If you compile this code
#include <fstream>
void test()
{
std::ifstream in;
}
against the actual CVS version of STLport 5.0
(http://www.breaken.de/temp/STLport.zip) you get this warning:
In member function 'typename stlp_std::basic_filebuf<_CharT,
_Traits>::pos_type stlp_std::basic_filebuf<_CharT, _Traits>::seekoff(typename
_Traits::off_type, int, int) [with _CharT = char, _Traits =
stlp_std::char_traits<char>]':
372 C:\cvs\STLport\stlport\stl\_fstream.c [Warning] control reaches end of
non-void function
Because the STLport is very complex I wasn't able to reduce the code properly.
Maybe it can already be done by just posting the function causing it:
template <class _CharT, class _Traits>
__BF_pos_type__
basic_filebuf<_CharT, _Traits>::seekoff(off_type __off,
ios_base::seekdir __whence,
ios_base::openmode /* dummy */) {
if (this->is_open() &&
(__off == 0 || (_M_constant_width && this->_M_base._M_in_binary_mode())))
{
if (!_M_seek_init(__off != 0 || __whence != ios_base::cur))
return pos_type(-1);
// Seek to beginning or end, regardless of whether we're in input mode.
if (__whence == ios_base::beg || __whence == ios_base::end)
return _M_seek_return(_M_base._M_seek(_M_width * __off, __whence),
_State_type());
// Seek relative to current position. Complicated if we're in input mode.
else if (__whence == ios_base::cur) {
if (!_M_in_input_mode)
return _M_seek_return(_M_base._M_seek(_M_width * __off, __whence),
_State_type());
else if (_M_mmap_base != 0) {
// __off is relative to gptr(). We need to do a bit of arithmetic
// to get an offset relative to the external file pointer.
streamoff __adjust = _M_mmap_len - (this->gptr() - (_CharT*)
_M_mmap_base);
// if __off == 0, we do not need to exit input mode and to shift file
pointer
if (__off == 0) {
return pos_type(_M_base._M_seek(0, ios_base::cur) - __adjust);
}
else
return _M_seek_return(_M_base._M_seek(__off - __adjust,
ios_base::cur), _State_type());
}
else if (_M_constant_width) { // Get or set the position.
streamoff __iadj = _M_width * (this->gptr() - this->eback());
// Compensate for offset relative to gptr versus offset relative
// to external pointer. For a text-oriented stream, where the
// compensation is more than just pointer arithmetic, we may get
// but not set the current position.
if (__iadj <= _M_ext_buf_end - _M_ext_buf) {
streamoff __eadj = _M_base._M_get_offset(_M_ext_buf + __iadj,
_M_ext_buf_end);
if (__off == 0) {
return pos_type(_M_base._M_seek(0, ios_base::cur) - __eadj);
} else {
return _M_seek_return(_M_base._M_seek(__off - __eadj,
ios_base::cur), _State_type());
}
}
else
return pos_type(-1);
}
else { // Get the position. Encoding is var width.
// Get position in internal buffer.
ptrdiff_t __ipos = this->gptr() - this->eback();
// Get corresponding position in external buffer.
_State_type __state = _M_state;
int __epos = _M_codecvt->length(__state, _M_ext_buf, _M_ext_buf_end,
__ipos);
// Sanity check (expensive): make sure __epos is the right answer.
_State_type __tmp_state = _M_state;
_Filebuf_Tmp_Buf<_CharT> __buf(__ipos);
_CharT* __ibegin = __buf._M_ptr;
_CharT* __inext = __ibegin;
const char* __dummy;
typename _Codecvt::result __status
= _M_codecvt->in(__tmp_state,
_M_ext_buf, _M_ext_buf + __epos, __dummy,
__ibegin, __ibegin + __ipos, __inext);
if (__status != _Codecvt::error &&
(__status == _Codecvt::noconv ||
(__inext == __ibegin + __ipos &&
equal(this->gptr(), this->eback(), __ibegin,
_Eq_traits<traits_type>())))) {
// Get the current position (at the end of the external buffer),
// then adjust it. Again, it might be a text-oriented stream.
streamoff __cur = _M_base._M_seek(0, ios_base::cur);
streamoff __adj =
_M_base._M_get_offset(_M_ext_buf, _M_ext_buf + __epos) -
_M_base._M_get_offset(_M_ext_buf, _M_ext_buf_end);
if (__cur != -1 && __cur + __adj >= 0)
return _M_seek_return(__cur + __adj, __state);
else
return pos_type(-1);
}
else // We failed the sanity check.
return pos_type(-1);
}
}
else // Unrecognized value for __whence.
return pos_type(-1);
}
else
return pos_type(-1);
}
I also got another piece of code, that also causes a wrong warning, but I wasn't
able to reduce that code either.
I am using
Target: i686-pc-mingw32
Configured with: /datal/gcc/gcc/configure --prefix=/datal/gcc/build/wingcc
--build=i686-pc-linux-gnu --host=i686-pc-mingw32 --target=i686-pc-mingw32
--enable-languages=c,c++,java --with-gcc --with-gnu-as --with-gnu-ld
--enable-threads=win32 --disable-nls --disable-win32-registry --disable-shared
--disable-debug --without-newlib --enable-libgcj --disable-java-awt --without-x
--enable-java-gc=boehm --disable-libgcj-debug --enable-interpreter
--enable-hash-synchronization --enable-sjlj-exceptions --enable-libgcj-multifile
--enable-libgcj-mingw-osapi=ansi
Thread model: win32
gcc version 4.0.0 20050320 (prerelease)
--
Summary: wrong "control reaches end of non-void function" warning
Product: gcc
Version: 4.0.0
Status: UNCONFIRMED
Severity: normal
Priority: P2
Component: c++
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: oliverst at online dot de
CC: gcc-bugs at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20624
