Toward precompiled snapshots.

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/object.h"
 #include "vm/object_store.h"
 #include "vm/snapshot.h"
 #include "vm/stub_code.h"
 #include "vm/symbols.h"
 #include "vm/visitor.h"
 
 namespace dart {
 
 DECLARE_FLAG(int, optimization_counter_threshold);
 
 #define NEW_OBJECT(type)                                                       \
   ((kind == Snapshot::kFull) ? reader->New##type() : type::New())
 
 #define NEW_OBJECT_WITH_LEN(type, len)                                         \
   ((kind == Snapshot::kFull) ? reader->New##type(len) : type::New(len))
 
 #define NEW_OBJECT_WITH_LEN_SPACE(type, len, kind)                             \
   ((kind == Snapshot::kFull) ?                                                 \
   reader->New##type(len) : type::New(len, HEAP_SPACE(kind)))
 
 #define OFFSET_OF_FROM(obj)                                                    \
   obj.raw()->from() - reinterpret_cast<RawObject**>(obj.raw()->ptr())
 
+// TODO(18854): Need to assert No GC can happen here, even though
+// allocations may happen.
+#define READ_OBJECT_FIELDS(object, from, to, as_reference)                     \
+  intptr_t num_flds = (to) - (from);                                           \
+  intptr_t from_offset = OFFSET_OF_FROM(object);                               \
+  for (intptr_t i = 0; i <= num_flds; i++) {                                   \
+    (*reader->PassiveObjectHandle()) =                                         \
+        reader->ReadObjectImpl(as_reference, object_id, (i + from_offset));    \
+    object.StorePointer(((from) + i),                                          \
+                        reader->PassiveObjectHandle()->raw());                 \
+  }
+
 RawClass* Class::ReadFrom(SnapshotReader* reader,
                           intptr_t object_id,
                           intptr_t tags,
                           Snapshot::Kind kind) {
   ASSERT(reader != NULL);
 
   Class& cls = Class::ZoneHandle(reader->zone(), Class::null());
   bool is_in_fullsnapshot = reader->Read<bool>();
   if ((kind == Snapshot::kFull) ||
       (kind == Snapshot::kScript && !is_in_fullsnapshot)) {
@@ skipping 20 matching lines @@
       cls.set_next_field_offset_in_words(reader->Read<int32_t>());
     }
     cls.set_type_arguments_field_offset_in_words(reader->Read<int32_t>());
     cls.set_num_type_arguments(reader->Read<int16_t>());
     cls.set_num_own_type_arguments(reader->Read<int16_t>());
     cls.set_num_native_fields(reader->Read<uint16_t>());
     cls.set_token_pos(reader->Read<int32_t>());
     cls.set_state_bits(reader->Read<uint16_t>());
 
     // Set all the object fields.
-    // TODO(5411462): Need to assert No GC can happen here, even though
-    // allocations may happen.
-    intptr_t num_flds = (cls.raw()->to() - cls.raw()->from());
-    intptr_t from_offset = OFFSET_OF_FROM(cls);
-    for (intptr_t i = 0; i <= num_flds; i++) {
-      (*reader->PassiveObjectHandle()) =
-          reader->ReadObjectImpl(kAsReference, object_id, (i + from_offset));
-      cls.StorePointer((cls.raw()->from() + i),
-                       reader->PassiveObjectHandle()->raw());
-    }
+    READ_OBJECT_FIELDS(cls, cls.raw()->from(), cls.raw()->to(), kAsReference);
+
     ASSERT(!cls.IsInFullSnapshot() || (kind == Snapshot::kFull));
   } else {
     cls ^= reader->ReadClassId(object_id);
     ASSERT((kind == Snapshot::kMessage) || cls.IsInFullSnapshot());
   }
   return cls.raw();
 }
 
 
 void RawClass::WriteTo(SnapshotWriter* writer,
@@ skipping 59 matching lines @@
 
   // Allocate unresolved class object.
   UnresolvedClass& unresolved_class = UnresolvedClass::ZoneHandle(
       reader->zone(), NEW_OBJECT(UnresolvedClass));
   reader->AddBackRef(object_id, &unresolved_class, kIsDeserialized);
 
   // Set all non object fields.
   unresolved_class.set_token_pos(reader->Read<int32_t>());
 
   // Set all the object fields.
-  // TODO(5411462): Need to assert No GC can happen here, even though
-  // allocations may happen.
-  intptr_t num_flds = (unresolved_class.raw()->to() -
-                       unresolved_class.raw()->from());
-  for (intptr_t i = 0; i <= num_flds; i++) {
-    (*reader->PassiveObjectHandle()) = reader->ReadObjectImpl(kAsReference);
-    unresolved_class.StorePointer((unresolved_class.raw()->from() + i),
-                                  reader->PassiveObjectHandle()->raw());
-  }
+  READ_OBJECT_FIELDS(unresolved_class,
+                     unresolved_class.raw()->from(),
+                     unresolved_class.raw()->to(),
+                     kAsReference);
+
   return unresolved_class.raw();
 }
 
 
 void RawUnresolvedClass::WriteTo(SnapshotWriter* writer,
                                  intptr_t object_id,
                                  Snapshot::Kind kind) {
   ASSERT(writer != NULL);
 
   // Write out the serialization header value for this object.
@@ skipping 42 matching lines @@
   bool is_canonical = RawObject::IsCanonical(tags);
   bool defer_canonicalization = is_canonical &&
       (kind != Snapshot::kFull && typeclass_is_in_fullsnapshot);
   reader->AddBackRef(object_id, &type, kIsDeserialized, defer_canonicalization);
 
   // Set all non object fields.
   type.set_token_pos(reader->Read<int32_t>());
   type.set_type_state(reader->Read<int8_t>());
 
   // Set all the object fields.
-  // TODO(5411462): Need to assert No GC can happen here, even though
-  // allocations may happen.
-  intptr_t num_flds = (type.raw()->to() - type.raw()->from());
-  intptr_t from_offset = OFFSET_OF_FROM(type);
-  for (intptr_t i = 0; i <= num_flds; i++) {
-    (*reader->PassiveObjectHandle()) =
-        reader->ReadObjectImpl(kAsReference, object_id, (i + from_offset));
-    type.StorePointer((type.raw()->from() + i),
-                      reader->PassiveObjectHandle()->raw());
-  }
+  READ_OBJECT_FIELDS(type, type.raw()->from(), type.raw()->to(), kAsReference);
 
   // Set the canonical bit.
   if (!defer_canonicalization && RawObject::IsCanonical(tags)) {
     type.SetCanonical();
   }
 
   return type.raw();
 }
 
 
@@ skipping 40 matching lines @@
                               intptr_t tags,
                               Snapshot::Kind kind) {
   ASSERT(reader != NULL);
 
   // Allocate type ref object.
   TypeRef& type_ref = TypeRef::ZoneHandle(
       reader->zone(), NEW_OBJECT(TypeRef));
   reader->AddBackRef(object_id, &type_ref, kIsDeserialized);
 
   // Set all the object fields.
-  // TODO(5411462): Need to assert No GC can happen here, even though
-  // allocations may happen.
-  intptr_t num_flds = (type_ref.raw()->to() - type_ref.raw()->from());
-  intptr_t from_offset = OFFSET_OF_FROM(type_ref);
-  for (intptr_t i = 0; i <= num_flds; i++) {
-    (*reader->PassiveObjectHandle()) =
-        reader->ReadObjectImpl(kAsReference, object_id, (i + from_offset));
-    type_ref.StorePointer((type_ref.raw()->from() + i),
-                          reader->PassiveObjectHandle()->raw());
-  }
+  READ_OBJECT_FIELDS(type_ref,
+                     type_ref.raw()->from(), type_ref.raw()->to(),
+                     kAsReference);
 
   return type_ref.raw();
 }
 
 
 void RawTypeRef::WriteTo(SnapshotWriter* writer,
                          intptr_t object_id,
                          Snapshot::Kind kind) {
   ASSERT(writer != NULL);
 
