thirdparty: vendor pyre2

Summary:
We recently found issues where it seems "hg" in some environment uses an
ABI-incompatible re2 library and segfaults. pyre2 is small and was
originally written by Facebook for Mercurial use-case. So let's just vendor
it.

Reviewed By: markbt

Differential Revision: D7622774

fbshipit-source-id: db01183c9881bf9c3ed21fceed195b2059d40208

mercurial/thirdparty/pyre2/__init__.py

@@ -0,0 +1,72 @@
+# Copyright (c) 2010, David Reiss and Facebook, Inc. All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+# * Redistributions of source code must retain the above copyright
+#   notice, this list of conditions and the following disclaimer.
+# * Redistributions in binary form must reproduce the above copyright
+#   notice, this list of conditions and the following disclaimer in the
+#   documentation and/or other materials provided with the distribution.
+# * Neither the name of Facebook nor the names of its contributors
+#   may be used to endorse or promote products derived from this software
+#   without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+# PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+from __future__ import absolute_import
+
+from . import _re2
+import sre_constants
+
+__all__ = [
+    "error",
+    "escape",
+    "compile",
+    "search",
+    "match",
+    "fullmatch",
+    "Set",
+    "UNANCHORED",
+    "ANCHOR_START",
+    "ANCHOR_BOTH",
+    ]
+
+# Module-private compilation function, for future caching, other enhancements
+_compile = _re2._compile
+
+error = sre_constants.error
+escape = _re2.escape
+Set = _re2.Set
+UNANCHORED = _re2.UNANCHORED
+ANCHOR_START = _re2.ANCHOR_START
+ANCHOR_BOTH = _re2.ANCHOR_BOTH
+
+def compile(pattern):
+    "Compile a regular expression pattern, returning a pattern object."
+    return _compile(pattern, error)
+
+def search(pattern, string):
+    """Scan through string looking for a match to the pattern, returning
+    a match object, or None if no match was found."""
+    return _compile(pattern, error).search(string)
+
+def match(pattern, string):
+    """Try to apply the pattern at the start of the string, returning
+    a match object, or None if no match was found."""
+    return _compile(pattern, error).match(string)
+
+def fullmatch(pattern, string):
+    """Try to apply the pattern to the entire string, returning
+    a match object, or None if no match was found."""
+    return _compile(pattern, error).fullmatch(string)