Re: [C++ PATCH] Fix diagnostics ICE (PR c++/71835)

[Jason Merrill <jason@redhat.com>]

OK.

On Mon, Jul 11, 2016 at 4:15 PM, Jakub Jelinek <jakub@redhat.com> wrote:
> Hi!
>
> add_conv_candidate creates cand->fn which is not a FUNCTION_DECL, but
> some type, all spots in convert_like_real assume that if fn is non-NULL, it
> is some decl.  Just a couple of lines above this hunk we even have a comment
> reminding us on cand->fn not having to be a decl:
>       /* Since cand->fn will be a type, not a function, for a conversion
>          function, we must be careful not to unconditionally look at
>          DECL_NAME here.  */
> So, this patch uses just convert_like instead of convert_like_with_context
> if cand->fn is not a decl (or shall I test for TREE_CODE (cand->fn) ==
> FUNCTION_DECL instead?).
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk/6.2?
>
> 2016-07-11  Jakub Jelinek  <jakub@redhat.com>
>
>         PR c++/71835
>         * call.c (build_op_call_1): Use convert_like_with_context only
>         if cand->fn is a decl.
>
>         * g++.dg/conversion/ambig3.C: New test.
>
> --- gcc/cp/call.c.jj    2016-07-11 11:14:28.000000000 +0200
> +++ gcc/cp/call.c       2016-07-11 14:42:44.466186449 +0200
> @@ -4406,8 +4406,11 @@ build_op_call_1 (tree obj, vec<tree, va_
>         result = build_over_call (cand, LOOKUP_NORMAL, complain);
>        else
>         {
> -         obj = convert_like_with_context (cand->convs[0], obj, cand->fn, -1,
> -                                          complain);
> +         if (DECL_P (cand->fn))
> +           obj = convert_like_with_context (cand->convs[0], obj, cand->fn,
> +                                            -1, complain);
> +         else
> +           obj = convert_like (cand->convs[0], obj, complain);
>           obj = convert_from_reference (obj);
>           result = cp_build_function_call_vec (obj, args, complain);
>         }
> --- gcc/testsuite/g++.dg/conversion/ambig3.C.jj 2016-07-11 14:47:26.668826075 +0200
> +++ gcc/testsuite/g++.dg/conversion/ambig3.C    2016-07-11 14:46:49.000000000 +0200
> @@ -0,0 +1,13 @@
> +// PR c++/71835
> +// { dg-do compile }
> +
> +typedef void T (int);
> +struct A { operator T * (); }; // { dg-message "candidate" }
> +struct B { operator T * (); }; // { dg-message "candidate" }
> +struct C : A, B {} c;
> +
> +void
> +foo ()
> +{
> +  c (0);               // { dg-error "is ambiguous" }
> +}
>
>         Jakub