[cfe-dev] libc++ internals visibility rational

[Eric Fiselier via cfe-dev]

Honestly I've been wondering about the same things.

Libc++ needs to re-evaluate it's entire approach to symbol visibility
especially w.r.t ABI management.
I think a lot of the existing behavior is purely historical, and newer
parts of the library just try to mimic that
regardless of QoI. In particular I'm sceptical that libc++'s use of
__always_inline__ helps prevent "ABI problems".

I would love to start a discussion on this, especially if it leads to
concrete example
that can be turned into test cases

/Eric


On Fri, Mar 31, 2017 at 11:57 PM, Mehdi Amini via cfe-dev <
cfe-dev at lists.llvm.org> wrote:

> Similarly with the public free template functions:
>
>
> template <class _L0, class _L1>
> void
> lock(_L0& __l0, _L1& __l1)
>
> and
>
> template <class _L0, class _L1, class _L2, class ..._L3>
> inline _LIBCPP_INLINE_VISIBILITY
> void
> lock(_L0& __l0, _L1& __l1, _L2& __l2, _L3& …__l3)
>
>
> —
> Mehdi
>
>
>
> > On Mar 31, 2017, at 10:46 PM, Mehdi Amini via cfe-dev <
> cfe-dev at lists.llvm.org> wrote:
> >
> > Hi,
> >
> > I’m wondering about libc++ visibility for the internals of the library.
> For example why do we define:
> >
> > _LIBCPP_INLINE_VISIBILITY
> >    void __construct_at_end(size_type __n, const_reference __x);
> >
> > with inline/hidden visibility, but not this one:
> >
> > template <class _ForwardIterator>
> > typename enable_if  <__is_forward_iterator<_ForwardIterator>::value,
> void>::type
> > __construct_at_end(_ForwardIterator __first, _ForwardIterator __last,
> size_type __n);
> >
> >
> > Thanks,
> >
> > —
> > Mehdi
> >
> > _______________________________________________
> > cfe-dev mailing list
> > cfe-dev at lists.llvm.org
> > http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-dev
>
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