working around batch mode command errors

working around batch mode command errors

[Maucci, Cyrille]

Hello gdb'ers,


I've got a batch script that is meant to be invoked on customer production systems, should a process dump a core file. The goal of this script is to quickly and easily collect and send to support people very basic information about the coredump, because :
1- that is often painful and slow to get the core file itself (and dependant libs) out of the system for in depth analysis.
2- most of the time information contained in the script output is enough for the source code owners to understand what the problem is.


So the script looks like this:

set pagination off
info sharedlibrary
info threads
up 128
info args
info locals
frame 0
info source
info args
info locals
info frame
info all-registers
print *this
thread apply all bt
thread apply all bt full
quit


One of the problem I have is that when frame 0 is not C++ code, "print *this" fails and the script aborts with the following error

Error in sourced command file:
No symbol "this" in current context.

And therefore all subsequent commands are not executed.
I wanted to know if there would be any possiblity to avoid halting on such errors.

An aside question would be is there any built-in commands allowing to do something like

for each frame do
info source
info args
info locals
info frame
info all-registers
print *this
done  


Thanks a bunch for your help
++Cyrille

Re: working around batch mode command errors

[Jan Kratochvil]

On Sun, 28 Oct 2012 23:28:32 +0100, Maucci, Cyrille wrote:
> Error in sourced command file:
> No symbol "this" in current context.
> 
> And therefore all subsequent commands are not executed.

Use:
	gdb <file
instead of
	gdb -x file


> An aside question would be is there any built-in commands allowing to do
> something like

Use ABRT or Apport which hook globally on system via
/proc/sys/kernel/core_pattern . You can also provide per-application custom
info dumpers.


Regards,
Jan

Re: working around batch mode command errors

[Pedro Alves]

On 10/28/2012 10:28 PM, Maucci, Cyrille wrote:

> One of the problem I have is that when frame 0 is not C++ code, "print *this" fails and the script aborts with the following error
> 
> Error in sourced command file:
> No symbol "this" in current context.
> 
> And therefore all subsequent commands are not executed.
> I wanted to know if there would be any possiblity to avoid halting on such errors.

There's no try/catch mechanism in the CLI unfortunately, but I think you could
come up with one in python gdb.  ISTR Tromey had a python command wrapper that
swallows CLI errors?

> An aside question would be is there any built-in commands allowing to do something like
> 
> for each frame do
> info source
> info args
> info locals
> info frame
> info all-registers
> print *this
> done  

Nope.  But could construct something like that using gdb's builtin python support.

-- 
Pedro Alves

Re: working around batch mode command errors

[Tom Tromey]

>>>>> "Pedro" == Pedro Alves <palves@redhat.com> writes:

Pedro> There's no try/catch mechanism in the CLI unfortunately, but I
Pedro> think you could come up with one in python gdb.  ISTR Tromey had
Pedro> a python command wrapper that swallows CLI errors?

Yeah, http://www.sourceware.org/ml/gdb/2010-06/msg00100.html

There's a more full-blown try/catch implementation in bugzilla.
That one isn't in Python.  I don't know why it never went in.

This seems to be a frequently requested feature.

Tom

Re: working around batch mode command errors

[Doug Evans]

On Tue, Oct 30, 2012 at 10:43 AM, Tom Tromey <tromey@redhat.com> wrote:
>>>>>> "Pedro" == Pedro Alves <palves@redhat.com> writes:
>
> Pedro> There's no try/catch mechanism in the CLI unfortunately, but I
> Pedro> think you could come up with one in python gdb.  ISTR Tromey had
> Pedro> a python command wrapper that swallows CLI errors?
>
> Yeah, http://www.sourceware.org/ml/gdb/2010-06/msg00100.html
>
> There's a more full-blown try/catch implementation in bugzilla.
> That one isn't in Python.  I don't know why it never went in.
>
> This seems to be a frequently requested feature.
>
> Tom

I went looking for the bugzilla entry but couldn't find it.

try:
   gdb.execute (...)
except:
  pass

is just too much to type.
</sarcasm> :-)

Re: working around batch mode command errors

[Tom Tromey]

>>>>> "Doug" == Doug Evans <dje@google.com> writes:

Doug> I went looking for the bugzilla entry but couldn't find it.

http://sourceware.org/bugzilla/show_bug.cgi?id=8487

Doug> try:
Doug>    gdb.execute (...)
Doug> except:
Doug>   pass
Doug> is just too much to type.
Doug> </sarcasm> :-)

:)

We can have both try/catch and ignore-errors, if we want.

Tom