target-defstruct.lisp

;;;; 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!KERNEL")

(/show0 "target-defstruct.lisp 12")

;;;; structure frobbing primitives

;;; Allocate a new instance with LENGTH data slots.
(defun %make-instance (length)
  (declare (type index length))
  (%make-instance length))

;;; Given an instance, return its length.
(defun %instance-length (instance)
  (declare (type instance instance))
  (%instance-length instance))

;;; Return the value from the INDEXth slot of INSTANCE. This is SETFable.
(defun %instance-ref (instance index)
  (%instance-ref instance index))

;;; Set the INDEXth slot of INSTANCE to NEW-VALUE.
(defun %instance-set (instance index new-value)
  (setf (%instance-ref instance index) new-value))

#!-hppa
(progn
  (defun %raw-instance-ref/word (instance index)
    (declare (type index index))
    (%raw-instance-ref/word instance index))
  (defun %raw-instance-set/word (instance index new-value)
    (declare (type index index)
             (type sb!vm:word new-value))
    (%raw-instance-set/word instance index new-value))

  (defun %raw-instance-ref/single (instance index)
    (declare (type index index))
    (%raw-instance-ref/single instance index))
  (defun %raw-instance-set/single (instance index new-value)
    (declare (type index index)
             (type single-float new-value))
    (%raw-instance-set/single instance index new-value))

  (defun %raw-instance-ref/double (instance index)
    (declare (type index index))
    (%raw-instance-ref/double instance index))
  (defun %raw-instance-set/double (instance index new-value)
    (declare (type index index)
             (type double-float new-value))
    (%raw-instance-set/double instance index new-value))

  (defun %raw-instance-ref/complex-single (instance index)
    (declare (type index index))
    (%raw-instance-ref/complex-single instance index))
  (defun %raw-instance-set/complex-single (instance index new-value)
    (declare (type index index)
             (type (complex single-float) new-value))
    (%raw-instance-set/complex-single instance index new-value))

  (defun %raw-instance-ref/complex-double (instance index)
    (declare (type index index))
    (%raw-instance-ref/complex-double instance index))
  (defun %raw-instance-set/complex-double (instance index new-value)
    (declare (type index index)
             (type (complex double-float) new-value))
    (%raw-instance-set/complex-double instance index new-value))
) ; #!-HPPA

#!+hppa
(progn
(defun %raw-ref-single (vec index)
  (declare (type index index))
  (%raw-ref-single vec index))

(defun %raw-ref-double (vec index)
  (declare (type index index))
  (%raw-ref-double vec index))

#!+long-float
(defun %raw-ref-long (vec index)
  (declare (type index index))
  (%raw-ref-long vec index))

(defun %raw-set-single (vec index val)
  (declare (type index index))
  (%raw-set-single vec index val))

(defun %raw-set-double (vec index val)
  (declare (type index index))
  (%raw-set-double vec index val))

#!+long-float
(defun %raw-set-long (vec index val)
  (declare (type index index))
  (%raw-set-long vec index val))

(defun %raw-ref-complex-single (vec index)
  (declare (type index index))
  (%raw-ref-complex-single vec index))

(defun %raw-ref-complex-double (vec index)
  (declare (type index index))
  (%raw-ref-complex-double vec index))

#!+long-float
(defun %raw-ref-complex-long (vec index)
  (declare (type index index))
  (%raw-ref-complex-long vec index))

(defun %raw-set-complex-single (vec index val)
  (declare (type index index))
  (%raw-set-complex-single vec index val))

(defun %raw-set-complex-double (vec index val)
  (declare (type index index))
  (%raw-set-complex-double vec index val))

#!+long-float
(defun %raw-set-complex-long (vec index val)
  (declare (type index index))
  (%raw-set-complex-long vec index val))
) ; #!+HPPA

(defun %instance-layout (instance)
  (%instance-layout instance))

(defun %set-instance-layout (instance new-value)
  (%set-instance-layout instance new-value))

(defun %make-funcallable-instance (len)
  (%make-funcallable-instance len))

(defun funcallable-instance-p (x) (funcallable-instance-p x))

