[open-cobol-list] Re: feature request: implementation "IS EXTERNAL" (semantics)

[Thomas Biehler]

On Sunday 09 November 2003 01:22, you wrote:
> At Tue, 4 Nov 2003 14:11:25 +0100,
>
> Thomas Biehler wrote:
> > in the application which i am trying to port to open-cobol
> > there are many programs which call (many) subprograms
> > and report the success or failure in the calling program
> > via an "external message block".
> >
> > They use a message field (IS EXTERNAL) which the subprogram
> > fills and the calling program references.
> >
> > Without the (full) implementation of is EXTERNAL all program's
> > are to change. (I assume that would be the death of that port !)
> > (Passing the message via Parameter or in another way ...)
> >
> > I have seen that "IS EXTERNAL" is already partially implemented.
> >
> > It would be a great help for me, if it would be completed.
> > (I know that's not trivial)
>
> I have implemented it in CVS.  Could you please test it?
>
> Keisuke

Hi Keisuke,

i have tested it with no success.
(First i try our real application. 
After that i wrote the two (short) test programs
for the demonstration of the problem)

I have attached my two testprograms:
   EXTERNALBUG.cob  which calls UPROG.cob

here is the compiler output 
with the current CVS-Version of open-cobol:
==============================================================
1) EXTERNALBUG.cob

#> cobc -save-temps -g -v -std=cobol85 EXTERNALBUG.cob
preprocessing EXTERNALBUG.cob into EXTERNALBUG.i
translating EXTERNALBUG.i into EXTERNALBUG.c
gcc -c -o EXTERNALBUG.o -I~/devel/include -g EXTERNALBUG.c
gcc -rdynamic  -o EXTERNALBUG EXTERNALBUG.o  -L~/devel/lib -lcob -lm -ldb 
-lgmp -lltdl -lncurses
EXTERNALBUG.o: In function `EXTERNALBUG':
~/cobol/testprog/EXTERNALBUG.c:42: undefined reference to 
`EXTERNAL_GROUP_FIELD'
~/cobol/testprog/EXTERNALBUG.c:43: undefined reference to 
`EXTERNAL_GROUP_FIELD'
~/cobol/testprog/EXTERNALBUG.c:36: undefined reference to 
`EXTERNAL_GROUP_FIELD'
collect2: ld returned 1 exit status

2) UPROG.cob

#> cobc -save-temps -m -g -v -std=cobol85 UPROG.cob
preprocessing UPROG.cob into UPROG.i
translating UPROG.i into UPROG.c
gcc -c -o UPROG.o -I~/devel/include -g UPROG.c
gcc -shared  -o UPROG.so UPROG.o -L~/devel/lib -lcob -lm -ldb -lgmp -lltdl 
-lncurses


And here is the expected result :  (compiled and running with MF-COBOL)
==============================================================
#> cobrun EXTERNALBUG.int
BEFORE CALL UPROG
ALPHA-FIELD:VALUE FROM EXTERNALBUG        
I am the UPROG Program
AFTER CALL UPROG
ALPHA-FIELD:VALUE FROM UPROG              


I need some more time for testing and supporting you with the standard 
requirements of the "IS EXTERNAL" Feature. 
(First i must reread the standards ...)
Perhaps my testprograms are clear enought ?! 
(for the (first) problem)

Bye

Thomas

EXTERNALBUG.cob
Description: Text document

UPROG.cob
Description: Text document