HP 3000 Manuals

HP Pascal/iX Reference Manual

CALL_PRIVILEGE and EXEC_PRIVILEGE 

CALL_PRIVILEGE and EXEC_PRIVILEGE are System-Dependent MPE/iX Options.

The CALL_PRIVILEGE and EXEC_PRIVILEGE compiler options allow routines to
call and execute privileged mode routines.  To use these compiler
options, the option STANDARD_LEVEL 'EXT_MODCAL'  is required.

The CALL_PRIVILEGE option specifies, for a given routine, the minimum
privilege level that other routines must have to call the specified
routine.  The EXEC_PRIVILEGE option specifies the privilege level at
which a routine will execute.


CAUTION  Routines not specified by the CALL_PRIVILEGE or EXEC_PRIVILEGE
         compiler options are given the lowest privilege level by
         default.  If you specify a routine to have a higher calling or
         executing privilege level, the routine is allowed to override
         safety features in the MPE/iX operating system.  Therefore,
         exercise caution when using CALL_PRIVILEGE and EXEC_PRIVILEGE
         because misuse can destroy your operating system.


Syntax 

$CALL_PRIVILEGE integer$

$EXEC_PRIVILEGE integer$

Parameter 

integer       An integer in the range 0 .  .  3, with 0 being the most
              privileged level and 3 the least.

Default       Privilege level 3.

Location      Before the body of the routine, but after the reserved
              words PROCEDURE or FUNCTION.

Example 

     $STANDARD_LEVEL 'EXT_MODCAL'$
     PROGRAM p;

     PROCEDURE proc1 $CALL_PRIVILEGE 1$ (
        VAR i : integer);
     BEGIN
     END;

     PROCEDURE proc2 $EXEC_PRIVILEGE 2$ (
        VAR i : integer);
     BEGIN
     END;

     PROCEDURE proc3 $CALL_PRIVILEGE 1$
                     $EXEC_PRIVILEGE 0$ (
        VAR i: integer);
     BEGIN
     END;

     BEGIN
     END.

Any routine calling procedure proc1 must execute at privilege level 1 or
level 0.  By default, proc1 executes at privilege level 3.  Procedure
proc2 executes at level 2; a routine calling proc2 may be executing at
any level.  Procedure proc3 executes at privilege level 0; any routine
calling proc3 must be executing at level 1 or higher.

MPE/iX 5.0 Documentation