1 ;;;; the PARSE-DEFMACRO function and related code
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!KERNEL")
14 ;;; variables for accumulating the results of parsing a DEFMACRO. (Declarations
15 ;;; in DEFMACRO are the reason this isn't as easy as it sounds.)
16 (defvar *arg-tests
*) ; tests that do argument counting at expansion time
17 (declaim (type list
*arg-tests
*))
18 (defvar *system-lets
*) ; LET bindings done to allow lambda-list parsing
19 (declaim (type list
*system-lets
*))
20 (defvar *user-lets
*) ; LET bindings that the user has explicitly supplied
21 (declaim (type list
*user-lets
*))
22 (defvar *env-var
*) ; &ENVIRONMENT variable name
24 ;; the default default for unsupplied &OPTIONAL and &KEY args
25 (defvar *default-default
*)
27 ;;; temps that we introduce and might not reference
28 (defvar *ignorable-vars
*)
29 (declaim (type list
*ignorable-vars
*))
31 ;;; Return, as multiple values, a body, possibly a DECLARE form to put
32 ;;; where this code is inserted, the documentation for the parsed
33 ;;; body, and bounds on the number of arguments.
34 (defun parse-defmacro (lambda-list arg-list-name body name context
37 (doc-string-allowed t
)
38 ((:environment env-arg-name
))
39 ((:default-default
*default-default
*))
42 (multiple-value-bind (forms declarations documentation
)
43 (parse-body body
:doc-string-allowed doc-string-allowed
)
44 (let ((*arg-tests
* ())
49 (multiple-value-bind (env-arg-used minimum maximum
)
50 (parse-defmacro-lambda-list lambda-list arg-list-name name
51 context error-fun
(not anonymousp
)
53 (values `(let* (,@(when env-arg-used
54 `((,*env-var
* ,env-arg-name
)))
55 ,@(nreverse *system-lets
*))
56 ,@(when *ignorable-vars
*
57 `((declare (ignorable ,@*ignorable-vars
*))))
59 (let* ,(nreverse *user-lets
*)
62 `((block ,(fun-name-block-name name
)
65 `(,@(when (and env-arg-name
(not env-arg-used
))
66 `((declare (ignore ,env-arg-name
)))))
71 ;;; partial reverse-engineered documentation:
72 ;;; TOPLEVEL is true for calls through PARSE-DEFMACRO from DEFSETF and
73 ;;; DESTRUCTURING-BIND, false otherwise.
75 (defun parse-defmacro-lambda-list (possibly-dotted-lambda-list
83 (let* (;; PATH is a sort of pointer into the part of the lambda list we're
84 ;; considering at this point in the code. PATH-0 is the root of the
85 ;; lambda list, which is the initial value of PATH.
89 (path path-0
) ; (will change below)
90 (now-processing :required
)
97 ;; ANSI specifies that dotted lists are "treated exactly as if the
98 ;; parameter name that ends the list had appeared preceded by &rest."
99 ;; We force this behavior by transforming dotted lists into ordinary
100 ;; lists with explicit &REST elements.
101 (lambda-list (do ((in-pdll possibly-dotted-lambda-list
(cdr in-pdll
))
102 (reversed-result nil
))
104 (nreverse (if in-pdll
105 (list* in-pdll
'&rest reversed-result
)
107 (push (car in-pdll
) reversed-result
)))
108 rest-name restp allow-other-keys-p env-arg-used
)
109 (when (member '&whole
(rest lambda-list
))
110 (error "&WHOLE may only appear first in ~S lambda-list." context
))
111 (do ((rest-of-args lambda-list
(cdr rest-of-args
)))
112 ((null rest-of-args
))
113 (macrolet ((process-sublist (var sublist-name path
)
114 (once-only ((var var
))
116 (let ((sub-list-name (gensym ,sublist-name
)))
117 (push-sub-list-binding sub-list-name
