3 Bugs can be reported on the help mailing list
4 sbcl-help@lists.sourceforge.net
5 or on the development mailing list
6 sbcl-devel@lists.sourceforge.net
8 Please include enough information in a bug report that someone reading
9 it can reproduce the problem, i.e. don't write
10 Subject: apparent bug in PRINT-OBJECT (or *PRINT-LENGTH*?)
11 PRINT-OBJECT doesn't seem to work with *PRINT-LENGTH*. Is this a bug?
13 Subject: apparent bug in PRINT-OBJECT (or *PRINT-LENGTH*?)
14 In sbcl-1.2.3 running under OpenBSD 4.5 on my Alpha box, when
15 I compile and load the file
16 (DEFSTRUCT (FOO (:PRINT-OBJECT (LAMBDA (X Y)
17 (LET ((*PRINT-LENGTH* 4))
20 then at the command line type
22 the program loops endlessly instead of printing the object.
27 There is also some information on bugs in the manual page and
28 in the TODO file. Eventually more such information may move here.
30 The gaps in the number sequence belong to old bug descriptions which
31 have gone away (typically because they were fixed, but sometimes for
32 other reasons, e.g. because they were moved elsewhere).
35 KNOWN BUGS OF NO SPECIAL CLASS:
38 DEFSTRUCT almost certainly should overwrite the old LAYOUT information
39 instead of just punting when a contradictory structure definition
40 is loaded. As it is, if you redefine DEFSTRUCTs in a way which
41 changes their layout, you probably have to rebuild your entire
42 program, even if you know or guess enough about the internals of
43 SBCL to wager that this (undefined in ANSI) operation would be safe.
46 ANSI specifies that a type mismatch in a structure slot
47 initialization value should not cause a warning.
49 This one might not be fixed for a while because while we're big
50 believers in ANSI compatibility and all, (1) there's no obvious
51 simple way to do it (short of disabling all warnings for type
52 mismatches everywhere), and (2) there's a good portable
53 workaround. ANSI justifies this specification by saying
54 The restriction against issuing a warning for type mismatches
55 between a slot-initform and the corresponding slot's :TYPE
56 option is necessary because a slot-initform must be specified
57 in order to specify slot options; in some cases, no suitable
59 In SBCL, as in CMU CL (or, for that matter, any compiler which
60 really understands Common Lisp types) a suitable default does
61 exist, in all cases, because the compiler understands the concept
62 of functions which never return (i.e. has return type NIL, e.g.
63 ERROR). Thus, as a portable workaround, you can use a call to
64 some known-never-to-return function as the default. E.g.
66 (BAR (ERROR "missing :BAR argument")
67 :TYPE SOME-TYPE-TOO-HAIRY-TO-CONSTRUCT-AN-INSTANCE-OF))
69 (DECLAIM (FTYPE () NIL) MISSING-ARG)
70 (DEFUN REQUIRED-ARG () ; workaround for SBCL non-ANSI slot init typing
71 (ERROR "missing required argument"))
73 (BAR (REQUIRED-ARG) :TYPE TRICKY-TYPE-OF-SOME-SORT)
74 (BLETCH (REQUIRED-ARG) :TYPE TRICKY-TYPE-OF-SOME-SORT)
75 (N-REFS-SO-FAR 0 :TYPE (INTEGER 0)))
76 Such code will compile without complaint and work correctly either
77 on SBCL or on a completely compliant Common Lisp system.
80 bogus warnings about undefined functions for magic functions like
81 SB!C::%%DEFUN and SB!C::%DEFCONSTANT when cross-compiling files
82 like src/code/float.lisp. Fixing this will probably require
83 straightening out enough bootstrap consistency issues that
84 the cross-compiler can run with *TYPE-SYSTEM-INITIALIZED*.
85 Instead, the cross-compiler runs in a slightly flaky state
86 which is sane enough to compile SBCL itself, but which is
87 also unstable in several ways, including its inability
88 to really grok function declarations.
91 The "byte compiling top-level form:" output ought to be condensed.
92 Perhaps any number of such consecutive lines ought to turn into a
93 single "byte compiling top-level forms:" line.
96 The way that the compiler munges types with arguments together
97 with types with no arguments (in e.g. TYPE-EXPAND) leads to
98 weirdness visible to the user:
99 (DEFTYPE FOO () 'FIXNUM)
101 (TYPEP 11 '(FOO)) => T, which seems weird
102 (TYPEP 11 'FIXNUM) => T
103 (TYPEP 11 '(FIXNUM)) signals an error, as it should
104 The situation is complicated by the presence of Common Lisp types
105 like UNSIGNED-BYTE (which can either be used in list form or alone)
106 so I'm not 100% sure that the behavior above is actually illegal.
107 But I'm 90+% sure, and the following related behavior,
109 treating the bare symbol AND as equivalent to '(AND), is specifically
110 forbidden (by the ANSI specification of the AND type).
113 It would be nice if the
115 (during macroexpansion)
116 said what macroexpansion was at fault, e.g.
118 (during macroexpansion of IN-PACKAGE,
119 during macroexpansion of DEFFOO)
122 (SUBTYPEP '(FUNCTION (T BOOLEAN) NIL)
123 '(FUNCTION (FIXNUM FIXNUM) NIL)) => T, T
124 (Also, when this is fixed, we can enable the code in PROCLAIM which
125 checks for incompatible FTYPE redeclarations.)
128 from DTC on the CMU CL mailing list 25 Feb 2000:
129 ;;; Compiler fails when this file is compiled.
131 ;;; Problem shows up in delete-block within ir1util.lisp. The assertion
132 ;;; (assert (member (functional-kind lambda) '(:let :mv-let :assignment)))
133 ;;; fails within bind node branch.
135 ;;; Note that if c::*check-consistency* is enabled then an un-reached
136 ;;; entry is also reported.