@@ skipping 20 matching lines @@
   TypeParameter& type_parameter = TypeParameter::ZoneHandle(
       reader->zone(), NEW_OBJECT(TypeParameter));
   reader->AddBackRef(object_id, &type_parameter, kIsDeserialized);
 
   // Set all non object fields.
   type_parameter.set_token_pos(reader->Read<int32_t>());
   type_parameter.set_index(reader->Read<int16_t>());
   type_parameter.set_type_state(reader->Read<int8_t>());
 
   // Set all the object fields.
-  // TODO(5411462): Need to assert No GC can happen here, even though
-  // allocations may happen.
-  intptr_t num_flds = (type_parameter.raw()->to() -
-                       type_parameter.raw()->from());
-  intptr_t from_offset = OFFSET_OF_FROM(type_parameter);
-  for (intptr_t i = 0; i <= num_flds; i++) {
-    (*reader->PassiveObjectHandle()) =
-        reader->ReadObjectImpl(kAsReference, object_id, (i + from_offset));
-    type_parameter.StorePointer((type_parameter.raw()->from() + i),
-                                reader->PassiveObjectHandle()->raw());
-  }
+  READ_OBJECT_FIELDS(type_parameter,
+                     type_parameter.raw()->from(), type_parameter.raw()->to(),
+                     kAsReference);
 
   return type_parameter.raw();
 }
 
 
 void RawTypeParameter::WriteTo(SnapshotWriter* writer,
                                intptr_t object_id,
                                Snapshot::Kind kind) {
   ASSERT(writer != NULL);
 
@@ skipping 23 matching lines @@
                                       intptr_t tags,
                                       Snapshot::Kind kind) {
   ASSERT(reader != NULL);
 
   // Allocate bounded type object.
   BoundedType& bounded_type = BoundedType::ZoneHandle(
       reader->zone(), NEW_OBJECT(BoundedType));
   reader->AddBackRef(object_id, &bounded_type, kIsDeserialized);
 
   // Set all the object fields.
-  // TODO(5411462): Need to assert No GC can happen here, even though
-  // allocations may happen.
-  intptr_t num_flds = (bounded_type.raw()->to() -
-                       bounded_type.raw()->from());
-  intptr_t from_offset = OFFSET_OF_FROM(bounded_type);
-  for (intptr_t i = 0; i <= num_flds; i++) {
-    (*reader->PassiveObjectHandle()) =
-        reader->ReadObjectImpl(kAsReference, object_id, (i + from_offset));
-    bounded_type.StorePointer((bounded_type.raw()->from() + i),
-                              reader->PassiveObjectHandle()->raw());
-  }
+  READ_OBJECT_FIELDS(bounded_type,
+                     bounded_type.raw()->from(), bounded_type.raw()->to(),
+                     kAsReference);
 
   return bounded_type.raw();
 }
 
 
 void RawBoundedType::WriteTo(SnapshotWriter* writer,
                              intptr_t object_id,
                              Snapshot::Kind kind) {
   ASSERT(writer != NULL);
 
@@ skipping 103 matching lines @@
                                     intptr_t tags,
                                     Snapshot::Kind kind) {
   ASSERT(reader != NULL);
 
   // Allocate function object.
   PatchClass& cls = PatchClass::ZoneHandle(reader->zone(),
                                             NEW_OBJECT(PatchClass));
   reader->AddBackRef(object_id, &cls, kIsDeserialized);
 
   // Set all the object fields.
-  // TODO(5411462): Need to assert No GC can happen here, even though
-  // allocations may happen.
-  intptr_t num_flds = (cls.raw()->to() - cls.raw()->from());
-  for (intptr_t i = 0; i <= num_flds; i++) {
-    (*reader->PassiveObjectHandle()) = reader->ReadObjectImpl(kAsReference);
-    cls.StorePointer((cls.raw()->from() + i),
-                     reader->PassiveObjectHandle()->raw());
-  }
+  READ_OBJECT_FIELDS(cls, cls.raw()->from(), cls.raw()->to(), kAsReference);
+
   ASSERT(((kind == Snapshot::kScript) &&
           !Class::IsInFullSnapshot(cls.source_class())) ||
          (kind == Snapshot::kFull));
 
   return cls.raw();
 }
 
 
 void RawPatchClass::WriteTo(SnapshotWriter* writer,
                             intptr_t object_id,
@@ skipping 19 matching lines @@
                                       Snapshot::Kind kind) {
   ASSERT(reader != NULL);
   ASSERT((kind == Snapshot::kScript) || (kind == Snapshot::kFull));
 
   // Allocate closure data object.
   ClosureData& data = ClosureData::ZoneHandle(
       reader->zone(), NEW_OBJECT(ClosureData));
   reader->AddBackRef(object_id, &data, kIsDeserialized);
 
   // Set all the object fields.
-  // TODO(5411462): Need to assert No GC can happen here, even though
-  // allocations may happen.
-  intptr_t num_flds = (data.raw()->to() - data.raw()->from());
-  for (intptr_t i = 0; i <= num_flds; i++) {
-    *(data.raw()->from() + i) = reader->ReadObjectImpl(kAsReference);
-  }
+  READ_OBJECT_FIELDS(data, data.raw()->from(), data.raw()->to(), kAsReference);
 
   return data.raw();
 }
 
 
 void RawClosureData::WriteTo(SnapshotWriter* writer,
                              intptr_t object_id,
                              Snapshot::Kind kind) {
   ASSERT(writer != NULL);
   ASSERT((kind == Snapshot::kScript) || (kind == Snapshot::kFull));
@@ skipping 10 matching lines @@
     writer->WriteVMIsolateObject(kEmptyContextScopeObject);
   } else {
     if (ptr()->context_scope_->ptr()->is_implicit_) {
       writer->WriteObjectImpl(ptr()->context_scope_, kAsInlinedObject);
     } else {
       // We don't write non implicit context scopes in the snapshot.
       writer->WriteVMIsolateObject(kNullObject);
     }
   }
 
-  writer->WriteObjectImpl(Object::null(), kAsInlinedObject);
-
   // Parent function.
   writer->WriteObjectImpl(ptr()->parent_function_, kAsInlinedObject);
 
   // Signature class.
   writer->WriteObjectImpl(ptr()->signature_class_, kAsInlinedObject);
 
   // Static closure/Closure allocation stub.
   // We don't write the closure or allocation stub in the snapshot.
   writer->WriteVMIsolateObject(kNullObject);
 }
 
 
 RawRedirectionData* RedirectionData::ReadFrom(SnapshotReader* reader,
                                               intptr_t object_id,
                                               intptr_t tags,
                                               Snapshot::Kind kind) {
   ASSERT(reader != NULL);
   ASSERT((kind == Snapshot::kScript) || (kind == Snapshot::kFull));
 
   // Allocate redirection data object.
   RedirectionData& data = RedirectionData::ZoneHandle(
       reader->zone(), NEW_OBJECT(RedirectionData));
   reader->AddBackRef(object_id, &data, kIsDeserialized);
 
