only create and write the annotations dict if there are any

Author: timfel

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/nodes/function/FunctionDefinitionNode.java

@@ -25,14 +25,18 @@
  */
 package com.oracle.graal.python.nodes.function;
 
+import static com.oracle.graal.python.nodes.SpecialAttributeNames.__ANNOTATIONS__;
+
+import java.util.Map;
+
 import com.oracle.graal.python.PythonLanguage;
 import com.oracle.graal.python.builtins.objects.cell.PCell;
+import com.oracle.graal.python.builtins.objects.common.HashingCollectionNodes;
 import com.oracle.graal.python.builtins.objects.dict.PDict;
 import com.oracle.graal.python.builtins.objects.function.PArguments;
 import com.oracle.graal.python.builtins.objects.function.PFunction;
 import com.oracle.graal.python.builtins.objects.function.PKeyword;
 import com.oracle.graal.python.nodes.SpecialAttributeNames;
-import static com.oracle.graal.python.nodes.SpecialAttributeNames.__ANNOTATIONS__;
 import com.oracle.graal.python.nodes.attributes.WriteAttributeToDynamicObjectNode;
 import com.oracle.graal.python.nodes.attributes.WriteAttributeToObjectNode;
 import com.oracle.graal.python.nodes.expression.ExpressionNode;
@@ -49,7 +53,6 @@
 import com.oracle.truffle.api.frame.VirtualFrame;
 import com.oracle.truffle.api.nodes.ExplodeLoop;
 import com.oracle.truffle.api.nodes.RootNode;
-import java.util.Map;
 
 public class FunctionDefinitionNode extends ExpressionDefinitionNode {
     @CompilationFinal private ContextReference<PythonContext> contextRef;
@@ -63,6 +66,7 @@ public class FunctionDefinitionNode extends ExpressionDefinitionNode {
     @Child private WriteAttributeToObjectNode writeAttrNode = WriteAttributeToObjectNode.create();
     @Child private WriteAttributeToDynamicObjectNode writeNameNode = WriteAttributeToDynamicObjectNode.create();
     @Child private PythonObjectFactory factory = PythonObjectFactory.create();
+    @Child private HashingCollectionNodes.SetItemNode setItemNode;
 
     @CompilerDirectives.CompilationFinal(dimensions = 1) private final String[] annotationNames;
     @Children private ExpressionNode[] annotationTypes;
@@ -134,10 +138,8 @@ public Object execute(VirtualFrame frame) {
 
         // Processing annotated arguments.
         // The __annotations__ dictionary is created even there are is not any annotated arg.
-        PDict annotations = factory().createDict();
-        writeAttrNode.execute(func, __ANNOTATIONS__, annotations);
         if (annotationNames != null) {
-            writeAnnotations(frame, annotations);
+            writeAnnotations(frame, func);
         }
         return func;
     }
@@ -175,12 +177,18 @@ private Object[] computeDefaultValues(VirtualFrame frame) {
     }
 
     @ExplodeLoop
-    private void writeAnnotations(VirtualFrame frame, PDict annotations) {
+    private void writeAnnotations(VirtualFrame frame, PFunction func) {
+        PDict annotations = factory().createDict();
+        writeAttrNode.execute(func, __ANNOTATIONS__, annotations);
+        if (setItemNode == null) {
+            CompilerDirectives.transferToInterpreterAndInvalidate();
+            setItemNode = insert(HashingCollectionNodes.SetItemNode.create());
+        }
         for (int i = 0; i < annotationNames.length; i++) {
             // compute the types of the arg
             Object type = annotationTypes[i].execute(frame);
             // set the annotations
-            annotations.setItem(annotationNames[i], type);
+            setItemNode.execute(frame, annotations, annotationNames[i], type);
         }
     }