diff --git a/liberty/Liberty.hh b/liberty/Liberty.hh
index 3b62acc7..6f45bc82 100644
--- a/liberty/Liberty.hh
+++ b/liberty/Liberty.hh
@@ -114,7 +114,7 @@ class LibertyLibrary : public ConcreteLibrary
 public:
   LibertyLibrary(const char *name,
 		 const char *filename);
-  ~LibertyLibrary();
+  virtual ~LibertyLibrary();
   LibertyCell *findLibertyCell(const char *name) const;
   void findLibertyCellsMatching(PatternMatch *pattern,
 				LibertyCellSeq *cells);
@@ -383,7 +383,7 @@ public:
   LibertyCell(LibertyLibrary *library,
 	      const char *name,
 	      const char *filename);
-  ~LibertyCell();
+  virtual ~LibertyCell();
   LibertyLibrary *libertyLibrary() const { return liberty_library_; }
   LibertyLibrary *libertyLibrary() { return liberty_library_; }
   LibertyPort *findLibertyPort(const char *name) const;
@@ -589,7 +589,7 @@ class LibertyCellPortBitIterator : public Iterator<LibertyPort*>
 {
 public:
   explicit LibertyCellPortBitIterator(const LibertyCell *cell);
-  ~LibertyCellPortBitIterator();
+  virtual ~LibertyCellPortBitIterator();
   bool hasNext();
   LibertyPort *next();
 
@@ -750,7 +750,7 @@ protected:
 	      int to_index,
 	      bool is_bundle,
 	      ConcretePortSeq *members);
-  ~LibertyPort();
+  virtual ~LibertyPort();
   void setDirection(PortDirection *dir);
   void setMinPort(LibertyPort *min);
   void addScaledPort(OperatingConditions *op_cond,
@@ -800,7 +800,7 @@ class LibertyPortMemberIterator : public Iterator<LibertyPort*>
 {
 public:
   explicit LibertyPortMemberIterator(const LibertyPort *port);
-  ~LibertyPortMemberIterator();
+  virtual ~LibertyPortMemberIterator();
   virtual bool hasNext();
   virtual LibertyPort *next();
 
@@ -817,6 +817,7 @@ public:
   Pvt(float process,
       float voltage,
       float temperature);
+  virtual ~Pvt() {}
   float process() const { return process_; }
   void setProcess(float process);
   float voltage() const { return voltage_; }
@@ -842,7 +843,7 @@ public:
 		      float voltage,
 		      float temperature,
 		      WireloadTree wire_load_tree);
-  ~OperatingConditions();
+  virtual ~OperatingConditions();
   const char *name() const { return name_; }
   WireloadTree wireloadTree() const { return wire_load_tree_; }
   void setWireloadTree(WireloadTree tree);
diff --git a/network/ConcreteLibrary.hh b/network/ConcreteLibrary.hh
index 2d40c8d6..83941d0a 100644
--- a/network/ConcreteLibrary.hh
+++ b/network/ConcreteLibrary.hh
@@ -50,7 +50,7 @@ public:
   explicit ConcreteLibrary(const char *name,
 			   const char *filename,
 			   bool is_liberty);
-  ~ConcreteLibrary();
+  virtual ~ConcreteLibrary();
   const char *name() const { return name_; }
   void setName(const char *name);
   bool isLiberty() const { return is_liberty_; }
@@ -90,7 +90,7 @@ class ConcreteCell
 {
 public:
   // Use ConcreteLibrary::deleteCell.
-  ~ConcreteCell();
+  virtual ~ConcreteCell();
   ConcreteLibrary *library() const { return library_; }
   const char *name() const { return name_; }
   const char *filename() const { return filename_; }
@@ -164,7 +164,7 @@ private:
 class ConcretePort
 {
 public:
-  ~ConcretePort();
+  virtual ~ConcretePort();
   const char *name() const { return name_; }
   const char *busName() const;
   Cell *cell() const;
diff --git a/network/ConcreteNetwork.hh b/network/ConcreteNetwork.hh
index 5f7d49d5..a4c5266f 100644
--- a/network/ConcreteNetwork.hh
+++ b/network/ConcreteNetwork.hh
@@ -321,12 +321,11 @@ public:
   VertexIndex vertexIndex() const { return vertex_index_; }
   void setVertexIndex(VertexIndex index);
 
-private:
-  DISALLOW_COPY_AND_ASSIGN(ConcretePin);
+protected:
+  ~ConcretePin() {}
   ConcretePin(ConcreteInstance *instance,
 	      ConcretePort *port,
 	      ConcreteNet *net);
-  ~ConcretePin() {}
 
   ConcreteInstance *instance_;
   ConcretePort *port_;
@@ -337,6 +336,9 @@ private:
   ConcretePin *net_prev_;
   VertexIndex vertex_index_;
 
+private:
+  DISALLOW_COPY_AND_ASSIGN(ConcretePin);
+
   friend class ConcreteNetwork;
   friend class ConcreteNet;
   friend class ConcreteNetPinIterator;
@@ -349,17 +351,19 @@ public:
   ConcreteNet *net() const { return net_; }
   ConcretePin *pin() const { return pin_; }
 
-private:
-  DISALLOW_COPY_AND_ASSIGN(ConcreteTerm);
+protected:
+  ~ConcreteTerm() {}
   ConcreteTerm(ConcretePin *pin,
 	       ConcreteNet *net);
-  ~ConcreteTerm() {}
 
   ConcretePin *pin_;
   ConcreteNet *net_;
   // Linked list of net terms.
   ConcreteTerm *net_next_;
 
+private:
+  DISALLOW_COPY_AND_ASSIGN(ConcreteTerm);
+
   friend class ConcreteNetwork;
   friend class ConcreteNet;
   friend class ConcreteNetTermIterator;
@@ -382,8 +386,6 @@ protected:
   ConcreteNet(const char *name,
 	      ConcreteInstance *instance);
   ~ConcreteNet();
-
-private:
   const char *name_;
   ConcreteInstance *instance_;
   // Pointer to head of linked list of pins.
diff --git a/network/SdcNetwork.cc b/network/SdcNetwork.cc
index 85131e54..e4ffe597 100644
--- a/network/SdcNetwork.cc
+++ b/network/SdcNetwork.cc
@@ -14,6 +14,7 @@
 // You should have received a copy of the GNU General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
+#include <functional>
 #include "Machine.hh"
 #include "StringUtil.hh"
 #include "PatternMatch.hh"
diff --git a/search/ReportPath.cc b/search/ReportPath.cc
index 40562cec..862195d7 100644
--- a/search/ReportPath.cc
+++ b/search/ReportPath.cc
@@ -1017,6 +1017,7 @@ void
 ReportPath::reportSummaryHeader(string &result)
 {
   reportDescription("Startpoint", result);
+  result += ' ';
   reportDescription("Endpoint", result);
   result += ' ';
   reportField("Slack", field_total_, result);
@@ -1034,6 +1035,7 @@ ReportPath::reportSummaryLine(PathEnd *end,
   const EarlyLate *early_late = end->pathEarlyLate(this);
   auto startpoint = pathStartpoint(end, expanded);
   reportDescription(startpoint.c_str(), result);
+  result += ' ';
   auto endpoint = pathEndpoint(end);
   reportDescription(endpoint.c_str(), result);
   if (end->isUnconstrained())