Re: [PATCH] PR c++/80473 allow suppressing notes about over-aligned new

[Jonathan Wakely <jwakely at redhat dot com>]

On 20/04/17 17:22 +0200, Jakub Jelinek wrote:
> On Thu, Apr 20, 2017 at 04:09:20PM +0100, Jonathan Wakely wrote:
> > --- a/gcc/cp/init.c
> > +++ b/gcc/cp/init.c
> > @@ -3128,11 +3128,14 @@ build_new_1 (vec<tree, va_gc> **placement, tree type, tree nelts,
> >      {
> >        warning (OPT_Waligned_new_, "%<new%> of type %qT with extended "
> >  	       "alignment %d", elt_type, TYPE_ALIGN_UNIT (elt_type));
> > -      inform (input_location, "uses %qD, which does not have an alignment "
> > -	      "parameter", alloc_fn);
> > -      if (!aligned_new_threshold)
> > -	inform (input_location, "use %<-faligned-new%> to enable C++17 "
> > -				"over-aligned new support");
> > +      if (diagnostic_report_warnings_p (global_dc, input_location))
> > +	{
> > +	  inform (input_location, "uses %qD, which does not have an alignment "
> > +		  "parameter", alloc_fn);
> > +	  if (!aligned_new_threshold)
> > +	    inform (input_location, "use %<-faligned-new%> to enable C++17 "
> > +				    "over-aligned new support");
> > +	}
>
> This looks weird.  I'd expect instead:
>      if (warning (OPT_Waligned_new_, "%<new%> of type %qT with extended "
> 		   "alignment %d", elt_type, TYPE_ALIGN_UNIT (elt_type)))
> 	{
> 	  inform (input_location, "uses %qD, which does not have an alignment "
> 		  "parameter", alloc_fn);
> 	  if (!aligned_new_threshold)
> 	    inform (input_location, "use %<-faligned-new%> to enable C++17 "
> 				    "over-aligned new support");
> 	}
> That is a standard idiom used if some inform or later warning/error depends
> on whether earlier warning/error has been diagnosed.

Aha, thanks.

> If that works, this is ok for trunk and 7.1 (we don't have a rc1 yet, it is
> ok now).

OK, I'll test it now.