(defun %funcallable-instance-info (fin i)
  (%funcallable-instance-info fin i))

(defun %set-funcallable-instance-info (fin i new-value)
  (%set-funcallable-instance-info fin i new-value))

(defun funcallable-instance-fun (fin)
  (%funcallable-instance-function fin))

(defun (setf funcallable-instance-fun) (new-value fin)
  (setf (%funcallable-instance-function fin) new-value))

;;;; target-only parts of the DEFSTRUCT top level code

;;; A list of hooks designating functions of one argument, the
;;; classoid, to be called when a defstruct is evaluated.
(defvar *defstruct-hooks* nil)

;;; Catch attempts to mess up definitions of symbols in the CL package.
(defun protect-cl (symbol)
  (/show0 "entering PROTECT-CL, SYMBOL=..")
  (/hexstr symbol)
  (when (and *cold-init-complete-p*
             (eq (symbol-package symbol) *cl-package*))
    (cerror "Go ahead and patch the system."
            "attempting to modify a symbol in the COMMON-LISP package: ~S"
            symbol))
  (/show0 "leaving PROTECT-CL")
  (values))

;;; the part of %DEFSTRUCT which makes sense only on the target SBCL
;;;
;;; (The "static" in the name is because it needs to be done not only
;;; in ordinary toplevel %DEFSTRUCT, but also in cold init as early as
;;; possible, to simulate static linking of structure functions as
;;; nearly as possible.)
(defun %target-defstruct (dd layout)
  (declare (type defstruct-description dd))
  (declare (type layout layout))

  (/show0 "entering %TARGET-DEFSTRUCT")

  (remhash (dd-name dd) *typecheckfuns*)

  ;; (Constructors aren't set up here, because constructors are
  ;; varied enough (possibly parsing any specified argument list)
  ;; that we can't reasonably implement them as closures, so we
  ;; implement them with DEFUN instead.)

  ;; Set FDEFINITIONs for slot accessors.
  (dolist (dsd (dd-slots dd))
    (/show0 "doing FDEFINITION for slot accessor")
    (let ((accessor-name (dsd-accessor-name dsd)))
      ;; We mustn't step on any inherited accessors
      (unless (accessor-inherited-data accessor-name dd)
        (/show0 "ACCESSOR-NAME=..")
        (/hexstr accessor-name)
        (protect-cl accessor-name)
        (/hexstr "getting READER-FUN and WRITER-FUN")
        (multiple-value-bind (reader-fun writer-fun)
            (slot-accessor-funs dd dsd)
          (declare (type function reader-fun writer-fun))
          (/show0 "got READER-FUN and WRITER-FUN=..")
          (/hexstr reader-fun)
          (setf (symbol-function accessor-name) reader-fun)
          (unless (dsd-read-only dsd)
            (/show0 "setting FDEFINITION for WRITER-FUN=..")
            (/hexstr writer-fun)
            (setf (fdefinition `(setf ,accessor-name)) writer-fun))))))

  ;; Set FDEFINITION for copier.
  (when (dd-copier-name dd)
    (/show0 "doing FDEFINITION for copier")
    (protect-cl (dd-copier-name dd))
    ;; We can't use COPY-STRUCTURE for other kinds of objects, notably
    ;; funcallable structures, since it returns a STRUCTURE-OBJECT.
    ;; (And funcallable instances don't need copiers anyway.)
    (aver (eql (dd-type dd) 'structure))
    (setf (symbol-function (dd-copier-name dd))
          ;; FIXME: should use a closure which checks arg type before copying
          #'copy-structure))

