stdint.h question

Eric Norum norume at aps.anl.gov
Mon May 7 15:11:10 UTC 2007


On May 7, 2007, at 9:54 AM, Till Straumann wrote:

>>
> You are right, thx.
> Unfortunately, there still seems to be a bug in the newlib headers:
> Compiling the snippet
>
> #include <inttypes.h>
> #include <stdio.h>
>
> uintptr_t blah(void *arg)
> {
> uintptr_t rval = (uintptr_t)arg;
>     printf("%"PRIxPTR"\n", rval);
>     return rval;
> }
>
> produces:
>
> tst.c: In function 'blah':
> tst.c:7: warning: format '%llx' expects type 'long long unsigned int',
> but argument 2 has type 'uintptr_t'
>
> I.e., the formatting macro expands to 'unsigned long long int' but
> uintptr_t is only 'unsigned int'
> (which seems to be ok on a 32-bit machine).
>
> (gcc 4.1.1, newlib 1.14.0)
>

Seems to be fixed in the latest newlib (1.15.0 with rtems4.7-20070208  
patch):

1) The format string seems correct:
 > m68k-rtems4.7-gcc -E a.c | grep 'printf.*rval'
     printf("%""lx""\n", rval);

2) And it compiles without warning:
 > m68k-rtems4.7-gcc -Wall -c -O4 a.c


I got similar results with the powerpc and i386 cross-compilers.

-- 
Eric Norum <norume at aps.anl.gov>
Advanced Photon Source
Argonne National Laboratory
(630) 252-4793





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