From patchwork Thu Jan 11 09:09:34 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: 858951 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-470797-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="RTNhb4zN"; 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 3zHKp34QVZz9t3h for ; Thu, 11 Jan 2018 20:09:47 +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=tFZuYB+TvQec5TB7g8mFAMTW8iOwvBOYcYwm6inO1/Uv+x8uVO rAZDDQ15qVXCulJje69T/tOASMPj9irNDRxDSEyH2Kc/WHgIEk2oXroubm4y2tj2 TpjbOL5ZndtjbPl5qW9IslhUsgO8UhuK9TsyjL4YJYykL5ttFXMupTnUw= 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=cg5gR8L/VRGTlgKxoE+YI8SXlAA=; b=RTNhb4zNWUzSyMRsfyrt 4xNu9/7VBM3z7tBlJG8GOGiATAu0OWQ9uwCJGLnOVwfOLoVQBMZh9aypgZruTI9I f297H19DTOsy1uQSq9+x+dCmUtjYn9J+dDGmoW1pf4EtgD3J1J4EmBdjx+eQVbwI lhZoOUEo4M+h70UuiqUDwl0= Received: (qmail 64864 invoked by alias); 11 Jan 2018 09:09:38 -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 64780 invoked by uid 89); 11 Jan 2018 09:09:37 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-11.9 required=5.0 tests=BAYES_00, GIT_PATCH_2, GIT_PATCH_3, RCVD_IN_DNSWL_NONE, SPF_PASS autolearn=ham version=3.3.2 spammy=dispatching, sk:check_a 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 09:09:35 +0000 Received: from localhost (localhost.localdomain [127.0.0.1]) by filtered-rock.gnat.com (Postfix) with ESMTP id 48EDF117BC0; Thu, 11 Jan 2018 04:09:34 -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 IXjXUmUdy7vv; Thu, 11 Jan 2018 04:09:34 -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 36520117BBE; Thu, 11 Jan 2018 04:09:34 -0500 (EST) Received: by tron.gnat.com (Postfix, from userid 4862) id 3516250B; Thu, 11 Jan 2018 04:09:34 -0500 (EST) Date: Thu, 11 Jan 2018 04:09:34 -0500 From: Pierre-Marie de Rodat To: gcc-patches@gcc.gnu.org Cc: Ed Schonberg Subject: [Ada] Crash on expression function as completion, with implicit dereference Message-ID: <20180111090934.GA103294@adacore.com> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.5.23 (2014-03-12) X-IsSubscribed: yes An implicit dereference freezes the corresponding designated type. Most implicit dereferences are made explicit during expansion, but this is not the case for a dispatching call where the the controlling parameter and the corresponding controlling argument are access to a tagged type. In that case, to enforce the rule that an expression function that is a completion freezes type references within, we must locate controlling arguments of an access type and freeze explicitly the corresponding designated type. Tested on x86_64-pc-linux-gnu, committed on trunk 2018-01-11 Ed Schonberg gcc/ada/ * sem_ch6.adb (Freeze_Expr_Types): If an access value is the controlling argument of a dispatching call. freeze the corresponding designated type. gcc/testsuite/ * gnat.dg/expr_func3.adb, gnat.dg/expr_func3.ads: New testcase. --- gcc/ada/sem_ch6.adb +++ gcc/ada/sem_ch6.adb @@ -423,6 +423,20 @@ package body Sem_Ch6 is Check_And_Freeze_Type (Designated_Type (Etype (Node))); end if; + -- An implicit dereference freezes the designated type. In the + -- case of a dispatching call whose controlling argument is an + -- access type, the dereference is not made explicit, so we must + -- check for such a call and freeze the designated type. + + if Nkind (Node) in N_Has_Etype + and then Present (Etype (Node)) + and then Is_Access_Type (Etype (Node)) + and then Nkind (Parent (Node)) = N_Function_Call + and then Node = Controlling_Argument (Parent (Node)) + then + Check_And_Freeze_Type (Designated_Type (Etype (Node))); + end if; + -- No point in posting several errors on the same expression if Serious_Errors_Detected > 0 then--- /dev/null new file mode 100644 +++ gcc/testsuite/gnat.dg/expr_func3.adb @@ -0,0 +1,7 @@ +-- { dg-do compile } + +package body Expr_Func3 is + + procedure Dummy is null; + +end Expr_Func3;--- /dev/null new file mode 100644 +++ gcc/testsuite/gnat.dg/expr_func3.ads @@ -0,0 +1,18 @@ +package Expr_Func3 is + + type Obj_T is abstract tagged null record; + + type T is access all Obj_T'Class; + + function Slave (Obj : access Obj_T) return T is (T(Obj)); + + function Optional_Slave (Obj : T) return T; + + procedure Dummy; + +private + + function Optional_Slave (Obj : T) return T is + (if Obj = null then null else Slave (Obj)); + +end Expr_Func3;