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 #!-64-bit
  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   #!-64-bit (filler)
  77   (value :c-type "double" :length #.(/ 64 n-word-bits)))
  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   (debug-info :type t
 162               :ref-known (flushable)
 163               :ref-trans %code-debug-info
 164               :set-known ()
 165               :set-trans (setf %code-debug-info))
 166   #!-64-bit
 167   (n-entries :type fixnum
 168              :set-known ()
 169              :set-trans (setf %code-n-entries)
 170              :ref-trans %code-n-entries
 171              :ref-known (flushable foldable))
 172   (constants :rest-p t))
 173
 174 (!define-primitive-object (fdefn :type fdefn
 175                                 :lowtag other-pointer-lowtag
 176                                 :widetag fdefn-widetag)
 177   (name :ref-trans fdefn-name
 178         :set-trans %set-fdefn-name :set-known ())
 179   (fun :type (or function null) :ref-trans fdefn-fun)
 180   (raw-addr :c-type #!-alpha "char *" #!+alpha "u32"))
 181
 182 ;;; a simple function (as opposed to hairier things like closures
 183 ;;; which are also subtypes of Common Lisp's FUNCTION type)
 184 (!define-primitive-object (simple-fun :type function
 185                                      :lowtag fun-pointer-lowtag
 186                                      :widetag simple-fun-header-widetag)
 187   #!-(or x86 x86-64) (self :ref-trans %simple-fun-self
 188                :set-trans (setf %simple-fun-self))
 189   ;; FIXME: we don't currently detect/prevent at compile-time the bad
 190   ;; scenario this comment claims to disallow, as determined by re-enabling
 191   ;; these SET- and REF- specifiers, which led to a cold-init crash.
 192   #!+(or x86 x86-64) (self
 193           ;; KLUDGE: There's no :SET-KNOWN, :SET-TRANS, :REF-KNOWN, or
 194           ;; :REF-TRANS here in this case. Instead, there's separate
 195           ;; DEFKNOWN/DEFINE-VOP/DEFTRANSFORM stuff in
 196           ;; compiler/x86/system.lisp to define and declare them by
 197           ;; hand. I don't know why this is, but that's (basically)
 198           ;; the way it was done in CMU CL, and it works. (It's not
 199           ;; exactly the same way it was done in CMU CL in that CMU
 200           ;; CL's allows duplicate DEFKNOWNs, blithely overwriting any
 201           ;; previous data associated with the previous DEFKNOWN, and
 202           ;; that property was used to mask the definitions here. In
 203           ;; SBCL as of 0.6.12.64 that's not allowed -- too confusing!
 204           ;; -- so we have to explicitly suppress the DEFKNOWNish
 205           ;; stuff here in order to allow this old hack to work in the
 206           ;; new world. -- WHN 2001-08-82
 207           )
 208   (name :ref-known (flushable)
 209         :ref-trans %simple-fun-name
 210         :set-known ()
 211         :set-trans (setf %simple-fun-name))
 212   (arglist :type list
 213            :ref-known (flushable)
 214            :ref-trans %simple-fun-arglist
 215            :set-known ()
 216            :set-trans (setf %simple-fun-arglist))
 217   (type :ref-known (flushable)
 218         ;; %%SIMPLE-FUN-TYPE is used only by %SIMPLE-FUN-TYPE.
 219         ;; Nobody should care that %SIMPLE-FUN-TYPE isn't open-coded.
 220         :ref-trans %%simple-fun-type
 221         :set-known ()
 222         :set-trans (setf %simple-fun-type))
 223   ;; NIL for empty, STRING for a docstring, SIMPLE-VECTOR for XREFS, and (CONS
 224   ;; STRING SIMPLE-VECTOR) for both.
 225   (info :init :null
 226         :ref-trans %simple-fun-info
 227         :ref-known (flushable)
 228         :set-trans (setf %simple-fun-info)
 229         :set-known ())
 230   ;; the SB!C::DEBUG-FUN object corresponding to this object, or NIL for none
 231   #+nil ; FIXME: doesn't work (gotcha, lowly maintenoid!) See notes on bug 137.
