Path: utzoo!mnetor!uunet!lll-winken!lll-tis!mordor!sri-spam!sri-unix!quintus!ok
From: ok@quintus.UUCP (Richard A. O'Keefe)
Newsgroups: comp.software-eng
Subject: Re: Question Re: Configuration Management
Message-ID: <735@cresswell.quintus.UUCP>
Date: 5 Mar 88 01:41:22 GMT
References: <497@aimt.UUCP> <2640@ihlpe.ATT.COM> <188@dinl.mmc.UUCP> <2745@mmintl.UUCP>
Organization: Quintus Computer Systems, Mountain View, CA
Lines: 24
Keywords: linkers, software design, ADA

In article <2745@mmintl.UUCP>, franka@mmintl.UUCP (Frank Adams) writes:
a In article <697@cresswell.quintus.UUCP> ok@quintus.UUCP (Richard A. O'Keefe) writes:
a o We could profitably turn this into a survey of what the linker
a o requirements of various languages are:  could an ADA compiler easily
a o use the UNIX / VMS / MVS / PR1MOS linker?
a In a word, no.  A linker for Ada must check for matching of user-defined
a types in different modules.

In two words, not quite.  There are two things:  planning a link (which
involves working out where to find things and checking that the operation
requested makes sense) and *doing* the link.  Is there any reason why an
ADA compiler could not generate two files: a description file and an
object file, and an ADA linker could not use the information in the
description files to validate and plan the link, and then use the
UNIX / VMS / MVS / PR1MOS linker to *do* the link?  If an ADA program is
to include foreign code (ADA-FORTRAN is a particularly interesting case)
mustn't something like this be done?  Simula has similar link validation
requirements, but Simula compilers normally use the system-supplied linker.

I'm not claiming that this is the best way to do it.
I'm just trying to draw a distinction between finishing off a compilation
and linking.  Maybe there isn't any such distinction if you look hard
enough.  The Burroughs BINDER certainly managed to check interfaces as it
bound together COBOL, ALGOL, and FORTRAN.  Is the fact that the UNIX
linker doesn't check interfaces its greatest weakness?