Building with clang, we get a warning for each use of COMPLETION_INITIALIZER_ONSTACK, e.g.:
block/blk-exec.c:103:29: warning: variable 'wait' is uninitialized when used within its own initialization [-Wuninitialized] include/linux/completion.h:61:58: note: expanded from macro 'DECLARE_COMPLETION_ONSTACK' include/linux/completion.h:34:29: note: expanded from macro 'COMPLETION_INITIALIZER_ONSTACK' This seems to be a problem in clang, but it's relatively easy to work around by changing the assignment. I filed a bug against clang for the warning, but if we want to support old versions, we may want this change as well. I have not yet checked if the new version produces worse object code. Link: https://llvm.org/bugs/show_bug.cgi?id=31829 Cc: Ingo Molnar <[email protected]> Signed-off-by: Arnd Bergmann <[email protected]> --- include/linux/completion.h | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/include/linux/completion.h b/include/linux/completion.h index fa5d3efaba56..5d5aaae3af43 100644 --- a/include/linux/completion.h +++ b/include/linux/completion.h @@ -31,7 +31,7 @@ struct completion { { 0, __WAIT_QUEUE_HEAD_INITIALIZER((work).wait) } #define COMPLETION_INITIALIZER_ONSTACK(work) \ - (*init_completion(&work)) + ({ init_completion(&work); work; }) /** * DECLARE_COMPLETION - declare and initialize a completion structure @@ -70,11 +70,10 @@ struct completion { * This inline function will initialize a dynamically created completion * structure. */ -static inline struct completion *init_completion(struct completion *x) +static inline void init_completion(struct completion *x) { x->done = 0; init_waitqueue_head(&x->wait); - return x; } /** -- 2.9.0
