[PATCH][_GLIBCXX_DEBUG][__cplusplus >= 201103L] Remove useless workaround

[Jonathan Wakely]

On Sat, 21 Mar 2026 at 16:03, Jonathan Wakely <jwakely@redhat.com> wrote:
>
> On Sat, 21 Mar 2026 at 13:45, Jonathan Wakely <jwakely.gcc@gmail.com> wrote:
> >
> >
> >
> > On Sat, 21 Mar 2026, 13:36 François Dumont, <frs.dumont@gmail.com> wrote:
> >>
> >> Still no chance to reproduce this problem.
> >>
> >> I think the patch is good and that you are simply missing it in the below build.
> >>
> >> The compiler is reporting the error coming from:
> >>
> >> /home/tkaminsk/build/gcc/16/x86_64-pc-linux-gnu/libstdc++-v3/include/debug/string:238:   required from '__gnu_debug::basic_string<_CharT, _Traits, _Allocator>::basic_string(_InputIterator, _InputIterator, const _Allocator&) [with _InputIterator = int; _CharT = char; _Traits = std::char_traits<char>; _Allocator = std::allocator<char>]'
> >>
> >> Line 238 is the former line of the call to __glibcxx_check_valid_constructor_range(__begin, __end) that is leading to the error.
> >>
> >> After my patch it is on line 243.
> >
> >
> > Tomasz and I are both testing current trunk. If we're missing your patch, then it means it hasn't been pushed to trunk.
>
> I see the problem, the errors are with -D_GLIBCXX_USE_CXX11_ABI=0 and
> -D_GLIBCXX_DEBUG
>
> e.g.
> make check RUNTESTFLAGS="conformance.exp=28_regex/match_results/swap.cc
> --target_board=unix/-D_GLIBCXX_USE_CXX11_ABI=0/
> -D_GLIBCXX_DEBUG"

The COW string has this function, which doesn't care if it's called
with iterators or integers, because it dispatches to
_M_replace_dispatch:

      template<class _InputIterator>
    basic_string&
    replace(iterator __i1, iterator __i2,
        _InputIterator __k1, _InputIterator __k2)
    {
      _GLIBCXX_DEBUG_PEDASSERT(_M_ibegin() <= __i1 && __i1 <= __i2
                   && __i2 <= _M_iend());
      __glibcxx_requires_valid_range(__k1, __k2);
      typedef typename std::__is_integer<_InputIterator>::__type _Integral;
      return _M_replace_dispatch(__i1, __i2, __k1, __k2, _Integral());
    }

Calling __glibcxx_requires_valid_range gives an error, because that is
no longer valid for non-iterators.

We should just move the __glibcxx_requires_valid_range to the correct
_M_replace_dispatch function, like this:

--- a/libstdc++-v3/include/bits/cow_string.h
+++ b/libstdc++-v3/include/bits/cow_string.h
@@ -2124,7 +2124,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       {
         _GLIBCXX_DEBUG_PEDASSERT(_M_ibegin() <= __i1 && __i1 <= __i2
                                  && __i2 <= _M_iend());
-         __glibcxx_requires_valid_range(__k1, __k2);
         typedef typename std::__is_integer<_InputIterator>::__type _Integral;
         return _M_replace_dispatch(__i1, __i2, __k1, __k2, _Integral());
       }
@@ -3833,6 +3832,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
      _M_replace_dispatch(iterator __i1, iterator __i2, _InputIterator __k1,
                         _InputIterator __k2, __false_type)
      {
+       __glibcxx_requires_valid_range(__k1, __k2);
       const basic_string __s(__k1, __k2);
       const size_type __n1 = __i2 - __i1;
       _M_check_length(__n1, __s.size(), "basic_string::_M_replace_dispatch");