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) 1999-2009, 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 3,  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.                                     --
17--                                                                          --
18-- As a special exception under Section 7 of GPL version 3, you are granted --
19-- additional permissions described in the GCC Runtime Library Exception,   --
20-- version 3.1, as published by the Free Software Foundation.               --
21--                                                                          --
22-- You should have received a copy of the GNU General Public License and    --
23-- a copy of the GCC Runtime Library Exception along with this program;     --
24-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
25-- <http://www.gnu.org/licenses/>.                                          --
26--                                                                          --
27-- GNAT was originally developed  by the GNAT team at  New York University. --
28-- Extensive contributions were provided by Ada Core Technologies Inc.      --
29--                                                                          --
30------------------------------------------------------------------------------
31
32--  This is the default version of this package
33
34--  Note: this unit must be compiled using -fno-optimize-sibling-calls.
35--  See comment below in body of Call_Chain for details on the reason.
36
37pragma Compiler_Unit;
38
39package body System.Traceback is
40
41   ------------------
42   -- C_Call_Chain --
43   ------------------
44
45   function C_Call_Chain
46     (Traceback : System.Address;
47      Max_Len   : Natural)
48      return      Natural
49   is
50      Val : Natural;
51
52   begin
53      Call_Chain (Traceback, Max_Len, Val);
54      return Val;
55   end C_Call_Chain;
56
57   ----------------
58   -- Call_Chain --
59   ----------------
60
61   function Backtrace
62     (Traceback   : System.Address;
63      Len         : Integer;
64      Exclude_Min : System.Address;
65      Exclude_Max : System.Address;
66      Skip_Frames : Integer)
67      return        Integer;
68   pragma Import (C, Backtrace, "__gnat_backtrace");
69
70   procedure Call_Chain
71     (Traceback   : System.Address;
72      Max_Len     : Natural;
73      Len         : out Natural;
74      Exclude_Min : System.Address := System.Null_Address;
75      Exclude_Max : System.Address := System.Null_Address;
76      Skip_Frames : Natural := 1)
77   is
78   begin
79      --  Note: Backtrace relies on the following call actually creating a
80      --  stack frame. To ensure that this is the case, it is essential to
81      --  compile this unit without sibling call optimization.
82
83      --  We want the underlying engine to skip its own frame plus the
84      --  ones we have been requested to skip ourselves.
85
86      Len := Backtrace (Traceback   => Traceback,
87                        Len         => Max_Len,
88                        Exclude_Min => Exclude_Min,
89                        Exclude_Max => Exclude_Max,
90                        Skip_Frames => Skip_Frames + 1);
91   end Call_Chain;
92
93end System.Traceback;
94