+ (inst mov temp
+ (make-ea-for-symbol-tls-index *alien-stack*))
+ (inst fs-segment-prefix)
+ (inst add (make-ea :dword :base temp) delta))))
+ #!-sb-thread
+ (:generator 0
+ (unless (zerop amount)
+ (let ((delta (logandc2 (+ amount 3) 3)))
+ (inst add (make-ea-for-symbol-value *alien-stack*)
+ delta)))))
+
+;;; not strictly part of the c-call convention, but needed for the
+;;; WITH-PINNED-OBJECTS macro used for "locking down" lisp objects so
+;;; that GC won't move them while foreign functions go to work.
+(define-vop (touch-object)
+ (:translate touch-object)
+ (:args (object))
+ (:ignore object)
+ (:policy :fast-safe)
+ (:arg-types t)
+ (:generator 0))
+
+#-sb-xc-host
+(defun alien-callback-accessor-form (type sp offset)
+ `(deref (sap-alien (sap+ ,sp ,offset) (* ,type))))
+
+#-sb-xc-host
+(defun alien-callback-assembler-wrapper (index return-type arg-types)
+ "Cons up a piece of code which calls call-callback with INDEX and a
+pointer to the arguments."
+ (declare (ignore arg-types))
+ (let* ((segment (make-segment))
+ (eax eax-tn)
+ (edx edx-tn)
+ (ebp ebp-tn)
+ (esp esp-tn)
+ ([ebp-8] (make-ea :dword :base ebp :disp -8))
+ ([ebp-4] (make-ea :dword :base ebp :disp -4)))
+ (assemble (segment)
+ (inst push ebp) ; save old frame pointer
+ (inst mov ebp esp) ; establish new frame
+ (inst mov eax esp) ;
+ (inst sub eax 8) ; place for result
+ (inst push eax) ; arg2
+ (inst add eax 16) ; arguments
+ (inst push eax) ; arg1
+ (inst push (ash index 2)) ; arg0
+
+ ;; Indirect the access to ENTER-ALIEN-CALLBACK through
+ ;; the symbol-value slot of SB-ALIEN::*ENTER-ALIEN-CALLBACK*
+ ;; to ensure it'll work even if the GC moves ENTER-ALIEN-CALLBACK.
+ ;; Skip any SB-THREAD TLS magic, since we don't expecte anyone
+ ;; to rebind the variable. -- JES, 2006-01-01
+ (load-symbol-value eax sb!alien::*enter-alien-callback*)
+ (inst push eax) ; function
+ (inst mov eax (foreign-symbol-address "funcall3"))
+ (inst call eax)
+ ;; now put the result into the right register
+ (cond
+ ((and (alien-integer-type-p return-type)
+ (eql (alien-type-bits return-type) 64))
+ (inst mov eax [ebp-8])
+ (inst mov edx [ebp-4]))
+ ((or (alien-integer-type-p return-type)
+ (alien-pointer-type-p return-type)
+ (alien-type-= #.(parse-alien-type 'system-area-pointer nil)
+ return-type))
+ (inst mov eax [ebp-8]))
+ ((alien-single-float-type-p return-type)
+ (inst fld [ebp-8]))
+ ((alien-double-float-type-p return-type)
+ (inst fldd [ebp-8]))
+ ((alien-void-type-p return-type))
+ (t
+ (error "unrecognized alien type: ~A" return-type)))
+ (inst mov esp ebp) ; discard frame
+ (inst pop ebp) ; restore frame pointer
+ (inst ret))
+ (finalize-segment segment)
+ ;; Now that the segment is done, convert it to a static
+ ;; vector we can point foreign code to.
+ (let ((buffer (sb!assem::segment-buffer segment)))
+ (make-static-vector (length buffer)
+ :element-type '(unsigned-byte 8)
+ :initial-contents buffer))))