1 /* RunTime Type Identification
2 Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004
3 Free Software Foundation, Inc.
4 Mostly written by Jason Merrill (jason@cygnus.com).
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2, or (at your option)
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING. If not, write to
20 the Free Software Foundation, 59 Temple Place - Suite 330,
21 Boston, MA 02111-1307, USA. */
26 #include "coretypes.h"
36 /* C++ returns type information to the user in struct type_info
37 objects. We also use type information to implement dynamic_cast and
38 exception handlers. Type information for a particular type is
39 indicated with an ABI defined structure derived from type_info.
40 This would all be very straight forward, but for the fact that the
41 runtime library provides the definitions of the type_info structure
42 and the ABI defined derived classes. We cannot build declarations
43 of them directly in the compiler, but we need to layout objects of
44 their type. Somewhere we have to lie.
46 We define layout compatible POD-structs with compiler-defined names
47 and generate the appropriate initializations for them (complete
48 with explicit mention of their vtable). When we have to provide a
49 type_info to the user we reinterpret_cast the internal compiler
50 type to type_info. A well formed program can only explicitly refer
51 to the type_infos of complete types (& cv void). However, we chain
52 pointer type_infos to the pointed-to-type, and that can be
53 incomplete. We only need the addresses of such incomplete
54 type_info objects for static initialization.
56 The type information VAR_DECL of a type is held on the
57 IDENTIFIER_GLOBAL_VALUE of the type's mangled name. That VAR_DECL
58 will be the internal type. It will usually have the correct
59 internal type reflecting the kind of type it represents (pointer,
60 array, function, class, inherited class, etc). When the type it
61 represents is incomplete, it will have the internal type
62 corresponding to type_info. That will only happen at the end of
63 translation, when we are emitting the type info objects. */
65 /* Accessors for the type_info objects. We need to remember several things
66 about each of the type_info types. The global tree nodes such as
67 bltn_desc_type_node are TREE_LISTs, and these macros are used to access
68 the required information. */
69 /* The RECORD_TYPE of a type_info derived class. */
70 #define TINFO_PSEUDO_TYPE(NODE) TREE_TYPE (NODE)
71 /* The VAR_DECL of the vtable for the type_info derived class.
72 This is only filled in at the end of the translation. */
73 #define TINFO_VTABLE_DECL(NODE) TREE_VALUE (NODE)
74 /* The IDENTIFIER_NODE naming the real class. */
75 #define TINFO_REAL_NAME(NODE) TREE_PURPOSE (NODE)
77 /* A varray of all tinfo decls that haven't yet been emitted. */
78 varray_type unemitted_tinfo_decls
;
80 static tree
build_headof (tree
);
81 static tree
ifnonnull (tree
, tree
);
82 static tree
tinfo_name (tree
);
83 static tree
build_dynamic_cast_1 (tree
, tree
);
84 static tree
throw_bad_cast (void);
85 static tree
throw_bad_typeid (void);
86 static tree
get_tinfo_decl_dynamic (tree
);
87 static tree
get_tinfo_ptr (tree
);
88 static bool typeid_ok_p (void);
89 static int qualifier_flags (tree
);
90 static bool target_incomplete_p (tree
);
91 static tree
tinfo_base_init (tree
, tree
);
92 static tree
generic_initializer (tree
, tree
);
93 static tree
ptr_initializer (tree
, tree
, bool *);
94 static tree
ptm_initializer (tree
, tree
, bool *);
95 static tree
dfs_class_hint_mark (tree
, void *);
96 static tree
dfs_class_hint_unmark (tree
, void *);
97 static int class_hint_flags (tree
);
98 static tree
class_initializer (tree
, tree
, tree
);
99 static tree
create_pseudo_type_info (const char *, int, ...);
100 static tree
get_pseudo_ti_init (tree
, tree
, bool *);
101 static tree
get_pseudo_ti_desc (tree
);
102 static void create_tinfo_types (void);
103 static bool typeinfo_in_lib_p (tree
);
104 static bool unemitted_tinfo_decl_p (tree
);
106 static int doing_runtime
= 0;
109 /* Declare language defined type_info type and a pointer to const
110 type_info. This is incomplete here, and will be completed when
111 the user #includes <typeinfo>. There are language defined
112 restrictions on what can be done until that is included. Create
113 the internal versions of the ABI types. */
116 init_rtti_processing (void)
118 tree const_type_info_type
;
120 push_namespace (std_identifier
);
122 = xref_tag (class_type
, get_identifier ("type_info"),
125 const_type_info_type
= build_qualified_type (type_info_type_node
,
127 type_info_ptr_type
= build_pointer_type (const_type_info_type
);
128 type_info_ref_type
= build_reference_type (const_type_info_type
);
130 VARRAY_TREE_INIT (unemitted_tinfo_decls
, 10, "RTTI decls");
132 create_tinfo_types ();
135 /* Given the expression EXP of type `class *', return the head of the
136 object pointed to by EXP with type cv void*, if the class has any
137 virtual functions (TYPE_POLYMORPHIC_P), else just return the
141 build_headof (tree exp
)
143 tree type
= TREE_TYPE (exp
);
147 my_friendly_assert (TREE_CODE (type
) == POINTER_TYPE
, 20000112);
148 type
= TREE_TYPE (type
);
150 if (!TYPE_POLYMORPHIC_P (type
))
153 /* We use this a couple of times below, protect it. */
154 exp
= save_expr (exp
);
156 /* The offset-to-top field is at index -2 from the vptr. */
157 index
= build_int_2 (-2 * TARGET_VTABLE_DATA_ENTRY_DISTANCE
, -1);
159 offset
= build_vtbl_ref (build_indirect_ref (exp
, NULL
), index
);
161 type
= build_qualified_type (ptr_type_node
,
162 cp_type_quals (TREE_TYPE (exp
)));
163 return build (PLUS_EXPR
, type
, exp
,
164 convert_to_integer (ptrdiff_type_node
, offset
));
167 /* Get a bad_cast node for the program to throw...
