From patchwork Fri Apr 27 18:56:36 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Mahoney X-Patchwork-Id: 10369641 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 2FB54601D3 for ; Fri, 27 Apr 2018 18:56:57 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1F639291B0 for ; Fri, 27 Apr 2018 18:56:57 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 143652921A; Fri, 27 Apr 2018 18:56:57 +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=ham 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 53D20291B0 for ; Fri, 27 Apr 2018 18:56:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758282AbeD0S4y (ORCPT ); Fri, 27 Apr 2018 14:56:54 -0400 Received: from mx2.suse.de ([195.135.220.15]:42190 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758020AbeD0S4x (ORCPT ); Fri, 27 Apr 2018 14:56:53 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 2AAFBADAE for ; Fri, 27 Apr 2018 18:56:52 +0000 (UTC) Received: from sled4.home.jeffm.io (sled4.home.jeffm.io [IPv6:2001:559:c0d4:6f::8]) by mail.home.jeffm.io (Postfix) with ESMTPS id BF76481AD3E6; Fri, 27 Apr 2018 14:56:19 -0400 (EDT) Received: by sled4.home.jeffm.io (Postfix, from userid 1000) id 5D9A33F68; Fri, 27 Apr 2018 14:56:38 -0400 (EDT) From: jeffm@suse.com To: linux-btrfs@vger.kernel.org Cc: dsterba@suse.com, Jeff Mahoney Subject: [PATCH 2/3] btrfs-progs: build: detect whether -std=gnu90 is supported Date: Fri, 27 Apr 2018 14:56:36 -0400 Message-Id: <20180427185637.16642-3-jeffm@suse.com> X-Mailer: git-send-email 2.12.3 In-Reply-To: <20180427185637.16642-1-jeffm@suse.com> References: <20180427185637.16642-1-jeffm@suse.com> Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Jeff Mahoney Older versions of gcc don't support -std=gnu90 so btrfs-progs won't build at all on older distros. We can detect whether the compiler supports -std=gnu90 and fall back to -std=gnu89 if it doesn't. Signed-off-by: Jeff Mahoney --- Makefile | 1 - Makefile.inc.in | 1 + configure.ac | 2 ++ m4/ax_check_compile_flag.m4 | 74 +++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 77 insertions(+), 1 deletion(-) create mode 100644 m4/ax_check_compile_flag.m4 diff --git a/Makefile b/Makefile index 5ba76d2e..c0eb3d68 100644 --- a/Makefile +++ b/Makefile @@ -63,7 +63,6 @@ ABSTOPDIR = $(shell pwd) TOPDIR := . # Common build flags -CSTD = -std=gnu90 CFLAGS = $(SUBST_CFLAGS) \ $(CSTD) \ -include config.h \ diff --git a/Makefile.inc.in b/Makefile.inc.in index 52410f69..fc3dec69 100644 --- a/Makefile.inc.in +++ b/Makefile.inc.in @@ -4,6 +4,7 @@ export CC = @CC@ +CSTD = @CSTD@ LN_S = @LN_S@ AR = @AR@ RM = @RM@ diff --git a/configure.ac b/configure.ac index 2dea1c64..17880206 100644 --- a/configure.ac +++ b/configure.ac @@ -30,6 +30,8 @@ AC_CANONICAL_HOST AC_C_CONST AC_C_VOLATILE AC_C_BIGENDIAN +AX_CHECK_COMPILE_FLAG([-std=gnu90],[CSTD=-std=gnu90],[CSTD=-std=gnu89]) +AC_SUBST([CSTD]) AC_SYS_LARGEFILE diff --git a/m4/ax_check_compile_flag.m4 b/m4/ax_check_compile_flag.m4 new file mode 100644 index 00000000..dcabb92a --- /dev/null +++ b/m4/ax_check_compile_flag.m4 @@ -0,0 +1,74 @@ +# =========================================================================== +# https://www.gnu.org/software/autoconf-archive/ax_check_compile_flag.html +# =========================================================================== +# +# SYNOPSIS +# +# AX_CHECK_COMPILE_FLAG(FLAG, [ACTION-SUCCESS], [ACTION-FAILURE], [EXTRA-FLAGS], [INPUT]) +# +# DESCRIPTION +# +# Check whether the given FLAG works with the current language's compiler +# or gives an error. (Warnings, however, are ignored) +# +# ACTION-SUCCESS/ACTION-FAILURE are shell commands to execute on +# success/failure. +# +# If EXTRA-FLAGS is defined, it is added to the current language's default +# flags (e.g. CFLAGS) when the check is done. The check is thus made with +# the flags: "CFLAGS EXTRA-FLAGS FLAG". This can for example be used to +# force the compiler to issue an error when a bad flag is given. +# +# INPUT gives an alternative input source to AC_COMPILE_IFELSE. +# +# NOTE: Implementation based on AX_CFLAGS_GCC_OPTION. Please keep this +# macro in sync with AX_CHECK_{PREPROC,LINK}_FLAG. +# +# LICENSE +# +# Copyright (c) 2008 Guido U. Draheim +# Copyright (c) 2011 Maarten Bosmans +# +# This program is free software: you can redistribute it and/or modify it +# under the terms of the GNU General Public License as published by the +# Free Software Foundation, either version 3 of the License, or (at your +# option) any later version. +# +# This program is distributed in the hope that it will be useful, but +# WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General +# Public License for more details. +# +# You should have received a copy of the GNU General Public License along +# with this program. If not, see . +# +# As a special exception, the respective Autoconf Macro's copyright owner +# gives unlimited permission to copy, distribute and modify the configure +# scripts that are the output of Autoconf when processing the Macro. You +# need not follow the terms of the GNU General Public License when using +# or distributing such scripts, even though portions of the text of the +# Macro appear in them. The GNU General Public License (GPL) does govern +# all other use of the material that constitutes the Autoconf Macro. +# +# This special exception to the GPL applies to versions of the Autoconf +# Macro released by the Autoconf Archive. When you make and distribute a +# modified version of the Autoconf Macro, you may extend this special +# exception to the GPL to apply to your modified version as well. + +#serial 5 + +AC_DEFUN([AX_CHECK_COMPILE_FLAG], +[AC_PREREQ(2.64)dnl for _AC_LANG_PREFIX and AS_VAR_IF +AS_VAR_PUSHDEF([CACHEVAR],[ax_cv_check_[]_AC_LANG_ABBREV[]flags_$4_$1])dnl +AC_CACHE_CHECK([whether _AC_LANG compiler accepts $1], CACHEVAR, [ + ax_check_save_flags=$[]_AC_LANG_PREFIX[]FLAGS + _AC_LANG_PREFIX[]FLAGS="$[]_AC_LANG_PREFIX[]FLAGS $4 $1" + AC_COMPILE_IFELSE([m4_default([$5],[AC_LANG_PROGRAM()])], + [AS_VAR_SET(CACHEVAR,[yes])], + [AS_VAR_SET(CACHEVAR,[no])]) + _AC_LANG_PREFIX[]FLAGS=$ax_check_save_flags]) +AS_VAR_IF(CACHEVAR,yes, + [m4_default([$2], :)], + [m4_default([$3], :)]) +AS_VAR_POPDEF([CACHEVAR])dnl +])dnl AX_CHECK_COMPILE_FLAGS