Re: backport fix for PR 82063 to GCC 7 and 8

[Jakub Jelinek <jakub at redhat dot com>]

On Thu, Jun 07, 2018 at 02:56:13PM -0600, Martin Sebor wrote:
> As I mentioned in my reply to Jeff below, I'd like to backport
> the fix for PR 82063 to the two release branches, GCC 7 and 8.
> If there are no concerns/objections I'll go ahead and commit
> the patch to both sometime next week.
> 
>   https://gcc.gnu.org/ml/gcc-patches/2018-05/msg01822.html

This results in -Wno-no-alloc-size-larger-than being accepted, I don't think
that is desirable (at least if any warnings are emitted).
Short testcase:
echo 'int foo (void) { int i; return i; }' > test.c
./xgcc -B ./ -Wno-no-alloc-size-larger-than -Wuninitialized test.c
So I think you want RejectNegative on that option.
Also, the option is not documented in doc/invoke.texi, it is just mentioned
in description of the -Walloc-size-larger-than= option, that is not enough;
it needs to be listed in the Warning Options list, and it should have
@itemx next to -Walloc-size-larger-than=.

What about the other -W...-larger-than options?
Don't you want also -Wno-alloca-larger-than and -Wno-vla-larger-than ?
What about -Wno-frame-larger-than and -Wno-larger-than?

I'm not convinced backporting the addition of the new options to release
branches is desirable, fixing the bug in alloc_max_size is ok for the
branches.

	Jakub