c-call.lisp

开源跨平台Lisp编译器

         (args :more t))
  (:results (results :more t))
  (:temporary (:sc unsigned-reg :offset rax-offset :to :result) rax)
  (:ignore results)
  (:vop-var vop)
  (:save-p t)
  (:generator 0
    ;; ABI: Direction flag must be clear on function entry. -- JES, 2006-01-20
    (inst cld)
    ;; ABI: AL contains amount of arguments passed in XMM registers
    ;; for vararg calls.
    (move-immediate rax
                    (loop for tn-ref = args then (tn-ref-across tn-ref)
                       while tn-ref
                       count (eq (sb-name (sc-sb (tn-sc (tn-ref-tn tn-ref))))
                                 'float-registers)))
    (inst call function)
    ;; To give the debugger a clue. XX not really internal-error?
    (note-this-location vop :internal-error)))

(define-vop (alloc-number-stack-space)
  (:info amount)
  (:results (result :scs (sap-reg any-reg)))
  (:result-types system-area-pointer)
  (:generator 0
    (aver (location= result rsp-tn))
    (unless (zerop amount)
      (let ((delta (logandc2 (+ amount 7) 7)))
        (inst sub rsp-tn delta)))
    ;; C stack must be 16 byte aligned
    (inst and rsp-tn -16)
    (move result rsp-tn)))

(define-vop (dealloc-number-stack-space)
  (:info amount)
  (:generator 0
    (unless (zerop amount)
      (let ((delta (logandc2 (+ amount 7) 7)))
        (inst add rsp-tn delta)))))

(define-vop (alloc-alien-stack-space)
  (:info amount)
  #!+sb-thread (:temporary (:sc unsigned-reg) temp)
  (:results (result :scs (sap-reg any-reg)))
  (:result-types system-area-pointer)
  #!+sb-thread
  (:generator 0
    (aver (not (location= result rsp-tn)))
    (unless (zerop amount)
      (let ((delta (logandc2 (+ amount 7) 7)))
        (inst mov temp
              (make-ea :qword
                       :disp (+ nil-value
                                (static-symbol-offset '*alien-stack*)
                                (ash symbol-tls-index-slot word-shift)
                                (- other-pointer-lowtag))))
        (inst sub (make-ea :qword :base thread-base-tn
                           :scale 1 :index temp) delta)))
    (load-tl-symbol-value result *alien-stack*))
  #!-sb-thread
  (:generator 0
    (aver (not (location= result rsp-tn)))
    (unless (zerop amount)
      (let ((delta (logandc2 (+ amount 7) 7)))
        (inst sub (make-ea :qword
                           :disp (+ nil-value
                                    (static-symbol-offset '*alien-stack*)
                                    (ash symbol-value-slot word-shift)
                                    (- other-pointer-lowtag)))
              delta)))
    (load-symbol-value result *alien-stack*)))

(define-vop (dealloc-alien-stack-space)
  (:info amount)
  #!+sb-thread (:temporary (:sc unsigned-reg) temp)
  #!+sb-thread
  (:generator 0
    (unless (zerop amount)
      (let ((delta (logandc2 (+ amount 7) 7)))
        (inst mov temp
              (make-ea :qword
                       :disp (+ nil-value
                                (static-symbol-offset '*alien-stack*)
                                (ash symbol-tls-index-slot word-shift)
                                (- other-pointer-lowtag))))
        (inst add (make-ea :qword :base thread-base-tn :scale 1 :index temp)
              delta))))
  #!-sb-thread
  (:generator 0
    (unless (zerop amount)
      (let ((delta (logandc2 (+ amount 7) 7)))
        (inst add (make-ea :qword
                           :disp (+ nil-value
                                    (static-symbol-offset '*alien-stack*)
                                    (ash symbol-value-slot word-shift)
                                    (- other-pointer-lowtag)))
              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))

