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* [PATCH v2 1/4] kbuild: use $(CC_VERSION_TEXT) to evaluate CC_IS_GCC and CC_IS_CLANG
@ 2020-04-23 14:23 Masahiro Yamada
  2020-04-23 14:23 ` [PATCH v2 2/4] kbuild: ensure full rebuild when the compiler is updated Masahiro Yamada
                   ` (4 more replies)
  0 siblings, 5 replies; 7+ messages in thread
From: Masahiro Yamada @ 2020-04-23 14:23 UTC (permalink / raw)
  To: linux-kbuild; +Cc: Masahiro Yamada, clang-built-linux, linux-kernel

The result of '$(CC) --version | head -n 1' is already computed by the
top Makefile, and stored in the environment variable, CC_VERSION_TEXT.

'echo' is probably less expensive than the two commands $(CC) and
'head' although this optimization is not noticeable level.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---

Changes in v2:
  - new patch

 init/Kconfig | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/init/Kconfig b/init/Kconfig
index 9e22ee8fbd75..5f797df3f043 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -9,7 +9,7 @@ config DEFCONFIG_LIST
 	default "arch/$(SRCARCH)/configs/$(KBUILD_DEFCONFIG)"
 
 config CC_IS_GCC
-	def_bool $(success,$(CC) --version | head -n 1 | grep -q gcc)
+	def_bool $(success,echo "$(CC_VERSION_TEXT)" | grep -q gcc)
 
 config GCC_VERSION
 	int
@@ -21,7 +21,7 @@ config LD_VERSION
 	default $(shell,$(LD) --version | $(srctree)/scripts/ld-version.sh)
 
 config CC_IS_CLANG
-	def_bool $(success,$(CC) --version | head -n 1 | grep -q clang)
+	def_bool $(success,echo "$(CC_VERSION_TEXT)" | grep -q clang)
 
 config CLANG_VERSION
 	int
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 7+ messages in thread
end of thread, other threads:[~2020-05-01  5:35 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
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2020-04-23 14:23 [PATCH v2 1/4] kbuild: use $(CC_VERSION_TEXT) to evaluate CC_IS_GCC and CC_IS_CLANG Masahiro Yamada
2020-04-23 14:23 ` [PATCH v2 2/4] kbuild: ensure full rebuild when the compiler is updated Masahiro Yamada
2020-04-23 14:23 ` [PATCH v2 3/4] kbuild: use -MMD instead of -MD to exclude system headers from dependency Masahiro Yamada
2020-04-23 14:23 ` [PATCH v2 4/4] kbuild: use CONFIG_CC_VERSION_TEXT to construct LINUX_COMPILER macro Masahiro Yamada
2020-04-27 15:29   ` Masahiro Yamada
2020-04-23 16:48 ` [PATCH v2 1/4] kbuild: use $(CC_VERSION_TEXT) to evaluate CC_IS_GCC and CC_IS_CLANG Nathan Chancellor
2020-05-01  5:34 ` Masahiro Yamada

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