From 0b3c00ff3c53818110484f9e295523a0c3c7f324 Mon Sep 17 00:00:00 2001 From: Jonathan Wakely Date: Tue, 14 May 2019 13:19:05 +0100 Subject: [PATCH] Make std::match_results::_M_resize more useful As both callers of match_results::_M_resize(unsigned) immediately follow it with a loop to update the value of each sub_match, that behaviour can be moved into _M_resize itself. The first caller fills the container with unmatched subs, which can be done with vector::assign, and the second caller clears the container to establish a specific state, which can be provided by a new member function specific to that purpose. Tangentially, I also noticed that match_results::max_size() doesn't account for the three special sub_match objects that are always present in a fully established result state. This patch also fixes that. * include/bits/regex.h (match_results::max_size()): Adjust return value to account for prefix/suffix/unmatched subs. (match_results::_M_resize(unsigned int)): Use _Base_type::assign to reset the contained sub matches. (match_results::_M_establish_failed_match(_Bi_iter)): Add new member function to set result state following a failed match. * include/bits/regex.tcc (__regex_algo_impl): Remove loop to set sub_match states after _M_resize. Use _M_establish_failed_match. From-SVN: r271167 --- libstdc++-v3/ChangeLog | 9 +++++++++ libstdc++-v3/include/bits/regex.h | 15 +++++++++++++-- libstdc++-v3/include/bits/regex.tcc | 9 +-------- 3 files changed, 23 insertions(+), 10 deletions(-) diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog index 995f2ce1d45..3cfcd0623c1 100644 --- a/libstdc++-v3/ChangeLog +++ b/libstdc++-v3/ChangeLog @@ -1,5 +1,14 @@ 2019-05-14 Jonathan Wakely + * include/bits/regex.h (match_results::max_size()): Adjust return + value to account for prefix/suffix/unmatched subs. + (match_results::_M_resize(unsigned int)): Use _Base_type::assign to + reset the contained sub matches. + (match_results::_M_establish_failed_match(_Bi_iter)): Add new member + function to set result state following a failed match. + * include/bits/regex.tcc (__regex_algo_impl): Remove loop to set + sub_match states after _M_resize. Use _M_establish_failed_match. + PR libstdc++/69724 * include/std/thread (thread::_State_impl, thread::_S_make_state): Replace single _Callable parameter with variadic _Args pack, to diff --git a/libstdc++-v3/include/bits/regex.h b/libstdc++-v3/include/bits/regex.h index 76219b5ae3b..b30b41a0759 100644 --- a/libstdc++-v3/include/bits/regex.h +++ b/libstdc++-v3/include/bits/regex.h @@ -1707,7 +1707,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11 size_type max_size() const noexcept - { return _Base_type::max_size(); } + { return _Base_type::max_size() - 3; } /** * @brief Indicates if the %match_results contains no results. @@ -1953,9 +1953,20 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11 const basic_regex<_Cp, _Rp>&, regex_constants::match_flag_type); + // Reset contents to __size unmatched sub_match objects + // (plus additional objects for prefix, suffix and unmatched sub). void _M_resize(unsigned int __size) - { _Base_type::resize(__size + 3); } + { _Base_type::assign(__size + 3, sub_match<_Bi_iter>{}); } + + // Set state to a failed match for the given past-the-end iterator. + void + _M_establish_failed_match(_Bi_iter __end) + { + sub_match<_Bi_iter> __sm; + __sm.first = __sm.second = __end; + _Base_type::assign(3, __sm); + } const_reference _M_unmatched_sub() const diff --git a/libstdc++-v3/include/bits/regex.tcc b/libstdc++-v3/include/bits/regex.tcc index dbe348dbfe8..53cf1ffa01e 100644 --- a/libstdc++-v3/include/bits/regex.tcc +++ b/libstdc++-v3/include/bits/regex.tcc @@ -59,8 +59,6 @@ namespace __detail typename match_results<_BiIter, _Alloc>::_Base_type& __res = __m; __m._M_begin = __s; __m._M_resize(__re._M_automaton->_M_sub_count()); - for (auto& __it : __res) - __it.matched = false; bool __ret; if ((__re.flags() & regex_constants::__polynomial) @@ -111,12 +109,7 @@ namespace __detail } else { - __m._M_resize(0); - for (auto& __it : __res) - { - __it.matched = false; - __it.first = __it.second = __e; - } + __m._M_establish_failed_match(__e); } return __ret; } -- 2.30.2