implement __init_subclass__ call after creating a new type as per PEP 487

Author: timfel

graalpython/com.oracle.graal.python.test/src/tests/test_genericclass.py

@@ -184,15 +184,15 @@ class D(C): ...
         self.assertEqual(D[int], 'D[int]')
         self.assertEqual(D[D], 'D[D]')
 
-    # def test_class_getitem_patched(self):
-    #     class C:
-    #         def __init_subclass__(cls):
-    #             def __class_getitem__(cls, item):
-    #                 return '{0}[{1}]'.format(cls.__name__, item.__name__)
-    #             cls.__class_getitem__ = classmethod(__class_getitem__)
-    #     class D(C): ...
-    #     self.assertEqual(D[int], 'D[int]')
-    #     self.assertEqual(D[D], 'D[D]')
+    def test_class_getitem_patched(self):
+        class C:
+            def __init_subclass__(cls):
+                def __class_getitem__(cls, item):
+                    return '{0}[{1}]'.format(cls.__name__, item.__name__)
+                cls.__class_getitem__ = classmethod(__class_getitem__)
+        class D(C): ...
+        self.assertEqual(D[int], 'D[int]')
+        self.assertEqual(D[D], 'D[D]')
 
     def test_class_getitem_with_builtins(self):
         class A(dict):

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/modules/BuiltinConstructors.java

@@ -119,6 +119,7 @@
 import com.oracle.graal.python.builtins.objects.set.PSet;
 import com.oracle.graal.python.builtins.objects.set.SetNodes;
 import com.oracle.graal.python.builtins.objects.str.PString;
+import com.oracle.graal.python.builtins.objects.superobject.SuperObject;
 import com.oracle.graal.python.builtins.objects.tuple.PTuple;
 import com.oracle.graal.python.builtins.objects.type.LazyPythonClass;
 import com.oracle.graal.python.builtins.objects.type.PythonAbstractClass;
@@ -130,6 +131,7 @@
 import com.oracle.graal.python.builtins.objects.type.TypeNodes.GetNameNode;
 import com.oracle.graal.python.nodes.PGuards;
 import com.oracle.graal.python.nodes.SpecialMethodNames;
+import com.oracle.graal.python.nodes.attributes.GetAttributeNode;
 import com.oracle.graal.python.nodes.attributes.GetAttributeNode.GetAnyAttributeNode;
 import com.oracle.graal.python.nodes.attributes.LookupAttributeInMRONode;
 import com.oracle.graal.python.nodes.attributes.LookupInheritedAttributeNode;
@@ -1813,6 +1815,8 @@ public Object type(Object cls, Object obj, PNone bases, PNone dict, PKeyword[] k
         public Object type(VirtualFrame frame, PythonAbstractClass cls, String name, PTuple bases, PDict namespace, PKeyword[] kwds,
                         @Cached("create()") GetClassNode getMetaclassNode,
                         @Cached("create(__NEW__)") LookupInheritedAttributeNode getNewFuncNode,
+                        @Cached("create(__INIT_SUBCLASS__)") GetAttributeNode getInitSubclassNode,
+                        @Cached("create()") CallNode callInitSubclassNode,
                         @Cached("create()") CallNode callNewFuncNode) {
             // Determine the proper metatype to deal with this
             PythonAbstractClass metaclass = calculate_metaclass(cls, bases, getMetaclassNode);
@@ -1827,7 +1831,14 @@ public Object type(VirtualFrame frame, PythonAbstractClass cls, String name, PTu
             }
 
             try {
-                Object newType = typeMetaclass(name, bases, namespace, metaclass);
+                PythonClass newType = typeMetaclass(name, bases, namespace, metaclass);
+
+                // TODO: Call __set_name__ on all descriptors in a newly generated type
+
+                // Call __init_subclass__ on the parent of a newly generated type
+                SuperObject superObject = factory().createSuperObject(PythonBuiltinClassType.Super);
+                superObject.init(newType, newType, newType);
+                callInitSubclassNode.execute(frame, getInitSubclassNode.executeObject(superObject), new Object[0], kwds);
 
                 // set '__module__' attribute
                 Object moduleAttr = ensureReadAttrNode().execute(newType, __MODULE__);
@@ -1863,7 +1874,7 @@ private String getModuleNameFromGlobals(PythonObject globals) {
         }
 
         @TruffleBoundary
-        private Object typeMetaclass(String name, PTuple bases, PDict namespace, PythonAbstractClass metaclass) {
+        private PythonClass typeMetaclass(String name, PTuple bases, PDict namespace, PythonAbstractClass metaclass) {
 
             Object[] array = bases.getArray();
 

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/object/ObjectBuiltins.java

@@ -39,6 +39,7 @@
 import static com.oracle.graal.python.nodes.SpecialMethodNames.__GETATTR__;
 import static com.oracle.graal.python.nodes.SpecialMethodNames.__GET__;
 import static com.oracle.graal.python.nodes.SpecialMethodNames.__HASH__;
+import static com.oracle.graal.python.nodes.SpecialMethodNames.__INIT_SUBCLASS__;
 import static com.oracle.graal.python.nodes.SpecialMethodNames.__INIT__;
 import static com.oracle.graal.python.nodes.SpecialMethodNames.__LEN__;
 import static com.oracle.graal.python.nodes.SpecialMethodNames.__NE__;
@@ -631,4 +632,13 @@ boolean richcmp(Object left, Object right, @SuppressWarnings("unused") String op
             return node.executeBool(left, right);
         }
     }
+
+    @Builtin(name = __INIT_SUBCLASS__, minNumOfPositionalArgs = 1)
+    @GenerateNodeFactory
+    abstract static class InitSubclass extends PythonUnaryBuiltinNode {
+        @Specialization
+        PNone initSubclass(@SuppressWarnings("unused") Object self) {
+            return PNone.NONE;
+        }
+    }
 }