1 ;;;; tests of the INFO/globaldb system
3 ;;;; KLUDGE: Unlike most of the system's tests, these are not in the
4 ;;;; problem domain, but in the implementation domain, so modification
5 ;;;; of the system could cause these tests to fail even if the system
6 ;;;; was still a correct implementation of ANSI Common Lisp + SBCL
7 ;;;; extensions. Perhaps such tests should be separate from tests in
8 ;;;; the problem domain. -- WHN 2001-02-11
10 ;;;; This software is part of the SBCL system. See the README file for
11 ;;;; more information.
13 ;;;; While most of SBCL is derived from the CMU CL system, the test
14 ;;;; files (like this one) were written from scratch after the fork
17 ;;;; This software is in the public domain and is provided with
18 ;;;; absolutely no warranty. See the COPYING and CREDITS files for
19 ;;;; more information.
23 (defun foo (a) (list a
))
26 (assert (eq (sb-int:info
:function
:where-from
'foo
)
29 (defun foo (a b
) (list a b
))
30 (let ((x 1)) (foo x
2))
36 ;;; FIXME: This one is commented out since it doesn't work when
37 ;;; the DEFUN is just LOADed instead of COMPILE-FILEd, and it's
38 ;;; not immediately obvious what's the best way to set up
39 ;;; the COMPILE-FILE test.
43 (format nil
"~A" (sb-int:info
:function
:type
'foo
))
44 "#<FUN-TYPE (FUNCTION (T T) LIST)>"))
49 (test-util:with-test
(:name
:globaldb-sxhashoid-discrimination
)
50 (assert (not (eql (globaldb-sxhashoid '(a b c d e
))
51 (globaldb-sxhashoid '(a b c d mumble
))))))
53 (test-util:with-test
(:name
:bug-458015
)
54 ;; Make sure layouts have sane source-locations
55 (sb-c::call-with-each-globaldb-name
57 (when (and (symbolp info-name
) (info :type
:kind info-name
))
58 (let* ((classoid (find-classoid info-name nil
))
59 (layout (and classoid
(classoid-layout classoid
)))
60 (srcloc (and layout
(sb-kernel::layout-source-location layout
))))
62 (assert (or (definition-source-location-p srcloc
)
65 (test-util:with-test
(:name
:find-classoid-signal-error
)
66 ;; (EVAL ''SILLY) dumbs down the compiler for this test.
67 ;; FIND-CLASSOID on a constant symbol becomes
68 ;; `(CLASSOID-CELL-CLASSOID ',(FIND-CLASSOID-CELL name :create t))
69 ;; and I want just the primitive operations without muddying the water.
70 (let ((name (eval ''silly
)))
71 (assert (not (find-classoid name nil
)))
72 (assert (typep (handler-case (find-classoid name
) (error (e) e
)) 'error
))
73 (find-classoid-cell name
:create t
) ; After this, have cell but no classoid
74 (assert (typep (handler-case (find-classoid name
) (error (e) e
)) 'error
))))
76 (test-util:with-test
(:name
:set-info-value-type-check
)
77 (loop for type-info across
*info-types
*
78 when
(and type-info
(not (eq (type-info-type-spec type-info
) 't
)))
80 (let ((key1 (type-info-class type-info
))
81 (key2 (type-info-name type-info
))
82 (sillyval (make-string-output-stream))) ; nothing should be this
83 ;; check the type-checker function
86 (declare (notinline (setf info
)))
87 (setf (info ,key1
,key2
'grrr
) x
)))))
88 (assert (typep (nth-value 1 (ignore-errors (funcall f sillyval
)))
90 ;; Demonstrate that the SETF disallows the illegal value
91 ;; even though this lambda attempts to be non-type-safe.
