Makefile: add moduledeps target.

make moduledeps ROOTNODE=T.P.Parsing

Makefile

@@ -180,6 +180,11 @@ modules.dot: $(SOURCEFILES)
 modules.pdf: modules.dot
 	gvpr -f tools/cliptree.gvpr -a '"$(ROOTNODE)"' $< | dot -Tpdf > $@
 
+# make moduledeps ROOTNODE=T.P.Parsing
+moduledeps: modules.dot  ## Print dependencies of a module ROOTNODE
+	gvpr -f tools/depthfirst.gvpr -a '"$(ROOTNODE)"' modules.dot
+.PHONY: moduledeps
+
 clean: ## clean up
 	cabal clean
 .PHONY: clean

tools/depthfirst.gvpr

@@ -0,0 +1,18 @@
+BEGIN {
+  int i, indent;
+  int seen[string];
+  void prInd (int cnt) {
+  for (i = 0; i < cnt; i++) printf (" "); }
+}
+BEG_G {
+  $tvtype = TV_prepostfwd; $tvroot = node($,ARGV[0]);
+} N{
+  if (seen[$.name]) {
+    indent--;
+    if (indent == 0) exit(0);
+  } else {
+    prInd(indent); print ($.name);
+    seen[$.name] = 1;
+    indent++;
+  }
+}