169 See libstdc++/exception.cc for __throw_bad_cast */
172 throw_bad_cast (void)
174 tree fn
= get_identifier ("__cxa_bad_cast");
175 if (!get_global_value_if_present (fn
, &fn
))
176 fn
= push_throw_library_fn (fn
, build_function_type (ptr_type_node
,
179 return build_cxx_call (fn
, NULL_TREE
, NULL_TREE
);
182 /* Return an expression for "__cxa_bad_typeid()". The expression
183 returned is an lvalue of type "const std::type_info". */
186 throw_bad_typeid (void)
188 tree fn
= get_identifier ("__cxa_bad_typeid");
189 if (!get_global_value_if_present (fn
, &fn
))
191 tree t
= build_qualified_type (type_info_type_node
, TYPE_QUAL_CONST
);
192 t
= build_function_type (build_reference_type (t
), void_list_node
);
193 fn
= push_throw_library_fn (fn
, t
);
196 return convert_from_reference (build_cxx_call (fn
, NULL_TREE
, NULL_TREE
));
199 /* Return an lvalue expression whose type is "const std::type_info"
200 and whose value indicates the type of the expression EXP. If EXP
201 is a reference to a polymorphic class, return the dynamic type;
202 otherwise return the static type of the expression. */
205 get_tinfo_decl_dynamic (tree exp
)
210 if (exp
== error_mark_node
)
211 return error_mark_node
;
213 /* peel back references, so they match. */
214 type
= non_reference (TREE_TYPE (exp
));
216 /* Peel off cv qualifiers. */
217 type
= TYPE_MAIN_VARIANT (type
);
219 if (!VOID_TYPE_P (type
))
220 type
= complete_type_or_else (type
, exp
);
223 return error_mark_node
;
225 /* If exp is a reference to polymorphic type, get the real type_info. */
226 if (TYPE_POLYMORPHIC_P (type
) && ! resolves_to_fixed_type_p (exp
, 0))
228 /* build reference to type_info from vtable. */
231 /* The RTTI information is at index -1. */
232 index
= build_int_2 (-1 * TARGET_VTABLE_DATA_ENTRY_DISTANCE
, -1);
233 t
= build_vtbl_ref (exp
, index
);
234 TREE_TYPE (t
) = type_info_ptr_type
;
237 /* Otherwise return the type_info for the static type of the expr. */
238 t
= get_tinfo_ptr (TYPE_MAIN_VARIANT (type
));
240 return build_indirect_ref (t
, NULL
);
248 error ("cannot use typeid with -fno-rtti");
252 if (!COMPLETE_TYPE_P (type_info_type_node
))
254 error ("must #include <typeinfo> before using typeid");
261 /* Return an expression for "typeid(EXP)". The expression returned is
262 an lvalue of type "const std::type_info". */
265 build_typeid (tree exp
)
267 tree cond
= NULL_TREE
;
270 if (exp
== error_mark_node
|| !typeid_ok_p ())
271 return error_mark_node
;
273 if (processing_template_decl
)
274 return build_min (TYPEID_EXPR
, type_info_ref_type
, exp
);
276 if (TREE_CODE (exp
) == INDIRECT_REF
277 && TREE_CODE (TREE_TYPE (TREE_OPERAND (exp
, 0))) == POINTER_TYPE
278 && TYPE_POLYMORPHIC_P (TREE_TYPE (exp
))
279 && ! resolves_to_fixed_type_p (exp
, &nonnull
)
282 exp
= stabilize_reference (exp
);
283 cond
= cp_convert (boolean_type_node
, TREE_OPERAND (exp
, 0));
286 exp
= get_tinfo_decl_dynamic (exp
);
288 if (exp
== error_mark_node
)
289 return error_mark_node
;
293 tree bad
= throw_bad_typeid ();
295 exp
= build (COND_EXPR
, TREE_TYPE (exp
), cond
, exp
, bad
);
301 /* Generate the NTBS name of a type. */
303 tinfo_name (tree type
)
308 name
= mangle_type_string (type
);
309 name_string
= fix_string_type (build_string (strlen (name
) + 1, name
));
313 /* Return a VAR_DECL for the internal ABI defined type_info object for
314 TYPE. You must arrange that the decl is mark_used, if actually use
315 it --- decls in vtables are only used if the vtable is output. */
318 get_tinfo_decl (tree type
)
323 if (COMPLETE_TYPE_P (type
)
324 && TREE_CODE (TYPE_SIZE (type
)) != INTEGER_CST
)
326 error ("cannot create type information for type `%T' because its size is variable",
328 return error_mark_node
;
331 if (TREE_CODE (type
) == METHOD_TYPE
)
332 type
= build_function_type (TREE_TYPE (type
),
333 TREE_CHAIN (TYPE_ARG_TYPES (type
)));
335 /* For a class type, the variable is cached in the type node
337 if (CLASS_TYPE_P (type
))
339 d
= CLASSTYPE_TYPEINFO_VAR (TYPE_MAIN_VARIANT (type
));
344 name
= mangle_typeinfo_for_type (type
);
346 d
= IDENTIFIER_GLOBAL_VALUE (name
);
349 tree var_desc
= get_pseudo_ti_desc (type
);
351 d
= build_lang_decl (VAR_DECL
, name
, TINFO_PSEUDO_TYPE (var_desc
));
353 DECL_ARTIFICIAL (d
) = 1;
354 TREE_READONLY (d
) = 1;
356 DECL_EXTERNAL (d
) = 1;
359 SET_DECL_ASSEMBLER_NAME (d
, name
);
361 pushdecl_top_level_and_finish (d
, NULL_TREE
);
363 if (CLASS_TYPE_P (type
))
364 CLASSTYPE_TYPEINFO_VAR (TYPE_MAIN_VARIANT (type
)) = d
;
366 /* Remember the type it is for. */
367 TREE_TYPE (name
) = type
;
369 /* Add decl to the global array of tinfo decls. */
370 my_friendly_assert (unemitted_tinfo_decls
!= 0, 20030312);
371 VARRAY_PUSH_TREE (unemitted_tinfo_decls
, d
);
