On Sat, Mar 1, 2008 at 9:00 AM, Greg Parker <[EMAIL PROTECTED]> wrote:
libffi is smart enough to know about all of the ABI rules. If your ffi_types
> correctly describe the method's parameters, then libffi will marshal them
> properly. (If it doesn't, then that's a libffi bug.)
>
> I don't think libffi does any type promotion.
>
Indeed not - the sample below prints different results when run on PPC
(including Rosetta) and i386. On PPC, only the promoted version returns the
correct result. On Intel, both of them do. The question then, becomes -
should libffi be handling this difference transparently?
sherm--
#include <stdio.h>
#define MACOSX
#include <ffi.h>
char getCharFunction() {
return 5;
}
int main (int argc, const char * argv[]) {
ffi_cif cif_nopromote;
ffi_cif cif_promote;
long returnLongValue;
char returnCharValue;
if (ffi_prep_cif( &cif_nopromote,
FFI_DEFAULT_ABI,
0,
&ffi_type_schar,
NULL
)
!= FFI_OK ) {
printf("%s", "Error creating ffi cif_nopromote\n");
return 1;
}
if (ffi_prep_cif( &cif_promote,
FFI_DEFAULT_ABI,
0,
&ffi_type_slong,
NULL
)
!= FFI_OK ) {
printf("%s", "Error creating ffi cif_promote\n");
return 1;
}
ffi_call(&cif_nopromote,
(void(*)(void))getCharFunction,
&returnCharValue,
NULL
);
printf("Return value from cif_nopromote is %d.\n", returnCharValue);
ffi_call(&cif_promote,
(void(*)(void))getCharFunction,
&returnLongValue,
NULL
);
printf("Return value from cif_promote is %d.\n", returnLongValue);
return 0;
}
>
>
> --
> Greg Parker [EMAIL PROTECTED] Runtime Wrangler
>
>
>
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