nsz Git - cparser/blob - parser.c

   1 /*
   2  * This file is part of cparser.
   3  * Copyright (C) 2007-2009 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 "adt/strutil.h"
  27 #include "parser.h"
  28 #include "diagnostic.h"
  29 #include "format_check.h"
  30 #include "lexer.h"
  31 #include "symbol_t.h"
  32 #include "token_t.h"
  33 #include "types.h"
  34 #include "type_t.h"
  35 #include "type_hash.h"
  36 #include "ast_t.h"
  37 #include "entity_t.h"
  38 #include "attribute_t.h"
  39 #include "lang_features.h"
  40 #include "walk.h"
  41 #include "warning.h"
  42 #include "printer.h"
  43 #include "adt/bitfiddle.h"
  44 #include "adt/error.h"
  45 #include "adt/array.h"
  46
  47 //#define PRINT_TOKENS
  48 #define MAX_LOOKAHEAD 1
  49
  50 typedef struct {
  51         entity_t           *old_entity;
  52         symbol_t           *symbol;
  53         entity_namespace_t  namespc;
  54 } stack_entry_t;
  55
  56 typedef struct declaration_specifiers_t  declaration_specifiers_t;
  57 struct declaration_specifiers_t {
  58         source_position_t  source_position;
  59         storage_class_t    storage_class;
  60         unsigned char      alignment;         /**< Alignment, 0 if not set. */
  61         bool               is_inline    : 1;
  62         bool               thread_local : 1;  /**< GCC __thread */
  63         attribute_t       *attributes;        /**< list of attributes */
  64         type_t            *type;
  65 };
  66
  67 /**
  68  * An environment for parsing initializers (and compound literals).
  69  */
  70 typedef struct parse_initializer_env_t {
  71         type_t     *type;   /**< the type of the initializer. In case of an
  72                                  array type with unspecified size this gets
  73                                  adjusted to the actual size. */
  74         entity_t   *entity; /**< the variable that is initialized if any */
  75         bool        must_be_constant;
  76 } parse_initializer_env_t;
  77
  78 typedef entity_t* (*parsed_declaration_func) (entity_t *declaration, bool is_definition);
  79
  80 /** The current token. */
  81 static token_t              token;
  82 /** The lookahead ring-buffer. */
  83 static token_t              lookahead_buffer[MAX_LOOKAHEAD];
  84 /** Position of the next token in the lookahead buffer. */
  85 static size_t               lookahead_bufpos;
  86 static stack_entry_t       *environment_stack = NULL;
  87 static stack_entry_t       *label_stack       = NULL;
  88 static scope_t             *file_scope        = NULL;
  89 static scope_t             *current_scope     = NULL;
  90 /** Point to the current function declaration if inside a function. */
  91 static function_t          *current_function  = NULL;
  92 static entity_t            *current_entity    = NULL;
  93 static switch_statement_t  *current_switch    = NULL;
  94 static statement_t         *current_loop      = NULL;
  95 static statement_t         *current_parent    = NULL;
  96 static ms_try_statement_t  *current_try       = NULL;
  97 static linkage_kind_t       current_linkage;
  98 static goto_statement_t    *goto_first        = NULL;
  99 static goto_statement_t   **goto_anchor       = NULL;
 100 static label_statement_t   *label_first       = NULL;
 101 static label_statement_t  **label_anchor      = NULL;
 102 /** current translation unit. */
 103 static translation_unit_t  *unit              = NULL;
 104 /** true if we are in an __extension__ context. */
 105 static bool                 in_gcc_extension  = false;
 106 static struct obstack       temp_obst;
 107 static entity_t            *anonymous_entity;
 108 static declaration_t      **incomplete_arrays;
 109 static elf_visibility_tag_t default_visibility = ELF_VISIBILITY_DEFAULT;
 110
 111
 112 #define PUSH_CURRENT_ENTITY(entity) \
 113         entity_t *const new_current_entity = (entity); \
 114         entity_t *const old_current_entity = current_entity; \
 115         ((void)(current_entity = new_current_entity))
 116 #define POP_CURRENT_ENTITY() (assert(current_entity == new_current_entity), (void)(current_entity = old_current_entity))
 117
 118 #define PUSH_PARENT(stmt) \
 119         statement_t *const new_parent = (stmt); \
 120         statement_t *const old_parent = current_parent; \
 121         ((void)(current_parent = new_parent))
 122 #define POP_PARENT() (assert(current_parent == new_parent), (void)(current_parent = old_parent))
 123
 124 #define PUSH_SCOPE(scope) \
 125         size_t   const top       = environment_top(); \
 126         scope_t *const new_scope = (scope); \
 127         scope_t *const old_scope = (new_scope ? scope_push(new_scope) : NULL)
 128 #define PUSH_SCOPE_STATEMENT(scope) PUSH_SCOPE(c_mode & (_C99 | _CXX) ? (scope) : NULL)
 129 #define POP_SCOPE() (new_scope ? assert(current_scope == new_scope), scope_pop(old_scope), environment_pop_to(top) : (void)0)
 130
 131 #define PUSH_EXTENSION() \
 132         (void)0; \
 133         bool const old_gcc_extension = in_gcc_extension; \
 134         while (next_if(T___extension__)) { \
 135                 in_gcc_extension = true; \
 136         } \
 137         do {} while (0)
 138 #define POP_EXTENSION() \
 139         ((void)(in_gcc_extension = old_gcc_extension))
 140
 141 /** special symbol used for anonymous entities. */
 142 static symbol_t *sym_anonymous = NULL;
 143
 144 /** The token anchor set */
 145 static unsigned short token_anchor_set[T_LAST_TOKEN];
 146
 147 /** The current source position. */
 148 #define HERE (&token.base.source_position)
 149
 150 /** true if we are in GCC mode. */
 151 #define GNU_MODE ((c_mode & _GNUC) || in_gcc_extension)
 152
 153 static statement_t *parse_compound_statement(bool inside_expression_statement);
 154 static statement_t *parse_statement(void);
 155
 156 static expression_t *parse_subexpression(precedence_t);
 157 static expression_t *parse_expression(void);
 158 static type_t       *parse_typename(void);
 159 static void          parse_externals(void);
 160 static void          parse_external(void);
 161
 162 static void parse_compound_type_entries(compound_t *compound_declaration);
 163
 164 static void check_call_argument(type_t          *expected_type,
 165                                                                 call_argument_t *argument, unsigned pos);
 166
 167 typedef enum declarator_flags_t {
 168         DECL_FLAGS_NONE             = 0,
 169         DECL_MAY_BE_ABSTRACT        = 1U << 0,
 170         DECL_CREATE_COMPOUND_MEMBER = 1U << 1,
 171         DECL_IS_PARAMETER           = 1U << 2
 172 } declarator_flags_t;
 173
 174 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
 175                                   declarator_flags_t flags);
 176
 177 static void semantic_comparison(binary_expression_t *expression);
 178
 179 #define STORAGE_CLASSES       \
 180         STORAGE_CLASSES_NO_EXTERN \
 181         case T_extern:
 182
 183 #define STORAGE_CLASSES_NO_EXTERN \
 184         case T_typedef:         \
 185         case T_static:          \
 186         case T_auto:            \
 187         case T_register:        \
 188         case T___thread:
 189
 190 #define TYPE_QUALIFIERS     \
 191         case T_const:           \
 192         case T_restrict:        \
 193         case T_volatile:        \
 194         case T_inline:          \
 195         case T__forceinline:    \
 196         case T___attribute__:
 197
 198 #define COMPLEX_SPECIFIERS  \
 199         case T__Complex:
 200 #define IMAGINARY_SPECIFIERS \
 201         case T__Imaginary:
 202
 203 #define TYPE_SPECIFIERS       \
 204         case T__Bool:             \
 205         case T___builtin_va_list: \
 206         case T___typeof__:        \
 207         case T__declspec:         \
 208         case T_bool:              \
 209         case T_char:              \
 210         case T_double:            \
 211         case T_enum:              \
 212         case T_float:             \
 213         case T_int:               \
 214         case T_long:              \
 215         case T_short:             \
 216         case T_signed:            \
 217         case T_struct:            \
 218         case T_union:             \
 219         case T_unsigned:          \
 220         case T_void:              \
 221         case T_wchar_t:           \
 222         case T__int8:             \
 223         case T__int16:            \
 224         case T__int32:            \
 225         case T__int64:            \
 226         case T__int128:           \
 227         COMPLEX_SPECIFIERS        \
 228         IMAGINARY_SPECIFIERS
 229
 230 #define DECLARATION_START   \
 231         STORAGE_CLASSES         \
 232         TYPE_QUALIFIERS         \
 233         TYPE_SPECIFIERS
 234
 235 #define DECLARATION_START_NO_EXTERN \
 236         STORAGE_CLASSES_NO_EXTERN       \
 237         TYPE_QUALIFIERS                 \
 238         TYPE_SPECIFIERS
 239
 240 #define EXPRESSION_START              \
 241         case '!':                         \
 242         case '&':                         \
 243         case '(':                         \
 244         case '*':                         \
 245         case '+':                         \
 246         case '-':                         \
 247         case '~':                         \
 248         case T_ANDAND:                    \
 249         case T_CHARACTER_CONSTANT:        \
 250         case T_FLOATINGPOINT:             \
 251         case T_FLOATINGPOINT_HEXADECIMAL: \
 252         case T_INTEGER:                   \
 253         case T_INTEGER_HEXADECIMAL:       \
 254         case T_INTEGER_OCTAL:             \
 255         case T_MINUSMINUS:                \
 256         case T_PLUSPLUS:                  \
 257         case T_STRING_LITERAL:            \
 258         case T_WIDE_CHARACTER_CONSTANT:   \
 259         case T_WIDE_STRING_LITERAL:       \
 260         case T___FUNCDNAME__:             \
 261         case T___FUNCSIG__:               \
 262         case T___FUNCTION__:              \
 263         case T___PRETTY_FUNCTION__:       \
 264         case T___alignof__:               \
 265         case T___builtin_classify_type:   \
 266         case T___builtin_constant_p:      \
 267         case T___builtin_isgreater:       \
 268         case T___builtin_isgreaterequal:  \
 269         case T___builtin_isless:          \
 270         case T___builtin_islessequal:     \
 271         case T___builtin_islessgreater:   \
 272         case T___builtin_isunordered:     \
 273         case T___builtin_offsetof:        \
 274         case T___builtin_va_arg:          \
 275         case T___builtin_va_copy:         \
 276         case T___builtin_va_start:        \
 277         case T___func__:                  \
 278         case T___noop:                    \
 279         case T__assume:                   \
 280         case T_delete:                    \
 281         case T_false:                     \
 282         case T_sizeof:                    \
 283         case T_throw:                     \
 284         case T_true:
 285
 286 /**
 287  * Returns the size of a statement node.
 288  *
 289  * @param kind  the statement kind
 290  */
 291 static size_t get_statement_struct_size(statement_kind_t kind)
 292 {
 293         static const size_t sizes[] = {
 294                 [STATEMENT_ERROR]         = sizeof(statement_base_t),
 295                 [STATEMENT_EMPTY]         = sizeof(statement_base_t),
 296                 [STATEMENT_COMPOUND]      = sizeof(compound_statement_t),
 297                 [STATEMENT_RETURN]        = sizeof(return_statement_t),
 298                 [STATEMENT_DECLARATION]   = sizeof(declaration_statement_t),
 299                 [STATEMENT_IF]            = sizeof(if_statement_t),
 300                 [STATEMENT_SWITCH]        = sizeof(switch_statement_t),
 301                 [STATEMENT_EXPRESSION]    = sizeof(expression_statement_t),
 302                 [STATEMENT_CONTINUE]      = sizeof(statement_base_t),
 303                 [STATEMENT_BREAK]         = sizeof(statement_base_t),
 304                 [STATEMENT_COMPUTED_GOTO] = sizeof(computed_goto_statement_t),
 305                 [STATEMENT_GOTO]          = sizeof(goto_statement_t),
 306                 [STATEMENT_LABEL]         = sizeof(label_statement_t),
 307                 [STATEMENT_CASE_LABEL]    = sizeof(case_label_statement_t),
 308                 [STATEMENT_WHILE]         = sizeof(while_statement_t),
 309                 [STATEMENT_DO_WHILE]      = sizeof(do_while_statement_t),
 310                 [STATEMENT_FOR]           = sizeof(for_statement_t),
 311                 [STATEMENT_ASM]           = sizeof(asm_statement_t),
 312                 [STATEMENT_MS_TRY]        = sizeof(ms_try_statement_t),
 313                 [STATEMENT_LEAVE]         = sizeof(leave_statement_t)
 314         };
 315         assert((size_t)kind < lengthof(sizes));
 316         assert(sizes[kind] != 0);
 317         return sizes[kind];
 318 }
 319
 320 /**
 321  * Returns the size of an expression node.
 322  *
 323  * @param kind  the expression kind
 324  */
 325 static size_t get_expression_struct_size(expression_kind_t kind)
 326 {
 327         static const size_t sizes[] = {
 328                 [EXPR_ERROR]                      = sizeof(expression_base_t),
 329                 [EXPR_REFERENCE]                  = sizeof(reference_expression_t),
 330                 [EXPR_ENUM_CONSTANT]              = sizeof(reference_expression_t),
 331                 [EXPR_LITERAL_BOOLEAN]            = sizeof(literal_expression_t),
 332                 [EXPR_LITERAL_INTEGER]            = sizeof(literal_expression_t),
 333                 [EXPR_LITERAL_INTEGER_OCTAL]      = sizeof(literal_expression_t),
 334                 [EXPR_LITERAL_INTEGER_HEXADECIMAL]= sizeof(literal_expression_t),
 335                 [EXPR_LITERAL_FLOATINGPOINT]      = sizeof(literal_expression_t),
 336                 [EXPR_LITERAL_FLOATINGPOINT_HEXADECIMAL] = sizeof(literal_expression_t),
 337                 [EXPR_LITERAL_CHARACTER]          = sizeof(literal_expression_t),
 338                 [EXPR_LITERAL_WIDE_CHARACTER]     = sizeof(literal_expression_t),
 339                 [EXPR_STRING_LITERAL]             = sizeof(string_literal_expression_t),
 340                 [EXPR_WIDE_STRING_LITERAL]        = sizeof(string_literal_expression_t),
 341                 [EXPR_COMPOUND_LITERAL]           = sizeof(compound_literal_expression_t),
 342                 [EXPR_CALL]                       = sizeof(call_expression_t),
 343                 [EXPR_UNARY_FIRST]                = sizeof(unary_expression_t),
 344                 [EXPR_BINARY_FIRST]               = sizeof(binary_expression_t),
 345                 [EXPR_CONDITIONAL]                = sizeof(conditional_expression_t),
 346                 [EXPR_SELECT]                     = sizeof(select_expression_t),
 347                 [EXPR_ARRAY_ACCESS]               = sizeof(array_access_expression_t),
 348                 [EXPR_SIZEOF]                     = sizeof(typeprop_expression_t),
 349                 [EXPR_ALIGNOF]                    = sizeof(typeprop_expression_t),
 350                 [EXPR_CLASSIFY_TYPE]              = sizeof(classify_type_expression_t),
 351                 [EXPR_FUNCNAME]                   = sizeof(funcname_expression_t),
 352                 [EXPR_BUILTIN_CONSTANT_P]         = sizeof(builtin_constant_expression_t),
 353                 [EXPR_BUILTIN_TYPES_COMPATIBLE_P] = sizeof(builtin_types_compatible_expression_t),
 354                 [EXPR_OFFSETOF]                   = sizeof(offsetof_expression_t),
 355                 [EXPR_VA_START]                   = sizeof(va_start_expression_t),
 356                 [EXPR_VA_ARG]                     = sizeof(va_arg_expression_t),
 357                 [EXPR_VA_COPY]                    = sizeof(va_copy_expression_t),
 358                 [EXPR_STATEMENT]                  = sizeof(statement_expression_t),
 359                 [EXPR_LABEL_ADDRESS]              = sizeof(label_address_expression_t),
 360         };
 361         if (kind >= EXPR_UNARY_FIRST && kind <= EXPR_UNARY_LAST) {
 362                 return sizes[EXPR_UNARY_FIRST];
 363         }
 364         if (kind >= EXPR_BINARY_FIRST && kind <= EXPR_BINARY_LAST) {
 365                 return sizes[EXPR_BINARY_FIRST];
 366         }
 367         assert((size_t)kind < lengthof(sizes));
 368         assert(sizes[kind] != 0);
 369         return sizes[kind];
 370 }
 371
 372 /**
 373  * Allocate a statement node of given kind and initialize all
 374  * fields with zero. Sets its source position to the position
 375  * of the current token.
 376  */
 377 static statement_t *allocate_statement_zero(statement_kind_t kind)
 378 {
 379         size_t       size = get_statement_struct_size(kind);
 380         statement_t *res  = allocate_ast_zero(size);
 381
 382         res->base.kind            = kind;
 383         res->base.parent          = current_parent;
 384         res->base.source_position = token.base.source_position;
 385         return res;
 386 }
 387
 388 /**
 389  * Allocate an expression node of given kind and initialize all
 390  * fields with zero.
 391  *
 392  * @param kind  the kind of the expression to allocate
 393  */
 394 static expression_t *allocate_expression_zero(expression_kind_t kind)
 395 {
 396         size_t        size = get_expression_struct_size(kind);
 397         expression_t *res  = allocate_ast_zero(size);
 398
 399         res->base.kind            = kind;
 400         res->base.type            = type_error_type;
 401         res->base.source_position = token.base.source_position;
 402         return res;
 403 }
 404
 405 /**
 406  * Creates a new invalid expression at the source position
 407  * of the current token.
 408  */
 409 static expression_t *create_error_expression(void)
 410 {
 411         expression_t *expression = allocate_expression_zero(EXPR_ERROR);
 412         expression->base.type = type_error_type;
 413         return expression;
 414 }
 415
 416 /**
 417  * Creates a new invalid statement.
 418  */
 419 static statement_t *create_error_statement(void)
 420 {
 421         return allocate_statement_zero(STATEMENT_ERROR);
 422 }
 423
 424 /**
 425  * Allocate a new empty statement.
 426  */
 427 static statement_t *create_empty_statement(void)
 428 {
 429         return allocate_statement_zero(STATEMENT_EMPTY);
 430 }
 431
 432 /**
 433  * Returns the size of an initializer node.
 434  *
 435  * @param kind  the initializer kind
 436  */
 437 static size_t get_initializer_size(initializer_kind_t kind)
 438 {
 439         static const size_t sizes[] = {
 440                 [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
 441                 [INITIALIZER_STRING]      = sizeof(initializer_string_t),
 442                 [INITIALIZER_WIDE_STRING] = sizeof(initializer_wide_string_t),
 443                 [INITIALIZER_LIST]        = sizeof(initializer_list_t),
 444                 [INITIALIZER_DESIGNATOR]  = sizeof(initializer_designator_t)
 445         };
 446         assert((size_t)kind < lengthof(sizes));
 447         assert(sizes[kind] != 0);
 448         return sizes[kind];
 449 }
 450
 451 /**
 452  * Allocate an initializer node of given kind and initialize all
 453  * fields with zero.
 454  */
 455 static initializer_t *allocate_initializer_zero(initializer_kind_t kind)
 456 {
 457         initializer_t *result = allocate_ast_zero(get_initializer_size(kind));
 458         result->kind          = kind;
 459
 460         return result;
 461 }
 462
 463 /**
 464  * Returns the index of the top element of the environment stack.
 465  */
 466 static size_t environment_top(void)
 467 {
 468         return ARR_LEN(environment_stack);
 469 }
 470
 471 /**
 472  * Returns the index of the top element of the global label stack.
 473  */
 474 static size_t label_top(void)
 475 {
 476         return ARR_LEN(label_stack);
 477 }
 478
 479 /**
 480  * Return the next token.
 481  */
 482 static inline void next_token(void)
 483 {
 484         token                              = lookahead_buffer[lookahead_bufpos];
 485         lookahead_buffer[lookahead_bufpos] = lexer_token;
 486         lexer_next_token();
 487
 488         lookahead_bufpos = (lookahead_bufpos + 1) % MAX_LOOKAHEAD;
 489
 490 #ifdef PRINT_TOKENS
 491         print_token(stderr, &token);
 492         fprintf(stderr, "\n");
 493 #endif
 494 }
 495
 496 static inline bool next_if(token_kind_t const type)
 497 {
 498         if (token.kind == type) {
 499                 next_token();
 500                 return true;
 501         } else {
 502                 return false;
 503         }
 504 }
 505
 506 /**
 507  * Return the next token with a given lookahead.
 508  */
 509 static inline const token_t *look_ahead(size_t num)
 510 {
 511         assert(0 < num && num <= MAX_LOOKAHEAD);
 512         size_t pos = (lookahead_bufpos + num - 1) % MAX_LOOKAHEAD;
 513         return &lookahead_buffer[pos];
 514 }
 515
 516 /**
 517  * Adds a token type to the token type anchor set (a multi-set).
 518  */
 519 static void add_anchor_token(token_kind_t const token_kind)
 520 {
 521         assert(token_kind < T_LAST_TOKEN);
 522         ++token_anchor_set[token_kind];
 523 }
 524
 525 /**
 526  * Remove a token type from the token type anchor set (a multi-set).
 527  */
 528 static void rem_anchor_token(token_kind_t const token_kind)
 529 {
 530         assert(token_kind < T_LAST_TOKEN);
 531         assert(token_anchor_set[token_kind] != 0);
 532         --token_anchor_set[token_kind];
 533 }
 534
 535 /**
 536  * Eat tokens until a matching token type is found.
 537  */
 538 static void eat_until_matching_token(token_kind_t const type)
 539 {
 540         token_kind_t end_token;
 541         switch (type) {
 542                 case '(': end_token = ')';  break;
 543                 case '{': end_token = '}';  break;
 544                 case '[': end_token = ']';  break;
 545                 default:  end_token = type; break;
 546         }
 547
 548         unsigned parenthesis_count = 0;
 549         unsigned brace_count       = 0;
 550         unsigned bracket_count     = 0;
 551         while (token.kind        != end_token ||
 552                parenthesis_count != 0         ||
 553                brace_count       != 0         ||
 554                bracket_count     != 0) {
 555                 switch (token.kind) {
 556                 case T_EOF: return;
 557                 case '(': ++parenthesis_count; break;
 558                 case '{': ++brace_count;       break;
 559                 case '[': ++bracket_count;     break;
 560
 561                 case ')':
 562                         if (parenthesis_count > 0)
 563                                 --parenthesis_count;
 564                         goto check_stop;
 565
 566                 case '}':
 567                         if (brace_count > 0)
 568                                 --brace_count;
 569                         goto check_stop;
 570
 571                 case ']':
 572                         if (bracket_count > 0)
 573                                 --bracket_count;
 574 check_stop:
 575                         if (token.kind        == end_token &&
 576                             parenthesis_count == 0         &&
 577                             brace_count       == 0         &&
 578                             bracket_count     == 0)
 579                                 return;
 580                         break;
 581
 582                 default:
 583                         break;
 584                 }
 585                 next_token();
 586         }
 587 }
 588
 589 /**
 590  * Eat input tokens until an anchor is found.
 591  */
 592 static void eat_until_anchor(void)
 593 {
 594         while (token_anchor_set[token.kind] == 0) {
 595                 if (token.kind == '(' || token.kind == '{' || token.kind == '[')
 596                         eat_until_matching_token(token.kind);
 597                 next_token();
 598         }
 599 }
 600
 601 /**
 602  * Eat a whole block from input tokens.
 603  */
 604 static void eat_block(void)
 605 {
 606         eat_until_matching_token('{');
 607         next_if('}');
 608 }
 609
 610 #define eat(token_kind) (assert(token.kind == (token_kind)), next_token())
 611
 612 /**
 613  * Report a parse error because an expected token was not found.
 614  */
 615 static
 616 #if defined __GNUC__ && __GNUC__ >= 4
 617 __attribute__((sentinel))
 618 #endif
 619 void parse_error_expected(const char *message, ...)
 620 {
 621         if (message != NULL) {
 622                 errorf(HERE, "%s", message);
 623         }
 624         va_list ap;
 625         va_start(ap, message);
 626         errorf(HERE, "got %K, expected %#k", &token, &ap, ", ");
 627         va_end(ap);
 628 }
 629
 630 /**
 631  * Report an incompatible type.
 632  */
 633 static void type_error_incompatible(const char *msg,
 634                 const source_position_t *source_position, type_t *type1, type_t *type2)
 635 {
 636         errorf(source_position, "%s, incompatible types: '%T' - '%T'",
 637                msg, type1, type2);
 638 }
 639
 640 /**
 641  * Expect the current token is the expected token.
 642  * If not, generate an error and skip until the next anchor.
 643  */
 644 static void expect(token_kind_t const expected)
 645 {
 646         if (UNLIKELY(token.kind != expected)) {
 647                 parse_error_expected(NULL, expected, NULL);
 648                 add_anchor_token(expected);
 649                 eat_until_anchor();
 650                 rem_anchor_token(expected);
 651                 if (token.kind != expected)
 652                         return;
 653         }
 654         eat(expected);
 655 }
 656
 657 static symbol_t *expect_identifier(char const *const context, source_position_t *const pos)
 658 {
 659         if (token.kind != T_IDENTIFIER) {
 660                 parse_error_expected(context, T_IDENTIFIER, NULL);
 661                 add_anchor_token(T_IDENTIFIER);
 662                 eat_until_anchor();
 663                 rem_anchor_token(T_IDENTIFIER);
 664                 if (token.kind != T_IDENTIFIER)
 665                         return NULL;
 666         }
 667         symbol_t *const sym = token.identifier.symbol;
 668         if (pos)
 669                 *pos = *HERE;
 670         eat(T_IDENTIFIER);
 671         return sym;
 672 }
 673
 674 /**
 675  * Push a given scope on the scope stack and make it the
 676  * current scope
 677  */
 678 static scope_t *scope_push(scope_t *new_scope)
 679 {
 680         if (current_scope != NULL) {
 681                 new_scope->depth = current_scope->depth + 1;
 682         }
 683
 684         scope_t *old_scope = current_scope;
 685         current_scope      = new_scope;
 686         return old_scope;
 687 }
 688
 689 /**
 690  * Pop the current scope from the scope stack.
 691  */
 692 static void scope_pop(scope_t *old_scope)
 693 {
 694         current_scope = old_scope;
 695 }
 696
 697 /**
 698  * Search an entity by its symbol in a given namespace.
 699  */
 700 static entity_t *get_entity(const symbol_t *const symbol,
 701                             namespace_tag_t namespc)
 702 {
 703         entity_t *entity = symbol->entity;
 704         for (; entity != NULL; entity = entity->base.symbol_next) {
 705                 if ((namespace_tag_t)entity->base.namespc == namespc)
 706                         return entity;
 707         }
 708
 709         return NULL;
 710 }
 711
 712 /* §6.2.3:1 24)  There is only one name space for tags even though three are
 713  * possible. */
 714 static entity_t *get_tag(symbol_t const *const symbol,
 715                          entity_kind_tag_t const kind)
 716 {
 717         entity_t *entity = get_entity(symbol, NAMESPACE_TAG);
 718         if (entity != NULL && (entity_kind_tag_t)entity->kind != kind) {
 719                 errorf(HERE,
 720                                 "'%Y' defined as wrong kind of tag (previous definition %P)",
 721                                 symbol, &entity->base.source_position);
 722                 entity = NULL;
 723         }
 724         return entity;
 725 }
 726
 727 /**
 728  * pushs an entity on the environment stack and links the corresponding symbol
 729  * it.
 730  */
 731 static void stack_push(stack_entry_t **stack_ptr, entity_t *entity)
 732 {
 733         symbol_t           *symbol  = entity->base.symbol;
 734         entity_namespace_t  namespc = entity->base.namespc;
 735         assert(namespc != 0);
 736
 737         /* replace/add entity into entity list of the symbol */
 738         entity_t **anchor;
 739         entity_t  *iter;
 740         for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 741                 iter = *anchor;
 742                 if (iter == NULL)
 743                         break;
 744
 745                 /* replace an entry? */
 746                 if (iter->base.namespc == namespc) {
 747                         entity->base.symbol_next = iter->base.symbol_next;
 748                         break;
 749                 }
 750         }
 751         *anchor = entity;
 752
 753         /* remember old declaration */
 754         stack_entry_t entry;
 755         entry.symbol     = symbol;
 756         entry.old_entity = iter;
 757         entry.namespc    = namespc;
 758         ARR_APP1(stack_entry_t, *stack_ptr, entry);
 759 }
 760
 761 /**
 762  * Push an entity on the environment stack.
 763  */
 764 static void environment_push(entity_t *entity)
 765 {
 766         assert(entity->base.source_position.input_name != NULL);
 767         assert(entity->base.parent_scope != NULL);
 768         stack_push(&environment_stack, entity);
 769 }
 770
 771 /**
 772  * Push a declaration on the global label stack.
 773  *
 774  * @param declaration  the declaration
 775  */
 776 static void label_push(entity_t *label)
 777 {
 778         /* we abuse the parameters scope as parent for the labels */
 779         label->base.parent_scope = &current_function->parameters;
 780         stack_push(&label_stack, label);
 781 }
 782
 783 /**
 784  * pops symbols from the environment stack until @p new_top is the top element
 785  */
 786 static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
 787 {
 788         stack_entry_t *stack = *stack_ptr;
 789         size_t         top   = ARR_LEN(stack);
 790         size_t         i;
 791
 792         assert(new_top <= top);
 793         if (new_top == top)
 794                 return;
 795
 796         for (i = top; i > new_top; --i) {
 797                 stack_entry_t *entry = &stack[i - 1];
 798
 799                 entity_t           *old_entity = entry->old_entity;
 800                 symbol_t           *symbol     = entry->symbol;
 801                 entity_namespace_t  namespc    = entry->namespc;
 802
 803                 /* replace with old_entity/remove */
 804                 entity_t **anchor;
 805                 entity_t  *iter;
 806                 for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 807                         iter = *anchor;
 808                         assert(iter != NULL);
 809                         /* replace an entry? */
 810                         if (iter->base.namespc == namespc)
 811                                 break;
 812                 }
 813
 814                 /* restore definition from outer scopes (if there was one) */
 815                 if (old_entity != NULL) {
 816                         old_entity->base.symbol_next = iter->base.symbol_next;
 817                         *anchor                      = old_entity;
 818                 } else {
 819                         /* remove entry from list */
 820                         *anchor = iter->base.symbol_next;
 821                 }
 822         }
 823
 824         ARR_SHRINKLEN(*stack_ptr, new_top);
 825 }
 826
 827 /**
 828  * Pop all entries from the environment stack until the new_top
 829  * is reached.
 830  *
 831  * @param new_top  the new stack top
 832  */
 833 static void environment_pop_to(size_t new_top)
 834 {
 835         stack_pop_to(&environment_stack, new_top);
 836 }
 837
 838 /**
 839  * Pop all entries from the global label stack until the new_top
 840  * is reached.
 841  *
 842  * @param new_top  the new stack top
 843  */
 844 static void label_pop_to(size_t new_top)
 845 {
 846         stack_pop_to(&label_stack, new_top);
 847 }
 848
 849 static atomic_type_kind_t get_akind(const type_t *type)
 850 {
 851         assert(type->kind == TYPE_ATOMIC || type->kind == TYPE_COMPLEX
 852                || type->kind == TYPE_IMAGINARY || type->kind == TYPE_ENUM);
 853         return type->atomic.akind;
 854 }
 855
 856 /**
 857  * §6.3.1.1:2  Do integer promotion for a given type.
 858  *
 859  * @param type  the type to promote
 860  * @return the promoted type
 861  */
 862 static type_t *promote_integer(type_t *type)
 863 {
 864         if (get_akind_rank(get_akind(type)) < get_akind_rank(ATOMIC_TYPE_INT))
 865                 type = type_int;
 866
 867         return type;
 868 }
 869
 870 /**
 871  * Check if a given expression represents a null pointer constant.
 872  *
 873  * @param expression  the expression to check
 874  */
 875 static bool is_null_pointer_constant(const expression_t *expression)
 876 {
 877         /* skip void* cast */
 878         if (expression->kind == EXPR_UNARY_CAST) {
 879                 type_t *const type = skip_typeref(expression->base.type);
 880                 if (types_compatible(type, type_void_ptr))
 881                         expression = expression->unary.value;
 882         }
 883
 884         type_t *const type = skip_typeref(expression->base.type);
 885         if (!is_type_integer(type))
 886                 return false;
 887         switch (is_constant_expression(expression)) {
 888                 case EXPR_CLASS_ERROR:    return true;
 889                 case EXPR_CLASS_CONSTANT: return !fold_constant_to_bool(expression);
 890                 default:                  return false;
 891         }
 892 }
 893
 894 /**
 895  * Create an implicit cast expression.
 896  *
 897  * @param expression  the expression to cast
 898  * @param dest_type   the destination type
 899  */
 900 static expression_t *create_implicit_cast(expression_t *expression,
 901                                           type_t *dest_type)
 902 {
 903         type_t *const source_type = expression->base.type;
 904
 905         if (source_type == dest_type)
 906                 return expression;
 907
 908         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
 909         cast->unary.value   = expression;
 910         cast->base.type     = dest_type;
 911         cast->base.implicit = true;
 912
 913         return cast;
 914 }
 915
 916 typedef enum assign_error_t {
 917         ASSIGN_SUCCESS,
 918         ASSIGN_ERROR_INCOMPATIBLE,
 919         ASSIGN_ERROR_POINTER_QUALIFIER_MISSING,
 920         ASSIGN_WARNING_POINTER_INCOMPATIBLE,
 921         ASSIGN_WARNING_POINTER_FROM_INT,
 922         ASSIGN_WARNING_INT_FROM_POINTER
 923 } assign_error_t;
 924
 925 static void report_assign_error(assign_error_t error, type_t *orig_type_left, expression_t const *const right, char const *const context, source_position_t const *const pos)
 926 {
 927         type_t *const orig_type_right = right->base.type;
 928         type_t *const type_left       = skip_typeref(orig_type_left);
 929         type_t *const type_right      = skip_typeref(orig_type_right);
 930
 931         switch (error) {
 932         case ASSIGN_SUCCESS:
 933                 return;
 934         case ASSIGN_ERROR_INCOMPATIBLE:
 935                 errorf(pos, "destination type '%T' in %s is incompatible with type '%T'", orig_type_left, context, orig_type_right);
 936                 return;
 937
 938         case ASSIGN_ERROR_POINTER_QUALIFIER_MISSING: {
 939                 type_t *points_to_left  = skip_typeref(type_left->pointer.points_to);
 940                 type_t *points_to_right = skip_typeref(type_right->pointer.points_to);
 941
 942                 /* the left type has all qualifiers from the right type */
 943                 unsigned missing_qualifiers = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 944                 warningf(WARN_OTHER, pos, "destination type '%T' in %s from type '%T' lacks qualifiers '%Q' in pointer target type", orig_type_left, context, orig_type_right, missing_qualifiers);
 945                 return;
 946         }
 947
 948         case ASSIGN_WARNING_POINTER_INCOMPATIBLE:
 949                 warningf(WARN_OTHER, pos, "destination type '%T' in %s is incompatible with '%E' of type '%T'", orig_type_left, context, right, orig_type_right);
 950                 return;
 951
 952         case ASSIGN_WARNING_POINTER_FROM_INT:
 953                 warningf(WARN_OTHER, pos, "%s makes pointer '%T' from integer '%T' without a cast", context, orig_type_left, orig_type_right);
 954                 return;
 955
 956         case ASSIGN_WARNING_INT_FROM_POINTER:
 957                 warningf(WARN_OTHER, pos, "%s makes integer '%T' from pointer '%T' without a cast", context, orig_type_left, orig_type_right);
 958                 return;
 959
 960         default:
 961                 panic("invalid error value");
 962         }
 963 }
 964
 965 /** Implements the rules from §6.5.16.1 */
 966 static assign_error_t semantic_assign(type_t *orig_type_left,
 967                                       const expression_t *const right)
 968 {
 969         type_t *const orig_type_right = right->base.type;
 970         type_t *const type_left       = skip_typeref(orig_type_left);
 971         type_t *const type_right      = skip_typeref(orig_type_right);
 972
 973         if (is_type_pointer(type_left)) {
 974                 if (is_null_pointer_constant(right)) {
 975                         return ASSIGN_SUCCESS;
 976                 } else if (is_type_pointer(type_right)) {
 977                         type_t *points_to_left
 978                                 = skip_typeref(type_left->pointer.points_to);
 979                         type_t *points_to_right
 980                                 = skip_typeref(type_right->pointer.points_to);
 981                         assign_error_t res = ASSIGN_SUCCESS;
 982
 983                         /* the left type has all qualifiers from the right type */
 984                         unsigned missing_qualifiers
 985                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 986                         if (missing_qualifiers != 0) {
 987                                 res = ASSIGN_ERROR_POINTER_QUALIFIER_MISSING;
 988                         }
 989
 990                         points_to_left  = get_unqualified_type(points_to_left);
 991                         points_to_right = get_unqualified_type(points_to_right);
 992
 993                         if (is_type_void(points_to_left))
 994                                 return res;
 995
 996                         if (is_type_void(points_to_right)) {
 997                                 /* ISO/IEC 14882:1998(E) §C.1.2:6 */
 998                                 return c_mode & _CXX ? ASSIGN_ERROR_INCOMPATIBLE : res;
 999                         }
1000
1001                         if (!types_compatible(points_to_left, points_to_right)) {
1002                                 return ASSIGN_WARNING_POINTER_INCOMPATIBLE;
1003                         }
1004
1005                         return res;
1006                 } else if (is_type_integer(type_right)) {
1007                         return ASSIGN_WARNING_POINTER_FROM_INT;
1008                 }
1009         } else if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
1010                         (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
1011                                 && is_type_pointer(type_right))) {
1012                 return ASSIGN_SUCCESS;
1013         } else if (is_type_compound(type_left) && is_type_compound(type_right)) {
1014                 type_t *const unqual_type_left  = get_unqualified_type(type_left);
1015                 type_t *const unqual_type_right = get_unqualified_type(type_right);
1016                 if (types_compatible(unqual_type_left, unqual_type_right)) {
1017                         return ASSIGN_SUCCESS;
1018                 }
1019         } else if (is_type_integer(type_left) && is_type_pointer(type_right)) {
1020                 return ASSIGN_WARNING_INT_FROM_POINTER;
1021         }
1022
1023         if (!is_type_valid(type_left) || !is_type_valid(type_right))
1024                 return ASSIGN_SUCCESS;
1025
1026         return ASSIGN_ERROR_INCOMPATIBLE;
1027 }
1028
1029 static expression_t *parse_constant_expression(void)
1030 {
1031         expression_t *result = parse_subexpression(PREC_CONDITIONAL);
1032
1033         if (is_constant_expression(result) == EXPR_CLASS_VARIABLE) {
1034                 errorf(&result->base.source_position,
1035                        "expression '%E' is not constant", result);
1036         }
1037
1038         return result;
1039 }
1040
1041 static expression_t *parse_assignment_expression(void)
1042 {
1043         return parse_subexpression(PREC_ASSIGNMENT);
1044 }
1045
1046 static void warn_string_concat(const source_position_t *pos)
1047 {
1048         warningf(WARN_TRADITIONAL, pos, "traditional C rejects string constant concatenation");
1049 }
1050
1051 static string_t parse_string_literals(void)
1052 {
1053         assert(token.kind == T_STRING_LITERAL);
1054         string_t result = token.string.string;
1055
1056         next_token();
1057
1058         while (token.kind == T_STRING_LITERAL) {
1059                 warn_string_concat(&token.base.source_position);
1060                 result = concat_strings(&result, &token.string.string);
1061                 next_token();
1062         }
1063
1064         return result;
1065 }
1066
1067 static attribute_t *allocate_attribute_zero(attribute_kind_t kind)
1068 {
1069         attribute_t *attribute = allocate_ast_zero(sizeof(*attribute));
1070         attribute->kind            = kind;
1071         attribute->source_position = *HERE;
1072         return attribute;
1073 }
1074
1075 /**
1076  * Parse (gcc) attribute argument. From gcc comments in gcc source:
1077  *
1078  *  attribute:
1079  *    __attribute__ ( ( attribute-list ) )
1080  *
1081  *  attribute-list:
1082  *    attrib
1083  *    attribute_list , attrib
1084  *
1085  *  attrib:
1086  *    empty
1087  *    any-word
1088  *    any-word ( identifier )
1089  *    any-word ( identifier , nonempty-expr-list )
1090  *    any-word ( expr-list )
1091  *
1092  *  where the "identifier" must not be declared as a type, and
1093  *  "any-word" may be any identifier (including one declared as a
1094  *  type), a reserved word storage class specifier, type specifier or
1095  *  type qualifier.  ??? This still leaves out most reserved keywords
1096  *  (following the old parser), shouldn't we include them, and why not
1097  *  allow identifiers declared as types to start the arguments?
1098  *
1099  *  Matze: this all looks confusing and little systematic, so we're even less
1100  *  strict and parse any list of things which are identifiers or
1101  *  (assignment-)expressions.
1102  */
1103 static attribute_argument_t *parse_attribute_arguments(void)
1104 {
1105         attribute_argument_t  *first  = NULL;
1106         attribute_argument_t **anchor = &first;
1107         if (token.kind != ')') do {
1108                 attribute_argument_t *argument = allocate_ast_zero(sizeof(*argument));
1109
1110                 /* is it an identifier */
1111                 if (token.kind == T_IDENTIFIER
1112                                 && (look_ahead(1)->kind == ',' || look_ahead(1)->kind == ')')) {
1113                         symbol_t *symbol   = token.identifier.symbol;
1114                         argument->kind     = ATTRIBUTE_ARGUMENT_SYMBOL;
1115                         argument->v.symbol = symbol;
1116                         next_token();
1117                 } else {
1118                         /* must be an expression */
1119                         expression_t *expression = parse_assignment_expression();
1120
1121                         argument->kind         = ATTRIBUTE_ARGUMENT_EXPRESSION;
1122                         argument->v.expression = expression;
1123                 }
1124
1125                 /* append argument */
1126                 *anchor = argument;
1127                 anchor  = &argument->next;
1128         } while (next_if(','));
1129         expect(')');
1130         return first;
1131 }
1132
1133 static attribute_t *parse_attribute_asm(void)
1134 {
1135         attribute_t *attribute = allocate_attribute_zero(ATTRIBUTE_GNU_ASM);
1136         eat(T_asm);
1137         expect('(');
1138         attribute->a.arguments = parse_attribute_arguments();
1139         return attribute;
1140 }
1141
1142 static symbol_t *get_symbol_from_token(void)
1143 {
1144         switch(token.kind) {
1145         case T_CHARACTER_CONSTANT:
1146         case T_EOF:
1147         case T_FLOATINGPOINT:
1148         case T_FLOATINGPOINT_HEXADECIMAL:
1149         case T_INTEGER:
1150         case T_INTEGER_HEXADECIMAL:
1151         case T_INTEGER_OCTAL:
1152         case T_STRING_LITERAL:
1153         case T_WIDE_CHARACTER_CONSTANT:
1154         case T_WIDE_STRING_LITERAL:
1155                 return NULL;
1156
1157         default:
1158                 return token.identifier.symbol;
1159         }
1160 }
1161
1162 static attribute_t *parse_attribute_gnu_single(void)
1163 {
1164         /* parse "any-word" */
1165         symbol_t *symbol = get_symbol_from_token();
1166         if (symbol == NULL) {
1167                 parse_error_expected("while parsing attribute((", T_IDENTIFIER, NULL);
1168                 return NULL;
1169         }
1170
1171         attribute_kind_t  kind;
1172         char const *const name = symbol->string;
1173         for (kind = ATTRIBUTE_GNU_FIRST;; ++kind) {
1174                 if (kind > ATTRIBUTE_GNU_LAST) {
1175                         warningf(WARN_ATTRIBUTE, HERE, "unknown attribute '%s' ignored", name);
1176                         /* TODO: we should still save the attribute in the list... */
1177                         kind = ATTRIBUTE_UNKNOWN;
1178                         break;
1179                 }
1180
1181                 const char *attribute_name = get_attribute_name(kind);
1182                 if (attribute_name != NULL && streq_underscore(attribute_name, name))
1183                         break;
1184         }
1185
1186         attribute_t *attribute = allocate_attribute_zero(kind);
1187         next_token();
1188
1189         /* parse arguments */
1190         if (next_if('('))
1191                 attribute->a.arguments = parse_attribute_arguments();
1192
1193         return attribute;
1194 }
1195
1196 static attribute_t *parse_attribute_gnu(void)
1197 {
1198         attribute_t  *first  = NULL;
1199         attribute_t **anchor = &first;
1200
1201         eat(T___attribute__);
1202         expect('(');
1203         expect('(');
1204
1205         add_anchor_token(')');
1206         add_anchor_token(',');
1207         if (token.kind != ')') do {
1208                 attribute_t *attribute = parse_attribute_gnu_single();
1209                 if (attribute) {
1210                         *anchor = attribute;
1211                         anchor  = &attribute->next;
1212                 }
1213         } while (next_if(','));
1214         rem_anchor_token(',');
1215         rem_anchor_token(')');
1216
1217         expect(')');
1218         expect(')');
1219         return first;
1220 }
1221
1222 /** Parse attributes. */
1223 static attribute_t *parse_attributes(attribute_t *first)
1224 {
1225         attribute_t **anchor = &first;
1226         for (;;) {
1227                 while (*anchor != NULL)
1228                         anchor = &(*anchor)->next;
1229
1230                 attribute_t *attribute;
1231                 switch (token.kind) {
1232                 case T___attribute__:
1233                         attribute = parse_attribute_gnu();
1234                         if (attribute == NULL)
1235                                 continue;
1236                         break;
1237
1238                 case T_asm:
1239                         attribute = parse_attribute_asm();
1240                         break;
1241
1242                 case T_cdecl:
1243                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_CDECL);
1244                         eat(T_cdecl);
1245                         break;
1246
1247                 case T__fastcall:
1248                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FASTCALL);
1249                         eat(T__fastcall);
1250                         break;
1251
1252                 case T__forceinline:
1253                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FORCEINLINE);
1254                         eat(T__forceinline);
1255                         break;
1256
1257                 case T__stdcall:
1258                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_STDCALL);
1259                         eat(T__stdcall);
1260                         break;
1261
1262                 case T___thiscall:
1263                         /* TODO record modifier */
1264                         warningf(WARN_OTHER, HERE, "Ignoring declaration modifier %K", &token);
1265                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_THISCALL);
1266                         eat(T___thiscall);
1267                         break;
1268
1269                 default:
1270                         return first;
1271                 }
1272
1273                 *anchor = attribute;
1274                 anchor  = &attribute->next;
1275         }
1276 }
1277
1278 static void mark_vars_read(expression_t *expr, entity_t *lhs_ent);
1279
1280 static entity_t *determine_lhs_ent(expression_t *const expr,
1281                                    entity_t *lhs_ent)
1282 {
1283         switch (expr->kind) {
1284                 case EXPR_REFERENCE: {
1285                         entity_t *const entity = expr->reference.entity;
1286                         /* we should only find variables as lvalues... */
1287                         if (entity->base.kind != ENTITY_VARIABLE
1288                                         && entity->base.kind != ENTITY_PARAMETER)
1289                                 return NULL;
1290
1291                         return entity;
1292                 }
1293
1294                 case EXPR_ARRAY_ACCESS: {
1295                         expression_t *const ref = expr->array_access.array_ref;
1296                         entity_t     *      ent = NULL;
1297                         if (is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1298                                 ent     = determine_lhs_ent(ref, lhs_ent);
1299                                 lhs_ent = ent;
1300                         } else {
1301                                 mark_vars_read(ref, lhs_ent);
1302                         }
1303                         mark_vars_read(expr->array_access.index, lhs_ent);
1304                         return ent;
1305                 }
1306
1307                 case EXPR_SELECT: {
1308                         mark_vars_read(expr->select.compound, lhs_ent);
1309                         if (is_type_compound(skip_typeref(expr->base.type)))
1310                                 return determine_lhs_ent(expr->select.compound, lhs_ent);
1311                         return NULL;
1312                 }
1313
1314                 case EXPR_UNARY_DEREFERENCE: {
1315                         expression_t *const val = expr->unary.value;
1316                         if (val->kind == EXPR_UNARY_TAKE_ADDRESS) {
1317                                 /* *&x is a NOP */
1318                                 return determine_lhs_ent(val->unary.value, lhs_ent);
1319                         } else {
1320                                 mark_vars_read(val, NULL);
1321                                 return NULL;
1322                         }
1323                 }
1324
1325                 default:
1326                         mark_vars_read(expr, NULL);
1327                         return NULL;
1328         }
1329 }
1330
1331 #define ENT_ANY ((entity_t*)-1)
1332
1333 /**
1334  * Mark declarations, which are read.  This is used to detect variables, which
1335  * are never read.
