Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!bloom-beacon!athena.mit.edu!jfc
From: jfc@athena.mit.edu (John F Carr)
Newsgroups: comp.lang.c
Subject: Re: Question about linking files
Message-ID: <10126@bloom-beacon.MIT.EDU>
Date: 27 Mar 89 03:17:17 GMT
References: <18925@iuvax.cs.indiana.edu> <16541@mimsy.UUCP> <16546@mimsy.UUCP>
Sender: daemon@bloom-beacon.MIT.EDU
Reply-To: jfc@athena.mit.edu (John F Carr)
Organization: Massachusetts Institute of Technology
Lines: 31

In article <16546@mimsy.UUCP> chris@mimsy.UUCP (Chris Torek) writes:
>>Given that the pANS does not have the concept of a `library', or
>>even of `separate compilation', ...

>The VAX-assembly-code function foo() [deleted] calls whichever function is
>linked immediately following it, so eliding that function because it
>appears unused changes the execution.

Does the standard have anything to say about linking to programs written
in other languages, or even compiled by different compilers?  Would a 
compiler & environment (i.e. linker) that loaded by C function instead of
file (and therefore broke the deleted example) be conforming?  Assume
that this hypothetical compiler works correctly on all C programs.

A more important problem is this:  there are at least two strategies for
passing structures to and from functions.  One is to pass the structure
on the stack, the other is for the caller to pass a pointer.  Modules
compiled using different methods will not work together.  Does the
standard offer any guidance in this case?  As long as not all compilers are
bug-free, there will be reasons to use different compilers on parts of the
same program.  

(My guess at the answer to the above questions: "the standard can not attempt
to define behavior when different compilers are used for different source
files, or when interacting with languages other than standard C.")

--
   John Carr             "When they turn the pages of history,
   jfc@Athena.mit.edu     When these days have passed long ago,
   bloom-beacon!          Will they read of us with sadness
   athena.mit.edu!jfc     For the seeds that we let grow?"  --Neil Peart