From: Eli Bendersky <eliben@gmail.com>
Date: Sat, 9 Mar 2013 13:56:35 +0000 (-0800)
Subject: Add warning in ctypes documentation for #16575 and #16576
X-Git-Tag: v2.7.4rc1~55
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=26e2faf57da5e1c26f7ea25e5a1cb066ad7020cb;p=thirdparty%2FPython%2Fcpython.git

Add warning in ctypes documentation for #16575 and #16576
---

diff --git a/Doc/library/ctypes.rst b/Doc/library/ctypes.rst
index 7f62e30561eb..c72a0b5a4eda 100644
--- a/Doc/library/ctypes.rst
+++ b/Doc/library/ctypes.rst
@@ -602,6 +602,13 @@ for debugging because they can provide useful information::
 
 .. _ctypes-structureunion-alignment-byte-order:
 
+.. warning::
+
+   :mod:`ctypes` does not support passing unions or structures with bit-fields
+   to functions by value.  While this may work on 32-bit x86, it's not
+   guaranteed by the library to work in the general case.  Unions and
+   structures with bit-fields should always be passed to functions by pointer.
+
 Structure/union alignment and byte order
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^