Customizing C-mode indentation

[John Mastro]

Hello Emacsers,

I have a question about customizing c-mode's indention, specifically
regarding teaching c-mode about loop macros. I have some C code that
defines a preprocessor macro like:

#define iter_each(iter, v) (void * v; iter_next((iter), v); )

An example use would be:

struct iter it;
iter_init(&it, data);

for iter_each(&it, p) {
    /* ... */
}

However, because the `iter_each' hides the fact that this is a `for'
loop, c-mode indents it like this:

for iter_each(&it, p) {
        /* ... */
    }

What's the best way to teach c-mode the correct way to indent this
construct? So far what I've found is `c-special-indent-hook', which
works, but I'm wondering if there's a better way I haven't found (e.g.
by customizing a regexp, which would be easier to stick in a
.dir-locals.el).

Thanks

        John