python · JukkaL · Apr 3, 2017 · Apr 1, 2017 · Apr 1, 2017 · Apr 1, 2017
diff --git a/mypy/checkmember.py b/mypy/checkmember.py
@@ -406,7 +406,9 @@ def analyze_class_attribute_access(itype: Instance,
         return AnyType()
 
     if isinstance(node.node, TypeVarExpr):
-        return TypeVarType(node.tvar_def, node.tvar_def.line, node.tvar_def.column)
+        msg.fail('Type variable "{}" is invalid except as a parameter to another type'.format(
+                 node.node.fullname() or node.node.name()), context)
+        return AnyType()
 
     if isinstance(node.node, TypeInfo):
         return type_object_type(node.node, builtin_type)

diff --git a/mypy/typeanal.py b/mypy/typeanal.py
@@ -43,6 +43,9 @@ def analyze_type_alias(node: Expression,
     # that we don't support straight string literals as type aliases
     # (only string literals within index expressions).
     if isinstance(node, RefExpr):
+        # Note that this misses the case where someone tried to use a
+        # class-referenced type variable as a type alias.  It's easier to catch
+        # that one in checkmemeber.py
         if node.kind == UNBOUND_TVAR or node.kind == BOUND_TVAR:
             fail_func('Type variable "{}" is invalid as target for type alias'.format(
                 node.fullname), node)

diff --git a/test-data/unit/check-typevar-values.test b/test-data/unit/check-typevar-values.test
@@ -496,12 +496,18 @@ def outer(x: T) -> T:
 [out]
 
 [case testClassMemberTypeVarInFunctionBody]
-from typing import TypeVar
+from typing import TypeVar, List
 class C:
     T = TypeVar('T', bound=int)
     def f(self, x: T) -> T:
-        A = C.T
-        return x
+        L = List[C.T] # a valid type alias
+        l: L = []
+        l.append(x)
+        C.T  # E: Type variable "T" is invalid except as a parameter to another type
+        A = C.T  # E: Type variable "T" is invalid except as a parameter to another type
+        return l[0]
+
+[builtins fixtures/list.pyi]
 
 [case testParameterLessGenericAsRestriction]
 from typing import Sequence, Iterable, TypeVar