(T___builtin_va_start);
6701
6702         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
6703
6704         expect('(');
6705         add_anchor_token(',');
6706         expression->va_starte.ap = parse_assignment_expression();
6707         rem_anchor_token(',');
6708         expect(',');
6709         expression_t *const expr = parse_assignment_expression();
6710         if (expr->kind == EXPR_REFERENCE) {
6711                 declaration_t *const decl = expr->reference.declaration;
6712                 if (decl->parent_scope != &current_function->scope || decl->next != NULL) {
6713                         errorf(&expr->base.source_position,
6714                                "second argument of 'va_start' must be last parameter of the current function");
6715                 }
6716                 expression->va_starte.parameter = decl;
6717                 expect(')');
6718                 return expression;
6719         }
6720         expect(')');
6721 end_error:
6722         return create_invalid_expression();
6723 }
6724
6725 /**
6726  * Parses a _builtin_va_arg() expression.
6727  */
6728 static expression_t *parse_va_arg(void)
6729 {
6730         eat(T___builtin_va_arg);
6731
6732         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
6733
6734         expect('(');
6735         expression->va_arge.ap = parse_assignment_expression();
6736         expect(',');
6737         expression->base.type = parse_typename();
6738         expect(')');
6739
6740         return expression;
6741 end_error:
6742         return create_invalid_expression();
6743 }
6744
6745 static expression_t *parse_builtin_symbol(void)
6746 {
6747         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_SYMBOL);
6748
6749         symbol_t *symbol = token.v.symbol;
6750
6751         expression->builtin_symbol.symbol = symbol;
6752         next_token();
6753
6754         type_t *type = get_builtin_symbol_type(symbol);
6755         type = automatic_type_conversion(type);
6756
6757         expression->base.type = type;
6758         return expression;
6759 }
6760
6761 /**
6762  * Parses a __builtin_constant() expression.
6763  */
6764 static expression_t *parse_builtin_constant(void)
6765 {
6766         eat(T___builtin_constant_p);
6767
6768         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
6769
6770         expect('(');
6771         add_anchor_token(')');
6772         expression->builtin_constant.value = parse_assignment_expression();
6773         rem_anchor_token(')');
6774         expect(')');
6775         expression->base.type = type_int;
6776
6777         return expression;
6778 end_error:
6779         return create_invalid_expression();
6780 }
6781
6782 /**
6783  * Parses a __builtin_prefetch() expression.
6784  */
6785 static expression_t *parse_builtin_prefetch(void)
6786 {
6787         eat(T___builtin_prefetch);
6788
6789         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_PREFETCH);
6790
6791         expect('(');
6792         add_anchor_token(')');
6793         expression->builtin_prefetch.adr = parse_assignment_expression();
6794         if (token.type == ',') {
6795                 next_token();
6796                 expression->builtin_prefetch.rw = parse_assignment_expression();
6797         }
6798         if (token.type == ',') {
6799                 next_token();
6800                 expression->builtin_prefetch.locality = parse_assignment_expression();
6801         }
6802         rem_anchor_token(')');
6803         expect(')');
6804         expression->base.type = type_void;
6805
6806         return expression;
6807 end_error:
6808         return create_invalid_expression();
6809 }
6810
6811 /**
6812  * Parses a __builtin_is_*() compare expression.
6813  */
6814 static expression_t *parse_compare_builtin(void)
6815 {
6816         expression_t *expression;
6817
6818         switch(token.type) {
6819         case T___builtin_isgreater:
6820                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATER);
6821                 break;
6822         case T___builtin_isgreaterequal:
6823                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATEREQUAL);
6824                 break;
6825         case T___builtin_isless:
6826                 expression = allocate_expression_zero(EXPR_BINARY_ISLESS);
6827                 break;
6828         case T___builtin_islessequal:
6829                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSEQUAL);
6830                 break;
6831         case T___builtin_islessgreater:
6832                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSGREATER);
6833                 break;
6834         case T___builtin_isunordered:
6835                 expression = allocate_expression_zero(EXPR_BINARY_ISUNORDERED);
6836                 break;
6837         default:
6838                 internal_errorf(HERE, "invalid compare builtin found");
6839         }
6840         expression->base.source_position = *HERE;
6841         next_token();
6842
6843         expect('(');
6844         expression->binary.left = parse_assignment_expression();
6845         expect(',');
6846         expression->binary.right = parse_assignment_expression();
6847         expect(')');
6848
6849         type_t *const orig_type_left  = expression->binary.left->base.type;
6850         type_t *const orig_type_right = expression->binary.right->base.type;
6851
6852         type_t *const type_left  = skip_typeref(orig_type_left);
6853         type_t *const type_right = skip_typeref(orig_type_right);
6854         if (!is_type_float(type_left) && !is_type_float(type_right)) {
6855                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
6856                         type_error_incompatible("invalid operands in comparison",
6857                                 &expression->base.source_position, orig_type_left, orig_type_right);
6858                 }
6859         } else {
6860                 semantic_comparison(&expression->binary);
6861         }
6862
6863         return expression;
6864 end_error:
6865         return create_invalid_expression();
6866 }
6867
6868 #if 0
6869 /**
6870  * Parses a __builtin_expect() expression.
6871  */
6872 static expression_t *parse_builtin_expect(void)
6873 {
6874         eat(T___builtin_expect);
6875
6876         expression_t *expression
6877                 = allocate_expression_zero(EXPR_BINARY_BUILTIN_EXPECT);
6878
6879         expect('(');
6880         expression->binary.left = parse_assignment_expression();
6881         expect(',');
6882         expression->binary.right = parse_constant_expression();
6883         expect(')');
6884
6885         expression->base.type = expression->binary.left->base.type;
6886
6887         return expression;
6888 end_error:
6889         return create_invalid_expression();
6890 }
6891 #endif
6892
6893 /**
6894  * Parses a MS assume() expression.
6895  */
6896 static expression_t *parse_assume(void)
6897 {
6898         eat(T__assume);
6899
6900         expression_t *expression
6901                 = allocate_expression_zero(EXPR_UNARY_ASSUME);
6902
6903         expect('(');
6904         add_anchor_token(')');
6905         expression->unary.value = parse_assignment_expression();
6906         rem_anchor_token(')');
6907         expect(')');
6908
6909         expression->base.type = type_void;
6910         return expression;
6911 end_error:
6912         return create_invalid_expression();
6913 }
6914
6915 /**
6916  * Return the declaration for a given label symbol or create a new one.
6917  *
6918  * @param symbol  the symbol of the label
6919  */
6920 static declaration_t *get_label(symbol_t *symbol)
6921 {
6922         declaration_t *candidate;
6923         assert(current_function != NULL);
6924
6925         candidate = get_declaration(symbol, NAMESPACE_LOCAL_LABEL);
6926         /* if we found a local label, we already created the declaration */
6927         if (candidate != NULL) {
6928                 if (candidate->parent_scope != scope) {
6929                         assert(candidate->parent_scope->depth < scope->depth);
6930                         current_function->goto_to_outer = true;
6931                 }
6932                 return candidate;
6933         }
6934
6935         candidate = get_declaration(symbol, NAMESPACE_LABEL);
6936         /* if we found a label in the same function, then we already created the
6937          * declaration */
6938         if (candidate != NULL
6939                         && candidate->parent_scope == &current_function->scope) {
6940                 return candidate;
6941         }
6942
6943         /* otherwise we need to create a new one */
6944         declaration_t *const declaration = allocate_declaration_zero();
6945         declaration->namespc       = NAMESPACE_LABEL;
6946         declaration->symbol        = symbol;
6947
6948         label_push(declaration);
6949
6950         return declaration;
6951 }
6952
6953 /**
6954  * Parses a GNU && label address expression.
6955  */
6956 static expression_t *parse_label_address(void)
6957 {
6958         source_position_t source_position = token.source_position;
6959         eat(T_ANDAND);
6960         if (token.type != T_IDENTIFIER) {
6961                 parse_error_expected("while parsing label address", T_IDENTIFIER, NULL);
6962                 goto end_error;
6963         }
6964         symbol_t *symbol = token.v.symbol;
6965         next_token();
6966
6967         declaration_t *label = get_label(symbol);
6968
6969         label->used          = true;
6970         label->address_taken = true;
6971
6972         expression_t *expression = allocate_expression_zero(EXPR_LABEL_ADDRESS);
6973         expression->base.source_position = source_position;
6974
6975         /* label address is threaten as a void pointer */
6976         expression->base.type                 = type_void_ptr;
6977         expression->label_address.declaration = label;
6978         return expression;
6979 end_error:
6980         return create_invalid_expression();
6981 }
6982
6983 /**
6984  * Parse a microsoft __noop expression.
6985  */
6986 static expression_t *parse_noop_expression(void)
6987 {
6988         source_position_t source_position = *HERE;
6989         eat(T___noop);
6990
6991         if (token.type == '(') {
6992                 /* parse arguments */
6993                 eat('(');
6994                 add_anchor_token(')');
6995                 add_anchor_token(',');
6996
6997                 if (token.type != ')') {
6998                         while(true) {
6999                                 (void)parse_assignment_expression();
7000                                 if (token.type != ',')
7001                                         break;
7002                                 next_token();
7003                         }
7004                 }
7005         }
7006         rem_anchor_token(',');
7007         rem_anchor_token(')');
7008         expect(')');
7009
7010         /* the result is a (int)0 */
7011         expression_t *cnst         = allocate_expression_zero(EXPR_CONST);
7012         cnst->base.source_position = source_position;
7013         cnst->base.type            = type_int;
7014         cnst->conste.v.int_value   = 0;
7015         cnst->conste.is_ms_noop    = true;
7016
7017         return cnst;
7018
7019 end_error:
7020         return create_invalid_expression();
7021 }
7022
7023 /**
7024  * Parses a primary expression.
7025  */
7026 static expression_t *parse_primary_expression(void)
7027 {
7028         switch (token.type) {
7029                 case T_INTEGER:                  return parse_int_const();
7030                 case T_CHARACTER_CONSTANT:       return parse_character_constant();
7031                 case T_WIDE_CHARACTER_CONSTANT:  return parse_wide_character_constant();
7032                 case T_FLOATINGPOINT:            return parse_float_const();
7033                 case T_STRING_LITERAL:
7034                 case T_WIDE_STRING_LITERAL:      return parse_string_const();
7035                 case T_IDENTIFIER:               return parse_reference();
7036                 case T___FUNCTION__:
7037                 case T___func__:                 return parse_function_keyword();
7038                 case T___PRETTY_FUNCTION__:      return parse_pretty_function_keyword();
7039                 case T___FUNCSIG__:              return parse_funcsig_keyword();
7040                 case T___FUNCDNAME__:            return parse_funcdname_keyword();
7041                 case T___builtin_offsetof:       return parse_offsetof();
7042                 case T___builtin_va_start:       return parse_va_start();
7043                 case T___builtin_va_arg:         return parse_va_arg();
7044                 case T___builtin_expect:
7045                 case T___builtin_alloca:
7046                 case T___builtin_inf:
7047                 case T___builtin_inff:
7048                 case T___builtin_infl:
7049                 case T___builtin_nan:
7050                 case T___builtin_nanf:
7051                 case T___builtin_nanl:
7052                 case T___builtin_huge_val:
7053                 case T___builtin_va_end:         return parse_builtin_symbol();
7054                 case T___builtin_isgreater:
7055                 case T___builtin_isgreaterequal:
7056                 case T___builtin_isless:
7057                 case T___builtin_islessequal:
7058                 case T___builtin_islessgreater:
7059                 case T___builtin_isunordered:    return parse_compare_builtin();
7060                 case T___builtin_constant_p:     return parse_builtin_constant();
7061                 case T___builtin_prefetch:       return parse_builtin_prefetch();
7062                 case T__assume:                  return parse_assume();
7063                 case T_ANDAND:
7064                         if (GNU_MODE)
7065                                 return parse_label_address();
7066                         break;
7067
7068                 case '(':                        return parse_parenthesized_expression();
7069                 case T___noop:                   return parse_noop_expression();
7070         }
7071
7072         errorf(HERE, "unexpected token %K, expected an expression", &token);
7073         return create_invalid_expression();
7074 }
7075
7076 /**
7077  * Check if the expression has the character type and issue a warning then.
