Re: [open-cobol-list] gdb support from gcc-cobol

[Keisuke Nishida]

At Sun, 01 Jun 2003 22:19:18 +0200,
Bernard Giroud wrote:
> 
> >   WORKING-STORAGE SECTION.
> >   01 G.
> >     02 X PIC X(2).
> >     02 Y PIC X(2).
> >
> > the address of X and Y are expressed by "b_G + 0" and
> > "b_G + 2" respectively.  How could you store these information?
> 
> I checked this; it is not sufficient actually.
> Only the group information is present.

The current compiler does an optimization that eliminates
unused field descriptions from the output.  That is, the
following program

       IDENTIFICATION DIVISION.
       PROGRAM-ID. prog.
       DATA DIVISION.
       WORKING-STORAGE SECTION.
       01 G.
         02 X PIC X(2).
         02 Y PIC X(2).
       PROCEDURE DIVISION.
         DISPLAY Y.

will be converted into something like this:

int prog ()
{
  ...
  static unsigned char b_G[4];
  static cob_field f_Y = {2, b_G + 2, &cob_alnum_attr};

  cob_display (&f_Y);
  ...
}

Probably we should output all field descriptions (i.e.,
f_G, f_X, and f_Y) when the option `-g' is turned on.
Do you think this is sufficient to access all fields?

There might be other issues on field access.  The output
does not contain anything about the OCCURS ... [DEPENDING
ON ...] clause.  Maybe we need some extension.

Keisuke