From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt0-f199.google.com (mail-qt0-f199.google.com [209.85.216.199]) by kanga.kvack.org (Postfix) with ESMTP id 9B5186B0038 for ; Wed, 1 Feb 2017 11:40:36 -0500 (EST) Received: by mail-qt0-f199.google.com with SMTP id h56so153887870qtc.1 for ; Wed, 01 Feb 2017 08:40:36 -0800 (PST) Received: from mout.kundenserver.de (mout.kundenserver.de. [212.227.126.134]) by mx.google.com with ESMTPS id h125si24569424wme.3.2017.02.01.08.40.35 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 01 Feb 2017 08:40:35 -0800 (PST) From: Arnd Bergmann Subject: [PATCH] [RFC v2] sched: make DECLARE_COMPLETION_ONSTACK() work with clang Date: Wed, 1 Feb 2017 17:40:19 +0100 Message-Id: <20170201164030.2379546-1-arnd@arndb.de> Sender: owner-linux-mm@kvack.org List-ID: To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, Arnd Bergmann , Ingo Molnar 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 Signed-off-by: Arnd Bergmann --- v2: send the correct patch --- include/linux/completion.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/include/linux/completion.h b/include/linux/completion.h index 5d5aaae3af43..fa5d3efaba56 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); work; }) + (*init_completion(&work)) /** * DECLARE_COMPLETION - declare and initialize a completion structure @@ -70,10 +70,11 @@ struct completion { * This inline function will initialize a dynamically created completion * structure. */ -static inline void init_completion(struct completion *x) +static inline struct completion *init_completion(struct completion *x) { x->done = 0; init_waitqueue_head(&x->wait); + return x; } /** -- 2.9.0 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org