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 ;;;;   * The GC scavenging code (and for all I know other GC code too)
  18 ;;;;     is not automatically generated from these layouts, but instead
  19 ;;;;     was hand-written to correspond to them. The offsets are
  20 ;;;;     automatically propagated into the GC scavenging code, but the
  21 ;;;;     existence of slots, and whether they should be scavenged, is
  22 ;;;;     not automatically propagated. Thus e.g. if you add a
  23 ;;;;     SIMPLE-FUN-DEBUG-INFO slot holding a tagged object which needs
  24 ;;;;     to be GCed, you need to tweak scav_code_header() and
  25 ;;;;     verify_space() in gencgc.c, and the corresponding code in gc.c.
  26 ;;;;   * The src/runtime/print.c code (used by LDB) is implemented
  27 ;;;;     using hand-written lists of slot names, which aren't automatically
  28 ;;;;     generated from the code in this file.
  29 ;;;;   * Various code (e.g. STATIC-FSET in genesis.lisp) is hard-wired
  30 ;;;;     to know the name of the last slot of the object the code works
  31 ;;;;     with, and implicitly to know that the last slot is special (being
  32 ;;;;     the beginning of an arbitrary-length sequence of bytes following
  33 ;;;;     the fixed-layout slots).
  34 ;;;; -- WHN 2001-12-29
  35 \f
  36 ;;;; the primitive objects themselves
  37
  38 (!define-primitive-object (cons :type cons
  39                                :lowtag list-pointer-lowtag
  40                                :alloc-trans cons)
  41   (car :ref-trans car :set-trans sb!c::%rplaca :init :arg
  42        :cas-trans %compare-and-swap-car)
  43   (cdr :ref-trans cdr :set-trans sb!c::%rplacd :init :arg
  44        :cas-trans %compare-and-swap-cdr))
  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 "sword_t" #!+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 #!+#.(cl:if (cl:= sb!vm:n-word-bits 32) '(and) '(or))
  70 (!define-primitive-object (single-float :lowtag other-pointer-lowtag
  71                                        :widetag single-float-widetag)
  72   (value :c-type "float"))
  73
  74 (!define-primitive-object (double-float :lowtag other-pointer-lowtag
  75                                        :widetag double-float-widetag)
  76   #!-x86-64 (filler)
  77   (value :c-type "double" :length #!-x86-64 2 #!+x86-64 1))
  78
  79 #!+long-float
  80 (!define-primitive-object (long-float :lowtag other-pointer-lowtag
  81                                      :widetag long-float-widetag)
  82   #!+sparc (filler)
  83   (value :c-type "long double" :length #!+x86 3 #!+sparc 4))
  84
  85 (!define-primitive-object (complex :type complex
  86                                   :lowtag other-pointer-lowtag
  87                                   :widetag complex-widetag
  88                                   :alloc-trans %make-complex)
  89   (real :type real
  90         :ref-known (flushable movable)
  91         :ref-trans %realpart
  92         :init :arg)
  93   (imag :type real
  94         :ref-known (flushable movable)
  95         :ref-trans %imagpart
  96         :init :arg))
  97
  98 (!define-primitive-object (array :lowtag other-pointer-lowtag
  99                                 :widetag t)
 100   ;; FILL-POINTER of an ARRAY is in the same place as LENGTH of a
 101   ;; VECTOR -- see SHRINK-VECTOR.
 102   (fill-pointer :type index
 103                 :ref-trans %array-fill-pointer
 104                 :ref-known (flushable foldable)
 105                 :set-trans (setf %array-fill-pointer)
 106                 :set-known ())
 107   (fill-pointer-p :type (member t nil)
 108                   :ref-trans %array-fill-pointer-p
 109                   :ref-known (flushable foldable)
 110                   :set-trans (setf %array-fill-pointer-p)
 111                   :set-known ())
 112   (elements :type index
 113             :ref-trans %array-available-elements
 114             :ref-known (flushable foldable)
 115             :set-trans (setf %array-available-elements)
 116             :set-known ())
 117   (data :type array
 118         ;; FIXME: terrible name for the accessor.