92 (let ((f (compile nil
`(lambda (x)
93 (declare (optimize (safety 0)))
94 (setf (info ,key1
,key2
'grrr
) x
)))))
95 (assert (typep (nth-value 1 (ignore-errors (funcall f sillyval
)))
97 ;; but if I *really* want, a bad value can be installed
98 (set-info-value (gensym)
99 (type-info-number (type-info-or-lose :variable
:kind
))
102 (test-util:with-test
(:name
:unrecognize-recognized-declaration
)
103 (proclaim '(declaration happiness
))
104 (let ((saved (copy-list *recognized-declarations
*)))
105 (assert (member 'happiness
*recognized-declarations
*))
106 (proclaim '(declaration happiness
))
107 (assert (equal *recognized-declarations
* saved
)) ; not pushed again
108 (setf (info :declaration
:recognized
'happiness
) nil
)
109 (assert (not (member 'happiness
*recognized-declarations
*)))))
111 (test-util:with-test
(:name
:recognized-decl-not-also-type
)
112 (deftype pear
(x) `(cons ,x
,x
))
113 (assert (typep (nth-value 1 (ignore-errors (proclaim '(declaration pear
))))
114 'declaration-type-conflict-error
))
115 (proclaim '(declaration nthing
))
116 (assert (typep (nth-value 1 (ignore-errors (deftype nthing
(x) `(not ,x
))))
117 'declaration-type-conflict-error
)))
119 (test-util:with-test
(:name
:info-env-clear
)
120 (setf (info :variable
:kind
'fruitbaskets
) :macro
121 (info :variable
:macro-expansion
'fruitbaskets
) 32)
122 (clear-info :variable
:kind
'fruitbaskets
)
123 (multiple-value-bind (data foundp
)
124 (info :variable
:kind
'fruitbaskets
)
125 (assert (and (eq data
:unknown
) (not foundp
))))
126 (multiple-value-bind (data foundp
)
127 (info :variable
:macro-expansion
'fruitbaskets
)
128 (assert (and foundp
(eql data
32))))
129 (clear-info :variable
:macro-expansion
'fruitbaskets
)
130 (multiple-value-bind (data foundp
)
131 (info :variable
:macro-expansion
'fruitbaskets
)
132 (assert (and (not foundp
) (not data
)))))
134 ;; packed info vector tests
136 (test-util:with-test
(:name
:globaldb-info-iterate
)
139 (test-util:with-test
(:name
:find-fdefn-agreement
)
140 ;; Shows that GET-INFO-VALUE agrees with FIND-FDEFN on all symbols,
141 ;; since they use diffent code. Something would have crashed long before here...
143 (assert (eq (find-fdefn x
) (info :function
:definition x
)))))
149 (defun shuffle (vector) ; destructive
150 (loop for lim from
(1- (length vector
)) downto
0
151 for chosen
= (random (1+ lim
))
152 unless
(= chosen lim
)
153 do
(rotatef (aref vector chosen
) (aref vector lim
)))
156 (test-util:with-test
(:name
:quick-packed-info-insert
)
157 ;; Exercise some bit patterns that touch the sign bit on 32-bit machines.
160 (let ((iv1 +nil-packed-infos
+)
161 (iv2 +nil-packed-infos
+)
163 (cons 1 (subseq '(#b100000
#b110000
#b010000
#b011000
164 #b000100
#b000010
#b000011
#b000001
)
165 0 (- +infos-per-word
+ 2)))))
166 ;; Randomize because maybe there's an ordering constraint more
167 ;; complicated than fdefn always getting to be first.
168 ;; (there isn't, but could be)
169 (dolist (num (coerce (shuffle (coerce type-nums
'vector
)) 'list
))
170 (let ((val (format nil
"value for ~D" num
)))
171 (setq iv1
(quick-packed-info-insert iv1 num val
)
172 iv2
(%packed-info-insert
; not PACKED-INFO-INSERT
173 iv2
+no-auxilliary-key
+ num val
))
174 (assert (equalp iv1 iv2
))))
175 ;; the first and only info descriptor should be full
176 (assert (not (info-quickly-insertable-p iv1
))))))
178 (defun crossprod (a b
)
179 (mapcan (lambda (x) (mapcar (lambda (y) (cons x y
)) b
))
182 ;; The real GET-INFO-VALUE AVERs that TYPE-NUMBER is legal. This one doesn't.
183 (defun cheating-get-info-value (sym aux-key type-number
)
184 (let* ((vector (symbol-info-vector sym
))
185 (index (packed-info-value-index vector aux-key type-number
)))
187 (values (svref vector index
) t
)
190 ;; Info vectors may be concurrently updated. If more than one thread writes
191 ;; the same name/type-number, it's random which thread prevails, but for
192 ;; non-colliding updates, none should be lost.
193 ;; This is not a "reasonable" use of packed info vectors.
194 ;; It's just a check of the response of the algorithm to heavy pounding.
