Re: [PATCH] Fix -Wmaybe-uninitialized warnings under -O0

> On Wed, Apr 01, 2020 at 03:30:16AM -0400, Denton Liu wrote:
> 
> > When compiling Git under -O0, gcc (Arch Linux 9.3.0-1) 9.3.0 produces
> > many -Wmaybe-uninitialized warnings. These are false positives since
> > when Git is compiled under -O2, gcc is smart enough to see that the
> > code paths that use these variables all initialise them beforehand.
> > Nonetheless, these warnings block the compilation process when
> > DEVELOPER=1 is enabled (which enables -Werror).
> > 
> > Fix these warnings by initializing these variables with dummy values (0,
> > -1 or NULL as appropriate).
> 
> Hmph. I almost always compile with -O0 and have been using gcc 9.3.0
> since it was packaged for Debian a few weeks ago, but I don't see any of
> these warnings.
> 
> The current version in Debian unstable is 9.3.0-8, which picks up some
> extra patches from the upstream gcc-9 branch. But even if I download a
> snapshot of the original 9.3.0 release, it builds fine.
> 
> So why does your version behave differently? And if this is a temporary
> state for a buggy version of gcc (that may be fixed in the next point
> release), is it worth changing our source code to appease it?