[Patch to gcc/function] PR 58362

[Gabriel Dos Reis]

On Mon, Sep 9, 2013 at 5:04 AM, Richard Biener <rguenther@suse.de> wrote:
> On Mon, 9 Sep 2013, Jakub Jelinek wrote:
>
>> On Mon, Sep 09, 2013 at 11:45:08AM +0200, Richard Biener wrote:
>> > Well, in this case the patch should IMHO be a no-op.
>> >
>> > -      warning (OPT_Wunused_parameter, "unused parameter %q+D", decl);
>> > +      warning_at (DECL_SOURCE_LOCATION (decl), OPT_Wunused_parameter,
>> > +             "unused parameter %qD", decl);
>> >
>> > no?  Unless I misunderstand what %q+D should do.
>>
>> The question is how exactly is %q+D defined, if it is
>> warning_at (location_of (decl), OPT_Wunused_parameter, "unused parameter %qD", decl); in this case, or
>> DECL_SOURCE_LOCATION (decl) instead.
>
> It can't be 'location_of' because that's a C++ FE speciality but
> warning_at and %q+D are diagnostic machinery level.

%+D was, and has for long, been a C++ FE-specific marker.

I don't recall when we decided to make that available to all front-ends.

> Unless of course the meaning of %q+D depends on the frontend which
> would make its use from the middle-end ill-defined.

We introduced xxx_at so that a different locus (different from the
decl and different from current locus, if ever defined) can be specified.

-- Gaby