7078  */
7079 static void check_for_char_index_type(const expression_t *expression)
7080 {
7081         type_t       *const type      = expression->base.type;
7082         const type_t *const base_type = skip_typeref(type);
7083
7084         if (is_type_atomic(base_type, ATOMIC_TYPE_CHAR) &&
7085                         warning.char_subscripts) {
7086                 warningf(&expression->base.source_position,
7087                          "array subscript has type '%T'", type);
7088         }
7089 }
7090
7091 static expression_t *parse_array_expression(expression_t *left)
7092 {
7093         eat('[');
7094         add_anchor_token(']');
7095
7096         expression_t *inside = parse_expression();
7097
7098         expression_t *expression = allocate_expression_zero(EXPR_ARRAY_ACCESS);
7099
7100         array_access_expression_t *array_access = &expression->array_access;
7101
7102         type_t *const orig_type_left   = left->base.type;
7103         type_t *const orig_type_inside = inside->base.type;
7104
7105         type_t *const type_left   = skip_typeref(orig_type_left);
7106         type_t *const type_inside = skip_typeref(orig_type_inside);
7107
7108         type_t *return_type;
7109         if (is_type_pointer(type_left)) {
7110                 return_type             = type_left->pointer.points_to;
7111                 array_access->array_ref = left;
7112                 array_access->index     = inside;
7113                 check_for_char_index_type(inside);
7114         } else if (is_type_pointer(type_inside)) {
7115                 return_type             = type_inside->pointer.points_to;
7116                 array_access->array_ref = inside;
7117                 array_access->index     = left;
7118                 array_access->flipped   = true;
7119                 check_for_char_index_type(left);
7120         } else {
7121                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
7122                         errorf(HERE,
7123                                 "array access on object with non-pointer types '%T', '%T'",
7124                                 orig_type_left, orig_type_inside);
7125                 }
7126                 return_type             = type_error_type;
7127                 array_access->array_ref = left;
7128                 array_access->index     = inside;
7129         }
7130
7131         expression->base.type = automatic_type_conversion(return_type);
7132
7133         rem_anchor_token(']');
7134         if (token.type == ']') {
7135                 next_token();
7136         } else {
7137                 parse_error_expected("Problem while parsing array access", ']', NULL);
7138         }
7139         return expression;
7140 }
7141
7142 static expression_t *parse_typeprop(expression_kind_t const kind,
7143                                     source_position_t const pos)
7144 {
7145         expression_t  *tp_expression = allocate_expression_zero(kind);
7146         tp_expression->base.type            = type_size_t;
7147         tp_expression->base.source_position = pos;
7148
7149         char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
7150
7151         /* we only refer to a type property, mark this case */
7152         bool old     = in_type_prop;
7153         in_type_prop = true;
7154         if (token.type == '(' && is_declaration_specifier(look_ahead(1), true)) {
7155                 next_token();
7156                 add_anchor_token(')');
7157                 type_t* const orig_type = parse_typename();
7158                 tp_expression->typeprop.type = orig_type;
7159
7160                 type_t const* const type = skip_typeref(orig_type);
7161                 char const* const wrong_type =
7162                         is_type_incomplete(type)    ? "incomplete"          :
7163                         type->kind == TYPE_FUNCTION ? "function designator" :
7164                         type->kind == TYPE_BITFIELD ? "bitfield"            :
7165                         NULL;
7166                 if (wrong_type != NULL) {
7167                         errorf(&pos, "operand of %s expression must not be %s type '%T'",
7168                                what, wrong_type, type);
7169                 }
7170
7171                 rem_anchor_token(')');
7172                 expect(')');
7173         } else {
7174                 expression_t *expression = parse_sub_expression(PREC_UNARY);
7175
7176                 type_t* const orig_type = revert_automatic_type_conversion(expression);
7177                 expression->base.type = orig_type;
7178
7179                 type_t const* const type = skip_typeref(orig_type);
7180                 char const* const wrong_type =
7181                         is_type_incomplete(type)    ? "incomplete"          :
7182                         type->kind == TYPE_FUNCTION ? "function designator" :
7183                         type->kind == TYPE_BITFIELD ? "bitfield"            :
7184                         NULL;
7185                 if (wrong_type != NULL) {
7186                         errorf(&pos, "operand of %s expression must not be expression of %s type '%T'", what, wrong_type, type);
7187                 }
7188
7189                 tp_expression->typeprop.type          = expression->base.type;
7190                 tp_expression->typeprop.tp_expression = expression;
7191         }
7192
7193 end_error:
7194         in_type_prop = old;
7195         return tp_expression;
7196 }
7197
7198 static expression_t *parse_sizeof(void)
7199 {
7200         source_position_t pos = *HERE;
7201         eat(T_sizeof);
7202         return parse_typeprop(EXPR_SIZEOF, pos);
7203 }
7204
7205 static expression_t *parse_alignof(void)
7206 {
7207         source_position_t pos = *HERE;
7208         eat(T___alignof__);
7209         return parse_typeprop(EXPR_ALIGNOF, pos);
7210 }
7211
7212 static expression_t *parse_select_expression(expression_t *compound)
7213 {
7214         assert(token.type == '.' || token.type == T_MINUSGREATER);
7215
7216         bool is_pointer = (token.type == T_MINUSGREATER);
7217         next_token();
7218
7219         expression_t *select    = allocate_expression_zero(EXPR_SELECT);
7220         select->select.compound = compound;
7221
7222         if (token.type != T_IDENTIFIER) {
7223                 parse_error_expected("while parsing select", T_IDENTIFIER, NULL);
7224                 return select;
7225         }
7226         symbol_t *symbol = token.v.symbol;
7227         next_token();
7228
7229         type_t *const orig_type = compound->base.type;
7230         type_t *const type      = skip_typeref(orig_type);
7231
7232         type_t *type_left;
7233         bool    saw_error = false;
7234         if (is_type_pointer(type)) {
7235                 if (!is_pointer) {
7236                         errorf(HERE,
7237                                "request for member '%Y' in something not a struct or union, but '%T'",
7238                                symbol, orig_type);
7239                         saw_error = true;
7240                 }
7241                 type_left = skip_typeref(type->pointer.points_to);
7242         } else {
7243                 if (is_pointer && is_type_valid(type)) {
7244                         errorf(HERE, "left hand side of '->' is not a pointer, but '%T'", orig_type);
7245                         saw_error = true;
7246                 }
7247                 type_left = type;
7248         }
7249
7250         declaration_t *entry;
7251         if (type_left->kind == TYPE_COMPOUND_STRUCT ||
7252             type_left->kind == TYPE_COMPOUND_UNION) {
7253                 declaration_t *const declaration = type_left->compound.declaration;
7254
7255                 if (!declaration->init.complete) {
7256                         errorf(HERE, "request for member '%Y' of incomplete type '%T'",
7257                                symbol, type_left);
7258                         goto create_error_entry;
7259                 }
7260
7261                 entry = find_compound_entry(declaration, symbol);
7262                 if (entry == NULL) {
7263                         errorf(HERE, "'%T' has no member named '%Y'", orig_type, symbol);
7264                         goto create_error_entry;
7265                 }
7266         } else {
7267                 if (is_type_valid(type_left) && !saw_error) {
7268                         errorf(HERE,
7269                                "request for member '%Y' in something not a struct or union, but '%T'",
7270                                symbol, type_left);
7271                 }
7272 create_error_entry:
7273                 entry         = allocate_declaration_zero();
7274                 entry->symbol = symbol;
7275         }
7276
7277         select->select.compound_entry = entry;
7278
7279         type_t *const res_type =
7280                 get_qualified_type(entry->type, type_left->base.qualifiers);
7281
7282         /* we always do the auto-type conversions; the & and sizeof parser contains
7283          * code to revert this! */
7284         select->base.type = automatic_type_conversion(res_type);
7285
7286         type_t *skipped = skip_typeref(res_type);
7287         if (skipped->kind == TYPE_BITFIELD) {
7288                 select->base.type = skipped->bitfield.base_type;
7289         }
7290
7291         return select;
7292 }
7293
7294 static void check_call_argument(const function_parameter_t *parameter,
7295                                 call_argument_t *argument, unsigned pos)
7296 {
7297         type_t         *expected_type      = parameter->type;
7298         type_t         *expected_type_skip = skip_typeref(expected_type);
7299         assign_error_t  error              = ASSIGN_ERROR_INCOMPATIBLE;
7300         expression_t   *arg_expr           = argument->expression;
7301         type_t         *arg_type           = skip_typeref(arg_expr->base.type);
7302
7303         /* handle transparent union gnu extension */
7304         if (is_type_union(expected_type_skip)
7305                         && (expected_type_skip->base.modifiers
7306                                 & TYPE_MODIFIER_TRANSPARENT_UNION)) {
7307                 declaration_t  *union_decl = expected_type_skip->compound.declaration;
7308
7309                 declaration_t *declaration = union_decl->scope.declarations;
7310                 type_t        *best_type   = NULL;
7311                 for ( ; declaration != NULL; declaration = declaration->next) {
7312                         type_t *decl_type = declaration->type;
7313                         error = semantic_assign(decl_type, arg_expr);
7314                         if (error == ASSIGN_ERROR_INCOMPATIBLE
7315                                 || error == ASSIGN_ERROR_POINTER_QUALIFIER_MISSING)
7316                                 continue;
7317
7318                         if (error == ASSIGN_SUCCESS) {
7319                                 best_type = decl_type;
7320                         } else if (best_type == NULL) {
7321                                 best_type = decl_type;
7322                         }
7323                 }
7324
7325                 if (best_type != NULL) {
7326                         expected_type = best_type;
7327                 }
7328         }
7329
7330         error                = semantic_assign(expected_type, arg_expr);
7331         argument->expression = create_implicit_cast(argument->expression,
7332                                                     expected_type);
7333
7334         if (error != ASSIGN_SUCCESS) {
7335                 /* report exact scope in error messages (like "in argument 3") */
7336                 char buf[64];
7337                 snprintf(buf, sizeof(buf), "call argument %u", pos);
7338                 report_assign_error(error, expected_type, arg_expr,     buf,
7339                                                         &arg_expr->base.source_position);
7340         } else if (warning.traditional || warning.conversion) {
7341                 type_t *const promoted_type = get_default_promoted_type(arg_type);
7342                 if (!types_compatible(expected_type_skip, promoted_type) &&
7343                     !types_compatible(expected_type_skip, type_void_ptr) &&
7344                     !types_compatible(type_void_ptr,      promoted_type)) {
7345                         /* Deliberately show the skipped types in this warning */
7346                         warningf(&arg_expr->base.source_position,
7347                                 "passing call argument %u as '%T' rather than '%T' due to prototype",
7348                                 pos, expected_type_skip, promoted_type);
7349                 }
7350         }
7351 }
7352
7353 /**
7354  * Parse a call expression, ie. expression '( ... )'.
7355  *
7356  * @param expression  the function address
7357  */
7358 static expression_t *parse_call_expression(expression_t *expression)
7359 {
7360         expression_t *result = allocate_expression_zero(EXPR_CALL);
7361         result->base.source_position = expression->base.source_position;
7362
7363         call_expression_t *call = &result->call;
7364         call->function          = expression;
7365
7366         type_t *const orig_type = expression->base.type;
7367         type_t *const type      = skip_typeref(orig_type);
7368
7369         function_type_t *function_type = NULL;
7370         if (is_type_pointer(type)) {
7371                 type_t *const to_type = skip_typeref(type->pointer.points_to);
7372
7373                 if (is_type_function(to_type)) {
7374                         function_type   = &to_type->function;
7375                         call->base.type = function_type->return_type;
7376                 }
7377         }
7378
7379         if (function_type == NULL && is_type_valid(type)) {
7380                 errorf(HERE, "called object '%E' (type '%T') is not a pointer to a function", expression, orig_type);
7381         }
7382
7383         /* parse arguments */
7384         eat('(');
7385         add_anchor_token(')');
7386         add_anchor_token(',');
7387
7388         if (token.type != ')') {
7389                 call_argument_t *last_argument = NULL;
7390
7391                 while (true) {
7392                         call_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
7393
7394                         argument->expression = parse_assignment_expression();
7395                         if (last_argument == NULL) {
7396                                 call->arguments = argument;
7397                         } else {
7398                                 last_argument->next = argument;
7399                         }
7400                         last_argument = argument;
7401
7402                         if (token.type != ',')
7403                                 break;
7404                         next_token();
7405                 }
7406         }
7407         rem_anchor_token(',');
7408         rem_anchor_token(')');
7409         expect(')');
7410
7411         if (function_type == NULL)
7412                 return result;
7413
7414         function_parameter_t *parameter = function_type->parameters;
7415         call_argument_t      *argument  = call->arguments;
7416         if (!function_type->unspecified_parameters) {
7417                 for (unsigned pos = 0; parameter != NULL && argument != NULL;
7418                                 parameter = parameter->next, argument = argument->next) {
7419                         check_call_argument(parameter, argument, ++pos);
7420                 }
7421
7422                 if (parameter != NULL) {
7423                         errorf(HERE, "too few arguments to function '%E'", expression);
7424                 } else if (argument != NULL && !function_type->variadic) {
7425                         errorf(HERE, "too many arguments to function '%E'", expression);
7426                 }
7427         }
7428
7429         /* do default promotion */
7430         for( ; argument != NULL; argument = argument->next) {
7431                 type_t *type = argument->expression->base.type;
7432
7433                 type = get_default_promoted_type(type);
7434
7435                 argument->expression
7436                         = create_implicit_cast(argument->expression, type);
7437         }
7438
7439         check_format(&result->call);
7440
7441         if (warning.aggregate_return &&
7442             is_type_compound(skip_typeref(function_type->return_type))) {
7443                 warningf(&result->base.source_position,
7444                          "function call has aggregate value");
7445         }
7446
7447 end_error:
7448         return result;
7449 }
7450
7451 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
7452
7453 static bool same_compound_type(const type_t *type1, const type_t *type2)
7454 {
7455         return
7456                 is_type_compound(type1) &&
7457                 type1->kind == type2->kind &&
7458                 type1->compound.declaration == type2->compound.declaration;
7459 }
7460
7461 /**
7462  * Parse a conditional expression, ie. 'expression ? ... : ...'.
7463  *
7464  * @param expression  the conditional expression
7465  */
7466 static expression_t *parse_conditional_expression(expression_t *expression)
7467 {
7468         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
7469
7470         conditional_expression_t *conditional = &result->conditional;
7471         conditional->base.source_position = *HERE;
7472         conditional->condition            = expression;
7473
7474         eat('?');
7475         add_anchor_token(':');
7476
7477         /* 6.5.15.2 */
7478         type_t *const condition_type_orig = expression->base.type;
7479         type_t *const condition_type      = skip_typeref(condition_type_orig);
7480         if (!is_type_scalar(condition_type) && is_type_valid(condition_type)) {
7481                 type_error("expected a scalar type in conditional condition",
7482                            &expression->base.source_position, condition_type_orig);
7483         }
7484
7485         expression_t *true_expression = expression;
7486         bool          gnu_cond = false;
7487         if (GNU_MODE && token.type == ':') {
7488                 gnu_cond = true;
7489         } else
7490                 true_expression = parse_expression();
7491         rem_anchor_token(':');
7492         expect(':');
7493         expression_t *false_expression =
7494                 parse_sub_expression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
7495
7496         type_t *const orig_true_type  = true_expression->base.type;
7497         type_t *const orig_false_type = false_expression->base.type;
7498         type_t *const true_type       = skip_typeref(orig_true_type);
7499         type_t *const false_type      = skip_typeref(orig_false_type);
7500
7501         /* 6.5.15.3 */
7502         type_t *result_type;
7503         if (is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
7504                         is_type_atomic(false_type, ATOMIC_TYPE_VOID)) {
7505                 if (warning.other && (
7506                                         !is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
7507                                         !is_type_atomic(false_type, ATOMIC_TYPE_VOID)
7508                                 )) {
7509                         warningf(&conditional->base.source_position,
7510                                         "ISO C forbids conditional expression with only one void side");
7511                 }
7512                 result_type = type_void;
7513         } else if (is_type_arithmetic(true_type)
7514                    && is_type_arithmetic(false_type)) {
7515                 result_type = semantic_arithmetic(true_type, false_type);
7516
7517                 true_expression  = create_implicit_cast(true_expression, result_type);
7518                 false_expression = create_implicit_cast(false_expression, result_type);
7519
7520                 conditional->true_expression  = true_expression;
7521                 conditional->false_expression = false_expression;
7522                 conditional->base.type        = result_type;
7523         } else if (same_compound_type(true_type, false_type)) {
7524                 /* just take 1 of the 2 types */
7525                 result_type = true_type;
7526         } else if (is_type_pointer(true_type) || is_type_pointer(false_type)) {
7527                 type_t *pointer_type;
7528                 type_t *other_type;
7529                 expression_t *other_expression;
7530                 if (is_type_pointer(true_type) &&
7531                                 (!is_type_pointer(false_type) || is_null_pointer_constant(false_expression))) {
7532                         pointer_type     = true_type;
7533                         other_type       = false_type;
7534                         other_expression = false_expression;
7535                 } else {
7536                         pointer_type     = false_type;
7537                         other_type       = true_type;
7538                         other_expression = true_expression;
7539                 }
7540
7541                 if (is_null_pointer_constant(other_expression)) {
7542                         result_type = pointer_type;
7543                 } else if (is_type_pointer(other_type)) {
7544                         type_t *to1 = skip_typeref(pointer_type->pointer.points_to);
7545                         type_t *to2 = skip_typeref(other_type->pointer.points_to);
7546
7547                         type_t *to;
7548                         if (is_type_atomic(to1, ATOMIC_TYPE_VOID) ||
7549                             is_type_atomic(to2, ATOMIC_TYPE_VOID)) {
7550                                 to = type_void;
7551                         } else if (types_compatible(get_unqualified_type(to1),
7552                                                     get_unqualified_type(to2))) {
7553                                 to = to1;
7554                         } else {
7555                                 if (warning.other) {
7556                                         warningf(&conditional->base.source_position,
7557                                                         "pointer types '%T' and '%T' in conditional expression are incompatible",
7558                                                         true_type, false_type);
7559                                 }
7560                                 to = type_void;
7561                         }
7562
7563                         type_t *const type =
7564                                 get_qualified_type(to, to1->base.qualifiers | to2->base.qualifiers);
7565                         result_type = make_pointer_type(type, TYPE_QUALIFIER_NONE);
7566                 } else if (is_type_integer(other_type)) {
7567                         if (warning.other) {
7568                                 warningf(&conditional->base.source_position,
7569                                                 "pointer/integer type mismatch in conditional expression ('%T' and '%T')", true_type, false_type);
7570                         }
7571                         result_type = pointer_type;
7572                 } else {
7573                         if (is_type_valid(other_type)) {
7574                                 type_error_incompatible("while parsing conditional",
7575                                                 &expression->base.source_position, true_type, false_type);
7576                         }
7577                         result_type = type_error_type;
7578                 }
7579         } else {
7580                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
7581                         type_error_incompatible("while parsing conditional",
7582                                                 &conditional->base.source_position, true_type,
7583                                                 false_type);
7584                 }
7585                 result_type = type_error_type;
7586         }
7587
7588         conditional->true_expression
7589                 = gnu_cond ? NULL : create_implicit_cast(true_expression, result_type);
7590         conditional->false_expression
7591                 = create_implicit_cast(false_expression, result_type);
7592         conditional->base.type = result_type;
7593         return result;
7594 end_error:
7595         return create_invalid_expression();
7596 }
7597
7598 /**
7599  * Parse an extension expression.
7600  */
7601 static expression_t *parse_extension(void)
7602 {
7603         eat(T___extension__);
7604
7605         bool old_gcc_extension   = in_gcc_extension;
7606         in_gcc_extension         = true;
7607         expression_t *expression = parse_sub_expression(PREC_UNARY);
7608         in_gcc_extension         = old_gcc_extension;
7609         return expression;
7610 }
7611
7612 /**
7613  * Parse a __builtin_classify_type() expression.
