[libstdc++/67015, patch] Fix regex POSIX bracket parsing
Kinda important, since "[a-z0-9-]" may be a common case. Bootstrapped and tested. Guess it can also be backported to 5, or even 4.9? Thanks! -- Regards, Tim Shen
Re: [libstdc++/67015, patch] Fix regex POSIX bracket parsing
On Sun, Jul 26, 2015 at 5:19 AM, Tim Shen wrote: > Kinda important, since "[a-z0-9-]" may be a common case. > > Bootstrapped and tested. Actual patch... -- Regards, Tim Shen commit e0e6c2e3b722e1453d29ad3a56d0de80046453b0 Author: Tim Shen Date: Sun Jul 26 04:37:45 2015 -0700 PR libstdc++/67015 * include/bits/regex_compiler.h (_Compiler<>::_M_expression_term, _BracketMatcher<>::_M_add_collating_element): Change signature to make checking the and of bracket expression easier. * include/bits/regex_compiler.tcc (_Compiler<>::_M_expression_term): Treat '-' as a valid literal if it's at the end of bracket expression. * testsuite/28_regex/algorithms/regex_match/cstring_bracket_01.cc: New testcases. diff --git a/libstdc++-v3/include/bits/regex_compiler.h b/libstdc++-v3/include/bits/regex_compiler.h index 4472116..6d9799e 100644 --- a/libstdc++-v3/include/bits/regex_compiler.h +++ b/libstdc++-v3/include/bits/regex_compiler.h @@ -116,8 +116,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION void _M_insert_bracket_matcher(bool __neg); + // Returns true if successfully matched one term and should continue. + // Returns false if the compiler should move on. template - void + bool _M_expression_term(pair& __last_char, _BracketMatcher<_TraitsT, __icase, __collate>& __matcher); @@ -389,7 +391,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION #endif } - void + _StringT _M_add_collating_element(const _StringT& __s) { auto __st = _M_traits.lookup_collatename(__s.data(), @@ -400,6 +402,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION #ifdef _GLIBCXX_DEBUG _M_is_ready = false; #endif + return __st; } void diff --git a/libstdc++-v3/include/bits/regex_compiler.tcc b/libstdc++-v3/include/bits/regex_compiler.tcc index 33d7118..f48e3c1 100644 --- a/libstdc++-v3/include/bits/regex_compiler.tcc +++ b/libstdc++-v3/include/bits/regex_compiler.tcc @@ -424,8 +424,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION __last_char.first = true; __last_char.second = _M_value[0]; } - while (!_M_match_token(_ScannerT::_S_token_bracket_end)) - _M_expression_term(__last_char, __matcher); + while (_M_expression_term(__last_char, __matcher)); __matcher._M_ready(); _M_stack.push(_StateSeqT( *_M_nfa, @@ -434,21 +433,31 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION template template -void +bool _Compiler<_TraitsT>:: _M_expression_term(pair& __last_char, _BracketMatcher<_TraitsT, __icase, __collate>& __matcher) { + if (_M_match_token(_ScannerT::_S_token_bracket_end)) + return false; + if (_M_match_token(_ScannerT::_S_token_collsymbol)) - __matcher._M_add_collating_element(_M_value); + { + auto __symbol = __matcher._M_add_collating_element(_M_value); + if (__symbol.size() == 1) + { + __last_char.first = true; + __last_char.second = __symbol[0]; + } + } else if (_M_match_token(_ScannerT::_S_token_equiv_class_name)) __matcher._M_add_equivalence_class(_M_value); else if (_M_match_token(_ScannerT::_S_token_char_class_name)) __matcher._M_add_character_class(_M_value, false); - // POSIX doesn't permit '-' as a start-range char (say [a-z--0]), - // except when the '-' is the first character in the bracket expression - // ([--0]). ECMAScript treats all '-' after a range as a normal character. - // Also see above, where _M_expression_term gets called. + // POSIX doesn't allow '-' as a start-range char (say [a-z--0]), + // except when the '-' is the first or last character in the bracket + // expression ([--0]). ECMAScript treats all '-' after a range as a + // normal character. Also see above, where _M_expression_term gets called. // // As a result, POSIX rejects [-], but ECMAScript doesn't. // Boost (1.57.0) always uses POSIX style even in its ECMAScript syntax. @@ -459,10 +468,14 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION { if (!__last_char.first) { + __matcher._M_add_char(_M_value[0]); if (_M_value[0] == '-' && !(_M_flags & regex_constants::ECMAScript)) - __throw_regex_error(regex_constants::error_range); - __matcher._M_add_char(_M_value[0]); + { + if (_M_match_token(_ScannerT::_S_token_bracket_end)) + return false; + __throw_regex_error(regex_constants::error_range); + } __last_char.first = true; __last_char.second = _M_value[0]; } @@ -496,6 +509,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
