[DTC PATCH] libfdt: Add ft_get_next_node(), ft_get_next_prop(), and ft_getprop_offset().

Scott Wood scottwood at freescale.com
Wed Jan 16 03:52:30 EST 2008

On Tue, Jan 15, 2008 at 11:16:57AM +1100, David Gibson wrote:
> On Mon, Jan 14, 2008 at 10:30:04AM -0600, Scott Wood wrote:
> > ft_get_next_node() enumerates children of a given node.
> > ft_get_next_prop() enumerates propreties of a given node.
> > 
> > ft_getprop_offset() is like ft_getprop(), but takes a property offset rather
> > than a node offset and property name; it is primarily intended for use
> > with ft_get_next_prop().
> Urg... this kind of serves me right for not getting my act together on
> iterator functions yet.  I really don't like this approach much.  I'll
> see if I can come up with something I prefer this afternoon.


> The biggest thing I dislike is that I've deliberately avoided having
> any offsets-to-properties exposed to the library user.  That's because
> the whole offsets change when you write the tree problem is worse for
> properties than nodes (in that likely idiomatic uses will be bitten by
> changes in property offsets).

We can drop the property iteration for now; I wrote it for an attempt at
node merging which I postponed.

> > +	if (depth != 0)
> > +		return -FDT_ERR_BADSTRUCTURE;
> I think this should be FDT_ERR_TRUNCATED.

I'd expect TRUNCATED when we hit totalsize without an FDT_END, not when
we hit FDT_END in an inappropriate context.

> > +	return -FDT_ERR_NOTFOUND;
> In fact, so should this.  This function should never actually reach
> the FDT_END tag.

No, it's valid if you're iterating over all nodes (node -1, depth -1).

> > +#define FDT_ERR_BADDEPTH	8
> > +	/* FDT_ERR_BADDEPTH: Function was passed a negative
> > +	 * (or otherwise invalid) depth. */
> You've added this error code, but you don't actually return it
> anywhere...

Oops, it must have been from the aforementioned node merging code, and I
thought it was from fdt_get_next_node when splitting things up.

> This description is incorrect - you've copied the fdt_getprop()
> description and forgotten to update it.

/me hides in shame


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