,path
,var
118 name context error-fun
)
119 (parse-defmacro-lambda-list ,var sub-list-name name
121 (push-let-binding ,var
,path nil
))))
122 (normalize-singleton (var)
123 `(when (null (cdr ,var
))
124 (setf (cdr ,var
) (list *default-default
*)))))
125 (let ((var (car rest-of-args
)))
131 (defmacro-error (format nil
"required argument after ~A" restp
)
133 (process-sublist var
"SUBLIST-" `(car ,path
))
134 (setq path
`(cdr ,path
)
136 maximum
(1+ maximum
)))
138 (normalize-singleton var
)
139 (destructuring-bind (varname &optional initform supplied-p
)
141 (push-optional-binding varname initform supplied-p
142 `(not (null ,path
)) `(car ,path
)
143 name context error-fun
))
144 (setq path
`(cdr ,path
)
145 maximum
(1+ maximum
)))
147 (normalize-singleton var
)
148 (let* ((keyword-given (consp (car var
)))
149 (variable (if keyword-given
152 (keyword (if keyword-given
154 (keywordicate variable
)))
155 (supplied-p (caddr var
)))
156 (push-optional-binding variable
(cadr var
) supplied-p
157 `(keyword-supplied-p ',keyword
159 `(lookup-keyword ',keyword
161 name context error-fun
)
162 (push keyword keys
)))
164 (push-let-binding (car var
) (cadr var
) nil
))))
165 ((and symbol
(not (eql nil
)))
168 (cond ((cdr rest-of-args
)
169 (setq rest-of-args
(cdr rest-of-args
))
170 ;; Special case for compiler-macros: if car of
171 ;; the form is FUNCALL skip over it for
172 ;; destructuring, pretending cdr of the form is
174 (when (eq context
'define-compiler-macro
)
179 `(not (and (listp ,arg-list-name
)
180 (eq 'funcall
(car ,arg-list-name
))))
181 `(setf ,arg-list-name
(cdr ,arg-list-name
))))
182 (process-sublist (car rest-of-args
)
183 "WHOLE-LIST-" arg-list-name
))
185 (defmacro-error "&WHOLE" context name
))))
188 (error "&ENVIRONMENT is not valid with ~S." context
))
190 (error "&ENVIRONMENT is only valid at top level of ~
193 (error "Repeated &ENVIRONMENT.")))
194 (cond ((and (cdr rest-of-args
) (symbolp (cadr rest-of-args
)))
195 (setq rest-of-args
(cdr rest-of-args
))
196 (check-defmacro-arg (car rest-of-args
))
197 (setq *env-var
* (car rest-of-args
)
200 (defmacro-error "&ENVIRONMENT" context name
))))
202 (cond ((or key-seen aux-seen
)
203 (error "~A after ~A in ~A" var
(or key-seen aux-seen
) context
))
204 ((and (not restp
) (cdr rest-of-args
))
205 (setq rest-of-args
(cdr rest-of-args
)
207 (process-sublist (car rest-of-args
) "REST-LIST-" path
))
209 (defmacro-error (symbol-name var
) context name
))))
211 (when (or key-seen aux-seen restp
)
212 (error "~A after ~A in ~A lambda-list." var
(or key-seen aux-seen restp
) context
))
214 (error "Multiple ~A in ~A lambda list." var context
))
215 (setq now-processing
:optionals
219 (error "~A after ~A in ~A lambda-list." '&key
'&aux context
))
221 (error "Multiple ~A in ~A lambda-list." '&key context
))
222 (setf now-processing
:keywords
223 rest-name
(gensym "KEYWORDS-")
226 (push rest-name
*ignorable-vars
*)
227 (push-let-binding rest-name path t
))
229 (unless (eq now-processing
:keywords
)
230 (error "~A outside ~A section of lambda-list in ~A." var
'&key context
))
231 (when allow-other-keys-p
232 (error "Multiple ~A in ~A lambda-list." var context
))
233 (setq allow-other-keys-p t
))
236 (error "Multiple ~A in ~A lambda-list." '&aux context
))
237 (setq now-processing
:auxs
239 ;; FIXME: Other lambda list keywords.
