[PATCH 25/44] Add _IOC_NEWLEN() and _IOC_NEWTYPE() macros.

[Sebastian Huber]

From: brooks <brooks@FreeBSD.org>

These macros take an existing ioctl(2) command and replace the length
with the specified length or length of the specified type respectively.
These can be used to define commands for 32-bit compatibility with fewer
opportunities for cut-and-paste errors then a whole new definition.

Reviewed by:	cem, kib
Obtained from:	CheriBSD
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D14706
---
 newlib/libc/sys/rtems/include/sys/ioccom.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/newlib/libc/sys/rtems/include/sys/ioccom.h b/newlib/libc/sys/rtems/include/sys/ioccom.h
index 34ea1e16d..2a8416c41 100644
--- a/newlib/libc/sys/rtems/include/sys/ioccom.h
+++ b/newlib/libc/sys/rtems/include/sys/ioccom.h
@@ -68,6 +68,10 @@ typedef unsigned long ioctl_command_t;
 #define	_IOW(g,n,t)	_IOC(IOC_IN,	(g), (n), sizeof(t))
 /* this should be _IORW, but stdio got there first */
 #define	_IOWR(g,n,t)	_IOC(IOC_INOUT,	(g), (n), sizeof(t))
+/* Replace length/type in an ioctl command. */
+#define	_IOC_NEWLEN(ioc, len) \
+    (((~(IOCPARM_MASK << 16)) & (ioc)) | (((len) & IOCPARM_MASK) << 16))
+#define	_IOC_NEWTYPE(ioc, type)	_IOC_NEWLEN((ioc), sizeof(type))
 
 #ifdef _KERNEL
 
-- 
2.13.7