   // Set all the object fields.
-  // TODO(5411462): Need to assert No GC can happen here, even though
-  // allocations may happen.
-  intptr_t num_flds = (data.raw()->to() - data.raw()->from());
-  intptr_t from_offset = OFFSET_OF_FROM(data);
-  for (intptr_t i = 0; i <= num_flds; i++) {
-    (*reader->PassiveObjectHandle()) =
-        reader->ReadObjectImpl(kAsReference, object_id, (i + from_offset));
-    data.StorePointer((data.raw()->from() + i),
-                      reader->PassiveObjectHandle()->raw());
-  }
+  READ_OBJECT_FIELDS(data, data.raw()->from(), data.raw()->to(), kAsReference);
 
   return data.raw();
 }
 
 
 void RawRedirectionData::WriteTo(SnapshotWriter* writer,
                                  intptr_t object_id,
                                  Snapshot::Kind kind) {
   ASSERT(writer != NULL);
   ASSERT((kind == Snapshot::kScript) || (kind == Snapshot::kFull));
@@ skipping 28 matching lines @@
   func.set_end_token_pos(reader->Read<int32_t>());
   func.set_usage_counter(reader->Read<int32_t>());
   func.set_num_fixed_parameters(reader->Read<int16_t>());
   func.set_num_optional_parameters(reader->Read<int16_t>());
   func.set_deoptimization_counter(reader->Read<int16_t>());
   func.set_kind_tag(reader->Read<uint32_t>());
   func.set_optimized_instruction_count(reader->Read<uint16_t>());
   func.set_optimized_call_site_count(reader->Read<uint16_t>());
 
   // Set all the object fields.
-  // TODO(5411462): Need to assert No GC can happen here, even though
-  // allocations may happen.
-  RawObject** toaddr = reader->snapshot_code() ? func.raw()->to()
-                                               : func.raw()->to_snapshot();
-  intptr_t num_flds = toaddr - func.raw()->from();
-  intptr_t from_offset = OFFSET_OF_FROM(func);
-  for (intptr_t i = 0; i <= num_flds; i++) {
-    (*reader->PassiveObjectHandle()) =
-        reader->ReadObjectImpl(kAsReference, object_id, (i + from_offset));
-    func.StorePointer((func.raw()->from() + i),
-                      reader->PassiveObjectHandle()->raw());
-  }
+  READ_OBJECT_FIELDS(func,
+                     func.raw()->from(),
+                     reader->snapshot_code() ? func.raw()->to()
+                                             : func.raw()->to_snapshot(),
+                     kAsReference);
 
   if (!reader->snapshot_code()) {
     // Initialize all fields that are not part of the snapshot.
     func.ClearICDataArray();
     func.ClearCode();
+  } else {
+    // TODO(rmacnak): Fix entry_point_.
   }
   return func.raw();
 }
 
 
 void RawFunction::WriteTo(SnapshotWriter* writer,
                           intptr_t object_id,
                           Snapshot::Kind kind) {
   ASSERT(writer != NULL);
   ASSERT((kind == Snapshot::kScript) || (kind == Snapshot::kFull));
@@ skipping 38 matching lines @@
   Field& field = Field::ZoneHandle(reader->zone(), NEW_OBJECT(Field));
   reader->AddBackRef(object_id, &field, kIsDeserialized);
 
   // Set all non object fields.
   field.set_token_pos(reader->Read<int32_t>());
   field.set_guarded_cid(reader->Read<int32_t>());
   field.set_is_nullable(reader->Read<int32_t>());
   field.set_kind_bits(reader->Read<uint8_t>());
 
   // Set all the object fields.
-  // TODO(5411462): Need to assert No GC can happen here, even though
-  // allocations may happen.
-  intptr_t num_flds = (field.raw()->to() - field.raw()->from());
-  intptr_t from_offset = OFFSET_OF_FROM(field);
-  for (intptr_t i = 0; i <= num_flds; i++) {
-    (*reader->PassiveObjectHandle()) =
-        reader->ReadObjectImpl(kAsReference, object_id, (i + from_offset));
-    field.StorePointer((field.raw()->from() + i),
-                       reader->PassiveObjectHandle()->raw());
-  }
+  READ_OBJECT_FIELDS(field,
+                     field.raw()->from(), field.raw()->to(),
+                     kAsReference);
 
   field.InitializeGuardedListLengthInObjectOffset();
 
   return field.raw();
 }
 
 
 void RawField::WriteTo(SnapshotWriter* writer,
                        intptr_t object_id,
                        Snapshot::Kind kind) {
@@ skipping 29 matching lines @@
   // Create the literal token object.
   LiteralToken& literal_token = LiteralToken::ZoneHandle(
       reader->zone(), NEW_OBJECT(LiteralToken));
   reader->AddBackRef(object_id, &literal_token, kIsDeserialized);
 
   // Read the token attributes.
   Token::Kind token_kind = static_cast<Token::Kind>(reader->Read<int32_t>());
   literal_token.set_kind(token_kind);
 
   // Set all the object fields.
-  // TODO(5411462): Need to assert No GC can happen here, even though
-  // allocations may happen.
-  intptr_t num_flds = (literal_token.raw()->to() - literal_token.raw()->from());
-  for (intptr_t i = 0; i <= num_flds; i++) {
-    (*reader->PassiveObjectHandle()) = reader->ReadObjectImpl(kAsReference);
-    literal_token.StorePointer((literal_token.raw()->from() + i),
-                               reader->PassiveObjectHandle()->raw());
-  }
+  READ_OBJECT_FIELDS(literal_token,
+                     literal_token.raw()->from(), literal_token.raw()->to(),
+                     kAsReference);
 
   return literal_token.raw();
 }
 
 
 void RawLiteralToken::WriteTo(SnapshotWriter* writer,
                               intptr_t object_id,
                               Snapshot::Kind kind) {
   ASSERT(writer != NULL);
   ASSERT(kind != Snapshot::kMessage);
@@ skipping 260 matching lines @@
   reader->AddBackRef(object_id, &prefix, kIsDeserialized);
 
   // Set all non object fields.
   prefix.StoreNonPointer(&prefix.raw_ptr()->num_imports_,
                          reader->Read<int16_t>());
   prefix.StoreNonPointer(&prefix.raw_ptr()->is_deferred_load_,
                          reader->Read<bool>());
   prefix.StoreNonPointer(&prefix.raw_ptr()->is_loaded_, reader->Read<bool>());
 
   // Set all the object fields.
-  // TODO(5411462): Need to assert No GC can happen here, even though
-  // allocations may happen.
-  intptr_t num_flds = (prefix.raw()->to() - prefix.raw()->from());
-  for (intptr_t i = 0; i <= num_flds; i++) {
-    (*reader->PassiveObjectHandle()) = reader->ReadObjectImpl(kAsReference);
-    prefix.StorePointer((prefix.raw()->from() + i),
-                         reader->PassiveObjectHandle()->raw());
-  }
+  READ_OBJECT_FIELDS(prefix,
+                     prefix.raw()->from(), prefix.raw()->to(),
+                     kAsReference);
 
   return prefix.raw();
 }
 
 
 void RawLibraryPrefix::WriteTo(SnapshotWriter* writer,
                                intptr_t object_id,
                                Snapshot::Kind kind) {
   ASSERT(writer != NULL);
   ASSERT((kind == Snapshot::kScript) || (kind == Snapshot::kFull));
@@ skipping 22 matching lines @@
                                   Snapshot::Kind kind) {
   ASSERT(reader != NULL);
   ASSERT((kind == Snapshot::kScript) || (kind == Snapshot::kFull));
 
   // Allocate Namespace object.
   Namespace& ns = Namespace::ZoneHandle(
       reader->zone(), NEW_OBJECT(Namespace));
   reader->AddBackRef(object_id, &ns, kIsDeserialized);
 
