IDENTIFICATION DIVISION.
       PROGRAM-ID. CallEdgeCase.
      *> ============================================================
      *> CALL境界テスト (CALL Edge Cases)
      *> CALL CANCEL, 静的CALL, 動的CALL,
      *> CALL ON EXCEPTION, ネストプログラム
      *> ============================================================

       DATA DIVISION.
       WORKING-STORAGE SECTION.
       01 WS-PGM-NAME      PIC X(8) VALUE "SUB-EDGE".
       01 WS-VAL-A         PIC 9(5) VALUE 100.
       01 WS-VAL-B         PIC 9(5) VALUE 200.
       01 WS-RESULT        PIC 9(10) VALUE 0.
       01 WS-EXPECTED      PIC 9(10) VALUE 300.
       01 WS-PASS          PIC 9(2) VALUE 0.
       01 WS-FAIL          PIC 9(2) VALUE 0.
       01 WS-TC            PIC 9(2) VALUE 0.

       PROCEDURE DIVISION.
       MAIN.
           DISPLAY "CALL-EDGE: CALL edge case tests"

      *> T1: CALL ON EXCEPTION (存在しないプログラム)
           ADD 1 TO WS-TC.
           DISPLAY "T1: CALL nonexistent ON EXCEPTION"
           CALL 'NOPGM000' USING WS-VAL-A
               ON EXCEPTION
                   DISPLAY "T1: Exception caught PASS"
                   ADD 1 TO WS-PASS
               NOT ON EXCEPTION
                   DISPLAY "T1: No exception FAIL"
                   ADD 1 TO WS-FAIL
           END-CALL.

      *> T2: CALL CANCEL (呼出→CANCEL→再呼出)
           ADD 1 TO WS-TC.
           DISPLAY "T2: CALL CANCEL cycle"
           MOVE 100 TO WS-VAL-A.
           MOVE 200 TO WS-VAL-B.
           CALL 'SUB-EDGE' USING WS-VAL-A WS-VAL-B WS-RESULT.
           DISPLAY "T2-1: RESULT=" WS-RESULT " (expect 300)".
           CANCEL 'SUB-EDGE'.
           MOVE 50 TO WS-VAL-A.
           MOVE 70 TO WS-VAL-B.
           CALL 'SUB-EDGE' USING WS-VAL-A WS-VAL-B WS-RESULT.
           IF WS-RESULT = 120
               DISPLAY "T2: CANCEL+recall PASS"
               ADD 1 TO WS-PASS
           ELSE
               DISPLAY "T2: CANCEL+recall FAIL (result=" WS-RESULT ")"
               ADD 1 TO WS-FAIL
           END-IF.

      *> T3: CALL with RETURN-CODE
           ADD 1 TO WS-TC.
           MOVE 15 TO WS-VAL-A.
           MOVE 25 TO WS-VAL-B.
           CALL 'SUB-EDGE' USING WS-VAL-A WS-VAL-B WS-RESULT.
           IF RETURN-CODE = 0
               DISPLAY "T3: RETURN-CODE=0 PASS"
               ADD 1 TO WS-PASS
           ELSE
               DISPLAY "T3: RETURN-CODE=" RETURN-CODE " FAIL"
               ADD 1 TO WS-FAIL
           END-IF.

           DISPLAY " "
           DISPLAY "CALL-EDGE: PASS=" WS-PASS " FAIL=" WS-FAIL
           IF WS-FAIL = 0
               DISPLAY "ALL PASSED"
               STOP RUN RETURNING 0
           ELSE
               STOP RUN RETURNING 1
           END-IF
           .

       END PROGRAM CallEdgeCase.

      *> ============================================================
      *> ネストサブプログラム (Nested Subprogram)
      *> ============================================================
       IDENTIFICATION DIVISION.
       PROGRAM-ID. SUB-EDGE.
       DATA DIVISION.
       LINKAGE SECTION.
       01 LK-A             PIC 9(5).
       01 LK-B             PIC 9(5).
       01 LK-RES           PIC 9(10).
       PROCEDURE DIVISION USING LK-A LK-B LK-RES.
           COMPUTE LK-RES = LK-A + LK-B.
           GOBACK.
       END PROGRAM SUB-EDGE.