1336  * Example:
1337  * x = x + 1;
1338  *   x is not marked as "read", because it is only read to calculate its own new
1339  *   value.
1340  *
1341  * x += y; y += x;
1342  *   x and y are not detected as "not read", because multiple variables are
1343  *   involved.
1344  */
1345 static void mark_vars_read(expression_t *const expr, entity_t *lhs_ent)
1346 {
1347         switch (expr->kind) {
1348                 case EXPR_REFERENCE: {
1349                         entity_t *const entity = expr->reference.entity;
1350                         if (entity->kind != ENTITY_VARIABLE
1351                                         && entity->kind != ENTITY_PARAMETER)
1352                                 return;
1353
1354                         if (lhs_ent != entity && lhs_ent != ENT_ANY) {
1355                                 if (entity->kind == ENTITY_VARIABLE) {
1356                                         entity->variable.read = true;
1357                                 } else {
1358                                         entity->parameter.read = true;
1359                                 }
1360                         }
1361                         return;
1362                 }
1363
1364                 case EXPR_CALL:
1365                         // TODO respect pure/const
1366                         mark_vars_read(expr->call.function, NULL);
1367                         for (call_argument_t *arg = expr->call.arguments; arg != NULL; arg = arg->next) {
1368                                 mark_vars_read(arg->expression, NULL);
1369                         }
1370                         return;
1371
1372                 case EXPR_CONDITIONAL:
1373                         // TODO lhs_decl should depend on whether true/false have an effect
1374                         mark_vars_read(expr->conditional.condition, NULL);
1375                         if (expr->conditional.true_expression != NULL)
1376                                 mark_vars_read(expr->conditional.true_expression, lhs_ent);
1377                         mark_vars_read(expr->conditional.false_expression, lhs_ent);
1378                         return;
1379
1380                 case EXPR_SELECT:
1381                         if (lhs_ent == ENT_ANY
1382                                         && !is_type_compound(skip_typeref(expr->base.type)))
1383                                 lhs_ent = NULL;
1384                         mark_vars_read(expr->select.compound, lhs_ent);
1385                         return;
1386
1387                 case EXPR_ARRAY_ACCESS: {
1388                         mark_vars_read(expr->array_access.index, lhs_ent);
1389                         expression_t *const ref = expr->array_access.array_ref;
1390                         if (!is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1391                                 if (lhs_ent == ENT_ANY)
1392                                         lhs_ent = NULL;
1393                         }
1394                         mark_vars_read(ref, lhs_ent);
1395                         return;
1396                 }
1397
1398                 case EXPR_VA_ARG:
1399                         mark_vars_read(expr->va_arge.ap, lhs_ent);
1400                         return;
1401
1402                 case EXPR_VA_COPY:
1403                         mark_vars_read(expr->va_copye.src, lhs_ent);
1404                         return;
1405
1406                 case EXPR_UNARY_CAST:
1407                         /* Special case: Use void cast to mark a variable as "read" */
1408                         if (is_type_void(skip_typeref(expr->base.type)))
1409                                 lhs_ent = NULL;
1410                         goto unary;
1411
1412
1413                 case EXPR_UNARY_THROW:
1414                         if (expr->unary.value == NULL)
1415                                 return;
1416                         /* FALLTHROUGH */
1417                 case EXPR_UNARY_DEREFERENCE:
1418                 case EXPR_UNARY_DELETE:
1419                 case EXPR_UNARY_DELETE_ARRAY:
1420                         if (lhs_ent == ENT_ANY)
1421                                 lhs_ent = NULL;
1422                         goto unary;
1423
1424                 case EXPR_UNARY_NEGATE:
1425                 case EXPR_UNARY_PLUS:
1426                 case EXPR_UNARY_BITWISE_NEGATE:
1427                 case EXPR_UNARY_NOT:
1428                 case EXPR_UNARY_TAKE_ADDRESS:
1429                 case EXPR_UNARY_POSTFIX_INCREMENT:
1430                 case EXPR_UNARY_POSTFIX_DECREMENT:
1431                 case EXPR_UNARY_PREFIX_INCREMENT:
1432                 case EXPR_UNARY_PREFIX_DECREMENT:
1433                 case EXPR_UNARY_ASSUME:
1434 unary:
1435                         mark_vars_read(expr->unary.value, lhs_ent);
1436                         return;
1437
1438                 case EXPR_BINARY_ADD:
1439                 case EXPR_BINARY_SUB:
1440                 case EXPR_BINARY_MUL:
1441                 case EXPR_BINARY_DIV:
1442                 case EXPR_BINARY_MOD:
1443                 case EXPR_BINARY_EQUAL:
1444                 case EXPR_BINARY_NOTEQUAL:
1445                 case EXPR_BINARY_LESS:
1446                 case EXPR_BINARY_LESSEQUAL:
1447                 case EXPR_BINARY_GREATER:
1448                 case EXPR_BINARY_GREATEREQUAL:
1449                 case EXPR_BINARY_BITWISE_AND:
1450                 case EXPR_BINARY_BITWISE_OR:
1451                 case EXPR_BINARY_BITWISE_XOR:
1452                 case EXPR_BINARY_LOGICAL_AND:
1453                 case EXPR_BINARY_LOGICAL_OR:
1454                 case EXPR_BINARY_SHIFTLEFT:
1455                 case EXPR_BINARY_SHIFTRIGHT:
1456                 case EXPR_BINARY_COMMA:
1457                 case EXPR_BINARY_ISGREATER:
1458                 case EXPR_BINARY_ISGREATEREQUAL:
1459                 case EXPR_BINARY_ISLESS:
1460                 case EXPR_BINARY_ISLESSEQUAL:
1461                 case EXPR_BINARY_ISLESSGREATER:
1462                 case EXPR_BINARY_ISUNORDERED:
1463                         mark_vars_read(expr->binary.left,  lhs_ent);
1464                         mark_vars_read(expr->binary.right, lhs_ent);
1465                         return;
1466
1467                 case EXPR_BINARY_ASSIGN:
1468                 case EXPR_BINARY_MUL_ASSIGN:
1469                 case EXPR_BINARY_DIV_ASSIGN:
1470                 case EXPR_BINARY_MOD_ASSIGN:
1471                 case EXPR_BINARY_ADD_ASSIGN:
1472                 case EXPR_BINARY_SUB_ASSIGN:
1473                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:
1474                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:
1475                 case EXPR_BINARY_BITWISE_AND_ASSIGN:
1476                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:
1477                 case EXPR_BINARY_BITWISE_OR_ASSIGN: {
1478                         if (lhs_ent == ENT_ANY)
1479                                 lhs_ent = NULL;
1480                         lhs_ent = determine_lhs_ent(expr->binary.left, lhs_ent);
1481                         mark_vars_read(expr->binary.right, lhs_ent);
1482                         return;
1483                 }
1484
1485                 case EXPR_VA_START:
1486                         determine_lhs_ent(expr->va_starte.ap, lhs_ent);
1487                         return;
1488
1489                 case EXPR_LITERAL_CASES:
1490                 case EXPR_ERROR:
1491                 case EXPR_STRING_LITERAL:
1492                 case EXPR_WIDE_STRING_LITERAL:
1493                 case EXPR_COMPOUND_LITERAL: // TODO init?
1494                 case EXPR_SIZEOF:
1495                 case EXPR_CLASSIFY_TYPE:
1496                 case EXPR_ALIGNOF:
1497                 case EXPR_FUNCNAME:
1498                 case EXPR_BUILTIN_CONSTANT_P:
1499                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
1500                 case EXPR_OFFSETOF:
1501                 case EXPR_STATEMENT: // TODO
1502                 case EXPR_LABEL_ADDRESS:
1503                 case EXPR_ENUM_CONSTANT:
1504                         return;
1505         }
1506
1507         panic("unhandled expression");
1508 }
1509
1510 static designator_t *parse_designation(void)
1511 {
1512         designator_t  *result = NULL;
1513         designator_t **anchor = &result;
1514
1515         for (;;) {
1516                 designator_t *designator;
1517                 switch (token.kind) {
1518                 case '[':
1519                         designator = allocate_ast_zero(sizeof(designator[0]));
1520                         designator->source_position = token.base.source_position;
1521                         next_token();
1522                         add_anchor_token(']');
1523                         designator->array_index = parse_constant_expression();
1524                         rem_anchor_token(']');
1525                         expect(']');
1526                         break;
1527                 case '.':
1528                         designator = allocate_ast_zero(sizeof(designator[0]));
1529                         designator->source_position = token.base.source_position;
1530                         next_token();
1531                         designator->symbol = expect_identifier("while parsing designator", NULL);
1532                         if (!designator->symbol)
1533                                 return NULL;
1534                         break;
1535                 default:
1536                         expect('=');
1537                         return result;
1538                 }
1539
1540                 assert(designator != NULL);
1541                 *anchor = designator;
1542                 anchor  = &designator->next;
1543         }
1544 }
1545
1546 static initializer_t *initializer_from_string(array_type_t *const type,
1547                                               const string_t *const string)
1548 {
1549         /* TODO: check len vs. size of array type */
1550         (void) type;
1551
1552         initializer_t *initializer = allocate_initializer_zero(INITIALIZER_STRING);
1553         initializer->string.string = *string;
1554
1555         return initializer;
1556 }
1557
1558 static initializer_t *initializer_from_wide_string(array_type_t *const type,
1559                                                    const string_t *const string)
1560 {
1561         /* TODO: check len vs. size of array type */
1562         (void) type;
1563
1564         initializer_t *const initializer =
1565                 allocate_initializer_zero(INITIALIZER_WIDE_STRING);
1566         initializer->wide_string.string = *string;
1567
1568         return initializer;
1569 }
1570
1571 /**
1572  * Build an initializer from a given expression.
1573  */
1574 static initializer_t *initializer_from_expression(type_t *orig_type,
1575                                                   expression_t *expression)
1576 {
1577         /* TODO check that expression is a constant expression */
1578
1579         /* §6.7.8.14/15 char array may be initialized by string literals */
1580         type_t *type           = skip_typeref(orig_type);
1581         type_t *expr_type_orig = expression->base.type;
1582         type_t *expr_type      = skip_typeref(expr_type_orig);
1583
1584         if (is_type_array(type) && expr_type->kind == TYPE_POINTER) {
1585                 array_type_t *const array_type   = &type->array;
1586                 type_t       *const element_type = skip_typeref(array_type->element_type);
1587
1588                 if (element_type->kind == TYPE_ATOMIC) {
1589                         atomic_type_kind_t akind = element_type->atomic.akind;
1590                         switch (expression->kind) {
1591                         case EXPR_STRING_LITERAL:
1592                                 if (akind == ATOMIC_TYPE_CHAR
1593                                                 || akind == ATOMIC_TYPE_SCHAR
1594                                                 || akind == ATOMIC_TYPE_UCHAR) {
1595                                         return initializer_from_string(array_type,
1596                                                         &expression->string_literal.value);
1597                                 }
1598                                 break;
1599
1600                         case EXPR_WIDE_STRING_LITERAL: {
1601                                 type_t *bare_wchar_type = skip_typeref(type_wchar_t);
1602                                 if (get_unqualified_type(element_type) == bare_wchar_type) {
1603                                         return initializer_from_wide_string(array_type,
1604                                                         &expression->string_literal.value);
1605                                 }
1606                                 break;
1607                         }
1608
1609                         default:
1610                                 break;
1611                         }
1612                 }
1613         }
1614
1615         assign_error_t error = semantic_assign(type, expression);
1616         if (error == ASSIGN_ERROR_INCOMPATIBLE)
1617                 return NULL;
1618         report_assign_error(error, type, expression, "initializer",
1619                             &expression->base.source_position);
1620
1621         initializer_t *const result = allocate_initializer_zero(INITIALIZER_VALUE);
1622         result->value.value = create_implicit_cast(expression, type);
1623
1624         return result;
1625 }
1626
1627 /**
1628  * Parses an scalar initializer.
1629  *
1630  * §6.7.8.11; eat {} without warning
1631  */
1632 static initializer_t *parse_scalar_initializer(type_t *type,
1633                                                bool must_be_constant)
1634 {
1635         /* there might be extra {} hierarchies */
1636         int braces = 0;
1637         if (token.kind == '{') {
1638                 warningf(WARN_OTHER, HERE, "extra curly braces around scalar initializer");
1639                 do {
1640                         eat('{');
1641                         ++braces;
1642                 } while (token.kind == '{');
1643         }
1644
1645         expression_t *expression = parse_assignment_expression();
1646         mark_vars_read(expression, NULL);
1647         if (must_be_constant && !is_linker_constant(expression)) {
1648                 errorf(&expression->base.source_position,
1649                        "initialisation expression '%E' is not constant",
1650                        expression);
1651         }
1652
1653         initializer_t *initializer = initializer_from_expression(type, expression);
1654
1655         if (initializer == NULL) {
1656                 errorf(&expression->base.source_position,
1657                        "expression '%E' (type '%T') doesn't match expected type '%T'",
1658                        expression, expression->base.type, type);
1659                 /* TODO */
1660                 return NULL;
1661         }
1662
1663         bool additional_warning_displayed = false;
1664         while (braces > 0) {
1665                 next_if(',');
1666                 if (token.kind != '}') {
1667                         if (!additional_warning_displayed) {
1668                                 warningf(WARN_OTHER, HERE, "additional elements in scalar initializer");
1669                                 additional_warning_displayed = true;
1670                         }
1671                 }
1672                 eat_block();
1673                 braces--;
1674         }
1675
1676         return initializer;
1677 }
1678
1679 /**
1680  * An entry in the type path.
1681  */
1682 typedef struct type_path_entry_t type_path_entry_t;
1683 struct type_path_entry_t {
1684         type_t *type;       /**< the upper top type. restored to path->top_tye if this entry is popped. */
1685         union {
1686                 size_t         index;          /**< For array types: the current index. */
1687                 declaration_t *compound_entry; /**< For compound types: the current declaration. */
1688         } v;
1689 };
1690
1691 /**
1692  * A type path expression a position inside compound or array types.
1693  */
1694 typedef struct type_path_t type_path_t;
1695 struct type_path_t {
1696         type_path_entry_t *path;         /**< An flexible array containing the current path. */
1697         type_t            *top_type;     /**< type of the element the path points */
1698         size_t             max_index;    /**< largest index in outermost array */
1699 };
1700
1701 /**
1702  * Prints a type path for debugging.
1703  */
1704 static __attribute__((unused)) void debug_print_type_path(
1705                 const type_path_t *path)
1706 {
1707         size_t len = ARR_LEN(path->path);
1708
1709         for (size_t i = 0; i < len; ++i) {
1710                 const type_path_entry_t *entry = & path->path[i];
1711
1712                 type_t *type = skip_typeref(entry->type);
1713                 if (is_type_compound(type)) {
1714                         /* in gcc mode structs can have no members */
1715                         if (entry->v.compound_entry == NULL) {
1716                                 assert(i == len-1);
1717                                 continue;
1718                         }
1719                         fprintf(stderr, ".%s",
1720                                 entry->v.compound_entry->base.symbol->string);
1721                 } else if (is_type_array(type)) {
1722                         fprintf(stderr, "[%u]", (unsigned) entry->v.index);
1723                 } else {
1724                         fprintf(stderr, "-INVALID-");
1725                 }
1726         }
1727         if (path->top_type != NULL) {
1728                 fprintf(stderr, "  (");
1729                 print_type(path->top_type);
1730                 fprintf(stderr, ")");
1731         }
1732 }
1733
1734 /**
1735  * Return the top type path entry, ie. in a path
1736  * (type).a.b returns the b.
1737  */
1738 static type_path_entry_t *get_type_path_top(const type_path_t *path)
1739 {
1740         size_t len = ARR_LEN(path->path);
1741         assert(len > 0);
1742         return &path->path[len-1];
1743 }
1744
1745 /**
1746  * Enlarge the type path by an (empty) element.
1747  */
1748 static type_path_entry_t *append_to_type_path(type_path_t *path)
1749 {
1750         size_t len = ARR_LEN(path->path);
1751         ARR_RESIZE(type_path_entry_t, path->path, len+1);
1752
1753         type_path_entry_t *result = & path->path[len];
1754         memset(result, 0, sizeof(result[0]));
1755         return result;
1756 }
1757
1758 /**
1759  * Descending into a sub-type. Enter the scope of the current top_type.
1760  */
1761 static void descend_into_subtype(type_path_t *path)
1762 {
1763         type_t *orig_top_type = path->top_type;
1764         type_t *top_type      = skip_typeref(orig_top_type);
1765
1766         type_path_entry_t *top = append_to_type_path(path);
1767         top->type              = top_type;
1768
1769         if (is_type_compound(top_type)) {
1770                 compound_t *const compound = top_type->compound.compound;
1771                 entity_t   *const entry    = skip_unnamed_bitfields(compound->members.entities);
1772
1773                 if (entry != NULL) {
1774                         top->v.compound_entry = &entry->declaration;
1775                         path->top_type = entry->declaration.type;
1776                 } else {
1777                         path->top_type = NULL;
1778                 }
1779         } else if (is_type_array(top_type)) {
1780                 top->v.index   = 0;
1781                 path->top_type = top_type->array.element_type;
1782         } else {
1783                 assert(!is_type_valid(top_type));
1784         }
1785 }
1786
1787 /**
1788  * Pop an entry from the given type path, ie. returning from
1789  * (type).a.b to (type).a
1790  */
1791 static void ascend_from_subtype(type_path_t *path)
1792 {
1793         type_path_entry_t *top = get_type_path_top(path);
1794
1795         path->top_type = top->type;
1796
1797         size_t len = ARR_LEN(path->path);
1798         ARR_RESIZE(type_path_entry_t, path->path, len-1);
1799 }
1800
1801 /**
1802  * Pop entries from the given type path until the given
1803  * path level is reached.
1804  */
1805 static void ascend_to(type_path_t *path, size_t top_path_level)
1806 {
1807         size_t len = ARR_LEN(path->path);
1808
1809         while (len > top_path_level) {
1810                 ascend_from_subtype(path);
1811                 len = ARR_LEN(path->path);
1812         }
1813 }
1814
1815 static bool walk_designator(type_path_t *path, const designator_t *designator,
1816                             bool used_in_offsetof)
1817 {
1818         for (; designator != NULL; designator = designator->next) {
1819                 type_path_entry_t *top       = get_type_path_top(path);
1820                 type_t            *orig_type = top->type;
1821
1822                 type_t *type = skip_typeref(orig_type);
1823
1824                 if (designator->symbol != NULL) {
1825                         symbol_t *symbol = designator->symbol;
1826                         if (!is_type_compound(type)) {
1827                                 if (is_type_valid(type)) {
1828                                         errorf(&designator->source_position,
1829                                                "'.%Y' designator used for non-compound type '%T'",
1830                                                symbol, orig_type);
1831                                 }
1832
1833                                 top->type             = type_error_type;
1834                                 top->v.compound_entry = NULL;
1835                                 orig_type             = type_error_type;
1836                         } else {
1837                                 compound_t *compound = type->compound.compound;
1838                                 entity_t   *iter     = compound->members.entities;
1839                                 for (; iter != NULL; iter = iter->base.next) {
1840                                         if (iter->base.symbol == symbol) {
1841                                                 break;
1842                                         }
1843                                 }
1844                                 if (iter == NULL) {
1845                                         errorf(&designator->source_position,
1846                                                "'%T' has no member named '%Y'", orig_type, symbol);
1847                                         return false;
1848                                 }
1849                                 assert(iter->kind == ENTITY_COMPOUND_MEMBER);
1850                                 if (used_in_offsetof && iter->compound_member.bitfield) {
1851                                         errorf(&designator->source_position,
1852                                                    "offsetof designator '%Y' must not specify bitfield",
1853                                                    symbol);
1854                                         return false;
1855                                 }
1856
1857                                 top->type             = orig_type;
1858                                 top->v.compound_entry = &iter->declaration;
1859                                 orig_type             = iter->declaration.type;
1860                         }
1861                 } else {
1862                         expression_t *array_index = designator->array_index;
1863                         assert(designator->array_index != NULL);
1864
1865                         if (!is_type_array(type)) {
1866                                 if (is_type_valid(type)) {
1867                                         errorf(&designator->source_position,
1868                                                "[%E] designator used for non-array type '%T'",
1869                                                array_index, orig_type);
1870                                 }
1871                                 return false;
1872                         }
1873
1874                         long index = fold_constant_to_int(array_index);
1875                         if (!used_in_offsetof) {
1876                                 if (index < 0) {
1877                                         errorf(&designator->source_position,
1878                                                "array index [%E] must be positive", array_index);
1879                                 } else if (type->array.size_constant) {
1880                                         long array_size = type->array.size;
1881                                         if (index >= array_size) {
1882                                                 errorf(&designator->source_position,
1883                                                        "designator [%E] (%d) exceeds array size %d",
1884                                                        array_index, index, array_size);
1885                                         }
1886                                 }
1887                         }
1888
1889                         top->type    = orig_type;
1890                         top->v.index = (size_t) index;
1891                         orig_type    = type->array.element_type;
1892                 }
1893                 path->top_type = orig_type;
1894
1895                 if (designator->next != NULL) {
1896                         descend_into_subtype(path);
1897                 }
1898         }
1899         return true;
1900 }
1901
1902 static void advance_current_object(type_path_t *path, size_t top_path_level)
1903 {
1904         type_path_entry_t *top = get_type_path_top(path);
1905
1906         type_t *type = skip_typeref(top->type);
1907         if (is_type_union(type)) {
1908                 /* in unions only the first element is initialized */
1909                 top->v.compound_entry = NULL;
1910         } else if (is_type_struct(type)) {
1911                 declaration_t *entry = top->v.compound_entry;
1912
1913                 entity_t *const next_entity = skip_unnamed_bitfields(entry->base.next);
1914                 if (next_entity != NULL) {
1915                         assert(is_declaration(next_entity));
1916                         entry = &next_entity->declaration;
1917                 } else {
1918                         entry = NULL;
1919                 }
1920
1921                 top->v.compound_entry = entry;
1922                 if (entry != NULL) {
1923                         path->top_type = entry->type;
1924                         return;
1925                 }
1926         } else if (is_type_array(type)) {
1927                 assert(is_type_array(type));
1928
1929                 top->v.index++;
1930
1931                 if (!type->array.size_constant || top->v.index < type->array.size) {
1932                         return;
1933                 }
1934         } else {
1935                 assert(!is_type_valid(type));
1936                 return;
1937         }
1938
1939         /* we're past the last member of the current sub-aggregate, try if we
1940          * can ascend in the type hierarchy and continue with another subobject */
1941         size_t len = ARR_LEN(path->path);
1942
1943         if (len > top_path_level) {
1944                 ascend_from_subtype(path);
1945                 advance_current_object(path, top_path_level);
1946         } else {
1947                 path->top_type = NULL;
1948         }
1949 }
1950
1951 /**
1952  * skip any {...} blocks until a closing bracket is reached.
1953  */
1954 static void skip_initializers(void)
1955 {
1956         next_if('{');
1957
1958         while (token.kind != '}') {
1959                 if (token.kind == T_EOF)
1960                         return;
1961                 if (token.kind == '{') {
1962                         eat_block();
1963                         continue;
1964                 }
1965                 next_token();
1966         }
1967 }
1968
1969 static initializer_t *create_empty_initializer(void)
1970 {
1971         static initializer_t empty_initializer
1972                 = { .list = { { INITIALIZER_LIST }, 0 } };
1973         return &empty_initializer;
1974 }
1975
1976 /**
1977  * Parse a part of an initialiser for a struct or union,
1978  */
1979 static initializer_t *parse_sub_initializer(type_path_t *path,
1980                 type_t *outer_type, size_t top_path_level,
1981                 parse_initializer_env_t *env)
1982 {
1983         if (token.kind == '}') {
1984                 /* empty initializer */
1985                 return create_empty_initializer();
1986         }
1987
1988         type_t *orig_type = path->top_type;
1989         type_t *type      = NULL;
1990
1991         if (orig_type == NULL) {
1992                 /* We are initializing an empty compound. */
1993         } else {
1994                 type = skip_typeref(orig_type);
1995         }
1996
1997         initializer_t **initializers = NEW_ARR_F(initializer_t*, 0);
1998
1999         while (true) {
2000                 designator_t *designator = NULL;
2001                 if (token.kind == '.' || token.kind == '[') {
2002                         designator = parse_designation();
2003                         goto finish_designator;
2004                 } else if (token.kind == T_IDENTIFIER && look_ahead(1)->kind == ':') {
2005                         /* GNU-style designator ("identifier: value") */
2006                         designator = allocate_ast_zero(sizeof(designator[0]));
2007                         designator->source_position = token.base.source_position;
2008                         designator->symbol          = token.identifier.symbol;
2009                         eat(T_IDENTIFIER);
2010                         eat(':');
2011
2012 finish_designator:
2013                         /* reset path to toplevel, evaluate designator from there */
2014                         ascend_to(path, top_path_level);
2015                         if (!walk_designator(path, designator, false)) {
2016                                 /* can't continue after designation error */
2017                                 goto end_error;
2018                         }
2019
2020                         initializer_t *designator_initializer
2021                                 = allocate_initializer_zero(INITIALIZER_DESIGNATOR);
2022                         designator_initializer->designator.designator = designator;
2023                         ARR_APP1(initializer_t*, initializers, designator_initializer);
2024
2025                         orig_type = path->top_type;
2026                         type      = orig_type != NULL ? skip_typeref(orig_type) : NULL;
2027                 }
2028
2029                 initializer_t *sub;
2030
2031                 if (token.kind == '{') {
2032                         if (type != NULL && is_type_scalar(type)) {
2033                                 sub = parse_scalar_initializer(type, env->must_be_constant);
2034                         } else {
2035                                 if (type == NULL) {
2036                                         if (env->entity != NULL) {
2037                                                 errorf(HERE,
2038                                                      "extra brace group at end of initializer for '%Y'",
2039                                                      env->entity->base.symbol);
2040                                         } else {
2041                                                 errorf(HERE, "extra brace group at end of initializer");
2042                                         }
2043                                         eat('{');
2044                                 } else {
2045                                         eat('{');
2046                                         descend_into_subtype(path);
2047                                 }
2048
2049                                 add_anchor_token('}');
2050                                 sub = parse_sub_initializer(path, orig_type, top_path_level+1,
2051                                                             env);
2052                                 rem_anchor_token('}');
2053
2054                                 expect('}');
2055
2056                                 if (!type)
2057                                         goto error_parse_next;
2058
2059                                 ascend_from_subtype(path);
2060                         }
2061                 } else {
2062                         /* must be an expression */
2063                         expression_t *expression = parse_assignment_expression();
2064                         mark_vars_read(expression, NULL);
2065
2066                         if (env->must_be_constant && !is_linker_constant(expression)) {
2067                                 errorf(&expression->base.source_position,
2068                                        "Initialisation expression '%E' is not constant",
2069                                        expression);
2070                         }
2071
2072                         if (type == NULL) {
2073                                 /* we are already outside, ... */
2074                                 if (outer_type == NULL)
2075                                         goto error_parse_next;
2076                                 type_t *const outer_type_skip = skip_typeref(outer_type);
2077                                 if (is_type_compound(outer_type_skip) &&
2078                                                 !outer_type_skip->compound.compound->complete) {
2079                                         goto error_parse_next;
2080                                 }
2081
2082                                 source_position_t const* const pos = &expression->base.source_position;
2083                                 if (env->entity != NULL) {
2084                                         warningf(WARN_OTHER, pos, "excess elements in initializer for '%Y'", env->entity->base.symbol);
2085                                 } else {
2086                                         warningf(WARN_OTHER, pos, "excess elements in initializer");
2087                                 }
2088                                 goto error_parse_next;
2089                         }
2090
2091                         /* handle { "string" } special case */
2092                         if ((expression->kind == EXPR_STRING_LITERAL
2093                                         || expression->kind == EXPR_WIDE_STRING_LITERAL)
2094                                         && outer_type != NULL) {
2095                                 sub = initializer_from_expression(outer_type, expression);
2096                                 if (sub != NULL) {
2097                                         next_if(',');
2098                                         if (token.kind != '}') {
2099                                                 warningf(WARN_OTHER, HERE, "excessive elements in initializer for type '%T'", orig_type);
2100                                         }
2101                                         /* TODO: eat , ... */
2102                                         return sub;
2103                                 }
2104                         }
2105
2106                         /* descend into subtypes until expression matches type */
2107                         while (true) {
2108                                 orig_type = path->top_type;
2109                                 type      = skip_typeref(orig_type);
2110
2111                                 sub = initializer_from_expression(orig_type, expression);
2112                                 if (sub != NULL) {
2113                                         break;
2114                                 }
2115                                 if (!is_type_valid(type)) {
2116                                         goto end_error;
2117                                 }
2118                                 if (is_type_scalar(type)) {
2119                                         errorf(&expression->base.source_position,
2120                                                         "expression '%E' doesn't match expected type '%T'",
2121                                                         expression, orig_type);
2122                                         goto end_error;
2123                                 }
2124
2125                                 descend_into_subtype(path);
2126                         }
2127                 }
2128
2129                 /* update largest index of top array */
2130                 const type_path_entry_t *first      = &path->path[0];
2131                 type_t                  *first_type = first->type;
2132                 first_type                          = skip_typeref(first_type);
2133                 if (is_type_array(first_type)) {
2134                         size_t index = first->v.index;
2135                         if (index > path->max_index)
2136                                 path->max_index = index;
2137                 }
2138
2139                 /* append to initializers list */
2140                 ARR_APP1(initializer_t*, initializers, sub);
2141
2142 error_parse_next:
2143                 if (token.kind == '}') {
2144                         break;
2145                 }
2146                 add_anchor_token('}');
2147                 expect(',');
2148                 rem_anchor_token('}');
2149                 if (token.kind == '}') {
2150                         break;
2151                 }
2152
2153                 if (type != NULL) {
2154                         /* advance to the next declaration if we are not at the end */
2155                         advance_current_object(path, top_path_level);
2156                         orig_type = path->top_type;
2157                         if (orig_type != NULL)
2158                                 type = skip_typeref(orig_type);
2159                         else
2160                                 type = NULL;
2161                 }
2162         }
2163
2164         size_t len  = ARR_LEN(initializers);
2165         size_t size = sizeof(initializer_list_t) + len * sizeof(initializers[0]);
2166         initializer_t *result = allocate_ast_zero(size);
2167         result->kind          = INITIALIZER_LIST;
2168         result->list.len      = len;
2169         memcpy(&result->list.initializers, initializers,
2170                len * sizeof(initializers[0]));
2171
2172         DEL_ARR_F(initializers);
2173         ascend_to(path, top_path_level+1);
2174
2175         return result;
2176
2177 end_error:
2178         skip_initializers();
2179         DEL_ARR_F(initializers);
2180         ascend_to(path, top_path_level+1);
2181         return NULL;
2182 }
2183
2184 static expression_t *make_size_literal(size_t value)
2185 {
2186         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_INTEGER);
2187         literal->base.type    = type_size_t;
2188
2189         char buf[128];
2190         snprintf(buf, sizeof(buf), "%u", (unsigned) value);
2191         literal->literal.value = make_string(buf);
2192
2193         return literal;
2194 }
2195
2196 /**
2197  * Parses an initializer. Parsers either a compound literal
2198  * (env->declaration == NULL) or an initializer of a declaration.
2199  */
2200 static initializer_t *parse_initializer(parse_initializer_env_t *env)
2201 {
2202         type_t        *type      = skip_typeref(env->type);
2203         size_t         max_index = 0;
2204         initializer_t *result;
2205
2206         if (is_type_scalar(type)) {
2207                 result = parse_scalar_initializer(type, env->must_be_constant);
2208         } else if (token.kind == '{') {
2209                 eat('{');
2210
2211                 type_path_t path;
2212                 memset(&path, 0, sizeof(path));
2213                 path.top_type = env->type;
2214                 path.path     = NEW_ARR_F(type_path_entry_t, 0);
2215
2216                 descend_into_subtype(&path);
2217
2218                 add_anchor_token('}');
2219                 result = parse_sub_initializer(&path, env->type, 1, env);
2220                 rem_anchor_token('}');
2221
2222                 max_index = path.max_index;
2223                 DEL_ARR_F(path.path);
2224
2225                 expect('}');
2226         } else {
2227                 /* parse_scalar_initializer() also works in this case: we simply
2228                  * have an expression without {} around it */
2229                 result = parse_scalar_initializer(type, env->must_be_constant);
2230         }
2231
2232         /* §6.7.8:22 array initializers for arrays with unknown size determine
2233          * the array type size */
2234         if (is_type_array(type) && type->array.size_expression == NULL
2235                         && result != NULL) {
2236                 size_t size;
2237                 switch (result->kind) {
2238                 case INITIALIZER_LIST:
2239                         assert(max_index != 0xdeadbeaf);
2240                         size = max_index + 1;
2241                         break;
2242
2243                 case INITIALIZER_STRING:
2244                         size = result->string.string.size;
2245                         break;
2246
2247                 case INITIALIZER_WIDE_STRING:
2248                         size = result->wide_string.string.size;
2249                         break;
2250
2251                 case INITIALIZER_DESIGNATOR:
2252                 case INITIALIZER_VALUE:
2253                         /* can happen for parse errors */
2254                         size = 0;
2255                         break;
2256
2257                 default:
2258                         internal_errorf(HERE, "invalid initializer type");
2259                 }
2260
2261                 type_t *new_type = duplicate_type(type);
2262
2263                 new_type->array.size_expression   = make_size_literal(size);
2264                 new_type->array.size_constant     = true;
2265                 new_type->array.has_implicit_size = true;
2266                 new_type->array.size              = size;
2267                 env->type = new_type;
2268         }
2269
2270         return result;
2271 }
2272
2273 static void append_entity(scope_t *scope, entity_t *entity)
2274 {
2275         if (scope->last_entity != NULL) {
2276                 scope->last_entity->base.next = entity;
2277         } else {
2278                 scope->entities = entity;
2279         }
2280         entity->base.parent_entity = current_entity;
2281         scope->last_entity         = entity;
2282 }
2283
2284
2285 static compound_t *parse_compound_type_specifier(bool is_struct)
2286 {
2287         source_position_t const pos = *HERE;
2288         eat(is_struct ? T_struct : T_union);
2289
2290         symbol_t    *symbol     = NULL;
2291         entity_t    *entity     = NULL;
2292         attribute_t *attributes = NULL;
2293
2294         if (token.kind == T___attribute__) {
2295                 attributes = parse_attributes(NULL);
2296         }
2297
2298         entity_kind_tag_t const kind = is_struct ? ENTITY_STRUCT : ENTITY_UNION;
2299         if (token.kind == T_IDENTIFIER) {
2300                 /* the compound has a name, check if we have seen it already */
2301                 symbol = token.identifier.symbol;
2302                 entity = get_tag(symbol, kind);
2303                 next_token();
2304
2305                 if (entity != NULL) {
2306                         if (entity->base.parent_scope != current_scope &&
2307                             (token.kind == '{' || token.kind == ';')) {
2308                                 /* we're in an inner scope and have a definition. Shadow
2309                                  * existing definition in outer scope */
2310                                 entity = NULL;
2311                         } else if (entity->compound.complete && token.kind == '{') {
2312                                 source_position_t const *const ppos = &entity->base.source_position;
2313                                 errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
2314                                 /* clear members in the hope to avoid further errors */
2315                                 entity->compound.members.entities = NULL;
2316                         }
2317                 }
2318         } else if (token.kind != '{') {
2319                 char const *const msg =
2320                         is_struct ? "while parsing struct type specifier" :
2321                                     "while parsing union type specifier";
2322                 parse_error_expected(msg, T_IDENTIFIER, '{', NULL);
2323
2324                 return NULL;
2325         }
2326
2327         if (entity == NULL) {
2328                 entity = allocate_entity_zero(kind, NAMESPACE_TAG, symbol, &pos);
2329                 entity->compound.alignment = 1;
2330                 entity->base.parent_scope  = current_scope;
2331                 if (symbol != NULL) {
2332                         environment_push(entity);
2333                 }
2334                 append_entity(current_scope, entity);
2335         }
2336
2337         if (token.kind == '{') {
2338                 parse_compound_type_entries(&entity->compound);
2339
2340                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2341                 if (symbol == NULL) {
2342                         assert(anonymous_entity == NULL);
2343                         anonymous_entity = entity;
2344                 }
2345         }
2346
2347         if (attributes != NULL) {
2348                 handle_entity_attributes(attributes, entity);
2349         }
2350
2351         return &entity->compound;
2352 }
2353
2354 static void parse_enum_entries(type_t *const enum_type)
2355 {
2356         eat('{');
2357
2358         if (token.kind == '}') {
2359                 errorf(HERE, "empty enum not allowed");
2360                 next_token();
2361                 return;
2362         }
2363
2364         add_anchor_token('}');
2365         add_anchor_token(',');
2366         do {
2367                 add_anchor_token('=');
2368                 source_position_t pos;
2369                 symbol_t *const symbol = expect_identifier("while parsing enum entry", &pos);
2370                 entity_t *const entity = allocate_entity_zero(ENTITY_ENUM_VALUE, NAMESPACE_NORMAL, symbol, &pos);
2371                 entity->enum_value.enum_type = enum_type;
2372                 rem_anchor_token('=');
2373
2374                 if (next_if('=')) {
2375                         expression_t *value = parse_constant_expression();
2376
2377                         value = create_implicit_cast(value, enum_type);
2378                         entity->enum_value.value = value;
2379
2380                         /* TODO semantic */
2381                 }
2382
2383                 record_entity(entity, false);
2384         } while (next_if(',') && token.kind != '}');
2385         rem_anchor_token(',');
2386         rem_anchor_token('}');
2387
2388         expect('}');
2389 }
2390
2391 static type_t *parse_enum_specifier(void)
2392 {
2393         source_position_t const pos = *HERE;
2394         entity_t               *entity;
2395         symbol_t               *symbol;
2396
2397         eat(T_enum);
2398         switch (token.kind) {
2399                 case T_IDENTIFIER:
2400                         symbol = token.identifier.symbol;
2401                         entity = get_tag(symbol, ENTITY_ENUM);
2402                         next_token();
2403
2404                         if (entity != NULL) {
2405                                 if (entity->base.parent_scope != current_scope &&
2406                                                 (token.kind == '{' || token.kind == ';')) {
2407                                         /* we're in an inner scope and have a definition. Shadow
2408                                          * existing definition in outer scope */
2409                                         entity = NULL;
2410                                 } else if (entity->enume.complete && token.kind == '{') {
2411                                         source_position_t const *const ppos = &entity->base.source_position;
2412                                         errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
2413                                 }
2414                         }
2415                         break;
2416
2417                 case '{':
2418                         entity = NULL;
2419                         symbol = NULL;
2420                         break;
2421
2422                 default:
2423                         parse_error_expected("while parsing enum type specifier",
2424                                         T_IDENTIFIER, '{', NULL);
2425                         return NULL;
2426         }
2427
2428         if (entity == NULL) {
2429                 entity = allocate_entity_zero(ENTITY_ENUM, NAMESPACE_TAG, symbol, &pos);
2430                 entity->base.parent_scope = current_scope;
2431         }
2432
2433         type_t *const type     = allocate_type_zero(TYPE_ENUM);
2434         type->enumt.enume      = &entity->enume;
2435         type->enumt.base.akind = ATOMIC_TYPE_INT;
2436
2437         if (token.kind == '{') {
2438                 if (symbol != NULL) {
2439                         environment_push(entity);
2440                 }
2441                 append_entity(current_scope, entity);
2442                 entity->enume.complete = true;
2443
2444                 parse_enum_entries(type);
2445                 parse_attributes(NULL);
2446
2447                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2448                 if (symbol == NULL) {
2449                         assert(anonymous_entity == NULL);
2450                         anonymous_entity = entity;
2451                 }
2452         } else if (!entity->enume.complete && !(c_mode & _GNUC)) {
2453                 errorf(HERE, "'%T' used before definition (incomplete enums are a GNU extension)", type);
2454         }
2455
2456         return type;
2457 }
2458
2459 /**
2460  * if a symbol is a typedef to another type, return true
2461  */
2462 static bool is_typedef_symbol(symbol_t *symbol)
2463 {
2464         const entity_t *const entity = get_entity(symbol, NAMESPACE_NORMAL);
2465         return entity != NULL && entity->kind == ENTITY_TYPEDEF;
2466 }
2467
2468 static type_t *parse_typeof(void)
2469 {
2470         eat(T___typeof__);
2471
2472         type_t *type;
2473
2474         expect('(');
2475         add_anchor_token(')');
2476
2477         expression_t *expression  = NULL;
2478
2479         switch (token.kind) {
2480         case T_IDENTIFIER:
2481                 if (is_typedef_symbol(token.identifier.symbol)) {
2482         DECLARATION_START
2483                         type = parse_typename();
2484                 } else {
2485         default:
2486                         expression = parse_expression();
2487                         type       = revert_automatic_type_conversion(expression);
2488                 }
2489                 break;
2490         }
2491
2492         rem_anchor_token(')');
2493         expect(')');
2494
2495         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF);
2496         typeof_type->typeoft.expression  = expression;
2497         typeof_type->typeoft.typeof_type = type;
2498
2499         return typeof_type;
2500 }
2501
2502 typedef enum specifiers_t {
2503         SPECIFIER_SIGNED    = 1 << 0,
2504         SPECIFIER_UNSIGNED  = 1 << 1,
2505         SPECIFIER_LONG      = 1 << 2,
2506         SPECIFIER_INT       = 1 << 3,
2507         SPECIFIER_DOUBLE    = 1 << 4,
2508         SPECIFIER_CHAR      = 1 << 5,
2509         SPECIFIER_WCHAR_T   = 1 << 6,
2510         SPECIFIER_SHORT     = 1 << 7,
2511         SPECIFIER_LONG_LONG = 1 << 8,
2512         SPECIFIER_FLOAT     = 1 << 9,
2513         SPECIFIER_BOOL      = 1 << 10,
2514         SPECIFIER_VOID      = 1 << 11,
2515         SPECIFIER_INT8      = 1 << 12,
2516         SPECIFIER_INT16     = 1 << 13,
2517         SPECIFIER_INT32     = 1 << 14,
2518         SPECIFIER_INT64     = 1 << 15,
2519         SPECIFIER_INT128    = 1 << 16,
2520         SPECIFIER_COMPLEX   = 1 << 17,
2521         SPECIFIER_IMAGINARY = 1 << 18,
2522 } specifiers_t;
2523
2524 static type_t *get_typedef_type(symbol_t *symbol)
2525 {
2526         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
2527         if (entity == NULL || entity->kind != ENTITY_TYPEDEF)
2528                 return NULL;
2529
2530         type_t *type            = allocate_type_zero(TYPE_TYPEDEF);
2531         type->typedeft.typedefe = &entity->typedefe;
2532
2533         return type;
2534 }
2535
2536 static attribute_t *parse_attribute_ms_property(attribute_t *attribute)
2537 {
2538         attribute_property_argument_t *const property = allocate_ast_zero(sizeof(*property));
2539
2540         expect('(');
2541
2542         add_anchor_token(')');
2543         add_anchor_token(',');
2544         do {
2545                 add_anchor_token('=');
2546                 source_position_t pos;
2547                 symbol_t *const prop_sym = expect_identifier("while parsing property declspec", &pos);
2548                 rem_anchor_token('=');
2549
2550                 symbol_t **prop = NULL;
2551                 if (prop_sym) {
2552                         if (streq(prop_sym->string, "put")) {
2553                                 prop = &property->put_symbol;
2554                         } else if (streq(prop_sym->string, "get")) {
2555                                 prop = &property->get_symbol;
2556                         } else {
2557                                 errorf(&pos, "expected put or get in property declspec, but got '%Y'", prop_sym);
2558                         }
2559                 }
2560
2561                 add_anchor_token(T_IDENTIFIER);
2562                 expect('=');
2563                 rem_anchor_token(T_IDENTIFIER);
2564
2565                 symbol_t *const sym = expect_identifier("while parsing property declspec", NULL);
2566                 if (prop != NULL)
2567                         *prop = sym ? sym : sym_anonymous;
2568         } while (next_if(','));
2569         rem_anchor_token(',');
2570         rem_anchor_token(')');
2571
2572         attribute->a.property = property;
2573
2574         expect(')');
2575         return attribute;
2576 }
2577
2578 static attribute_t *parse_microsoft_extended_decl_modifier_single(void)
2579 {
2580         attribute_kind_t kind = ATTRIBUTE_UNKNOWN;
2581         if (next_if(T_restrict)) {
2582                 kind = ATTRIBUTE_MS_RESTRICT;
2583         } else if (token.kind == T_IDENTIFIER) {
2584                 const char *name = token.identifier.symbol->string;
2585                 for (attribute_kind_t k = ATTRIBUTE_MS_FIRST; k <= ATTRIBUTE_MS_LAST;
2586                      ++k) {
2587                         const char *attribute_name = get_attribute_name(k);
2588                         if (attribute_name != NULL && streq(attribute_name, name)) {
2589                                 kind = k;
2590                                 break;
2591                         }
2592                 }
2593
2594                 if (kind == ATTRIBUTE_UNKNOWN) {
2595                         warningf(WARN_ATTRIBUTE, HERE, "unknown __declspec '%s' ignored", name);
2596                 }
2597         } else {
2598                 parse_error_expected("while parsing __declspec", T_IDENTIFIER, NULL);
2599                 return NULL;
2600         }
2601
2602         attribute_t *attribute = allocate_attribute_zero(kind);
2603         eat(T_IDENTIFIER);
2604
2605         if (kind == ATTRIBUTE_MS_PROPERTY) {
2606                 return parse_attribute_ms_property(attribute);
2607         }
2608
2609         /* parse arguments */
2610         if (next_if('('))
2611                 attribute->a.arguments = parse_attribute_arguments();
2612
2613         return attribute;
2614 }
2615
2616 static attribute_t *parse_microsoft_extended_decl_modifier(attribute_t *first)
2617 {
2618         eat(T__declspec);
2619
2620         expect('(');
2621         if (token.kind != ')') {
2622                 add_anchor_token(')');
2623
2624                 attribute_t **anchor = &first;
2625                 do {
2626                         while (*anchor != NULL)
2627                                 anchor = &(*anchor)->next;
2628
2629                         attribute_t *attribute
2630                                 = parse_microsoft_extended_decl_modifier_single();
2631                         if (attribute == NULL)
2632                                 break;
2633
2634                         *anchor = attribute;
2635                         anchor  = &attribute->next;
2636                 } while (next_if(','));
2637
2638                 rem_anchor_token(')');
2639         }
2640         expect(')');
2641         return first;
2642 }
2643
2644 static entity_t *create_error_entity(symbol_t *symbol, entity_kind_tag_t kind)
2645 {
2646         entity_t *const entity = allocate_entity_zero(kind, NAMESPACE_NORMAL, symbol, HERE);
2647         if (is_declaration(entity)) {
2648                 entity->declaration.type     = type_error_type;
2649                 entity->declaration.implicit = true;
2650         } else if (kind == ENTITY_TYPEDEF) {
2651                 entity->typedefe.type    = type_error_type;
2652                 entity->typedefe.builtin = true;
2653         }
2654         if (kind != ENTITY_COMPOUND_MEMBER)
2655                 record_entity(entity, false);
2656         return entity;
2657 }
2658
2659 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
2660 {
2661         type_t            *type            = NULL;
2662         type_qualifiers_t  qualifiers      = TYPE_QUALIFIER_NONE;
2663         unsigned           type_specifiers = 0;
2664         bool               newtype         = false;
2665         bool               saw_error       = false;
2666
2667         memset(specifiers, 0, sizeof(*specifiers));
2668         specifiers->source_position = token.base.source_position;
2669
2670         while (true) {
2671                 specifiers->attributes = parse_attributes(specifiers->attributes);
2672
2673                 switch (token.kind) {
2674                 /* storage class */
2675 #define MATCH_STORAGE_CLASS(token, class)                                  \
2676                 case token:                                                        \
2677                         if (specifiers->storage_class != STORAGE_CLASS_NONE) {         \
2678                                 errorf(HERE, "multiple storage classes in declaration specifiers"); \
2679                         }                                                              \
2680                         specifiers->storage_class = class;                             \
2681                         if (specifiers->thread_local)                                  \
2682                                 goto check_thread_storage_class;                           \
2683                         next_token();                                                  \
2684                         break;
2685
2686                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
2687                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
2688                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
2689                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
2690                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
2691
2692                 case T__declspec:
2693                         specifiers->attributes
2694                                 = parse_microsoft_extended_decl_modifier(specifiers->attributes);
2695                         break;
2696
2697                 case T___thread:
2698                         if (specifiers->thread_local) {
2699                                 errorf(HERE, "duplicate '__thread'");
2700                         } else {
2701                                 specifiers->thread_local = true;
2702 check_thread_storage_class:
2703                                 switch (specifiers->storage_class) {
2704                                         case STORAGE_CLASS_EXTERN:
2705                                         case STORAGE_CLASS_NONE:
2706                                         case STORAGE_CLASS_STATIC:
