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 [170.10.133.124]) by sourceware.org (Postfix) with ESMTPS id A610F3858CDB for ; Sat, 18 Mar 2023 12:55:03 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org A610F3858CDB Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=redhat.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1679144103; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:in-reply-to:in-reply-to: references:references; bh=B+aq4BEt3h9/I19qcwhmxcGfiZ4WVO/IuKJjSXcNt54=; b=ILyrKYP7eMM9XpZewOllHWM33MHhWiQEC9Nz+I8PwCAES0Ru9sSv99J0DGM2W/BVPgrGuS BG/dB8mogb+AacT3lNQxKeZDmmambdTkrOeNx+vqMF/B5f1JF2wvfhvzhjyqnBRhBpCrYu PcIFZuPTjSk8xLgdSmePv1rmuKVL4nM= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-594-HlCSHGhJO7uI5mn5BiPvCw-1; Sat, 18 Mar 2023 08:55:02 -0400 X-MC-Unique: HlCSHGhJO7uI5mn5BiPvCw-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id F3FA585A5A3 for ; Sat, 18 Mar 2023 12:55:01 +0000 (UTC) Received: from tucnak.zalov.cz (unknown [10.39.192.16]) by smtp.corp.redhat.com (Postfix) with ESMTPS id B235E40C6E67; Sat, 18 Mar 2023 12:55:01 +0000 (UTC) Received: from tucnak.zalov.cz (localhost [127.0.0.1]) by tucnak.zalov.cz (8.17.1/8.17.1) with ESMTPS id 32ICsxEh3150154 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Sat, 18 Mar 2023 13:54:59 +0100 Received: (from jakub@localhost) by tucnak.zalov.cz (8.17.1/8.17.1/Submit) id 32ICswFw3150153; Sat, 18 Mar 2023 13:54:58 +0100 Date: Sat, 18 Mar 2023 13:54:58 +0100 From: Jakub Jelinek To: Jason Merrill Cc: gcc-patches@gcc.gnu.org Subject: Re: [PATCH] c++: Drop TREE_READONLY on vars (possibly) initialized by tls wrapper [PR109164] Message-ID: Reply-To: Jakub Jelinek References: MIME-Version: 1.0 In-Reply-To: X-Scanned-By: MIMEDefang 3.1 on 10.11.54.2 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=-3.4 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_NONE,TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: On Sat, Mar 18, 2023 at 08:39:45AM -0400, Jason Merrill wrote: > On 3/17/23 13:51, Jakub Jelinek wrote: > > The following two testcases are miscompiled, because we keep TREE_READONLY > > on the vars even when they are (possibly) dynamically initialized by a TLS > > wrapper function. Normally cp_finish_decl drops TREE_READONLY from vars > > which need dynamic initialization, but for TLS we do this kind of > > initialization upon every access to those variables. > > Why not handle this case in cp_finish_decl, too? That is, add > DECL_THREAD_LOCAL_P to the TREE_STATIC check in The patch is mostly about DECL_EXTERNAL cases, the others are supposedly handled by the var_definition_p code there (or at least I assumed; testcases certainly test only DECL_EXTERNAL). I guess it could be done in cp_finish_decl, maybe better next to the /* A reference will be modified here, as it is initialized. */ if (! DECL_EXTERNAL (decl) && TREE_READONLY (decl) && TYPE_REF_P (type)) { was_readonly = 1; TREE_READONLY (decl) = 0; } spot, but we'd need to export the decl2.cc helpers for it, because not all DECL_THREAD_LOCAL_P vars need to be treated that way. if (VAR_P (decl) && CP_DECL_THREAD_LOCAL_P (decl) && var_needs_tls_wrapper (decl) && (!DECL_EXTERNAL (decl) || flag_extern_tls_init)) TREE_READONLY (decl) = 0; where var_needs_tls_wrapper would need to be exported from decl2.cc. Though, var_needs_tls_wrapper -> var_defined_without_dynamic_init needs DECL_NONTRIVIALLY_INITIALIZED_P/DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P, so perhaps that is accurate only closer to the end of cp_finish_decl? Jakub