From d952e6bb30f6bfb1f1100a6b8ec263fc08073d51 Mon Sep 17 00:00:00 2001
From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Sun, 10 Nov 2019 13:41:00 +0000
Subject: [PATCH 1/1] GO BACK TO HIER

---
 build-aux/subdirmk-setup | 43 +++++++++++++++++++++-------------------
 1 file changed, 23 insertions(+), 20 deletions(-)

diff --git a/build-aux/subdirmk-setup b/build-aux/subdirmk-setup
index 11d0f26..c1866f6 100644
--- a/build-aux/subdirmk-setup
+++ b/build-aux/subdirmk-setup
@@ -8,38 +8,41 @@
 
 use strict;
 
-our @allsubdirs = @ARGV;
+our $root = [ '.', [ ] ];
+# each node is [ 'relative subdir name', \@children ]
+
+sub build_tree () {
+    foreach my $subdir (@ARGV) {
+	my @path = $subdir eq '.' ? () : split m{/+}, $subdir;
+	my $node = $root;
+	foreach my $d (@path) {
+	    my ($c,) = grep { $_->[0] eq $d } @{ $node->[1] };
+	    if (!$c) {
+		$c = [ $d, [ ] ];
+		push @{ $node->[1] }, $c;
+	    }
+	    $node = $c;
+	}
+    }
+}
+
+
 
 sub write_makefile ($$) {
-    my ($subdir,$depth)
+    my ($subdir,$depth) = @_;
     start_output_file("Makefile");
     my $cd = $depth ? join('/', ('..',) x $depth) : '.';
     print O <<END;
-# autogenerated - do not edit
 %:
-	\$(MAKE) -C $cd $subdir/\$@
+	$(MAKE) -C $cd $subdir/$@
 END
 }
 
-sub require_subdir ($) {
-    # => list of descendant subdirs
-    my ($here) = (@_);
-    my $prefix = $here eq '.' ? qr{} : qr{$prefix/};
-    my @children = grep { m{^$prefix[^/]+$} } @allsubdirs;
-    my @descendants;
-    foreach my $child (@children) {
-	push @descendants, require_subdir(
-
-	$subdir, grep { $_ =~ m{^$subdir/} } 
-    printf O "include $_/Subdir.mk"
-	
-
-
 sub process_subdir ($$) {
     my ($subdir) = @_;
     my $depth = $subdir eq '.' ? 0 : scalar split m{/+}, $subdir;
     write_makefile($subdir,$depth);
-    require_subdir($subdir);
+    filter_subdir_mk();
 }
 
-foreach (@allsubdirs) { process_subdir($_); }
+build_tree();
-- 
2.30.2