Very Computer

I'm trying to get my C program to stack trace itself using gdb.

Upon detecting an error my program does a

system("gdb -x configfile programname programPID > outputfile");

Where the configfile contains the lines:-

bt
quit

Now that works fine from a bash shell but all I get when my program
hits it is a frozen program that needs a Ctrl-C.

Whats going on? Can I use this technique to stack trace my program?

It is a multi-threaded (pthreads) program, compiled using -gstabs+ in
the compile line, with gcc 3.1.

I don't want to have to write my own stack tracing routines!

Thanks,

Joe

[...]

Quote:> I don't want to have to write my own stack tracing routines!

% info '(libc) Debugging Support'

Many MANY thanks!

There is so much information it is hard to know where to look sometimes.

Joe.

Unfortunately this gives you only the function names and addresses.

If you want the source file name and line numbers, you have to use
system("addr2line ...

--
Michel Bardiaux
Peaktime Belgium S.A.  Bd. du Souverain, 191  B-1160 Bruxelles
Tel : +32 2 790.29.41

Reason: you see it when doing that manually:

(gdb) quit
The program is running.  Quit anyway (and detach it)? (y or n) yes
Detaching from program:
/usrco/dsk2/people/colin/dev/rh7.1/pktbe/horo/horo, process 11116

Hence you need a 3rd line in your script.

BTW I'm running GNU gdb 5.0rh-5 Red Hat Linux 7.1 and it has a slight
bug: the prompt is 'y or n' but the proper answer is "yes"; if you just
answer "y" it says "Not implemented yet".

Quote:

> Whats going on? Can I use this technique to stack trace my program?

> It is a multi-threaded (pthreads) program, compiled using -gstabs+ in
> the compile line, with gcc 3.1.

> I don't want to have to write my own stack tracing routines!

I give some pointers in my reply to someone else's reply to your
question.

Quote:

> Thanks,

> Joe

Greetings,
--
Michel Bardiaux

Well, I'm getting there... But.

All I get is the addresses of the functions, and no symbols. Now,
according to the info page I need to pass -rdynamic to the gnu linker.
I do this, and yet it makes no difference. Also in the man page for ld
I see no -rdynamic flag, though ld happily takes it. What am I doing
wrong?

I'm creating a whole slew of object files, then linking them together
with -rdynamic then linking the final executable together to the
system libs, without -rdynamic because using -rdynamic causes the
linker to fail when linking libc, which strangely enough, is the only
part of my stack trace that does show symbols!

Ooooh. Confusing. Also which approach do you suggest is best? Using
GDB or using the backtrace function of libc?

Thanks,

Joe