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1) Disabled recursive implementation for VC8: stack overflows can't be reliably detected unless the whole program is compiled with asynchronous exceptions.

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2) Changed std::copy calls on VC8 to avoid "dangerous code" warnings.
3) Moved backreference and octal escape code into line with POSIX-extended requirements.
4) Changed match_results leftmost-longest rules to stop unnecessary std::distance computations (an optimisation for non-random access iterators).
5) Changed C lib calls to use "safe" versions of string API's where available.
6) Added many new POSIX-extended leftmost-longest tests, to verify the above.


[SVN r27880]
This commit is contained in:
John Maddock
2005-03-30 11:38:51 +00:00
parent ca144bb2b3
commit de28eb9b18
17 changed files with 361 additions and 106 deletions
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62
include/boost/regex/v4/match_results.hpp
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@ -300,29 +300,73 @@ void BOOST_REGEX_CALL match_results<BidiIterator, Allocator>::maybe_assign(const
const_iterator p1, p2;
p1 = begin();
p2 = m.begin();
BidiIterator base = (*this)[-1].first;
std::size_t len1 = 0;
std::size_t len2 = 0;
std::size_t base1 = 0;
std::size_t base2 = 0;
//
// Distances are measured from the start of *this* match, unless this isn't
// a valid match in which case we use the start of the whole sequence. Note that
// no subsequent match-candidate can ever be to the left of the first match found.
// This ensures that when we are using bidirectional iterators, that distances
// measured are as short as possible, and therefore as efficient as possible
// to compute. Finally note that we don't use the "matched" data member to test
// whether a sub-expression is a valid match, because partial matches set this
// to false for sub-expression 0.
//
BidiIterator end = this->suffix().second;
BidiIterator base = (p1->first == end) ? this->prefix().first : (*this)[0].first;
difference_type len1 = 0;
difference_type len2 = 0;
difference_type base1 = 0;
difference_type base2 = 0;
std::size_t i;
for(i = 0; i < size(); ++i)
for(i = 0; i < size(); ++i, ++p1, ++p2)
{
//
// leftmost takes priority over longest:
// Leftmost takes priority over longest; handle special cases
// where distances need not be computed first (an optimisation
// for bidirectional iterators: ensure that we don't accidently
// compute the length of the whole sequence, as this can be really
// expensive).
//
if(p1->first == end)
{
if(p2->first != end)
{
// p2 must be better than p1, and no need to calculate
// actual distances:
base1 = 1;
base2 = 0;
break;
}
else
{
// *p1 and *p2 are either unmatched or match end-of sequence,
// either way no need to calculate distances:
if((p1->matched == false) && (p2->matched == true))
break;
if((p1->matched == true) && (p2->matched == false))
return;
continue;
}
}
else if(p2->first == end)
{
// p1 better than p2, and no need to calculate distances:
return;
}
base1 = ::boost::re_detail::distance(base, p1->first);
base2 = ::boost::re_detail::distance(base, p2->first);
BOOST_ASSERT(base1 >= 0);
BOOST_ASSERT(base2 >= 0);
if(base1 < base2) return;
if(base2 < base1) break;
len1 = ::boost::re_detail::distance((BidiIterator)p1->first, (BidiIterator)p1->second);
len2 = ::boost::re_detail::distance((BidiIterator)p2->first, (BidiIterator)p2->second);
BOOST_ASSERT(len1 >= 0);
BOOST_ASSERT(len2 >= 0);
if((len1 != len2) || ((p1->matched == false) && (p2->matched == true)))
break;
if((p1->matched == true) && (p2->matched == false))
return;
++p1;
++p2;
}
if(i == size())
return;