src/compiler/generic/objdef.lisp

   1 ;;;; machine-independent aspects of the object representation
   2
   3 ;;;; This software is part of the SBCL system. See the README file for
   4 ;;;; more information.
   5 ;;;;
   6 ;;;; This software is derived from the CMU CL system, which was
   7 ;;;; written at Carnegie Mellon University and released into the
   8 ;;;; public domain. The software is in the public domain and is
   9 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
  10 ;;;; files for more information.
  11
  12 (in-package "SB!VM")
  13
  14 ;;;; KLUDGE: The primitive objects here may look like self-contained
  15 ;;;; definitions, but in general they're not. In particular, if you
  16 ;;;; try to add a slot to them, beware of the following:
  17 ;;;;   * (mysterious crashes which occur after changing the length
  18 ;;;;     of SIMPLE-FUN, just adding a new slot not even doing anything
  19 ;;;;     with it, still dunno why)
  20 ;;;;   * The GC scavenging code (and for all I know other GC code too)
  21 ;;;;     is not automatically generated from these layouts, but instead
  22 ;;;;     was hand-written to correspond to them. The offsets are
  23 ;;;;     automatically propagated into the GC scavenging code, but the
  24 ;;;;     existence of slots, and whether they should be scavenged, is
  25 ;;;;     not automatically propagated. Thus e.g. if you add a
  26 ;;;;     SIMPLE-FUN-DEBUG-INFO slot holding a tagged object which needs
  27 ;;;;     to be GCed, you need to tweak scav_code_header() and
  28 ;;;;     verify_space() in gencgc.c, and the corresponding code in gc.c.
  29 ;;;;   * The src/runtime/print.c code (used by LDB) is implemented
  30 ;;;;     using hand-written lists of slot names, which aren't automatically
  31 ;;;;     generated from the code in this file.
  32 ;;;;   * Various code (e.g. STATIC-FSET in genesis.lisp) is hard-wired
  33 ;;;;     to know the name of the last slot of the object the code works
  34 ;;;;     with, and implicitly to know that the last slot is special (being
  35 ;;;;     the beginning of an arbitrary-length sequence of bytes following
  36 ;;;;     the fixed-layout slots).
  37 ;;;; -- WHN 2001-12-29
  38 \f
  39 ;;;; the primitive objects themselves
  40
  41 (define-primitive-object (cons :lowtag list-pointer-lowtag
  42                                :alloc-trans cons)
  43   (car :ref-trans car :set-trans sb!c::%rplaca :init :arg)
  44   (cdr :ref-trans cdr :set-trans sb!c::%rplacd :init :arg))
  45
  46 (define-primitive-object (instance :lowtag instance-pointer-lowtag
  47                                    :widetag instance-header-widetag
  48                                    :alloc-trans %make-instance)
  49   (slots :rest-p t))
  50
  51 (define-primitive-object (bignum :lowtag other-pointer-lowtag
  52                                  :widetag bignum-widetag
  53                                  :alloc-trans sb!bignum::%allocate-bignum)
  54   (digits :rest-p t :c-type #!-alpha "long" #!+alpha "u32"))
  55
  56 (define-primitive-object (ratio :type ratio
  57                                 :lowtag other-pointer-lowtag
  58                                 :widetag ratio-widetag
  59                                 :alloc-trans %make-ratio)
  60   (numerator :type integer
  61              :ref-known (flushable movable)
  62              :ref-trans %numerator
  63              :init :arg)
  64   (denominator :type integer
  65                :ref-known (flushable movable)
  66                :ref-trans %denominator
  67                :init :arg))
  68
  69 (define-primitive-object (single-float :lowtag other-pointer-lowtag
  70                                        :widetag single-float-widetag)
  71   (value :c-type "float"))
  72
  73 (define-primitive-object (double-float :lowtag other-pointer-lowtag
  74                                        :widetag double-float-widetag)
  75   (filler)
  76   (value :c-type "double" :length 2))
  77
  78 #!+long-float
  79 (define-primitive-object (long-float :lowtag other-pointer-lowtag
  80                                      :widetag long-float-widetag)
  81   #!+sparc (filler)
  82   (value :c-type "long double" :length #!+x86 3 #!+sparc 4))
  83
  84 (define-primitive-object (complex :type complex
  85                                   :lowtag other-pointer-lowtag
  86                                   :widetag complex-widetag
  87                                   :alloc-trans %make-complex)
  88   (real :type real
