From ea631f6fb8dbffe3081ecf29eafa62ecd38ec64f Mon Sep 17 00:00:00 2001 From: Michael Brown Date: Mon, 8 Nov 2010 02:51:18 +0000 Subject: [list] Add list_first_entry() There are several points in the iPXE codebase where list_for_each_entry() is (ab)used to extract only the first entry from a list. Add a macro list_first_entry() to make this code easier to read. Signed-off-by: Michael Brown --- src/include/ipxe/list.h | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'src/include/ipxe') diff --git a/src/include/ipxe/list.h b/src/include/ipxe/list.h index fb00bc531..ab4c119dd 100644 --- a/src/include/ipxe/list.h +++ b/src/include/ipxe/list.h @@ -157,6 +157,19 @@ static inline int list_empty ( const struct list_head *list ) { list_check ( (list) ); \ container_of ( list, type, member ); } ) +/** + * Get the container of the first entry in a list + * + * @v list List head + * @v type Containing type + * @v member Name of list field within containing type + * @ret first First list entry, or NULL + */ +#define list_first_entry( list, type, member ) \ + ( list_empty ( (list) ) ? \ + ( type * ) NULL : \ + list_entry ( (list)->next, type, member ) ) + /** * Iterate over entries in a list * -- cgit v1.2.3-55-g7522