2707                                                 break;
2708
2709                                                 char const* wrong;
2710                                         case STORAGE_CLASS_AUTO:     wrong = "auto";     goto wrong_thread_storage_class;
2711                                         case STORAGE_CLASS_REGISTER: wrong = "register"; goto wrong_thread_storage_class;
2712                                         case STORAGE_CLASS_TYPEDEF:  wrong = "typedef";  goto wrong_thread_storage_class;
2713 wrong_thread_storage_class:
2714                                                 errorf(HERE, "'__thread' used with '%s'", wrong);
2715                                                 break;
2716                                 }
2717                         }
2718                         next_token();
2719                         break;
2720
2721                 /* type qualifiers */
2722 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
2723                 case token:                                                     \
2724                         qualifiers |= qualifier;                                    \
2725                         next_token();                                               \
2726                         break
2727
2728                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
2729                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
2730                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
2731                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
2732                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
2733                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
2734                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
2735                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
2736
2737                 /* type specifiers */
2738 #define MATCH_SPECIFIER(token, specifier, name)                         \
2739                 case token:                                                     \
2740                         if (type_specifiers & specifier) {                           \
2741                                 errorf(HERE, "multiple " name " type specifiers given"); \
2742                         } else {                                                    \
2743                                 type_specifiers |= specifier;                           \
2744                         }                                                           \
2745                         next_token();                                               \
2746                         break
2747
2748                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool");
2749                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex");
2750                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary");
2751                 MATCH_SPECIFIER(T__int128,    SPECIFIER_INT128,    "_int128");
2752                 MATCH_SPECIFIER(T__int16,     SPECIFIER_INT16,     "_int16");
2753                 MATCH_SPECIFIER(T__int32,     SPECIFIER_INT32,     "_int32");
2754                 MATCH_SPECIFIER(T__int64,     SPECIFIER_INT64,     "_int64");
2755                 MATCH_SPECIFIER(T__int8,      SPECIFIER_INT8,      "_int8");
2756                 MATCH_SPECIFIER(T_bool,       SPECIFIER_BOOL,      "bool");
2757                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char");
2758                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double");
2759                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float");
2760                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int");
2761                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short");
2762                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed");
2763                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned");
2764                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void");
2765                 MATCH_SPECIFIER(T_wchar_t,    SPECIFIER_WCHAR_T,   "wchar_t");
2766
2767                 case T_inline:
2768                         next_token();
2769                         specifiers->is_inline = true;
2770                         break;
2771
2772 #if 0
2773                 case T__forceinline:
2774                         next_token();
2775                         specifiers->modifiers |= DM_FORCEINLINE;
2776                         break;
2777 #endif
2778
2779                 case T_long:
2780                         if (type_specifiers & SPECIFIER_LONG_LONG) {
2781                                 errorf(HERE, "too many long type specifiers given");
2782                         } else if (type_specifiers & SPECIFIER_LONG) {
2783                                 type_specifiers |= SPECIFIER_LONG_LONG;
2784                         } else {
2785                                 type_specifiers |= SPECIFIER_LONG;
2786                         }
2787                         next_token();
2788                         break;
2789
2790 #define CHECK_DOUBLE_TYPE() \
2791         (type != NULL ? errorf(HERE, "multiple types in declaration specifiers") : (void)0)
2792
2793                 case T_struct:
2794                         CHECK_DOUBLE_TYPE();
2795                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
2796
2797                         type->compound.compound = parse_compound_type_specifier(true);
2798                         break;
2799                 case T_union:
2800                         CHECK_DOUBLE_TYPE();
2801                         type = allocate_type_zero(TYPE_COMPOUND_UNION);
2802                         type->compound.compound = parse_compound_type_specifier(false);
2803                         break;
2804                 case T_enum:
2805                         CHECK_DOUBLE_TYPE();
2806                         type = parse_enum_specifier();
2807                         break;
2808                 case T___typeof__:
2809                         CHECK_DOUBLE_TYPE();
2810                         type = parse_typeof();
2811                         break;
2812                 case T___builtin_va_list:
2813                         CHECK_DOUBLE_TYPE();
2814                         type = duplicate_type(type_valist);
2815                         next_token();
2816                         break;
2817
2818                 case T_IDENTIFIER: {
2819                         /* only parse identifier if we haven't found a type yet */
2820                         if (type != NULL || type_specifiers != 0) {
2821                                 /* Be somewhat resilient to typos like 'unsigned lng* f()' in a
2822                                  * declaration, so it doesn't generate errors about expecting '(' or
2823                                  * '{' later on. */
2824                                 switch (look_ahead(1)->kind) {
2825                                         STORAGE_CLASSES
2826                                         TYPE_SPECIFIERS
2827                                         case T_const:
2828                                         case T_restrict:
2829                                         case T_volatile:
2830                                         case T_inline:
2831                                         case T__forceinline: /* ^ DECLARATION_START except for __attribute__ */
2832                                         case T_IDENTIFIER:
2833                                         case '&':
2834                                         case '*':
2835                                                 errorf(HERE, "discarding stray %K in declaration specifier", &token);
2836                                                 next_token();
2837                                                 continue;
2838
2839                                         default:
2840                                                 goto finish_specifiers;
2841                                 }
2842                         }
2843
2844                         type_t *const typedef_type = get_typedef_type(token.identifier.symbol);
2845                         if (typedef_type == NULL) {
2846                                 /* Be somewhat resilient to typos like 'vodi f()' at the beginning of a
2847                                  * declaration, so it doesn't generate 'implicit int' followed by more
2848                                  * errors later on. */
2849                                 token_kind_t const la1_type = (token_kind_t)look_ahead(1)->kind;
2850                                 switch (la1_type) {
2851                                         DECLARATION_START
2852                                         case T_IDENTIFIER:
2853                                         case '&':
2854                                         case '*': {
2855                                                 errorf(HERE, "%K does not name a type", &token);
2856
2857                                                 symbol_t *symbol = token.identifier.symbol;
2858                                                 entity_t *entity
2859                                                         = create_error_entity(symbol, ENTITY_TYPEDEF);
2860
2861                                                 type = allocate_type_zero(TYPE_TYPEDEF);
2862                                                 type->typedeft.typedefe = &entity->typedefe;
2863
2864                                                 next_token();
2865                                                 saw_error = true;
2866                                                 continue;
2867                                         }
2868
2869                                         default:
2870                                                 goto finish_specifiers;
2871                                 }
2872                         }
2873
2874                         next_token();
2875                         type = typedef_type;
2876                         break;
2877                 }
2878
2879                 /* function specifier */
2880                 default:
2881                         goto finish_specifiers;
2882                 }
2883         }
2884
2885 finish_specifiers:
2886         specifiers->attributes = parse_attributes(specifiers->attributes);
2887
2888         if (type == NULL || (saw_error && type_specifiers != 0)) {
2889                 atomic_type_kind_t atomic_type;
2890
2891                 /* match valid basic types */
2892                 switch (type_specifiers) {
2893                 case SPECIFIER_VOID:
2894                         atomic_type = ATOMIC_TYPE_VOID;
2895                         break;
2896                 case SPECIFIER_WCHAR_T:
2897                         atomic_type = ATOMIC_TYPE_WCHAR_T;
2898                         break;
2899                 case SPECIFIER_CHAR:
2900                         atomic_type = ATOMIC_TYPE_CHAR;
2901                         break;
2902                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
2903                         atomic_type = ATOMIC_TYPE_SCHAR;
2904                         break;
2905                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
2906                         atomic_type = ATOMIC_TYPE_UCHAR;
2907                         break;
2908                 case SPECIFIER_SHORT:
2909                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
2910                 case SPECIFIER_SHORT | SPECIFIER_INT:
2911                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
2912                         atomic_type = ATOMIC_TYPE_SHORT;
2913                         break;
2914                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
2915                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
2916                         atomic_type = ATOMIC_TYPE_USHORT;
2917                         break;
2918                 case SPECIFIER_INT:
2919                 case SPECIFIER_SIGNED:
2920                 case SPECIFIER_SIGNED | SPECIFIER_INT:
2921                         atomic_type = ATOMIC_TYPE_INT;
2922                         break;
2923                 case SPECIFIER_UNSIGNED:
2924                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
2925                         atomic_type = ATOMIC_TYPE_UINT;
2926                         break;
2927                 case SPECIFIER_LONG:
2928                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
2929                 case SPECIFIER_LONG | SPECIFIER_INT:
2930                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
2931                         atomic_type = ATOMIC_TYPE_LONG;
2932                         break;
2933                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
2934                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
2935                         atomic_type = ATOMIC_TYPE_ULONG;
2936                         break;
2937
2938                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2939                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2940                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
2941                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
2942                         | SPECIFIER_INT:
2943                         atomic_type = ATOMIC_TYPE_LONGLONG;
2944                         goto warn_about_long_long;
2945
2946                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2947                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
2948                         | SPECIFIER_INT:
2949                         atomic_type = ATOMIC_TYPE_ULONGLONG;
2950 warn_about_long_long:
2951                         warningf(WARN_LONG_LONG, &specifiers->source_position, "ISO C90 does not support 'long long'");
2952                         break;
2953
2954                 case SPECIFIER_UNSIGNED | SPECIFIER_INT8:
2955                         atomic_type = unsigned_int8_type_kind;
2956                         break;
2957
2958                 case SPECIFIER_UNSIGNED | SPECIFIER_INT16:
2959                         atomic_type = unsigned_int16_type_kind;
2960                         break;
2961
2962                 case SPECIFIER_UNSIGNED | SPECIFIER_INT32:
2963                         atomic_type = unsigned_int32_type_kind;
2964                         break;
2965
2966                 case SPECIFIER_UNSIGNED | SPECIFIER_INT64:
2967                         atomic_type = unsigned_int64_type_kind;
2968                         break;
2969
2970                 case SPECIFIER_UNSIGNED | SPECIFIER_INT128:
2971                         atomic_type = unsigned_int128_type_kind;
2972                         break;
2973
2974                 case SPECIFIER_INT8:
2975                 case SPECIFIER_SIGNED | SPECIFIER_INT8:
2976                         atomic_type = int8_type_kind;
2977                         break;
2978
2979                 case SPECIFIER_INT16:
2980                 case SPECIFIER_SIGNED | SPECIFIER_INT16:
2981                         atomic_type = int16_type_kind;
2982                         break;
2983
2984                 case SPECIFIER_INT32:
2985                 case SPECIFIER_SIGNED | SPECIFIER_INT32:
2986                         atomic_type = int32_type_kind;
2987                         break;
2988
2989                 case SPECIFIER_INT64:
2990                 case SPECIFIER_SIGNED | SPECIFIER_INT64:
2991                         atomic_type = int64_type_kind;
2992                         break;
2993
2994                 case SPECIFIER_INT128:
2995                 case SPECIFIER_SIGNED | SPECIFIER_INT128:
2996                         atomic_type = int128_type_kind;
2997                         break;
2998
2999                 case SPECIFIER_FLOAT:
3000                         atomic_type = ATOMIC_TYPE_FLOAT;
3001                         break;
3002                 case SPECIFIER_DOUBLE:
3003                         atomic_type = ATOMIC_TYPE_DOUBLE;
3004                         break;
3005                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
3006                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
3007                         break;
3008                 case SPECIFIER_BOOL:
3009                         atomic_type = ATOMIC_TYPE_BOOL;
3010                         break;
3011                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
3012                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
3013                         atomic_type = ATOMIC_TYPE_FLOAT;
3014                         break;
3015                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3016                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3017                         atomic_type = ATOMIC_TYPE_DOUBLE;
3018                         break;
3019                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3020                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3021                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
3022                         break;
3023                 default: {
3024                         /* invalid specifier combination, give an error message */
3025                         source_position_t const* const pos = &specifiers->source_position;
3026                         if (type_specifiers == 0) {
3027                                 if (!saw_error) {
3028                                         /* ISO/IEC 14882:1998(E) §C.1.5:4 */
3029                                         if (!(c_mode & _CXX) && !strict_mode) {
3030                                                 warningf(WARN_IMPLICIT_INT, pos, "no type specifiers in declaration, using 'int'");
3031                                                 atomic_type = ATOMIC_TYPE_INT;
3032                                                 break;
3033                                         } else {
3034                                                 errorf(pos, "no type specifiers given in declaration");
3035                                         }
3036                                 }
3037                         } else if ((type_specifiers & SPECIFIER_SIGNED) &&
3038                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
3039                                 errorf(pos, "signed and unsigned specifiers given");
3040                         } else if (type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
3041                                 errorf(pos, "only integer types can be signed or unsigned");
3042                         } else {
3043                                 errorf(pos, "multiple datatypes in declaration");
3044                         }
3045                         goto end_error;
3046                 }
3047                 }
3048
3049                 if (type_specifiers & SPECIFIER_COMPLEX) {
3050                         type = allocate_type_zero(TYPE_COMPLEX);
3051                 } else if (type_specifiers & SPECIFIER_IMAGINARY) {
3052                         type = allocate_type_zero(TYPE_IMAGINARY);
3053                 } else {
3054                         type = allocate_type_zero(TYPE_ATOMIC);
3055                 }
3056                 type->atomic.akind = atomic_type;
3057                 newtype = true;
3058         } else if (type_specifiers != 0) {
3059                 errorf(&specifiers->source_position, "multiple datatypes in declaration");
3060         }
3061
3062         /* FIXME: check type qualifiers here */
3063         type->base.qualifiers = qualifiers;
3064
3065         if (newtype) {
3066                 type = identify_new_type(type);
3067         } else {
3068                 type = typehash_insert(type);
3069         }
3070
3071         if (specifiers->attributes != NULL)
3072                 type = handle_type_attributes(specifiers->attributes, type);
3073         specifiers->type = type;
3074         return;
3075
3076 end_error:
3077         specifiers->type = type_error_type;
3078 }
3079
3080 static type_qualifiers_t parse_type_qualifiers(void)
3081 {
3082         type_qualifiers_t qualifiers = TYPE_QUALIFIER_NONE;
3083
3084         while (true) {
3085                 switch (token.kind) {
3086                 /* type qualifiers */
3087                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3088                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3089                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3090                 /* microsoft extended type modifiers */
3091                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3092                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3093                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3094                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3095                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3096
3097                 default:
3098                         return qualifiers;
3099                 }
3100         }
3101 }
3102
3103 /**
3104  * Parses an K&R identifier list
3105  */
3106 static void parse_identifier_list(scope_t *scope)
3107 {
3108         assert(token.kind == T_IDENTIFIER);
3109         do {
3110                 entity_t *const entity = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, token.identifier.symbol, HERE);
3111                 /* a K&R parameter has no type, yet */
3112                 next_token();
3113
3114                 if (scope != NULL)
3115                         append_entity(scope, entity);
3116         } while (next_if(',') && token.kind == T_IDENTIFIER);
3117 }
3118
3119 static entity_t *parse_parameter(void)
3120 {
3121         declaration_specifiers_t specifiers;
3122         parse_declaration_specifiers(&specifiers);
3123
3124         entity_t *entity = parse_declarator(&specifiers,
3125                         DECL_MAY_BE_ABSTRACT | DECL_IS_PARAMETER);
3126         anonymous_entity = NULL;
3127         return entity;
3128 }
3129
3130 static void semantic_parameter_incomplete(const entity_t *entity)
3131 {
3132         assert(entity->kind == ENTITY_PARAMETER);
3133
3134         /* §6.7.5.3:4  After adjustment, the parameters in a parameter type
3135          *             list in a function declarator that is part of a
3136          *             definition of that function shall not have
3137          *             incomplete type. */
3138         type_t *type = skip_typeref(entity->declaration.type);
3139         if (is_type_incomplete(type)) {
3140                 errorf(&entity->base.source_position, "'%N' has incomplete type", entity);
3141         }
3142 }
3143
3144 static bool has_parameters(void)
3145 {
3146         /* func(void) is not a parameter */
3147         if (look_ahead(1)->kind != ')')
3148                 return true;
3149         if (token.kind == T_IDENTIFIER) {
3150                 entity_t const *const entity
3151                         = get_entity(token.identifier.symbol, NAMESPACE_NORMAL);
3152                 if (entity == NULL)
3153                         return true;
3154                 if (entity->kind != ENTITY_TYPEDEF)
3155                         return true;
3156                 type_t const *const type = skip_typeref(entity->typedefe.type);
3157                 if (!is_type_void(type))
3158                         return true;
3159                 if (c_mode & _CXX) {
3160                         /* ISO/IEC 14882:1998(E) §8.3.5:2  It must be literally (void).  A typedef
3161                          * is not allowed. */
3162                         errorf(HERE, "empty parameter list defined with a typedef of 'void' not allowed in C++");
3163                 } else if (type->base.qualifiers != TYPE_QUALIFIER_NONE) {
3164                         /* §6.7.5.3:10  Qualification is not allowed here. */
3165                         errorf(HERE, "'void' as parameter must not have type qualifiers");
3166                 }
3167         } else if (token.kind != T_void) {
3168                 return true;
3169         }
3170         next_token();
3171         return false;
3172 }
3173
3174 /**
3175  * Parses function type parameters (and optionally creates variable_t entities
3176  * for them in a scope)
3177  */
3178 static void parse_parameters(function_type_t *type, scope_t *scope)
3179 {
3180         eat('(');
3181         add_anchor_token(')');
3182
3183         if (token.kind == T_IDENTIFIER                  &&
3184             !is_typedef_symbol(token.identifier.symbol) &&
3185             (look_ahead(1)->kind == ',' || look_ahead(1)->kind == ')')) {
3186                 type->kr_style_parameters = true;
3187                 parse_identifier_list(scope);
3188         } else if (token.kind == ')') {
3189                 /* ISO/IEC 14882:1998(E) §C.1.6:1 */
3190                 if (!(c_mode & _CXX))
3191                         type->unspecified_parameters = true;
3192         } else if (has_parameters()) {
3193                 function_parameter_t **anchor = &type->parameters;
3194                 add_anchor_token(',');
3195                 do {
3196                         switch (token.kind) {
3197                         case T_DOTDOTDOT:
3198                                 next_token();
3199                                 type->variadic = true;
3200                                 goto parameters_finished;
3201
3202                         case T_IDENTIFIER:
3203                         DECLARATION_START
3204                         {
3205                                 entity_t *entity = parse_parameter();
3206                                 if (entity->kind == ENTITY_TYPEDEF) {
3207                                         errorf(&entity->base.source_position,
3208                                                         "typedef not allowed as function parameter");
3209                                         break;
3210                                 }
3211                                 assert(is_declaration(entity));
3212
3213                                 semantic_parameter_incomplete(entity);
3214
3215                                 function_parameter_t *const parameter =
3216                                         allocate_parameter(entity->declaration.type);
3217
3218                                 if (scope != NULL) {
3219                                         append_entity(scope, entity);
3220                                 }
3221
3222                                 *anchor = parameter;
3223                                 anchor  = &parameter->next;
3224                                 break;
3225                         }
3226
3227                         default:
3228                                 goto parameters_finished;
3229                         }
3230                 } while (next_if(','));
3231 parameters_finished:
3232                 rem_anchor_token(',');
3233         }
3234
3235         rem_anchor_token(')');
3236         expect(')');
3237 }
3238
3239 typedef enum construct_type_kind_t {
3240         CONSTRUCT_POINTER = 1,
3241         CONSTRUCT_REFERENCE,
3242         CONSTRUCT_FUNCTION,
3243         CONSTRUCT_ARRAY
3244 } construct_type_kind_t;
3245
3246 typedef union construct_type_t construct_type_t;
3247
3248 typedef struct construct_type_base_t {
3249         construct_type_kind_t  kind;
3250         source_position_t      pos;
3251         construct_type_t      *next;
3252 } construct_type_base_t;
3253
3254 typedef struct parsed_pointer_t {
3255         construct_type_base_t  base;
3256         type_qualifiers_t      type_qualifiers;
3257         variable_t            *base_variable;  /**< MS __based extension. */
3258 } parsed_pointer_t;
3259
3260 typedef struct parsed_reference_t {
3261         construct_type_base_t base;
3262 } parsed_reference_t;
3263
3264 typedef struct construct_function_type_t {
3265         construct_type_base_t  base;
3266         type_t                *function_type;
3267 } construct_function_type_t;
3268
3269 typedef struct parsed_array_t {
3270         construct_type_base_t  base;
3271         type_qualifiers_t      type_qualifiers;
3272         bool                   is_static;
3273         bool                   is_variable;
3274         expression_t          *size;
3275 } parsed_array_t;
3276
3277 union construct_type_t {
3278         construct_type_kind_t     kind;
3279         construct_type_base_t     base;
3280         parsed_pointer_t          pointer;
3281         parsed_reference_t        reference;
3282         construct_function_type_t function;
3283         parsed_array_t            array;
3284 };
3285
3286 static construct_type_t *allocate_declarator_zero(construct_type_kind_t const kind, size_t const size)
3287 {
3288         construct_type_t *const cons = obstack_alloc(&temp_obst, size);
3289         memset(cons, 0, size);
3290         cons->kind     = kind;
3291         cons->base.pos = *HERE;
3292         return cons;
3293 }
3294
3295 /* §6.7.5.1 */
3296 static construct_type_t *parse_pointer_declarator(void)
3297 {
3298         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_POINTER, sizeof(parsed_pointer_t));
3299         eat('*');
3300         cons->pointer.type_qualifiers = parse_type_qualifiers();
3301         //cons->pointer.base_variable   = base_variable;
3302
3303         return cons;
3304 }
3305
3306 /* ISO/IEC 14882:1998(E) §8.3.2 */
3307 static construct_type_t *parse_reference_declarator(void)
3308 {
3309         if (!(c_mode & _CXX))
3310                 errorf(HERE, "references are only available for C++");
3311
3312         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_REFERENCE, sizeof(parsed_reference_t));
3313         eat('&');
3314
3315         return cons;
3316 }
3317
3318 /* §6.7.5.2 */
3319 static construct_type_t *parse_array_declarator(void)
3320 {
3321         construct_type_t *const cons  = allocate_declarator_zero(CONSTRUCT_ARRAY, sizeof(parsed_array_t));
3322         parsed_array_t   *const array = &cons->array;
3323
3324         eat('[');
3325         add_anchor_token(']');
3326
3327         bool is_static = next_if(T_static);
3328
3329         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
3330
3331         if (!is_static)
3332                 is_static = next_if(T_static);
3333
3334         array->type_qualifiers = type_qualifiers;
3335         array->is_static       = is_static;
3336
3337         expression_t *size = NULL;
3338         if (token.kind == '*' && look_ahead(1)->kind == ']') {
3339                 array->is_variable = true;
3340                 next_token();
3341         } else if (token.kind != ']') {
3342                 size = parse_assignment_expression();
3343
3344                 /* §6.7.5.2:1  Array size must have integer type */
3345                 type_t *const orig_type = size->base.type;
3346                 type_t *const type      = skip_typeref(orig_type);
3347                 if (!is_type_integer(type) && is_type_valid(type)) {
3348                         errorf(&size->base.source_position,
3349                                "array size '%E' must have integer type but has type '%T'",
3350                                size, orig_type);
3351                 }
3352
3353                 array->size = size;
3354                 mark_vars_read(size, NULL);
3355         }
3356
3357         if (is_static && size == NULL)
3358                 errorf(&array->base.pos, "static array parameters require a size");
3359
3360         rem_anchor_token(']');
3361         expect(']');
3362         return cons;
3363 }
3364
3365 /* §6.7.5.3 */
3366 static construct_type_t *parse_function_declarator(scope_t *scope)
3367 {
3368         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_FUNCTION, sizeof(construct_function_type_t));
3369
3370         type_t          *type  = allocate_type_zero(TYPE_FUNCTION);
3371         function_type_t *ftype = &type->function;
3372
3373         ftype->linkage            = current_linkage;
3374         ftype->calling_convention = CC_DEFAULT;
3375
3376         parse_parameters(ftype, scope);
3377
3378         cons->function.function_type = type;
3379
3380         return cons;
3381 }
3382
3383 typedef struct parse_declarator_env_t {
3384         bool               may_be_abstract : 1;
3385         bool               must_be_abstract : 1;
3386         decl_modifiers_t   modifiers;
3387         symbol_t          *symbol;
3388         source_position_t  source_position;
3389         scope_t            parameters;
3390         attribute_t       *attributes;
3391 } parse_declarator_env_t;
3392
3393 /* §6.7.5 */
3394 static construct_type_t *parse_inner_declarator(parse_declarator_env_t *env)
3395 {
3396         /* construct a single linked list of construct_type_t's which describe
3397          * how to construct the final declarator type */
3398         construct_type_t  *first      = NULL;
3399         construct_type_t **anchor     = &first;
3400
3401         env->attributes = parse_attributes(env->attributes);
3402
3403         for (;;) {
3404                 construct_type_t *type;
3405                 //variable_t       *based = NULL; /* MS __based extension */
3406                 switch (token.kind) {
3407                         case '&':
3408                                 type = parse_reference_declarator();
3409                                 break;
3410
3411                         case T__based: {
3412                                 panic("based not supported anymore");
3413                                 /* FALLTHROUGH */
3414                         }
3415
3416                         case '*':
3417                                 type = parse_pointer_declarator();
3418                                 break;
3419
3420                         default:
3421                                 goto ptr_operator_end;
3422                 }
3423
3424                 *anchor = type;
3425                 anchor  = &type->base.next;
3426
3427                 /* TODO: find out if this is correct */
3428                 env->attributes = parse_attributes(env->attributes);
3429         }
3430
3431 ptr_operator_end: ;
3432         construct_type_t *inner_types = NULL;
3433
3434         switch (token.kind) {
3435         case T_IDENTIFIER:
3436                 if (env->must_be_abstract) {
3437                         errorf(HERE, "no identifier expected in typename");
3438                 } else {
3439                         env->symbol          = token.identifier.symbol;
3440                         env->source_position = token.base.source_position;
3441                 }
3442                 next_token();
3443                 break;
3444
3445         case '(': {
3446                 /* Parenthesized declarator or function declarator? */
3447                 token_t const *const la1 = look_ahead(1);
3448                 switch (la1->kind) {
3449                         case T_IDENTIFIER:
3450                                 if (is_typedef_symbol(la1->identifier.symbol)) {
3451                         case ')':
3452                                         /* §6.7.6:2 footnote 126:  Empty parentheses in a type name are
3453                                          * interpreted as ``function with no parameter specification'', rather
3454                                          * than redundant parentheses around the omitted identifier. */
3455                         default:
3456                                         /* Function declarator. */
3457                                         if (!env->may_be_abstract) {
3458                                                 errorf(HERE, "function declarator must have a name");
3459                                         }
3460                                 } else {
3461                         case '&':
3462                         case '(':
3463                         case '*':
3464                         case '[':
3465                         case T___attribute__: /* FIXME __attribute__ might also introduce a parameter of a function declarator. */
3466                                         /* Paranthesized declarator. */
3467                                         next_token();
3468                                         add_anchor_token(')');
3469                                         inner_types = parse_inner_declarator(env);
3470                                         if (inner_types != NULL) {
3471                                                 /* All later declarators only modify the return type */
3472                                                 env->must_be_abstract = true;
3473                                         }
3474                                         rem_anchor_token(')');
3475                                         expect(')');
3476                                 }
3477                                 break;
3478                 }
3479                 break;
3480         }
3481
3482         default:
3483                 if (env->may_be_abstract)
3484                         break;
3485                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', NULL);
3486                 eat_until_anchor();
3487                 return NULL;
3488         }
3489
3490         construct_type_t **const p = anchor;
3491
3492         for (;;) {
3493                 construct_type_t *type;
3494                 switch (token.kind) {
3495                 case '(': {
3496                         scope_t *scope = NULL;
3497                         if (!env->must_be_abstract) {
3498                                 scope = &env->parameters;
3499                         }
3500
3501                         type = parse_function_declarator(scope);
3502                         break;
3503                 }
3504                 case '[':
3505                         type = parse_array_declarator();
3506                         break;
3507                 default:
3508                         goto declarator_finished;
3509                 }
3510
3511                 /* insert in the middle of the list (at p) */
3512                 type->base.next = *p;
3513                 *p              = type;
3514                 if (anchor == p)
3515                         anchor = &type->base.next;
3516         }
3517
3518 declarator_finished:
3519         /* append inner_types at the end of the list, we don't to set anchor anymore
3520          * as it's not needed anymore */
3521         *anchor = inner_types;
3522
3523         return first;
3524 }
3525
3526 static type_t *construct_declarator_type(construct_type_t *construct_list,
3527                                          type_t *type)
3528 {
3529         construct_type_t *iter = construct_list;
3530         for (; iter != NULL; iter = iter->base.next) {
3531                 source_position_t const* const pos = &iter->base.pos;
3532                 switch (iter->kind) {
3533                 case CONSTRUCT_FUNCTION: {
3534                         construct_function_type_t *function      = &iter->function;
3535                         type_t                    *function_type = function->function_type;
3536
3537                         function_type->function.return_type = type;
3538
3539                         type_t *skipped_return_type = skip_typeref(type);
3540                         /* §6.7.5.3:1 */
3541                         if (is_type_function(skipped_return_type)) {
3542                                 errorf(pos, "function returning function is not allowed");
3543                         } else if (is_type_array(skipped_return_type)) {
3544                                 errorf(pos, "function returning array is not allowed");
3545                         } else {
3546                                 if (skipped_return_type->base.qualifiers != 0) {
3547                                         warningf(WARN_IGNORED_QUALIFIERS, pos, "type qualifiers in return type of function type are meaningless");
3548                                 }
3549                         }
3550
3551                         /* The function type was constructed earlier.  Freeing it here will
3552                          * destroy other types. */
3553                         type = typehash_insert(function_type);
3554                         continue;
3555                 }
3556
3557                 case CONSTRUCT_POINTER: {
3558                         if (is_type_reference(skip_typeref(type)))
3559                                 errorf(pos, "cannot declare a pointer to reference");
3560
3561                         parsed_pointer_t *pointer = &iter->pointer;
3562                         type = make_based_pointer_type(type, pointer->type_qualifiers, pointer->base_variable);
3563                         continue;
3564                 }
3565
3566                 case CONSTRUCT_REFERENCE:
3567                         if (is_type_reference(skip_typeref(type)))
3568                                 errorf(pos, "cannot declare a reference to reference");
3569
3570                         type = make_reference_type(type);
3571                         continue;
3572
3573                 case CONSTRUCT_ARRAY: {
3574                         if (is_type_reference(skip_typeref(type)))
3575                                 errorf(pos, "cannot declare an array of references");
3576
3577                         parsed_array_t *array      = &iter->array;
3578                         type_t         *array_type = allocate_type_zero(TYPE_ARRAY);
3579
3580                         expression_t *size_expression = array->size;
3581                         if (size_expression != NULL) {
3582                                 size_expression
3583                                         = create_implicit_cast(size_expression, type_size_t);
3584                         }
3585
3586                         array_type->base.qualifiers       = array->type_qualifiers;
3587                         array_type->array.element_type    = type;
3588                         array_type->array.is_static       = array->is_static;
3589                         array_type->array.is_variable     = array->is_variable;
3590                         array_type->array.size_expression = size_expression;
3591
3592                         if (size_expression != NULL) {
3593                                 switch (is_constant_expression(size_expression)) {
3594                                 case EXPR_CLASS_CONSTANT: {
3595                                         long const size = fold_constant_to_int(size_expression);
3596                                         array_type->array.size          = size;
3597                                         array_type->array.size_constant = true;
3598                                         /* §6.7.5.2:1  If the expression is a constant expression,
3599                                          * it shall have a value greater than zero. */
3600                                         if (size < 0) {
3601                                                 errorf(&size_expression->base.source_position,
3602                                                            "size of array must be greater than zero");
3603                                         } else if (size == 0 && !GNU_MODE) {
3604                                                 errorf(&size_expression->base.source_position,
3605                                                            "size of array must be greater than zero (zero length arrays are a GCC extension)");
3606                                         }
3607                                         break;
3608                                 }
3609
3610                                 case EXPR_CLASS_VARIABLE:
3611                                         array_type->array.is_vla = true;
3612                                         break;
3613
3614                                 case EXPR_CLASS_ERROR:
3615                                         break;
3616                                 }
3617                         }
3618
3619                         type_t *skipped_type = skip_typeref(type);
3620                         /* §6.7.5.2:1 */
3621                         if (is_type_incomplete(skipped_type)) {
3622                                 errorf(pos, "array of incomplete type '%T' is not allowed", type);
3623                         } else if (is_type_function(skipped_type)) {
3624                                 errorf(pos, "array of functions is not allowed");
3625                         }
3626                         type = identify_new_type(array_type);
3627                         continue;
3628                 }
3629                 }
3630                 internal_errorf(pos, "invalid type construction found");
3631         }
3632
3633         return type;
3634 }
3635
3636 static type_t *automatic_type_conversion(type_t *orig_type);
3637
3638 static type_t *semantic_parameter(const source_position_t *pos,
3639                                   type_t *type,
3640                                   const declaration_specifiers_t *specifiers,
3641                                   entity_t const *const param)
3642 {
3643         /* §6.7.5.3:7  A declaration of a parameter as ``array of type''
3644          *             shall be adjusted to ``qualified pointer to type'',
3645          *             [...]
3646          * §6.7.5.3:8  A declaration of a parameter as ``function returning
3647          *             type'' shall be adjusted to ``pointer to function
3648          *             returning type'', as in 6.3.2.1. */
3649         type = automatic_type_conversion(type);
3650
3651         if (specifiers->is_inline && is_type_valid(type)) {
3652                 errorf(pos, "'%N' declared 'inline'", param);
3653         }
3654
3655         /* §6.9.1:6  The declarations in the declaration list shall contain
3656          *           no storage-class specifier other than register and no
3657          *           initializations. */
3658         if (specifiers->thread_local || (
3659                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3660                         specifiers->storage_class != STORAGE_CLASS_REGISTER)
3661            ) {
3662                 errorf(pos, "invalid storage class for '%N'", param);
3663         }
3664
3665         /* delay test for incomplete type, because we might have (void)
3666          * which is legal but incomplete... */
3667
3668         return type;
3669 }
3670
3671 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
3672                                   declarator_flags_t flags)
3673 {
3674         parse_declarator_env_t env;
3675         memset(&env, 0, sizeof(env));
3676         env.may_be_abstract = (flags & DECL_MAY_BE_ABSTRACT) != 0;
3677
3678         construct_type_t *construct_type = parse_inner_declarator(&env);
3679         type_t           *orig_type      =
3680                 construct_declarator_type(construct_type, specifiers->type);
3681         type_t           *type           = skip_typeref(orig_type);
3682
3683         if (construct_type != NULL) {
3684                 obstack_free(&temp_obst, construct_type);
3685         }
3686
3687         attribute_t *attributes = parse_attributes(env.attributes);
3688         /* append (shared) specifier attribute behind attributes of this
3689          * declarator */
3690         attribute_t **anchor = &attributes;
3691         while (*anchor != NULL)
3692                 anchor = &(*anchor)->next;
3693         *anchor = specifiers->attributes;
3694
3695         entity_t *entity;
3696         if (specifiers->storage_class == STORAGE_CLASS_TYPEDEF) {
3697                 entity = allocate_entity_zero(ENTITY_TYPEDEF, NAMESPACE_NORMAL, env.symbol, &env.source_position);
3698                 entity->typedefe.type = orig_type;
3699
3700                 if (anonymous_entity != NULL) {
3701                         if (is_type_compound(type)) {
3702                                 assert(anonymous_entity->compound.alias == NULL);
3703                                 assert(anonymous_entity->kind == ENTITY_STRUCT ||
3704                                        anonymous_entity->kind == ENTITY_UNION);
3705                                 anonymous_entity->compound.alias = entity;
3706                                 anonymous_entity = NULL;
3707                         } else if (is_type_enum(type)) {
3708                                 assert(anonymous_entity->enume.alias == NULL);
3709                                 assert(anonymous_entity->kind == ENTITY_ENUM);
3710                                 anonymous_entity->enume.alias = entity;
3711                                 anonymous_entity = NULL;
3712                         }
3713                 }
3714         } else {
3715                 /* create a declaration type entity */
3716                 source_position_t const *const pos = env.symbol ? &env.source_position : &specifiers->source_position;
3717                 if (flags & DECL_CREATE_COMPOUND_MEMBER) {
3718                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER, NAMESPACE_NORMAL, env.symbol, pos);
3719
3720                         if (env.symbol != NULL) {
3721                                 if (specifiers->is_inline && is_type_valid(type)) {
3722                                         errorf(&env.source_position,
3723                                                         "compound member '%Y' declared 'inline'", env.symbol);
3724                                 }
3725
3726                                 if (specifiers->thread_local ||
3727                                                 specifiers->storage_class != STORAGE_CLASS_NONE) {
3728                                         errorf(&env.source_position,
3729                                                         "compound member '%Y' must have no storage class",
3730                                                         env.symbol);
3731                                 }
3732                         }
3733                 } else if (flags & DECL_IS_PARAMETER) {
3734                         entity    = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, env.symbol, pos);
3735                         orig_type = semantic_parameter(&env.source_position, orig_type, specifiers, entity);
3736                 } else if (is_type_function(type)) {
3737                         entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, env.symbol, pos);
3738                         entity->function.is_inline      = specifiers->is_inline;
3739                         entity->function.elf_visibility = default_visibility;
3740                         entity->function.parameters     = env.parameters;
3741
3742                         if (env.symbol != NULL) {
3743                                 /* this needs fixes for C++ */
3744                                 bool in_function_scope = current_function != NULL;
3745
3746                                 if (specifiers->thread_local || (
3747                                                         specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3748                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3749                                                         (in_function_scope || specifiers->storage_class != STORAGE_CLASS_STATIC)
3750                                                 )) {
3751                                         errorf(&env.source_position, "invalid storage class for '%N'", entity);
3752                                 }
3753                         }
3754                 } else {
3755                         entity = allocate_entity_zero(ENTITY_VARIABLE, NAMESPACE_NORMAL, env.symbol, pos);
3756                         entity->variable.elf_visibility = default_visibility;
3757                         entity->variable.thread_local   = specifiers->thread_local;
3758
3759                         if (env.symbol != NULL) {
3760                                 if (specifiers->is_inline && is_type_valid(type)) {
3761                                         errorf(&env.source_position, "'%N' declared 'inline'", entity);
3762                                 }
3763
3764                                 bool invalid_storage_class = false;
3765                                 if (current_scope == file_scope) {
3766                                         if (specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3767                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3768                                                         specifiers->storage_class != STORAGE_CLASS_STATIC) {
3769                                                 invalid_storage_class = true;
3770                                         }
3771                                 } else {
3772                                         if (specifiers->thread_local &&
3773                                                         specifiers->storage_class == STORAGE_CLASS_NONE) {
3774                                                 invalid_storage_class = true;
3775                                         }
3776                                 }
3777                                 if (invalid_storage_class) {
3778                                         errorf(&env.source_position, "invalid storage class for variable '%N'", entity);
3779                                 }
3780                         }
3781                 }
3782
3783                 entity->declaration.type       = orig_type;
3784                 entity->declaration.alignment  = get_type_alignment(orig_type);
3785                 entity->declaration.modifiers  = env.modifiers;
3786                 entity->declaration.attributes = attributes;
3787
3788                 storage_class_t storage_class = specifiers->storage_class;
3789                 entity->declaration.declared_storage_class = storage_class;
3790
3791                 if (storage_class == STORAGE_CLASS_NONE && current_function != NULL)
3792                         storage_class = STORAGE_CLASS_AUTO;
3793                 entity->declaration.storage_class = storage_class;
3794         }
3795
3796         if (attributes != NULL) {
3797                 handle_entity_attributes(attributes, entity);
3798         }
3799
3800         if (entity->kind == ENTITY_FUNCTION && !freestanding) {
3801                 adapt_special_functions(&entity->function);
3802         }
3803
3804         return entity;
3805 }
3806
3807 static type_t *parse_abstract_declarator(type_t *base_type)
3808 {
3809         parse_declarator_env_t env;
3810         memset(&env, 0, sizeof(env));
3811         env.may_be_abstract = true;
3812         env.must_be_abstract = true;
3813
3814         construct_type_t *construct_type = parse_inner_declarator(&env);
3815
3816         type_t *result = construct_declarator_type(construct_type, base_type);
3817         if (construct_type != NULL) {
3818                 obstack_free(&temp_obst, construct_type);
3819         }
3820         result = handle_type_attributes(env.attributes, result);
3821
3822         return result;
3823 }
3824
3825 /**
3826  * Check if the declaration of main is suspicious.  main should be a
3827  * function with external linkage, returning int, taking either zero
3828  * arguments, two, or three arguments of appropriate types, ie.
3829  *
3830  * int main([ int argc, char **argv [, char **env ] ]).
3831  *
3832  * @param decl    the declaration to check
3833  * @param type    the function type of the declaration
3834  */
3835 static void check_main(const entity_t *entity)
3836 {
3837         const source_position_t *pos = &entity->base.source_position;
3838         if (entity->kind != ENTITY_FUNCTION) {
3839                 warningf(WARN_MAIN, pos, "'main' is not a function");
3840                 return;
3841         }
3842
3843         if (entity->declaration.storage_class == STORAGE_CLASS_STATIC) {
3844                 warningf(WARN_MAIN, pos, "'main' is normally a non-static function");
3845         }
3846
3847         type_t *type = skip_typeref(entity->declaration.type);
3848         assert(is_type_function(type));
3849
3850         function_type_t const *const func_type = &type->function;
3851         type_t                *const ret_type  = func_type->return_type;
3852         if (!types_compatible(skip_typeref(ret_type), type_int)) {
3853                 warningf(WARN_MAIN, pos, "return type of 'main' should be 'int', but is '%T'", ret_type);
3854         }
3855         const function_parameter_t *parm = func_type->parameters;
3856         if (parm != NULL) {
3857                 type_t *const first_type        = skip_typeref(parm->type);
3858                 type_t *const first_type_unqual = get_unqualified_type(first_type);
3859                 if (!types_compatible(first_type_unqual, type_int)) {
3860                         warningf(WARN_MAIN, pos, "first argument of 'main' should be 'int', but is '%T'", parm->type);
3861                 }
3862                 parm = parm->next;
3863                 if (parm != NULL) {
3864                         type_t *const second_type = skip_typeref(parm->type);
3865                         type_t *const second_type_unqual
3866                                 = get_unqualified_type(second_type);
3867                         if (!types_compatible(second_type_unqual, type_char_ptr_ptr)) {
3868                                 warningf(WARN_MAIN, pos, "second argument of 'main' should be 'char**', but is '%T'", parm->type);
3869                         }
3870                         parm = parm->next;
3871                         if (parm != NULL) {
3872                                 type_t *const third_type = skip_typeref(parm->type);
3873                                 type_t *const third_type_unqual
3874                                         = get_unqualified_type(third_type);
3875                                 if (!types_compatible(third_type_unqual, type_char_ptr_ptr)) {
3876                                         warningf(WARN_MAIN, pos, "third argument of 'main' should be 'char**', but is '%T'", parm->type);
3877                                 }
3878                                 parm = parm->next;
3879                                 if (parm != NULL)
3880                                         goto warn_arg_count;
3881                         }
3882                 } else {
3883 warn_arg_count:
3884                         warningf(WARN_MAIN, pos, "'main' takes only zero, two or three arguments");
3885                 }
3886         }
3887 }
3888
3889 /**
3890  * Check if a symbol is the equal to "main".
3891  */
3892 static bool is_sym_main(const symbol_t *const sym)
3893 {
3894         return streq(sym->string, "main");
3895 }
3896
3897 static void error_redefined_as_different_kind(const source_position_t *pos,
3898                 const entity_t *old, entity_kind_t new_kind)
3899 {
3900         char              const *const what = get_entity_kind_name(new_kind);
3901         source_position_t const *const ppos = &old->base.source_position;
3902         errorf(pos, "redeclaration of '%N' as %s (declared %P)", old, what, ppos);
3903 }
3904
3905 static bool is_entity_valid(entity_t *const ent)
3906 {
3907         if (is_declaration(ent)) {
3908                 return is_type_valid(skip_typeref(ent->declaration.type));
3909         } else if (ent->kind == ENTITY_TYPEDEF) {
3910                 return is_type_valid(skip_typeref(ent->typedefe.type));
3911         }
3912         return true;
3913 }
3914
3915 static bool contains_attribute(const attribute_t *list, const attribute_t *attr)
3916 {
3917         for (const attribute_t *tattr = list; tattr != NULL; tattr = tattr->next) {
3918                 if (attributes_equal(tattr, attr))
3919                         return true;
3920         }
3921         return false;
3922 }
3923
3924 /**
3925  * test wether new_list contains any attributes not included in old_list
3926  */
3927 static bool has_new_attributes(const attribute_t *old_list,
3928                                const attribute_t *new_list)
3929 {
3930         for (const attribute_t *attr = new_list; attr != NULL; attr = attr->next) {
3931                 if (!contains_attribute(old_list, attr))
3932                         return true;
3933         }
3934         return false;
3935 }
3936
3937 /**
3938  * Merge in attributes from an attribute list (probably from a previous
3939  * declaration with the same name). Warning: destroys the old structure
3940  * of the attribute list - don't reuse attributes after this call.