  89         :ref-known (flushable movable)
  90         :ref-trans %realpart
  91         :init :arg)
  92   (imag :type real
  93         :ref-known (flushable movable)
  94         :ref-trans %imagpart
  95         :init :arg))
  96
  97 (define-primitive-object (array :lowtag other-pointer-lowtag
  98                                 :widetag t)
  99   (fill-pointer :type index
 100                 :ref-trans %array-fill-pointer
 101                 :ref-known (flushable foldable)
 102                 :set-trans (setf %array-fill-pointer)
 103                 :set-known (unsafe))
 104   (fill-pointer-p :type (member t nil)
 105                   :ref-trans %array-fill-pointer-p
 106                   :ref-known (flushable foldable)
 107                   :set-trans (setf %array-fill-pointer-p)
 108                   :set-known (unsafe))
 109   (elements :type index
 110             :ref-trans %array-available-elements
 111             :ref-known (flushable foldable)
 112             :set-trans (setf %array-available-elements)
 113             :set-known (unsafe))
 114   (data :type array
 115         :ref-trans %array-data-vector
 116         :ref-known (flushable foldable)
 117         :set-trans (setf %array-data-vector)
 118         :set-known (unsafe))
 119   (displacement :type (or index null)
 120                 :ref-trans %array-displacement
 121                 :ref-known (flushable foldable)
 122                 :set-trans (setf %array-displacement)
 123                 :set-known (unsafe))
 124   (displaced-p :type (member t nil)
 125                :ref-trans %array-displaced-p
 126                :ref-known (flushable foldable)
 127                :set-trans (setf %array-displaced-p)
 128                :set-known (unsafe))
 129   (dimensions :rest-p t))
 130
 131 (define-primitive-object (vector :type vector
 132                                  :lowtag other-pointer-lowtag
 133                                  :widetag t)
 134   (length :ref-trans sb!c::vector-length
 135           :type index)
 136   (data :rest-p t :c-type #!-alpha "unsigned long" #!+alpha "u32"))
 137
 138 (define-primitive-object (code :type code-component
 139                                :lowtag other-pointer-lowtag
 140                                :widetag t)
 141   (code-size :type index
 142              :ref-known (flushable movable)
 143              :ref-trans %code-code-size)
 144   (entry-points :type (or function null)
 145                 :ref-known (flushable)
 146                 :ref-trans %code-entry-points
 147                 :set-known (unsafe)
 148                 :set-trans (setf %code-entry-points))
 149   (debug-info :type t
 150               :ref-known (flushable)
 151               :ref-trans %code-debug-info
 152               :set-known (unsafe)
 153               :set-trans (setf %code-debug-info))
 154   (trace-table-offset)
 155   (constants :rest-p t))
 156
 157 (define-primitive-object (fdefn :type fdefn
 158                                 :lowtag other-pointer-lowtag
 159                                 :widetag fdefn-widetag)
 160   (name :ref-trans fdefn-name)
 161   (fun :type (or function null) :ref-trans fdefn-fun)
 162   (raw-addr :c-type #!-alpha "char *" #!+alpha "u32"))
 163
 164 ;;; a simple function (as opposed to hairier things like closures
 165 ;;; which are also subtypes of Common Lisp's FUNCTION type)
 166 (define-primitive-object (simple-fun :type function
 167                                      :lowtag fun-pointer-lowtag
 168                                      :widetag simple-fun-header-widetag)
 169   #!-x86 (self :ref-trans %simple-fun-self
 170                :set-trans (setf %simple-fun-self))
 171   #!+x86 (self
 172           ;; KLUDGE: There's no :SET-KNOWN, :SET-TRANS, :REF-KNOWN, or
 173           ;; :REF-TRANS here in this case. Instead, there's separate
 174           ;; DEFKNOWN/DEFINE-VOP/DEFTRANSFORM stuff in
 175           ;; compiler/x86/system.lisp to define and declare them by
 176           ;; hand. I don't know why this is, but that's (basically)
 177           ;; the way it was done in CMU CL, and it works. (It's not
 178           ;; exactly the same way it was done in CMU CL in that CMU
 179           ;; CL's allows duplicate DEFKNOWNs, blithely overwriting any
 180           ;; previous data associated with the previous DEFKNOWN, and
 181           ;; that property was used to mask the definitions here. In
 182           ;; SBCL as of 0.6.12.64 that's not allowed -- too confusing!
