From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 106453 invoked by alias); 2 May 2017 16:52:55 -0000 Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org Received: (qmail 105338 invoked by uid 89); 2 May 2017 16:52:54 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-25.6 required=5.0 tests=BAYES_00,GIT_PATCH_0,GIT_PATCH_1,GIT_PATCH_2,GIT_PATCH_3,KAM_LAZY_DOMAIN_SECURITY,KAM_LOTSOFHASH,KAM_STOCKGEN,RP_MATCHES_RCVD autolearn=ham version=3.3.2 spammy=habe, sk:transpa, 1788 X-HELO: foss.arm.com Received: from foss.arm.com (HELO foss.arm.com) (217.140.101.70) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Tue, 02 May 2017 16:52:52 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 544E7142F; Tue, 2 May 2017 09:52:53 -0700 (PDT) Received: from [10.2.206.52] (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 2A2CB3F41F; Tue, 2 May 2017 09:52:52 -0700 (PDT) Subject: Re: [PATCH, GCC/LTO, ping3] Fix PR69866: LTO with def for weak alias in regular object file To: "gcc-patches@gcc.gnu.org" , Jan Hubicka References: <654b4277-ced9-e778-bcda-3054e1983727@foss.arm.com> <1db1d20c-6f06-9bd3-2e7d-e862e31199cd@foss.arm.com> <2924a838-1869-9cd4-8b32-3c2c51a12bc5@redhat.com> Cc: Richard Biener , Jeff Law From: Thomas Preudhomme Message-ID: <2485e103-8b05-2019-10e2-b75d8cc0f374@foss.arm.com> Date: Tue, 02 May 2017 16:56:00 -0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: multipart/mixed; boundary="------------4C15BD092984074B716F829C" X-IsSubscribed: yes X-SW-Source: 2017-05/txt/msg00131.txt.bz2 This is a multi-part message in MIME format. --------------4C15BD092984074B716F829C Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-length: 1657 Now that GCC 7 is released, ping? Original message below: Hi, This patch fixes an assert failure when linking one LTOed object file having a weak alias with a regular object file containing a strong definition for that same symbol. The patch is twofold: + do not add an alias to a partition if it is external + do not declare (.globl) an alias if it is external ChangeLog entries are as follow: *** gcc/lto/ChangeLog *** 2017-03-01 Thomas Preud'homme PR lto/69866 * lto/lto-partition.c (add_symbol_to_partition_1): Do not add external aliases to partition. *** gcc/ChangeLog *** 2017-03-01 Thomas Preud'homme PR lto/69866 * cgraphunit.c (cgraph_node::assemble_thunks_and_aliases): Do not declare external aliases. *** gcc/testsuite/ChangeLog *** 2017-02-28 Thomas Preud'homme PR lto/69866 * gcc.dg/lto/pr69866_0.c: New test. * gcc.dg/lto/pr69866_1.c: Likewise. Testing: Testsuite shows no regression when targeting Cortex-M3 with an arm-none-eabi GCC cross-compiler, neither does it show any regression with native LTO-bootstrapped x86-64_linux-gnu and aarch64-linux-gnu compilers. Is this ok for stage4? Best regards, Thomas On 31/03/17 18:07, Richard Biener wrote: > On March 31, 2017 5:23:03 PM GMT+02:00, Jeff Law wrote: >> On 03/16/2017 08:05 AM, Thomas Preudhomme wrote: >>> Ping? >>> >>> Is this ok for stage4? >> Given the lack of response from Richi, I'd suggest deferring to stage1. > > Honza needs to review this, i habe too little knowledge here. > > Richard. > >> jeff > --------------4C15BD092984074B716F829C Content-Type: text/x-patch; name="fix_pr69866.patch" Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename="fix_pr69866.patch" Content-length: 2370 diff --git a/gcc/cgraphunit.c b/gcc/cgraphunit.c index c82a88a599ca61b068dd9783d2a6158163809b37..580500ff922b8546d33119261a2455235edbf16d 100644 --- a/gcc/cgraphunit.c +++ b/gcc/cgraphunit.c @@ -1972,7 +1972,7 @@ cgraph_node::assemble_thunks_and_aliases (void) FOR_EACH_ALIAS (this, ref) { cgraph_node *alias = dyn_cast (ref->referring); - if (!alias->transparent_alias) + if (!alias->transparent_alias && !DECL_EXTERNAL (alias->decl)) { bool saved_written = TREE_ASM_WRITTEN (decl); diff --git a/gcc/lto/lto-partition.c b/gcc/lto/lto-partition.c index e27d0d1690c1fcfb39e2fac03ce0f4154031fc7c..f44fd435ed075a27e373bdfdf0464eb06e1731ef 100644 --- a/gcc/lto/lto-partition.c +++ b/gcc/lto/lto-partition.c @@ -178,7 +178,8 @@ add_symbol_to_partition_1 (ltrans_partition part, symtab_node *node) /* Add all aliases associated with the symbol. */ FOR_EACH_ALIAS (node, ref) - if (!ref->referring->transparent_alias) + if (!ref->referring->transparent_alias + && ref->referring->get_partitioning_class () != SYMBOL_EXTERNAL) add_symbol_to_partition_1 (part, ref->referring); else { @@ -189,7 +190,8 @@ add_symbol_to_partition_1 (ltrans_partition part, symtab_node *node) { /* Nested transparent aliases are not permitted. */ gcc_checking_assert (!ref2->referring->transparent_alias); - add_symbol_to_partition_1 (part, ref2->referring); + if (ref2->referring->get_partitioning_class () != SYMBOL_EXTERNAL) + add_symbol_to_partition_1 (part, ref2->referring); } } diff --git a/gcc/testsuite/gcc.dg/lto/pr69866_0.c b/gcc/testsuite/gcc.dg/lto/pr69866_0.c new file mode 100644 index 0000000000000000000000000000000000000000..f49ef8d4c1da7a21d1bfb5409d647bd18141595b --- /dev/null +++ b/gcc/testsuite/gcc.dg/lto/pr69866_0.c @@ -0,0 +1,13 @@ +/* { dg-lto-do link } */ + +int _umh(int i) +{ + return i+1; +} + +int weaks(int i) __attribute__((weak, alias("_umh"))); + +int main() +{ + return weaks(10); +} diff --git a/gcc/testsuite/gcc.dg/lto/pr69866_1.c b/gcc/testsuite/gcc.dg/lto/pr69866_1.c new file mode 100644 index 0000000000000000000000000000000000000000..3a14f850eefaffbf659ce4642adef7900330f4ed --- /dev/null +++ b/gcc/testsuite/gcc.dg/lto/pr69866_1.c @@ -0,0 +1,6 @@ +/* { dg-options { -fno-lto } } */ + +int weaks(int i) +{ + return i+1; +} --------------4C15BD092984074B716F829C--