;;; Callbacks

#-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 result-type argument-types)
  (labels ((make-tn-maker (sc-name)
             (lambda (offset)
               (make-random-tn :kind :normal
                               :sc (sc-or-lose sc-name)
                               :offset offset)))
           (out-of-registers-error ()
             (error "Too many arguments in callback")))
    (let* ((segment (make-segment))
           (rax rax-tn)
           (rcx rcx-tn)
           (rdi rdi-tn)
           (rsi rsi-tn)
           (rdx rdx-tn)
           (rbp rbp-tn)
           (rsp rsp-tn)
           (xmm0 float0-tn)
           ([rsp] (make-ea :qword :base rsp :disp 0))
           ;; How many arguments have been copied
           (arg-count 0)
           ;; How many arguments have been copied from the stack
           (stack-argument-count 0)
           (gprs (mapcar (make-tn-maker 'any-reg) *c-call-register-arg-offsets*))
           (fprs (mapcar (make-tn-maker 'double-reg)
                         ;; Only 8 first XMM registers are used for
                         ;; passing arguments
                         (subseq *float-regs* 0 8))))
      (assemble (segment)
        ;; Make room on the stack for arguments.
        (inst sub rsp (* n-word-bytes (length argument-types)))
        ;; Copy arguments from registers to stack
        (dolist (type argument-types)
          (let ((integerp (not (alien-float-type-p type)))
                ;; A TN pointing to the stack location where the
                ;; current argument should be stored for the purposes
                ;; of ENTER-ALIEN-CALLBACK.
                (target-tn (make-ea :qword :base rsp
                                   :disp (* arg-count
                                            n-word-bytes)))
                ;; A TN pointing to the stack location that contains
                ;; the next argument passed on the stack.
                (stack-arg-tn (make-ea :qword :base rsp
                                       :disp (* (+ 1
                                                   (length argument-types)
                                                   stack-argument-count)
                                                n-word-bytes))))
            (incf arg-count)
            (cond (integerp
                   (let ((gpr (pop gprs)))
                     ;; Argument not in register, copy it from the old
                     ;; stack location to a temporary register.
                     (unless gpr
                       (incf stack-argument-count)
                       (setf gpr temp-reg-tn)
                       (inst mov gpr stack-arg-tn))
                     ;; Copy from either argument register or temporary
                     ;; register to target.
                     (inst mov target-tn gpr)))
                  ((or (alien-single-float-type-p type)
                       (alien-double-float-type-p type))
                   (let ((fpr (pop fprs)))
                     (cond (fpr
                            ;; Copy from float register to target location.
                            (inst movq target-tn fpr))
                           (t
                            ;; Not in float register. Copy from stack to
                            ;; temporary (general purpose) register, and
                            ;; from there to the target location.
                            (incf stack-argument-count)
                            (inst mov temp-reg-tn stack-arg-tn)
                            (inst mov target-tn temp-reg-tn)))))
                  (t
                   (bug "Unknown alien floating point type: ~S" type)))))

        ;; arg0 to FUNCALL3 (function)
        ;;
        ;; 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 expect anyone
        ;; to rebind the variable. -- JES, 2006-01-01
        (inst mov rdi (+ nil-value (static-symbol-offset
                                    'sb!alien::*enter-alien-callback*)))
        (loadw rdi rdi symbol-value-slot other-pointer-lowtag)
        ;; arg0 to ENTER-ALIEN-CALLBACK (trampoline index)
        (inst mov rsi (fixnumize index))
        ;; arg1 to ENTER-ALIEN-CALLBACK (pointer to argument vector)
        (inst mov rdx rsp)
        ;; add room on stack for return value
        (inst sub rsp 8)
        ;; arg2 to ENTER-ALIEN-CALLBACK (pointer to return value)
        (inst mov rcx rsp)

        ;; Make new frame
        (inst push rbp)
        (inst mov  rbp rsp)

        ;; Call
        (inst mov  rax (foreign-symbol-address "funcall3"))
        (inst call rax)

        ;; Back! Restore frame
        (inst mov rsp rbp)
        (inst pop rbp)

        ;; Result now on top of stack, put it in the right register
        (cond
          ((or (alien-integer-type-p result-type)
               (alien-pointer-type-p result-type)
               (alien-type-= #.(parse-alien-type 'system-area-pointer nil)
                             result-type))
           (inst mov rax [rsp]))
          ((or (alien-single-float-type-p result-type)
               (alien-double-float-type-p result-type))
           (inst movq xmm0 [rsp]))
          ((alien-void-type-p result-type))
          (t
           (error "unrecognized alien type: ~A" result-type)))

        ;; Pop the arguments and the return value from the stack to get
        ;; the return address at top of stack.
        (inst add rsp (* (1+ (length argument-types)) n-word-bytes))
        ;; Return
        (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)))))