From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by sourceware.org (Postfix) with ESMTPS id 635AB385B83F for ; Thu, 18 Nov 2021 15:45:17 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 635AB385B83F Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-317-hZhgiqz7MiKibGMSCgeQ7Q-1; Thu, 18 Nov 2021 10:45:14 -0500 X-MC-Unique: hZhgiqz7MiKibGMSCgeQ7Q-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 06DD48189C2; Thu, 18 Nov 2021 15:45:13 +0000 (UTC) Received: from tucnak.zalov.cz (unknown [10.39.192.54]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 59BD8694B5; Thu, 18 Nov 2021 15:45:10 +0000 (UTC) Received: from tucnak.zalov.cz (localhost [127.0.0.1]) by tucnak.zalov.cz (8.16.1/8.16.1) with ESMTPS id 1AIFj7uF2648025 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Thu, 18 Nov 2021 16:45:07 +0100 Received: (from jakub@localhost) by tucnak.zalov.cz (8.16.1/8.16.1/Submit) id 1AIFj7rZ2648024; Thu, 18 Nov 2021 16:45:07 +0100 Date: Thu, 18 Nov 2021 16:45:06 +0100 From: Jakub Jelinek To: Florian Weimer Cc: gcc-patches@gcc.gnu.org, libc-alpha@sourceware.org, Jason Merrill Subject: Re: [PATCH 4/4] libgcc: Use _dl_find_eh_frame in _Unwind_Find_FDE Message-ID: <20211118154506.GG2646553@tucnak> Reply-To: Jakub Jelinek References: MIME-Version: 1.0 In-Reply-To: X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Spam-Status: No, score=-5.7 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, RCVD_IN_DNSWL_LOW, RCVD_IN_MSPIKE_H4, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_NONE, TXREP autolearn=unavailable autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 18 Nov 2021 15:45:18 -0000 On Wed, Nov 03, 2021 at 05:28:55PM +0100, Florian Weimer wrote: > --- a/libgcc/unwind-dw2-fde-dip.c > +++ b/libgcc/unwind-dw2-fde-dip.c > @@ -129,6 +129,30 @@ unw_eh_callback_data_dbase (const struct unw_eh_callback_data *data > #endif > } > > +#ifdef DL_FIND_EH_FRAME_DBASE > +#if DL_FIND_EH_FRAME_DBASE != NEED_DBASE_MEMBER > +#error "DL_FIND_EH_FRAME_DBASE != NEED_DBASE_MEMBER" Instead of #error just don't define USE_DL_FIND_EH_FRAME? I.e. #ifdef DL_FIND_EH_FRAME_DBASE #if DL_FIND_EH_FRAME_DBASE == NEED_DBASE_MEMBER > +#define USE_DL_FIND_EH_FRAME 1 > +#define DL_FIND_EH_FRAME_CONDITION 1 > +#endif ? Is it a good idea to have different arguments of the function for i386/nios2/frv/bfind vs. the rest, wouldn't just always passing void **__dbase argument be cleaner? Internally it is fine to differentiate based on NEED_DBASE_MEMBER, but doing that on a public interface? > +/* Fallback declaration for old glibc headers. DL_FIND_EH_FRAME_DBASE is used > + as a proxy to determine if declares _dl_find_eh_frame. */ > +#if defined __GLIBC__ && !defined DL_FIND_EH_FRAME_DBASE > +#if NEED_DBASE_MEMBER > +void *_dl_find_eh_frame (void *__pc, void **__dbase) __attribute__ ((weak)); > +#else > +void *_dl_find_eh_frame (void *__pc) __attribute__ ((weak)); > +#endif > +#define USE_DL_FIND_EH_FRAME 1 > +#define DL_FIND_EH_FRAME_CONDITION (_dl_find_eh_frame != NULL) > +#endif I'd prefer not to do this. If we find glibc with the support in the headers, let's use it, otherwise let's keep using what we were doing before. > +#if NEED_DBASE_MEMBER > + eh_frame = _dl_find_eh_frame (pc, &dbase); > +#else > + dbase = NULL; > + eh_frame = _dl_find_eh_frame (pc); > +#endif > + if (eh_frame == NULL) > + return NULL; > + > + struct find_fde_tail_result result > + = find_fde_tail ((_Unwind_Ptr) pc, eh_frame, (_Unwind_Ptr) dbase); > + if (result.entry != NULL) > + { > + bases->tbase = NULL; > + bases->dbase = (void *) dbase; > + bases->func = result.func; > + } > + return result.entry; > + } > +#endif > + > data.pc = (_Unwind_Ptr) pc; > #if NEED_DBASE_MEMBER > data.dbase = NULL; > -- > 2.31.1 Otherwise LGTM. Jakub