From owner-sc22wg5@open-std.org Wed Dec 3 17:27:12 2008 Return-Path: X-Original-To: sc22wg5-dom7 Delivered-To: sc22wg5-dom7@www2.open-std.org Received: by www2.open-std.org (Postfix, from userid 521) id 04A9AC56CF8; Wed, 3 Dec 2008 17:27:12 +0100 (CET) X-Original-To: sc22wg5@open-std.org Delivered-To: sc22wg5@open-std.org Received: from mail1.cray.com (mail1.cray.com [136.162.0.111]) by www2.open-std.org (Postfix) with ESMTP id 29370C4596D for ; Wed, 3 Dec 2008 17:27:09 +0100 (CET) Received: from beaver.us.cray.com (beaver.us.cray.com [172.30.74.51]) by mail1.cray.com (8.13.6/8.13.3/gw-5323) with ESMTP id mB3GR5Mb000400 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Wed, 3 Dec 2008 10:27:05 -0600 (CST) Received: from CFEXFE01.us.cray.com (cfexfe01.us.cray.com [172.30.74.93]) by beaver.us.cray.com (8.13.8/8.13.3/hub-5273) with ESMTP id mB3GR4Qb028375; Wed, 3 Dec 2008 10:27:04 -0600 Received: from mh-dhcp-172-31-16-160.us.cray.com ([172.31.16.160]) by CFEXFE01.us.cray.com over TLS secured channel with Microsoft SMTPSVC(6.0.3790.3959); Wed, 3 Dec 2008 10:27:04 -0600 Message-ID: <4936B3D3.9060500@cray.com> Date: Wed, 03 Dec 2008 10:29:07 -0600 From: Bill Long Reply-To: longb@cray.com Organization: Cray Inc. User-Agent: Thunderbird 2.0.0.9 (Macintosh/20071031) MIME-Version: 1.0 To: fortran standards email list for J3 Cc: sc22wg5@open-std.org Subject: Re: (j3.2006) (SC22WG5.3708) Comment on N1761 References: <20081127195627.3CEA7C178D6@www2.open-std.org> <200812011440.22725.donev1@llnl.gov> <20081202134612.5BECAC178E1@www2.open-std.org> <200812021000.58528.donev1@llnl.gov> <20081203132148.DA084C178E0@www2.open-std.org> In-Reply-To: <20081203132148.DA084C178E0@www2.open-std.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 03 Dec 2008 16:27:04.0209 (UTC) FILETIME=[FA0DA010:01C95563] X-Cray-VirusStatus: clean Sender: owner-sc22wg5@open-std.org Precedence: bulk Reinhold Bader wrote: > > before taking this offline, I'd like to understand something about BIND(C) > which other people might know ... > > Take the following example program: > > module mod_label_interf > use, intrinsic :: iso_c_binding > implicit none > interface foo > subroutine foo_1(x, n, i) bind(c, name='Foo') > import :: c_float, c_int > real(c_float) :: x > integer(c_int), value :: n, i > end subroutine > subroutine foo_2(x, n, i) bind(c, name='Foo') > import :: c_float, c_int > real(c_float) :: x(*) > integer(c_int), value :: n, i > end subroutine > end interface > end module > program label_interf > use mod_label_interf > implicit none > integer(c_int) :: i > real(c_float) :: xx, xxx(3) > i = 2 > call foo(xx, 1, i) > call foo(xxx, 3, i) > write(*, *) xx > write(*, *) xxx > end program > > together with the C implementation > > #include > > void Foo(float *x, int n, int i) { > int j; > for (j=0; j *(x+j) = (float) (i + j) + 0.1; > } > } > > This code is accepted by various processors and executes in accordance with my > personal expectations (for what that is worth :-)). > It is not accepted by NAG's compiler, and also not by IBM xlf. NAG's error message is > > Error: label_interf.f90: Duplicate binding label 'Foo' for external procedure FOO_2 and external procedure FOO_1 > This error message is consistent with the Fortran 2003 rules. An (non-abstract) interface declares the procedure name to be external. However, in the case of a separate binding label, that rule is being changed in Fortran 2008 to be the way you want it. If there is a separate binding label then the procedure's name becomes a local name, not external. Cheers, Bill -- Bill Long longb@cray.com Fortran Technical Support & voice: 651-605-9024 Bioinformatics Software Development fax: 651-605-9142 Cray Inc., 1340 Mendota Heights Rd., Mendota Heights, MN, 55120