1 ;;;; lots of basic macros for the target SBCL
3 ;;;; This software is part of the SBCL system. See the README file for
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.
12 (in-package "SB!IMPL")
14 ;;;; ASSERT and CHECK-TYPE
16 ;;; ASSERT is written this way, to call ASSERT-ERROR, because of how
17 ;;; closures are compiled. RESTART-CASE has forms with closures that
18 ;;; the compiler causes to be generated at the top of any function
19 ;;; using RESTART-CASE, regardless of whether they are needed. Thus if
20 ;;; we just wrapped a RESTART-CASE around the call to ERROR, we'd have
21 ;;; to do a significant amount of work at runtime allocating and
22 ;;; deallocating the closures regardless of whether they were ever
25 ;;; ASSERT-ERROR isn't defined until a later file because it uses the
26 ;;; macro RESTART-CASE, which isn't defined until a later file.
27 (defmacro-mundanely assert (test-form &optional places datum &rest arguments)
29 "Signals an error if the value of test-form is nil. Continuing from this
30 error using the CONTINUE restart will allow the user to alter the value of
31 some locations known to SETF, starting over with test-form. Returns NIL."
33 (assert-error ',test-form ',places ,datum ,@arguments)
34 ,@(mapcar (lambda (place)
35 `(setf ,place (assert-prompt ',place ,place)))
38 (defun assert-prompt (name value)
39 (cond ((y-or-n-p "The old value of ~S is ~S.~
40 ~%Do you want to supply a new value? "
42 (format *query-io* "~&Type a form to be evaluated:~%")
43 (flet ((read-it () (eval (read *query-io*))))
44 (if (symbolp name) ;help user debug lexical variables
45 (progv (list name) (list value) (read-it))
49 ;;; CHECK-TYPE is written this way, to call CHECK-TYPE-ERROR, because
50 ;;; of how closures are compiled. RESTART-CASE has forms with closures
51 ;;; that the compiler causes to be generated at the top of any
52 ;;; function using RESTART-CASE, regardless of whether they are
53 ;;; needed. Because it would be nice if CHECK-TYPE were cheap to use,
54 ;;; and some things (e.g., READ-CHAR) can't afford this excessive
55 ;;; consing, we bend backwards a little.
57 ;;; CHECK-TYPE-ERROR isn't defined until a later file because it uses
58 ;;; the macro RESTART-CASE, which isn't defined until a later file.
59 (defmacro-mundanely check-type (place type &optional type-string
62 "Signal a restartable error of type TYPE-ERROR if the value of PLACE
63 is not of the specified type. If an error is signalled and the restart
64 is used to return, this can only return if the STORE-VALUE restart is
65 invoked. In that case it will store into PLACE and start over."
66 ;; Detect a common user-error.
67 (when (and (consp type) (eq 'quote (car type)))
68 (error 'simple-reference-error
69 :format-control "Quoted type specifier in ~S: ~S"
70 :format-arguments (list 'check-type type)
71 :references (list '(:ansi-cl :macro check-type))))
72 ;; KLUDGE: We use a simpler form of expansion if PLACE is just a
73 ;; variable to work around Python's blind spot in type derivation.
74 ;; For more complex places getting the type derived should not
75 ;; matter so much anyhow.
76 (let ((expanded (sb!xc:macroexpand place env)))
77 (if (symbolp expanded)
79 ((typep ,place ',type))
80 (setf ,place (check-type-error ',place ,place ',type ,type-string)))
81 (let ((value (gensym)))
82 `(do ((,value ,place ,place))
83 ((typep ,value ',type))
85 (check-type-error ',place ,value ',type ,type-string)))))))
87 ;;;; DEFINE-SYMBOL-MACRO
89 (defmacro-mundanely define-symbol-macro (name expansion)
90 `(eval-when (:compile-toplevel :load-toplevel :execute)
91 (sb!c::%define-symbol-macro ',name ',expansion (sb!c:source-location))))
93 (defun sb!c::%define-symbol-macro (name expansion source-location)
94 (unless (symbolp name)
95 (error 'simple-type-error :datum name :expected-type 'symbol
96 :format-control "Symbol macro name is not a symbol: ~S."
97 :format-arguments (list name)))
98 (with-single-package-locked-error
99 (:symbol name "defining ~A as a symbol-macro"))
100 (sb!c:with-source-location (source-location)
101 (setf (info :source-location :symbol-macro name) source-location))
102 (let ((kind (info :variable :kind name)))
105 (setf (info :variable :kind name) :macro)
106 (setf (info :variable :macro-expansion name) expansion))
108 (error 'simple-program-error
109 :format-control "Symbol macro name already declared ~A: ~S."
