From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Mon, 11 Nov 2019 01:46:10 +0000 (+0000)
Subject: WIP
X-Git-Tag: subdirmk/0.1~111
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ian/git?p=subdirmk.git;a=commitdiff_plain;h=03e85f8934e2a1b68970d762a53c6bd890dd65fc

WIP
---

diff --git a/Makefile.in b/Makefile.in
index f7c845b..dcf875d 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -92,19 +92,6 @@ $(call descend-subdirs, $(SUBDIRS))
 ###--------------------------------------------------------------------------
 ### Maintaining the build system.
 
-$(srcdir)/configure: $(srcdir)/configure.ac
-	$(call v-tag,AUTOCONF)cd $(srcdir) && autoconf
-
-config.status: $(srcdir)/configure
-	$(call v-tag,CONFIG)./config.status --recheck
-
-Makefile: config.status $(srcdir)/Makefile.in \
-		$(foreach d,$(ALL_SUBDIRS), $d/Makefile)
-	$(call v-tag,SUBST)./config.status Makefile
-$(foreach d,$(ALL_SUBDIRS), \
-	$(eval $d/Makefile: config.status $$(srcdir)/$d/Makefile.in; \
-		$$(call v-tag,SUBST)./config.status $$@))
-
 ###--------------------------------------------------------------------------
 ### More machinery.
 
diff --git a/Subdir.mk.in b/Subdir.mk.in
index e29c332..804880f 100644
--- a/Subdir.mk.in
+++ b/Subdir.mk.in
@@ -23,3 +23,14 @@ COMPILE		?= $(CC) -c -o$@ -MD $(DEFS) $(INCLUDES) $(CFLAGS)
 %.o: %.c
 	$(COMPILE) $<
 
+&^/configure: &^/configure.ac
+	cd &^ && autoconf
+
+config.status: &^/configure
+	./config.status --recheck
+
+subdirs.mk: config.status &^/build-aux/subdirmk-setup
+	./config.status $@
+
+%/Subdir.mk: &^/%/Subdir.mk.in subdirs.mk
+	./config.status $@
diff --git a/build-aux/subdirmk-setup b/build-aux/subdirmk-setup
index 000417f..f781325 100755
--- a/build-aux/subdirmk-setup
+++ b/build-aux/subdirmk-setup
@@ -16,6 +16,8 @@ die unless @ARGV>=2;
 shift @ARGV;
 ($srcdir, @subdirs) = @ARGV;
 
+s{/+$}{} foreach @subdirs;
+
 our $root = [ '.', [ ] ];
 # each node is [ 'relative subdir name', \@children ]
 
@@ -77,6 +79,7 @@ sub write_makefile ($$) {
     my $cd = $depth ? join('/', ('..',) x $depth) : '.';
     o <<END;
 default: all
+.SUFFIXES:
 %:
 	\$(MAKE) -C $cd -f subdirs.mk ${dir_prefix}\$@
 END
diff --git a/configure.ac b/configure.ac
index 4557f95..e56fee9 100644
--- a/configure.ac
+++ b/configure.ac
@@ -36,8 +36,16 @@ m4_define([SUBDIRSMK_SUBDIRS],
 [m4_map_args_w([$1],[_SUBDIRSMK_SUBDIR(],[/)])])dnl
 
 AC_CONFIG_FILES([subdirs.mk:subdirs.mk.tmp Subdir.mk:Subdir.mk.tmp],[],
-[echo 'running subdirmk-setup'
-'$srcdir'/build-aux/subdirmk-setup --srcdir '$srcdir' $subdirsmk_subdirs])
+[
+subdirsmk_need_prep=false
+AS_IF([\$ac_need_defaults],
+[subdirsmk_need_prep=true],[
+AS_CASE([" \$ac_config_targets "],[*" subdirs.mk "*],
+[subdirsmk_need_prep=true])])
+AS_IF([\$subdirsmk_need_prep],[
+ echo 'running subdirmk-setup'
+ '$srcdir'/build-aux/subdirmk-setup --srcdir '$srcdir' $subdirsmk_subdirs
+])])
 
 m4_define([_SUBDIRSMK_SUBDIR],
 [subdirsmk_subdirs="$subdirsmk_subdirs '$1'"