 183           ;; -- so we have to explicitly suppress the DEFKNOWNish
 184           ;; stuff here in order to allow this old hack to work in the
 185           ;; new world. -- WHN 2001-08-82
 186           )
 187   (next :type (or function null)
 188         :ref-known (flushable)
 189         :ref-trans %simple-fun-next
 190         :set-known (unsafe)
 191         :set-trans (setf %simple-fun-next))
 192   (name :ref-known (flushable)
 193         :ref-trans %simple-fun-name
 194         :set-known (unsafe)
 195         :set-trans (setf %simple-fun-name))
 196   (arglist :type list
 197            :ref-known (flushable)
 198            :ref-trans %simple-fun-arglist
 199            :set-known (unsafe)
 200            :set-trans (setf %simple-fun-arglist))
 201   (type :ref-known (flushable)
 202         :ref-trans %simple-fun-type
 203         :set-known (unsafe)
 204         :set-trans (setf %simple-fun-type))
 205   ;; the SB!C::DEBUG-FUN object corresponding to this object, or NIL for none
 206   #+nil ; FIXME: doesn't work (gotcha, lowly maintenoid!) See notes on bug 137.
 207   (debug-fun :ref-known (flushable)
 208              :ref-trans %simple-fun-debug-fun
 209              :set-known (unsafe)
 210              :set-trans (setf %simple-fun-debug-fun))
 211   (code :rest-p t :c-type "unsigned char"))
 212
 213 (define-primitive-object (return-pc :lowtag other-pointer-lowtag :widetag t)
 214   (return-point :c-type "unsigned char" :rest-p t))
 215
 216 (define-primitive-object (closure :lowtag fun-pointer-lowtag
 217                                   :widetag closure-header-widetag)
 218   (fun :init :arg :ref-trans %closure-fun)
 219   (info :rest-p t))
 220
 221 (define-primitive-object (funcallable-instance
 222                           :lowtag fun-pointer-lowtag
 223                           :widetag funcallable-instance-header-widetag
 224                           :alloc-trans %make-funcallable-instance)
 225   #!-x86
 226   (fun
 227    :ref-known (flushable) :ref-trans %funcallable-instance-fun
 228    :set-known (unsafe) :set-trans (setf %funcallable-instance-fun))
 229   #!+x86
 230   (fun
 231    :ref-known (flushable) :ref-trans %funcallable-instance-fun
 232    ;; KLUDGE: There's no :SET-KNOWN or :SET-TRANS in this case.