139 (declare (values nil))
156 (let ((ttt #'(lambda () (go cccc))))
157 (declare (special ttt))
158 (return-from bbbb nil))
161 (return-from bbbb nil))))))
164 (I *think* this is a bug. It certainly seems like strange behavior. But
165 the ANSI spec is scary, dark, and deep..)
166 (FORMAT NIL "~,1G" 1.4) => "1. "
167 (FORMAT NIL "~3,1G" 1.4) => "1. "
170 from Marco Antoniotti on cmucl-imp mailing list 1 Mar 2000:
172 (setf (find-class 'ccc1) (find-class 'ccc))
173 (defmethod zut ((c ccc1)) 123)
174 DTC's recommended workaround from the mailing list 3 Mar 2000:
175 (setf (pcl::find-class 'ccc1) (pcl::find-class 'ccc))
178 The ANSI spec, in section "22.3.5.2 Tilde Less-Than-Sign: Logical Block",
179 says that an error is signalled if ~W, ~_, ~<...~:>, ~I, or ~:T is used
180 inside "~<..~>" (without the colon modifier on the closing syntax).
181 However, SBCL doesn't do this:
182 * (FORMAT T "~<munge~wegnum~>" 12)
187 When too many files are opened, OPEN will fail with an
188 uninformative error message
189 error in function OPEN: error opening #P"/tmp/foo.lisp": NIL
190 instead of saying that too many files are open.
193 reported by Sam Steingold on the cmucl-imp mailing list 12 May 2000:
194 Also, there is another bug: `array-displacement' should return an
195 array or nil as first value (as per ANSI CL), while CMUCL declares
196 it as returning an array as first value always.
197 (Actually, I think the old CMU CL version in SBCL never returns NIL,
198 i.e. it's not just a declaration problem, but the definition doesn't
202 Sometimes (SB-EXT:QUIT) fails with
203 Argh! maximum interrupt nesting depth (4096) exceeded, exiting
204 Process inferior-lisp exited abnormally with code 1
205 I haven't noticed a repeatable case of this yet.
208 some sort of bug in inlining and RETURN-FROM in sbcl-0.6.5: Compiling
211 (BLOCK USED-BY-SOME-Y?
214 (UNLESS (REJECTED? Y)
215 (RETURN-FROM USED-BY-SOME-Y? T)))))
216 (DECLARE (INLINE FROB))
221 error in function SB-KERNEL:ASSERT-ERROR:
222 The assertion (EQ (SB-C::CONTINUATION-KIND SB-C::CONT) :BLOCK-START) failed.
223 This is still present in sbcl-0.6.8.
226 In some cases the compiler believes type declarations on array
227 elements without checking them, e.g.
228 (DECLAIM (OPTIMIZE (SAFETY 3) (SPEED 1) (SPACE 1)))
231 (DECLARE (TYPE (SIMPLE-ARRAY CONS 1) X))
232 (WHEN (CONSP (AREF X 0))
234 (BAR (VECTOR (MAKE-FOO :A 11 :B 12)))
237 in SBCL 0.6.5 (and also in CMU CL 18b). This does not happen for
238 all cases, e.g. the type assumption *is* checked if the array
239 elements are declared to be of some structure type instead of CONS.
242 The printer doesn't report closures very well. This is true in
246 #<Closure Over Function "DEFUN STRUCTURE-SLOT-ACCESSOR" {134D1A1}>
247 It would be nice to make closures have a settable name slot,
248 and make things like DEFSTRUCT and FLET, which create closures,
249 set helpful values into this slot.
252 And as long as we're wishing, it would be awfully nice if INSPECT could
253 also report on closures, telling about the values of the bound variables.
256 The compiler assumes that any time a function of declared FTYPE
257 doesn't signal an error, its arguments were of the declared type.
258 E.g. compiling and loading
259 (DECLAIM (OPTIMIZE (SAFETY 3)))
260 (DEFUN FACTORIAL (X) (GAMMA (1+ X)))
261 (DECLAIM (FTYPE (FUNCTION (UNSIGNED-BYTE) FACTORIAL)))
263 (COND ((> (FACTORIAL X) 1.0E6)
264 (FORMAT T "too big~%"))
266 (FORMAT T "exactly ~S~%" (FACTORIAL X)))
268 (FORMAT T "approximately ~S~%" (FACTORIAL X)))))
271 will cause the INTEGERP case to be selected, giving bogus output a la
273 This violates the "declarations are assertions" principle.
274 According to the ANSI spec, in the section "System Class FUNCTION",
275 this is a case of "lying to the compiler", but the lying is done
276 by the code which calls FACTORIAL with non-UNSIGNED-BYTE arguments,
277 not by the unexpectedly general definition of FACTORIAL. In any case,
278 "declarations are assertions" means that lying to the compiler should
279 cause an error to be signalled, and should not cause a bogus
280 result to be returned. Thus, the compiler should not assume
281 that arbitrary functions check their argument types. (It might
282 make sense to add another flag (CHECKED?) to DEFKNOWN to
283 identify functions which *do* check their argument types.)
286 DEFMETHOD doesn't check the syntax of &REST argument lists properly,
287 accepting &REST even when it's not followed by an argument name:
288 (DEFMETHOD FOO ((X T) &REST) NIL)
291 TYPEP of VALUES types is sometimes implemented very inefficiently, e.g. in
292 (DEFTYPE INDEXOID () '(INTEGER 0 1000))
294 (DECLARE (TYPE INDEXOID X))
295 (THE (VALUES INDEXOID)
297 where the implementation of the type check in function FOO
298 includes a full call to %TYPEP. There are also some fundamental problems
299 with the interpretation of VALUES types (inherited from CMU CL, and
300 from the ANSI CL standard) as discussed on the cmucl-imp@cons.org
301 mailing list, e.g. in Robert Maclachlan's post of 21 Jun 2000.
