OK.
On Sat, Aug 25, 2018 at 7:02 AM, Marek Polacek <pola...@redhat.com> wrote:
> The problem in this testcase was that we were calling is_std_move_p from
> template context, which breaks in cp_get_fndecl_from_callee. This warning
> is not meant to warn while parsing a template, so I think we should apply
> this.
>
> Bootstrapped/regtested on x86_64-linux, ok for trunk?
>
> 2018-08-24 Marek Polacek <pola...@redhat.com>
>
> PR c++/87080
> * typeck.c (maybe_warn_pessimizing_move): Do nothing in a template.
>
> * g++.dg/cpp0x/Wpessimizing-move5.C: New test.
>
> diff --git gcc/cp/typeck.c gcc/cp/typeck.c
> index 122d9dcd4b3..24647e29a55 100644
> --- gcc/cp/typeck.c
> +++ gcc/cp/typeck.c
> @@ -9192,6 +9192,11 @@ maybe_warn_pessimizing_move (tree retval, tree
> functype)
> if (cxx_dialect < cxx11)
> return;
>
> + /* Wait until instantiation time, since we can't gauge if we should do
> + the NRVO until then. */
> + if (processing_template_decl)
> + return;
> +
> /* This is only interesting for class types. */
> if (!CLASS_TYPE_P (functype))
> return;
> diff --git gcc/testsuite/g++.dg/cpp0x/Wpessimizing-move5.C
> gcc/testsuite/g++.dg/cpp0x/Wpessimizing-move5.C
> index e69de29bb2d..02ad2113505 100644
> --- gcc/testsuite/g++.dg/cpp0x/Wpessimizing-move5.C
> +++ gcc/testsuite/g++.dg/cpp0x/Wpessimizing-move5.C
> @@ -0,0 +1,14 @@
> +// PR c++/87080
> +// { dg-do compile { target c++11 } }
> +// { dg-options "-Wpessimizing-move" }
> +
> +struct a {
> + template<typename b> a &operator<<(b);
> +};
> +a c();
> +template<typename>
> +a fn2()
> +{
> + int d = 42;
> + return c() << d;
> +}
