1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
|
// RTTI support for -*- C++ -*-
// Copyright (C) 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002,
// 2003, 2004, 2005, 2006, 2007, 2009, 2010
// Free Software Foundation
//
// This file is part of GCC.
//
// GCC is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 3, or (at your option)
// any later version.
//
// GCC is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.
// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
// <http://www.gnu.org/licenses/>.
/** @file typeinfo
* This is a Standard C++ Library header.
*/
#ifndef _TYPEINFO
#define _TYPEINFO
#pragma GCC system_header
#include <exception>
#pragma GCC visibility push(default)
extern "C++" {
namespace __cxxabiv1
{
class __class_type_info;
} // namespace __cxxabiv1
// Determine whether typeinfo names for the same type are merged (in which
// case comparison can just compare pointers) or not (in which case strings
// must be compared), and whether comparison is to be implemented inline or
// not. We used to do inline pointer comparison by default if weak symbols
// are available, but even with weak symbols sometimes names are not merged
// when objects are loaded with RTLD_LOCAL, so now we always use strcmp by
// default. For ABI compatibility, we do the strcmp inline if weak symbols
// are available, and out-of-line if not. Out-of-line pointer comparison
// is used where the object files are to be portable to multiple systems,
// some of which may not be able to use pointer comparison, but the
// particular system for which libstdc++ is being built can use pointer
// comparison; in particular for most ARM EABI systems, where the ABI
// specifies out-of-line comparison. The compiler's target configuration
// can override the defaults by defining __GXX_TYPEINFO_EQUALITY_INLINE to
// 1 or 0 to indicate whether or not comparison is inline, and
// __GXX_MERGED_TYPEINFO_NAMES to 1 or 0 to indicate whether or not pointer
// comparison can be used.
#ifndef __GXX_MERGED_TYPEINFO_NAMES
// By default, typeinfo names are not merged.
#define __GXX_MERGED_TYPEINFO_NAMES 0
#endif
// By default follow the old inline rules to avoid ABI changes.
#ifndef __GXX_TYPEINFO_EQUALITY_INLINE
#if !__GXX_WEAK__
#define __GXX_TYPEINFO_EQUALITY_INLINE 0
#else
#define __GXX_TYPEINFO_EQUALITY_INLINE 1
#endif
#endif
namespace std
{
/**
* @brief Part of RTTI.
*
* The @c type_info class describes type information generated by
* an implementation.
*/
class type_info
{
public:
/** Destructor first. Being the first non-inline virtual function, this
* controls in which translation unit the vtable is emitted. The
* compiler makes use of that information to know where to emit
* the runtime-mandated type_info structures in the new-abi. */
virtual ~type_info();
/** Returns an @e implementation-defined byte string; this is not
* portable between compilers! */
const char* name() const
{ return __name[0] == '*' ? __name + 1 : __name; }
#if !__GXX_TYPEINFO_EQUALITY_INLINE
// In old abi, or when weak symbols are not supported, there can
// be multiple instances of a type_info object for one
// type. Uniqueness must use the _name value, not object address.
bool before(const type_info& __arg) const;
bool operator==(const type_info& __arg) const;
#else
#if !__GXX_MERGED_TYPEINFO_NAMES
/** Returns true if @c *this precedes @c __arg in the implementation's
* collation order. */
// Even with the new abi, on systems that support dlopen
// we can run into cases where type_info names aren't merged,
// so we still need to do string comparison.
bool before(const type_info& __arg) const
{ return (__name[0] == '*' && __arg.__name[0] == '*')
? __name < __arg.__name
: __builtin_strcmp (__name, __arg.__name) < 0; }
bool operator==(const type_info& __arg) const
{
return ((__name == __arg.__name)
|| (__name[0] != '*' &&
__builtin_strcmp (__name, __arg.__name) == 0));
}
#else
// On some targets we can rely on type_info's NTBS being unique,
// and therefore address comparisons are sufficient.
bool before(const type_info& __arg) const
{ return __name < __arg.__name; }
bool operator==(const type_info& __arg) const
{ return __name == __arg.__name; }
#endif
#endif
bool operator!=(const type_info& __arg) const
{ return !operator==(__arg); }
// Return true if this is a pointer type of some kind
virtual bool __is_pointer_p() const;
// Return true if this is a function type
virtual bool __is_function_p() const;
// Try and catch a thrown type. Store an adjusted pointer to the
// caught type in THR_OBJ. If THR_TYPE is not a pointer type, then
// THR_OBJ points to the thrown object. If THR_TYPE is a pointer
// type, then THR_OBJ is the pointer itself. OUTER indicates the
// number of outer pointers, and whether they were const
// qualified.
virtual bool __do_catch(const type_info *__thr_type, void **__thr_obj,
unsigned __outer) const;
// Internally used during catch matching
virtual bool __do_upcast(const __cxxabiv1::__class_type_info *__target,
void **__obj_ptr) const;
protected:
const char *__name;
explicit type_info(const char *__n): __name(__n) { }
private:
/// Assigning type_info is not supported.
type_info& operator=(const type_info&);
type_info(const type_info&);
};
/**
* @brief Thrown during incorrect typecasting.
* @ingroup exceptions
*
* If you attempt an invalid @c dynamic_cast expression, an instance of
* this class (or something derived from this class) is thrown. */
class bad_cast : public exception
{
public:
bad_cast() throw() { }
// This declaration is not useless:
// http://gcc.gnu.org/onlinedocs/gcc-3.0.2/gcc_6.html#SEC118
virtual ~bad_cast() throw();
// See comment in eh_exception.cc.
virtual const char* what() const throw();
};
/**
* @brief Thrown when a NULL pointer in a @c typeid expression is used.
* @ingroup exceptions
*/
class bad_typeid : public exception
{
public:
bad_typeid () throw() { }
// This declaration is not useless:
// http://gcc.gnu.org/onlinedocs/gcc-3.0.2/gcc_6.html#SEC118
virtual ~bad_typeid() throw();
// See comment in eh_exception.cc.
virtual const char* what() const throw();
};
} // namespace std
#pragma GCC visibility pop
} // extern "C++"
#endif
|