Guardian Procedure Calls Reference Manual

Entry point bit<4>

Variable bit<5>

Extensible bit<6>

PEP number<7:15>

input

INT:value

specifies that p-reg and stack-env see the process identified by pin rather than the calling

process. The pin parameter can be supplied only by privileged callers.

Returned Value

INT

A file-system error code that indicates the outcome of the call:

Successful call; the procedure name is deposited into proc-name for proc-name-length bytes.0

A procedure name was not found. This value is returned if an I/O error occurs during the read of the associated

object file or if p-reg, stackenv, and the optional pin are valid but do not indicate a code location

associated with a procedure (for example, a location in the PEP or XEP).

One of the parameters specifies an address that is out of bounds.22

The p-reg, stack-env, and optional pin parameters do not indicate a valid code location.23

The pin parameter was supplied and the caller is not privileged.24

A required parameter was not supplied29

The supplied value of proc-name-size is less than the length of the procedure name that is to be returned

into proc-name. The procedure name (and any other requested output parameters) is returned in

proc-namebut is truncated to the value of proc-name-size.

122

Considerations

• The maximum value of proc-name-length, and hence the address space that must be

available at the location given by proc-name, depends on the language that was used to

create the code to which p-reg, stack-env, and the optional pin refer.

• Read access to the associated object file is not required in order to obtain the requested output

parameters associated with the given p-reg, stack-env, and optional pin.

Example

INT STACK^ENV = 'L' - 1; ! calling procedure’s stack

ENV

INT P^REG = 'L' - 2; ! calling procedure’s P

LITERAL PROC^NAME^SIZE = 80;

STRING PROC^NAME ! returned ASCII procedure

name

[ 0:PROC^NAME^SIZE-1 ];

INT LENGTH; ! length of returned proc

name

INT BASE; ! procedure base address

INT OFFSET; ! word offset within

procedure

IF (ERROR := ADDRTOPROCNAME ( P^REG, STACK^ENV, PROC^NAME,

PROC^NAME^SIZE, LENGTH,

BASE ) ) THEN

! an error occurred, ERROR has the error code

56 Guardian Procedure Calls (A-B)