Fix for issue 23647 (https://github.com/dart-lang/sdk/issues/23647)

runtime/vm/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/snapshot.h"
 
 #include "platform/assert.h"
 #include "vm/bootstrap.h"
 #include "vm/class_finalizer.h"
 #include "vm/dart.h"
@@ skipping 1264 matching lines @@
       can_send_any_object_(can_send_any_object) {
   ASSERT(forward_list_ != NULL);
 }
 
 
 void SnapshotWriter::WriteObject(RawObject* rawobj) {
   WriteObjectImpl(rawobj);
   WriteForwardedObjects();
 }
 
+#define VM_OBJECT_CLASS_LIST(V)                                                \
+  V(OneByteString)                                                             \
+  V(Mint)                                                                      \
+  V(Bigint)                                                                    \
+  V(Double)                                                                    \
+
+#define VM_OBJECT_WRITE(clazz)                                                 \
+  case clazz::kClassId: {                                                      \
+    object_id = forward_list_->AddObject(rawobj, kIsSerialized);               \
+    Raw##clazz* raw_obj = reinterpret_cast<Raw##clazz*>(rawobj);               \
+    raw_obj->WriteTo(this, object_id, kind());                                 \
+    return;                                                                    \
+  }                                                                            \
 
 void SnapshotWriter::HandleVMIsolateObject(RawObject* rawobj) {
   // Check if it is a singleton null object.
   if (rawobj == Object::null()) {
     WriteVMIsolateObject(kNullObject);
     return;
   }
 
   // Check if it is a singleton sentinel object.
   if (rawobj == Object::sentinel().raw()) {
@@ skipping 43 matching lines @@
   if (id == kClassCid) {
     RawClass* raw_class = reinterpret_cast<RawClass*>(rawobj);
     intptr_t class_id = raw_class->ptr()->id_;
     if (IsSingletonClassId(class_id)) {
       intptr_t object_id = ObjectIdFromClassId(class_id);
       WriteVMIsolateObject(object_id);
       return;
     }
   }
 
-  // Check it is a predefined symbol in the VM isolate.
-  id = Symbols::LookupVMSymbol(rawobj);
-  if (id != kInvalidIndex) {
-    WriteVMIsolateObject(id);
-    return;
-  }
+  if (kind() == Snapshot::kFull) {
+    // Check it is a predefined symbol in the VM isolate.
+    id = Symbols::LookupVMSymbol(rawobj);
+    if (id != kInvalidIndex) {
+      WriteVMIsolateObject(id);
+      return;
+    }
 
-  // Check if it is an object from the vm isolate snapshot object table.
-  id = FindVmSnapshotObject(rawobj);
-  if (id != kInvalidIndex) {
-    WriteIndexedObject(id);
-    return;
+    // Check if it is an object from the vm isolate snapshot object table.
+    id = FindVmSnapshotObject(rawobj);
+    if (id != kInvalidIndex) {
+      WriteIndexedObject(id);
+      return;
+    }
+  } else {
+    // In the case of script snapshots or for messages we do not use
+    // the index into the vm isolate snapshot object table, instead we
+    // explicitly write the object out.
+    intptr_t object_id = forward_list_->FindObject(rawobj);
+    if (object_id != -1) {

[rmacnak, 2015/06/18 20:34:55]

kInvalidIndex

+      WriteIndexedObject(object_id);
+      return;
+    } else {
+      switch (id) {
+        VM_OBJECT_CLASS_LIST(VM_OBJECT_WRITE)
+        case kTypedDataUint32ArrayCid: {
+          object_id = forward_list_->AddObject(rawobj, kIsSerialized);
+          RawTypedData* raw_obj = reinterpret_cast<RawTypedData*>(rawobj);
+          raw_obj->WriteTo(this, object_id, kind());
+          return;
+        }
+        default:
+          OS::Print("class id = %d\n", id);
+          break;
+      }
+    }
   }
   UNREACHABLE();
 }
 
+#undef VM_OBJECT_WRITE
+
 
 void SnapshotWriter::WriteObjectRef(RawObject* raw) {
   // First check if object can be written as a simple predefined type.
   if (CheckAndWritePredefinedObject(raw)) {
     return;
   }
 
   NoSafepointScope no_safepoint;
   RawClass* cls = class_table_->At(raw->GetClassId());
   intptr_t class_id = cls->ptr()->id_;
@@ skipping 314 matching lines @@
   uword tags = raw->ptr()->tags_;
   ASSERT(SerializedHeaderTag::decode(tags) != kObjectId);
   raw->ptr()->tags_ = value;
   Node* node = new Node(raw, tags, state);
   ASSERT(node != NULL);
   nodes_.Add(node);
   return object_id;
 }
 
 
+intptr_t ForwardList::AddObject(RawObject* raw, SerializeState state) {
+  NoSafepointScope no_safepoint;
+  intptr_t object_id = next_object_id();
+  ASSERT(object_id > 0 && object_id <= kMaxObjectId);
+  uword tags = raw->ptr()->tags_;
+  // OS::Print("tags = 0x%x\n", tags);

[rmacnak, 2015/06/18 20:34:55]

slip

+  ASSERT(SerializedHeaderTag::decode(tags) != kObjectId);
+  Node* node = new Node(raw, tags, state);
+  ASSERT(node != NULL);
+  nodes_.Add(node);
+  return object_id;
+}
+
+
+intptr_t ForwardList::FindObject(RawObject* raw) {
+  NoSafepointScope no_safepoint;
+  intptr_t id;
+  for (id = first_object_id(); id < next_object_id(); ++id) {
+    const Node* node = NodeForObjectId(id);
+    if (raw == node->raw()) {
+      return id;
+    }
+  }
+  return kInvalidIndex;
+}
+
+
 void ForwardList::UnmarkAll() const {
   for (intptr_t id = first_object_id(); id < next_object_id(); ++id) {
     const Node* node = NodeForObjectId(id);
     RawObject* raw = node->raw();
-    raw->ptr()->tags_ = node->tags();  // Restore original tags.
+    if (SerializedHeaderTag::decode(raw->ptr()->tags_) == kObjectId) {
+      raw->ptr()->tags_ = node->tags();  // Restore original tags.
+    }
   }
   Isolate::Current()->DecrementNoSafepointScopeDepth();
 }
 
 
 bool SnapshotWriter::CheckAndWritePredefinedObject(RawObject* rawobj) {
   // Check if object can be written in one of the following ways:
   // - Smi: the Smi value is written as is (last bit is not tagged).
   // - VM internal class (from VM isolate): (index of class in vm isolate | 0x3)
   // - Object that has already been written: (negative id in stream | 0x3)
@@ skipping 561 matching lines @@
     NoSafepointScope no_safepoint;
     WriteObject(obj.raw());
     UnmarkAll();
   } else {
     ThrowException(exception_type(), exception_msg());
   }
 }
 
 
 }  // namespace dart