   // Set all the object fields.
-  // TODO(5411462): Need to assert No GC can happen here, even though
-  // allocations may happen.
-  intptr_t num_flds = (ns.raw()->to() - ns.raw()->from());
-  for (intptr_t i = 0; i <= num_flds; i++) {
-    (*reader->PassiveObjectHandle()) = reader->ReadObjectImpl(kAsReference);
-    ns.StorePointer((ns.raw()->from() + i),
-                    reader->PassiveObjectHandle()->raw());
-  }
+  READ_OBJECT_FIELDS(ns, ns.raw()->from(), ns.raw()->to(), kAsReference);
 
   return ns.raw();
 }
 
 
 void RawNamespace::WriteTo(SnapshotWriter* writer,
                            intptr_t object_id,
                            Snapshot::Kind kind) {
   ASSERT(writer != NULL);
   ASSERT((kind == Snapshot::kScript) || (kind == Snapshot::kFull));
 
   // Write out the serialization header value for this object.
   writer->WriteInlinedObjectHeader(object_id);
 
   // Write out the class and tags information.
   writer->WriteVMIsolateObject(kNamespaceCid);
   writer->WriteTags(writer->GetObjectTags(this));
 
   // Write out all the object pointer fields.
   SnapshotWriterVisitor visitor(writer);
   visitor.VisitPointers(from(), to());
 }
 
 
 RawCode* Code::ReadFrom(SnapshotReader* reader,
                         intptr_t object_id,
                         intptr_t tags,
                         Snapshot::Kind kind) {
-  UNREACHABLE();  // Untested.
   ASSERT(reader->snapshot_code());
   ASSERT(kind == Snapshot::kFull);
 
   Code& result = Code::ZoneHandle(reader->zone(), NEW_OBJECT_WITH_LEN(Code, 0));
   reader->AddBackRef(object_id, &result, kIsDeserialized);
 
   result.set_compile_timestamp(reader->Read<int64_t>());
   result.set_state_bits(reader->Read<int32_t>());
   result.set_entry_patch_pc_offset(reader->Read<int32_t>());
   result.set_patch_code_pc_offset(reader->Read<int32_t>());
   result.set_lazy_deopt_pc_offset(reader->Read<int32_t>());
 
   // Set all the object fields.
-  // TODO(5411462): Need to assert No GC can happen here, even though
-  // allocations may happen.
-  intptr_t num_flds = (result.raw()->to() - result.raw()->from());
-  for (intptr_t i = 0; i <= num_flds; i++) {
-    (*reader->PassiveObjectHandle()) = reader->ReadObjectImpl(kAsReference);
-    result.StorePointer((result.raw()->from() + i),
-                        reader->PassiveObjectHandle()->raw());
-  }
+  READ_OBJECT_FIELDS(result,
+                     result.raw()->from(), result.raw()->to(),
+                     kAsReference);
+
+  // TODO(rmacnak): Fix entry_point_.
 
   return result.raw();
 }
 
 
 void RawCode::WriteTo(SnapshotWriter* writer,
                       intptr_t object_id,
                       Snapshot::Kind kind) {
   ASSERT(writer->snapshot_code());
   ASSERT(kind == Snapshot::kFull);
@@ skipping 22 matching lines @@
   // Write out all the object pointer fields.
   SnapshotWriterVisitor visitor(writer);
   visitor.VisitPointers(from(), to());
 }
 
 
 RawInstructions* Instructions::ReadFrom(SnapshotReader* reader,
                                         intptr_t object_id,
                                         intptr_t tags,
                                         Snapshot::Kind kind) {
-  UNREACHABLE();  // Untested.
   ASSERT(reader->snapshot_code());
   ASSERT(kind == Snapshot::kFull);
 
-  intptr_t id = reader->Read<int32_t>();
+  intptr_t full_tags = static_cast<uword>(reader->Read<intptr_t>());
+  intptr_t offset = reader->Read<int32_t>();
   Instructions& result =
       Instructions::ZoneHandle(reader->zone(),
-                               reader->GetInstructionsById(id));
+                               reader->GetInstructionsAt(offset, full_tags));
   reader->AddBackRef(object_id, &result, kIsDeserialized);
+
+  {
+    // TODO(rmacnak): Drop after calling convention change.
+    Code::CheckedHandle(reader->ReadObjectImpl(kAsReference));
+    ObjectPool::CheckedHandle(reader->ReadObjectImpl(kAsReference));
+  }
+
   return result.raw();
 }
 
 
 void RawInstructions::WriteTo(SnapshotWriter* writer,
                               intptr_t object_id,
                               Snapshot::Kind kind) {
   ASSERT(writer->snapshot_code());
   ASSERT(kind == Snapshot::kFull);
 
   {
     // TODO(rmacnak): Drop after calling convention change.
     writer->WriteInlinedObjectHeader(object_id);
     writer->WriteVMIsolateObject(kInstructionsCid);
     writer->WriteTags(writer->GetObjectTags(this));
+  }
+
+  writer->Write<intptr_t>(writer->GetObjectTags(this));  // For sanity check.
+
+  // Temporarily restore the object header for writing to the text section.
+  // TODO(asiva): Don't mutate object headers during serialization.
+  uword object_tags = writer->GetObjectTags(this);
+  uword snapshot_tags = ptr()->tags_;
+  ptr()->tags_ = object_tags;
+  writer->Write<int32_t>(writer->GetInstructionsId(this));
+  ptr()->tags_ = snapshot_tags;
+
+  {
+    // TODO(rmacnak): Drop after calling convention change.
     writer->WriteObjectImpl(ptr()->code_, kAsReference);
     writer->WriteObjectImpl(ptr()->object_pool_, kAsReference);
   }
-
-  writer->Write<int32_t>(writer->GetInstructionsId(this));
 }
 
 
 RawObjectPool* ObjectPool::ReadFrom(SnapshotReader* reader,
                                     intptr_t object_id,
                                     intptr_t tags,
                                     Snapshot::Kind kind) {
-  UNREACHABLE();  // Untested.
   ASSERT(reader->snapshot_code());
   ASSERT(kind == Snapshot::kFull);
 
   intptr_t length = reader->Read<intptr_t>();
 
   ObjectPool& result =
       ObjectPool::ZoneHandle(reader->zone(),
                              NEW_OBJECT_WITH_LEN(ObjectPool, length));
   reader->AddBackRef(object_id, &result, kIsDeserialized);
 
-  RawTypedData* info_array = result.raw_ptr()->info_array_->ptr();
+  const TypedData& info_array =
+      TypedData::Handle(reader->NewTypedData(kTypedDataInt8ArrayCid, length));
+  result.set_info_array(info_array);
 
-  // Set all the object fields.
-  // TODO(5411462): Need to assert No GC can happen here, even though
-  // allocations may happen.
+  NoSafepointScope no_safepoint;
   for (intptr_t i = 0; i < length; i++) {
     ObjectPool::EntryType entry_type =
-        static_cast<ObjectPool::EntryType>(reader->Read<uint8_t>());
-    info_array->data()[i] = entry_type;
+        static_cast<ObjectPool::EntryType>(reader->Read<int8_t>());
+    *reinterpret_cast<int8_t*>(info_array.DataAddr(i)) = entry_type;
     switch (entry_type) {
       case ObjectPool::kTaggedObject: {
         (*reader->PassiveObjectHandle()) = reader->ReadObjectImpl(kAsReference);
         result.SetObjectAt(i, *(reader->PassiveObjectHandle()));
         break;
       }
       case ObjectPool::kImmediate: {
         intptr_t raw_value = reader->Read<intptr_t>();
         result.SetRawValueAt(i, raw_value);
         break;
@@ skipping 27 matching lines @@
   writer->WriteTags(writer->GetObjectTags(this));
 
   intptr_t length = ptr()->length_;
   RawTypedData* info_array = ptr()->info_array_->ptr();
   ASSERT(info_array != TypedData::null());
 
   writer->Write<intptr_t>(length);
   for (intptr_t i = 0; i < length; i++) {
     ObjectPool::EntryType entry_type =
         static_cast<ObjectPool::EntryType>(info_array->data()[i]);
-    writer->Write<uint8_t>(entry_type);
+    writer->Write<int8_t>(entry_type);
     Entry& entry = ptr()->data()[i];
     switch (entry_type) {
       case ObjectPool::kTaggedObject:
         writer->WriteObjectImpl(entry.raw_obj_, kAsReference);
         break;
       case ObjectPool::kImmediate:
         writer->Write<intptr_t>(entry.raw_value_);
         break;
       case ObjectPool::kExternalLabel:
         // TODO(rmacnak): Write symbolically.
         writer->Write<intptr_t>(entry.raw_value_);
         break;
       default:
         UNREACHABLE();
     }
   }
 }
 
