+2002-12-26 Phil Edwards <pme@gcc.gnu.org>
+
+ * include/std/std_bitset.h (_Base_bitset::_M_do_left_shift,
+ _Base_bitset::_M_do_right_shift): Expect a non-zero shift.
+ (bitset::operator<<=, bitset::operator>>=): When shifting more bits
+ than are in the bitset, zero memory rather than segfault.
+ (operator>>(basic_istream,bitset): Only call setstate once, after
+ all work has been done.
+
+ * testsuite/23_containers/bitset_members.cc (test03): New test.
+ * testsuite/23_containers/bitset_shift.cc (test02): New test.
+
2002-12-26 Phil Edwards <pme@gcc.gnu.org>
* libsupc++/vterminate.cc (writestr): Use __builtin_strlen.
void
_Base_bitset<_Nw>::_M_do_left_shift(size_t __shift)
{
- if (__shift != 0)
+ if (__builtin_expect(__shift != 0, 1))
{
const size_t __wshift = __shift / _GLIBCPP_BITSET_BITS_PER_WORD;
const size_t __offset = __shift % _GLIBCPP_BITSET_BITS_PER_WORD;
void
_Base_bitset<_Nw>::_M_do_right_shift(size_t __shift)
{
- if (__shift != 0)
+ if (__builtin_expect(__shift != 0, 1))
{
const size_t __wshift = __shift / _GLIBCPP_BITSET_BITS_PER_WORD;
const size_t __offset = __shift % _GLIBCPP_BITSET_BITS_PER_WORD;
* The template argument, @a _Nb, may be any non-negative number of type
* size_t.
*
- * A %bitset of size N has N % (sizeof(unsigned long) * CHAR_BIT) unused
- * bits. (They are the high-order bits in the highest word.) It is
- * a class invariant that those unused bits are always zero.
+ * A %bitset of size N uses U bits, where
+ * U = (N % (sizeof(unsigned long) * CHAR_BIT)).
+ * Thus, N - U bits are unused. (They are the high-order bits in the
+ * highest word.) It is a class invariant that those unused bits are
+ * always zero.
*
* If you think of %bitset as "a simple array of bits," be aware that
* your mental picture is reversed: a %bitset behaves the same way as
bitset<_Nb>&
operator<<=(size_t __pos)
{
- this->_M_do_left_shift(__pos);
- this->_M_do_sanitize();
+ if (__builtin_expect(__pos < _Nb, 1))
+ {
+ this->_M_do_left_shift(__pos);
+ this->_M_do_sanitize();
+ }
+ else
+ this->_M_do_reset();
return *this;
}
bitset<_Nb>&
operator>>=(size_t __pos)
{
- this->_M_do_right_shift(__pos);
- this->_M_do_sanitize();
+ if (__builtin_expect(__pos < _Nb, 1))
+ {
+ this->_M_do_right_shift(__pos);
+ this->_M_do_sanitize();
+ }
+ else
+ this->_M_do_reset();
return *this;
}
//@}
typename basic_istream<_CharT, _Traits>::sentry __sentry(__is);
if (__sentry)
{
+ ios_base::iostate __state = ios_base::goodbit;
basic_streambuf<_CharT, _Traits>* __buf = __is.rdbuf();
for (size_t __i = 0; __i < _Nb; ++__i)
{
typename _Traits::int_type __c1 = __buf->sbumpc();
if (_Traits::eq_int_type(__c1, __eof))
{
- __is.setstate(ios_base::eofbit);
+ __state |= ios_base::eofbit;
break;
}
else
if (__c == '0' || __c == '1')
__tmp.push_back(__c);
- else if (_Traits::eq_int_type(__buf->sputbackc(__c2),
- __eof))
+ else if (_Traits::eq_int_type(__buf->sputbackc(__c2), __eof))
{
- __is.setstate(ios_base::failbit);
+ __state |= ios_base::failbit;
break;
}
}
}
if (__tmp.empty() && !_Nb)
- __is.setstate(ios_base::failbit);
+ __state |= ios_base::failbit;
else
__x._M_copy_from_string(__tmp, static_cast<size_t>(0), _Nb);
+
+ if (__state != ios_base::goodbit)
+ __is.setstate(__state); // may throw an exception
}
return __is;