Daniel Axtens <d...@axtens.net> writes: > Hi Alexey, > >> The $(CPP) (do only preprocessing) macro is already defined in Makefile. >> However POWERPC redefines it and adds $(KBUILD_CFLAGS) which results >> in flags duplication. Which is not a big deal by itself except for >> the flags which depend on other flags and the compiler checks them >> as it parses the command line. >> >> Specifically, scripts/Makefile.build:304 generates ksyms for .S files. >> If clang+llvm+sanitizer are enabled, this results in >> -fno-lto -flto -fsanitize=cfi-mfcall .... -fno-lto -flto >> -fsanitize=cfi-mfcall > > Checkpatch doesn't like this line: > WARNING:COMMIT_LOG_LONG_LINE: Possible unwrapped commit description (prefer a > maximum 75 chars per line) > #14: > -fno-lto -flto -fsanitize=cfi-mfcall .... -fno-lto -flto > -fsanitize=cfi-mfcall > However, it doesn't make sense to wrap the line so we should just ignore > checkpatch here. > >> in the clang command line and triggers error: >> >> clang-13: error: invalid argument '-fsanitize=cfi-mfcall' only allowed with >> '-flto' >> >> This removes unnecessary CPP redifinition. >> >> Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru> >> --- >> arch/powerpc/Makefile | 1 - >> 1 file changed, 1 deletion(-) >> >> diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile >> index c9d2c7825cd6..3a2f2001c62b 100644 >> --- a/arch/powerpc/Makefile >> +++ b/arch/powerpc/Makefile >> @@ -214,7 +214,6 @@ KBUILD_CPPFLAGS += -I $(srctree)/arch/$(ARCH) $(asinstr) >> KBUILD_AFLAGS += $(AFLAGS-y) >> KBUILD_CFLAGS += $(call cc-option,-msoft-float) >> KBUILD_CFLAGS += -pipe $(CFLAGS-y) >> -CPP = $(CC) -E $(KBUILD_CFLAGS) > > I was trying to check the history to see why powerpc has its own > definition. It seems to date back at least as far as merging the two > powerpc platforms into one, maybe it was helpful then. I agree it > doesn't seem to be needed now. > > Snowpatch claims that this breaks the build, but I haven't been able to > reproduce the issue in either pmac32 or ppc64 defconfig. I have sent it > off to a fork of mpe's linux-ci repo to see if any of those builds hit > any issues: https://github.com/daxtens/linux-ci/actions
It does break the build. cheers