110 :format-arguments (list kind name)))
112 (error 'simple-program-error
113 :format-control "Symbol macro name already defined as a constant: ~S."
114 :format-arguments (list name)))))
117 ;;;; DEFINE-COMPILER-MACRO
119 (defmacro-mundanely define-compiler-macro (name lambda-list &body body)
121 "Define a compiler-macro for NAME."
122 (legal-fun-name-or-type-error name)
123 (when (and (symbolp name) (special-operator-p name))
124 (error 'simple-program-error
125 :format-control "cannot define a compiler-macro for a special operator: ~S"
126 :format-arguments (list name)))
127 (with-unique-names (whole environment)
128 (multiple-value-bind (body local-decs doc)
129 (parse-defmacro lambda-list whole body name 'define-compiler-macro
130 :environment environment)
131 (let ((def `(lambda (,whole ,environment)
134 (debug-name (sb!c::debug-name 'compiler-macro-function name)))
135 `(eval-when (:compile-toplevel :load-toplevel :execute)
136 (sb!c::%define-compiler-macro ',name
142 ;;; FIXME: This will look remarkably similar to those who have already
143 ;;; seen the code for %DEFMACRO in src/code/defmacro.lisp. Various
144 ;;; bits of logic should be shared (notably arglist setting).
147 `(eval-when (,@times)
148 (defun sb!c::%define-compiler-macro
149 (name definition lambda-list doc debug-name)
151 '((declare (ignore lambda-list debug-name))))
152 ;; FIXME: warn about incompatible lambda list with
153 ;; respect to parent function?
154 (setf (sb!xc:compiler-macro-function name) definition)
155 (setf (fdocumentation name 'compiler-macro) doc)
157 `(case (widetag-of definition)
158 (#.sb!vm:closure-header-widetag
159 (setf (%simple-fun-arglist (%closure-fun definition))
161 (%simple-fun-name (%closure-fun definition))
163 (#.sb!vm:simple-fun-header-widetag
164 (setf (%simple-fun-arglist definition) lambda-list
165 (%simple-fun-name definition) debug-name))))
168 (def (:load-toplevel :execute) #-sb-xc-host t #+sb-xc-host nil)
169 #-sb-xc (def (:compile-toplevel) nil)))
171 ;;;; CASE, TYPECASE, and friends
173 (eval-when (#-sb-xc :compile-toplevel :load-toplevel :execute)
175 (define-condition duplicate-case-key-warning (style-warning)
177 :reader case-warning-key)
178 (case-kind :initarg :case-kind
179 :reader case-warning-case-kind)
180 (occurrences :initarg :occurrences
182 :reader duplicate-case-key-warning-occurrences))
184 (lambda (condition stream)
186 "Duplicate key ~S in ~S form, ~
187 occurring in~{~#[~; and~]~{ the ~:R clause:~%~< ~S~:>~}~^,~}."
188 (case-warning-key condition)
189 (case-warning-case-kind condition)
190 (duplicate-case-key-warning-occurrences condition)))))
192 ;;; CASE-BODY returns code for all the standard "case" macros. NAME is
193 ;;; the macro name, and KEYFORM is the thing to case on. MULTI-P
194 ;;; indicates whether a branch may fire off a list of keys; otherwise,
195 ;;; a key that is a list is interpreted in some way as a single key.
196 ;;; When MULTI-P, TEST is applied to the value of KEYFORM and each key
197 ;;; for a given branch; otherwise, TEST is applied to the value of
198 ;;; KEYFORM and the entire first element, instead of each part, of the
199 ;;; case branch. When ERRORP, no OTHERWISE-CLAUSEs are recognized,
200 ;;; and an ERROR form is generated where control falls off the end
201 ;;; of the ordinary clauses. When PROCEEDP, it is an error to
202 ;;; omit ERRORP, and the ERROR form generated is executed within a
203 ;;; RESTART-CASE allowing KEYFORM to be set and retested.