Re: [libstdc++/67015, patch] Fix regex POSIX bracket parsing
On 26/07/15 05:20 -0700, Tim Shen wrote: @@ -389,7 +391,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION #endif } - void + _StringT _M_add_collating_element(const _StringT& __s) { auto __st = _M_traits.lookup_collatename(__s.data(), Changing this return type is an ABI change. When compiled with older versions of GCC this function will not return anything, so code compiled with newer versions that links to that older code will read garbage off the stack if linked to the old version. (This isn't a problem for _M_expression_term because the return type is part of the mangled name for function templates). One solution would be to rename the function, so that code compiled with the new GCC will use the new function, not link to the old version that doesn't return anything.
Re: [libstdc++/67015, patch] Fix regex POSIX bracket parsing
On Mon, Jul 27, 2015 at 4:45 AM, Jonathan Wakely wrote: > On 26/07/15 05:20 -0700, Tim Shen wrote: >> >> @@ -389,7 +391,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION >> #endif >> } >> >> - void >> + _StringT >> _M_add_collating_element(const _StringT& __s) >> { >> auto __st = _M_traits.lookup_collatename(__s.data(), > > > Changing this return type is an ABI change. When compiled with older > versions of GCC this function will not return anything, so code > compiled with newer versions that links to that older code will read > garbage off the stack if linked to the old version. > > (This isn't a problem for _M_expression_term because the return type > is part of the mangled name for function templates). > > One solution would be to rename the function, so that code compiled > with the new GCC will use the new function, not link to the old > version that doesn't return anything. Done by s/_M_add_collating_element/_M_add_collate_element/. -- Regards, Tim Shen commit 4a3b4ab285b0ecabb706a776551dabf5a37059aa Author: Tim Shen Date: Sun Jul 26 04:37:45 2015 -0700 PR libstdc++/67015 * include/bits/regex_compiler.h (_Compiler<>::_M_expression_term, _BracketMatcher<>::_M_add_collating_element): Change signature to make checking the and of bracket expression easier. * include/bits/regex_compiler.tcc (_Compiler<>::_M_expression_term): Treat '-' as a valid literal if it's at the end of bracket expression. * testsuite/28_regex/algorithms/regex_match/cstring_bracket_01.cc: New testcases. diff --git a/libstdc++-v3/include/bits/regex_compiler.h b/libstdc++-v3/include/bits/regex_compiler.h index 4472116..0cb0c04 100644 --- a/libstdc++-v3/include/bits/regex_compiler.h +++ b/libstdc++-v3/include/bits/regex_compiler.h @@ -116,8 +116,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION void _M_insert_bracket_matcher(bool __neg); + // Returns true if successfully matched one term and should continue. + // Returns false if the compiler should move on. template - void + bool _M_expression_term(pair& __last_char, _BracketMatcher<_TraitsT, __icase, __collate>& __matcher); @@ -389,8 +391,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION #endif } - void - _M_add_collating_element(const _StringT& __s) + _StringT + _M_add_collate_element(const _StringT& __s) { auto __st = _M_traits.lookup_collatename(__s.data(), __s.data() + __s.size()); @@ -400,6 +402,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION #ifdef _GLIBCXX_DEBUG _M_is_ready = false; #endif + return __st; } void diff --git a/libstdc++-v3/include/bits/regex_compiler.tcc b/libstdc++-v3/include/bits/regex_compiler.tcc index 33d7118..9a62311 100644 --- a/libstdc++-v3/include/bits/regex_compiler.tcc +++ b/libstdc++-v3/include/bits/regex_compiler.tcc @@ -424,8 +424,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION __last_char.first = true; __last_char.second = _M_value[0]; } - while (!