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>
40 
41 extern "C++" {
42 
43 namespace std
44 {
45  /**
46  * @defgroup exceptions Exceptions
47  * @ingroup diagnostics
48  *
49  * Classes and functions for reporting errors via exception classes.
50  * @{
51  */
52 
53  /**
54  * @brief Base class for all library exceptions.
55  *
56  * This is the base class for all exceptions thrown by the standard
57  * library, and by certain language expressions. You are free to derive
58  * your own %exception classes, or use a different hierarchy, or to
59  * throw non-class data (e.g., fundamental types).
60  */
61  class exception
62  {
63  public:
64  exception() throw() { }
65  virtual ~exception() throw();
66 
67  /** Returns a C-style character string describing the general cause
68  * of the current error. */
69  virtual const char* what() const throw();
70  };
71 
72  /** If an %exception is thrown which is not listed in a function's
73  * %exception specification, one of these may be thrown. */
74  class bad_exception : public exception
75  {
76  public:
77  bad_exception() throw() { }
78 
79  // This declaration is not useless:
80  // http://gcc.gnu.org/onlinedocs/gcc-3.0.2/gcc_6.html#SEC118
81  virtual ~bad_exception() throw();
82 
83  // See comment in eh_exception.cc.
84  virtual const char* what() const throw();
85  };
86 
87  /// If you write a replacement %terminate handler, it must be of this type.
88  typedef void (*terminate_handler) ();
89 
90  /// If you write a replacement %unexpected handler, it must be of this type.
91  typedef void (*unexpected_handler) ();
92 
93  /// Takes a new handler function as an argument, returns the old function.
95 
96  /** The runtime will call this function if %exception handling must be
97  * abandoned for any reason. It can also be called by the user. */
98  void terminate() throw() __attribute__ ((__noreturn__));
99 
100  /// Takes a new handler function as an argument, returns the old function.
102 
103  /** The runtime will call this function if an %exception is thrown which
104  * violates the function's %exception specification. */
105  void unexpected() __attribute__ ((__noreturn__));
106 
107  /** [18.6.4]/1: 'Returns true after completing evaluation of a
108  * throw-expression until either completing initialization of the
109  * exception-declaration in the matching handler or entering @c unexpected()
110  * due to the throw; or after entering @c terminate() for any reason
111  * other than an explicit call to @c terminate(). [Note: This includes
112  * stack unwinding [15.2]. end note]'
113  *
114  * 2: 'When @c uncaught_exception() is true, throwing an
115  * %exception can result in a call of @c terminate()
116  * (15.5.1).'
117  */
118  bool uncaught_exception() throw() __attribute__ ((__pure__));
119 
120  // @} group exceptions
121 } // namespace std
122 
123 namespace __gnu_cxx
124 {
125 _GLIBCXX_BEGIN_NAMESPACE_VERSION
126 
127  /**
128  * @brief A replacement for the standard terminate_handler which
129  * prints more information about the terminating exception (if any)
130  * on stderr.
131  *
132  * @ingroup exceptions
133  *
134  * Call
135  * @code
136  * std::set_terminate(__gnu_cxx::__verbose_terminate_handler)
137  * @endcode
138  * to use. For more info, see
139  * http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt02ch06s02.html
140  *
141  * In 3.4 and later, this is on by default.
142  */
144 
145 _GLIBCXX_END_NAMESPACE_VERSION
146 } // namespace
147 
148 } // extern "C++"
149 
150 #pragma GCC visibility pop
151 
152 #if (defined(__GXX_EXPERIMENTAL_CXX0X__) \
153  && defined(_GLIBCXX_ATOMIC_BUILTINS_4))
154 #include <bits/exception_ptr.h>
155 #include <bits/nested_exception.h>
156 #endif
157 
158 #endif