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| author | Nick Desaulniers <ndesaulniers@google.com> | 2021-02-05 14:01:25 -0800 |
|---|---|---|
| committer | Masahiro Yamada <masahiroy@kernel.org> | 2021-02-24 15:11:17 +0900 |
| commit | db07562aeac77923370bff4733d8b0e09cbc93c4 (patch) | |
| tree | b69799d84344cbf543cbf5b810c56e7c2f93d18c /Makefile | |
| parent | 02aff85922043cf175ebbe5fc3430acfeaeb8393 (diff) | |
| download | linux-db07562aeac77923370bff4733d8b0e09cbc93c4.tar.bz2 | |
Makefile: reuse CC_VERSION_TEXT
I noticed we're invoking $(CC) via $(shell) more than once to check the
version. Let's reuse the first string captured in $CC_VERSION_TEXT.
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
[masahiro.yamada:
CC_VERSION_TEXT is assigned by = instead of :=, so this $(shell ) is
evaluated multiple times anyway. The number of $(CC) invocations will
be still the same. Replacing 'grep' with the built-in $(findstring )
will give real performance benefit.]
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Diffstat (limited to 'Makefile')
| -rw-r--r-- | Makefile | 14 |
1 files changed, 7 insertions, 7 deletions
@@ -557,7 +557,13 @@ ifdef building_out_of_srctree { echo "# this is build directory, ignore it"; echo "*"; } > .gitignore endif -ifneq ($(shell $(CC) --version 2>&1 | head -n 1 | grep clang),) +# The expansion should be delayed until arch/$(SRCARCH)/Makefile is included. +# Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile. +# CC_VERSION_TEXT is referenced from Kconfig (so it needs export), +# and from include/config/auto.conf.cmd to detect the compiler upgrade. +CC_VERSION_TEXT = $(shell $(CC) --version 2>/dev/null | head -n 1) + +ifneq ($(findstring clang,$(CC_VERSION_TEXT)),) ifneq ($(CROSS_COMPILE),) CLANG_FLAGS += --target=$(notdir $(CROSS_COMPILE:%-=%)) GCC_TOOLCHAIN_DIR := $(dir $(shell which $(CROSS_COMPILE)elfedit)) @@ -576,12 +582,6 @@ KBUILD_AFLAGS += $(CLANG_FLAGS) export CLANG_FLAGS endif -# The expansion should be delayed until arch/$(SRCARCH)/Makefile is included. -# Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile. -# CC_VERSION_TEXT is referenced from Kconfig (so it needs export), -# and from include/config/auto.conf.cmd to detect the compiler upgrade. -CC_VERSION_TEXT = $(shell $(CC) --version 2>/dev/null | head -n 1) - ifdef config-build # =========================================================================== # *config targets only - make sure prerequisites are updated, and descend |