196 (test-util:with-test
(:name
:info-vector-concurrency
)
198 (a (make-array 1 :element-type
'sb-ext
:word
)))
199 (let* ((aux-keys '(0 a b c d e f g h nil i j k l m n o p setf q r s
))
200 (info-types (loop for i from
1 below
64 collect i
))
201 (work (shuffle (coerce (crossprod aux-keys info-types
) 'vector
)))
202 (n (floor (length work
) 4))
206 (sb-thread:make-thread
208 (loop for x across work
209 do
(set-info-value (if (eq (car x
) 0) s
`(,(car x
) ,s
))
211 (list (atomic-incf (aref a
0)) my-id
214 :arguments
(list (subseq work
(* i n
) (if (= i
3) nil
(* (1+ i
) n
)))
217 (dolist (thread threads
)
218 (sb-thread:join-thread thread
))
219 (let ((foo (make-array (aref a
0))))
220 ;; Returning FOO is to give a rough visual indication that
221 ;; there were in fact intermingled updates.
222 (dolist (k aux-keys foo
)
224 (let ((answer (cheating-get-info-value s k i
)))
226 (setf (aref foo
(car answer
)) answer
))
227 (assert (equal (third answer
)
229 (format nil
"~A,~A" k i
)))))))))))
231 ;; specialized concurrent hashtable tests
233 (defun integer-range (min max
)
234 (let* ((n (1+ (- max min
)))
237 (setf (aref a j
) (+ j min
)))))
239 (defun randomize (key random-state
)
241 (logior (ash key
10) (random (ash 1 10) random-state
))
242 key
)) ; not randomizing
244 (defun show-tally (table tally verb
)
245 (format t
"Hashtable has ~D entries~%" (info-env-count table
))
247 (dotimes (thread-id (length tally
) tot
)
248 (let ((n (aref tally thread-id
)))
249 (format t
"Thread ~2d ~A ~7d time~:P~%" thread-id verb n
)
252 (defun test-concurrent-incf (&key
(table (make-info-hashtable))
253 (n-threads 40) (n-inserts 50000))
254 (declare (optimize safety
))
256 (worklists (make-array n-threads
))
258 (tries (make-array n-threads
:initial-element
0)))
259 (dotimes (i n-threads
)
260 ;; Insert the integers [-n .. -2]. Keys 0 and -1 are illegal.
261 (setf (aref worklists i
)
262 (shuffle (integer-range (- (1+ n-inserts
)) -
2))))
263 (dotimes (i n-threads
)
264 (push (sb-thread:make-thread
265 (lambda (worklist me
)
266 (declare (simple-vector worklist
))
268 (incf (aref tries me
))
270 (declare (dynamic-extent #'doer
))
271 ;; for each item in worklist, increment that key
272 (loop for key across worklist do
273 (info-puthash table key
#'doer
))
274 ;; again backwards just for fun
275 (loop for j downfrom
(1- (length worklist
)) to
0 do
276 (info-puthash table
(svref worklist j
) #'doer
))))
277 :name
(format nil
"Worker ~D" i
)
278 :arguments
(list (aref worklists i
) i
))
280 (format t
"Started ~D threads doing INCF~%" n-threads
)
281 (dolist (thread threads
)
282 (sb-thread:join-thread thread
))
283 (assert (= (info-env-count table
) n-inserts
))
284 (show-tally table tries
"updated")
285 ;; expect val[key] = 2*n-threads for all keys
286 (info-maphash (lambda (k v
)
287 (unless (= v
(* 2 n-threads
))
288 (push (cons k v
) failures
)))
291 (format t
"Fail: ~S~%" failures
))
292 (assert (not failures
))
295 (defun test-concurrent-consing (&key
(table (make-info-hashtable))
296 (n-threads 40) (n-inserts 100000)
298 (declare (optimize safety
))
299 (assert (evenp n-threads
))
301 (rs (make-random-state)))
302 ;; Under each key, the value stored will be a list of the threads
303 ;; which pushed their ID. For any pair of even/odd numbered threads,
304 ;; exactly one should win the race to push its ID on behalf of the pair.
305 (dotimes (i n-threads
)
306 (push (sb-thread:make-thread
308 ;; Randomizing makes keys be used up in a quasi-random
309 ;; order without having to pre-compute a shuffle.
