gcc/ada/a-excach.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --             A D A . E X C E P T I O N S . C A L L _ C H A I N            --
   6 --                                                                          --
   7 --                                 B o d y                                  --
   8 --                                                                          --
   9 --          Copyright (C) 1992-2005, Free Software Foundation, Inc.         --
  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 pragma Warnings (Off);
  35 --  Allow withing of non-Preelaborated units in Ada 2005 mode where this
  36 --  package will be categorized as Preelaborate. See AI-362 for details.
  37 --  It is safe in the context of the run-time to violate the rules!
  38
  39 with System.Traceback;
  40
  41 pragma Warnings (On);
  42
  43 separate (Ada.Exceptions)
  44 procedure Call_Chain (Excep : EOA) is
  45
  46    Exception_Tracebacks : Integer;
  47    pragma Import (C, Exception_Tracebacks, "__gl_exception_tracebacks");
  48    --  Boolean indicating whether tracebacks should be stored in exception
  49    --  occurrences.
  50
  51 begin
  52    if Exception_Tracebacks /= 0 and Excep.Num_Tracebacks = 0 then
  53
  54       --  If Exception_Tracebacks = 0 then the program was not
  55       --  compiled for storing tracebacks in exception occurrences
  56       --  (-bargs -E switch) so that we do not generate them.
  57       --
  58       --  If Excep.Num_Tracebacks /= 0 then this is a reraise, no need
  59       --  to store a new (wrong) chain.
  60
  61       --  We ask System.Traceback.Call_Chain to skip 3 frames to ensure that
  62       --  itself, ourselves and our caller are not part of the result. Our
  63       --  caller is always an exception propagation actor that we don't want
  64       --  to see, and it may be part of a separate subunit which pulls it
  65       --  outside the AAA/ZZZ range.
  66
  67       System.Traceback.Call_Chain
  68         (Traceback   => Excep.Tracebacks'Address,
  69          Max_Len     => Max_Tracebacks,
  70          Len         => Excep.Num_Tracebacks,
  71          Exclude_Min => Code_Address_For_AAA,
  72          Exclude_Max => Code_Address_For_ZZZ,
  73          Skip_Frames => 3);
  74    end if;
  75
  76 end Call_Chain;