Write the type arguments instantiations field to full snapshots only.

runtime/vm/raw_object_snapshot.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/bigint_operations.h"
 #include "vm/object.h"
 #include "vm/object_store.h"
 #include "vm/snapshot.h"
 #include "vm/symbols.h"
 #include "vm/visitor.h"
@@ skipping 430 matching lines @@
                                           Snapshot::Kind kind) {
   ASSERT(reader != NULL);
 
   // Read the length so that we can determine instance size to allocate.
   intptr_t len = reader->ReadSmiValue();
 
   TypeArguments& type_arguments = TypeArguments::ZoneHandle(
       reader->isolate(), NEW_OBJECT_WITH_LEN_SPACE(TypeArguments, len, kind));
   reader->AddBackRef(object_id, &type_arguments, kIsDeserialized);
 
-  // Now set all the object fields.
-  *reader->ArrayHandle() ^= reader->ReadObjectImpl();
-  type_arguments.set_instantiations(*reader->ArrayHandle());
+  // Set the instantiations field, which is only read from a full snapshot.
+  if (kind == Snapshot::kFull) {
+    *reader->ArrayHandle() ^= reader->ReadObjectImpl();
+    type_arguments.set_instantiations(*reader->ArrayHandle());
+  } else {
+    // TODO(regis): Change to Object::zero_array() once supported.
+    type_arguments.set_instantiations(Object::empty_array());
+  }
+
+  // Now set all the type fields.
   for (intptr_t i = 0; i < len; i++) {
     *reader->TypeHandle() ^= reader->ReadObjectImpl();
     type_arguments.set_type_at(i, *reader->TypeHandle());
   }
 
   // If object needs to be a canonical object, Canonicalize it.
   // When reading a full snapshot we don't need to canonicalize the object
   // as it would already be a canonical object.
   // When reading a script snapshot we need to canonicalize only those object
   // references that are objects from the core library (loaded from a
@@ skipping 24 matching lines @@
   // Write out the serialization header value for this object.
   writer->WriteInlinedObjectHeader(object_id);
 
   // Write out the class and tags information.
   writer->WriteVMIsolateObject(kTypeArgumentsCid);
   writer->WriteIntptrValue(writer->GetObjectTags(this));
 
   // Write out the length field.
   writer->Write<RawObject*>(ptr()->length_);
 
-  // Write out the instantiations field.
-  writer->WriteObjectImpl(ptr()->instantiations_);
+  // Write out the instantiations field, but only in a full snapshot.
+  if (kind == Snapshot::kFull) {
+    writer->WriteObjectImpl(ptr()->instantiations_);
+  }
 
   // Write out the individual types.
   intptr_t len = Smi::Value(ptr()->length_);
   for (intptr_t i = 0; i < len; i++) {
     writer->WriteObjectImpl(ptr()->types_[i]);
   }
 }
 
 
 RawPatchClass* PatchClass::ReadFrom(SnapshotReader* reader,
@@ skipping 2157 matching lines @@
     // We do not allow objects with native fields in an isolate message.
     writer->SetWriteException(Exceptions::kArgument,
                               "Illegal argument in isolate message"
                               " : (object is a MirrorReference)");
   } else {
     UNREACHABLE();
   }
 }
 
 }  // namespace dart