Fix sphinx-doc#8443: autodata directive does not support PEP-526 ivars

CHANGES

@@ -14,6 +14,7 @@ Deprecated
 ----------
 
 * The ``follow_wrapped`` argument of ``sphinx.util.inspect.signature()``
+* ``sphinx.ext.autodoc.DataDeclarationDocumenter``
 * ``sphinx.util.requests.is_ssl_error()``
 
 Features added
@@ -42,6 +43,8 @@ Bugs fixed
   is decorated
 * #8434: autodoc: :confval:`autodoc_type_aliases` does not effect to variables
   and attributes
+* #8443: autodoc: autodata directive can't create document for PEP-526 based
+  type annotated variables
 
 Testing
 --------

doc/extdev/deprecated.rst

@@ -31,6 +31,11 @@ The following is a list of deprecated interfaces.
      - 5.0
      - N/A
 
+   * - ``sphinx.ext.autodoc.DataDeclarationDocumenter``
+     - 3.4
+     - 5.0
+     - ``sphinx.ext.autodoc.DataDocumenter``
+
    * - ``sphinx.util.requests.is_ssl_error()``
      - 3.4
      - 5.0

sphinx/ext/autodoc/__init__.py

@@ -1697,6 +1697,29 @@ def can_document_member(cls, member: Any, membername: str, isattr: bool, parent:
                             ) -> bool:
         return isinstance(parent, ModuleDocumenter) and isattr
 
+    def import_object(self, raiseerror: bool = False) -> bool:
+        """Never import anything."""
+        try:
+            return super().import_object(raiseerror=True)
+        except ImportError as exc:
+            # annotation only instance variable (PEP-526)
+            try:
+                self.parent = importlib.import_module(self.modname)
+                annotations = get_type_hints(self.parent, None,
+                                             self.config.autodoc_type_aliases)
+                if self.objpath[-1] in annotations:
+                    self.object = UNINITIALIZED_ATTR
+                    return True
+            except ImportError:
+                pass
+
+            if raiseerror:
+                raise
+            else:
+                logger.warning(exc.args[0], type='autodoc', subtype='import_object')
+                self.env.note_reread()
+                return False
+
     def add_directive_header(self, sig: str) -> None:
         super().add_directive_header(sig)
         sourcename = self.get_sourcename()
@@ -1733,6 +1756,14 @@ def get_real_modname(self) -> str:
         return self.get_attr(self.parent or self.object, '__module__', None) \
             or self.modname
 
+    def add_content(self, more_content: Any, no_docstring: bool = False) -> None:
+        """Never try to get a docstring from the object."""
+        if self.object is UNINITIALIZED_ATTR:
+            # suppress docstring of the value
+            super().add_content(more_content, no_docstring=True)
+        else:
+            super().add_content(more_content, no_docstring=no_docstring)
+
 
 class DataDeclarationDocumenter(DataDocumenter):
     """
@@ -1746,30 +1777,10 @@ class DataDeclarationDocumenter(DataDocumenter):
     # must be higher than AttributeDocumenter
     priority = 11
 
-    @classmethod
-    def can_document_member(cls, member: Any, membername: str, isattr: bool, parent: Any
-                            ) -> bool:
-        """This documents only INSTANCEATTR members."""
-        return (isinstance(parent, ModuleDocumenter) and
-                isattr and
-                member is INSTANCEATTR)
-
-    def import_object(self, raiseerror: bool = False) -> bool:
-        """Never import anything."""
-        # disguise as a data
-        self.objtype = 'data'
-        self.object = UNINITIALIZED_ATTR
-        try:
-            # import module to obtain type annotation
-            self.parent = importlib.import_module(self.modname)
-        except ImportError:
-            pass
-
-        return True
-
-    def add_content(self, more_content: Any, no_docstring: bool = False) -> None:
-        """Never try to get a docstring from the object."""
-        super().add_content(more_content, no_docstring=True)
+    def __init__(self, *args: Any, **kwargs: Any) -> None:
+        warnings.warn("%s is deprecated." % self.__class__.__name__,
+                      RemovedInSphinx50Warning, stacklevel=2)
+        super().__init__(*args, **kwargs)
 
 
 class GenericAliasDocumenter(DataDocumenter):
@@ -2282,7 +2293,6 @@ def setup(app: Sphinx) -> Dict[str, Any]:
     app.add_autodocumenter(ClassDocumenter)
     app.add_autodocumenter(ExceptionDocumenter)
     app.add_autodocumenter(DataDocumenter)
-    app.add_autodocumenter(DataDeclarationDocumenter)
     app.add_autodocumenter(GenericAliasDocumenter)
     app.add_autodocumenter(TypeVarDocumenter)
     app.add_autodocumenter(FunctionDocumenter)

sphinx/ext/autosummary/generate.py

@@ -85,8 +85,7 @@ def emit_firstresult(self, *args: Any) -> None:
 
 
 def setup_documenters(app: Any) -> None:
-    from sphinx.ext.autodoc import (AttributeDocumenter, ClassDocumenter,
-                                    DataDeclarationDocumenter, DataDocumenter,
+    from sphinx.ext.autodoc import (AttributeDocumenter, ClassDocumenter, DataDocumenter,
                                     DecoratorDocumenter, ExceptionDocumenter,
                                     FunctionDocumenter, GenericAliasDocumenter,
                                     InstanceAttributeDocumenter, MethodDocumenter,
@@ -96,8 +95,7 @@ def setup_documenters(app: Any) -> None:
         ModuleDocumenter, ClassDocumenter, ExceptionDocumenter, DataDocumenter,
         FunctionDocumenter, MethodDocumenter, AttributeDocumenter,
         InstanceAttributeDocumenter, DecoratorDocumenter, PropertyDocumenter,
-        SlotsAttributeDocumenter, DataDeclarationDocumenter, GenericAliasDocumenter,
-        SingledispatchFunctionDocumenter,
+        SlotsAttributeDocumenter, GenericAliasDocumenter, SingledispatchFunctionDocumenter,
     ]  # type: List[Type[Documenter]]
     for documenter in documenters:
         app.registry.add_documenter(documenter.objtype, documenter)

tests/test_ext_autodoc_autodata.py

@@ -9,6 +9,8 @@
     :license: BSD, see LICENSE for details.
 """
 
+import sys
+
 import pytest
 from test_ext_autodoc import do_autodoc
 
@@ -39,3 +41,34 @@ def test_autodata_novalue(app):
         '   documentation for the integer',
         '',
     ]
+
+
+@pytest.mark.skipif(sys.version_info < (3, 6), reason='python 3.6+ is required.')
+@pytest.mark.sphinx('html', testroot='ext-autodoc')
+def test_autodata_typed_variable(app):
+    actual = do_autodoc(app, 'data', 'target.typed_vars.attr2')
+    assert list(actual) == [
+        '',
+        '.. py:data:: attr2',
+        '   :module: target.typed_vars',
+        '   :type: str',
+        '',
+        '   attr2',
+        '',
+    ]
+
+
+@pytest.mark.skipif(sys.version_info < (3, 6), reason='python 3.6+ is required.')
+@pytest.mark.sphinx('html', testroot='ext-autodoc')
+def test_autodata_type_comment(app):
+    actual = do_autodoc(app, 'data', 'target.typed_vars.attr3')
+    assert list(actual) == [
+        '',
+        '.. py:data:: attr3',
+        '   :module: target.typed_vars',
+        '   :type: str',
+        "   :value: ''",
+        '',
+        '   attr3',
+        '',
+    ]