>> Maybe changing all functions that take enum args is easier.
> If this is true, perhaps using K&C style function definition with
> __P() macro may be better than current ANSI style function style.

...??  As I recall C, a prototype declaration is incompatible with an
old-style definition (at least if the prototype uses any types that
change when run through the default promotions), and if you __P() the
prototype away, you've just got a plain old-style everything.  In gcc,
an old-style definition with a previous prototype declaration is
silently converted to a new-style definition, so you have the same
incompatability you do with a wholly new-style approach.

> Because gcc can automatically generate warning message against such
> usage (manual checking is not nice....).

I must be missing something here.  Can you give an example of how your
suggestion improves matters?

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