Merge branch 'master' into TypeVar-02-basic-validation

Author: JelleZijlstra

mypy/nodes.py

@@ -2446,6 +2446,8 @@ class TypeVarLikeExpr(SymbolNode, Expression):
     # Upper bound: only subtypes of upper_bound are valid as values. By default
     # this is 'object', meaning no restriction.
     upper_bound: mypy.types.Type
+    # Default: used to resolve the TypeVar if the default is not explicitly given.
+    # By default this is 'AnyType(TypeOfAny.from_omitted_generics)'. See PEP 696.
     default: mypy.types.Type
     # Variance of the type variable. Invariant is the default.
     # TypeVar(..., covariant=True) defines a covariant type variable.

mypy/semanal.py

@@ -4283,6 +4283,8 @@ def process_paramspec_declaration(self, s: AssignmentStmt) -> bool:
                     s,
                 )
 
+        default: Type = AnyType(TypeOfAny.from_omitted_generics)
+
         # PEP 612 reserves the right to define bound, covariant and contravariant arguments to
         # ParamSpec in a later PEP. If and when that happens, we should do something
         # on the lines of process_typevar_parameters
@@ -4347,6 +4349,8 @@ def process_typevartuple_declaration(self, s: AssignmentStmt) -> bool:
                     s,
                 )
 
+        default: Type = AnyType(TypeOfAny.from_omitted_generics)
+
         if not self.incomplete_feature_enabled(TYPE_VAR_TUPLE, s):
             return False