HP 3000 Manuals HP 3000 Manuals
func symval
Returns the value of a simple data type specified by a virtual address
and a path.
Syntax
symval (virtaddr path)
Formal Declaration
symval:any (virtaddr:ptr path:str)
Parameters
virtaddr The virtual address of the data structure.
Virtaddr can be a short pointer, a long pointer, or a
full logical code pointer.
path A path specification, as described in chapter 5,
"Symbolic Formatting/Symbolic Access."
Examples
$nmdebug > symopen gradtyp.demo
Opens the symbolic data type file gradtyp.demo. It is assumed that the
Debug variable addr contains the address of a StudentRecord data
structure in virtual memory. The following code fragment is from this
file:
CONST MINGRADES = 1; MAXGRADES = 10;
MINSTUDENTS = 1; MAXSTUDENTS = 5;
TYPE
GradeRange = MINGRADES .. MAXGRADES;
GradesArray = ARRAY [ GradeRange ] OF integer;
Class = ( SENIOR, JUNIOR, SOPHOMORE, FRESHMAN );
NameStr = string[8];
StudentRecord = RECORD
Name : NameStr;
Id : Integer;
Year : Class;
NumGrades : GradeRange;
Grades : GradesArray;
END;
$nmdebug > wl symval(addr "StudentRecord.Name")
Bill
$nmdebug > wl symval(addr, "StudentRecord.Year")
SENIOR
$nmdebug > IF symval(addr "StudentRecord.Year") = "SENIOR" THEN wl "GRAD!"
GRAD!
Refer to the section "Using the Symbolic Formatter" in chapter 5 for more
examples including pointers, arrays, and variant/invariant record
structures.
Limitations, Restrictions
The path specification used by the SYMVAL function must evaluate to a
simple type or a string. In particular, SYMVAL does not return an array,
a record, or a set data structure.