7614  */
7615 static expression_t *parse_builtin_classify_type(void)
7616 {
7617         eat(T___builtin_classify_type);
7618
7619         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
7620         result->base.type    = type_int;
7621
7622         expect('(');
7623         add_anchor_token(')');
7624         expression_t *expression = parse_expression();
7625         rem_anchor_token(')');
7626         expect(')');
7627         result->classify_type.type_expression = expression;
7628
7629         return result;
7630 end_error:
7631         return create_invalid_expression();
7632 }
7633
7634 static bool check_pointer_arithmetic(const source_position_t *source_position,
7635                                      type_t *pointer_type,
7636                                      type_t *orig_pointer_type)
7637 {
7638         type_t *points_to = pointer_type->pointer.points_to;
7639         points_to = skip_typeref(points_to);
7640
7641         if (is_type_incomplete(points_to)) {
7642                 if (!GNU_MODE || !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
7643                         errorf(source_position,
7644                                "arithmetic with pointer to incomplete type '%T' not allowed",
7645                                orig_pointer_type);
7646                         return false;
7647                 } else if (warning.pointer_arith) {
7648                         warningf(source_position,
7649                                  "pointer of type '%T' used in arithmetic",
7650                                  orig_pointer_type);
7651                 }
7652         } else if (is_type_function(points_to)) {
7653                 if (!GNU_MODE) {
7654                         errorf(source_position,
7655                                "arithmetic with pointer to function type '%T' not allowed",
7656                                orig_pointer_type);
7657                         return false;
7658                 } else if (warning.pointer_arith) {
7659                         warningf(source_position,
7660                                  "pointer to a function '%T' used in arithmetic",
7661                                  orig_pointer_type);
7662                 }
7663         }
7664         return true;
7665 }
7666
7667 static bool is_lvalue(const expression_t *expression)
7668 {
7669         switch (expression->kind) {
7670         case EXPR_REFERENCE:
7671         case EXPR_ARRAY_ACCESS:
7672         case EXPR_SELECT:
7673         case EXPR_UNARY_DEREFERENCE:
7674                 return true;
7675
7676         default:
7677                 /* Claim it is an lvalue, if the type is invalid.  There was a parse
7678                  * error before, which maybe prevented properly recognizing it as
7679                  * lvalue. */
7680                 return !is_type_valid(skip_typeref(expression->base.type));
7681         }
7682 }
7683
7684 static void semantic_incdec(unary_expression_t *expression)
7685 {
7686         type_t *const orig_type = expression->value->base.type;
7687         type_t *const type      = skip_typeref(orig_type);
7688         if (is_type_pointer(type)) {
7689                 if (!check_pointer_arithmetic(&expression->base.source_position,
7690                                               type, orig_type)) {
7691                         return;
7692                 }
7693         } else if (!is_type_real(type) && is_type_valid(type)) {
7694                 /* TODO: improve error message */
7695                 errorf(&expression->base.source_position,
7696                        "operation needs an arithmetic or pointer type");
7697                 return;
7698         }
7699         if (!is_lvalue(expression->value)) {
7700                 /* TODO: improve error message */
7701                 errorf(&expression->base.source_position, "lvalue required as operand");
7702         }
7703         expression->base.type = orig_type;
7704 }
7705
7706 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
7707 {
7708         type_t *const orig_type = expression->value->base.type;
7709         type_t *const type      = skip_typeref(orig_type);
7710         if (!is_type_arithmetic(type)) {
7711                 if (is_type_valid(type)) {
7712                         /* TODO: improve error message */
7713                         errorf(&expression->base.source_position,
7714                                 "operation needs an arithmetic type");
7715                 }
7716                 return;
7717         }
7718
7719         expression->base.type = orig_type;
7720 }
7721
7722 static void semantic_unexpr_plus(unary_expression_t *expression)
7723 {
7724         semantic_unexpr_arithmetic(expression);
7725         if (warning.traditional)
7726                 warningf(&expression->base.source_position,
7727                         "traditional C rejects the unary plus operator");
7728 }
7729
7730 static expression_t const *get_reference_address(expression_t const *expr)
7731 {
7732         bool regular_take_address = true;
7733         for (;;) {
7734                 if (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
7735                         expr = expr->unary.value;
7736                 } else {
7737                         regular_take_address = false;
7738                 }
7739
7740                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
7741                         break;
7742
7743                 expr = expr->unary.value;
7744         }
7745
7746         if (expr->kind != EXPR_REFERENCE)
7747                 return NULL;
7748
7749         if (!regular_take_address &&
7750             !is_type_function(skip_typeref(expr->reference.declaration->type))) {
7751                 return NULL;
7752         }
7753
7754         return expr;
7755 }
7756
7757 static void warn_function_address_as_bool(expression_t const* expr)
7758 {
7759         if (!warning.address)
7760                 return;
7761
7762         expr = get_reference_address(expr);
7763         if (expr != NULL) {
7764                 warningf(&expr->base.source_position,
7765                         "the address of '%Y' will always evaluate as 'true'",
7766                         expr->reference.declaration->symbol);
7767         }
7768 }
7769
7770 static void semantic_not(unary_expression_t *expression)
7771 {
7772         type_t *const orig_type = expression->value->base.type;
7773         type_t *const type      = skip_typeref(orig_type);
7774         if (!is_type_scalar(type) && is_type_valid(type)) {
7775                 errorf(&expression->base.source_position,
7776                        "operand of ! must be of scalar type");
7777         }
7778
7779         warn_function_address_as_bool(expression->value);
7780
7781         expression->base.type = type_int;
7782 }
7783
7784 static void semantic_unexpr_integer(unary_expression_t *expression)
7785 {
7786         type_t *const orig_type = expression->value->base.type;
7787         type_t *const type      = skip_typeref(orig_type);
7788         if (!is_type_integer(type)) {
7789                 if (is_type_valid(type)) {
7790                         errorf(&expression->base.source_position,
7791                                "operand of ~ must be of integer type");
7792                 }
7793                 return;
7794         }
7795
7796         expression->base.type = orig_type;
7797 }
7798
7799 static void semantic_dereference(unary_expression_t *expression)
7800 {
7801         type_t *const orig_type = expression->value->base.type;
7802         type_t *const type      = skip_typeref(orig_type);
7803         if (!is_type_pointer(type)) {
7804                 if (is_type_valid(type)) {
7805                         errorf(&expression->base.source_position,
7806                                "Unary '*' needs pointer or array type, but type '%T' given", orig_type);
7807                 }
7808                 return;
7809         }
7810
7811         type_t *result_type   = type->pointer.points_to;
7812         result_type           = automatic_type_conversion(result_type);
7813         expression->base.type = result_type;
7814 }
7815
7816 /**
7817  * Record that an address is taken (expression represents an lvalue).
7818  *
7819  * @param expression       the expression
7820  * @param may_be_register  if true, the expression might be an register
7821  */
7822 static void set_address_taken(expression_t *expression, bool may_be_register)
7823 {
7824         if (expression->kind != EXPR_REFERENCE)
7825                 return;
7826
7827         declaration_t *const declaration = expression->reference.declaration;
7828         /* happens for parse errors */
7829         if (declaration == NULL)
7830                 return;
7831
7832         if (declaration->storage_class == STORAGE_CLASS_REGISTER && !may_be_register) {
7833                 errorf(&expression->base.source_position,
7834                                 "address of register variable '%Y' requested",
7835                                 declaration->symbol);
7836         } else {
7837                 declaration->address_taken = 1;
7838         }
7839 }
7840
7841 /**
7842  * Check the semantic of the address taken expression.
7843  */
7844 static void semantic_take_addr(unary_expression_t *expression)
7845 {
7846         expression_t *value = expression->value;
7847         value->base.type    = revert_automatic_type_conversion(value);
7848
7849         type_t *orig_type = value->base.type;
7850         if (!is_type_valid(skip_typeref(orig_type)))
7851                 return;
7852
7853         set_address_taken(value, false);
7854
7855         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
7856 }
7857
7858 #define CREATE_UNARY_EXPRESSION_PARSER(token_type, unexpression_type, sfunc) \
7859 static expression_t *parse_##unexpression_type(void)                         \
7860 {                                                                            \
7861         expression_t *unary_expression                                           \
7862                 = allocate_expression_zero(unexpression_type);                       \
7863         unary_expression->base.source_position = *HERE;                          \
7864         eat(token_type);                                                         \
7865         unary_expression->unary.value = parse_sub_expression(PREC_UNARY);        \
7866                                                                                  \
7867         sfunc(&unary_expression->unary);                                         \
7868                                                                                  \
7869         return unary_expression;                                                 \
7870 }
7871
7872 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
7873                                semantic_unexpr_arithmetic)
7874 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
7875                                semantic_unexpr_plus)
7876 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
7877                                semantic_not)
7878 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
7879                                semantic_dereference)
7880 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
7881                                semantic_take_addr)
7882 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
7883                                semantic_unexpr_integer)
7884 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
7885                                semantic_incdec)
7886 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
7887                                semantic_incdec)
7888
7889 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_type, unexpression_type, \
7890                                                sfunc)                         \
7891 static expression_t *parse_##unexpression_type(expression_t *left)            \
7892 {                                                                             \
7893         expression_t *unary_expression                                            \
7894                 = allocate_expression_zero(unexpression_type);                        \
7895         unary_expression->base.source_position = *HERE;                           \
7896         eat(token_type);                                                          \
7897         unary_expression->unary.value          = left;                            \
7898                                                                                   \
7899         sfunc(&unary_expression->unary);                                          \
7900                                                                               \
7901         return unary_expression;                                                  \
7902 }
7903
7904 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
7905                                        EXPR_UNARY_POSTFIX_INCREMENT,
7906                                        semantic_incdec)
7907 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
7908                                        EXPR_UNARY_POSTFIX_DECREMENT,
7909                                        semantic_incdec)
7910
7911 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
7912 {
7913         /* TODO: handle complex + imaginary types */
7914
7915         type_left  = get_unqualified_type(type_left);
7916         type_right = get_unqualified_type(type_right);
7917
7918         /* § 6.3.1.8 Usual arithmetic conversions */
7919         if (type_left == type_long_double || type_right == type_long_double) {
7920                 return type_long_double;
7921         } else if (type_left == type_double || type_right == type_double) {
7922                 return type_double;
7923         } else if (type_left == type_float || type_right == type_float) {
7924                 return type_float;
7925         }
7926
7927         type_left  = promote_integer(type_left);
7928         type_right = promote_integer(type_right);
7929
7930         if (type_left == type_right)
7931                 return type_left;
7932
7933         bool const signed_left  = is_type_signed(type_left);
7934         bool const signed_right = is_type_signed(type_right);
7935         int const  rank_left    = get_rank(type_left);
7936         int const  rank_right   = get_rank(type_right);
7937
7938         if (signed_left == signed_right)
7939                 return rank_left >= rank_right ? type_left : type_right;
7940
7941         int     s_rank;
7942         int     u_rank;
7943         type_t *s_type;
7944         type_t *u_type;
7945         if (signed_left) {
7946                 s_rank = rank_left;
7947                 s_type = type_left;
7948                 u_rank = rank_right;
7949                 u_type = type_right;
7950         } else {
7951                 s_rank = rank_right;
7952                 s_type = type_right;
7953                 u_rank = rank_left;
7954                 u_type = type_left;
7955         }
7956
7957         if (u_rank >= s_rank)
7958                 return u_type;
7959
7960         /* casting rank to atomic_type_kind is a bit hacky, but makes things
7961          * easier here... */
7962         if (get_atomic_type_size((atomic_type_kind_t) s_rank)
7963                         > get_atomic_type_size((atomic_type_kind_t) u_rank))
7964                 return s_type;
7965
7966         switch (s_rank) {
7967                 case ATOMIC_TYPE_INT:      return type_unsigned_int;
7968                 case ATOMIC_TYPE_LONG:     return type_unsigned_long;
7969                 case ATOMIC_TYPE_LONGLONG: return type_unsigned_long_long;
7970
7971                 default: panic("invalid atomic type");
7972         }
7973 }
7974
7975 /**
7976  * Check the semantic restrictions for a binary expression.
7977  */
7978 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
7979 {
7980         expression_t *const left            = expression->left;
7981         expression_t *const right           = expression->right;
7982         type_t       *const orig_type_left  = left->base.type;
7983         type_t       *const orig_type_right = right->base.type;
7984         type_t       *const type_left       = skip_typeref(orig_type_left);
7985         type_t       *const type_right      = skip_typeref(orig_type_right);
7986
7987         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
7988                 /* TODO: improve error message */
7989                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7990                         errorf(&expression->base.source_position,
7991                                "operation needs arithmetic types");
7992                 }
7993                 return;
7994         }
7995
7996         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7997         expression->left      = create_implicit_cast(left, arithmetic_type);
7998         expression->right     = create_implicit_cast(right, arithmetic_type);
7999         expression->base.type = arithmetic_type;
8000 }
8001
8002 static void warn_div_by_zero(binary_expression_t const *const expression)
8003 {
8004         if (!warning.div_by_zero ||
8005             !is_type_integer(expression->base.type))
8006                 return;
8007
8008         expression_t const *const right = expression->right;
8009         /* The type of the right operand can be different for /= */
8010         if (is_type_integer(right->base.type) &&
8011             is_constant_expression(right)     &&
8012             fold_constant(right) == 0) {
8013                 warningf(&expression->base.source_position, "division by zero");
8014         }
8015 }
8016
8017 /**
8018  * Check the semantic restrictions for a div/mod expression.
8019  */
8020 static void semantic_divmod_arithmetic(binary_expression_t *expression) {
8021         semantic_binexpr_arithmetic(expression);
8022         warn_div_by_zero(expression);
8023 }
8024
8025 static void semantic_shift_op(binary_expression_t *expression)
8026 {
8027         expression_t *const left            = expression->left;
8028         expression_t *const right           = expression->right;
8029         type_t       *const orig_type_left  = left->base.type;
8030         type_t       *const orig_type_right = right->base.type;
8031         type_t       *      type_left       = skip_typeref(orig_type_left);
8032         type_t       *      type_right      = skip_typeref(orig_type_right);
8033
8034         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8035                 /* TODO: improve error message */
8036                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8037                         errorf(&expression->base.source_position,
8038                                "operands of shift operation must have integer types");
8039                 }
8040                 return;
8041         }
8042
8043         type_left  = promote_integer(type_left);
8044         type_right = promote_integer(type_right);
8045
8046         expression->left      = create_implicit_cast(left, type_left);
8047         expression->right     = create_implicit_cast(right, type_right);
8048         expression->base.type = type_left;
8049 }
8050
8051 static void semantic_add(binary_expression_t *expression)
8052 {
8053         expression_t *const left            = expression->left;
8054         expression_t *const right           = expression->right;
8055         type_t       *const orig_type_left  = left->base.type;
8056         type_t       *const orig_type_right = right->base.type;
8057         type_t       *const type_left       = skip_typeref(orig_type_left);
8058         type_t       *const type_right      = skip_typeref(orig_type_right);
8059
8060         /* § 6.5.6 */
8061         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8062                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8063                 expression->left  = create_implicit_cast(left, arithmetic_type);
8064                 expression->right = create_implicit_cast(right, arithmetic_type);
8065                 expression->base.type = arithmetic_type;
8066                 return;
8067         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8068                 check_pointer_arithmetic(&expression->base.source_position,
8069                                          type_left, orig_type_left);
8070                 expression->base.type = type_left;
8071         } else if (is_type_pointer(type_right) && is_type_integer(type_left)) {
8072                 check_pointer_arithmetic(&expression->base.source_position,
8073                                          type_right, orig_type_right);
8074                 expression->base.type = type_right;
8075         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8076                 errorf(&expression->base.source_position,
8077                        "invalid operands to binary + ('%T', '%T')",
8078                        orig_type_left, orig_type_right);
8079         }
8080 }
8081
8082 static void semantic_sub(binary_expression_t *expression)
8083 {
8084         expression_t            *const left            = expression->left;
8085         expression_t            *const right           = expression->right;
8086         type_t                  *const orig_type_left  = left->base.type;
8087         type_t                  *const orig_type_right = right->base.type;
8088         type_t                  *const type_left       = skip_typeref(orig_type_left);
8089         type_t                  *const type_right      = skip_typeref(orig_type_right);
8090         source_position_t const *const pos             = &expression->base.source_position;
8091
8092         /* § 5.6.5 */
8093         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8094                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8095                 expression->left        = create_implicit_cast(left, arithmetic_type);
8096                 expression->right       = create_implicit_cast(right, arithmetic_type);
8097                 expression->base.type =  arithmetic_type;
8098                 return;
8099         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8100                 check_pointer_arithmetic(&expression->base.source_position,
8101                                          type_left, orig_type_left);
8102                 expression->base.type = type_left;
8103         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8104                 type_t *const unqual_left  = get_unqualified_type(skip_typeref(type_left->pointer.points_to));
8105                 type_t *const unqual_right = get_unqualified_type(skip_typeref(type_right->pointer.points_to));
8106                 if (!types_compatible(unqual_left, unqual_right)) {
8107                         errorf(pos,
8108                                "subtracting pointers to incompatible types '%T' and '%T'",
8109                                orig_type_left, orig_type_right);
8110                 } else if (!is_type_object(unqual_left)) {
8111                         if (!is_type_atomic(unqual_left, ATOMIC_TYPE_VOID)) {
8112                                 errorf(pos, "subtracting pointers to non-object types '%T'",
8113                                        orig_type_left);
8114                         } else if (warning.other) {
8115                                 warningf(pos, "subtracting pointers to void");
8116                         }
8117                 }
8118                 expression->base.type = type_ptrdiff_t;
8119         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8120                 errorf(pos, "invalid operands of types '%T' and '%T' to binary '-'",
8121                        orig_type_left, orig_type_right);
8122         }
8123 }
8124
8125 static void warn_string_literal_address(expression_t const* expr)
8126 {
8127         while (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
8128                 expr = expr->unary.value;
8129                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
8130                         return;
8131                 expr = expr->unary.value;
8132         }
8133
8134         if (expr->kind == EXPR_STRING_LITERAL ||
8135             expr->kind == EXPR_WIDE_STRING_LITERAL) {
8136                 warningf(&expr->base.source_position,
8137                         "comparison with string literal results in unspecified behaviour");
8138         }
8139 }
8140
8141 /**
8142  * Check the semantics of comparison expressions.