304 The definitions of SIGCONTEXT-FLOAT-REGISTER and
305 %SET-SIGCONTEXT-FLOAT-REGISTER in x86-vm.lisp say they're not
306 supported on FreeBSD because the floating point state is not saved,
307 but at least as of FreeBSD 4.0, the floating point state *is* saved,
308 so they could be supported after all. Very likely
309 SIGCONTEXT-FLOATING-POINT-MODES could now be supported, too.
312 (as discussed by Douglas Crosher on the cmucl-imp mailing list ca.
313 Aug. 10, 2000): CMUCL currently interprets 'member as '(member); same
314 issue with 'union, 'and, 'or etc. So even though according to the
315 ANSI spec, bare 'MEMBER, 'AND, and 'OR are not legal types, CMUCL
316 (and now SBCL) interpret them as legal types.
319 ANSI specifies DEFINE-SYMBOL-MACRO, but it's not defined in SBCL.
320 CMU CL added it ca. Aug 13, 2000, after some discussion on the mailing
321 list, and it is probably possible to use substantially the same
322 patches to add it to SBCL.
325 a slew of floating-point-related errors reported by Peter Van Eynde
327 a: (fixed in sbcl-0.6.11.25)
328 b: SBCL's value for LEAST-POSITIVE-SHORT-FLOAT is bogus, and
329 should probably be 1.4012985e-45. In SBCL,
330 (/ LEAST-POSITIVE-SHORT-FLOAT 2) returns a number smaller
331 than LEAST-POSITIVE-SHORT-FLOAT. Similar problems
332 exist for LEAST-NEGATIVE-SHORT-FLOAT, LEAST-POSITIVE-LONG-FLOAT,
333 and LEAST-NEGATIVE-LONG-FLOAT.
334 c: Many expressions generate floating infinity:
339 PVE's regression tests want them to raise errors. SBCL
340 generates the infinities instead, which may or may not be
342 d: (in section12.erg) various forms a la
343 (FLOAT 1 DOUBLE-FLOAT-EPSILON)
344 don't give the right behavior.
347 type safety errors reported by Peter Van Eynde July 25, 2000:
348 a: (COERCE (QUOTE (A B C)) (QUOTE (VECTOR * 4)))
350 In general lengths of array type specifications aren't
351 checked by COERCE, so it fails when the spec is
352 (VECTOR 4), (STRING 2), (SIMPLE-BIT-VECTOR 3), or whatever.
353 b: CONCATENATE has the same problem of not checking the length
354 of specified output array types. MAKE-SEQUENCE and MAP and
355 MERGE also have the same problem.
356 c: (COERCE 'AND 'FUNCTION) returns something related to
357 (MACRO-FUNCTION 'AND), but ANSI says it should raise an error.
358 d: ELT signals SIMPLE-ERROR if its index argument
359 isn't a valid index for its sequence argument, but should
360 signal TYPE-ERROR instead.
361 e: FILE-LENGTH is supposed to signal a type error when its
362 argument is not a stream associated with a file, but doesn't.
363 f: (FLOAT-RADIX 2/3) should signal an error instead of
365 g: (LOAD "*.lsp") should signal FILE-ERROR.
366 h: (MAKE-CONCATENATED-STREAM (MAKE-STRING-OUTPUT-STREAM))
367 should signal TYPE-ERROR.
368 i: MAKE-TWO-WAY-STREAM doesn't check that its arguments can
369 be used for input and output as needed. It should fail with
370 TYPE-ERROR when handed e.g. the results of
371 MAKE-STRING-INPUT-STREAM or MAKE-STRING-OUTPUT-STREAM in
372 the inappropriate positions, but doesn't.
373 j: (PARSE-NAMESTRING (COERCE (LIST #\f #\o #\o (CODE-CHAR 0) #\4 #\8)
375 should probably signal an error instead of making a pathname with
377 k: READ-BYTE is supposed to signal TYPE-ERROR when its argument is
378 not a binary input stream, but instead cheerfully reads from
379 character streams, e.g. (MAKE-STRING-INPUT-STREAM "abc").
382 DEFCLASS bugs reported by Peter Van Eynde July 25, 2000:
383 a: (DEFCLASS FOO () (A B A)) should signal a PROGRAM-ERROR, and
385 b: (DEFCLASS FOO () (A B A) (:DEFAULT-INITARGS X A X B)) should
386 signal a PROGRAM-ERROR, and doesn't.
387 c: (DEFCLASS FOO07 NIL ((A :ALLOCATION :CLASS :ALLOCATION :CLASS))),
388 and other DEFCLASS forms with duplicate specifications in their
389 slots, should signal a PROGRAM-ERROR, and doesn't.
390 d: (DEFGENERIC IF (X)) should signal a PROGRAM-ERROR, but instead
391 causes a COMPILER-ERROR.
394 SYMBOL-MACROLET bugs reported by Peter Van Eynde July 25, 2000:
395 a: (SYMBOL-MACROLET ((T TRUE)) ..) should probably signal
396 PROGRAM-ERROR, but SBCL accepts it instead.
397 b: SYMBOL-MACROLET should refuse to bind something which is
398 declared as a global variable, signalling PROGRAM-ERROR.
399 c: SYMBOL-MACROLET should signal PROGRAM-ERROR if something
400 it binds is declared SPECIAL inside.
403 LOOP bugs reported by Peter Van Eynde July 25, 2000:
404 a: (LOOP WITH (A B) DO (PRINT 1)) is a syntax error according to
405 the definition of WITH clauses given in the ANSI spec, but
406 compiles and runs happily in SBCL.
407 b: a messy one involving package iteration:
408 interpreted Form: (LET ((PACKAGE (MAKE-PACKAGE "LOOP-TEST"))) (INTERN "blah" PACKAGE) (LET ((BLAH2 (INTERN "blah2" PACKAGE))) (EXPORT BLAH2 PACKAGE)) (LIST (SORT (LOOP FOR SYM BEING EACH PRESENT-SYMBOL OF PACKAGE FOR SYM-NAME = (SYMBOL-NAME SYM) COLLECT SYM-NAME) (FUNCTION STRING<)) (SORT (LOOP FOR SYM BEING EACH EXTERNAL-SYMBOL OF PACKAGE FOR SYM-NAME = (SYMBOL-NAME SYM) COLLECT SYM-NAME) (FUNCTION STRING<))))
409 Should be: (("blah" "blah2") ("blah2"))
410 SBCL: (("blah") ("blah2"))
411 * (LET ((X 1)) (LOOP FOR I BY (INCF X) FROM X TO 10 COLLECT I))
412 doesn't work -- SBCL's LOOP says BY isn't allowed in a FOR clause.
