diff --git a/Lib/codeop.py b/Lib/codeop.py index 7e192ea6a10..547629262d0 100644 --- a/Lib/codeop.py +++ b/Lib/codeop.py @@ -84,9 +84,11 @@ def _maybe_compile(compiler, source, filename, symbol): except SyntaxError: pass - # Suppress warnings after the first compile to avoid duplication. + # Catch syntax warnings after the first compile + # to emit SyntaxWarning at most once. with warnings.catch_warnings(): - warnings.simplefilter("ignore") + warnings.simplefilter("error", SyntaxWarning) + try: code1 = compiler(source + "\n", filename, symbol) except SyntaxError as e: diff --git a/Lib/test/test_codeop.py b/Lib/test/test_codeop.py index 6e821df6b0e..7984e5f1e5a 100644 --- a/Lib/test/test_codeop.py +++ b/Lib/test/test_codeop.py @@ -4,6 +4,7 @@ """ import sys import unittest +import warnings from test import support from test.support import warnings_helper @@ -310,5 +311,11 @@ class CodeopTests(unittest.TestCase): compile_command("0 is 0") self.assertEqual(len(w.warnings), 1) + # bpo-41520: check SyntaxWarning treated as an SyntaxError + with self.assertRaises(SyntaxError): + warnings.simplefilter('error', SyntaxWarning) + compile_command('1 is 1\n', symbol='exec') + + if __name__ == "__main__": unittest.main() diff --git a/Misc/NEWS.d/next/Library/2020-08-12-13-25-16.bpo-41520.BEUWa4.rst b/Misc/NEWS.d/next/Library/2020-08-12-13-25-16.bpo-41520.BEUWa4.rst new file mode 100644 index 00000000000..ca5501c2aee --- /dev/null +++ b/Misc/NEWS.d/next/Library/2020-08-12-13-25-16.bpo-41520.BEUWa4.rst @@ -0,0 +1 @@ +Fix :mod:`codeop` regression: it no longer ignores :exc:`SyntaxWarning`.