From patchwork Wed Jan 4 19:54:18 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nathan Chancellor X-Patchwork-Id: 13088877 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CCC1DC63707 for ; Wed, 4 Jan 2023 19:55:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240104AbjADTzH (ORCPT ); Wed, 4 Jan 2023 14:55:07 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52446 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235156AbjADTy5 (ORCPT ); Wed, 4 Jan 2023 14:54:57 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 88BFD1AD9D; Wed, 4 Jan 2023 11:54:56 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 267CFB81714; Wed, 4 Jan 2023 19:54:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 310B3C433D2; Wed, 4 Jan 2023 19:54:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1672862093; bh=L+MNyD4+J2gyZIniEp1jnrEedIiPMHOYlb+OJsuTqoA=; h=From:Subject:Date:To:Cc:From; b=Bltnvl8eBa4iWRprtH8bhHBNd74MinRaprS5FPLE+O5X6NBm8prVFG4+kC5eqetEg VNS7V9184Yyke96GgYZlNYf3pkuCgFEGExspz1qbRiA33+TFMSTZ9OIcrUBDYP/RJU lCJ08b+WRoNrRYMGRmzI76Xv4lbPY+TMDAvIns8E7OiO2gppVFzRlnJ2i/6B/VZ0lc JeVhbZwEdi7VcDsLeeyfvwITTem2fW09O5wf3FU+jPNQmhV+adDUqnYxZ8HuEf5Onv zScIVPQjZpVQ+X7an9Vh4Pd6wqSAbA08PJOq8xe5gaCZaU8j8GfaTM1rwJHCovACyQ EIyet6WRohvsg== From: Nathan Chancellor Subject: [PATCH 00/14] Remove clang's -Qunused-arguments from KBUILD_CPPFLAGS Date: Wed, 04 Jan 2023 12:54:18 -0700 Message-Id: <20221228-drop-qunused-arguments-v1-0-658cbc8fc592@kernel.org> MIME-Version: 1.0 X-B4-Tracking: v=1; b=H4sIAGvZtWMC/x2NQQqDQAwAvyI5N6BLpaVfKT1kd6PmYLSJWwri3 7v2OAzD7OBswg6PZgfjj7gsWqG7NJAm0pFRcmUIbQhdCHfMtqz4LlqcM5KNZWbdHNvUp1sm7q9D hBpHcsZopGk685l8YzvFajzI9398vo7jB9ivTEOBAAAA To: masahiroy@kernel.org, ndesaulniers@google.com Cc: nicolas@fjasle.eu, trix@redhat.com, linux-kbuild@vger.kernel.org, llvm@lists.linux.dev, Nathan Chancellor , kernel test robot , tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, tsbogend@alpha.franken.de, linux-mips@vger.kernel.org, mpe@ellerman.id.au, npiggin@gmail.com, christophe.leroy@csgroup.eu, linuxppc-dev@lists.ozlabs.org, hca@linux.ibm.com, gor@linux.ibm.com, agordeev@linux.ibm.com, borntraeger@linux.ibm.com, svens@linux.ibm.com, linux-s390@vger.kernel.org, harry.wentland@amd.com, sunpeng.li@amd.com, Rodrigo.Siqueira@amd.com, alexander.deucher@amd.com, christian.koenig@amd.com, Xinhui.Pan@amd.com, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org X-Mailer: b4 0.11.1 X-Developer-Signature: v=1; a=openpgp-sha256; l=4767; i=nathan@kernel.org; h=from:subject:message-id; bh=L+MNyD4+J2gyZIniEp1jnrEedIiPMHOYlb+OJsuTqoA=; b=owGbwMvMwCEmm602sfCA1DTG02pJDMlbb3ZW1WS5GXp9rDnt/6hu/3G7mYecz4f8sPovxa91XotL 2e5CRykLgxgHg6yYIkv1Y9XjhoZzzjLeODUJZg4rE8gQBi5OAZhI9wdGhsttn4qEr1577ln566Myr/ BNt4db9/dNrVRYwLP66qbc7LkM/z28WKNDG/Vum/jOz8p4fvzjYZvp+1xdA27LmtopzX7qzwgA X-Developer-Key: i=nathan@kernel.org; a=openpgp; fpr=2437CB76E544CB6AB3D9DFD399739260CB6CB716 Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org Hi all, Clang can emit a few different warnings when it encounters a flag that it recognizes but does not support internally. These warnings are elevated to errors within {as,cc}-option via -Werror to catch unsupported flags that should not be added to KBUILD_{A,C}FLAGS; see commit c3f0d0bc5b01 ("kbuild, LLVMLinux: Add -Werror to cc-option to support clang"). If an unsupported flag is unconditionally to KBUILD_{A,C}FLAGS, all subsequent {as,cc}-option will always fail, preventing supported and even potentially necessary flags from getting adding to the tool flags. One would expect these warnings to