 119         ;; It is in general just an ARRAY,
 120         ;; and should be named %ARRAY-DATA.
 121         :ref-trans %array-data-vector
 122         :ref-known (flushable foldable)
 123         :set-trans (setf %array-data-vector)
 124         :set-known ())
 125   (displacement :type (or index null)
 126                 :ref-trans %array-displacement
 127                 :ref-known (flushable foldable)
 128                 :set-trans (setf %array-displacement)
 129                 :set-known ())
 130   (displaced-p :type t
 131                :ref-trans %array-displaced-p
 132                :ref-known (flushable foldable)
 133                :set-trans (setf %array-displaced-p)
 134                :set-known ())
 135   (displaced-from :type list
 136                   :ref-trans %array-displaced-from
 137                   :ref-known (flushable)
 138                   :set-trans (setf %array-displaced-from)
 139                   :set-known ())
 140   (dimensions :rest-p t))
 141
 142 (!define-primitive-object (vector :type vector
 143                                  :lowtag other-pointer-lowtag
 144                                  :widetag t)
 145   ;; FILL-POINTER of an ARRAY is in the same place as LENGTH of a
 146   ;; VECTOR -- see SHRINK-VECTOR.
 147   (length :ref-trans sb!c::vector-length
 148           :type index)
 149   (data :rest-p t :c-type #!-alpha "uword_t" #!+alpha "u32"))
 150
 151 ;;; The header contains the size of slots and constants in words.
 152 (!define-primitive-object (code :type code-component
 153                                :lowtag other-pointer-lowtag
 154                                :widetag t)
 155   ;; This is the size of instructions in bytes, not aligned.
 156   ;; Adding the size from the header and aligned code-size will yield
 157   ;; the total size of the code-object.
 158   (code-size :type index
 159              :ref-known (flushable movable)
 160              :ref-trans %code-code-size)
 161   (entry-points :type (or function null)
 162                 :ref-known (flushable)
 163                 :ref-trans %code-entry-points
 164                 :set-known ()
 165                 :set-trans (setf %code-entry-points))
 166   (debug-info :type t
 167               :ref-known (flushable)
 168               :ref-trans %code-debug-info
 169               :set-known ()
 170               :set-trans (setf %code-debug-info))
 171   (constants :rest-p t))
 172
 173 (!define-primitive-object (fdefn :type fdefn
 174                                 :lowtag other-pointer-lowtag
 175                                 :widetag fdefn-widetag)
 176   (name :ref-trans fdefn-name)
 177   (fun :type (or function null) :ref-trans fdefn-fun)
 178   (raw-addr :c-type #!-alpha "char *" #!+alpha "u32"))
 179
 180 ;;; a simple function (as opposed to hairier things like closures
 181 ;;; which are also subtypes of Common Lisp's FUNCTION type)
 182 (!define-primitive-object (simple-fun :type function
 183                                      :lowtag fun-pointer-lowtag
 184                                      :widetag simple-fun-header-widetag)
 185   #!-(or x86 x86-64) (self :ref-trans %simple-fun-self
 186                :set-trans (setf %simple-fun-self))
 187   ;; FIXME: we don't currently detect/prevent at compile-time the bad
 188   ;; scenario this comment claims to disallow, as determined by re-enabling
 189   ;; these SET- and REF- specifiers, which led to a cold-init crash.
 190   #!+(or x86 x86-64) (self
 191           ;; KLUDGE: There's no :SET-KNOWN, :SET-TRANS, :REF-KNOWN, or
 192           ;; :REF-TRANS here in this case. Instead, there's separate
 193           ;; DEFKNOWN/DEFINE-VOP/DEFTRANSFORM stuff in
 194           ;; compiler/x86/system.lisp to define and declare them by
 195           ;; hand. I don't know why this is, but that's (basically)
 196           ;; the way it was done in CMU CL, and it works. (It's not
 197           ;; exactly the same way it was done in CMU CL in that CMU
 198           ;; CL's allows duplicate DEFKNOWNs, blithely overwriting any
 199           ;; previous data associated with the previous DEFKNOWN, and
 200           ;; that property was used to mask the definitions here. In
 201           ;; SBCL as of 0.6.12.64 that's not allowed -- too confusing!
