# - If they are equal no change, and no timestamp update
# - stdin is piped in from the first prerequisite ($<) so one has
# to specify a valid file as first prerequisite (often the kbuild file)
+ chk_filechk = :
+ quiet_chk_filechk = echo ' CHK $@'
+silent_chk_filechk = :
+ upd_filechk = :
+ quiet_upd_filechk = echo ' UPD $@'
+silent_upd_filechk = :
+
define filechk
$(Q)set -e; \
- echo ' CHK $@'; \
+ $($(quiet)chk_filechk); \
mkdir -p $(dir $@); \
$(filechk_$(1)) < $< > $@.tmp; \
if [ -r $@ ] && cmp -s $@ $@.tmp; then \
rm -f $@.tmp; \
else \
- echo ' UPD $@'; \
+ $($(quiet)upd_filechk); \
mv -f $@.tmp $@; \
fi
endef