File Coverage

/usr/include/c++/5/typeinfo
Criterion Covered Total %
statement 2 2 100.0
branch 1 2 50.0
condition n/a
subroutine n/a
pod n/a
total 3 4 75.0


line stmt bran cond sub pod time code
1             // RTTI support for -*- C++ -*-
2             // Copyright (C) 1994-2015 Free Software Foundation, Inc.
3             //
4             // This file is part of GCC.
5             //
6             // GCC is free software; you can redistribute it and/or modify
7             // it under the terms of the GNU General Public License as published by
8             // the Free Software Foundation; either version 3, or (at your option)
9             // any later version.
10             //
11             // GCC is distributed in the hope that it will be useful,
12             // but WITHOUT ANY WARRANTY; without even the implied warranty of
13             // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14             // GNU General Public License for more details.
15             //
16             // Under Section 7 of GPL version 3, you are granted additional
17             // permissions described in the GCC Runtime Library Exception, version
18             // 3.1, as published by the Free Software Foundation.
19              
20             // You should have received a copy of the GNU General Public License and
21             // a copy of the GCC Runtime Library Exception along with this program;
22             // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23             // .
24              
25             /** @file typeinfo
26             * This is a Standard C++ Library header.
27             */
28              
29             #ifndef _TYPEINFO
30             #define _TYPEINFO
31              
32             #pragma GCC system_header
33              
34             #include
35             #if __cplusplus >= 201103L
36             #include
37             #endif
38              
39             #pragma GCC visibility push(default)
40              
41             extern "C++" {
42              
43             namespace __cxxabiv1
44             {
45             class __class_type_info;
46             } // namespace __cxxabiv1
47              
48             // Determine whether typeinfo names for the same type are merged (in which
49             // case comparison can just compare pointers) or not (in which case strings
50             // must be compared), and whether comparison is to be implemented inline or
51             // not. We used to do inline pointer comparison by default if weak symbols
52             // are available, but even with weak symbols sometimes names are not merged
53             // when objects are loaded with RTLD_LOCAL, so now we always use strcmp by
54             // default. For ABI compatibility, we do the strcmp inline if weak symbols
55             // are available, and out-of-line if not. Out-of-line pointer comparison
56             // is used where the object files are to be portable to multiple systems,
57             // some of which may not be able to use pointer comparison, but the
58             // particular system for which libstdc++ is being built can use pointer
59             // comparison; in particular for most ARM EABI systems, where the ABI
60             // specifies out-of-line comparison. The compiler's target configuration
61             // can override the defaults by defining __GXX_TYPEINFO_EQUALITY_INLINE to
62             // 1 or 0 to indicate whether or not comparison is inline, and
63             // __GXX_MERGED_TYPEINFO_NAMES to 1 or 0 to indicate whether or not pointer
64             // comparison can be used.
65              
66             #ifndef __GXX_MERGED_TYPEINFO_NAMES
67             // By default, typeinfo names are not merged.
68             #define __GXX_MERGED_TYPEINFO_NAMES 0
69             #endif
70              
71             // By default follow the old inline rules to avoid ABI changes.
72             #ifndef __GXX_TYPEINFO_EQUALITY_INLINE
73             #if !__GXX_WEAK__
74             #define __GXX_TYPEINFO_EQUALITY_INLINE 0
75             #else
76             #define __GXX_TYPEINFO_EQUALITY_INLINE 1
77             #endif
78             #endif
79              
80             namespace std
81             {
82             /**
83             * @brief Part of RTTI.
84             *
85             * The @c type_info class describes type information generated by
86             * an implementation.
87             */
88             class type_info
89             {
90             public:
91             /** Destructor first. Being the first non-inline virtual function, this
92             * controls in which translation unit the vtable is emitted. The
93             * compiler makes use of that information to know where to emit
94             * the runtime-mandated type_info structures in the new-abi. */
95             virtual ~type_info();
96              
97             /** Returns an @e implementation-defined byte string; this is not
98             * portable between compilers! */
99 455           const char* name() const _GLIBCXX_NOEXCEPT
100 455 50         { return __name[0] == '*' ? __name + 1 : __name; }
101              
102             #if !__GXX_TYPEINFO_EQUALITY_INLINE
103             // In old abi, or when weak symbols are not supported, there can
104             // be multiple instances of a type_info object for one
105             // type. Uniqueness must use the _name value, not object address.
