Browse Prior Art Database

Run-Time Output Parameter Checking

IP.com Disclosure Number: IPCOM000117734D
Original Publication Date: 1996-May-01
Included in the Prior Art Database: 2005-Mar-31
Document File: 2 page(s) / 54K

Publishing Venue

IBM

Related People

Breslau, FC: AUTHOR [+3]

Abstract

Disclosed is a mechanism for compilers to generate run-time checks for the number or validity of returned (output) parameters.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 53% of the total text.

Run-Time Output Parameter Checking

      Disclosed is a mechanism for compilers to generate run-time
checks for the number or validity of returned (output) parameters.

      It is a mechanism for a compiler to generate a check for the
number of parameters, their correctness in terms of type (e.g.,
floating point or fixed point), and any other ascertainable values
for returned (output) parameters to a subroutine or program.

      (*) contains a mechanism for automatically checking whether or
not calling parameters correspond to called parameters during a
programs' linkage operation.  A similar mechanism may be employed for
verifying the presence and validity of parameters returned by an
invoked program (i.e., output parameters).  When generating code for
a program invocation, the following checks may be embedded in the
generated instruction sequence by the compiler after the return from
the called program has been handled:
  o  Check that the parameter list is still present on return from
the
      invoked program.
  o  Check that the parameter list on return from the invoked program
      is at the same address as the parameter list that was passed to
      the program.
  o  Check that the number of parameters in the list is that expected
      by the invoking program.
  o  For each parameter in the list that was not to be modified by
the
      invoked program, verify that it indeed has not been modified.
  o  For each parameter in the list that was intended to be modified
      by the invoked program, ve...