Fix #8219: autodoc: Parameters for generic base class are not shown

CHANGES

@@ -26,6 +26,8 @@ Bugs fixed
   autodoc_default_options
 * #8103: autodoc: functools.cached_property is not considered as a property
 * #8219: autodoc: A signature of constructor of generic class is incorrect
+* #8219: autodoc: Parameters for generic class are not shown when super class is
+  a generic class and show-inheritance option is given
 * #8192: napoleon: description is disappeared when it contains inline literals
 * #8169: LaTeX: pxjahyper loaded even when latex_engine is not platex
 * #8093: The highlight warning has wrong location in some builders (LaTeX,

sphinx/ext/autodoc/__init__.py

@@ -1494,13 +1494,32 @@ def add_directive_header(self, sig: str) -> None:
         if not self.doc_as_attr and self.options.show_inheritance:
             sourcename = self.get_sourcename()
             self.add_line('', sourcename)
-            if hasattr(self.object, '__bases__') and len(self.object.__bases__):
-                bases = [':class:`%s`' % b.__name__
-                         if b.__module__ in ('__builtin__', 'builtins')
-                         else ':class:`%s.%s`' % (b.__module__, b.__qualname__)
-                         for b in self.object.__bases__]
-                self.add_line('   ' + _('Bases: %s') % ', '.join(bases),
-                              sourcename)
+
+            def restify(cls: "Type") -> str:
+                """Convert class to reST text."""
+                if cls.__module__ in ('__builtin__', 'builtins'):
+                    return ':class:`%s`' % cls.__name__
+                elif inspect.isgenericalias(cls):
+                    if cls._name:
+                        text = ':class:`%s.%s`' % (cls.__module__, cls._name)
+                    else:
+                        text = restify(cls.__origin__)
+
+                    if cls.__args__:
+                        text += r"\ [%s]" % ", ".join(restify(a) for a in cls.__args__)
+                    return text
+                elif hasattr(cls, '__qualname__'):
+                    return ':class:`%s.%s`' % (cls.__module__, cls.__qualname__)
+                else:
+                    # not a class (ex. TypeVar)
+                    return ':obj:`%s.%s`' % (cls.__module__, cls.__name__)
+
+            if hasattr(self.object, '__orig_bases__') and len(self.object.__orig_bases__):
+                bases = [restify(cls) for cls in self.object.__orig_bases__]
+                self.add_line('   ' + _('Bases: %s') % ', '.join(bases), sourcename)
+            elif hasattr(self.object, '__bases__') and len(self.object.__bases__):
+                bases = [restify(cls) for cls in self.object.__bases__]
+                self.add_line('   ' + _('Bases: %s') % ', '.join(bases), sourcename)
 
     def get_doc(self, encoding: str = None, ignore: int = None) -> List[List[str]]:
         if encoding is not None:

tests/test_ext_autodoc_autoclass.py

@@ -16,10 +16,13 @@
 
 @pytest.mark.sphinx('html', testroot='ext-autodoc')
 def test_generic_class(app):
-    actual = do_autodoc(app, 'class', 'target.classes.Qux')
+    options = {"show-inheritance": None}
+    actual = do_autodoc(app, 'class', 'target.classes.Qux', options)
     assert list(actual) == [
         '',
         '.. py:class:: Qux(x, y)',
         '   :module: target.classes',
         '',
+        '   Bases: :class:`typing.Generic`[:obj:`target.classes.T`]',
+        '',
     ]