1 ;;;; support and placeholders for System Area Pointers (SAPs) in the host
2 ;;;; Common Lisp at cross-compile time
4 ;;;; This software is part of the SBCL system. See the README file for
7 ;;;; This software is derived from the CMU CL system, which was
8 ;;;; written at Carnegie Mellon University and released into the
9 ;;;; public domain. The software is in the public domain and is
10 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
11 ;;;; files for more information.
15 ;;; SYSTEM-AREA-POINTER is not a primitive type in ANSI Common Lisp,
16 ;;; so we need a compound type to represent it in the host Common Lisp
17 ;;; at cross-compile time:
18 (defstruct (system-area-pointer (:constructor make-sap) (:conc-name "SAP-"))
19 ;; the integer representation of the address
20 (int (error "missing SAP-INT argument") :type sap-int-type :read-only t))
22 ;;; cross-compilation-host analogues of target-CMU CL primitive SAP operations
25 (defun sap+ (sap offset)
26 (declare (type system-area-pointer sap) (type sap-int-type offset))
27 (make-sap :int (+ (sap-int sap) offset)))
29 ,@(mapcar (lambda (info)
30 (destructuring-bind (sap-fun int-fun) info
31 `(defun ,sap-fun (x y)
32 (,int-fun (sap-int x) (sap-int y)))))
33 '((sap< <) (sap<= <=) (sap= =) (sap>= >=) (sap> >) (sap- -))))
35 ;;; dummies, defined so that we can declare they never return and thereby
36 ;;; eliminate a thundering herd of optimization notes a la "can't optimize this
37 ;;; expression because we don't know the return type of SAP-REF-8"
38 (defun sap-ref-stub (name)
39 (error "~S doesn't make sense on cross-compilation host." name))
41 ,@(mapcan (lambda (name)
42 `((declaim (ftype (function (system-area-pointer fixnum) nil)
44 (defun ,name (sap offset)
45 (declare (ignore sap offset))
46 (sap-ref-stub ',name))
47 ,@(let ((setter-stub (gensym "SAP-SETTER-STUB-")))
48 `((defun ,setter-stub (foo sap offset)
49 (declare (ignore foo sap offset))
50 (sap-ref-stub '(setf ,name)))
51 (defsetf ,name ,setter-stub)))))