377 /* Return a pointer to a type_info object describing TYPE, suitably
378 cast to the language defined type. */
381 get_tinfo_ptr (tree type
)
383 tree decl
= get_tinfo_decl (type
);
386 return build_nop (type_info_ptr_type
,
387 build_address (decl
));
390 /* Return the type_info object for TYPE. */
393 get_typeid (tree type
)
395 if (type
== error_mark_node
|| !typeid_ok_p ())
396 return error_mark_node
;
398 if (processing_template_decl
)
399 return build_min (TYPEID_EXPR
, type_info_ref_type
, type
);
401 /* If the type of the type-id is a reference type, the result of the
402 typeid expression refers to a type_info object representing the
404 type
= non_reference (type
);
406 /* The top-level cv-qualifiers of the lvalue expression or the type-id
407 that is the operand of typeid are always ignored. */
408 type
= TYPE_MAIN_VARIANT (type
);
410 if (!VOID_TYPE_P (type
))
411 type
= complete_type_or_else (type
, NULL_TREE
);
414 return error_mark_node
;
416 return build_indirect_ref (get_tinfo_ptr (type
), NULL
);
419 /* Check whether TEST is null before returning RESULT. If TEST is used in
420 RESULT, it must have previously had a save_expr applied to it. */
423 ifnonnull (tree test
, tree result
)
425 return build (COND_EXPR
, TREE_TYPE (result
),
426 build (EQ_EXPR
, boolean_type_node
, test
, integer_zero_node
),
427 cp_convert (TREE_TYPE (result
), integer_zero_node
),
431 /* Execute a dynamic cast, as described in section 5.2.6 of the 9/93 working
435 build_dynamic_cast_1 (tree type
, tree expr
)
437 enum tree_code tc
= TREE_CODE (type
);
438 tree exprtype
= TREE_TYPE (expr
);
440 tree old_expr
= expr
;
441 const char *errstr
= NULL
;
443 /* T shall be a pointer or reference to a complete class type, or
444 `pointer to cv void''. */
448 if (TREE_CODE (TREE_TYPE (type
)) == VOID_TYPE
)
451 if (! IS_AGGR_TYPE (TREE_TYPE (type
)))
453 errstr
= "target is not pointer or reference to class";
456 if (!COMPLETE_TYPE_P (complete_type (TREE_TYPE (type
))))
458 errstr
= "target is not pointer or reference to complete type";
464 errstr
= "target is not pointer or reference";
468 if (tc
== POINTER_TYPE
)
469 expr
= convert_from_reference (expr
);
470 else if (TREE_CODE (exprtype
) != REFERENCE_TYPE
)
472 /* Apply trivial conversion T -> T& for dereferenced ptrs. */
473 exprtype
= build_reference_type (exprtype
);
474 expr
= convert_to_reference (exprtype
, expr
, CONV_IMPLICIT
,
475 LOOKUP_NORMAL
, NULL_TREE
);
478 exprtype
= TREE_TYPE (expr
);
480 if (tc
== POINTER_TYPE
)
482 /* If T is a pointer type, v shall be an rvalue of a pointer to
483 complete class type, and the result is an rvalue of type T. */
485 if (TREE_CODE (exprtype
) != POINTER_TYPE
)
487 errstr
= "source is not a pointer";
490 if (! IS_AGGR_TYPE (TREE_TYPE (exprtype
)))
492 errstr
= "source is not a pointer to class";
495 if (!COMPLETE_TYPE_P (complete_type (TREE_TYPE (exprtype
))))
497 errstr
= "source is a pointer to incomplete type";
503 /* T is a reference type, v shall be an lvalue of a complete class
504 type, and the result is an lvalue of the type referred to by T. */
506 if (! IS_AGGR_TYPE (TREE_TYPE (exprtype
)))
508 errstr
= "source is not of class type";
511 if (!COMPLETE_TYPE_P (complete_type (TREE_TYPE (exprtype
))))
513 errstr
= "source is of incomplete class type";
519 /* The dynamic_cast operator shall not cast away constness. */
520 if (!at_least_as_qualified_p (TREE_TYPE (type
),
521 TREE_TYPE (exprtype
)))
523 errstr
= "conversion casts away constness";
527 /* If *type is an unambiguous accessible base class of *exprtype,
528 convert statically. */
532 binfo
= lookup_base (TREE_TYPE (exprtype
), TREE_TYPE (type
),
533 ba_not_special
, NULL
);
537 expr
= build_base_path (PLUS_EXPR
, convert_from_reference (expr
),
539 if (TREE_CODE (exprtype
) == POINTER_TYPE
)
540 expr
= non_lvalue (expr
);
545 /* Otherwise *exprtype must be a polymorphic class (have a vtbl). */
546 if (TYPE_POLYMORPHIC_P (TREE_TYPE (exprtype
)))
549 /* if TYPE is `void *', return pointer to complete object. */
550 if (tc
== POINTER_TYPE
&& VOID_TYPE_P (TREE_TYPE (type
)))
552 /* if b is an object, dynamic_cast<void *>(&b) == (void *)&b. */
553 if (TREE_CODE (expr
) == ADDR_EXPR
554 && TREE_CODE (TREE_OPERAND (expr
, 0)) == VAR_DECL
555 && TREE_CODE (TREE_TYPE (TREE_OPERAND (expr
, 0))) == RECORD_TYPE
)
556 return build1 (NOP_EXPR
, type
, expr
);
558 /* Since expr is used twice below, save it. */
559 expr
= save_expr (expr
);
561 expr1
= build_headof (expr
);
562 if (TREE_TYPE (expr1
) != type
)
563 expr1
= build1 (NOP_EXPR
, type
, expr1
);
564 return ifnonnull (expr
, expr1
);
569 tree result
, td2
, td3
, elems
;
570 tree static_type
, target_type
, boff
;
572 /* If we got here, we can't convert statically. Therefore,
573 dynamic_cast<D&>(b) (b an object) cannot succeed. */
