odb, rsz: Fixed incorrect BTerm iteration in mergeNet(). Changed a wrong code sequence in removeBuffer().

- Fixes #8093

Signed-off-by: Jaehyun Kim <[email protected]>

Author: jhkim-pii

src/odb/src/db/dbNet.cpp

@@ -2234,6 +2234,9 @@ void dbNet::mergeNet(dbNet* in_net)
   _dbNet* net = (_dbNet*) this;
   _dbBlock* block = (_dbBlock*) net->getOwner();
 
+  // in_net->getITerms() returns a terminal iterator, andibterm->connect() can
+  // invalidate the iterator by disconnecting a dbITerm. So storing all dbITerms
+  // is needed for safe dbITerms iteration.
   std::vector<dbITerm*> iterms;
   for (dbITerm* iterm : in_net->getITerms()) {
     iterms.push_back(iterm);
@@ -2247,7 +2250,15 @@ void dbNet::mergeNet(dbNet* in_net)
     iterm->connect(this);
   }
 
+  // in_net->getBTerms() returns an BTerm iterator, and bterm->connect() can
+  // invalidate the iterator by disconnecting a dbBTerm. So storing all BTerms
+  // is needed for safe BTerms iteration.
+  std::vector<dbBTerm*> bterms;
   for (dbBTerm* bterm : in_net->getBTerms()) {
+    bterms.push_back(bterm);
+  }
+
+  for (dbBTerm* bterm : bterms) {
     bterm->connect(this);
   }
 }

src/rsz/src/UnbufferMove.cc

@@ -405,7 +405,7 @@ void UnbufferMove::removeBuffer(Instance* buffer)
     }
   }
 
-  // Remove buffer from the database and handle the nets
+  // Disconnect the buffer and handle the nets
   debugPrint(logger_,
              RSZ,
              "remove_buffer",
@@ -423,10 +423,6 @@ void UnbufferMove::removeBuffer(Instance* buffer)
   }
   sta_->disconnectPin(in_pin);
   sta_->disconnectPin(out_pin);
-  sta_->deleteInstance(buffer);
-  if (removed) {
-    sta_->deleteNet(removed);
-  }
 
   // Hierarchical case supported:
   // moving an output hierarchical net to the input pin driver.
@@ -447,6 +443,12 @@ void UnbufferMove::removeBuffer(Instance* buffer)
     db_network_->connectPin(driver_pin, db_network_->dbToSta(op_modnet));
   }
 
+  // Deletion
+  sta_->deleteInstance(buffer);
+  if (removed) {
+    sta_->deleteNet(removed);
+  }
+
   estimate_parasitics_->removeNetFromParasiticsInvalid(removed);
   estimate_parasitics_->parasiticsInvalid(survivor);
   estimate_parasitics_->updateParasitics();