310 (dotimes (i n-inserts
)
312 table
(randomize (1+ i
) rs
)
314 (let ((peer (logxor me
1)))
315 (if (member peer list
) list
(cons me list
)))))))
316 :name
(format nil
"Worker ~D" i
)
317 :arguments
(list i
(if randomize
(make-random-state rs
))))
319 (format t
"Started ~D threads doing CONS~%" n-threads
)
320 (dolist (thread threads
)
321 (sb-thread:join-thread thread
))
322 (assert (= (info-env-count table
) n-inserts
))
323 ;; Collect the distribution of threads which inserted, for display only
324 ;; since it not expected to be particularly "fair"
325 (let ((tally (make-array n-threads
:initial-element
0)))
327 (lambda (key id-list
)
328 (let ((scoreboard (make-array (/ n-threads
2) :element-type
'bit
)))
329 (dolist (thread-id id-list
)
330 (let ((group-id (floor thread-id
2)))
331 ;; assert no duplicate for a peer group
332 (if (= (sbit scoreboard group-id
) 1)
333 (error "Fail: ~S ~S~%" key id-list
))
334 (setf (sbit scoreboard group-id
) 1)
335 (incf (aref tally thread-id
))))
336 ;; the scoreboard should be full
337 (when (find 0 scoreboard
)
338 (error "Fail: ~S -> ~S (~S)~%" key id-list scoreboard
))))
340 ;; There should be half as many puthash operations that succeeded
341 ;; as the product of n-threads and n-inserts.
342 (assert (= (show-tally table tally
"inserted")
343 (* 1/2 n-threads n-inserts
)))))
348 (test-util:with-test
(:name
:lockfree-hash-concurrent-twiddling
)
349 (test-concurrent-incf))
350 (test-util:with-test
(:name
:lockfree-hash-concurrent-consing
)
351 (test-concurrent-consing)))
355 (in-package "SB-IMPL")
357 (defglobal *make-classoid-cell-callcount
* (make-array 1 :element-type
'sb-ext
:word
))
358 (defglobal *really-make-classoid-cell
* #'sb-kernel
::make-classoid-cell
)
359 (without-package-locks
360 (defun sb-kernel::make-classoid-cell
(name &optional classoid
)
361 (sb-ext:atomic-incf
(aref *make-classoid-cell-callcount
* 0))
362 (funcall *really-make-classoid-cell
* name classoid
)))
364 ;; Return a set of symbols to play around with
365 (defun classoid-cell-test-get-lotsa-symbols ()
368 (package-hashtable-table
369 (package-internal-symbols (find-package "SB-C")))))
371 ;; Make every symbol in the test set have a classoid-cell
372 (defun be-a-classoid-cell-writer ()
373 (let* ((symbols (classoid-cell-test-get-lotsa-symbols))
374 (result (make-array (length symbols
) :initial-element nil
)))
375 (loop for s across symbols
377 do
(setf (aref result i
) (find-classoid-cell s
:create t
)))
380 ;; Get the classoid-cells
381 (defun be-a-classoid-cell-reader ()
382 (let* ((symbols (classoid-cell-test-get-lotsa-symbols))
383 (result (make-array (length symbols
) :initial-element nil
)))
385 (loop for i below
(length symbols
)
386 do
(pushnew (find-classoid-cell (svref symbols i
))
388 ;; The thread shall have observed at most two different values
389 ;; for FIND-CLASSOID-CELL - nil and/or a CLASSOID-CELL.
390 ;; For each symbol, if the thread observed a classoid cell, store that.
391 (loop for list across result
393 do
(let ((observed-value (remove nil list
)))
394 (if (cdr observed-value
)
395 (error "Should not happen: find-classoid-cell => ~S" list
)
396 (setf (svref result i
) (car observed-value
)))))
399 ;; Perform some silly updates to plists, because they mess with
400 ;; the symbol-info slot alongside globaldb writers.
