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: 1492832 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 4G4fFL63fSz9sXL for ; Wed, 16 Jun 2021 18:56:54 +1000 (AEST) Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 47CF8399C00F for ; Wed, 16 Jun 2021 08:56:52 +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 ESMTPS id 376A8393C856 for ; Wed, 16 Jun 2021 08:44:01 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 376A8393C856 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 4DCA95615F; 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 KAsnoCTI+O7e; 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 2B6C956157; Wed, 16 Jun 2021 04:43:56 -0400 (EDT) Received: by tron.gnat.com (Postfix, from userid 4862) id 2A6C9180; 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] Ignore volatile restrictions in preanalysis Message-ID: <20210616084356.GA96276@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: Piotr Trojanek Errors-To: gcc-patches-bounces+incoming=patchwork.ozlabs.org@gcc.gnu.org Sender: "Gcc-patches" When detecting references to volatile objects in expressions of the expression functions we couldn't determine the enclosing function. This was because we examined a copy of the expression made for preanalysis and this copy is not properly decorated. Consequently, we wrongly rejected valid references like: Data : Integer with Atomic, Async_Readers => True, Async_Writers => True; function F return Integer is (Data) with Volatile_Function; This patch effectively disables the detection of references to volatile objects in preanalysis by assuming all such references to be legal. Tested on x86_64-pc-linux-gnu, committed on trunk gcc/ada/ * sem_util.adb (Is_OK_Volatile_Context): All references to volatile objects are legal in preanalysis. (Within_Volatile_Function): Previously it was wrongly called on Empty entities; now it is only called on E_Return_Statement, which allow the body to be greatly simplified. diff --git a/gcc/ada/sem_util.adb b/gcc/ada/sem_util.adb --- a/gcc/ada/sem_util.adb +++ b/gcc/ada/sem_util.adb @@ -18871,27 +18871,14 @@ package body Sem_Util is ------------------------------ function Within_Volatile_Function (Id : Entity_Id) return Boolean is - Func_Id : Entity_Id; + pragma Assert (Ekind (Id) = E_Return_Statement); - begin - -- Traverse the scope stack looking for a [generic] function - - Func_Id := Id; - while Present (Func_Id) and then Func_Id /= Standard_Standard loop - if Ekind (Func_Id) in E_Function | E_Generic_Function then - - -- ??? This routine could just use Return_Applies_To, but it - -- is currently wrongly called by unanalyzed return statements - -- coming from expression functions. - pragma Assert (Func_Id = Return_Applies_To (Id)); + Func_Id : constant Entity_Id := Return_Applies_To (Id); - return Is_Volatile_Function (Func_Id); - end if; - - Func_Id := Scope (Func_Id); - end loop; + begin + pragma Assert (Ekind (Func_Id) in E_Function | E_Generic_Function); - return False; + return Is_Volatile_Function (Func_Id); end Within_Volatile_Function; -- Local variables @@ -18901,6 +18888,15 @@ package body Sem_Util is -- Start of processing for Is_OK_Volatile_Context begin + -- Ignore context restriction when doing preanalysis, e.g. on a copy of + -- an expression function, because this copy is not fully decorated and + -- it is not possible to reliably decide the legality of the context. + -- Any violations will be reported anyway when doing the full analysis. + + if not Full_Analysis then + return True; + end if; + -- For actual parameters within explicit parameter associations switch -- the context to the corresponding subprogram call.