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| author | Masahiro Yamada <yamada.masahiro@socionext.com> | 2017-11-13 19:29:34 +0900 |
|---|---|---|
| committer | Masahiro Yamada <yamada.masahiro@socionext.com> | 2017-11-16 09:07:32 +0900 |
| commit | 9a234a2e384349f21afac8d718aa294a668ad4fa (patch) | |
| tree | 43d0b8a9ca7c6aa953a0bf849e457813e3892108 /scripts/Kbuild.include | |
| parent | 859fd5860cd1bbbd0370ba4f20725999681b66c8 (diff) | |
| download | lwn-9a234a2e384349f21afac8d718aa294a668ad4fa.tar.gz lwn-9a234a2e384349f21afac8d718aa294a668ad4fa.zip | |
kbuild: create directory for make cache only when necessary
Currently, the existence of $(dir $(make-cache)) is always checked,
and created if it is missing.
We can avoid unnecessary system calls by some tricks.
[1] If KBUILD_SRC is unset, we are building in the source tree.
The output directory checks can be entirely skipped.
[2] If at least one cache data is found, it means the cache file
was included. Obviously its directory exists. Skip "mkdir -p".
[3] If Makefile does not contain any call of __run-and-store, it will
not create a cache file. No need to create its directory.
[4] The "mkdir -p" should be only invoked by the first call of
__run-and-store
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Diffstat (limited to 'scripts/Kbuild.include')
| -rw-r--r-- | scripts/Kbuild.include | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include index be1c9d65eaf4..065324a8046f 100644 --- a/scripts/Kbuild.include +++ b/scripts/Kbuild.include @@ -99,18 +99,19 @@ cc-cross-prefix = \ # Include values from last time make-cache := $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/,$(if $(obj),$(obj)/)).cache.mk -ifeq ($(wildcard $(dir $(make-cache))),) -$(shell mkdir -p '$(dir $(make-cache))') -endif $(make-cache): ; -include $(make-cache) +cached-data := $(filter __cached_%, $(.VARIABLES)) + # If cache exceeds 1000 lines, shrink it down to 500. -ifneq ($(word 1000,$(filter __cached_%, $(.VARIABLES))),) +ifneq ($(word 1000,$(cached-data)),) $(shell tail -n 500 $(make-cache) > $(make-cache).tmp; \ mv $(make-cache).tmp $(make-cache)) endif +create-cache-dir := $(if $(KBUILD_SRC),$(if $(cache-data),,1)) + # Usage: $(call __sanitize-opt,Hello=Hola$(comma)Goodbye Adios) # # Convert all '$', ')', '(', '\', '=', ' ', ',', ':' to '_' @@ -136,6 +137,10 @@ __sanitize-opt = $(subst $$,_,$(subst $(right_paren),_,$(subst $(left_paren),_,$ define __run-and-store ifeq ($(origin $(1)),undefined) $$(eval $(1) := $$(shell $$(2))) +ifeq ($(create-cache-dir),1) + $$(shell mkdir -p $(dir $(make-cache))) + $$(eval create-cache-dir :=) +endif $$(shell echo '$(1) := $$($(1))' >> $(make-cache)) endif endef |