From 9d5fdcc5db1b5246028dc871e5f0fb908dd64771 Mon Sep 17 00:00:00 2001 From: Michael Forney Date: Wed, 14 Apr 2021 00:41:27 -0700 Subject: [PATCH] libext2fs: use statement-expression for container_of only on GNU-compatible compilers Functionally, the statement-expression is not necessary here; it just gives a bit of type-safety to make sure the pointer really does have a compatible type with the specified member of the struct. When statement expressions are not available, we can just use a portable fallback macro that skips this member type check. Signed-off-by: Michael Forney Signed-off-by: Theodore Ts'o --- lib/ext2fs/compiler.h | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/lib/ext2fs/compiler.h b/lib/ext2fs/compiler.h index 9aa9b4e..03c35ab 100644 --- a/lib/ext2fs/compiler.h +++ b/lib/ext2fs/compiler.h @@ -14,9 +14,14 @@ #define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER) #endif +#ifdef __GNUC__ #define container_of(ptr, type, member) ({ \ const __typeof__( ((type *)0)->member ) *__mptr = (ptr); \ (type *)( (char *)__mptr - offsetof(type,member) );}) +#else +#define container_of(ptr, type, member) \ + ((type *)((char *)(ptr) - offsetof(type, member))) +#endif #endif /* _EXT2FS_COMPILER_H */ -- 1.8.3.1