From: Masahiro Yamada masahiroy@kernel.org
commit 7e20e47c70f810d678d02941fa3c671209c4ca97 upstream.
The 'AS' variable is unused for building the kernel. Only the remaining usage is to turn on the integrated assembler. A boolean flag is a better fit for this purpose.
AS=clang was added for experts. So, I replaced it with LLVM_IAS=1, breaking the backward compatibility.
Suggested-by: Nick Desaulniers ndesaulniers@google.com Signed-off-by: Masahiro Yamada masahiroy@kernel.org Reviewed-by: Nathan Chancellor natechancellor@gmail.com Reviewed-by: Nick Desaulniers ndesaulniers@google.com Signed-off-by: Nick Desaulniers ndesaulniers@google.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- Documentation/kbuild/llvm.rst | 5 ++++- Makefile | 2 ++ 2 files changed, 6 insertions(+), 1 deletion(-)
--- a/Documentation/kbuild/llvm.rst +++ b/Documentation/kbuild/llvm.rst @@ -50,11 +50,14 @@ LLVM Utilities LLVM has substitutes for GNU binutils utilities. These can be invoked as additional parameters to `make`.
- make CC=clang AS=clang LD=ld.lld AR=llvm-ar NM=llvm-nm STRIP=llvm-strip \ + make CC=clang LD=ld.lld AR=llvm-ar NM=llvm-nm STRIP=llvm-strip \ OBJCOPY=llvm-objcopy OBJDUMP=llvm-objdump OBJSIZE=llvm-size \ READELF=llvm-readelf HOSTCC=clang HOSTCXX=clang++ HOSTAR=llvm-ar \ HOSTLD=ld.lld
+Currently, the integrated assembler is disabled by default. You can pass +`LLVM_IAS=1` to enable it. + Getting Help ------------
--- a/Makefile +++ b/Makefile @@ -492,7 +492,9 @@ endif ifneq ($(GCC_TOOLCHAIN),) CLANG_FLAGS += --gcc-toolchain=$(GCC_TOOLCHAIN) endif +ifneq ($(LLVM_IAS),1) CLANG_FLAGS += -no-integrated-as +endif CLANG_FLAGS += -Werror=unknown-warning-option KBUILD_CFLAGS += $(CLANG_FLAGS) KBUILD_AFLAGS += $(CLANG_FLAGS)