As always it depends.
We had decent COBOL standards in our shop and no programmer "funny
business" (no pushing the bounds). we dropped in every version of
COBOL and had very few issues we also had no issue with LE per se it
wasn't quite a no oops but pretty much.
One shop I was at hit practically every LE issue in the world (that
is where I learned to hate LE which I won't comment on too much here).
The one issue we had with COBOL was that it insisted on putting out
"self explanatory" messages. We had programmers calling our phones
solid for several months. Another COBOL error was to put out a really
mysterious error (its been 15 years so pardon me if I forget what the
error was). I had to call IBM myself as it didn't click any bells.
IBM's response was something like oh yea how about that (or words to
that effect). I suggested to the programmer that he might drop some
of the FD's that weren't used. He did so and the error went away.
Overall if you have decent programmers that don't push the bounds of
reality I would say that you will have more issues with LE than with
COBOL. However if you do god help you.
Ed
On Mar 31, 2015, at 5:51 PM, Frank Swarbrick wrote:
Does anyone have a good list of best practices when migrating to a
new version of a compiler? While our shop is 35+ years old, we
have rarely actually migrated compilers (or even compiler
versions), so we don't have a lot of experience in this area.
When migrating from DOS/VS COBOL to VS COBOL II there were almost
always source code changes, so all programs were tested before they
were migrated, and no program was simply "automatically migrated",
as it were. I'm sure we had COBOL II for at least ten years before
all of our DOS/VS COBOL programs were eliminated. (From what I
hear that's actually better than many shops, which STILL have pre-
COBOL II programs out there!)
Going from VS COBOL II to IBM COBOL for VSE/ESA was a more "normal"
migration. If I remember correctly (and I should because I was
pretty much "in charge" of the migration) we at first only migrated
to the new compiler if other changes were being made to a program
and a special "flag" was set to indicate that this program should
be compiled with the new compiler instead of the older one. Only
after many, many programs were migrated in this fashion (and it
probably took us several years to get to this point, though I
honestly do not recall) did we finally eliminate the COBOL II
compiler altogether. But I believe at no point did we do any kind
of "mass recompile". We simply used COBOL for VSE/ESA for all
programs going forward (old-COBOL had all been converted to COBOL
II or COBOL for VSE/ESA already).
Then we migrated to z/OS and IBM Enterprise COBOL 4.2. Of course
in this situation EVERYTHING was recompiled and regression tested.
So now we're pondering how to get the Enterprise COBOL 5.2. The
easiest thing, of course, would be to simply change our compile
procs to use COBOL 5.2. But being as how COBOL 5.2 has been out
for only a month that's probably not a good idea. Probably the
best thing to do would be to have developers "choose" to use COBOL
5.2 by this 'setting a flag' for an individual program indicating
that their test compiles should use 5.2, and in turn so should
their production compiles. Should we also, at least at first, have
them do a regression test of the current 4.2 results comparing
against the results of the program compiled with 5.2? And for how
long should we keep that up? At some point (6 months? a year?)
we'd want to stop using 4.2 altogether. But we also (I don't
think!) don't want to regression test every single program.
All advice appreciated. Thanks!
Frank SwarbrickApplication Development ArchitectFirstBank --
Lakewood, CO USA
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