415 type system errors reported by Peter Van Eynde July 25, 2000:
416 a: (SUBTYPEP 'BIGNUM 'INTEGER) => NIL, NIL
417 but should be (VALUES T T) instead.
418 b: (SUBTYPEP 'EXTENDED-CHAR 'CHARACTER) => NIL, NIL
419 but should be (VALUES T T) instead.
420 c: (SUBTYPEP '(INTEGER (0) (0)) 'NIL) dies with nested errors.
421 d: In general, the system doesn't like '(INTEGER (0) (0)) -- it
422 blows up at the level of SPECIFIER-TYPE with
423 "Lower bound (0) is greater than upper bound (0)." Probably
424 SPECIFIER-TYPE should return NIL instead.
425 e: (TYPEP 0 '(COMPLEX (EQL 0)) fails with
426 "Component type for Complex is not numeric: (EQL 0)."
427 This might be easy to fix; the type system already knows
428 that (SUBTYPEP '(EQL 0) 'NUMBER) is true.
429 f: The type system doesn't know about the condition system,
430 so that e.g. (TYPEP 'SIMPLE-ERROR 'ERROR)=>NIL.
431 g: The type system isn't all that smart about relationships
432 between hairy types, as shown in the type.erg test results,
433 e.g. (SUBTYPEP 'CONS '(NOT ATOM)) => NIL, NIL.
436 miscellaneous errors reported by Peter Van Eynde July 25, 2000:
438 (DEFGENERIC FOO02 (X))
439 (DEFMETHOD FOO02 ((X NUMBER)) T)
440 (LET ((M (FIND-METHOD (FUNCTION FOO02)
442 (LIST (FIND-CLASS (QUOTE NUMBER))))))
443 (REMOVE-METHOD (FUNCTION FOO02) M)
444 (DEFGENERIC FOO03 (X))
445 (ADD-METHOD (FUNCTION FOO03) M)))
446 should give an error, but SBCL allows it.
447 b: READ should probably return READER-ERROR, not the bare
448 arithmetic error, when input a la "1/0" or "1e1000" causes
452 It has been reported (e.g. by Peter Van Eynde) that there are
453 several metaobject protocol "errors". (In order to fix them, we might
454 need to document exactly what metaobject protocol specification
455 we're following -- the current code is just inherited from PCL.)
458 another error from Peter Van Eynde 5 September 2000:
459 (FORMAT NIL "~F" "FOO") should work, but instead reports an error.
460 PVE submitted a patch to deal with this bug, but it exposes other
461 comparably serious bugs, so I didn't apply it. It looks as though
462 the FORMAT code needs a fair amount of rewriting in order to comply
463 with the various details of the ANSI spec.
466 The implementation of #'+ returns its single argument without
467 type checking, e.g. (+ "illegal") => "illegal".
470 In sbcl-0.6.7, there is no doc string for CL:PUSH, probably
471 because it's defined with the DEFMACRO-MUNDANELY macro and something
472 is wrong with doc string setting in that macro.
475 Attempting to use COMPILE on something defined by DEFMACRO fails:
476 (DEFMACRO FOO (X) (CONS X X))
478 Error in function C::GET-LAMBDA-TO-COMPILE:
479 #<Closure Over Function "DEFUN (SETF MACRO-FUNCTION)" {480E21B1}> was defined in a non-null environment.
482 (SUBTYPEP '(AND ZILCH INTEGER) 'ZILCH) => NIL, NIL
483 Note: I looked into fixing this in 0.6.11.15, but gave up. The
484 problem seems to be that there are two relevant type methods for
485 the subtypep operation, HAIRY :COMPLEX-SUBTYPEP-ARG2 and
486 INTERSECTION :COMPLEX-SUBTYPEP-ARG1, and only the first is
487 called. This could be fixed, but type dispatch is messy and
488 confusing enough already, I don't want to complicate it further.
489 Perhaps someday we can make CLOS cross-compiled (instead of compiled
490 after bootstrapping) so that we don't need to have the type system
491 available before CLOS, and then we can rewrite the type methods to
492 CLOS methods, and then expressing the solutions to stuff like this
493 should become much more straightforward. -- WHN 2001-03-14
496 The debugger LIST-LOCATIONS command doesn't work properly.
499 Compiling and loading
500 (DEFUN FAIL (X) (THROW 'FAIL-TAG X))
502 then requesting a BACKTRACE at the debugger prompt gives no information
503 about where in the user program the problem occurred.
506 The compiler is supposed to do type inference well enough that
509 ((SIMPLE-ARRAY SINGLE-FLOAT)
511 (DECLARE (TYPE (SIMPLE-ARRAY SINGLE-FLOAT) X))
514 is redundant. However, as reported by Juan Jose Garcia Ripoll for
515 CMU CL, it sometimes doesn't. Adding declarations is a pretty good
516 workaround for the problem for now, but can't be done by the TYPECASE
517 macros themselves, since it's too hard for the macro to detect
518 assignments to the variable within the clause.
