RE: tracepoint frames

["Newman, Mark (N-Superior Technical Resource Inc)" <mark dot newman at lmco dot com>]

Jim -

When a trace point is hit some data is collected - certainly at a
minimum the data specified by the collect statements.  However from some
earlier conversations and a converstaion with Ramana that additional
information should be collected.  Michael indicated that he collected a
"frame" in addition to the registers, data items, etc specified in the
collect commands.

Is it necessary to collect enough information to support say a
"backtrace" command (after a tfind)? 

I have found that simple "print" commands will work and that "printf"
commands will not work unless one sets up the complete environment. Is
there a requirement or a preference on the part of the community as to
what needs to be available when analyzing a tracepoint?

                                                   Mark

                                             
-----Original Message-----
From: Jim Blandy [mailto:jimb@redhat.com]
Sent: Friday, October 03, 2003 7:57 PM
To: Newman, Mark (N-Superior Technical Resource Inc)
Cc: gdb@sources.redhat.com
Subject: Re: tracepoint frames



"Newman, Mark (N-Superior Technical Resource Inc)"
<mark.newman@lmco.com> writes:
> The question has come up as to what needs to be collected when a
> tracepoint is hit.  I understand that a "frame" needs to be
> collected.  Can someone tell me what a "frame" is.  Is it a stack
> frame, a trace frame, or what?

Well, we do have trace frames; a trace frame is the clump of
information collected for a single tracepoint hit.  It includes
registers, and assorted regions of memory.

You can also ask a trace frame to collect things like local variables,
arguments, or registers.  But all that gets parsed by the code in
tracepoint.c and turned into a 'struct collection_list', that's just a
set of registers, memory regions, and agent expressions to collect;
it's all parsed for you.  So at that level, there are no frames any
more --- everything is explicit

But I don't feel like I've answered the question.  In what context did
it come up?