  ;; Set FDEFINITION for predicate.
  (when (dd-predicate-name dd)
    (/show0 "doing FDEFINITION for predicate")
    (protect-cl (dd-predicate-name dd))
    (setf (symbol-function (dd-predicate-name dd))
          (ecase (dd-type dd)
            ;; structures with LAYOUTs
            ((structure funcallable-structure)
             (/show0 "with-LAYOUT case")
             (lambda (object)
               (locally ; <- to keep SAFETY 0 from affecting arg count checking
                 (declare (optimize (speed 3) (safety 0)))
                 (/noshow0 "in with-LAYOUT structure predicate closure, OBJECT,LAYOUT=..")
                 (/nohexstr object)
                 (/nohexstr layout)
                 (typep-to-layout object layout))))
            ;; structures with no LAYOUT (i.e. :TYPE VECTOR or :TYPE LIST)
            ;;
            ;; FIXME: should handle the :NAMED T case in these cases
            (vector
             (/show0 ":TYPE VECTOR case")
             #'vectorp)
            (list
             (/show0 ":TYPE LIST case")
             #'listp))))

  (when (dd-doc dd)
    (setf (fdocumentation (dd-name dd) 'structure)
          (dd-doc dd)))

  ;; the BOUNDP test here is to get past cold-init.
  (when (boundp '*defstruct-hooks*)
    (dolist (fun *defstruct-hooks*)
      (funcall fun (find-classoid (dd-name dd)))))

  (/show0 "leaving %TARGET-DEFSTRUCT")
  (values))

;;;; generating out-of-line slot accessor functions

;;; FIXME: Ideally, the presence of the type checks in the functions
;;; here would be conditional on the optimization policy at the point
;;; of expansion of DEFSTRUCT. (For now we're just doing the simpler
;;; thing, putting in the type checks unconditionally.)

;;; KLUDGE: Why use this closure approach at all?  The macrology in
;;; SLOT-ACCESSOR-FUNS seems to be half stub, half OAOOM to me.  --DFL

;;; Return (VALUES SLOT-READER-FUN SLOT-WRITER-FUN).
(defun slot-accessor-funs (dd dsd)

  #+sb-xc (/show0 "entering SLOT-ACCESSOR-FUNS")

  ;; various code generators
  ;;
  ;; Note: They're only minimally parameterized, and cavalierly grab
  ;; things like INSTANCE and DSD-INDEX from the namespace they're
  ;; expanded in.
  (macrolet (;; code shared between funcallable instance case and the
             ;; ordinary STRUCTURE-OBJECT case: Handle native
             ;; structures with LAYOUTs and (possibly) raw slots.
             (%native-slot-accessor-funs (dd-ref-fun-name)
               (let ((instance-type-check-form
                      '(%check-structure-type-from-layout instance layout)))
                 (/show "macroexpanding %NATIVE-SLOT-ACCESSOR-FUNS" dd-ref-fun-name instance-type-check-form)
                 `(let ((layout (dd-layout-or-lose dd))
                        (dsd-raw-type (dsd-raw-type dsd)))
                    #+sb-xc (/show0 "in %NATIVE-SLOT-ACCESSOR-FUNS macroexpanded code")
                    ;; Map over all the possible RAW-TYPEs, compiling
                    ;; a different closure function for each one, so
                    ;; that once the COND over RAW-TYPEs happens (at
                    ;; the time closure is allocated) there are no
                    ;; more decisions to be made and things execute
                    ;; reasonably efficiently.
                    (cond
                     ;; nonraw slot case
                     ((eql dsd-raw-type t)
                      #+sb-xc (/show0 "in nonraw slot case")
                      (%slotplace-accessor-funs
                       (,dd-ref-fun-name instance dsd-index)
                       ,instance-type-check-form))
                     ;; raw slot cases
                     ,@(mapcar (lambda (rtd)
                                 (let ((raw-type (raw-slot-data-raw-type rtd))
                                       (accessor-name
                                        (raw-slot-data-accessor-name rtd)))
                                   `((equal dsd-raw-type ',raw-type)
                                     #+sb-xc (/show0 "in raw slot case")
                                     (%slotplace-accessor-funs
                                      (,accessor-name instance dsd-index)
                                      ,instance-type-check-form))))
                               *raw-slot-data-list*)
                     ;; oops
                     (t
                      (bug "unexpected DSD-RAW-TYPE ~S" dsd-raw-type))))))
             ;; code shared between DEFSTRUCT :TYPE LIST and
             ;; DEFSTRUCT :TYPE VECTOR cases: Handle the "typed
             ;; structure" case, with no LAYOUTs and no raw slots.
             (%colontyped-slot-accessor-funs () (error "stub"))
             ;; the common structure of the raw-slot and not-raw-slot
             ;; cases, defined in terms of the writable SLOTPLACE. All
             ;; possible flavors of slot access should be able to pass
             ;; through here.
             (%slotplace-accessor-funs (slotplace instance-type-check-form)
               (/show "macroexpanding %SLOTPLACE-ACCESSOR-FUNS" slotplace instance-type-check-form)
               `(let ((typecheckfun (typespec-typecheckfun dsd-type)))
                  (values (if (dsd-safe-p dsd)
                              (lambda (instance)
                                (/noshow0 "in %SLOTPLACE-ACCESSOR-FUNS-defined reader")
                                ,instance-type-check-form
                                (/noshow0 "back from INSTANCE-TYPE-CHECK-FORM")
                                ,slotplace)
                              (lambda (instance)
                                (/noshow0 "in %SLOTPLACE-ACCESSOR-FUNS-defined reader")
                                ,instance-type-check-form
                                (/noshow0 "back from INSTANCE-TYPE-CHECK-FORM")
                                (let ((value ,slotplace))
                                  (funcall typecheckfun value)
                                  value)))
                          (lambda (new-value instance)
                            (/noshow0 "in %SLOTPLACE-ACCESSOR-FUNS-defined writer")
                            ,instance-type-check-form
                            (/noshow0 "back from INSTANCE-TYPE-CHECK-FORM")
                            (funcall typecheckfun new-value)
                            (/noshow0 "back from TYPECHECKFUN")
                            (setf ,slotplace new-value))))))

