On Mon, Sep 9, 2013 at 5:13 AM, Richard Biener <rguent...@suse.de> wrote: > On Mon, 9 Sep 2013, Paolo Carlini wrote: > >> On 09/09/2013 12:04 PM, Richard Biener 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. >> Everything happens via call backs. Thus from the generic diagnostic >> machinery, >> you go to cp_printer for C++, thus location_of for C++. In C is different, >> but >> again there is, evidently, a mechanism which uses DECL_CONTEXT for PARM_DECLs >> which leads to an inaccurate location when we *really* want the location of >> the parameter (exactly as I explained for C++). > > I understand that. But I question it. Why would that ever be useful? > Can't the places that want that simply use warning/error_at with the > proper location?
I agree with Richard that if you want a locus that is not the current locus, and is not the locus of the decl, you should use the _at version. -- Gaby
