Hi Stefan, 2018-09-18 11:31 GMT+09:00 Stefan Agner <stefan@xxxxxxxx>: > When using a GCC cross toolchain which is not in a compiled in > Clang search path, Clang reverts to the system assembler and > linker. This leads to assembler or linker errors, depending on > which tool is first used for a given architecture. > > It seems that Clang is not searching $PATH for a matching > assembler or linker. The current code passes the absolute path of toolchains to --gcc-toolchain option. In my understanding, this is enough for Clang to find the proper linker and the assembler. Why is the --prefix option also needed ? Am I missing something? > Make sure that Clang picks up the correct assembler or linker by > passing the cross compilers bin directory as search path. > > This allows to use Clang provided by distributions with GCC > toolchains not in /usr/bin. > > Link: https://github.com/ClangBuiltLinux/linux/issues/78 > Signed-off-by: Stefan Agner <stefan@xxxxxxxx> > --- > Nick, I removed your Reviewed-by since I had to change variable > assignment slightly... > > Makefile | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) > > diff --git a/Makefile b/Makefile > index 4d5c883a98e5..d5de2db4b549 100644 > --- a/Makefile > +++ b/Makefile > @@ -495,13 +495,15 @@ endif > ifeq ($(cc-name),clang) > ifneq ($(CROSS_COMPILE),) > CLANG_TARGET := --target=$(notdir $(CROSS_COMPILE:%-=%)) > -GCC_TOOLCHAIN := $(realpath $(dir $(shell which $(LD)))/..) > +GCC_TOOLCHAIN_DIR := $(dir $(shell which $(LD))) > +CLANG_PREFIX := --prefix=$(GCC_TOOLCHAIN_DIR) > +GCC_TOOLCHAIN := $(realpath $(GCC_TOOLCHAIN_DIR)/..) > endif > ifneq ($(GCC_TOOLCHAIN),) > CLANG_GCC_TC := --gcc-toolchain=$(GCC_TOOLCHAIN) > endif > -KBUILD_CFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC) > -KBUILD_AFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC) > +KBUILD_CFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC) $(CLANG_PREFIX) > +KBUILD_AFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC) $(CLANG_PREFIX) > KBUILD_CFLAGS += $(call cc-option, -no-integrated-as) > KBUILD_AFLAGS += $(call cc-option, -no-integrated-as) > endif > -- > 2.19.0 > -- Best Regards Masahiro Yamada
