On Sat, Feb 26, 2022 at 2:14 PM Arnd Bergmann <arnd@xxxxxxxx> wrote:
>
> Could gcc follow the clang behavior then and skip the warning and
> sanitizer for this case when -fno-strict-overflow or -fwrapv are used?
Well, for the kernel, that horse has already left the barn, and we'd
have to use -Wno-shift-negative-value anyway.
But yes, from a sanity standpoint, it would be good to shut that
warning up automatically if compiling for a 2's complement machine (ie
"all of them") with -fwrapv.
Considering that gcc doesn't support any non-2's-complement machines
anyway afaik, and that the C standards people are also fixing the
standard, and gcc has never done anything odd in this area in the
first place, I think the warning is probably best removed entirely.
But we'll have to do it manually for the existing situation.
Linus
