1// Exception Handling support header for -*- C++ -*-
2
3// Copyright (C) 1995-2016 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
40extern "C++" {
41
42namespace 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_TXN_SAFE_DYN _GLIBCXX_USE_NOEXCEPT;
65
66    /** Returns a C-style character string describing the general cause
67     *  of the current error.  */
68    virtual const char*
69    what() const _GLIBCXX_TXN_SAFE_DYN _GLIBCXX_USE_NOEXCEPT;
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() _GLIBCXX_USE_NOEXCEPT { }
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() _GLIBCXX_TXN_SAFE_DYN _GLIBCXX_USE_NOEXCEPT;
82
83    // See comment in eh_exception.cc.
84    virtual const char*
85    what() const _GLIBCXX_TXN_SAFE_DYN _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#if __cplusplus >= 201103L
98  /// Return the current terminate handler.
99  terminate_handler get_terminate() noexcept;
100#endif
101
102  /** The runtime will call this function if %exception handling must be
103   *  abandoned for any reason.  It can also be called by the user.  */
104  void terminate() _GLIBCXX_USE_NOEXCEPT __attribute__ ((__noreturn__));
105
106  /// Takes a new handler function as an argument, returns the old function.
107  unexpected_handler set_unexpected(unexpected_handler) _GLIBCXX_USE_NOEXCEPT;
108
109#if __cplusplus >= 201103L
110  /// Return the current unexpected handler.
111  unexpected_handler get_unexpected() noexcept;
112#endif
113
114  /** The runtime will call this function if an %exception is thrown which
115   *  violates the function's %exception specification.  */
116  void unexpected() __attribute__ ((__noreturn__));
117
118  /** [18.6.4]/1:  'Returns true after completing evaluation of a
119   *  throw-expression until either completing initialization of the
120   *  exception-declaration in the matching handler or entering @c unexpected()
121   *  due to the throw; or after entering @c terminate() for any reason
122   *  other than an explicit call to @c terminate().  [Note: This includes
123   *  stack unwinding [15.2].  end note]'
124   *
125   *  2: 'When @c uncaught_exception() is true, throwing an
126   *  %exception can result in a call of @c terminate()
127   *  (15.5.1).'
128   */
129  bool uncaught_exception() _GLIBCXX_USE_NOEXCEPT __attribute__ ((__pure__));
130
131#if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++98
132#define __cpp_lib_uncaught_exceptions 201411
133  /// The number of uncaught exceptions.
134  int uncaught_exceptions() _GLIBCXX_USE_NOEXCEPT __attribute__ ((__pure__));
135#endif
136
137  // @} group exceptions
138} // namespace std
139
140namespace __gnu_cxx
141{
142_GLIBCXX_BEGIN_NAMESPACE_VERSION
143
144  /**
145   *  @brief A replacement for the standard terminate_handler which
146   *  prints more information about the terminating exception (if any)
147   *  on stderr.
148   *
149   *  @ingroup exceptions
150   *
151   *  Call
152   *   @code
153   *     std::set_terminate(__gnu_cxx::__verbose_terminate_handler)
154   *   @endcode
155   *  to use.  For more info, see
156   *  http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt02ch06s02.html
157   *
158   *  In 3.4 and later, this is on by default.
159   */
160  void __verbose_terminate_handler();
161
162_GLIBCXX_END_NAMESPACE_VERSION
163} // namespace
164
165} // extern "C++"
166
167#pragma GCC visibility pop
168
169#if (__cplusplus >= 201103L) && (ATOMIC_INT_LOCK_FREE > 1)
170#include <bits/exception_ptr.h>
171#include <bits/nested_exception.h>
172#endif
173
174#endif
175