Guardian Procedure Calls Reference Manual (G06.25+)

Introduction to Guardian Procedure Calls
Guardian Procedure Calls Reference Manual—522629-013
1-9
TAL Syntax for a Guardian Procedure Call
INT 16-bit integer
INT(32) 32-bit integer
STRING character string (8-bit character)
FIXED 64-bit fixed-point number
REAL 32-bit floating-point number
EXTADDR 32-bit address
Refer to the
pTAL Reference Manual for a complete discussion
of formal parameter specifications.
The parameter type is followed by a colon. Additional
information after the colon includes:
value means the actual value or contents of a
parameter are passed.
ref:x means that this is a reference parameter, that
is, the address of the parameter is passed.
(The statements within the program must
access the actual parameter contents indirectly
through the parameter location.)
x indicates
the number of elements the parameter
contains. In this example, * indicates that the
number of elements in the
nodename
parameter depends on another variable (in this
case,
length).
.EXT means the parameter is a reference parameter
accessed by an extended pointer.
If a parameter is defined as “STRING:ref,” or “STRING
.EXT:ref,” an integer variable can be passed for “STRING:ref”
parameter in TAL, the compiler produces instructions to convert
address of the integer variable to the address (as a number of 8-
bit characters) of the first character (byte) of that integer
variable; this conversion is erroneous if the original address is
greater than 32767.
For “STRING:ref,” parameters in TAL or for pTAL, no address
conversion is necessary and the limit does not apply.
7 This describes the information that is passed or returned in the
parameter.