7.2->8.0 compatibility [Informational]

[barmar@Think.COM (Barry Margolin)]

    Date: Wed, 21 Mar 90 15:07 PST
    From: Mark Freeman <MFreeman@VERMITHRAX.SCH.Symbolics.COM>

    There is no guarantee that binaries compiled in 7.2.2 will load
    and run successfully in 8.0, although it might work in some
    instances.  Source code is upwardly compatable; sources written
    in releases before 8.0 can be compiled and run in 8.0.

Just thought I'd let you know that this may be a royal pain for us.  We
are shipping a new release of our software this summer, just after 8.0
is released.  Some of the customers may not be able to upgrade to 8.0 by
then (this will cause particular problems with QA, since we may be doing
our beta release at about the same time as 8.0's customer release, so
our beta sites probably won't have 8.0 running).  How do you propose we
maintain and distribute a release when our customers are likely to be
running a mix of 7.2 and 8.0?  I'm considering modifying our
DEF-FILE-SET facility to name binary files with a different suffix in
8.0 (e.g.  ".8bin") so that they can coexist in the same directory.  If
I do this, is there a way to make ordinary LOAD recognize these as well,
so that when the user executes (load "file") it looks for file.8bin
before looking for file.bin (sometimes users use LOAD to load files
compiled by DEF-FILE-SET, and I also need a way to bootstrap
DEF-FILE-SET).

The simple answer for us would be to delay support for 8.0 until the
following release.  But we have at least one customer that is pushing us
for 8.0 support (they're an 8.0 beta site, and they're considering
recompiling everything right now, and taking their chances running in a
configuration we can't duplicate).  I would also like to run 8.0 here as
soon as possible, so delaying 8.0 support is not attractive to me.

I take it from your answer that 8.0 won't automatically complain when
asked to load a pre-8.0 binary.  This sucks as well.  If they aren't
compatible then it should complain; if it doesn't complain then they
should be compatible.  How are we supposed to find all the binary files
that need to be recompiled?  I'm not just talking about the files in our
release, which we could automate, I mean all the users' files.  I
remember lots of complaints (not just from this site) about the same
aspect of 7.0 and 7.2, yet you still haven't addressed it.

                                                barmar