204 (defun case-body (name keyform cases multi-p test errorp proceedp needcasesp)
205 (unless (or cases (not needcasesp))
206 (warn "no clauses in ~S" name))
207 (let ((keyform-value (gensym))
210 (keys-seen (make-hash-table :test #'eql)))
211 (do* ((cases cases (cdr cases))
212 (case (car cases) (car cases))
213 (case-position 1 (1+ case-position)))
215 (flet ((check-clause (case-keys)
216 (loop for k in case-keys
217 for existing = (gethash k keys-seen)
219 (let ((sb!c::*current-path*
220 (when (boundp 'sb!c::*source-paths*)
221 (or (sb!c::get-source-path case)
222 sb!c::*current-path*))))
223 (warn 'duplicate-case-key-warning
226 :occurrences `(,existing (,case-position (,case)))))))
227 (let ((record (list case-position (list case))))
228 (dolist (k case-keys)
229 (setf (gethash k keys-seen) record)))))
230 (unless (list-of-length-at-least-p case 1)
231 (error "~S -- bad clause in ~S" case name))
232 (destructuring-bind (keyoid &rest forms) case
233 (cond (;; an OTHERWISE-CLAUSE
235 ;; By the way... The old code here tried gave
236 ;; STYLE-WARNINGs for normal-clauses which looked as
237 ;; though they might've been intended to be
238 ;; otherwise-clauses. As Tony Martinez reported on
239 ;; sbcl-devel 2004-11-09 there are sometimes good
240 ;; reasons to write clauses like that; and as I noticed
241 ;; when trying to understand the old code so I could
242 ;; understand his patch, trying to guess which clauses
243 ;; don't have good reasons is fundamentally kind of a
244 ;; mess. SBCL does issue style warnings rather
245 ;; enthusiastically, and I have often justified that by
246 ;; arguing that we're doing that to detect issues which
247 ;; are tedious for programmers to detect for by
248 ;; proofreading (like small typoes in long symbol
249 ;; names, or duplicate function definitions in large
250 ;; files). This doesn't seem to be an issue like that,
251 ;; and I can't think of a comparably good justification
252 ;; for giving STYLE-WARNINGs for legal code here, so
253 ;; now we just hope the programmer knows what he's
254 ;; doing. -- WHN 2004-11-20
255 (and (not errorp) ; possible only in CASE or TYPECASE,
256 ; not in [EC]CASE or [EC]TYPECASE
257 (memq keyoid '(t otherwise))
259 (push `(t nil ,@forms) clauses))
260 ((and multi-p (listp keyoid))
261 (setf keys (append keyoid keys))
262 (check-clause keyoid)
263 (push `((or ,@(mapcar (lambda (key)
264 `(,test ,keyform-value ',key))
271 (check-clause (list keyoid))
272 (push `((,test ,keyform-value ',keyoid)
276 (case-body-aux name keyform keyform-value clauses keys errorp proceedp
277 `(,(if multi-p 'member 'or) ,@keys))))
279 ;;; CASE-BODY-AUX provides the expansion once CASE-BODY has groveled
280 ;;; all the cases. Note: it is not necessary that the resulting code
281 ;;; signal case-failure conditions, but that's what KMP's prototype
282 ;;; code did. We call CASE-BODY-ERROR, because of how closures are
283 ;;; compiled. RESTART-CASE has forms with closures that the compiler
284 ;;; causes to be generated at the top of any function using the case
285 ;;; macros, regardless of whether they are needed.
287 ;;; The CASE-BODY-ERROR function is defined later, when the
288 ;;; RESTART-CASE macro has been defined.
289 (defun case-body-aux (name keyform keyform-value clauses keys
290 errorp proceedp expected-type)
292 (let ((block (gensym))
294 `(let ((,keyform-value ,keyform))
300 (cond ,@(nreverse clauses)
305 ',name ',keyform ,keyform-value
306 ',expected-type ',keys)))
308 `(let ((,keyform-value ,keyform))
309 (declare (ignorable ,keyform-value)) ; e.g. (CASE KEY (T))
313 `((t (error 'case-failure
315 :datum ,keyform-value
316 :expected-type ',expected-type
317 :possibilities ',keys))))))))
320 (defmacro-mundanely case (keyform &body cases)
322 "CASE Keyform {({(Key*) | Key} Form*)}*
323 Evaluates the Forms in the first clause with a Key EQL to the value of
324 Keyform. If a singleton key is T then the clause is a default clause."
325 (case-body 'case keyform cases t 'eql nil nil nil))
327 (defmacro-mundanely ccase (keyform &body cases)
329 "CCASE Keyform {({(Key*) | Key} Form*)}*
330 Evaluates the Forms in the first clause with a Key EQL to the value of
331 Keyform. If none of the keys matches then a correctable error is
333 (case-body 'ccase keyform cases t 'eql t t t))
335 (defmacro-mundanely ecase (keyform &body cases)
337 "ECASE Keyform {({(Key*) | Key} Form*)}*
338 Evaluates the Forms in the first clause with a Key EQL to the value of
339 Keyform. If none of the keys matches then an error is signalled."
340 (case-body 'ecase keyform cases t 'eql t nil t))
342 (defmacro-mundanely typecase (keyform &body cases)
344 "TYPECASE Keyform {(Type Form*)}*
345 Evaluates the Forms in the first clause for which TYPEP of Keyform and Type
347 (case-body 'typecase keyform cases nil 'typep nil nil nil))
349 (defmacro-mundanely ctypecase (keyform &body cases)
351 "CTYPECASE Keyform {(Type Form*)}*
352 Evaluates the Forms in the first clause for which TYPEP of Keyform and Type
353 is true. If no form is satisfied then a correctable error is signalled."
