From patchwork Thu Sep 6 09:19:24 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 10590191 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 4C0DD14BD for ; Thu, 6 Sep 2018 09:19:33 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 38ED02A400 for ; Thu, 6 Sep 2018 09:19:33 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2CFB52A40A; Thu, 6 Sep 2018 09:19:33 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CAD492A400 for ; Thu, 6 Sep 2018 09:19:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728679AbeIFNx6 (ORCPT ); Thu, 6 Sep 2018 09:53:58 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:36168 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728650AbeIFNx6 (ORCPT ); Thu, 6 Sep 2018 09:53:58 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id C5FD840241D4; Thu, 6 Sep 2018 09:19:25 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-123-84.rdu2.redhat.com [10.10.123.84]) by smtp.corp.redhat.com (Postfix) with ESMTP id E581D105543F; Thu, 6 Sep 2018 09:19:24 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH 09/11] UAPI: ndctl: Fix g++-unsupported initialisation in headers [ver #2] From: David Howells To: linux-api@vger.kernel.org, linux-kbuild@vger.kernel.org Cc: Dan Williams , linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org, dhowells@redhat.com Date: Thu, 06 Sep 2018 10:19:24 +0100 Message-ID: <153622556444.14298.5971956747198405225.stgit@warthog.procyon.org.uk> In-Reply-To: <153622549721.14298.8116794954073122489.stgit@warthog.procyon.org.uk> References: <153622549721.14298.8116794954073122489.stgit@warthog.procyon.org.uk> User-Agent: StGit/unknown-version MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.78 on 10.11.54.3 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.7]); Thu, 06 Sep 2018 09:19:25 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.7]); Thu, 06 Sep 2018 09:19:25 +0000 (UTC) for IP:'10.11.54.3' DOMAIN:'int-mx03.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'dhowells@redhat.com' RCPT:'' Sender: linux-kbuild-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The following code in the linux/ndctl header file: static inline const char *nvdimm_bus_cmd_name(unsigned cmd) { static const char * const names[] = { [ND_CMD_ARS_CAP] = "ars_cap", [ND_CMD_ARS_START] = "ars_start", [ND_CMD_ARS_STATUS] = "ars_status", [ND_CMD_CLEAR_ERROR] = "clear_error", [ND_CMD_CALL] = "cmd_call", }; if (cmd < ARRAY_SIZE(names) && names[cmd]) return names[cmd]; return "unknown"; } is broken in a number of ways: (1) ARRAY_SIZE() is not generally defined. (2) g++ does not support "non-trivial" array initialisers fully yet. (3) Every file that calls this function will acquire a copy of names[]. The same goes for nvdimm_cmd_name(). Fix all three by converting to a switch statement where each case returns a string. That way if cmd is a constant, the compiler can trivially reduce it and, if not, the compiler can use a shared lookup table if it thinks that is more efficient. A better way would be to remove these functions and their arrays from the header entirely. Signed-off-by: David Howells cc: Dan Williams cc: linux-nvdimm@lists.01.org Acked-by: Dan Williams --- include/uapi/linux/ndctl.h | 48 +++++++++++++++++++------------------------- 1 file changed, 21 insertions(+), 27 deletions(-) diff --git a/include/uapi/linux/ndctl.h b/include/uapi/linux/ndctl.h index 7e27070b9440..2f2c43d633c5 100644 --- a/include/uapi/linux/ndctl.h +++ b/include/uapi/linux/ndctl.h @@ -128,37 +128,31 @@ enum { static inline const char *nvdimm_bus_cmd_name(unsigned cmd) { - static const char * const names[] = { - [ND_CMD_ARS_CAP] = "ars_cap", - [ND_CMD_ARS_START] = "ars_start", - [ND_CMD_ARS_STATUS] = "ars_status", - [ND_CMD_CLEAR_ERROR] = "clear_error", - [ND_CMD_CALL] = "cmd_call", - }; - - if (cmd < ARRAY_SIZE(names) && names[cmd]) - return names[cmd]; - return "unknown"; + switch (cmd) { + case ND_CMD_ARS_CAP: return "ars_cap"; + case ND_CMD_ARS_START: return "ars_start"; + case ND_CMD_ARS_STATUS: return "ars_status"; + case ND_CMD_CLEAR_ERROR: return "clear_error"; + case ND_CMD_CALL: return "cmd_call"; + default: return "unknown"; + } } static inline const char *nvdimm_cmd_name(unsigned cmd) { - static const char * const names[] = { - [ND_CMD_SMART] = "smart", - [ND_CMD_SMART_THRESHOLD] = "smart_thresh", - [ND_CMD_DIMM_FLAGS] = "flags", - [ND_CMD_GET_CONFIG_SIZE] = "get_size", - [ND_CMD_GET_CONFIG_DATA] = "get_data", - [ND_CMD_SET_CONFIG_DATA] = "set_data", - [ND_CMD_VENDOR_EFFECT_LOG_SIZE] = "effect_size", - [ND_CMD_VENDOR_EFFECT_LOG] = "effect_log", - [ND_CMD_VENDOR] = "vendor", - [ND_CMD_CALL] = "cmd_call", - }; - - if (cmd < ARRAY_SIZE(names) && names[cmd]) - return names[cmd]; - return "unknown"; + switch (cmd) { + case ND_CMD_SMART: return "smart"; + case ND_CMD_SMART_THRESHOLD: return "smart_thresh"; + case ND_CMD_DIMM_FLAGS: return "flags"; + case ND_CMD_GET_CONFIG_SIZE: return "get_size"; + case ND_CMD_GET_CONFIG_DATA: return "get_data"; + case ND_CMD_SET_CONFIG_DATA: return "set_data"; + case ND_CMD_VENDOR_EFFECT_LOG_SIZE: return "effect_size"; + case ND_CMD_VENDOR_EFFECT_LOG: return "effect_log"; + case ND_CMD_VENDOR: return "vendor"; + case ND_CMD_CALL: return "cmd_call"; + default: return "unknown"; + } } #define ND_IOCTL 'N'