[PATCH] libfdt: Add fdt_next_subnode() to permit easy subnode iteration

[David Gibson]

On Thu, Apr 25, 2013 at 11:22:56AM -0700, Simon Glass wrote:
> Iterating through subnodes with libfdt is a little painful to write as we
> need something like this:
> 
> for (depth = 0, count = 0,
> 	offset = fdt_next_node(fdt, parent_offset, &depth);
>      (offset >= 0) && (depth > 0);
>      offset = fdt_next_node(fdt, offset, &depth)) {
> 	if (depth == 1) {
> 		/* code body */
> 	}
> }
> 
> Using fdt_next_subnode() we can instead write this, which is shorter and
> easier to get right:
> 
> for (depth = 0, offset = fdt_next_subnode(fdt, parent_offset, &depth);
>      offset >= 0;
>      offset = fdt_next_subnode(fdt, offset, &depth)) {
> 	/* code body */
> }
> 
> Also, it doesn't require two levels of indentation for the loop
> body.

I like the idea in principle.  But if you split this into
find_first_subnode() and find_next_subnode() functions, you should be
able to get rid of the requirement for the caller to provide the depth
variable.

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson
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