From patchwork Thu Jan 11 09:08:34 2018 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: 858947 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-470793-incoming=patchwork.ozlabs.org@gcc.gnu.org; receiver=) Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=gcc.gnu.org header.i=@gcc.gnu.org header.b="FM7OVVfn"; 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 3zHKmv03Fnz9t3k for ; Thu, 11 Jan 2018 20:08:44 +1100 (AEDT) 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=clSz0d+jIAmvyNSTG0F4Y+am3QO+mgANGhjf7mgHqgxb2VBywn g7KBcmSm8x35ifoRs3E4/vn6fgE/dNirtIo1JISeL93Y9iD3gqCZifN6kVgc5gZC xTCZorFe3T6GyooSlBJR4W0elDGUzDXJ825Z+gEtERgIFSIvE5Ftu7Vwk= 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=+TQFt2yYVAyKHYYARhslRgzNQDU=; b=FM7OVVfnNd/o5LcrMtzL ErbzRAkukJ7kNrFUhNGKXi/5aVy78Meg4modmNH9buWoHbZFmAffbjG0zhTnEjfJ 00wcWOBEJ6TdgM9VsaQPL3K/C1Fo/dBnxJ+uVpHOtdrBvzMuXEIQ/Rh7uriiwOcB w0AIImGCCl4gVgT8hv/PnaA= Received: (qmail 55251 invoked by alias); 11 Jan 2018 09:08:37 -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 54737 invoked by uid 89); 11 Jan 2018 09:08:37 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-11.9 required=5.0 tests=AWL, BAYES_00, GIT_PATCH_2, GIT_PATCH_3, RCVD_IN_DNSWL_NONE, SPF_PASS autolearn=ham version=3.3.2 spammy= X-HELO: rock.gnat.com Received: from rock.gnat.com (HELO rock.gnat.com) (205.232.38.15) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Thu, 11 Jan 2018 09:08:35 +0000 Received: from localhost (localhost.localdomain [127.0.0.1]) by filtered-rock.gnat.com (Postfix) with ESMTP id 79FDB117BC0; Thu, 11 Jan 2018 04:08:34 -0500 (EST) 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 x46kIq4dqwSX; Thu, 11 Jan 2018 04:08:34 -0500 (EST) Received: from tron.gnat.com (tron.gnat.com [205.232.38.10]) by rock.gnat.com (Postfix) with ESMTP id 69564117BBE; Thu, 11 Jan 2018 04:08:34 -0500 (EST) Received: by tron.gnat.com (Postfix, from userid 4862) id 651E950B; Thu, 11 Jan 2018 04:08:34 -0500 (EST) Date: Thu, 11 Jan 2018 04:08:34 -0500 From: Pierre-Marie de Rodat To: gcc-patches@gcc.gnu.org Cc: Hristian Kirtchev Subject: [Ada] Secondary stack leak due to controlled component Message-ID: <20180111090834.GA103210@adacore.com> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.5.23 (2014-03-12) X-IsSubscribed: yes This pach modifies the expansion related to initialization calls and secondary stack usage to inspec the components of a type derived from Limited_Controlled or Controlled. Previously controlled types were treated as never utilizing the secondary stack, however this is not true because a controlled type may contain a component initialized by a function which returns on the secondary stack. ------------ -- Source -- ------------ -- pack1.ads with Ada.Finalization; use Ada.Finalization; package Pack1 is type Ctrl is new Controlled with record Comp : Integer; end record; function Make_Ctrl return Ctrl; end Pack1; -- pack1.adb package body Pack1 is Empty : constant Ctrl := (Controlled with Comp => 123); function Make_Ctrl return Ctrl is begin return Empty; end Make_Ctrl; end Pack1; -- pack2.ads with Ada.Finalization; use Ada.Finalization; with Pack1; use Pack1; package Pack2 is type Ctrl_Wrap is new Controlled with record Comp : Ctrl := Make_Ctrl; end record; end Pack2; -- main.adb with Pack2; use Pack2; procedure Main is procedure Make_Ctrl_Wrap is Obj : Ctrl_Wrap; pragma Warnings (Off, Obj); begin null; end Make_Ctrl_Wrap; begin for Iter in 1 .. 10_000 loop Make_Ctrl_Wrap; end loop; end Main; ---------------------------- -- Compilation and output -- ---------------------------- $ gnatmake -q main.adb $ valgrind ./main >& valgrind.log $ grep -c "still reachable" valgrind.log 0 Tested on x86_64-pc-linux-gnu, committed on trunk 2018-01-11 Hristian Kirtchev gcc/ada/ * sem_res.adb (Uses_SS): A controlled type requires the secondary stack if it contains at least one component declaration employing a function call returning on the secondary stack. --- gcc/ada/sem_res.adb +++ gcc/ada/sem_res.adb @@ -889,10 +889,7 @@ package body Sem_Res is Full_Type := T; end if; - if Is_Controlled (Full_Type) then - return False; - - elsif Is_Array_Type (Full_Type) then + if Is_Array_Type (Full_Type) then return Uses_SS (Component_Type (Full_Type)); elsif Is_Record_Type (Full_Type) then