;-*- Mode:LISP; Package:MACSYMA; Readtable:CL; Base:10 -*-
; This work was produced under the sponsorship of the
;  U.S. Department of Energy.  The Government retains
;  certain rights therein.

; autoload handler for LMI LISPMACHINE ENVIRONMENT for use with DOE-MACSYMA.
; 8/27/85 17:38:33 George Carrette, Paradigm Associates Inc.

(DEFUN SET-UP-AUTOLOAD-CONDITION-HANDLER ()
  ;; this is LISPM specific
  (or (assq 'si:undefined-function eh:condition-default-handlers)
      (push (cons 'si:undefined-function 'autoload-undefined-function-handler)
	    eh:condition-default-handlers)))

(DEFVAR *NOW-AUTOLOADING* ())

(DEFUN AUTOLOAD-UNDEFINED-FUNCTION-HANDLER (condition)
  (let ((f (send condition ':containing-structure)))
    (cond ((not (symbolp f))
	   (values))
	  ('ELSE
	   (LET ((FILE-NAME (GET F 'AUTOLOAD)))
	     (COND ((OR (NULL FILE-NAME)
			(GET F 'ALREADY-TRIED-TO-AUTOLOAD))
		    (VALUES))
		   ((ASSQ F *NOW-AUTOLOADING*)
		    (MERROR "Recursive autoload attempt on ~M" F))
		   ('ELSE
		    (LET ((OLD *NOW-AUTOLOADING*))
		      (unwind-protect
			  (progn (setq *NOW-AUTOLOADING* (cons (cons f file-name)
							       *NOW-AUTOLOADING*))
				 (LET (MEXPRP) (LOAD-FILE FILE-NAME)))
			(setq *now-autoloading* old)))
		    (PUTPROP F FILE-NAME 'ALREADY-TRIED-TO-AUTOLOAD)
		    ;; now some code taken from JPG's FIND0 in SUPRV...
		    (COND ((AND MEXPRP (GET F 'MACRO))
			   (MERROR "LISP MACROs may not be called from MACSYMA level."))
			  ((OR (FBOUNDP F) (AND MEXPRP (MFBOUNDP F)))
			   ;; Win.  Lisp-defined, or called from macsyma level and
			   ;; is macsyma-defined.
			   (VALUES :NEW-VALUE F))
			  ((AND (NOT MEXPRP) (MFBOUNDP F))
			   ;; Sort of a loss, called from lisp level, but defined
			   ;; only at macsyma level.  We want the undefined function
			   ;; handler to take over now, and make sure we never get called
			   ;; on this loser again.
			   (REMPROP F 'AUTOLOAD)
			   (VALUES))
			  (T
			   (MERROR "~A not found" F))))))))))


(set-up-autoload-condition-handler)