bpo-30639: Lazily compute repr for error

Lib/inspect.py

@@ -662,8 +662,9 @@ def getfile(object):
         object = object.f_code
     if iscode(object):
         return object.co_filename
-    raise TypeError('{!r} is not a module, class, method, '
-                    'function, traceback, frame, or code object'.format(object))
+    raise TypeError('module, class, method, function, traceback, frame, or '
+                    'code object was expected, got {}'.format(
+                    type(object).__name__))
 
 def getmodulename(path):
     """Return the module name for a given file, or None."""

Lib/test/test_inspect.py

@@ -463,6 +463,14 @@ class C(metaclass=CM):
         with self.assertRaises(TypeError):
             inspect.getfile(C)
 
+    def test_getfile_broken_repr(self):
+        class ErrorRepr:
+            def __repr__(self):
+                raise Exception('xyz')
+        er = ErrorRepr()
+        with self.assertRaises(TypeError):
+            inspect.getfile(er)
+
     def test_getmodule_recursion(self):
         from types import ModuleType
         name = '__inspect_dummy'

Misc/NEWS.d/next/Library/2017-10-24-12-24-56.bpo-30639.ptNM9a.rst

@@ -0,0 +1,2 @@
+:func:`inspect.getfile` no longer computes the repr of unknown objects to
+display in an error message, to protect against badly behaved custom reprs.