+
+(define-vop (unwind-to-frame-and-call)
+ (:args (ofp :scs (descriptor-reg))
+ (uwp :scs (descriptor-reg))
+ (function :scs (descriptor-reg)))
+ (:arg-types system-area-pointer system-area-pointer t)
+ (:temporary (:sc sap-reg) temp)
+ (:temporary (:sc unsigned-reg :offset eax-offset) block)
+ (:generator 22
+ ;; Store the function into a non-stack location, since we'll be
+ ;; unwinding the stack and destroying register contents before we
+ ;; use it.
+ (store-tl-symbol-value function
+ *unwind-to-frame-function*
+ temp)
+
+ ;; Allocate space for magic UWP block.
+ (inst sub esp-tn unwind-block-size)
+ ;; Set up magic catch / UWP block.
+ (move block esp-tn)
+ (loadw temp uwp sap-pointer-slot other-pointer-lowtag)
+ (storew temp block unwind-block-current-uwp-slot)
+ (loadw temp ofp sap-pointer-slot other-pointer-lowtag)
+ (storew temp block unwind-block-current-cont-slot)
+
+ (storew (make-fixup nil :code-object entry-label)
+ block
+ catch-block-entry-pc-slot)
+
+ ;; Run any required UWPs.
+ (inst jmp (make-fixup 'unwind :assembly-routine))
+ ENTRY-LABEL
+
+ ;; Load function from symbol
+ (load-tl-symbol-value block *unwind-to-frame-function*)
+
+ ;; No parameters
+ (inst xor ecx-tn ecx-tn)
+
+ ;; Clear the stack
+ (inst lea esp-tn
+ (make-ea :dword :base ebp-tn :disp (* -3 n-word-bytes)))
+
+ ;; Push the return-pc so it looks like we just called.
+ (pushw ebp-tn -2)
+
+ ;; Call it
+ (inst jmp (make-ea :dword :base block
+ :disp (- (* closure-fun-slot n-word-bytes)
+ fun-pointer-lowtag)))))