 233    ;; Instead, later in compiler/x86/system.lisp there's a separate
 234    ;; DEFKNOWN for (SETF %FUNCALLABLE-INSTANCE-FUN), and a weird
 235    ;; unexplained DEFTRANSFORM from (SETF %SIMPLE-FUN-INSTANCE-FUN)
 236    ;; into (SETF %SIMPLE-FUN-SELF). The #!+X86 wrapped around this case
 237    ;; is a literal translation of the old CMU CL implementation into
 238    ;; the new world of sbcl-0.6.12.63, where multiple DEFKNOWNs for
 239    ;; the same operator cause an error (instead of silently deleting
 240    ;; all information associated with the old DEFKNOWN, as before).
 241    ;; It's definitely not very clean, with too many #!+ conditionals and
 242    ;; too little documentation, but I have more urgent things to
 243    ;; clean up right now, so I've just left it as a literal
 244    ;; translation without trying to fix it. -- WHN 2001-08-02
 245    )
 246   (lexenv :ref-known (flushable) :ref-trans %funcallable-instance-lexenv
 247           :set-known (unsafe) :set-trans (setf %funcallable-instance-lexenv))
 248   (layout :init :arg
 249           :ref-known (flushable) :ref-trans %funcallable-instance-layout
 250           :set-known (unsafe) :set-trans (setf %funcallable-instance-layout))
 251   (info :rest-p t))
 252
 253 (define-primitive-object (value-cell :lowtag other-pointer-lowtag
 254                                      :widetag value-cell-header-widetag
 255                                      :alloc-trans make-value-cell)
 256   (value :set-trans value-cell-set
 257          :set-known (unsafe)
 258          :ref-trans value-cell-ref
 259          :ref-known (flushable)
 260          :init :arg))
 261
 262 #!+alpha
 263 (define-primitive-object (sap :lowtag other-pointer-lowtag
 264                               :widetag sap-widetag)
 265   (padding)
 266   (pointer :c-type "char *" :length 2))
 267
 268 #!-alpha
 269 (define-primitive-object (sap :lowtag other-pointer-lowtag
 270                               :widetag sap-widetag)
 271   (pointer :c-type "char *"))
 272
 273
 274 (define-primitive-object (weak-pointer :type weak-pointer
 275                                        :lowtag other-pointer-lowtag
 276                                        :widetag weak-pointer-widetag
 277                                        :alloc-trans make-weak-pointer)
 278   (value :ref-trans sb!c::%weak-pointer-value :ref-known (flushable)
 279          :init :arg)
 280   (broken :type (member t nil)
 281           :ref-trans sb!c::%weak-pointer-broken :ref-known (flushable)
 282           :init :null)
 283   (next :c-type #!-alpha "struct weak_pointer *" #!+alpha "u32"))
 284
 285 ;;;; other non-heap data blocks
 286
 287 (define-primitive-object (binding)
 288   value
 289   symbol)
 290
 291 (define-primitive-object (unwind-block)
 292   (current-uwp :c-type #!-alpha "struct unwind_block *" #!+alpha "u32")
 293   (current-cont :c-type #!-alpha "lispobj *" #!+alpha "u32")
 294   #!-x86 current-code
 295   entry-pc)
 296
 297 (define-primitive-object (catch-block)
 298   (current-uwp :c-type #!-alpha "struct unwind_block *" #!+alpha "u32")
 299   (current-cont :c-type #!-alpha "lispobj *" #!+alpha "u32")
 300   #!-x86 current-code
 301   entry-pc
 302   tag
 303   (previous-catch :c-type #!-alpha "struct catch_block *" #!+alpha "u32")
 304   size)
 305
 306 ;;; (For an explanation of this, see the comments at the definition of
 307 ;;; KLUDGE-NONDETERMINISTIC-CATCH-BLOCK-SIZE.)
