From 135b98c26456adbfbc72fb12e4753ee0716b1f92 Mon Sep 17 00:00:00 2001 From: Tavian Barnes Date: Tue, 28 Mar 2023 14:18:08 -0400 Subject: list: New generic linked list API --- src/config.h | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'src/config.h') diff --git a/src/config.h b/src/config.h index 34ae11d..cee8511 100644 --- a/src/config.h +++ b/src/config.h @@ -147,6 +147,17 @@ */ #define BFS_COUNTOF(array) (sizeof(array) / sizeof(0[array])) +// BFS_CONTAINER_OF() helper +static inline char *bfs_container_offset(char *ptr, ptrdiff_t offset, size_t unused) { + return ptr ? ptr - offset : NULL; +} + +/** + * Move a pointer from a field to its outer struct. + */ +#define BFS_CONTAINER_OF(ptr, type, member) \ + ((type *)bfs_container_offset((char *)(ptr), offsetof(type, member), sizeof((ptr) - &((type *)NULL)->member))) + // Lower bound on BFS_FLEX_SIZEOF() #define BFS_FLEX_LB(type, member, length) (offsetof(type, member) + sizeof(((type *)NULL)->member[0]) * (length)) -- cgit v1.2.3