 202           ;; -- so we have to explicitly suppress the DEFKNOWNish
 203           ;; stuff here in order to allow this old hack to work in the
 204           ;; new world. -- WHN 2001-08-82
 205           )
 206   (next :type (or function null)
 207         :ref-known (flushable)
 208         :ref-trans %simple-fun-next
 209         :set-known ()
 210         :set-trans (setf %simple-fun-next))
 211   (name :ref-known (flushable)
 212         :ref-trans %simple-fun-name
 213         :set-known ()
 214         :set-trans (setf %simple-fun-name))
 215   (arglist :type list
 216            :ref-known (flushable)
 217            :ref-trans %simple-fun-arglist
 218            :set-known ()
 219            :set-trans (setf %simple-fun-arglist))
 220   (type :ref-known (flushable)
 221         :ref-trans %simple-fun-type
 222         :set-known ()
 223         :set-trans (setf %simple-fun-type))
 224   ;; NIL for empty, STRING for a docstring, SIMPLE-VECTOR for XREFS, and (CONS
 225   ;; STRING SIMPLE-VECTOR) for both.
 226   (info :init :null
 227         :ref-trans %simple-fun-info
 228         :ref-known (flushable)
 229         :set-trans (setf %simple-fun-info)
 230         :set-known ())
 231   ;; the SB!C::DEBUG-FUN object corresponding to this object, or NIL for none
 232   #+nil ; FIXME: doesn't work (gotcha, lowly maintenoid!) See notes on bug 137.
 233   (debug-fun :ref-known (flushable)
 234              :ref-trans %simple-fun-debug-fun
 235              :set-known ()
 236              :set-trans (setf %simple-fun-debug-fun))
 237   (code :rest-p t :c-type "unsigned char"))
 238
 239 (!define-primitive-object (return-pc :lowtag other-pointer-lowtag :widetag t)
 240   (return-point :c-type "unsigned char" :rest-p t))
 241
 242 (!define-primitive-object (closure :lowtag fun-pointer-lowtag
 243                                   :widetag closure-header-widetag)
 244   ;; %CLOSURE-FUN should never be invoked on x86[-64].
 245   ;; The above remark at %SIMPLE-FUN-SELF is relevant in its sentiment,
 246   ;; but actually no longer true - the confusing situation is not caught
 247   ;; until too late. But at least this one was nonfatal.
 248   #!-(or x86 x86-64) (fun :init :arg :ref-trans %closure-fun)
 249   #!+(or x86 x86-64) (fun :init :arg)
 250   (info :rest-p t))
 251
 252 (!define-primitive-object (funcallable-instance
 253                           :lowtag fun-pointer-lowtag
 254                           :widetag funcallable-instance-header-widetag
 255                           :alloc-trans %make-funcallable-instance)
 256   (trampoline :init :funcallable-instance-tramp)
 257   (function :ref-known (flushable) :ref-trans %funcallable-instance-function
 258             :set-known () :set-trans (setf %funcallable-instance-function))
 259   (info :rest-p t))
 260
 261 (!define-primitive-object (value-cell :lowtag other-pointer-lowtag
 262                                      :widetag value-cell-header-widetag
 263                                      ;; FIXME: We also have an explicit VOP
 264                                      ;; for this. Is this needed as well?
