EXCEPTION_INTERCEPTOR

This is a linkable Macro module that intercepts exceptions that pass through
specified stack frames. The arrays that describe the exceptions are saved in
dynamically-allocated memory.  The handling of the exceptions (or lack of
handling) is not affected in any way.

For a discussion of exceptions (also called conditions or signals), see
the VAX/VMS System Services Reference Manual, chapter 10, and the
VAX/VMS Run-Time Library Routines Reference Manual chapter 7.

This module is useful mainly in Ada programs.  Why?  Exceptions are part
of the Ada language.  This is good and bad.  Good:  it's a standard, portable
way of dealing with exceptions.  Bad:  Ada does not have nearly
the power of VMS's Condition Handling Facility.

In Ada, exceptions are simply static names, e.g., CONSTRAINT_ERROR.
There is no way to associate additional information with an Ada exception,
nor is there a way to generate or handle new or unexpected exceptions
in any dynamic sense.

The Exception Interceptor allows Ada programs to handle exceptions as they
are intended to be handled under VMS.  It gives Ada programs access to
the signal and mechanism arrays of exceptions, whether they are Ada exceptions
or general VMS exceptions.

The source file EXCEPTION_INTERCEPTOR.MAR contains instructions for its use.
Included in this submission is an example of using it, EXAMPLE.ADA.  The example
includes a sample Ada interface to the Exception Interceptor.

I would like to hear any questions about, suggestions for, or problems
with this submission.

Submitted by:
	Greg Janée
	General Research Corporation
	5383 Hollister Ave.
	Santa Barbara, CA 93111
	805-964-7724