On Mon, 12 May 2025 at 16:13, Jason Merrill <ja...@redhat.com> wrote:
>
> On 5/9/25 1:31 PM, Jonathan Wakely wrote:
> > On Fri, 9 May 2025 at 18:13, Jonathan Wakely <jwak...@redhat.com> wrote:
> >>
> >> On Fri, 9 May 2025 at 11:19, Jonathan Wakely <jwak...@redhat.com> wrote:
> >>>
> >>> On Thu, 8 May 2025 at 20:56, Jason Merrill <ja...@redhat.com> wrote:
> >>>>
> >>>> Tested x86_64-pc-linux-gnu. Does this make sense for trunk?
> >>>
> >>> Yes, it looks useful. I'm going to test it with my "very -std and -m32
> >>> and old-string ABI" test settings to be sure it doesn't cause any
> >>> problems.
> >>
> >> There are a few failures when using GLIBCXX_TESTSUITE_STDS=20 to run
> >> tests as C++20 or later:
> >>
> >> FAIL: experimental/net/internet/resolver/ops/lookup.cc -std=gnu++23
> >> (test for excess errors)
> >> Excess errors:
> >> /tmp/build/x86_64-pc-linux-gnu/libstdc++-v3/include/experimental/internet:2100:
> >> warning: offset of
> >> 'std::experimental::net::v1::ip::basic_resolver<std::experimental::net::v1::ip::tcp>::_M_ctx'
> >> for '-std=c++20' and up changes in '-fabi-version=21' (GCC 16) [-Wabi]
> >
> > We have code like this in the networking TS headers:
> >
> > struct Base {
> > protected:
> > Base() = default;
> > ~Base() = default;
> > };
> >
> > struct Derived : Base {
> > void* ptr;
> > };
> >
> > Is the warning wrong?
>
> Hmm, it seems to be: sizeof(Derived) isn't affected by -std=c++20 before
> the fix, I guess the warning doesn't handle empty bases properly.
Thanks for the fix, I'll rerun the tests.
