Map deleted enum values to a sentinel value.

runtime/vm/parser.cc

Index: runtime/vm/parser.cc
diff --git a/runtime/vm/parser.cc b/runtime/vm/parser.cc
index 86264b9b2308c14281548bc15378f97f132ccecb..7932301034d0ed95f7a187326b3a8b741b83f4bb 100644
--- a/runtime/vm/parser.cc
+++ b/runtime/vm/parser.cc
@@ -4865,6 +4865,17 @@ void Parser::ParseEnumDefinition(const Class& cls) {
                  Type::Handle(Z, Type::ArrayType()), cls.token_pos());
   enum_members.AddField(values_field);
 
+  // Add static field 'const _deleted_enum_sentinel'.
+  Field& deleted_enum_sentinel = Field::ZoneHandle(Z);
+  deleted_enum_sentinel =
+      Field::New(Symbols::_DeletedEnumSentinel(),
+                 /* is_static = */ true,
+                 /* is_final = */ true,
+                 /* is_const = */ true,
+                 /* is_reflectable = */ false, cls,
+                 Type::Handle(Z, Type::ArrayType()), cls.token_pos());

[siva, 2016/11/14 22:18:23]

Type::Handle(Z, Type::ArrayType()) could be hoisted out from the two Field::New
calls.

Also we could hoist this above and use values_field handle for both cases.

[Cutch, 2016/11/15 22:13:55]

Done.

+  enum_members.AddField(deleted_enum_sentinel);
+
   // Allocate the immutable array containing the enumeration values.
   // The actual enum instance values will be patched in later.
   const Array& values_array = Array::Handle(Z, Array::New(i, Heap::kOld));