3941  */
3942 static void merge_in_attributes(declaration_t *decl, attribute_t *attributes)
3943 {
3944         attribute_t *next;
3945         for (attribute_t *attr = attributes; attr != NULL; attr = next) {
3946                 next = attr->next;
3947                 if (contains_attribute(decl->attributes, attr))
3948                         continue;
3949
3950                 /* move attribute to new declarations attributes list */
3951                 attr->next       = decl->attributes;
3952                 decl->attributes = attr;
3953         }
3954 }
3955
3956 /**
3957  * record entities for the NAMESPACE_NORMAL, and produce error messages/warnings
3958  * for various problems that occur for multiple definitions
3959  */
3960 entity_t *record_entity(entity_t *entity, const bool is_definition)
3961 {
3962         const symbol_t *const    symbol  = entity->base.symbol;
3963         const namespace_tag_t    namespc = (namespace_tag_t)entity->base.namespc;
3964         const source_position_t *pos     = &entity->base.source_position;
3965
3966         /* can happen in error cases */
3967         if (symbol == NULL)
3968                 return entity;
3969
3970         entity_t *const previous_entity = get_entity(symbol, namespc);
3971         /* pushing the same entity twice will break the stack structure */
3972         assert(previous_entity != entity);
3973
3974         if (entity->kind == ENTITY_FUNCTION) {
3975                 type_t *const orig_type = entity->declaration.type;
3976                 type_t *const type      = skip_typeref(orig_type);
3977
3978                 assert(is_type_function(type));
3979                 if (type->function.unspecified_parameters &&
3980                     previous_entity == NULL               &&
3981                     !entity->declaration.implicit) {
3982                         warningf(WARN_STRICT_PROTOTYPES, pos, "function declaration '%#N' is not a prototype", entity);
3983                 }
3984
3985                 if (current_scope == file_scope && is_sym_main(symbol)) {
3986                         check_main(entity);
3987                 }
3988         }
3989
3990         if (is_declaration(entity)                                    &&
3991             entity->declaration.storage_class == STORAGE_CLASS_EXTERN &&
3992             current_scope != file_scope                               &&
3993             !entity->declaration.implicit) {
3994                 warningf(WARN_NESTED_EXTERNS, pos, "nested extern declaration of '%#N'", entity);
3995         }
3996
3997         if (previous_entity != NULL) {
3998                 source_position_t const *const ppos = &previous_entity->base.source_position;
3999
4000                 if (previous_entity->base.parent_scope == &current_function->parameters &&
4001                                 previous_entity->base.parent_scope->depth + 1 == current_scope->depth) {
4002                         assert(previous_entity->kind == ENTITY_PARAMETER);
4003                         errorf(pos, "declaration of '%N' redeclares the '%N' (declared %P)", entity, previous_entity, ppos);
4004                         goto finish;
4005                 }
4006
4007                 if (previous_entity->base.parent_scope == current_scope) {
4008                         if (previous_entity->kind != entity->kind) {
4009                                 if (is_entity_valid(previous_entity) && is_entity_valid(entity)) {
4010                                         error_redefined_as_different_kind(pos, previous_entity,
4011                                                         entity->kind);
4012                                 }
4013                                 goto finish;
4014                         }
4015                         if (previous_entity->kind == ENTITY_ENUM_VALUE) {
4016                                 errorf(pos, "redeclaration of '%N' (declared %P)", entity, ppos);
4017                                 goto finish;
4018                         }
4019                         if (previous_entity->kind == ENTITY_TYPEDEF) {
4020                                 type_t *const type      = skip_typeref(entity->typedefe.type);
4021                                 type_t *const prev_type
4022                                         = skip_typeref(previous_entity->typedefe.type);
4023                                 if (c_mode & _CXX) {
4024                                         /* C++ allows double typedef if they are identical
4025                                          * (after skipping typedefs) */
4026                                         if (type == prev_type)
4027                                                 goto finish;
4028                                 } else {
4029                                         /* GCC extension: redef in system headers is allowed */
4030                                         if ((pos->is_system_header || ppos->is_system_header) &&
4031                                             types_compatible(type, prev_type))
4032                                                 goto finish;
4033                                 }
4034                                 errorf(pos, "redefinition of '%N' (declared %P)",
4035                                        entity, ppos);
4036                                 goto finish;
4037                         }
4038
4039                         /* at this point we should have only VARIABLES or FUNCTIONS */
4040                         assert(is_declaration(previous_entity) && is_declaration(entity));
4041
4042                         declaration_t *const prev_decl = &previous_entity->declaration;
4043                         declaration_t *const decl      = &entity->declaration;
4044
4045                         /* can happen for K&R style declarations */
4046                         if (prev_decl->type       == NULL             &&
4047                                         previous_entity->kind == ENTITY_PARAMETER &&
4048                                         entity->kind          == ENTITY_PARAMETER) {
4049                                 prev_decl->type                   = decl->type;
4050                                 prev_decl->storage_class          = decl->storage_class;
4051                                 prev_decl->declared_storage_class = decl->declared_storage_class;
4052                                 prev_decl->modifiers              = decl->modifiers;
4053                                 return previous_entity;
4054                         }
4055
4056                         type_t *const type      = skip_typeref(decl->type);
4057                         type_t *const prev_type = skip_typeref(prev_decl->type);
4058
4059                         if (!types_compatible(type, prev_type)) {
4060                                 errorf(pos, "declaration '%#N' is incompatible with '%#N' (declared %P)", entity, previous_entity, ppos);
4061                         } else {
4062                                 unsigned old_storage_class = prev_decl->storage_class;
4063
4064                                 if (is_definition                     &&
4065                                                 !prev_decl->used                  &&
4066                                                 !(prev_decl->modifiers & DM_USED) &&
4067                                                 prev_decl->storage_class == STORAGE_CLASS_STATIC) {
4068                                         warningf(WARN_REDUNDANT_DECLS, ppos, "unnecessary static forward declaration for '%#N'", previous_entity);
4069                                 }
4070
4071                                 storage_class_t new_storage_class = decl->storage_class;
4072
4073                                 /* pretend no storage class means extern for function
4074                                  * declarations (except if the previous declaration is neither
4075                                  * none nor extern) */
4076                                 if (entity->kind == ENTITY_FUNCTION) {
4077                                         /* the previous declaration could have unspecified parameters or
4078                                          * be a typedef, so use the new type */
4079                                         if (prev_type->function.unspecified_parameters || is_definition)
4080                                                 prev_decl->type = type;
4081
4082                                         switch (old_storage_class) {
4083                                                 case STORAGE_CLASS_NONE:
4084                                                         old_storage_class = STORAGE_CLASS_EXTERN;
4085                                                         /* FALLTHROUGH */
4086
4087                                                 case STORAGE_CLASS_EXTERN:
4088                                                         if (is_definition) {
4089                                                                 if (prev_type->function.unspecified_parameters && !is_sym_main(symbol)) {
4090                                                                         warningf(WARN_MISSING_PROTOTYPES, pos, "no previous prototype for '%#N'", entity);
4091                                                                 }
4092                                                         } else if (new_storage_class == STORAGE_CLASS_NONE) {
4093                                                                 new_storage_class = STORAGE_CLASS_EXTERN;
4094                                                         }
4095                                                         break;
4096
4097                                                 default:
4098                                                         break;
4099                                         }
4100                                 } else if (is_type_incomplete(prev_type)) {
4101                                         prev_decl->type = type;
4102                                 }
4103
4104                                 if (old_storage_class == STORAGE_CLASS_EXTERN &&
4105                                                 new_storage_class == STORAGE_CLASS_EXTERN) {
4106
4107 warn_redundant_declaration: ;
4108                                         bool has_new_attrs
4109                                                 = has_new_attributes(prev_decl->attributes,
4110                                                                      decl->attributes);
4111                                         if (has_new_attrs) {
4112                                                 merge_in_attributes(decl, prev_decl->attributes);
4113                                         } else if (!is_definition        &&
4114                                                         is_type_valid(prev_type) &&
4115                                                         !pos->is_system_header) {
4116                                                 warningf(WARN_REDUNDANT_DECLS, pos, "redundant declaration for '%Y' (declared %P)", symbol, ppos);
4117                                         }
4118                                 } else if (current_function == NULL) {
4119                                         if (old_storage_class != STORAGE_CLASS_STATIC &&
4120                                                         new_storage_class == STORAGE_CLASS_STATIC) {
4121                                                 errorf(pos, "static declaration of '%Y' follows non-static declaration (declared %P)", symbol, ppos);
4122                                         } else if (old_storage_class == STORAGE_CLASS_EXTERN) {
4123                                                 prev_decl->storage_class          = STORAGE_CLASS_NONE;
4124                                                 prev_decl->declared_storage_class = STORAGE_CLASS_NONE;
4125                                         } else {
4126                                                 /* ISO/IEC 14882:1998(E) §C.1.2:1 */
4127                                                 if (c_mode & _CXX)
4128                                                         goto error_redeclaration;
4129                                                 goto warn_redundant_declaration;
4130                                         }
4131                                 } else if (is_type_valid(prev_type)) {
4132                                         if (old_storage_class == new_storage_class) {
4133 error_redeclaration:
4134                                                 errorf(pos, "redeclaration of '%Y' (declared %P)", symbol, ppos);
4135                                         } else {
4136                                                 errorf(pos, "redeclaration of '%Y' with different linkage (declared %P)", symbol, ppos);
4137                                         }
4138                                 }
4139                         }
4140
4141                         prev_decl->modifiers |= decl->modifiers;
4142                         if (entity->kind == ENTITY_FUNCTION) {
4143                                 previous_entity->function.is_inline |= entity->function.is_inline;
4144                         }
4145                         return previous_entity;
4146                 }
4147
4148                 warning_t why;
4149                 if (is_warn_on(why = WARN_SHADOW) ||
4150                     (is_warn_on(why = WARN_SHADOW_LOCAL) && previous_entity->base.parent_scope != file_scope)) {
4151                         char const *const what = get_entity_kind_name(previous_entity->kind);
4152                         warningf(why, pos, "'%N' shadows %s (declared %P)", entity, what, ppos);
4153                 }
4154         }
4155
4156         if (entity->kind == ENTITY_FUNCTION) {
4157                 if (is_definition &&
4158                                 entity->declaration.storage_class != STORAGE_CLASS_STATIC &&
4159                                 !is_sym_main(symbol)) {
4160                         if (is_warn_on(WARN_MISSING_PROTOTYPES)) {
4161                                 warningf(WARN_MISSING_PROTOTYPES, pos, "no previous prototype for '%#N'", entity);
4162                         } else {
4163                                 goto warn_missing_declaration;
4164                         }
4165                 }
4166         } else if (entity->kind == ENTITY_VARIABLE) {
4167                 if (current_scope                     == file_scope &&
4168                                 entity->declaration.storage_class == STORAGE_CLASS_NONE &&
4169                                 !entity->declaration.implicit) {
4170 warn_missing_declaration:
4171                         warningf(WARN_MISSING_DECLARATIONS, pos, "no previous declaration for '%#N'", entity);
4172                 }
4173         }
4174
4175 finish:
4176         assert(entity->base.parent_scope == NULL);
4177         assert(current_scope != NULL);
4178
4179         entity->base.parent_scope = current_scope;
4180         environment_push(entity);
4181         append_entity(current_scope, entity);
4182
4183         return entity;
4184 }
4185
4186 static void parser_error_multiple_definition(entity_t *entity,
4187                 const source_position_t *source_position)
4188 {
4189         errorf(source_position, "multiple definition of '%Y' (declared %P)",
4190                entity->base.symbol, &entity->base.source_position);
4191 }
4192
4193 static bool is_declaration_specifier(const token_t *token)
4194 {
4195         switch (token->kind) {
4196                 DECLARATION_START
4197                         return true;
4198                 case T_IDENTIFIER:
4199                         return is_typedef_symbol(token->identifier.symbol);
4200
4201                 default:
4202                         return false;
4203         }
4204 }
4205
4206 static void parse_init_declarator_rest(entity_t *entity)
4207 {
4208         type_t *orig_type = type_error_type;
4209
4210         if (entity->base.kind == ENTITY_TYPEDEF) {
4211                 source_position_t const *const pos = &entity->base.source_position;
4212                 errorf(pos, "'%N' is initialized (use __typeof__ instead)", entity);
4213         } else {
4214                 assert(is_declaration(entity));
4215                 orig_type = entity->declaration.type;
4216         }
4217
4218         type_t *type = skip_typeref(orig_type);
4219
4220         if (entity->kind == ENTITY_VARIABLE
4221                         && entity->variable.initializer != NULL) {
4222                 parser_error_multiple_definition(entity, HERE);
4223         }
4224         eat('=');
4225
4226         declaration_t *const declaration = &entity->declaration;
4227         bool must_be_constant = false;
4228         if (declaration->storage_class == STORAGE_CLASS_STATIC ||
4229             entity->base.parent_scope  == file_scope) {
4230                 must_be_constant = true;
4231         }
4232
4233         if (is_type_function(type)) {
4234                 source_position_t const *const pos = &entity->base.source_position;
4235                 errorf(pos, "'%N' is initialized like a variable", entity);
4236                 orig_type = type_error_type;
4237         }
4238
4239         parse_initializer_env_t env;
4240         env.type             = orig_type;
4241         env.must_be_constant = must_be_constant;
4242         env.entity           = entity;
4243
4244         initializer_t *initializer = parse_initializer(&env);
4245
4246         if (entity->kind == ENTITY_VARIABLE) {
4247                 /* §6.7.5:22  array initializers for arrays with unknown size
4248                  * determine the array type size */
4249                 declaration->type            = env.type;
4250                 entity->variable.initializer = initializer;
4251         }
4252 }
4253
4254 /* parse rest of a declaration without any declarator */
4255 static void parse_anonymous_declaration_rest(
4256                 const declaration_specifiers_t *specifiers)
4257 {
4258         eat(';');
4259         anonymous_entity = NULL;
4260
4261         source_position_t const *const pos = &specifiers->source_position;
4262         if (specifiers->storage_class != STORAGE_CLASS_NONE ||
4263                         specifiers->thread_local) {
4264                 warningf(WARN_OTHER, pos, "useless storage class in empty declaration");
4265         }
4266
4267         type_t *type = specifiers->type;
4268         switch (type->kind) {
4269                 case TYPE_COMPOUND_STRUCT:
4270                 case TYPE_COMPOUND_UNION: {
4271                         if (type->compound.compound->base.symbol == NULL) {
4272                                 warningf(WARN_OTHER, pos, "unnamed struct/union that defines no instances");
4273                         }
4274                         break;
4275                 }
4276
4277                 case TYPE_ENUM:
4278                         break;
4279
4280                 default:
4281                         warningf(WARN_OTHER, pos, "empty declaration");
4282                         break;
4283         }
4284 }
4285
4286 static void check_variable_type_complete(entity_t *ent)
4287 {
4288         if (ent->kind != ENTITY_VARIABLE)
4289                 return;
4290
4291         /* §6.7:7  If an identifier for an object is declared with no linkage, the
4292          *         type for the object shall be complete [...] */
4293         declaration_t *decl = &ent->declaration;
4294         if (decl->storage_class == STORAGE_CLASS_EXTERN ||
4295                         decl->storage_class == STORAGE_CLASS_STATIC)
4296                 return;
4297
4298         type_t *const type = skip_typeref(decl->type);
4299         if (!is_type_incomplete(type))
4300                 return;
4301
4302         /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
4303          * are given length one. */
4304         if (is_type_array(type) && ent->base.parent_scope == file_scope) {
4305                 ARR_APP1(declaration_t*, incomplete_arrays, decl);
4306                 return;
4307         }
4308
4309         errorf(&ent->base.source_position, "variable '%#N' has incomplete type", ent);
4310 }
4311
4312
4313 static void parse_declaration_rest(entity_t *ndeclaration,
4314                 const declaration_specifiers_t *specifiers,
4315                 parsed_declaration_func         finished_declaration,
4316                 declarator_flags_t              flags)
4317 {
4318         add_anchor_token(';');
4319         add_anchor_token(',');
4320         while (true) {
4321                 entity_t *entity = finished_declaration(ndeclaration, token.kind == '=');
4322
4323                 if (token.kind == '=') {
4324                         parse_init_declarator_rest(entity);
4325                 } else if (entity->kind == ENTITY_VARIABLE) {
4326                         /* ISO/IEC 14882:1998(E) §8.5.3:3  The initializer can be omitted
4327                          * [...] where the extern specifier is explicitly used. */
4328                         declaration_t *decl = &entity->declaration;
4329                         if (decl->storage_class != STORAGE_CLASS_EXTERN &&
4330                             is_type_reference(skip_typeref(decl->type))) {
4331                                 source_position_t const *const pos = &entity->base.source_position;
4332                                 errorf(pos, "reference '%#N' must be initialized", entity);
4333                         }
4334                 }
4335
4336                 check_variable_type_complete(entity);
4337
4338                 if (!next_if(','))
4339                         break;
4340
4341                 add_anchor_token('=');
4342                 ndeclaration = parse_declarator(specifiers, flags);
4343                 rem_anchor_token('=');
4344         }
4345         rem_anchor_token(',');
4346         rem_anchor_token(';');
4347         expect(';');
4348
4349         anonymous_entity = NULL;
4350 }
4351
4352 static entity_t *finished_kr_declaration(entity_t *entity, bool is_definition)
4353 {
4354         symbol_t *symbol = entity->base.symbol;
4355         if (symbol == NULL)
4356                 return entity;
4357
4358         assert(entity->base.namespc == NAMESPACE_NORMAL);
4359         entity_t *previous_entity = get_entity(symbol, NAMESPACE_NORMAL);
4360         if (previous_entity == NULL
4361                         || previous_entity->base.parent_scope != current_scope) {
4362                 errorf(&entity->base.source_position, "expected declaration of a function parameter, found '%Y'",
4363                        symbol);
4364                 return entity;
4365         }
4366
4367         if (is_definition) {
4368                 errorf(HERE, "'%N' is initialised", entity);
4369         }
4370
4371         return record_entity(entity, false);
4372 }
4373
4374 static void parse_declaration(parsed_declaration_func finished_declaration,
4375                               declarator_flags_t      flags)
4376 {
4377         add_anchor_token(';');
4378         declaration_specifiers_t specifiers;
4379         parse_declaration_specifiers(&specifiers);
4380         rem_anchor_token(';');
4381
4382         if (token.kind == ';') {
4383                 parse_anonymous_declaration_rest(&specifiers);
4384         } else {
4385                 entity_t *entity = parse_declarator(&specifiers, flags);
4386                 parse_declaration_rest(entity, &specifiers, finished_declaration, flags);
4387         }
4388 }
4389
4390 /* §6.5.2.2:6 */
4391 static type_t *get_default_promoted_type(type_t *orig_type)
4392 {
4393         type_t *result = orig_type;
4394
4395         type_t *type = skip_typeref(orig_type);
4396         if (is_type_integer(type)) {
4397                 result = promote_integer(type);
4398         } else if (is_type_atomic(type, ATOMIC_TYPE_FLOAT)) {
4399                 result = type_double;
4400         }
4401
4402         return result;
4403 }
4404
4405 static void parse_kr_declaration_list(entity_t *entity)
4406 {
4407         if (entity->kind != ENTITY_FUNCTION)
4408                 return;
4409
4410         type_t *type = skip_typeref(entity->declaration.type);
4411         assert(is_type_function(type));
4412         if (!type->function.kr_style_parameters)
4413                 return;
4414
4415         add_anchor_token('{');
4416
4417         PUSH_SCOPE(&entity->function.parameters);
4418
4419         entity_t *parameter = entity->function.parameters.entities;
4420         for ( ; parameter != NULL; parameter = parameter->base.next) {
4421                 assert(parameter->base.parent_scope == NULL);
4422                 parameter->base.parent_scope = current_scope;
4423                 environment_push(parameter);
4424         }
4425
4426         /* parse declaration list */
4427         for (;;) {
4428                 switch (token.kind) {
4429                         DECLARATION_START
4430                         /* This covers symbols, which are no type, too, and results in
4431                          * better error messages.  The typical cases are misspelled type
4432                          * names and missing includes. */
4433                         case T_IDENTIFIER:
4434                                 parse_declaration(finished_kr_declaration, DECL_IS_PARAMETER);
4435                                 break;
4436                         default:
4437                                 goto decl_list_end;
4438                 }
4439         }
4440 decl_list_end:
4441
4442         POP_SCOPE();
4443
4444         /* update function type */
4445         type_t *new_type = duplicate_type(type);
4446
4447         function_parameter_t  *parameters = NULL;
4448         function_parameter_t **anchor     = &parameters;
4449
4450         /* did we have an earlier prototype? */
4451         entity_t *proto_type = get_entity(entity->base.symbol, NAMESPACE_NORMAL);
4452         if (proto_type != NULL && proto_type->kind != ENTITY_FUNCTION)
4453                 proto_type = NULL;
4454
4455         function_parameter_t *proto_parameter = NULL;
4456         if (proto_type != NULL) {
4457                 type_t *proto_type_type = proto_type->declaration.type;
4458                 proto_parameter         = proto_type_type->function.parameters;
4459                 /* If a K&R function definition has a variadic prototype earlier, then
4460                  * make the function definition variadic, too. This should conform to
4461                  * §6.7.5.3:15 and §6.9.1:8. */
4462                 new_type->function.variadic = proto_type_type->function.variadic;
4463         } else {
4464                 /* §6.9.1.7: A K&R style parameter list does NOT act as a function
4465                  * prototype */
4466                 new_type->function.unspecified_parameters = true;
4467         }
4468
4469         bool need_incompatible_warning = false;
4470         parameter = entity->function.parameters.entities;
4471         for (; parameter != NULL; parameter = parameter->base.next,
4472                         proto_parameter =
4473                                 proto_parameter == NULL ? NULL : proto_parameter->next) {
4474                 if (parameter->kind != ENTITY_PARAMETER)
4475                         continue;
4476
4477                 type_t *parameter_type = parameter->declaration.type;
4478                 if (parameter_type == NULL) {
4479                         source_position_t const* const pos = &parameter->base.source_position;
4480                         if (strict_mode) {
4481                                 errorf(pos, "no type specified for function '%N'", parameter);
4482                                 parameter_type = type_error_type;
4483                         } else {
4484                                 warningf(WARN_IMPLICIT_INT, pos, "no type specified for function parameter '%N', using 'int'", parameter);
4485                                 parameter_type = type_int;
4486                         }
4487                         parameter->declaration.type = parameter_type;
4488                 }
4489
4490                 semantic_parameter_incomplete(parameter);
4491
4492                 /* we need the default promoted types for the function type */
4493                 type_t *not_promoted = parameter_type;
4494                 parameter_type       = get_default_promoted_type(parameter_type);
4495
4496                 /* gcc special: if the type of the prototype matches the unpromoted
4497                  * type don't promote */
4498                 if (!strict_mode && proto_parameter != NULL) {
4499                         type_t *proto_p_type = skip_typeref(proto_parameter->type);
4500                         type_t *promo_skip   = skip_typeref(parameter_type);
4501                         type_t *param_skip   = skip_typeref(not_promoted);
4502                         if (!types_compatible(proto_p_type, promo_skip)
4503                                 && types_compatible(proto_p_type, param_skip)) {
4504                                 /* don't promote */
4505                                 need_incompatible_warning = true;
4506                                 parameter_type = not_promoted;
4507                         }
4508                 }
4509                 function_parameter_t *const function_parameter
4510                         = allocate_parameter(parameter_type);
4511
4512                 *anchor = function_parameter;
4513                 anchor  = &function_parameter->next;
4514         }
4515
4516         new_type->function.parameters = parameters;
4517         new_type = identify_new_type(new_type);
4518
4519         if (need_incompatible_warning) {
4520                 symbol_t          const *const sym  = entity->base.symbol;
4521                 source_position_t const *const pos  = &entity->base.source_position;
4522                 source_position_t const *const ppos = &proto_type->base.source_position;
4523                 warningf(WARN_OTHER, pos, "declaration '%#N' is incompatible with '%#T' (declared %P)", proto_type, new_type, sym, ppos);
4524         }
4525         entity->declaration.type = new_type;
4526
4527         rem_anchor_token('{');
4528 }
4529
4530 static bool first_err = true;
4531
4532 /**
4533  * When called with first_err set, prints the name of the current function,
4534  * else does noting.
4535  */
4536 static void print_in_function(void)
4537 {
4538         if (first_err) {
4539                 first_err = false;
4540                 char const *const file = current_function->base.base.source_position.input_name;
4541                 diagnosticf("%s: In '%N':\n", file, (entity_t const*)current_function);
4542         }
4543 }
4544
4545 /**
4546  * Check if all labels are defined in the current function.
4547  * Check if all labels are used in the current function.
4548  */
4549 static void check_labels(void)
4550 {
4551         for (const goto_statement_t *goto_statement = goto_first;
4552             goto_statement != NULL;
4553             goto_statement = goto_statement->next) {
4554                 label_t *label = goto_statement->label;
4555                 if (label->base.source_position.input_name == NULL) {
4556                         print_in_function();
4557                         source_position_t const *const pos = &goto_statement->base.source_position;
4558                         errorf(pos, "'%N' used but not defined", (entity_t const*)label);
4559                  }
4560         }
4561
4562         if (is_warn_on(WARN_UNUSED_LABEL)) {
4563                 for (const label_statement_t *label_statement = label_first;
4564                          label_statement != NULL;
4565                          label_statement = label_statement->next) {
4566                         label_t *label = label_statement->label;
4567
4568                         if (! label->used) {
4569                                 print_in_function();
4570                                 source_position_t const *const pos = &label_statement->base.source_position;
4571                                 warningf(WARN_UNUSED_LABEL, pos, "'%N' defined but not used", (entity_t const*)label);
4572                         }
4573                 }
4574         }
4575 }
4576
4577 static void warn_unused_entity(warning_t const why, entity_t *entity, entity_t *const last)
4578 {
4579         entity_t const *const end = last != NULL ? last->base.next : NULL;
4580         for (; entity != end; entity = entity->base.next) {
4581                 if (!is_declaration(entity))
4582                         continue;
4583
4584                 declaration_t *declaration = &entity->declaration;
4585                 if (declaration->implicit)
4586                         continue;
4587
4588                 if (!declaration->used) {
4589                         print_in_function();
4590                         warningf(why, &entity->base.source_position, "'%N' is unused", entity);
4591                 } else if (entity->kind == ENTITY_VARIABLE && !entity->variable.read) {
4592                         print_in_function();
4593                         warningf(why, &entity->base.source_position, "'%N' is never read", entity);
4594                 }
4595         }
4596 }
4597
4598 static void check_unused_variables(statement_t *const stmt, void *const env)
4599 {
4600         (void)env;
4601
4602         switch (stmt->kind) {
4603                 case STATEMENT_DECLARATION: {
4604                         declaration_statement_t const *const decls = &stmt->declaration;
4605                         warn_unused_entity(WARN_UNUSED_VARIABLE, decls->declarations_begin, decls->declarations_end);
4606                         return;
4607                 }
4608
4609                 case STATEMENT_FOR:
4610                         warn_unused_entity(WARN_UNUSED_VARIABLE, stmt->fors.scope.entities, NULL);
4611                         return;
4612
4613                 default:
4614                         return;
4615         }
4616 }
4617
4618 /**
4619  * Check declarations of current_function for unused entities.
4620  */
4621 static void check_declarations(void)
4622 {
4623         if (is_warn_on(WARN_UNUSED_PARAMETER)) {
4624                 const scope_t *scope = &current_function->parameters;
4625                 warn_unused_entity(WARN_UNUSED_PARAMETER, scope->entities, NULL);
4626         }
4627         if (is_warn_on(WARN_UNUSED_VARIABLE)) {
4628                 walk_statements(current_function->statement, check_unused_variables,
4629                                 NULL);
4630         }
4631 }
4632
4633 static int determine_truth(expression_t const* const cond)
4634 {
4635         return
4636                 is_constant_expression(cond) != EXPR_CLASS_CONSTANT ? 0 :
4637                 fold_constant_to_bool(cond)                         ? 1 :
4638                 -1;
4639 }
4640
4641 static void check_reachable(statement_t *);
4642 static bool reaches_end;
4643
4644 static bool expression_returns(expression_t const *const expr)
4645 {
4646         switch (expr->kind) {
4647                 case EXPR_CALL: {
4648                         expression_t const *const func = expr->call.function;
4649                         type_t       const *const type = skip_typeref(func->base.type);
4650                         if (type->kind == TYPE_POINTER) {
4651                                 type_t const *const points_to
4652                                         = skip_typeref(type->pointer.points_to);
4653                                 if (points_to->kind == TYPE_FUNCTION
4654                                     && points_to->function.modifiers & DM_NORETURN)
4655                                         return false;
4656                         }
4657
4658                         if (!expression_returns(func))
4659                                 return false;
4660
4661                         for (call_argument_t const* arg = expr->call.arguments; arg != NULL; arg = arg->next) {
4662                                 if (!expression_returns(arg->expression))
4663                                         return false;
4664                         }
4665
4666                         return true;
4667                 }
4668
4669                 case EXPR_REFERENCE:
4670                 case EXPR_ENUM_CONSTANT:
4671                 case EXPR_LITERAL_CASES:
4672                 case EXPR_STRING_LITERAL:
4673                 case EXPR_WIDE_STRING_LITERAL:
4674                 case EXPR_COMPOUND_LITERAL: // TODO descend into initialisers
4675                 case EXPR_LABEL_ADDRESS:
4676                 case EXPR_CLASSIFY_TYPE:
4677                 case EXPR_SIZEOF: // TODO handle obscure VLA case
4678                 case EXPR_ALIGNOF:
4679                 case EXPR_FUNCNAME:
4680                 case EXPR_BUILTIN_CONSTANT_P:
4681                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
4682                 case EXPR_OFFSETOF:
4683                 case EXPR_ERROR:
4684                         return true;
4685
4686                 case EXPR_STATEMENT: {
4687                         bool old_reaches_end = reaches_end;
4688                         reaches_end = false;
4689                         check_reachable(expr->statement.statement);
4690                         bool returns = reaches_end;
4691                         reaches_end = old_reaches_end;
4692                         return returns;
4693                 }
4694
4695                 case EXPR_CONDITIONAL:
4696                         // TODO handle constant expression
4697
4698                         if (!expression_returns(expr->conditional.condition))
4699                                 return false;
4700
4701                         if (expr->conditional.true_expression != NULL
4702                                         && expression_returns(expr->conditional.true_expression))
4703                                 return true;
4704
4705                         return expression_returns(expr->conditional.false_expression);
4706
4707                 case EXPR_SELECT:
4708                         return expression_returns(expr->select.compound);
4709
4710                 case EXPR_ARRAY_ACCESS:
4711                         return
4712                                 expression_returns(expr->array_access.array_ref) &&
4713                                 expression_returns(expr->array_access.index);
4714
4715                 case EXPR_VA_START:
4716                         return expression_returns(expr->va_starte.ap);
4717
4718                 case EXPR_VA_ARG:
4719                         return expression_returns(expr->va_arge.ap);
4720
4721                 case EXPR_VA_COPY:
4722                         return expression_returns(expr->va_copye.src);
4723
4724                 case EXPR_UNARY_CASES_MANDATORY:
4725                         return expression_returns(expr->unary.value);
4726
4727                 case EXPR_UNARY_THROW:
4728                         return false;
4729
4730                 case EXPR_BINARY_CASES:
4731                         // TODO handle constant lhs of && and ||
4732                         return
4733                                 expression_returns(expr->binary.left) &&
4734                                 expression_returns(expr->binary.right);
4735         }
4736
4737         panic("unhandled expression");
4738 }
4739
4740 static bool initializer_returns(initializer_t const *const init)
4741 {
4742         switch (init->kind) {
4743                 case INITIALIZER_VALUE:
4744                         return expression_returns(init->value.value);
4745
4746                 case INITIALIZER_LIST: {
4747                         initializer_t * const*       i       = init->list.initializers;
4748                         initializer_t * const* const end     = i + init->list.len;
4749                         bool                         returns = true;
4750                         for (; i != end; ++i) {
4751                                 if (!initializer_returns(*i))
4752                                         returns = false;
4753                         }
4754                         return returns;
4755                 }
4756
4757                 case INITIALIZER_STRING:
4758                 case INITIALIZER_WIDE_STRING:
4759                 case INITIALIZER_DESIGNATOR: // designators have no payload
4760                         return true;
4761         }
4762         panic("unhandled initializer");
4763 }
4764
4765 static bool noreturn_candidate;
4766
4767 static void check_reachable(statement_t *const stmt)
4768 {
4769         if (stmt->base.reachable)
4770                 return;
4771         if (stmt->kind != STATEMENT_DO_WHILE)
4772                 stmt->base.reachable = true;
4773
4774         statement_t *last = stmt;
4775         statement_t *next;
4776         switch (stmt->kind) {
4777                 case STATEMENT_ERROR:
4778                 case STATEMENT_EMPTY:
4779                 case STATEMENT_ASM:
4780                         next = stmt->base.next;
4781                         break;
4782
4783                 case STATEMENT_DECLARATION: {
4784                         declaration_statement_t const *const decl = &stmt->declaration;
4785                         entity_t                const *      ent  = decl->declarations_begin;
4786                         entity_t                const *const last_decl = decl->declarations_end;
4787                         if (ent != NULL) {
4788                                 for (;; ent = ent->base.next) {
4789                                         if (ent->kind                 == ENTITY_VARIABLE &&
4790                                             ent->variable.initializer != NULL            &&
4791                                             !initializer_returns(ent->variable.initializer)) {
4792                                                 return;
4793                                         }
4794                                         if (ent == last_decl)
4795                                                 break;
4796                                 }
4797                         }
4798                         next = stmt->base.next;
4799                         break;
4800                 }
4801
4802                 case STATEMENT_COMPOUND:
4803                         next = stmt->compound.statements;
4804                         if (next == NULL)
4805                                 next = stmt->base.next;
4806                         break;
4807
4808                 case STATEMENT_RETURN: {
4809                         expression_t const *const val = stmt->returns.value;
4810                         if (val == NULL || expression_returns(val))
4811                                 noreturn_candidate = false;
4812                         return;
4813                 }
4814
4815                 case STATEMENT_IF: {
4816                         if_statement_t const *const ifs  = &stmt->ifs;
4817                         expression_t   const *const cond = ifs->condition;
4818
4819                         if (!expression_returns(cond))
4820                                 return;
4821
4822                         int const val = determine_truth(cond);
4823
4824                         if (val >= 0)
4825                                 check_reachable(ifs->true_statement);
4826
4827                         if (val > 0)
4828                                 return;
4829
4830                         if (ifs->false_statement != NULL) {
4831                                 check_reachable(ifs->false_statement);
4832                                 return;
4833                         }
4834
4835                         next = stmt->base.next;
4836                         break;
4837                 }
4838
4839                 case STATEMENT_SWITCH: {
4840                         switch_statement_t const *const switchs = &stmt->switchs;
4841                         expression_t       const *const expr    = switchs->expression;
4842
4843                         if (!expression_returns(expr))
4844                                 return;
4845
4846                         if (is_constant_expression(expr) == EXPR_CLASS_CONSTANT) {
4847                                 long                    const val      = fold_constant_to_int(expr);
4848                                 case_label_statement_t *      defaults = NULL;
4849                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
4850                                         if (i->expression == NULL) {
4851                                                 defaults = i;
4852                                                 continue;
4853                                         }
4854
4855                                         if (i->first_case <= val && val <= i->last_case) {
4856                                                 check_reachable((statement_t*)i);
4857                                                 return;
4858                                         }
4859                                 }
4860
4861                                 if (defaults != NULL) {
4862                                         check_reachable((statement_t*)defaults);
4863                                         return;
4864                                 }
4865                         } else {
4866                                 bool has_default = false;
4867                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
4868                                         if (i->expression == NULL)
4869                                                 has_default = true;
4870
4871                                         check_reachable((statement_t*)i);
4872                                 }
4873
4874                                 if (has_default)
4875                                         return;
4876                         }
4877
4878                         next = stmt->base.next;
4879                         break;
4880                 }
4881
4882                 case STATEMENT_EXPRESSION: {
4883                         /* Check for noreturn function call */
4884                         expression_t const *const expr = stmt->expression.expression;
4885                         if (!expression_returns(expr))
4886                                 return;
4887
4888                         next = stmt->base.next;
4889                         break;
4890                 }
4891
4892                 case STATEMENT_CONTINUE:
4893                         for (statement_t *parent = stmt;;) {
4894                                 parent = parent->base.parent;
4895                                 if (parent == NULL) /* continue not within loop */
4896                                         return;
4897
4898                                 next = parent;
4899                                 switch (parent->kind) {
4900                                         case STATEMENT_WHILE:    goto continue_while;
4901                                         case STATEMENT_DO_WHILE: goto continue_do_while;
4902                                         case STATEMENT_FOR:      goto continue_for;
4903
4904                                         default: break;
4905                                 }
4906                         }
4907
4908                 case STATEMENT_BREAK:
4909                         for (statement_t *parent = stmt;;) {
4910                                 parent = parent->base.parent;
4911                                 if (parent == NULL) /* break not within loop/switch */
4912                                         return;
4913
4914                                 switch (parent->kind) {
4915                                         case STATEMENT_SWITCH:
4916                                         case STATEMENT_WHILE:
4917                                         case STATEMENT_DO_WHILE:
4918                                         case STATEMENT_FOR:
4919                                                 last = parent;
4920                                                 next = parent->base.next;
4921                                                 goto found_break_parent;
4922
4923                                         default: break;
4924                                 }
4925                         }
4926 found_break_parent:
4927                         break;
4928
4929                 case STATEMENT_COMPUTED_GOTO: {
4930                         if (!expression_returns(stmt->computed_goto.expression))
4931                                 return;
4932
4933                         statement_t *parent = stmt->base.parent;
4934                         if (parent == NULL) /* top level goto */
4935                                 return;
4936                         next = parent;
4937                         break;
4938                 }
4939
4940                 case STATEMENT_GOTO:
4941                         next = stmt->gotos.label->statement;
4942                         if (next == NULL) /* missing label */
4943                                 return;
4944                         break;
4945
4946                 case STATEMENT_LABEL:
4947                         next = stmt->label.statement;
4948                         break;
4949
4950                 case STATEMENT_CASE_LABEL:
4951                         next = stmt->case_label.statement;
4952                         break;
4953
4954                 case STATEMENT_WHILE: {
4955                         while_statement_t const *const whiles = &stmt->whiles;
4956                         expression_t      const *const cond   = whiles->condition;
4957
4958                         if (!expression_returns(cond))
4959                                 return;
4960
4961                         int const val = determine_truth(cond);
4962
4963                         if (val >= 0)
4964                                 check_reachable(whiles->body);
4965
4966                         if (val > 0)
4967                                 return;
4968
4969                         next = stmt->base.next;
4970                         break;
4971                 }
4972
4973                 case STATEMENT_DO_WHILE:
4974                         next = stmt->do_while.body;
4975                         break;
4976
4977                 case STATEMENT_FOR: {
4978                         for_statement_t *const fors = &stmt->fors;
4979
4980                         if (fors->condition_reachable)
4981                                 return;
4982                         fors->condition_reachable = true;
4983
4984                         expression_t const *const cond = fors->condition;
4985
4986                         int val;
4987                         if (cond == NULL) {
4988                                 val = 1;
4989                         } else if (expression_returns(cond)) {
4990                                 val = determine_truth(cond);
4991                         } else {
4992                                 return;
4993                         }
4994
4995                         if (val >= 0)
4996                                 check_reachable(fors->body);
4997
4998                         if (val > 0)
4999                                 return;
5000
5001                         next = stmt->base.next;
5002                         break;
5003                 }
5004
5005                 case STATEMENT_MS_TRY: {
5006                         ms_try_statement_t const *const ms_try = &stmt->ms_try;
5007                         check_reachable(ms_try->try_statement);
5008                         next = ms_try->final_statement;
5009                         break;
5010                 }
5011
5012                 case STATEMENT_LEAVE: {
5013                         statement_t *parent = stmt;
5014                         for (;;) {
5015                                 parent = parent->base.parent;
5016                                 if (parent == NULL) /* __leave not within __try */
5017                                         return;
5018
5019                                 if (parent->kind == STATEMENT_MS_TRY) {
5020                                         last = parent;
5021                                         next = parent->ms_try.final_statement;
5022                                         break;
5023                                 }
5024                         }
5025                         break;
5026                 }
5027
5028                 default:
5029                         panic("invalid statement kind");
5030         }
5031
5032         while (next == NULL) {
5033                 next = last->base.parent;
5034                 if (next == NULL) {
5035                         noreturn_candidate = false;
5036
5037                         type_t *const type = skip_typeref(current_function->base.type);
5038                         assert(is_type_function(type));
5039                         type_t *const ret  = skip_typeref(type->function.return_type);
5040                         if (!is_type_void(ret) &&
5041                             is_type_valid(ret) &&
5042                             !is_sym_main(current_function->base.base.symbol)) {
5043                                 source_position_t const *const pos = &stmt->base.source_position;
5044                                 warningf(WARN_RETURN_TYPE, pos, "control reaches end of non-void function");
5045                         }
5046                         return;
5047                 }
5048
5049                 switch (next->kind) {
5050                         case STATEMENT_ERROR:
5051                         case STATEMENT_EMPTY:
5052                         case STATEMENT_DECLARATION:
5053                         case STATEMENT_EXPRESSION:
5054                         case STATEMENT_ASM:
5055                         case STATEMENT_RETURN:
5056                         case STATEMENT_CONTINUE:
5057                         case STATEMENT_BREAK:
5058                         case STATEMENT_COMPUTED_GOTO:
5059                         case STATEMENT_GOTO:
5060                         case STATEMENT_LEAVE:
5061                                 panic("invalid control flow in function");
5062
5063                         case STATEMENT_COMPOUND:
5064                                 if (next->compound.stmt_expr) {
5065                                         reaches_end = true;
5066                                         return;
5067                                 }
5068                                 /* FALLTHROUGH */
5069                         case STATEMENT_IF:
5070                         case STATEMENT_SWITCH:
5071                         case STATEMENT_LABEL:
5072                         case STATEMENT_CASE_LABEL:
5073                                 last = next;
5074                                 next = next->base.next;
5075                                 break;
5076
5077                         case STATEMENT_WHILE: {
5078 continue_while:
5079                                 if (next->base.reachable)
5080                                         return;
5081                                 next->base.reachable = true;
5082
5083                                 while_statement_t const *const whiles = &next->whiles;
5084                                 expression_t      const *const cond   = whiles->condition;
5085
5086                                 if (!expression_returns(cond))
5087                                         return;
5088
5089                                 int const val = determine_truth(cond);
5090
5091                                 if (val >= 0)
5092                                         check_reachable(whiles->body);
5093
5094                                 if (val > 0)
5095                                         return;
5096
5097                                 last = next;
5098                                 next = next->base.next;
5099                                 break;
5100                         }
5101
5102                         case STATEMENT_DO_WHILE: {
5103 continue_do_while:
5104                                 if (next->base.reachable)
5105                                         return;
5106                                 next->base.reachable = true;
5107
5108                                 do_while_statement_t const *const dw   = &next->do_while;
5109                                 expression_t         const *const cond = dw->condition;
5110
5111                                 if (!expression_returns(cond))
5112                                         return;
5113
5114                                 int const val = determine_truth(cond);
5115
5116                                 if (val >= 0)
5117                                         check_reachable(dw->body);
5118
5119                                 if (val > 0)
5120                                         return;
5121
5122                                 last = next;
5123                                 next = next->base.next;
5124                                 break;
5125                         }
5126
5127                         case STATEMENT_FOR: {
5128 continue_for:;
5129                                 for_statement_t *const fors = &next->fors;
5130
5131                                 fors->step_reachable = true;
5132
5133                                 if (fors->condition_reachable)
5134                                         return;
5135                                 fors->condition_reachable = true;
5136
5137                                 expression_t const *const cond = fors->condition;
5138
5139                                 int val;
5140                                 if (cond == NULL) {
5141                                         val = 1;
5142                                 } else if (expression_returns(cond)) {
5143                                         val = determine_truth(cond);
5144                                 } else {
5145                                         return;
5146                                 }
5147
5148                                 if (val >= 0)
5149                                         check_reachable(fors->body);
5150
5151                                 if (val > 0)
5152                                         return;
5153
5154                                 last = next;
5155                                 next = next->base.next;
5156                                 break;
5157                         }
5158
5159                         case STATEMENT_MS_TRY:
5160                                 last = next;
5161                                 next = next->ms_try.final_statement;
5162                                 break;
5163                 }
5164         }
5165
5166         check_reachable(next);
5167 }
5168
5169 static void check_unreachable(statement_t* const stmt, void *const env)
5170 {
5171         (void)env;
5172
5173         switch (stmt->kind) {
5174                 case STATEMENT_DO_WHILE:
5175                         if (!stmt->base.reachable) {
5176                                 expression_t const *const cond = stmt->do_while.condition;
5177                                 if (determine_truth(cond) >= 0) {
5178                                         source_position_t const *const pos = &cond->base.source_position;
5179                                         warningf(WARN_UNREACHABLE_CODE, pos, "condition of do-while-loop is unreachable");
5180                                 }
5181                         }
5182                         return;
5183
5184                 case STATEMENT_FOR: {
5185                         for_statement_t const* const fors = &stmt->fors;
5186
5187                         // if init and step are unreachable, cond is unreachable, too
5188                         if (!stmt->base.reachable && !fors->step_reachable) {
5189                                 goto warn_unreachable;
5190                         } else {
5191                                 if (!stmt->base.reachable && fors->initialisation != NULL) {
5192                                         source_position_t const *const pos = &fors->initialisation->base.source_position;
5193                                         warningf(WARN_UNREACHABLE_CODE, pos, "initialisation of for-statement is unreachable");
5194                                 }
5195
5196                                 if (!fors->condition_reachable && fors->condition != NULL) {
5197                                         source_position_t const *const pos = &fors->condition->base.source_position;
5198                                         warningf(WARN_UNREACHABLE_CODE, pos, "condition of for-statement is unreachable");
5199                                 }
5200
5201                                 if (!fors->step_reachable && fors->step != NULL) {
5202                                         source_position_t const *const pos = &fors->step->base.source_position;
5203                                         warningf(WARN_UNREACHABLE_CODE, pos, "step of for-statement is unreachable");
5204                                 }
5205                         }
5206                         return;
5207                 }
5208
5209                 case STATEMENT_COMPOUND:
5210                         if (stmt->compound.statements != NULL)
5211                                 return;
5212                         goto warn_unreachable;
5213
5214                 case STATEMENT_DECLARATION: {
5215                         /* Only warn if there is at least one declarator with an initializer.