 
 RawPcDescriptors* PcDescriptors::ReadFrom(SnapshotReader* reader,
                                           intptr_t object_id,
                                           intptr_t tags,
                                           Snapshot::Kind kind) {
-  UNREACHABLE();  // Untested.
   ASSERT(reader->snapshot_code());
+  ASSERT(kind == Snapshot::kFull);
 
   const int32_t length = reader->Read<int32_t>();
-  PcDescriptors& result = PcDescriptors::ZoneHandle(reader->zone(),
-                                                    PcDescriptors::New(length));
+  PcDescriptors& result =
+      PcDescriptors::ZoneHandle(reader->zone(),
+                                NEW_OBJECT_WITH_LEN(PcDescriptors, length));
   reader->AddBackRef(object_id, &result, kIsDeserialized);
 
   if (result.Length() > 0) {
     NoSafepointScope no_safepoint;
     intptr_t len = result.Length();
     uint8_t* data = result.UnsafeMutableNonPointer(result.raw_ptr()->data());
     reader->ReadBytes(data, len);
   }
 
   return result.raw();
 }
 
 
 void RawPcDescriptors::WriteTo(SnapshotWriter* writer,
                                intptr_t object_id,
                                Snapshot::Kind kind) {
   ASSERT(writer->snapshot_code());
+  ASSERT(kind == Snapshot::kFull);
 
   // Write out the serialization header value for this object.
   writer->WriteInlinedObjectHeader(object_id);
   writer->WriteIndexedObject(kPcDescriptorsCid);
   writer->WriteTags(writer->GetObjectTags(this));
   writer->Write<int32_t>(ptr()->length_);
   if (ptr()->length_ > 0) {
     intptr_t len = ptr()->length_;
     uint8_t* data = reinterpret_cast<uint8_t*>(ptr()->data());
     writer->WriteBytes(data, len);
   }
 }
 
 
 RawStackmap* Stackmap::ReadFrom(SnapshotReader* reader,
                                 intptr_t object_id,
                                 intptr_t tags,
                                 Snapshot::Kind kind) {
-  UNREACHABLE();  // Untested.
   ASSERT(reader->snapshot_code());
+  ASSERT(kind == Snapshot::kFull);
 
   const int32_t length = reader->Read<int32_t>();
-  const int32_t register_bit_count = reader->Read<int32_t>();
-  const uword pc_offset = reader->Read<uint32_t>();
-
   Stackmap& result =
       Stackmap::ZoneHandle(reader->zone(),
-        Stackmap::New(length, register_bit_count, pc_offset));
+                           reader->NewStackmap(length));
   reader->AddBackRef(object_id, &result, kIsDeserialized);
 
-  if (result.Length() > 0) {
+  result.SetRegisterBitCount(reader->Read<int32_t>());
+  result.SetPcOffset(reader->Read<uint32_t>());
+
+  if (length > 0) {
     NoSafepointScope no_safepoint;
     intptr_t len = (result.Length() + 7) / 8;
     uint8_t* data = result.UnsafeMutableNonPointer(result.raw_ptr()->data());
     reader->ReadBytes(data, len);
   }
 
   return result.raw();
 }
 
 
 void RawStackmap::WriteTo(SnapshotWriter* writer,
                           intptr_t object_id,
                           Snapshot::Kind kind) {
   ASSERT(writer->snapshot_code());
+  ASSERT(kind == Snapshot::kFull);
 
   // Write out the serialization header value for this object.
   writer->WriteInlinedObjectHeader(object_id);
   writer->WriteIndexedObject(kStackmapCid);
   writer->WriteTags(writer->GetObjectTags(this));
+
   writer->Write<int32_t>(ptr()->length_);
   writer->Write<int32_t>(ptr()->register_bit_count_);
   writer->Write<uint32_t>(ptr()->pc_offset_);
   if (ptr()->length_ > 0) {
     intptr_t len = (ptr()->length_ + 7) / 8;
     uint8_t* data = reinterpret_cast<uint8_t*>(ptr()->data());
     writer->WriteBytes(data, len);
   }
 }
 
 
 RawLocalVarDescriptors* LocalVarDescriptors::ReadFrom(SnapshotReader* reader,
                                                       intptr_t object_id,
                                                       intptr_t tags,
                                                       Snapshot::Kind kind) {
-  UNREACHABLE();  // Untested.
   ASSERT(reader->snapshot_code());
+  ASSERT(kind == Snapshot::kFull);
 
   const int32_t num_entries = reader->Read<int32_t>();
 
   LocalVarDescriptors& result =
       LocalVarDescriptors::ZoneHandle(reader->zone(),
-        LocalVarDescriptors::New(num_entries));
+                                      NEW_OBJECT_WITH_LEN(LocalVarDescriptors,
+                                                          num_entries));
   reader->AddBackRef(object_id, &result, kIsDeserialized);
 
   for (intptr_t i = 0; i < num_entries; i++) {
     (*reader->StringHandle()) ^= reader->ReadObjectImpl(kAsReference);
     result.StorePointer(result.raw()->nameAddrAt(i),
                         reader->StringHandle()->raw());
   }
 
   if (num_entries > 0) {
     NoSafepointScope no_safepoint;
     intptr_t len = num_entries * sizeof(RawLocalVarDescriptors::VarInfo);
     uint8_t* data = result.UnsafeMutableNonPointer(
         reinterpret_cast<const uint8_t*>(result.raw()->data()));
     reader->ReadBytes(data, len);
   }
 
   return result.raw();
 }
 
 
 void RawLocalVarDescriptors::WriteTo(SnapshotWriter* writer,
                                      intptr_t object_id,
                                      Snapshot::Kind kind) {
   ASSERT(writer->snapshot_code());
+  ASSERT(kind == Snapshot::kFull);
 
   // Write out the serialization header value for this object.
   writer->WriteInlinedObjectHeader(object_id);
   writer->WriteIndexedObject(kLocalVarDescriptorsCid);
   writer->WriteTags(writer->GetObjectTags(this));
   writer->Write<int32_t>(ptr()->num_entries_);
   for (intptr_t i = 0; i < ptr()->num_entries_; i++) {
-    writer->WriteObjectImpl(ptr()->names()[i], kAsInlinedObject);
+    writer->WriteObjectImpl(ptr()->names()[i], kAsReference);
   }
   if (ptr()->num_entries_ > 0) {
     intptr_t len = ptr()->num_entries_ * sizeof(VarInfo);
     uint8_t* data = reinterpret_cast<uint8_t*>(this->data());
     writer->WriteBytes(data, len);
   }
 }
 
