From patchwork Wed Nov 23 11:25:19 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Richard Biener X-Patchwork-Id: 698168 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from sourceware.org (server1.sourceware.org [209.132.180.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3tP0Q36qX1z9t2F for ; Wed, 23 Nov 2016 22:25:45 +1100 (AEDT) Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=gcc.gnu.org header.i=@gcc.gnu.org header.b="BFrbyprm"; dkim-atps=neutral DomainKey-Signature: a=rsa-sha1; c=nofws; d=gcc.gnu.org; h=list-id :list-unsubscribe:list-archive:list-post:list-help:sender:date :from:to:subject:in-reply-to:message-id:references:mime-version :content-type; q=dns; s=default; b=amHR2wvBkXkzfh0jMFXHDvUEsrgj2 SU+wvpYO9pCelwwOTkSsuwxpsxOWDr+0JviZMwsWOcs1wYN2iTNskWLUD/B1c0Xd CyVeGqWup9109FZhprQicXtgxLR2LUAZRy03lONllRPtFXVNkf2ILobiYBQETjAA g1wwCsSWk9edVE= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=gcc.gnu.org; h=list-id :list-unsubscribe:list-archive:list-post:list-help:sender:date :from:to:subject:in-reply-to:message-id:references:mime-version :content-type; s=default; bh=Fkkj06SqXuMCs4d1pZemPy5rcdY=; b=BFr byprm0H53TM+QQZEhOToqbhfwJpsMRFYfOnG7NS96GtMNxngNIuk27EmCV7B0P/P 9W7QM75nbHxd42qlP1wMUHTSxr3A1+oRC9jBV0EEBb+6JtBrK4jfrbtU+jpkCLvj A2R7gpOFg1qCdTuU7k5l8AlmkncP7AhAikKAv2gs= Received: (qmail 94717 invoked by alias); 23 Nov 2016 11:25:32 -0000 Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org Delivered-To: mailing list gcc-patches@gcc.gnu.org Received: (qmail 94704 invoked by uid 89); 23 Nov 2016 11:25:32 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-4.0 required=5.0 tests=BAYES_00, KAM_ASCII_DIVIDERS, RP_MATCHES_RCVD, SPF_PASS autolearn=ham version=3.3.2 spammy= X-HELO: mx2.suse.de Received: from mx2.suse.de (HELO mx2.suse.de) (195.135.220.15) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Wed, 23 Nov 2016 11:25:21 +0000 Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 8C125ADB6 for ; Wed, 23 Nov 2016 11:25:19 +0000 (UTC) Date: Wed, 23 Nov 2016 12:25:19 +0100 (CET) From: Richard Biener To: gcc-patches@gcc.gnu.org Subject: Re: [PATCH] Fix PR78472 In-Reply-To: Message-ID: References: User-Agent: Alpine 2.11 (LSU 23 2013-08-11) MIME-Version: 1.0 On Tue, 22 Nov 2016, Richard Biener wrote: > > The following fixes a C/C++ interoperability issue with LTO when > zero-sized fields appear in one variant of a struct but not in another. > > Bootstrap & regtest in progress on x86_64-unknown-linux-gnu. This is what I have applied. Richard. 2016-11-23 Richard Biener PR lto/78472 * tree.c (gimple_canonical_types_compatible_p): Ignore zero-sized fields. lto/ * lto.c (hash_canonical_type): Ignore zero-sized fields. * g++.dg/lto/pr78472_0.c: New testcase. * g++.dg/lto/pr78472_1.C: Likewise. Index: gcc/tree.c =================================================================== --- gcc/tree.c (revision 242740) +++ gcc/tree.c (working copy) @@ -13708,10 +13708,14 @@ gimple_canonical_types_compatible_p (con f1 || f2; f1 = TREE_CHAIN (f1), f2 = TREE_CHAIN (f2)) { - /* Skip non-fields. */ - while (f1 && TREE_CODE (f1) != FIELD_DECL) + /* Skip non-fields and zero-sized fields. */ + while (f1 && (TREE_CODE (f1) != FIELD_DECL + || (DECL_SIZE (f1) + && integer_zerop (DECL_SIZE (f1))))) f1 = TREE_CHAIN (f1); - while (f2 && TREE_CODE (f2) != FIELD_DECL) + while (f2 && (TREE_CODE (f2) != FIELD_DECL + || (DECL_SIZE (f2) + && integer_zerop (DECL_SIZE (f2))))) f2 = TREE_CHAIN (f2); if (!f1 || !f2) break; Index: gcc/lto/lto.c =================================================================== --- gcc/lto/lto.c (revision 242740) +++ gcc/lto/lto.c (working copy) @@ -373,7 +373,9 @@ hash_canonical_type (tree type) tree f; for (f = TYPE_FIELDS (type), nf = 0; f; f = TREE_CHAIN (f)) - if (TREE_CODE (f) == FIELD_DECL) + if (TREE_CODE (f) == FIELD_DECL + && (! DECL_SIZE (f) + || ! integer_zerop (DECL_SIZE (f)))) { iterative_hash_canonical_type (TREE_TYPE (f), hstate); nf++; Index: gcc/testsuite/g++.dg/lto/pr78472_0.c =================================================================== --- gcc/testsuite/g++.dg/lto/pr78472_0.c (revision 0) +++ gcc/testsuite/g++.dg/lto/pr78472_0.c (revision 0) @@ -0,0 +1,12 @@ +// { dg-lto-do link } + +extern struct S +{ + unsigned i:4; + unsigned :0; +} s; +static void *f(void) +{ + return &s; +} +int main() {} Index: gcc/testsuite/g++.dg/lto/pr78472_1.C =================================================================== --- gcc/testsuite/g++.dg/lto/pr78472_1.C (revision 0) +++ gcc/testsuite/g++.dg/lto/pr78472_1.C (revision 0) @@ -0,0 +1,9 @@ +struct S +{ + unsigned i:4; + unsigned :0; +} s; +static void *f(void) +{ + return &s; +}