kbuild: shrink .cache.mk when it exceeds 1000 lines

The cache files are only cleaned away by "make clean".  If you continue
incremental builds, the cache files will grow up little by little.
It is not a big deal in general use cases because compiler flags do not
change quite often.

However, if you do build-test for various architectures, compilers, and
kernel configurations, you will end up with huge cache files soon.

When the cache file exceeds 1000 lines, shrink it down to 500 by "tail".
The Least Recently Added lines are cut. (not Least Recently Used)
I hope it will work well enough.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
This commit is contained in:
Masahiro Yamada 2017-10-13 20:25:29 +09:00
parent 433dc2ebe7
commit e17c400ae1
1 changed files with 6 additions and 0 deletions

View File

@ -105,6 +105,12 @@ endif
$(make-cache): ;
-include $(make-cache)
# If cache exceeds 1000 lines, shrink it down to 500.
ifneq ($(word 1000,$(filter __cached_%, $(.VARIABLES))),)
$(shell tail -n 500 $(make-cache) > $(make-cache).tmp; \
mv $(make-cache).tmp $(make-cache))
endif
# Usage: $(call __sanitize-opt,Hello=Hola$(comma)Goodbye Adios)
#
# Convert all '$', ')', '(', '\', '=', ' ', ',', ':' to '_'