diff options
Diffstat (limited to 'scripts')
137 files changed, 3236 insertions, 871 deletions
diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include index 9ffd3dda3889..065324a8046f 100644 --- a/scripts/Kbuild.include +++ b/scripts/Kbuild.include @@ -8,6 +8,8 @@ squote := ' empty := space := $(empty) $(empty) space_escape := _-_SPACE_-_ +right_paren := ) +left_paren := ( ### # Name of target with a '.' as filename prefix. foo/bar.o => foo/.bar.o @@ -80,6 +82,71 @@ cc-cross-prefix = \ echo $(c); \ fi))) +# Tools for caching Makefile variables that are "expensive" to compute. +# +# Here we want to help deal with variables that take a long time to compute +# by making it easy to store these variables in a cache. +# +# The canonical example here is testing for compiler flags. On a simple system +# each call to the compiler takes 10 ms, but on a system with a compiler that's +# called through various wrappers it can take upwards of 100 ms. If we have +# 100 calls to the compiler this can take 1 second (on a simple system) or 10 +# seconds (on a complicated system). +# +# The "cache" will be in Makefile syntax and can be directly included. +# Any time we try to reference a variable that's not in the cache we'll +# calculate it and store it in the cache for next time. + +# Include values from last time +make-cache := $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/,$(if $(obj),$(obj)/)).cache.mk +$(make-cache): ; +-include $(make-cache) + +cached-data := $(filter __cached_%, $(.VARIABLES)) + +# If cache exceeds 1000 lines, shrink it down to 500. +ifneq ($(word 1000,$(cached-data)),) +$(shell tail -n 500 $(make-cache) > $(make-cache).tmp; \ + mv $(make-cache).tmp $( |