fix-ltdl: Fix order-only hack with FreeBSD make.

FreeBSD make does not work well when undefined variables are used in
nested expansions.  When such an expansion appears in the prerequisites
of a target, FreeBSD make exits with a fatal error.  For example:

  A = $(var$(B))
  foo : $(A)

  % make
  Error expanding embedded variable.

This causes the order-only hack to fail because FreeBSD make does not
define .FEATURES.  The workaround is simple: add another variable which
is assigned the value of .FEATURES.  That variable can be used in the
nested expansion to avoid the error.

diff --git a/scripts/fix-ltdl.pl b/scripts/fix-ltdl.pl
index 7dd1c8b0ef6e7991b2adb8e8cda86e4c28eb84db..f65265dfaf8ad05d53801bc5b6b41b8b37c9b030 100755 (executable)
--- a/scripts/fix-ltdl.pl
+++ b/scripts/fix-ltdl.pl
@@ -1,6 +1,6 @@
 #!/usr/bin/env perl
 #
-# Copyright © 2012 Nick Bowler
+# Copyright © 2012, 2014 Nick Bowler
 #
 # Fixup a non-recursive libltdl makefile fragment.  While libltdl purports to
 # support inclusion into non-recursive automake builds, it does a few things
@@ -98,7 +98,8 @@ while (<STDIN>) {
                print "# Postprocessed by ", basename($0), "\n";
                print <<'EOF';
 # This trick should define ltdl_orderonly to | iff we're using GNU make.
-ltdl_have_orderonly = $(findstring order-only,$(.FEATURES))
+ltdl_make_features = $(.FEATURES)
+ltdl_have_orderonly = $(findstring order-only,$(ltdl_make_features))
 ltdl_orderonly = $(ltdl_have_orderonly:order-only=|)
 ltdl_core_headers =
 ltdl_src_headers = $(ltdl_orderonly) $(ltdl_core_headers)