diff --git a/include/sta/ExceptionPath.hh b/include/sta/ExceptionPath.hh
index 75d7f287..4ea98699 100644
--- a/include/sta/ExceptionPath.hh
+++ b/include/sta/ExceptionPath.hh
@@ -322,8 +322,7 @@ public:
   virtual void mergeInto(ExceptionPt *pt,
                          const Network *network) = 0;
   // All pins and instance/net pins.
-  virtual void allPins(const Network *network,
-		       PinSet *pins) = 0;
+  virtual PinSet allPins(const Network *network) = 0;
   virtual int typePriority() const = 0;
   virtual const char *asString(const Network *network) const = 0;
   virtual size_t objectCount() const = 0;
@@ -378,8 +377,7 @@ public:
   bool hasObjects() const;
   void deleteObjects(ExceptionFromTo *pt,
                      const Network *network);
-  virtual void allPins(const Network *network,
-		       PinSet *pins);
+  virtual PinSet allPins(const Network *network);
   bool equal(ExceptionFromTo *from_to) const;
   virtual int compare(ExceptionPt *pt,
 		      const Network *network) const;
@@ -505,8 +503,7 @@ public:
   bool hasObjects() const;
   void deleteObjects(ExceptionThru *pt,
                      const Network *network);
-  virtual void allPins(const Network *network,
-		       PinSet *pins);
+  virtual PinSet allPins(const Network *network);
   bool matches(const Pin *from_pin,
 	       const Pin *to_pin,
 	       const RiseFall *to_rf,
diff --git a/sdc/ExceptionPath.cc b/sdc/ExceptionPath.cc
index ed885a69..9cf06ec9 100644
--- a/sdc/ExceptionPath.cc
+++ b/sdc/ExceptionPath.cc
@@ -1,3 +1,4 @@
+
 // OpenSTA, Static Timing Analyzer
 // Copyright (c) 2023, Parallax Software, Inc.
 // 
@@ -933,24 +934,25 @@ ExceptionFromTo::hasObjects() const
   return hasPins() || hasClocks() || hasInstances();
 }
 
-void
-ExceptionFromTo::allPins(const Network *network,
-			 PinSet *pins)
+PinSet
+ExceptionFromTo::allPins(const Network *network)
 {
+  PinSet pins(network);
   if (pins_) {
     for (const Pin *pin : *pins_)
-      pins->insert(pin);
+      pins.insert(pin);
   }
   if (insts_) {
     for (const Instance *inst : *insts_) {
       InstancePinIterator *pin_iter = network->pinIterator(inst);
       while (pin_iter->hasNext()) {
 	const Pin *pin = pin_iter->next();
-	pins->insert(pin);
+	pins.insert(pin);
       }
       delete pin_iter;
     }
   }
+  return pins;
 }
 
 void
@@ -1777,20 +1779,20 @@ ExceptionThru::deleteEdge(const EdgePins &edge)
     edges_->erase(edge);
 }
 
-void
-ExceptionThru::allPins(const Network *network,
-		       PinSet *pins)
+PinSet
+ExceptionThru::allPins(const Network *network)
 {
+  PinSet pins(network);
   if (pins_) {
     for (const Pin *pin : *pins_)
-      pins->insert(pin);
+      pins.insert(pin);
   }
   if (insts_) {
     for (const Instance *inst : *insts_) {
       InstancePinIterator *pin_iter = network->pinIterator(inst);
       while (pin_iter->hasNext()) {
 	Pin *pin = pin_iter->next();
-	pins->insert(pin);
+	pins.insert(pin);
       }
       delete pin_iter;
     }
@@ -1800,11 +1802,12 @@ ExceptionThru::allPins(const Network *network,
       NetConnectedPinIterator *pin_iter = network->connectedPinIterator(net);
       while (pin_iter->hasNext()) {
 	const Pin *pin = pin_iter->next();
-	pins->insert(pin);
+	pins.insert(pin);
       }
       delete pin_iter;
     }
   }
+  return pins;
 }
 
