3.4.5 Reporting errors

Classes defined using define-automation-component allow extended error information to be returned for all Automation methods. Within the body of a define-com-method definition, the function set-error-info can be called to describe the error. In addition, this function returns the value of DISP_E_EXCEPTION , which can be returned directly as the hresult from the method.

For example:

(define-com-method (i-test-suite-1 fx) 
    ((this c-test-suite-1))
  (print "in fx")
  (set-error-info :description "foo"
                  :iid 'i-test-suite-1
                  :source "fx"))

LispWorks COM/Automation User Guide and Reference Manual - 21 Feb 2008