Re: h8300, m32c and PRIuPTR

[Corinna Vinschen <vinschen at redhat dot com>]

On Mar 16 10:54, Joel Sherrill wrote:
> On 3/16/2015 10:08 AM, Corinna Vinschen wrote:
> > On Mar 16 09:38, Joel Sherrill wrote:
> >> I am wondering if when we avoided changing newlib-stdint.h to match the
> >> logic
> >> in glibc-stdint.h for uintptr_t by adding configure time logic, we just
> >> pushed
> >> off the problem. At this point, all I can see as a solution is something
> >> like this
> >> in inttypes.h:
> >>
> >> #if defined(__m32c__) || defined(__h8300__)
> >>   /* do whatever is needed */
> >> #else
> >>   /* we can rely on the value provided by configure, use current logic */
> >> #endif
> > Did you see my mail mentioning sys/config.h?
> This one?
> > Ideally the setting is available via compile time macros and can be used
> > to set _UINTPTR_EQ_ULONG or _UINTPTR_EQ_ULONGLONG from include/sys/config.h.
> So remove the configure.in logic and try to do the same thing dynamically
> with conditionals based on __SIZEOF_PTRDIFF__ and __SIZEOF_LONG_LONG__,
> __SIZEOF_LONG__, and __SIZEOF_INT__?
> 
> This will work in some cases but with sizeof(int) == sizeof(long),
> newlib-stdint.h
> is inconsistent whether uintptr_t is "unsigned int" or "long unsigned
> int". 
> And that was the more easily hit inttypes.h problem that added the logic
> to configure.in.
> > Again, the size of pointer values as well as the fact what multilib
> > we're building for should be available from gcc at compile time.  This
> > information should ideally be used to influence the logic of inttypes.h
> > in sys/config.h.
> >
> Can we reliably determine long or int for uintptr_t with cpp conditionals?

Using m32c as example, if you're building for m32cm, or with flags like
-mint32, there should be builtin macros showing that.  There are already
similar conditionals in sys/config.h:

  #ifdef __m32c__
  [...]
  #if defined(__r8c_cpu__) || defined(__m16c_cpu__)
  #define _POINTER_INT short
  #else
  #define _POINTER_INT long
  #endif
  [...]
  #endif /* __m32c__ */

So why not set _UINTPTR_EQ_ULONG or _UINTPTR_EQ_ULONGLONG here, too,
based on a builtin macro?


Corinna

-- 
Corinna Vinschen
Cygwin Maintainer
Red Hat

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