Shrink some fields and add some bounds checks.

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"
@@ skipping 14 matching lines @@
 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());
   if ((kind == Snapshot::kFull) ||
       (kind == Snapshot::kScript && !RawObject::IsCreatedFromSnapshot(tags))) {
     // Read in the base information.
-    int32_t class_id = reader->Read<int32_t>();
+    classid_t class_id = reader->Read<classid_t>();
 
     // Allocate class object of specified kind.
     if (kind == Snapshot::kFull) {
       cls = reader->NewClass(class_id);
     } else {
       if (class_id < kNumPredefinedCids) {
         ASSERT((class_id >= kInstanceCid) && (class_id <= kMirrorReferenceCid));
         cls = reader->isolate()->class_table()->At(class_id);
       } else {
         cls = New<Instance>(kIllegalCid);
@@ skipping 43 matching lines @@
 
   if ((kind == Snapshot::kFull) ||
       (kind == Snapshot::kScript &&
        !RawObject::IsCreatedFromSnapshot(writer->GetObjectTags(this)))) {
     // Write out the class and tags information.
     writer->WriteVMIsolateObject(kClassCid);
     writer->WriteTags(writer->GetObjectTags(this));
 
     // Write out all the non object pointer fields.
     // NOTE: cpp_vtable_ is not written.
-    int32_t class_id = ptr()->id_;
-    writer->Write<int32_t>(class_id);
+    classid_t class_id = ptr()->id_;
+    writer->Write<classid_t>(class_id);
     if (!RawObject::IsInternalVMdefinedClassId(class_id)) {
       // We don't write the instance size of VM defined classes as they
       // are already setup during initialization as part of pre populating
       // the class table.
       writer->Write<int32_t>(ptr()->instance_size_in_words_);
       writer->Write<int32_t>(ptr()->next_field_offset_in_words_);
     }
     writer->Write<int32_t>(ptr()->type_arguments_field_offset_in_words_);
-    writer->Write<int16_t>(ptr()->num_type_arguments_);
-    writer->Write<int16_t>(ptr()->num_own_type_arguments_);
+    writer->Write<uint16_t>(ptr()->num_type_arguments_);
+    writer->Write<uint16_t>(ptr()->num_own_type_arguments_);
     writer->Write<uint16_t>(ptr()->num_native_fields_);
     writer->Write<int32_t>(ptr()->token_pos_);
     writer->Write<uint16_t>(ptr()->state_bits_);
 
     // Write out all the object pointer fields.
     SnapshotWriterVisitor visitor(writer);
     visitor.VisitPointers(from(), to());
   } else {
     if (writer->can_send_any_object() ||
         writer->AllowObjectsInDartLibrary(ptr()->library_)) {
@@ skipping 204 matching lines @@
 
   // Allocate type parameter object.
   TypeParameter& type_parameter = TypeParameter::ZoneHandle(
       reader->zone(), NEW_OBJECT(TypeParameter));
   reader->AddBackRef(object_id, &type_parameter, kIsDeserialized);
 
   // Set the object tags.
   type_parameter.set_tags(tags);
 
   // Set all non object fields.
-  type_parameter.set_index(reader->Read<int32_t>());
   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());
   for (intptr_t i = 0; i <= num_flds; i++) {
     (*reader->PassiveObjectHandle()) = reader->ReadObjectRef();
     type_parameter.StorePointer((type_parameter.raw()->from() + i),
@@ skipping 13 matching lines @@
   ASSERT(ptr()->type_state_ == RawTypeParameter::kFinalizedUninstantiated);
 
   // Write out the serialization header value for this object.
   writer->WriteInlinedObjectHeader(object_id);
 
   // Write out the class and tags information.
   writer->WriteIndexedObject(kTypeParameterCid);
   writer->WriteTags(writer->GetObjectTags(this));
 
   // Write out all the non object pointer fields.
-  writer->Write<int32_t>(ptr()->index_);
   writer->Write<int32_t>(ptr()->token_pos_);
+  writer->Write<int16_t>(ptr()->index_);
   writer->Write<int8_t>(ptr()->type_state_);
 
   // Write out all the object pointer fields.
   SnapshotWriterVisitor visitor(writer);
   visitor.VisitPointers(from(), to());
 }
 
 
 RawBoundedType* BoundedType::ReadFrom(SnapshotReader* reader,
                                       intptr_t object_id,
@@ skipping 317 matching lines @@
   // Set the object tags.
   func.set_tags(tags);
 
   // Set all the non object fields.
   func.set_token_pos(reader->Read<int32_t>());
   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_regexp_cid(reader->Read<int16_t>());
+  func.set_regexp_cid(reader->Read<classid_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.
   intptr_t num_flds = (func.raw()->to_snapshot() - func.raw()->from());
   for (intptr_t i = 0; i <= num_flds; i++) {
     (*reader->PassiveObjectHandle()) = reader->ReadObjectRef();
@@ skipping 23 matching lines @@
   writer->WriteVMIsolateObject(kFunctionCid);
   writer->WriteTags(writer->GetObjectTags(this));
 
   // Write out all the non object fields.
   writer->Write<int32_t>(ptr()->token_pos_);
   writer->Write<int32_t>(ptr()->end_token_pos_);
   writer->Write<int32_t>(ptr()->usage_counter_);
   writer->Write<int16_t>(ptr()->num_fixed_parameters_);
   writer->Write<int16_t>(ptr()->num_optional_parameters_);
   writer->Write<int16_t>(ptr()->deoptimization_counter_);
-  writer->Write<int16_t>(ptr()->regexp_cid_);
+  writer->Write<classid_t>(ptr()->regexp_cid_);
   writer->Write<uint32_t>(ptr()->kind_tag_);
   writer->Write<uint16_t>(ptr()->optimized_instruction_count_);
   writer->Write<uint16_t>(ptr()->optimized_call_site_count_);
 
