kbuild: consolidate Clang compiler flags

commit 238bcbc4e07fad2fff99c5b157d0c37ccd4d093c upstream.

Collect basic Clang options such as --target, --prefix, --gcc-toolchain,
-no-integrated-as into a single variable CLANG_FLAGS so that it can be
easily reused in other parts of Makefile.

Signed-off-by: Masahiro Yamada <[email protected]>
Reviewed-by: Nick Desaulniers <[email protected]>
Tested-by: Nick Desaulniers <[email protected]>
Acked-by: Greg Hackmann <[email protected]>
Signed-off-by: Nathan Chancellor <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Makefile

@@ -566,18 +566,17 @@ endif
 
 ifeq ($(cc-name),clang)
 ifneq ($(CROSS_COMPILE),)
-CLANG_TARGET	:= --target=$(notdir $(CROSS_COMPILE:%-=%))
+CLANG_FLAGS	:= --target=$(notdir $(CROSS_COMPILE:%-=%))
 GCC_TOOLCHAIN_DIR := $(dir $(shell which $(LD)))
-CLANG_PREFIX	:= --prefix=$(GCC_TOOLCHAIN_DIR)
+CLANG_FLAGS	+= --prefix=$(GCC_TOOLCHAIN_DIR)
 GCC_TOOLCHAIN	:= $(realpath $(GCC_TOOLCHAIN_DIR)/..)
 endif
 ifneq ($(GCC_TOOLCHAIN),)
-CLANG_GCC_TC	:= --gcc-toolchain=$(GCC_TOOLCHAIN)
+CLANG_FLAGS	+= --gcc-toolchain=$(GCC_TOOLCHAIN)
 endif
-KBUILD_CFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC) $(CLANG_PREFIX)
-KBUILD_AFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC) $(CLANG_PREFIX)
-KBUILD_CFLAGS += -no-integrated-as
-KBUILD_AFLAGS += -no-integrated-as
+CLANG_FLAGS	+= -no-integrated-as
+KBUILD_CFLAGS	+= $(CLANG_FLAGS)
+KBUILD_AFLAGS	+= $(CLANG_FLAGS)
 endif