8143  *
8144  * @param expression   The expression to check.
8145  */
8146 static void semantic_comparison(binary_expression_t *expression)
8147 {
8148         expression_t *left  = expression->left;
8149         expression_t *right = expression->right;
8150
8151         if (warning.address) {
8152                 warn_string_literal_address(left);
8153                 warn_string_literal_address(right);
8154
8155                 expression_t const* const func_left = get_reference_address(left);
8156                 if (func_left != NULL && is_null_pointer_constant(right)) {
8157                         warningf(&expression->base.source_position,
8158                                 "the address of '%Y' will never be NULL",
8159                                 func_left->reference.declaration->symbol);
8160                 }
8161
8162                 expression_t const* const func_right = get_reference_address(right);
8163                 if (func_right != NULL && is_null_pointer_constant(right)) {
8164                         warningf(&expression->base.source_position,
8165                                 "the address of '%Y' will never be NULL",
8166                                 func_right->reference.declaration->symbol);
8167                 }
8168         }
8169
8170         type_t *orig_type_left  = left->base.type;
8171         type_t *orig_type_right = right->base.type;
8172         type_t *type_left       = skip_typeref(orig_type_left);
8173         type_t *type_right      = skip_typeref(orig_type_right);
8174
8175         /* TODO non-arithmetic types */
8176         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8177                 /* test for signed vs unsigned compares */
8178                 if (warning.sign_compare &&
8179                     (expression->base.kind != EXPR_BINARY_EQUAL &&
8180                      expression->base.kind != EXPR_BINARY_NOTEQUAL) &&
8181                     (is_type_signed(type_left) != is_type_signed(type_right))) {
8182
8183                         /* check if 1 of the operands is a constant, in this case we just
8184                          * check wether we can safely represent the resulting constant in
8185                          * the type of the other operand. */
8186                         expression_t *const_expr = NULL;
8187                         expression_t *other_expr = NULL;
8188
8189                         if (is_constant_expression(left)) {
8190                                 const_expr = left;
8191                                 other_expr = right;
8192                         } else if (is_constant_expression(right)) {
8193                                 const_expr = right;
8194                                 other_expr = left;
8195                         }
8196
8197                         if (const_expr != NULL) {
8198                                 type_t *other_type = skip_typeref(other_expr->base.type);
8199                                 long    val        = fold_constant(const_expr);
8200                                 /* TODO: check if val can be represented by other_type */
8201                                 (void) other_type;
8202                                 (void) val;
8203                         }
8204                         warningf(&expression->base.source_position,
8205                                  "comparison between signed and unsigned");
8206                 }
8207                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8208                 expression->left        = create_implicit_cast(left, arithmetic_type);
8209                 expression->right       = create_implicit_cast(right, arithmetic_type);
8210                 expression->base.type   = arithmetic_type;
8211                 if (warning.float_equal &&
8212                     (expression->base.kind == EXPR_BINARY_EQUAL ||
8213                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
8214                     is_type_float(arithmetic_type)) {
8215                         warningf(&expression->base.source_position,
8216                                  "comparing floating point with == or != is unsafe");
8217                 }
8218         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8219                 /* TODO check compatibility */
8220         } else if (is_type_pointer(type_left)) {
8221                 expression->right = create_implicit_cast(right, type_left);
8222         } else if (is_type_pointer(type_right)) {
8223                 expression->left = create_implicit_cast(left, type_right);
8224         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8225                 type_error_incompatible("invalid operands in comparison",
8226                                         &expression->base.source_position,
8227                                         type_left, type_right);
8228         }
8229         expression->base.type = type_int;
8230 }
8231
8232 /**
8233  * Checks if a compound type has constant fields.
8234  */
8235 static bool has_const_fields(const compound_type_t *type)
8236 {
8237         const scope_t       *scope       = &type->declaration->scope;
8238         const declaration_t *declaration = scope->declarations;
8239
8240         for (; declaration != NULL; declaration = declaration->next) {
8241                 if (declaration->namespc != NAMESPACE_NORMAL)
8242                         continue;
8243
8244                 const type_t *decl_type = skip_typeref(declaration->type);
8245                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
8246                         return true;
8247         }
8248         /* TODO */
8249         return false;
8250 }
8251
8252 static bool is_valid_assignment_lhs(expression_t const* const left)
8253 {
8254         type_t *const orig_type_left = revert_automatic_type_conversion(left);
8255         type_t *const type_left      = skip_typeref(orig_type_left);
8256
8257         if (!is_lvalue(left)) {
8258                 errorf(HERE, "left hand side '%E' of assignment is not an lvalue",
8259                        left);
8260                 return false;
8261         }
8262
8263         if (is_type_array(type_left)) {
8264                 errorf(HERE, "cannot assign to arrays ('%E')", left);
8265                 return false;
8266         }
8267         if (type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
8268                 errorf(HERE, "assignment to readonly location '%E' (type '%T')", left,
8269                        orig_type_left);
8270                 return false;
8271         }
8272         if (is_type_incomplete(type_left)) {
8273                 errorf(HERE, "left-hand side '%E' of assignment has incomplete type '%T'",
8274                        left, orig_type_left);
8275                 return false;
8276         }
8277         if (is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
8278                 errorf(HERE, "cannot assign to '%E' because compound type '%T' has readonly fields",
8279                        left, orig_type_left);
8280                 return false;
8281         }
8282
8283         return true;
8284 }
8285
8286 static void semantic_arithmetic_assign(binary_expression_t *expression)
8287 {
8288         expression_t *left            = expression->left;
8289         expression_t *right           = expression->right;
8290         type_t       *orig_type_left  = left->base.type;
8291         type_t       *orig_type_right = right->base.type;
8292
8293         if (!is_valid_assignment_lhs(left))
8294                 return;
8295
8296         type_t *type_left  = skip_typeref(orig_type_left);
8297         type_t *type_right = skip_typeref(orig_type_right);
8298
8299         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8300                 /* TODO: improve error message */
8301                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8302                         errorf(&expression->base.source_position,
8303                                "operation needs arithmetic types");
8304                 }
8305                 return;
8306         }
8307
8308         /* combined instructions are tricky. We can't create an implicit cast on
8309          * the left side, because we need the uncasted form for the store.
8310          * The ast2firm pass has to know that left_type must be right_type
8311          * for the arithmetic operation and create a cast by itself */
8312         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8313         expression->right       = create_implicit_cast(right, arithmetic_type);
8314         expression->base.type   = type_left;
8315 }
8316
8317 static void semantic_divmod_assign(binary_expression_t *expression)
8318 {
8319         semantic_arithmetic_assign(expression);
8320         warn_div_by_zero(expression);
8321 }
8322
8323 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
8324 {
8325         expression_t *const left            = expression->left;
8326         expression_t *const right           = expression->right;
8327         type_t       *const orig_type_left  = left->base.type;
8328         type_t       *const orig_type_right = right->base.type;
8329         type_t       *const type_left       = skip_typeref(orig_type_left);
8330         type_t       *const type_right      = skip_typeref(orig_type_right);
8331
8332         if (!is_valid_assignment_lhs(left))
8333                 return;
8334
8335         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8336                 /* combined instructions are tricky. We can't create an implicit cast on
8337                  * the left side, because we need the uncasted form for the store.
8338                  * The ast2firm pass has to know that left_type must be right_type
8339                  * for the arithmetic operation and create a cast by itself */
8340                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
8341                 expression->right     = create_implicit_cast(right, arithmetic_type);
8342                 expression->base.type = type_left;
8343         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8344                 check_pointer_arithmetic(&expression->base.source_position,
8345                                          type_left, orig_type_left);
8346                 expression->base.type = type_left;
8347         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8348                 errorf(&expression->base.source_position,
8349                        "incompatible types '%T' and '%T' in assignment",
8350                        orig_type_left, orig_type_right);
8351         }
8352 }
8353
8354 /**
8355  * Check the semantic restrictions of a logical expression.
8356  */
8357 static void semantic_logical_op(binary_expression_t *expression)
8358 {
8359         expression_t *const left            = expression->left;
8360         expression_t *const right           = expression->right;
8361         type_t       *const orig_type_left  = left->base.type;
8362         type_t       *const orig_type_right = right->base.type;
8363         type_t       *const type_left       = skip_typeref(orig_type_left);
8364         type_t       *const type_right      = skip_typeref(orig_type_right);
8365
8366         warn_function_address_as_bool(left);
8367         warn_function_address_as_bool(right);
8368
8369         if (!is_type_scalar(type_left) || !is_type_scalar(type_right)) {
8370                 /* TODO: improve error message */
8371                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8372                         errorf(&expression->base.source_position,
8373                                "operation needs scalar types");
8374                 }
8375                 return;
8376         }
8377
8378         expression->base.type = type_int;
8379 }
8380
8381 /**
8382  * Check the semantic restrictions of a binary assign expression.
8383  */
8384 static void semantic_binexpr_assign(binary_expression_t *expression)
8385 {
8386         expression_t *left           = expression->left;
8387         type_t       *orig_type_left = left->base.type;
8388
8389         if (!is_valid_assignment_lhs(left))
8390                 return;
8391
8392         assign_error_t error = semantic_assign(orig_type_left, expression->right);
8393         report_assign_error(error, orig_type_left, expression->right,
8394                         "assignment", &left->base.source_position);
8395         expression->right = create_implicit_cast(expression->right, orig_type_left);
8396         expression->base.type = orig_type_left;
8397 }
8398
8399 /**
8400  * Determine if the outermost operation (or parts thereof) of the given
8401  * expression has no effect in order to generate a warning about this fact.
8402  * Therefore in some cases this only examines some of the operands of the
8403  * expression (see comments in the function and examples below).
8404  * Examples:
8405  *   f() + 23;    // warning, because + has no effect
8406  *   x || f();    // no warning, because x controls execution of f()
8407  *   x ? y : f(); // warning, because y has no effect
8408  *   (void)x;     // no warning to be able to suppress the warning
8409  * This function can NOT be used for an "expression has definitely no effect"-
8410  * analysis. */
8411 static bool expression_has_effect(const expression_t *const expr)
8412 {
8413         switch (expr->kind) {
8414                 case EXPR_UNKNOWN:                   break;
8415                 case EXPR_INVALID:                   return true; /* do NOT warn */
8416                 case EXPR_REFERENCE:                 return false;
8417                 /* suppress the warning for microsoft __noop operations */
8418                 case EXPR_CONST:                     return expr->conste.is_ms_noop;
8419                 case EXPR_CHARACTER_CONSTANT:        return false;
8420                 case EXPR_WIDE_CHARACTER_CONSTANT:   return false;
8421                 case EXPR_STRING_LITERAL:            return false;
8422                 case EXPR_WIDE_STRING_LITERAL:       return false;
8423                 case EXPR_LABEL_ADDRESS:             return false;
8424
8425                 case EXPR_CALL: {
8426                         const call_expression_t *const call = &expr->call;
8427                         if (call->function->kind != EXPR_BUILTIN_SYMBOL)
8428                                 return true;
8429
8430                         switch (call->function->builtin_symbol.symbol->ID) {
8431                                 case T___builtin_va_end: return true;
8432                                 default:                 return false;
8433                         }
8434                 }
8435
8436                 /* Generate the warning if either the left or right hand side of a
8437                  * conditional expression has no effect */
8438                 case EXPR_CONDITIONAL: {
8439                         const conditional_expression_t *const cond = &expr->conditional;
8440                         return
8441                                 expression_has_effect(cond->true_expression) &&
8442                                 expression_has_effect(cond->false_expression);
8443                 }
8444
8445                 case EXPR_SELECT:                    return false;
8446                 case EXPR_ARRAY_ACCESS:              return false;
8447                 case EXPR_SIZEOF:                    return false;
8448                 case EXPR_CLASSIFY_TYPE:             return false;
8449                 case EXPR_ALIGNOF:                   return false;
8450
8451                 case EXPR_FUNCNAME:                  return false;
8452                 case EXPR_BUILTIN_SYMBOL:            break; /* handled in EXPR_CALL */
8453                 case EXPR_BUILTIN_CONSTANT_P:        return false;
8454                 case EXPR_BUILTIN_PREFETCH:          return true;
8455                 case EXPR_OFFSETOF:                  return false;
8456                 case EXPR_VA_START:                  return true;
8457                 case EXPR_VA_ARG:                    return true;
8458                 case EXPR_STATEMENT:                 return true; // TODO
8459                 case EXPR_COMPOUND_LITERAL:          return false;
8460
8461                 case EXPR_UNARY_NEGATE:              return false;
8462                 case EXPR_UNARY_PLUS:                return false;
8463                 case EXPR_UNARY_BITWISE_NEGATE:      return false;
8464                 case EXPR_UNARY_NOT:                 return false;
8465                 case EXPR_UNARY_DEREFERENCE:         return false;
8466                 case EXPR_UNARY_TAKE_ADDRESS:        return false;
8467                 case EXPR_UNARY_POSTFIX_INCREMENT:   return true;
8468                 case EXPR_UNARY_POSTFIX_DECREMENT:   return true;
8469                 case EXPR_UNARY_PREFIX_INCREMENT:    return true;
8470                 case EXPR_UNARY_PREFIX_DECREMENT:    return true;
8471
8472                 /* Treat void casts as if they have an effect in order to being able to
8473                  * suppress the warning */
8474                 case EXPR_UNARY_CAST: {
8475                         type_t *const type = skip_typeref(expr->base.type);
8476                         return is_type_atomic(type, ATOMIC_TYPE_VOID);
8477                 }
8478
8479                 case EXPR_UNARY_CAST_IMPLICIT:       return true;
8480                 case EXPR_UNARY_ASSUME:              return true;
8481
8482                 case EXPR_BINARY_ADD:                return false;
8483                 case EXPR_BINARY_SUB:                return false;
8484                 case EXPR_BINARY_MUL:                return false;
8485                 case EXPR_BINARY_DIV:                return false;
8486                 case EXPR_BINARY_MOD:                return false;
8487                 case EXPR_BINARY_EQUAL:              return false;
8488                 case EXPR_BINARY_NOTEQUAL:           return false;
8489                 case EXPR_BINARY_LESS:               return false;
8490                 case EXPR_BINARY_LESSEQUAL:          return false;
8491                 case EXPR_BINARY_GREATER:            return false;
8492                 case EXPR_BINARY_GREATEREQUAL:       return false;
8493                 case EXPR_BINARY_BITWISE_AND:        return false;
8494                 case EXPR_BINARY_BITWISE_OR:         return false;
8495                 case EXPR_BINARY_BITWISE_XOR:        return false;
8496                 case EXPR_BINARY_SHIFTLEFT:          return false;
8497                 case EXPR_BINARY_SHIFTRIGHT:         return false;
8498                 case EXPR_BINARY_ASSIGN:             return true;
8499                 case EXPR_BINARY_MUL_ASSIGN:         return true;
8500                 case EXPR_BINARY_DIV_ASSIGN:         return true;
8501                 case EXPR_BINARY_MOD_ASSIGN:         return true;
8502                 case EXPR_BINARY_ADD_ASSIGN:         return true;
8503                 case EXPR_BINARY_SUB_ASSIGN:         return true;
8504                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:   return true;
8505                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:  return true;
8506                 case EXPR_BINARY_BITWISE_AND_ASSIGN: return true;
8507                 case EXPR_BINARY_BITWISE_XOR_ASSIGN: return true;
8508                 case EXPR_BINARY_BITWISE_OR_ASSIGN:  return true;
8509
8510                 /* Only examine the right hand side of && and ||, because the left hand
8511                  * side already has the effect of controlling the execution of the right
8512                  * hand side */
8513                 case EXPR_BINARY_LOGICAL_AND:
8514                 case EXPR_BINARY_LOGICAL_OR:
8515                 /* Only examine the right hand side of a comma expression, because the left
8516                  * hand side has a separate warning */
8517                 case EXPR_BINARY_COMMA:
8518                         return expression_has_effect(expr->binary.right);
8519
8520                 case EXPR_BINARY_BUILTIN_EXPECT:     return true;
8521                 case EXPR_BINARY_ISGREATER:          return false;
8522                 case EXPR_BINARY_ISGREATEREQUAL:     return false;
