To:		SC22

From:		Miles Ellis, Convenor: SC22/WG5

Date:		1995-07-24

Subject:Request for subdivision of project JTC1.22.02.01 to produce a

Technical Report (Type 2) on Interoperability between Fortran and C





WG5 requests SC22 to subdivide project JTC1.22.02.01 in order to permit work on

the following sub-project:





1.	Title



Interoperability between Fortran and C





2.	Scope



To define language facilities that will permit Fortran procedures to call C

procedures.





3.	Purpose and justification



A significant fraction of the standard computing environment (bothde facto or de

jure) comes with a C API.  Examples include X-windows libraries, Motif, TCP/IP

socket calls and interfaces to system routines.  The Fortran programmer is

currently unable to exploit this wealth of software in a portable manner.  This

causes many problems for those who, for example, wish to front-end a powerful

scientific visualisation package, written in Fortran, with a sophisticated graphical

user interface (GUI).  Due to the difficulties of providing such an interface in a

standard fashion, many users are turning to alternative languages for such

applications, even if Fortran is ideally suited to the "computational" component

of the task.



It is therefore very important that a standard mechanism by which C procedures

can be called from Fortran procedures is defined as soon as possible.



At its meeting in Tokyo, Japan, 1995-04-17/21, WG5 resolved to adopt a new

approach for accelerating standardization of certain key features which were

deemed to be too urgent to wait for the next revision of the Fortran Standard. 

This approach, which is based on the production of Type 2 Technical Reports that

would be incorporated unaltered in the next revision unless experience in their

implementation and use demanded changes, is described in SC22 N1862.



It is proposed, therefore, to produce a type 2 technical report to define the

necessary language extensions and to place them in the public domain.  It is

intended that these extensions will be included without change in a subsequent

revision of the Fortran standard, unless experience in implementing and using

them indicates that there are serious inadequacies in the definition.  It is hoped

that this will allow for a rapid technical development and for early testing well

before a subsequent language revision.  





4.	Programe of work



A Type 2 Technical Report will be developed for this project.





5.	Relevant documents to be considered



ISO/IEC 1539-1 : Draft CD 1995Programming Language Fortran Part 1 (SC22

N1842



The following are the major relevant WG5 papers (minor papers responding to

these are not cited here):



N1088 (1995-03)	Ineroperability and the CERN Program Library (J Shiers)

N1089 (1995-03)	Inter-operability (K Bierman)

N1096 (1995-03)	Extrinsic C Interfaces (J L Wagener)





6.	Cooperation and liaison



ANSI/X3J3 _ US Fortran Technical Committee





7.	Preparatory work offered with target date(s)



This topic has been considered by WG5, and it is expected that a document will be

ready for balloting as a PDTR by April 1996.



The Convenor, Miles Ellis (UK), is the proposed editor for this technical report.



There will be no requirement for a maintenance agency or registration authority

for this project.



There are no known requirements for coding.



The proposed technical report does not concern any known patented items.