Implement PEP 3115 -- new metaclass syntax and semantics.

The compiler package hasn't been updated yet; test_compiler.py fails.
Otherwise all tests seem to be passing now.  There are no occurrences
of __metaclass__ left in the standard library.
Docs have not been updated.

1 files changed, 16 insertions, 73 deletions

diff --git a/Python/ceval.c b/Python/ceval.c
index 5cad632..5a3fc59 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -117,7 +117,6 @@ static int assign_slice(PyObject *, PyObject *,
 static PyObject * cmp_outcome(int, PyObject *, PyObject *);
 static PyObject * import_from(PyObject *, PyObject *);
 static int import_all_from(PyObject *, PyObject *);
-static PyObject * build_class(PyObject *, PyObject *, PyObject *);
 static void set_exc_info(PyThreadState *, PyObject *, PyObject *, PyObject *);
 static void reset_exc_info(PyThreadState *);
 static void format_exc_check_arg(PyObject *, char *, PyObject *);
@@ -1532,14 +1531,12 @@ PyEval_EvalFrameEx(PyFrameObject *f, int throwflag)
 			}
 			break;
 
-		case LOAD_LOCALS:
-			if ((x = f->f_locals) != NULL) {
-				Py_INCREF(x);
-				PUSH(x);
-				continue;
-			}
-			PyErr_SetString(PyExc_SystemError, "no locals");
-			break;
+		case STORE_LOCALS:
+			x = POP();
+			v = f->f_locals;
+			Py_XDECREF(v);
+			f->f_locals = x;
+			continue;
 
 		case RETURN_VALUE:
 			retval = POP();
@@ -1586,16 +1583,16 @@ PyEval_EvalFrameEx(PyFrameObject *f, int throwflag)
 			Py_DECREF(v);
 			break;
 
-		case BUILD_CLASS:
-			u = TOP();
-			v = SECOND();
-			w = THIRD();
-			STACKADJ(-2);
-			x = build_class(u, v, w);
-			SET_TOP(x);
-			Py_DECREF(u);
-			Py_DECREF(v);
-			Py_DECREF(w);
+		case LOAD_BUILD_CLASS:
+			x = PyDict_GetItemString(f->f_builtins,
+						 "__build_class__");
+			if (x == NULL) {
+				PyErr_SetString(PyExc_ImportError,
+						"__build_class__ not found");
+				break;
+			}
+			Py_INCREF(x);
+			PUSH(x);
 			break;
 
 		case STORE_NAME:
@@ -4023,60 +4020,6 @@ import_all_from(PyObject *locals, PyObject *v)
 	return err;
 }
 
-static PyObject *
-build_class(PyObject *methods, PyObject *bases, PyObject *name)
-{
-	PyObject *metaclass = NULL, *result, *base;
-
-	if (PyDict_Check(methods))
-		metaclass = PyDict_GetItemString(methods, "__metaclass__");
-	if (metaclass != NULL)
-		Py_INCREF(metaclass);
-	else if (PyTuple_Check(bases) && PyTuple_GET_SIZE(bases) > 0) {
-		base = PyTuple_GET_ITEM(bases, 0);
-		metaclass = PyObject_GetAttrString(base, "__class__");
-		if (metaclass == NULL) {
-			PyErr_Clear();
-			metaclass = (PyObject *)base->ob_type;
-			Py_INCREF(metaclass);
-		}
-	}
-	else {
-		PyObject *g = PyEval_GetGlobals();
-		if (g != NULL && PyDict_Check(g))
-			metaclass = PyDict_GetItemString(g, "__metaclass__");
-		if (metaclass == NULL)
-			metaclass = (PyObject *) &PyType_Type;
-		Py_INCREF(metaclass);
-	}
-	result = PyObject_CallFunctionObjArgs(metaclass, name, bases, methods,
-                                              NULL);
-	Py_DECREF(metaclass);
-	if (result == NULL && PyErr_ExceptionMatches(PyExc_TypeError)) {
-		/* A type error here likely means that the user passed
-		   in a base that was not a class (such the random module
-		   instead of the random.random type).  Help them out with
-		   by augmenting the error message with more information.*/
-
-		PyObject *ptype, *pvalue, *ptraceback;
-
-		PyErr_Fetch(&ptype, &pvalue, &ptraceback);
-		if (PyString_Check(pvalue)) {
-			PyObject *newmsg;
-			newmsg = PyString_FromFormat(
-				"Error when calling the metaclass bases\n"
-                                "    %s",
-				PyString_AS_STRING(pvalue));
-			if (newmsg != NULL) {
-				Py_DECREF(pvalue);
-				pvalue = newmsg;
-			}
-		}
-		PyErr_Restore(ptype, pvalue, ptraceback);
-	}
-	return result;
-}
-
 static void
 format_exc_check_arg(PyObject *exc, char *format_str, PyObject *obj)
 {