System Debug Reference Manual (32650-90888)

Chapter 7 301
Symbolic Formatting Symbolic Access
The Path Specification
$nmdat > SYMFILES
GRADTYP GRADTYP.DEMO.TELESUP
$nmdat >
In summary the following steps must be performed before a symbolic data type file is ready
for use by System Debug:
1. Construct a small program which contains all type declarations to be made available to
System Debug. The program must have at least one executable statement, and the type
declarations must all appear at the level of the outer block.
2. Compile data types with the $SYMDEBUG 'xdb'$ option.
3. Run the relocatable library generated by the compiler through the Link Editor.
4. Run the program file generated by the Link Editor through PXDB.
5. Prepare the modified program file generated by PXDB with System Debug SYMPREP
command.
6. Open the program file with System Debug SYMOPEN command.
The Path Specification
Path specifications are used to qualify data structure references to some desired level of
granularity.
Syntax
[ symname : ] typename [ selector ... ][, variantinfo ]
Parameters
symname A symbolic name assigned to a symbolic data type file in the SYMOPEN
command. This parameter specifies the file in which
typename is to be
found. If omitted, the last symbolic file referenced is used.
typename The name of the data structure to be formatted.
selector ... The selectors used to dereference particular components of the data
structure identified by
typename . Multiple selectors are permitted.
The following selectors, based on Pascal syntax, are recognized:
[
index ]
Array selector specifies a component of an array.
.
field
Record selector specifies a field within a record.
^ Pointer selector specifies pointer dereferencing.
variantinfo A list of variant tag values to be used when formatting tagless variants, or