1 ;;;; various user-level definitions which need to be done particularly
4 ;;;; This software is part of the SBCL system. See the README file for
7 ;;;; This software is derived from the CMU CL system, which was
8 ;;;; written at Carnegie Mellon University and released into the
9 ;;;; public domain. The software is in the public domain and is
10 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
11 ;;;; files for more information.
13 (in-package "SB!IMPL")
15 ;;;; target constants which need to appear as early as possible
17 ;;; an internal tag for marking empty slots, which needs to be defined
18 ;;; as early as possible because it appears in macroexpansions for
19 ;;; iteration over hash tables
21 ;;; CMU CL 18b used :EMPTY for this purpose, which was somewhat nasty
22 ;;; since it's easily accessible to the user, so that e.g.
23 ;;; (DEFVAR *HT* (MAKE-HASH-TABLE))
24 ;;; (SETF (GETHASH :EMPTY *HT*) :EMPTY)
25 ;;; (MAPHASH (LAMBDA (K V) (FORMAT T "~&~S ~S~%" K V)))
26 ;;; gives no output -- oops!
28 ;;; FIXME: It'd probably be good to use the unbound marker for this.
29 ;;; However, there might be some gotchas involving assumptions by
30 ;;; e.g. AREF that they're not going to return the unbound marker,
31 ;;; and there's also the noted-below problem that the C-level code
32 ;;; contains implicit assumptions about this marker.
34 ;;; KLUDGE: Note that as of version 0.pre7 there's a dependence in the
35 ;;; gencgc.c code on this value being a symbol. (This is only one of
36 ;;; several nasty dependencies between that code and this, alas.)
38 (eval-when (:compile-toplevel
:load-toplevel
:execute
)
39 (def!constant
+empty-ht-slot
+ '%empty-ht-slot%
))
40 ;;; We shouldn't need this mess now that EVAL-WHEN works.
42 ;;; KLUDGE: Using a private symbol still leaves us vulnerable to users
43 ;;; getting nonconforming behavior by messing around with
44 ;;; DO-ALL-SYMBOLS. That seems like a fairly obscure problem, so for
45 ;;; now we just don't worry about it. If for some reason it becomes
46 ;;; worrisome and the magic value needs replacement:
47 ;;; * The replacement value needs to be LOADable with EQL preserved,
48 ;;; so that the macroexpansion for WITH-HASH-TABLE-ITERATOR will
49 ;;; work when compiled into a file and loaded back into SBCL.
50 ;;; (Thus, just uninterning %EMPTY-HT-SLOT% doesn't work.)
51 ;;; * The replacement value needs to be acceptable to the
52 ;;; low-level gencgc.lisp hash table scavenging code.
53 ;;; * The change will break binary compatibility, since comparisons
54 ;;; against the value used at the time of compilation are wired
58 ;;;; DO-related stuff which needs to be visible on the cross-compilation host
60 (eval-when (:compile-toplevel
:load-toplevel
:execute
)
61 (defun frob-do-body (varlist endlist decls-and-code bind step name block
)
62 (let* ((r-inits nil
) ; accumulator for reversed list
63 (r-steps nil
) ; accumulator for reversed list
66 ;; Check for illegal old-style DO.
67 (when (or (not (listp varlist
)) (atom endlist
))
68 (error "ill-formed ~S -- possibly illegal old style DO?" name
))
69 ;; Parse VARLIST to get R-INITS and R-STEPS.
71 (flet (;; (We avoid using CL:PUSH here so that CL:PUSH can be
72 ;; defined in terms of CL:SETF, and CL:SETF can be
73 ;; defined in terms of CL:DO, and CL:DO can be defined
74 ;; in terms of the current function.)
76 (setq r-inits
(cons x r-inits
)))
77 ;; common error-handling
79 (error "~S is an illegal form for a ~S varlist." v name
)))
80 (cond ((symbolp v
) (push-on-r-inits v
))
82 (unless (symbolp (first v
))
83 (error "~S step variable is not a symbol: ~S"
86 (let ((lv (length v
)))
87 ;; (We avoid using CL:CASE here so that CL:CASE can
88 ;; be defined in terms of CL:SETF, and CL:SETF can
89 ;; be defined in terms of CL:DO, and CL:DO can be
90 ;; defined in terms of the current function.)
