Re: [C++ RFC / Patch] Implementing "Deducing "noexcept" for destructors"

[Paolo Carlini <paolo dot carlini at oracle dot com>]

Hi again,

On 03/30/2012 12:26 AM, Paolo Carlini wrote:
> On 03/29/2012 09:27 PM, Jason Merrill wrote:
> > On 03/29/2012 03:06 PM, Paolo Carlini wrote:
> > > > The exception specification on old_decl doesn't matter; we can drop
> > > > that test.
> > > I seem to remember something going wrong with templates otherwise,
> > > because implicitly_declare_fn has gcc_assert (!dependent_type_p 
> > > (type));
> >
> > We shouldn't be doing this for templates anyway, as in general we 
> > can't know what the implicitly declared function will look like.
> Oh my, as simple as the below appears to work!
>
> I simply added a !processing_template_decl check. Then I removed the 
> deduce_noexcept_on_destructor calls in register_specialization and 
> when I found a proper place in grokfndecl (must be before 
> check_explicit_specialization) I noticed that apparently I can remove 
> the other deduce_noexcept_on_destructor call which I had later on in 
> grokfndecl. Thus the below passes the (updated) testsuite on 
> x86_64-linux.
Sorry for essentially self-replying, but today, while I was traveling, I 
reviewed in my mind your comments over the last days, and I think I had 
a buglet in the patch which I sent in the last message: it doesn't make 
sure, in grokfndecl, to *not* call deduce_noexcept_on_destructor on a 
destructor of a class still being defined. Thus I'm adding a 
!TYPE_BEING_DEFINED (DECL_CONTEXT (decl)) check and the complete patch 
(which I'm attaching below) still passes testing. I also double checked 
that, for a simple case like:

struct A
{
  ~A();
};

A::~A() { }

we process the declaration from check_bases_and_members and then the 
definition from grokfndecl.

Thanks,
Paolo.

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Attachment: patch_50043_draft_3
Description: Text document