From lrr@cray.com Fri Feb 2 22:17:27 1996 Received: from timbuk.cray.com (root@timbuk.cray.com [128.162.19.7]) by dkuug.dk (8.6.12/8.6.12) with ESMTP id WAA01499 for ; Fri, 2 Feb 1996 22:17:15 +0100 Received: from ironwood.cray.com (root@ironwood-fddi.cray.com [128.162.21.36]) by timbuk.cray.com (8.6.12/CRI-gate-8-2.11) with ESMTP id PAA15065 for ; Fri, 2 Feb 1996 15:17:00 -0600 Received: from poplar409 (lrr@poplar409 [128.162.149.9]) by ironwood.cray.com (8.6.12/CRI-ccm_serv-8-2.8) with SMTP id PAA26462 for ; Fri, 2 Feb 1996 15:16:57 -0600 From: Larry Rolison Received: by poplar409 (5.x/btd-b3) id AA17307; Fri, 2 Feb 1996 15:16:55 -0600 Message-Id: <9602022116.AA17307@poplar409> Subject: Erik Kruyt's interface question To: SC22WG5@dkuug.dk Date: Fri, 2 Feb 1996 15:16:54 -0600 (CST) X-Mailer: ELM [version 2.4 PL24-CRI-b] Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sorry that I'm sending this to everyone but I dug through the messages from Erik and could not find an address just for him. But others might be interested in my response to his question anyway. Erik asked: 4. What is wrong with the following code (the compilers I tried did not accept it): subroutine sub(dum1, dum2) !subroutine with two dummy procedure arguments interface subroutine dum1(dum) interface real function dum(arg) real, intent(in) :: arg end function dum end interface end subroutine dum1 real function dum2(arg) real, intent(in) :: arg end function dum2 end interface call dum1(dum2(1.)) end subroutine sub In fact, NONE of the compilers I tried it with accepted it. And they all rejected it for the same reason (but different wording): Our compiler said: %>$g90 -en -m0 kruyt.f call dum1(dum2(1.)) ^ cf90-502 cft90: ERROR SUB, File = kruyt.f, Line = 15, Column = 19 This actual argument is not a program unit. Dummy argument "DUM" is a dummy procedure. Nag said: %>nagc kruyt.f Error: Expected procedure for argument DUM (no. 1) of DUM1 at line 15 [f90 error termination] And EPC said: %>epc kruyt.f EPC Fortran-90 Version 1.0.1 Sparc:200194:105916 Copyright (c) 1993,1994 EPCL. All Rights Reserved. kruyt.f external subroutine SUB call dum1(dum2(1.)) ^ Error 260 at (15:kruyt.f) : This subroutine has the wrong number of arguments or arguments with the wrong name, type or rank The problem with your program, Erik, is that you are passing a VALUE to DUM1, not a procedure name. Look at the call to DUM1 again in our message just above. You are passing DUM2(1.). Since this dummy argument is an expression, the expression is evaluated, which of course causes DUM2 to be executed and a real result returned. Thus, you are trying to pass a real value to DUM1 rather than a procedure name. To get this right, you need to change it to call dum1(dum2) and then from within DUM1 call the dummy argument corresponding to DUM2 passing the value "1.". ------------------------------------------------------------------------------ Larry Rolison lrr@cray.com Cray Research, Inc. 655F Lone Oak Drive Eagan, MN 55121 ------------------------------------------------------------------------------