Support attrwrapper as globals argument to execfile

Or rather, have execfile() be more permissive in what it accepts.
It may still abort when we get to pickGlobalsAndLocals() and we
discover that we can't actually execute in that particular attrwrapper.

src/codegen/irgen/hooks.cpp

@@ -502,7 +502,8 @@ static void pickGlobalsAndLocals(Box*& globals, Box*& locals) {
     if (globals->cls == attrwrapper_cls)
         globals = unwrapAttrWrapper(globals);
 
-    assert(globals && (globals->cls == module_cls || globals->cls == dict_cls));
+    RELEASE_ASSERT(globals && (globals->cls == module_cls || globals->cls == dict_cls), "Unspported globals type: %s",
+                   globals ? globals->cls->tp_name : "NULL");
 
     if (globals) {
         // From CPython (they set it to be f->f_builtins):

src/runtime/builtin_modules/builtins.cpp

@@ -1932,7 +1932,8 @@ static PyObject* builtin_execfile(PyObject* self, PyObject* args) noexcept {
     if (PyErr_WarnPy3k("execfile() not supported in 3.x; use exec()", 1) < 0)
         return NULL;
 
-    if (!PyArg_ParseTuple(args, "s|O!O:execfile", &filename, &PyDict_Type, &globals, &locals))
+    // Pyston change: allow attrwrappers here
+    if (!PyArg_ParseTuple(args, "s|OO:execfile", &filename, &globals, &locals))
         return NULL;
     if (locals != Py_None && !PyMapping_Check(locals)) {
         PyErr_SetString(PyExc_TypeError, "locals must be a mapping");
@@ -1945,6 +1946,11 @@ static PyObject* builtin_execfile(PyObject* self, PyObject* args) noexcept {
     } else if (locals == Py_None)
         locals = globals;
 
+    if (!PyDict_CheckExact(globals) && globals->cls != attrwrapper_cls) {
+        PyErr_Format(TypeError, "execfile() globals must be dict, not %s", globals->cls->tp_name);
+        return NULL;
+    }
+
     if (PyDict_GetItemString(globals, "__builtins__") == NULL) {
         if (PyDict_SetItemString(globals, "__builtins__", PyEval_GetBuiltins()) != 0)
             return NULL;

test/tests/execfile_test.py

@@ -8,6 +8,11 @@ fn = os.path.join(os.path.dirname(__file__), 'execfile_target.py')
 execfile(fn)
 print "done with first execfile"
 execfile(fn)
+execfile(fn, globals())
+try:
+    execfile(fn, [])
+except Exception as e:
+    print type(e)
 
 print test_name
 print type(execfile_target)