On Fri, Sep 02, 2022 at 10:59:54AM -0500, Segher Boessenkool wrote: > On Fri, Sep 02, 2022 at 08:37:23AM -0700, Nathan Chancellor wrote: > > On Fri, Sep 02, 2022 at 12:08:55PM +0200, Christophe Leroy wrote: > > > This should have been detected by gcc at build time, but due to > > > '-w' flag it went undetected. > > > > > > Removing that flag leads to many warnings hence errors. > > > Thanks for figuring out what was going on here! I took this patch for a > > spin with clang and it has a few more errors around > > -Wimplicit-fallthrough: > > Maybe add -Wno-implicit-fallthrough? This code is a copy from outside > the kernel, no one has ever wanted to maintain it, if nothing else (the > more politically correct formulation is "we cannot as easily pick up > improvements from upstream if we modify stuff").
Sure, we could do something like this if you preferred: diff --git a/arch/powerpc/math-emu/Makefile b/arch/powerpc/math-emu/Makefile index 26fef2e5672e..ed775747a2a5 100644 --- a/arch/powerpc/math-emu/Makefile +++ b/arch/powerpc/math-emu/Makefile @@ -16,3 +16,7 @@ obj-$(CONFIG_SPE) += math_efp.o CFLAGS_fabs.o = -fno-builtin-fabs CFLAGS_math.o = -fno-builtin-fabs + +ifdef CONFIG_CC_IS_CLANG +ccflags-remove-y := $(CONFIG_CC_IMPLICIT_FALLTHROUGH) +endif At the same time, I see other modifications to these files that appear to be for the kernel only so I suspect that this is already in the "we cannot as easily pick up improvements from upstream" category, regardless of that diff. No strong opinion from me, although I see Christophe already included my suggestion in the most recent series: https://lore.kernel.org/2663961738a46073713786d4efeb53100ca156e7.1662134272.git.christophe.le...@csgroup.eu/ Cheers, Nathan