如何让Emacs正确缩进C99复合文字？

Question

I'm writing a C99 program and using compound literals quite often. However, Emacs doesn't seem to indent them properly.

For example, here's a simple function, indented by hand:

SDL_Point
random_point_within_rect(SDL_Rect r)
{
    return (SDL_Point) {
        .x = (r.x + (rand() % r.w)),
        .y = (r.y + (rand() % r.h)),
    };
}

And here is how that looks when I use Mx indent-region :

SDL_Point
random_point_within_rect(SDL_Rect r)
{
    return (SDL_Point) {
        .x = (r.x + (rand() % r.w)),
            .y = (r.y + (rand() % r.h)),
            };
}

My hypothesis is that Emacs doesn't recognise the braces in (type) { ... } as being the same sort of thing as in type x = { ... } , since this, which has exactly the same contents in the braces, works fine:

SDL_Point
random_point_within_rect(SDL_Rect r)
{
    SDL_Point p = {
        .x = (r.x + (rand() % r.w)),
        .y = (r.y + (rand() % r.h)),
    };
    return p;
}

Is there a way I can get Emacs to treat compound literals like struct literals, or some other way to fix the indentation here?

Thanks.

Answer 1

I filed a bug report for that exact problem; I believe emacs is treating your list as a series of statements, and commas as comma operators.

You can circumvent the problem by putting ; at the end of your lines. You can also use unnamed struct initializers, ie

return (SDL_Point){r.x + rand()%r.w, r.y + rand()%r.h}