-- Here's a sample interface to the Exception Interceptor.

Package Exception_interceptor is

   Type Integer_array_type is array (Integer range <>) of Integer;

   Type Exception_array_type ( Length: Natural ) is record
     Data: Integer_array_type (1..Length);
   end record;
   Type Exception_array_pointer_type is access Exception_array_type;

   Type Frame_type is private;

   -- Now for the 4 subprograms...

   Function Enable return Frame_type;

   Procedure Disable;

   Procedure Retrieve (
      Frame: in Frame_type;
      Signal_array: out Exception_array_pointer_type;
      Mechanism_array: out Exception_array_pointer_type );

   Procedure Free ( Frame: in Frame_type );

private

   Type Frame_type is new Integer;

   Pragma Interface ( Macro, Enable );
   Pragma Import_function ( Enable, Enable_exception_interceptor );

   Pragma Interface ( Macro, Disable );
   Pragma Import_procedure ( Disable, Disable_exception_interceptor );

   Pragma Interface ( Macro, Retrieve );
   Pragma Import_procedure ( Retrieve, Retrieve_exception_arrays,
      Mechanism=>( Value, Reference, Reference ) );

   Pragma Interface ( Macro, Free );
   Pragma Import_procedure ( Free, Free_interceptor_memory,
      Mechanism=>( Value ) );

end;


-- Here's an example of the use of the Exception Interceptor.
-- Step through this program in the debugger to see how it works.

With Exception_interceptor; Use Exception_interceptor;
Procedure Example is

   Frame: Frame_type;
   Signal_array, Mechanism_array: Exception_array_pointer_type;
   I, J: Integer;

begin

   -- Enable the interceptor for this call frame.
   Frame := Exception_interceptor.Enable;

   -- Generate an exception...
   J := 0;
   I := I / J;

   -- If there weren't an exception, we would do this:
   Exception_interceptor.Disable;
   Return;

exception when others =>

   -- Get the arrays.
   Exception_interceptor.Retrieve ( Frame, Signal_array, Mechanism_array );

   -- <In a real program we would do something here>

   -- Now free the arrays.
   Exception_interceptor.Free ( Frame );

   Return;

end;