8523                 case EXPR_BINARY_ISLESS:             return false;
8524                 case EXPR_BINARY_ISLESSEQUAL:        return false;
8525                 case EXPR_BINARY_ISLESSGREATER:      return false;
8526                 case EXPR_BINARY_ISUNORDERED:        return false;
8527         }
8528
8529         internal_errorf(HERE, "unexpected expression");
8530 }
8531
8532 static void semantic_comma(binary_expression_t *expression)
8533 {
8534         if (warning.unused_value) {
8535                 const expression_t *const left = expression->left;
8536                 if (!expression_has_effect(left)) {
8537                         warningf(&left->base.source_position,
8538                                  "left-hand operand of comma expression has no effect");
8539                 }
8540         }
8541         expression->base.type = expression->right->base.type;
8542 }
8543
8544 /**
8545  * @param prec_r precedence of the right operand
8546  */
8547 #define CREATE_BINEXPR_PARSER(token_type, binexpression_type, prec_r, sfunc) \
8548 static expression_t *parse_##binexpression_type(expression_t *left)          \
8549 {                                                                            \
8550         expression_t *binexpr = allocate_expression_zero(binexpression_type);    \
8551         binexpr->base.source_position = *HERE;                                   \
8552         binexpr->binary.left          = left;                                    \
8553         eat(token_type);                                                         \
8554                                                                              \
8555         expression_t *right = parse_sub_expression(prec_r);                      \
8556                                                                              \
8557         binexpr->binary.right = right;                                           \
8558         sfunc(&binexpr->binary);                                                 \
8559                                                                              \
8560         return binexpr;                                                          \
8561 }
8562
8563 CREATE_BINEXPR_PARSER('*',                    EXPR_BINARY_MUL,                PREC_CAST,           semantic_binexpr_arithmetic)
8564 CREATE_BINEXPR_PARSER('/',                    EXPR_BINARY_DIV,                PREC_CAST,           semantic_divmod_arithmetic)
8565 CREATE_BINEXPR_PARSER('%',                    EXPR_BINARY_MOD,                PREC_CAST,           semantic_divmod_arithmetic)
8566 CREATE_BINEXPR_PARSER('+',                    EXPR_BINARY_ADD,                PREC_MULTIPLICATIVE, semantic_add)
8567 CREATE_BINEXPR_PARSER('-',                    EXPR_BINARY_SUB,                PREC_MULTIPLICATIVE, semantic_sub)
8568 CREATE_BINEXPR_PARSER(T_LESSLESS,             EXPR_BINARY_SHIFTLEFT,          PREC_ADDITIVE,       semantic_shift_op)
8569 CREATE_BINEXPR_PARSER(T_GREATERGREATER,       EXPR_BINARY_SHIFTRIGHT,         PREC_ADDITIVE,       semantic_shift_op)
8570 CREATE_BINEXPR_PARSER('<',                    EXPR_BINARY_LESS,               PREC_SHIFT,          semantic_comparison)
8571 CREATE_BINEXPR_PARSER('>',                    EXPR_BINARY_GREATER,            PREC_SHIFT,          semantic_comparison)
8572 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,          PREC_SHIFT,          semantic_comparison)
8573 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,       PREC_SHIFT,          semantic_comparison)
8574 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,           PREC_RELATIONAL,     semantic_comparison)
8575 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,              PREC_RELATIONAL,     semantic_comparison)
8576 CREATE_BINEXPR_PARSER('&',                    EXPR_BINARY_BITWISE_AND,        PREC_EQUALITY,       semantic_binexpr_arithmetic)
8577 CREATE_BINEXPR_PARSER('^',                    EXPR_BINARY_BITWISE_XOR,        PREC_AND,            semantic_binexpr_arithmetic)
8578 CREATE_BINEXPR_PARSER('|',                    EXPR_BINARY_BITWISE_OR,         PREC_XOR,            semantic_binexpr_arithmetic)
8579 CREATE_BINEXPR_PARSER(T_ANDAND,               EXPR_BINARY_LOGICAL_AND,        PREC_OR,             semantic_logical_op)
8580 CREATE_BINEXPR_PARSER(T_PIPEPIPE,             EXPR_BINARY_LOGICAL_OR,         PREC_LOGICAL_AND,    semantic_logical_op)
8581 CREATE_BINEXPR_PARSER('=',                    EXPR_BINARY_ASSIGN,             PREC_ASSIGNMENT,     semantic_binexpr_assign)
8582 CREATE_BINEXPR_PARSER(T_PLUSEQUAL,            EXPR_BINARY_ADD_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8583 CREATE_BINEXPR_PARSER(T_MINUSEQUAL,           EXPR_BINARY_SUB_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8584 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL,        EXPR_BINARY_MUL_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_assign)
8585 CREATE_BINEXPR_PARSER(T_SLASHEQUAL,           EXPR_BINARY_DIV_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8586 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL,         EXPR_BINARY_MOD_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8587 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL,        EXPR_BINARY_SHIFTLEFT_ASSIGN,   PREC_ASSIGNMENT,     semantic_arithmetic_assign)
8588 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL,  EXPR_BINARY_SHIFTRIGHT_ASSIGN,  PREC_ASSIGNMENT,     semantic_arithmetic_assign)
8589 CREATE_BINEXPR_PARSER(T_ANDEQUAL,             EXPR_BINARY_BITWISE_AND_ASSIGN, PREC_ASSIGNMENT,     semantic_arithmetic_assign)
8590 CREATE_BINEXPR_PARSER(T_PIPEEQUAL,            EXPR_BINARY_BITWISE_OR_ASSIGN,  PREC_ASSIGNMENT,     semantic_arithmetic_assign)
8591 CREATE_BINEXPR_PARSER(T_CARETEQUAL,           EXPR_BINARY_BITWISE_XOR_ASSIGN, PREC_ASSIGNMENT,     semantic_arithmetic_assign)
8592 CREATE_BINEXPR_PARSER(',',                    EXPR_BINARY_COMMA,              PREC_ASSIGNMENT,     semantic_comma)
8593
8594
8595 static expression_t *parse_sub_expression(precedence_t precedence)
8596 {
8597         if (token.type < 0) {
8598                 return expected_expression_error();
8599         }
8600
8601         expression_parser_function_t *parser
8602                 = &expression_parsers[token.type];
8603         source_position_t             source_position = token.source_position;
8604         expression_t                 *left;
8605
8606         if (parser->parser != NULL) {
8607                 left = parser->parser();
8608         } else {
8609                 left = parse_primary_expression();
8610         }
8611         assert(left != NULL);
8612         left->base.source_position = source_position;
8613
8614         while(true) {
8615                 if (token.type < 0) {
8616                         return expected_expression_error();
8617                 }
8618
8619                 parser = &expression_parsers[token.type];
8620                 if (parser->infix_parser == NULL)
8621                         break;
8622                 if (parser->infix_precedence < precedence)
8623                         break;
8624
8625                 left = parser->infix_parser(left);
8626
8627                 assert(left != NULL);
8628                 assert(left->kind != EXPR_UNKNOWN);
8629                 left->base.source_position = source_position;
8630         }
8631
8632         return left;
8633 }
8634
8635 /**
8636  * Parse an expression.
8637  */
8638 static expression_t *parse_expression(void)
8639 {
8640         return parse_sub_expression(PREC_EXPRESSION);
8641 }
8642
8643 /**
8644  * Register a parser for a prefix-like operator.
8645  *
8646  * @param parser      the parser function
8647  * @param token_type  the token type of the prefix token
8648  */
8649 static void register_expression_parser(parse_expression_function parser,
8650                                        int token_type)
8651 {
8652         expression_parser_function_t *entry = &expression_parsers[token_type];
8653
8654         if (entry->parser != NULL) {
8655                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
8656                 panic("trying to register multiple expression parsers for a token");
8657         }
8658         entry->parser = parser;
8659 }
8660
8661 /**
8662  * Register a parser for an infix operator with given precedence.
8663  *
8664  * @param parser      the parser function
8665  * @param token_type  the token type of the infix operator
8666  * @param precedence  the precedence of the operator
8667  */
8668 static void register_infix_parser(parse_expression_infix_function parser,
8669                 int token_type, unsigned precedence)
8670 {
8671         expression_parser_function_t *entry = &expression_parsers[token_type];
8672
8673         if (entry->infix_parser != NULL) {
8674                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
8675                 panic("trying to register multiple infix expression parsers for a "
8676                       "token");
8677         }
8678         entry->infix_parser     = parser;
8679         entry->infix_precedence = precedence;
8680 }
8681
8682 /**
8683  * Initialize the expression parsers.
8684  */
8685 static void init_expression_parsers(void)
8686 {
8687         memset(&expression_parsers, 0, sizeof(expression_parsers));
8688
8689         register_infix_parser(parse_array_expression,               '[',                    PREC_POSTFIX);
8690         register_infix_parser(parse_call_expression,                '(',                    PREC_POSTFIX);
8691         register_infix_parser(parse_select_expression,              '.',                    PREC_POSTFIX);
8692         register_infix_parser(parse_select_expression,              T_MINUSGREATER,         PREC_POSTFIX);
8693         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,   T_PLUSPLUS,             PREC_POSTFIX);
8694         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,   T_MINUSMINUS,           PREC_POSTFIX);
8695         register_infix_parser(parse_EXPR_BINARY_MUL,                '*',                    PREC_MULTIPLICATIVE);
8696         register_infix_parser(parse_EXPR_BINARY_DIV,                '/',                    PREC_MULTIPLICATIVE);
8697         register_infix_parser(parse_EXPR_BINARY_MOD,                '%',                    PREC_MULTIPLICATIVE);
8698         register_infix_parser(parse_EXPR_BINARY_ADD,                '+',                    PREC_ADDITIVE);
8699         register_infix_parser(parse_EXPR_BINARY_SUB,                '-',                    PREC_ADDITIVE);
8700         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,          T_LESSLESS,             PREC_SHIFT);
8701         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,         T_GREATERGREATER,       PREC_SHIFT);
8702         register_infix_parser(parse_EXPR_BINARY_LESS,               '<',                    PREC_RELATIONAL);
8703         register_infix_parser(parse_EXPR_BINARY_GREATER,            '>',                    PREC_RELATIONAL);
8704         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,          T_LESSEQUAL,            PREC_RELATIONAL);
8705         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL,       T_GREATEREQUAL,         PREC_RELATIONAL);
8706         register_infix_parser(parse_EXPR_BINARY_EQUAL,              T_EQUALEQUAL,           PREC_EQUALITY);
8707         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,           T_EXCLAMATIONMARKEQUAL, PREC_EQUALITY);
8708         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,        '&',                    PREC_AND);
8709         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,        '^',                    PREC_XOR);
8710         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,         '|',                    PREC_OR);
8711         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,        T_ANDAND,               PREC_LOGICAL_AND);
8712         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,         T_PIPEPIPE,             PREC_LOGICAL_OR);
8713         register_infix_parser(parse_conditional_expression,         '?',                    PREC_CONDITIONAL);
8714         register_infix_parser(parse_EXPR_BINARY_ASSIGN,             '=',                    PREC_ASSIGNMENT);
8715         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,         T_PLUSEQUAL,            PREC_ASSIGNMENT);
8716         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,         T_MINUSEQUAL,           PREC_ASSIGNMENT);
8717         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,         T_ASTERISKEQUAL,        PREC_ASSIGNMENT);
8718         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,         T_SLASHEQUAL,           PREC_ASSIGNMENT);
8719         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,         T_PERCENTEQUAL,         PREC_ASSIGNMENT);
8720         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,   T_LESSLESSEQUAL,        PREC_ASSIGNMENT);
8721         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,  T_GREATERGREATEREQUAL,  PREC_ASSIGNMENT);
8722         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN, T_ANDEQUAL,             PREC_ASSIGNMENT);
8723         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,  T_PIPEEQUAL,            PREC_ASSIGNMENT);
8724         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN, T_CARETEQUAL,           PREC_ASSIGNMENT);
8725         register_infix_parser(parse_EXPR_BINARY_COMMA,              ',',                    PREC_EXPRESSION);
8726
8727         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-');
8728         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+');
8729         register_expression_parser(parse_EXPR_UNARY_NOT,              '!');
8730         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~');
8731         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*');
8732         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&');
8733         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT, T_PLUSPLUS);
8734         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT, T_MINUSMINUS);
8735         register_expression_parser(parse_sizeof,                      T_sizeof);
8736         register_expression_parser(parse_alignof,                     T___alignof__);
8737         register_expression_parser(parse_extension,                   T___extension__);
8738         register_expression_parser(parse_builtin_classify_type,       T___builtin_classify_type);
8739 }
8740
8741 /**
8742  * Parse a asm statement arguments specification.
8743  */
8744 static asm_argument_t *parse_asm_arguments(bool is_out)
8745 {
8746         asm_argument_t *result = NULL;
8747         asm_argument_t *last   = NULL;
8748
8749         while (token.type == T_STRING_LITERAL || token.type == '[') {
8750                 asm_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
8751                 memset(argument, 0, sizeof(argument[0]));
8752
8753                 if (token.type == '[') {
8754                         eat('[');
8755                         if (token.type != T_IDENTIFIER) {
8756                                 parse_error_expected("while parsing asm argument",
8757                                                      T_IDENTIFIER, NULL);
8758                                 return NULL;
8759                         }
8760                         argument->symbol = token.v.symbol;
8761
8762                         expect(']');
8763                 }
8764
8765                 argument->constraints = parse_string_literals();
8766                 expect('(');
8767                 add_anchor_token(')');
8768                 expression_t *expression = parse_expression();
8769                 rem_anchor_token(')');
8770                 if (is_out) {
8771                         /* Ugly GCC stuff: Allow lvalue casts.  Skip casts, when they do not
8772                          * change size or type representation (e.g. int -> long is ok, but
8773                          * int -> float is not) */
8774                         if (expression->kind == EXPR_UNARY_CAST) {
8775                                 type_t      *const type = expression->base.type;
8776                                 type_kind_t  const kind = type->kind;
8777                                 if (kind == TYPE_ATOMIC || kind == TYPE_POINTER) {
8778                                         unsigned flags;
8779                                         unsigned size;
8780                                         if (kind == TYPE_ATOMIC) {
8781                                                 atomic_type_kind_t const akind = type->atomic.akind;
8782                                                 flags = get_atomic_type_flags(akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
8783                                                 size  = get_atomic_type_size(akind);
8784                                         } else {
8785                                                 flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
8786                                                 size  = get_atomic_type_size(get_intptr_kind());
8787                                         }
8788
8789                                         do {
8790                                                 expression_t *const value      = expression->unary.value;
8791                                                 type_t       *const value_type = value->base.type;
8792                                                 type_kind_t   const value_kind = value_type->kind;
8793
8794                                                 unsigned value_flags;
8795                                                 unsigned value_size;
8796                                                 if (value_kind == TYPE_ATOMIC) {
8797                                                         atomic_type_kind_t const value_akind = value_type->atomic.akind;
8798                                                         value_flags = get_atomic_type_flags(value_akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
8799                                                         value_size  = get_atomic_type_size(value_akind);
8800                                                 } else if (value_kind == TYPE_POINTER) {
8801                                                         value_flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
8802                                                         value_size  = get_atomic_type_size(get_intptr_kind());
8803                                                 } else {
8804                                                         break;
8805                                                 }
8806
8807                                                 if (value_flags != flags || value_size != size)
8808                                                         break;
8809
8810                                                 expression = value;
8811                                         } while (expression->kind == EXPR_UNARY_CAST);
8812                                 }
8813                         }
8814
8815                         if (!is_lvalue(expression)) {
8816                                 errorf(&expression->base.source_position,
8817                                        "asm output argument is not an lvalue");
8818                         }
8819
8820                         if (argument->constraints.begin[0] == '+')
8821                                 mark_decls_read(expression, NULL);
8822                 } else {
8823                         mark_decls_read(expression, NULL);
8824                 }
8825                 argument->expression = expression;
8826                 expect(')');
8827
8828                 set_address_taken(expression, true);
8829
8830                 if (last != NULL) {
8831                         last->next = argument;
8832                 } else {
8833                         result = argument;
8834                 }
8835                 last = argument;
8836
8837                 if (token.type != ',')
8838                         break;
8839                 eat(',');
8840         }
8841
8842         return result;
8843 end_error:
8844         return NULL;
8845 }
8846
8847 /**
8848  * Parse a asm statement clobber specification.