401 (defun be-a-plist-writer ()
402 (loop for s across
(classoid-cell-test-get-lotsa-symbols)
404 (loop (let ((old (symbol-plist s
)))
405 (when (or (member 'foo old
)
406 (eq (cas (symbol-plist s
) old
(list* 'foo s old
)) old
))
410 (test-util:with-test
(:name
:info-vector-classoid-cell
)
411 (let (readers writers more-threads results
)
413 (push (sb-thread:make-thread
#'be-a-classoid-cell-writer
) writers
))
415 (push (sb-thread:make-thread
#'be-a-classoid-cell-reader
) readers
)
416 (push (sb-thread:make-thread
#'be-a-plist-writer
) more-threads
))
417 (mapc #'sb-thread
:join-thread more-threads
)
418 (dolist (thread (append readers writers
))
419 (push (sb-thread:join-thread thread
) results
))
420 (let ((result-vect (make-array 10)))
421 (loop for i below
(length (first results
))
423 (dotimes (thread-num 10)
424 (setf (aref result-vect thread-num
)
425 (aref (nth thread-num results
) i
)))
426 ;; some thread should have observed a classoid-cell
427 (let ((representative (find-if-not #'null result-vect
)))
428 ;; For each thread which observed a classoid-cell,
429 ;; assert that the cell is EQ to the representative.
430 (dotimes (thread-num 10)
431 (let ((cell (aref result-vect thread-num
)))
433 (assert (eq cell representative
))))))))
434 ;; and make sure the property list updates also weren't lost
435 (let ((symbols (classoid-cell-test-get-lotsa-symbols)))
436 (loop for s across symbols
437 do
(assert (eq (get s
'foo
) s
)))
438 ;; a statistic of no real merit, but verifies that
439 ;; the lockfree logic does discard some created objects.
440 (format t
"Consed ~D classoid-cells (~D symbols)~%"
441 (aref *make-classoid-cell-callcount
* 0)
444 ;;; test %GET-INFO-VALUE-INITIALIZING using generalized function names
446 (defun be-an-fdefn-reader (names)
447 (declare (simple-vector names
))
448 (let ((result (make-array (length names
) :initial-element nil
)))
450 (loop for i below
(length names
)
451 do
(pushnew (find-fdefn (aref names i
)) (aref result i
))))
452 ;; The thread shall observe either nil or an fdefn, and at most one fdefn.
453 (loop for list across result
455 do
(let ((observed-value (remove nil list
)))
456 (if (cdr observed-value
)
457 (error "Should not happen: fdefn => ~S" list
)
458 (setf (aref result i
) (car observed-value
)))))
461 (defun be-an-fdefn-writer (names)
462 (declare (simple-vector names
))
463 (let ((fdefn-result (make-array (length names
) :initial-element nil
))
464 (random-result (make-array (length names
) :initial-element nil
))
467 (position-if #'identity sb-c
::*info-types
*
468 :end sb-c
::+fdefn-type-num
+ :from-end t
)))
469 (loop for name across names
471 do
(setf (aref fdefn-result i
)
472 (get-info-value-initializing
473 :function
:definition name
474 (progn (incf n-created
) (make-fdefn name
))))
475 (dotimes (i (random 3))
476 ;; Set random info for other names to cause CAS failures.
477 ;; Pick an info-type number and give it a random value.
478 ;; Store the random value so that we can assert on it later.
479 ;; Never touch reserved type numbers 0 or 63.
480 (let ((random-name-index (random (length names
)))
481 (random-type (+ (random (1- highest-type-num
)) 2))
482 (random-value (random most-positive-fixnum
)))
483 (push (cons random-type random-value
)
484 (aref random-result random-name-index
))
485 (sb-c::set-info-value
(aref names random-name-index
)
486 random-type random-value
))))
487 (values n-created fdefn-result random-result
)))
489 (test-util:with-test
(:name
:get-info-value-initializing
490 :skipped-on
'(not :sb-thread
))
491 ;; Precompute random generalized function names for testing, some of which
492 ;; are "simple" (per the taxonomy of globaldb) and some hairy.