519 Note: The compiler *is* smart enough to do the type inference in
520 many cases. This case, derived from a couple of MACROEXPAND-1
521 calls on Ripoll's original test case,
523 (DECLARE (OPTIMIZE SPEED (SAFETY 0)))
524 (COND ((TYPEP A '(SIMPLE-ARRAY SINGLE-FLOAT)) NIL
525 (LET ((LENGTH (ARRAY-TOTAL-SIZE A)))
526 (LET ((I 0) (G2554 LENGTH))
527 (DECLARE (TYPE REAL G2554) (TYPE REAL I))
530 (WHEN (>= I G2554) (GO SB-LOOP::END-LOOP))
531 (SETF (ROW-MAJOR-AREF A I) (- (ROW-MAJOR-AREF A I)))
532 (GO SB-LOOP::NEXT-LOOP)
533 SB-LOOP::END-LOOP))))))
534 demonstrates the problem; but the problem goes away if the TAGBODY
535 and GO forms are removed (leaving the SETF in ordinary, non-looping
536 code), or if the TAGBODY and GO forms are retained, but the
537 assigned value becomes 0.0 instead of (- (ROW-MAJOR-AREF A I)).
540 Paul Werkowski wrote on cmucl-imp@cons.org 2000-11-15
541 I am looking into this problem that showed up on the cmucl-help
542 list. It seems to me that the "implementation specific environment
543 hacking functions" found in pcl/walker.lisp are completely messed
544 up. The good thing is that they appear to be barely used within
545 PCL and the munged environment object is passed to cmucl only
546 in calls to macroexpand-1, which is probably why this case fails.
547 SBCL uses essentially the same code, so if the environment hacking
548 is screwed up, it affects us too.
551 Using the pretty-printer from the command prompt gives funny
552 results, apparently because the pretty-printer doesn't know
553 about user's command input, including the user's carriage return
554 that the user, and therefore the pretty-printer thinks that
555 the new output block should start indented 2 or more characters
556 rightward of the correct location.
559 (probably related to bug #70)
560 As reported by Carl Witty on submit@bugs.debian.org 1999-05-08,
562 (in-package "CL-USER")
563 (defun equal-terms (termx termy)
565 ((alpha-equal-bound-term-lists (listx listy)
566 (or (and (null listx) (null listy))
568 (let ((bindings-x (bindings-of-bound-term (car listx)))
569 (bindings-y (bindings-of-bound-term (car listy))))
570 (if (and (null bindings-x) (null bindings-y))
571 (alpha-equal-terms (term-of-bound-term (car listx))
572 (term-of-bound-term (car listy)))
573 (and (= (length bindings-x) (length bindings-y))
575 (enter-binding-pairs (bindings-of-bound-term (car listx))
576 (bindings-of-bound-term (car listy)))
577 (alpha-equal-terms (term-of-bound-term (car listx))
578 (term-of-bound-term (car listy)))
579 (exit-binding-pairs (bindings-of-bound-term (car listx))
580 (bindings-of-bound-term (car listy)))))))
581 (alpha-equal-bound-term-lists (cdr listx) (cdr listy)))))
583 (alpha-equal-terms (termx termy)
584 (if (and (variable-p termx)
586 (equal-bindings (id-of-variable-term termx)
587 (id-of-variable-term termy))
588 (and (equal-operators-p (operator-of-term termx) (operator-of-term termy))
589 (alpha-equal-bound-term-lists (bound-terms-of-term termx)
590 (bound-terms-of-term termy))))))
594 (with-variable-invocation (alpha-equal-terms termx termy))))))
595 causes an assertion failure
596 The assertion (EQ (C::LAMBDA-TAIL-SET C::CALLER)
597 (C::LAMBDA-TAIL-SET (C::LAMBDA-HOME C::CALLEE))) failed.
599 Bob Rogers reports (1999-07-28 on cmucl-imp@cons.org) a smaller test
600 case with the same problem:
601 (defun parse-fssp-alignment ()
602 ;; Given an FSSP alignment file named by the argument . . .
603 (labels ((get-fssp-char ()
607 ;; Stub body, enough to tickle the bug.
608 (list (read-fssp-char)
612 ANSI specifies that the RESULT-TYPE argument of CONCATENATE must be
613 a subtype of SEQUENCE, but CONCATENATE doesn't check this properly:
614 (CONCATENATE 'SIMPLE-ARRAY #(1 2) '(3)) => #(1 2 3)
615 This also leads to funny behavior when derived type specifiers
616 are used, as originally reported by Milan Zamazal for CMU CL (on the
617 Debian bugs mailing list (?) 2000-02-27), then reported by Martin
618 Atzmueller for SBCL (2000-10-01 on sbcl-devel@lists.sourceforge.net):
619 (DEFTYPE FOO () 'SIMPLE-ARRAY)
620 (CONCATENATE 'FOO #(1 2) '(3))
621 => #<ARRAY-TYPE SIMPLE-ARRAY> is a bad type specifier for
623 The derived type specifier FOO should act the same way as the
624 built-in type SIMPLE-ARRAY here, but it doesn't. That problem
625 doesn't seem to exist for sequence types:
626 (DEFTYPE BAR () 'SIMPLE-VECTOR)
627 (CONCATENATE 'BAR #(1 2) '(3)) => #(1 2 3)
630 As reported by Winton Davies on a CMU CL mailing list 2000-01-10,
631 and reported for SBCL by Martin Atzmueller 2000-10-20: (TRACE GETHASH)
632 crashes SBCL. In general tracing anything which is used in the
633 implementation of TRACE is likely to have the same problem.
636 As reported by Daniel Solaz on cmucl-help@cons.org 2000-11-23,
637 SXHASH returns the same value for all non-STRUCTURE-OBJECT instances,
638 notably including all PCL instances. There's a limit to how much
639 SXHASH can do to return unique values for instances, but at least
640 it should probably look at the class name, the way that it does
641 for STRUCTURE-OBJECTs.
644 As reported by Martin Atzmueller on the sbcl-devel list 2000-11-22,
645 > There remains one issue, that is a bug in SBCL:
646 > According to my interpretation of the spec, the ":" and "@" modifiers
647 > should appear _after_ the comma-seperated arguments.
648 > Well, SBCL (and CMUCL for that matter) accept
649 > (ASSERT (STRING= (FORMAT NIL "~:8D" 1) " 1"))
650 > where the correct way (IMHO) should be
651 > (ASSERT (STRING= (FORMAT NIL "~8:D" 1) " 1"))
652 Probably SBCL should stop accepting the "~:8D"-style format arguments,
653 or at least issue a warning.
