;;;; the definition of non-local exit for the x86 VM;;;; This software is part of the SBCL system. See the README file for;;;; more information.;;;;;;;; This software is derived from the CMU CL system, which was;;;; written at Carnegie Mellon University and released into the;;;; public domain. The software is in the public domain and is;;;; provided with absolutely no warranty. See the COPYING and CREDITS;;;; files for more information.(in-package "SB!VM");;; Make an environment-live stack TN for saving the SP for NLX entry.(!def-vm-support-routine make-nlx-sp-tn (env)  (physenv-live-tn   (make-representation-tn *fixnum-primitive-type* any-reg-sc-number)   env));;; Make a TN for the argument count passing location for a non-local entry.(!def-vm-support-routine make-nlx-entry-arg-start-location ()  (make-wired-tn *fixnum-primitive-type* any-reg-sc-number rbx-offset))(defun catch-block-ea (tn)  (aver (sc-is tn catch-block))  (make-ea :qword :base rbp-tn           :disp (- (* (+ (tn-offset tn) catch-block-size) n-word-bytes))));;;; Save and restore dynamic environment.;;;;;;;; These VOPs are used in the reentered function to restore the;;;; appropriate dynamic environment. Currently we only save the;;;; Current-Catch and the alien stack pointer. (Before sbcl-0.7.0,;;;; when there were IR1 and byte interpreters, we had to save;;;; the interpreter "eval stack" too.);;;;;;;; We don't need to save/restore the current UNWIND-PROTECT, since;;;; UNWIND-PROTECTs are implicitly processed during unwinding.;;;;;;;; We don't need to save the BSP, because that is handled automatically.(define-vop (save-dynamic-state)  (:results (catch :scs (descriptor-reg))            (alien-stack :scs (descriptor-reg)))  (:generator 13    (load-tl-symbol-value catch *current-catch-block*)    (load-tl-symbol-value alien-stack *alien-stack*)))(define-vop (restore-dynamic-state)  (:args (catch :scs (descriptor-reg))         (alien-stack :scs (descriptor-reg)))  #!+sb-thread (:temporary (:sc unsigned-reg) temp)  (:generator 10    (store-tl-symbol-value catch *current-catch-block* temp)    (store-tl-symbol-value alien-stack *alien-stack* temp)))(define-vop (current-stack-pointer)  (:results (res :scs (any-reg control-stack)))  (:generator 1    (move res rsp-tn)))(define-vop (current-binding-pointer)  (:results (res :scs (any-reg descriptor-reg)))  (:generator 1    (load-binding-stack-pointer res)));;;; unwind block hackery;;; Compute the address of the catch block from its TN, then store into the;;; block the current Fp, Env, Unwind-Protect, and the entry PC.(define-vop (make-unwind-block)  (:args (tn))  (:info entry-label)  (:temporary (:sc unsigned-reg) temp)  (:results (block :scs (any-reg)))  (:generator 22    (inst lea block (catch-block-ea tn))    (load-tl-symbol-value temp *current-unwind-protect-block*)    (storew temp block unwind-block-current-uwp-slot)    (storew rbp-tn block unwind-block-current-cont-slot)    (inst lea temp (make-fixup nil :code-object entry-label))    (storew temp block catch-block-entry-pc-slot)));;; like MAKE-UNWIND-BLOCK, except that we also store in the specified;;; tag, and link the block into the CURRENT-CATCH list(define-vop (make-catch-block)  (:args (tn)         (tag :scs (any-reg descriptor-reg) :to (:result 1)))  (:info entry-label)  (:results (block :scs (any-reg)))  (:temporary (:sc descriptor-reg) temp)  (:generator 44    (inst lea block (catch-block-ea tn))    (load-tl-symbol-value temp *current-unwind-protect-block*)    (storew temp block  unwind-block-current-uwp-slot)    (storew rbp-tn block  unwind-block-current-cont-slot)    (inst lea temp (make-fixup nil :code-object entry-label))    (storew temp block catch-block-entry-pc-slot)    (storew tag block catch-block-tag-slot)    (load-tl-symbol-value temp *current-catch-block*)    (storew temp block catch-block-previous-catch-slot)    (store-tl-symbol-value block *current-catch-block* temp)));;; Just set the current unwind-protect to TN's address. This instantiates an;;; unwind block as an unwind-protect.(define-vop (set-unwind-protect)  (:args (tn))  (:temporary (:sc unsigned-reg) new-uwp #!+sb-thread tls)  (:generator 7    (inst lea new-uwp (catch-block-ea tn))    (store-tl-symbol-value new-uwp *current-unwind-protect-block* tls)))(define-vop (unlink-catch-block)  (:temporary (:sc unsigned-reg) #!+sb-thread tls block)  (:policy :fast-safe)  (:translate %catch-breakup)  (:generator 17    (load-tl-symbol-value block *current-catch-block*)    (loadw block block catch-block-previous-catch-slot)    (store-tl-symbol-value block *current-catch-block* tls)))(define-vop (unlink-unwind-protect)    (:temporary (:sc unsigned-reg) block #!