From patchwork Thu Nov 26 08:41:01 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: 1406484 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 4ChWTt58Tmz9sTv for ; Thu, 26 Nov 2020 19:42:26 +1100 (AEDT) Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 8FD66396EC0D; Thu, 26 Nov 2020 08:41:13 +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 [205.232.38.15]) by sourceware.org (Postfix) with ESMTP id 06C13396E46B for ; Thu, 26 Nov 2020 08:41:04 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 06C13396E46B 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 2C5BE117AE6; Thu, 26 Nov 2020 03:41:01 -0500 (EST) 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 E+azjqeGUzx8; Thu, 26 Nov 2020 03:41:01 -0500 (EST) Received: from tron.gnat.com (tron.gnat.com [IPv6:2620:20:4000:0:46a8:42ff:fe0e:e294]) by rock.gnat.com (Postfix) with ESMTP id 088DA117AD4; Thu, 26 Nov 2020 03:41:01 -0500 (EST) Received: by tron.gnat.com (Postfix, from userid 4862) id 076F1DF; Thu, 26 Nov 2020 03:41:01 -0500 (EST) Date: Thu, 26 Nov 2020 03:41:01 -0500 From: Pierre-Marie de Rodat To: gcc-patches@gcc.gnu.org Subject: [Ada] Ada 2020 AI12-0401 Renaming of qualified expression of variable Message-ID: <20201126084101.GA20700@adacore.com> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.5.23 (2014-03-12) X-Spam-Status: No, score=-11.1 required=5.0 tests=BAYES_00, GIT_PATCH_0, 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 restricts renaming of a qualified expression to cases where the operand is a constant, or the target subtype statically matches the nominal subtype of the operand, or is unconstrained with no predicates. Tested on x86_64-pc-linux-gnu, committed on trunk gcc/ada/ * sem_ch8.adb (Analyze_Object_Renaming): Check for AI12-0401. diff --git a/gcc/ada/sem_ch8.adb b/gcc/ada/sem_ch8.adb --- a/gcc/ada/sem_ch8.adb +++ b/gcc/ada/sem_ch8.adb @@ -1038,6 +1038,22 @@ package body Sem_Ch8 is Mark_Ghost_Renaming (N, Entity (Nam)); end if; + -- Check against AI12-0401 here before Resolve may rewrite Nam and + -- potentially generate spurious warnings. + + if Nkind (Nam) = N_Qualified_Expression + and then Is_Variable (Expression (Nam)) + and then not + (Subtypes_Statically_Match (T, Etype (Expression (Nam))) + or else + Subtypes_Statically_Match (Base_Type (T), Etype (Nam))) + then + Error_Msg_N + ("subtype of renamed qualified expression does not " & + "statically match", N); + return; + end if; + Resolve (Nam, T); -- If the renamed object is a function call of a limited type,