574 if (tc
== REFERENCE_TYPE
)
576 if (TREE_CODE (old_expr
) == VAR_DECL
577 && TREE_CODE (TREE_TYPE (old_expr
)) == RECORD_TYPE
)
579 tree expr
= throw_bad_cast ();
580 warning ("dynamic_cast of `%#D' to `%#T' can never succeed",
582 /* Bash it to the expected type. */
583 TREE_TYPE (expr
) = type
;
587 /* Ditto for dynamic_cast<D*>(&b). */
588 else if (TREE_CODE (expr
) == ADDR_EXPR
)
590 tree op
= TREE_OPERAND (expr
, 0);
591 if (TREE_CODE (op
) == VAR_DECL
592 && TREE_CODE (TREE_TYPE (op
)) == RECORD_TYPE
)
594 warning ("dynamic_cast of `%#D' to `%#T' can never succeed",
596 retval
= build_int_2 (0, 0);
597 TREE_TYPE (retval
) = type
;
602 target_type
= TYPE_MAIN_VARIANT (TREE_TYPE (type
));
603 static_type
= TYPE_MAIN_VARIANT (TREE_TYPE (exprtype
));
604 td2
= get_tinfo_decl (target_type
);
606 td2
= build_unary_op (ADDR_EXPR
, td2
, 0);
607 td3
= get_tinfo_decl (static_type
);
609 td3
= build_unary_op (ADDR_EXPR
, td3
, 0);
611 /* Determine how T and V are related. */
612 boff
= get_dynamic_cast_base_type (static_type
, target_type
);
614 /* Since expr is used twice below, save it. */
615 expr
= save_expr (expr
);
618 if (tc
== REFERENCE_TYPE
)
619 expr1
= build_unary_op (ADDR_EXPR
, expr1
, 0);
622 (NULL_TREE
, expr1
, tree_cons
623 (NULL_TREE
, td3
, tree_cons
624 (NULL_TREE
, td2
, tree_cons
625 (NULL_TREE
, boff
, NULL_TREE
))));
627 dcast_fn
= dynamic_cast_node
;
635 push_nested_namespace (ns
);
636 tinfo_ptr
= xref_tag (class_type
,
637 get_identifier ("__class_type_info"),
640 tinfo_ptr
= build_pointer_type
641 (build_qualified_type
642 (tinfo_ptr
, TYPE_QUAL_CONST
));
643 name
= "__dynamic_cast";
645 (NULL_TREE
, const_ptr_type_node
, tree_cons
646 (NULL_TREE
, tinfo_ptr
, tree_cons
647 (NULL_TREE
, tinfo_ptr
, tree_cons
648 (NULL_TREE
, ptrdiff_type_node
, void_list_node
))));
649 tmp
= build_function_type (ptr_type_node
, tmp
);
650 dcast_fn
= build_library_fn_ptr (name
, tmp
);
651 DECL_IS_PURE (dcast_fn
) = 1;
652 pop_nested_namespace (ns
);
653 dynamic_cast_node
= dcast_fn
;
655 result
= build_cxx_call (dcast_fn
, elems
, elems
);
657 if (tc
== REFERENCE_TYPE
)
659 tree bad
= throw_bad_cast ();
661 result
= save_expr (result
);
662 return build (COND_EXPR
, type
, result
, result
, bad
);
665 /* Now back to the type we want from a void*. */
666 result
= cp_convert (type
, result
);
667 return ifnonnull (expr
, result
);
671 errstr
= "source type is not polymorphic";
674 error ("cannot dynamic_cast `%E' (of type `%#T') to type `%#T' (%s)",
675 expr
, exprtype
, type
, errstr
);
676 return error_mark_node
;
680 build_dynamic_cast (tree type
, tree expr
)
682 if (type
== error_mark_node
|| expr
== error_mark_node
)
683 return error_mark_node
;
685 if (processing_template_decl
)
687 expr
= build_min (DYNAMIC_CAST_EXPR
, type
, expr
);
688 TREE_SIDE_EFFECTS (expr
) = 1;
693 return convert_from_reference (build_dynamic_cast_1 (type
, expr
));
696 /* Return the runtime bit mask encoding the qualifiers of TYPE. */
699 qualifier_flags (tree type
)
702 int quals
= cp_type_quals (type
);
704 if (quals
& TYPE_QUAL_CONST
)
706 if (quals
& TYPE_QUAL_VOLATILE
)
708 if (quals
& TYPE_QUAL_RESTRICT
)
713 /* Return true, if the pointer chain TYPE ends at an incomplete type, or
714 contains a pointer to member of an incomplete class. */
717 target_incomplete_p (tree type
)
720 if (TYPE_PTRMEM_P (type
))
722 if (!COMPLETE_TYPE_P (TYPE_PTRMEM_CLASS_TYPE (type
)))
724 type
= TYPE_PTRMEM_POINTED_TO_TYPE (type
);
726 else if (TREE_CODE (type
) == POINTER_TYPE
)
727 type
= TREE_TYPE (type
);
729 return !COMPLETE_OR_VOID_TYPE_P (type
);
732 /* Return a CONSTRUCTOR for the common part of the type_info objects. This
733 is the vtable pointer and NTBS name. The NTBS name is emitted as a
734 comdat const char array, so it becomes a unique key for the type. Generate
735 and emit that VAR_DECL here. (We can't always emit the type_info itself
736 as comdat, because of pointers to incomplete.) */
739 tinfo_base_init (tree desc
, tree target
)
741 tree init
= NULL_TREE
;
748 /* Generate the NTBS array variable. */
749 tree name_type
= build_cplus_array_type
750 (build_qualified_type (char_type_node
, TYPE_QUAL_CONST
),
752 tree name_string
= tinfo_name (target
);
754 name_name
= mangle_typeinfo_string_for_type (target
);
755 name_decl
= build_lang_decl (VAR_DECL
, name_name
, name_type
);
757 DECL_ARTIFICIAL (name_decl
) = 1;
758 TREE_READONLY (name_decl
) = 1;
759 TREE_STATIC (name_decl
) = 1;
760 DECL_EXTERNAL (name_decl
) = 0;
761 TREE_PUBLIC (name_decl
) = 1;
762 import_export_tinfo (name_decl
, target
, typeinfo_in_lib_p (target
));
763 /* External name of the string containing the type's name has a
765 SET_DECL_ASSEMBLER_NAME (name_decl
,
766 mangle_typeinfo_string_for_type (target
