From 5a72679338f9dc0e38c98befe65aac73de1822ab Mon Sep 17 00:00:00 2001 From: Marshall Clow Date: Tue, 12 Sep 2017 17:56:59 +0000 Subject: Apply D28224: 'Throw exception after too many steps' Fixes PR#20291. Thanks to Tim Shen for the patch llvm-svn: 313056 --- libcxx/include/regex | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'libcxx/include/regex') diff --git a/libcxx/include/regex b/libcxx/include/regex index 77ca648109b..dfc97c58a3f 100644 --- a/libcxx/include/regex +++ b/libcxx/include/regex @@ -773,6 +773,8 @@ _LIBCPP_PUSH_MACROS #include <__undef_macros> +#define _LIBCPP_REGEX_COMPLEXITY_FACTOR 4096 + _LIBCPP_BEGIN_NAMESPACE_STD namespace regex_constants @@ -5552,8 +5554,14 @@ basic_regex<_CharT, _Traits>::__match_at_start_ecma( __states.back().__node_ = __st; __states.back().__flags_ = __flags; __states.back().__at_first_ = __at_first; + int __counter = 0; + int __length = __last - __first; do { + ++__counter; + if (__counter % _LIBCPP_REGEX_COMPLEXITY_FACTOR == 0 && + __counter / _LIBCPP_REGEX_COMPLEXITY_FACTOR >= __length) + __throw_regex_error(); __state& __s = __states.back(); if (__s.__node_) __s.__node_->__exec(__s); @@ -5627,8 +5635,14 @@ basic_regex<_CharT, _Traits>::__match_at_start_posix_nosubs( __states.back().__flags_ = __flags; __states.back().__at_first_ = __at_first; bool __matched = false; + int __counter = 0; + int __length = __last - __first; do { + ++__counter; + if (__counter % _LIBCPP_REGEX_COMPLEXITY_FACTOR == 0 && + __counter / _LIBCPP_REGEX_COMPLEXITY_FACTOR >= __length) + __throw_regex_error(); __state& __s = __states.back(); if (__s.__node_) __s.__node_->__exec(__s); @@ -5724,8 +5738,14 @@ basic_regex<_CharT, _Traits>::__match_at_start_posix_subs( __states.back().__at_first_ = __at_first; const _CharT* __current = __first; bool __matched = false; + int __counter = 0; + int __length = __last - __first; do { + ++__counter; + if (__counter % _LIBCPP_REGEX_COMPLEXITY_FACTOR == 0 && + __counter / _LIBCPP_REGEX_COMPLEXITY_FACTOR >= __length) + __throw_regex_error(); __state& __s = __states.back(); if (__s.__node_) __s.__node_->__exec(__s); -- cgit v1.2.3