X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ian/git?p=subdirmk.git;a=blobdiff_plain;f=subdirmk%2Fregen.mk.in;fp=subdirmk%2Fregen.mk.in;h=83952c9e648527eaf74b85b1c68317f13718ef50;hp=a6d9ad2544837b83b5d2ee2386b1328fe69cb430;hb=c8c7630c9523d18365953077522995995de0fc58;hpb=b48380652d2974f9d615a5c942a82f3dfb002ca3

diff --git a/subdirmk/regen.mk.in b/subdirmk/regen.mk.in
index a6d9ad2..83952c9 100644
--- a/subdirmk/regen.mk.in
+++ b/subdirmk/regen.mk.in
@@ -3,6 +3,20 @@
 #  Copyright 2019 Ian Jackson
 # SPDX-License-Identifier: LGPL-2.0-or-later
 
+# Usage:
+#   include subdirmk/regen.mk
+# (probably in toplevel Subdir.sd.mk)
+#
+# Arranges that config.status is automatically rerun to update
+# makefiles from templates, whenever a template *.sd.mk or *.mk.in is
+# edited; and that autoconf is rerun if configure's inputs are edited.
+#
+# If you add includes to configure.ac, add them to CONFIGURE_ACS.
+#
+# Also provides a `realclean::' target at the toplevel which deletes
+# the autoconf output.  This may be made into a recursive target
+# by mentioning &TARGETS_realclean in appropriate .sd.mk.
+
 CONFIGURE	?= configure
 CONFIGURE_AC	?= $(CONFIGURE).ac
 CONFIG_STATUS	?= config.status