));
767 DECL_INITIAL (name_decl
) = name_string
;
768 mark_used (name_decl
);
769 pushdecl_top_level_and_finish (name_decl
, name_string
);
772 vtable_ptr
= TINFO_VTABLE_DECL (desc
);
777 push_nested_namespace (abi_node
);
778 real_type
= xref_tag (class_type
, TINFO_REAL_NAME (desc
),
780 pop_nested_namespace (abi_node
);
782 if (!COMPLETE_TYPE_P (real_type
))
784 /* We never saw a definition of this type, so we need to
785 tell the compiler that this is an exported class, as
786 indeed all of the __*_type_info classes are. */
787 SET_CLASSTYPE_INTERFACE_KNOWN (real_type
);
788 CLASSTYPE_INTERFACE_ONLY (real_type
) = 1;
791 vtable_ptr
= get_vtable_decl (real_type
, /*complete=*/1);
792 vtable_ptr
= build_unary_op (ADDR_EXPR
, vtable_ptr
, 0);
794 /* We need to point into the middle of the vtable. */
796 (PLUS_EXPR
, TREE_TYPE (vtable_ptr
), vtable_ptr
,
797 size_binop (MULT_EXPR
,
798 size_int (2 * TARGET_VTABLE_DATA_ENTRY_DISTANCE
),
799 TYPE_SIZE_UNIT (vtable_entry_type
)));
800 TREE_CONSTANT (vtable_ptr
) = 1;
802 TINFO_VTABLE_DECL (desc
) = vtable_ptr
;
805 init
= tree_cons (NULL_TREE
, vtable_ptr
, init
);
807 init
= tree_cons (NULL_TREE
, decay_conversion (name_decl
), init
);
809 init
= build_constructor (NULL_TREE
, nreverse (init
));
810 TREE_CONSTANT (init
) = TREE_STATIC (init
) = 1;
811 init
= tree_cons (NULL_TREE
, init
, NULL_TREE
);
816 /* Return the CONSTRUCTOR expr for a type_info of TYPE. DESC provides the
817 information about the particular type_info derivation, which adds no
818 additional fields to the type_info base. */
821 generic_initializer (tree desc
, tree target
)
823 tree init
= tinfo_base_init (desc
, target
);
825 init
= build_constructor (NULL_TREE
, init
);
826 TREE_CONSTANT (init
) = TREE_STATIC (init
) = 1;
830 /* Return the CONSTRUCTOR expr for a type_info of pointer TYPE.
831 DESC provides information about the particular type_info derivation,
832 which adds target type and qualifier flags members to the type_info base. */
835 ptr_initializer (tree desc
, tree target
, bool *non_public_ptr
)
837 tree init
= tinfo_base_init (desc
, target
);
838 tree to
= TREE_TYPE (target
);
839 int flags
= qualifier_flags (to
);
840 bool incomplete
= target_incomplete_p (to
);
845 *non_public_ptr
= true;
847 init
= tree_cons (NULL_TREE
, build_int_2 (flags
, 0), init
);
848 init
= tree_cons (NULL_TREE
,
849 get_tinfo_ptr (TYPE_MAIN_VARIANT (to
)),
852 init
= build_constructor (NULL_TREE
, nreverse (init
));
853 TREE_CONSTANT (init
) = TREE_STATIC (init
) = 1;
857 /* Return the CONSTRUCTOR expr for a type_info of pointer to member data TYPE.
858 DESC provides information about the particular type_info derivation,
859 which adds class, target type and qualifier flags members to the type_info
863 ptm_initializer (tree desc
, tree target
, bool *non_public_ptr
)
865 tree init
= tinfo_base_init (desc
, target
);
866 tree to
= TYPE_PTRMEM_POINTED_TO_TYPE (target
);
867 tree klass
= TYPE_PTRMEM_CLASS_TYPE (target
);
868 int flags
= qualifier_flags (to
);
869 bool incomplete
= target_incomplete_p (to
);
874 *non_public_ptr
= true;
876 if (!COMPLETE_TYPE_P (klass
))
879 *non_public_ptr
= true;
881 init
= tree_cons (NULL_TREE
, build_int_2 (flags
, 0), init
);
882 init
= tree_cons (NULL_TREE
,
883 get_tinfo_ptr (TYPE_MAIN_VARIANT (to
)),
885 init
= tree_cons (NULL_TREE
,
886 get_tinfo_ptr (klass
),
889 init
= build_constructor (NULL_TREE
, nreverse (init
));
890 TREE_CONSTANT (init
) = TREE_STATIC (init
) = 1;
894 /* Check base BINFO to set hint flags in *DATA, which is really an int.
895 We use CLASSTYPE_MARKED to tag types we've found as non-virtual bases and
896 CLASSTYPE_MARKED2 to tag those which are virtual bases. Remember it is
897 possible for a type to be both a virtual and non-virtual base. */
900 dfs_class_hint_mark (tree binfo
, void *data
)
902 tree basetype
= BINFO_TYPE (binfo
);
903 int *hint
= (int *) data
;
905 if (TREE_VIA_VIRTUAL (binfo
))
907 if (CLASSTYPE_MARKED (basetype
))
909 if (CLASSTYPE_MARKED2 (basetype
))
911 SET_CLASSTYPE_MARKED2 (basetype
);
915 if (CLASSTYPE_MARKED (basetype
) || CLASSTYPE_MARKED2 (basetype
))
917 SET_CLASSTYPE_MARKED (basetype
);
922 /* Clear the base's dfs marks, after searching for duplicate bases. */
925 dfs_class_hint_unmark (tree binfo
, void *data ATTRIBUTE_UNUSED
)
927 tree basetype
= BINFO_TYPE (binfo
);
929 CLEAR_CLASSTYPE_MARKED (basetype
);
930 CLEAR_CLASSTYPE_MARKED2 (basetype
);
934 /* Determine the hint flags describing the features of a class's hierarchy. */
937 class_hint_flags (tree type
)
941 dfs_walk (TYPE_BINFO (type
), dfs_class_hint_mark
, NULL
, &hint_flags
);
942 dfs_walk (TYPE_BINFO (type
), dfs_class_hint_unmark
, NULL
, NULL
);
947 /* Return the CONSTRUCTOR expr for a type_info of class TYPE.