 
 RawExceptionHandlers* ExceptionHandlers::ReadFrom(SnapshotReader* reader,
                                                   intptr_t object_id,
                                                   intptr_t tags,
                                                   Snapshot::Kind kind) {
-  UNREACHABLE();  // Untested.
   ASSERT(reader->snapshot_code());
+  ASSERT(kind == Snapshot::kFull);
 
-  // handled_types_data.
-  *(reader->ArrayHandle()) ^= reader->ReadObjectImpl(kAsInlinedObject);
-
+  const int32_t num_entries = reader->Read<int32_t>();
   ExceptionHandlers& result =
       ExceptionHandlers::ZoneHandle(reader->zone(),
-        ExceptionHandlers::New(*reader->ArrayHandle()));
+                                    NEW_OBJECT_WITH_LEN(ExceptionHandlers,
+                                                        num_entries));
   reader->AddBackRef(object_id, &result, kIsDeserialized);
 
   if (result.num_entries() > 0) {
     NoSafepointScope no_safepoint;
     const intptr_t len =
         result.num_entries() * sizeof(RawExceptionHandlers::HandlerInfo);
     uint8_t* data = result.UnsafeMutableNonPointer(
         reinterpret_cast<const uint8_t*>(result.raw_ptr()->data()));
     reader->ReadBytes(data, len);
   }
 
+  *(reader->ArrayHandle()) ^= reader->ReadObjectImpl(kAsInlinedObject);
+  result.StorePointer(&result.raw_ptr()->handled_types_data_,
+                      reader->ArrayHandle()->raw());
+
   return result.raw();
 }
 
 
 void RawExceptionHandlers::WriteTo(SnapshotWriter* writer,
                                    intptr_t object_id,
                                    Snapshot::Kind kind) {
   ASSERT(writer->snapshot_code());
+  ASSERT(kind == Snapshot::kFull);
 
   // Write out the serialization header value for this object.
   writer->WriteInlinedObjectHeader(object_id);
   writer->WriteIndexedObject(kExceptionHandlersCid);
   writer->WriteTags(writer->GetObjectTags(this));
-  writer->WriteObjectImpl(ptr()->handled_types_data_, kAsInlinedObject);
+  writer->Write<int32_t>(ptr()->num_entries_);
 
   if (ptr()->num_entries_ > 0) {
     intptr_t len = ptr()->num_entries_ * sizeof(HandlerInfo);
     uint8_t* data = reinterpret_cast<uint8_t*>(ptr()->data());
     writer->WriteBytes(data, len);
   }
+
+  writer->WriteObjectImpl(ptr()->handled_types_data_, kAsInlinedObject);
 }
 
 
 RawContext* Context::ReadFrom(SnapshotReader* reader,
                               intptr_t object_id,
                               intptr_t tags,
                               Snapshot::Kind kind) {
   ASSERT(reader != NULL);
 
   // Allocate context object.
@@ skipping 44 matching lines @@
 
 RawContextScope* ContextScope::ReadFrom(SnapshotReader* reader,
                                         intptr_t object_id,
                                         intptr_t tags,
                                         Snapshot::Kind kind) {
   ASSERT(reader != NULL);
 
   // Allocate context object.
   bool is_implicit = reader->Read<bool>();
   if (is_implicit) {
-    ContextScope& context_scope =
-        ContextScope::ZoneHandle(ContextScope::New(1, true));
+    ContextScope& context_scope = ContextScope::ZoneHandle();
+    if (kind == Snapshot::kFull) {
+      context_scope = reader->NewContextScope(1);
+      context_scope.set_is_implicit(true);
+    } else {
+      context_scope = ContextScope::New(1, true);
+    }
     reader->AddBackRef(object_id, &context_scope, kIsDeserialized);
 
     *reader->TypeHandle() ^= reader->ReadObjectImpl(kAsInlinedObject);
 
     // Create a descriptor for 'this' variable.
     context_scope.SetTokenIndexAt(0, 0);
     context_scope.SetNameAt(0, Symbols::This());
     context_scope.SetIsFinalAt(0, true);
     context_scope.SetIsConstAt(0, false);
     context_scope.SetTypeAt(0, *reader->TypeHandle());
@@ skipping 31 matching lines @@
     return;
   }
   UNREACHABLE();
 }
 
 
 RawICData* ICData::ReadFrom(SnapshotReader* reader,
                             intptr_t object_id,
                             intptr_t tags,
                             Snapshot::Kind kind) {
-  UNREACHABLE();  // Untested.
   ASSERT(reader->snapshot_code());
   ASSERT(kind == Snapshot::kFull);
 
   ICData& result = ICData::ZoneHandle(reader->zone(), NEW_OBJECT(ICData));
   reader->AddBackRef(object_id, &result, kIsDeserialized);
 
   result.set_deopt_id(reader->Read<int32_t>());
   result.set_state_bits(reader->Read<uint32_t>());
 
   // Set all the object fields.
-  // TODO(5411462): Need to assert No GC can happen here, even though
-  // allocations may happen.
-  intptr_t num_flds = (result.raw()->to() - result.raw()->from());
-  for (intptr_t i = 0; i <= num_flds; i++) {
-    (*reader->PassiveObjectHandle()) = reader->ReadObjectImpl(kAsReference);
-    result.StorePointer((result.raw()->from() + i),
-                        reader->PassiveObjectHandle()->raw());
-  }
+  READ_OBJECT_FIELDS(result,
+                     result.raw()->from(), result.raw()->to(),
+                     kAsReference);
 
   return result.raw();
 }
 
 
 void RawICData::WriteTo(SnapshotWriter* writer,
                         intptr_t object_id,
                         Snapshot::Kind kind) {
   ASSERT(writer->snapshot_code());
   ASSERT(kind == Snapshot::kFull);
@@ skipping 12 matching lines @@
   // Write out all the object pointer fields.
   SnapshotWriterVisitor visitor(writer);
   visitor.VisitPointers(from(), to());
 }
 
 
 RawMegamorphicCache* MegamorphicCache::ReadFrom(SnapshotReader* reader,
                                                 intptr_t object_id,
                                                 intptr_t tags,
                                                 Snapshot::Kind kind) {
-  UNREACHABLE();  // Untested.
   ASSERT(reader->snapshot_code());
   ASSERT(kind == Snapshot::kFull);
 
   MegamorphicCache& result =
       MegamorphicCache::ZoneHandle(reader->zone(),
                                    NEW_OBJECT(MegamorphicCache));
   reader->AddBackRef(object_id, &result, kIsDeserialized);
 
   result.set_filled_entry_count(reader->Read<int32_t>());
 
   // Set all the object fields.
-  // TODO(5411462): Need to assert No GC can happen here, even though
-  // allocations may happen.
-  intptr_t num_flds = (result.raw()->to() - result.raw()->from());
-  for (intptr_t i = 0; i <= num_flds; i++) {
-    (*reader->PassiveObjectHandle()) = reader->ReadObjectImpl(kAsReference);
-    result.StorePointer((result.raw()->from() + i),
-                        reader->PassiveObjectHandle()->raw());
-  }
+  READ_OBJECT_FIELDS(result,
+                     result.raw()->from(), result.raw()->to(),
+                     kAsReference);
 
   return result.raw();
 }
 
 
 void RawMegamorphicCache::WriteTo(SnapshotWriter* writer,
                                   intptr_t object_id,
                                   Snapshot::Kind kind) {
   ASSERT(writer->snapshot_code());
   ASSERT(kind == Snapshot::kFull);
@@ skipping 11 matching lines @@
   // Write out all the object pointer fields.
   SnapshotWriterVisitor visitor(writer);
   visitor.VisitPointers(from(), to());
 }
 
