On Wed, Oct 22, 2014 at 7:34 AM, Jonathan Wakely <jwak...@redhat.com> wrote:
> Only if it's likely to catch problems in future. If you'd be putting
> it in only to make a testcase fail then it's not worth it.
No, since I think with this patch _M_current is clearly valid when
being dereferenced.
> You could even simplify it further using std::prev:
>
> if (_M_is_word(*std::prev(__pre)))
> __left_is_word = true;
Done.
--
Regards,
Tim Shen
commit 386598d6edb729053325921a0bad66c413dc93ea
Author: timshen <tims...@google.com>
Date: Sun Oct 19 15:14:55 2014 -0700
PR libstdc++/63497
include/bits/regex_executor.h (_Executor::_M_word_boundary): Remove
unused parameter.
include/bits/regex_executor.tcc (_Executor::_M_dfs,
_Executor::_M_word_boundary): Avoid dereferecing _M_current at _M_end
or other invalid position.
diff --git a/libstdc++-v3/include/bits/regex_executor.h
b/libstdc++-v3/include/bits/regex_executor.h
index cd9e55d..b26992c 100644
--- a/libstdc++-v3/include/bits/regex_executor.h
+++ b/libstdc++-v3/include/bits/regex_executor.h
@@ -145,7 +145,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
}
bool
- _M_word_boundary(_State<_TraitsT> __state) const;
+ _M_word_boundary() const;
bool
_M_lookahead(_State<_TraitsT> __state);
diff --git a/libstdc++-v3/include/bits/regex_executor.tcc
b/libstdc++-v3/include/bits/regex_executor.tcc
index 5eab852..38d4781 100644
--- a/libstdc++-v3/include/bits/regex_executor.tcc
+++ b/libstdc++-v3/include/bits/regex_executor.tcc
@@ -274,7 +274,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_M_dfs(__match_mode, __state._M_next);
break;
case _S_opcode_word_boundary:
- if (_M_word_boundary(__state) == !__state._M_neg)
+ 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.
@@ -284,9 +284,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_M_dfs(__match_mode, __state._M_next);
break;
case _S_opcode_match:
+ if (_M_current == _M_end)
+ break;
if (__dfs_mode)
{
- if (_M_current != _M_end && __state._M_matches(*_M_current))
+ if (__state._M_matches(*_M_current))
{
++_M_current;
_M_dfs(__match_mode, __state._M_next);
@@ -407,25 +409,26 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename _BiIter, typename _Alloc, typename _TraitsT,
bool __dfs_mode>
bool _Executor<_BiIter, _Alloc, _TraitsT, __dfs_mode>::
- _M_word_boundary(_State<_TraitsT>) const
+ _M_word_boundary() const
{
- // By definition.
- bool __ans = false;
- auto __pre = _M_current;
- --__pre;
- if (!(_M_at_begin() && _M_at_end()))
+ bool __left_is_word = false;
+ if (_M_current != _M_begin
+ || (_M_flags & regex_constants::match_prev_avail))
{
- if (_M_at_begin())
- __ans = _M_is_word(*_M_current)
- && !(_M_flags & regex_constants::match_not_bow);
- else if (_M_at_end())
- __ans = _M_is_word(*__pre)
- && !(_M_flags & regex_constants::match_not_eow);
- else
- __ans = _M_is_word(*_M_current)
- != _M_is_word(*__pre);
+ auto __prev = _M_current;
+ if (_M_is_word(*std::prev(__prev)))
+ __left_is_word = true;
}
- return __ans;
+ bool __right_is_word =
+ _M_current != _M_end && _M_is_word(*_M_current);
+
+ if (__left_is_word == __right_is_word)
+ return false;
+ if (__left_is_word && !(_M_flags & regex_constants::match_not_eow))
+ return true;
+ if (__right_is_word && !(_M_flags & regex_constants::match_not_bow))
+ return true;
+ return false;
}
_GLIBCXX_END_NAMESPACE_VERSION
