[Bug cobol/126541] New: cobol1: error recovery: implicit define missing data items

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126541

            Bug ID: 126541
           Summary: cobol1: error recovery: implicit define missing data
                    items
           Product: gcc
           Version: 17.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: cobol
          Assignee: unassigned at gcc dot gnu.org
          Reporter: simonsobisch at gnu dot org
  Target Milestone: ---

in case when there's a typo in the DATA DIVISION - or a missing/wrong copybook,
the same variable is error'd all over the place - and quickly fills
-fmax-errors

test.cob:658:23: error: DATA-ITEM ‘S-GEWM’ not found
  658 |               COMPUTE S-GEWM = S-GEWSALDOZSM /
      |                       ^~~~~~~~~
test.cob:661:25: error: DATA-ITEM ‘Z-S-GEWM’ not found
  661 |               MOVE 0 TO S-GEWM.
      |                         ^~~~~~~~~
test.cob:689:25: error: DATA-ITEM ‘Z-S-GEWM’ not found
  689 |               MOVE 0 TO S-GEWM.
      |                         ^~~~~~~~~
test.cob:702:17: error: DATA-ITEM ‘S-GEWM’ not found
  702 |            MOVE S-GEWM       TO DNL-GEWM.
      |                 ^~~~~~~~~
test.cob:777:25: error: DATA-ITEM ‘Z-S-GEWM’ not found
  777 |               MOVE 0 TO S-GEWM.
      |                         ^~~~~~~~~
test.cob:956:25: error: DATA-ITEM ‘Z-S-GEWM’ not found
  956 |               MOVE 0 TO S-GEWM.
      |                         ^~~~~~~~~

I suggest to internally define it, preferably per its use; which is what
GnuCOBOL does.

Example: the COMPUTE above would copy the S-GEWSALDOZSM defintion in - or
simply defines a PIC S9(18)v(12) item.
If there is a MOVE "ABCD" TO UNDEF-VAR it would be defined as PIC X(4), or
bigger...
That would be similar for other user-defined names like "OPEN fd-name".


Also note the cc1 way of "not defined"... and then suppress all follow-up
warnings on that same data-item.