_M_match_token(_ScannerT::_S_token_bracket_end)) - _M_expression_term(__last_char, __matcher); + while (_M_expression_term(__last_char, __matcher)); __matcher._M_ready(); _M_stack.push(_StateSeqT( *_M_nfa, @@ -434,21 +433,31 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION template template -void +bool _Compiler<_TraitsT>:: _M_expression_term(pair& __last_char, _BracketMatcher<_TraitsT, __icase, __collate>& __matcher) { + if (_M_match_token(_ScannerT::_S_token_bracket_end)) + return false; + if (_M_match_token(_ScannerT::_S_token_collsymbol)) - __matcher._M_add_collating_element(_M_value); + { + auto __symbol = __matcher._M_add_collate_element(_M_value); + if (__symbol.size() == 1) + { + __last_char.first = true; + __last_char.second = __symbol[0]; + } + } else if (_M_match_token(_ScannerT::_S_token_equiv_class_name)) __matcher._M_add_equivalence_class(_M_value); else if (_M_match_token(_ScannerT::_S_token_char_class_name)) __matcher._M_add_character_class(_M_value, false); - // POSIX doesn't permit '-' as a start-range char (say [a-z--0]), - // except when the '-' is the first character in the bracket expression - // ([--0]). ECMAScript treats all '-' after a range as a normal character. - // Also see above, where _M_expression_term gets called. + // POSIX doesn't allow '-' as a start-range char (say [a-z--0]), + // except when the '-' is the first or last character in the bracket + // expression ([--0]). ECMAScript treats all '-' after a range as a + // normal character. Also see above, where _M_expression_term gets called
Re: [libstdc++/67015, patch] Fix regex POSIX bracket parsing
On 27/07/15 19:40 -0700, Tim Shen wrote: Done by s/_M_add_collating_element/_M_add_collate_element/. Great, thanks. OK for trunk and gcc-5-branch.
Re: [libstdc++/67015, patch] Fix regex POSIX bracket parsing
On Tue, Jul 28, 2015 at 3:27 AM, Jonathan Wakely wrote: > On 27/07/15 19:40 -0700, Tim Shen wrote: >> >> Done by s/_M_add_collating_element/_M_add_collate_element/. > > > Great, thanks. OK for trunk and gcc-5-branch. Committed. Is there no need for gcc-4_9-branch? What's the general policy for backporting fixes? Thanks! -- Regards, Tim Shen
Re: [libstdc++/67015, patch] Fix regex POSIX bracket parsing
On 28/07/15 21:44 -0700, Tim Shen wrote: On Tue, Jul 28, 2015 at 3:27 AM, Jonathan Wakely wrote: On 27/07/15 19:40 -0700, Tim Shen wrote: Done by s/_M_add_collating_element/_M_add_collate_element/. Great, thanks. OK for trunk and gcc-5-branch. Committed. Is there no need for gcc-4_9-branch? What's the general policy for backporting fixes? In general, only fixes for regressions (and changes to documentation or tests) should be backported. The 4.9 branch is the oldest one we still support, so should be very stable now, although C++11 support in 4.9 is still labelled experimental, and this only changes C++11 code. How important is it to fix?
Re: [libstdc++/67015, patch] Fix regex POSIX bracket parsing
On Wed, Jul 29, 2015 at 1:35 AM, Jonathan Wakely wrote: > The 4.9 branch is the oldest one we still support, so should be very > stable now, although C++11 support in 4.9 is still labelled > experimental, and this only changes C++11 code. How important is it to > fix? Um... I'd say medium importance, for [a-z0-9-] not working in POSIX syntax (while ECMAScript seems to be more popular, which works correctly). If 4.9 is `stable` and expected to be experimetal, which by my definition should only include important changes, we may leave it as is? -- Regards, Tim Shen
Re: [libstdc++/67015, patch] Fix regex POSIX bracket parsing
On 29/07/15 01:56 -0700, Tim Shen wrote: If 4.9 is `stable` and expected to be experimetal, which by my definition should only include important changes, we may leave it as is? Yes, let's not change the 4.9 version.