Re: [PATCH v13 6/7] overlay: Add syntactic sugar version of overlays

Hi Grant,

On Nov 20, 2017, at 18:12 , Grant Likely [off-list ref] wrote:

On Wed, Dec 7, 2016 at 12:48 PM, Pantelis Antoniou
[off-list ref] wrote:

quoted

For simple overlays that use a single target there exists a
simpler syntax version.

&foo { }; generates an overlay with a single target at foo.

Signed-off-by: Pantelis Antoniou <pantelis.antoniou-OWPKS81ov/FWk0Htik3J/w@public.gmane.org>
---
dtc-parser.y | 20 +++++++++++++++++---
dtc.h        |  1 +
livetree.c   | 22 ++++++++++++++++++++++
3 files changed, 40 insertions(+), 3 deletions(-)

diff --git a/dtc-parser.y b/dtc-parser.y
index 27d358f..50da917 100644
--- a/dtc-parser.y
+++ b/dtc-parser.y

@@ -183,10 +183,19 @@ devicetree:
               {
                       struct node *target = get_node_by_ref($1, $2);

-                       if (target)
+                       if (target) {
                               merge_nodes(target, $3);
-                       else
-                               ERROR(&@2, "Label or path %s not found", $2);
+                       } else {
+                               /*
+                                * We rely on the rule being always:
+                                *   versioninfo plugindecl memreserves devicetree
+                                * so $-1 is what we want (plugindecl)
+                                */
+                               if ($<flags>-1 & DTSF_PLUGIN)
+                                       add_orphan_node($1, $3, $2);
+                               else
+                                       ERROR(&@2, "Label or path %s not found", $2);
+                       }

It seems to me that the changes to this rule also need to be made to
the "devicetree DT_LABEL DT_REF nodedef" rule immediately above it.
Aside from applying the label, the rules are identical.
kkk

I don’t think this occurs for the intended case, i.e. a reference at root instead of /

quoted

                       $$ = $1;
               }
       | devicetree DT_DEL_NODE DT_REF ';'

@@ -201,6 +210,11 @@ devicetree:

                       $$ = $1;
               }
+       | /* empty */
+               {
+                       /* build empty node */
+                       $$ = name_node(build_node(NULL, NULL), "");
+               }
       ;

This change to the parser results in shift/reduce warnings due to an
ambiguous parser. Just discovered this while playing with the mainline
dtc.

I *think* what you're trying to do here is allow for files whose first
tree is not '/', but a DT_REF. I've got a fix which I'll post as soon
as I get email from my Linux box working again.

Yes, that’s the only use case.

g.

Regards

— Pantelis

quoted

nodedef:

diff --git a/dtc.h b/dtc.h
index 2ca8601..c97e291 100644
--- a/dtc.h
+++ b/dtc.h

@@ -198,6 +198,7 @@ struct node *build_node_delete(void);

struct node *name_node(struct node *node, char *name);
struct node *chain_node(struct node *first, struct node *list);
struct node *merge_nodes(struct node *old_node, struct node *new_node);
+void add_orphan_node(struct node *old_node, struct node *new_node, char *ref);

void add_property(struct node *node, struct property *prop);
void delete_property_by_name(struct node *node, char *name);

diff --git a/livetree.c b/livetree.c
index df1bc04..0806e47 100644
--- a/livetree.c
+++ b/livetree.c

@@ -216,6 +216,28 @@ struct node *merge_nodes(struct node *old_node, struct node *new_node)
       return old_node;

}

+void add_orphan_node(struct node *dt, struct node *new_node, char *ref)
+{
+       static unsigned int next_orphan_fragment = 0;
+       struct node *node;
+       struct property *p;
+       struct data d = empty_data;
+       char *name;
+
+       d = data_add_marker(d, REF_PHANDLE, ref);
+       d = data_append_integer(d, 0xffffffff, 32);
+
+       p = build_property("target", d);
+
+       xasprintf(&name, "fragment@%u",
+                       next_orphan_fragment++);
+       name_node(new_node, "__overlay__");
+       node = build_node(p, new_node);
+       name_node(node, name);
+
+       add_child(dt, node);
+}
+
struct node *chain_node(struct node *first, struct node *list)
{
       assert(first->next_sibling == NULL);
--
2.1.4