This fixes regressions at levels >= 1 which were failing

* implement zombification and garbage collection of NodeValues
  (but GC not turned on yet)

* implement removal of key nodes from all attribute tables

* audit NodeBuilder and fix memory leaks and improper reference-count
  management.  This is in many places a re-write.  Clearly documented
  invariants on NodeBuilder state.  (Closes Bug 38)

* created a "BackedNodeBuilder" that can be used to construct
  NodeBuilders with a stack-based backing store for a size that's not
  a compile-time constant.

* NodeValues no longer depend on Node for toStream()'ing

* make unit test-building "silent" with --enable-silent-rules

* (Makefile.am, Makefile.builds.in) fix top-level build system so that
  "make regressN" works with unbuilt/out-of-date source trees in the
  expected way.

* (various) code cleanup, documentation, formatting

1 files changed, 5 insertions, 3 deletions

diff --git a/src/expr/node_value.cpp b/src/expr/node_value.cpp
index 5c5765011..5dbfac169 100644
--- a/src/expr/node_value.cpp
+++ b/src/expr/node_value.cpp
@@ -38,9 +38,11 @@ string NodeValue::toString() const {
 
 void NodeValue::toStream(std::ostream& out) const {
   if(d_kind == kind::VARIABLE) {
-    Node n(this);
     string s;
-    if(n.hasAttribute(VarNameAttr(), s)) {
+    // conceptually "this" is const, and hasAttribute() doesn't change
+    // its argument, but it requires a non-const key arg (for now)
+    if(NodeManager::currentNM()->hasAttribute(const_cast<NodeValue*>(this),
+                                              VarNameAttr(), s)) {
       out << s;
     } else {
       out << "var_" << d_id;
@@ -51,7 +53,7 @@ void NodeValue::toStream(std::ostream& out) const {
       if(i != nv_end()) {
         out << " ";
       }
-      Node(*i).toStream(out);
+      (*i)->toStream(out);
     }
     out << ")";
   }