 265                                      :alloc-trans make-value-cell)
 266   (value :set-trans value-cell-set
 267          :set-known ()
 268          :ref-trans value-cell-ref
 269          :ref-known (flushable)
 270          :init :arg))
 271
 272 #!+alpha
 273 (!define-primitive-object (sap :lowtag other-pointer-lowtag
 274                               :widetag sap-widetag)
 275   (padding)
 276   (pointer :c-type "char *" :length 2))
 277
 278 #!-alpha
 279 (!define-primitive-object (sap :lowtag other-pointer-lowtag
 280                               :widetag sap-widetag)
 281   (pointer :c-type "char *"))
 282
 283
 284 (!define-primitive-object (weak-pointer :type weak-pointer
 285                                        :lowtag other-pointer-lowtag
 286                                        :widetag weak-pointer-widetag
 287                                        :alloc-trans make-weak-pointer)
 288   (value :ref-trans sb!c::%weak-pointer-value :ref-known (flushable)
 289          :init :arg)
 290   (broken :type (member t nil)
 291           :ref-trans sb!c::%weak-pointer-broken :ref-known (flushable)
 292           :init :null)
 293   (next :c-type #!-alpha "struct weak_pointer *" #!+alpha "u32"))
 294
 295 ;;;; other non-heap data blocks
 296
 297 (!define-primitive-object (binding)
 298   value
 299   symbol) ;; on sb-thread, this is actually a tls-index
 300
 301 (!define-primitive-object (unwind-block)
 302   (current-uwp :c-type #!-alpha "struct unwind_block *" #!+alpha "u32")
 303   (current-cont :c-type #!-alpha "lispobj *" #!+alpha "u32")
 304   #!-(or x86 x86-64) current-code
 305   entry-pc
 306   #!+win32 next-seh-frame
 307   #!+win32 seh-frame-handler)
 308
 309 (!define-primitive-object (catch-block)
 310   (current-uwp :c-type #!-alpha "struct unwind_block *" #!+alpha "u32")
 311   (current-cont :c-type #!-alpha "lispobj *" #!+alpha "u32")
 312   #!-(or x86 x86-64) current-code
 313   entry-pc
 314   #!+(and win32 x86) next-seh-frame
 315   #!+(and win32 x86) seh-frame-handler
 316   tag
 317   (previous-catch :c-type #!-alpha "struct catch_block *" #!+alpha "u32"))
 318 \f
 319 ;;;; symbols
 320
 321 (!define-primitive-object (symbol :lowtag other-pointer-lowtag
 322                                  :widetag symbol-header-widetag
 323                                  :alloc-trans %make-symbol
 324                                  :type symbol)
 325
 326   ;; Beware when changing this definition.  NIL-the-symbol is defined
 327   ;; using this layout, and NIL-the-end-of-list-marker is the cons
 328   ;; ( NIL . NIL ), living in the first two slots of NIL-the-symbol
 329   ;; (conses have no header).  Careful selection of lowtags ensures
 330   ;; that the same pointer can be used for both purposes:
 331   ;; OTHER-POINTER-LOWTAG is 7, LIST-POINTER-LOWTAG is 3, so if you
 332   ;; subtract 3 from (SB-KERNEL:GET-LISP-OBJ-ADDRESS 'NIL) you get the
 333   ;; first data slot, and if you subtract 7 you get a symbol header.
 334
 335   ;; also the CAR of NIL-as-end-of-list
 336   (value :init :unbound
 337          :set-trans %set-symbol-global-value
 338          :set-known ())
 339   ;; also the CDR of NIL-as-end-of-list.  Its reffer needs special
 340   ;; care for this reason, as hash values must be fixnums.
 341   (hash :set-trans %set-symbol-hash)
 342
 343   (info :ref-trans symbol-info :ref-known (flushable)
 344         :set-trans (setf symbol-info)
 345         :set-known ()
 346         :cas-trans %compare-and-swap-symbol-info
 347         :type (or simple-vector list)
 348         :init :null)
 349   (name :ref-trans symbol-name :init :arg)
 350   (package :ref-trans symbol-package
 351            :set-trans %set-symbol-package
 352            :init :null)
 353   ;; 0 tls-index means no tls-index is allocated
 354   ;; x86-64 puts the tls-index in the header word.
