update to new C roles and directives
diff --git a/Doc/library/warnings.rst b/Doc/library/warnings.rst
index dbcf148..6f3c105 100644
--- a/Doc/library/warnings.rst
+++ b/Doc/library/warnings.rst
@@ -19,7 +19,7 @@
might want to issue a warning when a program uses an obsolete module.
Python programmers issue warnings by calling the :func:`warn` function defined
-in this module. (C programmers use :cfunc:`PyErr_WarnEx`; see
+in this module. (C programmers use :c:func:`PyErr_WarnEx`; see
:ref:`exceptionhandling` for details).
Warning messages are normally written to ``sys.stderr``, but their disposition