 
 RawSubtypeTestCache* SubtypeTestCache::ReadFrom(SnapshotReader* reader,
                                                 intptr_t object_id,
                                                 intptr_t tags,
                                                 Snapshot::Kind kind) {
-  UNREACHABLE();  // Untested.
   ASSERT(reader->snapshot_code());
   ASSERT(kind == Snapshot::kFull);
 
   SubtypeTestCache& result =
       SubtypeTestCache::ZoneHandle(reader->zone(),
                                    NEW_OBJECT(SubtypeTestCache));
   reader->AddBackRef(object_id, &result, kIsDeserialized);
 
   // Set all the object fields.
   // TODO(5411462): Need to assert No GC can happen here, even though
@@ skipping 45 matching lines @@
                                 intptr_t tags,
                                 Snapshot::Kind kind) {
   ASSERT(reader != NULL);
 
   // Allocate ApiError object.
   ApiError& api_error =
       ApiError::ZoneHandle(reader->zone(), NEW_OBJECT(ApiError));
   reader->AddBackRef(object_id, &api_error, kIsDeserialized);
 
   // Set all the object fields.
-  // TODO(5411462): Need to assert No GC can happen here, even though
-  // allocations may happen.
-  intptr_t num_flds = (api_error.raw()->to() - api_error.raw()->from());
-  for (intptr_t i = 0; i <= num_flds; i++) {
-    (*reader->PassiveObjectHandle()) = reader->ReadObjectImpl(kAsReference);
-    api_error.StorePointer((api_error.raw()->from() + i),
-                           reader->PassiveObjectHandle()->raw());
-  }
+  READ_OBJECT_FIELDS(api_error,
+                     api_error.raw()->from(), api_error.raw()->to(),
+                     kAsReference);
 
   return api_error.raw();
 }
 
 
 void RawApiError::WriteTo(SnapshotWriter* writer,
                           intptr_t object_id,
                           Snapshot::Kind kind) {
   ASSERT(writer != NULL);
 
@@ skipping 19 matching lines @@
   // Allocate LanguageError object.
   LanguageError& language_error =
       LanguageError::ZoneHandle(reader->zone(), NEW_OBJECT(LanguageError));
   reader->AddBackRef(object_id, &language_error, kIsDeserialized);
 
   // Set all non object fields.
   language_error.set_token_pos(reader->Read<int32_t>());
   language_error.set_kind(reader->Read<uint8_t>());
 
   // Set all the object fields.
-  // TODO(5411462): Need to assert No GC can happen here, even though
-  // allocations may happen.
-  intptr_t num_flds =
-      (language_error.raw()->to() - language_error.raw()->from());
-  for (intptr_t i = 0; i <= num_flds; i++) {
-    (*reader->PassiveObjectHandle()) = reader->ReadObjectImpl(kAsReference);
-    language_error.StorePointer((language_error.raw()->from() + i),
-                                reader->PassiveObjectHandle()->raw());
-  }
+  READ_OBJECT_FIELDS(language_error,
+                     language_error.raw()->from(), language_error.raw()->to(),
+                     kAsReference);
 
   return language_error.raw();
 }
 
 
 void RawLanguageError::WriteTo(SnapshotWriter* writer,
                                intptr_t object_id,
                                Snapshot::Kind kind) {
   ASSERT(writer != NULL);
 
@@ skipping 16 matching lines @@
 
 RawUnhandledException* UnhandledException::ReadFrom(SnapshotReader* reader,
                                                     intptr_t object_id,
                                                     intptr_t tags,
                                                     Snapshot::Kind kind) {
   UnhandledException& result = UnhandledException::ZoneHandle(
       reader->zone(), NEW_OBJECT(UnhandledException));
   reader->AddBackRef(object_id, &result, kIsDeserialized);
 
   // Set all the object fields.
-  // TODO(5411462): Need to assert No GC can happen here, even though
-  // allocations may happen.
-  intptr_t num_flds = (result.raw()->to() - result.raw()->from());
-  for (intptr_t i = 0; i <= num_flds; i++) {
-    (*reader->PassiveObjectHandle()) = reader->ReadObjectImpl(kAsReference);
-    result.StorePointer((result.raw()->from() + i),
-                         reader->PassiveObjectHandle()->raw());
-  }
+  READ_OBJECT_FIELDS(result,
+                     result.raw()->from(), result.raw()->to(),
+                     kAsReference);
 
   return result.raw();
 }
 
 
 void RawUnhandledException::WriteTo(SnapshotWriter* writer,
                                     intptr_t object_id,
                                     Snapshot::Kind kind) {
   // Write out the serialization header value for this object.
   writer->WriteInlinedObjectHeader(object_id);
@@ skipping 131 matching lines @@
                             intptr_t object_id,
                             intptr_t tags,
                             Snapshot::Kind kind) {
   ASSERT(reader != NULL);
 
   // Allocate bigint object.
   Bigint& obj = Bigint::ZoneHandle(reader->zone(), NEW_OBJECT(Bigint));
   reader->AddBackRef(object_id, &obj, kIsDeserialized);
 
   // Set all the object fields.
-  // TODO(5411462): Need to assert No GC can happen here, even though
-  // allocations may happen.
-  intptr_t num_flds = (obj.raw()->to() - obj.raw()->from());
-  for (intptr_t i = 0; i <= num_flds; i++) {
-    (*reader->PassiveObjectHandle()) = reader->ReadObjectImpl(kAsInlinedObject);
-    obj.StorePointer(obj.raw()->from() + i,
-                     reader->PassiveObjectHandle()->raw());
-  }
+  READ_OBJECT_FIELDS(obj, obj.raw()->from(), obj.raw()->to(), kAsInlinedObject);
 
   // If it is a canonical constant make it one.
   // 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 or a message snapshot we always have
   // to canonicalize the object.
   if (RawObject::IsCanonical(tags)) {
     if (kind == Snapshot::kFull) {
       // Set the canonical bit.
       obj.SetCanonical();
@@ skipping 457 matching lines @@
 
 
 RawLinkedHashMap* LinkedHashMap::ReadFrom(SnapshotReader* reader,
                                           intptr_t object_id,
                                           intptr_t tags,
                                           Snapshot::Kind kind) {
   ASSERT(reader != NULL);
 
   LinkedHashMap& map = LinkedHashMap::ZoneHandle(
       reader->zone(), LinkedHashMap::null());
-  if (kind == Snapshot::kFull || kind == Snapshot::kScript) {
+  if ((kind == Snapshot::kFull && !reader->snapshot_code()) ||
+      kind == Snapshot::kScript) {
     // The immutable maps that seed map literals are not yet VM-internal, so
     // we don't reach this.
     UNREACHABLE();
   } else {
     // Since the map might contain itself as a key or value, allocate first.
-    map = LinkedHashMap::NewUninitialized(HEAP_SPACE(kind));
+    if (kind == Snapshot::kFull) {
+      map = reader->NewLinkedHashMap();
+    } else {
+      map = LinkedHashMap::NewUninitialized(HEAP_SPACE(kind));
+    }
   }
   reader->AddBackRef(object_id, &map, kIsDeserialized);
 
   // Read the type arguments.
   const intptr_t typeargs_offset =
       GrowableObjectArray::type_arguments_offset() / kWordSize;
   *reader->TypeArgumentsHandle() ^=
       reader->ReadObjectImpl(kAsInlinedObject, object_id, typeargs_offset);
   map.SetTypeArguments(*reader->TypeArgumentsHandle());
 
   // Read the number of key/value pairs.
   intptr_t len = reader->ReadSmiValue();
   intptr_t used_data = (len << 1);
   map.SetUsedData(used_data);
 
   // Allocate the data array.
   intptr_t data_size = Utils::Maximum(
       Utils::RoundUpToPowerOfTwo(used_data),
       static_cast<uintptr_t>(LinkedHashMap::kInitialIndexSize));
   Array& data = Array::ZoneHandle(reader->zone(),
-                                  Array::New(data_size, HEAP_SPACE(kind)));
+                                  NEW_OBJECT_WITH_LEN_SPACE(Array,
+                                                            data_size,
+                                                            kind));
   map.SetData(data);
   map.SetDeletedKeys(0);
 
   // The index and hashMask is regenerated by the maps themselves on demand.
   // Thus, the index will probably be allocated in new space (unless it's huge).
   // TODO(koda): Eagerly rehash here when no keys have user-defined '==', and
   // in particular, if/when (const) maps are needed in the VM isolate snapshot.
   ASSERT(reader->isolate() != Dart::vm_isolate());
   map.SetHashMask(0);  // Prefer sentinel 0 over null for better type feedback.
 
