From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Sat, 7 Dec 2019 15:28:29 +0000 (+0000)
Subject: subdirmk: Suppress MAKEFILE_TEMPLATES when running `make clean'
X-Git-Tag: v0.6.0~265
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?a=commitdiff_plain;h=6bdac29dbe716ebc6fd6bb4f98e4f6c84e1c5df7;p=secnet.git

subdirmk: Suppress MAKEFILE_TEMPLATES when running `make clean'

See the README hunk for the reasoning.

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
---

diff --git a/subdirmk/README b/subdirmk/README
index 518dd08..27dd855 100644
--- a/subdirmk/README
+++ b/subdirmk/README
@@ -371,6 +371,13 @@ makefiles, you may find that just `make' is broken now and cannot get
 far enough to regenerate a working set of makefiles.  If this happens
 just rerun ./config.status by hand.
 
+If you go back and forth between different versions of your code you
+can sometimes find that `make' complains that one of your Subdir.sd.mk
+files is missing: typically, if iot was used and therefore a
+dependency in some other version of your code.  If you run `make
+clean' (or `make realclean') these dependencies are suppressed, which
+will clear up the problem.
+
 
 Legal information
 -----------------
diff --git a/subdirmk/generate b/subdirmk/generate
index 22e8aff..32c6fbf 100755
--- a/subdirmk/generate
+++ b/subdirmk/generate
@@ -97,13 +97,16 @@ sub write_makefile ($$) {
     #print STDERR "write_makefile @_\n";
     start_output_file("${dir_prefix}Makefile");
     my $cd = $depth ? join('/', ('..',) x $depth) : '.';
+    my $suppress_templates=
+	'$(if $(filter-out clean real-clean, $(subdirmk_targets)),,'.
+	' MAKEFILE_TEMPLATES=)';
     o <<END;
 default: all
 \$(filter-out all,\$(MAKECMDGOALS)) all: run-main.mk
 	\@:
 subdirmk_targets:=\$(or \$(MAKECMDGOALS),all)
 Makefile run-main.mk:
-	\$(MAKE) -C $cd -f main.mk \$(addprefix ${dir_prefix},\$(subdirmk_targets))
+	\$(MAKE) -C $cd -f main.mk \$(addprefix ${dir_prefix},\$(subdirmk_targets))$suppress_templates
 .SUFFIXES:
 .PHONY:	run-main.mk
 END