Messages in this thread | | | From | Masahiro Yamada <> | Date | Thu, 26 Mar 2020 15:13:50 +0900 | Subject | Re: [PATCH 3/3] kbuild: remove AS variable |
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Hi Nick,
On Wed, Mar 25, 2020 at 4:59 AM Nick Desaulniers <ndesaulniers@google.com> wrote: > > On Tue, Mar 24, 2020 at 12:38 PM Nick Desaulniers > <ndesaulniers@google.com> wrote: > > consistent in this regard (and not using the compiler as the driver), > > Ah, the preprocessor; we need to preprocess the .S files, .s files are > fine (though we have .lds.S files that are not `-x > assembler-with-cpp`)
Right, there is no '*.s' source file in the kernel tree.
If we want to de-couple $(AS), we must the compilation before the assemble stage ( $(CC) -S ), but doing so does not buy us.
So, $(CC) always works as the front-end for compiling both .c and .S files.
You can see the internal database by 'make --print-data-base'.
I see the following for *.S -> *.o rule.
# default COMPILE.S = $(CC) $(ASFLAGS) $(CPPFLAGS) $(TARGET_MACH) -c
So, using $(CC) is the right thing.
Even if we keep AS, we cannot do like AS=llvm-as since llvm-as is a different kind of tool that processes LLVM assembly (.ll) .
-- Best Regards Masahiro Yamada
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