8849  */
8850 static asm_clobber_t *parse_asm_clobbers(void)
8851 {
8852         asm_clobber_t *result = NULL;
8853         asm_clobber_t *last   = NULL;
8854
8855         while(token.type == T_STRING_LITERAL) {
8856                 asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
8857                 clobber->clobber       = parse_string_literals();
8858
8859                 if (last != NULL) {
8860                         last->next = clobber;
8861                 } else {
8862                         result = clobber;
8863                 }
8864                 last = clobber;
8865
8866                 if (token.type != ',')
8867                         break;
8868                 eat(',');
8869         }
8870
8871         return result;
8872 }
8873
8874 /**
8875  * Parse an asm statement.
8876  */
8877 static statement_t *parse_asm_statement(void)
8878 {
8879         statement_t     *statement     = allocate_statement_zero(STATEMENT_ASM);
8880         asm_statement_t *asm_statement = &statement->asms;
8881
8882         eat(T_asm);
8883
8884         if (token.type == T_volatile) {
8885                 next_token();
8886                 asm_statement->is_volatile = true;
8887         }
8888
8889         expect('(');
8890         add_anchor_token(')');
8891         add_anchor_token(':');
8892         asm_statement->asm_text = parse_string_literals();
8893
8894         if (token.type != ':') {
8895                 rem_anchor_token(':');
8896                 goto end_of_asm;
8897         }
8898         eat(':');
8899
8900         asm_statement->outputs = parse_asm_arguments(true);
8901         if (token.type != ':') {
8902                 rem_anchor_token(':');
8903                 goto end_of_asm;
8904         }
8905         eat(':');
8906
8907         asm_statement->inputs = parse_asm_arguments(false);
8908         if (token.type != ':') {
8909                 rem_anchor_token(':');
8910                 goto end_of_asm;
8911         }
8912         rem_anchor_token(':');
8913         eat(':');
8914
8915         asm_statement->clobbers = parse_asm_clobbers();
8916
8917 end_of_asm:
8918         rem_anchor_token(')');
8919         expect(')');
8920         expect(';');
8921
8922         if (asm_statement->outputs == NULL) {
8923                 /* GCC: An 'asm' instruction without any output operands will be treated
8924                  * identically to a volatile 'asm' instruction. */
8925                 asm_statement->is_volatile = true;
8926         }
8927
8928         return statement;
8929 end_error:
8930         return create_invalid_statement();
8931 }
8932
8933 /**
8934  * Parse a case statement.
8935  */
8936 static statement_t *parse_case_statement(void)
8937 {
8938         statement_t       *const statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
8939         source_position_t *const pos       = &statement->base.source_position;
8940
8941         eat(T_case);
8942
8943         expression_t *const expression   = parse_expression();
8944         statement->case_label.expression = expression;
8945         if (!is_constant_expression(expression)) {
8946                 /* This check does not prevent the error message in all cases of an
8947                  * prior error while parsing the expression.  At least it catches the
8948                  * common case of a mistyped enum entry. */
8949                 if (is_type_valid(skip_typeref(expression->base.type))) {
8950                         errorf(pos, "case label does not reduce to an integer constant");
8951                 }
8952                 statement->case_label.is_bad = true;
8953         } else {
8954                 long const val = fold_constant(expression);
8955                 statement->case_label.first_case = val;
8956                 statement->case_label.last_case  = val;
8957         }
8958
8959         if (GNU_MODE) {
8960                 if (token.type == T_DOTDOTDOT) {
8961                         next_token();
8962                         expression_t *const end_range   = parse_expression();
8963                         statement->case_label.end_range = end_range;
8964                         if (!is_constant_expression(end_range)) {
8965                                 /* This check does not prevent the error message in all cases of an
8966                                  * prior error while parsing the expression.  At least it catches the
8967                                  * common case of a mistyped enum entry. */
8968                                 if (is_type_valid(skip_typeref(end_range->base.type))) {
8969                                         errorf(pos, "case range does not reduce to an integer constant");
8970                                 }
8971                                 statement->case_label.is_bad = true;
8972                         } else {
8973                                 long const val = fold_constant(end_range);
8974                                 statement->case_label.last_case = val;
8975
8976                                 if (warning.other && val < statement->case_label.first_case) {
8977                                         statement->case_label.is_empty_range = true;
8978                                         warningf(pos, "empty range specified");
8979                                 }
8980                         }
8981                 }
8982         }
8983
8984         PUSH_PARENT(statement);
8985
8986         expect(':');
8987
8988         if (current_switch != NULL) {
8989                 if (! statement->case_label.is_bad) {
8990                         /* Check for duplicate case values */
8991                         case_label_statement_t *c = &statement->case_label;
8992                         for (case_label_statement_t *l = current_switch->first_case; l != NULL; l = l->next) {
8993                                 if (l->is_bad || l->is_empty_range || l->expression == NULL)
8994                                         continue;
8995
8996                                 if (c->last_case < l->first_case || c->first_case > l->last_case)
8997                                         continue;
8998
8999                                 errorf(pos, "duplicate case value (previously used %P)",
9000                                        &l->base.source_position);
9001                                 break;
9002                         }
9003                 }
9004                 /* link all cases into the switch statement */
9005                 if (current_switch->last_case == NULL) {
9006                         current_switch->first_case      = &statement->case_label;
9007                 } else {
9008                         current_switch->last_case->next = &statement->case_label;
9009                 }
9010                 current_switch->last_case = &statement->case_label;
9011         } else {
9012                 errorf(pos, "case label not within a switch statement");
9013         }
9014
9015         statement_t *const inner_stmt = parse_statement();
9016         statement->case_label.statement = inner_stmt;
9017         if (inner_stmt->kind == STATEMENT_DECLARATION) {
9018                 errorf(&inner_stmt->base.source_position, "declaration after case label");
9019         }
9020
9021         POP_PARENT;
9022         return statement;
9023 end_error:
9024         POP_PARENT;
9025         return create_invalid_statement();
9026 }
9027
9028 /**
9029  * Parse a default statement.
9030  */
9031 static statement_t *parse_default_statement(void)
9032 {
9033         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9034
9035         eat(T_default);
9036
9037         PUSH_PARENT(statement);
9038
9039         expect(':');
9040         if (current_switch != NULL) {
9041                 const case_label_statement_t *def_label = current_switch->default_label;
9042                 if (def_label != NULL) {
9043                         errorf(HERE, "multiple default labels in one switch (previous declared %P)",
9044                                &def_label->base.source_position);
9045                 } else {
9046                         current_switch->default_label = &statement->case_label;
9047
9048                         /* link all cases into the switch statement */
9049                         if (current_switch->last_case == NULL) {
9050                                 current_switch->first_case      = &statement->case_label;
9051                         } else {
9052                                 current_switch->last_case->next = &statement->case_label;
9053                         }
9054                         current_switch->last_case = &statement->case_label;
9055                 }
9056         } else {
9057                 errorf(&statement->base.source_position,
9058                         "'default' label not within a switch statement");
9059         }
9060
9061         statement_t *const inner_stmt = parse_statement();
9062         statement->case_label.statement = inner_stmt;
9063         if (inner_stmt->kind == STATEMENT_DECLARATION) {
9064                 errorf(&inner_stmt->base.source_position, "declaration after default label");
9065         }
9066
9067         POP_PARENT;
9068         return statement;
9069 end_error:
9070         POP_PARENT;
9071         return create_invalid_statement();
9072 }
9073
9074 /**
9075  * Parse a label statement.
9076  */
9077 static statement_t *parse_label_statement(void)
9078 {
9079         assert(token.type == T_IDENTIFIER);
9080         symbol_t      *symbol = token.v.symbol;
9081         declaration_t *label  = get_label(symbol);
9082
9083         statement_t *const statement = allocate_statement_zero(STATEMENT_LABEL);
9084         statement->label.label       = label;
9085
9086         next_token();
9087
9088         PUSH_PARENT(statement);
9089
9090         /* if statement is already set then the label is defined twice,
9091          * otherwise it was just mentioned in a goto/local label declaration so far */
9092         if (label->init.statement != NULL) {
9093                 errorf(HERE, "duplicate label '%Y' (declared %P)",
9094                        symbol, &label->source_position);
9095         } else {
9096                 label->source_position = token.source_position;
9097                 label->init.statement  = statement;
9098         }
9099
9100         eat(':');
9101
9102         if (token.type == '}') {
9103                 /* TODO only warn? */
9104                 if (warning.other && false) {
9105                         warningf(HERE, "label at end of compound statement");
9106                         statement->label.statement = create_empty_statement();
9107                 } else {
9108                         errorf(HERE, "label at end of compound statement");
9109                         statement->label.statement = create_invalid_statement();
9110                 }
9111         } else if (token.type == ';') {
9112                 /* Eat an empty statement here, to avoid the warning about an empty
9113                  * statement after a label.  label:; is commonly used to have a label
9114                  * before a closing brace. */
9115                 statement->label.statement = create_empty_statement();
9116                 next_token();
9117         } else {
9118                 statement_t *const inner_stmt = parse_statement();
9119                 statement->label.statement = inner_stmt;
9120                 if (inner_stmt->kind == STATEMENT_DECLARATION) {
9121                         errorf(&inner_stmt->base.source_position, "declaration after label");
9122                 }
9123         }
9124
9125         /* remember the labels in a list for later checking */
9126         if (label_last == NULL) {
9127                 label_first = &statement->label;
9128         } else {
9129                 label_last->next = &statement->label;
9130         }
9131         label_last = &statement->label;
9132
9133         POP_PARENT;
9134         return statement;
9135 }
9136
9137 /**
9138  * Parse an if statement.
9139  */
9140 static statement_t *parse_if(void)
9141 {
9142         statement_t *statement = allocate_statement_zero(STATEMENT_IF);
9143
9144         eat(T_if);
9145
9146         PUSH_PARENT(statement);
9147
9148         add_anchor_token('{');
9149
9150         expect('(');
9151         add_anchor_token(')');
9152         expression_t *const expr = parse_expression();
9153         statement->ifs.condition = expr;
9154         mark_decls_read(expr, NULL);
9155         rem_anchor_token(')');
9156         expect(')');
9157
9158 end_error:
9159         rem_anchor_token('{');
9160
9161         add_anchor_token(T_else);
9162         statement->ifs.true_statement = parse_statement();
9163         rem_anchor_token(T_else);
9164
9165         if (token.type == T_else) {
9166                 next_token();
9167                 statement->ifs.false_statement = parse_statement();
9168         }
9169
9170         POP_PARENT;
9171         return statement;
9172 }
9173
9174 /**
9175  * Check that all enums are handled in a switch.
9176  *
9177  * @param statement  the switch statement to check
9178  */
9179 static void check_enum_cases(const switch_statement_t *statement) {
9180         const type_t *type = skip_typeref(statement->expression->base.type);
9181         if (! is_type_enum(type))
9182                 return;
9183         const enum_type_t *enumt = &type->enumt;
9184
9185         /* if we have a default, no warnings */
9186         if (statement->default_label != NULL)
9187                 return;
9188
9189         /* FIXME: calculation of value should be done while parsing */
9190         const declaration_t *declaration;
9191         long last_value = -1;
9192         for (declaration = enumt->declaration->next;
9193              declaration != NULL && declaration->storage_class == STORAGE_CLASS_ENUM_ENTRY;
9194                  declaration = declaration->next) {
9195                 const expression_t *expression = declaration->init.enum_value;
9196                 long                value      = expression != NULL ? fold_constant(expression) : last_value + 1;
9197                 bool                found      = false;
9198                 for (const case_label_statement_t *l = statement->first_case; l != NULL; l = l->next) {
9199                         if (l->expression == NULL)
9200                                 continue;
9201                         if (l->first_case <= value && value <= l->last_case) {
9202                                 found = true;
9203                                 break;
9204                         }
9205                 }
9206                 if (! found) {
9207                         warningf(&statement->base.source_position,
9208                                 "enumeration value '%Y' not handled in switch", declaration->symbol);
9209                 }
9210                 last_value = value;
9211         }
9212 }
9213
9214 /**
9215  * Parse a switch statement.
9216  */
9217 static statement_t *parse_switch(void)
9218 {
9219         statement_t *statement = allocate_statement_zero(STATEMENT_SWITCH);
9220
9221         eat(T_switch);
9222
9223         PUSH_PARENT(statement);
9224
9225         expect('(');
9226         add_anchor_token(')');
9227         expression_t *const expr = parse_expression();
9228         mark_decls_read(expr, NULL);
9229         type_t       *      type = skip_typeref(expr->base.type);
9230         if (is_type_integer(type)) {
9231                 type = promote_integer(type);
9232                 if (warning.traditional) {
9233                         if (get_rank(type) >= get_akind_rank(ATOMIC_TYPE_LONG)) {
9234                                 warningf(&expr->base.source_position,
9235                                         "'%T' switch expression not converted to '%T' in ISO C",
9236                                         type, type_int);
9237                         }
9238                 }
9239         } else if (is_type_valid(type)) {
9240                 errorf(&expr->base.source_position,
9241                        "switch quantity is not an integer, but '%T'", type);
9242                 type = type_error_type;
9243         }
9244         statement->switchs.expression = create_implicit_cast(expr, type);
9245         expect(')');
9246         rem_anchor_token(')');
9247
9248         switch_statement_t *rem = current_switch;
9249         current_switch          = &statement->switchs;
9250         statement->switchs.body = parse_statement();
9251         current_switch          = rem;
9252
9253         if (warning.switch_default &&
9254             statement->switchs.default_label == NULL) {
9255                 warningf(&statement->base.source_position, "switch has no default case");
9256         }
9257         if (warning.switch_enum)
9258                 check_enum_cases(&statement->switchs);
9259
9260         POP_PARENT;
9261         return statement;
9262 end_error:
9263         POP_PARENT;
9264         return create_invalid_statement();
9265 }
9266
9267 static statement_t *parse_loop_body(statement_t *const loop)
9268 {
9269         statement_t *const rem = current_loop;
9270         current_loop = loop;
9271
9272         statement_t *const body = parse_statement();
9273
9274         current_loop = rem;
9275         return body;
9276 }
9277
9278 /**
9279  * Parse a while statement.
9280  */
9281 static statement_t *parse_while(void)
9282 {
9283         statement_t *statement = allocate_statement_zero(STATEMENT_WHILE);
9284
9285         eat(T_while);
9286
9287         PUSH_PARENT(statement);
9288
9289         expect('(');
9290         add_anchor_token(')');
9291         expression_t *const cond = parse_expression();
9292         statement->whiles.condition = cond;
9293         mark_decls_read(cond, NULL);
9294         rem_anchor_token(')');
9295         expect(')');
9296
9297         statement->whiles.body = parse_loop_body(statement);
9298
9299         POP_PARENT;
9300         return statement;
9301 end_error:
9302         POP_PARENT;
9303         return create_invalid_statement();
9304 }
9305
9306 /**
9307  * Parse a do statement.