    (let ((dsd-index (dsd-index dsd))
          (dsd-type (dsd-type dsd)))

      #+sb-xc (/show0 "got DSD-TYPE=..")
      #+sb-xc (/hexstr dsd-type)
      (ecase (dd-type dd)

        ;; native structures
        (structure
         #+sb-xc (/show0 "case of DSD-TYPE = STRUCTURE")
         (%native-slot-accessor-funs %instance-ref))

        ;; structures with the :TYPE option

        ;; FIXME: Worry about these later..
        #|
        ;; In :TYPE LIST and :TYPE VECTOR structures, ANSI specifies the
        ;; layout completely, so that raw slots are impossible.
        (list
         (dd-type-slot-accessor-funs nth-but-with-sane-arg-order
                                 `(%check-structure-type-from-dd
                                 :maybe-raw-p nil))
        (vector
         (dd-type-slot-accessor-funs aref
                                 :maybe-raw-p nil)))
        |#
        ))))

;;; Copy any old kind of structure.
(defun copy-structure (structure)
  #!+sb-doc
  "Return a copy of STRUCTURE with the same (EQL) slot values."
  (declare (type structure-object structure))
  (let* ((len (%instance-length structure))
         (res (%make-instance len))
         (layout (%instance-layout structure))
         (nuntagged (layout-n-untagged-slots layout)))

    (declare (type index len))
    (when (layout-invalid layout)
      (error "attempt to copy an obsolete structure:~%  ~S" structure))

    ;; Copy ordinary slots.
    (dotimes (i (- len nuntagged))
      (declare (type index i))
      (setf (%instance-ref res i)
            (%instance-ref structure i)))

    ;; Copy raw slots.
    (dotimes (i nuntagged)
      (declare (type index i))
      (setf (%raw-instance-ref/word res i)
            (%raw-instance-ref/word structure i)))

    res))