948 DESC provides information about the particular __class_type_info derivation,
949 which adds hint flags and TRAIL initializers to the type_info base. */
952 class_initializer (tree desc
, tree target
, tree trail
)
954 tree init
= tinfo_base_init (desc
, target
);
956 TREE_CHAIN (init
) = trail
;
957 init
= build_constructor (NULL_TREE
, init
);
958 TREE_CONSTANT (init
) = TREE_STATIC (init
) = 1;
962 /* Returns true if the typeinfo for type should be placed in
963 the runtime library. */
966 typeinfo_in_lib_p (tree type
)
968 /* The typeinfo objects for `T*' and `const T*' are in the runtime
969 library for simple types T. */
970 if (TREE_CODE (type
) == POINTER_TYPE
971 && (cp_type_quals (TREE_TYPE (type
)) == TYPE_QUAL_CONST
972 || cp_type_quals (TREE_TYPE (type
)) == TYPE_UNQUALIFIED
))
973 type
= TREE_TYPE (type
);
975 switch (TREE_CODE (type
))
989 /* Generate the initializer for the type info describing
990 TYPE. VAR_DESC is a . NON_PUBLIC_P is set nonzero, if the VAR_DECL
991 should not be exported from this object file. This should only be
992 called at the end of translation, when we know that no further
993 types will be completed. */
996 get_pseudo_ti_init (tree type
, tree var_desc
, bool *non_public_p
)
998 my_friendly_assert (at_eof
, 20021120);
999 switch (TREE_CODE (type
))
1002 return ptm_initializer (var_desc
, type
, non_public_p
);
1004 return ptr_initializer (var_desc
, type
, non_public_p
);
1006 return generic_initializer (var_desc
, type
);
1009 return generic_initializer (var_desc
, type
);
1012 return generic_initializer (var_desc
, type
);
1016 if (TYPE_PTRMEMFUNC_P (type
))
1017 return ptm_initializer (var_desc
, type
, non_public_p
);
1018 else if (var_desc
== class_desc_type_node
)
1020 if (!COMPLETE_TYPE_P (type
))
1021 /* Emit a non-public class_type_info. */
1022 *non_public_p
= true;
1023 return class_initializer (var_desc
, type
, NULL_TREE
);
1025 else if (var_desc
== si_class_desc_type_node
)
1027 tree base_binfos
= BINFO_BASETYPES (TYPE_BINFO (type
));
1028 tree base_binfo
= TREE_VEC_ELT (base_binfos
, 0);
1029 tree tinfo
= get_tinfo_ptr (BINFO_TYPE (base_binfo
));
1030 tree base_inits
= tree_cons (NULL_TREE
, tinfo
, NULL_TREE
);
1032 return class_initializer (var_desc
, type
, base_inits
);
1036 int hint
= class_hint_flags (type
);
1037 tree binfo
= TYPE_BINFO (type
);
1038 int nbases
= BINFO_N_BASETYPES (binfo
);
1039 tree base_binfos
= BINFO_BASETYPES (binfo
);
1040 tree base_accesses
= BINFO_BASEACCESSES (binfo
);
1041 tree base_inits
= NULL_TREE
;
1044 /* Generate the base information initializer. */
1045 for (ix
= nbases
; ix
--;)
1047 tree base_binfo
= TREE_VEC_ELT (base_binfos
, ix
);
1048 tree base_init
= NULL_TREE
;
1053 if (TREE_VEC_ELT (base_accesses
, ix
) == access_public_node
)
1055 tinfo
= get_tinfo_ptr (BINFO_TYPE (base_binfo
));
1056 if (TREE_VIA_VIRTUAL (base_binfo
))
1058 /* We store the vtable offset at which the virtual
1059 base offset can be found. */
1060 offset
= BINFO_VPTR_FIELD (base_binfo
);
1061 offset
= convert (sizetype
, offset
);
1065 offset
= BINFO_OFFSET (base_binfo
);
1067 /* Combine offset and flags into one field. */
1068 offset
= cp_build_binary_op (LSHIFT_EXPR
, offset
,
1069 build_int_2 (8, 0));
1070 offset
= cp_build_binary_op (BIT_IOR_EXPR
, offset
,
1071 build_int_2 (flags
, 0));
1072 base_init
= tree_cons (NULL_TREE
, offset
, base_init
);
1073 base_init
= tree_cons (NULL_TREE
, tinfo
, base_init
);
1074 base_init
= build_constructor (NULL_TREE
, base_init
);
1075 base_inits
= tree_cons (NULL_TREE
, base_init
, base_inits
);
1077 base_inits
= build_constructor (NULL_TREE
, base_inits
);
1078 base_inits
= tree_cons (NULL_TREE
, base_inits
, NULL_TREE
);
1079 /* Prepend the number of bases. */
1080 base_inits
= tree_cons (NULL_TREE
,
1081 build_int_2 (nbases
, 0), base_inits
);
1082 /* Prepend the hint flags. */
1083 base_inits
= tree_cons (NULL_TREE
,
1084 build_int_2 (hint
, 0), base_inits
);
1086 return class_initializer (var_desc
, type
, base_inits
);
1091 return generic_initializer (var_desc
, type
);
1095 /* Generate the RECORD_TYPE containing the data layout of a type_info
1096 derivative as used by the runtime. This layout must be consistent with
1097 that defined in the runtime support. Also generate the VAR_DECL for the
1098 type's vtable. We explicitly manage the vtable member, and name it for
1099 real type as used in the runtime. The RECORD type has a different name,
1100 to avoid collisions. Return a TREE_LIST who's TINFO_PSEUDO_TYPE
1101 is the generated type and TINFO_VTABLE_NAME is the name of the
1102 vtable. We have to delay generating the VAR_DECL of the vtable
1103 until the end of the translation, when we'll have seen the library
1104 definition, if there was one.
1106 REAL_NAME is the runtime's name of the type. Trailing arguments are
1107 additional FIELD_DECL's for the structure. The final argument must be
1111 create_pseudo_type_info (const char *real_name
, int ident
, ...)
