Re: GNOME Summary, Oct26-Nov9

[Miroslav Silovic <silovic zesoi fer hr>]

Havoc Pennington <hp@redhat.com> writes:

> Owen released an exciting new development tool that should interest
> all developers using the Linux kernel and the GNU C library (2.0 or
> 2.1). Have a look here:
> 
>   http://people.redhat.com/~otaylor/memprof/index.html
> 
> MemProf basically does conservative garbage collection to detect
> memory leaks.  It even has a nice GUI. For the moment, threads confuse
> it a little bit, but it works great otherwise.
> 
> Commercial tools to do this cost on the order of $1000 per seat; Owen
> wrote this in a couple weeks. Go figure.

Commercial tools that cost $1000 per seat do this and a lot more: they
detect -all- memory access problems (i.e. read from uninitialised,
write uninitialised data, write freed memory, free freed memory, index
overflow, illegal stack access, delete instead of delete[] in C++)
This requires either tempering with compiled code (to check all
accesses), as done by Purify and Sun SPARC Workshop, or tricks with
paging (a-la Electric Fence) - but the latter burns more swap than
most people have and still won't detect read/write uninitialised and
index overflows.

A free, full featured Purify-like tool (I refer to the access checks,
not just leaks - hacked gcc could do this, perhaps) would be
unbelievably cool, though.

-- 
How to eff the ineffable?