On Thu, 15 Feb 2024 at 18:38, François Dumont <frs.dum...@gmail.com> wrote:
> > On 15/02/2024 14:17, Jonathan Wakely wrote: > > > > On Wed, 14 Feb 2024 at 21:48, François Dumont <frs.dum...@gmail.com> > wrote: > >> >> On 14/02/2024 20:44, Jonathan Wakely wrote: >> >> >> >> On Wed, 14 Feb 2024 at 18:39, François Dumont <frs.dum...@gmail.com> >> wrote: >> >>> libstdc++: [_GLIBCXX_DEBUG] Fix std::__niter_base behavior >>> >>> std::__niter_base is used in _GLIBCXX_DEBUG mode to remove >>> _Safe_iterator<> >>> wrapper on random access iterators. But doing so it should also preserve >>> original >>> behavior to remove __normal_iterator wrapper. >>> >>> libstdc++-v3/ChangeLog: >>> >>> * include/bits/stl_algobase.h (std::__niter_base): Redefine the >>> overload >>> definitions for __gnu_debug::_Safe_iterator. >>> * include/debug/safe_iterator.tcc (std::__niter_base): Adapt >>> declarations. >>> >>> Ok to commit once all tests completed (still need to check pre-c++11) ? >>> >> >> >> The declaration in include/bits/stl_algobase.h has a noexcept-specifier >> but the definition in include/debug/safe_iterator.tcc does not have one - >> that seems wrong (I'm surprised it even compiles). >> >> It does ! >> > > The diagnostic is suppressed without -Wsystem-headers: > > /home/jwakely/gcc/14/include/c++/14.0.1/debug/safe_iterator.tcc:255:5: > warning: > declaration of 'template<class _Ite, class _Seq> constexpr decltype > (std::__ > niter_base(declval<_Ite>())) std::__niter_base(const > __gnu_debug::_Safe_iterator<_Iterator, _Sequence, > random_access_iterator_tag>&)' has a different except > ion specifier [-Wsystem-headers] > 255 | __niter_base(const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, > | ^~~~~~~~~~~~ > /home/jwakely/gcc/14/include/c++/14.0.1/bits/stl_algobase.h:335:5: note: from > previous declaration 'template<class _Ite, class _Seq> constexpr decltype > (std > ::__niter_base(declval<_Ite>())) std::__niter_base(const > __gnu_debug::_Safe_iterator<_Iterator, _Sequence, > random_access_iterator_tag>&) noexcept (noexcept > (is_nothrow_copy_constructible<decltype > (std::__niter_base(declval<_Ite>()))>::value))' > 335 | __niter_base(const ::__gnu_debug::_Safe_iterator<_Ite, _Seq, > | ^~~~~~~~~~~~ > > > It's a hard error with Clang though: > > deb.cc:7:10: error: call to '__niter_base' is ambiguous > > > Yes, I eventually got the error too, I hadn't run enough tests yet. > > > > > > >> I thought it was only necessary at declaration, and I also had troubles >> doing it right at definition because of the interaction with the auto and >> ->. >> > > The trailing-return-type has to come after the noexcept-specifier. > > > >> Now simplified and consistent in this new proposal. >> >> >> Just using std::is_nothrow_copy_constructible<_Ite> seems simpler, that >> will be true for __normal_iterator<I, C> if >> is_nothrow_copy_constructible<I> is true. >> >> Ok >> >> >> The definition in include/debug/safe_iterator.tcc should use >> std::declval<_Ite>() not declval<_Ite>(). Is there any reason why the >> definition uses a late-specified-return-type (i.e. auto and ->) when the >> declaration doesn't? >> >> >> I initially plan to use '-> >> std::decltype(std::__niter_base(__it.base()))' but this did not compile, >> ambiguity issue. So I resort to using std::declval and I could have then >> done it the same way as declaration, done now. >> >> Attached is what I'm testing, ok to commit once fully tested ? >> > > OK, thanks. > > Thanks for validation but I have a problem to test for c++98. > > When I do: > > make CXXFLAGS=-std=c++98 check-debug > That doesn't work any more, see https://gcc.gnu.org/onlinedocs/libstdc++/manual/test.html#test.run.permutations > I see in debug/libstdc++.log for example: > > Executing on host: /home/fdumont/dev/gcc/build/./gcc/xg++ -shared-libgcc > ... -mshstk -std=c++98 -g -O2 -DLOCALEDIR="." -nostdinc++ > -I/home/fdumont/dev/gcc/... > /home/fdumont/dev/gcc/git/libstdc++-v3/testsuite/25_algorithms/copy/3.cc > -D_GLIBCXX_DEBUG -std=gnu++17 -include bits/stdc++.h ... -lm -o > ./3.exe (timeout = 360) > > The -std=c++98 is there but later comes the -std=gnu++17 so I think it > runs in C++17, no ? > > I also tried the documented alternative: > > make check > 'RUNTESTFLAGS=--target_board=unix/-O3\"{-std=gnu++98,-std=gnu++11,-std=gnu++14}\"' > > > but same problem, -std=gnu++17 comes last. > > I'll try to rebuild all from scratch but I won't commit soon then. > > >
