diff options
| author | grr <grr@cvs.openbsd.org> | 1997-06-25 12:52:12 +0000 |
|---|---|---|
| committer | grr <grr@cvs.openbsd.org> | 1997-06-25 12:52:12 +0000 |
| commit | 47dc7a62ced6f83086840c994b7fd839a808721b (patch) | |
| tree | 6e5e2bcdb6560d3a9bb57cda0a3611226fcb535d /sys/arch/m68k/include/endian.h | |
| parent | 9f5b8216c2af91286d9d2beb109f93ce776885ca (diff) | |
Include usage notes in the rest of the endian.h files for consistancy.
Diffstat (limited to 'sys/arch/m68k/include/endian.h')
| -rw-r--r-- | sys/arch/m68k/include/endian.h | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/sys/arch/m68k/include/endian.h b/sys/arch/m68k/include/endian.h index 02875635f86..b9514134c68 100644 --- a/sys/arch/m68k/include/endian.h +++ b/sys/arch/m68k/include/endian.h @@ -1,4 +1,4 @@ -/* $OpenBSD: endian.h,v 1.7 1997/06/25 12:32:50 downsj Exp $ */ +/* $OpenBSD: endian.h,v 1.8 1997/06/25 12:52:09 grr Exp $ */ /* $NetBSD: endian.h,v 1.10 1996/10/13 02:59:55 christos Exp $ */ /* @@ -139,6 +139,13 @@ __END_DECLS /* * Macros for network/external number representation conversion. + * + * The way this works is that HTONS(x) modifies x and *can't* be used as + * and rvalue i.e. foo=HTONS(bar) is wrong. Likewise x=htons(x) should + * never be used where HTONS(x) will serve i.e. foo=htons(foo) is wrong. + * Failing to observe these rule will result in code that appears to work + * and probably does work, but generates gcc warnings on architectures + * where the macros are used to optimize away an unneeded conversion. */ #define ntohl(x) betoh32(x) #define ntohs(x) betoh16(x) |