PARMCHECK
PARMCHECK should only be used in development. It instructs the compiler to allocate a buffer following the last item in the WORKING-STORAGE section. Additional overhead is needed to check the buffer to determine if a called subprogram corrupted data beyond the end of WORKING-STORAGE. NOPARMCHECK is the default setting and is fastest.
PARMCHECK(MSG,n) will output a runtime warning message indicating corrupted storage.
PARMCHECK(ABD,n) will cause an abend when the program storage is corrupt.