5216                          * This typically occurs in switch statements. */
5217                         declaration_statement_t const *const decl = &stmt->declaration;
5218                         entity_t                const *      ent  = decl->declarations_begin;
5219                         entity_t                const *const last = decl->declarations_end;
5220                         if (ent != NULL) {
5221                                 for (;; ent = ent->base.next) {
5222                                         if (ent->kind                 == ENTITY_VARIABLE &&
5223                                                         ent->variable.initializer != NULL) {
5224                                                 goto warn_unreachable;
5225                                         }
5226                                         if (ent == last)
5227                                                 return;
5228                                 }
5229                         }
5230                 }
5231
5232                 default:
5233 warn_unreachable:
5234                         if (!stmt->base.reachable) {
5235                                 source_position_t const *const pos = &stmt->base.source_position;
5236                                 warningf(WARN_UNREACHABLE_CODE, pos, "statement is unreachable");
5237                         }
5238                         return;
5239         }
5240 }
5241
5242 static bool is_main(entity_t *entity)
5243 {
5244         static symbol_t *sym_main = NULL;
5245         if (sym_main == NULL) {
5246                 sym_main = symbol_table_insert("main");
5247         }
5248
5249         if (entity->base.symbol != sym_main)
5250                 return false;
5251         /* must be in outermost scope */
5252         if (entity->base.parent_scope != file_scope)
5253                 return false;
5254
5255         return true;
5256 }
5257
5258 static void prepare_main_collect2(entity_t*);
5259
5260 static void parse_external_declaration(void)
5261 {
5262         /* function-definitions and declarations both start with declaration
5263          * specifiers */
5264         add_anchor_token(';');
5265         declaration_specifiers_t specifiers;
5266         parse_declaration_specifiers(&specifiers);
5267         rem_anchor_token(';');
5268
5269         /* must be a declaration */
5270         if (token.kind == ';') {
5271                 parse_anonymous_declaration_rest(&specifiers);
5272                 return;
5273         }
5274
5275         add_anchor_token(',');
5276         add_anchor_token('=');
5277         add_anchor_token(';');
5278         add_anchor_token('{');
5279
5280         /* declarator is common to both function-definitions and declarations */
5281         entity_t *ndeclaration = parse_declarator(&specifiers, DECL_FLAGS_NONE);
5282
5283         rem_anchor_token('{');
5284         rem_anchor_token(';');
5285         rem_anchor_token('=');
5286         rem_anchor_token(',');
5287
5288         /* must be a declaration */
5289         switch (token.kind) {
5290                 case ',':
5291                 case ';':
5292                 case '=':
5293                         parse_declaration_rest(ndeclaration, &specifiers, record_entity,
5294                                         DECL_FLAGS_NONE);
5295                         return;
5296         }
5297
5298         /* must be a function definition */
5299         parse_kr_declaration_list(ndeclaration);
5300
5301         if (token.kind != '{') {
5302                 parse_error_expected("while parsing function definition", '{', NULL);
5303                 eat_until_matching_token(';');
5304                 return;
5305         }
5306
5307         assert(is_declaration(ndeclaration));
5308         type_t *const orig_type = ndeclaration->declaration.type;
5309         type_t *      type      = skip_typeref(orig_type);
5310
5311         if (!is_type_function(type)) {
5312                 if (is_type_valid(type)) {
5313                         errorf(HERE, "declarator '%#N' has a body but is not a function type", ndeclaration);
5314                 }
5315                 eat_block();
5316                 return;
5317         }
5318
5319         source_position_t const *const pos = &ndeclaration->base.source_position;
5320         if (is_typeref(orig_type)) {
5321                 /* §6.9.1:2 */
5322                 errorf(pos, "type of function definition '%#N' is a typedef", ndeclaration);
5323         }
5324
5325         if (is_type_compound(skip_typeref(type->function.return_type))) {
5326                 warningf(WARN_AGGREGATE_RETURN, pos, "'%N' returns an aggregate", ndeclaration);
5327         }
5328         if (type->function.unspecified_parameters) {
5329                 warningf(WARN_OLD_STYLE_DEFINITION, pos, "old-style definition of '%N'", ndeclaration);
5330         } else {
5331                 warningf(WARN_TRADITIONAL, pos, "traditional C rejects ISO C style definition of '%N'", ndeclaration);
5332         }
5333
5334         /* §6.7.5.3:14 a function definition with () means no
5335          * parameters (and not unspecified parameters) */
5336         if (type->function.unspecified_parameters &&
5337                         type->function.parameters == NULL) {
5338                 type_t *copy                          = duplicate_type(type);
5339                 copy->function.unspecified_parameters = false;
5340                 type                                  = identify_new_type(copy);
5341
5342                 ndeclaration->declaration.type = type;
5343         }
5344
5345         entity_t *const entity = record_entity(ndeclaration, true);
5346         assert(entity->kind == ENTITY_FUNCTION);
5347         assert(ndeclaration->kind == ENTITY_FUNCTION);
5348
5349         function_t *const function = &entity->function;
5350         if (ndeclaration != entity) {
5351                 function->parameters = ndeclaration->function.parameters;
5352         }
5353
5354         PUSH_SCOPE(&function->parameters);
5355
5356         entity_t *parameter = function->parameters.entities;
5357         for (; parameter != NULL; parameter = parameter->base.next) {
5358                 if (parameter->base.parent_scope == &ndeclaration->function.parameters) {
5359                         parameter->base.parent_scope = current_scope;
5360                 }
5361                 assert(parameter->base.parent_scope == NULL
5362                                 || parameter->base.parent_scope == current_scope);
5363                 parameter->base.parent_scope = current_scope;
5364                 if (parameter->base.symbol == NULL) {
5365                         errorf(&parameter->base.source_position, "parameter name omitted");
5366                         continue;
5367                 }
5368                 environment_push(parameter);
5369         }
5370
5371         if (function->statement != NULL) {
5372                 parser_error_multiple_definition(entity, HERE);
5373                 eat_block();
5374         } else {
5375                 /* parse function body */
5376                 int         label_stack_top      = label_top();
5377                 function_t *old_current_function = current_function;
5378                 current_function                 = function;
5379                 PUSH_CURRENT_ENTITY(entity);
5380                 PUSH_PARENT(NULL);
5381
5382                 goto_first   = NULL;
5383                 goto_anchor  = &goto_first;
5384                 label_first  = NULL;
5385                 label_anchor = &label_first;
5386
5387                 statement_t *const body = parse_compound_statement(false);
5388                 function->statement = body;
5389                 first_err = true;
5390                 check_labels();
5391                 check_declarations();
5392                 if (is_warn_on(WARN_RETURN_TYPE)      ||
5393                     is_warn_on(WARN_UNREACHABLE_CODE) ||
5394                     (is_warn_on(WARN_MISSING_NORETURN) && !(function->base.modifiers & DM_NORETURN))) {
5395                         noreturn_candidate = true;
5396                         check_reachable(body);
5397                         if (is_warn_on(WARN_UNREACHABLE_CODE))
5398                                 walk_statements(body, check_unreachable, NULL);
5399                         if (noreturn_candidate &&
5400                             !(function->base.modifiers & DM_NORETURN)) {
5401                                 source_position_t const *const pos = &body->base.source_position;
5402                                 warningf(WARN_MISSING_NORETURN, pos, "function '%#N' is candidate for attribute 'noreturn'", entity);
5403                         }
5404                 }
5405
5406                 if (is_main(entity) && enable_main_collect2_hack)
5407                         prepare_main_collect2(entity);
5408
5409                 POP_CURRENT_ENTITY();
5410                 POP_PARENT();
5411                 assert(current_function == function);
5412                 current_function = old_current_function;
5413                 label_pop_to(label_stack_top);
5414         }
5415
5416         POP_SCOPE();
5417 }
5418
5419 static entity_t *find_compound_entry(compound_t *compound, symbol_t *symbol)
5420 {
5421         entity_t *iter = compound->members.entities;
5422         for (; iter != NULL; iter = iter->base.next) {
5423                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5424                         continue;
5425
5426                 if (iter->base.symbol == symbol) {
5427                         return iter;
5428                 } else if (iter->base.symbol == NULL) {
5429                         /* search in anonymous structs and unions */
5430                         type_t *type = skip_typeref(iter->declaration.type);
5431                         if (is_type_compound(type)) {
5432                                 if (find_compound_entry(type->compound.compound, symbol)
5433                                                 != NULL)
5434                                         return iter;
5435                         }
5436                         continue;
5437                 }
5438         }
5439
5440         return NULL;
5441 }
5442
5443 static void check_deprecated(const source_position_t *source_position,
5444                              const entity_t *entity)
5445 {
5446         if (!is_declaration(entity))
5447                 return;
5448         if ((entity->declaration.modifiers & DM_DEPRECATED) == 0)
5449                 return;
5450
5451         source_position_t const *const epos = &entity->base.source_position;
5452         char              const *const msg  = get_deprecated_string(entity->declaration.attributes);
5453         if (msg != NULL) {
5454                 warningf(WARN_DEPRECATED_DECLARATIONS, source_position, "'%N' is deprecated (declared %P): \"%s\"", entity, epos, msg);
5455         } else {
5456                 warningf(WARN_DEPRECATED_DECLARATIONS, source_position, "'%N' is deprecated (declared %P)", entity, epos);
5457         }
5458 }
5459
5460
5461 static expression_t *create_select(const source_position_t *pos,
5462                                    expression_t *addr,
5463                                    type_qualifiers_t qualifiers,
5464                                                                    entity_t *entry)
5465 {
5466         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
5467
5468         check_deprecated(pos, entry);
5469
5470         expression_t *select          = allocate_expression_zero(EXPR_SELECT);
5471         select->select.compound       = addr;
5472         select->select.compound_entry = entry;
5473
5474         type_t *entry_type = entry->declaration.type;
5475         type_t *res_type   = get_qualified_type(entry_type, qualifiers);
5476
5477         /* bitfields need special treatment */
5478         if (entry->compound_member.bitfield) {
5479                 unsigned bit_size = entry->compound_member.bit_size;
5480                 /* if fewer bits than an int, convert to int (see §6.3.1.1) */
5481                 if (bit_size < get_atomic_type_size(ATOMIC_TYPE_INT) * BITS_PER_BYTE) {
5482                         res_type = type_int;
5483                 }
5484         }
5485
5486         /* we always do the auto-type conversions; the & and sizeof parser contains
5487          * code to revert this! */
5488         select->base.type = automatic_type_conversion(res_type);
5489
5490
5491         return select;
5492 }
5493
5494 /**
5495  * Find entry with symbol in compound. Search anonymous structs and unions and
5496  * creates implicit select expressions for them.
5497  * Returns the adress for the innermost compound.
5498  */
5499 static expression_t *find_create_select(const source_position_t *pos,
5500                                         expression_t *addr,
5501                                         type_qualifiers_t qualifiers,
5502                                         compound_t *compound, symbol_t *symbol)
5503 {
5504         entity_t *iter = compound->members.entities;
5505         for (; iter != NULL; iter = iter->base.next) {
5506                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5507                         continue;
5508
5509                 symbol_t *iter_symbol = iter->base.symbol;
5510                 if (iter_symbol == NULL) {
5511                         type_t *type = iter->declaration.type;
5512                         if (type->kind != TYPE_COMPOUND_STRUCT
5513                                         && type->kind != TYPE_COMPOUND_UNION)
5514                                 continue;
5515
5516                         compound_t *sub_compound = type->compound.compound;
5517
5518                         if (find_compound_entry(sub_compound, symbol) == NULL)
5519                                 continue;
5520
5521                         expression_t *sub_addr = create_select(pos, addr, qualifiers, iter);
5522                         sub_addr->base.source_position = *pos;
5523                         sub_addr->base.implicit        = true;
5524                         return find_create_select(pos, sub_addr, qualifiers, sub_compound,
5525                                                   symbol);
5526                 }
5527
5528                 if (iter_symbol == symbol) {
5529                         return create_select(pos, addr, qualifiers, iter);
5530                 }
5531         }
5532
5533         return NULL;
5534 }
5535
5536 static void parse_bitfield_member(entity_t *entity)
5537 {
5538         eat(':');
5539
5540         expression_t *size = parse_constant_expression();
5541         long          size_long;
5542
5543         assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5544         type_t *type = entity->declaration.type;
5545         if (!is_type_integer(skip_typeref(type))) {
5546                 errorf(HERE, "bitfield base type '%T' is not an integer type",
5547                            type);
5548         }
5549
5550         if (is_constant_expression(size) != EXPR_CLASS_CONSTANT) {
5551                 /* error already reported by parse_constant_expression */
5552                 size_long = get_type_size(type) * 8;
5553         } else {
5554                 size_long = fold_constant_to_int(size);
5555
5556                 const symbol_t *symbol = entity->base.symbol;
5557                 const symbol_t *user_symbol
5558                         = symbol == NULL ? sym_anonymous : symbol;
5559                 unsigned bit_size = get_type_size(type) * 8;
5560                 if (size_long < 0) {
5561                         errorf(HERE, "negative width in bit-field '%Y'", user_symbol);
5562                 } else if (size_long == 0 && symbol != NULL) {
5563                         errorf(HERE, "zero width for bit-field '%Y'", user_symbol);
5564                 } else if (bit_size > 0 && (unsigned)size_long > bit_size) {
5565                         errorf(HERE, "width of bitfield '%Y' exceeds its type",
5566                                    user_symbol);
5567                 } else {
5568                         /* hope that people don't invent crazy types with more bits
5569                          * than our struct can hold */
5570                         assert(size_long <
5571                                    (1 << sizeof(entity->compound_member.bit_size)*8));
5572                 }
5573         }
5574
5575         entity->compound_member.bitfield = true;
5576         entity->compound_member.bit_size = (unsigned char)size_long;
5577 }
5578
5579 static void parse_compound_declarators(compound_t *compound,
5580                 const declaration_specifiers_t *specifiers)
5581 {
5582         add_anchor_token(';');
5583         add_anchor_token(',');
5584         do {
5585                 entity_t *entity;
5586
5587                 if (token.kind == ':') {
5588                         /* anonymous bitfield */
5589                         type_t *type = specifiers->type;
5590                         entity_t *const entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER, NAMESPACE_NORMAL, NULL, HERE);
5591                         entity->declaration.declared_storage_class = STORAGE_CLASS_NONE;
5592                         entity->declaration.storage_class          = STORAGE_CLASS_NONE;
5593                         entity->declaration.type                   = type;
5594
5595                         parse_bitfield_member(entity);
5596
5597                         attribute_t  *attributes = parse_attributes(NULL);
5598                         attribute_t **anchor     = &attributes;
5599                         while (*anchor != NULL)
5600                                 anchor = &(*anchor)->next;
5601                         *anchor = specifiers->attributes;
5602                         if (attributes != NULL) {
5603                                 handle_entity_attributes(attributes, entity);
5604                         }
5605                         entity->declaration.attributes = attributes;
5606
5607                         append_entity(&compound->members, entity);
5608                 } else {
5609                         entity = parse_declarator(specifiers,
5610                                         DECL_MAY_BE_ABSTRACT | DECL_CREATE_COMPOUND_MEMBER);
5611                         source_position_t const *const pos = &entity->base.source_position;
5612                         if (entity->kind == ENTITY_TYPEDEF) {
5613                                 errorf(pos, "typedef not allowed as compound member");
5614                         } else {
5615                                 assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5616
5617                                 /* make sure we don't define a symbol multiple times */
5618                                 symbol_t *symbol = entity->base.symbol;
5619                                 if (symbol != NULL) {
5620                                         entity_t *prev = find_compound_entry(compound, symbol);
5621                                         if (prev != NULL) {
5622                                                 source_position_t const *const ppos = &prev->base.source_position;
5623                                                 errorf(pos, "multiple declarations of symbol '%Y' (declared %P)", symbol, ppos);
5624                                         }
5625                                 }
5626
5627                                 if (token.kind == ':') {
5628                                         parse_bitfield_member(entity);
5629
5630                                         attribute_t *attributes = parse_attributes(NULL);
5631                                         handle_entity_attributes(attributes, entity);
5632                                 } else {
5633                                         type_t *orig_type = entity->declaration.type;
5634                                         type_t *type      = skip_typeref(orig_type);
5635                                         if (is_type_function(type)) {
5636                                                 errorf(pos, "'%N' must not have function type '%T'", entity, orig_type);
5637                                         } else if (is_type_incomplete(type)) {
5638                                                 /* §6.7.2.1:16 flexible array member */
5639                                                 if (!is_type_array(type)       ||
5640                                                                 token.kind          != ';' ||
5641                                                                 look_ahead(1)->kind != '}') {
5642                                                         errorf(pos, "'%N' has incomplete type '%T'", entity, orig_type);
5643                                                 } else if (compound->members.entities == NULL) {
5644                                                         errorf(pos, "flexible array member in otherwise empty struct");
5645                                                 }
5646                                         }
5647                                 }
5648
5649                                 append_entity(&compound->members, entity);
5650                         }
5651                 }
5652         } while (next_if(','));
5653         rem_anchor_token(',');
5654         rem_anchor_token(';');
5655         expect(';');
5656
5657         anonymous_entity = NULL;
5658 }
5659
5660 static void parse_compound_type_entries(compound_t *compound)
5661 {
5662         eat('{');
5663         add_anchor_token('}');
5664
5665         for (;;) {
5666                 switch (token.kind) {
5667                         DECLARATION_START
5668                         case T___extension__:
5669                         case T_IDENTIFIER: {
5670                                 PUSH_EXTENSION();
5671                                 declaration_specifiers_t specifiers;
5672                                 parse_declaration_specifiers(&specifiers);
5673                                 parse_compound_declarators(compound, &specifiers);
5674                                 POP_EXTENSION();
5675                                 break;
5676                         }
5677
5678                         default:
5679                                 rem_anchor_token('}');
5680                                 expect('}');
5681                                 /* §6.7.2.1:7 */
5682                                 compound->complete = true;
5683                                 return;
5684                 }
5685         }
5686 }
5687
5688 static type_t *parse_typename(void)
5689 {
5690         declaration_specifiers_t specifiers;
5691         parse_declaration_specifiers(&specifiers);
5692         if (specifiers.storage_class != STORAGE_CLASS_NONE
5693                         || specifiers.thread_local) {
5694                 /* TODO: improve error message, user does probably not know what a
5695                  * storage class is...
5696                  */
5697                 errorf(&specifiers.source_position, "typename must not have a storage class");
5698         }
5699
5700         type_t *result = parse_abstract_declarator(specifiers.type);
5701
5702         return result;
5703 }
5704
5705
5706
5707
5708 typedef expression_t* (*parse_expression_function)(void);
5709 typedef expression_t* (*parse_expression_infix_function)(expression_t *left);
5710
5711 typedef struct expression_parser_function_t expression_parser_function_t;
5712 struct expression_parser_function_t {
5713         parse_expression_function        parser;
5714         precedence_t                     infix_precedence;
5715         parse_expression_infix_function  infix_parser;
5716 };
5717
5718 static expression_parser_function_t expression_parsers[T_LAST_TOKEN];
5719
5720 static type_t *get_string_type(void)
5721 {
5722         return is_warn_on(WARN_WRITE_STRINGS) ? type_const_char_ptr : type_char_ptr;
5723 }
5724
5725 static type_t *get_wide_string_type(void)
5726 {
5727         return is_warn_on(WARN_WRITE_STRINGS) ? type_const_wchar_t_ptr : type_wchar_t_ptr;
5728 }
5729
5730 /**
5731  * Parse a string constant.
5732  */
5733 static expression_t *parse_string_literal(void)
5734 {
5735         source_position_t begin   = token.base.source_position;
5736         string_t          res     = token.string.string;
5737         bool              is_wide = (token.kind == T_WIDE_STRING_LITERAL);
5738
5739         next_token();
5740         while (token.kind == T_STRING_LITERAL
5741                         || token.kind == T_WIDE_STRING_LITERAL) {
5742                 warn_string_concat(&token.base.source_position);
5743                 res = concat_strings(&res, &token.string.string);
5744                 next_token();
5745                 is_wide |= token.kind == T_WIDE_STRING_LITERAL;
5746         }
5747
5748         expression_t *literal;
5749         if (is_wide) {
5750                 literal = allocate_expression_zero(EXPR_WIDE_STRING_LITERAL);
5751                 literal->base.type = get_wide_string_type();
5752         } else {
5753                 literal = allocate_expression_zero(EXPR_STRING_LITERAL);
5754                 literal->base.type = get_string_type();
5755         }
5756         literal->base.source_position = begin;
5757         literal->literal.value        = res;
5758
5759         return literal;
5760 }
5761
5762 /**
5763  * Parse a boolean constant.
5764  */
5765 static expression_t *parse_boolean_literal(bool value)
5766 {
5767         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_BOOLEAN);
5768         literal->base.type           = type_bool;
5769         literal->literal.value.begin = value ? "true" : "false";
5770         literal->literal.value.size  = value ? 4 : 5;
5771
5772         next_token();
5773         return literal;
5774 }
5775
5776 static void warn_traditional_suffix(void)
5777 {
5778         warningf(WARN_TRADITIONAL, HERE, "traditional C rejects the '%S' suffix",
5779                  &token.number.suffix);
5780 }
5781
5782 static void check_integer_suffix(void)
5783 {
5784         const string_t *suffix = &token.number.suffix;
5785         if (suffix->size == 0)
5786                 return;
5787
5788         bool not_traditional = false;
5789         const char *c = suffix->begin;
5790         if (*c == 'l' || *c == 'L') {
5791                 ++c;
5792                 if (*c == *(c-1)) {
5793                         not_traditional = true;
5794                         ++c;
5795                         if (*c == 'u' || *c == 'U') {
5796                                 ++c;
5797                         }
5798                 } else if (*c == 'u' || *c == 'U') {
5799                         not_traditional = true;
5800                         ++c;
5801                 }
5802         } else if (*c == 'u' || *c == 'U') {
5803                 not_traditional = true;
5804                 ++c;
5805                 if (*c == 'l' || *c == 'L') {
5806                         ++c;
5807                         if (*c == *(c-1)) {
5808                                 ++c;
5809                         }
5810                 }
5811         }
5812         if (*c != '\0') {
5813                 errorf(&token.base.source_position,
5814                        "invalid suffix '%S' on integer constant", suffix);
5815         } else if (not_traditional) {
5816                 warn_traditional_suffix();
5817         }
5818 }
5819
5820 static type_t *check_floatingpoint_suffix(void)
5821 {
5822         const string_t *suffix = &token.number.suffix;
5823         type_t         *type   = type_double;
5824         if (suffix->size == 0)
5825                 return type;
5826
5827         bool not_traditional = false;
5828         const char *c = suffix->begin;
5829         if (*c == 'f' || *c == 'F') {
5830                 ++c;
5831                 type = type_float;
5832         } else if (*c == 'l' || *c == 'L') {
5833                 ++c;
5834                 type = type_long_double;
5835         }
5836         if (*c != '\0') {
5837                 errorf(&token.base.source_position,
5838                        "invalid suffix '%S' on floatingpoint constant", suffix);
5839         } else if (not_traditional) {
5840                 warn_traditional_suffix();
5841         }
5842
5843         return type;
5844 }
5845
5846 /**
5847  * Parse an integer constant.
5848  */
5849 static expression_t *parse_number_literal(void)
5850 {
5851         expression_kind_t  kind;
5852         type_t            *type;
5853
5854         switch (token.kind) {
5855         case T_INTEGER:
5856                 kind = EXPR_LITERAL_INTEGER;
5857                 check_integer_suffix();
5858                 type = type_int;
5859                 break;
5860         case T_INTEGER_OCTAL:
5861                 kind = EXPR_LITERAL_INTEGER_OCTAL;
5862                 check_integer_suffix();
5863                 type = type_int;
5864                 break;
5865         case T_INTEGER_HEXADECIMAL:
5866                 kind = EXPR_LITERAL_INTEGER_HEXADECIMAL;
5867                 check_integer_suffix();
5868                 type = type_int;
5869                 break;
5870         case T_FLOATINGPOINT:
5871                 kind = EXPR_LITERAL_FLOATINGPOINT;
5872                 type = check_floatingpoint_suffix();
5873                 break;
5874         case T_FLOATINGPOINT_HEXADECIMAL:
5875                 kind = EXPR_LITERAL_FLOATINGPOINT_HEXADECIMAL;
5876                 type = check_floatingpoint_suffix();
5877                 break;
5878         default:
5879                 panic("unexpected token type in parse_number_literal");
5880         }
5881
5882         expression_t *literal = allocate_expression_zero(kind);
5883         literal->base.type      = type;
5884         literal->literal.value  = token.number.number;
5885         literal->literal.suffix = token.number.suffix;
5886         next_token();
5887
5888         /* integer type depends on the size of the number and the size
5889          * representable by the types. The backend/codegeneration has to determine
5890          * that
5891          */
5892         determine_literal_type(&literal->literal);
5893         return literal;
5894 }
5895
5896 /**
5897  * Parse a character constant.
5898  */
5899 static expression_t *parse_character_constant(void)
5900 {
5901         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_CHARACTER);
5902         literal->base.type     = c_mode & _CXX ? type_char : type_int;
5903         literal->literal.value = token.string.string;
5904
5905         size_t len = literal->literal.value.size;
5906         if (len > 1) {
5907                 if (!GNU_MODE && !(c_mode & _C99)) {
5908                         errorf(HERE, "more than 1 character in character constant");
5909                 } else {
5910                         literal->base.type = type_int;
5911                         warningf(WARN_MULTICHAR, HERE, "multi-character character constant");
5912                 }
5913         }
5914
5915         next_token();
5916         return literal;
5917 }
5918
5919 /**
5920  * Parse a wide character constant.
5921  */
5922 static expression_t *parse_wide_character_constant(void)
5923 {
5924         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_WIDE_CHARACTER);
5925         literal->base.type     = type_int;
5926         literal->literal.value = token.string.string;
5927
5928         size_t len = wstrlen(&literal->literal.value);
5929         if (len > 1) {
5930                 warningf(WARN_MULTICHAR, HERE, "multi-character character constant");
5931         }
5932
5933         next_token();
5934         return literal;
5935 }
5936
5937 static entity_t *create_implicit_function(symbol_t *symbol, source_position_t const *const pos)
5938 {
5939         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
5940         ntype->function.return_type            = type_int;
5941         ntype->function.unspecified_parameters = true;
5942         ntype->function.linkage                = LINKAGE_C;
5943         type_t *type                           = identify_new_type(ntype);
5944
5945         entity_t *const entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, symbol, pos);
5946         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
5947         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
5948         entity->declaration.type                   = type;
5949         entity->declaration.implicit               = true;
5950
5951         if (current_scope != NULL)
5952                 record_entity(entity, false);
5953
5954         return entity;
5955 }
5956
5957 /**
5958  * Performs automatic type cast as described in §6.3.2.1.
5959  *
5960  * @param orig_type  the original type
5961  */
5962 static type_t *automatic_type_conversion(type_t *orig_type)
5963 {
5964         type_t *type = skip_typeref(orig_type);
5965         if (is_type_array(type)) {
5966                 array_type_t *array_type   = &type->array;
5967                 type_t       *element_type = array_type->element_type;
5968                 unsigned      qualifiers   = array_type->base.qualifiers;
5969
5970                 return make_pointer_type(element_type, qualifiers);
5971         }
5972
5973         if (is_type_function(type)) {
5974                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
5975         }
5976
5977         return orig_type;
5978 }
5979
5980 /**
5981  * reverts the automatic casts of array to pointer types and function
5982  * to function-pointer types as defined §6.3.2.1
5983  */
5984 type_t *revert_automatic_type_conversion(const expression_t *expression)
5985 {
5986         switch (expression->kind) {
5987         case EXPR_REFERENCE: {
5988                 entity_t *entity = expression->reference.entity;
5989                 if (is_declaration(entity)) {
5990                         return entity->declaration.type;
5991                 } else if (entity->kind == ENTITY_ENUM_VALUE) {
5992                         return entity->enum_value.enum_type;
5993                 } else {
5994                         panic("no declaration or enum in reference");
5995                 }
5996         }
5997
5998         case EXPR_SELECT: {
5999                 entity_t *entity = expression->select.compound_entry;
6000                 assert(is_declaration(entity));
6001                 type_t   *type   = entity->declaration.type;
6002                 return get_qualified_type(type, expression->base.type->base.qualifiers);
6003         }
6004
6005         case EXPR_UNARY_DEREFERENCE: {
6006                 const expression_t *const value = expression->unary.value;
6007                 type_t             *const type  = skip_typeref(value->base.type);
6008                 if (!is_type_pointer(type))
6009                         return type_error_type;
6010                 return type->pointer.points_to;
6011         }
6012
6013         case EXPR_ARRAY_ACCESS: {
6014                 const expression_t *array_ref = expression->array_access.array_ref;
6015                 type_t             *type_left = skip_typeref(array_ref->base.type);
6016                 if (!is_type_pointer(type_left))
6017                         return type_error_type;
6018                 return type_left->pointer.points_to;
6019         }
6020
6021         case EXPR_STRING_LITERAL: {
6022                 size_t size = expression->string_literal.value.size;
6023                 return make_array_type(type_char, size, TYPE_QUALIFIER_NONE);
6024         }
6025
6026         case EXPR_WIDE_STRING_LITERAL: {
6027                 size_t size = wstrlen(&expression->string_literal.value);
6028                 return make_array_type(type_wchar_t, size, TYPE_QUALIFIER_NONE);
6029         }
6030
6031         case EXPR_COMPOUND_LITERAL:
6032                 return expression->compound_literal.type;
6033
6034         default:
6035                 break;
6036         }
6037         return expression->base.type;
6038 }
6039
6040 /**
6041  * Find an entity matching a symbol in a scope.
6042  * Uses current scope if scope is NULL
6043  */
6044 static entity_t *lookup_entity(const scope_t *scope, symbol_t *symbol,
6045                                namespace_tag_t namespc)
6046 {
6047         if (scope == NULL) {
6048                 return get_entity(symbol, namespc);
6049         }
6050
6051         /* we should optimize here, if scope grows above a certain size we should
6052            construct a hashmap here... */
6053         entity_t *entity = scope->entities;
6054         for ( ; entity != NULL; entity = entity->base.next) {
6055                 if (entity->base.symbol == symbol
6056                     && (namespace_tag_t)entity->base.namespc == namespc)
6057                         break;
6058         }
6059
6060         return entity;
6061 }
6062
6063 static entity_t *parse_qualified_identifier(void)
6064 {
6065         /* namespace containing the symbol */
6066         symbol_t          *symbol;
6067         source_position_t  pos;
6068         const scope_t     *lookup_scope = NULL;
6069
6070         if (next_if(T_COLONCOLON))
6071                 lookup_scope = &unit->scope;
6072
6073         entity_t *entity;
6074         while (true) {
6075                 symbol = expect_identifier("while parsing identifier", &pos);
6076                 if (!symbol)
6077                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6078
6079                 /* lookup entity */
6080                 entity = lookup_entity(lookup_scope, symbol, NAMESPACE_NORMAL);
6081
6082                 if (!next_if(T_COLONCOLON))
6083                         break;
6084
6085                 switch (entity->kind) {
6086                 case ENTITY_NAMESPACE:
6087                         lookup_scope = &entity->namespacee.members;
6088                         break;
6089                 case ENTITY_STRUCT:
6090                 case ENTITY_UNION:
6091                 case ENTITY_CLASS:
6092                         lookup_scope = &entity->compound.members;
6093                         break;
6094                 default:
6095                         errorf(&pos, "'%Y' must be a namespace, class, struct or union (but is a %s)",
6096                                symbol, get_entity_kind_name(entity->kind));
6097
6098                         /* skip further qualifications */
6099                         while (next_if(T_IDENTIFIER) && next_if(T_COLONCOLON)) {}
6100
6101                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6102                 }
6103         }
6104
6105         if (entity == NULL) {
6106                 if (!strict_mode && token.kind == '(') {
6107                         /* an implicitly declared function */
6108                         warningf(WARN_IMPLICIT_FUNCTION_DECLARATION, &pos,
6109                                  "implicit declaration of function '%Y'", symbol);
6110                         entity = create_implicit_function(symbol, &pos);
6111                 } else {
6112                         errorf(&pos, "unknown identifier '%Y' found.", symbol);
6113                         entity = create_error_entity(symbol, ENTITY_VARIABLE);
6114                 }
6115         }
6116
6117         return entity;
6118 }
6119
6120 static expression_t *parse_reference(void)
6121 {
6122         source_position_t const pos    = token.base.source_position;
6123         entity_t         *const entity = parse_qualified_identifier();
6124
6125         type_t *orig_type;
6126         if (is_declaration(entity)) {
6127                 orig_type = entity->declaration.type;
6128         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6129                 orig_type = entity->enum_value.enum_type;
6130         } else {
6131                 panic("expected declaration or enum value in reference");
6132         }
6133
6134         /* we always do the auto-type conversions; the & and sizeof parser contains
6135          * code to revert this! */
6136         type_t *type = automatic_type_conversion(orig_type);
6137
6138         expression_kind_t kind = EXPR_REFERENCE;
6139         if (entity->kind == ENTITY_ENUM_VALUE)
6140                 kind = EXPR_ENUM_CONSTANT;
6141
6142         expression_t *expression         = allocate_expression_zero(kind);
6143         expression->base.source_position = pos;
6144         expression->base.type            = type;
6145         expression->reference.entity     = entity;
6146
6147         /* this declaration is used */
6148         if (is_declaration(entity)) {
6149                 entity->declaration.used = true;
6150         }
6151
6152         if (entity->base.parent_scope != file_scope
6153                 && (current_function != NULL
6154                         && entity->base.parent_scope->depth < current_function->parameters.depth)
6155                 && (entity->kind == ENTITY_VARIABLE || entity->kind == ENTITY_PARAMETER)) {
6156                 if (entity->kind == ENTITY_VARIABLE) {
6157                         /* access of a variable from an outer function */
6158                         entity->variable.address_taken = true;
6159                 } else if (entity->kind == ENTITY_PARAMETER) {
6160                         entity->parameter.address_taken = true;
6161                 }
6162                 current_function->need_closure = true;
6163         }
6164
6165         check_deprecated(&pos, entity);
6166
6167         return expression;
6168 }
6169
6170 static bool semantic_cast(expression_t *cast)
6171 {
6172         expression_t            *expression      = cast->unary.value;
6173         type_t                  *orig_dest_type  = cast->base.type;
6174         type_t                  *orig_type_right = expression->base.type;
6175         type_t            const *dst_type        = skip_typeref(orig_dest_type);
6176         type_t            const *src_type        = skip_typeref(orig_type_right);
6177         source_position_t const *pos             = &cast->base.source_position;
6178
6179         /* §6.5.4 A (void) cast is explicitly permitted, more for documentation than for utility. */
6180         if (is_type_void(dst_type))
6181                 return true;
6182
6183         /* only integer and pointer can be casted to pointer */
6184         if (is_type_pointer(dst_type)  &&
6185             !is_type_pointer(src_type) &&
6186             !is_type_integer(src_type) &&
6187             is_type_valid(src_type)) {
6188                 errorf(pos, "cannot convert type '%T' to a pointer type", orig_type_right);
6189                 return false;
6190         }
6191
6192         if (!is_type_scalar(dst_type) && is_type_valid(dst_type)) {
6193                 errorf(pos, "conversion to non-scalar type '%T' requested", orig_dest_type);
6194                 return false;
6195         }
6196
6197         if (!is_type_scalar(src_type) && is_type_valid(src_type)) {
6198                 errorf(pos, "conversion from non-scalar type '%T' requested", orig_type_right);
6199                 return false;
6200         }
6201
6202         if (is_type_pointer(src_type) && is_type_pointer(dst_type)) {
6203                 type_t *src = skip_typeref(src_type->pointer.points_to);
6204                 type_t *dst = skip_typeref(dst_type->pointer.points_to);
6205                 unsigned missing_qualifiers =
6206                         src->base.qualifiers & ~dst->base.qualifiers;
6207                 if (missing_qualifiers != 0) {
6208                         warningf(WARN_CAST_QUAL, pos, "cast discards qualifiers '%Q' in pointer target type of '%T'", missing_qualifiers, orig_type_right);
6209                 }
6210         }
6211         return true;
6212 }
6213
6214 static expression_t *parse_compound_literal(source_position_t const *const pos, type_t *type)
6215 {
6216         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
6217         expression->base.source_position = *pos;
6218
6219         parse_initializer_env_t env;
6220         env.type             = type;
6221         env.entity           = NULL;
6222         env.must_be_constant = false;
6223         initializer_t *initializer = parse_initializer(&env);
6224         type = env.type;
6225
6226         expression->compound_literal.initializer = initializer;
6227         expression->compound_literal.type        = type;
6228         expression->base.type                    = automatic_type_conversion(type);
6229
6230         return expression;
6231 }
6232
6233 /**
6234  * Parse a cast expression.
6235  */
6236 static expression_t *parse_cast(void)
6237 {
6238         source_position_t const pos = *HERE;
6239
6240         eat('(');
6241         add_anchor_token(')');
6242
6243         type_t *type = parse_typename();
6244
6245         rem_anchor_token(')');
6246         expect(')');
6247
6248         if (token.kind == '{') {
6249                 return parse_compound_literal(&pos, type);
6250         }
6251
6252         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
6253         cast->base.source_position = pos;
6254
6255         expression_t *value = parse_subexpression(PREC_CAST);
6256         cast->base.type   = type;
6257         cast->unary.value = value;
6258
6259         if (! semantic_cast(cast)) {
6260                 /* TODO: record the error in the AST. else it is impossible to detect it */
6261         }
6262
6263         return cast;
6264 }
6265
6266 /**
6267  * Parse a statement expression.
6268  */
6269 static expression_t *parse_statement_expression(void)
6270 {
6271         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
6272
6273         eat('(');
6274         add_anchor_token(')');
6275
6276         statement_t *statement          = parse_compound_statement(true);
6277         statement->compound.stmt_expr   = true;
6278         expression->statement.statement = statement;
6279
6280         /* find last statement and use its type */
6281         type_t *type = type_void;
6282         const statement_t *stmt = statement->compound.statements;
6283         if (stmt != NULL) {
6284                 while (stmt->base.next != NULL)
6285                         stmt = stmt->base.next;
6286
6287                 if (stmt->kind == STATEMENT_EXPRESSION) {
6288                         type = stmt->expression.expression->base.type;
6289                 }
6290         } else {
6291                 source_position_t const *const pos = &expression->base.source_position;
6292                 warningf(WARN_OTHER, pos, "empty statement expression ({})");
6293         }
6294         expression->base.type = type;
6295
6296         rem_anchor_token(')');
6297         expect(')');
6298         return expression;
6299 }
6300
6301 /**
6302  * Parse a parenthesized expression.
6303  */
6304 static expression_t *parse_parenthesized_expression(void)
6305 {
6306         token_t const* const la1 = look_ahead(1);
6307         switch (la1->kind) {
6308         case '{':
6309                 /* gcc extension: a statement expression */
6310                 return parse_statement_expression();
6311
6312         case T_IDENTIFIER:
6313                 if (is_typedef_symbol(la1->identifier.symbol)) {
6314         DECLARATION_START
6315                         return parse_cast();
6316                 }
6317         }
6318
6319         eat('(');
6320         add_anchor_token(')');
6321         expression_t *result = parse_expression();
6322         result->base.parenthesized = true;
6323         rem_anchor_token(')');
6324         expect(')');
6325
6326         return result;
6327 }
6328
6329 static expression_t *parse_function_keyword(void)
6330 {
6331         /* TODO */
6332
6333         if (current_function == NULL) {
6334                 errorf(HERE, "'__func__' used outside of a function");
6335         }
6336
6337         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6338         expression->base.type     = type_char_ptr;
6339         expression->funcname.kind = FUNCNAME_FUNCTION;
6340
6341         next_token();
6342
6343         return expression;
6344 }
6345
6346 static expression_t *parse_pretty_function_keyword(void)
6347 {
6348         if (current_function == NULL) {
6349                 errorf(HERE, "'__PRETTY_FUNCTION__' used outside of a function");
6350         }
6351
6352         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6353         expression->base.type     = type_char_ptr;
6354         expression->funcname.kind = FUNCNAME_PRETTY_FUNCTION;
6355
6356         eat(T___PRETTY_FUNCTION__);
6357
6358         return expression;
6359 }
6360
6361 static expression_t *parse_funcsig_keyword(void)
6362 {
6363         if (current_function == NULL) {
6364                 errorf(HERE, "'__FUNCSIG__' used outside of a function");
6365         }
6366
6367         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6368         expression->base.type     = type_char_ptr;
6369         expression->funcname.kind = FUNCNAME_FUNCSIG;
6370
6371         eat(T___FUNCSIG__);
6372
6373         return expression;
6374 }
6375
6376 static expression_t *parse_funcdname_keyword(void)
6377 {
6378         if (current_function == NULL) {
6379                 errorf(HERE, "'__FUNCDNAME__' used outside of a function");
6380         }
6381
6382         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6383         expression->base.type     = type_char_ptr;
6384         expression->funcname.kind = FUNCNAME_FUNCDNAME;
6385
6386         eat(T___FUNCDNAME__);
6387
6388         return expression;
6389 }
6390
6391 static designator_t *parse_designator(void)
6392 {
6393         designator_t *const result = allocate_ast_zero(sizeof(result[0]));
6394         result->symbol = expect_identifier("while parsing member designator", &result->source_position);
6395         if (!result->symbol)
6396                 return NULL;
6397
6398         designator_t *last_designator = result;
6399         while (true) {
6400                 if (next_if('.')) {
6401                         designator_t *const designator = allocate_ast_zero(sizeof(result[0]));
6402                         designator->symbol = expect_identifier("while parsing member designator", &designator->source_position);
6403                         if (!designator->symbol)
6404                                 return NULL;
6405
6406                         last_designator->next = designator;
6407                         last_designator       = designator;
6408                         continue;
6409                 }
6410                 if (next_if('[')) {
6411                         add_anchor_token(']');
6412                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
6413                         designator->source_position = *HERE;
6414                         designator->array_index     = parse_expression();
6415                         rem_anchor_token(']');
6416                         expect(']');
6417                         if (designator->array_index == NULL) {
6418                                 return NULL;
6419                         }
6420
6421                         last_designator->next = designator;
6422                         last_designator       = designator;
6423                         continue;
6424                 }
6425                 break;
6426         }
6427
6428         return result;
6429 }
6430
6431 /**
6432  * Parse the __builtin_offsetof() expression.
6433  */
6434 static expression_t *parse_offsetof(void)
6435 {
6436         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
6437         expression->base.type    = type_size_t;
6438
6439         eat(T___builtin_offsetof);
6440
6441         expect('(');
6442         add_anchor_token(')');
6443         add_anchor_token(',');
6444         type_t *type = parse_typename();
6445         rem_anchor_token(',');
6446         expect(',');
6447         designator_t *designator = parse_designator();
6448         rem_anchor_token(')');
6449         expect(')');
6450
6451         expression->offsetofe.type       = type;
6452         expression->offsetofe.designator = designator;
6453
6454         type_path_t path;
6455         memset(&path, 0, sizeof(path));
6456         path.top_type = type;
6457         path.path     = NEW_ARR_F(type_path_entry_t, 0);
6458
6459         descend_into_subtype(&path);
6460
6461         if (!walk_designator(&path, designator, true)) {
6462                 return create_error_expression();
6463         }
6464
6465         DEL_ARR_F(path.path);
6466
6467         return expression;
6468 }
6469
6470 /**
6471  * Parses a _builtin_va_start() expression.
6472  */
6473 static expression_t *parse_va_start(void)
6474 {
6475         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
6476
6477         eat(T___builtin_va_start);
6478
6479         expect('(');
6480         add_anchor_token(')');
6481         add_anchor_token(',');
6482         expression->va_starte.ap = parse_assignment_expression();
6483         rem_anchor_token(',');
6484         expect(',');
6485         expression_t *const expr = parse_assignment_expression();
6486         if (expr->kind == EXPR_REFERENCE) {
6487                 entity_t *const entity = expr->reference.entity;
6488                 if (!current_function->base.type->function.variadic) {
6489                         errorf(&expr->base.source_position,
6490                                         "'va_start' used in non-variadic function");
6491                 } else if (entity->base.parent_scope != &current_function->parameters ||
6492                                 entity->base.next != NULL ||
6493                                 entity->kind != ENTITY_PARAMETER) {
6494                         errorf(&expr->base.source_position,
6495                                "second argument of 'va_start' must be last parameter of the current function");
6496                 } else {
6497                         expression->va_starte.parameter = &entity->variable;
6498                 }
6499         } else {
6500                 expression = create_error_expression();
6501         }
6502         rem_anchor_token(')');
6503         expect(')');
6504         return expression;
6505 }
6506
6507 /**
6508  * Parses a __builtin_va_arg() expression.
6509  */
6510 static expression_t *parse_va_arg(void)
6511 {
6512         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
6513
6514         eat(T___builtin_va_arg);
6515
6516         expect('(');
6517         add_anchor_token(')');
6518         add_anchor_token(',');
6519         call_argument_t ap;
6520         ap.expression = parse_assignment_expression();
6521         expression->va_arge.ap = ap.expression;
6522         check_call_argument(type_valist, &ap, 1);
6523
6524         rem_anchor_token(',');
6525         expect(',');
6526         expression->base.type = parse_typename();
6527         rem_anchor_token(')');
6528         expect(')');
6529
6530         return expression;
6531 }
6532
6533 /**
6534  * Parses a __builtin_va_copy() expression.
6535  */
6536 static expression_t *parse_va_copy(void)
6537 {
6538         expression_t *expression = allocate_expression_zero(EXPR_VA_COPY);
6539
6540         eat(T___builtin_va_copy);
6541
6542         expect('(');
6543         add_anchor_token(')');
6544         add_anchor_token(',');
6545         expression_t *dst = parse_assignment_expression();
6546         assign_error_t error = semantic_assign(type_valist, dst);
6547         report_assign_error(error, type_valist, dst, "call argument 1",
6548                             &dst->base.source_position);
6549         expression->va_copye.dst = dst;
6550
6551         rem_anchor_token(',');
6552         expect(',');
6553
6554         call_argument_t src;
6555         src.expression = parse_assignment_expression();
6556         check_call_argument(type_valist, &src, 2);
6557         expression->va_copye.src = src.expression;
6558         rem_anchor_token(')');
6559         expect(')');
6560
6561         return expression;
6562 }
6563
6564 /**
6565  * Parses a __builtin_constant_p() expression.
6566  */
6567 static expression_t *parse_builtin_constant(void)
6568 {
6569         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
6570
6571         eat(T___builtin_constant_p);
6572
6573         expect('(');
6574         add_anchor_token(')');
6575         expression->builtin_constant.value = parse_assignment_expression();
6576         rem_anchor_token(')');
6577         expect(')');
6578         expression->base.type = type_int;
6579
6580         return expression;
6581 }
6582
6583 /**
6584  * Parses a __builtin_types_compatible_p() expression.
6585  */
6586 static expression_t *parse_builtin_types_compatible(void)
6587 {
6588         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_TYPES_COMPATIBLE_P);
6589
6590         eat(T___builtin_types_compatible_p);
6591
6592         expect('(');
6593         add_anchor_token(')');
6594         add_anchor_token(',');
6595         expression->builtin_types_compatible.left = parse_typename();
6596         rem_anchor_token(',');
6597         expect(',');
6598         expression->builtin_types_compatible.right = parse_typename();
6599         rem_anchor_token(')');
6600         expect(')');
6601         expression->base.type = type_int;
6602
6603         return expression;
6604 }
6605
6606 /**
6607  * Parses a __builtin_is_*() compare expression.
6608  */
6609 static expression_t *parse_compare_builtin(void)
6610 {
6611         expression_t *expression;
6612
6613         switch (token.kind) {
6614         case T___builtin_isgreater:
6615                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATER);
6616                 break;
6617         case T___builtin_isgreaterequal:
6618                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATEREQUAL);
6619                 break;
6620         case T___builtin_isless:
6621                 expression = allocate_expression_zero(EXPR_BINARY_ISLESS);
6622                 break;
6623         case T___builtin_islessequal:
6624                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSEQUAL);
6625                 break;
6626         case T___builtin_islessgreater:
6627                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSGREATER);
6628                 break;
6629         case T___builtin_isunordered:
6630                 expression = allocate_expression_zero(EXPR_BINARY_ISUNORDERED);
6631                 break;
6632         default:
6633                 internal_errorf(HERE, "invalid compare builtin found");
6634         }
6635         expression->base.source_position = *HERE;
6636         next_token();
6637
6638         expect('(');
6639         add_anchor_token(')');
6640         add_anchor_token(',');
6641         expression->binary.left = parse_assignment_expression();
6642         rem_anchor_token(',');
6643         expect(',');
6644         expression->binary.right = parse_assignment_expression();
6645         rem_anchor_token(')');
6646         expect(')');
6647
6648         type_t *const orig_type_left  = expression->binary.left->base.type;
6649         type_t *const orig_type_right = expression->binary.right->base.type;
6650
6651         type_t *const type_left  = skip_typeref(orig_type_left);
6652         type_t *const type_right = skip_typeref(orig_type_right);
6653         if (!is_type_float(type_left) && !is_type_float(type_right)) {
6654                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
6655                         type_error_incompatible("invalid operands in comparison",
6656                                 &expression->base.source_position, orig_type_left, orig_type_right);
6657                 }
6658         } else {
6659                 semantic_comparison(&expression->binary);
6660         }
6661
6662         return expression;
6663 }
6664
6665 /**
6666  * Parses a MS assume() expression.
