Cast to `char *' instead of to u_long to help add byte offsets to

pointers.  Neither is portable, but "correct" casts to integral
types are much uglier - they lead to expressions like

        ptr = (struct struct_with_too_long_a_name *)(void *)(uintptr_t)
	    ((uintptr_t)(void *)ptr + offset);

Here the cast to the struct pointer is to match the surrounding
style of this file (and not depend on C's feature of properly
converting `void *' on assignment or cast), the `void *' casts are
because uintptr_t is only specified to work on `void *' pointers
(I missed this in about 100 lines of previous changes from [u]long
to [u]intptr_t), the outer cast to a uintptr_t is in case the
addition promoted the type, and the inner cast to a uintptr_t
corresponds to the one cast to an integer in the original code.

Don't depend on gcc's feature of casting lvalues.

1 files changed, 5 insertions, 4 deletions

diff --git a/sys/scsi/ch.c b/sys/scsi/ch.c
index 3ba80fb..9b970fb 100644
--- a/sys/scsi/ch.c
+++ b/sys/scsi/ch.c
@@ -33,7 +33,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *      $Id: ch.c,v 1.46 1998/06/07 17:12:47 dfr Exp $
+ *      $Id: ch.c,v 1.47 1998/06/17 14:13:13 bde Exp $
  */
 
 #include "opt_devfs.h"
@@ -544,7 +544,7 @@ ch_usergetelemstatus(sc, chet, uptr)
 		goto done;
 
 	st_hdr = (struct read_element_status_header *)data;
-	pg_hdr = (struct read_element_status_page_header *)((u_long)st_hdr +
+	pg_hdr = (struct read_element_status_page_header *)((char *)st_hdr +
 	    sizeof(struct read_element_status_header));
 	desclen = scsi_2btou(pg_hdr->edl);
 
@@ -583,12 +583,13 @@ ch_usergetelemstatus(sc, chet, uptr)
 
 	user_data = (u_int8_t *)malloc(avail, M_DEVBUF, M_WAITOK);
 
-	desc = (struct read_element_status_descriptor *)((u_long)data +
+	desc = (struct read_element_status_descriptor *)((char *)data +
 	    sizeof(struct read_element_status_header) +
 	    sizeof(struct read_element_status_page_header));
 	for (i = 0; i < avail; ++i) {
 		user_data[i] = desc->flags1;
-		(u_long)desc += desclen;
+		desc = (struct read_element_status_descriptor *)
+		    ((char *)desc + desclen);
 	}
 
 	/* Copy flags array out to userspace. */