   // Write out all the object pointer fields.
   SnapshotWriterVisitor visitor(writer);
   visitor.VisitPointers(from(), to_snapshot());
 }
 
 
@@ skipping 268 matching lines @@
     library = Library::LookupLibrary(*reader->StringHandle());
   } else {
     // Allocate library object.
     library = NEW_OBJECT(Library);
 
     // Set the object tags.
     library.set_tags(tags);
 
     // Set all non object fields.
     library.StoreNonPointer(&library.raw_ptr()->index_,
-                            reader->Read<int32_t>());
+                            reader->Read<classid_t>());
+    library.StoreNonPointer(&library.raw_ptr()->num_anonymous_,
+                            reader->Read<classid_t>());
     library.StoreNonPointer(&library.raw_ptr()->num_imports_,
-                            reader->Read<int32_t>());
-    library.StoreNonPointer(&library.raw_ptr()->num_anonymous_,
-                            reader->Read<int32_t>());
+                            reader->Read<uint16_t>());
+    library.StoreNonPointer(&library.raw_ptr()->load_state_,
+                            reader->Read<int8_t>());
     library.StoreNonPointer(&library.raw_ptr()->corelib_imported_,
                             reader->Read<bool>());
     library.StoreNonPointer(&library.raw_ptr()->is_dart_scheme_,
                             reader->Read<bool>());
     library.StoreNonPointer(&library.raw_ptr()->debuggable_,
                             reader->Read<bool>());
-    library.StoreNonPointer(&library.raw_ptr()->load_state_,
-                            reader->Read<int8_t>());
     // The native resolver is not serialized.
     Dart_NativeEntryResolver resolver =
         reader->Read<Dart_NativeEntryResolver>();
     ASSERT(resolver == NULL);
     library.set_native_entry_resolver(resolver);
     // The symbol resolver is not serialized.
     Dart_NativeEntrySymbol symbol_resolver =
         reader->Read<Dart_NativeEntrySymbol>();
     ASSERT(symbol_resolver == NULL);
     library.set_native_entry_symbol_resolver(symbol_resolver);
@@ skipping 30 matching lines @@
   writer->WriteVMIsolateObject(kLibraryCid);
   writer->WriteTags(writer->GetObjectTags(this));
 
   if ((kind == Snapshot::kScript) &&
       RawObject::IsCreatedFromSnapshot(writer->GetObjectTags(this))) {
     ASSERT(kind != Snapshot::kFull);
     // Write out library URL so that it can be looked up when reading.
     writer->WriteObjectImpl(ptr()->url_);
   } else {
     // Write out all non object fields.
-    writer->Write<int32_t>(ptr()->index_);
-    writer->Write<int32_t>(ptr()->num_imports_);
-    writer->Write<int32_t>(ptr()->num_anonymous_);
+    writer->Write<classid_t>(ptr()->index_);
+    writer->Write<classid_t>(ptr()->num_anonymous_);
+    writer->Write<uint16_t>(ptr()->num_imports_);
+    writer->Write<int8_t>(ptr()->load_state_);
     writer->Write<bool>(ptr()->corelib_imported_);
     writer->Write<bool>(ptr()->is_dart_scheme_);
     writer->Write<bool>(ptr()->debuggable_);
-    writer->Write<int8_t>(ptr()->load_state_);
     // We do not serialize the native resolver over, this needs to be explicitly
     // set after deserialization.
     writer->Write<Dart_NativeEntryResolver>(NULL);
     // We do not serialize the native entry symbol, this needs to be explicitly
     // set after deserialization.
     writer->Write<Dart_NativeEntrySymbol>(NULL);
     // We do not write the loaded_scripts_ cache to the snapshot. It gets
     // set to NULL when reading the library from the snapshot, and will
     // be rebuilt lazily.
 
@@ skipping 16 matching lines @@
   // Allocate library prefix object.
   LibraryPrefix& prefix = LibraryPrefix::ZoneHandle(
       reader->zone(), NEW_OBJECT(LibraryPrefix));
   reader->AddBackRef(object_id, &prefix, kIsDeserialized);
 
   // Set the object tags.
   prefix.set_tags(tags);
 
   // Set all non object fields.
   prefix.StoreNonPointer(&prefix.raw_ptr()->num_imports_,
-                         reader->Read<int32_t>());
+                         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->ReadObjectRef();
@@ skipping 14 matching lines @@
          (kind == Snapshot::kFull));
 
   // Write out the serialization header value for this object.
   writer->WriteInlinedObjectHeader(object_id);
 
   // Write out the class and tags information.
   writer->WriteIndexedObject(kLibraryPrefixCid);
   writer->WriteTags(writer->GetObjectTags(this));
 
   // Write out all non object fields.
-  writer->Write<int32_t>(ptr()->num_imports_);
+  writer->Write<int16_t>(ptr()->num_imports_);
   writer->Write<bool>(ptr()->is_deferred_load_);
   writer->Write<bool>(ptr()->is_loaded_);
 
   // Write out all the object pointer fields.
   SnapshotWriterVisitor visitor(writer);
   visitor.VisitPointers(from(), to());
 }
 
 
 RawNamespace* Namespace::ReadFrom(SnapshotReader* reader,
@@ skipping 1753 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