git
/
gcc
mirror of git://gcc.gnu.org/git/gcc.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Split _M_dfs() into smaller functions. 

* regex_executor.h(_M_handle_repeat, _M_handle_subexpr_begin)
	(_M_handle_subexpr_end, _M_handle_line_begin_assertion)
	(_M_handle_line_end_assertion, _M_handle_word_boundary)
	(_M_handle_subexpr_lookahead, _M_handle_match)
	(_M_handle_backref, _M_handle_accept, _M_handle_alternative):
	Add separate function declarations.
	* regex_executor.tcc: Split _M_dfs() into multiple handler functions.

From-SVN: r239673
This commit is contained in:
Tim Shen 2016-08-22 19:50:15 +00:00 committed by Tim Shen
parent bef18c6382
commit d79d625275
3 changed files with 313 additions and 187 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
libstdc++-v3/ChangeLog
View File

@ -1,3 +1,14 @@
2016-08-22 Tim Shen <timshen@google.com>
Split _M_dfs() into smaller functions.
* regex_executor.h(_M_handle_repeat, _M_handle_subexpr_begin)
(_M_handle_subexpr_end, _M_handle_line_begin_assertion)
(_M_handle_line_end_assertion, _M_handle_word_boundary)
(_M_handle_subexpr_lookahead, _M_handle_match)
(_M_handle_backref, _M_handle_accept, _M_handle_alternative):
Add separate function declarations.
* regex_executor.tcc: Split _M_dfs() into multiple handler functions.
2016-08-22 Gleb Natapov <gleb@scylladb.com>
PR libstdc++/68297

33
libstdc++-v3/include/bits/regex_executor.h
View File

@ -108,6 +108,39 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
void
_M_rep_once_more(_Match_mode __match_mode, _StateIdT);
void
_M_handle_repeat(_Match_mode, _StateIdT);
void
_M_handle_subexpr_begin(_Match_mode, _StateIdT);
void
_M_handle_subexpr_end(_Match_mode, _StateIdT);
void
_M_handle_line_begin_assertion(_Match_mode, _StateIdT);
void
_M_handle_line_end_assertion(_Match_mode, _StateIdT);
void
_M_handle_word_boundary(_Match_mode, _StateIdT);
void
_M_handle_subexpr_lookahead(_Match_mode, _StateIdT);
void
_M_handle_match(_Match_mode, _StateIdT);
void
_M_handle_backref(_Match_mode, _StateIdT);
void
_M_handle_accept(_Match_mode, _StateIdT);
void
_M_handle_alternative(_Match_mode, _StateIdT);
void
_M_dfs(_Match_mode __match_mode, _StateIdT __start);