;; Do an EQUALP comparison on the raw slots (only, not the normal slots) of a
;; structure.
(defun raw-instance-slots-equalp (layout x y)
  ;; This implementation sucks, but hopefully EQUALP on raw structures
  ;; won't be a major bottleneck for anyone. It'd be tempting to do
  ;; all this with %RAW-INSTANCE-REF/WORD and bitwise comparisons, but
  ;; that'll fail in some cases. For example -0.0 and 0.0 are EQUALP
  ;; but have different bit patterns. -- JES, 2007-08-21
  (loop with i = -1
        for dsd in (dd-slots (layout-info layout))
        for raw-type = (dsd-raw-type dsd)
        for rsd = (when raw-type
                    (find raw-type
                          *raw-slot-data-list*
                          :key 'raw-slot-data-raw-type))
        for accessor = (when rsd
                         (raw-slot-data-accessor-name rsd))
        always (or (not accessor)
                   (progn
                     (incf i)
                     (equalp (funcall accessor x i)
                             (funcall accessor y i))))))

;;; default PRINT-OBJECT method

(defun %print-structure-sans-layout-info (name stream)
  ;; KLUDGE: during PCL build debugging, we can sometimes
  ;; attempt to print out a PCL object (with null LAYOUT-INFO).
  (pprint-logical-block (stream nil :prefix "#<" :suffix ">")
    (prin1 name stream)
    (write-char #\space stream)
    (write-string "(no LAYOUT-INFO)" stream)))

(defun %print-structure-sans-slots (name stream)
  ;; the structure type doesn't count as a component for *PRINT-LEVEL*
  ;; processing. We can likewise elide the logical block processing,
  ;; since all we have to print is the type name. -- CSR, 2004-10-05
  (write-string "#S(" stream)
  (prin1 name stream)
  (write-char #\) stream))

(defun %default-structure-pretty-print (structure stream)
  (let* ((layout (%instance-layout structure))
         (name (classoid-name (layout-classoid layout)))
         (dd (layout-info layout)))
    (cond ((not dd)
           (%print-structure-sans-layout-info name stream))
          ((not (dd-slots dd))
           (%print-structure-sans-slots name stream))
          (t
           (pprint-logical-block (stream nil :prefix "#S(" :suffix ")")
             (prin1 name stream)
             (let ((remaining-slots (dd-slots dd)))
               (when remaining-slots
                 (write-char #\space stream)
                 ;; CMU CL had (PPRINT-INDENT :BLOCK 2 STREAM) here,
                 ;; but I can't see why. -- WHN 20000205
                 (pprint-newline :linear stream)
                 (loop
                   (pprint-pop)
                   (let ((slot (pop remaining-slots)))
                     (write-char #\: stream)
                     (output-symbol-name (symbol-name (dsd-name slot)) stream)
                     (write-char #\space stream)
                     (pprint-newline :miser stream)
                     (output-object (funcall (fdefinition (dsd-accessor-name slot))
                                             structure)
                                    stream)
                     (when (null remaining-slots)
                       (return))
                     (write-char #\space stream)
                     (pprint-newline :linear stream))))))))))

(defun %default-structure-ugly-print (structure stream)
  (let* ((layout (%instance-layout structure))
         (name (classoid-name (layout-classoid layout)))
         (dd (layout-info layout)))
    (cond ((not dd)
           (%print-structure-sans-layout-info name stream))
          ((not (dd-slots dd))
           (%print-structure-sans-slots name stream))
          (t
           (descend-into (stream)
             (write-string "#S(" stream)
             (prin1 name stream)
             (do ((index 0 (1+ index))
                  (remaining-slots (dd-slots dd) (cdr remaining-slots)))
                 ((or (null remaining-slots)
                      (and (not *print-readably*)
                           *print-length*
                           (>= index *print-length*)))
                  (if (null remaining-slots)
                      (write-string ")" stream)
                      (write-string " ...)" stream)))
               (declare (type index index))
               (write-string " :" stream)
               (let ((slot (first remaining-slots)))
                 (output-symbol-name (symbol-name (dsd-name slot)) stream)
                 (write-char #\space stream)
                 (output-object
                  (funcall (fdefinition (dsd-accessor-name slot))
                           structure)
                  stream))))))))

(defun default-structure-print (structure stream depth)
  (declare (ignore depth))
  (cond ((funcallable-instance-p structure)
         (print-unreadable-object (structure stream :identity t :type t)))
        (*print-pretty*
         (%default-structure-pretty-print structure stream))
        (t
         (%default-structure-ugly-print structure stream))))

