From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 89793 invoked by alias); 28 Jun 2018 19:04:07 -0000 Mailing-List: contact fortran-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: fortran-owner@gcc.gnu.org Received: (qmail 89217 invoked by uid 89); 28 Jun 2018 19:04:02 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-9.9 required=5.0 tests=BAYES_00,DATE_IN_PAST_06_12,GIT_PATCH_2,GIT_PATCH_3,KAM_NUMSUBJECT,SPF_PASS autolearn=ham version=3.3.2 spammy= X-HELO: mx1.suse.de Received: from mx2.suse.de (HELO mx1.suse.de) (195.135.220.15) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Thu, 28 Jun 2018 19:04:00 +0000 Received: from relay1.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id C3E4DADE9; Thu, 28 Jun 2018 19:03:56 +0000 (UTC) Date: Fri, 29 Jun 2018 02:37:00 -0000 From: Richard Biener To: gcc-patches@gcc.gnu.org cc: fortran@gcc.gnu.org, Jakub Jelinek Subject: [PATCH] Fix PR86321 Message-ID: User-Agent: Alpine 2.20 (LSU 67 2015-01-07) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-SW-Source: 2018-06/txt/msg00213.txt.bz2 The fortran FE creates array descriptor types via build_distinct_type_copy which ends up re-using the TYPE_FIELDs chain of FIELD_DECLs between types in different type-variant chains. While that seems harmless in practice it breaks once we try to generate C-like debug info for it because dwarf2out doesn't expect such sharing to occur (and I wouldn't be surprised of other odd behavior elsewhere that simply doesn't manifest in a as fatal way as PR86321). We generate C-like debug info when you use LTO and -g0 at compile-time and -g at link-time (that's the way targets w/o debug-copy implementation end up wired). For non-LTO we avoid directly generating debug for the array descriptor types by detecting them via a langhook. The solution seems to be to adhere to the invariant that TYPE_FIELDs (and thus FIELD_DECL) sharing is only valid between variant types and their main variant. Thus, copy the chain. Bootstrap / regtest pending on x86_64-unknown-linux-gnu. I suppose verify_type () could check proper ownership of the FIELD_DECLs (simply verify that DECL_CONTEXT is TYPE_MAIN_VARIANT). But I guess this may break in different ways. Honza - did you originally try to verify that? It currently says for (tree fld = TYPE_FIELDS (t); fld; fld = TREE_CHAIN (fld)) { /* TODO: verify properties of decls. */ if (TREE_CODE (fld) == FIELD_DECL) ; ... OK for trunk? Thanks, Richard. 2018-06-28 Richard Biener fortran/ PR lto/86321 * trans-types.c (gfc_get_array_type_bounds): Unshare TYPE_FIELDs for the distinct type copy. Index: gcc/fortran/trans-types.c =================================================================== --- gcc/fortran/trans-types.c (revision 262132) +++ gcc/fortran/trans-types.c (working copy) @@ -1923,6 +1923,14 @@ gfc_get_array_type_bounds (tree etype, i base_type = gfc_get_array_descriptor_base (dimen, codimen, restricted); fat_type = build_distinct_type_copy (base_type); + /* Unshare TYPE_FIELDs. */ + for (tree *tp = &TYPE_FIELDS (fat_type); *tp; tp = &DECL_CHAIN (*tp)) + { + tree next = DECL_CHAIN (*tp); + *tp = copy_node (*tp); + DECL_CONTEXT (*tp) = fat_type; + DECL_CHAIN (*tp) = next; + } /* Make sure that nontarget and target array type have the same canonical type (and same stub decl for debug info). */ base_type = gfc_get_array_descriptor_base (dimen, codimen, false);