DeleteClassAttributeNode: do not cache locals dict

Author: steve-s

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/nodes/classes/DeleteClassAttributeNode.java

@@ -46,6 +46,7 @@
 import com.oracle.graal.python.nodes.argument.ReadIndexedArgumentNode;
 import com.oracle.graal.python.nodes.statement.StatementNode;
 import com.oracle.graal.python.nodes.subscript.DeleteItemNode;
+import com.oracle.truffle.api.dsl.Bind;
 import com.oracle.truffle.api.dsl.Cached;
 import com.oracle.truffle.api.dsl.Specialization;
 import com.oracle.truffle.api.frame.VirtualFrame;
@@ -55,12 +56,13 @@
 public abstract class DeleteClassAttributeNode extends StatementNode {
     private final String identifier;
 
-    @Child private StatementNode deleteNsItem;
-
     DeleteClassAttributeNode(String identifier) {
         this.identifier = identifier;
+    }
+
+    protected StatementNode createDeleteNsItem() {
         ReadIndexedArgumentNode namespace = ReadIndexedArgumentNode.create(0);
-        this.deleteNsItem = PythonLanguage.getCurrent().getNodeFactory().createDeleteItem(namespace.asExpression(), this.identifier);
+        return PythonLanguage.getCurrent().getNodeFactory().createDeleteItem(namespace.asExpression(), identifier);
     }
 
     public static DeleteClassAttributeNode create(String name) {
@@ -77,15 +79,17 @@ Object getLocalsDict(VirtualFrame frame) {
     }
 
     @Specialization(guards = "localsDict != null")
-    void deleteFromLocals(@SuppressWarnings("unused") VirtualFrame frame,
-                    @Cached("getLocalsDict(frame)") Object localsDict,
+    void deleteFromLocals(VirtualFrame frame,
+                    @Bind("getLocalsDict(frame)") Object localsDict,
                     @Cached("create()") DeleteItemNode delItemNode) {
         // class namespace overrides closure
         delItemNode.executeWith(frame, localsDict, identifier);
     }
 
-    @Specialization
-    void delete(VirtualFrame frame) {
+    @Specialization(guards = "localsDict == null")
+    void delete(VirtualFrame frame,
+                    @Bind("getLocalsDict(frame)") Object localsDict,
+                    @Cached("createDeleteNsItem()") StatementNode deleteNsItem) {
         // delete attribute actual attribute
         deleteNsItem.executeVoid(frame);
     }