1120 va_start (ap
, ident
);
1122 /* Generate the pseudo type name. */
1123 pseudo_name
= alloca (strlen (real_name
) + 30);
1124 strcpy (pseudo_name
, real_name
);
1125 strcat (pseudo_name
, "_pseudo");
1127 sprintf (pseudo_name
+ strlen (pseudo_name
), "%d", ident
);
1129 /* First field is the pseudo type_info base class. */
1130 fields
= build_decl (FIELD_DECL
, NULL_TREE
, ti_desc_type_node
);
1132 /* Now add the derived fields. */
1133 while ((field_decl
= va_arg (ap
, tree
)))
1135 TREE_CHAIN (field_decl
) = fields
;
1136 fields
= field_decl
;
1139 /* Create the pseudo type. */
1140 pseudo_type
= make_aggr_type (RECORD_TYPE
);
1141 finish_builtin_struct (pseudo_type
, pseudo_name
, fields
, NULL_TREE
);
1142 CLASSTYPE_AS_BASE (pseudo_type
) = pseudo_type
;
1144 result
= tree_cons (NULL_TREE
, NULL_TREE
, NULL_TREE
);
1145 TINFO_REAL_NAME (result
) = get_identifier (real_name
);
1146 TINFO_PSEUDO_TYPE (result
) =
1147 cp_build_qualified_type (pseudo_type
, TYPE_QUAL_CONST
);
1153 /* Return a pseudo type info type node used to describe TYPE. TYPE
1154 must be a complete type (or cv void), except at the end of the
1155 translation unit. */
1158 get_pseudo_ti_desc (tree type
)
1160 switch (TREE_CODE (type
))
1163 return ptm_desc_type_node
;
1165 return ptr_desc_type_node
;
1167 return enum_desc_type_node
;
1169 return func_desc_type_node
;
1171 return ary_desc_type_node
;
1174 if (TYPE_PTRMEMFUNC_P (type
))
1175 return ptm_desc_type_node
;
1176 else if (!COMPLETE_TYPE_P (type
))
1179 cxx_incomplete_type_error (NULL_TREE
, type
);
1180 return class_desc_type_node
;
1182 else if (!CLASSTYPE_N_BASECLASSES (type
))
1183 return class_desc_type_node
;
1186 tree binfo
= TYPE_BINFO (type
);
1187 tree base_binfos
= BINFO_BASETYPES (binfo
);
1188 tree base_accesses
= BINFO_BASEACCESSES (binfo
);
1189 tree base_binfo
= TREE_VEC_ELT (base_binfos
, 0);
1190 int num_bases
= TREE_VEC_LENGTH (base_binfos
);
1193 && TREE_VEC_ELT (base_accesses
, 0) == access_public_node
1194 && !TREE_VIA_VIRTUAL (base_binfo
)
1195 && integer_zerop (BINFO_OFFSET (base_binfo
)))
1196 /* single non-virtual public. */
1197 return si_class_desc_type_node
;
1201 tree array_domain
, base_array
;
1203 if (TREE_VEC_LENGTH (vmi_class_desc_type_node
) <= num_bases
)
1206 tree extend
= make_tree_vec (num_bases
+ 5);
1208 for (ix
= TREE_VEC_LENGTH (vmi_class_desc_type_node
); ix
--;)
1209 TREE_VEC_ELT (extend
, ix
)
1210 = TREE_VEC_ELT (vmi_class_desc_type_node
, ix
);
1211 vmi_class_desc_type_node
= extend
;
1213 var_desc
= TREE_VEC_ELT (vmi_class_desc_type_node
, num_bases
);
1217 /* Create the array of __base_class_type_info entries.
1218 G++ 3.2 allocated an array that had one too many
1219 entries, and then filled that extra entries with
1221 if (abi_version_at_least (2))
1222 array_domain
= build_index_type (size_int (num_bases
- 1));
1224 array_domain
= build_index_type (size_int (num_bases
));
1226 build_array_type (base_desc_type_node
, array_domain
);
1228 push_nested_namespace (abi_node
);
1229 var_desc
= create_pseudo_type_info
1230 ("__vmi_class_type_info", num_bases
,
1231 build_decl (FIELD_DECL
, NULL_TREE
, integer_type_node
),
1232 build_decl (FIELD_DECL
, NULL_TREE
, integer_type_node
),
1233 build_decl (FIELD_DECL
, NULL_TREE
, base_array
),
1235 pop_nested_namespace (abi_node
);
1237 TREE_VEC_ELT (vmi_class_desc_type_node
, num_bases
) = var_desc
;
1242 return bltn_desc_type_node
;
1246 /* Make sure the required builtin types exist for generating the type_info
1247 variable definitions. */
1250 create_tinfo_types (void)
1252 my_friendly_assert (!ti_desc_type_node
, 20020609);
1254 push_nested_namespace (abi_node
);
1256 /* Create the internal type_info structure. This is used as a base for
1257 the other structures. */
1261 ti_desc_type_node
= make_aggr_type (RECORD_TYPE
);
1262 field
= build_decl (FIELD_DECL
, NULL_TREE
, const_ptr_type_node
);
1265 field
= build_decl (FIELD_DECL
, NULL_TREE
, const_string_type_node
);
1266 TREE_CHAIN (field
) = fields
;
1269 finish_builtin_struct (ti_desc_type_node
, "__type_info_pseudo",
1271 TYPE_HAS_CONSTRUCTOR (ti_desc_type_node
) = 1;
1274 /* Fundamental type_info */
1275 bltn_desc_type_node
= create_pseudo_type_info
1276 ("__fundamental_type_info", 0,
1279 /* Array, function and enum type_info. No additional fields. */
1280 ary_desc_type_node
= create_pseudo_type_info
1281 ("__array_type_info", 0,
1283 func_desc_type_node
= create_pseudo_type_info
1284 ("__function_type_info", 0,
1286 enum_desc_type_node
= create_pseudo_type_info
1287 ("__enum_type_info", 0,
1290 /* Class type_info. Add a flags field. */
1291 class_desc_type_node
= create_pseudo_type_info
1292 ("__class_type_info", 0,
1295 /* Single public non-virtual base class. Add pointer to base class.