354 (case-body 'ctypecase keyform cases nil 'typep t t t))
356 (defmacro-mundanely etypecase (keyform &body cases)
358 "ETYPECASE Keyform {(Type Form*)}*
359 Evaluates the Forms in the first clause for which TYPEP of Keyform and Type
360 is true. If no form is satisfied then an error is signalled."
361 (case-body 'etypecase keyform cases nil 'typep t nil t))
363 ;;;; WITH-FOO i/o-related macros
365 (defmacro-mundanely with-open-stream ((var stream) &body forms-decls)
366 (multiple-value-bind (forms decls)
367 (parse-body forms-decls :doc-string-allowed nil)
368 (let ((abortp (gensym)))
369 `(let ((,var ,stream)
373 (multiple-value-prog1
377 (close ,var :abort ,abortp)))))))
379 (defmacro-mundanely with-open-file ((stream filespec &rest options)
381 `(with-open-stream (,stream (open ,filespec ,@options))
384 (defmacro-mundanely with-input-from-string ((var string &key index start end)
386 (multiple-value-bind (forms decls)
387 (parse-body forms-decls :doc-string-allowed nil)
388 ;; The ONCE-ONLY inhibits compiler note for unreachable code when
390 (once-only ((string string))
393 `(make-string-input-stream ,string ,(or start 0)))
396 (make-string-input-stream ,string
399 (make-string-input-stream ,string
402 `(make-string-input-stream ,string
406 (multiple-value-prog1
411 `((setf ,index (string-input-stream-current ,var)))))))))
413 (defmacro-mundanely with-output-to-string
414 ((var &optional string &key (element-type ''character))
416 (multiple-value-bind (forms decls)
417 (parse-body forms-decls :doc-string-allowed nil)
419 (let ((element-type-var (gensym)))
420 `(let ((,var (make-fill-pointer-output-stream ,string))
421 ;; ELEMENT-TYPE isn't currently used for anything
422 ;; (see FILL-POINTER-OUTPUT-STREAM FIXME in stream.lisp),
423 ;; but it still has to be evaluated for side-effects.
424 (,element-type-var ,element-type))
425 (declare (ignore ,element-type-var))
430 `(let ((,var (make-string-output-stream :element-type ,element-type)))
435 (get-output-stream-string ,var)))))
437 ;;;; miscellaneous macros
439 (defmacro-mundanely nth-value (n form)
441 "Evaluate FORM and return the Nth value (zero based). This involves no
442 consing when N is a trivial constant integer."
443 ;; FIXME: The above is true, if slightly misleading. The
444 ;; MULTIPLE-VALUE-BIND idiom [ as opposed to MULTIPLE-VALUE-CALL
445 ;; (LAMBDA (&REST VALUES) (NTH N VALUES)) ] does indeed not cons at
446 ;; runtime. However, for large N (say N = 200), COMPILE on such a
447 ;; form will take longer than can be described as adequate, as the
448 ;; optional dispatch mechanism for the M-V-B gets increasingly
451 (let ((dummy-list (make-gensym-list n))
452 (keeper (sb!xc:gensym "KEEPER")))
453 `(multiple-value-bind (,@dummy-list ,keeper) ,form
454 (declare (ignore ,@dummy-list))
457 `(case (the fixnum ,n)
458 (0 (nth-value 0 ,form))
459 (1 (nth-value 1 ,form))
460 (2 (nth-value 2 ,form))
461 (t (nth (the fixnum ,n) (multiple-value-list ,form)))))))
463 (defmacro-mundanely declaim (&rest specs)
465 "DECLAIM Declaration*
466 Do a declaration or declarations for the global environment."
467 `(eval-when (:compile-toplevel :load-toplevel :execute)
468 ,@(mapcar (lambda (spec) `(sb!xc:proclaim ',spec))
471 (defmacro-mundanely print-unreadable-object ((object stream &key type identity)
473 "Output OBJECT to STREAM with \"#<\" prefix, \">\" suffix, optionally
474 with object-type prefix and object-identity suffix, and executing the
475 code in BODY to provide possible further output."
476 `(%print-unreadable-object ,object ,stream ,type ,identity
481 (defmacro-mundanely ignore-errors (&rest forms)
483 "Execute FORMS handling ERROR conditions, returning the result of the last
484 form, or (VALUES NIL the-ERROR-that-was-caught) if an ERROR was handled."
485 `(handler-case (progn ,@forms)
486 (error (condition) (values nil condition))))