User Tools

Site Tools


ibm:vm370-lib:cmshelp:define.helpdbg

DEFINE

DEBUG Commands

define.helpdbg.txt
DEFINE                                                         DEBUG subcommand

Use the DEFINE subcommand to assign a symbolic name to a specific storage
address.  Once a symbolic name is assigned to a storage address, that symbolic
name can be used to refer to that address in any of the other DEBUG
subcommands.

The format of the DEFINE subcommand is:
+----------+------------------------------------------------------------------+
| DEFine   | symbol hexloc [4|count]                                          |
+----------+------------------------------------------------------------------+
where:

symbol   is the name to be assigned to the storage address derived from the
         second operand, hexloc.  Symbol may be from one to eight characters
         long, and must contain at least one nonhexadecimal character.  Any
         symbolic name longer than eight characters is left-justified and
         truncated on the right after the eighth character.

hexloc   is the hexadecimal storage location, in relation to the current
         origin, to which the name specified in the first operand (symbol),
         is assigned.

count    is a decimal number, between 1 and 56 inclusive, which specifies the
         length in bytes of the field whose name is specified by the first
         operand (symbol) and whose starting location is specified by the
         second operand (hexloc).  When bytecount is not specified, 4 is
         assumed.


Usage Notes:

1.  Issuing the DEFINE subcommand creates an entry in the debug symbol table.
    The entry consists of the symbol name, the storage address, and the length
    of the field.  A maximum of 16 symbols can be defined in the debug symbol
    table at any given time.

2.  When a DEFINE subcommand specifies a symbol that already exists in the
    debug symbol table, the storage address derived from the current request
    replaces the previous storage address.  Several symbols may be assigned to
    the same storage address, but each of these symbols constitutes one entry
    in the debug symbol table.  The symbols remain defined until they are
    redefined or until an IPL subcommand loads a new copy of CMS.

3.  When you assign a symbolic name to a storage location, you must know the
    current origin (set by the ORIGIN subcommand).  The hexloc you specify is
    added to the current origin to create the entry in the symbol table used by
    DEBUG subcommands.  If you change the current origin, existing entries are
    not changed.

4.  You can use symbolic names to refer to storage locations when you issue the
    DEBUG subcommands BREAK, DUMP, GO, ORIGIN, STORE, and X.
ibm/vm370-lib/cmshelp/define.helpdbg.txt ยท Last modified: 2023/08/06 13:36 by Site Administrator