[PATCH 1/2] kbuild: replace cc-name test with CONFIG_CC_IS_CLANG

From: Masahiro Yamada
Date: Tue Oct 30 2018 - 00:23:46 EST


Evaluating cc-name invokes the compiler every time even when you are
not compiling anything, like 'make help'. This is not efficient.

The compiler type has been already detected in the Kconfig stage.
Use CONFIG_CC_IS_CLANG, instead.

Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
---

Makefile | 2 +-
arch/mips/Makefile | 2 +-
arch/mips/vdso/Makefile | 2 +-
arch/powerpc/Makefile | 4 ++--
scripts/Makefile.extrawarn | 2 +-
5 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/Makefile b/Makefile
index 0a42d06..bd93bc3 100644
--- a/Makefile
+++ b/Makefile
@@ -707,7 +707,7 @@ stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG) := -fstack-protector-strong

KBUILD_CFLAGS += $(stackp-flags-y)

-ifeq ($(cc-name),clang)
+ifeq ($(CONFIG_CC_IS_CLANG),y)
KBUILD_CPPFLAGS += $(call cc-option,-Qunused-arguments,)
KBUILD_CFLAGS += $(call cc-disable-warning, format-invalid-specifier)
KBUILD_CFLAGS += $(call cc-disable-warning, gnu)
diff --git a/arch/mips/Makefile b/arch/mips/Makefile
index 15a84cf..ad1c418 100644
--- a/arch/mips/Makefile
+++ b/arch/mips/Makefile
@@ -128,7 +128,7 @@ cflags-y += -ffreestanding
# clang's output will be based upon the build machine. So for clang we simply
# unconditionally specify -EB or -EL as appropriate.
#
-ifeq ($(cc-name),clang)
+ifeq ($(CONFIG_CC_IS_CLANG),y)
cflags-$(CONFIG_CPU_BIG_ENDIAN) += -EB
cflags-$(CONFIG_CPU_LITTLE_ENDIAN) += -EL
else
diff --git a/arch/mips/vdso/Makefile b/arch/mips/vdso/Makefile
index 34605ca..e2b055e 100644
--- a/arch/mips/vdso/Makefile
+++ b/arch/mips/vdso/Makefile
@@ -10,7 +10,7 @@ ccflags-vdso := \
$(filter -march=%,$(KBUILD_CFLAGS)) \
-D__VDSO__

-ifeq ($(cc-name),clang)
+ifeq ($(CONFIG_CC_IS_CLANG),y)
ccflags-vdso += $(filter --target=%,$(KBUILD_CFLAGS))
endif

diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index 17be664..338e827 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -96,7 +96,7 @@ aflags-$(CONFIG_CPU_BIG_ENDIAN) += $(call cc-option,-mabi=elfv1)
aflags-$(CONFIG_CPU_LITTLE_ENDIAN) += -mabi=elfv2
endif

-ifneq ($(cc-name),clang)
+ifneq ($(CONFIG_CC_IS_CLANG),y)
cflags-$(CONFIG_CPU_LITTLE_ENDIAN) += -mno-strict-align
endif

@@ -175,7 +175,7 @@ endif
# Work around gcc code-gen bugs with -pg / -fno-omit-frame-pointer in gcc <= 4.8
# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=44199
# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=52828
-ifneq ($(cc-name),clang)
+ifneq ($(CONFIG_CC_IS_CLANG),y)
CC_FLAGS_FTRACE += $(call cc-ifversion, -lt, 0409, -mno-sched-epilog)
endif
endif
diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn
index 24b2fb1..88129e5 100644
--- a/scripts/Makefile.extrawarn
+++ b/scripts/Makefile.extrawarn
@@ -64,7 +64,7 @@ endif
KBUILD_CFLAGS += $(warning)
else

-ifeq ($(cc-name),clang)
+ifeq ($(CONFIG_CC_IS_CLANG),y)
KBUILD_CFLAGS += $(call cc-disable-warning, initializer-overrides)
KBUILD_CFLAGS += $(call cc-disable-warning, unused-value)
KBUILD_CFLAGS += $(call cc-disable-warning, format)
--
2.7.4