Newsgroups: comp.unix.sysv386
Path: utzoo!telly!evan
From: evan@telly.on.ca (Evan Leibovitch)
Subject: Why can't elves cough?
Organization: Somewhere just far enough out of Toronto
Date: Tue, 5 Mar 91 03:47:42 GMT
Message-ID: <27D314DF.1D4E@telly.on.ca>

This question is about
	"elf" (the format of executable files under System V release 4)
and
	"coff" (the format now used in Release 3.2)

At the recent meeting of Uniforum Toronto, we received a fairly detailed
description of Release 4. It was mentioned that Release 4 will properly
execute coff-format files, even though they prefer elf (through an
emulator?).

As I understand it, however, the elf-format files produced on Release 4
systems will not run on 3.2 systems. This means that someone wanting to
produce software for the 386 UNIX market cannot rely totally on the
Release 4 software to develop software for the entire marketplace, since
SCO in its wisdom :-P has decided not to bother with Release 4.

Or does it mean something else?

Is there indeed no backwards compatability in the R4 compiler? Although
the obvious answer is to buy SCO because binaries compiled on it will
run on all UNIX vendors' current releases, I'm very hesitant to buy
software mainly because it's the lowest common denominator.

So what are the other choices? Which of these options is best? Are they
even possible? Are there other options?

- If you have a present copy of Interactive/Dell/ESIX R3.2, can you hang
  onto the 3.2 software development set when you upgrade to R4? Then you
  could load the 3.2 compiler, which should run fine under R4 (though the
  libraries will still be the old ones).

- Are there any plans for SCO 3.2 to support elf? Considering the
  direction the company is going (back to the Xenix philosophy), it
  seems that such a move would not be in the company's strategic
  interest. But we can hope...

- Use gcc. Can it possibly be built to use the R4 libraries, while
  having a run-time switch to produce either coff or elf?

- Will it be economically worthwhile for a commercial compiler vendor to
  offer a development set with cross-compiling options?

A larger question is "what are the advantages of compiling for elf when
coff is more portable?" What features of R4 *require* something to be
compiled with elf?

Thanks for your patience. And sorry for the pun.

-- 
 Evan Leibovitch, Sound Software, located in beautiful Brampton, Ontario
       evan@telly.on.ca / uunet!attcan!telly!evan / (416) 452-0504
           Vanilla Ice is a few cubes short of a full tray...