;;;; 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) (cdr :ref-trans cdr :set-trans sb!c::%rplacd :init :arg)) (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)) (arglist :type list :ref-known (flushable) :ref-trans %simple-fun-arglist :set-known (unsafe) :set-trans (setf %simple-fun-arglist)) (type :ref-known (flushable) :ref-trans %simple-fun-type :set-known (unsafe) :set-trans (setf %simple-fun-type)) ;; the SB!C::DEBUG-FUN object corresponding to this object, or NIL for none #+nil ; FIXME: doesn't work (gotcha, lowly maintenoid!) See notes on bug 137. (debug-fun :ref-known (flushable) :ref-trans %simple-fun-debug-fun :set-known (unsafe) :set-trans (setf %simple-fun-debug-fun)) (code :rest-p t :c-type "unsigned char")) (define-primitive-object (return-pc :lowtag other-pointer-lowtag :widetag t) (return-point :c-type "unsigned char" :rest-p t)) (define-primitive-object (closure :lowtag fun-pointer-lowtag :widetag closure-header-widetag) (fun :init :arg :ref-trans %closure-fun) ;; This SELF slot needs explanation. ;; ;; Ordinary closures did not need this slot before version 0.9.3.xx, ;; as the closure object was already in some dedicated register -- ;; EAX/RAX on x86(-64), reg_LEXENV on register-rich platforms -- and ;; consequently setting up the environment (from the INFO slot, ;; below) was easy. ;; ;; However, it is not easy to support calling FUNCALLABLE-INSTANCEs ;; in the same way; in a FUNCALLABLE-INSTANCE, there are ;; conceptually two variable-length data areas: the closure ;; environment, if any, and the slots of the instance. ;; ;; Until sbcl-0.9.3.xx, it was required that closures to be set as a ;; FUNCALLABLE-INSTANCE-FUNCTION be defined using the magical ;; keyword SB-KERNEL:INSTANCE-LAMBDA, rather than ordinary LAMBDA; ;; this caused an extra indirection to be compiled into the closure ;; code to load the closure from the FUNCALLABLE-INSTANCE-LEXENV ;; slot before setting up the environment for the function body. ;; Failure to obey this protocol yielded confusing error messages as ;; either INSTANCE-LAMBDAs tried to dereference environments that ;; weren't there, or ordinary LAMBDAs got hold of the LAYOUT and ;; LEXENV slots of a FUNCALLABLE-INSTANCE. ;; ;; By adding this SELF slot, which is at the same offset in a ;; regular CLOSURE as the LEXENV slot is in a FUNCALLABLE-INSTANCE, ;; we enable the extra indirection (VOP FUNCALLABLE-INSTANCE-LEXENV, ;; in src/compiler/ir2tran.lisp) to be compiled unconditionally ;; (provided that we set this slot to the closure object itself). ;; Relative to the code before, this adds a word to the space ;; requirements of a closure, and one instruction (a memory fetch) ;; to the body of a closure function. ;; ;; There are potentially other implementation strategies which would ;; remove the need for this extra indirection in regular closures, ;; such as setting up a trampoline for funcallable instances (though ;; it was not clear to me that there are enough registers free in ;; the x86 backend to permit this). This indirection should not be ;; too disastrous, given that for regular closures the fetch is from ;; memory which is known to be active. ;; ;; CSR, 2005-08-05 (self) ; KLUDGE (see above comment) (info :rest-p t)) (define-primitive-object (funcallable-instance :lowtag fun-pointer-lowtag :widetag funcallable-instance-header-widetag :alloc-trans %make-funcallable-instance) #!-(or x86 x86-64) (fun :ref-known (flushable) :ref-trans %funcallable-instance-fun :set-known (unsafe) :set-trans (setf %funcallable-instance-fun)) #!+(or x86 x86-64) (fun :ref-known (flushable) :ref-trans %funcallable-instance-fun ;; KLUDGE: There's no :SET-KNOWN or :SET-TRANS in this case. ;; Instead, later in compiler/x86/system.lisp there's a separate ;; DEFKNOWN for (SETF %FUNCALLABLE-INSTANCE-FUN), and a weird ;; unexplained DEFTRANSFORM from (SETF %SIMPLE-FUN-INSTANCE-FUN) ;; into (SETF %SIMPLE-FUN-SELF). The #!+X86 wrapped around this case ;; is a literal translation of the old CMU CL implementation into ;; the new world of sbcl-0.6.12.63, where multiple DEFKNOWNs for ;; the same operator cause an error (instead of silently deleting ;; all information associated with the old DEFKNOWN, as before). ;; It's definitely not very clean, with too many #!+ conditionals and ;; too little documentation, but I have more urgent things to ;; clean up right now, so I've just left it as a literal ;; translation without trying to fix it. -- WHN 2001-08-02 ) (lexenv :ref-known (flushable) :ref-trans %funcallable-instance-lexenv :set-known (unsafe) :set-trans (setf %funcallable-instance-lexenv)) (info :rest-p t)) (define-primitive-object (value-cell :lowtag other-pointer-lowtag :widetag value-cell-header-widetag :alloc-trans make-value-cell) (value :set-trans value-cell-set :set-known (unsafe) :ref-trans value-cell-ref :ref-known (flushable) :init :arg)) #!+alpha (define-primitive-object (sap :lowtag other-pointer-lowtag :widetag sap-widetag) (padding) (pointer :c-type "char *" :length 2)) #!