$(CONFIG_STATUS) \
$(top_srcdir)/Perdir.mk.in \
$(foreach m,$(MAKEFILES),$(top_srcdir)/$(m).in)
- : $? X $(filter-out Subdir.mk.in regen.mk.in, $(notdir $?))
+# This filtering arranges that we can often run config.status to
+# generate only particular output files. We look for *inputs* that
+# have changed. If the only inputs that have changed are ones that we
+# know affect only one output (Subdir.mk.in and regen.mk.in), we pass
+# config.status the corresponding output file names. Otherwise we
+# pass nothing and config.status does them all. We need to mention
+# regen.mk.in twice because if $(top_srcdir) is `.', make elides the
+# directory part from $?.
./$(CONFIG_STATUS) $(if \
- $(filter-out Subdir.mk.in regen.mk.in, $(notdir $?)),, \
+ $(filter-out Subdir.mk.in %/Subdir.mk.in \
+ subdirmk/regen.mk.in \
+ $(top_srcdir)/subdirmk/regen.mk.in \
+ , $?),, \
$(patsubst %.mk.in,%.mk,$(filter %.mk.in,$?)))
touch $@