From patchwork Thu Sep 19 13:28:19 2019 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: 1164619 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=gcc.gnu.org (client-ip=209.132.180.131; helo=sourceware.org; envelope-from=gcc-patches-return-509280-incoming=patchwork.ozlabs.org@gcc.gnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=adacore.com Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=gcc.gnu.org header.i=@gcc.gnu.org header.b="TntaqrXR"; dkim-atps=neutral Received: from sourceware.org (server1.sourceware.org [209.132.180.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 46YyQj5Gx9z9sN1 for ; Thu, 19 Sep 2019 23:30:37 +1000 (AEST) DomainKey-Signature: a=rsa-sha1; c=nofws; d=gcc.gnu.org; h=list-id :list-unsubscribe:list-archive:list-post:list-help:sender:date :from:to:cc:subject:message-id:mime-version:content-type; q=dns; s=default; b=bfaAjcyPRclP8S2Fehmge1KPsUrDhmjPORv0bXF1G7RnSoUb2I HenqoLs8BVuIvaxVcjhbeHYeUBE7ozEpteZTd0SBGBq4w8UcHRrN2BJu10Dv7A08 vatrDWgxddVvnSOOTO+rkHvk0zAL74gmn4xG+ochvfOjq3wdHXpL8oV6U= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=gcc.gnu.org; h=list-id :list-unsubscribe:list-archive:list-post:list-help:sender:date :from:to:cc:subject:message-id:mime-version:content-type; s= default; bh=3Vnoh/K+iBISBendWduYAMLVCAI=; b=TntaqrXRnQkAFioMbPfY C7udYTfND24ib8fzGoTU9cB8PBma2Ec2QWliWzzYS4kujC2GkFRRXtHuoBRdGduj c2JFUGJLN8Q53O5jXq35GWscM8sdK52WVDkQHunpxK6TFE10oqxpbLdW1mf8t0dD qgHEoxPtcSH/M+JDhZZHUvk= Received: (qmail 2275 invoked by alias); 19 Sep 2019 13:28:31 -0000 Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org Delivered-To: mailing list gcc-patches@gcc.gnu.org Received: (qmail 2016 invoked by uid 89); 19 Sep 2019 13:28:29 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-10.8 required=5.0 tests=AWL, BAYES_00, GIT_PATCH_2, GIT_PATCH_3, SPF_NEUTRAL autolearn=ham version=3.3.1 spammy=is_type, current_scope, Is_Type, Current_Scope X-HELO: eggs.gnu.org Received: from eggs.gnu.org (HELO eggs.gnu.org) (209.51.188.92) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Thu, 19 Sep 2019 13:28:28 +0000 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iAwTw-0001Nm-Vo for gcc-patches@gcc.gnu.org; Thu, 19 Sep 2019 09:28:26 -0400 Received: from rock.gnat.com ([2620:20:4000:0:a9e:1ff:fe9b:1d1]:58698) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iAwTv-0001K9-7f for gcc-patches@gcc.gnu.org; Thu, 19 Sep 2019 09:28:23 -0400 Received: from localhost (localhost.localdomain [127.0.0.1]) by filtered-rock.gnat.com (Postfix) with ESMTP id 5EDFE56023; Thu, 19 Sep 2019 09:28:19 -0400 (EDT) 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 wUr1x-X5G1w4; Thu, 19 Sep 2019 09:28:19 -0400 (EDT) Received: from tron.gnat.com (tron.gnat.com [205.232.38.10]) by rock.gnat.com (Postfix) with ESMTP id 4978156020; Thu, 19 Sep 2019 09:28:19 -0400 (EDT) Received: by tron.gnat.com (Postfix, from userid 4862) id 485B06B4; Thu, 19 Sep 2019 09:28:19 -0400 (EDT) Date: Thu, 19 Sep 2019 09:28:19 -0400 From: Pierre-Marie de Rodat To: gcc-patches@gcc.gnu.org Cc: Bob Duff Subject: [Ada] Memory leak with 'Range of a function call in a loop Message-ID: <20190919132819.GA41719@adacore.com> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.5.23 (2014-03-12) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 2620:20:4000:0:a9e:1ff:fe9b:1d1 X-IsSubscribed: yes If a for loop starts with "for X in F (...)'Range loop", where F is a function returning an unconstrained array, then memory is leaked. This patch fixes that bug. Running these commands: gnatmake -q -f main.adb main On the following sources: with Text_IO; use Text_IO; package P is function Get_Objects return String; end P; package body P is function Get_Objects return String is begin return "xyzzy"; end Get_Objects; end P; with Text_IO; use Text_IO; pragma Warnings (Off, "an internal GNAT unit"); with System.Secondary_Stack; pragma Warnings (On, "an internal GNAT unit"); with P; use P; procedure Main is Max_Iterations : constant Integer := 1_000; procedure Leak_Call is begin for Id in Get_Objects'Range loop null; end loop; end Leak_Call; procedure SS_Info is new System.Secondary_Stack.SS_Info (Text_IO.Put_Line); begin for Iteration in 1 .. Max_Iterations loop Leak_Call; end loop; SS_Info; end Main; Should produce the following output: Secondary Stack information: Total size : 10240 bytes Current allocated space : 0 bytes Number of Chunks : 1 Default size of Chunks : 10240 Tested on x86_64-pc-linux-gnu, committed on trunk 2019-09-19 Bob Duff gcc/ada/ * sem_attr.adb (Resolve_Attribute): Make sure the secondary stack is properly managed in the case of a 'Range attribute in a loop. --- gcc/ada/sem_attr.adb +++ gcc/ada/sem_attr.adb @@ -11570,6 +11570,16 @@ package body Sem_Attr is begin if not Is_Entity_Name (P) or else not Is_Type (Entity (P)) then Resolve (P); + + -- If the prefix is a function call returning on the secondary + -- stack, we must make sure to mark/release the stack. + + if Nkind (P) = N_Function_Call + and then Nkind (Parent (N)) = N_Loop_Parameter_Specification + and then Requires_Transient_Scope (Etype (P)) + then + Set_Uses_Sec_Stack (Scope (Current_Scope)); + end if; end if; Dims := Expressions (N);