244 (defmacro-error (format nil
"required argument after ~A" restp
)
246 (push-let-binding var
`(car ,path
) nil
)
247 (setq minimum
(1+ minimum
)
251 (push-let-binding var
`(car ,path
) nil
`(not (null ,path
)))
252 (setq path
`(cdr ,path
)
253 maximum
(1+ maximum
)))
255 (let ((key (keywordicate var
)))
258 `(lookup-keyword ,key
,rest-name
)
260 `(keyword-supplied-p ,key
,rest-name
))
263 (push-let-binding var nil nil
))))))
265 (error "non-symbol in lambda-list: ~S" var
))))))
266 (let (;; common subexpression, suitable for passing to functions
267 ;; which expect a MAXIMUM argument regardless of whether
268 ;; there actually is a maximum number of arguments
269 ;; (expecting MAXIMUM=NIL when there is no maximum)
270 (explicit-maximum (and (not restp
) maximum
)))
271 (unless (and restp
(zerop minimum
))
272 (push `(unless ,(if restp
273 ;; (If RESTP, then the argument list might be
274 ;; dotted, in which case ordinary LENGTH won't
276 `(list-of-length-at-least-p ,path-0
,minimum
)
277 `(proper-list-of-length-p ,path-0
,minimum
,maximum
))
278 ,(if (eq error-fun
'error
)
279 `(arg-count-error ',context
',name
,path-0
280 ',lambda-list
,minimum
282 `(,error-fun
'arg-count-error
284 ,@(when name
`(:name
',name
))
286 :lambda-list
',lambda-list
288 :maximum
,explicit-maximum
)))
291 (let ((problem (gensym "KEY-PROBLEM-"))
292 (info (gensym "INFO-")))
293 (push `(multiple-value-bind (,problem
,info
)
294 (verify-keywords ,rest-name
296 ',allow-other-keys-p
)
299 'defmacro-lambda-list-broken-key-list-error
301 ,@(when name
`(:name
',name
))
305 (values env-arg-used minimum explicit-maximum
))))
307 ;;; We save space in macro definitions by calling this function.
308 (defun arg-count-error (context name args lambda-list minimum maximum
)
310 (sb!debug
:*stack-top-hint
* (nth-value 1 (find-caller-name-and-frame))))
311 (error 'arg-count-error
315 :lambda-list lambda-list
319 (defun push-sub-list-binding (variable path object name context error-fun
)
320 (check-defmacro-arg variable
)
321 (let ((var (gensym "TEMP-")))
326 (,error-fun
'defmacro-bogus-sublist-error
328 ,@(when name
`(:name
',name
))
330 :lambda-list
',object
))))
333 (defun push-let-binding (variable path systemp
&optional condition
334 (init-form *default-default
*))
335 (check-defmacro-arg variable
)
336 (let ((let-form (if condition
337 `(,variable
(if ,condition
,path
,init-form
))
338 `(,variable
,path
))))
340 (push let-form
*system-lets
*)
341 (push let-form
*user-lets
*))))
343 (defun push-optional-binding (value-var init-form supplied-var condition path
344 name context error-fun
)
346 (setq supplied-var
(gensym "SUPPLIEDP-")))
347 (push-let-binding supplied-var condition t
)
348 (cond ((consp value-var
)
349 (let ((whole-thing (gensym "OPTIONAL-SUBLIST-")))
350 (push-sub-list-binding whole-thing
351 `(if ,supplied-var
,path
,init-form
)
352 value-var name context error-fun
)
353 (parse-defmacro-lambda-list value-var whole-thing name
356 (push-let-binding value-var path nil supplied-var init-form
))
358 (error "illegal optional variable name: ~S" value-var
))))
360 (defun defmacro-error (problem context name
)
361 (error "illegal or ill-formed ~A argument in ~A~@[ ~S~]"
362 problem context name
))
364 (defun check-defmacro-arg (arg)
365 (when (or (and *env-var
* (eq arg
*env-var
*))
366 (member arg
*system-lets
* :key
#'car
)
367 (member arg
*user-lets
* :key
#'car
))
368 (error "variable ~S occurs more than once" arg
)))
370 ;;; Determine whether KEY-LIST is a valid list of keyword/value pairs.
371 ;;; Do not signal the error directly, 'cause we don't know how it
372 ;;; should be signaled.
373 (defun verify-keywords (key-list valid-keys allow-other-keys
)
374 (do ((already-processed nil
)
375 (unknown-keyword nil
)
376 (remaining key-list
(cddr remaining
)))
378 (if (and unknown-keyword
379 (not allow-other-keys
)
380 (not (lookup-keyword :allow-other-keys key-list
)))
381 (values :unknown-keyword
(list unknown-keyword valid-keys
))
383 (cond ((not (and (consp remaining
) (listp (cdr remaining
))))
384 (return (values :dotted-list key-list
)))
385 ((null (cdr remaining
))
386 (return (values :odd-length key-list
)))
387 ((or (eq (car remaining
) :allow-other-keys
)
388 (member (car remaining
) valid-keys
))
389 (push (car remaining
) already-processed
))
391 (setq unknown-keyword
(car remaining
))))))
393 (defun lookup-keyword (keyword key-list
)
394 (do ((remaining key-list
(cddr remaining
)))
396 (when (eq keyword
(car remaining
))
397 (return (cadr remaining
)))))
399 (defun keyword-supplied-p (keyword key-list
)
400 (do ((remaining key-list
(cddr remaining
)))
402 (when (eq keyword
(car remaining
))