Re: [PATCH 1/2] kbuild: replace cc-name test with CONFIG_CC_IS_CLANG

[Michael Ellerman]

Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx> writes:
> On Tue, Oct 30, 2018 at 9:36 PM Michael Ellerman <mpe@xxxxxxxxxxxxxx> wrote:
>>
>> Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx> writes:
>> > diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
>> > index 17be664..338e827 100644
>> > --- a/arch/powerpc/Makefile
>> > +++ b/arch/powerpc/Makefile
>> > @@ -96,7 +96,7 @@ aflags-$(CONFIG_CPU_BIG_ENDIAN)             += $(call cc-option,-mabi=elfv1)
>> >  aflags-$(CONFIG_CPU_LITTLE_ENDIAN)   += -mabi=elfv2
>> >  endif
>> >
>> > -ifneq ($(cc-name),clang)
>> > +ifneq ($(CONFIG_CC_IS_CLANG),y)
>> >    cflags-$(CONFIG_CPU_LITTLE_ENDIAN) += -mno-strict-align
>> >  endif
>> >
>> > @@ -175,7 +175,7 @@ endif
>> >  # Work around gcc code-gen bugs with -pg / -fno-omit-frame-pointer in gcc <= 4.8
>> >  # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=44199
>> >  # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=52828
>> > -ifneq ($(cc-name),clang)
>> > +ifneq ($(CONFIG_CC_IS_CLANG),y)
>> >  CC_FLAGS_FTRACE      += $(call cc-ifversion, -lt, 0409, -mno-sched-epilog)
>> >  endif
>> >  endif
>>
>> Does this behave like other CONFIG variables, ie. it will not be defined
>> when it's false?
>
> Right.
>
>> And if so can't we use ifdef/ifndef? eg:
>>
>> ifndef CONFIG_CC_IS_CLANG
>>   CC_FLAGS_FTRACE       += $(call cc-ifversion, -lt, 0409, -mno-sched-epilog)
>>
>> That reads cleaner to me.
>
>
> OK, will do respin if you prefer ifdef/ifndef style.

I do prefer it, but I can also fix it up later if you're in a hurry to
get this merged.

cheers