Fix a crash caused by SimpleValue not implementing instantiate().

PiperOrigin-RevId: 412116246

Author: rchen152

pytype/abstract/abstract.py

@@ -396,10 +396,17 @@ def _unique_parameters(self):
     parameters.extend(self.instance_type_parameters.values())
     return parameters
 
+  def instantiate(self, node, container=None):
+    return Instance.from_value(self, container).to_variable(node)
+
 
 class Instance(SimpleValue):
   """An instance of some object."""
 
+  @classmethod
+  def from_value(cls, value, container=None):
+    return cls(value, value.ctx, container=container)
+
   def __init__(self, cls, ctx, container=None):
     super().__init__(cls.name, ctx)
     self.cls = cls
@@ -2694,7 +2701,7 @@ def instantiate(self, node, container=None):
       # When the analyze_x methods in CallTracer instantiate classes in
       # preparation for analysis, often there is no frame on the stack yet, or
       # the frame is a SimpleFrame with no opcode.
-      return self._to_instance(container).to_variable(node)
+      return super().instantiate(node, container)
 
   def __repr__(self):
     return "InterpreterClass(%s)" % self.name

pytype/abstract/class_mixin.py

@@ -381,9 +381,6 @@ def call_init(self, node, value, args):
       node = self._call_method(node, value, method, function.Args(()))
     return node
 
-  def _to_instance(self, container):
-    return self._instance_abstract_class(self, self.ctx, container=container)
-
   def _new_instance(self, container, node, args):
     """Returns a (possibly cached) instance of 'self'."""
     del args  # unused
@@ -394,7 +391,8 @@ def _new_instance(self, container, node, args):
       key = node
     assert key
     if key not in self._instance_cache:
-      self._instance_cache[key] = self._to_instance(container)
+      self._instance_cache[key] = self._instance_abstract_class.from_value(
+          self, container)
     return self._instance_cache[key]
 
   def _check_not_instantiable(self):