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=-9.0 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=unavailable 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 9A2BDC2BBCF for ; Fri, 18 Dec 2020 09:45:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 704ED23A82 for ; Fri, 18 Dec 2020 09:45:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389036AbgLRJow (ORCPT ); Fri, 18 Dec 2020 04:44:52 -0500 Received: from conssluserg-03.nifty.com ([210.131.2.82]:34447 "EHLO conssluserg-03.nifty.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725884AbgLRJov (ORCPT ); Fri, 18 Dec 2020 04:44:51 -0500 Received: from mail-pf1-f169.google.com (mail-pf1-f169.google.com [209.85.210.169]) (authenticated) by conssluserg-03.nifty.com with ESMTP id 0BI9hnaF028988; Fri, 18 Dec 2020 18:43:50 +0900 DKIM-Filter: OpenDKIM Filter v2.10.3 conssluserg-03.nifty.com 0BI9hnaF028988 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nifty.com; s=dec2015msa; t=1608284630; bh=alQmUM5+tWJqBj5AGDAC6yCMV4c4CFP866srY1VNulo=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=uW4s18H/citZM+QfCrscS8WfmMi/Mn4nct5x80/L9fR1m/GWAz3ZEpIJAyXvWBMVw F7xYudp8f+khjxr5Pi4qKWlTBzCqmuQHVQeY8hdJCKynAY2+IQ/W4zrpebm3IdkSJC 1ydLE4+FxHBqvW64Mc/tCRBSgjRbH1T7tpGl9EJeYGM7NtaR62IAyC6MLL8UTpgWjk yLnUIGKDC77pA5qEHCUFcJt0ikL0mZJa/oYcOPdvaEpTt4P8IDChI0Wq/mL7yUQh94 2WWzhahUkHIpKsrcJqLbn0rCBWpWnLboLhZjgBmFQ61I7VOPgaof3PhlljEubwki1k 1cDlqJgIB1/kw== X-Nifty-SrcIP: [209.85.210.169] Received: by mail-pf1-f169.google.com with SMTP id w6so1235918pfu.1; Fri, 18 Dec 2020 01:43:50 -0800 (PST) X-Gm-Message-State: AOAM532SOnYrZ1bLpARS0aONbyyjNZzXdn6Cwsz0WEigWHfh/HDUnZXv 1Yucjq41FYQbSl4ymbxcx9VFq5q20mIJhRGN5yM= X-Google-Smtp-Source: ABdhPJxhOqKe4b7iWEFn5mk6GAS2pz/7Os/zKCbpu4MrKTP1oYIv1m0VhMMQWsllL5LQ9mgudsNp7eeM2e/87DkdZO4= X-Received: by 2002:a65:6a16:: with SMTP id m22mr3370270pgu.175.1608284629399; Fri, 18 Dec 2020 01:43:49 -0800 (PST) MIME-Version: 1.0 References: <20201203125700.161354-1-masahiroy@kernel.org> In-Reply-To: From: Masahiro Yamada Date: Fri, 18 Dec 2020 18:43:12 +0900 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH] gcc-plugins: simplify GCC plugin-dev capability test To: Marek Szyprowski Cc: Linux Kbuild mailing list , Kees Cook , Emese Revfy , linux-hardening@vger.kernel.org, Linus Torvalds , Nathan Chancellor , Nick Desaulniers , clang-built-linux , Linux Kernel Mailing List Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Dec 18, 2020 at 4:58 PM Marek Szyprowski wrote: > > Hi, > > On 03.12.2020 13:57, Masahiro Yamada wrote: > > Linus pointed out a third of the time in the Kconfig parse stage comes > > from the single invocation of cc1plus in scripts/gcc-plugin.sh [1], > > and directly testing plugin-version.h for existence cuts down the > > overhead a lot. [2] > > > > This commit takes one step further to kill the build test entirely. > > > > The small piece of code was probably intended to test the C++ designated > > initializer, which was not supported until C++20. > > > > In fact, with -pedantic option given, both GCC and Clang emit a warning. > > > > $ echo 'class test { public: int test; } test = { .test = 1 };' | g++ -x c++ -pedantic - -fsyntax-only > > :1:43: warning: C++ designated initializers