456
libstdc++-v3/include/bits/regex_executor.tcc
View File

@ -195,6 +195,263 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
}
};
// _M_alt branch is "match once more", while _M_next is "get me out
// of this quantifier". Executing _M_next first or _M_alt first don't
// mean the same thing, and we need to choose the correct order under
// given greedy mode.
template<typename _BiIter, typename _Alloc, typename _TraitsT,
bool __dfs_mode>
void _Executor<_BiIter, _Alloc, _TraitsT, __dfs_mode>::
_M_handle_repeat(_Match_mode __match_mode, _StateIdT __i)
{
const auto& __state = _M_nfa[__i];
// Greedy.
if (!__state._M_neg)
{
_M_rep_once_more(__match_mode, __i);
// If it's DFS executor and already accepted, we're done.
if (!__dfs_mode || !_M_has_sol)
_M_dfs(__match_mode, __state._M_next);
}
else // Non-greedy mode
{
if (__dfs_mode)
{
// vice-versa.
_M_dfs(__match_mode, __state._M_next);
if (!_M_has_sol)
_M_rep_once_more(__match_mode, __i);
}
else
{
// DON'T attempt anything, because there's already another
// state with higher priority accepted. This state cannot
// be better by attempting its next node.
if (!_M_has_sol)
{
_M_dfs(__match_mode, __state._M_next);
// DON'T attempt anything if it's already accepted. An
// accepted state *must* be better than a solution that
// matches a non-greedy quantifier one more time.
if (!_M_has_sol)
_M_rep_once_more(__match_mode, __i);
}
}
}
}
template<typename _BiIter, typename _Alloc, typename _TraitsT,
bool __dfs_mode>
void _Executor<_BiIter, _Alloc, _TraitsT, __dfs_mode>::
_M_handle_subexpr_begin(_Match_mode __match_mode, _StateIdT __i)
{
const auto& __state = _M_nfa[__i];
auto& __res = _M_cur_results[__state._M_subexpr];
auto __back = __res.first;
__res.first = _M_current;
_M_dfs(__match_mode, __state._M_next);
__res.first = __back;
}
template<typename _BiIter, typename _Alloc, typename _TraitsT,
bool __dfs_mode>
void _Executor<_BiIter, _Alloc, _TraitsT, __dfs_mode>::
_M_handle_subexpr_end(_Match_mode __match_mode, _StateIdT __i)
{
const auto& __state = _M_nfa[__i];
auto& __res = _M_cur_results[__state._M_subexpr];
auto __back = __res;
__res.second = _M_current;
__res.matched = true;
_M_dfs(__match_mode, __state._M_next);
__res = __back;
}
template<typename _BiIter, typename _Alloc, typename _TraitsT,
bool __dfs_mode>
inline void _Executor<_BiIter, _Alloc, _TraitsT, __dfs_mode>::
_M_handle_line_begin_assertion(_Match_mode __match_mode, _StateIdT __i)
{
const auto& __state = _M_nfa[__i];
if (_M_at_begin())
_M_dfs(__match_mode, __state._M_next);
}
template<typename _BiIter, typename _Alloc, typename _TraitsT,
bool __dfs_mode>
inline void _Executor<_BiIter, _Alloc, _TraitsT, __dfs_mode>::
_M_handle_line_end_assertion(_Match_mode __match_mode, _StateIdT __i)
{
const auto& __state = _M_nfa[__i];
if (_M_at_end())
_M_dfs(__match_mode, __state._M_next);
}
template<typename _BiIter, typename _Alloc, typename _TraitsT,
bool __dfs_mode>
inline void _Executor<_BiIter, _Alloc, _TraitsT, __dfs_mode>::
_M_handle_word_boundary(_Match_mode __match_mode, _StateIdT __i)
{
const auto& __state = _M_nfa[__i];
if (_M_word_boundary() == !__state._M_neg)
_M_dfs(__match_mode, __state._M_next);
}
// Here __state._M_alt offers a single start node for a sub-NFA.
// We recursively invoke our algorithm to match the sub-NFA.
template<typename _BiIter, typename _Alloc, typename _TraitsT,
bool __dfs_mode>
void _Executor<_BiIter, _Alloc, _TraitsT, __dfs_mode>::
_M_handle_subexpr_lookahead(_Match_mode __match_mode, _StateIdT __i)
{
const auto& __state = _M_nfa[__i];
if (_M_lookahead(__state._M_alt) == !__state._M_neg)
_M_dfs(__match_mode, __state._M_next);
}
template<typename _BiIter, typename _Alloc, typename _TraitsT,
bool __dfs_mode>
void _Executor<_BiIter, _Alloc, _TraitsT, __dfs_mode>::
_M_handle_match(_Match_mode __match_mode, _StateIdT __i)
{
const auto& __state = _M_nfa[__i];
if (_M_current == _M_end)
return;
if (__dfs_mode)
{
if (__state._M_matches(*_M_current))
{
++_M_current;
_M_dfs(__match_mode, __state._M_next);
--_M_current;
}
}
else
if (__state._M_matches(*_M_current))
_M_states._M_queue(__state._M_next, _M_cur_results);
}
// First fetch the matched result from _M_cur_results as __submatch;
// then compare it with
// (_M_current, _M_current + (__submatch.second - __submatch.first)).
// If matched, keep going; else just return and try another state.
template<typename _BiIter, typename _Alloc, typename _TraitsT,
bool __dfs_mode>