 355   #!+(and sb-thread (not x86-64))
 356   (tls-index :ref-known (flushable) :ref-trans symbol-tls-index))
 357
 358 (!define-primitive-object (complex-single-float
 359                           :lowtag other-pointer-lowtag
 360                           :widetag complex-single-float-widetag)
 361   #!+x86-64
 362   (data :c-type "struct { float data[2]; } ")
 363   #!-x86-64
 364   (real :c-type "float")
 365   #!-x86-64
 366   (imag :c-type "float"))
 367
 368 (!define-primitive-object (complex-double-float
 369                           :lowtag other-pointer-lowtag
 370                           :widetag complex-double-float-widetag)
 371   (filler)
 372   (real :c-type "double" :length #!-x86-64 2 #!+x86-64 1)
 373   (imag :c-type "double" :length #!-x86-64 2 #!+x86-64 1))
 374
 375 #!+sb-simd-pack
 376 (!define-primitive-object (simd-pack
 377                           :lowtag other-pointer-lowtag
 378                           :widetag simd-pack-widetag)
 379   (tag :ref-trans %simd-pack-tag
 380        :attributes (movable flushable)
 381        :type fixnum)
 382   (lo-value :c-type "long" :type (unsigned-byte 64))
 383   (hi-value :c-type "long" :type (unsigned-byte 64)))
 384
 385 ;;; this isn't actually a lisp object at all, it's a c structure that lives
 386 ;;; in c-land.  However, we need sight of so many parts of it from Lisp that
 387 ;;; it makes sense to define it here anyway, so that the GENESIS machinery
 388 ;;; can take care of maintaining Lisp and C versions.
 389 (!define-primitive-object (thread)
 390   ;; no_tls_value_marker is borrowed very briefly at thread startup to
 391   ;; pass the address of initial-function into new_thread_trampoline.
 392   ;; tls[0] = NO_TLS_VALUE_MARKER_WIDETAG because a the tls index slot
 393   ;; of a symbol is initialized to zero
 394   (no-tls-value-marker)
 395   (os-thread :c-type "os_thread_t")
 396   ;; This is the original address at which the memory was allocated,
 397   ;; which may have different alignment then what we prefer to use.
 398   ;; Kept here so that when the thread dies we can release the whole
 399   ;; memory we reserved.
 400   (os-address :c-type "void *" :length #!+alpha 2 #!-alpha 1)
 401
 402   ;; Keep these next six slots (alloc-region being figured in as 1 slot)
 403   ;; near the beginning of the structure so that x86[-64] assembly code
 404   ;; can use single-byte displacements from thread-base-tn.
 405   ;; Doing so reduces code size for allocation sequences and special variable
 406   ;; manipulations by fixing their TLS offsets to be < 2^7, the largest
 407   ;; aligned displacement fitting in a signed byte.
 408   #!+gencgc (alloc-region :c-type "struct alloc_region" :length 5)
 409   #!+(or x86 x86-64 sb-thread) (pseudo-atomic-bits :special *pseudo-atomic-bits*)
 410   ;; next two not used in C, but this wires the TLS offsets to small values
 411   #!+(and x86-64 sb-thread)
 412   (current-catch-block :special *current-catch-block*)
 413   #!+(and x86-64 sb-thread)
 414   (current-unwind-protect-block :special *current-unwind-protect-block*)
 415   (alien-stack-pointer :c-type "lispobj *" :length #!+alpha 2 #!-alpha 1
 416                        :special *alien-stack-pointer*)
 417   (binding-stack-pointer :c-type "lispobj *" :length #!+alpha 2 #!-alpha 1
 418                          :special *binding-stack-pointer*)
 419   ;; END of slots to keep near the beginning.
 420
 421   ;; These aren't accessed (much) from Lisp, so don't really care
 422   ;; if it takes a 4-byte displacement.
