Re: [PATCH 0/6] more small leak fixes

[Jeff King <peff@peff.net>]

On Fri, Aug 14, 2020 at 12:25:25PM -0400, Jeff King wrote:

> On Fri, Aug 14, 2020 at 12:13:28PM -0400, Jeff King wrote:
> 
> > Based on the discussion over in [1], I wondered how close we were to
> > being able to run some test scripts with a leak-checker like LSan not
> > complaining. The answer is...not close.
> > 
> > I picked t5526 more or less at random (it was the first failure when I
> > did a parallel "make test") to see what it would take to get it passing.
> > After much effort...I have t5526.1, the setup test, running clean. :)
> 
> For reference, here are the UNLEAK() calls I had to add to silence the
> false positives. Some of these are kind of sketchy. For example,
> declaring that wt_status_collect_changes_index() is allowed to leak is a
> bit low-level for my tastes (in general it's probably only called once
> per program, but it's getting quite far from the bottom of the stack).
> But there's actually no convenient way to free the various bits of a
> rev_info, so marking it with UNLEAK() is an expedient hack.

And by the way, having gone through this exercise, I'm re-convinced that
UNLEAK() is reasonable to keep. A lot of these cases would have been
very awkward with free(). Not insurmountable, but cases where a variable
is sometimes-allocated and sometimes-not get rather tricky.

-Peff