gcc/ada/s-traceb.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                     S Y S T E M . T R A C E B A C K                      --
   6 --                                                                          --
   7 --                                 B o d y                                  --
   8 --                                                                          --
   9 --          Copyright (C) 1999-2007, 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 --  This is the default version of this package
  35
  36 --  Note: this unit must be compiled using -fno-optimize-sibling-calls.
  37 --  See comment below in body of Call_Chain for details on the reason.
  38
  39 pragma Warnings (Off);
  40 pragma Compiler_Unit;
  41 pragma Warnings (On);
  42
  43 package body System.Traceback is
  44
  45    ------------------
  46    -- C_Call_Chain --
  47    ------------------
  48
  49    function C_Call_Chain
  50      (Traceback : System.Address;
  51       Max_Len   : Natural)
  52       return      Natural
  53    is
  54       Val : Natural;
  55
  56    begin
  57       Call_Chain (Traceback, Max_Len, Val);
  58       return Val;
  59    end C_Call_Chain;
  60
  61    ----------------
  62    -- Call_Chain --
  63    ----------------
  64
  65    function Backtrace
  66      (Traceback   : System.Address;
  67       Len         : Integer;
  68       Exclude_Min : System.Address;
  69       Exclude_Max : System.Address;
  70       Skip_Frames : Integer)
  71       return        Integer;
  72    pragma Import (C, Backtrace, "__gnat_backtrace");
  73
  74    procedure Call_Chain
  75      (Traceback   : System.Address;
  76       Max_Len     : Natural;
  77       Len         : out Natural;
  78       Exclude_Min : System.Address := System.Null_Address;
  79       Exclude_Max : System.Address := System.Null_Address;
  80       Skip_Frames : Natural := 1)
  81    is
  82    begin
  83       --  Note: Backtrace relies on the following call actually creating a
  84       --  stack frame. To ensure that this is the case, it is essential to
  85       --  compile this unit without sibling call optimization.
  86
  87       --  We want the underlying engine to skip its own frame plus the
  88       --  ones we have been requested to skip ourselves.
  89
  90       Len := Backtrace (Traceback   => Traceback,
  91                         Len         => Max_Len,
  92                         Exclude_Min => Exclude_Min,
  93                         Exclude_Max => Exclude_Max,
  94                         Skip_Frames => Skip_Frames + 1);
  95    end Call_Chain;
  96
  97 end System.Traceback;