gcc/ada/g-moreex.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT LIBRARY COMPONENTS                          --
   4 --                                                                          --
   5 --            G N A T . M O S T _ R E C E N T _ E X C E P T I O N           --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                                                                          --
   9 --                     Copyright (C) 2000-2008, AdaCore                     --
  10 --                                                                          --
  11 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  12 -- terms of the  GNU General Public License as published  by the Free Soft- --
  13 -- ware  Foundation;  either version 2,  or (at your option) any later ver- --
  14 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  15 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  16 -- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
  17 -- for  more details.  You should have  received  a copy of the GNU General --
  18 -- Public License  distributed with GNAT;  see file COPYING.  If not, write --
  19 -- to  the  Free Software Foundation,  51  Franklin  Street,  Fifth  Floor, --
  20 -- Boston, MA 02110-1301, USA.                                              --
  21 --                                                                          --
  22 -- As a special exception,  if other files  instantiate  generics from this --
  23 -- unit, or you link  this unit with other files  to produce an executable, --
  24 -- this  unit  does not  by itself cause  the resulting  executable  to  be --
  25 -- covered  by the  GNU  General  Public  License.  This exception does not --
  26 -- however invalidate  any other reasons why  the executable file  might be --
  27 -- covered by the  GNU Public License.                                      --
  28 --                                                                          --
  29 -- GNAT was originally developed  by the GNAT team at  New York University. --
  30 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  31 --                                                                          --
  32 ------------------------------------------------------------------------------
  33
  34 --  This package provides routines for accessing the most recently raised
  35 --  exception. This may be useful for certain logging activities. It may
  36 --  also be useful for mimicking implementation dependent capabilities in
  37 --  Ada 83 compilers, but see also GNAT.Current_Exceptions for this usage.
  38
  39 with Ada.Exceptions;
  40 package GNAT.Most_Recent_Exception is
  41
  42    -----------------
  43    -- Subprograms --
  44    -----------------
  45
  46    function Occurrence
  47      return Ada.Exceptions.Exception_Occurrence;
  48    --  Returns the Exception_Occurrence for the most recently raised exception
  49    --  in the current task. If no exception has been raised in the current task
  50    --  prior to the call, returns Null_Occurrence.
  51
  52    function Occurrence_Access
  53      return Ada.Exceptions.Exception_Occurrence_Access;
  54    --  Similar to the above, but returns an access to the occurrence value.
  55    --  This value is in a task specific location, and may be validly accessed
  56    --  as long as no further exception is raised in the calling task.
  57
  58    --  Note: unlike the routines in GNAT.Current_Exception, these functions
  59    --  access the most recently raised exception, regardless of where they
  60    --  are called. Consider the following example:
  61
  62    --     exception
  63    --        when Constraint_Error =>
  64    --          begin
  65    --             ...
  66    --          exception
  67    --             when Tasking_Error => ...
  68    --          end;
  69    --
  70    --          --  Assuming a Tasking_Error was raised in the inner block,
  71    --          --  a call to GNAT.Most_Recent_Exception.Occurrence will
  72    --          --  return information about this Tasking_Error exception,
  73    --          --  not about the Constraint_Error exception being handled
  74    --          --  by the current handler code.
  75
  76 end GNAT.Most_Recent_Exception;