[PATCH v2 2/2] kbuild: consolidate Clang compiler flags

From: Masahiro Yamada
Date: Mon Nov 05 2018 - 22:06:45 EST


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 <yamada.masahiro@xxxxxxxxxxxxx>
---

Changes in v2:
- Use := flavor instead of = because $(CLANG_FLAGS) is expanded soon anyway

Makefile | 13 ++++++-------
1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/Makefile b/Makefile
index da11700..e173a73 100644
--- a/Makefile
+++ b/Makefile
@@ -487,18 +487,17 @@ endif

ifneq ($(shell $(CC) --version 2>&1 | head -n 1 | grep clang),)
ifneq ($(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

RETPOLINE_CFLAGS_GCC := -mindirect-branch=thunk-extern -mindirect-branch-register
--
2.7.4