From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf1-x42e.google.com (mail-pf1-x42e.google.com [IPv6:2607:f8b0:4864:20::42e]) by sourceware.org (Postfix) with ESMTPS id BBA0A3858C53 for ; Wed, 1 Mar 2023 17:50:43 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org BBA0A3858C53 Authentication-Results: sourceware.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=google.com Received: by mail-pf1-x42e.google.com with SMTP id ce7so8462827pfb.9 for ; Wed, 01 Mar 2023 09:50:43 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; t=1677693043; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=DpL6DwFkyuaEtEvh0ArhxR/cUeifrKQ0QYmfCAMdbVU=; b=lagi4xfM5lhItTQDuRxproJWvwcvRV2ufiYbfodtWrckZ9+0sW1ahRDIVSF1/ru37a iHjqSfwo67gCHwutTwpxMZqhFvMGxAHTEhw6mb6VL0iuZes7SSdXJRb7kt9/jU5Rjn/k 7dPOZx7m8j2Z+rUdxYZfd2BB3F0T/G/6qn5xLtGLK3JyBD7nj85IMMOQGMRiDBz3fCvS 8rpnjHLfybMAgEC0FVsBNE0YPItotziNHYW4dTwBLVy7wVjWGwTd6s0tBZeu7i1WwynB t6HgD+TNCzshFzJI6hyIbTjAJveFkmeHYGT0L46AP7u+zvz1rI93vWkmEWOkMUrSO/Ke 8CWA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1677693043; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=DpL6DwFkyuaEtEvh0ArhxR/cUeifrKQ0QYmfCAMdbVU=; b=060+cNDnMFZ5qLJVrxl5Oc2I7/JZoRt/6xG47AyErO8+7QMPGkI9BQrDabeIZCj1ID w0Ntt0DUczYcqr8XVhzSZveehq3W3Eca3YXGid7OeSq4YzjS9BA6cAr7t9S2orFnKQP+ /5Xn7UPbNOPi+BqMTHEEiE3qBMOxo20SK6pzu5r/okzNCa2q6DLU5wE2U6UBI02vPZGu 6spDDnmDirDPcSL8Ir67P60vhecpK1AZM+bo3tiK/l9JHP0lxZ5kQrvW1AXKa+UvXxXU WM2RDSW8rSdXoB5SZdIivN5kaWEVzAE7XkdqJbLywPB0BCvQ9KODwyzGtKTJkge9ZKuQ /aEg== X-Gm-Message-State: AO0yUKU8n6cPeT35WsWoGtnKjnl5MYzxxVlzTxjZqIXtZzoQn7jG7RQl 24yDSD2KZMjvdi/KKxbbiftlbFAdMahWJWYHvQDkxQ== X-Google-Smtp-Source: AK7set+sa5Lpwqw5kyGG4/qPXxMgWH2tZf+nBVEHopmtPWoZRNrFsf1qn2TKiNLI7IHyHoSIS55/eR0Qis04PyU96jg= X-Received: by 2002:a63:8c1d:0:b0:503:354c:41ad with SMTP id m29-20020a638c1d000000b00503354c41admr2372184pgd.11.1677693042346; Wed, 01 Mar 2023 09:50:42 -0800 (PST) MIME-Version: 1.0 References: <20230301075402.4578-1-quic_johmoo@quicinc.com> In-Reply-To: <20230301075402.4578-1-quic_johmoo@quicinc.com> From: Nick Desaulniers Date: Wed, 1 Mar 2023 09:50:30 -0800 Message-ID: Subject: Re: [PATCH v2 0/2] Validating UAPI backwards compatibility To: John Moon Cc: Masahiro Yamada , Nathan Chancellor , Nicolas Schier , linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-arm-msm@vger.kernel.org, Greg Kroah-Hartman , Randy Dunlap , Arnd Bergmann , Bjorn Andersson , Todd Kjos , Matthias Maennich , Giuliano Procida , kernel-team@android.com, libabigail@sourceware.org, Jordan Crouse , Trilok Soni , Satya Durga Srinivasu Prabhala , Elliot Berman Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Spam-Status: No, score=-16.4 required=5.0 tests=BAYES_00,DKIMWL_WL_MED,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,ENV_AND_HDR_SPF_MATCH,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS,TXREP,USER_IN_DEF_DKIM_WL,USER_IN_DEF_SPF_WL autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: On Tue, Feb 28, 2023 at 11:54=E2=80=AFPM John Moon wrote: > > Currently, the script works with gcc. It generates output like this when > a backwards-incompatible change is made to a UAPI header: > > !!! ABI differences detected in include/uapi/linux/acct.h (compared to > file at HEAD^1) !!! > > [C] 'struct acct' changed: > type size changed from 512 to 544 (in bits) > 1 data member insertion: > '__u32 new_val', at offset 512 (in bits) at acct.h:71:1 > > 0/1 UAPI header file changes are backwards compatible > UAPI header ABI check failed > > However, we have not had success with clang. It seems clang is more > aggressive in optimizing dead code away (no matter which options we > pass). Therefore, no ABI differences are found. Hi John, Do you have the list of bugs you've filed upstream against clang wrt. information missing when using `-fno-eliminate-unused-debug-types`? https://github.com/llvm/llvm-project/issues is the issue tracker. Seeing a strong participant in both the Android and LLVM ecosystems supply scripts that lack clang support...raises eyebrows. --=20 Thanks, ~Nick Desaulniers