9308  */
9309 static statement_t *parse_do(void)
9310 {
9311         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
9312
9313         eat(T_do);
9314
9315         PUSH_PARENT(statement);
9316
9317         add_anchor_token(T_while);
9318         statement->do_while.body = parse_loop_body(statement);
9319         rem_anchor_token(T_while);
9320
9321         expect(T_while);
9322         expect('(');
9323         add_anchor_token(')');
9324         expression_t *const cond = parse_expression();
9325         statement->do_while.condition = cond;
9326         mark_decls_read(cond, NULL);
9327         rem_anchor_token(')');
9328         expect(')');
9329         expect(';');
9330
9331         POP_PARENT;
9332         return statement;
9333 end_error:
9334         POP_PARENT;
9335         return create_invalid_statement();
9336 }
9337
9338 /**
9339  * Parse a for statement.
9340  */
9341 static statement_t *parse_for(void)
9342 {
9343         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
9344
9345         eat(T_for);
9346
9347         PUSH_PARENT(statement);
9348
9349         size_t const top = environment_top();
9350         scope_push(&statement->fors.scope);
9351
9352         expect('(');
9353         add_anchor_token(')');
9354
9355         if (token.type != ';') {
9356                 if (is_declaration_specifier(&token, false)) {
9357                         parse_declaration(record_declaration);
9358                 } else {
9359                         add_anchor_token(';');
9360                         expression_t *const init = parse_expression();
9361                         statement->fors.initialisation = init;
9362                         mark_decls_read(init, DECL_ANY);
9363                         if (warning.unused_value && !expression_has_effect(init)) {
9364                                 warningf(&init->base.source_position,
9365                                          "initialisation of 'for'-statement has no effect");
9366                         }
9367                         rem_anchor_token(';');
9368                         expect(';');
9369                 }
9370         } else {
9371                 expect(';');
9372         }
9373
9374         if (token.type != ';') {
9375                 add_anchor_token(';');
9376                 expression_t *const cond = parse_expression();
9377                 statement->fors.condition = cond;
9378                 mark_decls_read(cond, NULL);
9379                 rem_anchor_token(';');
9380         }
9381         expect(';');
9382         if (token.type != ')') {
9383                 expression_t *const step = parse_expression();
9384                 statement->fors.step = step;
9385                 mark_decls_read(step, DECL_ANY);
9386                 if (warning.unused_value && !expression_has_effect(step)) {
9387                         warningf(&step->base.source_position,
9388                                  "step of 'for'-statement has no effect");
9389                 }
9390         }
9391         rem_anchor_token(')');
9392         expect(')');
9393         statement->fors.body = parse_loop_body(statement);
9394
9395         assert(scope == &statement->fors.scope);
9396         scope_pop();
9397         environment_pop_to(top);
9398
9399         POP_PARENT;
9400         return statement;
9401
9402 end_error:
9403         POP_PARENT;
9404         rem_anchor_token(')');
9405         assert(scope == &statement->fors.scope);
9406         scope_pop();
9407         environment_pop_to(top);
9408
9409         return create_invalid_statement();
9410 }
9411
9412 /**
9413  * Parse a goto statement.
9414  */
9415 static statement_t *parse_goto(void)
9416 {
9417         statement_t *statement = allocate_statement_zero(STATEMENT_GOTO);
9418         eat(T_goto);
9419
9420         if (GNU_MODE && token.type == '*') {
9421                 next_token();
9422                 expression_t *expression = parse_expression();
9423                 mark_decls_read(expression, NULL);
9424
9425                 /* Argh: although documentation say the expression must be of type void *,
9426                  * gcc excepts anything that can be casted into void * without error */
9427                 type_t *type = expression->base.type;
9428
9429                 if (type != type_error_type) {
9430                         if (!is_type_pointer(type) && !is_type_integer(type)) {
9431                                 errorf(&expression->base.source_position,
9432                                         "cannot convert to a pointer type");
9433                         } else if (warning.other && type != type_void_ptr) {
9434                                 warningf(&expression->base.source_position,
9435                                         "type of computed goto expression should be 'void*' not '%T'", type);
9436                         }
9437                         expression = create_implicit_cast(expression, type_void_ptr);
9438                 }
9439
9440                 statement->gotos.expression = expression;
9441         } else {
9442                 if (token.type != T_IDENTIFIER) {
9443                         if (GNU_MODE)
9444                                 parse_error_expected("while parsing goto", T_IDENTIFIER, '*', NULL);
9445                         else
9446                                 parse_error_expected("while parsing goto", T_IDENTIFIER, NULL);
9447                         eat_until_anchor();
9448                         goto end_error;
9449                 }
9450                 symbol_t *symbol = token.v.symbol;
9451                 next_token();
9452
9453                 statement->gotos.label = get_label(symbol);
9454         }
9455
9456         /* remember the goto's in a list for later checking */
9457         if (goto_last == NULL) {
9458                 goto_first = &statement->gotos;
9459         } else {
9460                 goto_last->next = &statement->gotos;
9461         }
9462         goto_last = &statement->gotos;
9463
9464         expect(';');
9465
9466         return statement;
9467 end_error:
9468         return create_invalid_statement();
9469 }
9470
9471 /**
9472  * Parse a continue statement.
9473  */
9474 static statement_t *parse_continue(void)
9475 {
9476         if (current_loop == NULL) {
9477                 errorf(HERE, "continue statement not within loop");
9478         }
9479
9480         statement_t *statement = allocate_statement_zero(STATEMENT_CONTINUE);
9481
9482         eat(T_continue);
9483         expect(';');
9484
9485 end_error:
9486         return statement;
9487 }
9488
9489 /**
9490  * Parse a break statement.
9491  */
9492 static statement_t *parse_break(void)
9493 {
9494         if (current_switch == NULL && current_loop == NULL) {
9495                 errorf(HERE, "break statement not within loop or switch");
9496         }
9497
9498         statement_t *statement = allocate_statement_zero(STATEMENT_BREAK);
9499
9500         eat(T_break);
9501         expect(';');
9502
9503 end_error:
9504         return statement;
9505 }
9506
9507 /**
9508  * Parse a __leave statement.
9509  */
9510 static statement_t *parse_leave_statement(void)
9511 {
9512         if (current_try == NULL) {
9513                 errorf(HERE, "__leave statement not within __try");
9514         }
9515
9516         statement_t *statement = allocate_statement_zero(STATEMENT_LEAVE);
9517
9518         eat(T___leave);
9519         expect(';');
9520
9521 end_error:
9522         return statement;
9523 }
9524
9525 /**
9526  * Check if a given declaration represents a local variable.
9527  */
9528 static bool is_local_var_declaration(const declaration_t *declaration)
9529 {
9530         switch ((storage_class_tag_t) declaration->storage_class) {
9531         case STORAGE_CLASS_AUTO:
9532         case STORAGE_CLASS_REGISTER: {
9533                 const type_t *type = skip_typeref(declaration->type);
9534                 if (is_type_function(type)) {
9535                         return false;
9536                 } else {
9537                         return true;
9538                 }
9539         }
9540         default:
9541                 return false;
9542         }
9543 }
9544
9545 /**
9546  * Check if a given declaration represents a variable.
9547  */
9548 static bool is_var_declaration(const declaration_t *declaration)
9549 {
9550         if (declaration->storage_class == STORAGE_CLASS_TYPEDEF)
9551                 return false;
9552
9553         const type_t *type = skip_typeref(declaration->type);
9554         return !is_type_function(type);
9555 }
9556
9557 /**
9558  * Check if a given expression represents a local variable.
9559  */
9560 static bool is_local_variable(const expression_t *expression)
9561 {
9562         if (expression->base.kind != EXPR_REFERENCE) {
9563                 return false;
9564         }
9565         const declaration_t *declaration = expression->reference.declaration;
9566         return is_local_var_declaration(declaration);
9567 }
9568
9569 /**
9570  * Check if a given expression represents a local variable and
9571  * return its declaration then, else return NULL.
9572  */
9573 declaration_t *expr_is_variable(const expression_t *expression)
9574 {
9575         if (expression->base.kind != EXPR_REFERENCE) {
9576                 return NULL;
9577         }
9578         declaration_t *declaration = expression->reference.declaration;
9579         if (is_var_declaration(declaration))
9580                 return declaration;
9581         return NULL;
9582 }
9583
9584 /**
9585  * Parse a return statement.
9586  */
9587 static statement_t *parse_return(void)
9588 {
9589         eat(T_return);
9590
9591         statement_t *statement = allocate_statement_zero(STATEMENT_RETURN);
9592
9593         expression_t *return_value = NULL;
9594         if (token.type != ';') {
9595                 return_value = parse_expression();
9596                 mark_decls_read(return_value, NULL);
9597         }
9598
9599         const type_t *const func_type = current_function->type;
9600         assert(is_type_function(func_type));
9601         type_t *const return_type = skip_typeref(func_type->function.return_type);
9602
9603         if (return_value != NULL) {
9604                 type_t *return_value_type = skip_typeref(return_value->base.type);
9605
9606                 if (is_type_atomic(return_type,        ATOMIC_TYPE_VOID) &&
9607                                 !is_type_atomic(return_value_type, ATOMIC_TYPE_VOID)) {
9608                         if (warning.other) {
9609                                 warningf(&statement->base.source_position,
9610                                                 "'return' with a value, in function returning void");
9611                         }
9612                         return_value = NULL;
9613                 } else {
9614                         assign_error_t error = semantic_assign(return_type, return_value);
9615                         report_assign_error(error, return_type, return_value, "'return'",
9616                                             &statement->base.source_position);
9617                         return_value = create_implicit_cast(return_value, return_type);
9618                 }
9619                 /* check for returning address of a local var */
9620                 if (warning.other        &&
9621                                 return_value != NULL &&
9622                                 return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
9623                         const expression_t *expression = return_value->unary.value;
9624                         if (is_local_variable(expression)) {
9625                                 warningf(&statement->base.source_position,
9626                                          "function returns address of local variable");
9627                         }
9628                 }
9629         } else if (warning.other && !is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
9630                 warningf(&statement->base.source_position,
9631                                 "'return' without value, in function returning non-void");
9632         }
9633         statement->returns.value = return_value;
9634
9635         expect(';');
9636
9637 end_error:
9638         return statement;
9639 }
9640
9641 /**
9642  * Parse a declaration statement.
9643  */
9644 static statement_t *parse_declaration_statement(void)
9645 {
9646         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9647
9648         declaration_t *before = last_declaration;
9649         if (GNU_MODE)
9650                 parse_external_declaration();
9651         else
9652                 parse_declaration(record_declaration);
9653
9654         if (before == NULL) {
9655                 statement->declaration.declarations_begin = scope->declarations;
9656         } else {
9657                 statement->declaration.declarations_begin = before->next;
9658         }
9659         statement->declaration.declarations_end = last_declaration;
9660
9661         return statement;
9662 }
9663
9664 /**
9665  * Parse an expression statement, ie. expr ';'.
9666  */
9667 static statement_t *parse_expression_statement(void)
9668 {
9669         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
9670
9671         expression_t *const expr         = parse_expression();
9672         statement->expression.expression = expr;
9673         mark_decls_read(expr, DECL_ANY);
9674
9675         expect(';');
9676
9677 end_error:
9678         return statement;
9679 }
9680
9681 /**
9682  * Parse a microsoft __try { } __finally { } or
9683  * __try{ } __except() { }
9684  */
9685 static statement_t *parse_ms_try_statment(void)
9686 {
9687         statement_t *statement = allocate_statement_zero(STATEMENT_MS_TRY);
9688         eat(T___try);
9689
9690         PUSH_PARENT(statement);
9691
9692         ms_try_statement_t *rem = current_try;
9693         current_try = &statement->ms_try;
9694         statement->ms_try.try_statement = parse_compound_statement(false);
9695         current_try = rem;
9696
9697         POP_PARENT;
9698
9699         if (token.type == T___except) {
9700                 eat(T___except);
9701                 expect('(');
9702                 add_anchor_token(')');
9703                 expression_t *const expr = parse_expression();
9704                 mark_decls_read(expr, NULL);
9705                 type_t       *      type = skip_typeref(expr->base.type);
9706                 if (is_type_integer(type)) {
9707                         type = promote_integer(type);
9708                 } else if (is_type_valid(type)) {
9709                         errorf(&expr->base.source_position,
9710                                "__expect expression is not an integer, but '%T'", type);
9711                         type = type_error_type;
9712                 }
9713                 statement->ms_try.except_expression = create_implicit_cast(expr, type);
9714                 rem_anchor_token(')');
9715                 expect(')');
9716                 statement->ms_try.final_statement = parse_compound_statement(false);
9717         } else if (token.type == T__finally) {
9718                 eat(T___finally);
9719                 statement->ms_try.final_statement = parse_compound_statement(false);
9720         } else {
9721                 parse_error_expected("while parsing __try statement", T___except, T___finally, NULL);
9722                 return create_invalid_statement();
9723         }
9724         return statement;
9725 end_error:
9726         return create_invalid_statement();
9727 }
9728
9729 static statement_t *parse_empty_statement(void)
9730 {
9731         if (warning.empty_statement) {
9732                 warningf(HERE, "statement is empty");
9733         }
9734         statement_t *const statement = create_empty_statement();
9735         eat(';');
9736         return statement;
9737 }
9738
9739 static statement_t *parse_local_label_declaration(void) {
9740         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9741
9742         eat(T___label__);
9743
9744         declaration_t *begin = NULL, *end = NULL;
9745
9746         while (true) {
9747                 if (token.type != T_IDENTIFIER) {
9748                         parse_error_expected("while parsing local label declaration",
9749                                 T_IDENTIFIER, NULL);
9750                         goto end_error;
9751                 }
9752                 symbol_t      *symbol      = token.v.symbol;
9753                 declaration_t *declaration = get_declaration(symbol, NAMESPACE_LOCAL_LABEL);
9754                 if (declaration != NULL) {
9755                         errorf(HERE, "multiple definitions of '__label__ %Y' (previous definition at %P)",
9756                                 symbol, &declaration->source_position);
9757                 } else {
9758                         declaration = allocate_declaration_zero();
9759                         declaration->namespc         = NAMESPACE_LOCAL_LABEL;
9760                         declaration->source_position = token.source_position;
9761                         declaration->symbol          = symbol;
9762                         declaration->parent_scope    = scope;
9763                         declaration->init.statement  = NULL;
9764
9765                         if (end != NULL)
9766                                 end->next = declaration;
9767                         end = declaration;
9768                         if (begin == NULL)
9769                                 begin = declaration;
9770
9771                         local_label_push(declaration);
9772                 }
9773                 next_token();
9774
9775                 if (token.type != ',')
9776                         break;
9777                 next_token();
9778         }
9779         eat(';');
9780 end_error:
9781         statement->declaration.declarations_begin = begin;
9782         statement->declaration.declarations_end   = end;
9783         return statement;
9784 }
9785
9786 /**
9787  * Parse a statement.
9788  * There's also parse_statement() which additionally checks for
9789  * "statement has no effect" warnings
9790  */
9791 static statement_t *intern_parse_statement(void)
9792 {
9793         statement_t *statement = NULL;
9794
9795         /* declaration or statement */
9796         add_anchor_token(';');
9797         switch (token.type) {
9798         case T_IDENTIFIER: {
9799                 token_type_t la1_type = (token_type_t)look_ahead(1)->type;
9800                 if (la1_type == ':') {
9801                         statement = parse_label_statement();
9802                 } else if (is_typedef_symbol(token.v.symbol)) {
9803                         statement = parse_declaration_statement();
9804                 } else switch (la1_type) {
9805                         case '*':
9806                                 if (get_declaration(token.v.symbol, NAMESPACE_NORMAL) != NULL)
9807                                         goto expression_statment;
9808                                 /* FALLTHROUGH */
9809
9810                         DECLARATION_START
9811                         case T_IDENTIFIER:
9812                                 statement = parse_declaration_statement();
9813                                 break;
9814
9815                         default:
9816 expression_statment:
9817                                 statement = parse_expression_statement();
9818                                 break;
9819                 }
9820                 break;
9821         }
9822
9823         case T___extension__:
9824                 /* This can be a prefix to a declaration or an expression statement.