(def!method print-object ((x structure-object) stream)
  (default-structure-print x stream *current-level-in-print*))

;;;; testing structure types

;;; Return true if OBJ is an object of the structure type
;;; corresponding to LAYOUT. This is called by the accessor closures,
;;; which have a handle on the type's LAYOUT.
;;;
;;; FIXME: This is fairly big, so it should probably become
;;; MAYBE-INLINE instead of INLINE, or its inlineness should become
;;; conditional (probably through DEFTRANSFORM) on (> SPEED SPACE). Or
;;; else we could fix things up so that the things which call it are
;;; all closures, so that it's expanded only in a small number of
;;; places.
#!-sb-fluid (declaim (inline typep-to-layout))
(defun typep-to-layout (obj layout)
  (declare (type layout layout) (optimize (speed 3) (safety 0)))
  (/noshow0 "entering TYPEP-TO-LAYOUT, OBJ,LAYOUT=..")
  (/nohexstr obj)
  (/nohexstr layout)
  (when (layout-invalid layout)
    (error "An obsolete structure accessor function was called."))
  (/noshow0 "back from testing LAYOUT-INVALID LAYOUT")
  (and (%instancep obj)
       (let ((obj-layout (%instance-layout obj)))
         (cond ((eq obj-layout layout)
                ;; (In this case OBJ-LAYOUT can't be invalid, because
                ;; we determined LAYOUT is valid in the test above.)
                (/noshow0 "EQ case")
                t)
               ((layout-invalid obj-layout)
                (/noshow0 "LAYOUT-INVALID case")
                (error 'layout-invalid
                       :expected-type (layout-classoid obj-layout)
                       :datum obj))
               (t
                (let ((depthoid (layout-depthoid layout)))
                  (/noshow0 "DEPTHOID case, DEPTHOID,LAYOUT-INHERITS=..")
                  (/nohexstr depthoid)
                  (/nohexstr layout-inherits)
                  (and (> (layout-depthoid obj-layout) depthoid)
                       (eq (svref (layout-inherits obj-layout) depthoid)
                           layout))))))))

;;;; checking structure types

;;; Check that X is an instance of the named structure type.
(defmacro %check-structure-type-from-name (x name)
  `(%check-structure-type-from-layout ,x ,(compiler-layout-or-lose name)))

;;; Check that X is a structure of the type described by DD.
(defmacro %check-structure-type-from-dd (x dd)
  (declare (type defstruct-description dd))
  (let ((class-name (dd-name dd)))
    (ecase (dd-type dd)
      ((structure funcallable-instance)
       `(%check-structure-type-from-layout
         ,x
         ,(compiler-layout-or-lose class-name)))
      ((vector)
       (with-unique-names (xx)
         `(let ((,xx ,x))
            (declare (type vector ,xx))
            ,@(when (dd-named dd)
                `((unless (eql (aref ,xx 0) ',class-name)
                    (error
                     'simple-type-error
                     :datum (aref ,xx 0)
                     :expected-type `(member ,class-name)
                     :format-control
                     "~@<missing name in instance of ~
                      VECTOR-typed structure ~S: ~2I~_S~:>"
                     :format-arguments (list ',class-name ,xx)))))
            (values))))
      ((list)
       (with-unique-names (xx)
         `(let ((,xx ,x))
            (declare (type list ,xx))
            ,@(when (dd-named dd)
                `((unless (eql (first ,xx) ',class-name)
                    (error
                     'simple-type-error
                     :datum (aref ,xx 0)
                     :expected-type `(member ,class-name)
                     :format-control
                     "~@<missing name in instance of LIST-typed structure ~S: ~
                      ~2I~_S~:>"
                     :format-arguments (list ',class-name ,xx)))))
            (values)))))))

;;; Check that X is an instance of the structure class with layout LAYOUT.
(defun %check-structure-type-from-layout (x layout)
  (unless (typep-to-layout x layout)
    (error 'type-error
           :datum x
           :expected-type (classoid-name (layout-classoid layout))))
  (values))


(/show0 "target-defstruct.lisp end of file")