only available with '-std=c++2a' or '-std=gnu++2a' [-Wpedantic] > > $ echo 'class test { public: int test; } test = { .test = 1 };' | clang++ -x c++ -pedantic - -fsyntax-only > > :1:43: warning: designated initializers are a C++20 extension [-Wc++20-designator] > > class test { public: int test; } test = { .test = 1 }; > > ^ > > 1 warning generated. > > > > Otherwise, modern C++ compilers should be able to build the code, and > > hopefully skipping this test should not make any practical problem. > > > > Checking the existence of plugin-version.h is still needed to ensure > > the plugin-dev package is installed. The test code is now small enough > > to be embedded in scripts/gcc-plugins/Kconfig. > > > > [1] https://lore.kernel.org/lkml/CAHk-=wjU4DCuwQ4pXshRbwDCUQB31ScaeuDo1tjoZ0_PjhLHzQ@mail.gmail.com/ > > [2] https://lore.kernel.org/lkml/CAHk-=whK0aQxs6Q5ijJmYF1n2ch8cVFSUzU5yUM_HOjig=+vnw@mail.gmail.com/ > > > > Reported-by: Linus Torvalds > > Signed-off-by: Masahiro Yamada > > This patch landed in linux next-20201217 as commit 1e860048c53e > ("gcc-plugins: simplify GCC plugin-dev capability test"). > > It causes a build break with my tests setup, but I'm not sure weather it > is really an issue of this commit or a toolchain I use. However I've > checked various versions of the gcc cross-compilers released by Linaro > at https://releases.linaro.org/components/toolchain/binaries/ and all > fails with the same error: > > $ make ARCH=arm > CROSS_COMPILE=../../cross/gcc-arm-10.2-2020.11-x86_64-arm-none-eabi/bin/arm-none-eabi- > zImage > HOSTCXX scripts/gcc-plugins/arm_ssp_per_task_plugin.so > In file included from > /home/mszyprow/dev/cross/gcc-arm-10.2-2020.11-x86_64-arm-none-eabi/bin/../lib/gcc/arm-none-eabi/10.2.1/plugin/include/gcc-plugin.h:28:0, > from scripts/gcc-plugins/gcc-common.h:7, > from scripts/gcc-plugins/arm_ssp_per_task_plugin.c:3: > /home/mszyprow/dev/cross/gcc-arm-10.2-2020.11-x86_64-arm-none-eabi/bin/../lib/gcc/arm-none-eabi/10.2.1/plugin/include/system.h:687:10: > fatal error: gmp.h: No such file or directory > #include > ^~~~~~~ > compilation terminated. > scripts/gcc-plugins/Makefile:47: recipe for target > 'scripts/gcc-plugins/arm_ssp_per_task_plugin.so' failed > make[2]: *** [scripts/gcc-plugins/arm_ssp_per_task_plugin.so] Error 1 > scripts/Makefile.build:496: recipe for target 'scripts/gcc-plugins' failed > make[1]: *** [scripts/gcc-plugins] Error 2 > Makefile:1190: recipe for target 'scripts' failed > make: *** [scripts] Error 2 > > Compilation works if I use the cross-gcc provided by > gcc-7-arm-linux-gnueabi/gcc-arm-linux-gnueabi Ubuntu packages, which is: > > $ arm-linux-gnueabi-gcc --version > arm-linux-gnueabi-gcc (Ubuntu/Linaro 7.5.0-3ubuntu1~18.04) 7.5.0 > > Best regards > > -- > Marek Szyprowski, PhD > Samsung R&D Institute Poland > I can compile gcc-plugins with Linaro toolchians. The version of mine is this: masahiro@oscar:~/ref/linux-next$ ~/tools/arm-linaro-7.5/bin/arm-linux-gnueabihf-gcc --version arm-linux-gnueabihf-gcc (Linaro GCC 7.5-2019.12) 7.5.0 Copyright (C) 2017 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. Maybe, it depends on the host environment? Please try this: $ sudo apt install libgmp-dev -- Best Regards Masahiro Yamada