Implement gi_yieldfrom

Author: msimacek

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/generator/GeneratorBuiltins.java

@@ -69,6 +69,8 @@
 import com.oracle.graal.python.nodes.function.PythonBuiltinNode;
 import com.oracle.graal.python.nodes.function.builtins.PythonBinaryBuiltinNode;
 import com.oracle.graal.python.nodes.function.builtins.PythonUnaryBuiltinNode;
+import com.oracle.graal.python.nodes.generator.AbstractYieldNode;
+import com.oracle.graal.python.nodes.generator.YieldFromNode;
 import com.oracle.graal.python.nodes.object.IsBuiltinClassProfile;
 import com.oracle.graal.python.runtime.exception.PException;
 import com.oracle.graal.python.runtime.object.PythonObjectFactory;
@@ -542,6 +544,21 @@ static Object getFrame(PGenerator self,
         }
     }
 
+    @Builtin(name = "gi_yieldfrom", minNumOfPositionalArgs = 1, isGetter = true)
+    @GenerateNodeFactory
+    public abstract static class GetYieldFromNode extends PythonUnaryBuiltinNode {
+        @Specialization
+        static Object getYieldFrom(PGenerator self) {
+            AbstractYieldNode currentYield = self.getCurrentYieldNode();
+            if (currentYield instanceof YieldFromNode) {
+                int iteratorSlot = ((YieldFromNode) currentYield).getIteratorSlot();
+                return PArguments.getControlDataFromGeneratorArguments(self.getArguments()).getIteratorAt(iteratorSlot);
+            } else {
+                return PNone.NONE;
+            }
+        }
+    }
+
     @Builtin(name = __REPR__, minNumOfPositionalArgs = 1)
     @GenerateNodeFactory
     abstract static class ReprNode extends PythonUnaryBuiltinNode {

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/nodes/generator/YieldFromNode.java

@@ -217,6 +217,10 @@ public Object execute(VirtualFrame frame) {
         }
     }
 
+    public int getIteratorSlot() {
+        return iteratorSlot;
+    }
+
     private GetAttributeNode getGetValue() {
         if (getValue == null) {
             CompilerDirectives.transferToInterpreterAndInvalidate();