493 (let ((work (coerce (loop repeat
10000
494 nconc
(list `(sb-pcl::ctor
,(gensym) ,(gensym))
495 `(defmacro ,(gensym)) ; simple name
496 (gensym))) ; very simple name
498 (n-threads 10) readers writers fdefn-results random-results
)
499 (dotimes (i (ash n-threads -
1))
500 (push (sb-thread:make-thread
501 #'be-an-fdefn-writer
:arguments
(list work
)
502 :name
(write-to-string i
)) writers
))
503 (dotimes (i (ash n-threads -
1))
504 (push (sb-thread:make-thread
#'be-an-fdefn-reader
:arguments
(list work
))
506 (dolist (thread readers
)
507 (push (sb-thread:join-thread thread
) fdefn-results
))
509 (dolist (thread writers
)
510 (multiple-value-bind (n-created fdefn-result random-result
)
511 (sb-thread:join-thread thread
)
513 (format t
"~5D fdefns from ~A~%" n-created
514 (sb-thread:thread-name thread
))
515 (push fdefn-result fdefn-results
)
516 (push random-result random-results
)))
517 (format t
"~5D total~%" tot
))
518 (let ((aggregate (make-array n-threads
)))
519 (dotimes (name-index (length work
))
520 (dotimes (thread-num n-threads
)
521 (setf (aref aggregate thread-num
)
522 (aref (nth thread-num fdefn-results
) name-index
)))
523 ;; some thread should have observed an fdefn
524 (let ((representative (find-if-not #'null aggregate
)))
525 ;; For each thread which observed an fdefn,
526 ;; assert that the cell is EQ to the representative.
527 (dotimes (thread-num n-threads
)
528 (awhen (aref aggregate thread-num
)
529 (assert (eq it representative
)))))))
530 ;; For each name and each info type number that some thread inserted,
531 ;; verify that the info-value is among the set of random values.
532 (dotimes (name-index (length work
))
533 (dotimes (type-num 64)
534 ;; some thread says that TYPE-NUM exists for NAME-INDEX
535 (when (some (lambda (output)
536 (assoc type-num
(aref output name-index
)))
538 (let ((actual (sb-c::get-info-value
(aref work name-index
)
540 (unless (some (lambda (output)
542 (and (eq (car cell
) type-num
)
543 (eql (cdr cell
) actual
)))
544 (aref output name-index
)))
546 (error "Fail ~S ~S => ~S.~%Choices are ~S"
547 (aref work name-index
) type-num actual
548 (mapcar (lambda (output)
549 (aref output name-index
))
550 random-results
)))))))))
552 ;; As explained in the comments at the top of 'info-vector.lisp',
553 ;; it is a bad idea to use globaldb to store an atomic counter as
554 ;; a piece of info for a name, as it is quite brutal and consy,
555 ;; but for this test, that's precisely the goal.
556 ;; This test conses ~5 Megabytes on 64-bit almost entirely due
557 ;; to allocation of each immutable info storage vector.
558 (test-util:with-test
(:name
:get-info-value-updating
559 :skipped-on
'(not :sb-thread
))
561 (declare (simple-vector names
))
562 (let* ((n (length names
))
563 (counts (make-array n
:element-type
'sb-ext
:word
))
566 (push (sb-thread:make-thread
569 ;; increment (:variable :macro-expansion)
570 ;; for a randomly chosen name. That particular
571 ;; info-type harmlessly accepts any data type.
572 (let* ((index (random n
))
573 (name (aref names index
)))
574 (atomic-incf (aref counts index
))
575 ;; should probably be SB-INT:
576 (sb-c::atomic-set-info-value
577 :variable
:macro-expansion name
579 (if old-p
(1+ old
) 1))))
580 ;; randomly touch an item of info
581 ;; for another (or the same) name.
582 (let* ((index (random n
))
583 (name (aref names index
)))
584 ;; source-location also accepts anything :-(
585 (setf (info :type
:source-location name
) iter
)))))
587 (mapc #'sb-thread
:join-thread threads
)
588 ;; assert that no updates were lost
589 (loop for name across names
590 for count across counts
591 for val
= (info :variable
:macro-expansion name
)
592 do
(assert (eql (or val
0) count
))))))
593 ;; Try it when names are symbols or "simple" 2-list names
594 (run (coerce (loop repeat
50
596 nconc
(list `(setf ,sym
) sym
))
598 ;; For hairy names, the tricky piece is in the rehash algorithm,
599 ;; but there's no way to stress-test that because *INFO-ENVIRONMENT*
600 ;; would have to keep doubling in size. To that end, it would have to begin
601 ;; as a tiny table again, but it can't, without destroying the Lisp runtime.
602 ;; The :lockfree-hash-concurrent-twiddling test should give high confidence
603 ;; that it works, by creating and testing a standalone hash-table.
604 (run (coerce (loop repeat
50 collect
`(foo ,(gensym) hair
)) 'vector
))))