From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-lf1-f44.google.com (mail-lf1-f44.google.com [209.85.167.44]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 877804C95 for ; Fri, 17 Jun 2022 23:26:16 +0000 (UTC) Received: by mail-lf1-f44.google.com with SMTP id be31so8988215lfb.10 for ; Fri, 17 Jun 2022 16:26:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=EXgpKpIVzT6qnZVCgCn3/+ZdUQI+LHK0/bEVe7Lb4mY=; b=hldD5704PosVIx7pUYS/I5Fkd39xNzHxffHQ4mZN1Dqeeuu2C4pwCxAQJNgtGLYwk9 w7FJIcrUIRSS7x7h7nxefPG9ErzMKZMCYjFXnwB6jDP9vW9l7w3v44r21dvY+UO/roaH DuoO8nTSDMIPRijv/rUkB+5O/ifpxQW5EsEk/kcxRq9igUh8BEY3NEIxapGHRXPEivrV mEubtXEvlefXACss71A3Yow9/ml9N4sTH4bxhcrDrh4VpAU+l17QlhYYZuNW98vzP9tg nWdM5nclxBc/2bwkBpTMkpG+KU30Q0CgYJD/wbMLZRWwW2OIMr9AzbNDc9dxSlEJaxPO Zx/w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=EXgpKpIVzT6qnZVCgCn3/+ZdUQI+LHK0/bEVe7Lb4mY=; b=dTCIww35p0uO2JvC9vDXHDHY8bvEnLXBzHibEcq9AC4n/iYxL5xra02RGxAfHFwuxZ KIN+JFGX91MOQ+85wrHpdLYuEizakae95A/XkzLZsymWoIAq1eae83M8cc/OIz0MWZVQ 3oj/2ZG9aNG5eldUhk173sfIaZJTtfWbY2jyWHXIWrbHTOB8Yso6hEfdYE6XbAktG39G IqTXSyJwnyXVK3qwLGZn+FyNA+GovII+uRt5dMotZqnaxsaKohtaPrjLdGRoVrzVw+7X QGhh/dSgH2b0bSfBxun3DbIwOP3PYOtp0CWKd8ApsX7I5wzJ27MIjLIHC1Tue+dJ6EFm cQ4A== X-Gm-Message-State: AJIora9ses0nJTfvBLBbOLgQ7rDoe4yUFcl1BjpoL180QGUOR1G7JRno VfT6Ld5xh9Sc0f+0DlqEQ9PzZAUmoYP4Z2l3hMsjow== X-Google-Smtp-Source: AGRyM1vuSCrUYcJ+fn+AGYw7Otfa1ERbN93s/Se2G5Qnqe8WDMwXm36GodOORpoZgx9wT9vyGeqywndfeQfffGCwypI= X-Received: by 2002:a05:6512:3f9f:b0:47d:c87e:f8f3 with SMTP id x31-20020a0565123f9f00b0047dc87ef8f3mr7012832lfa.401.1655508374233; Fri, 17 Jun 2022 16:26:14 -0700 (PDT) Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <20220617203948.3714905-1-ndesaulniers@google.com> In-Reply-To: From: Nick Desaulniers Date: Fri, 17 Jun 2022 16:26:02 -0700 Message-ID: Subject: Re: [PATCH] scripts/Makefile.clang: set --target for host based on make -v To: Nathan Chancellor Cc: Masahiro Yamada , Michal Marek , Tom Rix , Linux Kbuild mailing list , LKML , clang-built-linux Content-Type: text/plain; charset="UTF-8" On Fri, Jun 17, 2022 at 4:21 PM Nathan Chancellor wrote: > > On Fri, Jun 17, 2022 at 01:39:48PM -0700, Nick Desaulniers wrote: > > We're working on providing statically linked images of clang to host on > > kernel.org. We're building them in Alpine Linux based Docker containers, > > which are MUSL based systems. > > > > In order to keep bootstrapping simpler, I'd like for them to have an > > implicit default --target of x86_64-alpine-linux-musl (set via LLVM's > > cmake variable LLVM_DEFAULT_TARGET_TRIPLE). > > > > Similarly, if one were to use a different build of clang meant for a > > glibc or bionic based system on a MUSL based host, we'd prefer to use > > the correct MUSL based triple for target hosts. > > > > Borrowed from the Zen of Python: Explicit is better than implicit. Let's > > be explicit about the target triple for HOSTCC when building with > > HOSTCC=clang or LLVM=1. > > > > Signed-off-by: Nick Desaulniers > > I have tested this with a few different distributions on both aarch64 > and x86_64: > > Reviewed-by: Nathan Chancellor > Tested-by: Nathan Chancellor > > One small comment below. > > > --- > > Makefile | 3 +-- > > scripts/Makefile.clang | 10 ++++++++++ > > 2 files changed, 11 insertions(+), 2 deletions(-) > > > > diff --git a/Makefile b/Makefile > > index 1a6678d817bd..87712d9b043c 100644 > > --- a/Makefile > > +++ b/Makefile > > @@ -600,10 +600,9 @@ endif > > # CC_VERSION_TEXT is referenced from Kconfig (so it needs export), > > # and from include/config/auto.conf.cmd to detect the compiler upgrade. > > CC_VERSION_TEXT = $(subst $(pound),,$(shell LC_ALL=C $(CC) --version 2>/dev/null | head -n 1)) > > +HOSTCC_VERSION_TEXT = $(subst $(pound),,$(shell LC_ALL=C $(HOSTCC) --version 2>/dev/null | head -n 1)) > > > > -ifneq ($(findstring clang,$(CC_VERSION_TEXT)),) > > include $(srctree)/scripts/Makefile.clang > > -endif > > > > # Include this also for config targets because some architectures need > > # cc-cross-prefix to determine CROSS_COMPILE. > > diff --git a/scripts/Makefile.clang b/scripts/Makefile.clang > > index 87285b76adb2..a4505cd62d7b 100644 > > --- a/scripts/Makefile.clang > > +++ b/scripts/Makefile.clang > > @@ -1,3 +1,4 @@ > > +ifneq ($(findstring clang,$(CC_VERSION_TEXT)),) > > # Individual arch/{arch}/Makefiles should use -EL/-EB to set intended > > # endianness and -m32/-m64 to set word size based on Kconfigs instead of > > # relying on the target triple. > > @@ -39,3 +40,12 @@ CLANG_FLAGS += -Werror=ignored-optimization-argument > > KBUILD_CFLAGS += $(CLANG_FLAGS) > > KBUILD_AFLAGS += $(CLANG_FLAGS) > > export CLANG_FLAGS > > +endif > > + > > +# If HOSTCC is clang, set the host target triple explicitly; do not rely on > > +# implicit defaults. > > +ifneq ($(findstring clang,$(HOSTCC_VERSION_TEXT)),) > > +HOST_TRIPLE := --target=$(shell make --version | head -n2 | tail -n1 | cut -d ' ' -f 3) > > Should we use $(MAKE) instead of make here? I guess the only case where oh! yeah, good call. I think so. Will wait until next Tuesday (Juneteenth holiday in the US on Monday) to send a v2. Thanks for taking a look! > it would matter is if someone was calling make via an explicit path and > did not have it available in their PATH so maybe it is not worth > worrying about. > > > +KBUILD_HOSTCFLAGS += $(HOST_TRIPLE) > > +KBUILD_HOSTLDFLAGS += $(HOST_TRIPLE) > > +endif > > > > base-commit: 79fe0f863f920c5fcf9dea61676742f813f0b7a6 > > -- > > 2.36.1.476.g0c4daa206d-goog > > > > -- Thanks, ~Nick Desaulniers