Fix #3135: `sphinx.ext.autodoc` crashes with plain Callable

CHANGES

@@ -9,6 +9,7 @@ Bugs fixed
   results in warning / error
 * #3068: Allow the '=' character in the -D option of sphinx-build.py
 * #3074: ``add_source_parser()`` crashes in debug mode
+* #3135: ``sphinx.ext.autodoc`` crashes with plain Callable
 
 Release 1.4.8 (released Oct 1, 2016)
 ====================================

sphinx/ext/autodoc.py

@@ -306,7 +306,9 @@ def format_annotation(annotation):
                 hasattr(annotation, '__args__') and \
                 hasattr(annotation, '__result__'):
             args = annotation.__args__
-            if args is Ellipsis:
+            if args is None:
+                return qualified_name
+            elif args is Ellipsis:
                 args_str = '...'
             else:
                 formatted_args = (format_annotation(a) for a in args)

test-reqs.txt

@@ -13,3 +13,4 @@ whoosh>=2.0
 alabaster
 sphinx_rtd_theme
 imagesize
+typing

tests/test_autodoc.py

@@ -1025,7 +1025,7 @@ def test_type_hints():
     from sphinx.util.inspect import getargspec
 
     try:
-        from typing_test_data import f0, f1, f2, f3, f4, f5, f6, f7, f8, f9
+        from typing_test_data import f0, f1, f2, f3, f4, f5, f6, f7, f8, f9, f10
     except (ImportError, SyntaxError):
         raise SkipTest('Cannot import Python code with function annotations')
 
@@ -1057,10 +1057,11 @@ def test_type_hints():
 
     # Callable types
     verify_arg_spec(f7, '(x: typing.Callable[[int, str], int]) -> None')
+    verify_arg_spec(f8, '(x: typing.Callable) -> None')
 
     # Tuple types
-    verify_arg_spec(f8, '(x: typing.Tuple[int, str],'
+    verify_arg_spec(f9, '(x: typing.Tuple[int, str],'
                         ' y: typing.Tuple[int, ...]) -> None')
 
     # Instance annotations
-    verify_arg_spec(f9, '(x: CustomAnnotation, y: 123) -> None')
+    verify_arg_spec(f10, '(x: CustomAnnotation, y: 123) -> None')

tests/typing_test_data.py

@@ -44,7 +44,11 @@ def f7(x: Callable[[int, str], int]) -> None:
     pass
 
 
-def f8(x: Tuple[int, str], y: Tuple[int, ...]) -> None:
+def f8(x: Callable) -> None:
+    pass
+
+
+def f9(x: Tuple[int, str], y: Tuple[int, ...]) -> None:
     pass
 
 
@@ -52,5 +56,6 @@ class CustomAnnotation:
     def __repr__(self):
         return 'CustomAnnotation'
 
-def f9(x: CustomAnnotation(), y: 123) -> None:
+
+def f10(x: CustomAnnotation(), y: 123) -> None:
     pass

tox.ini

@@ -6,6 +6,7 @@ deps=
     nose
     sqlalchemy
     whoosh
+    typing
 setenv =
     SPHINX_TEST_TEMPDIR = {envdir}/testbuild
 commands=