From patchwork Tue Sep 21 22:29:24 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matt Jacobson X-Patchwork-Id: 45255 Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id AC3C6385841C for ; Tue, 21 Sep 2021 22:29:57 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org AC3C6385841C DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1632263397; bh=jnsTNJUanL3awzh4AtSyXI0cDwNEDA74qqaLMPL2w9U=; h=Subject:Date:To:List-Id:List-Unsubscribe:List-Archive:List-Post: List-Help:List-Subscribe:From:Reply-To:From; b=my8PvkLc347mypUCgccZkfps0dOuIbHJeCEj4yRV3rgO065zShtrBN+FajkO38p4O wCE+jcZOpUPhQIQ85YWA4wzfBrmlANc9BPbmIkSCzdEOqXUchxJPSNCcsn/oMwfJOa IOhqxp5q5ngQdgsi2MV8CIUZWiROX5c83UiONjdU= X-Original-To: gcc-patches@gcc.gnu.org Delivered-To: gcc-patches@gcc.gnu.org Received: from pv34p98im-ztdg02162201.me.com (pv34p98im-ztdg02162201.me.com [17.143.234.141]) by sourceware.org (Postfix) with ESMTPS id A7C143858D39 for ; Tue, 21 Sep 2021 22:29:28 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org A7C143858D39 Received: from [10.0.1.20] (cpe-98-26-0-177.nc.res.rr.com [98.26.0.177]) by pv34p98im-ztdg02162201.me.com (Postfix) with ESMTPSA id C0C0F1C008D for ; Tue, 21 Sep 2021 22:29:26 +0000 (UTC) Mime-Version: 1.0 (Mac OS X Mail 13.4 \(3608.120.23.2.7\)) Subject: [PATCH] Objective-C: fix class_ro layout for non-LP64 Message-Id: <5311422B-0209-43F1-A93F-61FE2C183831@me.com> Date: Tue, 21 Sep 2021 18:29:24 -0400 To: gcc-patches@gcc.gnu.org X-Mailer: Apple Mail (2.3608.120.23.2.7) X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.391, 18.0.790 definitions=2021-09-21_07:2021-09-20, 2021-09-21 signatures=0 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 mlxscore=0 mlxlogscore=989 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-2009150000 definitions=main-2109210134 X-Spam-Status: No, score=-11.6 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, FREEMAIL_FROM, GIT_PATCH_0, KAM_NUMSUBJECT, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: gcc-patches@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-Patchwork-Original-From: Matt Jacobson via Gcc-patches From: Matt Jacobson Reply-To: Matt Jacobson Errors-To: gcc-patches-bounces+patchwork=sourceware.org@gcc.gnu.org Sender: "Gcc-patches" Fix class_ro layout for non-LP64. On LP64, the requisite padding is added at a lower level. For non-LP64, this fixes binary compatibility with clang-built classes/runtimes. Tested by examining the generated assembly for a class_ro in both cases (and in the case of clang), for both x86_64 (64-bit pointers) and AVR (16-bit pointers). Tested by running a program on AVR with a GCC-built class using a clang-built Objective-C runtime. Tested by running a program on x86_64/Darwin with a GCC- built class and the clang-built system Objective-C runtime. Patch also available at: I don't have commit access, so if this patch is suitable, I'd need someone else to commit it for me. Thanks. gcc/objc/ChangeLog: 2021-09-21 Matt Jacobson * objc-next-runtime-abi-02.c (struct class_ro_t): Remove explicit alignment padding. (build_v2_class_templates): Remove explicit alignment padding. (build_v2_class_ro_t_initializer): Adjust initializer. diff --git a/gcc/objc/objc-next-runtime-abi-02.c b/gcc/objc/objc-next-runtime-abi-02.c index 42645e22316..c3af369ff0d 100644 --- a/gcc/objc/objc-next-runtime-abi-02.c +++ b/gcc/objc/objc-next-runtime-abi-02.c @@ -632,9 +632,7 @@ struct class_ro_t uint32_t const flags; uint32_t const instanceStart; uint32_t const instanceSize; -#ifdef __LP64__ - uint32_t const reserved; -#endif + // [32 bits of reserved space here on LP64 platforms] const uint8_t * const ivarLayout; const char *const name; const struct method_list_t * const baseMethods; @@ -677,11 +675,6 @@ build_v2_class_templates (void) /* uint32_t const instanceSize; */ add_field_decl (integer_type_node, "instanceSize", &chain); - /* This ABI is currently only used on m64 NeXT. We always - explicitly declare the alignment padding. */ - /* uint32_t const reserved; */ - add_field_decl (integer_type_node, "reserved", &chain); - /* const uint8_t * const ivarLayout; */ cnst_strg_type = build_pointer_type (unsigned_char_type_node); add_field_decl (cnst_strg_type, "ivarLayout", &chain); @@ -3225,12 +3218,6 @@ build_v2_class_ro_t_initializer (tree type, tree name, CONSTRUCTOR_APPEND_ELT (initlist, NULL_TREE, build_int_cst (integer_type_node, instanceSize)); - /* This ABI is currently only used on m64 NeXT. We always - explicitly declare the alignment padding. */ - /* reserved, pads alignment. */ - CONSTRUCTOR_APPEND_ELT (initlist, NULL_TREE, - build_int_cst (integer_type_node, 0)); - /* ivarLayout */ unsigned_char_star = build_pointer_type (unsigned_char_type_node); if (ivarLayout)