-alpha (define-primitive-object (sap :lowtag other-pointer-lowtag :widetag sap-widetag) (pointer :c-type "char *")) (define-primitive-object (weak-pointer :type weak-pointer :lowtag other-pointer-lowtag :widetag weak-pointer-widetag :alloc-trans make-weak-pointer) (value :ref-trans sb!c::%weak-pointer-value :ref-known (flushable) :init :arg) (broken :type (member t nil) :ref-trans sb!c::%weak-pointer-broken :ref-known (flushable) :init :null) (next :c-type #!-alpha "struct weak_pointer *" #!+alpha "u32")) ;;;; other non-heap data blocks (define-primitive-object (binding) value symbol) (define-primitive-object (unwind-block) (current-uwp :c-type #!-alpha "struct unwind_block *" #!+alpha "u32") (current-cont :c-type #!-alpha "lispobj *" #!+alpha "u32") #!-(or x86 x86-64) current-code entry-pc) (define-primitive-object (catch-block) (current-uwp :c-type #!-alpha "struct unwind_block *" #!+alpha "u32") (current-cont :c-type #!-alpha "lispobj *" #!+alpha "u32") #!-(or x86 x86-64) current-code entry-pc tag (previous-catch :c-type #!-alpha "struct catch_block *" #!+alpha "u32") size) ;;; (For an explanation of this, see the comments at the definition of ;;; KLUDGE-NONDETERMINISTIC-CATCH-BLOCK-SIZE.) (aver (= kludge-nondeterministic-catch-block-size catch-block-size)) ;;;; symbols (define-primitive-object (symbol :lowtag other-pointer-lowtag :widetag symbol-header-widetag :alloc-trans %make-symbol) ;; Beware when changing this definition. NIL-the-symbol is defined ;; using this layout, and NIL-the-end-of-list-marker is the cons ;; ( NIL . NIL ), living in the first two slots of NIL-the-symbol ;; (conses have no header). Careful selection of lowtags ensures ;; that the same pointer can be used for both purposes: ;; OTHER-POINTER-LOWTAG is 7, LIST-POINTER-LOWTAG is 3, so if you ;; subtract 3 from (SB-KERNEL:GET-LISP-OBJ-ADDRESS 'NIL) you get the ;; first data slot, and if you subtract 7 you get a symbol header. ;; also the CAR of NIL-as-end-of-list (value :init :unbound :ref-known (flushable) :ref-trans symbol-global-value) ;; also the CDR of NIL-as-end-of-list. Its reffer needs special ;; care for this reason, as hash values must be fixnums. (hash :set-trans %set-symbol-hash) (plist :ref-trans symbol-plist :set-trans %set-symbol-plist :init :null) (name :ref-trans symbol-name :init :arg) (package :ref-trans symbol-package :set-trans %set-symbol-package :init :null) #!+sb-thread (tls-index :ref-known (flushable) :ref-trans symbol-tls-index)) (define-primitive-object (complex-single-float :lowtag other-pointer-lowtag :widetag complex-single-float-widetag) (real :c-type "float") (imag :c-type "float")) (define-primitive-object (complex-double-float :lowtag other-pointer-lowtag :widetag complex-double-float-widetag) #!-x86-64 (filler) (real :c-type "double" :length #!-x86-64 2 #!+x86-64 1) (imag :c-type "double" :length #!-x86-64 2 #!+x86-64 1)) #!+sb-lutex (define-primitive-object (lutex :lowtag other-pointer-lowtag :widetag lutex-widetag :alloc-trans %make-lutex) (gen :c-type "long" :length 1) (live :c-type "long" :length 1) (next :c-type "struct lutex *" :length 1) (prev :c-type "struct lutex *" :length 1) (mutex :c-type "pthread_mutex_t *" :length 1) (condition-variable :c-type "pthread_cond_t *" :length 1)) ;;; this isn't actually a lisp object at all, it's a c structure that lives ;;; in c-land. However, we need sight of so many parts of it from Lisp that ;;; it makes sense to define it here anyway, so that the GENESIS machinery ;;; can take care of maintaining Lisp and C versions. ;;; Hence the even-fixnum lowtag just so we don't get odd(sic) numbers ;;; added to the slot offsets (define-primitive-object (thread :lowtag even-fixnum-lowtag) ;; no_tls_value_marker is borrowed very briefly at thread startup to ;; pass the address of initial-function into new_thread_trampoline. ;; tls[0] = NO_TLS_VALUE_MARKER_WIDETAG because a the tls index slot ;; of a symbol is initialized to zero (no-tls-value-marker) (os-thread :c-type "volatile os_thread_t") (binding-stack-start :c-type "lispobj *" :length #!+alpha 2 #!-alpha 1) (binding-stack-pointer :c-type "lispobj *" :length #!+alpha 2 #!-alpha 1) (control-stack-start :c-type "lispobj *" :length #!+alpha 2 #!-alpha 1) (control-stack-end :c-type "lispobj *" :length #!+alpha 2 #!-alpha 1) (alien-stack-start :c-type "lispobj *" :length #!+alpha 2 #!-alpha 1) (alien-stack-pointer :c-type "lispobj *" :length #!+alpha 2 #!-alpha 1) #!+gencgc (alloc-region :c-type "struct alloc_region" :length 5) (this :c-type "struct thread *" :length #!+alpha 2 #!-alpha 1) (prev :c-type "struct thread *" :length #!+alpha 2 #!-alpha 1) (next :c-type "struct thread *" :length #!+alpha 2 #!-alpha 1) ;; starting, running, suspended, dead (state :c-type "volatile lispobj") (tls-cookie) ; on x86, the LDT index #!+(or x86 x86-64) (pseudo-atomic-atomic) #!+(or x86 x86-64) (pseudo-atomic-interrupted) (interrupt-data :c-type "struct interrupt_data *" :length #!+alpha 2 #!-alpha 1) (interrupt-contexts :c-type "os_context_t *" :rest-p t))