On Sat, 22 Dec 2018 15:09:34 +0000
Iain Sandoe <idsandoe@googlemail.com> wrote:

> Hi Julian,
> 
> > On 21 Dec 2018, at 16:47, Julian Brown <julian@codesourcery.com>
> > wrote: 
> 
> > On Fri, 21 Dec 2018 14:31:19 +0100
> > Jakub Jelinek <jakub@redhat.com> wrote:
> >   
> >> On Fri, Dec 21, 2018 at 01:23:03PM +0000, Julian Brown wrote:  
> >>> 2018-xx-yy  Nathan Sidwell  <nathan@acm.org>  
> >   
> 
> >>>    	* testsuite/libgomp.oacc-c++/pr71959-a.C: New.
> >>>    	* testsuite/libgomp.oacc-c++/pr71959.C: New.    
> >>   
> >>> +void apply (int (*fn)(), Iter out) asm
> >>> ("_ZN5Apply5applyEPFivE4Iter");    
> >> 
> >> Will this work even on targets that use _ or other symbol
> >> prefixes?  
> > 
> > I'd guess so, else there would be no portable way of using "asm" to
> > write pre-mangled C++ names. The only existing similar uses I could
> > find in the testsuite are for the ifunc attribute, not asm, though
> > (e.g. g++.dg/ext/attr-ifunc-*.C).  
> 
> It won’t work on such targets (e.g. Darwin)
> … but it’s not too hard to make it happen (see, for example,
> gcc.dg/memcmp-1.c)
> 
> One just has to remember that __USER_LABEL_PREFIX__ is a token, not a
> string.
> 
> so .. in the example above…
> 
> #define STR1(X) #X
> #define STR2(X) STR1(X)
> 
> ….
> 
>  asm(STR2(__USER_LABEL_PREFIX__) "_ZN5Apply5applyEPFivE4Iter”);

Thanks! I've amended the test to use this technique (though I can't
easily test on Darwin, so this is "best effort").

> > Anyway, OpenACC is only useful for a handful of targets at present,
> > neither of which use special symbol prefixes AFAIK.  
> 
> I have hopes of one day getting offloading to work on Darwin (the
> only limitation is developer time, not technical feasibility) .. 

Is this OK now (for stage 4)?

Thanks,

Julian