wchar_t printf() format warning

Joel Sherrill joel.sherrill@oarcorp.com
Thu Mar 19 16:12:00 GMT 2015

On 3/19/2015 10:51 AM, Eric Blake wrote:
> On 03/19/2015 09:46 AM, Jonathan Roelofs wrote:
>> That's a platform decision, not a gcc decision. AFAIK, there is no
>> language requirement that wint_t and wchar_t be the same type.
> In fact, on cygwin, wchar_t is 16-bit, but wint_t is 32-bit, because
> there is no free 16-bit value that can hold WEOF.  On the other hand, on
> cygwin, passing wchar_t through va_arg promotes to 32-bit, so it happens
> to promote to wint_t and programmers can get away without the cast -
> whereas your platform was a question of wchar_t (32-bit int) not
> promoting to wint_t (32-bit long), making the cast necessary unless you
> can fix gcc to not use inconsistent 32-bit types.
Eric.. you've hacked on gcc a long time. Is this worth the trouble with gcc?

It involves a fair number of target architectures and target OSes. Seems
of questionable value. What do you think?

Joel Sherrill, Ph.D.             Director of Research & Development
joel.sherrill@OARcorp.com        On-Line Applications Research
Ask me about RTEMS: a free RTOS  Huntsville AL 35805
Support Available                (256) 722-9985

More information about the Newlib mailing list