[PATCH] scripts/dtc: Simplify condition in get_node_by_path

[PATCH] scripts/dtc: Simplify condition in get_node_by_path

[Denis Efremov]

The strlen && strprefixeq check in get_node_by_path is
excessive, since strlen is checked in strprefixeq macro
internally. Thus, 'strlen(child->name) == p-path'
conjunct duplicates after macro expansion and could
be removed.

Signed-off-by: Denis Efremov <efremov@linux.com>
---
 scripts/dtc/livetree.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/scripts/dtc/livetree.c b/scripts/dtc/livetree.c
index 0c039993953a..032df5878ccc 100644
--- a/scripts/dtc/livetree.c
+++ b/scripts/dtc/livetree.c
@@ -526,8 +526,7 @@ struct node *get_node_by_path(struct node *tree, const char *path)
 	p = strchr(path, '/');
 
 	for_each_child(tree, child) {
-		if (p && (strlen(child->name) == p-path) &&
-		    strprefixeq(path, p - path, child->name))
+		if (p && strprefixeq(path, p - path, child->name))
 			return get_node_by_path(child, p+1);
 		else if (!p && streq(path, child->name))
 			return child;
-- 
2.21.0

Re: [PATCH] scripts/dtc: Simplify condition in get_node_by_path

[Frank Rowand]

Hi Denis,

On 8/27/19 7:57 AM, Denis Efremov wrote:
> The strlen && strprefixeq check in get_node_by_path is
> excessive, since strlen is checked in strprefixeq macro
> internally. Thus, 'strlen(child->name) == p-path'
> conjunct duplicates after macro expansion and could
> be removed.
> 
> Signed-off-by: Denis Efremov <efremov@linux.com>
> ---
>  scripts/dtc/livetree.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/scripts/dtc/livetree.c b/scripts/dtc/livetree.c
> index 0c039993953a..032df5878ccc 100644
> --- a/scripts/dtc/livetree.c
> +++ b/scripts/dtc/livetree.c
> @@ -526,8 +526,7 @@ struct node *get_node_by_path(struct node *tree, const char *path)
>  	p = strchr(path, '/');
>  
>  	for_each_child(tree, child) {
> -		if (p && (strlen(child->name) == p-path) &&
> -		    strprefixeq(path, p - path, child->name))
> +		if (p && strprefixeq(path, p - path, child->name))
>  			return get_node_by_path(child, p+1);
>  		else if (!p && streq(path, child->name))
>  			return child;
> 

livetree.c is maintained in the upstream dtc project.  We pull changes
from that project into the Linux kernel source tree.

Info on submitting patches is in the upstream file "Documentation/manual.txt":

   1) Sources

   Source code for the Device Tree Compiler can be found at git.kernel.org.

   The upstream repository is here:

       git://git.kernel.org/pub/scm/utils/dtc/dtc.git
       https://git.kernel.org/pub/scm/utils/dtc/dtc.git

   The gitweb interface for the upstream respository is:

       https://git.kernel.org/cgit/utils/dtc/dtc.git/

   1.1) Submitting Patches

   Patches should be sent to the maintainers:
           David Gibson <david@gibson.dropbear.id.au>
           Jon Loeliger <jdl@jdl.com>
   and CCed to <devicetree-compiler@vger.kernel.org>.