Don't serialize local variables.

pkg/analyzer/lib/src/dart/element/element.dart

Index: pkg/analyzer/lib/src/dart/element/element.dart
diff --git a/pkg/analyzer/lib/src/dart/element/element.dart b/pkg/analyzer/lib/src/dart/element/element.dart
index 2da9fd6d06c337ba892382898451c93bfc9067a1..b8851f9beb26ac3217bb3a116b6e70502c1454e1 100644
--- a/pkg/analyzer/lib/src/dart/element/element.dart
+++ b/pkg/analyzer/lib/src/dart/element/element.dart
@@ -3792,22 +3792,6 @@ abstract class ExecutableElementImpl extends ElementImpl
 
   @override
   List<LocalVariableElement> get localVariables {

[Brian Wilkerson, 2017/06/29 21:51:41]

If this method is always going to return an empty list, then can we remove
`_localVariables`?

More generally, though, I don't like the idea that one representation never has
local variable and others do. If we're removing them from the API, then it seems
like we should mark the getter as being deprecated and return an empty list from
all of the implementations. Am I missing something?

Should we remove other local elements as well (or at least mark the getters /
methods as deprecated)?

[scheglov, 2017/06/29 22:09:11]

This is an interesting question.
Now as I search to "localVariable" usages, I see that it is used only in a
couple of places.
We mostly SET it, but very rarely GET.

Tests use it pretty often, mostly to verify type inference; plus tests of
elements builders.

OK, I will try to clean up these clients first, and then we will get a change
that removes this API.

-    if (serializedExecutable != null && _localVariables == null) {
-      List<UnlinkedVariable> unlinkedVariables =
-          serializedExecutable.localVariables;
-      int length = unlinkedVariables.length;
-      if (length != 0) {
-        List<LocalVariableElementImpl> localVariables =
-            new List<LocalVariableElementImpl>(length);
-        for (int i = 0; i < length; i++) {
-          localVariables[i] = new LocalVariableElementImpl.forSerializedFactory(
-              unlinkedVariables[i], this);
-        }
-        _localVariables = localVariables;
-      } else {
-        _localVariables = const <LocalVariableElement>[];
-      }
-    }
     return _localVariables ?? const <LocalVariableElement>[];
   }