9825                  * We simply eat it now and parse the rest with tail recursion. */
9826                 do {
9827                         next_token();
9828                 } while (token.type == T___extension__);
9829                 bool old_gcc_extension = in_gcc_extension;
9830                 in_gcc_extension       = true;
9831                 statement = parse_statement();
9832                 in_gcc_extension = old_gcc_extension;
9833                 break;
9834
9835         DECLARATION_START
9836                 statement = parse_declaration_statement();
9837                 break;
9838
9839         case T___label__:
9840                 statement = parse_local_label_declaration();
9841                 break;
9842
9843         case ';':        statement = parse_empty_statement();         break;
9844         case '{':        statement = parse_compound_statement(false); break;
9845         case T___leave:  statement = parse_leave_statement();         break;
9846         case T___try:    statement = parse_ms_try_statment();         break;
9847         case T_asm:      statement = parse_asm_statement();           break;
9848         case T_break:    statement = parse_break();                   break;
9849         case T_case:     statement = parse_case_statement();          break;
9850         case T_continue: statement = parse_continue();                break;
9851         case T_default:  statement = parse_default_statement();       break;
9852         case T_do:       statement = parse_do();                      break;
9853         case T_for:      statement = parse_for();                     break;
9854         case T_goto:     statement = parse_goto();                    break;
9855         case T_if:       statement = parse_if();                      break;
9856         case T_return:   statement = parse_return();                  break;
9857         case T_switch:   statement = parse_switch();                  break;
9858         case T_while:    statement = parse_while();                   break;
9859
9860         case '!':
9861         case '&':
9862         case '(':
9863         case '*':
9864         case '+':
9865         case '-':
9866         case '~':
9867         case T_ANDAND:
9868         case T_CHARACTER_CONSTANT:
9869         case T_FLOATINGPOINT:
9870         case T_INTEGER:
9871         case T_MINUSMINUS:
9872         case T_PLUSPLUS:
9873         case T_STRING_LITERAL:
9874         case T_WIDE_CHARACTER_CONSTANT:
9875         case T_WIDE_STRING_LITERAL:
9876         case T___FUNCDNAME__:
9877         case T___FUNCSIG__:
9878         case T___FUNCTION__:
9879         case T___PRETTY_FUNCTION__:
9880         case T___alignof__:
9881         case T___builtin_alloca:
9882         case T___builtin_classify_type:
9883         case T___builtin_constant_p:
9884         case T___builtin_expect:
9885         case T___builtin_huge_val:
9886         case T___builtin_inf:
9887         case T___builtin_inff:
9888         case T___builtin_infl:
9889         case T___builtin_isgreater:
9890         case T___builtin_isgreaterequal:
9891         case T___builtin_isless:
9892         case T___builtin_islessequal:
9893         case T___builtin_islessgreater:
9894         case T___builtin_isunordered:
9895         case T___builtin_nan:
9896         case T___builtin_nanf:
9897         case T___builtin_nanl:
9898         case T___builtin_offsetof:
9899         case T___builtin_prefetch:
9900         case T___builtin_va_arg:
9901         case T___builtin_va_end:
9902         case T___builtin_va_start:
9903         case T___func__:
9904         case T___noop:
9905         case T__assume:
9906         case T_sizeof:
9907                 statement = parse_expression_statement();
9908                 break;
9909
9910         default:
9911                 errorf(HERE, "unexpected token %K while parsing statement", &token);
9912                 statement = create_invalid_statement();
9913                 if (!at_anchor())
9914                         next_token();
9915                 break;
9916         }
9917         rem_anchor_token(';');
9918
9919         assert(statement != NULL
9920                         && statement->base.source_position.input_name != NULL);
9921
9922         return statement;
9923 }
9924
9925 /**
9926  * parse a statement and emits "statement has no effect" warning if needed
9927  * (This is really a wrapper around intern_parse_statement with check for 1
9928  *  single warning. It is needed, because for statement expressions we have
9929  *  to avoid the warning on the last statement)
9930  */
9931 static statement_t *parse_statement(void)
9932 {
9933         statement_t *statement = intern_parse_statement();
9934
9935         if (statement->kind == STATEMENT_EXPRESSION && warning.unused_value) {
9936                 expression_t *expression = statement->expression.expression;
9937                 if (!expression_has_effect(expression)) {
9938                         warningf(&expression->base.source_position,
9939                                         "statement has no effect");
9940                 }
9941         }
9942
9943         return statement;
9944 }
9945
9946 /**
9947  * Parse a compound statement.
9948  */
9949 static statement_t *parse_compound_statement(bool inside_expression_statement)
9950 {
9951         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
9952
9953         PUSH_PARENT(statement);
9954
9955         eat('{');
9956         add_anchor_token('}');
9957
9958         size_t const top       = environment_top();
9959         size_t const top_local = local_label_top();
9960         scope_push(&statement->compound.scope);
9961
9962         statement_t **anchor            = &statement->compound.statements;
9963         bool          only_decls_so_far = true;
9964         while (token.type != '}') {
9965                 if (token.type == T_EOF) {
9966                         errorf(&statement->base.source_position,
9967                                "EOF while parsing compound statement");
9968                         break;
9969                 }
9970                 statement_t *sub_statement = intern_parse_statement();
9971                 if (is_invalid_statement(sub_statement)) {
9972                         /* an error occurred. if we are at an anchor, return */
9973                         if (at_anchor())
9974                                 goto end_error;
9975                         continue;
9976                 }
9977
9978                 if (warning.declaration_after_statement) {
9979                         if (sub_statement->kind != STATEMENT_DECLARATION) {
9980                                 only_decls_so_far = false;
9981                         } else if (!only_decls_so_far) {
9982                                 warningf(&sub_statement->base.source_position,
9983                                          "ISO C90 forbids mixed declarations and code");
9984                         }
9985                 }
9986
9987                 *anchor = sub_statement;
9988
9989                 while (sub_statement->base.next != NULL)
9990                         sub_statement = sub_statement->base.next;
9991
9992                 anchor = &sub_statement->base.next;
9993         }
9994         next_token();
9995
9996         /* look over all statements again to produce no effect warnings */
9997         if (warning.unused_value) {
9998                 statement_t *sub_statement = statement->compound.statements;
9999                 for( ; sub_statement != NULL; sub_statement = sub_statement->base.next) {
10000                         if (sub_statement->kind != STATEMENT_EXPRESSION)
10001                                 continue;
10002                         /* don't emit a warning for the last expression in an expression
10003                          * statement as it has always an effect */
10004                         if (inside_expression_statement && sub_statement->base.next == NULL)
10005                                 continue;
10006
10007                         expression_t *expression = sub_statement->expression.expression;
10008                         if (!expression_has_effect(expression)) {
10009                                 warningf(&expression->base.source_position,
10010                                          "statement has no effect");
10011                         }
10012                 }
10013         }
10014
10015 end_error:
10016         rem_anchor_token('}');
10017         assert(scope == &statement->compound.scope);
10018         scope_pop();
10019         environment_pop_to(top);
10020         local_label_pop_to(top_local);
10021
10022         POP_PARENT;
10023         return statement;
10024 }
10025
10026 /**
10027  * Initialize builtin types.
10028  */
10029 static void initialize_builtin_types(void)
10030 {
10031         type_intmax_t    = make_global_typedef("__intmax_t__",      type_long_long);
10032         type_size_t      = make_global_typedef("__SIZE_TYPE__",     type_unsigned_long);
10033         type_ssize_t     = make_global_typedef("__SSIZE_TYPE__",    type_long);
10034         type_ptrdiff_t   = make_global_typedef("__PTRDIFF_TYPE__",  type_long);
10035         type_uintmax_t   = make_global_typedef("__uintmax_t__",     type_unsigned_long_long);
10036         type_uptrdiff_t  = make_global_typedef("__UPTRDIFF_TYPE__", type_unsigned_long);
10037         type_wchar_t     = make_global_typedef("__WCHAR_TYPE__",    opt_short_wchar_t ? type_unsigned_short : type_int);
10038         type_wint_t      = make_global_typedef("__WINT_TYPE__",     type_int);
10039
10040         type_intmax_t_ptr  = make_pointer_type(type_intmax_t,  TYPE_QUALIFIER_NONE);
10041         type_ptrdiff_t_ptr = make_pointer_type(type_ptrdiff_t, TYPE_QUALIFIER_NONE);
10042         type_ssize_t_ptr   = make_pointer_type(type_ssize_t,   TYPE_QUALIFIER_NONE);
10043         type_wchar_t_ptr   = make_pointer_type(type_wchar_t,   TYPE_QUALIFIER_NONE);
10044
10045         /* const version of wchar_t */
10046         type_const_wchar_t = allocate_type_zero(TYPE_TYPEDEF);
10047         type_const_wchar_t->typedeft.declaration  = type_wchar_t->typedeft.declaration;
10048         type_const_wchar_t->base.qualifiers      |= TYPE_QUALIFIER_CONST;
10049
10050         type_const_wchar_t_ptr = make_pointer_type(type_const_wchar_t, TYPE_QUALIFIER_NONE);
10051 }
10052
10053 /**
10054  * Check for unused global static functions and variables
10055  */
10056 static void check_unused_globals(void)
10057 {
10058         if (!warning.unused_function && !warning.unused_variable)
10059                 return;
10060
10061         for (const declaration_t *decl = file_scope->declarations; decl != NULL; decl = decl->next) {
10062                 if (decl->used                  ||
10063                     decl->modifiers & DM_UNUSED ||
10064                     decl->modifiers & DM_USED   ||
10065                     decl->storage_class != STORAGE_CLASS_STATIC)
10066                         continue;
10067
10068                 type_t *const type = decl->type;
10069                 const char *s;
10070                 if (is_type_function(skip_typeref(type))) {
10071                         if (!warning.unused_function || decl->is_inline)
10072                                 continue;
10073
10074                         s = (decl->init.statement != NULL ? "defined" : "declared");
10075                 } else {
10076                         if (!warning.unused_variable)
10077                                 continue;
10078
10079                         s = "defined";
10080                 }
10081
10082                 warningf(&decl->source_position, "'%#T' %s but not used",
10083                         type, decl->symbol, s);
10084         }
10085 }
10086
10087 static void parse_global_asm(void)
10088 {
10089         statement_t *statement = allocate_statement_zero(STATEMENT_ASM);
10090
10091         eat(T_asm);
10092         expect('(');
10093
10094         statement->asms.asm_text = parse_string_literals();
10095         statement->base.next     = unit->global_asm;
10096         unit->global_asm         = statement;
10097
10098         expect(')');
10099         expect(';');
10100
10101 end_error:;
10102 }
10103
10104 /**
10105  * Parse a translation unit.
10106  */
10107 static void parse_translation_unit(void)
10108 {
10109         add_anchor_token(T_EOF);
10110
10111 #ifndef NDEBUG
10112         unsigned char token_anchor_copy[T_LAST_TOKEN];
10113         memcpy(token_anchor_copy, token_anchor_set, sizeof(token_anchor_copy));
10114 #endif
10115         for (;;) {
10116 #ifndef NDEBUG
10117                 bool anchor_leak = false;
10118                 for (int i = 0; i != T_LAST_TOKEN; ++i) {
10119                         unsigned char count = token_anchor_set[i] - token_anchor_copy[i];
10120                         if (count != 0) {
10121                                 errorf(HERE, "Leaked anchor token %k %d times", i, count);
10122                                 anchor_leak = true;
10123                         }
10124                 }
10125                 if (in_gcc_extension) {
10126                         errorf(HERE, "Leaked __extension__");
10127                         anchor_leak = true;
10128                 }
10129
10130                 if (anchor_leak)
10131                         abort();
10132 #endif
10133
10134                 switch (token.type) {
10135                         DECLARATION_START
10136                         case T_IDENTIFIER:
10137                         case T___extension__:
10138                                 parse_external_declaration();
10139                                 break;
10140
10141                         case T_asm:
10142                                 parse_global_asm();
10143                                 break;
10144
10145                         case T_EOF:
10146                                 rem_anchor_token(T_EOF);
10147                                 return;
10148
10149                         case ';':
10150                                 if (!strict_mode) {
10151                                         if (warning.other)
10152                                                 warningf(HERE, "stray ';' outside of function");
10153                                         next_token();
10154                                         break;
10155                                 }
10156                                 /* FALLTHROUGH */
10157
10158                         default:
10159                                 errorf(HERE, "stray %K outside of function", &token);
10160                                 if (token.type == '(' || token.type == '{' || token.type == '[')
10161                                         eat_until_matching_token(token.type);
10162                                 next_token();
10163                                 break;
10164                 }
10165         }
10166 }
10167
10168 /**
10169  * Parse the input.
10170  *
10171  * @return  the translation unit or NULL if errors occurred.
10172  */
10173 void start_parsing(void)
10174 {
10175         environment_stack = NEW_ARR_F(stack_entry_t, 0);
10176         label_stack       = NEW_ARR_F(stack_entry_t, 0);
10177         local_label_stack = NEW_ARR_F(stack_entry_t, 0);
10178         diagnostic_count  = 0;
10179         error_count       = 0;
10180         warning_count     = 0;
10181
10182         type_set_output(stderr);
10183         ast_set_output(stderr);
10184
10185         assert(unit == NULL);
10186         unit = allocate_ast_zero(sizeof(unit[0]));
10187
10188         assert(file_scope == NULL);
10189         file_scope = &unit->scope;
10190
10191         assert(scope == NULL);
10192         scope_push(&unit->scope);
10193
10194         initialize_builtin_types();
10195 }
10196
10197 translation_unit_t *finish_parsing(void)
10198 {
10199         /* do NOT use scope_pop() here, this will crash, will it by hand */
10200         assert(scope == &unit->scope);
10201         scope            = NULL;
10202         last_declaration = NULL;
10203
10204         assert(file_scope == &unit->scope);
10205         check_unused_globals();
10206         file_scope = NULL;
10207
10208         DEL_ARR_F(environment_stack);
10209         DEL_ARR_F(label_stack);
10210         DEL_ARR_F(local_label_stack);
10211
10212         translation_unit_t *result = unit;
10213         unit = NULL;
10214         return result;
10215 }
10216
10217 void parse(void)
10218 {
10219         lookahead_bufpos = 0;
10220         for (int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
10221                 next_token();
10222         }
10223         parse_translation_unit();
10224 }
10225
10226 /**
10227  * Initialize the parser.
10228  */
10229 void init_parser(void)
10230 {
10231         sym_anonymous = symbol_table_insert("<anonymous>");
10232
10233         if (c_mode & _MS) {
10234                 /* add predefined symbols for extended-decl-modifier */
10235                 sym_align      = symbol_table_insert("align");
10236                 sym_allocate   = symbol_table_insert("allocate");
10237                 sym_dllimport  = symbol_table_insert("dllimport");
10238                 sym_dllexport  = symbol_table_insert("dllexport");
10239                 sym_naked      = symbol_table_insert("naked");
10240                 sym_noinline   = symbol_table_insert("noinline");
10241                 sym_noreturn   = symbol_table_insert("noreturn");
10242                 sym_nothrow    = symbol_table_insert("nothrow");
10243                 sym_novtable   = symbol_table_insert("novtable");
10244                 sym_property   = symbol_table_insert("property");
10245                 sym_get        = symbol_table_insert("get");
10246                 sym_put        = symbol_table_insert("put");
10247                 sym_selectany  = symbol_table_insert("selectany");
10248                 sym_thread     = symbol_table_insert("thread");
10249                 sym_uuid       = symbol_table_insert("uuid");
10250                 sym_deprecated = symbol_table_insert("deprecated");
10251                 sym_restrict   = symbol_table_insert("restrict");
10252                 sym_noalias    = symbol_table_insert("noalias");
10253         }
10254         memset(token_anchor_set, 0, sizeof(token_anchor_set));
10255
10256         init_expression_parsers();
10257         obstack_init(&temp_obst);
10258
10259         symbol_t *const va_list_sym = symbol_table_insert("__builtin_va_list");
10260         type_valist = create_builtin_type(va_list_sym, type_void_ptr);
10261 }
10262
10263 /**
10264  * Terminate the parser.
10265  */
10266 void exit_parser(void)
10267 {
10268         obstack_free(&temp_obst, NULL);
10269 }