1// Exception Handling support header for -*- C++ -*-
2
3// Copyright (C) 1995, 1996, 1997, 1998, 2000, 2001, 2002
4// Free Software Foundation
5//
6// This file is part of GNU CC.
7//
8// GNU CC is free software; you can redistribute it and/or modify
9// it under the terms of the GNU General Public License as published by
10// the Free Software Foundation; either version 2, or (at your option)
11// any later version.
12//
13// GNU CC is distributed in the hope that it will be useful,
14// but WITHOUT ANY WARRANTY; without even the implied warranty of
15// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16// GNU General Public License for more details.
17//
18// You should have received a copy of the GNU General Public License
19// along with GNU CC; see the file COPYING.  If not, write to
20// the Free Software Foundation, 59 Temple Place - Suite 330,
21// Boston, MA 02111-1307, USA.
22
23// As a special exception, you may use this file as part of a free software
24// library without restriction.  Specifically, if other files instantiate
25// templates or use macros or inline functions from this file, or you compile
26// this file and link it with other files to produce an executable, this
27// file does not by itself cause the resulting executable to be covered by
28// the GNU General Public License.  This exception does not however
29// invalidate any other reasons why the executable file might be covered by
30// the GNU General Public License.
31
32/** @file exception
33 *  This header defines several types and functions relating to the
34 *  handling of exceptions in a C++ program.
35 */
36
37#ifndef __EXCEPTION__
38#define __EXCEPTION__
39
40extern "C++" {
41
42namespace std
43{
44  /** This is the base class for all exceptions thrown by the standard
45   *  library, and by certain language expressions.  You are free to derive
46   *  your own %exception classes, or use a different hierarchy, or to
47   *  throw non-class data (e.g., fundamental types).
48   *  @brief Base class for all library exceptions.
49   */
50  class exception
51  {
52  public:
53    exception() throw() { }
54    virtual ~exception() throw();
55    /** Returns a C-style character string describing the general cause
56     *  of the current error.  */
57    virtual const char* what() const throw();
58  };
59
60  /** If an %exception is thrown which is not listed in a function's
61   *  %exception specification, one of these may be thrown.  */
62  class bad_exception : public exception
63  {
64  public:
65    bad_exception() throw() { }
66    // This declaration is not useless:
67    // http://gcc.gnu.org/onlinedocs/gcc-3.0.2/gcc_6.html#SEC118
68    virtual ~bad_exception() throw();
69  };
70
71  /// If you write a replacement %terminate handler, it must be of this type.
72  typedef void (*terminate_handler) ();
73  /// If you write a replacement %unexpected handler, it must be of this type.
74  typedef void (*unexpected_handler) ();
75
76  /// Takes a new handler function as an argument, returns the old function.
77  terminate_handler set_terminate(terminate_handler) throw();
78  /** The runtime will call this function if %exception handling must be
79   *  abandoned for any reason.  */
80  void terminate() __attribute__ ((__noreturn__));
81
82  /// Takes a new handler function as an argument, returns the old function.
83  unexpected_handler set_unexpected(unexpected_handler) throw();
84  /** The runtime will call this function if an %exception is thrown which
85   *  violates the function's %exception specification.  */
86  void unexpected() __attribute__ ((__noreturn__));
87
88  /** [18.6.4]/1:  "Returns true after completing evaluation of a
89   *  throw-expression until either completing initialization of the
90   *  exception-declaration in the matching handler or entering @c unexpected()
91   *  due to the throw; or after entering @c terminate() for any reason
92   *  other than an explicit call to @c terminate().  [Note: This includes
93   *  stack unwinding [15.2].  end note]"
94   *
95   *  2:  "When @c uncaught_exception() is true, throwing an %exception can
96   *  result in a call of @c terminate() (15.5.1)."
97   */
98  bool uncaught_exception() throw();
99} // namespace std
100
101namespace __gnu_cxx
102{
103  /** A replacement for the standard terminate_handler which prints more
104      information about the terminating exception (if any) on stderr.  Call
105      @code
106        std::set_terminate (__gnu_cxx::__verbose_terminate_handler)
107      @endcode
108      to use.  For more info, see
109      http://gcc.gnu.org/onlinedocs/libstdc++/19_diagnostics/howto.html#4
110  */
111  void __verbose_terminate_handler ();
112} // namespace __gnu_cxx
113
114} // extern "C++"
115
116#endif
117