From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: + tools-build-tweak-unused-value-workaround.patch added to -mm tree Date: Tue, 14 Apr 2020 17:00:28 -0700 Message-ID: <20200415000028.0WXTVlaZl%akpm@linux-foundation.org> References: <20200412004155.1a8f4e081b4e03ef5903abb5@linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Return-path: Received: from mail.kernel.org ([198.145.29.99]:33394 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727849AbgDOAAa (ORCPT ); Tue, 14 Apr 2020 20:00:30 -0400 In-Reply-To: <20200412004155.1a8f4e081b4e03ef5903abb5@linux-foundation.org> Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: gbiv@google.com, mm-commits@vger.kernel.org, ndesaulniers@google.com The patch titled Subject: tools/build: tweak unused value workaround has been added to the -mm tree. Its filename is tools-build-tweak-unused-value-workaround.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/tools-build-tweak-unused-value-workaround.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/tools-build-tweak-unused-value-workaround.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: George Burgess IV Subject: tools/build: tweak unused value workaround Clang has -Wself-assign enabled by default under -Wall, which always gets -Werror'ed on this file, causing sync-compare-and-swap to be disabled by default. The generally-accepted way to spell "this value is intentionally unused," is casting it to `void`. This is accepted by both GCC and Clang with -Wall enabled: https://godbolt.org/z/qqZ9r3 Link: http://lkml.kernel.org/r/20200414195638.156123-1-gbiv@google.com Signed-off-by: George Burgess IV Cc: Nick Desaulniers Signed-off-by: Andrew Morton --- tools/build/feature/test-sync-compare-and-swap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/tools/build/feature/test-sync-compare-and-swap.c~tools-build-tweak-unused-value-workaround +++ a/tools/build/feature/test-sync-compare-and-swap.c @@ -7,7 +7,7 @@ int main(int argc, char *argv[]) { uint64_t old, new = argc; - argv = argv; + (void)argv; do { old = __sync_val_compare_and_swap(&x, 0, 0); } while (!__sync_bool_compare_and_swap(&x, old, new)); _ Patches currently in -mm which might be from gbiv@google.com are tools-build-tweak-unused-value-workaround.patch