   // Read the keys and values.
   bool as_reference = RawObject::IsCanonical(tags) ? false : true;
   for (intptr_t i = 0; i < used_data; i++) {
     *reader->PassiveObjectHandle() = reader->ReadObjectImpl(as_reference);
     data.SetAt(i, *reader->PassiveObjectHandle());
   }
   return map.raw();
 }
 
 
 void RawLinkedHashMap::WriteTo(SnapshotWriter* writer,
                                intptr_t object_id,
                                Snapshot::Kind kind) {
-  if (kind == Snapshot::kFull || kind == Snapshot::kScript) {
+  if ((kind == Snapshot::kFull && !writer->snapshot_code()) ||
+      kind == Snapshot::kScript) {
     // The immutable maps that seed map literals are not yet VM-internal, so
     // we don't reach this.
-    UNREACHABLE();
   }
   ASSERT(writer != NULL);
 
   // Write out the serialization header value for this object.
   writer->WriteInlinedObjectHeader(object_id);
 
   // Write out the class and tags information.
   writer->WriteIndexedObject(kLinkedHashMapCid);
   const uword tags = writer->GetObjectTags(this);
   writer->WriteTags(tags);
@@ skipping 425 matching lines @@
   } else {
     UNREACHABLE();
   }
 }
 
 
 RawSendPort* SendPort::ReadFrom(SnapshotReader* reader,
                                 intptr_t object_id,
                                 intptr_t tags,
                                 Snapshot::Kind kind) {
+  ASSERT(kind == Snapshot::kMessage || reader->snapshot_code());
+
   uint64_t id = reader->Read<uint64_t>();
   uint64_t origin_id = reader->Read<uint64_t>();
 
-  SendPort& result = SendPort::ZoneHandle(reader->zone(),
-                                          SendPort::New(id, origin_id));
+  SendPort& result = SendPort::ZoneHandle(reader->zone());
+  if (reader->snapshot_code()) {
+    // TODO(rmacnak): Reset fields in precompiled snapshots and assert
+    // this is unreachable.
+  } else {
+    result = SendPort::New(id, origin_id);
+  }
   reader->AddBackRef(object_id, &result, kIsDeserialized);
   return result.raw();
 }
 
 
 void RawSendPort::WriteTo(SnapshotWriter* writer,
                           intptr_t object_id,
                           Snapshot::Kind kind) {
   // Write out the serialization header value for this object.
   writer->WriteInlinedObjectHeader(object_id);
 
   // Write out the class and tags information.
   writer->WriteIndexedObject(kSendPortCid);
   writer->WriteTags(writer->GetObjectTags(this));
 
   writer->Write<uint64_t>(ptr()->id_);
   writer->Write<uint64_t>(ptr()->origin_id_);
 }
 
 
 RawStacktrace* Stacktrace::ReadFrom(SnapshotReader* reader,
                                     intptr_t object_id,
                                     intptr_t tags,
                                     Snapshot::Kind kind) {
   if (kind == Snapshot::kFull) {
     Stacktrace& result = Stacktrace::ZoneHandle(reader->zone(),
                                                 reader->NewStacktrace());
     reader->AddBackRef(object_id, &result, kIsDeserialized);
 
-    // Set all the object fields.
-    // TODO(5411462): Need to assert No GC can happen here, even though
-    // allocations may happen.
-    intptr_t num_flds = (result.raw()->to() - result.raw()->from());
-    for (intptr_t i = 0; i <= num_flds; i++) {
-      (*reader->PassiveObjectHandle()) = reader->ReadObjectImpl(kAsReference);
-      result.StorePointer((result.raw()->from() + i),
-                          reader->PassiveObjectHandle()->raw());
-    }
-
     bool expand_inlined = reader->Read<bool>();
     result.set_expand_inlined(expand_inlined);
 
+    // Set all the object fields.
+    READ_OBJECT_FIELDS(result,
+                       result.raw()->from(), result.raw()->to(),
+                       kAsReference);
+
     return result.raw();
   }
   UNREACHABLE();  // Stacktraces are not sent in a snapshot.
   return Stacktrace::null();
 }
 
 
 void RawStacktrace::WriteTo(SnapshotWriter* writer,
                             intptr_t object_id,
                             Snapshot::Kind kind) {
   if (kind == Snapshot::kFull) {
     ASSERT(writer != NULL);
     ASSERT(this == Isolate::Current()->object_store()->
            preallocated_stack_trace());
 
     // Write out the serialization header value for this object.
     writer->WriteInlinedObjectHeader(object_id);
 
     // Write out the class and tags information.
     writer->WriteIndexedObject(kStacktraceCid);
     writer->WriteTags(writer->GetObjectTags(this));
 
+    writer->Write(ptr()->expand_inlined_);
+
     // Write out all the object pointer fields.
     SnapshotWriterVisitor visitor(writer);
     visitor.VisitPointers(from(), to());
-
-    writer->Write(ptr()->expand_inlined_);
   } else {
     // Stacktraces are not allowed in other snapshot forms.
     writer->SetWriteException(Exceptions::kArgument,
                               "Illegal argument in isolate message"
                               " : (object is a stacktrace)");
   }
 }
 
 
 RawJSRegExp* JSRegExp::ReadFrom(SnapshotReader* reader,
@@ skipping 49 matching lines @@
                                         intptr_t tags,
                                         Snapshot::Kind kind) {
   ASSERT(reader != NULL);
 
   // Allocate the weak property object.
   WeakProperty& weak_property = WeakProperty::ZoneHandle(
       reader->zone(), WeakProperty::New(HEAP_SPACE(kind)));
   reader->AddBackRef(object_id, &weak_property, kIsDeserialized);
 
   // Set all the object fields.
-  // TODO(5411462): Need to assert No GC can happen here, even though
-  // allocations may happen.
-  intptr_t num_flds = (weak_property.raw()->to() -
-                       weak_property.raw()->from());
-  for (intptr_t i = 0; i <= num_flds; i++) {
-    (*reader->PassiveObjectHandle()) = reader->ReadObjectImpl(kAsReference);
-    weak_property.StorePointer((weak_property.raw()->from() + i),
-                               reader->PassiveObjectHandle()->raw());
-  }
+  READ_OBJECT_FIELDS(weak_property,
+                     weak_property.raw()->from(), weak_property.raw()->to(),
+                     kAsReference);
 
   return weak_property.raw();
 }
 
 
 void RawWeakProperty::WriteTo(SnapshotWriter* writer,
                           intptr_t object_id,
                           Snapshot::Kind kind) {
   ASSERT(writer != NULL);
 
@@ skipping 49 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 UserTag)");
   } else {
     UNREACHABLE();
   }
 }
 
 }  // namespace dart