Error for call to Any

docs/changelog.md

@@ -2,13 +2,14 @@
 
 ## Unreleased
 
+- Show an error on calls to `typing.Any` (#688)
 - Add command-line option `-c`/`--code` to typecheck code from
   the command line (#685)
 - Add a `pyanalyze.extensions.EnumName` predicate and infer it
   as the value for the `.name` attribute on enums. Also fix
   type inference for enum "properties" on Python 3.11 and up. (#682)
 - Allow `pyanalyze.runtime.is_compatible` to be used to narrow
-  types (#681)
+  types (#681, #687)
 - Fix usage of `assert_type()` with `Any` and with unions of
   `Annotated` objects (#680)
 - Support inferring `MinLen` and `MaxLen` annotations based

pyanalyze/implementation.py

@@ -1426,6 +1426,12 @@ def _bool_impl(ctx: CallContext) -> Value:
     return annotate_with_constraint(TypedValue(bool), constraint)
 
 
+# Any has a __call__ method at runtime that always raises.
+def _any_impl(ctx: CallContext) -> Value:
+    ctx.show_error("Any is not callable. Maybe you meant cast(Any, ...)?")
+    return AnyValue(AnySource.error)
+
+
 _POS_ONLY = ParameterKind.POSITIONAL_ONLY
 _ENCODING_PARAMETER = SigParameter(
     "encoding", annotation=TypedValue(str), default=KnownValue("")
@@ -1888,6 +1894,15 @@ def get_default_argspecs() -> Dict[object, Signature]:
             impl=_bool_impl,
             return_annotation=TypedValue(bool),
         ),
+        Signature.make(
+            [
+                SigParameter("args", ParameterKind.VAR_POSITIONAL),
+                SigParameter("kwargs", ParameterKind.VAR_KEYWORD),
+            ],
+            callable=typing.Any,
+            impl=_any_impl,
+            return_annotation=AnyValue(AnySource.error),
+        ),
         # Typeshed has it as TypeGuard[Callable[..., object]], which causes some
         # false positives.
         Signature.make(

pyanalyze/test_implementation.py

@@ -1345,3 +1345,12 @@ def capybara(x: object, unannotated, explicit_any: Any) -> None:
             assert_type(explicit_any, Any)
 
             assert_type(x, int)  # E: inference_failure
+
+
+class TestAny(TestNameCheckVisitorBase):
+    @assert_passes()
+    def test_call(self):
+        from typing import Any
+
+        def capybara():
+            Any(42)  # E: incompatible_call