+sb-thread tls)  (:policy :fast-safe)  (:translate %unwind-protect-breakup)  (:generator 17    (load-tl-symbol-value block *current-unwind-protect-block*)    (loadw block block unwind-block-current-uwp-slot)    (store-tl-symbol-value block *current-unwind-protect-block* tls)));;;; NLX entry VOPs(define-vop (nlx-entry)  ;; Note: we can't list an sc-restriction, 'cause any load vops would  ;; be inserted before the return-pc label.  (:args (sp)         (start)         (count))  (:results (values :more t))  (:temporary (:sc descriptor-reg) move-temp)  (:info label nvals)  (:save-p :force-to-stack)  (:vop-var vop)  (:generator 30    (emit-label label)    (note-this-location vop :non-local-entry)    (cond ((zerop nvals))          ((= nvals 1)           (let ((no-values (gen-label)))             (inst mov (tn-ref-tn values) nil-value)             (inst jrcxz no-values)             (loadw (tn-ref-tn values) start -1)             (emit-label no-values)))          (t           (collect ((defaults))             (do ((i 0 (1+ i))                  (tn-ref values (tn-ref-across tn-ref)))                 ((null tn-ref))               (let ((default-lab (gen-label))                     (tn (tn-ref-tn tn-ref)))                 (defaults (cons default-lab tn))                 (inst cmp count (fixnumize i))                 (inst jmp :le default-lab)                 (sc-case tn                   ((descriptor-reg any-reg)                    (loadw tn start (- (1+ i))))                   ((control-stack)                    (loadw move-temp start (- (1+ i)))                    (inst mov tn move-temp)))))             (let ((defaulting-done (gen-label)))               (emit-label defaulting-done)               (assemble (*elsewhere*)                 (dolist (def (defaults))                   (emit-label (car def))                   (inst mov (cdr def) nil-value))                 (inst jmp defaulting-done))))))    (inst mov rsp-tn sp)))(define-vop (nlx-entry-multiple)  (:args (top)         (source)         (count :target rcx))  ;; Again, no SC restrictions for the args, 'cause the loading would  ;; happen before the entry label.  (:info label)  (:temporary (:sc unsigned-reg :offset rcx-offset :from (:argument 2)) rcx)  (:temporary (:sc unsigned-reg :offset rsi-offset) rsi)  (:temporary (:sc unsigned-reg :offset rdi-offset) rdi)  (:results (result :scs (any-reg) :from (:argument 0))            (num :scs (any-reg control-stack)))  (:save-p :force-to-stack)  (:vop-var vop)  (:generator 30    (emit-label label)    (note-this-location vop :non-local-entry)    (inst lea rsi (make-ea :qword :base source :disp (- n-word-bytes)))    ;; The 'top' arg contains the %esp value saved at the time the    ;; catch block was created and points to where the thrown values    ;; should sit.    (move rdi top)    (move result rdi)    (inst sub rdi n-word-bytes)    (move rcx count)                    ; fixnum words == bytes    (move num rcx)    (inst shr rcx word-shift)           ; word count for <rep movs>    ;; If we got zero, we be done.    (inst jrcxz DONE)    ;; Copy them down.    (inst std)    (inst rep)    (inst movs :qword)    (inst cld)    DONE    ;; Reset the CSP at last moved arg.    (inst lea rsp-tn (make-ea :qword :base rdi :disp n-word-bytes))));;; This VOP is just to force the TNs used in the cleanup onto the stack.(define-vop (uwp-entry)  (:info label)  (:save-p :force-to-stack)  (:results (block) (start) (count))  (:ignore block start count)  (:vop-var vop)  (:generator 0    (emit-label label)    (note-this-location vop :non-local-entry)))(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 rax-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 rsp-tn unwind-block-size)    ;; Set up magic catch / UWP block.    (move block rsp-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)    (inst lea temp-reg-tn (make-fixup nil :code-object entry-label))    (storew temp-reg-tn            block            catch-block-entry-pc-slot)    ;; Run any required UWPs.    (inst lea temp-reg-tn (make-fixup 'unwind :assembly-routine))    (inst jmp temp-reg-tn)    ENTRY-LABEL    ;; Load function from symbol    (load-tl-symbol-value block *unwind-to-frame-function*)    ;; No parameters    (zeroize rcx-tn)    ;; Clear the stack    (inst lea rsp-tn          (make-ea :qword :base rbp-tn :disp (* -3 n-word-bytes)))    ;; Push the return-pc so it looks like we just called.    (pushw rbp-tn -2)    ;; Call it    (inst jmp (make-ea :qword :base block                       :disp (- (* closure-fun-slot n-word-bytes)                                fun-pointer-lowtag)))))