[Python-checkins] bpo-26868: Fix example usage of PyModule_AddObject. (GH-15725)
Miss Islington (bot)
webhook-mailer at python.org
Thu Sep 12 08:29:13 EDT 2019
https://github.com/python/cpython/commit/c8d1338441114fbc504625bc66607e7996018a5d
commit: c8d1338441114fbc504625bc66607e7996018a5d
branch: 3.7
author: Miss Islington (bot) <31488909+miss-islington at users.noreply.github.com>
committer: GitHub <noreply at github.com>
date: 2019-09-12T05:29:09-07:00
summary:
bpo-26868: Fix example usage of PyModule_AddObject. (GH-15725)
* Add a note to the PyModule_AddObject docs.
* Correct example usages of PyModule_AddObject.
* Whitespace.
* Clean up wording.
* 📜🤖 Added by blurb_it.
* First code review.
* Add < 0 in the tests with PyModule_AddObject
(cherry picked from commit 224b8aaa7e8f67f748e8b7b6a4a77a25f6554651)
Co-authored-by: Brandt Bucher <brandtbucher at gmail.com>
files:
A Misc/NEWS.d/next/Documentation/2019-09-07-15-55-46.bpo-26868.Raw0Gd.rst
M Doc/c-api/module.rst
M Doc/extending/extending.rst
M Doc/extending/newtypes_tutorial.rst
M Doc/includes/custom.c
M Doc/includes/custom2.c
M Doc/includes/custom3.c
M Doc/includes/custom4.c
M Doc/includes/sublist.c
diff --git a/Doc/c-api/module.rst b/Doc/c-api/module.rst
index 017b656854a8..7168dc7363ca 100644
--- a/Doc/c-api/module.rst
+++ b/Doc/c-api/module.rst
@@ -417,7 +417,22 @@ state:
Add an object to *module* as *name*. This is a convenience function which can
be used from the module's initialization function. This steals a reference to
- *value*. Return ``-1`` on error, ``0`` on success.
+ *value* on success. Return ``-1`` on error, ``0`` on success.
+
+ .. note::
+
+ Unlike other functions that steal references, ``PyModule_AddObject()`` only
+ decrements the reference count of *value* **on success**.
+
+ This means that its return value must be checked, and calling code must
+ :c:func:`Py_DECREF` *value* manually on error. Example usage::
+
+ Py_INCREF(spam);
+ if (PyModule_AddObject(module, "spam", spam) < 0) {
+ Py_DECREF(module);
+ Py_DECREF(spam);
+ return NULL;
+ }
.. c:function:: int PyModule_AddIntConstant(PyObject *module, const char *name, long value)
diff --git a/Doc/extending/extending.rst b/Doc/extending/extending.rst
index afed3aabb79a..73a77c781bc2 100644
--- a/Doc/extending/extending.rst
+++ b/Doc/extending/extending.rst
@@ -209,7 +209,7 @@ usually declare a static object variable at the beginning of your file::
static PyObject *SpamError;
and initialize it in your module's initialization function (:c:func:`PyInit_spam`)
-with an exception object (leaving out the error checking for now)::
+with an exception object::
PyMODINIT_FUNC
PyInit_spam(void)
@@ -221,8 +221,14 @@ with an exception object (leaving out the error checking for now)::
return NULL;
SpamError = PyErr_NewException("spam.error", NULL, NULL);
- Py_INCREF(SpamError);
- PyModule_AddObject(m, "error", SpamError);
+ Py_XINCREF(SpamError);
+ if (PyModule_AddObject(m, "error", SpamError) < 0) {
+ Py_XDECREF(SpamError);
+ Py_CLEAR(SpamError);
+ Py_DECREF(m);
+ return NULL;
+ }
+
return m;
}
@@ -1261,8 +1267,12 @@ function must take care of initializing the C API pointer array::
/* Create a Capsule containing the API pointer array's address */
c_api_object = PyCapsule_New((void *)PySpam_API, "spam._C_API", NULL);
- if (c_api_object != NULL)
- PyModule_AddObject(m, "_C_API", c_api_object);
+ if (PyModule_AddObject(m, "_C_API", c_api_object) < 0) {
+ Py_XDECREF(c_api_object);
+ Py_DECREF(m);
+ return NULL;
+ }
+
return m;
}
diff --git a/Doc/extending/newtypes_tutorial.rst b/Doc/extending/newtypes_tutorial.rst
index 07c2ef718aed..e6448e46411b 100644