6667  */
6668 static expression_t *parse_assume(void)
6669 {
6670         expression_t *expression = allocate_expression_zero(EXPR_UNARY_ASSUME);
6671
6672         eat(T__assume);
6673
6674         expect('(');
6675         add_anchor_token(')');
6676         expression->unary.value = parse_assignment_expression();
6677         rem_anchor_token(')');
6678         expect(')');
6679
6680         expression->base.type = type_void;
6681         return expression;
6682 }
6683
6684 /**
6685  * Return the label for the current symbol or create a new one.
6686  */
6687 static label_t *get_label(void)
6688 {
6689         assert(token.kind == T_IDENTIFIER);
6690         assert(current_function != NULL);
6691
6692         entity_t *label = get_entity(token.identifier.symbol, NAMESPACE_LABEL);
6693         /* If we find a local label, we already created the declaration. */
6694         if (label != NULL && label->kind == ENTITY_LOCAL_LABEL) {
6695                 if (label->base.parent_scope != current_scope) {
6696                         assert(label->base.parent_scope->depth < current_scope->depth);
6697                         current_function->goto_to_outer = true;
6698                 }
6699         } else if (label == NULL || label->base.parent_scope != &current_function->parameters) {
6700                 /* There is no matching label in the same function, so create a new one. */
6701                 source_position_t const nowhere = { NULL, 0, 0, false };
6702                 label = allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, token.identifier.symbol, &nowhere);
6703                 label_push(label);
6704         }
6705
6706         eat(T_IDENTIFIER);
6707         return &label->label;
6708 }
6709
6710 /**
6711  * Parses a GNU && label address expression.
6712  */
6713 static expression_t *parse_label_address(void)
6714 {
6715         source_position_t source_position = token.base.source_position;
6716         eat(T_ANDAND);
6717         if (token.kind != T_IDENTIFIER) {
6718                 parse_error_expected("while parsing label address", T_IDENTIFIER, NULL);
6719                 return create_error_expression();
6720         }
6721
6722         label_t *const label = get_label();
6723         label->used          = true;
6724         label->address_taken = true;
6725
6726         expression_t *expression = allocate_expression_zero(EXPR_LABEL_ADDRESS);
6727         expression->base.source_position = source_position;
6728
6729         /* label address is treated as a void pointer */
6730         expression->base.type           = type_void_ptr;
6731         expression->label_address.label = label;
6732         return expression;
6733 }
6734
6735 /**
6736  * Parse a microsoft __noop expression.
6737  */
6738 static expression_t *parse_noop_expression(void)
6739 {
6740         /* the result is a (int)0 */
6741         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_MS_NOOP);
6742         literal->base.type           = type_int;
6743         literal->literal.value.begin = "__noop";
6744         literal->literal.value.size  = 6;
6745
6746         eat(T___noop);
6747
6748         if (token.kind == '(') {
6749                 /* parse arguments */
6750                 eat('(');
6751                 add_anchor_token(')');
6752                 add_anchor_token(',');
6753
6754                 if (token.kind != ')') do {
6755                         (void)parse_assignment_expression();
6756                 } while (next_if(','));
6757
6758                 rem_anchor_token(',');
6759                 rem_anchor_token(')');
6760         }
6761         expect(')');
6762
6763         return literal;
6764 }
6765
6766 /**
6767  * Parses a primary expression.
6768  */
6769 static expression_t *parse_primary_expression(void)
6770 {
6771         switch (token.kind) {
6772         case T_false:                        return parse_boolean_literal(false);
6773         case T_true:                         return parse_boolean_literal(true);
6774         case T_INTEGER:
6775         case T_INTEGER_OCTAL:
6776         case T_INTEGER_HEXADECIMAL:
6777         case T_FLOATINGPOINT:
6778         case T_FLOATINGPOINT_HEXADECIMAL:    return parse_number_literal();
6779         case T_CHARACTER_CONSTANT:           return parse_character_constant();
6780         case T_WIDE_CHARACTER_CONSTANT:      return parse_wide_character_constant();
6781         case T_STRING_LITERAL:
6782         case T_WIDE_STRING_LITERAL:          return parse_string_literal();
6783         case T___FUNCTION__:
6784         case T___func__:                     return parse_function_keyword();
6785         case T___PRETTY_FUNCTION__:          return parse_pretty_function_keyword();
6786         case T___FUNCSIG__:                  return parse_funcsig_keyword();
6787         case T___FUNCDNAME__:                return parse_funcdname_keyword();
6788         case T___builtin_offsetof:           return parse_offsetof();
6789         case T___builtin_va_start:           return parse_va_start();
6790         case T___builtin_va_arg:             return parse_va_arg();
6791         case T___builtin_va_copy:            return parse_va_copy();
6792         case T___builtin_isgreater:
6793         case T___builtin_isgreaterequal:
6794         case T___builtin_isless:
6795         case T___builtin_islessequal:
6796         case T___builtin_islessgreater:
6797         case T___builtin_isunordered:        return parse_compare_builtin();
6798         case T___builtin_constant_p:         return parse_builtin_constant();
6799         case T___builtin_types_compatible_p: return parse_builtin_types_compatible();
6800         case T__assume:                      return parse_assume();
6801         case T_ANDAND:
6802                 if (GNU_MODE)
6803                         return parse_label_address();
6804                 break;
6805
6806         case '(':                            return parse_parenthesized_expression();
6807         case T___noop:                       return parse_noop_expression();
6808
6809         /* Gracefully handle type names while parsing expressions. */
6810         case T_COLONCOLON:
6811                 return parse_reference();
6812         case T_IDENTIFIER:
6813                 if (!is_typedef_symbol(token.identifier.symbol)) {
6814                         return parse_reference();
6815                 }
6816                 /* FALLTHROUGH */
6817         DECLARATION_START {
6818                 source_position_t const  pos = *HERE;
6819                 declaration_specifiers_t specifiers;
6820                 parse_declaration_specifiers(&specifiers);
6821                 type_t const *const type = parse_abstract_declarator(specifiers.type);
6822                 errorf(&pos, "encountered type '%T' while parsing expression", type);
6823                 return create_error_expression();
6824         }
6825         }
6826
6827         errorf(HERE, "unexpected token %K, expected an expression", &token);
6828         eat_until_anchor();
6829         return create_error_expression();
6830 }
6831
6832 static expression_t *parse_array_expression(expression_t *left)
6833 {
6834         expression_t              *const expr = allocate_expression_zero(EXPR_ARRAY_ACCESS);
6835         array_access_expression_t *const arr  = &expr->array_access;
6836
6837         eat('[');
6838         add_anchor_token(']');
6839
6840         expression_t *const inside = parse_expression();
6841
6842         type_t *const orig_type_left   = left->base.type;
6843         type_t *const orig_type_inside = inside->base.type;
6844
6845         type_t *const type_left   = skip_typeref(orig_type_left);
6846         type_t *const type_inside = skip_typeref(orig_type_inside);
6847
6848         expression_t *ref;
6849         expression_t *idx;
6850         type_t       *idx_type;
6851         type_t       *res_type;
6852         if (is_type_pointer(type_left)) {
6853                 ref      = left;
6854                 idx      = inside;
6855                 idx_type = type_inside;
6856                 res_type = type_left->pointer.points_to;
6857                 goto check_idx;
6858         } else if (is_type_pointer(type_inside)) {
6859                 arr->flipped = true;
6860                 ref      = inside;
6861                 idx      = left;
6862                 idx_type = type_left;
6863                 res_type = type_inside->pointer.points_to;
6864 check_idx:
6865                 res_type = automatic_type_conversion(res_type);
6866                 if (!is_type_integer(idx_type)) {
6867                         errorf(&idx->base.source_position, "array subscript must have integer type");
6868                 } else if (is_type_atomic(idx_type, ATOMIC_TYPE_CHAR)) {
6869                         source_position_t const *const pos = &idx->base.source_position;
6870                         warningf(WARN_CHAR_SUBSCRIPTS, pos, "array subscript has char type");
6871                 }
6872         } else {
6873                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
6874                         errorf(&expr->base.source_position, "invalid types '%T[%T]' for array access", orig_type_left, orig_type_inside);
6875                 }
6876                 res_type = type_error_type;
6877                 ref      = left;
6878                 idx      = inside;
6879         }
6880
6881         arr->array_ref = ref;
6882         arr->index     = idx;
6883         arr->base.type = res_type;
6884
6885         rem_anchor_token(']');
6886         expect(']');
6887         return expr;
6888 }
6889
6890 static bool is_bitfield(const expression_t *expression)
6891 {
6892         return expression->kind == EXPR_SELECT
6893                 && expression->select.compound_entry->compound_member.bitfield;
6894 }
6895
6896 static expression_t *parse_typeprop(expression_kind_t const kind)
6897 {
6898         expression_t  *tp_expression = allocate_expression_zero(kind);
6899         tp_expression->base.type     = type_size_t;
6900
6901         eat(kind == EXPR_SIZEOF ? T_sizeof : T___alignof__);
6902
6903         type_t       *orig_type;
6904         expression_t *expression;
6905         if (token.kind == '(' && is_declaration_specifier(look_ahead(1))) {
6906                 source_position_t const pos = *HERE;
6907                 next_token();
6908                 add_anchor_token(')');
6909                 orig_type = parse_typename();
6910                 rem_anchor_token(')');
6911                 expect(')');
6912
6913                 if (token.kind == '{') {
6914                         /* It was not sizeof(type) after all.  It is sizeof of an expression
6915                          * starting with a compound literal */
6916                         expression = parse_compound_literal(&pos, orig_type);
6917                         goto typeprop_expression;
6918                 }
6919         } else {
6920                 expression = parse_subexpression(PREC_UNARY);
6921
6922 typeprop_expression:
6923                 if (is_bitfield(expression)) {
6924                         char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6925                         errorf(&tp_expression->base.source_position,
6926                                    "operand of %s expression must not be a bitfield", what);
6927                 }
6928
6929                 tp_expression->typeprop.tp_expression = expression;
6930
6931                 orig_type = revert_automatic_type_conversion(expression);
6932                 expression->base.type = orig_type;
6933         }
6934
6935         tp_expression->typeprop.type   = orig_type;
6936         type_t const* const type       = skip_typeref(orig_type);
6937         char   const*       wrong_type = NULL;
6938         if (is_type_incomplete(type)) {
6939                 if (!is_type_void(type) || !GNU_MODE)
6940                         wrong_type = "incomplete";
6941         } else if (type->kind == TYPE_FUNCTION) {
6942                 if (GNU_MODE) {
6943                         /* function types are allowed (and return 1) */
6944                         source_position_t const *const pos  = &tp_expression->base.source_position;
6945                         char              const *const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6946                         warningf(WARN_OTHER, pos, "%s expression with function argument returns invalid result", what);
6947                 } else {
6948                         wrong_type = "function";
6949                 }
6950         }
6951
6952         if (wrong_type != NULL) {
6953                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6954                 errorf(&tp_expression->base.source_position,
6955                                 "operand of %s expression must not be of %s type '%T'",
6956                                 what, wrong_type, orig_type);
6957         }
6958
6959         return tp_expression;
6960 }
6961
6962 static expression_t *parse_sizeof(void)
6963 {
6964         return parse_typeprop(EXPR_SIZEOF);
6965 }
6966
6967 static expression_t *parse_alignof(void)
6968 {
6969         return parse_typeprop(EXPR_ALIGNOF);
6970 }
6971
6972 static expression_t *parse_select_expression(expression_t *addr)
6973 {
6974         assert(token.kind == '.' || token.kind == T_MINUSGREATER);
6975         bool select_left_arrow = (token.kind == T_MINUSGREATER);
6976         source_position_t const pos = *HERE;
6977         next_token();
6978
6979         symbol_t *const symbol = expect_identifier("while parsing select", NULL);
6980         if (!symbol)
6981                 return create_error_expression();
6982
6983         type_t *const orig_type = addr->base.type;
6984         type_t *const type      = skip_typeref(orig_type);
6985
6986         type_t *type_left;
6987         bool    saw_error = false;
6988         if (is_type_pointer(type)) {
6989                 if (!select_left_arrow) {
6990                         errorf(&pos,
6991                                "request for member '%Y' in something not a struct or union, but '%T'",
6992                                symbol, orig_type);
6993                         saw_error = true;
6994                 }
6995                 type_left = skip_typeref(type->pointer.points_to);
6996         } else {
6997                 if (select_left_arrow && is_type_valid(type)) {
6998                         errorf(&pos, "left hand side of '->' is not a pointer, but '%T'", orig_type);
6999                         saw_error = true;
7000                 }
7001                 type_left = type;
7002         }
7003
7004         if (type_left->kind != TYPE_COMPOUND_STRUCT &&
7005             type_left->kind != TYPE_COMPOUND_UNION) {
7006
7007                 if (is_type_valid(type_left) && !saw_error) {
7008                         errorf(&pos,
7009                                "request for member '%Y' in something not a struct or union, but '%T'",
7010                                symbol, type_left);
7011                 }
7012                 return create_error_expression();
7013         }
7014
7015         compound_t *compound = type_left->compound.compound;
7016         if (!compound->complete) {
7017                 errorf(&pos, "request for member '%Y' in incomplete type '%T'",
7018                        symbol, type_left);
7019                 return create_error_expression();
7020         }
7021
7022         type_qualifiers_t  qualifiers = type_left->base.qualifiers;
7023         expression_t      *result     =
7024                 find_create_select(&pos, addr, qualifiers, compound, symbol);
7025
7026         if (result == NULL) {
7027                 errorf(&pos, "'%T' has no member named '%Y'", orig_type, symbol);
7028                 return create_error_expression();
7029         }
7030
7031         return result;
7032 }
7033
7034 static void check_call_argument(type_t          *expected_type,
7035                                 call_argument_t *argument, unsigned pos)
7036 {
7037         type_t         *expected_type_skip = skip_typeref(expected_type);
7038         assign_error_t  error              = ASSIGN_ERROR_INCOMPATIBLE;
7039         expression_t   *arg_expr           = argument->expression;
7040         type_t         *arg_type           = skip_typeref(arg_expr->base.type);
7041
7042         /* handle transparent union gnu extension */
7043         if (is_type_union(expected_type_skip)
7044                         && (get_type_modifiers(expected_type) & DM_TRANSPARENT_UNION)) {
7045                 compound_t *union_decl  = expected_type_skip->compound.compound;
7046                 type_t     *best_type   = NULL;
7047                 entity_t   *entry       = union_decl->members.entities;
7048                 for ( ; entry != NULL; entry = entry->base.next) {
7049                         assert(is_declaration(entry));
7050                         type_t *decl_type = entry->declaration.type;
7051                         error = semantic_assign(decl_type, arg_expr);
7052                         if (error == ASSIGN_ERROR_INCOMPATIBLE
7053                                 || error == ASSIGN_ERROR_POINTER_QUALIFIER_MISSING)
7054                                 continue;
7055
7056                         if (error == ASSIGN_SUCCESS) {
7057                                 best_type = decl_type;
7058                         } else if (best_type == NULL) {
7059                                 best_type = decl_type;
7060                         }
7061                 }
7062
7063                 if (best_type != NULL) {
7064                         expected_type = best_type;
7065                 }
7066         }
7067
7068         error                = semantic_assign(expected_type, arg_expr);
7069         argument->expression = create_implicit_cast(arg_expr, expected_type);
7070
7071         if (error != ASSIGN_SUCCESS) {
7072                 /* report exact scope in error messages (like "in argument 3") */
7073                 char buf[64];
7074                 snprintf(buf, sizeof(buf), "call argument %u", pos);
7075                 report_assign_error(error, expected_type, arg_expr, buf,
7076                                     &arg_expr->base.source_position);
7077         } else {
7078                 type_t *const promoted_type = get_default_promoted_type(arg_type);
7079                 if (!types_compatible(expected_type_skip, promoted_type) &&
7080                     !types_compatible(expected_type_skip, type_void_ptr) &&
7081                     !types_compatible(type_void_ptr,      promoted_type)) {
7082                         /* Deliberately show the skipped types in this warning */
7083                         source_position_t const *const apos = &arg_expr->base.source_position;
7084                         warningf(WARN_TRADITIONAL, apos, "passing call argument %u as '%T' rather than '%T' due to prototype", pos, expected_type_skip, promoted_type);
7085                 }
7086         }
7087 }
7088
7089 /**
7090  * Handle the semantic restrictions of builtin calls
7091  */
7092 static void handle_builtin_argument_restrictions(call_expression_t *call)
7093 {
7094         entity_t *entity = call->function->reference.entity;
7095         switch (entity->function.btk) {
7096         case BUILTIN_FIRM:
7097                 switch (entity->function.b.firm_builtin_kind) {
7098                 case ir_bk_return_address:
7099                 case ir_bk_frame_address: {
7100                         /* argument must be constant */
7101                         call_argument_t *argument = call->arguments;
7102
7103                         if (is_constant_expression(argument->expression) == EXPR_CLASS_VARIABLE) {
7104                                 errorf(&call->base.source_position,
7105                                            "argument of '%Y' must be a constant expression",
7106                                            call->function->reference.entity->base.symbol);
7107                         }
7108                         break;
7109                 }
7110                 case ir_bk_prefetch:
7111                         /* second and third argument must be constant if existent */
7112                         if (call->arguments == NULL)
7113                                 break;
7114                         call_argument_t *rw = call->arguments->next;
7115                         call_argument_t *locality = NULL;
7116
7117                         if (rw != NULL) {
7118                                 if (is_constant_expression(rw->expression) == EXPR_CLASS_VARIABLE) {
7119                                         errorf(&call->base.source_position,
7120                                                    "second argument of '%Y' must be a constant expression",
7121                                                    call->function->reference.entity->base.symbol);
7122                                 }
7123                                 locality = rw->next;
7124                         }
7125                         if (locality != NULL) {
7126                                 if (is_constant_expression(locality->expression) == EXPR_CLASS_VARIABLE) {
7127                                         errorf(&call->base.source_position,
7128                                                    "third argument of '%Y' must be a constant expression",
7129                                                    call->function->reference.entity->base.symbol);
7130                                 }
7131                                 locality = rw->next;
7132                         }
7133                         break;
7134                 default:
7135                         break;
7136                 }
7137
7138         case BUILTIN_OBJECT_SIZE:
7139                 if (call->arguments == NULL)
7140                         break;
7141
7142                 call_argument_t *arg = call->arguments->next;
7143                 if (arg != NULL && is_constant_expression(arg->expression) == EXPR_CLASS_VARIABLE) {
7144                         errorf(&call->base.source_position,
7145                                    "second argument of '%Y' must be a constant expression",
7146                                    call->function->reference.entity->base.symbol);
7147                 }
7148                 break;
7149         default:
7150                 break;
7151         }
7152 }
7153
7154 /**
7155  * Parse a call expression, ie. expression '( ... )'.
7156  *
7157  * @param expression  the function address
7158  */
7159 static expression_t *parse_call_expression(expression_t *expression)
7160 {
7161         expression_t      *result = allocate_expression_zero(EXPR_CALL);
7162         call_expression_t *call   = &result->call;
7163         call->function            = expression;
7164
7165         type_t *const orig_type = expression->base.type;
7166         type_t *const type      = skip_typeref(orig_type);
7167
7168         function_type_t *function_type = NULL;
7169         if (is_type_pointer(type)) {
7170                 type_t *const to_type = skip_typeref(type->pointer.points_to);
7171
7172                 if (is_type_function(to_type)) {
7173                         function_type   = &to_type->function;
7174                         call->base.type = function_type->return_type;
7175                 }
7176         }
7177
7178         if (function_type == NULL && is_type_valid(type)) {
7179                 errorf(HERE,
7180                        "called object '%E' (type '%T') is not a pointer to a function",
7181                        expression, orig_type);
7182         }
7183
7184         /* parse arguments */
7185         eat('(');
7186         add_anchor_token(')');
7187         add_anchor_token(',');
7188
7189         if (token.kind != ')') {
7190                 call_argument_t **anchor = &call->arguments;
7191                 do {
7192                         call_argument_t *argument = allocate_ast_zero(sizeof(*argument));
7193                         argument->expression = parse_assignment_expression();
7194
7195                         *anchor = argument;
7196                         anchor  = &argument->next;
7197                 } while (next_if(','));
7198         }
7199         rem_anchor_token(',');
7200         rem_anchor_token(')');
7201         expect(')');
7202
7203         if (function_type == NULL)
7204                 return result;
7205
7206         /* check type and count of call arguments */
7207         function_parameter_t *parameter = function_type->parameters;
7208         call_argument_t      *argument  = call->arguments;
7209         if (!function_type->unspecified_parameters) {
7210                 for (unsigned pos = 0; parameter != NULL && argument != NULL;
7211                                 parameter = parameter->next, argument = argument->next) {
7212                         check_call_argument(parameter->type, argument, ++pos);
7213                 }
7214
7215                 if (parameter != NULL) {
7216                         errorf(&expression->base.source_position, "too few arguments to function '%E'", expression);
7217                 } else if (argument != NULL && !function_type->variadic) {
7218                         errorf(&argument->expression->base.source_position, "too many arguments to function '%E'", expression);
7219                 }
7220         }
7221
7222         /* do default promotion for other arguments */
7223         for (; argument != NULL; argument = argument->next) {
7224                 type_t *argument_type = argument->expression->base.type;
7225                 if (!is_type_object(skip_typeref(argument_type))) {
7226                         errorf(&argument->expression->base.source_position,
7227                                "call argument '%E' must not be void", argument->expression);
7228                 }
7229
7230                 argument_type = get_default_promoted_type(argument_type);
7231
7232                 argument->expression
7233                         = create_implicit_cast(argument->expression, argument_type);
7234         }
7235
7236         check_format(call);
7237
7238         if (is_type_compound(skip_typeref(function_type->return_type))) {
7239                 source_position_t const *const pos = &expression->base.source_position;
7240                 warningf(WARN_AGGREGATE_RETURN, pos, "function call has aggregate value");
7241         }
7242
7243         if (expression->kind == EXPR_REFERENCE) {
7244                 reference_expression_t *reference = &expression->reference;
7245                 if (reference->entity->kind == ENTITY_FUNCTION &&
7246                     reference->entity->function.btk != BUILTIN_NONE)
7247                         handle_builtin_argument_restrictions(call);
7248         }
7249
7250         return result;
7251 }
7252
7253 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
7254
7255 static bool same_compound_type(const type_t *type1, const type_t *type2)
7256 {
7257         return
7258                 is_type_compound(type1) &&
7259                 type1->kind == type2->kind &&
7260                 type1->compound.compound == type2->compound.compound;
7261 }
7262
7263 static expression_t const *get_reference_address(expression_t const *expr)
7264 {
7265         bool regular_take_address = true;
7266         for (;;) {
7267                 if (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
7268                         expr = expr->unary.value;
7269                 } else {
7270                         regular_take_address = false;
7271                 }
7272
7273                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
7274                         break;
7275
7276                 expr = expr->unary.value;
7277         }
7278
7279         if (expr->kind != EXPR_REFERENCE)
7280                 return NULL;
7281
7282         /* special case for functions which are automatically converted to a
7283          * pointer to function without an extra TAKE_ADDRESS operation */
7284         if (!regular_take_address &&
7285                         expr->reference.entity->kind != ENTITY_FUNCTION) {
7286                 return NULL;
7287         }
7288
7289         return expr;
7290 }
7291
7292 static void warn_reference_address_as_bool(expression_t const* expr)
7293 {
7294         expr = get_reference_address(expr);
7295         if (expr != NULL) {
7296                 source_position_t const *const pos = &expr->base.source_position;
7297                 entity_t          const *const ent = expr->reference.entity;
7298                 warningf(WARN_ADDRESS, pos, "the address of '%N' will always evaluate as 'true'", ent);
7299         }
7300 }
7301
7302 static void warn_assignment_in_condition(const expression_t *const expr)
7303 {
7304         if (expr->base.kind != EXPR_BINARY_ASSIGN)
7305                 return;
7306         if (expr->base.parenthesized)
7307                 return;
7308         source_position_t const *const pos = &expr->base.source_position;
7309         warningf(WARN_PARENTHESES, pos, "suggest parentheses around assignment used as truth value");
7310 }
7311
7312 static void semantic_condition(expression_t const *const expr,
7313                                char const *const context)
7314 {
7315         type_t *const type = skip_typeref(expr->base.type);
7316         if (is_type_scalar(type)) {
7317                 warn_reference_address_as_bool(expr);
7318                 warn_assignment_in_condition(expr);
7319         } else if (is_type_valid(type)) {
7320                 errorf(&expr->base.source_position,
7321                                 "%s must have scalar type", context);
7322         }
7323 }
7324
7325 /**
7326  * Parse a conditional expression, ie. 'expression ? ... : ...'.
7327  *
7328  * @param expression  the conditional expression
7329  */
7330 static expression_t *parse_conditional_expression(expression_t *expression)
7331 {
7332         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
7333
7334         conditional_expression_t *conditional = &result->conditional;
7335         conditional->condition                = expression;
7336
7337         eat('?');
7338         add_anchor_token(':');
7339
7340         /* §6.5.15:2  The first operand shall have scalar type. */
7341         semantic_condition(expression, "condition of conditional operator");
7342
7343         expression_t *true_expression = expression;
7344         bool          gnu_cond = false;
7345         if (GNU_MODE && token.kind == ':') {
7346                 gnu_cond = true;
7347         } else {
7348                 true_expression = parse_expression();
7349         }
7350         rem_anchor_token(':');
7351         expect(':');
7352         expression_t *false_expression =
7353                 parse_subexpression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
7354
7355         type_t *const orig_true_type  = true_expression->base.type;
7356         type_t *const orig_false_type = false_expression->base.type;
7357         type_t *const true_type       = skip_typeref(orig_true_type);
7358         type_t *const false_type      = skip_typeref(orig_false_type);
7359
7360         /* 6.5.15.3 */
7361         source_position_t const *const pos = &conditional->base.source_position;
7362         type_t                        *result_type;
7363         if (is_type_void(true_type) || is_type_void(false_type)) {
7364                 /* ISO/IEC 14882:1998(E) §5.16:2 */
7365                 if (true_expression->kind == EXPR_UNARY_THROW) {
7366                         result_type = false_type;
7367                 } else if (false_expression->kind == EXPR_UNARY_THROW) {
7368                         result_type = true_type;
7369                 } else {
7370                         if (!is_type_void(true_type) || !is_type_void(false_type)) {
7371                                 warningf(WARN_OTHER, pos, "ISO C forbids conditional expression with only one void side");
7372                         }
7373                         result_type = type_void;
7374                 }
7375         } else if (is_type_arithmetic(true_type)
7376                    && is_type_arithmetic(false_type)) {
7377                 result_type = semantic_arithmetic(true_type, false_type);
7378         } else if (same_compound_type(true_type, false_type)) {
7379                 /* just take 1 of the 2 types */
7380                 result_type = true_type;
7381         } else if (is_type_pointer(true_type) || is_type_pointer(false_type)) {
7382                 type_t *pointer_type;
7383                 type_t *other_type;
7384                 expression_t *other_expression;
7385                 if (is_type_pointer(true_type) &&
7386                                 (!is_type_pointer(false_type) || is_null_pointer_constant(false_expression))) {
7387                         pointer_type     = true_type;
7388                         other_type       = false_type;
7389                         other_expression = false_expression;
7390                 } else {
7391                         pointer_type     = false_type;
7392                         other_type       = true_type;
7393                         other_expression = true_expression;
7394                 }
7395
7396                 if (is_null_pointer_constant(other_expression)) {
7397                         result_type = pointer_type;
7398                 } else if (is_type_pointer(other_type)) {
7399                         type_t *to1 = skip_typeref(pointer_type->pointer.points_to);
7400                         type_t *to2 = skip_typeref(other_type->pointer.points_to);
7401
7402                         type_t *to;
7403                         if (is_type_void(to1) || is_type_void(to2)) {
7404                                 to = type_void;
7405                         } else if (types_compatible(get_unqualified_type(to1),
7406                                                     get_unqualified_type(to2))) {
7407                                 to = to1;
7408                         } else {
7409                                 warningf(WARN_OTHER, pos, "pointer types '%T' and '%T' in conditional expression are incompatible", true_type, false_type);
7410                                 to = type_void;
7411                         }
7412
7413                         type_t *const type =
7414                                 get_qualified_type(to, to1->base.qualifiers | to2->base.qualifiers);
7415                         result_type = make_pointer_type(type, TYPE_QUALIFIER_NONE);
7416                 } else if (is_type_integer(other_type)) {
7417                         warningf(WARN_OTHER, pos, "pointer/integer type mismatch in conditional expression ('%T' and '%T')", true_type, false_type);
7418                         result_type = pointer_type;
7419                 } else {
7420                         goto types_incompatible;
7421                 }
7422         } else {
7423 types_incompatible:
7424                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
7425                         type_error_incompatible("while parsing conditional", pos, true_type, false_type);
7426                 }
7427                 result_type = type_error_type;
7428         }
7429
7430         conditional->true_expression
7431                 = gnu_cond ? NULL : create_implicit_cast(true_expression, result_type);
7432         conditional->false_expression
7433                 = create_implicit_cast(false_expression, result_type);
7434         conditional->base.type = result_type;
7435         return result;
7436 }
7437
7438 /**
7439  * Parse an extension expression.
7440  */
7441 static expression_t *parse_extension(void)
7442 {
7443         PUSH_EXTENSION();
7444         expression_t *expression = parse_subexpression(PREC_UNARY);
7445         POP_EXTENSION();
7446         return expression;
7447 }
7448
7449 /**
7450  * Parse a __builtin_classify_type() expression.
7451  */
7452 static expression_t *parse_builtin_classify_type(void)
7453 {
7454         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
7455         result->base.type    = type_int;
7456
7457         eat(T___builtin_classify_type);
7458
7459         expect('(');
7460         add_anchor_token(')');
7461         expression_t *expression = parse_expression();
7462         rem_anchor_token(')');
7463         expect(')');
7464         result->classify_type.type_expression = expression;
7465
7466         return result;
7467 }
7468
7469 /**
7470  * Parse a delete expression
7471  * ISO/IEC 14882:1998(E) §5.3.5
7472  */
7473 static expression_t *parse_delete(void)
7474 {
7475         expression_t *const result = allocate_expression_zero(EXPR_UNARY_DELETE);
7476         result->base.type          = type_void;
7477
7478         eat(T_delete);
7479
7480         if (next_if('[')) {
7481                 result->kind = EXPR_UNARY_DELETE_ARRAY;
7482                 expect(']');
7483         }
7484
7485         expression_t *const value = parse_subexpression(PREC_CAST);
7486         result->unary.value = value;
7487
7488         type_t *const type = skip_typeref(value->base.type);
7489         if (!is_type_pointer(type)) {
7490                 if (is_type_valid(type)) {
7491                         errorf(&value->base.source_position,
7492                                         "operand of delete must have pointer type");
7493                 }
7494         } else if (is_type_void(skip_typeref(type->pointer.points_to))) {
7495                 source_position_t const *const pos = &value->base.source_position;
7496                 warningf(WARN_OTHER, pos, "deleting 'void*' is undefined");
7497         }
7498
7499         return result;
7500 }
7501
7502 /**
7503  * Parse a throw expression
7504  * ISO/IEC 14882:1998(E) §15:1
7505  */
7506 static expression_t *parse_throw(void)
7507 {
7508         expression_t *const result = allocate_expression_zero(EXPR_UNARY_THROW);
7509         result->base.type          = type_void;
7510
7511         eat(T_throw);
7512
7513         expression_t *value = NULL;
7514         switch (token.kind) {
7515                 EXPRESSION_START {
7516                         value = parse_assignment_expression();
7517                         /* ISO/IEC 14882:1998(E) §15.1:3 */
7518                         type_t *const orig_type = value->base.type;
7519                         type_t *const type      = skip_typeref(orig_type);
7520                         if (is_type_incomplete(type)) {
7521                                 errorf(&value->base.source_position,
7522                                                 "cannot throw object of incomplete type '%T'", orig_type);
7523                         } else if (is_type_pointer(type)) {
7524                                 type_t *const points_to = skip_typeref(type->pointer.points_to);
7525                                 if (is_type_incomplete(points_to) && !is_type_void(points_to)) {
7526                                         errorf(&value->base.source_position,
7527                                                         "cannot throw pointer to incomplete type '%T'", orig_type);
7528                                 }
7529                         }
7530                 }
7531
7532                 default:
7533                         break;
7534         }
7535         result->unary.value = value;
7536
7537         return result;
7538 }
7539
7540 static bool check_pointer_arithmetic(const source_position_t *source_position,
7541                                      type_t *pointer_type,
7542                                      type_t *orig_pointer_type)
7543 {
7544         type_t *points_to = pointer_type->pointer.points_to;
7545         points_to = skip_typeref(points_to);
7546
7547         if (is_type_incomplete(points_to)) {
7548                 if (!GNU_MODE || !is_type_void(points_to)) {
7549                         errorf(source_position,
7550                                "arithmetic with pointer to incomplete type '%T' not allowed",
7551                                orig_pointer_type);
7552                         return false;
7553                 } else {
7554                         warningf(WARN_POINTER_ARITH, source_position, "pointer of type '%T' used in arithmetic", orig_pointer_type);
7555                 }
7556         } else if (is_type_function(points_to)) {
7557                 if (!GNU_MODE) {
7558                         errorf(source_position,
7559                                "arithmetic with pointer to function type '%T' not allowed",
7560                                orig_pointer_type);
7561                         return false;
7562                 } else {
7563                         warningf(WARN_POINTER_ARITH, source_position, "pointer to a function '%T' used in arithmetic", orig_pointer_type);
7564                 }
7565         }
7566         return true;
7567 }
7568
7569 static bool is_lvalue(const expression_t *expression)
7570 {
7571         /* TODO: doesn't seem to be consistent with §6.3.2.1:1 */
7572         switch (expression->kind) {
7573         case EXPR_ARRAY_ACCESS:
7574         case EXPR_COMPOUND_LITERAL:
7575         case EXPR_REFERENCE:
7576         case EXPR_SELECT:
7577         case EXPR_UNARY_DEREFERENCE:
7578                 return true;
7579
7580         default: {
7581                 type_t *type = skip_typeref(expression->base.type);
7582                 return
7583                         /* ISO/IEC 14882:1998(E) §3.10:3 */
7584                         is_type_reference(type) ||
7585                         /* Claim it is an lvalue, if the type is invalid.  There was a parse
7586                          * error before, which maybe prevented properly recognizing it as
7587                          * lvalue. */
7588                         !is_type_valid(type);
7589         }
7590         }
7591 }
7592
7593 static void semantic_incdec(unary_expression_t *expression)
7594 {
7595         type_t *const orig_type = expression->value->base.type;
7596         type_t *const type      = skip_typeref(orig_type);
7597         if (is_type_pointer(type)) {
7598                 if (!check_pointer_arithmetic(&expression->base.source_position,
7599                                               type, orig_type)) {
7600                         return;
7601                 }
7602         } else if (!is_type_real(type) && is_type_valid(type)) {
7603                 /* TODO: improve error message */
7604                 errorf(&expression->base.source_position,
7605                        "operation needs an arithmetic or pointer type");
7606                 return;
7607         }
7608         if (!is_lvalue(expression->value)) {
7609                 /* TODO: improve error message */
7610                 errorf(&expression->base.source_position, "lvalue required as operand");
7611         }
7612         expression->base.type = orig_type;
7613 }
7614
7615 static void promote_unary_int_expr(unary_expression_t *const expr, type_t *const type)
7616 {
7617         type_t *const res_type = promote_integer(type);
7618         expr->base.type = res_type;
7619         expr->value     = create_implicit_cast(expr->value, res_type);
7620 }
7621
7622 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
7623 {
7624         type_t *const orig_type = expression->value->base.type;
7625         type_t *const type      = skip_typeref(orig_type);
7626         if (!is_type_arithmetic(type)) {
7627                 if (is_type_valid(type)) {
7628                         /* TODO: improve error message */
7629                         errorf(&expression->base.source_position,
7630                                 "operation needs an arithmetic type");
7631                 }
7632                 return;
7633         } else if (is_type_integer(type)) {
7634                 promote_unary_int_expr(expression, type);
7635         } else {
7636                 expression->base.type = orig_type;
7637         }
7638 }
7639
7640 static void semantic_unexpr_plus(unary_expression_t *expression)
7641 {
7642         semantic_unexpr_arithmetic(expression);
7643         source_position_t const *const pos = &expression->base.source_position;
7644         warningf(WARN_TRADITIONAL, pos, "traditional C rejects the unary plus operator");
7645 }
7646
7647 static void semantic_not(unary_expression_t *expression)
7648 {
7649         /* §6.5.3.3:1  The operand [...] of the ! operator, scalar type. */
7650         semantic_condition(expression->value, "operand of !");
7651         expression->base.type = c_mode & _CXX ? type_bool : type_int;
7652 }
7653
7654 static void semantic_unexpr_integer(unary_expression_t *expression)
7655 {
7656         type_t *const orig_type = expression->value->base.type;
7657         type_t *const type      = skip_typeref(orig_type);
7658         if (!is_type_integer(type)) {
7659                 if (is_type_valid(type)) {
7660                         errorf(&expression->base.source_position,
7661                                "operand of ~ must be of integer type");
7662                 }
7663                 return;
7664         }
7665
7666         promote_unary_int_expr(expression, type);
7667 }
7668
7669 static void semantic_dereference(unary_expression_t *expression)
7670 {
7671         type_t *const orig_type = expression->value->base.type;
7672         type_t *const type      = skip_typeref(orig_type);
7673         if (!is_type_pointer(type)) {
7674                 if (is_type_valid(type)) {
7675                         errorf(&expression->base.source_position,
7676                                "Unary '*' needs pointer or array type, but type '%T' given", orig_type);
7677                 }
7678                 return;
7679         }
7680
7681         type_t *result_type   = type->pointer.points_to;
7682         result_type           = automatic_type_conversion(result_type);
7683         expression->base.type = result_type;
7684 }
7685
7686 /**
7687  * Record that an address is taken (expression represents an lvalue).
7688  *
7689  * @param expression       the expression
7690  * @param may_be_register  if true, the expression might be an register
7691  */
7692 static void set_address_taken(expression_t *expression, bool may_be_register)
7693 {
7694         if (expression->kind != EXPR_REFERENCE)
7695                 return;
7696
7697         entity_t *const entity = expression->reference.entity;
7698
7699         if (entity->kind != ENTITY_VARIABLE && entity->kind != ENTITY_PARAMETER)
7700                 return;
7701
7702         if (entity->declaration.storage_class == STORAGE_CLASS_REGISTER
7703                         && !may_be_register) {
7704                 source_position_t const *const pos = &expression->base.source_position;
7705                 errorf(pos, "address of register '%N' requested", entity);
7706         }
7707
7708         if (entity->kind == ENTITY_VARIABLE) {
7709                 entity->variable.address_taken = true;
7710         } else {
7711                 assert(entity->kind == ENTITY_PARAMETER);
7712                 entity->parameter.address_taken = true;
7713         }
7714 }
7715
7716 /**
7717  * Check the semantic of the address taken expression.
7718  */
7719 static void semantic_take_addr(unary_expression_t *expression)
7720 {
7721         expression_t *value = expression->value;
7722         value->base.type    = revert_automatic_type_conversion(value);
7723
7724         type_t *orig_type = value->base.type;
7725         type_t *type      = skip_typeref(orig_type);
7726         if (!is_type_valid(type))
7727                 return;
7728
7729         /* §6.5.3.2 */
7730         if (!is_lvalue(value)) {
7731                 errorf(&expression->base.source_position, "'&' requires an lvalue");
7732         }
7733         if (is_bitfield(value)) {
7734                 errorf(&expression->base.source_position,
7735                        "'&' not allowed on bitfield");
7736         }
7737
7738         set_address_taken(value, false);
7739
7740         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
7741 }
7742
7743 #define CREATE_UNARY_EXPRESSION_PARSER(token_kind, unexpression_type, sfunc) \
7744 static expression_t *parse_##unexpression_type(void)                         \
7745 {                                                                            \
7746         expression_t *unary_expression                                           \
7747                 = allocate_expression_zero(unexpression_type);                       \
7748         eat(token_kind);                                                         \
7749         unary_expression->unary.value = parse_subexpression(PREC_UNARY);         \
7750                                                                                  \
7751         sfunc(&unary_expression->unary);                                         \
7752                                                                                  \
7753         return unary_expression;                                                 \
7754 }
7755
7756 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
7757                                semantic_unexpr_arithmetic)
7758 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
7759                                semantic_unexpr_plus)
7760 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
7761                                semantic_not)
7762 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
7763                                semantic_dereference)
7764 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
7765                                semantic_take_addr)
7766 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
7767                                semantic_unexpr_integer)
7768 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
7769                                semantic_incdec)
7770 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
7771                                semantic_incdec)
7772
7773 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_kind, unexpression_type, \
7774                                                sfunc)                         \
7775 static expression_t *parse_##unexpression_type(expression_t *left)            \
7776 {                                                                             \
7777         expression_t *unary_expression                                            \
7778                 = allocate_expression_zero(unexpression_type);                        \
7779         eat(token_kind);                                                          \
7780         unary_expression->unary.value = left;                                     \
7781                                                                                   \
7782         sfunc(&unary_expression->unary);                                          \
7783                                                                               \
7784         return unary_expression;                                                  \
7785 }
7786
7787 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
7788                                        EXPR_UNARY_POSTFIX_INCREMENT,
7789                                        semantic_incdec)
7790 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
7791                                        EXPR_UNARY_POSTFIX_DECREMENT,
7792                                        semantic_incdec)
7793
7794 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
7795 {
7796         /* TODO: handle complex + imaginary types */
7797
7798         type_left  = get_unqualified_type(type_left);
7799         type_right = get_unqualified_type(type_right);
7800
7801         /* §6.3.1.8 Usual arithmetic conversions */
7802         if (type_left == type_long_double || type_right == type_long_double) {
7803                 return type_long_double;
7804         } else if (type_left == type_double || type_right == type_double) {
7805                 return type_double;
7806         } else if (type_left == type_float || type_right == type_float) {
7807                 return type_float;
7808         }
7809
7810         type_left  = promote_integer(type_left);
7811         type_right = promote_integer(type_right);
7812
7813         if (type_left == type_right)
7814                 return type_left;
7815
7816         bool     const signed_left  = is_type_signed(type_left);
7817         bool     const signed_right = is_type_signed(type_right);
7818         unsigned const rank_left    = get_akind_rank(get_akind(type_left));
7819         unsigned const rank_right   = get_akind_rank(get_akind(type_right));
7820
7821         if (signed_left == signed_right)
7822                 return rank_left >= rank_right ? type_left : type_right;
7823
7824         unsigned           s_rank;
7825         unsigned           u_rank;
7826         atomic_type_kind_t s_akind;
7827         atomic_type_kind_t u_akind;
7828         type_t *s_type;
7829         type_t *u_type;
7830         if (signed_left) {
7831                 s_type = type_left;
7832                 u_type = type_right;
7833         } else {
7834                 s_type = type_right;
7835                 u_type = type_left;
7836         }
7837         s_akind = get_akind(s_type);
7838         u_akind = get_akind(u_type);
7839         s_rank  = get_akind_rank(s_akind);
7840         u_rank  = get_akind_rank(u_akind);
7841
7842         if (u_rank >= s_rank)
7843                 return u_type;
7844
7845         if (get_atomic_type_size(s_akind) > get_atomic_type_size(u_akind))
7846                 return s_type;
7847
7848         switch (s_akind) {
7849         case ATOMIC_TYPE_INT:      return type_unsigned_int;
7850         case ATOMIC_TYPE_LONG:     return type_unsigned_long;
7851         case ATOMIC_TYPE_LONGLONG: return type_unsigned_long_long;
7852
7853         default: panic("invalid atomic type");
7854         }
7855 }
7856
7857 /**
7858  * Check the semantic restrictions for a binary expression.
7859  */
7860 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
7861 {
7862         expression_t *const left            = expression->left;
7863         expression_t *const right           = expression->right;
7864         type_t       *const orig_type_left  = left->base.type;
7865         type_t       *const orig_type_right = right->base.type;
7866         type_t       *const type_left       = skip_typeref(orig_type_left);
7867         type_t       *const type_right      = skip_typeref(orig_type_right);
7868
7869         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
7870                 /* TODO: improve error message */
7871                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7872                         errorf(&expression->base.source_position,
7873                                "operation needs arithmetic types");
7874                 }
7875                 return;
7876         }
7877
7878         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7879         expression->left      = create_implicit_cast(left, arithmetic_type);
7880         expression->right     = create_implicit_cast(right, arithmetic_type);
7881         expression->base.type = arithmetic_type;
7882 }
7883
7884 static void semantic_binexpr_integer(binary_expression_t *const expression)
7885 {
7886         expression_t *const left            = expression->left;
7887         expression_t *const right           = expression->right;
7888         type_t       *const orig_type_left  = left->base.type;
7889         type_t       *const orig_type_right = right->base.type;
7890         type_t       *const type_left       = skip_typeref(orig_type_left);
7891         type_t       *const type_right      = skip_typeref(orig_type_right);
7892
7893         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
7894                 /* TODO: improve error message */
7895                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7896                         errorf(&expression->base.source_position,
7897                                "operation needs integer types");
7898                 }
7899                 return;
7900         }
7901
7902         type_t *const result_type = semantic_arithmetic(type_left, type_right);
7903         expression->left      = create_implicit_cast(left, result_type);
7904         expression->right     = create_implicit_cast(right, result_type);
7905         expression->base.type = result_type;
7906 }
7907
7908 static void warn_div_by_zero(binary_expression_t const *const expression)
7909 {
7910         if (!is_type_integer(expression->base.type))
7911                 return;
7912
7913         expression_t const *const right = expression->right;
7914         /* The type of the right operand can be different for /= */
7915         if (is_type_integer(right->base.type)                    &&
7916             is_constant_expression(right) == EXPR_CLASS_CONSTANT &&
7917             !fold_constant_to_bool(right)) {
7918                 source_position_t const *const pos = &expression->base.source_position;
7919                 warningf(WARN_DIV_BY_ZERO, pos, "division by zero");
7920         }
7921 }
7922
7923 /**
7924  * Check the semantic restrictions for a div/mod expression.
