The string returned by $(filter-out ...) does not contain any leading or trailing spaces. With the previous commit, 'any-prereq' no longer contains any excessive spaces. Nor does 'cmd-check' since it expands to a $(filter-out ...) call. So, only the space that matters is the one between 'any-prereq' and 'cmd-check'. By removing it from the code, we can save $(strip ...) evaluation. This refactoring is possible because $(any-prereq)$(cmd-check) is only passed to the first argument of $(if ...), so we are only interested in whether it is empty or not. Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx> --- scripts/Kbuild.include | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include index 0fa93f6de0b0..0e57a9524003 100644 --- a/scripts/Kbuild.include +++ b/scripts/Kbuild.include @@ -234,12 +234,12 @@ make-cmd = $(call escsq,$(subst $(pound),$$(pound),$(subst $$,$$$$,$(cmd_$(1)))) any-prereq = $(filter-out $(PHONY),$?)$(filter-out $(PHONY) $(wildcard $^),$^) # Execute command if command has changed or prerequisite(s) are updated. -if_changed = $(if $(strip $(any-prereq) $(cmd-check)), \ +if_changed = $(if $(any-prereq)$(cmd-check), \ $(cmd); \ printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd, @:) # Execute the command and also postprocess generated .d dependencies file. -if_changed_dep = $(if $(strip $(any-prereq) $(cmd-check)),$(cmd_and_fixdep),@:) +if_changed_dep = $(if $(any-prereq)$(cmd-check),$(cmd_and_fixdep),@:) cmd_and_fixdep = \ $(cmd); \ @@ -249,7 +249,7 @@ cmd_and_fixdep = \ # Usage: $(call if_changed_rule,foo) # Will check if $(cmd_foo) or any of the prerequisites changed, # and if so will execute $(rule_foo). -if_changed_rule = $(if $(strip $(any-prereq) $(cmd-check)),$(rule_$(1)),@:) +if_changed_rule = $(if $(any-prereq)$(cmd-check),$(rule_$(1)),@:) ### # why - tell why a target got built -- 2.17.1