>Discovered while building bmake on freebsd 4.8, where the default warnings
>include 
>-W -Wcast-qual -Wstrict-prototypes -Wwrite-strings -Wnon-const-format

Fixing this needs a few things that don't currently seem to be covered
by share/misc/style.

For instance, function args that are unused.
Do we 
1/ tag them with __unused	gcc specific?
2/ frob the function to use them

Also const correctness hell... needs things like:

      char default_op[] = "!=";
      ...
      op = default_op;

style explicitly says don't assign in variable decls but the above is
an obvious? exception.

and inevitably you need to be able to discard const without a simple
cast to be safe.  A static inline func discard_const() works well,
but I don't see evidence that we condone use of those.
I'm painfully aware that over use of static inlines leads to debug
hell.  The alternative is a global union variable used by a macro,
or a static variable in each file that needs to use the macro.

A work-around (which will likely be needed for now) is to put some
make foo in bmake/Makefile.in to ensure that CFLAGS does not contain 
any of the above -W flags.

--sjg