7925  */
7926 static void semantic_divmod_arithmetic(binary_expression_t *expression)
7927 {
7928         semantic_binexpr_arithmetic(expression);
7929         warn_div_by_zero(expression);
7930 }
7931
7932 static void warn_addsub_in_shift(const expression_t *const expr)
7933 {
7934         if (expr->base.parenthesized)
7935                 return;
7936
7937         char op;
7938         switch (expr->kind) {
7939                 case EXPR_BINARY_ADD: op = '+'; break;
7940                 case EXPR_BINARY_SUB: op = '-'; break;
7941                 default:              return;
7942         }
7943
7944         source_position_t const *const pos = &expr->base.source_position;
7945         warningf(WARN_PARENTHESES, pos, "suggest parentheses around '%c' inside shift", op);
7946 }
7947
7948 static bool semantic_shift(binary_expression_t *expression)
7949 {
7950         expression_t *const left            = expression->left;
7951         expression_t *const right           = expression->right;
7952         type_t       *const orig_type_left  = left->base.type;
7953         type_t       *const orig_type_right = right->base.type;
7954         type_t       *      type_left       = skip_typeref(orig_type_left);
7955         type_t       *      type_right      = skip_typeref(orig_type_right);
7956
7957         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
7958                 /* TODO: improve error message */
7959                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7960                         errorf(&expression->base.source_position,
7961                                "operands of shift operation must have integer types");
7962                 }
7963                 return false;
7964         }
7965
7966         type_left = promote_integer(type_left);
7967
7968         if (is_constant_expression(right) == EXPR_CLASS_CONSTANT) {
7969                 source_position_t const *const pos   = &right->base.source_position;
7970                 long                     const count = fold_constant_to_int(right);
7971                 if (count < 0) {
7972                         warningf(WARN_OTHER, pos, "shift count must be non-negative");
7973                 } else if ((unsigned long)count >=
7974                                 get_atomic_type_size(type_left->atomic.akind) * 8) {
7975                         warningf(WARN_OTHER, pos, "shift count must be less than type width");
7976                 }
7977         }
7978
7979         type_right        = promote_integer(type_right);
7980         expression->right = create_implicit_cast(right, type_right);
7981
7982         return true;
7983 }
7984
7985 static void semantic_shift_op(binary_expression_t *expression)
7986 {
7987         expression_t *const left  = expression->left;
7988         expression_t *const right = expression->right;
7989
7990         if (!semantic_shift(expression))
7991                 return;
7992
7993         warn_addsub_in_shift(left);
7994         warn_addsub_in_shift(right);
7995
7996         type_t *const orig_type_left = left->base.type;
7997         type_t *      type_left      = skip_typeref(orig_type_left);
7998
7999         type_left             = promote_integer(type_left);
8000         expression->left      = create_implicit_cast(left, type_left);
8001         expression->base.type = type_left;
8002 }
8003
8004 static void semantic_add(binary_expression_t *expression)
8005 {
8006         expression_t *const left            = expression->left;
8007         expression_t *const right           = expression->right;
8008         type_t       *const orig_type_left  = left->base.type;
8009         type_t       *const orig_type_right = right->base.type;
8010         type_t       *const type_left       = skip_typeref(orig_type_left);
8011         type_t       *const type_right      = skip_typeref(orig_type_right);
8012
8013         /* §6.5.6 */
8014         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8015                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8016                 expression->left  = create_implicit_cast(left, arithmetic_type);
8017                 expression->right = create_implicit_cast(right, arithmetic_type);
8018                 expression->base.type = arithmetic_type;
8019         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8020                 check_pointer_arithmetic(&expression->base.source_position,
8021                                          type_left, orig_type_left);
8022                 expression->base.type = type_left;
8023         } else if (is_type_pointer(type_right) && is_type_integer(type_left)) {
8024                 check_pointer_arithmetic(&expression->base.source_position,
8025                                          type_right, orig_type_right);
8026                 expression->base.type = type_right;
8027         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8028                 errorf(&expression->base.source_position,
8029                        "invalid operands to binary + ('%T', '%T')",
8030                        orig_type_left, orig_type_right);
8031         }
8032 }
8033
8034 static void semantic_sub(binary_expression_t *expression)
8035 {
8036         expression_t            *const left            = expression->left;
8037         expression_t            *const right           = expression->right;
8038         type_t                  *const orig_type_left  = left->base.type;
8039         type_t                  *const orig_type_right = right->base.type;
8040         type_t                  *const type_left       = skip_typeref(orig_type_left);
8041         type_t                  *const type_right      = skip_typeref(orig_type_right);
8042         source_position_t const *const pos             = &expression->base.source_position;
8043
8044         /* §5.6.5 */
8045         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8046                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8047                 expression->left        = create_implicit_cast(left, arithmetic_type);
8048                 expression->right       = create_implicit_cast(right, arithmetic_type);
8049                 expression->base.type =  arithmetic_type;
8050         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8051                 check_pointer_arithmetic(&expression->base.source_position,
8052                                          type_left, orig_type_left);
8053                 expression->base.type = type_left;
8054         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8055                 type_t *const unqual_left  = get_unqualified_type(skip_typeref(type_left->pointer.points_to));
8056                 type_t *const unqual_right = get_unqualified_type(skip_typeref(type_right->pointer.points_to));
8057                 if (!types_compatible(unqual_left, unqual_right)) {
8058                         errorf(pos,
8059                                "subtracting pointers to incompatible types '%T' and '%T'",
8060                                orig_type_left, orig_type_right);
8061                 } else if (!is_type_object(unqual_left)) {
8062                         if (!is_type_void(unqual_left)) {
8063                                 errorf(pos, "subtracting pointers to non-object types '%T'",
8064                                        orig_type_left);
8065                         } else {
8066                                 warningf(WARN_OTHER, pos, "subtracting pointers to void");
8067                         }
8068                 }
8069                 expression->base.type = type_ptrdiff_t;
8070         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8071                 errorf(pos, "invalid operands of types '%T' and '%T' to binary '-'",
8072                        orig_type_left, orig_type_right);
8073         }
8074 }
8075
8076 static void warn_string_literal_address(expression_t const* expr)
8077 {
8078         while (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
8079                 expr = expr->unary.value;
8080                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
8081                         return;
8082                 expr = expr->unary.value;
8083         }
8084
8085         if (expr->kind == EXPR_STRING_LITERAL
8086                         || expr->kind == EXPR_WIDE_STRING_LITERAL) {
8087                 source_position_t const *const pos = &expr->base.source_position;
8088                 warningf(WARN_ADDRESS, pos, "comparison with string literal results in unspecified behaviour");
8089         }
8090 }
8091
8092 static bool maybe_negative(expression_t const *const expr)
8093 {
8094         switch (is_constant_expression(expr)) {
8095                 case EXPR_CLASS_ERROR:    return false;
8096                 case EXPR_CLASS_CONSTANT: return constant_is_negative(expr);
8097                 default:                  return true;
8098         }
8099 }
8100
8101 static void warn_comparison(source_position_t const *const pos, expression_t const *const expr, expression_t const *const other)
8102 {
8103         warn_string_literal_address(expr);
8104
8105         expression_t const* const ref = get_reference_address(expr);
8106         if (ref != NULL && is_null_pointer_constant(other)) {
8107                 entity_t const *const ent = ref->reference.entity;
8108                 warningf(WARN_ADDRESS, pos, "the address of '%N' will never be NULL", ent);
8109         }
8110
8111         if (!expr->base.parenthesized) {
8112                 switch (expr->base.kind) {
8113                         case EXPR_BINARY_LESS:
8114                         case EXPR_BINARY_GREATER:
8115                         case EXPR_BINARY_LESSEQUAL:
8116                         case EXPR_BINARY_GREATEREQUAL:
8117                         case EXPR_BINARY_NOTEQUAL:
8118                         case EXPR_BINARY_EQUAL:
8119                                 warningf(WARN_PARENTHESES, pos, "comparisons like 'x <= y < z' do not have their mathematical meaning");
8120                                 break;
8121                         default:
8122                                 break;
8123                 }
8124         }
8125 }
8126
8127 /**
8128  * Check the semantics of comparison expressions.
8129  *
8130  * @param expression   The expression to check.
8131  */
8132 static void semantic_comparison(binary_expression_t *expression)
8133 {
8134         source_position_t const *const pos   = &expression->base.source_position;
8135         expression_t            *const left  = expression->left;
8136         expression_t            *const right = expression->right;
8137
8138         warn_comparison(pos, left, right);
8139         warn_comparison(pos, right, left);
8140
8141         type_t *orig_type_left  = left->base.type;
8142         type_t *orig_type_right = right->base.type;
8143         type_t *type_left       = skip_typeref(orig_type_left);
8144         type_t *type_right      = skip_typeref(orig_type_right);
8145
8146         /* TODO non-arithmetic types */
8147         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8148                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8149
8150                 /* test for signed vs unsigned compares */
8151                 if (is_type_integer(arithmetic_type)) {
8152                         bool const signed_left  = is_type_signed(type_left);
8153                         bool const signed_right = is_type_signed(type_right);
8154                         if (signed_left != signed_right) {
8155                                 /* FIXME long long needs better const folding magic */
8156                                 /* TODO check whether constant value can be represented by other type */
8157                                 if ((signed_left  && maybe_negative(left)) ||
8158                                                 (signed_right && maybe_negative(right))) {
8159                                         warningf(WARN_SIGN_COMPARE, pos, "comparison between signed and unsigned");
8160                                 }
8161                         }
8162                 }
8163
8164                 expression->left        = create_implicit_cast(left, arithmetic_type);
8165                 expression->right       = create_implicit_cast(right, arithmetic_type);
8166                 expression->base.type   = arithmetic_type;
8167                 if ((expression->base.kind == EXPR_BINARY_EQUAL ||
8168                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
8169                     is_type_float(arithmetic_type)) {
8170                         warningf(WARN_FLOAT_EQUAL, pos, "comparing floating point with == or != is unsafe");
8171                 }
8172         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8173                 /* TODO check compatibility */
8174         } else if (is_type_pointer(type_left)) {
8175                 expression->right = create_implicit_cast(right, type_left);
8176         } else if (is_type_pointer(type_right)) {
8177                 expression->left = create_implicit_cast(left, type_right);
8178         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8179                 type_error_incompatible("invalid operands in comparison", pos, type_left, type_right);
8180         }
8181         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8182 }
8183
8184 /**
8185  * Checks if a compound type has constant fields.
8186  */
8187 static bool has_const_fields(const compound_type_t *type)
8188 {
8189         compound_t *compound = type->compound;
8190         entity_t   *entry    = compound->members.entities;
8191
8192         for (; entry != NULL; entry = entry->base.next) {
8193                 if (!is_declaration(entry))
8194                         continue;
8195
8196                 const type_t *decl_type = skip_typeref(entry->declaration.type);
8197                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
8198                         return true;
8199         }
8200
8201         return false;
8202 }
8203
8204 static bool is_valid_assignment_lhs(expression_t const* const left)
8205 {
8206         type_t *const orig_type_left = revert_automatic_type_conversion(left);
8207         type_t *const type_left      = skip_typeref(orig_type_left);
8208
8209         if (!is_lvalue(left)) {
8210                 errorf(&left->base.source_position, "left hand side '%E' of assignment is not an lvalue",
8211                        left);
8212                 return false;
8213         }
8214
8215         if (left->kind == EXPR_REFERENCE
8216                         && left->reference.entity->kind == ENTITY_FUNCTION) {
8217                 errorf(&left->base.source_position, "cannot assign to function '%E'", left);
8218                 return false;
8219         }
8220
8221         if (is_type_array(type_left)) {
8222                 errorf(&left->base.source_position, "cannot assign to array '%E'", left);
8223                 return false;
8224         }
8225         if (type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
8226                 errorf(&left->base.source_position, "assignment to read-only location '%E' (type '%T')", left,
8227                        orig_type_left);
8228                 return false;
8229         }
8230         if (is_type_incomplete(type_left)) {
8231                 errorf(&left->base.source_position, "left-hand side '%E' of assignment has incomplete type '%T'",
8232                        left, orig_type_left);
8233                 return false;
8234         }
8235         if (is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
8236                 errorf(&left->base.source_position, "cannot assign to '%E' because compound type '%T' has read-only fields",
8237                        left, orig_type_left);
8238                 return false;
8239         }
8240
8241         return true;
8242 }
8243
8244 static void semantic_arithmetic_assign(binary_expression_t *expression)
8245 {
8246         expression_t *left            = expression->left;
8247         expression_t *right           = expression->right;
8248         type_t       *orig_type_left  = left->base.type;
8249         type_t       *orig_type_right = right->base.type;
8250
8251         if (!is_valid_assignment_lhs(left))
8252                 return;
8253
8254         type_t *type_left  = skip_typeref(orig_type_left);
8255         type_t *type_right = skip_typeref(orig_type_right);
8256
8257         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8258                 /* TODO: improve error message */
8259                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8260                         errorf(&expression->base.source_position,
8261                                "operation needs arithmetic types");
8262                 }
8263                 return;
8264         }
8265
8266         /* combined instructions are tricky. We can't create an implicit cast on
8267          * the left side, because we need the uncasted form for the store.
8268          * The ast2firm pass has to know that left_type must be right_type
8269          * for the arithmetic operation and create a cast by itself */
8270         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8271         expression->right       = create_implicit_cast(right, arithmetic_type);
8272         expression->base.type   = type_left;
8273 }
8274
8275 static void semantic_divmod_assign(binary_expression_t *expression)
8276 {
8277         semantic_arithmetic_assign(expression);
8278         warn_div_by_zero(expression);
8279 }
8280
8281 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
8282 {
8283         expression_t *const left            = expression->left;
8284         expression_t *const right           = expression->right;
8285         type_t       *const orig_type_left  = left->base.type;
8286         type_t       *const orig_type_right = right->base.type;
8287         type_t       *const type_left       = skip_typeref(orig_type_left);
8288         type_t       *const type_right      = skip_typeref(orig_type_right);
8289
8290         if (!is_valid_assignment_lhs(left))
8291                 return;
8292
8293         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8294                 /* combined instructions are tricky. We can't create an implicit cast on
8295                  * the left side, because we need the uncasted form for the store.
8296                  * The ast2firm pass has to know that left_type must be right_type
8297                  * for the arithmetic operation and create a cast by itself */
8298                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
8299                 expression->right     = create_implicit_cast(right, arithmetic_type);
8300                 expression->base.type = type_left;
8301         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8302                 check_pointer_arithmetic(&expression->base.source_position,
8303                                          type_left, orig_type_left);
8304                 expression->base.type = type_left;
8305         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8306                 errorf(&expression->base.source_position,
8307                        "incompatible types '%T' and '%T' in assignment",
8308                        orig_type_left, orig_type_right);
8309         }
8310 }
8311
8312 static void semantic_integer_assign(binary_expression_t *expression)
8313 {
8314         expression_t *left            = expression->left;
8315         expression_t *right           = expression->right;
8316         type_t       *orig_type_left  = left->base.type;
8317         type_t       *orig_type_right = right->base.type;
8318
8319         if (!is_valid_assignment_lhs(left))
8320                 return;
8321
8322         type_t *type_left  = skip_typeref(orig_type_left);
8323         type_t *type_right = skip_typeref(orig_type_right);
8324
8325         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8326                 /* TODO: improve error message */
8327                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8328                         errorf(&expression->base.source_position,
8329                                "operation needs integer types");
8330                 }
8331                 return;
8332         }
8333
8334         /* combined instructions are tricky. We can't create an implicit cast on
8335          * the left side, because we need the uncasted form for the store.
8336          * The ast2firm pass has to know that left_type must be right_type
8337          * for the arithmetic operation and create a cast by itself */
8338         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8339         expression->right       = create_implicit_cast(right, arithmetic_type);
8340         expression->base.type   = type_left;
8341 }
8342
8343 static void semantic_shift_assign(binary_expression_t *expression)
8344 {
8345         expression_t *left           = expression->left;
8346
8347         if (!is_valid_assignment_lhs(left))
8348                 return;
8349
8350         if (!semantic_shift(expression))
8351                 return;
8352
8353         expression->base.type = skip_typeref(left->base.type);
8354 }
8355
8356 static void warn_logical_and_within_or(const expression_t *const expr)
8357 {
8358         if (expr->base.kind != EXPR_BINARY_LOGICAL_AND)
8359                 return;
8360         if (expr->base.parenthesized)
8361                 return;
8362         source_position_t const *const pos = &expr->base.source_position;
8363         warningf(WARN_PARENTHESES, pos, "suggest parentheses around && within ||");
8364 }
8365
8366 /**
8367  * Check the semantic restrictions of a logical expression.
8368  */
8369 static void semantic_logical_op(binary_expression_t *expression)
8370 {
8371         /* §6.5.13:2  Each of the operands shall have scalar type.
8372          * §6.5.14:2  Each of the operands shall have scalar type. */
8373         semantic_condition(expression->left,   "left operand of logical operator");
8374         semantic_condition(expression->right, "right operand of logical operator");
8375         if (expression->base.kind == EXPR_BINARY_LOGICAL_OR) {
8376                 warn_logical_and_within_or(expression->left);
8377                 warn_logical_and_within_or(expression->right);
8378         }
8379         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8380 }
8381
8382 /**
8383  * Check the semantic restrictions of a binary assign expression.
8384  */
8385 static void semantic_binexpr_assign(binary_expression_t *expression)
8386 {
8387         expression_t *left           = expression->left;
8388         type_t       *orig_type_left = left->base.type;
8389
8390         if (!is_valid_assignment_lhs(left))
8391                 return;
8392
8393         assign_error_t error = semantic_assign(orig_type_left, expression->right);
8394         report_assign_error(error, orig_type_left, expression->right,
8395                         "assignment", &left->base.source_position);
8396         expression->right = create_implicit_cast(expression->right, orig_type_left);
8397         expression->base.type = orig_type_left;
8398 }
8399
8400 /**
8401  * Determine if the outermost operation (or parts thereof) of the given
8402  * expression has no effect in order to generate a warning about this fact.
8403  * Therefore in some cases this only examines some of the operands of the
8404  * expression (see comments in the function and examples below).
8405  * Examples:
8406  *   f() + 23;    // warning, because + has no effect
8407  *   x || f();    // no warning, because x controls execution of f()
8408  *   x ? y : f(); // warning, because y has no effect
8409  *   (void)x;     // no warning to be able to suppress the warning
8410  * This function can NOT be used for an "expression has definitely no effect"-
8411  * analysis. */
8412 static bool expression_has_effect(const expression_t *const expr)
8413 {
8414         switch (expr->kind) {
8415                 case EXPR_ERROR:                      return true; /* do NOT warn */
8416                 case EXPR_REFERENCE:                  return false;
8417                 case EXPR_ENUM_CONSTANT:              return false;
8418                 case EXPR_LABEL_ADDRESS:              return false;
8419
8420                 /* suppress the warning for microsoft __noop operations */
8421                 case EXPR_LITERAL_MS_NOOP:            return true;
8422                 case EXPR_LITERAL_BOOLEAN:
8423                 case EXPR_LITERAL_CHARACTER:
8424                 case EXPR_LITERAL_WIDE_CHARACTER:
8425                 case EXPR_LITERAL_INTEGER:
8426                 case EXPR_LITERAL_INTEGER_OCTAL:
8427                 case EXPR_LITERAL_INTEGER_HEXADECIMAL:
8428                 case EXPR_LITERAL_FLOATINGPOINT:
8429                 case EXPR_LITERAL_FLOATINGPOINT_HEXADECIMAL: return false;
8430                 case EXPR_STRING_LITERAL:             return false;
8431                 case EXPR_WIDE_STRING_LITERAL:        return false;
8432
8433                 case EXPR_CALL: {
8434                         const call_expression_t *const call = &expr->call;
8435                         if (call->function->kind != EXPR_REFERENCE)
8436                                 return true;
8437
8438                         switch (call->function->reference.entity->function.btk) {
8439                                 /* FIXME: which builtins have no effect? */
8440                                 default:                      return true;
8441                         }
8442                 }
8443
8444                 /* Generate the warning if either the left or right hand side of a
8445                  * conditional expression has no effect */
8446                 case EXPR_CONDITIONAL: {
8447                         conditional_expression_t const *const cond = &expr->conditional;
8448                         expression_t             const *const t    = cond->true_expression;
8449                         return
8450                                 (t == NULL || expression_has_effect(t)) &&
8451                                 expression_has_effect(cond->false_expression);
8452                 }
8453
8454                 case EXPR_SELECT:                     return false;
8455                 case EXPR_ARRAY_ACCESS:               return false;
8456                 case EXPR_SIZEOF:                     return false;
8457                 case EXPR_CLASSIFY_TYPE:              return false;
8458                 case EXPR_ALIGNOF:                    return false;
8459
8460                 case EXPR_FUNCNAME:                   return false;
8461                 case EXPR_BUILTIN_CONSTANT_P:         return false;
8462                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P: return false;
8463                 case EXPR_OFFSETOF:                   return false;
8464                 case EXPR_VA_START:                   return true;
8465                 case EXPR_VA_ARG:                     return true;
8466                 case EXPR_VA_COPY:                    return true;
8467                 case EXPR_STATEMENT:                  return true; // TODO
8468                 case EXPR_COMPOUND_LITERAL:           return false;
8469
8470                 case EXPR_UNARY_NEGATE:               return false;
8471                 case EXPR_UNARY_PLUS:                 return false;
8472                 case EXPR_UNARY_BITWISE_NEGATE:       return false;
8473                 case EXPR_UNARY_NOT:                  return false;
8474                 case EXPR_UNARY_DEREFERENCE:          return false;
8475                 case EXPR_UNARY_TAKE_ADDRESS:         return false;
8476                 case EXPR_UNARY_POSTFIX_INCREMENT:    return true;
8477                 case EXPR_UNARY_POSTFIX_DECREMENT:    return true;
8478                 case EXPR_UNARY_PREFIX_INCREMENT:     return true;
8479                 case EXPR_UNARY_PREFIX_DECREMENT:     return true;
8480
8481                 /* Treat void casts as if they have an effect in order to being able to
8482                  * suppress the warning */
8483                 case EXPR_UNARY_CAST: {
8484                         type_t *const type = skip_typeref(expr->base.type);
8485                         return is_type_void(type);
8486                 }
8487
8488                 case EXPR_UNARY_ASSUME:               return true;
8489                 case EXPR_UNARY_DELETE:               return true;
8490                 case EXPR_UNARY_DELETE_ARRAY:         return true;
8491                 case EXPR_UNARY_THROW:                return true;
8492
8493                 case EXPR_BINARY_ADD:                 return false;
8494                 case EXPR_BINARY_SUB:                 return false;
8495                 case EXPR_BINARY_MUL:                 return false;
8496                 case EXPR_BINARY_DIV:                 return false;
8497                 case EXPR_BINARY_MOD:                 return false;
8498                 case EXPR_BINARY_EQUAL:               return false;
8499                 case EXPR_BINARY_NOTEQUAL:            return false;
8500                 case EXPR_BINARY_LESS:                return false;
8501                 case EXPR_BINARY_LESSEQUAL:           return false;
8502                 case EXPR_BINARY_GREATER:             return false;
8503                 case EXPR_BINARY_GREATEREQUAL:        return false;
8504                 case EXPR_BINARY_BITWISE_AND:         return false;
8505                 case EXPR_BINARY_BITWISE_OR:          return false;
8506                 case EXPR_BINARY_BITWISE_XOR:         return false;
8507                 case EXPR_BINARY_SHIFTLEFT:           return false;
8508                 case EXPR_BINARY_SHIFTRIGHT:          return false;
8509                 case EXPR_BINARY_ASSIGN:              return true;
8510                 case EXPR_BINARY_MUL_ASSIGN:          return true;
8511                 case EXPR_BINARY_DIV_ASSIGN:          return true;
8512                 case EXPR_BINARY_MOD_ASSIGN:          return true;
8513                 case EXPR_BINARY_ADD_ASSIGN:          return true;
8514                 case EXPR_BINARY_SUB_ASSIGN:          return true;
8515                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:    return true;
8516                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:   return true;
8517                 case EXPR_BINARY_BITWISE_AND_ASSIGN:  return true;
8518                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:  return true;
8519                 case EXPR_BINARY_BITWISE_OR_ASSIGN:   return true;
8520
8521                 /* Only examine the right hand side of && and ||, because the left hand
8522                  * side already has the effect of controlling the execution of the right
8523                  * hand side */
8524                 case EXPR_BINARY_LOGICAL_AND:
8525                 case EXPR_BINARY_LOGICAL_OR:
8526                 /* Only examine the right hand side of a comma expression, because the left
8527                  * hand side has a separate warning */
8528                 case EXPR_BINARY_COMMA:
8529                         return expression_has_effect(expr->binary.right);
8530
8531                 case EXPR_BINARY_ISGREATER:           return false;
8532                 case EXPR_BINARY_ISGREATEREQUAL:      return false;
8533                 case EXPR_BINARY_ISLESS:              return false;
8534                 case EXPR_BINARY_ISLESSEQUAL:         return false;
8535                 case EXPR_BINARY_ISLESSGREATER:       return false;
8536                 case EXPR_BINARY_ISUNORDERED:         return false;
8537         }
8538
8539         internal_errorf(HERE, "unexpected expression");
8540 }
8541
8542 static void semantic_comma(binary_expression_t *expression)
8543 {
8544         const expression_t *const left = expression->left;
8545         if (!expression_has_effect(left)) {
8546                 source_position_t const *const pos = &left->base.source_position;
8547                 warningf(WARN_UNUSED_VALUE, pos, "left-hand operand of comma expression has no effect");
8548         }
8549         expression->base.type = expression->right->base.type;
8550 }
8551
8552 /**
8553  * @param prec_r precedence of the right operand
8554  */
8555 #define CREATE_BINEXPR_PARSER(token_kind, binexpression_type, prec_r, sfunc) \
8556 static expression_t *parse_##binexpression_type(expression_t *left)          \
8557 {                                                                            \
8558         expression_t *binexpr = allocate_expression_zero(binexpression_type);    \
8559         binexpr->binary.left  = left;                                            \
8560         eat(token_kind);                                                         \
8561                                                                              \
8562         expression_t *right = parse_subexpression(prec_r);                       \
8563                                                                              \
8564         binexpr->binary.right = right;                                           \
8565         sfunc(&binexpr->binary);                                                 \
8566                                                                              \
8567         return binexpr;                                                          \
8568 }
8569
8570 CREATE_BINEXPR_PARSER('*',                    EXPR_BINARY_MUL,                PREC_CAST,           semantic_binexpr_arithmetic)
8571 CREATE_BINEXPR_PARSER('/',                    EXPR_BINARY_DIV,                PREC_CAST,           semantic_divmod_arithmetic)
8572 CREATE_BINEXPR_PARSER('%',                    EXPR_BINARY_MOD,                PREC_CAST,           semantic_divmod_arithmetic)
8573 CREATE_BINEXPR_PARSER('+',                    EXPR_BINARY_ADD,                PREC_MULTIPLICATIVE, semantic_add)
8574 CREATE_BINEXPR_PARSER('-',                    EXPR_BINARY_SUB,                PREC_MULTIPLICATIVE, semantic_sub)
8575 CREATE_BINEXPR_PARSER(T_LESSLESS,             EXPR_BINARY_SHIFTLEFT,          PREC_ADDITIVE,       semantic_shift_op)
8576 CREATE_BINEXPR_PARSER(T_GREATERGREATER,       EXPR_BINARY_SHIFTRIGHT,         PREC_ADDITIVE,       semantic_shift_op)
8577 CREATE_BINEXPR_PARSER('<',                    EXPR_BINARY_LESS,               PREC_SHIFT,          semantic_comparison)
8578 CREATE_BINEXPR_PARSER('>',                    EXPR_BINARY_GREATER,            PREC_SHIFT,          semantic_comparison)
8579 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,          PREC_SHIFT,          semantic_comparison)
8580 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,       PREC_SHIFT,          semantic_comparison)
8581 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,           PREC_RELATIONAL,     semantic_comparison)
8582 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,              PREC_RELATIONAL,     semantic_comparison)
8583 CREATE_BINEXPR_PARSER('&',                    EXPR_BINARY_BITWISE_AND,        PREC_EQUALITY,       semantic_binexpr_integer)
8584 CREATE_BINEXPR_PARSER('^',                    EXPR_BINARY_BITWISE_XOR,        PREC_AND,            semantic_binexpr_integer)
8585 CREATE_BINEXPR_PARSER('|',                    EXPR_BINARY_BITWISE_OR,         PREC_XOR,            semantic_binexpr_integer)
8586 CREATE_BINEXPR_PARSER(T_ANDAND,               EXPR_BINARY_LOGICAL_AND,        PREC_OR,             semantic_logical_op)
8587 CREATE_BINEXPR_PARSER(T_PIPEPIPE,             EXPR_BINARY_LOGICAL_OR,         PREC_LOGICAL_AND,    semantic_logical_op)
8588 CREATE_BINEXPR_PARSER('=',                    EXPR_BINARY_ASSIGN,             PREC_ASSIGNMENT,     semantic_binexpr_assign)
8589 CREATE_BINEXPR_PARSER(T_PLUSEQUAL,            EXPR_BINARY_ADD_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8590 CREATE_BINEXPR_PARSER(T_MINUSEQUAL,           EXPR_BINARY_SUB_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8591 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL,        EXPR_BINARY_MUL_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_assign)
8592 CREATE_BINEXPR_PARSER(T_SLASHEQUAL,           EXPR_BINARY_DIV_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8593 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL,         EXPR_BINARY_MOD_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8594 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL,        EXPR_BINARY_SHIFTLEFT_ASSIGN,   PREC_ASSIGNMENT,     semantic_shift_assign)
8595 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL,  EXPR_BINARY_SHIFTRIGHT_ASSIGN,  PREC_ASSIGNMENT,     semantic_shift_assign)
8596 CREATE_BINEXPR_PARSER(T_ANDEQUAL,             EXPR_BINARY_BITWISE_AND_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8597 CREATE_BINEXPR_PARSER(T_PIPEEQUAL,            EXPR_BINARY_BITWISE_OR_ASSIGN,  PREC_ASSIGNMENT,     semantic_integer_assign)
8598 CREATE_BINEXPR_PARSER(T_CARETEQUAL,           EXPR_BINARY_BITWISE_XOR_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8599 CREATE_BINEXPR_PARSER(',',                    EXPR_BINARY_COMMA,              PREC_ASSIGNMENT,     semantic_comma)
8600
8601
8602 static expression_t *parse_subexpression(precedence_t precedence)
8603 {
8604         expression_parser_function_t *parser
8605                 = &expression_parsers[token.kind];
8606         expression_t                 *left;
8607
8608         if (parser->parser != NULL) {
8609                 left = parser->parser();
8610         } else {
8611                 left = parse_primary_expression();
8612         }
8613         assert(left != NULL);
8614
8615         while (true) {
8616                 parser = &expression_parsers[token.kind];
8617                 if (parser->infix_parser == NULL)
8618                         break;
8619                 if (parser->infix_precedence < precedence)
8620                         break;
8621
8622                 left = parser->infix_parser(left);
8623
8624                 assert(left != NULL);
8625         }
8626
8627         return left;
8628 }
8629
8630 /**
8631  * Parse an expression.
8632  */
8633 static expression_t *parse_expression(void)
8634 {
8635         return parse_subexpression(PREC_EXPRESSION);
8636 }
8637
8638 /**
8639  * Register a parser for a prefix-like operator.
8640  *
8641  * @param parser      the parser function
8642  * @param token_kind  the token type of the prefix token
8643  */
8644 static void register_expression_parser(parse_expression_function parser,
8645                                        int token_kind)
8646 {
8647         expression_parser_function_t *entry = &expression_parsers[token_kind];
8648
8649         if (entry->parser != NULL) {
8650                 diagnosticf("for token '%k'\n", (token_kind_t)token_kind);
8651                 panic("trying to register multiple expression parsers for a token");
8652         }
8653         entry->parser = parser;
8654 }
8655
8656 /**
8657  * Register a parser for an infix operator with given precedence.
8658  *
8659  * @param parser      the parser function
8660  * @param token_kind  the token type of the infix operator
8661  * @param precedence  the precedence of the operator
8662  */
8663 static void register_infix_parser(parse_expression_infix_function parser,
8664                                   int token_kind, precedence_t precedence)
8665 {
8666         expression_parser_function_t *entry = &expression_parsers[token_kind];
8667
8668         if (entry->infix_parser != NULL) {
8669                 diagnosticf("for token '%k'\n", (token_kind_t)token_kind);
8670                 panic("trying to register multiple infix expression parsers for a "
8671                       "token");
8672         }
8673         entry->infix_parser     = parser;
8674         entry->infix_precedence = precedence;
8675 }
8676
8677 /**
8678  * Initialize the expression parsers.
8679  */
8680 static void init_expression_parsers(void)
8681 {
8682         memset(&expression_parsers, 0, sizeof(expression_parsers));
8683
8684         register_infix_parser(parse_array_expression,               '[',                    PREC_POSTFIX);
8685         register_infix_parser(parse_call_expression,                '(',                    PREC_POSTFIX);
8686         register_infix_parser(parse_select_expression,              '.',                    PREC_POSTFIX);
8687         register_infix_parser(parse_select_expression,              T_MINUSGREATER,         PREC_POSTFIX);
8688         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,   T_PLUSPLUS,             PREC_POSTFIX);
8689         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,   T_MINUSMINUS,           PREC_POSTFIX);
8690         register_infix_parser(parse_EXPR_BINARY_MUL,                '*',                    PREC_MULTIPLICATIVE);
8691         register_infix_parser(parse_EXPR_BINARY_DIV,                '/',                    PREC_MULTIPLICATIVE);
8692         register_infix_parser(parse_EXPR_BINARY_MOD,                '%',                    PREC_MULTIPLICATIVE);
8693         register_infix_parser(parse_EXPR_BINARY_ADD,                '+',                    PREC_ADDITIVE);
8694         register_infix_parser(parse_EXPR_BINARY_SUB,                '-',                    PREC_ADDITIVE);
8695         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,          T_LESSLESS,             PREC_SHIFT);
8696         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,         T_GREATERGREATER,       PREC_SHIFT);
8697         register_infix_parser(parse_EXPR_BINARY_LESS,               '<',                    PREC_RELATIONAL);
8698         register_infix_parser(parse_EXPR_BINARY_GREATER,            '>',                    PREC_RELATIONAL);
8699         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,          T_LESSEQUAL,            PREC_RELATIONAL);
8700         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL,       T_GREATEREQUAL,         PREC_RELATIONAL);
8701         register_infix_parser(parse_EXPR_BINARY_EQUAL,              T_EQUALEQUAL,           PREC_EQUALITY);
8702         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,           T_EXCLAMATIONMARKEQUAL, PREC_EQUALITY);
8703         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,        '&',                    PREC_AND);
8704         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,        '^',                    PREC_XOR);
8705         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,         '|',                    PREC_OR);
8706         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,        T_ANDAND,               PREC_LOGICAL_AND);
8707         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,         T_PIPEPIPE,             PREC_LOGICAL_OR);
8708         register_infix_parser(parse_conditional_expression,         '?',                    PREC_CONDITIONAL);
8709         register_infix_parser(parse_EXPR_BINARY_ASSIGN,             '=',                    PREC_ASSIGNMENT);
8710         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,         T_PLUSEQUAL,            PREC_ASSIGNMENT);
8711         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,         T_MINUSEQUAL,           PREC_ASSIGNMENT);
8712         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,         T_ASTERISKEQUAL,        PREC_ASSIGNMENT);
8713         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,         T_SLASHEQUAL,           PREC_ASSIGNMENT);
8714         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,         T_PERCENTEQUAL,         PREC_ASSIGNMENT);
8715         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,   T_LESSLESSEQUAL,        PREC_ASSIGNMENT);
8716         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,  T_GREATERGREATEREQUAL,  PREC_ASSIGNMENT);
8717         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN, T_ANDEQUAL,             PREC_ASSIGNMENT);
8718         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,  T_PIPEEQUAL,            PREC_ASSIGNMENT);
8719         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN, T_CARETEQUAL,           PREC_ASSIGNMENT);
8720         register_infix_parser(parse_EXPR_BINARY_COMMA,              ',',                    PREC_EXPRESSION);
8721
8722         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-');
8723         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+');
8724         register_expression_parser(parse_EXPR_UNARY_NOT,              '!');
8725         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~');
8726         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*');
8727         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&');
8728         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT, T_PLUSPLUS);
8729         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT, T_MINUSMINUS);
8730         register_expression_parser(parse_sizeof,                      T_sizeof);
8731         register_expression_parser(parse_alignof,                     T___alignof__);
8732         register_expression_parser(parse_extension,                   T___extension__);
8733         register_expression_parser(parse_builtin_classify_type,       T___builtin_classify_type);
8734         register_expression_parser(parse_delete,                      T_delete);
8735         register_expression_parser(parse_throw,                       T_throw);
8736 }
8737
8738 /**
8739  * Parse a asm statement arguments specification.
8740  */
8741 static asm_argument_t *parse_asm_arguments(bool is_out)
8742 {
8743         asm_argument_t  *result = NULL;
8744         asm_argument_t **anchor = &result;
8745
8746         while (token.kind == T_STRING_LITERAL || token.kind == '[') {
8747                 asm_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
8748
8749                 if (next_if('[')) {
8750                         add_anchor_token(']');
8751                         argument->symbol = expect_identifier("while parsing asm argument", NULL);
8752                         rem_anchor_token(']');
8753                         expect(']');
8754                         if (!argument->symbol)
8755                                 return NULL;
8756                 }
8757
8758                 argument->constraints = parse_string_literals();
8759                 expect('(');
8760                 add_anchor_token(')');
8761                 expression_t *expression = parse_expression();
8762                 rem_anchor_token(')');
8763                 if (is_out) {
8764                         /* Ugly GCC stuff: Allow lvalue casts.  Skip casts, when they do not
8765                          * change size or type representation (e.g. int -> long is ok, but
8766                          * int -> float is not) */
8767                         if (expression->kind == EXPR_UNARY_CAST) {
8768                                 type_t      *const type = expression->base.type;
8769                                 type_kind_t  const kind = type->kind;
8770                                 if (kind == TYPE_ATOMIC || kind == TYPE_POINTER) {
8771                                         unsigned flags;
8772                                         unsigned size;
8773                                         if (kind == TYPE_ATOMIC) {
8774                                                 atomic_type_kind_t const akind = type->atomic.akind;
8775                                                 flags = get_atomic_type_flags(akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
8776                                                 size  = get_atomic_type_size(akind);
8777                                         } else {
8778                                                 flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
8779                                                 size  = get_type_size(type_void_ptr);
8780                                         }
8781
8782                                         do {
8783                                                 expression_t *const value      = expression->unary.value;
8784                                                 type_t       *const value_type = value->base.type;
8785                                                 type_kind_t   const value_kind = value_type->kind;
8786
8787                                                 unsigned value_flags;
8788                                                 unsigned value_size;
8789                                                 if (value_kind == TYPE_ATOMIC) {
8790                                                         atomic_type_kind_t const value_akind = value_type->atomic.akind;
8791                                                         value_flags = get_atomic_type_flags(value_akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
8792                                                         value_size  = get_atomic_type_size(value_akind);
8793                                                 } else if (value_kind == TYPE_POINTER) {
8794                                                         value_flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
8795                                                         value_size  = get_type_size(type_void_ptr);
8796                                                 } else {
8797                                                         break;
8798                                                 }
8799
8800                                                 if (value_flags != flags || value_size != size)
8801                                                         break;
8802
8803                                                 expression = value;
8804                                         } while (expression->kind == EXPR_UNARY_CAST);
8805                                 }
8806                         }
8807
8808                         if (!is_lvalue(expression)) {
8809                                 errorf(&expression->base.source_position,
8810                                        "asm output argument is not an lvalue");
8811                         }
8812
8813                         if (argument->constraints.begin[0] == '=')
8814                                 determine_lhs_ent(expression, NULL);
8815                         else
8816                                 mark_vars_read(expression, NULL);
8817                 } else {
8818                         mark_vars_read(expression, NULL);
8819                 }
8820                 argument->expression = expression;
8821                 expect(')');
8822
8823                 set_address_taken(expression, true);
8824
8825                 *anchor = argument;
8826                 anchor  = &argument->next;
8827
8828                 if (!next_if(','))
8829                         break;
8830         }
8831
8832         return result;
8833 }
8834
8835 /**
8836  * Parse a asm statement clobber specification.
8837  */
8838 static asm_clobber_t *parse_asm_clobbers(void)
8839 {
8840         asm_clobber_t *result  = NULL;
8841         asm_clobber_t **anchor = &result;
8842
8843         while (token.kind == T_STRING_LITERAL) {
8844                 asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
8845                 clobber->clobber       = parse_string_literals();
8846
8847                 *anchor = clobber;
8848                 anchor  = &clobber->next;
8849
8850                 if (!next_if(','))
8851                         break;
8852         }
8853
8854         return result;
8855 }
8856
8857 /**
8858  * Parse an asm statement.
8859  */
8860 static statement_t *parse_asm_statement(void)
8861 {
8862         statement_t     *statement     = allocate_statement_zero(STATEMENT_ASM);
8863         asm_statement_t *asm_statement = &statement->asms;
8864
8865         eat(T_asm);
8866
8867         if (next_if(T_volatile))
8868                 asm_statement->is_volatile = true;
8869
8870         expect('(');
8871         add_anchor_token(')');
8872         if (token.kind != T_STRING_LITERAL) {
8873                 parse_error_expected("after asm(", T_STRING_LITERAL, NULL);
8874                 goto end_of_asm;
8875         }
8876         asm_statement->asm_text = parse_string_literals();
8877
8878         add_anchor_token(':');
8879         if (!next_if(':')) {
8880                 rem_anchor_token(':');
8881                 goto end_of_asm;
8882         }
8883
8884         asm_statement->outputs = parse_asm_arguments(true);
8885         if (!next_if(':')) {
8886                 rem_anchor_token(':');
8887                 goto end_of_asm;
8888         }
8889
8890         asm_statement->inputs = parse_asm_arguments(false);
8891         if (!next_if(':')) {
8892                 rem_anchor_token(':');
8893                 goto end_of_asm;
8894         }
8895         rem_anchor_token(':');
8896
8897         asm_statement->clobbers = parse_asm_clobbers();
8898
8899 end_of_asm:
8900         rem_anchor_token(')');
8901         expect(')');
8902         expect(';');
8903
8904         if (asm_statement->outputs == NULL) {
8905                 /* GCC: An 'asm' instruction without any output operands will be treated
8906                  * identically to a volatile 'asm' instruction. */
8907                 asm_statement->is_volatile = true;
8908         }
8909
8910         return statement;
8911 }
8912
8913 static statement_t *parse_label_inner_statement(statement_t const *const label, char const *const label_kind)
8914 {
8915         statement_t *inner_stmt;
8916         switch (token.kind) {
8917                 case '}':
8918                         errorf(&label->base.source_position, "%s at end of compound statement", label_kind);
8919                         inner_stmt = create_error_statement();
8920                         break;
8921
8922                 case ';':
8923                         if (label->kind == STATEMENT_LABEL) {
8924                                 /* Eat an empty statement here, to avoid the warning about an empty
8925                                  * statement after a label.  label:; is commonly used to have a label
8926                                  * before a closing brace. */
8927                                 inner_stmt = create_empty_statement();
8928                                 next_token();
8929                                 break;
8930                         }
8931                         /* FALLTHROUGH */
8932
8933                 default:
8934                         inner_stmt = parse_statement();
8935                         /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
8936                         /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
8937                         if (inner_stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
8938                                 errorf(&inner_stmt->base.source_position, "declaration after %s", label_kind);
8939                         }
8940                         break;
8941         }
8942         return inner_stmt;
8943 }
8944
8945 /**
8946  * Parse a case statement.
8947  */
8948 static statement_t *parse_case_statement(void)
8949 {
8950         statement_t       *const statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
8951         source_position_t *const pos       = &statement->base.source_position;
8952
8953         eat(T_case);
8954         add_anchor_token(':');
8955
8956         expression_t *expression = parse_expression();
8957         type_t *expression_type = expression->base.type;
8958         type_t *skipped         = skip_typeref(expression_type);
8959         if (!is_type_integer(skipped) && is_type_valid(skipped)) {
8960                 errorf(pos, "case expression '%E' must have integer type but has type '%T'",
8961                        expression, expression_type);
8962         }
8963
8964         type_t *type = expression_type;
8965         if (current_switch != NULL) {
8966                 type_t *switch_type = current_switch->expression->base.type;
8967                 if (is_type_valid(switch_type)) {
8968                         expression = create_implicit_cast(expression, switch_type);
8969                 }
8970         }
8971
8972         statement->case_label.expression = expression;
8973         expression_classification_t const expr_class = is_constant_expression(expression);
8974         if (expr_class != EXPR_CLASS_CONSTANT) {
8975                 if (expr_class != EXPR_CLASS_ERROR) {
8976                         errorf(pos, "case label does not reduce to an integer constant");
8977                 }
8978                 statement->case_label.is_bad = true;
8979         } else {
8980                 long const val = fold_constant_to_int(expression);
8981                 statement->case_label.first_case = val;
8982                 statement->case_label.last_case  = val;
8983         }
8984
8985         if (GNU_MODE) {
8986                 if (next_if(T_DOTDOTDOT)) {
8987                         expression_t *end_range = parse_expression();
8988                         expression_type = expression->base.type;
8989                         skipped         = skip_typeref(expression_type);
8990                         if (!is_type_integer(skipped) && is_type_valid(skipped)) {
8991                                 errorf(pos, "case expression '%E' must have integer type but has type '%T'",
8992                                            expression, expression_type);
8993                         }
8994
8995                         end_range = create_implicit_cast(end_range, type);
8996                         statement->case_label.end_range = end_range;
8997                         expression_classification_t const end_class = is_constant_expression(end_range);
8998                         if (end_class != EXPR_CLASS_CONSTANT) {
8999                                 if (end_class != EXPR_CLASS_ERROR) {
9000                                         errorf(pos, "case range does not reduce to an integer constant");
9001                                 }
9002                                 statement->case_label.is_bad = true;
9003                         } else {
9004                                 long const val = fold_constant_to_int(end_range);
9005                                 statement->case_label.last_case = val;
9006
9007                                 if (val < statement->case_label.first_case) {
9008                                         statement->case_label.is_empty_range = true;
9009                                         warningf(WARN_OTHER, pos, "empty range specified");
9010                                 }
9011                         }
9012                 }
9013         }
9014
9015         PUSH_PARENT(statement);
9016
9017         rem_anchor_token(':');
9018         expect(':');
9019
9020         if (current_switch != NULL) {
9021                 if (! statement->case_label.is_bad) {
9022                         /* Check for duplicate case values */
9023                         case_label_statement_t *c = &statement->case_label;
9024                         for (case_label_statement_t *l = current_switch->first_case; l != NULL; l = l->next) {
9025                                 if (l->is_bad || l->is_empty_range || l->expression == NULL)
9026                                         continue;
9027
9028                                 if (c->last_case < l->first_case || c->first_case > l->last_case)
9029                                         continue;
9030
9031                                 errorf(pos, "duplicate case value (previously used %P)",
9032                                        &l->base.source_position);
9033                                 break;
9034                         }
9035                 }
9036                 /* link all cases into the switch statement */
9037                 if (current_switch->last_case == NULL) {
9038                         current_switch->first_case      = &statement->case_label;
9039                 } else {
9040                         current_switch->last_case->next = &statement->case_label;
9041                 }
9042                 current_switch->last_case = &statement->case_label;
9043         } else {
9044                 errorf(pos, "case label not within a switch statement");
9045         }
9046
9047         statement->case_label.statement = parse_label_inner_statement(statement, "case label");
9048
9049         POP_PARENT();
9050         return statement;
9051 }
9052
9053 /**
9054  * Parse a default statement.
9055  */
9056 static statement_t *parse_default_statement(void)
9057 {
9058         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9059
9060         eat(T_default);
9061
9062         PUSH_PARENT(statement);
9063
9064         expect(':');
9065
9066         if (current_switch != NULL) {
9067                 const case_label_statement_t *def_label = current_switch->default_label;
9068                 if (def_label != NULL) {
9069                         errorf(&statement->base.source_position, "multiple default labels in one switch (previous declared %P)", &def_label->base.source_position);
9070                 } else {
9071                         current_switch->default_label = &statement->case_label;
9072
9073                         /* link all cases into the switch statement */
9074                         if (current_switch->last_case == NULL) {
9075                                 current_switch->first_case      = &statement->case_label;
9076                         } else {
9077                                 current_switch->last_case->next = &statement->case_label;
9078                         }
9079                         current_switch->last_case = &statement->case_label;
9080                 }
9081         } else {
9082                 errorf(&statement->base.source_position,
9083                         "'default' label not within a switch statement");
9084         }
9085
9086         statement->case_label.statement = parse_label_inner_statement(statement, "default label");
9087
9088         POP_PARENT();
9089         return statement;
9090 }
9091
9092 /**
9093  * Parse a label statement.