be visible in the kernel build logs since they are added to KBUILD_{A,C}FLAGS but unfortunately, these warnings are hidden with clang's -Qunused-arguments flag, which is added to KBUILD_CPPFLAGS and used for both compiling and assembling files. Patches 1-4 address the internal inconsistencies of invoking the assembler within kbuild by using KBUILD_AFLAGS consistently and using '-x assembler-with-cpp' over '-x assembler'. This matches how assembly files are built across the kernel and helps avoid problems in situations where macro definitions or warning flags are present in KBUILD_AFLAGS, which cause instances of -Wunused-command-line-argument when the preprocessor is not called to consume them. There were a couple of places in architecture code where this change would break things so those are fixed first. Patches 5-12 clean up warnings that will show up when -Qunused-argument is dropped. I hope none of these are controversial. Patch 13 turns two warnings into errors so that the presence of unused flags cannot be easily ignored. Patch 14 drops -Qunused-argument. This is done last so that it can be easily reverted if need be. This series has seen my personal test framework, which tests several different configurations and architectures, with LLVM tip of tree (16.0.0). I have done defconfig, allmodconfig, and allnoconfig builds for arm, arm64, i386, mips, powerpc, riscv, s390, and x86_64 with GCC 12.2.0 as well but I am hoping the rest of the test infrastructure will catch any lurking problems. I would like this series to stay together so that there is no opportunity for breakage so please consider giving acks so that this can be carried via the kbuild tree. Acked-by: Heiko Carstens --- Nathan Chancellor (12): MIPS: Always use -Wa,-msoft-float and eliminate GAS_HAS_SET_HARDFLOAT MIPS: Prefer cc-option for additions to cflags powerpc: Remove linker flag from KBUILD_AFLAGS powerpc/vdso: Remove unused '-s' flag from ASFLAGS powerpc/vdso: Improve linker flags powerpc/vdso: Remove an unsupported flag from vgettimeofday-32.o with clang s390/vdso: Drop unused '-s' flag from KBUILD_AFLAGS_64 s390/vdso: Drop '-shared' from KBUILD_CFLAGS_64 s390/purgatory: Remove unused '-MD' and unnecessary '-c' flags drm/amd/display: Do not add '-mhard-float' to dml_ccflags for clang kbuild: Turn a couple more of clang's unused option warnings into errors kbuild: Stop using '-Qunused-arguments' with clang Nick Desaulniers (2): x86/boot/compressed: prefer cc-option for CFLAGS additions kbuild: Update assembler calls to use proper flags and language target Makefile | 1 - arch/mips/Makefile | 13 ++------- arch/mips/include/asm/asmmacro-32.h | 4 +-- arch/mips/include/asm/asmmacro.h | 42 ++++++++++++++--------------- arch/mips/include/asm/fpregdef.h | 14 ---------- arch/mips/include/asm/mipsregs.h | 20 +++----------- arch/mips/kernel/genex.S | 2 +- arch/mips/kernel/r2300_fpu.S | 4 +-- arch/mips/kernel/r4k_fpu.S | 12 ++++----- arch/mips/kvm/fpu.S | 6 ++--- arch/mips/loongson2ef/Platform | 2 +- arch/powerpc/Makefile | 2 +- arch/powerpc/kernel/vdso/Makefile | 25 +++++++++++------ arch/s390/kernel/vdso64/Makefile | 4 +-- arch/s390/purgatory/Makefile | 2 +- arch/x86/boot/compressed/Makefile | 2 +- drivers/gpu/drm/amd/display/dc/dml/Makefile | 3 ++- scripts/Kconfig.include | 2 +- scripts/Makefile.clang | 2 ++ scripts/Makefile.compiler | 8 +++--- scripts/as-version.sh | 2 +- 21 files changed, 74 insertions(+), 98 deletions(-) --- base-commit: 88603b6dc419445847923fcb7fe5080067a30f98 change-id: 20221228-drop-qunused-arguments-0c5c7dae54fb Best regards,