Re: C++ PATCH to implement deferred parsing of noexcept-specifiers (c++/86476, c++/52869)

[Jason Merrill <jason@redhat.com>]

On 6/3/19 9:01 PM, Marek Polacek wrote:

> I sort of ended up going down a rathole, but then I realized we don't need to
> delay parsing of noexcept-specifiers of member friend function declarations,
> because they aren't members of the class.

Where are you getting this from?  I'm definitely sympathetic to the idea 
that noexcept-specifiers of friend functions shouldn't need to be 
complete-class contexts, but 10.3 doesn't make that distinction that I 
can see.

> This was a huge relief because
> member friend function declarations can be redeclared, so we'd have to make
> sure to check if their noexcept-specifiers match.  But member function decls
> can't be redeclared.  I updated the comment to better reflect why what I'm
> doing there is correct, along with an assert.

But then why do you still need this:

> +  /* We can't compare unparsed noexcept-specifiers.  Save the decl
> +     and check this again after we've parsed the noexcept-specifiers
> +     for real.  */
> +  if (UNPARSED_NOEXCEPT_SPEC_P (new_exceptions))
> +    {
> +      DEFARG_DECL (TREE_PURPOSE (new_exceptions)) = copy_decl (old_decl);
> +      return;
> +    }

?

Jason