autodoc: add 'exclude-members' to user global options

As the previous commit explains, it is now possible to specify arguments
to the global options in config files. This means that we can now include
the `exclude-members` option in this global configuration.

Previously, there was no point including this option because it makes no
sense without arguments. Including this option means users have the
flexibility of explicitly including which special methods they want using
(e.g.):

  :special-members: __init__, __iter__

or explicitly excluding which special-members (or other members) they want
using (e.g.):

  :exclude-members: __weakref__, __hash__

doc/usage/extensions/autodoc.rst

@@ -341,7 +341,8 @@ There are also new config values that you can set:
    This value is a list of autodoc directive flags that should be automatically
    applied to all autodoc directives.  The supported flags are ``'members'``,
    ``'undoc-members'``, ``'private-members'``, ``'special-members'``,
-   ``'inherited-members'``, ``'show-inheritance'`` and ``'ignore-module-all'``.
+   ``'inherited-members'``, ``'show-inheritance'``, ``'ignore-module-all'``
+   and ``'exclude-members'``.
 
    If you set one of these flags in this config value, you can use a negated
    form, :samp:`'no-{flag}'`, in an autodoc directive, to disable it once.
@@ -361,6 +362,7 @@ There are also new config values that you can set:
         'member-order': 'bysource',
         'special-members': '__init__',
         'undoc-members': None,
+        'exclude-members': '__weakref__'
     }
 
     Setting ``None`` is equivalent to giving the option name in the list format

sphinx/ext/autodoc/directive.py

@@ -31,7 +31,7 @@ logger = logging.getLogger(__name__)
 # common option names for autodoc directives
 AUTODOC_DEFAULT_OPTIONS = ['members', 'undoc-members', 'inherited-members',
                            'show-inheritance', 'private-members', 'special-members',
-                           'ignore-module-all']
+                           'ignore-module-all', 'exclude-members']
 
 
 class DummyOptionSpec(object):

tests/test_autodoc.py

@@ -1484,6 +1484,32 @@ def test_autodoc_default_flags__with_flags(app):
         assert '   .. py:attribute:: CustomIter.__weakref__' in actual
         assert '      list of weak references to the object (if defined)' in actual
 
+    # :exclude-members: None - has no effect. Unlike :members:,
+    # :special-members:, etc. where None == "include all", here None means
+    # "no/false/off".
+    app.config.autodoc_default_flags = {
+        'members': None,
+        'exclude-members': None,
+    }
+    actual = do_autodoc(app, 'class', 'target.EnumCls')
+    assert '   .. py:attribute:: EnumCls.val1' in actual
+    assert '   .. py:attribute:: EnumCls.val4' not in actual
+    app.config.autodoc_default_flags = {
+        'members': None,
+        'special-members': None,
+        'exclude-members': None,
+    }
+    actual = do_autodoc(app, 'class', 'target.CustomIter')
+    assert '   .. py:method:: CustomIter.__init__()' in actual
+    assert '      Create a new `CustomIter`.' in actual
+    assert '   .. py:method:: CustomIter.__iter__()' in actual
+    assert '      Iterate squares of each value.' in actual
+    if not IS_PYPY:
+        assert '   .. py:attribute:: CustomIter.__weakref__' in actual
+        assert '      list of weak references to the object (if defined)' in actual
+    assert '   .. py:method:: CustomIter.snafucate()' in actual
+    assert '      Makes this snafucated.' in actual
+
 
 @pytest.mark.sphinx('html', testroot='ext-autodoc')
 def test_autodoc_default_flags__with_values(app):
@@ -1509,3 +1535,29 @@ def test_autodoc_default_flags__with_values(app):
     if not IS_PYPY:
         assert '   .. py:attribute:: CustomIter.__weakref__' not in actual
         assert '      list of weak references to the object (if defined)' not in actual
+
+    # with :exclude-members:
+    app.config.autodoc_default_flags = {
+        'members': None,
+        'exclude-members': 'val1'
+    }
+    actual = do_autodoc(app, 'class', 'target.EnumCls')
+    assert '   .. py:attribute:: EnumCls.val1' not in actual
+    assert '   .. py:attribute:: EnumCls.val2' in actual
+    assert '   .. py:attribute:: EnumCls.val3' in actual
+    assert '   .. py:attribute:: EnumCls.val4' not in actual
+    app.config.autodoc_default_flags = {
+        'members': None,
+        'special-members': None,
+        'exclude-members': '__weakref__,snafucate',
+    }
+    actual = do_autodoc(app, 'class', 'target.CustomIter')
+    assert '   .. py:method:: CustomIter.__init__()' in actual
+    assert '      Create a new `CustomIter`.' in actual
+    assert '   .. py:method:: CustomIter.__iter__()' in actual
+    assert '      Iterate squares of each value.' in actual
+    if not IS_PYPY:
+        assert '   .. py:attribute:: CustomIter.__weakref__' not in actual
+        assert '      list of weak references to the object (if defined)' not in actual
+    assert '   .. py:method:: CustomIter.snafucate()' not in actual
+    assert '      Makes this snafucated.' not in actual