 308 (aver (= kludge-nondeterministic-catch-block-size catch-block-size))
 309 \f
 310 ;;;; symbols
 311
 312 #!+x86
 313 (defknown symbol-hash (symbol) (integer 0 #.sb!xc:most-positive-fixnum)
 314   (flushable movable))
 315
 316 (define-primitive-object (symbol :lowtag other-pointer-lowtag
 317                                  :widetag symbol-header-widetag
 318                                  #!-x86 :alloc-trans #!-x86 make-symbol)
 319
 320   ;; Beware when changing this definition.  NIL-the-symbol is defined
 321   ;; using this layout, and NIL-the-end-of-list-marker is the cons
 322   ;; ( NIL . NIL ), living in the first two slots of NIL-the-symbol
 323   ;; (conses have no header).  Careful selection of lowtags ensures
 324   ;; that the same pointer can be used for both purposes:
 325   ;; OTHER-POINTER-LOWTAG is 7, LIST-POINTER-LOWTAG is 3, so if you
 326   ;; subtract 3 from (sb-kernel:get-lisp-obj-address 'NIL) you get the
 327   ;; first data slot, and if you subtract 7 you get a symbol header.
 328
 329   (value #!-sb-thread :set-trans #!-sb-thread %set-symbol-value
 330          :init :unbound)                ;also the CAR of NIL-as-end-of-list
 331   (hash)                                ;the CDR of NIL-as-end-of-list
 332
 333   (plist :ref-trans symbol-plist
 334          :set-trans %set-symbol-plist
 335          :init :null)
 336   (name :ref-trans symbol-name :init :arg)
 337   (package :ref-trans symbol-package
 338            :set-trans %set-symbol-package
 339            :init :null)
 340   #!+sb-thread (tls-index))
 341
 342 (define-primitive-object (complex-single-float
 343                           :lowtag other-pointer-lowtag
 344                           :widetag complex-single-float-widetag)
 345   (real :c-type "float")
 346   (imag :c-type "float"))
 347
 348 (define-primitive-object (complex-double-float
 349                           :lowtag other-pointer-lowtag
 350                           :widetag complex-double-float-widetag)
 351   (filler)
 352   (real :c-type "double" :length 2)
 353   (imag :c-type "double" :length 2))
 354
 355 #!+long-float
 356 (define-primitive-object (complex-long-float
 357                           :lowtag other-pointer-lowtag
 358                           :widetag complex-long-float-widetag)
 359   #!+sparc (filler)
 360   (real :c-type "long double" :length #!+x86 3 #!+sparc 4)
 361   (imag :c-type "long double" :length #!+x86 3 #!+sparc 4))
 362
 363 ;;; this isn't actually a lisp object at all, it's a c structure that lives
 364 ;;; in c-land.  However, we need sight of so many parts of it from Lisp that
 365 ;;; it makes sense to define it here anyway, so that the GENESIS machinery
 366 ;;; can take care of maintaining Lisp and C versions.
 367 ;;; Hence the even-fixnum lowtag just so we don't get odd(sic) numbers
 368 ;;; added to the slot offsets
 369 (define-primitive-object (thread :lowtag even-fixnum-lowtag)
 370   ;; unbound_marker is borrowed very briefly at thread startup to
 371   ;; pass the address of initial-function into new_thread_trampoline
 372   (unbound-marker :init :unbound) ; tls[0] = UNBOUND_MARKER_WIDETAG
 373   (binding-stack-start :c-type "lispobj *")
 374   (binding-stack-pointer :c-type "lispobj *")
 375   (control-stack-start :c-type "lispobj *")
 376   (alien-stack-start :c-type "lispobj *")
 377   (alien-stack-pointer :c-type "lispobj *")
 378   (alloc-region :c-type "struct alloc_region" :length 5)
 379   (pid :c-type "pid_t")
 380   (tls-cookie)                          ;  on x86, the LDT index
 381   (this :c-type "struct thread *")
 382   (next :c-type "struct thread *")
 383   (pseudo-atomic-atomic)
 384   (pseudo-atomic-interrupted)
 385   (interrupt-data :c-type "struct interrupt_data *")
 386   (interrupt-contexts :c-type "os_context_t *" :rest-p t))