1 // RTTI support for -*- C++ -*-
2 // Copyright (C) 1994, 1995, 1996, 1997, 1998, 2000, 2001, 2002
3 // Free Software Foundation
5 // This file is part of GCC.
7 // GCC is free software; you can redistribute it and/or modify
8 // it under the terms of the GNU General Public License as published by
9 // the Free Software Foundation; either version 2, or (at your option)
12 // GCC is distributed in the hope that it will be useful,
13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 // GNU General Public License for more details.
17 // You should have received a copy of the GNU General Public License
18 // along with GCC; see the file COPYING. If not, write to
19 // the Free Software Foundation, 51 Franklin Street, Fifth Floor,
20 // Boston, MA 02110-1301, USA.
22 // As a special exception, you may use this file as part of a free software
23 // library without restriction. Specifically, if other files instantiate
24 // templates or use macros or inline functions from this file, or you compile
25 // this file and link it with other files to produce an executable, this
26 // file does not by itself cause the resulting executable to be covered by
27 // the GNU General Public License. This exception does not however
28 // invalidate any other reasons why the executable file might be covered by
29 // the GNU General Public License.
32 * This is a Standard C++ Library header.
40 #pragma GCC visibility push(default)
46 class __class_type_info;
47 } // namespace __cxxabiv1
49 // Determine whether typeinfo names for the same type are merged (in which
50 // case comparison can just compare pointers) or not (in which case
51 // strings must be compared and g++.dg/abi/local1.C will fail), and
52 // whether comparison is to be implemented inline or not. By default we
53 // use inline pointer comparison if weak symbols are available, and
54 // out-of-line strcmp if not. Out-of-line pointer comparison is used
55 // where the object files are to be portable to multiple systems, some of
56 // which may not be able to use pointer comparison, but the particular
57 // system for which libstdc++ is being built can use pointer comparison;
58 // in particular for most ARM EABI systems, where the ABI specifies
59 // out-of-line comparison. Inline strcmp is not currently supported. The
60 // compiler's target configuration can override the defaults by defining
61 // __GXX_TYPEINFO_EQUALITY_INLINE to 1 or 0 to indicate whether or not
62 // comparison is inline, and __GXX_MERGED_TYPEINFO_NAMES to 1 or 0 to
63 // indicate whether or not pointer comparison can be used.
65 #ifndef __GXX_MERGED_TYPEINFO_NAMES
67 // If weak symbols are not supported, typeinfo names are not merged.
68 #define __GXX_MERGED_TYPEINFO_NAMES 0
70 // On platforms that support weak symbols, typeinfo names are merged.
71 #define __GXX_MERGED_TYPEINFO_NAMES 1
75 // By default follow the same rules as for __GXX_MERGED_TYPEINFO_NAMES.
76 #ifndef __GXX_TYPEINFO_EQUALITY_INLINE
78 #define __GXX_TYPEINFO_EQUALITY_INLINE 0
80 #define __GXX_TYPEINFO_EQUALITY_INLINE 1
87 * @brief Part of RTTI.
89 * The @c type_info class describes type information generated by
95 /** Destructor. Being the first non-inline virtual function, this
96 * controls in which translation unit the vtable is emitted. The
97 * compiler makes use of that information to know where to emit
98 * the runtime-mandated type_info structures in the new-abi. */
102 /// Assigning type_info is not supported. Made private.
103 type_info& operator=(const type_info&);
104 type_info(const type_info&);
110 explicit type_info(const char *__n): __name(__n) { }
113 // the public interface
114 /** Returns an @e implementation-defined byte string; this is not
115 * portable between compilers! */
116 const char* name() const
119 #if !__GXX_TYPEINFO_EQUALITY_INLINE
120 bool before(const type_info& __arg) const;
121 // In old abi, or when weak symbols are not supported, there can
122 // be multiple instances of a type_info object for one
123 // type. Uniqueness must use the _name value, not object address.
124 bool operator==(const type_info& __arg) const;
126 #if !__GXX_MERGED_TYPEINFO_NAMES
127 #error "Inline implementation of type_info comparision requires merging of type_info objects"
129 /** Returns true if @c *this precedes @c __arg in the implementation's
130 * collation order. */
131 // In new abi we can rely on type_info's NTBS being unique,
132 // and therefore address comparisons are sufficient.
133 bool before(const type_info& __arg) const
134 { return __name < __arg.__name; }
135 bool operator==(const type_info& __arg) const
136 { return __name == __arg.__name; }
138 bool operator!=(const type_info& __arg) const
139 { return !operator==(__arg); }
141 // the internal interface
143 // return true if this is a pointer type of some kind
144 virtual bool __is_pointer_p() const;
145 // return true if this is a function type
146 virtual bool __is_function_p() const;
148 // Try and catch a thrown type. Store an adjusted pointer to the
149 // caught type in THR_OBJ. If THR_TYPE is not a pointer type, then
150 // THR_OBJ points to the thrown object. If THR_TYPE is a pointer
151 // type, then THR_OBJ is the pointer itself. OUTER indicates the
152 // number of outer pointers, and whether they were const
154 virtual bool __do_catch(const type_info *__thr_type, void **__thr_obj,
155 unsigned __outer) const;
157 // internally used during catch matching
158 virtual bool __do_upcast(const __cxxabiv1::__class_type_info *__target,
159 void **__obj_ptr) const;
163 * @brief Thrown during incorrect typecasting.
165 * If you attempt an invalid @c dynamic_cast expression, an instance of
166 * this class (or something derived from this class) is thrown. */
167 class bad_cast : public exception
170 bad_cast() throw() { }
171 // This declaration is not useless:
172 // http://gcc.gnu.org/onlinedocs/gcc-3.0.2/gcc_6.html#SEC118
173 virtual ~bad_cast() throw();
176 /** If you use a NULL pointer in a @c typeid expression, this is thrown. */
177 class bad_typeid : public exception
180 bad_typeid () throw() { }
181 // This declaration is not useless:
182 // http://gcc.gnu.org/onlinedocs/gcc-3.0.2/gcc_6.html#SEC118
183 virtual ~bad_typeid() throw();
187 #pragma GCC visibility pop