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Re: Compile Time Memory Leak Analyses
- To: Joern Rennecke <amylaar at redhat dot com>
- Subject: Re: Compile Time Memory Leak Analyses
- From: Kevin Atkinson <kevina at users dot sourceforge dot net>
- Date: Mon, 16 Jul 2001 23:25:12 -0400 (EDT)
- Cc: Joe Buck <jbuck at synopsys dot COM>, <gcc at gcc dot gnu dot org>
On Tue, 17 Jul 2001, Joern Rennecke wrote:
> > Not at all. Undecidability theorems mean only that an analysis routine
> > that tries to establish whether property P is true must return a
> > three-valued result (yes, no, and "I don't know"). gcc is full of
> > such code. If there are many cases where a definite answer can be
> > given, the tool can be useful.
> > After all, reachability is also undecidable, but we still eliminate dead
> > code.
> Well, but that's an optimization. We optimize only when we know that it
> is safe (at least that's the theory ;-), so while we can't tolerate false
> positives, we can tolerate false negatives.
> However, for warnings, false positives are extremely annoying, while
> false negatives mean that you can miss potential bugs while you are
> lulled into a false security that the compiler will warn about problems.
> So we set ourselves up for a warning that is likely to become as awkward as
> the uninitialized warnings.
Actually I find the uninitialized warnings rather useful and every know
and then compile by program with "-O -Wall" just so I can get them and
make sure everything is OK.
kevina at users sourceforge net