1 ------------------------------------------------------------------------------
3 -- GNAT RUN-TIME COMPONENTS --
5 -- G N A T . T R A C E B A C K --
9 -- Copyright (C) 1999-2004 Ada Core Technologies, Inc. --
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, 59 Temple Place - Suite 330, Boston, --
20 -- MA 02111-1307, USA. --
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. --
29 -- GNAT was originally developed by the GNAT team at New York University. --
30 -- Extensive contributions were provided by Ada Core Technologies Inc. --
32 ------------------------------------------------------------------------------
34 -- Run-time non-symbolic traceback support
36 -- This package provides a method for generating a traceback of the
37 -- current execution location. The traceback shows the locations of
38 -- calls in the call chain, up to either the top or a designated
41 -- The traceback information is in the form of absolute code locations.
42 -- These code locations may be converted to corresponding source locations
43 -- using the external addr2line utility, or from within GDB.
45 -- In order to use this facility, in some cases the binder must be invoked
46 -- with -E switch (store the backtrace with exception occurence). Please
47 -- refer to gnatbind documentation for more information.
49 -- To analyze the code locations later using addr2line or gdb, the necessary
50 -- units must be compiled with the debugging switch -g in the usual manner.
51 -- Note that it is not necessary to compile with -g to use Call_Chain. In
52 -- other words, the following sequence of steps can be used:
55 -- Run the program, and call Call_Chain
57 -- Use addr2line to interpret the absolute call locations (note that
58 -- addr2line expects addresses in hexadecimal format).
60 -- This capability is currently supported on the following targets:
72 with Ada
.Exceptions
.Traceback
;
74 package GNAT
.Traceback
is
75 pragma Elaborate_Body
;
77 subtype Code_Loc
is System
.Address
;
78 -- Code location used in building tracebacks
80 subtype Tracebacks_Array
is Ada
.Exceptions
.Traceback
.Tracebacks_Array
;
81 -- Traceback array used to hold a generated traceback list.
87 procedure Call_Chain
(Traceback
: out Tracebacks_Array
; Len
: out Natural);
88 -- Store up to Traceback'Length tracebacks corresponding to the current
89 -- call chain. The first entry stored corresponds to the deepest level
90 -- of subprogram calls. Len shows the number of traceback entries stored.
91 -- It will be equal to Traceback'Length unless the entire traceback is
92 -- shorter, in which case positions in Traceback past the Len position
93 -- are undefined on return.