1296 This is really a descendant of __class_type_info. */
1297 si_class_desc_type_node
= create_pseudo_type_info
1298 ("__si_class_type_info", 0,
1299 build_decl (FIELD_DECL
, NULL_TREE
, type_info_ptr_type
),
1302 /* Base class internal helper. Pointer to base type, offset to base,
1307 field
= build_decl (FIELD_DECL
, NULL_TREE
, type_info_ptr_type
);
1310 field
= build_decl (FIELD_DECL
, NULL_TREE
, integer_types
[itk_long
]);
1311 TREE_CHAIN (field
) = fields
;
1314 base_desc_type_node
= make_aggr_type (RECORD_TYPE
);
1315 finish_builtin_struct (base_desc_type_node
, "__base_class_type_info_pseudo",
1317 TYPE_HAS_CONSTRUCTOR (base_desc_type_node
) = 1;
1320 /* General hierarchy is created as necessary in this vector. */
1321 vmi_class_desc_type_node
= make_tree_vec (10);
1323 /* Pointer type_info. Adds two fields, qualification mask
1324 and pointer to the pointed to type. This is really a descendant of
1325 __pbase_type_info. */
1326 ptr_desc_type_node
= create_pseudo_type_info
1327 ("__pointer_type_info", 0,
1328 build_decl (FIELD_DECL
, NULL_TREE
, integer_type_node
),
1329 build_decl (FIELD_DECL
, NULL_TREE
, type_info_ptr_type
),
1332 /* Pointer to member data type_info. Add qualifications flags,
1333 pointer to the member's type info and pointer to the class.
1334 This is really a descendant of __pbase_type_info. */
1335 ptm_desc_type_node
= create_pseudo_type_info
1336 ("__pointer_to_member_type_info", 0,
1337 build_decl (FIELD_DECL
, NULL_TREE
, integer_type_node
),
1338 build_decl (FIELD_DECL
, NULL_TREE
, type_info_ptr_type
),
1339 build_decl (FIELD_DECL
, NULL_TREE
, type_info_ptr_type
),
1342 pop_nested_namespace (abi_node
);
1345 /* Emit the type_info descriptors which are guaranteed to be in the runtime
1346 support. Generating them here guarantees consistency with the other
1347 structures. We use the following heuristic to determine when the runtime
1348 is being generated. If std::__fundamental_type_info is defined, and its
1349 destructor is defined, then the runtime is being built. */
1352 emit_support_tinfos (void)
1354 static tree
*const fundamentals
[] =
1359 &char_type_node
, &signed_char_type_node
, &unsigned_char_type_node
,
1360 &short_integer_type_node
, &short_unsigned_type_node
,
1361 &integer_type_node
, &unsigned_type_node
,
1362 &long_integer_type_node
, &long_unsigned_type_node
,
1363 &long_long_integer_type_node
, &long_long_unsigned_type_node
,
1364 &float_type_node
, &double_type_node
, &long_double_type_node
,
1368 tree bltn_type
, dtor
;
1370 push_nested_namespace (abi_node
);
1371 bltn_type
= xref_tag (class_type
,
1372 get_identifier ("__fundamental_type_info"),
1374 pop_nested_namespace (abi_node
);
1375 if (!COMPLETE_TYPE_P (bltn_type
))
1377 dtor
= TREE_VEC_ELT (CLASSTYPE_METHOD_VEC (bltn_type
), 1);
1378 if (DECL_EXTERNAL (dtor
))
1381 for (ix
= 0; fundamentals
[ix
]; ix
++)
1383 tree bltn
= *fundamentals
[ix
];
1384 tree bltn_ptr
= build_pointer_type (bltn
);
1385 tree bltn_const_ptr
= build_pointer_type
1386 (build_qualified_type (bltn
, TYPE_QUAL_CONST
));
1389 tinfo
= get_tinfo_decl (bltn
);
1390 TREE_USED (tinfo
) = 1;
1391 TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (tinfo
)) = 1;
1393 tinfo
= get_tinfo_decl (bltn_ptr
);
1394 TREE_USED (tinfo
) = 1;
1395 TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (tinfo
)) = 1;
1397 tinfo
= get_tinfo_decl (bltn_const_ptr
);
1398 TREE_USED (tinfo
) = 1;
1399 TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (tinfo
)) = 1;
1403 /* Return true, iff T is a type_info variable which has not had a
1404 definition emitted for it. */
1407 unemitted_tinfo_decl_p (tree t
)
1409 if (/* It's a var decl */
1410 TREE_CODE (t
) == VAR_DECL
1411 /* which has a name */
1413 /* whose name points back to itself */
1414 && IDENTIFIER_GLOBAL_VALUE (DECL_NAME (t
)) == t
1415 /* whose name's type is non-null */
1416 && TREE_TYPE (DECL_NAME (t
))
1417 /* and whose type is a struct */
1418 && TREE_CODE (TREE_TYPE (t
)) == RECORD_TYPE
1420 && TYPE_FIELDS (TREE_TYPE (t
))
1421 /* which is our pseudo type info */
1422 && TREE_TYPE (TYPE_FIELDS (TREE_TYPE (t
))) == ti_desc_type_node
)
1427 /* Finish a type info decl. DECL_PTR is a pointer to an unemitted
1428 tinfo decl. Determine whether it needs emitting, and if so
1429 generate the initializer. */
1432 emit_tinfo_decl (tree decl
)
1434 tree type
= TREE_TYPE (DECL_NAME (decl
));
1436 int in_library
= typeinfo_in_lib_p (type
);
1437 tree var_desc
, var_init
;
1439 my_friendly_assert (unemitted_tinfo_decl_p (decl
), 20030307);
1441 import_export_tinfo (decl
, type
, in_library
);
1442 if (DECL_REALLY_EXTERN (decl
) || !DECL_NEEDED_P (decl
))
1445 if (!doing_runtime
&& in_library
)
1449 var_desc
= get_pseudo_ti_desc (type
);
1450 var_init
= get_pseudo_ti_init (type
, var_desc
, &non_public
);
1452 DECL_EXTERNAL (decl
) = 0;
1453 TREE_PUBLIC (decl
) = !non_public
;
1455 DECL_COMDAT (decl
) = 0;
1457 DECL_INITIAL (decl
) = var_init
;
1459 cp_finish_decl (decl
, var_init
, NULL_TREE
, 0);
1460 /* cp_finish_decl will have dealt with linkage. */
1462 /* Say we've dealt with it. */
1463 TREE_TYPE (DECL_NAME (decl
)) = NULL_TREE
;