C, fix object types for xrefs

Add 'identifer' to all and 'type' to types.

Fixes sphinx-doc/sphinx#8341

sphinx/domains/c.py

@@ -3657,15 +3657,18 @@ class CDomain(Domain):
     name = 'c'
     label = 'C'
     object_types = {
-        'function': ObjType(_('function'), 'func'),
-        'member': ObjType(_('member'), 'member'),
-        'macro': ObjType(_('macro'), 'macro'),
-        'type': ObjType(_('type'), 'type'),
-        'var': ObjType(_('variable'), 'data'),
-        'enum': ObjType(_('enum'), 'enum'),
-        'enumerator': ObjType(_('enumerator'), 'enumerator'),
-        'struct': ObjType(_('struct'), 'struct'),
-        'union': ObjType(_('union'), 'union'),
+        # 'identifier' is the one used for xrefs generated in signatures, not in roles
+        'member': ObjType(_('member'), 'var', 'member', 'data', 'identifier'),
+        'var': ObjType(_('variable'),  'var', 'member', 'data', 'identifier'),
+        'function': ObjType(_('function'),     'func',          'identifier', 'type'),
+        'macro': ObjType(_('macro'),           'macro',         'identifier'),
+        'struct': ObjType(_('struct'),         'struct',        'identifier', 'type'),
+        'union': ObjType(_('union'),           'union',         'identifier', 'type'),
+        'enum': ObjType(_('enum'),             'enum',          'identifier', 'type'),
+        'enumerator': ObjType(_('enumerator'), 'enumerator',    'identifier'),
+        'type': ObjType(_('type'),                              'identifier', 'type'),
+        # generated object types
+        'functionParam': ObjType(_('function parameter'),       'identifier', 'var', 'member', 'data'),  # noqa
     }
 
     directives = {

tests/roots/test-domain-c-intersphinx/conf.py

@@ -0,0 +1,4 @@
+exclude_patterns = ['_build']
+extensions = [
+	'sphinx.ext.intersphinx',
+]

tests/roots/test-domain-c-intersphinx/index.rst

@@ -0,0 +1,62 @@
+.. c:member:: void __member = _member
+
+	- :any:`_member`
+	- :c:member:`_member`
+	- :c:var:`_member`
+	- :c:data:`_member`
+
+.. c:member:: void __var = _var
+
+	- :any:`_var`
+	- :c:member:`_var`
+	- :c:var:`_var`
+	- :c:data:`_var`
+
+.. c:member:: void __function = _function
+
+	- :any:`_function`
+	- :c:func:`_function`
+	- :c:type:`_function`
+
+.. c:member:: void __macro = _macro
+
+	- :any:`_macro`
+	- :c:macro:`_macro`
+
+.. c:type:: _struct __struct
+            struct _struct __structTagged
+
+	- :any:`_struct`
+	- :c:struct:`_struct`
+	- :c:type:`_struct`
+
+.. c:type:: _union __union
+            union _union __unionTagged
+
+	- :any:`_union`
+	- :c:union:`_union`
+	- :c:type:`_union`
+
+.. c:type:: _enum __enum
+            enum _enum __enumTagged
+
+	- :any:`_enum`
+	- :c:enum:`_enum`
+	- :c:type:`_enum`
+
+.. c:member:: void __enumerator = _enumerator
+
+	- :any:`_enumerator`
+	- :c:enumerator:`_enumerator`
+
+.. c:type:: _type __type
+
+	- :any:`_type`
+	- :c:type:`_type`
+
+.. c:member:: void __functionParam = _functionParam.param
+
+	- :any:`_functionParam.param`
+	- :c:member:`_functionParam.param`
+	- :c:var:`_functionParam.param`
+	- :c:data:`_functionParam.param`

tests/test_domain_c.py

@@ -7,6 +7,8 @@
     :copyright: Copyright 2007-2021 by the Sphinx team, see AUTHORS.
     :license: BSD, see LICENSE for details.
 """
+
+import zlib
 from xml.etree import ElementTree
 
 import pytest
@@ -14,6 +16,7 @@ import pytest
 from sphinx import addnodes
 from sphinx.addnodes import desc
 from sphinx.domains.c import DefinitionError, DefinitionParser, Symbol, _id_prefix, _max_id
+from sphinx.ext.intersphinx import load_mappings, normalize_intersphinx_mapping
 from sphinx.testing import restructuredtext
 from sphinx.testing.util import assert_node
 
@@ -642,3 +645,52 @@ def test_noindexentry(app):
     assert_node(doctree, (addnodes.index, desc, addnodes.index, desc))
     assert_node(doctree[0], addnodes.index, entries=[('single', 'f (C function)', 'c.f', '', None)])
     assert_node(doctree[2], addnodes.index, entries=[])
+
+
+@pytest.mark.sphinx(testroot='domain-c-intersphinx', confoverrides={'nitpicky': True})
+def test_intersphinx(tempdir, app, status, warning):
+    origSource = """\
+.. c:member:: int _member
+.. c:var:: int _var
+.. c:function:: void _function()
+.. c:macro:: _macro
+.. c:struct:: _struct
+.. c:union:: _union
+.. c:enum:: _enum
+
+    .. c:enumerator:: _enumerator
+
+.. c:type:: _type
+.. c:function:: void _functionParam(int param)
+"""  # noqa
+    inv_file = tempdir / 'inventory'
+    inv_file.write_bytes(b'''\
+# Sphinx inventory version 2
+# Project: C Intersphinx Test
+# Version: 
+# The remainder of this file is compressed using zlib.
+''' + zlib.compress(b'''\
+_enum c:enum 1 index.html#c.$ -
+_enum._enumerator c:enumerator 1 index.html#c.$ -
+_enumerator c:enumerator 1 index.html#c._enum.$ -
+_function c:function 1 index.html#c.$ -
+_functionParam c:function 1 index.html#c.$ -
+_functionParam.param c:functionParam 1 index.html#c._functionParam -
+_macro c:macro 1 index.html#c.$ -
+_member c:member 1 index.html#c.$ -
+_struct c:struct 1 index.html#c.$ -
+_type c:type 1 index.html#c.$ -
+_union c:union 1 index.html#c.$ -
+_var c:member 1 index.html#c.$ -
+'''))  # noqa
+    app.config.intersphinx_mapping = {
+        'https://localhost/intersphinx/c/': inv_file,
+    }
+    app.config.intersphinx_cache_limit = 0
+    # load the inventory and check if it's done correctly
+    normalize_intersphinx_mapping(app, app.config)
+    load_mappings(app)
+
+    app.builder.build_all()
+    ws = filter_warnings(warning, "index")
+    assert len(ws) == 0