RE: GOBACK vs EXIT PROGRAM

["Jon Paris" <Jon.Paris@xxxxxxxxxxxxxx>]

 >> please explain the difference between GOBACK and EXIT PROGRAM for me(and
maybe a lot of others?)

GOBACK was added in ANSI '85 (I think) as an answer to the age-old problem
caused by the fact that EXIT PROGRAM is ignored when in the main program.
It is just a no-op and cause the logic to drop-though to whatever is next in
the code.  Nasty and produces some very hard to debug situations.  This
causes problems in a multi-language environment where a generic routine may
be called form COBOL as a sub program or from another language, in which
case it would tend to become main.  In many cases programs would be coded as
EXIT PROGRAM followed by STOP RUN on the next line to avoid dropping through
into unexpected logic.  Alternatively in implementations that allowed
non-COBOL programs to appear within the run unit (such as the OS/400 COBOL
implementations) a "stub" program is often used in front of the non-COBOL
programs to ensure that any subsequent COBOL programs are sub programs.
This has the added benefit of increasing performance as the run unit is not
constantly being torn down and then rebuilt.

GOBACK was the "solution" since they couldn't change the definition of EXIT
PROGRAM.  GOBACK acts as an EXIT PROGRAM in a sub program and STOP RUN if it
is in a main.

Jon Paris
Partner400