From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-11.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C1318C32793 for ; Sun, 29 Sep 2019 20:07:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A71E82190F for ; Sun, 29 Sep 2019 20:07:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729239AbfI2UHv (ORCPT ); Sun, 29 Sep 2019 16:07:51 -0400 Received: from mail.kernel.org ([198.145.29.99]:59370 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729057AbfI2UHu (ORCPT ); Sun, 29 Sep 2019 16:07:50 -0400 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4BBDF21906; Sun, 29 Sep 2019 20:07:49 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.92) (envelope-from ) id 1iEfTw-00081l-GK; Sun, 29 Sep 2019 16:07:48 -0400 Message-Id: <20190929200748.397303700@goodmis.org> User-Agent: quilt/0.65 Date: Sun, 29 Sep 2019 16:06:44 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Nick Desaulniers , Nathan Chancellor Subject: [for-linus][PATCH 2/5] tracing: Fix clang -Wint-in-bool-context warnings in IF_ASSIGN macro References: <20190929200642.036511084@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Nathan Chancellor After r372664 in clang, the IF_ASSIGN macro causes a couple hundred warnings along the lines of: kernel/trace/trace_output.c:1331:2: warning: converting the enum constant to a boolean [-Wint-in-bool-context] kernel/trace/trace.h:409:3: note: expanded from macro 'trace_assign_type' IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry, ^ kernel/trace/trace.h:371:14: note: expanded from macro 'IF_ASSIGN' WARN_ON(id && (entry)->type != id); \ ^ 264 warnings generated. This warning can catch issues with constructs like: if (state == A || B) where the developer really meant: if (state == A || state == B) This is currently the only occurrence of the warning in the kernel tree across defconfig, allyesconfig, allmodconfig for arm32, arm64, and x86_64. Add the implicit '!= 0' to the WARN_ON statement to fix the warnings and find potential issues in the future. Link: https://github.com/llvm/llvm-project/commit/28b38c277a2941e9e891b2db30652cfd962f070b Link: https://github.com/ClangBuiltLinux/linux/issues/686 Link: http://lkml.kernel.org/r/20190926162258.466321-1-natechancellor@gmail.com Reviewed-by: Nick Desaulniers Signed-off-by: Nathan Chancellor Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace.h | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 26b0a08f3c7d..f801d154ff6a 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -365,11 +365,11 @@ static inline struct trace_array *top_trace_array(void) __builtin_types_compatible_p(typeof(var), type *) #undef IF_ASSIGN -#define IF_ASSIGN(var, entry, etype, id) \ - if (FTRACE_CMP_TYPE(var, etype)) { \ - var = (typeof(var))(entry); \ - WARN_ON(id && (entry)->type != id); \ - break; \ +#define IF_ASSIGN(var, entry, etype, id) \ + if (FTRACE_CMP_TYPE(var, etype)) { \ + var = (typeof(var))(entry); \ + WARN_ON(id != 0 && (entry)->type != id); \ + break; \ } /* Will cause compile errors if type is not found. */ -- 2.20.1