objdef.lisp

开源跨平台Lisp编译器

;;;; machine-independent aspects of the object representation

;;;; 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")

;;;; KLUDGE: The primitive objects here may look like self-contained
;;;; definitions, but in general they're not. In particular, if you
;;;; try to add a slot to them, beware of the following:
;;;;   * (mysterious crashes which occur after changing the length
;;;;     of SIMPLE-FUN, just adding a new slot not even doing anything
;;;;     with it, still dunno why)
;;;;   * The GC scavenging code (and for all I know other GC code too)
;;;;     is not automatically generated from these layouts, but instead
;;;;     was hand-written to correspond to them. The offsets are
;;;;     automatically propagated into the GC scavenging code, but the
;;;;     existence of slots, and whether they should be scavenged, is
;;;;     not automatically propagated. Thus e.g. if you add a
;;;;     SIMPLE-FUN-DEBUG-INFO slot holding a tagged object which needs
;;;;     to be GCed, you need to tweak scav_code_header() and
;;;;     verify_space() in gencgc.c, and the corresponding code in gc.c.
;;;;   * The src/runtime/print.c code (used by LDB) is implemented
;;;;     using hand-written lists of slot names, which aren't automatically
;;;;     generated from the code in this file.
;;;;   * Various code (e.g. STATIC-FSET in genesis.lisp) is hard-wired
;;;;     to know the name of the last slot of the object the code works
;;;;     with, and implicitly to know that the last slot is special (being
;;;;     the beginning of an arbitrary-length sequence of bytes following
;;;;     the fixed-layout slots).
;;;; -- WHN 2001-12-29

;;;; the primitive objects themselves

(define-primitive-object (cons :lowtag list-pointer-lowtag
                               :alloc-trans cons)
  (car :ref-trans car :set-trans sb!c::%rplaca :init :arg
       :cas-trans %compare-and-swap-car)
  (cdr :ref-trans cdr :set-trans sb!c::%rplacd :init :arg
       :cas-trans %compare-and-swap-cdr))

(define-primitive-object (instance :lowtag instance-pointer-lowtag
                                   :widetag instance-header-widetag
                                   :alloc-trans %make-instance)
  (slots :rest-p t))

(define-primitive-object (bignum :lowtag other-pointer-lowtag
                                 :widetag bignum-widetag
                                 :alloc-trans sb!bignum::%allocate-bignum)
  (digits :rest-p t :c-type #!-alpha "long" #!+alpha "u32"))

(define-primitive-object (ratio :type ratio
                                :lowtag other-pointer-lowtag
                                :widetag ratio-widetag
                                :alloc-trans %make-ratio)
  (numerator :type integer
             :ref-known (flushable movable)
             :ref-trans %numerator
             :init :arg)
  (denominator :type integer
               :ref-known (flushable movable)
               :ref-trans %denominator
               :init :arg))

#!+#.(cl:if (cl:= sb!vm:n-word-bits 32) '(and) '(or))
(define-primitive-object (single-float :lowtag other-pointer-lowtag
                                       :widetag single-float-widetag)
  (value :c-type "float"))

(define-primitive-object (double-float :lowtag other-pointer-lowtag
                                       :widetag double-float-widetag)
  #!-x86-64 (filler)
  (value :c-type "double" :length #!-x86-64 2 #!+x86-64 1))

#!+long-float
(define-primitive-object (long-float :lowtag other-pointer-lowtag
                                     :widetag long-float-widetag)
  #!+sparc (filler)
  (value :c-type "long double" :length #!+x86 3 #!+sparc 4))

(define-primitive-object (complex :type complex
                                  :lowtag other-pointer-lowtag
                                  :widetag complex-widetag
                                  :alloc-trans %make-complex)
  (real :type real
        :ref-known (flushable movable)
        :ref-trans %realpart
        :init :arg)
  (imag :type real
        :ref-known (flushable movable)
        :ref-trans %imagpart
        :init :arg))

