[Valgrind-users] about VGDB

Ivo Raisr

2017-06-28 12:14:39 UTC

Yes, that's the idea.
It is a problem i had quite often in the beginning, I searched on the
internet and also could'n find a solution. I ended up finding it by chance
when I was searching for something else.
When I first read about vgdb I thought, "what an awesome idea, get valgrind
and gdb to work together, I gotta learn it". There are still many things
that could be improved, one of those would be this small detail on the
documentation. Another thing that I think that is a idea worth working on is
to create a option that works simillar to break on gdb, but instead of
having a point where its supposed to stop it stops the execution at a memory
leak. The execution could be much slower, but it could save hours of work
searching for memory leaks for it would point pretty close to the root
cause. I don't know how valgrind works, but if could be done it would be a
life saver.

If you can propose a patch for the documentation bit mentioned above,
that would be awesome.
Source file for the relevant piece of documentation is found here:
docs/xml/manual-core-adv.xml
You can obtain Valgrind sources as described at
http://valgrind.org/downloads/repository.html.

Your other point was "instant" memory leak detection under gdb.
However that is not how Memcheck (the default Valgrind analysis tool) works [1].
It searches for leaks at the end of the program run.
It is however possible to perform incremental memory leak analysis
under gdb+vgdb,
see http://valgrind.org/docs/manual/mc-manual.html#mc-manual.monitor-commands,
gdb monitor command "leak_check".

Once upon a time there was also an experimental tool called "omega" [2] [3]
However I have no idea if it is still buildable with current Valgrind
release and usable.
It had also a design flaw which prohibited its reliable operation.

I.

[1] http://valgrind.org/docs/manual/mc-manual.html#mc-manual.leaks
[2] http://www.brainmurders.eclipse.co.uk/omega.html
[3] https://stackoverflow.com/questions/22517082/valgrind-how-to-understand-exactly-when-i-lose-control-of-a-pointer-to-a-memory

-------- Original Message --------
Subject: Re: [Valgrind-users] about VGDB
Local Time: June 20, 2017 2:03 AM
UTC Time: June 20, 2017 5:03 AM
2017-06-09 21:55 GMT+02:00 Alberthus via Valgrind-users

Hello,
I"m new to programing and have been learning how to debug my program with
gdb and find leaks with valgrind, and have been trying to do them both
together using the instructions described in section 3.2 of
http://valgrind.org/docs/manual/manual-core-adv.html
I have been having problems finishing the valgrind session, the suggestion
given by the answer at
https://stackoverflow.com/questions/37731497/quit-valgrind-cleanly-when-debugging-with-gdb,
works but is not always, is this the way it is expected we quit valgrind?
(gdb)monitor help
and I found the command v.kill that also worked for me.
I suggest that you change the manual so that it will also teach a way to
quit vgdb somewhere near where you teach how to use it, will be usefull in a
documentation

Hello Alberthus,
So if I understand it correctly, you would like to see command
"monitor v.kill" listed in a subsection
of section "3.2. Debugging your program using Valgrind gdbserver and GDB"?
For example a new subsection called "3.2.5 Disconnecting GDB from
Valgrind gdbserver"?
Let me know,
I.