656 (probably related to bug #65)
657 The compiler doesn't like &OPTIONAL arguments in LABELS and FLET
659 (DEFUN FIND-BEFORE (ITEM SEQUENCE &KEY (TEST #'EQL))
660 (LABELS ((FIND-ITEM (OBJ SEQ TEST &OPTIONAL (VAL NIL))
661 (LET ((ITEM (FIRST SEQ)))
664 ((FUNCALL TEST OBJ ITEM)
667 (FIND-ITEM OBJ (REST SEQ) TEST (NCONC VAL `(,ITEM))))))))
668 (FIND-ITEM ITEM SEQUENCE TEST)))
669 from David Young's bug report on cmucl-help@cons.org 30 Nov 2000
670 causes sbcl-0.6.9 to fail with
671 error in function SB-KERNEL:ASSERT-ERROR:
672 The assertion (EQ (SB-C::LAMBDA-TAIL-SET SB-C::CALLER)
673 (SB-C::LAMBDA-TAIL-SET
674 (SB-C::LAMBDA-HOME SB-C::CALLEE))) failed.
677 (DECLAIM (OPTIMIZE ..)) doesn't work. E.g. even after
678 (DECLAIM (OPTIMIZE (SPEED 3))), things are still optimized with
679 the previous SPEED policy. This bug will probably get fixed in
680 0.6.9.x in a general cleanup of optimization policy.
683 (DECLAIM (OPTIMIZE ..)) doesn't work properly inside LOCALLY forms.
686 As noted in the ANSI specification for COERCE, (COERCE 3 'COMPLEX)
687 gives a result which isn't COMPLEX. The result type optimizer
688 for COERCE doesn't know this, perhaps because it was written before
689 ANSI threw this curveball: the optimizer thinks that COERCE always
690 returns a result of the specified type. Thus while the interpreted
692 (DEFUN TRICKY (X) (TYPEP (COERCE X 'COMPLEX) 'COMPLEX))
693 returns the correct result,
695 the compiled function
701 As reported by Martin Atzmueller on sbcl-devel 26 Dec 2000,
702 ANSI says that WITH-OUTPUT-TO-STRING should have a keyword
703 :ELEMENT-TYPE, but in sbcl-0.6.9 this is not defined for
704 WITH-OUTPUT-TO-STRING.
707 ANSI says in one place that type declarations can be abbreviated even
708 when the type name is not a symbol, e.g.
709 (DECLAIM ((VECTOR T) *FOOVECTOR*))
710 SBCL doesn't support this. But ANSI says in another place that this
711 isn't allowed. So it's not clear this is a bug after all. (See the
712 e-mail on cmucl-help@cons.org on 2001-01-16 and 2001-01-17 from WHN
716 as pointed out by Dan Barlow on sbcl-devel 2000-07-02:
717 The PICK-TEMPORARY-FILE-NAME utility used by LOAD-FOREIGN uses
718 an easily guessable temporary filename in a way which might open
719 applications using LOAD-FOREIGN to hijacking by malicious users
720 on the same machine. Incantations for doing this safely are
721 floating around the net in various "how to write secure programs
722 despite Unix" documents, and it would be good to (1) fix this in
723 LOAD-FOREIGN, and (2) hunt for any other code which uses temporary
724 files and make it share the same new safe logic.
727 (fixed early Feb 2001 by MNA)
730 As reported by wbuss@TELDA.NET (Wolfhard Buss) on cmucl-help
733 (loop with (a . b) of-type float = '(0.0 . 1.0)
734 and (c . d) of-type float = '(2.0 . 3.0)
735 return (list a b c d))
736 should evaluate to (0.0 1.0 2.0 3.0). cmucl-18c disagrees and
737 invokes the debugger: "B is not of type list".
738 SBCL does the same thing.
741 Functions are assigned names based on the context in which they're
742 defined. This is less than ideal for the functions which are
743 used to implement CLOS methods. E.g. the output of
744 (DESCRIBE 'PRINT-OBJECT) lists functions like
745 #<FUNCTION "DEF!STRUCT (TRACE-INFO (:MAKE-LOAD-FORM-FUN SB-KERNEL:JUST-DUMP-IT-NORMALLY) (:PRINT-OBJECT #))" {1020E49}>
747 #<FUNCTION "MACROLET ((FORCE-DELAYED-DEF!METHODS NIL #))" {1242871}>
748 It would be better if these functions' names always identified
749 them as methods, and identified their generic functions and
753 RANDOM-INTEGER-EXTRA-BITS=10 may not be large enough for the RANDOM
754 RNG to be high quality near RANDOM-FIXNUM-MAX; it looks as though
755 the mean of the distribution can be systematically O(0.1%) wrong.
756 Just increasing R-I-E-B is probably not a good solution, since
757 it would decrease efficiency more than is probably necessary. Perhaps
758 using some sort of accept/reject method would be better.
761 (SUBTYPEP '(SATISFIES SOME-UNDEFINED-FUN) NIL)=>NIL,T (should be NIL,NIL)
764 Internally the compiler sometimes evaluates
765 (sb-kernel:type/= (specifier-type '*) (specifier-type t))
766 (I stumbled across this when I added an
767 (assert (not (eq type1 *wild-type*)))
768 in the NAMED :SIMPLE-= type method.) '* isn't really a type, and
769 in a type context should probably be translated to T, and so it's
770 probably to ask whether it's equal to the T type and then (using the
771 EQ type comparison in the NAMED :SIMPLE-= type method) return NIL.
772 (I haven't tried to investigate this bug enough to guess whether
773 there might be any user-level symptoms.)
