bpo-33237: Improve AttributeError message for partially initialized module. (GH-6398)

This commit is contained in:
Serhiy Storchaka 2018-10-30 13:19:51 +02:00 committed by GitHub
parent 95b6acf951
commit 3e429dcc24
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
7 changed files with 67 additions and 23 deletions

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@ -30,6 +30,7 @@ PyAPI_FUNC(PyObject *) PyModule_GetFilenameObject(PyObject *);
#ifndef Py_LIMITED_API
PyAPI_FUNC(void) _PyModule_Clear(PyObject *);
PyAPI_FUNC(void) _PyModule_ClearDict(PyObject *);
PyAPI_FUNC(int) _PyModuleSpec_IsInitializing(PyObject *);
#endif
PyAPI_FUNC(struct PyModuleDef*) PyModule_GetDef(PyObject*);
PyAPI_FUNC(void*) PyModule_GetState(PyObject*);

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@ -1271,6 +1271,19 @@ class CircularImportTests(unittest.TestCase):
except ImportError:
self.fail('circular import with binding a submodule to a name failed')
def test_crossreference1(self):
import test.test_import.data.circular_imports.use
import test.test_import.data.circular_imports.source
def test_crossreference2(self):
with self.assertRaises(AttributeError) as cm:
import test.test_import.data.circular_imports.source
errmsg = str(cm.exception)
self.assertIn('test.test_import.data.circular_imports.source', errmsg)
self.assertIn('spam', errmsg)
self.assertIn('partially initialized module', errmsg)
self.assertIn('circular import', errmsg)
if __name__ == '__main__':
# Test needs to be a package, so we can do relative imports.

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@ -0,0 +1,2 @@
from . import use
spam = 1

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@ -0,0 +1,2 @@
from . import source
source.spam

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@ -0,0 +1 @@
Improved :exc:`AttributeError` message for partially initialized module.

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@ -698,6 +698,27 @@ module_repr(PyModuleObject *m)
return PyObject_CallMethod(interp->importlib, "_module_repr", "O", m);
}
/* Check if the "_initializing" attribute of the module spec is set to true.
Clear the exception and return 0 if spec is NULL.
*/
int
_PyModuleSpec_IsInitializing(PyObject *spec)
{
if (spec != NULL) {
_Py_IDENTIFIER(_initializing);
PyObject *value = _PyObject_GetAttrId(spec, &PyId__initializing);
if (value != NULL) {
int initializing = PyObject_IsTrue(value);
Py_DECREF(value);
if (initializing >= 0) {
return initializing;
}
}
}
PyErr_Clear();
return 0;
}
static PyObject*
module_getattro(PyModuleObject *m, PyObject *name)
{
@ -717,8 +738,24 @@ module_getattro(PyModuleObject *m, PyObject *name)
_Py_IDENTIFIER(__name__);
mod_name = _PyDict_GetItemId(m->md_dict, &PyId___name__);
if (mod_name && PyUnicode_Check(mod_name)) {
_Py_IDENTIFIER(__spec__);
Py_INCREF(mod_name);
PyObject *spec = _PyDict_GetItemId(m->md_dict, &PyId___spec__);
Py_XINCREF(spec);
if (_PyModuleSpec_IsInitializing(spec)) {
PyErr_Format(PyExc_AttributeError,
"module '%U' has no attribute '%U'", mod_name, name);
"partially initialized "
"module '%U' has no attribute '%U' "
"(most likely due to a circular import)",
mod_name, name);
}
else {
PyErr_Format(PyExc_AttributeError,
"module '%U' has no attribute '%U'",
mod_name, name);
}
Py_XDECREF(spec);
Py_DECREF(mod_name);
return NULL;
}
}

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@ -1721,11 +1721,8 @@ PyImport_ImportModuleLevelObject(PyObject *name, PyObject *globals,
mod = PyImport_GetModule(abs_name);
if (mod != NULL && mod != Py_None) {
_Py_IDENTIFIER(__spec__);
_Py_IDENTIFIER(_initializing);
_Py_IDENTIFIER(_lock_unlock_module);
PyObject *value = NULL;
PyObject *spec;
int initializing = 0;
/* Optimization: only call _bootstrap._lock_unlock_module() if
__spec__._initializing is true.
@ -1733,26 +1730,17 @@ PyImport_ImportModuleLevelObject(PyObject *name, PyObject *globals,
stuffing the new module in sys.modules.
*/
spec = _PyObject_GetAttrId(mod, &PyId___spec__);
if (spec != NULL) {
value = _PyObject_GetAttrId(spec, &PyId__initializing);
Py_DECREF(spec);
}
if (value == NULL)
PyErr_Clear();
else {
initializing = PyObject_IsTrue(value);
Py_DECREF(value);
if (initializing == -1)
PyErr_Clear();
if (initializing > 0) {
value = _PyObject_CallMethodIdObjArgs(interp->importlib,
if (_PyModuleSpec_IsInitializing(spec)) {
PyObject *value = _PyObject_CallMethodIdObjArgs(interp->importlib,
&PyId__lock_unlock_module, abs_name,
NULL);
if (value == NULL)
if (value == NULL) {
Py_DECREF(spec);
goto error;
}
Py_DECREF(value);
}
}
Py_XDECREF(spec);
}
else {
Py_XDECREF(mod);