Size-independent byte order swapping functions.

[Pawel Jakub Dawidek]

Hello hackers...

Macros in attached patch are designed for doing life a little easier.

If one is using strictly defined types as uint8_t, uint16_t, int32_t, etc.
those macros are helpful IMHO, because futher value size changes does not
affects code for byte order managing. This also does not hit perfromance,
because this should be resolved at compile-time.

I'm not sure if dedicated epanic() is the best way to implement out-of-range
errors prevention - the more handy solution should cause compile error.

-- 
Pawel Jakub Dawidek                       pawel at dawidek.net
UNIX Systems Programmer/Administrator     http://garage.freebsd.pl
Am I Evil? Yes, I Am!                     http://cerber.sourceforge.net
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--- endian.h.orig	Sat Nov 22 13:15:40 2003
+++ endian.h	Mon Nov 24 10:57:02 2003
@@ -49,6 +49,46 @@
 #endif
  
 /*
+ * Size-independent byte order swapping functions.
+ */
+#ifdef _KERNEL
+#define	epanic(msg)	_epanic(msg, __FILE__, __LINE__)
+/* New function, because panic(9) type is void and this is not enough. */
+static __inline int
+_epanic(const char *msg, const char *file, unsigned line)
+{
+
+	panic("%s:%u: %s", file, line, msg);
+	/* NOTREACHED */
+}
+#define	bswap(x)	(sizeof(x) == 1 ? (x) = (x) :			\
+			(sizeof(x) == 2 ? bswap16(x) :			\
+			(sizeof(x) == 4 ? bswap32(x) :			\
+			(sizeof(x) == 8 ? bswap64(x) :			\
+			epanic("out of range in bswap()")))))
+#define	htobe(x)	(sizeof(x) == 1 ? (x) = (x) :			\
+			(sizeof(x) == 2 ? htobe16(x) :			\
+			(sizeof(x) == 4 ? htobe32(x) :			\
+			(sizeof(x) == 8 ? htobe64(x) :			\
+			epanic("out of range in htobe()")))))
+#define	htole(x)	(sizeof(x) == 1 ? (x) = (x) :			\
+			(sizeof(x) == 2 ? htole16(x) :			\
+			(sizeof(x) == 4 ? htole32(x) :			\
+			(sizeof(x) == 8 ? htole64(x) :			\
+			epanic("out of range in htole()")))))
+#define	betoh(x)	(sizeof(x) == 1 ? (x) = (x) :			\
+			(sizeof(x) == 2 ? betoh16(x) :			\
+			(sizeof(x) == 4 ? betoh32(x) :			\
+			(sizeof(x) == 8 ? betoh64(x) :			\
+			epanic("out of range in betoh()")))))
+#define	letoh(x)	(sizeof(x) == 1 ? (x) = (x) :			\
+			(sizeof(x) == 2 ? letoh16(x) :			\
+			(sizeof(x) == 4 ? letoh32(x) :			\
+			(sizeof(x) == 8 ? letoh64(x) :			\
+			epanic("out of range in letoh()")))))
+#endif
+
+/*
  * General byte order swapping functions.
  */
 #define	bswap16(x)	__bswap16(x)
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