--- a/Doc/extending/newtypes_tutorial.rst
+++ b/Doc/extending/newtypes_tutorial.rst
@@ -179,7 +179,12 @@ This initializes the :class:`Custom` type, filling in a number of members
to the appropriate default values, including :attr:`ob_type` that we initially
set to *NULL*. ::
- PyModule_AddObject(m, "Custom", (PyObject *) &CustomType);
+ Py_INCREF(&CustomType);
+ if (PyModule_AddObject(m, "Custom", (PyObject *) &CustomType) < 0) {
+ Py_DECREF(&CustomType);
+ PY_DECREF(m);
+ return NULL;
+ }
This adds the type to the module dictionary. This allows us to create
:class:`Custom` instances by calling the :class:`Custom` class:
@@ -864,7 +869,12 @@ function::
return NULL;
Py_INCREF(&SubListType);
- PyModule_AddObject(m, "SubList", (PyObject *) &SubListType);
+ if (PyModule_AddObject(m, "SubList", (PyObject *) &SubListType) < 0) {
+ Py_DECREF(&SubListType);
+ Py_DECREF(m);
+ return NULL;
+ }
+
return m;
}
diff --git a/Doc/includes/custom.c b/Doc/includes/custom.c
index 13d16f5424ae..bda32e2ad81d 100644
--- a/Doc/includes/custom.c
+++ b/Doc/includes/custom.c
@@ -35,6 +35,11 @@ PyInit_custom(void)
return NULL;
Py_INCREF(&CustomType);
- PyModule_AddObject(m, "Custom", (PyObject *) &CustomType);
+ if (PyModule_AddObject(m, "Custom", (PyObject *) &CustomType) < 0) {
+ Py_DECREF(&CustomType);
+ PY_DECREF(m);
+ return NULL;
+ }
+
return m;
}
diff --git a/Doc/includes/custom2.c b/Doc/includes/custom2.c
index 6477a19dafed..5bacab7a2a97 100644
--- a/Doc/includes/custom2.c
+++ b/Doc/includes/custom2.c
@@ -128,6 +128,11 @@ PyInit_custom2(void)
return NULL;
Py_INCREF(&CustomType);
- PyModule_AddObject(m, "Custom", (PyObject *) &CustomType);
+ if (PyModule_AddObject(m, "Custom", (PyObject *) &CustomType) < 0) {
+ Py_DECREF(&CustomType);
+ Py_DECREF(m);
+ return NULL;
+ }
+
return m;
}
diff --git a/Doc/includes/custom3.c b/Doc/includes/custom3.c
index 213d0864ce1c..2b7a99ecf96c 100644
--- a/Doc/includes/custom3.c
+++ b/Doc/includes/custom3.c
@@ -179,6 +179,11 @@ PyInit_custom3(void)
return NULL;
Py_INCREF(&CustomType);
- PyModule_AddObject(m, "Custom", (PyObject *) &CustomType);
+ if (PyModule_AddObject(m, "Custom", (PyObject *) &CustomType) < 0) {
+ Py_DECREF(&CustomType);
+ Py_DECREF(m);
+ return NULL;
+ }
+
return m;
}
diff --git a/Doc/includes/custom4.c b/Doc/includes/custom4.c
index b0b2906dbdc8..584992fc5f1a 100644
--- a/Doc/includes/custom4.c
+++ b/Doc/includes/custom4.c
@@ -193,6 +193,11 @@ PyInit_custom4(void)
return NULL;
Py_INCREF(&CustomType);
- PyModule_AddObject(m, "Custom", (PyObject *) &CustomType);
+ if (PyModule_AddObject(m, "Custom", (PyObject *) &CustomType) < 0) {
+ Py_DECREF(&CustomType);
+ Py_DECREF(m);
+ return NULL;
+ }
+
return m;
}
diff --git a/Doc/includes/sublist.c b/Doc/includes/sublist.c
index 76ff93948cfd..b2c26e73ebaf 100644
--- a/Doc/includes/sublist.c
+++ b/Doc/includes/sublist.c
@@ -59,6 +59,11 @@ PyInit_sublist(void)
return NULL;
Py_INCREF(&SubListType);
- PyModule_AddObject(m, "SubList", (PyObject *) &SubListType);
+ if (PyModule_AddObject(m, "SubList", (PyObject *) &SubListType) < 0) {
+ Py_DECREF(&SubListType);
+ Py_DECREF(m);
+ return NULL;
+ }
+
return m;
}
diff --git a/Misc/NEWS.d/next/Documentation/2019-09-07-15-55-46.bpo-26868.Raw0Gd.rst b/Misc/NEWS.d/next/Documentation/2019-09-07-15-55-46.bpo-26868.Raw0Gd.rst
new file mode 100644
index 000000000000..c668092b41a6
--- /dev/null
+++ b/Misc/NEWS.d/next/Documentation/2019-09-07-15-55-46.bpo-26868.Raw0Gd.rst
@@ -0,0 +1 @@
+Fix example usage of :c:func:`PyModule_AddObject` to properly handle errors.
\ No newline at end of file
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