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@xxxxxxxxxx> Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx> Reviewed-by: Nathan Chancellor <natechancellor@xxxxxxxxx> Reviewed-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> --- Changes in v3: - rename LLVM_IA to LLVM_IAS (per Fangrui Song) Changes in v2: - new patch Documentation/kbuild/llvm.rst | 5 ++++- Makefile | 2 +- 2 files changed, 5 insertions(+), 2 deletions(-) diff --git a/Documentation/kbuild/llvm.rst b/Documentation/kbuild/llvm.rst index eefbdfa3e4d9..0fefdf1737e9 100644 --- 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 ------------ diff --git a/Makefile b/Makefile index 1b2691057cb5..a2aadcf8a36c 100644 --- a/Makefile +++ b/Makefile @@ -538,7 +538,7 @@ endif ifneq ($(GCC_TOOLCHAIN),) CLANG_FLAGS += --gcc-toolchain=$(GCC_TOOLCHAIN) endif -ifeq ($(if $(AS),$(shell $(AS) --version 2>&1 | head -n 1 | grep clang)),) +ifneq ($(LLVM_IAS),1) CLANG_FLAGS += -no-integrated-as endif CLANG_FLAGS += -Werror=unknown-warning-option -- 2.17.1