 423   (alien-stack-start :c-type "lispobj *" :length #!+alpha 2 #!-alpha 1)
 424   (binding-stack-start :c-type "lispobj *" :length #!+alpha 2 #!-alpha 1
 425                        :special *binding-stack-start*)
 426   #!+sb-thread
 427   (os-attr :c-type "pthread_attr_t *" :length #!+alpha 2 #!-alpha 1)
 428   #!+sb-thread
 429   (state-sem :c-type "os_sem_t *" :length #!+alpha 2 #!-alpha 1)
 430   #!+sb-thread
 431   (state-not-running-sem :c-type "os_sem_t *" :length #!+alpha 2 #!-alpha 1)
 432   #!+sb-thread
 433   (state-not-running-waitcount :c-type "int" :length 1)
 434   #!+sb-thread
 435   (state-not-stopped-sem :c-type "os_sem_t *" :length #!+alpha 2 #!-alpha 1)
 436   #!+sb-thread
 437   (state-not-stopped-waitcount :c-type "int" :length 1)
 438   (control-stack-start :c-type "lispobj *" :length #!+alpha 2 #!-alpha 1
 439                        :special *control-stack-start*)
 440   (control-stack-end :c-type "lispobj *" :length #!+alpha 2 #!-alpha 1
 441                      :special *control-stack-end*)
 442   (control-stack-guard-page-protected)
 443   #!+win32 (private-events :c-type "struct private_events" :length 2)
 444   (this :c-type "struct thread *" :length #!+alpha 2 #!-alpha 1)
 445   (prev :c-type "struct thread *" :length #!+alpha 2 #!-alpha 1)
 446   (next :c-type "struct thread *" :length #!+alpha 2 #!-alpha 1)
 447   ;; starting, running, suspended, dead
 448   (state :c-type "lispobj")
 449   (tls-cookie)                          ;  on x86, the LDT index
 450   (interrupt-data :c-type "struct interrupt_data *"
 451                   :length #!+alpha 2 #!-alpha 1)
 452   (stepping)
 453   ;; For various reasons related to pseudo-atomic and interrupt
 454   ;; handling, we need to know if the machine context is in Lisp code
 455   ;; or not.  On non-threaded targets, this is a global variable in
 456   ;; the runtime, but it's clearly a per-thread value.
 457   #!+sb-thread
 458   (foreign-function-call-active :c-type "boolean")
 459   ;; Same as above for the location of the current control stack frame.
 460   #!+(and sb-thread (not (or x86 x86-64)))
 461   (control-frame-pointer :c-type "lispobj *")
 462   ;; Same as above for the location of the current control stack
 463   ;; pointer.  This is also used on threaded x86oids to allow LDB to
 464   ;; print an approximation of the CSP as needed.
 465   #!+sb-thread
 466   (control-stack-pointer :c-type "lispobj *")
 467   #!+mach-exception-handler
 468   (mach-port-name :c-type "mach_port_name_t")
 469   (nonpointer-data :c-type "struct nonpointer_thread_data *" :length #!+alpha 2 #!-alpha 1)
 470   #!+(and sb-safepoint x86) (selfptr :c-type "struct thread *")
 471   ;; Context base pointer for running on top of system libraries built using
 472   ;; -fomit-frame-pointer.  Currently truly required and implemented only
 473   ;; for (and win32 x86-64), but could be generalized to other platforms if
 474   ;; needed:
 475   #!+win32 (carried-base-pointer :c-type "os_context_register_t")
 476   #!+sb-safepoint (csp-around-foreign-call :c-type "lispobj *")
 477   #!+sb-safepoint (pc-around-foreign-call :c-type "lispobj *")
 478   #!+win32 (synchronous-io-handle-and-flag :c-type "HANDLE" :length 1)
 479   #!+(and sb-safepoint-strictly (not win32))
 480   (sprof-alloc-region :c-type "struct alloc_region" :length 5)
 481   ;; KLUDGE: On alpha, until STEPPING we have been lucky and the 32
 482   ;; bit slots came in pairs. However the C compiler will align
 483   ;; interrupt_contexts on a double word boundary. This logic should
 484   ;; be handled by !DEFINE-PRIMITIVE-OBJECT.
 485   #!+alpha
 486   (padding)
 487   (interrupt-contexts :c-type "os_context_t *" :rest-p t))