match: remove obsolete catching of OverflowError
authorMartin von Zweigbergk <martinvonz@google.com>
Wed, 28 Nov 2018 10:12:50 -0800
changeset 40757 2f14d1bbc9a7
parent 40756 c85964d715fd
child 40758 eb5948f29c60
match: remove obsolete catching of OverflowError Since 0f6a1bdf89fb (match: handle large regexes, 2007-08-19), we catch an OverflowError from the regex engine and split up the regex if that happens. In 59a9dc9562e2 (ignore: split up huge patterns, 2008-02-11), that was extended to raise an OverflowError in our code even if the regex engine doesn't raise it. It's unclear if there was a range of regex sizes where the OverflowError would be raised from the regex engine but that were still below the limit we added in our code. Either way, both limitations were probably removed in Python 2.7.4 when the regex code width was extended from 16bit to 32bit (or Py_UCS4) integer (thanks to Yuya for finding that out). If at least the first limitation was removed, we no longer should be using OverflowError for flow control, so this patch changes that. Differential Revision: https://phab.mercurial-scm.org/D5309
mercurial/match.py
--- a/mercurial/match.py	Tue Nov 27 02:10:14 2018 +0100
+++ b/mercurial/match.py	Wed Nov 28 10:12:50 2018 -0800
@@ -1190,16 +1190,15 @@
     try:
         regex = '(?:%s)' % '|'.join([_regex(k, p, globsuffix)
                                      for (k, p, s) in kindpats])
-        if len(regex) > 20000:
-            raise OverflowError
-        return regex, _rematcher(regex)
-    except OverflowError:
+        if len(regex) <= 20000:
+            return regex, _rematcher(regex)
         # We're using a Python with a tiny regex engine and we
         # made it explode, so we'll divide the pattern list in two
         # until it works
         l = len(kindpats)
         if l < 2:
-            raise
+            # TODO: raise error.Abort here
+            raise OverflowError
         regexa, a = _buildregexmatch(kindpats[:l//2], globsuffix)
         regexb, b = _buildregexmatch(kindpats[l//2:], globsuffix)
         return regex, lambda s: a(s) or b(s)