(define-primitive-object (array :lowtag other-pointer-lowtag
                                :widetag t)
  ;; FILL-POINTER of an ARRAY is in the same place as LENGTH of a
  ;; VECTOR -- see SHRINK-VECTOR.
  (fill-pointer :type index
                :ref-trans %array-fill-pointer
                :ref-known (flushable foldable)
                :set-trans (setf %array-fill-pointer)
                :set-known (unsafe))
  (fill-pointer-p :type (member t nil)
                  :ref-trans %array-fill-pointer-p
                  :ref-known (flushable foldable)
                  :set-trans (setf %array-fill-pointer-p)
                  :set-known (unsafe))
  (elements :type index
            :ref-trans %array-available-elements
            :ref-known (flushable foldable)
            :set-trans (setf %array-available-elements)
            :set-known (unsafe))
  (data :type array
        :ref-trans %array-data-vector
        :ref-known (flushable foldable)
        :set-trans (setf %array-data-vector)
        :set-known (unsafe))
  (displacement :type (or index null)
                :ref-trans %array-displacement
                :ref-known (flushable foldable)
                :set-trans (setf %array-displacement)
                :set-known (unsafe))
  (displaced-p :type (member t nil)
               :ref-trans %array-displaced-p
               :ref-known (flushable foldable)
               :set-trans (setf %array-displaced-p)
               :set-known (unsafe))
  (dimensions :rest-p t))

(define-primitive-object (vector :type vector
                                 :lowtag other-pointer-lowtag
                                 :widetag t)
  ;; FILL-POINTER of an ARRAY is in the same place as LENGTH of a
  ;; VECTOR -- see SHRINK-VECTOR.
  (length :ref-trans sb!c::vector-length
          :type index)
  (data :rest-p t :c-type #!-alpha "unsigned long" #!+alpha "u32"))

(define-primitive-object (code :type code-component
                               :lowtag other-pointer-lowtag
                               :widetag t)
  (code-size :type index
             :ref-known (flushable movable)
             :ref-trans %code-code-size)
  (entry-points :type (or function null)
                :ref-known (flushable)
                :ref-trans %code-entry-points
                :set-known (unsafe)
                :set-trans (setf %code-entry-points))
  (debug-info :type t
              :ref-known (flushable)
              :ref-trans %code-debug-info
              :set-known (unsafe)
              :set-trans (setf %code-debug-info))
  (trace-table-offset)
  (constants :rest-p t))

(define-primitive-object (fdefn :type fdefn
                                :lowtag other-pointer-lowtag
                                :widetag fdefn-widetag)
  (name :ref-trans fdefn-name)
  (fun :type (or function null) :ref-trans fdefn-fun)
  (raw-addr :c-type #!-alpha "char *" #!+alpha "u32"))

;;; a simple function (as opposed to hairier things like closures
;;; which are also subtypes of Common Lisp's FUNCTION type)
(define-primitive-object (simple-fun :type function
                                     :lowtag fun-pointer-lowtag
                                     :widetag simple-fun-header-widetag)
  #!-(or x86 x86-64) (self :ref-trans %simple-fun-self
               :set-trans (setf %simple-fun-self))
  #!+(or x86 x86-64) (self
          ;; KLUDGE: There's no :SET-KNOWN, :SET-TRANS, :REF-KNOWN, or
          ;; :REF-TRANS here in this case. Instead, there's separate
          ;; DEFKNOWN/DEFINE-VOP/DEFTRANSFORM stuff in
          ;; compiler/x86/system.lisp to define and declare them by
          ;; hand. I don't know why this is, but that's (basically)
          ;; the way it was done in CMU CL, and it works. (It's not
          ;; exactly the same way it was done in CMU CL in that CMU
          ;; CL's allows duplicate DEFKNOWNs, blithely overwriting any
          ;; previous data associated with the previous DEFKNOWN, and
          ;; that property was used to mask the definitions here. In
          ;; SBCL as of 0.6.12.64 that's not allowed -- too confusing!
          ;; -- so we have to explicitly suppress the DEFKNOWNish
          ;; stuff here in order to allow this old hack to work in the
          ;; new world. -- WHN 2001-08-82
          )
  (next :type (or function null)
        :ref-known (flushable)
        :ref-trans %simple-fun-next
        :set-known (unsafe)
        :set-trans (setf %simple-fun-next))
  (name :ref-known (flushable)
        :ref-trans %simple-fun-name
        :set-known (unsafe)
        :set-trans (setf %simple-fun-name))