Invocation of a procedure registered as a user handler

A PL/I parameter declared as a structure expects an extra PL/I descriptor; however, Language Environment passes argument lists by reference and has no knowledge of PL/I descriptors. Therefore for the parameter list to be received, declare the parameters with the OPTIONS(BYVALUE) option as shown in Figure 1.

Figure 1. Parameter declarations in a PL/I user-written condition handler

 PLIHDLR: PROC(ptr1, ptr2, ptr3, ptr4) OPTIONS(BYVALUE);

    DCL (ptr1, ptr2, ptr3, ptr4)  POINTER;
    DCL 1 Current_condition       BASED(ptr1)
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                                             ;
    DCL Token FIXED BIN(31)       BASED(ptr2);
    DCL Result_code FIXED BIN(31) BASED(ptr3);
    DCL 1 New_condition           BASED(ptr4)
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                                             ;