Fix some multi-chip issues.

dbChip::destroy: the dbDatabase's stored main chip ID should not be
cleared when the chip being destroyed is not the main chip.

dbSta::postReadDef: reading a DEF for a chip that isn't the main chip
should not update which block STA considers the main block.

Signed-off-by: Sean Luchen <[email protected]>

Author: Logikable

src/dbSta/src/dbSta.cc

@@ -284,7 +284,8 @@ void dbSta::postReadLef(dbTech* tech, dbLib* library)
 
 void dbSta::postReadDef(dbBlock* block)
 {
-  if (!block->getParent()) {
+  // If this is the top block of the main chip:
+  if (!block->getParent() && block->getChip() == block->getDb()->getChip()) {
     db_network_->readDefAfter(block);
     db_cbk_->addOwner(block);
     db_cbk_->setNetwork(db_network_);

src/odb/src/db/dbChip.cpp

@@ -662,8 +662,7 @@ void dbChip::destroy(dbChip* chip_)
   dbProperty::destroyProperties(chip);
   db->chip_hash_.remove(chip);
   db->chip_tbl_->destroy(chip);
-  db->_chip = 0;
 }
 // User Code End dbChipPublicMethods
 }  // namespace odb
-// Generator Code End Cpp
+// Generator Code End Cpp