Sta::netorkChangedNonSdc resolves #372

Signed-off-by: James Cherry <cherry@parallaxsw.com>

include/sta/Sta.hh

@@ -866,7 +866,9 @@ public:
   // User visible but non SDC commands.
 
   // Clear all state except network, scenes and liberty libraries.
-  virtual void clear();
+  void clear();
+  // Clear all state except network, scenes liberty libraries, and sdc.
+  void clearNonSdc();
   // Namespace used by command interpreter.
   CmdNamespace cmdNamespace();
   void setCmdNamespace(CmdNamespace namespc);
@@ -1261,6 +1263,8 @@ public:
   // editing API. For example, reading a netlist without using the
   // builtin network readers.
   void networkChanged();
+  // Network changed but all SDC references to instance/net/pin/port are preserved.
+  void networkChangedNonSdc();
   void deleteLeafInstanceBefore(const Instance *inst);
   void deleteInstancePinsBefore(const Instance *inst);
 

network/NetworkEdit.i

@@ -104,4 +104,11 @@ network_changed()
   Sta::sta()->networkChanged();
 }
 
+// Notify STA of network change without touching SDC network references.
+void
+network_changed_non_sdc()
+{
+  Sta::sta()->networkChangedNonSdc();
+}
+
 %} // inline

search/Sta.cc

@@ -534,6 +534,14 @@ Sta::~Sta()
 
 void
 Sta::clear()
+{
+  clearNonSdc();
+  for (Mode *mode : modes_)
+    mode->sdc()->clear();
+}
+
+void
+Sta::clearNonSdc()
 {
   // Sdc holds search filter, so clear search first.
   search_->clear();
@@ -548,10 +556,8 @@ Sta::clear()
   clk_skews_->clear();
 
   // scenes are NOT cleared because they are used to index liberty files.
-  for (Mode *mode : modes_) {
+  for (Mode *mode : modes_)
-    mode->sdc()->clear();
     mode->clkNetwork()->clkPinsInvalid();
-  }
 
   delete graph_;
   graph_ = nullptr;
@@ -616,6 +622,12 @@ Sta::networkChanged()
   clear();
 }
 
+void
+Sta::networkChangedNonSdc()
+{
+  clearNonSdc();
+}
+
 void
 Sta::setTclInterp(Tcl_Interp *interp)
 {