From 73fb45df0487144765808c5d25914c67232d83fe Mon Sep 17 00:00:00 2001 From: Serhiy Storchaka Date: Tue, 16 May 2017 18:16:15 +0300 Subject: [PATCH] [3.6] bpo-30375: Correct the stacklevel of regex compiling warnings. (GH-1595) (#1604) Warnings emitted when compile a regular expression now always point to the line in the user code. Previously they could point into inners of the re module if emitted from inside of groups or conditionals.. (cherry picked from commit c7ac7280c321b3c1679fe5f657a6be0f86adf173) --- Lib/sre_parse.py | 25 +++++++++++++------------ Lib/test/test_re.py | 17 ++++++++++++++--- Misc/NEWS | 4 ++++ 3 files changed, 31 insertions(+), 15 deletions(-) diff --git a/Lib/sre_parse.py b/Lib/sre_parse.py index e1c749634b..608f9a2664 100644 --- a/Lib/sre_parse.py +++ b/Lib/sre_parse.py @@ -404,7 +404,7 @@ def _escape(source, escape, state): pass raise source.error("bad escape %s" % escape, len(escape)) -def _parse_sub(source, state, verbose, nested=True): +def _parse_sub(source, state, verbose, nested): # parse an alternation: a|b|c items = [] @@ -412,7 +412,8 @@ def _parse_sub(source, state, verbose, nested=True): sourcematch = source.match start = source.tell() while True: - itemsappend(_parse(source, state, verbose, not nested and not items)) + itemsappend(_parse(source, state, verbose, nested + 1, + not nested and not items)) if not sourcematch("|"): break @@ -454,10 +455,10 @@ def _parse_sub(source, state, verbose, nested=True): subpattern.append((BRANCH, (None, items))) return subpattern -def _parse_sub_cond(source, state, condgroup, verbose): - item_yes = _parse(source, state, verbose) +def _parse_sub_cond(source, state, condgroup, verbose, nested): + item_yes = _parse(source, state, verbose, nested + 1) if source.match("|"): - item_no = _parse(source, state, verbose) + item_no = _parse(source, state, verbose, nested + 1) if source.next == "|": raise source.error("conditional backref with more than two branches") else: @@ -466,7 +467,7 @@ def _parse_sub_cond(source, state, condgroup, verbose): subpattern.append((GROUPREF_EXISTS, (condgroup, item_yes, item_no))) return subpattern -def _parse(source, state, verbose, first=False): +def _parse(source, state, verbose, nested, first=False): # parse a simple pattern subpattern = SubPattern(state) @@ -692,7 +693,7 @@ def _parse(source, state, verbose, first=False): lookbehindgroups = state.lookbehindgroups if lookbehindgroups is None: state.lookbehindgroups = state.groups - p = _parse_sub(source, state, verbose) + p = _parse_sub(source, state, verbose, nested + 1) if dir < 0: if lookbehindgroups is None: state.lookbehindgroups = None @@ -739,7 +740,7 @@ def _parse(source, state, verbose, first=False): source.string[:20], # truncate long regexes ' (truncated)' if len(source.string) > 20 else '', ), - DeprecationWarning, stacklevel=7 + DeprecationWarning, stacklevel=nested + 6 ) if (state.flags & SRE_FLAG_VERBOSE) and not verbose: raise Verbose @@ -757,11 +758,11 @@ def _parse(source, state, verbose, first=False): except error as err: raise source.error(err.msg, len(name) + 1) from None if condgroup: - p = _parse_sub_cond(source, state, condgroup, verbose) + p = _parse_sub_cond(source, state, condgroup, verbose, nested + 1) else: sub_verbose = ((verbose or (add_flags & SRE_FLAG_VERBOSE)) and not (del_flags & SRE_FLAG_VERBOSE)) - p = _parse_sub(source, state, sub_verbose) + p = _parse_sub(source, state, sub_verbose, nested + 1) if not source.match(")"): raise source.error("missing ), unterminated subpattern", source.tell() - start) @@ -851,7 +852,7 @@ def parse(str, flags=0, pattern=None): pattern.str = str try: - p = _parse_sub(source, pattern, flags & SRE_FLAG_VERBOSE, False) + p = _parse_sub(source, pattern, flags & SRE_FLAG_VERBOSE, 0) except Verbose: # the VERBOSE flag was switched on inside the pattern. to be # on the safe side, we'll parse the whole thing again... @@ -859,7 +860,7 @@ def parse(str, flags=0, pattern=None): pattern.flags = flags | SRE_FLAG_VERBOSE pattern.str = str source.seek(0) - p = _parse_sub(source, pattern, True, False) + p = _parse_sub(source, pattern, True, 0) p.pattern.flags = fix_flags(str, p.pattern.flags) diff --git a/Lib/test/test_re.py b/Lib/test/test_re.py index c52417ba00..e88d0b3dcf 100644 --- a/Lib/test/test_re.py +++ b/Lib/test/test_re.py @@ -1348,6 +1348,7 @@ class ReTests(unittest.TestCase): str(warns.warnings[0].message), 'Flags not at the start of the expression %s' % p ) + self.assertEqual(warns.warnings[0].filename, __file__) p = upper_char + '(?i)%s' % ('.?' * 100) with self.assertWarns(DeprecationWarning) as warns: @@ -1356,6 +1357,7 @@ class ReTests(unittest.TestCase): str(warns.warnings[0].message), 'Flags not at the start of the expression %s (truncated)' % p[:20] ) + self.assertEqual(warns.warnings[0].filename, __file__) with self.assertWarns(DeprecationWarning): self.assertTrue(re.match('(?s).(?i)' + upper_char, '\n' + lower_char)) @@ -1367,14 +1369,23 @@ class ReTests(unittest.TestCase): self.assertTrue(re.match('^(?i)' + upper_char, lower_char)) with self.assertWarns(DeprecationWarning): self.assertTrue(re.match('$|(?i)' + upper_char, lower_char)) - with self.assertWarns(DeprecationWarning): + with self.assertWarns(DeprecationWarning) as warns: self.assertTrue(re.match('(?:(?i)' + upper_char + ')', lower_char)) - with self.assertWarns(DeprecationWarning): + self.assertRegex(str(warns.warnings[0].message), + 'Flags not at the start') + self.assertEqual(warns.warnings[0].filename, __file__) + with self.assertWarns(DeprecationWarning) as warns: self.assertTrue(re.fullmatch('(^)?(?(1)(?i)' + upper_char + ')', lower_char)) - with self.assertWarns(DeprecationWarning): + self.assertRegex(str(warns.warnings[0].message), + 'Flags not at the start') + self.assertEqual(warns.warnings[0].filename, __file__) + with self.assertWarns(DeprecationWarning) as warns: self.assertTrue(re.fullmatch('($)?(?(1)|(?i)' + upper_char + ')', lower_char)) + self.assertRegex(str(warns.warnings[0].message), + 'Flags not at the start') + self.assertEqual(warns.warnings[0].filename, __file__) def test_dollar_matches_twice(self): diff --git a/Misc/NEWS b/Misc/NEWS index bfb14c1365..567f40976e 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -36,6 +36,10 @@ Core and Builtins Library ------- +- bpo-30375: Warnings emitted when compile a regular expression now always + point to the line in the user code. Previously they could point into inners + of the re module if emitted from inside of groups or conditionals. + - bpo-30048: Fixed ``Task.cancel()`` can be ignored when the task is running coroutine and the coroutine returned without any more ``await``. -- 2.50.1