libstdc++-v3/libsupc++/exception

   1 // Exception Handling support header for -*- C++ -*-
   2
   3 // Copyright (C) 1995, 1996, 1997, 1998, 2000, 2001, 2002, 2005
   4 // Free Software Foundation
   5 //
   6 // This file is part of GCC.
   7 //
   8 // GCC 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 // GCC 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 GCC; see the file COPYING.  If not, write to
  20 // the Free Software Foundation, 51 Franklin Street, Fifth Floor,
  21 // Boston, MA 02110-1301, 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 is a Standard C++ Library header.
  34  */
  35
  36 #ifndef __EXCEPTION__
  37 #define __EXCEPTION__
  38
  39 #pragma GCC visibility push(default)
  40
  41 #include <bits/c++config.h>
  42
  43 extern "C++" {
  44
  45 namespace std
  46 {
  47   /**
  48    *  @brief Base class for all library exceptions.
  49    *
  50    *  This is the base class for all exceptions thrown by the standard
  51    *  library, and by certain language expressions.  You are free to derive
  52    *  your own %exception classes, or use a different hierarchy, or to
  53    *  throw non-class data (e.g., fundamental types).
  54    */
  55   class exception
  56   {
  57   public:
  58     exception() throw() { }
  59     virtual ~exception() throw();
  60     /** Returns a C-style character string describing the general cause
  61      *  of the current error.  */
  62     virtual const char* what() const throw();
  63   };
  64
  65   /** If an %exception is thrown which is not listed in a function's
  66    *  %exception specification, one of these may be thrown.  */
  67   class bad_exception : public exception
  68   {
  69   public:
  70     bad_exception() throw() { }
  71     // This declaration is not useless:
  72     // http://gcc.gnu.org/onlinedocs/gcc-3.0.2/gcc_6.html#SEC118
  73     virtual ~bad_exception() throw();
  74   };
  75
  76   /// If you write a replacement %terminate handler, it must be of this type.
  77   typedef void (*terminate_handler) ();
  78   /// If you write a replacement %unexpected handler, it must be of this type.
  79   typedef void (*unexpected_handler) ();
  80
  81   /// Takes a new handler function as an argument, returns the old function.
  82   terminate_handler set_terminate(terminate_handler) throw();
  83   /** The runtime will call this function if %exception handling must be
  84    *  abandoned for any reason.  It can also be called by the user.  */
  85   void terminate() __attribute__ ((__noreturn__));
  86
  87   /// Takes a new handler function as an argument, returns the old function.
  88   unexpected_handler set_unexpected(unexpected_handler) throw();
  89   /** The runtime will call this function if an %exception is thrown which
  90    *  violates the function's %exception specification.  */
  91   void unexpected() __attribute__ ((__noreturn__));
  92
  93   /** [18.6.4]/1:  "Returns true after completing evaluation of a
  94    *  throw-expression until either completing initialization of the
  95    *  exception-declaration in the matching handler or entering @c unexpected()
  96    *  due to the throw; or after entering @c terminate() for any reason
  97    *  other than an explicit call to @c terminate().  [Note: This includes
  98    *  stack unwinding [15.2].  end note]"
  99    *
 100    *  2:  "When @c uncaught_exception() is true, throwing an %exception can
 101    *  result in a call of @c terminate() (15.5.1)."
 102    */
 103   bool uncaught_exception() throw();
 104 } // namespace std
 105
 106 _GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)
 107
 108   /** A replacement for the standard terminate_handler which prints more
 109       information about the terminating exception (if any) on stderr.  Call
 110       @code
 111         std::set_terminate (__gnu_cxx::__verbose_terminate_handler)
 112       @endcode
 113       to use.  For more info, see
 114       http://gcc.gnu.org/onlinedocs/libstdc++/19_diagnostics/howto.html#4
 115
 116       In 3.4 and later, this is on by default.
 117   */
 118   void __verbose_terminate_handler ();
 119
 120 _GLIBCXX_END_NAMESPACE
 121
 122 } // extern "C++"
 123
 124 #pragma GCC visibility pop
 125
 126 #endif