 232   (debug-fun :ref-known (flushable)
 233              :ref-trans %simple-fun-debug-fun
 234              :set-known ()
 235              :set-trans (setf %simple-fun-debug-fun))
 236   (code :rest-p t :c-type "unsigned char"))
 237
 238 (!define-primitive-object (return-pc :lowtag other-pointer-lowtag :widetag t)
 239   (return-point :c-type "unsigned char" :rest-p t))
 240
 241 (!define-primitive-object (closure :lowtag fun-pointer-lowtag
 242                                   :widetag closure-header-widetag)
 243   ;; %CLOSURE-FUN should never be invoked on x86[-64].
 244   ;; The above remark at %SIMPLE-FUN-SELF is relevant in its sentiment,
 245   ;; but actually no longer true - the confusing situation is not caught
 246   ;; until too late. But at least this one was nonfatal.
 247   #!-(or x86 x86-64) (fun :init :arg :ref-trans %closure-fun)
 248   #!+(or x86 x86-64) (fun :init :arg)
 249   (info :rest-p t))
 250
 251 (!define-primitive-object (funcallable-instance
 252                           :lowtag fun-pointer-lowtag
 253                           :widetag funcallable-instance-header-widetag
 254                           :alloc-trans %make-funcallable-instance)
 255   (trampoline :init :funcallable-instance-tramp)
 256   ;; TODO: if we can switch places of 'function' and 'fsc-instance-slots'
 257   ;; (at least for the builds with compact-instance-header)
 258   ;; then for both funcallable and non-funcallable instances,
 259   ;; the CLOS slot vector will be in the word 5 bytes past the tagged pointer.
 260   ;; This shouldn't be too hard to arrange, since nothing needs to know where
 261   ;; the tagged function lives except the funcallable instance trampoline.
 262   (function :ref-known (flushable) :ref-trans %funcallable-instance-function
 263             :set-known () :set-trans (setf %funcallable-instance-function))
 264   (info :rest-p t))
 265
 266 (!define-primitive-object (value-cell :lowtag other-pointer-lowtag
 267                                      :widetag value-cell-header-widetag
 268                                      ;; FIXME: We also have an explicit VOP
 269                                      ;; for this. Is this needed as well?
 270                                      :alloc-trans make-value-cell)
 271   (value :set-trans value-cell-set
 272          :set-known ()
 273          :ref-trans value-cell-ref
 274          :ref-known (flushable)
 275          :init :arg))
 276
 277 (!define-primitive-object (sap :lowtag other-pointer-lowtag
 278                               :widetag sap-widetag)
 279   (pointer :c-type "char *" :pointer t))
 280
 281
 282 (!define-primitive-object (weak-pointer :type weak-pointer
 283                                        :lowtag other-pointer-lowtag
 284                                        :widetag weak-pointer-widetag
 285                                        :alloc-trans make-weak-pointer)
 286   ;; FIXME: SB!C should be almost *anything* but that. Probably SB!KERNEL
 287   (value :ref-trans sb!c::%weak-pointer-value :ref-known (flushable)
 288          :init :arg)
 289   (broken :type (member t nil)
 290           :ref-trans sb!c::%weak-pointer-broken :ref-known (flushable)
 291           :init :null)
 292   (next :c-type #!-alpha "struct weak_pointer *" #!+alpha "u32"))
 293
 294 ;;;; other non-heap data blocks
 295
 296 (!define-primitive-object (binding)
 297   value
 298   symbol) ;; on sb-thread, this is actually a tls-index
 299
 300 (!define-primitive-object (unwind-block)
 301   (uwp :c-type #!-alpha "struct unwind_block *" #!+alpha "u32")
 302   (cfp :c-type #!-alpha "lispobj *" #!+alpha "u32")
 303   #!-(or x86 x86-64) code
 304   entry-pc
 305   #!+win32 next-seh-frame
 306   #!+win32 seh-frame-handler)
 307
 308 (!define-primitive-object (catch-block)
 309   (uwp :c-type #!-alpha "struct unwind_block *" #!+alpha "u32")
 310   (cfp :c-type #!-alpha "lispobj *" #!+alpha "u32")
 311   #!-(or x86 x86-64) code
 312   entry-pc
 313   #!+(and win32 x86) next-seh-frame
 314   #!+(and win32 x86) seh-frame-handler
 315   tag
 316   (previous-catch :c-type #!-alpha "struct catch_block *" #!+alpha "u32"))
 317 \f
 318 ;;;; symbols
 319
 320 (!define-primitive-object (symbol :lowtag other-pointer-lowtag
 321                                  :widetag symbol-header-widetag
 322                                  :alloc-trans %%make-symbol
 323                                  :type symbol)
 324
 325   ;; Beware when changing this definition.  NIL-the-symbol is defined
 326   ;; using this layout, and NIL-the-end-of-list-marker is the cons
 327   ;; ( NIL . NIL ), living in the first two slots of NIL-the-symbol
 328   ;; (conses have no header).  Careful selection of lowtags ensures
 329   ;; that the same pointer can be used for both purposes:
 330   ;; OTHER-POINTER-LOWTAG is 7, LIST-POINTER-LOWTAG is 3, so if you
 331   ;; subtract 3 from (SB-KERNEL:GET-LISP-OBJ-ADDRESS 'NIL) you get the
 332   ;; first data slot, and if you subtract 7 you get a symbol header.