void _Executor<_BiIter, _Alloc, _TraitsT, __dfs_mode>::
_M_handle_backref(_Match_mode __match_mode, _StateIdT __i)
{
__glibcxx_assert(__dfs_mode);
const auto& __state = _M_nfa[__i];
auto& __submatch = _M_cur_results[__state._M_backref_index];
if (!__submatch.matched)
return;
auto __last = _M_current;
for (auto __tmp = __submatch.first;
__last != _M_end && __tmp != __submatch.second;
++__tmp)
++__last;
if (_M_re._M_automaton->_M_traits.transform(__submatch.first,
__submatch.second)
== _M_re._M_automaton->_M_traits.transform(_M_current, __last))
{
if (__last != _M_current)
{
auto __backup = _M_current;
_M_current = __last;
_M_dfs(__match_mode, __state._M_next);
_M_current = __backup;
}
else
_M_dfs(__match_mode, __state._M_next);
}
}
template<typename _BiIter, typename _Alloc, typename _TraitsT,
bool __dfs_mode>
void _Executor<_BiIter, _Alloc, _TraitsT, __dfs_mode>::
_M_handle_accept(_Match_mode __match_mode, _StateIdT __i)
{
if (__dfs_mode)
{
__glibcxx_assert(!_M_has_sol);
if (__match_mode == _Match_mode::_Exact)
_M_has_sol = _M_current == _M_end;
else
_M_has_sol = true;
if (_M_current == _M_begin
&& (_M_flags & regex_constants::match_not_null))
_M_has_sol = false;
if (_M_has_sol)
{
if (_M_nfa._M_flags & regex_constants::ECMAScript)
_M_results = _M_cur_results;
else // POSIX
{
__glibcxx_assert(_M_states._M_get_sol_pos());
// Here's POSIX's logic: match the longest one. However
// we never know which one (lhs or rhs of "|") is longer
// unless we try both of them and compare the results.
// The member variable _M_sol_pos records the end
// position of the last successful match. It's better
// to be larger, because POSIX regex is always greedy.
// TODO: This could be slow.
if (*_M_states._M_get_sol_pos() == _BiIter()
|| std::distance(_M_begin,
*_M_states._M_get_sol_pos())
< std::distance(_M_begin, _M_current))
{
*_M_states._M_get_sol_pos() = _M_current;
_M_results = _M_cur_results;
}
}
}
}
else
{
if (_M_current == _M_begin
&& (_M_flags & regex_constants::match_not_null))
return;
if (__match_mode == _Match_mode::_Prefix || _M_current == _M_end)
if (!_M_has_sol)
{
_M_has_sol = true;
_M_results = _M_cur_results;
}
}
}
template<typename _BiIter, typename _Alloc, typename _TraitsT,
bool __dfs_mode>
void _Executor<_BiIter, _Alloc, _TraitsT, __dfs_mode>::
_M_handle_alternative(_Match_mode __match_mode, _StateIdT __i)
{
const auto& __state = _M_nfa[__i];
if (_M_nfa._M_flags & regex_constants::ECMAScript)
{
// TODO: Fix BFS support. It is wrong.
_M_dfs(__match_mode, __state._M_alt);
// Pick lhs if it matches. Only try rhs if it doesn't.
if (!_M_has_sol)
_M_dfs(__match_mode, __state._M_next);
}
else
{
// Try both and compare the result.
// See "case _S_opcode_accept:" handling above.
_M_dfs(__match_mode, __state._M_alt);
auto __has_sol = _M_has_sol;
_M_has_sol = false;
_M_dfs(__match_mode, __state._M_next);
_M_has_sol |= __has_sol;
}
}
template<typename _BiIter, typename _Alloc, typename _TraitsT,
bool __dfs_mode>
void _Executor<_BiIter, _Alloc, _TraitsT, __dfs_mode>::
@ -203,205 +460,30 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
if (_M_states._M_visited(__i))
return;
const auto& __state = _M_nfa[__i];
// Every change on _M_cur_results and _M_current will be rolled back after
// finishing the recursion step.
switch (__state._M_opcode())
switch (_M_nfa[__i]._M_opcode())
{
// _M_alt branch is "match once more", while _M_next is "get me out
// of this quantifier". Executing _M_next first or _M_alt first don't
// mean the same thing, and we need to choose the correct order under
// given greedy mode.
case _S_opcode_repeat:
{
// Greedy.
if (!__state._M_neg)
{
_M_rep_once_more(__match_mode, __i);
// If it's DFS executor and already accepted, we're done.
if (!__dfs_mode || !_M_has_sol)
_M_dfs(__match_mode, __state._M_next);
}
else // Non-greedy mode
{
if (__dfs_mode)
{
// vice-versa.
_M_dfs(__match_mode, __state._M_next);
if (!_M_has_sol)
_M_rep_once_more(__match_mode, __i);
}
else
{
// DON'T attempt anything, because there's already another
// state with higher priority accepted. This state cannot
// be better by attempting its next node.
if (!_M_has_sol)
{
_M_dfs(__match_mode, __state._M_next);
// DON'T attempt anything if it's already accepted. An
// accepted state *must* be better than a solution that
// matches a non-greedy quantifier one more time.
if (!_M_has_sol)
_M_rep_once_more(__match_mode, __i);
}
}
}
}
break;
_M_handle_repeat(__match_mode, __i); break;