92 (push-on-r-inits (first v
)))
96 (push-on-r-inits (list (first v
) (second v
)))
97 (setq r-steps
(list* (third v
) (first v
) r-steps
)))
98 (t (illegal-varlist)))))
99 (t (illegal-varlist)))))
100 ;; Construct the new form.
101 (multiple-value-bind (code decls
) (parse-body decls-and-code nil
)
103 (,bind
,(nreverse r-inits
)
109 (,step
,@(nreverse r-steps
))
111 (unless ,(first endlist
) (go ,label-1
))
112 (return-from ,block
(progn ,@(rest endlist
))))))))))
114 ;;; This is like DO, except it has no implicit NIL block. Each VAR is
115 ;;; initialized in parallel to the value of the specified INIT form.
116 ;;; On subsequent iterations, the VARS are assigned the value of the
117 ;;; STEP form (if any) in parallel. The TEST is evaluated before each
118 ;;; evaluation of the body FORMS. When the TEST is true, the
119 ;;; EXIT-FORMS are evaluated as a PROGN, with the result being the
121 (defmacro do-anonymous
(varlist endlist
&rest body
)
122 (frob-do-body varlist endlist body
'let
'psetq
'do-anonymous
(gensym)))
126 ;;; Lots of code wants to get to the KEYWORD package or the
127 ;;; COMMON-LISP package without a lot of fuss, so we cache them in
128 ;;; variables. TO DO: How much does this actually buy us? It sounds
129 ;;; sensible, but I don't know for sure that it saves space or time..
132 ;;; (The initialization forms here only matter on the cross-compilation
133 ;;; host; In the target SBCL, these variables are set in cold init.)
134 (declaim (type package
*cl-package
* *keyword-package
*))
135 (defvar *cl-package
* (find-package "COMMON-LISP"))
136 (defvar *keyword-package
* (find-package "KEYWORD"))
138 ;;; Concatenate together the names of some strings and symbols,
139 ;;; producing a symbol in the current package.
140 (eval-when (:compile-toplevel
:load-toplevel
:execute
)
141 (defun symbolicate (&rest things
)
142 (let ((name (case (length things
)
143 ;; why isn't this just the value in the T branch?
144 ;; Well, this is called early in cold-init, before
145 ;; the type system is set up; however, now that we
146 ;; check for bad lengths, the type system is needed
147 ;; for calls to CONCATENATE. So we need to make sure
148 ;; that the calls are transformed away:
149 (1 (concatenate 'string
(the simple-string
(string (car things
)))))
150 (2 (concatenate 'string
151 (the simple-string
(string (car things
)))
152 (the simple-string
(string (cadr things
)))))
153 (3 (concatenate 'string
154 (the simple-string
(string (car things
)))
155 (the simple-string
(string (cadr things
)))
156 (the simple-string
(string (caddr things
)))))
157 (t (apply #'concatenate
'string
(mapcar #'string things
))))))
158 (values (intern name
)))))
160 ;;; like SYMBOLICATE, but producing keywords
161 (defun keywordicate (&rest things
)
162 (let ((*package
* *keyword-package
*))
163 (apply #'symbolicate things
)))
165 ;;; Access *PACKAGE* in a way which lets us recover when someone has
166 ;;; done something silly like (SETF *PACKAGE* :CL-USER). (Such an
167 ;;; assignment is undefined behavior, so it's sort of reasonable for
168 ;;; it to cause the system to go totally insane afterwards, but it's a
169 ;;; fairly easy mistake to make, so let's try to recover gracefully
171 (defun sane-package ()
172 (let ((maybe-package *package
*))
173 (cond ((and (packagep maybe-package
)
174 ;; For good measure, we also catch the problem of
175 ;; *PACKAGE* being bound to a deleted package.
176 ;; Technically, this is not undefined behavior in itself,
177 ;; but it will immediately lead to undefined to behavior,
178 ;; since almost any operation on a deleted package is
180 (package-name maybe-package
))
183 ;; We're in the undefined behavior zone. First, munge the
184 ;; system back into a defined state.
