From patchwork Wed Jun 16 08:43:56 2021 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: 1492828 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+incoming=patchwork.ozlabs.org@gcc.gnu.org; receiver=) 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 4G4fBn0Zfsz9sXL for ; Wed, 16 Jun 2021 18:54:40 +1000 (AEST) Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 02AFF398900E for ; Wed, 16 Jun 2021 08:54:38 +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 ESMTPS id 1E7293989027 for ; Wed, 16 Jun 2021 08:44:00 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 1E7293989027 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=adacore.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=adacore.com Received: from localhost (localhost.localdomain [127.0.0.1]) by filtered-rock.gnat.com (Postfix) with ESMTP id 493F256158; Wed, 16 Jun 2021 04:43:56 -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 oY9Xuf-K1vQP; Wed, 16 Jun 2021 04:43:56 -0400 (EDT) Received: from tron.gnat.com (tron.gnat.com [205.232.38.10]) by rock.gnat.com (Postfix) with ESMTP id 223315615F; Wed, 16 Jun 2021 04:43:56 -0400 (EDT) Received: by tron.gnat.com (Postfix, from userid 4862) id 2146C180; Wed, 16 Jun 2021 04:43:56 -0400 (EDT) Date: Wed, 16 Jun 2021 04:43:56 -0400 From: Pierre-Marie de Rodat To: gcc-patches@gcc.gnu.org Subject: [Ada] Do not generate an Itype_Reference node for slices in GNATprove mode Message-ID: <20210616084356.GA96192@adacore.com> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.5.23 (2014-03-12) X-Spam-Status: No, score=-12.6 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: Yannick Moy Errors-To: gcc-patches-bounces+incoming=patchwork.ozlabs.org@gcc.gnu.org Sender: "Gcc-patches" As part of the work on changing side-effects removal in SPARK, a special case was introduced to generate an Itype_Reference for Itypes in slices. This was based on a misunderstanding of existing checks for bounds when analyzing slices. These Itype_Reference are actually not needed to get the corresponding run-time checks in GNATprove, and are actually harmful in some cases (inside quantified expressions) as the insertion point for the Itype_Reference ends up being outside of the quantifier scope, leading to unprovable checks. Tested on x86_64-pc-linux-gnu, committed on trunk gcc/ada/ * sem_res.adb (Set_Slice_Subtype): Revert special-case introduced previously, which is not needed as Itypes created for slices are precisely always used. 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 @@ -12607,10 +12607,9 @@ package body Sem_Res is -- the point where actions for the slice are analyzed). Note that this -- is different from freezing the itype immediately, which might be -- premature (e.g. if the slice is within a transient scope). This needs - -- to be done only if expansion is enabled, or in GNATprove mode to - -- capture the associated run-time exceptions if any. + -- to be done only if expansion is enabled. - elsif Expander_Active or GNATprove_Mode then + elsif Expander_Active then Ensure_Defined (Typ => Slice_Subtype, N => N); end if; end Set_Slice_Subtype;