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=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, 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 603C8C433DF for ; Thu, 20 Aug 2020 12:23:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 38A2B2078B for ; Thu, 20 Aug 2020 12:23:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597926204; bh=RmLckhIPfgcJl8zmFnS8sQ6RL1VKiWUn8UZASjLEwOM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=HnBb3nIdYE1DtqPzvN2s0F9MwT/G2ATfZtXuzk8nX+FePexeDXOV6Z6p7/x20QsiW BZ5wIRxkX7WQzUu7Wm5lCgearsztEoIuj3muEFlSO9aLTBsZgWb4s67gzseCkwVPRe PWNX9QTy+NGRwu6KdZVvjXW45iR00XZxhGlkpIcY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728018AbgHTMXW (ORCPT ); Thu, 20 Aug 2020 08:23:22 -0400 Received: from mail.kernel.org ([198.145.29.99]:37450 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729985AbgHTJyo (ORCPT ); Thu, 20 Aug 2020 05:54:44 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 EEDD62067C; Thu, 20 Aug 2020 09:54:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597917283; bh=RmLckhIPfgcJl8zmFnS8sQ6RL1VKiWUn8UZASjLEwOM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CpAhENYVFiWkEaY5LPL93zN+0ydB2Z0sS1xwbRp4yt9cVDlHa6kAxLUMgRhsNe+lO T3bDK89XL7VP/lict5GqzGPCP/ZWRdvvFCOYnyLl/vuPs4nNtDuT4uhATyxhPNgCOf jNSNQDxAI2+kwkdqI5ZKc62MT0xl9epkd0PpB/KY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Thomas Hebb , Jiri Olsa , David Carrillo-Cisneros , Ian Rogers , Igor Lubashev , Namhyung Kim , Quentin Monnet , Song Liu , Stephane Eranian , Arnaldo Carvalho de Melo , Sasha Levin Subject: [PATCH 4.19 68/92] tools build feature: Use CC and CXX from parent Date: Thu, 20 Aug 2020 11:21:53 +0200 Message-Id: <20200820091541.153941323@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200820091537.490965042@linuxfoundation.org> References: <20200820091537.490965042@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Thomas Hebb [ Upstream commit e3232c2f39acafd5a29128425bc30b9884642cfa ] commit c8c188679ccf ("tools build: Use the same CC for feature detection and actual build") changed these assignments from unconditional (:=) to conditional (?=) so that they wouldn't clobber values from the environment. However, conditional assignment does not work properly for variables that Make implicitly sets, among which are CC and CXX. To quote tools/scripts/Makefile.include, which handles this properly: # Makefiles suck: This macro sets a default value of $(2) for the # variable named by $(1), unless the variable has been set by # environment or command line. This is necessary for CC and AR # because make sets default values, so the simpler ?= approach # won't work as expected. In other words, the conditional assignments will not run even if the variables are not overridden in the environment; Make will set CC to "cc" and CXX to "g++" when it starts[1], meaning the variables are not empty by the time the conditional assignments are evaluated. This breaks cross-compilation when CROSS_COMPILE is set but CC isn't, since "cc" gets used for feature detection instead of the cross compiler (and likewise for CXX). To fix the issue, just pass down the values of CC and CXX computed by the parent Makefile, which gets included by the Makefile that actually builds whatever we're detecting features for and so is guaranteed to have good values. This is a better solution anyway, since it means we aren't trying to replicate the logic of the parent build system and so don't risk it getting out of sync. Leave PKG_CONFIG alone, since 1) there's no common logic to compute it in Makefile.include, and 2) it's not an implicit variable, so conditional assignment works properly. [1] https://www.gnu.org/software/make/manual/html_node/Implicit-Variables.html Fixes: c8c188679ccf ("tools build: Use the same CC for feature detection and actual build") Signed-off-by: Thomas Hebb Acked-by: Jiri Olsa Cc: David Carrillo-Cisneros Cc: Ian Rogers Cc: Igor Lubashev Cc: Namhyung Kim Cc: Quentin Monnet Cc: Song Liu Cc: Stephane Eranian Cc: thomas hebb Link: http://lore.kernel.org/lkml/0a6e69d1736b0fa231a648f50b0cce5d8a6734ef.1595822871.git.tommyhebb@gmail.com Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin --- tools/build/Makefile.feature | 2 +- tools/build/feature/Makefile | 2 -- 2 files changed, 1 insertion(+), 3 deletions(-) diff --git a/tools/build/Makefile.feature b/tools/build/Makefile.feature index 42a787856cd87..7d9d70c0b3800 100644 --- a/tools/build/Makefile.feature +++ b/tools/build/Makefile.feature @@ -7,7 +7,7 @@ endif feature_check = $(eval $(feature_check_code)) define feature_check_code - feature-$(1) := $(shell $(MAKE) OUTPUT=$(OUTPUT_FEATURES) CFLAGS="$(EXTRA_CFLAGS) $(FEATURE_CHECK_CFLAGS-$(1))" CXXFLAGS="$(EXTRA_CXXFLAGS) $(FEATURE_CHECK_CXXFLAGS-$(1))" LDFLAGS="$(LDFLAGS) $(FEATURE_CHECK_LDFLAGS-$(1))" -C $(feature_dir) $(OUTPUT_FEATURES)test-$1.bin >/dev/null 2>/dev/null && echo 1 || echo 0) + feature-$(1) := $(shell $(MAKE) OUTPUT=$(OUTPUT_FEATURES) CC=$(CC) CXX=$(CXX) CFLAGS="$(EXTRA_CFLAGS) $(FEATURE_CHECK_CFLAGS-$(1))" CXXFLAGS="$(EXTRA_CXXFLAGS) $(FEATURE_CHECK_CXXFLAGS-$(1))" LDFLAGS="$(LDFLAGS) $(FEATURE_CHECK_LDFLAGS-$(1))" -C $(feature_dir) $(OUTPUT_FEATURES)test-$1.bin >/dev/null 2>/dev/null && echo 1 || echo 0) endef feature_set = $(eval $(feature_set_code)) diff --git a/tools/build/feature/Makefile b/tools/build/feature/Makefile index bf8a8ebcca1eb..c4845b66b9baa 100644 --- a/tools/build/feature/Makefile +++ b/tools/build/feature/Makefile @@ -62,8 +62,6 @@ FILES= \ FILES := $(addprefix $(OUTPUT),$(FILES)) -CC ?= $(CROSS_COMPILE)gcc -CXX ?= $(CROSS_COMPILE)g++ PKG_CONFIG ?= $(CROSS_COMPILE)pkg-config LLVM_CONFIG ?= llvm-config -- 2.25.1