Compiling the following with "-Wunreachable-code -D_GLIBCXX_DEBUG"
--------------------------
#include <vector>
int main()
{
std::vector<int>::iterator a;
}
--------------------------
produces the warning :
--------------------------
/usr/lib/gcc/i386-redhat-linux/4.1.1/../../../../include/c++/4.1.1/debug/safe_iterator.h:
In constructor __gnu_debug::_Safe_iterator<_Iterator,
_Sequence>::_Safe_iterator() [with _Iterator =
__gnu_cxx::__normal_iterator<int*, __gnu_norm::vector<int, std::allocator<int>
> >, _Sequence = __gnu_debug_def::vector<int, std::allocator<int> >]:
/usr/lib/gcc/i386-redhat-linux/4.1.1/../../../../include/c++/4.1.1/debug/safe_iterator.h:103:
warning: will never be executed
--------------------------
I tried g++ 4.1, 4.2 and 4.3. They all produce this annoying warning.
Looking at the code in safe_iterator.h shows nothing obviously wrong.
This might even suggest a bug in -Wunreachable-code, although I categorized
it for now in libstdc++, as I have not been able to isolate a small piece
of code that reproduces the problem.
Some other compilers tend to have the equivalent of -Wunreachable-code
by default. It would be nice if it worked well, and if it was enabled
by -Wall or -Wextra.
--
Summary: Strange -Wunreachable-code warning with _GLIBCXX_DEBUG
Product: gcc
Version: 4.3.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: libstdc++
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: sylvain dot pion at sophia dot inria dot fr
GCC host triplet: i686-pc-linux-gnu
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31246