185 (let ((really-package (find-package :cl-user
)))
186 (setf *package
* really-package
)
188 (error 'simple-type-error
190 :expected-type
'(and package
(satisfies package-name
))
192 "~@<~S can't be a ~A: ~2I~_~S has been reset to ~S.~:>"
193 :format-arguments
(list '*package
*
194 (if (packagep maybe-package
)
196 (type-of maybe-package
))
197 '*package
* really-package
)))))))
199 ;;; Access *DEFAULT-PATHNAME-DEFAULTS*, issuing a warning if its value
200 ;;; is silly. (Unlike the vaguely-analogous SANE-PACKAGE, we don't
201 ;;; actually need to reset the variable when it's silly, since even
202 ;;; crazy values of *DEFAULT-PATHNAME-DEFAULTS* don't leave the system
203 ;;; in a state where it's hard to recover interactively.)
204 (defun sane-default-pathname-defaults ()
205 (let* ((dfd *default-pathname-defaults
*)
206 (dfd-dir (pathname-directory dfd
)))
207 ;; It's generally not good to use a relative pathname for
208 ;; *DEFAULT-PATHNAME-DEFAULTS*, since relative pathnames
209 ;; are defined by merging into a default pathname (which is,
210 ;; by default, *DEFAULT-PATHNAME-DEFAULTS*).
211 (when (and (consp dfd-dir
)
212 (eql (first dfd-dir
) :relative
))
214 "~@<~S is a relative pathname. (But we'll try using it anyway.)~@:>"
215 '*default-pathname-defaults
*))
218 ;;; Give names to elements of a numeric sequence.
219 (defmacro defenum
((&key
(prefix "") (suffix "") (start 0) (step 1))
225 (dolist (id identifiers
)
227 (multiple-value-bind (root docs
)
229 (values (car id
) (cdr id
))
231 (push `(def!constant
,(symbolicate prefix root suffix
)
232 ,(+ start
(* step index
))
237 ,@(nreverse results
))))
239 ;;; generalization of DEFCONSTANT to values which are the same not
240 ;;; under EQL but under e.g. EQUAL or EQUALP
242 ;;; DEFCONSTANT-EQX is to be used instead of DEFCONSTANT for values
243 ;;; which are appropriately compared using the function given by the
244 ;;; EQX argument instead of EQL.
246 ;;; Note: Be careful when using this macro, since it's easy to
247 ;;; unintentionally pessimize your code. A good time to use this macro
248 ;;; is when the values defined will be fed into optimization
249 ;;; transforms and never actually appear in the generated code; this
250 ;;; is especially common when defining BYTE expressions. Unintentional
251 ;;; pessimization can result when the values defined by this macro are
252 ;;; actually used in generated code: because of the way that the
253 ;;; dump/load system works, you'll typically get one copy of consed
254 ;;; structure for each object file which contains code referring to
255 ;;; the value, plus perhaps one more copy bound to the SYMBOL-VALUE of
256 ;;; the constant. If you don't want that to happen, you should
257 ;;; probably use DEFPARAMETER instead; or if you truly desperately
258 ;;; need to avoid runtime indirection through a symbol, you might be
259 ;;; able to do something with LOAD-TIME-VALUE or MAKE-LOAD-FORM.
260 (defmacro defconstant-eqx
(symbol expr eqx
&optional doc
)
261 `(def!constant
,symbol
262 (%defconstant-eqx-value
',symbol
,expr
,eqx
)
263 ,@(when doc
(list doc
))))
264 (defun %defconstant-eqx-value
(symbol expr eqx
)
265 (declare (type function eqx
))
266 (flet ((bummer (explanation)
267 (error "~@<bad DEFCONSTANT-EQX ~S ~2I~_~S: ~2I~_~A ~S~:>"
271 (symbol-value symbol
))))
272 (cond ((not (boundp symbol
))
274 ((not (constantp symbol
))
275 (bummer "already bound as a non-constant"))
276 ((not (funcall eqx
(symbol-value symbol
) expr
))
277 (bummer "already bound as a different constant value"))
279 (symbol-value symbol
)))))
281 ;;; a helper function for various macros which expect clauses of a
282 ;;; given length, etc.
284 ;;; Return true if X is a proper list whose length is between MIN and
286 (defun proper-list-of-length-p (x min
&optional
(max min
))
287 ;; FIXME: This implementation will hang on circular list
288 ;; structure. Since this is an error-checking utility, i.e. its
289 ;; job is to deal with screwed-up input, it'd be good style to fix
290 ;; it so that it can deal with circular list structure.
291 (cond ((minusp max
) nil
)
292 ((null x
) (zerop min
))
295 (proper-list-of-length-p (cdr x
)