Merge subdirmk

[secnet.git] / subdirmk / regen.mk.in

diff --git a/subdirmk/regen.mk.in b/subdirmk/regen.mk.in
index 0e8bb6a3245ddc82e8508a7119848c813da4e6da..5f24b08fd4e504cc50019a276df7850abb9b9dbf 100644 (file)
--- a/subdirmk/regen.mk.in
+++ b/subdirmk/regen.mk.in
@@ -1,17 +1,66 @@
+# subdirmk - rules for regenerating makefiles etc.
+#  Copyright 2019 Mark Wooding
+#  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
-SUBDIRMK       ?= subdirmk
+CONFIGURE_AC   ?= $(CONFIGURE).ac
+CONFIG_STATUS  ?= config.status
+
+CONFIGURE_ACS  += $(CONFIGURE_AC)
+CONFIGURE_ACS  += subdirmk/subdirmk.ac
 
-&^/$(CONFIGURE): &^/$(CONFIGURE_AC)
-       cd &^ && autoconf
+$(top_srcdir)/$(CONFIGURE): $(addprefix $(top_srcdir)/,$(CONFIGURE_ACS))
+       cd $(top_srcdir) && autoconf
 
-$(CONFIG_STATUS): &^/$(CONFIGURE)
+$(CONFIG_STATUS): $(top_srcdir)/$(CONFIGURE)
        ./$(CONFIG_STATUS) --recheck
 
-all-subdirs.mk $(MAKFILES): makefiles.phantom
-.INTERMEDIATE: makefiles.phantom
-makefiles.phantom: $(addprefix &^/,$(addsuffix .in,$(MAKEFILES)))      \
-               $(CONFIG_STATUS) &^/$(SUBDIRMK)/generate
-       ./$(CONFIG_STATUS)
+# Normally, generate will add all the inputs to MAKEFILE_TEMPLATES.
+MAKEFILE_TEMPLATES += $(addprefix $(top_srcdir)/, $(addsuffix .in, \
+       @_SUBDIRMK_MAKEFILES@ \
+       ))
+
+main.mk $(SUBDIRMK_MAKEFILES) $(CONFIG_STATUS_OUTPUTS): .makefiles.stamp
+               @:
+.makefiles.stamp:                                              \
+               $(top_srcdir)/subdirmk/generate                 \
+               $(CONFIG_STATUS)                                \
+               $(MAKEFILE_TEMPLATES)
+# 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.sd.mk and *.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
+# Subdir.sd.mk twice because if $(top_srcdir) is `.', make elides the
+# directory part from $?.
+       ./$(CONFIG_STATUS) $(if                                 \
+               $(filter-out Subdir.sd.mk %/Subdir.sd.mk        \
+                            %.mk.in                            \
+                       , $?),,                                 \
+               $(patsubst $(top_srcdir)/%,%, $(sort            \
+                       $(patsubst %.sd.mk,%.mk,$(filter %.sd.mk,$?)) \
+                       $(patsubst %.mk.in,%.mk,$(filter %.mk.in,$?)))))
+       touch $@
+
+realclean:: clean
+       $(RM) config.status config.log
+       $(RM) main.mk $(SUBDIRMK_MAKEFILES) @_SUBDIRMK_MAKEFILES@
+       $(RM) $(addsuffix Makefile,$(dir $(SUBDIRMK_MAKEFILES)))
+
+-include $(ALL_DEPFILES)