Re: [PATCH v2 1/6] Bypass GCC attributes on NonStop platform where used.

[Jeff King <peff@peff.net>]

On Fri, Jan 19, 2018 at 08:28:48PM +0000, Ramsay Jones wrote:

> > diff --git a/remote.c b/remote.c
> > index 4e93753e1..c18f9de7f 100644
> > --- a/remote.c
> > +++ b/remote.c
> > @@ -11,6 +11,10 @@
> >  #include "mergesort.h"
> >  #include "argv-array.h"
> >  
> > +#if defined (__TANDEM)
> > +#define __attribute(a)
> > +#endif
> > +
> 
> Hmm, the only use of __attribute() I can find is in compat/regex/.
> In particular, there is no use of __attribute() in regex.c.
> [__attribute__() is used in regex.c]
> 
> Is this an old patch which is no longer required?
> 
> puzzled.

I'm puzzled, too. The actual gcc thing is __attribute__(), and we
already turn that into a noop via macro expansion if __GNUC__ is not
defined (in git-compat-util.h, but see below).

__attribute(), without the trailing underscores, is used internally by
the regex compat code (but it also converts that into a noop on non-GNUC
platforms)>

However the logic in git-compat-util is weird:

  #if defined(__HP_cc) && (__HP_cc >= 61000)
  #define NORETURN __attribute__((noreturn))
  #define NORETURN_PTR
  #elif defined(__GNUC__) && !defined(NO_NORETURN)
  #define NORETURN __attribute__((__noreturn__))
  #define NORETURN_PTR __attribute__((__noreturn__))
  #elif defined(_MSC_VER)
  #define NORETURN __declspec(noreturn)
  #define NORETURN_PTR
  #else
  #define NORETURN
  #define NORETURN_PTR
  #ifndef __GNUC__
  #ifndef __attribute__
  #define __attribute__(x)
  #endif
  #endif
  #endif

Most of the conditional is dealing with NORETURN, but then we stick the
__attribute()__ handling in the "else" block. Is it possible that this
platform triggers __HP_cc, but doesn't actually understand
__attribute__?

-Peff