gh-107450: Check for overflow in the tokenizer and fix overflow test (#110832)

Co-authored-by: Filipe Laíns <lains@riseup.net>
Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>

1 files changed, 12 insertions, 4 deletions

diff --git a/Lib/test/test_exceptions.py b/Lib/test/test_exceptions.py
index eafa7d8..4031c5c 100644
--- a/Lib/test/test_exceptions.py
+++ b/Lib/test/test_exceptions.py
@@ -18,6 +18,12 @@ from test.support.os_helper import TESTFN, unlink
 from test.support.warnings_helper import check_warnings
 from test import support
 
+try:
+    from _testcapi import INT_MAX
+except ImportError:
+    INT_MAX = 2**31 - 1
+
+
 
 class NaiveException(Exception):
     def __init__(self, x):
@@ -318,11 +324,13 @@ class ExceptionTests(unittest.TestCase):
         check('(yield i) = 2', 1, 2)
         check('def f(*):\n  pass', 1, 7)
 
+    @unittest.skipIf(INT_MAX >= sys.maxsize, "Downcasting to int is safe for col_offset")
     @support.requires_resource('cpu')
-    @support.bigmemtest(support._2G, memuse=1.5)
-    def testMemoryErrorBigSource(self, _size):
-        with self.assertRaises(OverflowError):
-            exec(f"if True:\n {' ' * 2**31}print('hello world')")
+    @support.bigmemtest(INT_MAX, memuse=2, dry_run=False)
+    def testMemoryErrorBigSource(self, size):
+        src = b"if True:\n%*s" % (size, b"pass")
+        with self.assertRaisesRegex(OverflowError, "Parser column offset overflow"):
+            compile(src, '<fragment>', 'exec')
 
     @cpython_only
     def testSettingException(self):