Merge branch '3.0.x' into 3.x

doc/usage/configuration.rst

@@ -2479,6 +2479,30 @@ Options for the XML builder
        match any sequence of characters *including* slashes.
 
 
+.. _c-config:
+
+Options for the C domain
+------------------------
+
+.. confval:: c_id_attributes
+
+   A list of strings that the parser additionally should accept as attributes.
+   This can for example be used when attributes have been ``#define`` d for
+   portability.
+
+   .. versionadded:: 3.0
+
+.. confval:: c_paren_attributes
+
+   A list of strings that the parser additionally should accept as attributes
+   with one argument.  That is, if ``my_align_as`` is in the list, then
+   ``my_align_as(X)`` is parsed as an attribute for all strings ``X`` that have
+   balanced braces (``()``, ``[]``, and ``{}``).  This can for example be used
+   when attributes have been ``#define`` d for portability.
+
+   .. versionadded:: 3.0
+
+
 .. _cpp-config:
 
 Options for the C++ domain

doc/usage/restructuredtext/domains.rst

@@ -771,6 +771,11 @@ The ``c:namespace-pop`` directive undoes the most recent
 
       .. c:namespace-push:: A.B
 
+Configuration Variables
+~~~~~~~~~~~~~~~~~~~~~~~
+
+See :ref:`c-config`.
+
 
 .. _cpp-domain: