From owner-sc22wg5@open-std.org Fri Nov 27 01:33:41 2009 Return-Path: X-Original-To: sc22wg5-dom8 Delivered-To: sc22wg5-dom8@www2.open-std.org Received: by www2.open-std.org (Postfix, from userid 521) id DDFB5C77129; Fri, 27 Nov 2009 01:33:41 +0100 (CET) X-Original-To: sc22wg5@open-std.org Delivered-To: sc22wg5@open-std.org Received: from ns.nag-j.co.jp (218-42-159-107.cust.bit-drive.ne.jp [218.42.159.107]) by www2.open-std.org (Postfix) with ESMTP id CCD4FC77121 for ; Fri, 27 Nov 2009 01:33:38 +0100 (CET) Received: from 218-42-159-108.cust.bit-drive.ne.jp ([218.42.159.108] helo=Marucomputer) by ns.nag-j.co.jp with smtp (Exim 4.50) id 1NDokS-00062C-7O for sc22wg5@open-std.org; Fri, 27 Nov 2009 09:31:44 +0900 Message-ID: From: "Malcolm Cohen" To: "WG5" References: <4B0ECF95.1040209@lbl.gov> <20091126224156.4BCB9C76BCD@www2.open-std.org> In-Reply-To: <20091126224156.4BCB9C76BCD@www2.open-std.org> Subject: Re: [ukfortran] (SC22WG5.4129) (j3.2006) Interoperability of dummyarrays Date: Fri, 27 Nov 2009 09:34:07 +0900 Organization: =?utf-8?B?5pel5pysTkFH?= MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset="utf-8"; reply-type=response Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 14.0.8089.726 X-MimeOLE: Produced By Microsoft MimeOLE V14.0.8089.726 Sender: owner-sc22wg5@open-std.org Precedence: bulk > Aleksandar Donev schrieb: >> Hello, >> >> Ok, this is embarrassing, but...I was reading 15.3.6 again and realized I >> cannot quite figure this out. What is the C prototype for this interoperable >> routine? There is no unique prototype. >> subroutine test(n,x,y) It's not interoperable, because it does not have the BIND(C) attribute. SUBROUTINE test(n,x,y) BIND(C) >> use iso_c_binding >> integer(c_int), dimension(3), intent(in) :: n >> real(c_double), dimension(n(1),n(2),n(3)) :: x >> real(c_double), dimension(n(1),n(2),n(3),*) :: y >> end subroutine Well, one prototype that it interoperates with might be void test(int *,double *,double *); though a better one would be void test(int[3],double[],double[]); I am looking at F2003; note that 15.2.6 item (5) does not require that the dummy argument interoperates with the formal parameter, it merely requires that the formal parameter be a pointer type and that the dummy argument interoperates with "an entity of the referenced type". So all this requires is that such an entity exists, which it surely does (probably a different entity for each possible value of n(1:3), but that seems to be no problem). Reinhold Bader wrote: > my impression is that the intent of 15.3.6 is to inductively flatten this > into a one-dimensional > structure, so > > void test(n[3], x[NPROD], y[]); > > where NPROD must have the value n(1)*n(2)*n(3) I don't agree. The intent cannot have been to deliberately exclude adjustable arrays from C interoperability (which requiring the actual dimension to be written in would effectively do), that would be crazy. > (and you strictly speaking need to specify BIND(C) on the > subroutine statement). That's not "strictly"; there are a number of cases where specifying BIND(C) with a particular compiler gives you a different ABI in practice, not just in theory. Cheers, -- ................................Malcolm Cohen, Nihon NAG, Tokyo.