[PATCH 2/2] Allow nodes at the root to be specified by path as well as by label.

[Grant Likely]

On Mon, Oct 18, 2010 at 01:25:50PM -0700, John Bonesio wrote:
> Changes to allow us to specify a node by it's path. A path can be used in
> place of a label.
> 
> This is particularly useful when overriding existing nodes.
> This way we don't have to label every possible node in a device tree we know
> is a base device tree for a class of systems, and we know the tree will be
> modified for the specific systems.
> 
> Signed-off-by: John Bonesio <bones at secretlab.ca>
> ---
> 
>  dtc-parser.y |   16 ++++++++++++----
>  1 files changed, 12 insertions(+), 4 deletions(-)

Need to add test cases.

> 
> diff --git a/dtc-parser.y b/dtc-parser.y
> index 56d7789..0efd0cc 100644
> --- a/dtc-parser.y
> +++ b/dtc-parser.y
> @@ -134,22 +134,30 @@ devicetree:
>  		{
>  			struct node *target;
>  
> -			target = get_node_by_label($1, $2);
> +			if ($2[0] == '/')
> +				target = get_node_by_path($1, $2);
> +			else
> +				target = get_node_by_label($1, $2);
> +
>  			if (target)
>  				merge_nodes(target, $3);
>  			else
> -				print_error("label, '%s' not found", $2);
> +				print_error("label or path, '%s', not found", $2);
>  			$$ = $1;
>  		}
>  	| devicetree DT_REMOVENODE DT_REF ';'
>  		{
>  			struct node *target;
>  
> -			target = get_node_by_label($1, $3);
> +			if ($3[0] == '/')
> +				target = get_node_by_path($1, $3);
> +			else
> +				target = get_node_by_label($1, $3);
> +
>  			if (target)
>  				remove_nodes(target);
>  			else
> -				print_error("label, '%s' not found", $3);
> +				print_error("label or path, '%s', not found", $3);

Hmmm, this is effectively the same code block implemented twice.  Its
gotten complex enough with this patch that the common parts should be
factored out inot a common function...  In fact, after looking at the
code, it looks like it should be calling get_node_by_ref() here.

Also, this patch doesn't have any way to use the form
&<label>/path/based/on/label which is also a critical feature.

g.