try to use the same str object for all code filenames when compiling or unmarshalling (#12190)

This should reduce memory usage.

2 files changed, 26 insertions, 0 deletions

diff --git a/Lib/test/test_compile.py b/Lib/test/test_compile.py
index 58ef297..c5f9189 100644
--- a/Lib/test/test_compile.py
+++ b/Lib/test/test_compile.py
@@ -1,6 +1,7 @@
 import unittest
 import sys
 import _ast
+import types
 from test import support
 
 class TestSpecifics(unittest.TestCase):
@@ -433,6 +434,14 @@ if 1:
         ast.body = [_ast.BoolOp()]
         self.assertRaises(TypeError, compile, ast, '<ast>', 'exec')
 
+    @support.cpython_only
+    def test_same_filename_used(self):
+        s = """def f(): pass\ndef g(): pass"""
+        c = compile(s, "myfile", "exec")
+        for obj in c.co_consts:
+            if isinstance(obj, types.CodeType):
+                self.assertIs(obj.co_filename, c.co_filename)
+
 
 def test_main():
     support.run_unittest(TestSpecifics)
diff --git a/Lib/test/test_marshal.py b/Lib/test/test_marshal.py
index 81cf598..8a5590a 100644
--- a/Lib/test/test_marshal.py
+++ b/Lib/test/test_marshal.py
@@ -5,6 +5,7 @@ import marshal
 import sys
 import unittest
 import os
+import types
 
 class HelperMixin:
     def helper(self, sample, *extra):
@@ -113,6 +114,22 @@ class CodeTestCase(unittest.TestCase):
         codes = (ExceptionTestCase.test_exceptions.__code__,) * count
         marshal.loads(marshal.dumps(codes))
 
+    def test_different_filenames(self):
+        co1 = compile("x", "f1", "exec")
+        co2 = compile("y", "f2", "exec")
+        co1, co2 = marshal.loads(marshal.dumps((co1, co2)))
+        self.assertEqual(co1.co_filename, "f1")
+        self.assertEqual(co2.co_filename, "f2")
+
+    @support.cpython_only
+    def test_same_filename_used(self):
+        s = """def f(): pass\ndef g(): pass"""
+        co = compile(s, "myfile", "exec")
+        co = marshal.loads(marshal.dumps(co))
+        for obj in co.co_consts:
+            if isinstance(obj, types.CodeType):
+                self.assertIs(co.co_filename, obj.co_filename)
+
 class ContainerTestCase(unittest.TestCase, HelperMixin):
     d = {'astring': 'foo@bar.baz.spam',
          'afloat': 7283.43,