Implement const expressions for local variables

runtime/vm/scopes.cc

Index: runtime/vm/scopes.cc
===================================================================
--- runtime/vm/scopes.cc	(revision 14713)
+++ runtime/vm/scopes.cc	(working copy)
@@ -460,7 +460,12 @@
       context_scope.SetTokenIndexAt(captured_idx, variable->token_pos());
       context_scope.SetNameAt(captured_idx, variable->name());
       context_scope.SetIsFinalAt(captured_idx, variable->is_final());
-      context_scope.SetTypeAt(captured_idx, variable->type());
+      context_scope.SetIsConstAt(captured_idx, variable->IsConst());
+      if (variable->IsConst()) {
+        context_scope.SetConstValueAt(captured_idx, *variable->ConstValue());
+      } else {
+        context_scope.SetTypeAt(captured_idx, variable->type());
+      }
       context_scope.SetContextIndexAt(captured_idx, variable->index());
       // Adjust the context level relative to the current context level,
       // since the context of the current scope will be at level 0 when
@@ -482,10 +487,18 @@
   LocalScope* outer_scope = new LocalScope(NULL, -1, 0);
   // Add all variables as aliases to the outer scope.
   for (int i = 0; i < context_scope.num_variables(); i++) {
-    LocalVariable* variable =
-        new LocalVariable(context_scope.TokenIndexAt(i),
-                          String::ZoneHandle(context_scope.NameAt(i)),
-                          AbstractType::ZoneHandle(context_scope.TypeAt(i)));
+    LocalVariable* variable;
+    if (context_scope.IsConstAt(i)) {
+      variable = new LocalVariable(context_scope.TokenIndexAt(i),
+          String::ZoneHandle(context_scope.NameAt(i)),
+          AbstractType::ZoneHandle(Type::DynamicType()));
+      variable->SetConstValue(
+          Instance::ZoneHandle(context_scope.ConstValueAt(i)));
+    } else {
+      variable = new LocalVariable(context_scope.TokenIndexAt(i),
+          String::ZoneHandle(context_scope.NameAt(i)),
+          AbstractType::ZoneHandle(context_scope.TypeAt(i)));
+    }
     variable->set_is_captured();
     variable->set_index(context_scope.ContextIndexAt(i));
     if (context_scope.IsFinalAt(i)) {
@@ -516,6 +529,7 @@
   context_scope.SetTokenIndexAt(0, func.token_pos());
   context_scope.SetNameAt(0, name);
   context_scope.SetIsFinalAt(0, true);
+  context_scope.SetIsConstAt(0, false);
   const AbstractType& type = AbstractType::Handle(func.ParameterTypeAt(0));
   context_scope.SetTypeAt(0, type);
   context_scope.SetContextIndexAt(0, 0);