[05/29] Allow fd_mask type not be an array of long.
Commit Message
Even though XPG4.2 requires fd_set member be a long, AARCH64:ILP32
needs it to be the same size as AARCH64:LP64 for big-endian so we
need it to be long long.
* misc/sys/select.h (__FD_MASK_TYPE): Define.
(__FD_MASK_CONST): Define.
(__fd_mask): Change to base on __FD_MASK_TYPE.
(__FD_MASK): Use __FD_MASK_CONST.
---
misc/sys/select.h | 10 +++++++---
1 files changed, 7 insertions(+), 3 deletions(-)
Comments
On 10/27/2014 3:59 AM, Andrew Pinski wrote:
> +/* The fd_set member is required to be an array of longs by XPG4.2. */
So on aarch64 compat it's now an array of long longs. Is this a problem? Would it be better to make it an array of longs but twice as many longs on ILP32 as on LP64? I suppose this becomes problematic when supporting big-endian, though. But it would be good to address the XPG4.2 issue somewhere in the headers.
On 27 October 2014 16:32, Chris Metcalf <cmetcalf@tilera.com> wrote:
> On 10/27/2014 3:59 AM, Andrew Pinski wrote:
>>
>> +/* The fd_set member is required to be an array of longs by XPG4.2. */
>
>
> So on aarch64 compat it's now an array of long longs. Is this a problem?
> Would it be better to make it an array of longs but twice as many longs on
> ILP32 as on LP64? I suppose this becomes problematic when supporting
> big-endian, though. But it would be good to address the XPG4.2 issue
> somewhere in the headers.
Yes, this seems strange to me. Maybe it might be best handled by a
wrapper in the kernel?
@@ -49,16 +49,20 @@ typedef __suseconds_t suseconds_t;
# define __suseconds_t_defined
#endif
+/* The fd_set member is required to be an array of longs by XPG4.2. */
+#ifndef __FD_MASK_TYPE
+#define __FD_MASK_TYPE long
+#define __FD_MASK_CONST(a) a##ul
+#endif
-/* The fd_set member is required to be an array of longs. */
-typedef long int __fd_mask;
+typedef __FD_MASK_TYPE __fd_mask;
/* Some versions of <linux/posix_types.h> define this macros. */
#undef __NFDBITS
/* It's easier to assume 8-bit bytes than to get CHAR_BIT. */
#define __NFDBITS (8 * (int) sizeof (__fd_mask))
#define __FD_ELT(d) ((d) / __NFDBITS)
-#define __FD_MASK(d) ((__fd_mask) (1UL << ((d) % __NFDBITS)))
+#define __FD_MASK(d) ((__fd_mask) (__FD_MASK_CONST(1) << ((d) % __NFDBITS)))
/* fd_set for select and pselect. */
typedef struct