Re: New warnings on emacs-26 branch with gcc 8.2.0

[Paul Eggert <eggert@cs.ucla.edu>]

Andy Moreton wrote:
> Agreed, but the current solution minimises effort for gnulib imports,
> rather than emacs developers, whose machines waste time and energy on
> pointless configure checks for warnings.

It helps Emacs developers too, not all of whom use the same GCC (or clang) 
version. I care about these warnings more than most, and I don't want to go down 
the rabbit hole of tracking multiple GCC and clang versions by hand in the Emacs 
source code.

To improve 'configure' speed you can cache the results by using './configure 
--cache-file=FOO', as was mentioned elsewhere in this thread. On my platform 
(Ubuntu 18.04 x86-64, Xeon E3-1225 V2), this shrinks 'configure' time from 32.3 
to 4.4 user+system CPU seconds, an 86% savings.

If you can't use the cache for some reason, you can use a command like this:

./configure --disable-gcc-warnings

This avoids the 'configure' warning tests you're worried about, and shrinks my 
'configure' time from 32.3 to 25.8 user+system CPU seconds, a 20% savings. You 
can then build with "make WARN_CFLAGS='-Wall -Whatever'" with your own preferred 
hand-built warning list.