Omits size bits when writing RawObject tags to a snapshot.

runtime/vm/snapshot.cc

Index: runtime/vm/snapshot.cc
===================================================================
--- runtime/vm/snapshot.cc	(revision 37600)
+++ runtime/vm/snapshot.cc	(working copy)
@@ -302,7 +302,8 @@
   }
 
   // For all other internal VM classes we read the object inline.
-  intptr_t tags = ReadIntptrValue();
+  intptr_t tags = ReadTags();
+  tags = RawObject::ClassIdTag::update(class_id, tags);

[siva, 2014/06/23 21:45:53]

Is it necessary to or in the class_id here? I think all the uses of tags is in
set_tags which only uses the tag bits.

[zra, 2014/06/23 22:17:50]

The class id is taken from tags in TypedData::ReadFrom() and
ExternalTypedData::ReadFrom(). I've moved the or of the class id bits into the
cases, instead.

   switch (class_id) {
 #define SNAPSHOT_READ(clazz)                                                   \
     case clazz::kClassId: {                                                    \
@@ -812,7 +813,7 @@
 RawObject* SnapshotReader::ReadInlinedObject(intptr_t object_id) {
   // Read the class header information and lookup the class.
   intptr_t class_header = ReadIntptrValue();
-  intptr_t tags = ReadIntptrValue();
+  intptr_t tags = ReadTags();
   if (SerializedHeaderData::decode(class_header) == kInstanceObjectId) {
     // Object is regular dart instance.
     Instance* result = reinterpret_cast<Instance*>(GetBackRef(object_id));
@@ -880,6 +881,7 @@
   ASSERT((class_header & kSmiTagMask) != kSmiTag);
   cls_ = LookupInternalClass(class_header);
   ASSERT(!cls_.IsNull());
+  tags = RawObject::ClassIdTag::update(cls_.id(), tags);

[siva, 2014/06/23 21:45:53]

Ditto comment about oring in the class_id

[zra, 2014/06/23 22:17:50]

Same as above.

   switch (cls_.id()) {
 #define SNAPSHOT_READ(clazz)                                                   \
     case clazz::kClassId: {                                                    \
@@ -1388,7 +1390,7 @@
   // case.
   // Write out the class and tags information.
   WriteVMIsolateObject(kClassCid);
-  WriteIntptrValue(GetObjectTags(cls));
+  WriteTags(GetObjectTags(cls));
 
   // Write out the library url and class name.
   RawLibrary* library = cls->ptr()->library_;
@@ -1411,7 +1413,7 @@
 
   // Write out the class and tags information.
   WriteIndexedObject(array_kind);
-  WriteIntptrValue(tags);
+  WriteTags(tags);
 
   // Write out the length field.
   Write<RawObject*>(length);
@@ -1471,7 +1473,7 @@
   WriteIntptrValue(SerializedHeaderData::encode(kInstanceObjectId));
 
   // Write out the tags.
-  WriteIntptrValue(tags);
+  WriteTags(tags);
 
   // Write out the class information for this object.
   WriteObjectImpl(cls);