776 a latent cross-compilation/bootstrapping bug: The cross-compilation
777 host's CL:CHAR-CODE-LIMIT is used in target code in readtable.lisp
778 and possibly elsewhere. Instead, we should use the target system's
779 CHAR-CODE-LIMIT. This will probably cause problems if we try to
780 bootstrap on a system which uses a different value of CHAR-CODE-LIMIT
784 (subtypep '(or (integer -1 1)
788 (integer -1 1))) => NIL,T
789 An analogous problem with SINGLE-FLOAT and REAL types was fixed in
790 sbcl-0.6.11.22, but some peculiarites of the RATIO type make it
791 awkward to generalize the fix to INTEGER and RATIONAL. It's not
792 clear what's the best fix. (See the "bug in type handling" discussion
793 on cmucl-imp ca. 2001-03-22 and ca. 2001-02-12.)
796 In sbcl-0.6.11.26, (COMPILE 'IN-HOST-COMPILATION-MODE) in
797 src/cold/shared.lisp doesn't correctly translate the
799 (defun in-host-compilation-mode (fn)
800 (let ((*features* (cons :sb-xc-host *features*))
801 ;; the CROSS-FLOAT-INFINITY-KLUDGE, as documented in
802 ;; base-target-features.lisp-expr:
803 (*shebang-features* (set-difference *shebang-features*
804 '(:sb-propagate-float-type
805 :sb-propagate-fun-type))))
806 (with-additional-nickname ("SB-XC" "SB!XC")
808 No error is reported by the compiler, but when the function is executed,
810 TYPE-ERROR in SB-KERNEL::OBJECT-NOT-TYPE-ERROR-HANDLER:
811 (:LINUX :X86 :IEEE-FLOATING-POINT :SB-CONSTRAIN-FLOAT-TYPE :SB-TEST
812 :SB-INTERPRETER :SB-DOC :UNIX ...) is not of type SYMBOL.
815 Inconsistencies between derived and declared VALUES return types for
816 DEFUN aren't checked very well. E.g. the logic which successfully
817 catches problems like
818 (declaim (ftype (function (fixnum) float) foo))
820 (declare (type integer x))
821 (values x)) ; wrong return type, detected, gives warning, good!
823 (declaim (ftype (function (t) (values t t)) bar))
825 (values x)) ; wrong number of return values, no warning, bad!
826 The cause of this is seems to be that (1) the internal function
827 VALUES-TYPES-EQUAL-OR-INTERSECT used to make the check handles its
828 arguments symmetrically, and (2) when the type checking code was
829 written back when when SBCL's code was still CMU CL, the intent
831 (declaim (ftype (function (t) t) bar))
833 (values x x)) ; wrong number of return values; should give warning?
834 not be warned for, because a two-valued return value is considered
835 to be compatible with callers who expects a single value to be
836 returned. That intent is probably not appropriate for modern ANSI
837 Common Lisp, but fixing this might be complicated because of other
838 divergences between auld-style and new-style handling of
839 multiple-VALUES types. (Some issues related to this were discussed
840 on cmucl-imp at some length sometime in 2000.)
843 The facility for dumping a running Lisp image to disk gets confused
844 when run without the PURIFY option, and creates an unnecessarily large
845 core file (apparently representing memory usage up to the previous
846 high-water mark). Moreover, when the file is loaded, it confuses the
847 GC, so that thereafter memory usage can never be reduced below that
851 The TRACE facility can't be used on some kinds of functions.
852 (Basically, the breakpoint facility was incompletely implemented
853 in the X86 port of CMU CL, and hasn't been fixed in SBCL.)
856 In sbcl-0.6.11.41 (and in all earlier SBCL, and in CMU
857 CL), out-of-line structure slot setters are horribly inefficient
858 whenever the type of the slot is declared, because out-of-line
859 structure slot setters are implemented as closures to save space,
860 so the compiler doesn't compile the type test into code, but
861 instead just saves the type in a lexical closure and interprets it
863 A proper solution involves deciding whether it's really worth
864 saving space by implementing structure slot accessors as closures.
865 (If it's not worth it, the problem vanishes automatically. If it
866 is worth it, there are hacks we could use to force type tests to
867 be compiled anyway, and even shared. E.g. we could implement
868 an EQUAL hash table mapping from types to compiled type tests,
869 and save the appropriate compiled type test as part of each lexical
870 closure; or we could make the lexical closures be placeholders
871 which overwrite their old definition as a lexical closure with
872 a new compiled definition the first time that they're called.)
873 As a workaround for the problem, #'(SETF FOO) expressions can
874 be replaced with (EFFICIENT-SETF-FUNCTION FOO), where
875 (defmacro efficient-setf-function (place-function-name)
876 (or #+sbcl (and (sb-impl::info :function :accessor-for place-function-name)
877 ;; a workaround for the problem, encouraging the
878 ;; inline expansion of the structure accessor, so
879 ;; that the compiler can optimize its type test
880 (let ((new-value (gensym "NEW-VALUE-"))
881 (structure-value (gensym "STRUCTURE-VALUE-")))
882 `(lambda (,new-value ,structure-value)
883 (setf (,place-function-name ,structure-value)
885 ;; no problem, can just use the ordinary expansion
886 `(function (setf ,place-function-name))))
889 DESCRIBE interacts poorly with *PRINT-CIRCLE*, e.g. the output from
890 (let ((*print-circle* t)) (describe (make-hash-table)))
892 #<HASH-TABLE :TEST EQL :COUNT 0 {90BBFC5}> is an . (EQL)
894 Its REHASH-SIZE is 1.5. Its REHASH-THRESHOLD is . (1.0)
895 It holds 0 key/value pairs.
896 where the ". (EQL)" and ". (1.0)" substrings are screwups.
897 (This is likely a pretty-printer problem which happens to
898 be exercised by DESCRIBE, not actually a DESCRIBE problem.)
901 There's apparently a bug in CEILING optimization which caused
902 Douglas Crosher to patch the CMU CL version. Martin Atzmueller
903 applied the patches to SBCL and they didn't seem to cause problems
904 (as reported sbcl-devel 2001-05-04). However, since the patches
905 modify nontrivial code which was apparently written incorrectly
906 the first time around, until regression tests are written I'm not
907 comfortable merging the patches in the CVS version of SBCL.