case _S_opcode_subexpr_begin:
{
auto& __res = _M_cur_results[__state._M_subexpr];
auto __back = __res.first;
__res.first = _M_current;
_M_dfs(__match_mode, __state._M_next);
__res.first = __back;
}
break;
_M_handle_subexpr_begin(__match_mode, __i); break;
case _S_opcode_subexpr_end:
{
auto& __res = _M_cur_results[__state._M_subexpr];
auto __back = __res;
__res.second = _M_current;
__res.matched = true;
_M_dfs(__match_mode, __state._M_next);
__res = __back;
}
break;
_M_handle_subexpr_end(__match_mode, __i); break;
case _S_opcode_line_begin_assertion:
if (_M_at_begin())
_M_dfs(__match_mode, __state._M_next);
break;
_M_handle_line_begin_assertion(__match_mode, __i); break;
case _S_opcode_line_end_assertion:
if (_M_at_end())
_M_dfs(__match_mode, __state._M_next);
break;
_M_handle_line_end_assertion(__match_mode, __i); break;
case _S_opcode_word_boundary:
if (_M_word_boundary() == !__state._M_neg)
_M_dfs(__match_mode, __state._M_next);
break;
// Here __state._M_alt offers a single start node for a sub-NFA.
// We recursively invoke our algorithm to match the sub-NFA.
_M_handle_word_boundary(__match_mode, __i); break;
case _S_opcode_subexpr_lookahead:
if (_M_lookahead(__state._M_alt) == !__state._M_neg)
_M_dfs(__match_mode, __state._M_next);
break;
_M_handle_subexpr_lookahead(__match_mode, __i); break;
case _S_opcode_match:
if (_M_current == _M_end)
break;
if (__dfs_mode)
{
if (__state._M_matches(*_M_current))
{
++_M_current;
_M_dfs(__match_mode, __state._M_next);
--_M_current;
}
}
else
if (__state._M_matches(*_M_current))
_M_states._M_queue(__state._M_next, _M_cur_results);
break;
// First fetch the matched result from _M_cur_results as __submatch;
// then compare it with
// (_M_current, _M_current + (__submatch.second - __submatch.first)).
// If matched, keep going; else just return and try another state.
_M_handle_match(__match_mode, __i); break;
case _S_opcode_backref:
{
__glibcxx_assert(__dfs_mode);
auto& __submatch = _M_cur_results[__state._M_backref_index];
if (!__submatch.matched)
break;
auto __last = _M_current;
for (auto __tmp = __submatch.first;
__last != _M_end && __tmp != __submatch.second;
++__tmp)
++__last;
if (_M_re._M_automaton->_M_traits.transform(__submatch.first,
__submatch.second)
== _M_re._M_automaton->_M_traits.transform(_M_current, __last))
{
if (__last != _M_current)
{
auto __backup = _M_current;
_M_current = __last;
_M_dfs(__match_mode, __state._M_next);
_M_current = __backup;
}
else
_M_dfs(__match_mode, __state._M_next);
}
}
break;
_M_handle_backref(__match_mode, __i); break;
case _S_opcode_accept:
if (__dfs_mode)
{
__glibcxx_assert(!_M_has_sol);
if (__match_mode == _Match_mode::_Exact)
_M_has_sol = _M_current == _M_end;
else
_M_has_sol = true;
if (_M_current == _M_begin
&& (_M_flags & regex_constants::match_not_null))
_M_has_sol = false;
if (_M_has_sol)
{
if (_M_nfa._M_flags & regex_constants::ECMAScript)
_M_results = _M_cur_results;
else // POSIX
{
__glibcxx_assert(_M_states._M_get_sol_pos());
// Here's POSIX's logic: match the longest one. However
// we never know which one (lhs or rhs of "|") is longer
// unless we try both of them and compare the results.
// The member variable _M_sol_pos records the end
// position of the last successful match. It's better
// to be larger, because POSIX regex is always greedy.
// TODO: This could be slow.
if (*_M_states._M_get_sol_pos() == _BiIter()
|| std::distance(_M_begin,
*_M_states._M_get_sol_pos())
< std::distance(_M_begin, _M_current))
{
*_M_states._M_get_sol_pos() = _M_current;
_M_results = _M_cur_results;
}
}
}
}
else
{
if (_M_current == _M_begin
&& (_M_flags & regex_constants::match_not_null))
break;
if (__match_mode == _Match_mode::_Prefix || _M_current == _M_end)
if (!_M_has_sol)
{
_M_has_sol = true;
_M_results = _M_cur_results;
}
}
break;
_M_handle_accept(__match_mode, __i); break;
case _S_opcode_alternative:
if (_M_nfa._M_flags & regex_constants::ECMAScript)
{
// TODO: Fix BFS support. It is wrong.
_M_dfs(__match_mode, __state._M_alt);
// Pick lhs if it matches. Only try rhs if it doesn't.
if (!_M_has_sol)
_M_dfs(__match_mode, __state._M_next);
}
else
{
// Try both and compare the result.
// See "case _S_opcode_accept:" handling above.
_M_dfs(__match_mode, __state._M_alt);
auto __has_sol = _M_has_sol;
_M_has_sol = false;
_M_dfs(__match_mode, __state._M_next);
_M_has_sol |= __has_sol;
}
break;
_M_handle_alternative(__match_mode, __i); break;
default:
__glibcxx_assert(false);
}