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=-12.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 463D5C433ED for ; Sun, 11 Apr 2021 17:11:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0D12E6101D for ; Sun, 11 Apr 2021 17:11:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235366AbhDKRL1 (ORCPT ); Sun, 11 Apr 2021 13:11:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60154 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235095AbhDKRL1 (ORCPT ); Sun, 11 Apr 2021 13:11:27 -0400 Received: from mail-io1-xd2b.google.com (mail-io1-xd2b.google.com [IPv6:2607:f8b0:4864:20::d2b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B01E0C061574 for ; Sun, 11 Apr 2021 10:11:10 -0700 (PDT) Received: by mail-io1-xd2b.google.com with SMTP id b10so11023887iot.4 for ; Sun, 11 Apr 2021 10:11:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:reply-to:from:date:message-id :subject:to:cc; bh=4a63NpXNWAFDFa7yL9iq9bYB2QpG7WHimJG4F6v9UCk=; b=pP5FdiJhZelXhpzsoQgVzd2mb5kOds+mlWXM2UIgBpeRoG4w1HYF8aTyxmOYDyblBR aYi5IElc6zgF7PaV0PR7Mw1XxQFuEDGAFvZS6K6WJMwsjrAev+mVbdf7sKGfEwIWHzTT FNAyszU06QrmyRgrzaCSpKjkeXrKGzCZU7g4M1Um9kyFZGT9PJHVER9kr4U9FGe345G8 mdlOARVtSgKYAvzEwZ9qq9Q9/mh4MpLs5zwNKFkRDf389XeT3dJff9tvgkqIJHHDsyNg riOoVHbogCWRbp6DD2Zt4uiLxB4CD+R/n1tr6loEHrorg5bQN45ySTIFUpYGTlXt46tw BiCw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:reply-to :from:date:message-id:subject:to:cc; bh=4a63NpXNWAFDFa7yL9iq9bYB2QpG7WHimJG4F6v9UCk=; b=r80mfdRZW2LNUgpSifZaeCdX/20IkxHx0uImDvyFpB6KficiinYN9eoOE8VLwz/aED FI8vRzPFHQSyOtmw3EeMNYac0SPzkl7l/gm+/3mRv8ViiRkWu8AC+Uq+5Z6ax7VsCKKh v/Ay0xaJ58aXV2BqaZcI9KQgMTQY9A7PtMekzvZpFH7g9kt303aHnd2FrJDYU9kg/Be4 y/UgNxnxVA3P5XCOmWkEtQgjFz2QxDkb3rHAu+UEqikFQs0IQSiJFlUmpddLjzyiU6w4 JPQzLjDK7w9NXKxewEQa+Gw99JAUuT9owxdRlB09L2pua/ScyV40ApyytTOkILzXIkgW mR1g== X-Gm-Message-State: AOAM533j1AUIhMJLx3ZhidqPf3JULJfT5LAqcpQVywl+FmnJi6ktjIb7 a6n/XUxL9oovOqttLC2lSfQ4bZO/4mlHtnktWpE= X-Google-Smtp-Source: ABdhPJxu0Y1+B6NY5ptdaFzF6gwyTPQ107UrpF6OGfC5/yl54necR0uxrldN+bsFo8W6wKSPo8qGZ2BxIe0R/WRcwHI= X-Received: by 2002:a05:6638:35ab:: with SMTP id v43mr24409503jal.65.1618161070093; Sun, 11 Apr 2021 10:11:10 -0700 (PDT) MIME-Version: 1.0 References: <20210410164925.768741-1-yhs@fb.com> <20210410164930.769251-1-yhs@fb.com> In-Reply-To: Reply-To: sedat.dilek@gmail.com From: Sedat Dilek Date: Sun, 11 Apr 2021 19:10:34 +0200 Message-ID: Subject: Re: [PATCH bpf-next 1/5] selftests: set CC to clang in lib.mk if LLVM is set To: Yonghong Song Cc: bpf@vger.kernel.org, Andrii Nakryiko , Arnaldo Carvalho de Melo , kernel-team@fb.com, Nick Desaulniers Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Sun, Apr 11, 2021 at 6:51 PM Yonghong Song wrote: > > > > On 4/11/21 3:22 AM, Sedat Dilek wrote: > > On Sat, Apr 10, 2021 at 6:49 PM Yonghong Song wrote: > >> > >> selftests/bpf/Makefile includes lib.mk. With the following command > >> make -j60 LLVM=1 LLVM_IAS=1 <=== compile kernel > >> make -j60 -C tools/testing/selftests/bpf LLVM=1 LLVM_IAS=1 V=1 > >> some files are still compiled with gcc. This patch > >> fixed lib.mk issue which sets CC to gcc in all cases. > >> > >> Cc: Sedat Dilek > >> Signed-off-by: Yonghong Song > >> --- > >> tools/testing/selftests/lib.mk | 4 ++++ > >> 1 file changed, 4 insertions(+) > >> > >> diff --git a/tools/testing/selftests/lib.mk b/tools/testing/selftests/lib.mk > >> index a5ce26d548e4..9a41d8bb9ff1 100644 > >> --- a/tools/testing/selftests/lib.mk > >> +++ b/tools/testing/selftests/lib.mk > >> @@ -1,6 +1,10 @@ > >> # This mimics the top-level Makefile. We do it explicitly here so that this > >> # Makefile can operate with or without the kbuild infrastructure. > >> +ifneq ($(LLVM),) > >> +CC := clang > >> +else > >> CC := $(CROSS_COMPILE)gcc > >> +endif > >> > > > > Why not use include "include ../../../scripts/Makefile.include" here > > and include CC and GNU or LLVM (bin)utils from there? > > There is a comment above my change, > > >> # This mimics the top-level Makefile. We do it explicitly here so > that this > >> # Makefile can operate with or without the kbuild infrastructure. > > It is intentionally not depending on kbuild > (../../../scripts/Makefile.include). > > > > > Should the CC line have a $(CROSS_COMPILE) for people doing cross-compilation? > > > > CC := $(CROSS_COMPILE)clang > > The top linux/Makefile has > > ifneq ($(LLVM),) > CC = clang > LD = ld.lld > AR = llvm-ar > NM = llvm-nm > OBJCOPY = llvm-objcopy > OBJDUMP = llvm-objdump > READELF = llvm-readelf > STRIP = llvm-strip > else > CC = $(CROSS_COMPILE)gcc > LD = $(CROSS_COMPILE)ld > AR = $(CROSS_COMPILE)ar > NM = $(CROSS_COMPILE)nm > OBJCOPY = $(CROSS_COMPILE)objcopy > OBJDUMP = $(CROSS_COMPILE)objdump > READELF = $(CROSS_COMPILE)readelf > STRIP = $(CROSS_COMPILE)strip > endif > > There is no CROSS_COMPILE prefix for llvm. > Also see here: > https://clang.llvm.org/docs/CrossCompilation.html > for clang, cross compilation is mostly related to > tweaking compiler options than building a different > compiler. > > Hence, I didn't add $(CROSS_COMPILER) prefix. > OK, I see. My last cross-compilation for a linux-kernel is very long ago. I never used it with LLVM toolchain - might be $(CROSS_COMPILE) is only necessary with GNU toolchain. - Sedat - > > > > - Sedat - > > > > > >> ifeq (0,$(MAKELEVEL)) > >> ifeq ($(OUTPUT),) > >> -- > >> 2.30.2 > >>