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=-15.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 1431FC10F00 for ; Fri, 6 Mar 2020 19:12:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DCDD620714 for ; Fri, 6 Mar 2020 19:12:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583521922; bh=0brzviW2dYOg5GL5dKyfk0SiCXoOUz8EnoaLxh/ehkI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=I/utW/HvuIGi0rPhh3qoGiHtyNYsPj2hdzqDWurNzWSHaB47obgVHhr+DKRuSLeBL h1iqOO/ouTrfzQxFh2aOObuxYTNga0AgYuhhfh37ZYqNz1ytbPrsJjFBPvODMpdJZ+ DIGQnRBrOQt6AGtihVOueJn/w6JVLI3pgE0IUuXg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726932AbgCFTMB (ORCPT ); Fri, 6 Mar 2020 14:12:01 -0500 Received: from mail.kernel.org ([198.145.29.99]:39088 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726162AbgCFTL6 (ORCPT ); Fri, 6 Mar 2020 14:11:58 -0500 Received: from quaco.ghostprotocols.net (unknown [179.97.37.151]) (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 B6C3F20684; Fri, 6 Mar 2020 19:11:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583521917; bh=0brzviW2dYOg5GL5dKyfk0SiCXoOUz8EnoaLxh/ehkI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AdeQPfMv30VMnWpv3eu9QEyqZHKlxolxDt9lSBWZW2wLZmbVWx77N2n/TAa0gUCsz qgv0HWTZ3LJqX0LWgxIIpGsdWOIvY00g7lziKrWLZ5E9Nxp79QHbX0voKK/ZoKdF0e IBdHELhWVGr7hlF+TIwviD/CHXHNz+3kCc2kObm8= From: Arnaldo Carvalho de Melo To: Ingo Molnar , Thomas Gleixner Cc: Jiri Olsa , Namhyung Kim , Clark Williams , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Nick Desaulniers , Ian Rogers , Alexander Shishkin , Changbin Du , Jin Yao , Jiri Olsa , John Keeping , Mark Rutland , Peter Zijlstra , Song Liu , clang-built-linux@googlegroups.com, Arnaldo Carvalho de Melo Subject: [PATCH 1/6] perf diff: Fix undefined string comparision spotted by clang's -Wstring-compare Date: Fri, 6 Mar 2020 16:11:34 -0300 Message-Id: <20200306191144.12762-2-acme@kernel.org> X-Mailer: git-send-email 2.21.1 In-Reply-To: <20200306191144.12762-1-acme@kernel.org> References: <20200306191144.12762-1-acme@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Nick Desaulniers clang warns: util/block-info.c:298:18: error: result of comparison against a string literal is unspecified (use an explicit string comparison function instead) [-Werror,-Wstring-compare] if ((start_line != SRCLINE_UNKNOWN) && (end_line != SRCLINE_UNKNOWN)) { ^ ~~~~~~~~~~~~~~~ util/block-info.c:298:51: error: result of comparison against a string literal is unspecified (use an explicit string comparison function instead) [-Werror,-Wstring-compare] if ((start_line != SRCLINE_UNKNOWN) && (end_line != SRCLINE_UNKNOWN)) { ^ ~~~~~~~~~~~~~~~ util/block-info.c:298:18: error: result of comparison against a string literal is unspecified (use an explicit string comparison function instead) [-Werror,-Wstring-compare] if ((start_line != SRCLINE_UNKNOWN) && (end_line != SRCLINE_UNKNOWN)) { ^ ~~~~~~~~~~~~~~~ util/block-info.c:298:51: error: result of comparison against a string literal is unspecified (use an explicit string comparison function instead) [-Werror,-Wstring-compare] if ((start_line != SRCLINE_UNKNOWN) && (end_line != SRCLINE_UNKNOWN)) { ^ ~~~~~~~~~~~~~~~ util/map.c:434:15: error: result of comparison against a string literal is unspecified (use an explicit string comparison function instead) [-Werror,-Wstring-compare] if (srcline != SRCLINE_UNKNOWN) ^ ~~~~~~~~~~~~~~~ Reviewer Notes: Looks good to me. Some more context: https://clang.llvm.org/docs/DiagnosticsReference.html#wstring-compare The spec says: J.1 Unspecified behavior The following are unspecified: .. Whether two string literals result in distinct arrays (6.4.5). Signed-off-by: Nick Desaulniers Reviewed-by: Ian Rogers Cc: Alexander Shishkin Cc: Changbin Du Cc: Jin Yao Cc: Jiri Olsa Cc: John Keeping Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Song Liu Cc: clang-built-linux@googlegroups.com Link: https://github.com/ClangBuiltLinux/linux/issues/900 Link: http://lore.kernel.org/lkml/20200223193456.25291-1-nick.desaulniers@gmail.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-diff.c | 3 ++- tools/perf/util/block-info.c | 3 ++- tools/perf/util/map.c | 2 +- 3 files changed, 5 insertions(+), 3 deletions(-) diff --git a/tools/perf/builtin-diff.c b/tools/perf/builtin-diff.c index f8b6ae557d8b..c03c36fde7e2 100644 --- a/tools/perf/builtin-diff.c +++ b/tools/perf/builtin-diff.c @@ -1312,7 +1312,8 @@ static int cycles_printf(struct hist_entry *he, struct hist_entry *pair, end_line = map__srcline(he->ms.map, bi->sym->start + bi->end, he->ms.sym); - if ((start_line != SRCLINE_UNKNOWN) && (end_line != SRCLINE_UNKNOWN)) { + if ((strncmp(start_line, SRCLINE_UNKNOWN, strlen(SRCLINE_UNKNOWN)) != 0) && + (strncmp(end_line, SRCLINE_UNKNOWN, strlen(SRCLINE_UNKNOWN)) != 0)) { scnprintf(buf, sizeof(buf), "[%s -> %s] %4ld", start_line, end_line, block_he->diff.cycles); } else { diff --git a/tools/perf/util/block-info.c b/tools/perf/util/block-info.c index c4b030bf6ec2..fbbb6d640dad 100644 --- a/tools/perf/util/block-info.c +++ b/tools/perf/util/block-info.c @@ -295,7 +295,8 @@ static int block_range_entry(struct perf_hpp_fmt *fmt, struct perf_hpp *hpp, end_line = map__srcline(he->ms.map, bi->sym->start + bi->end, he->ms.sym); - if ((start_line != SRCLINE_UNKNOWN) && (end_line != SRCLINE_UNKNOWN)) { + if ((strncmp(start_line, SRCLINE_UNKNOWN, strlen(SRCLINE_UNKNOWN)) != 0) && + (strncmp(end_line, SRCLINE_UNKNOWN, strlen(SRCLINE_UNKNOWN)) != 0)) { scnprintf(buf, sizeof(buf), "[%s -> %s]", start_line, end_line); } else { diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c index a08ca276098e..95428511300d 100644 --- a/tools/perf/util/map.c +++ b/tools/perf/util/map.c @@ -431,7 +431,7 @@ int map__fprintf_srcline(struct map *map, u64 addr, const char *prefix, if (map && map->dso) { char *srcline = map__srcline(map, addr, NULL); - if (srcline != SRCLINE_UNKNOWN) + if (strncmp(srcline, SRCLINE_UNKNOWN, strlen(SRCLINE_UNKNOWN)) != 0) ret = fprintf(fp, "%s%s", prefix, srcline); free_srcline(srcline); } -- 2.21.1