File : s-traceb.ads


     ------------------------------------------------------------------------------
     --                                                                          --
     --                         GNAT COMPILER COMPONENTS                         --
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   5 --                     S Y S T E M . T R A C E B A C K                      --
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     --          Copyright (C) 1999-2001 Free Software Foundation, Inc.          --
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     -- GNAT is free software;  you can  redistribute it  and/or modify it under --
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     -- As a special exception,  if other files  instantiate  generics from this --
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     -- GNAT was originally developed  by the GNAT team at  New York University. --
     -- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
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     ------------------------------------------------------------------------------
  35 
     --  This package provides a method for generating a traceback of the
     --  current execution location. The traceback shows the locations of
     --  calls in the call chain, up to either the top or a designated
     --  number of levels.
  40 
     pragma Polling (Off);
     --  We must turn polling off for this unit, because otherwise we get
     --  elaboration circularities with System.Exception_Tables.
     
  45 package System.Traceback is
     
        ----------------
        -- Call_Chain --
        ----------------
  50 
        procedure Call_Chain
          (Traceback   : System.Address;
           Max_Len     : Natural;
           Len         : out Natural;
  55       Exclude_Min : System.Address := System.Null_Address;
           Exclude_Max : System.Address := System.Null_Address);
        --  Store up to Max_Len code locations in Traceback, corresponding to
        --  the current call chain.
        --
  60    --    Traceback is the address of an array of addresses where the
        --    result will be stored.
        --
        --    Max_Len is the length of the Traceback array. If the call chain
        --    is longer than this, then additional entries are discarded, and
  65    --    the traceback is missing some of the highest level entries.
        --
        --    Len is the returned actual number of addresses stored
        --    in the Traceback array.
        --
  70    --    Exclude_Min/Exclude_Max, if non null, provide a range of addresses
        --    to ignore from the computation of the traceback.
        --
        --  On return, the Traceback array is filled in, and Len indicates
        --  the number of stored entries. The first entry is the most recent
  75    --  call, and the last entry is the highest level call.
     
        function C_Call_Chain
          (Traceback : System.Address;
           Max_Len   : Natural)
  80       return      Natural;
        pragma Export (C, C_Call_Chain, "system__traceback__c_call_chain");
        --  Version that can be used directly from C.
     
     end System.Traceback;