On Wed, Oct 20, 2010 at 02:45:22PM -0700, John Bonesio wrote:
> When updating existing nodes in a device tree merge operation, properties
> can be removed by setting the value to /undef-prop/.
>
> if /undef-prop/ is assigned to a property that doesn't exist, the property
> is treated the same as if it had not been declared.
[snip]
> diff --git a/dtc.h b/dtc.h
> index a7f3667..b3fca6e 100644
> --- a/dtc.h
> +++ b/dtc.h
> @@ -130,7 +130,12 @@ struct label {
> struct label *next;
> };
>
> +#define PROP_DEFINED (0)
> +#define PROP_UNDEFINED (1)
You never actually use these constants.
> +
> struct property {
> + int undefined; /* if the property is set to undefined, this feild is
> + set to PROP_UNDEFINED */
> char *name;
> struct data val;
>
> @@ -170,6 +175,7 @@ void add_label(struct label **labels, char *label);
> struct property *build_property(char *name, struct data val);
> struct property *chain_property(struct property *first, struct property
> *list);
> struct property *reverse_properties(struct property *first);
> +void undefine_property(struct property *prop);
>
> struct node *build_node(struct property *proplist, struct node *children);
> struct node *name_node(struct node *node, char *name);
> @@ -177,6 +183,7 @@ struct node *chain_node(struct node *first, struct node
> *list);
> struct node *merge_nodes(struct node *old_node, struct node *new_node);
>
> void add_property(struct node *node, struct property *prop);
> +void remove_property(struct node *node, struct property *prop);
> void add_child(struct node *parent, struct node *child);
> void remove_child(struct node *parent, struct node *child);
>
> diff --git a/flattree.c b/flattree.c
> index ead0332..00439e9 100644
> --- a/flattree.c
> +++ b/flattree.c
> @@ -275,6 +275,9 @@ static void flatten_tree(struct node *tree, struct
> emitter *emit,
> for_each_property(tree, prop) {
> int nameoff;
>
> + if (prop->undefined)
> + continue;
> +
> if (streq(prop->name, "name"))
> seen_name_prop = 1;
>
> diff --git a/livetree.c b/livetree.c
> index bf8796b..2ef734d 100644
> --- a/livetree.c
> +++ b/livetree.c
> @@ -51,6 +51,11 @@ struct property *build_property(char *name, struct data
> val)
> return new;
> }
>
> +void undefine_property(struct property *prop)
> +{
> + prop->undefined = 1;
> +}
> +
> struct property *chain_property(struct property *first, struct property
> *list)
> {
> assert(first->next == NULL);
> @@ -121,11 +126,15 @@ struct node *merge_nodes(struct node *old_node, struct
> node *new_node)
> /* Look for a collision, set new value if there is */
> for_each_property(old_node, old_prop) {
> if (streq(old_prop->name, new_prop->name)) {
> - /* Add new labels to old property */
> - for_each_label(new_prop->labels, l)
> - add_label(&old_prop->labels, l->label);
> -
> - old_prop->val = new_prop->val;
> + if (new_prop->undefined) {
> + remove_property(old_node,
> old_prop);
This will lose property labels into the ether as your earlier patch
lost node labels.
> + } else {
> + /* Add new labels to old property */
> + for_each_label(new_prop->labels, l)
> + add_label(&old_prop->labels,
> l->label);
> +
> + old_prop->val = new_prop->val;
> + }
> free(new_prop);
> new_prop = NULL;
> break;
> @@ -188,6 +197,25 @@ void add_property(struct node *node, struct property
> *prop)
> *p = prop;
> }
>
> +void remove_property(struct node *node, struct property *prop)
> +{
> + struct property **p;
> + int found = 0;
> +
> + p = &node->proplist;
> + while (*p) {
> + if (*p == prop) {
> + *p = (*p)->next;
> + found = 1;
> + break;
> + }
> + p = &((*p)->next);
> + }
> + /* property not in the node? it's probably an error, so flag it. */
> + assert(found);
assert()s are for finding bugs in code, not detecting errors in user
input. AFAICT this *can* be generated by usre input so it should
print an error message and if possible continue, not cause a SIGABRT.
> +}
> +
> +
> void add_child(struct node *parent, struct node *child)
> {
> struct node **p;
>
--
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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