[PATCH] fix #19444 - build failures with -O1 due to -Wmaybe-uninitialized

[Mike Frysinger]

On 13 Jan 2016 10:02, Martin Sebor wrote:
> In his comments on the bug, Carlos suggests to fix these instances
> of false positives and to get -O1 to work.  The attached patch
> does just that.  In the patch, to minimize the impact of the
> (otherwise unnecessary) initialization, rather than initializing
> them for all the code paths, I reduced the scope of the local
> variables that are subject to the warning and added the redundant
> initialization only for the problem code paths.  This led to more
> changes that would otherwise be required but resulted in code
> that's easier to follow.

any time code is changed to address warnings, especially "harmless" ones,
the first question is "has the compiled output changed".  if gcc produces
worse code at -O2, then this is probably not the right direction.

> The patch also adds -Wno-error=maybe-uninitialized to the warning
> options when -O1 or lower is set in CFLAGS to prevent these false
> positives from causing build failures.  This change renders the
> changes above strictly unnecessary.  I include both since I think
> both are worthwhile but I can remove one or the other if others
> have a different preference.

i'm in favor of this myself.  we clearly do not test -O1 as the normal
course of things, so it'll be perpetually broken.
-mike
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