kbuild: check CONFIG_AS_IS_LLVM instead of LLVM_IAS

commit 52cc02b910284d6bddba46cce402044ab775f314 upstream.

LLVM_IAS is the user interface to set the -(no-)integrated-as flag,
and it should be used only for that purpose.

LLVM_IAS is checked in some places to determine the assembler type,
but it is not precise.

For example,

 $ make CC=gcc LLVM_IAS=1

... will use the GNU assembler (i.e. binutils) since LLVM_IAS=1 is
effective only when $(CC) is clang.

Of course, 'CC=gcc LLVM_IAS=1' is an odd combination, but the build
system can be more robust against such insane input.

Commit ba64beb17493a ("kbuild: check the minimum assembler version in
Kconfig") introduced CONFIG_AS_IS_GNU/LLVM, which is more precise
because Kconfig checks the version string from the assembler in use.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
[nathan: Backport to 5.10]
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Masahiro Yamada 2023-03-28 17:08:31 -07:00 committed by Greg Kroah-Hartman
parent d5f67f6d4e
commit c36a251011
2 changed files with 2 additions and 2 deletions

View File

@ -851,7 +851,7 @@ else
DEBUG_CFLAGS += -g
endif
ifeq ($(LLVM_IAS),1)
ifdef CONFIG_AS_IS_LLVM
KBUILD_AFLAGS += -g
else
KBUILD_AFLAGS += -Wa,-gdwarf-2

View File

@ -40,7 +40,7 @@ ifeq ($(CONFIG_LD_IS_LLD),y)
ifeq ($(shell test $(CONFIG_LLD_VERSION) -lt 150000; echo $$?),0)
KBUILD_CFLAGS += -mno-relax
KBUILD_AFLAGS += -mno-relax
ifneq ($(LLVM_IAS),1)
ifndef CONFIG_AS_IS_LLVM
KBUILD_CFLAGS += -Wa,-mno-relax
KBUILD_AFLAGS += -Wa,-mno-relax
endif