On Sun, Apr 11, 2021 at 6:51 PM Yonghong Song <yhs@xxxxxx> wrote: > > > > On 4/11/21 3:22 AM, Sedat Dilek wrote: > > On Sat, Apr 10, 2021 at 6:49 PM Yonghong Song <yhs@xxxxxx> wrote: > >> > >> selftests/bpf/Makefile includes lib.mk. With the following command > >> make -j60 LLVM=1 LLVM_IAS=1 <=== compile kernel > >> make -j60 -C tools/testing/selftests/bpf LLVM=1 LLVM_IAS=1 V=1 > >> some files are still compiled with gcc. This patch > >> fixed lib.mk issue which sets CC to gcc in all cases. > >> > >> Cc: Sedat Dilek <sedat.dilek@xxxxxxxxx> > >> Signed-off-by: Yonghong Song <yhs@xxxxxx> > >> --- > >> tools/testing/selftests/lib.mk | 4 ++++ > >> 1 file changed, 4 insertions(+) > >> > >> diff --git a/tools/testing/selftests/lib.mk b/tools/testing/selftests/lib.mk > >> index a5ce26d548e4..9a41d8bb9ff1 100644 > >> --- a/tools/testing/selftests/lib.mk > >> +++ b/tools/testing/selftests/lib.mk > >> @@ -1,6 +1,10 @@ > >> # This mimics the top-level Makefile. We do it explicitly here so that this > >> # Makefile can operate with or without the kbuild infrastructure. > >> +ifneq ($(LLVM),) > >> +CC := clang > >> +else > >> CC := $(CROSS_COMPILE)gcc > >> +endif > >> > > > > Why not use include "include ../../../scripts/Makefile.include" here > > and include CC and GNU or LLVM (bin)utils from there? > > There is a comment above my change, > > >> # This mimics the top-level Makefile. We do it explicitly here so > that this > >> # Makefile can operate with or without the kbuild infrastructure. > > It is intentionally not depending on kbuild > (../../../scripts/Makefile.include). > > > > > Should the CC line have a $(CROSS_COMPILE) for people doing cross-compilation? > > > > CC := $(CROSS_COMPILE)clang > > The top linux/Makefile has > > ifneq ($(LLVM),) > CC = clang > LD = ld.lld > AR = llvm-ar > NM = llvm-nm > OBJCOPY = llvm-objcopy > OBJDUMP = llvm-objdump > READELF = llvm-readelf > STRIP = llvm-strip > else > CC = $(CROSS_COMPILE)gcc > LD = $(CROSS_COMPILE)ld > AR = $(CROSS_COMPILE)ar > NM = $(CROSS_COMPILE)nm > OBJCOPY = $(CROSS_COMPILE)objcopy > OBJDUMP = $(CROSS_COMPILE)objdump > READELF = $(CROSS_COMPILE)readelf > STRIP = $(CROSS_COMPILE)strip > endif > > There is no CROSS_COMPILE prefix for llvm. > Also see here: > https://clang.llvm.org/docs/CrossCompilation.html > for clang, cross compilation is mostly related to > tweaking compiler options than building a different > compiler. > > Hence, I didn't add $(CROSS_COMPILER) prefix. > OK, I see. My last cross-compilation for a linux-kernel is very long ago. I never used it with LLVM toolchain - might be $(CROSS_COMPILE) is only necessary with GNU toolchain. - Sedat - > > > > - Sedat - > > > > > >> ifeq (0,$(MAKELEVEL)) > >> ifeq ($(OUTPUT),) > >> -- > >> 2.30.2 > >>