106             bool before(const type_info& __arg) const _GLIBCXX_NOEXCEPT;
107             bool operator==(const type_info& __arg) const _GLIBCXX_NOEXCEPT;
108             #else
109             #if !__GXX_MERGED_TYPEINFO_NAMES
110             /** Returns true if @c *this precedes @c __arg in the implementation's
111             * collation order. */
112             // Even with the new abi, on systems that support dlopen
113             // we can run into cases where type_info names aren't merged,
114             // so we still need to do string comparison.
115             bool before(const type_info& __arg) const _GLIBCXX_NOEXCEPT
116             { return (__name[0] == '*' && __arg.__name[0] == '*')
117             ? __name < __arg.__name
118             : __builtin_strcmp (__name, __arg.__name) < 0; }
119              
120             bool operator==(const type_info& __arg) const _GLIBCXX_NOEXCEPT
121             {
122             return ((__name == __arg.__name)
123             || (__name[0] != '*' &&
124             __builtin_strcmp (__name, __arg.__name) == 0));
125             }
126             #else
127             // On some targets we can rely on type_info's NTBS being unique,
128             // and therefore address comparisons are sufficient.
129             bool before(const type_info& __arg) const _GLIBCXX_NOEXCEPT
130             { return __name < __arg.__name; }
131              
132             bool operator==(const type_info& __arg) const _GLIBCXX_NOEXCEPT
133             { return __name == __arg.__name; }
134             #endif
135             #endif
136             bool operator!=(const type_info& __arg) const _GLIBCXX_NOEXCEPT
137             { return !operator==(__arg); }
138              
139             #if __cplusplus >= 201103L
140             size_t hash_code() const noexcept
141             {
142             # if !__GXX_MERGED_TYPEINFO_NAMES
143             return _Hash_bytes(name(), __builtin_strlen(name()),
144             static_cast(0xc70f6907UL));
145             # else
146             return reinterpret_cast(__name);
147             # endif
148             }
149             #endif // C++11
150              
151             // Return true if this is a pointer type of some kind
152             virtual bool __is_pointer_p() const;
153              
154             // Return true if this is a function type
155             virtual bool __is_function_p() const;
156              
157             // Try and catch a thrown type. Store an adjusted pointer to the
158             // caught type in THR_OBJ. If THR_TYPE is not a pointer type, then
159             // THR_OBJ points to the thrown object. If THR_TYPE is a pointer
160             // type, then THR_OBJ is the pointer itself. OUTER indicates the
161             // number of outer pointers, and whether they were const
162             // qualified.
163             virtual bool __do_catch(const type_info *__thr_type, void **__thr_obj,
164             unsigned __outer) const;
165              
166             // Internally used during catch matching
167             virtual bool __do_upcast(const __cxxabiv1::__class_type_info *__target,
168             void **__obj_ptr) const;
169              
170             protected:
171             const char *__name;
172              
173             explicit type_info(const char *__n): __name(__n) { }
174              
175             private:
176             /// Assigning type_info is not supported.
177             type_info& operator=(const type_info&);
178             type_info(const type_info&);
179             };
180              
181             /**
182             * @brief Thrown during incorrect typecasting.
183             * @ingroup exceptions
184             *
185             * If you attempt an invalid @c dynamic_cast expression, an instance of
186             * this class (or something derived from this class) is thrown. */
187             class bad_cast : public exception
188             {
189             public:
190             bad_cast() _GLIBCXX_USE_NOEXCEPT { }
191              
192             // This declaration is not useless:
193             // http://gcc.gnu.org/onlinedocs/gcc-3.0.2/gcc_6.html#SEC118
194             virtual ~bad_cast() _GLIBCXX_USE_NOEXCEPT;
195              
196             // See comment in eh_exception.cc.
197             virtual const char* what() const _GLIBCXX_USE_NOEXCEPT;
198             };
199              
200             /**
201             * @brief Thrown when a NULL pointer in a @c typeid expression is used.
202             * @ingroup exceptions
203             */
204             class bad_typeid : public exception
205             {
206             public:
207             bad_typeid () _GLIBCXX_USE_NOEXCEPT { }
208              
209             // This declaration is not useless:
210             // http://gcc.gnu.org/onlinedocs/gcc-3.0.2/gcc_6.html#SEC118
211             virtual ~bad_typeid() _GLIBCXX_USE_NOEXCEPT;
212              
213             // See comment in eh_exception.cc.
214             virtual const char* what() const _GLIBCXX_USE_NOEXCEPT;
215             };
216             } // namespace std
217              
218             } // extern "C++"
219              
220             #pragma GCC visibility pop
221              
222             #endif