Re: PATCH libffi win64 support

[Andrew Haley <aph at redhat dot com>]

Timothy Wall wrote:
> 
> On Jun 12, 2009, at 10:20 AM, Andrew Haley wrote:
> 
>> Timothy Wall wrote:
>>> applied.
>>>
>>> On Jun 10, 2009, at 5:45 AM, Andrew Haley wrote:
>>>
>>>> Timothy Wall wrote:
>>>>> 2009-06-08  Timothy Wall  <twall@users.sf.net>
>>>>>
>>>>>    * Makefile.am,
>>>>>       configure.ac,
>>>>>       include/ffi.h.in,
>>>>>       include/ffi_common.h,
>>>>>       src/closures.c,
>>>>>       src/dlmalloc.c,
>>>>>       src/x86/ffi.c,
>>>>>       src/x86/ffitarget.h,
>>>>>       src/x86/win64.S (new),
>>>>>    README: Added win64 support (mingw or MSVC)
>>>>>       * ltcf-c.sh: properly escape cygwin/w32 path
>>>>>       * man/ffi_call.3: Clarify size requirements for return value.
>>>>>       * src/x86/ffi64.c: Fix filename in comment.
>>>>
>>>> Please commit this and let me know as soon as you've done so.
>>
>> I've got a few new test failures.  They're of the form
>>
>> libffi/testsuite/libffi.call/cls_align_sint64.c:80: warning: format
>> '%ld' expects type 'long int', but argument 3 has type 'long long int'
>>
>> It's because of changes like this:
>>
>> -  printf("res: %d %lld %d\n", res_dbl.a, res_dbl.b, res_dbl.c);
>> +  printf("res: %d %" PRId64 " %d\n", res_dbl.a, res_dbl.b, res_dbl.c);
>>
>> which prints out a  long long  as an int64.  This is wrong, since
>> the type is "long long" and the printf format must match the
>> declaration of the object being printed.
> 
> When compiling with mingw(64), the underlying runtime library doesn't
> recognize "lld" (which is what PRId64 evaluates to on my OSX), but
> rather expects "I64" or some such (properly represented by PRId64 with
> mingw).
> 
> If PRId64 is evaluating to "%ld", then perhaps that's a bug in the
> inttypes.h header.

Why do you think it's a bug in the inttypes.h header?  PRId64 is perfectly
OK for an int64_t, but it's not OK for a long long.  Both are 64-bit ints,
but they are different types.  You can't just substitute a type that
happens to be the same size.

If we're to use PRId64 then we have to change the type of the arg to int64_t.

Andrew.