From patchwork Mon Jul 27 08:05:52 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pierre-Marie de Rodat X-Patchwork-Id: 1336726 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=gcc.gnu.org (client-ip=2620:52:3:1:0:246e:9693:128c; helo=sourceware.org; envelope-from=gcc-patches-bounces@gcc.gnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=adacore.com Received: from sourceware.org (server2.sourceware.org [IPv6:2620:52:3:1:0:246e:9693:128c]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4BFXTJ0B4Sz9sR4 for ; Mon, 27 Jul 2020 18:07:00 +1000 (AEST) Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 86E983865492; Mon, 27 Jul 2020 08:06:01 +0000 (GMT) X-Original-To: gcc-patches@gcc.gnu.org Delivered-To: gcc-patches@gcc.gnu.org Received: from rock.gnat.com (rock.gnat.com [IPv6:2620:20:4000:0:a9e:1ff:fe9b:1d1]) by sourceware.org (Postfix) with ESMTP id A1541386186A for ; Mon, 27 Jul 2020 08:05:53 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org A1541386186A Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=adacore.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=derodat@adacore.com Received: from localhost (localhost.localdomain [127.0.0.1]) by filtered-rock.gnat.com (Postfix) with ESMTP id 892CB116870; Mon, 27 Jul 2020 04:05:52 -0400 (EDT) X-Virus-Scanned: Debian amavisd-new at gnat.com Received: from rock.gnat.com ([127.0.0.1]) by localhost (rock.gnat.com [127.0.0.1]) (amavisd-new, port 10024) with LMTP id Hwxefm+N7fGu; Mon, 27 Jul 2020 04:05:52 -0400 (EDT) Received: from tron.gnat.com (tron.gnat.com [205.232.38.10]) by rock.gnat.com (Postfix) with ESMTP id 5BD70116825; Mon, 27 Jul 2020 04:05:52 -0400 (EDT) Received: by tron.gnat.com (Postfix, from userid 4862) id 5AEC513D; Mon, 27 Jul 2020 04:05:52 -0400 (EDT) Date: Mon, 27 Jul 2020 04:05:52 -0400 From: Pierre-Marie de Rodat To: gcc-patches@gcc.gnu.org Subject: [Ada] AI12-0377 View conversions and out parameters revisited Message-ID: <20200727080552.GA36399@adacore.com> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.5.23 (2014-03-12) X-Spam-Status: No, score=-8.5 required=5.0 tests=BAYES_00, GIT_PATCH_0, JMQ_SPF_NEUTRAL, KAM_DMARC_STATUS, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: gcc-patches@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Arnaud Charlet Errors-To: gcc-patches-bounces@gcc.gnu.org Sender: "Gcc-patches" This AI refines AI12-0074 to disallow cases of potential de-initializing of out parameters. Tested on x86_64-pc-linux-gnu, committed on trunk gcc/ada/ * sem_res.adb (Resolve_Actuals): Refine 6.4.1 rules as per AI12-0377. diff --git a/gcc/ada/sem_res.adb b/gcc/ada/sem_res.adb --- a/gcc/ada/sem_res.adb +++ b/gcc/ada/sem_res.adb @@ -4175,27 +4175,34 @@ package body Sem_Res is end if; end if; - -- AI12-0074 + -- AI12-0074 & AI12-0377 -- Check 6.4.1: If the mode is out, the actual parameter is -- a view conversion, and the type of the formal parameter - -- is a scalar type that has the Default_Value aspect - -- specified, then - -- - there shall exist a type (other than a root numeric - -- type) that is an ancestor of both the target type and - -- the operand type; and - -- - the type of the operand of the conversion shall have - -- the Default_Value aspect specified. + -- is a scalar type, then either: + -- - the target and operand type both do not have the + -- Default_Value aspect specified; or + -- - the target and operand type both have the + -- Default_Value aspect specified, and there shall exist + -- a type (other than a root numeric type) that is an + -- ancestor of both the target type and the operand + -- type. elsif Ekind (F) = E_Out_Parameter and then Is_Scalar_Type (Etype (F)) - and then Present (Default_Aspect_Value (Etype (F))) - and then - (not Same_Ancestor (Etype (F), Expr_Typ) - or else No (Default_Aspect_Value (Expr_Typ))) then - Error_Msg_N - ("view conversion between unrelated types with " - & "Default_Value not allowed (RM 6.4.1)", A); + if Has_Default_Aspect (Etype (F)) /= + Has_Default_Aspect (Expr_Typ) + then + Error_Msg_N + ("view conversion requires Default_Value on both " & + "types (RM 6.4.1)", A); + elsif Has_Default_Aspect (Expr_Typ) + and then not Same_Ancestor (Etype (F), Expr_Typ) + then + Error_Msg_N + ("view conversion between unrelated types with " + & "Default_Value not allowed (RM 6.4.1)", A); + end if; end if; end;