910 The error message for calls to structure accessors with the
911 wrong number of arguments is confusing and of the wrong
912 condition class (TYPE-ERROR instead of PROGRAM-ERROR):
913 * (defstruct foo x y)
915 debugger invoked on condition of type SIMPLE-TYPE-ERROR:
916 Structure for accessor FOO-X is not a FOO:
920 As reported by Arthur Lemmens sbcl-devel 2001-05-05, ANSI
921 requires that SYMBOL-MACROLET refuse to rebind special variables,
922 but SBCL doesn't do this. (Also as reported by AL in the same
923 message, SBCL depended on this nonconforming behavior to build
924 itself, because of the way that **CURRENT-SEGMENT** was implemented.
925 As of sbcl-0.6.12.x, this dependence on the nonconforming behavior
926 has been fixed, but the nonconforming behavior remains.)
929 As reported by Arthur Lemmens sbcl-devel 2001-05-05, ANSI's
930 definition of (LOOP .. DO ..) requires that the terms following
931 DO all be compound forms. SBCL's implementation of LOOP allows
932 non-compound forms (like the bare symbol COUNT, in his example)
936 (DESCRIBE 'SB-ALIEN:DEF-ALIEN-TYPE) reports the macro argument list
940 in #<PACKAGE "SB-ALIEN">.
941 Macro-function: #<FUNCTION "DEF!MACRO DEF-ALIEN-TYPE" {19F4A39}>
942 Macro arguments: (#:whole-470 #:environment-471)
943 On Sat, May 26, 2001 09:45:57 AM CDT it was compiled from:
944 /usr/stuff/sbcl/src/code/host-alieneval.lisp
945 Created: Monday, March 12, 2001 07:47:43 AM CST
948 (DESCRIBE 'STREAM-READ-BYTE)
951 (reported by Eric Marsden on cmucl-imp 2001-06-15)
953 (TYPEP 0 '(COMPLEX (EQL 0)))
954 signals an error in sbcl-0.6.12.34,
955 The component type for COMPLEX is not numeric: (EQL 0)
956 This is funny since sbcl-0.6.12.34 knows
957 (SUBTYPEP '(EQL 0) 'NUMBER) => T
960 (TIME (ROOM T)) reports more than 200 Mbytes consed even for
961 a clean, just-started SBCL system. And it seems to be right:
962 (ROOM T) can bring a small computer to its knees for a *long*
963 time trying to GC afterwards. Surely there's some more economical
964 way to implement (ROOM T).
966 KNOWN BUGS RELATED TO THE IR1 INTERPRETER
968 (Note: At some point, the pure interpreter (actually a semi-pure
969 interpreter aka "the IR1 interpreter") will probably go away, replaced
971 (DEFUN EVAL (X) (FUNCALL (COMPILE NIL (LAMBDA ..)))))
972 and at that time these bugs should either go away automatically or
973 become more tractable to fix. Until then, they'll probably remain,
974 since some of them aren't considered urgent, and the rest are too hard
975 to fix as long as so many special cases remain. After the IR1
976 interpreter goes away is also the preferred time to start
977 systematically exterminating cases where debugging functionality
978 (backtrace, breakpoint, etc.) breaks down, since getting rid of the
979 IR1 interpreter will reduce the number of special cases we need to
983 The FUNCTION special operator doesn't check properly whether its
984 argument is a function name. E.g. (FUNCTION (X Y)) returns a value
985 instead of failing with an error. (Later attempting to funcall the
986 value does cause an error.)
989 COMPILED-FUNCTION-P bogusly reports T for interpreted functions:
990 * (DEFUN FOO (X) (- 12 X))
992 * (COMPILED-FUNCTION-P #'FOO)
997 (DEFVAR *SUPPRESS-P* T)
998 (EVAL '(UNLESS *SUPPRESS-P*
999 (EVAL-WHEN (:COMPILE-TOPLEVEL :LOAD-TOPLEVEL :EXECUTE)
1000 (FORMAT T "surprise!"))))
1001 prints "surprise!". Probably the entire EVAL-WHEN mechanism ought to be
1002 rewritten from scratch to conform to the ANSI definition, abandoning
1003 the *ALREADY-EVALED-THIS* hack which is used in sbcl-0.6.8.9 (and
1004 in the original CMU CL source, too). This should be easier to do --
1005 though still nontrivial -- once the various IR1 interpreter special
1009 EVAL-WHEN's idea of what's a toplevel form is even more screwed up
1010 than the example in IR1-3 would suggest, since COMPILE-FILE and
1011 COMPILE both print both "right now!" messages when compiling the
1015 (EVAL-WHEN (:COMPILE-TOPLEVEL :LOAD-TOPLEVEL :EXECUTE)
1016 (PRINT "yes! right now!"))
1019 (EVAL-WHEN (:COMPILE-TOPLEVEL :LOAD-TOPLEVEL :EXECUTE)
1020 (PRINT "no! right now!"))
1022 and while EVAL doesn't print the "right now!" messages, the first
1023 FUNCALL on the value returned by EVAL causes both of them to be printed.
1026 The system accepts DECLAIM in most places where DECLARE would be
1027 accepted, without even issuing a warning. ANSI allows this, but since
1028 it's fairly easy to mistype DECLAIM instead of DECLARE, and the
1029 meaning is rather different, and it's unlikely that the user
1030 has a good reason for doing DECLAIM not at top level, it would be
1031 good to issue a STYLE-WARNING when this happens. A possible
1032 fix would be to issue STYLE-WARNINGs for DECLAIMs not at top level,
1033 or perhaps to issue STYLE-WARNINGs for any EVAL-WHEN not at top level.
1034 [This is considered an IR1-interpreter-related bug because until
1035 EVAL-WHEN is rewritten, which won't happen until after the IR1
1036 interpreter is gone, the system's notion of what's a top-level form
1037 and what's not will remain too confused to fix this problem.]