 333
 334   ;; also the CAR of NIL-as-end-of-list
 335   (value :init :unbound
 336          :set-trans %set-symbol-global-value
 337          :set-known ())
 338   ;; also the CDR of NIL-as-end-of-list.  Its reffer needs special
 339   ;; care for this reason, as hash values must be fixnums.
 340   (hash :set-trans %set-symbol-hash)
 341
 342   (info :ref-trans symbol-info :ref-known (flushable)
 343         :set-trans (setf symbol-info)
 344         :set-known ()
 345         :cas-trans %compare-and-swap-symbol-info
 346         :type (or simple-vector list)
 347         :init :null)
 348   (name :ref-trans symbol-name :init :arg)
 349   (package :ref-trans symbol-package
 350            :set-trans %set-symbol-package
 351            :init :null)
 352   ;; 0 tls-index means no tls-index is allocated
 353   ;; 64-bit put the tls-index in the header word.
 354   #!+(and sb-thread (not 64-bit))
 355   (tls-index :ref-known (flushable) :ref-trans symbol-tls-index))
 356
 357 (!define-primitive-object (complex-single-float
 358                           :lowtag other-pointer-lowtag
 359                           :widetag complex-single-float-widetag)
 360   #!+64-bit
 361   (data :c-type "struct { float data[2]; } ")
 362   #!-64-bit
 363   (real :c-type "float")
 364   #!-64-bit
 365   (imag :c-type "float"))
 366
 367 (!define-primitive-object (complex-double-float
 368                           :lowtag other-pointer-lowtag
 369                           :widetag complex-double-float-widetag)
 370   (filler)
 371   (real :c-type "double" :length #.(/ 64 n-word-bits))
 372   (imag :c-type "double" :length #.(/ 64 n-word-bits)))
 373
 374 #!+sb-simd-pack
 375 (!define-primitive-object (simd-pack
 376                           :lowtag other-pointer-lowtag
 377                           :widetag simd-pack-widetag)
 378   (tag :ref-trans %simd-pack-tag
 379        :attributes (movable flushable)
 380        :type fixnum)
 381   (lo-value :c-type "long" :type (unsigned-byte 64))
 382   (hi-value :c-type "long" :type (unsigned-byte 64)))
 383
 384 ;;; this isn't actually a lisp object at all, it's a c structure that lives
 385 ;;; in c-land.  However, we need sight of so many parts of it from Lisp that
 386 ;;; it makes sense to define it here anyway, so that the GENESIS machinery
 387 ;;; can take care of maintaining Lisp and C versions.
 388 (!define-primitive-object (thread)
 389   ;; no_tls_value_marker is borrowed very briefly at thread startup to
 390   ;; pass the address of initial-function into new_thread_trampoline.
 391   ;; tls[0] = NO_TLS_VALUE_MARKER_WIDETAG because a the tls index slot
 392   ;; of a symbol is initialized to zero
 393   (no-tls-value-marker)
 394   (os-thread :c-type "os_thread_t")
 395   ;; This is the original address at which the memory was allocated,
 396   ;; which may have different alignment then what we prefer to use.
 397   ;; Kept here so that when the thread dies we can release the whole
 398   ;; memory we reserved.
 399   (os-address :c-type "void *" :pointer t)
 400
 401   ;; Keep these next six slots (alloc-region being figured in as 1 slot)
 402   ;; near the beginning of the structure so that x86[-64] assembly code
 403   ;; can use single-byte displacements from thread-base-tn.
 404   ;; Doing so reduces code size for allocation sequences and special variable
 405   ;; manipulations by fixing their TLS offsets to be < 2^7, the largest
 406   ;; aligned displacement fitting in a signed byte.
