Implement const expressions for local variables

runtime/vm/ast.cc

 // Copyright (c) 2011, 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/ast.h"
 #include "vm/compiler.h"
 #include "vm/dart_entry.h"
 #include "vm/isolate.h"
 #include "vm/object_store.h"
 #include "vm/resolver.h"
@@ skipping 285 matching lines @@
 const char* UnaryOpNode::Name() const {
   return Token::Str(kind_);
 }
 
 
 const char* JumpNode::Name() const {
   return Token::Str(kind_);
 }
 
 
+const Instance* LoadLocalNode::EvalConstExpr() const {
+  if (local().IsConst()) {
+    return local().ConstValue();
+  }
+  return NULL;
+}
+
+
 AstNode* LoadLocalNode::MakeAssignmentNode(AstNode* rhs) {
   if (local().is_final()) {
     return NULL;
   }
   if (HasPseudo()) {
     return NULL;
   }
   return new StoreLocalNode(token_pos(), &local(), rhs);
 }
 
@@ skipping 111 matching lines @@
   if (result.IsError() || result.IsNull()) {
     // TODO(turnidge): We could get better error messages by returning
     // the Error object directly to the parser.  This will involve
     // replumbing all of the EvalConstExpr methods.
     return NULL;
   }
   return &Instance::ZoneHandle(Instance::Cast(result).raw());
 }
 
 }  // namespace dart