libstdc++
exception
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1 // Exception Handling support header for -*- C++ -*-
2 
3 // Copyright (C) 1995-2015 Free Software Foundation, Inc.
4 //
5 // This file is part of GCC.
6 //
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 3, or (at your option)
10 // any later version.
11 //
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.
16 //
17 // Under Section 7 of GPL version 3, you are granted additional
18 // permissions described in the GCC Runtime Library Exception, version
19 // 3.1, as published by the Free Software Foundation.
20 
21 // You should have received a copy of the GNU General Public License and
22 // a copy of the GCC Runtime Library Exception along with this program;
23 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
24 // <http://www.gnu.org/licenses/>.
25 
26 /** @file exception
27  * This is a Standard C++ Library header.
28  */
29 
30 #ifndef __EXCEPTION__
31 #define __EXCEPTION__
32 
33 #pragma GCC system_header
34 
35 #pragma GCC visibility push(default)
36 
37 #include <bits/c++config.h>
38 #include <bits/atomic_lockfree_defines.h>
39 
40 extern "C++" {
41 
42 namespace std
43 {
44  /**
45  * @defgroup exceptions Exceptions
46  * @ingroup diagnostics
47  *
48  * Classes and functions for reporting errors via exception classes.
49  * @{
50  */
51 
52  /**
53  * @brief Base class for all library exceptions.
54  *
55  * This is the base class for all exceptions thrown by the standard
56  * library, and by certain language expressions. You are free to derive
57  * your own %exception classes, or use a different hierarchy, or to
58  * throw non-class data (e.g., fundamental types).
59  */
60  class exception
61  {
62  public:
63  exception() _GLIBCXX_USE_NOEXCEPT { }
64  virtual ~exception() _GLIBCXX_USE_NOEXCEPT;
65 
66  /** Returns a C-style character string describing the general cause
67  * of the current error. */
68  virtual const char* what() const _GLIBCXX_USE_NOEXCEPT;
69  };
70 
71  /** If an %exception is thrown which is not listed in a function's
72  * %exception specification, one of these may be thrown. */
73  class bad_exception : public exception
74  {
75  public:
76  bad_exception() _GLIBCXX_USE_NOEXCEPT { }
77 
78  // This declaration is not useless:
79  // http://gcc.gnu.org/onlinedocs/gcc-3.0.2/gcc_6.html#SEC118
80  virtual ~bad_exception() _GLIBCXX_USE_NOEXCEPT;
81 
82  // See comment in eh_exception.cc.
83  virtual const char* what() const _GLIBCXX_USE_NOEXCEPT;
84  };
85 
86  /// If you write a replacement %terminate handler, it must be of this type.
87  typedef void (*terminate_handler) ();
88 
89  /// If you write a replacement %unexpected handler, it must be of this type.
90  typedef void (*unexpected_handler) ();
91 
92  /// Takes a new handler function as an argument, returns the old function.
93  terminate_handler set_terminate(terminate_handler) _GLIBCXX_USE_NOEXCEPT;
94 
95 #if __cplusplus >= 201103L
96  /// Return the current terminate handler.
97  terminate_handler get_terminate() noexcept;
98 #endif
99 
100  /** The runtime will call this function if %exception handling must be
101  * abandoned for any reason. It can also be called by the user. */
102  void terminate() _GLIBCXX_USE_NOEXCEPT __attribute__ ((__noreturn__));
103 
104  /// Takes a new handler function as an argument, returns the old function.
105  unexpected_handler set_unexpected(unexpected_handler) _GLIBCXX_USE_NOEXCEPT;
106 
107 #if __cplusplus >= 201103L
108  /// Return the current unexpected handler.
109  unexpected_handler get_unexpected() noexcept;
110 #endif
111 
112  /** The runtime will call this function if an %exception is thrown which
113  * violates the function's %exception specification. */
114  void unexpected() __attribute__ ((__noreturn__));
115 
116  /** [18.6.4]/1: 'Returns true after completing evaluation of a
117  * throw-expression until either completing initialization of the
118  * exception-declaration in the matching handler or entering @c unexpected()
119  * due to the throw; or after entering @c terminate() for any reason
120  * other than an explicit call to @c terminate(). [Note: This includes
121  * stack unwinding [15.2]. end note]'
122  *
123  * 2: 'When @c uncaught_exception() is true, throwing an
124  * %exception can result in a call of @c terminate()
125  * (15.5.1).'
126  */
127  bool uncaught_exception() _GLIBCXX_USE_NOEXCEPT __attribute__ ((__pure__));
128 
129  // @} group exceptions
130 } // namespace std
131 
132 namespace __gnu_cxx
133 {
134 _GLIBCXX_BEGIN_NAMESPACE_VERSION
135 
136  /**
137  * @brief A replacement for the standard terminate_handler which
138  * prints more information about the terminating exception (if any)
139  * on stderr.
140  *
141  * @ingroup exceptions
142  *
143  * Call
144  * @code
145  * std::set_terminate(__gnu_cxx::__verbose_terminate_handler)
146  * @endcode
147  * to use. For more info, see
148  * http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt02ch06s02.html
149  *
150  * In 3.4 and later, this is on by default.
151  */
152  void __verbose_terminate_handler();
153 
154 _GLIBCXX_END_NAMESPACE_VERSION
155 } // namespace
156 
157 } // extern "C++"
158 
159 #pragma GCC visibility pop
160 
161 #if (__cplusplus >= 201103L) && (ATOMIC_INT_LOCK_FREE > 1)
162 #include <bits/exception_ptr.h>
163 #include <bits/nested_exception.h>
164 #endif
165 
166 #endif