liberty valgrind issues

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

liberty/FuncExpr.cc

@@ -254,9 +254,13 @@ FuncExpr::bitSubExpr(int bit_offset)
 	return makePort(port);
       }
       else {
+        if (bit_offset < port_->size()) {
           LibertyPort *port = port_->findLibertyMember(bit_offset);
           return makePort(port);
         }
+        else
+          return nullptr;
+      }
     }
     else
       // Always copy so the subexpr doesn't share memory.

liberty/Liberty.cc

@@ -130,15 +130,13 @@ LibertyLibrary::~LibertyLibrary()
   wireloads_.deleteContents();
   wire_load_selections_.deleteContents();
   delete units_;
+  // Also deletes default_ocv_derate_
   ocv_derate_map_.deleteContents();
 
   delete buffers_;
   delete inverters_;
   driver_waveform_map_.deleteContents();
   delete driver_waveform_default_;
-
-  delete default_ocv_derate_;
-  default_ocv_derate_ = nullptr;
 }
 
 LibertyCell *

liberty/LibertyReader.cc

@@ -4909,7 +4909,7 @@ LibertyReader::visitWhen(LibertyAttr *attr)
                       false, "when", attr);
     }
   }
-  if (timing_) {
+  if (timing_ && !in_ccsn_) {
     const char *func = getAttrString(attr);
     if (func) {
       TimingArcAttrs *attrs = timing_->attrs().get();