libstdc++-v3/libsupc++/exception

   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
  40 extern "C++" {
  41
  42 namespace 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
 101 namespace __gnu_cxx
 102 {
 103   /** A replacement for the standard terminate_handler which prints more
 104       information about the terminating exception (if any) on stderr.
 105
 106         std::set_terminate (__gnu_cxx::__verbose_terminate_handler)
 107
 108       to use.  */
 109   void __verbose_terminate_handler ();
 110 } // namespace __gnu_cxx
 111
 112 } // extern "C++"
 113
 114 #endif