 bool
diff --git a/search/PathGroup.cc b/search/PathGroup.cc
index 9f88baa6..d7b75041 100644
--- a/search/PathGroup.cc
+++ b/search/PathGroup.cc
@@ -800,8 +800,7 @@ PathGroups::makeGroupPathEnds(ExceptionTo *to,
   else {
     // Only visit -to filter pins.
     VertexSet endpoints(graph_);
-    PinSet pins(network);
-    to->allPins(network, &pins);
+    PinSet pins = to->allPins(network);
     PinSet::Iterator pin_iter(pins);
     while (pin_iter.hasNext()) {
       const Pin *pin = pin_iter.next();
diff --git a/search/Search.cc b/search/Search.cc
index b8307a94..27135bb9 100644
--- a/search/Search.cc
+++ b/search/Search.cc
@@ -651,8 +651,7 @@ Search::seedFilterStarts()
 {
   ExceptionPt *first_pt = filter_->firstPt();
   if (first_pt) {
-    PinSet first_pins(network_);
-    first_pt->allPins(network_, &first_pins);
+    PinSet first_pins = first_pt->allPins(network_);
     for (const Pin *pin : first_pins) {
       if (network_->isHierarchical(pin)) {
         SeedFaninsThruHierPin visitor(graph_, this);
diff --git a/tcl/StaTcl.i b/tcl/StaTcl.i
index d427f067..1415b96a 100644
--- a/tcl/StaTcl.i
+++ b/tcl/StaTcl.i
@@ -2495,21 +2495,23 @@ filter_ports(const char *property,
 	     const char *pattern,
 	     PortSeq *ports)
 {
-  Sta *sta = Sta::sta();
   PortSeq filtered_ports;
-  bool exact_match = stringEq(op, "==");
-  bool pattern_match = stringEq(op, "=~");
-  bool not_match = stringEq(op, "!=");
-  for (const Port *port : *ports) {
-    PropertyValue value(getProperty(port, property, sta));
-    const char *prop = value.stringValue();
-    if (prop &&
-	((exact_match && stringEq(prop, pattern))
-         || (not_match && !stringEq(prop, pattern))
-	 || (pattern_match && patternMatch(pattern, prop))))
-      filtered_ports.push_back(port);
+  if (ports) {
+    Sta *sta = Sta::sta();
+    bool exact_match = stringEq(op, "==");
+    bool pattern_match = stringEq(op, "=~");
+    bool not_match = stringEq(op, "!=");
+    for (const Port *port : *ports) {
+      PropertyValue value(getProperty(port, property, sta));
+      const char *prop = value.stringValue();
+      if (prop &&
+          ((exact_match && stringEq(prop, pattern))
+           || (not_match && !stringEq(prop, pattern))
+           || (pattern_match && patternMatch(pattern, prop))))
+        filtered_ports.push_back(port);
+    }
+    delete ports;
   }
-  delete ports;
   return filtered_ports;
 }
 
@@ -2519,22 +2521,24 @@ filter_insts(const char *property,
 	     const char *pattern,
 	     InstanceSeq *insts)
 {
-  Sta *sta = Sta::sta();
-  cmdLinkedNetwork();
-  bool exact_match = stringEq(op, "==");
-  bool pattern_match = stringEq(op, "=~");
-  bool not_match = stringEq(op, "!=");
   InstanceSeq filtered_insts;
-  for (const Instance *inst : *insts) {
-    PropertyValue value(getProperty(inst, property, sta));
-    const char *prop = value.stringValue();
-    if (prop &&
-	((exact_match && stringEq(prop, pattern))
-         || (not_match && !stringEq(prop, pattern))
-	 || (pattern_match && patternMatch(pattern, prop))))
-      filtered_insts.push_back(inst);
+  if (insts) {
+    Sta *sta = Sta::sta();
+    cmdLinkedNetwork();
+    bool exact_match = stringEq(op, "==");
+    bool pattern_match = stringEq(op, "=~");
+    bool not_match = stringEq(op, "!=");
+    for (const Instance *inst : *insts) {
+      PropertyValue value(getProperty(inst, property, sta));
+      const char *prop = value.stringValue();
+      if (prop &&
+          ((exact_match && stringEq(prop, pattern))
+           || (not_match && !stringEq(prop, pattern))
+           || (pattern_match && patternMatch(pattern, prop))))
+        filtered_insts.push_back(inst);
+    }
+    delete insts;
   }
-  delete insts;
   return filtered_insts;
 }
 
@@ -2544,21 +2548,23 @@ filter_pins(const char *property,
 	    const char *pattern,
 	    PinSeq *pins)
 {
-  Sta *sta = Sta::sta();
   PinSeq filtered_pins;
-  bool exact_match = stringEq(op, "==");
-  bool pattern_match = stringEq(op, "=~");
-  bool not_match = stringEq(op, "!=");
-  for (const Pin *pin : *pins) {
-    PropertyValue value(getProperty(pin, property, sta));
-    const char *prop = value.stringValue();
-    if (prop &&
-	((exact_match && stringEq(prop, pattern))
-         || (not_match && !stringEq(prop, pattern))
-	 || (pattern_match && patternMatch(pattern, prop))))
-      filtered_pins.push_back(pin);
+  if (pins) {
+    Sta *sta = Sta::sta();
+    bool exact_match = stringEq(op, "==");
+    bool pattern_match = stringEq(op, "=~");
+    bool not_match = stringEq(op, "!=");
+    for (const Pin *pin : *pins) {
+      PropertyValue value(getProperty(pin, property, sta));
+      const char *prop = value.stringValue();
+      if (prop &&
+          ((exact_match && stringEq(prop, pattern))
+           || (not_match && !stringEq(prop, pattern))
+           || (pattern_match && patternMatch(pattern, prop))))
+        filtered_pins.push_back(pin);
+    }
+    delete pins;
   }
-  delete pins;
   return filtered_pins;
 }