From c16a71c0aa1223731fe0f47ed007ad0a597b3da7 Mon Sep 17 00:00:00 2001
From: Takeshi KOMIYA <i.tkomiya@gmail.com>
Date: Sun, 15 Nov 2020 13:58:12 +0900
Subject: [PATCH] autodoc: an imported TypeVar is not resolved (refs: #8415)

So far, a TypeVar is rendered without module name. As a result, it
could not be resolved if it is imported from other modules.  This
prepends its module name and make it resolvable.  This is available
only in Python 3.7 or above.

As a side effect, all of TypeVars are displayed with module name. It
should be fixed in latter step (refs: #7119)
---
 CHANGES                    |  2 ++
 sphinx/util/typing.py      |  5 ++++-
 tests/test_util_inspect.py |  6 +++++-
 tests/test_util_typing.py  | 14 ++++++++++----
 4 files changed, 21 insertions(+), 6 deletions(-)

diff --git a/CHANGES b/CHANGES
index a55a4368795..570a550e963 100644
--- a/CHANGES
+++ b/CHANGES
@@ -27,6 +27,8 @@ Features added
 * autodoc: Add ``Documenter.config`` as a shortcut to access the config object
 * autodoc: Add Optional[t] to annotation of function and method if a default
   value equal to None is set.
+* #8415: autodoc: a TypeVar imported from other module is not resolved (in
+  Python 3.7 or above)
 * #6914: Add a new event :event:`warn-missing-reference` to custom warning
   messages when failed to resolve a cross-reference
 * #6914: Emit a detailed warning when failed to resolve a ``:ref:`` reference
diff --git a/sphinx/util/typing.py b/sphinx/util/typing.py
index 28f9c5e383d..8f48073dca0 100644
--- a/sphinx/util/typing.py
+++ b/sphinx/util/typing.py
@@ -261,7 +261,10 @@ def stringify(annotation: Any) -> str:
         else:
             return annotation
     elif isinstance(annotation, TypeVar):
-        return annotation.__name__
+        if annotation.__module__ == 'typing':
+            return annotation.__name__
+        else:
+            return '.'.join([annotation.__module__, annotation.__name__])
     elif not annotation:
         return repr(annotation)
     elif annotation is NoneType:
diff --git a/tests/test_util_inspect.py b/tests/test_util_inspect.py
index 7b51cb7d136..82dc85c007c 100644
--- a/tests/test_util_inspect.py
+++ b/tests/test_util_inspect.py
@@ -142,7 +142,11 @@ def test_signature_annotations():
 
     # TypeVars and generic types with TypeVars
     sig = inspect.signature(f2)
-    assert stringify_signature(sig) == '(x: List[T], y: List[T_co], z: T) -> List[T_contra]'
+    if sys.version_info < (3, 7):
+        assert stringify_signature(sig) == '(x: List[T], y: List[T_co], z: T) -> List[T_contra]'
+    else:
+        assert stringify_signature(sig) == ('(x: List[typing_test_data.T], y: List[typing_test_data.T_co], '
+                                            'z: typing_test_data.T) -> List[typing_test_data.T_contra]')
 
     # Union types
     sig = inspect.signature(f3)
diff --git a/tests/test_util_typing.py b/tests/test_util_typing.py
index 354db15671a..f270a394623 100644
--- a/tests/test_util_typing.py
+++ b/tests/test_util_typing.py
@@ -174,10 +174,16 @@ def test_stringify_type_hints_typevars():
     T_co = TypeVar('T_co', covariant=True)
     T_contra = TypeVar('T_contra', contravariant=True)
 
-    assert stringify(T) == "T"
-    assert stringify(T_co) == "T_co"
-    assert stringify(T_contra) == "T_contra"
-    assert stringify(List[T]) == "List[T]"
+    if sys.version_info < (3, 7):
+        assert stringify(T) == "T"
+        assert stringify(T_co) == "T_co"
+        assert stringify(T_contra) == "T_contra"
+        assert stringify(List[T]) == "List[T]"
+    else:
+        assert stringify(T) == "test_util_typing.T"
+        assert stringify(T_co) == "test_util_typing.T_co"
+        assert stringify(T_contra) == "test_util_typing.T_contra"
+        assert stringify(List[T]) == "List[test_util_typing.T]"
 
 
 def test_stringify_type_hints_custom_class():