libstdc++
exception
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1 // Exception Handling support header for -*- C++ -*-
2 
3 // Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003,
4 // 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
5 // Free Software Foundation
6 //
7 // This file is part of GCC.
8 //
9 // GCC is free software; you can redistribute it and/or modify
10 // it under the terms of the GNU General Public License as published by
11 // the Free Software Foundation; either version 3, or (at your option)
12 // any later version.
13 //
14 // GCC is distributed in the hope that it will be useful,
15 // but WITHOUT ANY WARRANTY; without even the implied warranty of
16 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 // GNU General Public License for more details.
18 //
19 // Under Section 7 of GPL version 3, you are granted additional
20 // permissions described in the GCC Runtime Library Exception, version
21 // 3.1, as published by the Free Software Foundation.
22 
23 // You should have received a copy of the GNU General Public License and
24 // a copy of the GCC Runtime Library Exception along with this program;
25 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
26 // <http://www.gnu.org/licenses/>.
27 
28 /** @file exception
29  * This is a Standard C++ Library header.
30  */
31 
32 #ifndef __EXCEPTION__
33 #define __EXCEPTION__
34 
35 #pragma GCC system_header
36 
37 #pragma GCC visibility push(default)
38 
39 #include <bits/c++config.h>
41 
42 extern "C++" {
43 
44 namespace std
45 {
46  /**
47  * @defgroup exceptions Exceptions
48  * @ingroup diagnostics
49  *
50  * Classes and functions for reporting errors via exception classes.
51  * @{
52  */
53 
54  /**
55  * @brief Base class for all library exceptions.
56  *
57  * This is the base class for all exceptions thrown by the standard
58  * library, and by certain language expressions. You are free to derive
59  * your own %exception classes, or use a different hierarchy, or to
60  * throw non-class data (e.g., fundamental types).
61  */
62  class exception
63  {
64  public:
65  exception() _GLIBCXX_USE_NOEXCEPT { }
66  virtual ~exception() _GLIBCXX_USE_NOEXCEPT;
67 
68  /** Returns a C-style character string describing the general cause
69  * of the current error. */
70  virtual const char* what() const _GLIBCXX_USE_NOEXCEPT;
71  };
72 
73  /** If an %exception is thrown which is not listed in a function's
74  * %exception specification, one of these may be thrown. */
75  class bad_exception : public exception
76  {
77  public:
78  bad_exception() _GLIBCXX_USE_NOEXCEPT { }
79 
80  // This declaration is not useless:
81  // http://gcc.gnu.org/onlinedocs/gcc-3.0.2/gcc_6.html#SEC118
82  virtual ~bad_exception() _GLIBCXX_USE_NOEXCEPT;
83 
84  // See comment in eh_exception.cc.
85  virtual const char* what() const _GLIBCXX_USE_NOEXCEPT;
86  };
87 
88  /// If you write a replacement %terminate handler, it must be of this type.
89  typedef void (*terminate_handler) ();
90 
91  /// If you write a replacement %unexpected handler, it must be of this type.
92  typedef void (*unexpected_handler) ();
93 
94  /// Takes a new handler function as an argument, returns the old function.
95  terminate_handler set_terminate(terminate_handler) _GLIBCXX_USE_NOEXCEPT;
96 
97  /** The runtime will call this function if %exception handling must be
98  * abandoned for any reason. It can also be called by the user. */
99  void terminate() _GLIBCXX_USE_NOEXCEPT __attribute__ ((__noreturn__));
100 
101  /// Takes a new handler function as an argument, returns the old function.
103 
104  /** The runtime will call this function if an %exception is thrown which
105  * violates the function's %exception specification. */
106  void unexpected() __attribute__ ((__noreturn__));
107 
108  /** [18.6.4]/1: 'Returns true after completing evaluation of a
109  * throw-expression until either completing initialization of the
110  * exception-declaration in the matching handler or entering @c unexpected()
111  * due to the throw; or after entering @c terminate() for any reason
112  * other than an explicit call to @c terminate(). [Note: This includes
113  * stack unwinding [15.2]. end note]'
114  *
115  * 2: 'When @c uncaught_exception() is true, throwing an
116  * %exception can result in a call of @c terminate()
117  * (15.5.1).'
118  */
119  bool uncaught_exception() _GLIBCXX_USE_NOEXCEPT __attribute__ ((__pure__));
120 
121  // @} group exceptions
122 } // namespace std
123 
124 namespace __gnu_cxx
125 {
126 _GLIBCXX_BEGIN_NAMESPACE_VERSION
127 
128  /**
129  * @brief A replacement for the standard terminate_handler which
130  * prints more information about the terminating exception (if any)
131  * on stderr.
132  *
133  * @ingroup exceptions
134  *
135  * Call
136  * @code
137  * std::set_terminate(__gnu_cxx::__verbose_terminate_handler)
138  * @endcode
139  * to use. For more info, see
140  * http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt02ch06s02.html
141  *
142  * In 3.4 and later, this is on by default.
143  */
145 
146 _GLIBCXX_END_NAMESPACE_VERSION
147 } // namespace
148 
149 } // extern "C++"
150 
151 #pragma GCC visibility pop
152 
153 #if defined(__GXX_EXPERIMENTAL_CXX0X__) && (ATOMIC_INT_LOCK_FREE > 1)
154 #include <bits/exception_ptr.h>
155 #include <bits/nested_exception.h>
156 #endif
157 
158 #endif