libstdc++-v3/libsupc++/exception

   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
   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 visibility push(default)
  36
  37 #include <bits/c++config.h>
  38
  39 extern "C++" {
  40
  41 namespace std
  42 {
  43   /**
  44    * @defgroup exceptions Exceptions
  45    * @ingroup diagnostics
  46    *
  47    * Classes and functions for reporting errors via exception classes.
  48    * @{
  49    */
  50
  51   /**
  52    *  @brief Base class for all library exceptions.
  53    *
  54    *  This is the base class for all exceptions thrown by the standard
  55    *  library, and by certain language expressions.  You are free to derive
  56    *  your own %exception classes, or use a different hierarchy, or to
  57    *  throw non-class data (e.g., fundamental types).
  58    */
  59   class exception
  60   {
  61   public:
  62     exception() throw() { }
  63     virtual ~exception() throw();
  64
  65     /** Returns a C-style character string describing the general cause
  66      *  of the current error.  */
  67     virtual const char* what() const throw();
  68   };
  69
  70   /** If an %exception is thrown which is not listed in a function's
  71    *  %exception specification, one of these may be thrown.  */
  72   class bad_exception : public exception
  73   {
  74   public:
  75     bad_exception() throw() { }
  76
  77     // This declaration is not useless:
  78     // http://gcc.gnu.org/onlinedocs/gcc-3.0.2/gcc_6.html#SEC118
  79     virtual ~bad_exception() throw();
  80
  81     // See comment in eh_exception.cc.
  82     virtual const char* what() const throw();
  83   };
  84
  85   /// If you write a replacement %terminate handler, it must be of this type.
  86   typedef void (*terminate_handler) ();
  87
  88   /// If you write a replacement %unexpected handler, it must be of this type.
  89   typedef void (*unexpected_handler) ();
  90
  91   /// Takes a new handler function as an argument, returns the old function.
  92   terminate_handler set_terminate(terminate_handler) throw();
  93
  94   /** The runtime will call this function if %exception handling must be
  95    *  abandoned for any reason.  It can also be called by the user.  */
  96   void terminate() throw() __attribute__ ((__noreturn__));
  97
  98   /// Takes a new handler function as an argument, returns the old function.
  99   unexpected_handler set_unexpected(unexpected_handler) throw();
 100
 101   /** The runtime will call this function if an %exception is thrown which
 102    *  violates the function's %exception specification.  */
 103   void unexpected() __attribute__ ((__noreturn__));
 104
 105   /** [18.6.4]/1:  'Returns true after completing evaluation of a
 106    *  throw-expression until either completing initialization of the
 107    *  exception-declaration in the matching handler or entering @c unexpected()
 108    *  due to the throw; or after entering @c terminate() for any reason
 109    *  other than an explicit call to @c terminate().  [Note: This includes
 110    *  stack unwinding [15.2].  end note]'
 111    *
 112    *  2: 'When @c uncaught_exception() is true, throwing an
 113    *  %exception can result in a call of @c terminate()
 114    *  (15.5.1).'
 115    */
 116   bool uncaught_exception() throw() __attribute__ ((__pure__));
 117
 118   // @} group exceptions
 119 } // namespace std
 120
 121 _GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)
 122
 123   /**
 124    *  @brief A replacement for the standard terminate_handler which
 125    *  prints more information about the terminating exception (if any)
 126    *  on stderr.
 127    *
 128    *  @ingroup exceptions
 129    *
 130    *  Call
 131    *   @code
 132    *     std::set_terminate(__gnu_cxx::__verbose_terminate_handler)
 133    *   @endcode
 134    *  to use.  For more info, see
 135    *  http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt02ch06s02.html
 136    *
 137    *  In 3.4 and later, this is on by default.
 138    */
 139   void __verbose_terminate_handler();
 140
 141 _GLIBCXX_END_NAMESPACE
 142
 143 } // extern "C++"
 144
 145 #pragma GCC visibility pop
 146
 147 #if (defined(__GXX_EXPERIMENTAL_CXX0X__) \
 148      && defined(_GLIBCXX_ATOMIC_BUILTINS_4))
 149 #include <exception_ptr.h>
 150 #include <nested_exception.h>
 151 #endif
 152
 153 #endif