9094  */
9095 static statement_t *parse_label_statement(void)
9096 {
9097         statement_t *const statement = allocate_statement_zero(STATEMENT_LABEL);
9098         label_t     *const label     = get_label();
9099         statement->label.label = label;
9100
9101         PUSH_PARENT(statement);
9102
9103         /* if statement is already set then the label is defined twice,
9104          * otherwise it was just mentioned in a goto/local label declaration so far
9105          */
9106         source_position_t const* const pos = &statement->base.source_position;
9107         if (label->statement != NULL) {
9108                 errorf(pos, "duplicate '%N' (declared %P)", (entity_t const*)label, &label->base.source_position);
9109         } else {
9110                 label->base.source_position = *pos;
9111                 label->statement            = statement;
9112         }
9113
9114         eat(':');
9115
9116         if (token.kind == T___attribute__ && !(c_mode & _CXX)) {
9117                 parse_attributes(NULL); // TODO process attributes
9118         }
9119
9120         statement->label.statement = parse_label_inner_statement(statement, "label");
9121
9122         /* remember the labels in a list for later checking */
9123         *label_anchor = &statement->label;
9124         label_anchor  = &statement->label.next;
9125
9126         POP_PARENT();
9127         return statement;
9128 }
9129
9130 static statement_t *parse_inner_statement(void)
9131 {
9132         statement_t *const stmt = parse_statement();
9133         /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
9134         /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
9135         if (stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
9136                 errorf(&stmt->base.source_position, "declaration as inner statement, use {}");
9137         }
9138         return stmt;
9139 }
9140
9141 /**
9142  * Parse an expression in parentheses and mark its variables as read.
9143  */
9144 static expression_t *parse_condition(void)
9145 {
9146         expect('(');
9147         add_anchor_token(')');
9148         expression_t *const expr = parse_expression();
9149         mark_vars_read(expr, NULL);
9150         rem_anchor_token(')');
9151         expect(')');
9152         return expr;
9153 }
9154
9155 /**
9156  * Parse an if statement.
9157  */
9158 static statement_t *parse_if(void)
9159 {
9160         statement_t *statement = allocate_statement_zero(STATEMENT_IF);
9161
9162         eat(T_if);
9163
9164         PUSH_PARENT(statement);
9165         PUSH_SCOPE_STATEMENT(&statement->ifs.scope);
9166
9167         add_anchor_token(T_else);
9168
9169         expression_t *const expr = parse_condition();
9170         statement->ifs.condition = expr;
9171         /* §6.8.4.1:1  The controlling expression of an if statement shall have
9172          *             scalar type. */
9173         semantic_condition(expr, "condition of 'if'-statment");
9174
9175         statement_t *const true_stmt = parse_inner_statement();
9176         statement->ifs.true_statement = true_stmt;
9177         rem_anchor_token(T_else);
9178
9179         if (true_stmt->kind == STATEMENT_EMPTY) {
9180                 warningf(WARN_EMPTY_BODY, HERE,
9181                         "suggest braces around empty body in an ‘if’ statement");
9182         }
9183
9184         if (next_if(T_else)) {
9185                 statement->ifs.false_statement = parse_inner_statement();
9186
9187                 if (statement->ifs.false_statement->kind == STATEMENT_EMPTY) {
9188                         warningf(WARN_EMPTY_BODY, HERE,
9189                                         "suggest braces around empty body in an ‘if’ statement");
9190                 }
9191         } else if (true_stmt->kind == STATEMENT_IF &&
9192                         true_stmt->ifs.false_statement != NULL) {
9193                 source_position_t const *const pos = &true_stmt->base.source_position;
9194                 warningf(WARN_PARENTHESES, pos, "suggest explicit braces to avoid ambiguous 'else'");
9195         }
9196
9197         POP_SCOPE();
9198         POP_PARENT();
9199         return statement;
9200 }
9201
9202 /**
9203  * Check that all enums are handled in a switch.
9204  *
9205  * @param statement  the switch statement to check
9206  */
9207 static void check_enum_cases(const switch_statement_t *statement)
9208 {
9209         if (!is_warn_on(WARN_SWITCH_ENUM))
9210                 return;
9211         const type_t *type = skip_typeref(statement->expression->base.type);
9212         if (! is_type_enum(type))
9213                 return;
9214         const enum_type_t *enumt = &type->enumt;
9215
9216         /* if we have a default, no warnings */
9217         if (statement->default_label != NULL)
9218                 return;
9219
9220         /* FIXME: calculation of value should be done while parsing */
9221         /* TODO: quadratic algorithm here. Change to an n log n one */
9222         long            last_value = -1;
9223         const entity_t *entry      = enumt->enume->base.next;
9224         for (; entry != NULL && entry->kind == ENTITY_ENUM_VALUE;
9225              entry = entry->base.next) {
9226                 const expression_t *expression = entry->enum_value.value;
9227                 long                value      = expression != NULL ? fold_constant_to_int(expression) : last_value + 1;
9228                 bool                found      = false;
9229                 for (const case_label_statement_t *l = statement->first_case; l != NULL; l = l->next) {
9230                         if (l->expression == NULL)
9231                                 continue;
9232                         if (l->first_case <= value && value <= l->last_case) {
9233                                 found = true;
9234                                 break;
9235                         }
9236                 }
9237                 if (!found) {
9238                         source_position_t const *const pos = &statement->base.source_position;
9239                         warningf(WARN_SWITCH_ENUM, pos, "'%N' not handled in switch", entry);
9240                 }
9241                 last_value = value;
9242         }
9243 }
9244
9245 /**
9246  * Parse a switch statement.
9247  */
9248 static statement_t *parse_switch(void)
9249 {
9250         statement_t *statement = allocate_statement_zero(STATEMENT_SWITCH);
9251
9252         eat(T_switch);
9253
9254         PUSH_PARENT(statement);
9255         PUSH_SCOPE_STATEMENT(&statement->switchs.scope);
9256
9257         expression_t *const expr = parse_condition();
9258         type_t       *      type = skip_typeref(expr->base.type);
9259         if (is_type_integer(type)) {
9260                 type = promote_integer(type);
9261                 if (get_akind_rank(get_akind(type)) >= get_akind_rank(ATOMIC_TYPE_LONG)) {
9262                         warningf(WARN_TRADITIONAL, &expr->base.source_position, "'%T' switch expression not converted to '%T' in ISO C", type, type_int);
9263                 }
9264         } else if (is_type_valid(type)) {
9265                 errorf(&expr->base.source_position,
9266                        "switch quantity is not an integer, but '%T'", type);
9267                 type = type_error_type;
9268         }
9269         statement->switchs.expression = create_implicit_cast(expr, type);
9270
9271         switch_statement_t *rem = current_switch;
9272         current_switch          = &statement->switchs;
9273         statement->switchs.body = parse_inner_statement();
9274         current_switch          = rem;
9275
9276         if (statement->switchs.default_label == NULL) {
9277                 warningf(WARN_SWITCH_DEFAULT, &statement->base.source_position, "switch has no default case");
9278         }
9279         check_enum_cases(&statement->switchs);
9280
9281         POP_SCOPE();
9282         POP_PARENT();
9283         return statement;
9284 }
9285
9286 static statement_t *parse_loop_body(statement_t *const loop)
9287 {
9288         statement_t *const rem = current_loop;
9289         current_loop = loop;
9290
9291         statement_t *const body = parse_inner_statement();
9292
9293         current_loop = rem;
9294         return body;
9295 }
9296
9297 /**
9298  * Parse a while statement.
9299  */
9300 static statement_t *parse_while(void)
9301 {
9302         statement_t *statement = allocate_statement_zero(STATEMENT_WHILE);
9303
9304         eat(T_while);
9305
9306         PUSH_PARENT(statement);
9307         PUSH_SCOPE_STATEMENT(&statement->whiles.scope);
9308
9309         expression_t *const cond = parse_condition();
9310         statement->whiles.condition = cond;
9311         /* §6.8.5:2    The controlling expression of an iteration statement shall
9312          *             have scalar type. */
9313         semantic_condition(cond, "condition of 'while'-statement");
9314
9315         statement->whiles.body = parse_loop_body(statement);
9316
9317         POP_SCOPE();
9318         POP_PARENT();
9319         return statement;
9320 }
9321
9322 /**
9323  * Parse a do statement.
9324  */
9325 static statement_t *parse_do(void)
9326 {
9327         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
9328
9329         eat(T_do);
9330
9331         PUSH_PARENT(statement);
9332         PUSH_SCOPE_STATEMENT(&statement->do_while.scope);
9333
9334         add_anchor_token(T_while);
9335         statement->do_while.body = parse_loop_body(statement);
9336         rem_anchor_token(T_while);
9337
9338         expect(T_while);
9339         expression_t *const cond = parse_condition();
9340         statement->do_while.condition = cond;
9341         /* §6.8.5:2    The controlling expression of an iteration statement shall
9342          *             have scalar type. */
9343         semantic_condition(cond, "condition of 'do-while'-statement");
9344         expect(';');
9345
9346         POP_SCOPE();
9347         POP_PARENT();
9348         return statement;
9349 }
9350
9351 /**
9352  * Parse a for statement.
9353  */
9354 static statement_t *parse_for(void)
9355 {
9356         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
9357
9358         eat(T_for);
9359
9360         PUSH_PARENT(statement);
9361         PUSH_SCOPE_STATEMENT(&statement->fors.scope);
9362
9363         expect('(');
9364         add_anchor_token(')');
9365
9366         PUSH_EXTENSION();
9367
9368         if (next_if(';')) {
9369         } else if (is_declaration_specifier(&token)) {
9370                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9371         } else {
9372                 add_anchor_token(';');
9373                 expression_t *const init = parse_expression();
9374                 statement->fors.initialisation = init;
9375                 mark_vars_read(init, ENT_ANY);
9376                 if (!expression_has_effect(init)) {
9377                         warningf(WARN_UNUSED_VALUE, &init->base.source_position, "initialisation of 'for'-statement has no effect");
9378                 }
9379                 rem_anchor_token(';');
9380                 expect(';');
9381         }
9382
9383         POP_EXTENSION();
9384
9385         if (token.kind != ';') {
9386                 add_anchor_token(';');
9387                 expression_t *const cond = parse_expression();
9388                 statement->fors.condition = cond;
9389                 /* §6.8.5:2    The controlling expression of an iteration statement
9390                  *             shall have scalar type. */
9391                 semantic_condition(cond, "condition of 'for'-statement");
9392                 mark_vars_read(cond, NULL);
9393                 rem_anchor_token(';');
9394         }
9395         expect(';');
9396         if (token.kind != ')') {
9397                 expression_t *const step = parse_expression();
9398                 statement->fors.step = step;
9399                 mark_vars_read(step, ENT_ANY);
9400                 if (!expression_has_effect(step)) {
9401                         warningf(WARN_UNUSED_VALUE, &step->base.source_position, "step of 'for'-statement has no effect");
9402                 }
9403         }
9404         rem_anchor_token(')');
9405         expect(')');
9406         statement->fors.body = parse_loop_body(statement);
9407
9408         POP_SCOPE();
9409         POP_PARENT();
9410         return statement;
9411 }
9412
9413 /**
9414  * Parse a goto statement.
9415  */
9416 static statement_t *parse_goto(void)
9417 {
9418         statement_t *statement;
9419         if (GNU_MODE && look_ahead(1)->kind == '*') {
9420                 statement = allocate_statement_zero(STATEMENT_COMPUTED_GOTO);
9421                 eat(T_goto);
9422                 eat('*');
9423
9424                 expression_t *expression = parse_expression();
9425                 mark_vars_read(expression, NULL);
9426
9427                 /* Argh: although documentation says the expression must be of type void*,
9428                  * gcc accepts anything that can be casted into void* without error */
9429                 type_t *type = expression->base.type;
9430
9431                 if (type != type_error_type) {
9432                         if (!is_type_pointer(type) && !is_type_integer(type)) {
9433                                 errorf(&expression->base.source_position,
9434                                         "cannot convert to a pointer type");
9435                         } else if (type != type_void_ptr) {
9436                                 warningf(WARN_OTHER, &expression->base.source_position, "type of computed goto expression should be 'void*' not '%T'", type);
9437                         }
9438                         expression = create_implicit_cast(expression, type_void_ptr);
9439                 }
9440
9441                 statement->computed_goto.expression = expression;
9442         } else {
9443                 statement = allocate_statement_zero(STATEMENT_GOTO);
9444                 eat(T_goto);
9445                 if (token.kind == T_IDENTIFIER) {
9446                         label_t *const label = get_label();
9447                         label->used            = true;
9448                         statement->gotos.label = label;
9449
9450                         /* remember the goto's in a list for later checking */
9451                         *goto_anchor = &statement->gotos;
9452                         goto_anchor  = &statement->gotos.next;
9453                 } else {
9454                         if (GNU_MODE)
9455                                 parse_error_expected("while parsing goto", T_IDENTIFIER, '*', NULL);
9456                         else
9457                                 parse_error_expected("while parsing goto", T_IDENTIFIER, NULL);
9458                         eat_until_anchor();
9459                         statement->gotos.label = &allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, sym_anonymous, &builtin_source_position)->label;
9460                 }
9461         }
9462
9463         expect(';');
9464         return statement;
9465 }
9466
9467 /**
9468  * Parse a continue statement.
9469  */
9470 static statement_t *parse_continue(void)
9471 {
9472         if (current_loop == NULL) {
9473                 errorf(HERE, "continue statement not within loop");
9474         }
9475
9476         statement_t *statement = allocate_statement_zero(STATEMENT_CONTINUE);
9477
9478         eat(T_continue);
9479         expect(';');
9480         return statement;
9481 }
9482
9483 /**
9484  * Parse a break statement.
9485  */
9486 static statement_t *parse_break(void)
9487 {
9488         if (current_switch == NULL && current_loop == NULL) {
9489                 errorf(HERE, "break statement not within loop or switch");
9490         }
9491
9492         statement_t *statement = allocate_statement_zero(STATEMENT_BREAK);
9493
9494         eat(T_break);
9495         expect(';');
9496         return statement;
9497 }
9498
9499 /**
9500  * Parse a __leave statement.
9501  */
9502 static statement_t *parse_leave_statement(void)
9503 {
9504         if (current_try == NULL) {
9505                 errorf(HERE, "__leave statement not within __try");
9506         }
9507
9508         statement_t *statement = allocate_statement_zero(STATEMENT_LEAVE);
9509
9510         eat(T___leave);
9511         expect(';');
9512         return statement;
9513 }
9514
9515 /**
9516  * Check if a given entity represents a local variable.
9517  */
9518 static bool is_local_variable(const entity_t *entity)
9519 {
9520         if (entity->kind != ENTITY_VARIABLE)
9521                 return false;
9522
9523         switch ((storage_class_tag_t) entity->declaration.storage_class) {
9524         case STORAGE_CLASS_AUTO:
9525         case STORAGE_CLASS_REGISTER: {
9526                 const type_t *type = skip_typeref(entity->declaration.type);
9527                 if (is_type_function(type)) {
9528                         return false;
9529                 } else {
9530                         return true;
9531                 }
9532         }
9533         default:
9534                 return false;
9535         }
9536 }
9537
9538 /**
9539  * Check if a given expression represents a local variable.
9540  */
9541 static bool expression_is_local_variable(const expression_t *expression)
9542 {
9543         if (expression->base.kind != EXPR_REFERENCE) {
9544                 return false;
9545         }
9546         const entity_t *entity = expression->reference.entity;
9547         return is_local_variable(entity);
9548 }
9549
9550 /**
9551  * Check if a given expression represents a local variable and
9552  * return its declaration then, else return NULL.
9553  */
9554 entity_t *expression_is_variable(const expression_t *expression)
9555 {
9556         if (expression->base.kind != EXPR_REFERENCE) {
9557                 return NULL;
9558         }
9559         entity_t *entity = expression->reference.entity;
9560         if (entity->kind != ENTITY_VARIABLE)
9561                 return NULL;
9562
9563         return entity;
9564 }
9565
9566 static void err_or_warn(source_position_t const *const pos, char const *const msg)
9567 {
9568         if (c_mode & _CXX || strict_mode) {
9569                 errorf(pos, msg);
9570         } else {
9571                 warningf(WARN_OTHER, pos, msg);
9572         }
9573 }
9574
9575 /**
9576  * Parse a return statement.
9577  */
9578 static statement_t *parse_return(void)
9579 {
9580         statement_t *statement = allocate_statement_zero(STATEMENT_RETURN);
9581         eat(T_return);
9582
9583         expression_t *return_value = NULL;
9584         if (token.kind != ';') {
9585                 return_value = parse_expression();
9586                 mark_vars_read(return_value, NULL);
9587         }
9588
9589         const type_t *const func_type = skip_typeref(current_function->base.type);
9590         assert(is_type_function(func_type));
9591         type_t *const return_type = skip_typeref(func_type->function.return_type);
9592
9593         source_position_t const *const pos = &statement->base.source_position;
9594         if (return_value != NULL) {
9595                 type_t *return_value_type = skip_typeref(return_value->base.type);
9596
9597                 if (is_type_void(return_type)) {
9598                         if (!is_type_void(return_value_type)) {
9599                                 /* ISO/IEC 14882:1998(E) §6.6.3:2 */
9600                                 /* Only warn in C mode, because GCC does the same */
9601                                 err_or_warn(pos, "'return' with a value, in function returning 'void'");
9602                         } else if (!(c_mode & _CXX)) { /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9603                                 /* Only warn in C mode, because GCC does the same */
9604                                 err_or_warn(pos, "'return' with expression in function returning 'void'");
9605                         }
9606                 } else {
9607                         assign_error_t error = semantic_assign(return_type, return_value);
9608                         report_assign_error(error, return_type, return_value, "'return'",
9609                                             pos);
9610                 }
9611                 return_value = create_implicit_cast(return_value, return_type);
9612                 /* check for returning address of a local var */
9613                 if (return_value != NULL && return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
9614                         const expression_t *expression = return_value->unary.value;
9615                         if (expression_is_local_variable(expression)) {
9616                                 warningf(WARN_OTHER, pos, "function returns address of local variable");
9617                         }
9618                 }
9619         } else if (!is_type_void(return_type)) {
9620                 /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9621                 err_or_warn(pos, "'return' without value, in function returning non-void");
9622         }
9623         statement->returns.value = return_value;
9624
9625         expect(';');
9626         return statement;
9627 }
9628
9629 /**
9630  * Parse a declaration statement.
9631  */
9632 static statement_t *parse_declaration_statement(void)
9633 {
9634         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9635
9636         entity_t *before = current_scope->last_entity;
9637         if (GNU_MODE) {
9638                 parse_external_declaration();
9639         } else {
9640                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9641         }
9642
9643         declaration_statement_t *const decl  = &statement->declaration;
9644         entity_t                *const begin =
9645                 before != NULL ? before->base.next : current_scope->entities;
9646         decl->declarations_begin = begin;
9647         decl->declarations_end   = begin != NULL ? current_scope->last_entity : NULL;
9648
9649         return statement;
9650 }
9651
9652 /**
9653  * Parse an expression statement, ie. expr ';'.
9654  */
9655 static statement_t *parse_expression_statement(void)
9656 {
9657         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
9658
9659         expression_t *const expr         = parse_expression();
9660         statement->expression.expression = expr;
9661         mark_vars_read(expr, ENT_ANY);
9662
9663         expect(';');
9664         return statement;
9665 }
9666
9667 /**
9668  * Parse a microsoft __try { } __finally { } or
9669  * __try{ } __except() { }
9670  */
9671 static statement_t *parse_ms_try_statment(void)
9672 {
9673         statement_t *statement = allocate_statement_zero(STATEMENT_MS_TRY);
9674         eat(T___try);
9675
9676         PUSH_PARENT(statement);
9677
9678         ms_try_statement_t *rem = current_try;
9679         current_try = &statement->ms_try;
9680         statement->ms_try.try_statement = parse_compound_statement(false);
9681         current_try = rem;
9682
9683         POP_PARENT();
9684
9685         if (next_if(T___except)) {
9686                 expression_t *const expr = parse_condition();
9687                 type_t       *      type = skip_typeref(expr->base.type);
9688                 if (is_type_integer(type)) {
9689                         type = promote_integer(type);
9690                 } else if (is_type_valid(type)) {
9691                         errorf(&expr->base.source_position,
9692                                "__expect expression is not an integer, but '%T'", type);
9693                         type = type_error_type;
9694                 }
9695                 statement->ms_try.except_expression = create_implicit_cast(expr, type);
9696         } else if (!next_if(T__finally)) {
9697                 parse_error_expected("while parsing __try statement", T___except, T___finally, NULL);
9698         }
9699         statement->ms_try.final_statement = parse_compound_statement(false);
9700         return statement;
9701 }
9702
9703 static statement_t *parse_empty_statement(void)
9704 {
9705         warningf(WARN_EMPTY_STATEMENT, HERE, "statement is empty");
9706         statement_t *const statement = create_empty_statement();
9707         eat(';');
9708         return statement;
9709 }
9710
9711 static statement_t *parse_local_label_declaration(void)
9712 {
9713         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9714
9715         eat(T___label__);
9716
9717         entity_t *begin   = NULL;
9718         entity_t *end     = NULL;
9719         entity_t **anchor = &begin;
9720         do {
9721                 source_position_t pos;
9722                 symbol_t *const symbol = expect_identifier("while parsing local label declaration", &pos);
9723                 if (!symbol)
9724                         goto end_error;
9725
9726                 entity_t *entity = get_entity(symbol, NAMESPACE_LABEL);
9727                 if (entity != NULL && entity->base.parent_scope == current_scope) {
9728                         source_position_t const *const ppos = &entity->base.source_position;
9729                         errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
9730                 } else {
9731                         entity = allocate_entity_zero(ENTITY_LOCAL_LABEL, NAMESPACE_LABEL, symbol, &pos);
9732                         entity->base.parent_scope = current_scope;
9733
9734                         *anchor = entity;
9735                         anchor  = &entity->base.next;
9736                         end     = entity;
9737
9738                         environment_push(entity);
9739                 }
9740         } while (next_if(','));
9741         expect(';');
9742 end_error:
9743         statement->declaration.declarations_begin = begin;
9744         statement->declaration.declarations_end   = end;
9745         return statement;
9746 }
9747
9748 static void parse_namespace_definition(void)
9749 {
9750         eat(T_namespace);
9751
9752         entity_t *entity = NULL;
9753         symbol_t *symbol = NULL;
9754
9755         if (token.kind == T_IDENTIFIER) {
9756                 symbol = token.identifier.symbol;
9757                 next_token();
9758
9759                 entity = get_entity(symbol, NAMESPACE_NORMAL);
9760                 if (entity != NULL
9761                                 && entity->kind != ENTITY_NAMESPACE
9762                                 && entity->base.parent_scope == current_scope) {
9763                         if (is_entity_valid(entity)) {
9764                                 error_redefined_as_different_kind(&token.base.source_position,
9765                                                 entity, ENTITY_NAMESPACE);
9766                         }
9767                         entity = NULL;
9768                 }
9769         }
9770
9771         if (entity == NULL) {
9772                 entity = allocate_entity_zero(ENTITY_NAMESPACE, NAMESPACE_NORMAL, symbol, HERE);
9773                 entity->base.parent_scope = current_scope;
9774         }
9775
9776         if (token.kind == '=') {
9777                 /* TODO: parse namespace alias */
9778                 panic("namespace alias definition not supported yet");
9779         }
9780
9781         environment_push(entity);
9782         append_entity(current_scope, entity);
9783
9784         PUSH_SCOPE(&entity->namespacee.members);
9785         PUSH_CURRENT_ENTITY(entity);
9786
9787         add_anchor_token('}');
9788         expect('{');
9789         parse_externals();
9790         rem_anchor_token('}');
9791         expect('}');
9792
9793         POP_CURRENT_ENTITY();
9794         POP_SCOPE();
9795 }
9796
9797 /**
9798  * Parse a statement.
9799  * There's also parse_statement() which additionally checks for
9800  * "statement has no effect" warnings
9801  */
9802 static statement_t *intern_parse_statement(void)
9803 {
9804         /* declaration or statement */
9805         statement_t *statement;
9806         switch (token.kind) {
9807         case T_IDENTIFIER: {
9808                 token_kind_t la1_type = (token_kind_t)look_ahead(1)->kind;
9809                 if (la1_type == ':') {
9810                         statement = parse_label_statement();
9811                 } else if (is_typedef_symbol(token.identifier.symbol)) {
9812                         statement = parse_declaration_statement();
9813                 } else {
9814                         /* it's an identifier, the grammar says this must be an
9815                          * expression statement. However it is common that users mistype
9816                          * declaration types, so we guess a bit here to improve robustness
9817                          * for incorrect programs */
9818                         switch (la1_type) {
9819                         case '&':
9820                         case '*':
9821                                 if (get_entity(token.identifier.symbol, NAMESPACE_NORMAL) != NULL) {
9822                         default:
9823                                         statement = parse_expression_statement();
9824                                 } else {
9825                         DECLARATION_START
9826                         case T_IDENTIFIER:
9827                                         statement = parse_declaration_statement();
9828                                 }
9829                                 break;
9830                         }
9831                 }
9832                 break;
9833         }
9834
9835         case T___extension__: {
9836                 /* This can be a prefix to a declaration or an expression statement.
9837                  * We simply eat it now and parse the rest with tail recursion. */
9838                 PUSH_EXTENSION();
9839                 statement = intern_parse_statement();
9840                 POP_EXTENSION();
9841                 break;
9842         }
9843
9844         DECLARATION_START
9845                 statement = parse_declaration_statement();
9846                 break;
9847
9848         case T___label__:
9849                 statement = parse_local_label_declaration();
9850                 break;
9851
9852         case ';':         statement = parse_empty_statement();         break;
9853         case '{':         statement = parse_compound_statement(false); break;
9854         case T___leave:   statement = parse_leave_statement();         break;
9855         case T___try:     statement = parse_ms_try_statment();         break;
9856         case T_asm:       statement = parse_asm_statement();           break;
9857         case T_break:     statement = parse_break();                   break;
9858         case T_case:      statement = parse_case_statement();          break;
9859         case T_continue:  statement = parse_continue();                break;
9860         case T_default:   statement = parse_default_statement();       break;
9861         case T_do:        statement = parse_do();                      break;
9862         case T_for:       statement = parse_for();                     break;
9863         case T_goto:      statement = parse_goto();                    break;
9864         case T_if:        statement = parse_if();                      break;
9865         case T_return:    statement = parse_return();                  break;
9866         case T_switch:    statement = parse_switch();                  break;
9867         case T_while:     statement = parse_while();                   break;
9868
9869         EXPRESSION_START
9870                 statement = parse_expression_statement();
9871                 break;
9872
9873         default:
9874                 errorf(HERE, "unexpected token %K while parsing statement", &token);
9875                 statement = create_error_statement();
9876                 eat_until_anchor();
9877                 break;
9878         }
9879
9880         return statement;
9881 }
9882
9883 /**
9884  * parse a statement and emits "statement has no effect" warning if needed
9885  * (This is really a wrapper around intern_parse_statement with check for 1
9886  *  single warning. It is needed, because for statement expressions we have
9887  *  to avoid the warning on the last statement)
9888  */
9889 static statement_t *parse_statement(void)
9890 {
9891         statement_t *statement = intern_parse_statement();
9892
9893         if (statement->kind == STATEMENT_EXPRESSION) {
9894                 expression_t *expression = statement->expression.expression;
9895                 if (!expression_has_effect(expression)) {
9896                         warningf(WARN_UNUSED_VALUE, &expression->base.source_position, "statement has no effect");
9897                 }
9898         }
9899
9900         return statement;
9901 }
9902
9903 /**
9904  * Parse a compound statement.
9905  */
9906 static statement_t *parse_compound_statement(bool inside_expression_statement)
9907 {
9908         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
9909
9910         PUSH_PARENT(statement);
9911         PUSH_SCOPE(&statement->compound.scope);
9912
9913         eat('{');
9914         add_anchor_token('}');
9915         /* tokens, which can start a statement */
9916         /* TODO MS, __builtin_FOO */
9917         add_anchor_token('!');
9918         add_anchor_token('&');
9919         add_anchor_token('(');
9920         add_anchor_token('*');
9921         add_anchor_token('+');
9922         add_anchor_token('-');
9923         add_anchor_token(';');
9924         add_anchor_token('{');
9925         add_anchor_token('~');
9926         add_anchor_token(T_CHARACTER_CONSTANT);
9927         add_anchor_token(T_COLONCOLON);
9928         add_anchor_token(T_FLOATINGPOINT);
9929         add_anchor_token(T_IDENTIFIER);
9930         add_anchor_token(T_INTEGER);
9931         add_anchor_token(T_MINUSMINUS);
9932         add_anchor_token(T_PLUSPLUS);
9933         add_anchor_token(T_STRING_LITERAL);
9934         add_anchor_token(T_WIDE_CHARACTER_CONSTANT);
9935         add_anchor_token(T_WIDE_STRING_LITERAL);
9936         add_anchor_token(T__Bool);
9937         add_anchor_token(T__Complex);
9938         add_anchor_token(T__Imaginary);
9939         add_anchor_token(T___FUNCTION__);
9940         add_anchor_token(T___PRETTY_FUNCTION__);
9941         add_anchor_token(T___alignof__);
9942         add_anchor_token(T___attribute__);
9943         add_anchor_token(T___builtin_va_start);
9944         add_anchor_token(T___extension__);
9945         add_anchor_token(T___func__);
9946         add_anchor_token(T___imag__);
9947         add_anchor_token(T___label__);
9948         add_anchor_token(T___real__);
9949         add_anchor_token(T___thread);
9950         add_anchor_token(T_asm);
9951         add_anchor_token(T_auto);
9952         add_anchor_token(T_bool);
9953         add_anchor_token(T_break);
9954         add_anchor_token(T_case);
9955         add_anchor_token(T_char);
9956         add_anchor_token(T_class);
9957         add_anchor_token(T_const);
9958         add_anchor_token(T_const_cast);
9959         add_anchor_token(T_continue);
9960         add_anchor_token(T_default);
9961         add_anchor_token(T_delete);
9962         add_anchor_token(T_double);
9963         add_anchor_token(T_do);
9964         add_anchor_token(T_dynamic_cast);
9965         add_anchor_token(T_enum);
9966         add_anchor_token(T_extern);
9967         add_anchor_token(T_false);
9968         add_anchor_token(T_float);
9969         add_anchor_token(T_for);
9970         add_anchor_token(T_goto);
9971         add_anchor_token(T_if);
9972         add_anchor_token(T_inline);
9973         add_anchor_token(T_int);
9974         add_anchor_token(T_long);
9975         add_anchor_token(T_new);
9976         add_anchor_token(T_operator);
9977         add_anchor_token(T_register);
9978         add_anchor_token(T_reinterpret_cast);
9979         add_anchor_token(T_restrict);
9980         add_anchor_token(T_return);
9981         add_anchor_token(T_short);
9982         add_anchor_token(T_signed);
9983         add_anchor_token(T_sizeof);
9984         add_anchor_token(T_static);
9985         add_anchor_token(T_static_cast);
9986         add_anchor_token(T_struct);
9987         add_anchor_token(T_switch);
9988         add_anchor_token(T_template);
9989         add_anchor_token(T_this);
9990         add_anchor_token(T_throw);
9991         add_anchor_token(T_true);
9992         add_anchor_token(T_try);
9993         add_anchor_token(T_typedef);
9994         add_anchor_token(T_typeid);
9995         add_anchor_token(T_typename);
9996         add_anchor_token(T_typeof);
9997         add_anchor_token(T_union);
9998         add_anchor_token(T_unsigned);
9999         add_anchor_token(T_using);
10000         add_anchor_token(T_void);
10001         add_anchor_token(T_volatile);
10002         add_anchor_token(T_wchar_t);
10003         add_anchor_token(T_while);
10004
10005         statement_t **anchor            = &statement->compound.statements;
10006         bool          only_decls_so_far = true;
10007         while (token.kind != '}' && token.kind != T_EOF) {
10008                 statement_t *sub_statement = intern_parse_statement();
10009                 if (sub_statement->kind == STATEMENT_ERROR) {
10010                         break;
10011                 }
10012
10013                 if (sub_statement->kind != STATEMENT_DECLARATION) {
10014                         only_decls_so_far = false;
10015                 } else if (!only_decls_so_far) {
10016                         source_position_t const *const pos = &sub_statement->base.source_position;
10017                         warningf(WARN_DECLARATION_AFTER_STATEMENT, pos, "ISO C90 forbids mixed declarations and code");
10018                 }
10019
10020                 *anchor = sub_statement;
10021                 anchor  = &sub_statement->base.next;
10022         }
10023         expect('}');
10024
10025         /* look over all statements again to produce no effect warnings */
10026         if (is_warn_on(WARN_UNUSED_VALUE)) {
10027                 statement_t *sub_statement = statement->compound.statements;
10028                 for (; sub_statement != NULL; sub_statement = sub_statement->base.next) {
10029                         if (sub_statement->kind != STATEMENT_EXPRESSION)
10030                                 continue;
10031                         /* don't emit a warning for the last expression in an expression
10032                          * statement as it has always an effect */
10033                         if (inside_expression_statement && sub_statement->base.next == NULL)
10034                                 continue;
10035
10036                         expression_t *expression = sub_statement->expression.expression;
10037                         if (!expression_has_effect(expression)) {
10038                                 warningf(WARN_UNUSED_VALUE, &expression->base.source_position, "statement has no effect");
10039                         }
10040                 }
10041         }
10042
10043         rem_anchor_token(T_while);
10044         rem_anchor_token(T_wchar_t);
10045         rem_anchor_token(T_volatile);
10046         rem_anchor_token(T_void);
10047         rem_anchor_token(T_using);
10048         rem_anchor_token(T_unsigned);
10049         rem_anchor_token(T_union);
10050         rem_anchor_token(T_typeof);
10051         rem_anchor_token(T_typename);
10052         rem_anchor_token(T_typeid);
10053         rem_anchor_token(T_typedef);
10054         rem_anchor_token(T_try);
10055         rem_anchor_token(T_true);
10056         rem_anchor_token(T_throw);
10057         rem_anchor_token(T_this);
10058         rem_anchor_token(T_template);
10059         rem_anchor_token(T_switch);
10060         rem_anchor_token(T_struct);
10061         rem_anchor_token(T_static_cast);
10062         rem_anchor_token(T_static);
10063         rem_anchor_token(T_sizeof);
10064         rem_anchor_token(T_signed);
10065         rem_anchor_token(T_short);
10066         rem_anchor_token(T_return);
10067         rem_anchor_token(T_restrict);
10068         rem_anchor_token(T_reinterpret_cast);
10069         rem_anchor_token(T_register);
10070         rem_anchor_token(T_operator);
10071         rem_anchor_token(T_new);
10072         rem_anchor_token(T_long);
10073         rem_anchor_token(T_int);
10074         rem_anchor_token(T_inline);
10075         rem_anchor_token(T_if);
10076         rem_anchor_token(T_goto);
10077         rem_anchor_token(T_for);
10078         rem_anchor_token(T_float);
10079         rem_anchor_token(T_false);
10080         rem_anchor_token(T_extern);
10081         rem_anchor_token(T_enum);
10082         rem_anchor_token(T_dynamic_cast);
10083         rem_anchor_token(T_do);
10084         rem_anchor_token(T_double);
10085         rem_anchor_token(T_delete);
10086         rem_anchor_token(T_default);
10087         rem_anchor_token(T_continue);
10088         rem_anchor_token(T_const_cast);
10089         rem_anchor_token(T_const);
10090         rem_anchor_token(T_class);
10091         rem_anchor_token(T_char);
10092         rem_anchor_token(T_case);
10093         rem_anchor_token(T_break);
10094         rem_anchor_token(T_bool);
10095         rem_anchor_token(T_auto);
10096         rem_anchor_token(T_asm);
10097         rem_anchor_token(T___thread);
10098         rem_anchor_token(T___real__);
10099         rem_anchor_token(T___label__);
10100         rem_anchor_token(T___imag__);
10101         rem_anchor_token(T___func__);
10102         rem_anchor_token(T___extension__);
10103         rem_anchor_token(T___builtin_va_start);
10104         rem_anchor_token(T___attribute__);
10105         rem_anchor_token(T___alignof__);
10106         rem_anchor_token(T___PRETTY_FUNCTION__);
10107         rem_anchor_token(T___FUNCTION__);
10108         rem_anchor_token(T__Imaginary);
10109         rem_anchor_token(T__Complex);
10110         rem_anchor_token(T__Bool);
10111         rem_anchor_token(T_WIDE_STRING_LITERAL);
10112         rem_anchor_token(T_WIDE_CHARACTER_CONSTANT);
10113         rem_anchor_token(T_STRING_LITERAL);
10114         rem_anchor_token(T_PLUSPLUS);
10115         rem_anchor_token(T_MINUSMINUS);
10116         rem_anchor_token(T_INTEGER);
10117         rem_anchor_token(T_IDENTIFIER);
10118         rem_anchor_token(T_FLOATINGPOINT);
10119         rem_anchor_token(T_COLONCOLON);
10120         rem_anchor_token(T_CHARACTER_CONSTANT);
10121         rem_anchor_token('~');
10122         rem_anchor_token('{');
10123         rem_anchor_token(';');
10124         rem_anchor_token('-');
10125         rem_anchor_token('+');
10126         rem_anchor_token('*');
10127         rem_anchor_token('(');
10128         rem_anchor_token('&');
10129         rem_anchor_token('!');
10130         rem_anchor_token('}');
10131
10132         POP_SCOPE();
10133         POP_PARENT();
10134         return statement;
10135 }
10136
10137 /**
10138  * Check for unused global static functions and variables
10139  */
10140 static void check_unused_globals(void)
10141 {
10142         if (!is_warn_on(WARN_UNUSED_FUNCTION) && !is_warn_on(WARN_UNUSED_VARIABLE))
10143                 return;
10144
10145         for (const entity_t *entity = file_scope->entities; entity != NULL;
10146              entity = entity->base.next) {
10147                 if (!is_declaration(entity))
10148                         continue;
10149
10150                 const declaration_t *declaration = &entity->declaration;
10151                 if (declaration->used                  ||
10152                     declaration->modifiers & DM_UNUSED ||
10153                     declaration->modifiers & DM_USED   ||
10154                     declaration->storage_class != STORAGE_CLASS_STATIC)
10155                         continue;
10156
10157                 warning_t   why;
10158                 char const *s;
10159                 if (entity->kind == ENTITY_FUNCTION) {
10160                         /* inhibit warning for static inline functions */
10161                         if (entity->function.is_inline)
10162                                 continue;
10163
10164                         why = WARN_UNUSED_FUNCTION;
10165                         s   = entity->function.statement != NULL ? "defined" : "declared";
10166                 } else {
10167                         why = WARN_UNUSED_VARIABLE;
10168                         s   = "defined";
10169                 }
10170
10171                 warningf(why, &declaration->base.source_position, "'%#N' %s but not used", entity, s);
10172         }
10173 }
10174
10175 static void parse_global_asm(void)
10176 {
10177         statement_t *statement = allocate_statement_zero(STATEMENT_ASM);
10178
10179         eat(T_asm);
10180         add_anchor_token(';');
10181         add_anchor_token(')');
10182         add_anchor_token(T_STRING_LITERAL);
10183         expect('(');
10184
10185         rem_anchor_token(T_STRING_LITERAL);
10186         statement->asms.asm_text = parse_string_literals();
10187         statement->base.next     = unit->global_asm;
10188         unit->global_asm         = statement;
10189
10190         rem_anchor_token(')');
10191         expect(')');
10192         rem_anchor_token(';');
10193         expect(';');
10194 }
10195
10196 static void parse_linkage_specification(void)
10197 {
10198         eat(T_extern);
10199
10200         source_position_t const pos     = *HERE;
10201         char const       *const linkage = parse_string_literals().begin;
10202
10203         linkage_kind_t old_linkage = current_linkage;
10204         linkage_kind_t new_linkage;
10205         if (streq(linkage, "C")) {
10206                 new_linkage = LINKAGE_C;
10207         } else if (streq(linkage, "C++")) {
10208                 new_linkage = LINKAGE_CXX;
10209         } else {
10210                 errorf(&pos, "linkage string \"%s\" not recognized", linkage);
10211                 new_linkage = LINKAGE_C;
10212         }
10213         current_linkage = new_linkage;
10214
10215         if (next_if('{')) {
10216                 parse_externals();
10217                 expect('}');
10218         } else {
10219                 parse_external();
10220         }
10221
10222         assert(current_linkage == new_linkage);
10223         current_linkage = old_linkage;
10224 }
10225
10226 static void parse_external(void)
10227 {
10228         switch (token.kind) {
10229                 case T_extern:
10230                         if (look_ahead(1)->kind == T_STRING_LITERAL) {
10231                                 parse_linkage_specification();
10232                         } else {
10233                 DECLARATION_START_NO_EXTERN
10234                 case T_IDENTIFIER:
10235                 case T___extension__:
10236                 /* tokens below are for implicit int */
10237                 case '&':  /* & x; -> int& x; (and error later, because C++ has no
10238                               implicit int) */
10239                 case '*':  /* * x; -> int* x; */
10240                 case '(':  /* (x); -> int (x); */
10241                                 PUSH_EXTENSION();
10242                                 parse_external_declaration();
10243                                 POP_EXTENSION();
10244                         }
10245                         return;
10246
10247                 case T_asm:
10248                         parse_global_asm();
10249                         return;
10250
10251                 case T_namespace:
10252                         parse_namespace_definition();
10253                         return;
10254
10255                 case ';':
10256                         if (!strict_mode) {
10257                                 warningf(WARN_STRAY_SEMICOLON, HERE, "stray ';' outside of function");
10258                                 next_token();
10259                                 return;
10260                         }
10261                         /* FALLTHROUGH */
10262
10263                 default:
10264                         errorf(HERE, "stray %K outside of function", &token);
10265                         if (token.kind == '(' || token.kind == '{' || token.kind == '[')
10266                                 eat_until_matching_token(token.kind);
10267                         next_token();
10268                         return;
10269         }
10270 }
10271
10272 static void parse_externals(void)
10273 {
10274         add_anchor_token('}');
10275         add_anchor_token(T_EOF);
10276
10277 #ifndef NDEBUG
10278         /* make a copy of the anchor set, so we can check if it is restored after parsing */
10279         unsigned short token_anchor_copy[T_LAST_TOKEN];
10280         memcpy(token_anchor_copy, token_anchor_set, sizeof(token_anchor_copy));
10281 #endif
10282
10283         while (token.kind != T_EOF && token.kind != '}') {
10284 #ifndef NDEBUG
10285                 for (int i = 0; i < T_LAST_TOKEN; ++i) {
10286                         unsigned short count = token_anchor_set[i] - token_anchor_copy[i];
10287                         if (count != 0) {
10288                                 /* the anchor set and its copy differs */
10289                                 internal_errorf(HERE, "Leaked anchor token %k %d times", i, count);
10290                         }
10291                 }
10292                 if (in_gcc_extension) {
10293                         /* an gcc extension scope was not closed */
10294                         internal_errorf(HERE, "Leaked __extension__");
10295                 }
10296 #endif
10297
10298                 parse_external();
10299         }
10300
10301         rem_anchor_token(T_EOF);
10302         rem_anchor_token('}');
10303 }
10304
10305 /**
10306  * Parse a translation unit.
10307  */
10308 static void parse_translation_unit(void)
10309 {
10310         add_anchor_token(T_EOF);
10311
10312         while (true) {
10313                 parse_externals();
10314
10315                 if (token.kind == T_EOF)
10316                         break;
10317
10318                 errorf(HERE, "stray %K outside of function", &token);
10319                 if (token.kind == '(' || token.kind == '{' || token.kind == '[')
10320                         eat_until_matching_token(token.kind);
10321                 next_token();
10322         }
10323 }
10324
10325 void set_default_visibility(elf_visibility_tag_t visibility)
10326 {
10327         default_visibility = visibility;
10328 }
10329
10330 /**
10331  * Parse the input.
10332  *
10333  * @return  the translation unit or NULL if errors occurred.
10334  */
10335 void start_parsing(void)
10336 {
10337         environment_stack = NEW_ARR_F(stack_entry_t, 0);
10338         label_stack       = NEW_ARR_F(stack_entry_t, 0);
10339         diagnostic_count  = 0;
10340         error_count       = 0;
10341         warning_count     = 0;
10342
10343         print_to_file(stderr);
10344
10345         assert(unit == NULL);
10346         unit = allocate_ast_zero(sizeof(unit[0]));
10347
10348         assert(file_scope == NULL);
10349         file_scope = &unit->scope;
10350
10351         assert(current_scope == NULL);
10352         scope_push(&unit->scope);
10353
10354         create_gnu_builtins();
10355         if (c_mode & _MS)
10356                 create_microsoft_intrinsics();
10357 }
10358
10359 translation_unit_t *finish_parsing(void)
10360 {
10361         assert(current_scope == &unit->scope);
10362         scope_pop(NULL);
10363
10364         assert(file_scope == &unit->scope);
10365         check_unused_globals();
10366         file_scope = NULL;
10367
10368         DEL_ARR_F(environment_stack);
10369         DEL_ARR_F(label_stack);
10370
10371         translation_unit_t *result = unit;
10372         unit = NULL;
10373         return result;
10374 }
10375
10376 /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
10377  * are given length one. */
10378 static void complete_incomplete_arrays(void)
10379 {
10380         size_t n = ARR_LEN(incomplete_arrays);
10381         for (size_t i = 0; i != n; ++i) {
10382                 declaration_t *const decl = incomplete_arrays[i];
10383                 type_t        *const type = skip_typeref(decl->type);
10384
10385                 if (!is_type_incomplete(type))
10386                         continue;
10387
10388                 source_position_t const *const pos = &decl->base.source_position;
10389                 warningf(WARN_OTHER, pos, "array '%#N' assumed to have one element", (entity_t const*)decl);
10390
10391                 type_t *const new_type = duplicate_type(type);
10392                 new_type->array.size_constant     = true;
10393                 new_type->array.has_implicit_size = true;
10394                 new_type->array.size              = 1;
10395
10396                 type_t *const result = identify_new_type(new_type);
10397
10398                 decl->type = result;
10399         }
10400 }
10401
10402 static void prepare_main_collect2(entity_t *const entity)
10403 {
10404         PUSH_SCOPE(&entity->function.statement->compound.scope);
10405
10406         // create call to __main
10407         symbol_t *symbol         = symbol_table_insert("__main");
10408         entity_t *subsubmain_ent
10409                 = create_implicit_function(symbol, &builtin_source_position);
10410
10411         expression_t *ref         = allocate_expression_zero(EXPR_REFERENCE);
10412         type_t       *ftype       = subsubmain_ent->declaration.type;
10413         ref->base.source_position = builtin_source_position;
10414         ref->base.type            = make_pointer_type(ftype, TYPE_QUALIFIER_NONE);
10415         ref->reference.entity     = subsubmain_ent;
10416
10417         expression_t *call = allocate_expression_zero(EXPR_CALL);
10418         call->base.source_position = builtin_source_position;
10419         call->base.type            = type_void;
10420         call->call.function        = ref;
10421
10422         statement_t *expr_statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10423         expr_statement->base.source_position  = builtin_source_position;
10424         expr_statement->expression.expression = call;
10425
10426         statement_t *statement = entity->function.statement;
10427         assert(statement->kind == STATEMENT_COMPOUND);
10428         compound_statement_t *compounds = &statement->compound;
10429
10430         expr_statement->base.next = compounds->statements;
10431         compounds->statements     = expr_statement;
10432
10433         POP_SCOPE();
10434 }
10435
10436 void parse(void)
10437 {
10438         lookahead_bufpos = 0;
10439         for (int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
10440                 next_token();
10441         }
10442         current_linkage   = c_mode & _CXX ? LINKAGE_CXX : LINKAGE_C;
10443         incomplete_arrays = NEW_ARR_F(declaration_t*, 0);
10444         parse_translation_unit();
10445         complete_incomplete_arrays();
10446         DEL_ARR_F(incomplete_arrays);
10447         incomplete_arrays = NULL;
10448 }
10449
10450 /**
10451  * Initialize the parser.
10452  */
10453 void init_parser(void)
10454 {
10455         sym_anonymous = symbol_table_insert("<anonymous>");
10456
10457         memset(token_anchor_set, 0, sizeof(token_anchor_set));
10458
10459         init_expression_parsers();
10460         obstack_init(&temp_obst);
10461 }
10462
10463 /**
10464  * Terminate the parser.
10465  */
10466 void exit_parser(void)
10467 {
10468         obstack_free(&temp_obst, NULL);
10469 }