changing KASSERT()'s definition for non-diag kernels

[matthew green <mrg%eterna.com.au@localhost>]

hi folks.


as part of the GCC 4.8 preparation work, we're seeing many new
warnings where variables are only used inside KASSERT(), but
the non-diag kernel builds trigger errors.

my solution, rather than marking these variables with __USE(),
is to change KASSERT() into a real function that consumes its
arguments, but is still an empty function.

note that there is a re-direction to force the input to 
KASSERT() to be an integer type, as it is called with all sorts
of types of input (pointers, values, boolean expressions..)

comments?  suggestions?


.mrg.


Index: lib/libkern/libkern.h
===================================================================
RCS file: /cvsroot/src/sys/lib/libkern/libkern.h,v
retrieving revision 1.108
diff -p -r1.108 libkern.h
*** lib/libkern/libkern.h       28 Aug 2013 16:20:38 -0000      1.108
--- lib/libkern/libkern.h       19 Oct 2013 19:55:50 -0000
*************** tolower(int ch)
*** 194,207 ****
  #define       CTASSERT_UNSIGNED(x)    __CTASSERT(((typeof(x))-1) >= 0)
  
  #ifndef DIAGNOSTIC
! #define _DIAGASSERT(a)        (void)0
! #ifdef lint
! #define       KASSERTMSG(e, msg, ...) /* NOTHING */
! #define       KASSERT(e)              /* NOTHING */
! #else /* !lint */
! #define       KASSERTMSG(e, msg, ...) ((void)0)
! #define       KASSERT(e)              ((void)0)
! #endif /* !lint */
  #else /* DIAGNOSTIC */
  #define _DIAGASSERT(a)        assert(a)
  #define       KASSERTMSG(e, msg, ...)         \
--- 194,212 ----
  #define       CTASSERT_UNSIGNED(x)    __CTASSERT(((typeof(x))-1) >= 0)
  
  #ifndef DIAGNOSTIC
! /*
!  * Use actual inlines for these so that compilers see their arguments
!  * as consumed in non-DIAG builds.
!  */
! static __inline__ void __KASSERTMSG(int e, const char *msg, ...);
! static __inline__ void __KASSERT(int e);
! static __inline__ void
! __KASSERTMSG(int e, const char *msg, ...) { }
! static __inline__ void
! __KASSERT(int e) { }
! #define _DIAGASSERT(e) __KASSERT((int)(e))
! #define KASSERTMSG(e, msg, ...) __KASSERTMSG((int)(e), (msg), ## __VA_ARGS__)
! #define KASSERT(e) __KASSERT((int)(e))
  #else /* DIAGNOSTIC */
  #define _DIAGASSERT(a)        assert(a)
  #define       KASSERTMSG(e, msg, ...)         \