1 ------------------------------------------------------------------------------
3 -- GNAT RUN-TIME COMPONENTS --
5 -- G N A T . T R A C E B A C K --
11 -- Copyright (C) 1999-2001 Ada Core Technologies, Inc. --
13 -- GNAT is free software; you can redistribute it and/or modify it under --
14 -- terms of the GNU General Public License as published by the Free Soft- --
15 -- ware Foundation; either version 2, or (at your option) any later ver- --
16 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
17 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
18 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
19 -- for more details. You should have received a copy of the GNU General --
20 -- Public License distributed with GNAT; see file COPYING. If not, write --
21 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
22 -- MA 02111-1307, USA. --
24 -- As a special exception, if other files instantiate generics from this --
25 -- unit, or you link this unit with other files to produce an executable, --
26 -- this unit does not by itself cause the resulting executable to be --
27 -- covered by the GNU General Public License. This exception does not --
28 -- however invalidate any other reasons why the executable file might be --
29 -- covered by the GNU Public License. --
31 -- GNAT is maintained by Ada Core Technologies Inc (http://www.gnat.com). --
33 ------------------------------------------------------------------------------
35 -- Run-time non-symbolic traceback support
37 -- This package provides a method for generating a traceback of the
38 -- current execution location. The traceback shows the locations of
39 -- calls in the call chain, up to either the top or a designated
42 -- The traceback information is in the form of absolute code locations.
43 -- These code locations may be converted to corresponding source locations
44 -- using the external addr2line utility, or from within GDB.
46 -- To analyze the code locations later using addr2line or gdb, the necessary
47 -- units must be compiled with the debugging switch -g in the usual manner.
48 -- Note that it is not necessary to compile with -g to use Call_Chain. In
49 -- other words, the following sequence of steps can be used:
52 -- Run the program, and call Call_Chain
54 -- Use addr2line to interpret the absolute call locations
56 -- This capability is currently supported on the following targets:
69 package GNAT.Traceback is
70 pragma Elaborate_Body;
72 subtype Code_Loc is System.Address;
73 -- Code location used in building tracebacks
75 type Tracebacks_Array is array (Positive range <>) of Code_Loc;
76 -- Traceback array used to hold a generated traceback list.
82 procedure Call_Chain (Traceback : out Tracebacks_Array; Len : out Natural);
83 -- Store up to Traceback'Length tracebacks corresponding to the current
84 -- call chain. The first entry stored corresponds to the deepest level
85 -- of subprogram calls. Len shows the number of traceback entries stored.
86 -- It will be equal to Traceback'Length unless the entire traceback is
87 -- shorter, in which case positions in Traceback past the Len position
88 -- are undefined on return.