 407   #!+gencgc (alloc-region :c-type "struct alloc_region" :length 5)
 408   #!+sb-thread (pseudo-atomic-bits #!+(or x86 x86-64) :special #!+(or x86 x86-64) *pseudo-atomic-bits*)
 409   ;; next two not used in C, but this wires the TLS offsets to small values
 410   #!+(and x86-64 sb-thread)
 411   (current-catch-block :special *current-catch-block*)
 412   #!+(and x86-64 sb-thread)
 413   (current-unwind-protect-block :special *current-unwind-protect-block*)
 414   (alien-stack-pointer :c-type "lispobj *" :pointer t
 415                        :special *alien-stack-pointer*)
 416   (binding-stack-pointer :c-type "lispobj *" :pointer t
 417                          :special *binding-stack-pointer*)
 418   (stepping)
 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 *" :pointer t)
 424   (binding-stack-start :c-type "lispobj *" :pointer t
 425                        :special *binding-stack-start*)
 426
 427   #!+sb-thread
 428   (os-attr :c-type "pthread_attr_t *" :pointer t)
 429   #!+(and sb-thread (not sb-safepoint))
 430   (state-sem :c-type "os_sem_t *" :pointer t)
 431   #!+(and sb-thread (not sb-safepoint))
 432   (state-not-running-sem :c-type "os_sem_t *" :pointer t)
 433   #!+(and sb-thread (not sb-safepoint))
 434   (state-not-running-waitcount :c-type "int" :length 1)
 435   #!+(and sb-thread (not sb-safepoint))
 436   (state-not-stopped-sem :c-type "os_sem_t *" :pointer t)
 437   #!+(and sb-thread (not sb-safepoint))
 438   (state-not-stopped-waitcount :c-type "int" :length 1)
 439   (control-stack-start :c-type "lispobj *" :pointer t
 440                        :special *control-stack-start*)
 441   (control-stack-end :c-type "lispobj *" :pointer t
 442                      :special *control-stack-end*)
 443   (control-stack-guard-page-protected)
 444   #!+win32 (private-events :c-type "struct private_events" :length 2)
 445   (this :c-type "struct thread *" :pointer t)
 446   (prev :c-type "struct thread *" :pointer t)
 447   (next :c-type "struct thread *" :pointer t)
 448   ;; starting, running, suspended, dead
 449   (state :c-type "lispobj")
 450
 451   #!+x86 (tls-cookie)                          ;  LDT index
 452   (interrupt-data :c-type "struct interrupt_data *"
 453                   :pointer t)
 454   ;; For various reasons related to pseudo-atomic and interrupt
 455   ;; handling, we need to know if the machine context is in Lisp code
 456   ;; or not.  On non-threaded targets, this is a global variable in
 457   ;; the runtime, but it's clearly a per-thread value.
 458   #!+sb-thread
 459   (foreign-function-call-active :c-type "boolean")
 460   ;; Same as above for the location of the current control stack frame.
 461   #!+(and sb-thread (not (or x86 x86-64)))
 462   (control-frame-pointer :c-type "lispobj *")
 463   ;; Same as above for the location of the current control stack
 464   ;; pointer.  This is also used on threaded x86oids to allow LDB to
 465   ;; print an approximation of the CSP as needed.
 466   #!+sb-thread
 467   (control-stack-pointer :c-type "lispobj *")
 468   #!+mach-exception-handler
 469   (mach-port-name :c-type "mach_port_name_t")
 470   ;; Context base pointer for running on top of system libraries built using
 471   ;; -fomit-frame-pointer.  Currently truly required and implemented only
 472   ;; for (and win32 x86-64), but could be generalized to other platforms if
 473   ;; needed:
 474   #!+win32 (carried-base-pointer :c-type "os_context_register_t")
 475   #!+sb-safepoint (csp-around-foreign-call :c-type "lispobj *")
 476   #!+sb-safepoint (pc-around-foreign-call :c-type "lispobj *")
 477   #!+win32 (synchronous-io-handle-and-flag :c-type "HANDLE" :length 1)
 478   #!+(and sb-safepoint-strictly (not win32))
 479   (sprof-alloc-region :c-type "struct alloc_region" :length 5)
 480   (interrupt-contexts :c-type "os_context_t *" :rest-p t :pointer t))